CSY/reowolf Changeset - 637115283740 · Centrum Wiskunde & Informatica (CWI)

Changeset - 637115283740

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Max Henger - 3 years ago 2022-03-02 11:38:38
henger@cwi.nl

feat: select block evaluation

35 files changed with 5065 insertions and 3916 deletions:

Cargo.toml

docs/runtime/sync.md

src/collections/raw_vec.rs

src/collections/scoped_buffer.rs

src/collections/string_pool.rs

src/common.rs

245

src/lib.rs

src/macros.rs

src/protocol/ast.rs

293

208

src/protocol/ast_printer.rs

src/protocol/eval/error.rs

src/protocol/eval/executor.rs

103

src/protocol/eval/value.rs

src/protocol/input_source.rs

src/protocol/mod.rs

src/protocol/parser/mod.rs

147

src/protocol/parser/pass_definitions.rs

187

250

src/protocol/parser/pass_rewriting.rs

683

src/protocol/parser/pass_stack_size.rs

112

src/protocol/parser/pass_symbols.rs

src/protocol/parser/pass_typing.rs

1843

1750

src/protocol/parser/pass_validation_linking.rs

213

410

src/protocol/parser/type_table.rs

683

563

src/protocol/parser/visitor.rs

162

135

src/protocol/tests/parser_monomorphs.rs

src/protocol/tests/parser_validation.rs

src/protocol/tests/utils.rs

src/random.rs

src/runtime/connector.rs

src/runtime/consensus.rs

src/runtime2/component/component_context.rs

src/runtime2/component/component_pdl.rs

176

src/runtime2/component/consensus.rs

src/runtime2/store/component.rs

src/runtime2/tests/mod.rs

0 comments (0 inline, 0 general)

Cargo.toml

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 [package]
 name = "reowolf_rs"
 version = "1.2.0"
 authors = [
 	"Max Henger <henger@cwi.nl>",
 	"Christopher Esterhuyse <esterhuy@cwi.nl>",
 	"Hans-Dieter Hiep <hdh@cwi.nl>"
+]
 edition = "2021"
 [dependencies]
 # convenience macros
 maplit = "1.0.2"
 derive_more = "0.99.2"
 # runtime
 bincode = "1.3.1"
 serde = { version = "1.0.114", features = ["derive"] }
 getrandom = "0.1.14" # tiny crate. used to guess controller-id
 # network
 mio = { version = "0.7.0", package = "mio", features = ["udp", "tcp", "os-poll"] }
 socket2 = { version = "0.3.12", optional = true }
 # protocol
 backtrace = "0.3"
 lazy_static = "1.4.0"
 # ffi
 # socket ffi
 libc = { version = "^0.2", optional = true }
 os_socketaddr = { version = "0.1.0", optional = true }
-[dev-dependencies]
+# randomness
 rand = "0.8.4"
 rand_pcg = "0.3.1"
 [lib]
 crate-type = [
 	"rlib", # for use as a Rust dependency.
+]
@@ \ No newline at end of file @@

docs/runtime/sync.md

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		new file 100644
		# Synchronous Communication

		##
		\ No newline at end of file

src/collections/raw_vec.rs

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 use std::{mem, ptr, cmp};
 use std::alloc::{Layout, alloc, dealloc};
 #[derive(Debug)]
 enum AllocError {
     CapacityOverflow,
+}
 /// Generic raw vector. It has a base pointer, a capacity and a length. Basic
 /// operations are supported, but the user of the structure is responsible for
 /// ensuring that no illegal mutable access occurs.
 /// A lot of the logic is simply stolen from the std lib. The destructor will
 /// free the backing memory, but will not run any destructors.
 /// Try to use functions to modify the length. But feel free if you know what
 /// you're doing
 pub struct RawVec<T: Sized> {
     base: *mut T,
     cap: usize,
     pub len: usize,
+}
 impl<T: Sized> RawVec<T> {
     const T_ALIGNMENT: usize = mem::align_of::<T>();
     const T_SIZE: usize = mem::size_of::<T>();
     const GROWTH_RATE: usize = 2;
     pub fn new() -> Self {
         Self{
             base: ptr::null_mut(),
             cap: 0,
             len: 0,
+        }
+    }
     pub fn with_capacity(capacity: usize) -> Self {
         // Could be done a bit more efficiently
         let mut result = Self::new();
         result.ensure_space(capacity).unwrap();
         return result;
+    }
     #[inline]
     pub unsafe fn get(&self, idx: usize) -> *const T {
         debug_assert!(idx < self.len);
         return self.base.add(idx);
+    }
     #[inline]
     pub unsafe fn get_mut(&self, idx: usize) -> *mut T {
         debug_assert!(idx < self.len);
         return self.base.add(idx);
+    }
     /// Pushes a new element to the end of the list.
     pub fn push(&mut self, item: T) {
         self.ensure_space(1).unwrap();
         unsafe {
             let target = self.base.add(self.len);
             std::ptr::write(target, item);
             self.len += 1;
+        }
+    }
     /// Moves the elements in the range [from_idx, from_idx + num_to_move) to
     /// the range [to_idx, to_idx + num_to_move). Caller must make sure that all
     /// non-overlapping elements of the second range had their destructor called
     /// in case those elements were used.
     pub fn move_range(&mut self, from_idx: usize, to_idx: usize, num_to_move: usize) {
         debug_assert!(from_idx + num_to_move <= self.len);
         debug_assert!(to_idx + num_to_move <= self.len); // maybe not in future, for now this is fine
         unsafe {
             let source = self.base.add(from_idx);
             let target = self.base.add(to_idx);
             std::ptr::copy(source, target, num_to_move);
+        }
+    }
     pub fn len(&self) -> usize {
         return self.len;
+    }
     pub fn as_slice(&self) -> &[T] {
         return unsafe{
             std::slice::from_raw_parts(self.base, self.len)
         };
+    }
     fn ensure_space(&mut self, additional: usize) -> Result<(), AllocError>{
         debug_assert!(Self::T_SIZE != 0);
         debug_assert!(self.cap >= self.len);
         if self.cap - self.len < additional {
             // Need to resize. Note that due to all checked conditions we have
             // that new_cap >= 1.
             debug_assert!(additional > 0);
             let new_cap = self.len.checked_add(additional).unwrap();
             let new_cap = cmp::max(new_cap, self.cap * Self::GROWTH_RATE);
             let layout = Layout::array::<T>(new_cap)
                 .map_err(|_| AllocError::CapacityOverflow)?;
             debug_assert_eq!(new_cap * Self::T_SIZE, layout.size());
             unsafe {
                 // Allocate new storage, transfer bits, deallocate old store
                 let new_base = alloc(layout);
                 if self.cap > 0 {
                     let old_base = self.base as *mut u8;
                     let (old_size, old_layout) = self.current_layout();
                     ptr::copy_nonoverlapping(old_base, new_base, old_size);
                     dealloc(old_base, old_layout);
+                }
                 self.base = new_base as *mut T;
                 self.cap = new_cap;
+            }
         } // else: still enough space
         return Ok(());
+    }
     #[inline]
     fn current_layout(&self) -> (usize, Layout) {
         debug_assert!(Self::T_SIZE > 0);
         let old_size = self.cap * Self::T_SIZE;
         unsafe {
             return (
                 old_size,
                 Layout::from_size_align_unchecked(old_size, Self::T_ALIGNMENT)
             );
+        }
+    }
+}
 impl<T: Sized> Drop for RawVec<T> {
     fn drop(&mut self) {
         if self.cap > 0 {
             debug_assert!(!self.base.is_null());
             let (_, layout) = self.current_layout();
             unsafe {
                 dealloc(self.base as *mut u8, layout);
                 if cfg!(debug_assertions) {
                     self.base = ptr::null_mut();
+                }
                 dbg_code!({ self.base = ptr::null_mut(); });
+            }
+        }
+    }
+}
@@ \ No newline at end of file @@

src/collections/scoped_buffer.rs

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 /// scoped_buffer.rs
 ///
 /// Solves the common pattern where we are performing some kind of recursive
 /// pattern while using a temporary buffer. At the start, or during the
 /// procedure, we push stuff into the buffer. At the end we take out what we
 /// have put in.
 ///
 /// It is unsafe because we're using pointers to circumvent borrowing rules in
 /// the name of code cleanliness. The correctness of use is checked in debug
 /// mode at runtime.
 use std::iter::FromIterator;
 macro_rules! hide {
     ($v:block) => {
         #[cfg(debug_assertions)] $v
     };
     ($v:expr) => {
         #[cfg(debug_assertions)] $v
     };
+}
 pub(crate) struct ScopedBuffer<T: Sized> {
     pub inner: Vec<T>,
+}
 impl<T: Sized> ScopedBuffer<T> {
     pub(crate) fn with_capacity(capacity: usize) -> Self {
         Self {
             inner: Vec::with_capacity(capacity),
+        }
+    }
     pub(crate) fn start_section(&mut self) -> ScopedSection<T> {
         let start_size = self.inner.len() as u32;
         ScopedSection {
             inner: &mut self.inner,
             start_size,
             #[cfg(debug_assertions)] cur_size: start_size,
+        }
+    }
+}
 impl<T: Clone> ScopedBuffer<T> {
     pub(crate) fn start_section_initialized(&mut self, initialize_with: &[T]) -> ScopedSection<T> {
         let start_size = self.inner.len() as u32;
         let _data_size = initialize_with.len() as u32;
         self.inner.extend_from_slice(initialize_with);
         ScopedSection{
             inner: &mut self.inner,
             start_size,
             #[cfg(debug_assertions)] cur_size: start_size + _data_size,
+        }
+    }
+}
 #[cfg(debug_assertions)]
 impl<T: Sized> Drop for ScopedBuffer<T> {
     fn drop(&mut self) {
         // Make sure that everyone cleaned up the buffer neatly
         debug_assert!(self.inner.is_empty(), "dropped non-empty scoped buffer");
+    }
+}
 /// A section of the buffer. Keeps track of where we started the section. When
 /// done with the section one must call `into_vec` or `forget` to remove the
 /// section from the underlying buffer. This will also be done upon dropping the
 /// ScopedSection in case errors are being handled.
 pub(crate) struct ScopedSection<T: Sized> {
     inner: *mut Vec<T>,
     start_size: u32,
     #[cfg(debug_assertions)] cur_size: u32,
+}
 impl<T: Sized> ScopedSection<T> {
     /// Pushes value into section
     #[inline]
     pub(crate) fn push(&mut self, value: T) {
         self.check_length();
         let vec = unsafe{&mut *self.inner};
         hide!(debug_assert_eq!(
             vec.len(), self.cur_size as usize,
             "trying to push onto section, but size is larger than expected"
         ));
         vec.push(value);
         hide!(self.cur_size += 1);
+    }
     #[inline]
     pub(crate) fn len(&self) -> usize {
         self.check_length();
         let vec = unsafe{&mut *self.inner};
         hide!(debug_assert_eq!(
             vec.len(), self.cur_size as usize,
             "trying to get section length, but size is larger than expected"
         ));
         return vec.len() - self.start_size as usize;
+    }
     #[inline]
     #[allow(unused_mut)] // used in debug mode
     pub(crate) fn forget(mut self) {
         self.check_length();
         let vec = unsafe{&mut *self.inner};
         hide!({
             debug_assert_eq!(
                 vec.len(), self.cur_size as usize,
                 "trying to forget section, but size is larger than expected"
             );
             self.cur_size = self.start_size;
         });
         hide!(self.cur_size = self.start_size);
         vec.truncate(self.start_size as usize);
+    }
     #[inline]
     #[allow(unused_mut)] // used in debug mode
     pub(crate) fn into_vec(mut self) -> Vec<T> {
         self.check_length();
         let vec = unsafe{&mut *self.inner};
         hide!(self.cur_size = self.start_size);
         let section = Vec::from_iter(vec.drain(self.start_size as usize..));
         section
+    }
     #[inline]
     pub(crate) fn check_length(&self) {
         hide!({
             let vec = unsafe{&*self.inner};
             debug_assert_eq!(
                 vec.len(), self.cur_size as usize,
                 "trying to turn section into vec, but size is larger than expected"
             );
             self.cur_size = self.start_size;
         });
         let section = Vec::from_iter(vec.drain(self.start_size as usize..));
         section
                 "incorrect use of ScopedSection: underlying storage vector has changed size"
+            )
         })
+    }
+}
 impl<T: Sized + PartialEq> ScopedSection<T> {
     #[inline]
     pub(crate) fn push_unique(&mut self, value: T) {
         self.check_length();
         let vec = unsafe{&mut *self.inner};
         for item in &vec[self.start_size as usize..] {
             if *item == value {
                 // item already exists
                 return;
+            }
+        }
         vec.push(value);
         hide!(self.cur_size += 1);
+    }
     #[inline]
     pub(crate) fn contains(&self, value: &T) -> bool {
         self.check_length();
         let vec = unsafe{&*self.inner};
         for index in self.start_size as usize..vec.len() {
             if &vec[index] == value {
                 return true;
+            }
+        }
         return false;
+    }
+}
 impl<T: Copy> ScopedSection<T> {
     pub(crate) fn iter_copied(&self) -> ScopedIter<T> {
         return ScopedIter{
             inner: self.inner,
             cur_index: self.start_size,
             last_index: unsafe{ (*self.inner).len() as u32 },
+        }
+    }
+}
 impl<T> std::ops::Index<usize> for ScopedSection<T> {
     type Output = T;
     fn index(&self, index: usize) -> &Self::Output {
         let vec = unsafe{&*self.inner};
         return &vec[self.start_size as usize + index]
+    }
+}
 impl<T> std::ops::IndexMut<usize> for ScopedSection<T> {
     fn index_mut(&mut self, index: usize) -> &mut Self::Output {
         let vec = unsafe{&mut *self.inner};
         return &mut vec[self.start_size as usize + index]
+    }
+}
 #[cfg(debug_assertions)]
 impl<T: Sized> Drop for ScopedSection<T> {
     fn drop(&mut self) {
         let vec = unsafe{&mut *self.inner};
         hide!(debug_assert_eq!(vec.len(), self.cur_size as usize));
         vec.truncate(self.start_size as usize);
+    }
+}
 /// Small utility for iterating over a section of the buffer. Same conditions as
 /// the buffer apply: each time we retrieve an element the buffer must have the
 /// same size as the moment of creation.
 pub(crate) struct ScopedIter<T: Copy> {
     inner: *mut Vec<T>,
     cur_index: u32,
     last_index: u32,
+}
 impl<T: Copy> Iterator for ScopedIter<T> {
     type Item = T;
     fn next(&mut self) -> Option<Self::Item> {
         hide!(debug_assert_eq!(self.last_index as usize, unsafe { (*self.inner).len() }));
         if self.cur_index >= self.last_index {
             return None;
+        }
         let vec = unsafe{ &*self.inner };
         let index = self.cur_index as usize;
         self.cur_index += 1;
         return Some(vec[index]);
+    }
+}
@@ \ No newline at end of file @@

src/collections/string_pool.rs

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 use std::ptr::null_mut;
+use std::ptr::{null_mut, null};
 use std::hash::{Hash, Hasher};
 use std::marker::PhantomData;
 use std::fmt::{Debug, Display, Formatter, Result as FmtResult};
 const SLAB_SIZE: usize = u16::MAX as usize;
 #[derive(Clone)]
 pub struct StringRef<'a> {
     data: *const u8,
     length: usize,
     _phantom: PhantomData<&'a [u8]>,
+}
 // As the StringRef is an immutable thing:
 unsafe impl Sync for StringRef<'_> {}
 unsafe impl Send for StringRef<'_> {}
 impl<'a> StringRef<'a> {
     /// `new` constructs a new StringRef whose data is not owned by the
     /// `StringPool`, hence cannot have a `'static` lifetime.
     pub(crate) fn new(data: &'a [u8]) -> StringRef<'a> {
         // This is an internal (compiler) function: so debug_assert that the
         // string is valid ascii. Most commonly the input will come from the
         // code's source file, which is checked for ASCII-ness anyway.
         debug_assert!(data.is_ascii());
         let length = data.len();
         let data = data.as_ptr();
         StringRef{ data, length, _phantom: PhantomData }
+    }
     /// `new_empty` creates a empty StringRef. It is a null pointer with a
     /// length of zero.
     pub(crate) const fn new_empty() -> StringRef<'static> {
         StringRef{ data: null(), length: 0, _phantom: PhantomData }
+    }
     pub fn as_str(&self) -> &'a str {
         unsafe {
             let slice = std::slice::from_raw_parts::<'a, u8>(self.data, self.length);
             std::str::from_utf8_unchecked(slice)
+        }
+    }
     pub fn as_bytes(&self) -> &'a [u8] {
         unsafe {
             std::slice::from_raw_parts::<'a, u8>(self.data, self.length)
+        }
+    }
+}
 impl<'a> Debug for StringRef<'a> {
     fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
         f.write_str("StringRef{ value: ")?;
         f.write_str(self.as_str())?;
         f.write_str(" }")
+    }
+}
 impl<'a> Display for StringRef<'a> {
     fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
         f.write_str(self.as_str())
+    }
+}
 impl PartialEq for StringRef<'_> {
     fn eq(&self, other: &StringRef) -> bool {
         self.as_str() == other.as_str()
+    }
+}
 impl Eq for StringRef<'_> {}
 impl Hash for StringRef<'_> {
     fn hash<H: Hasher>(&self, state: &mut H) {
         state.write(self.as_bytes());
+    }
+}
 struct StringPoolSlab {
     prev: *mut StringPoolSlab,
     data: Vec<u8>,
     remaining: usize,
+}
 impl StringPoolSlab {
     fn new(prev: *mut StringPoolSlab) -> Self {
         Self{ prev, data: Vec::with_capacity(SLAB_SIZE), remaining: SLAB_SIZE }
+    }
+}
 /// StringPool is a ever-growing pool of strings. Strings have a maximum size
 /// equal to the slab size. The slabs are essentially a linked list to maintain
 /// pointer-stability of the strings themselves.
 /// All `StringRef` instances are invalidated when the string pool is dropped
 pub(crate) struct StringPool {
     last: *mut StringPoolSlab,
+}
 impl StringPool {
     pub(crate) fn new() -> Self {
         // To have some stability we just turn a box into a raw ptr.
         let initial_slab = Box::new(StringPoolSlab::new(null_mut()));
         let initial_slab = Box::into_raw(initial_slab);
         StringPool{
             last: initial_slab,
+        }
+    }
     /// Interns a string to the `StringPool`, returning a reference to it. The
     /// pointer owned by `StringRef` is `'static` as the `StringPool` doesn't
     /// reallocate/deallocate until dropped (which only happens at the end of
     /// the program.)
     pub(crate) fn intern(&mut self, data: &[u8]) -> StringRef<'static> {
         let data_len = data.len();
         assert!(data_len <= SLAB_SIZE, "string is too large for slab"); // if you hit this, create logic for large-string allocations
         debug_assert!(std::str::from_utf8(data).is_ok(), "string to intern is not valid UTF-8 encoded");
         let mut last = unsafe{&mut *self.last};
         if data.len() > last.remaining {
             // Doesn't fit: allocate new slab
             self.alloc_new_slab();
             last = unsafe{&mut *self.last};
+        }
         // Must fit now, compute hash and put in buffer
         debug_assert!(data_len <= last.remaining);
         let range_start = last.data.len();
         last.data.extend_from_slice(data);
         last.remaining -= data_len;
         debug_assert_eq!(range_start + data_len, last.data.len());
         unsafe {
             let start = last.data.as_ptr().offset(range_start as isize);
             StringRef{ data: start, length: data_len, _phantom: PhantomData }
+        }
+    }
     fn alloc_new_slab(&mut self) {
         let new_slab = Box::new(StringPoolSlab::new(self.last));
         let new_slab = Box::into_raw(new_slab);
         self.last = new_slab;
+    }
+}
 impl Drop for StringPool {
     fn drop(&mut self) {
         let mut new_slab = self.last;
         while !new_slab.is_null() {
             let cur_slab = new_slab;
             unsafe {
                 new_slab = (*cur_slab).prev;
                 Box::from_raw(cur_slab); // consume and deallocate
+            }
+        }
+    }
+}
 // String pool cannot be cloned, and the created `StringRef` instances remain
 // allocated until the end of the program, so it is always safe to send. It is
 // also sync in the sense that it becomes an immutable thing after compilation,
 // but lets not derive that if we would ever become a multithreaded compiler in
 // the future.
 unsafe impl Send for StringPool {}
 #[cfg(test)]
 mod tests {
     use super::*;
     #[test]
     fn display_empty_string_ref() {
         // Makes sure that null pointer inside StringRef will not cause issues
         let v = StringRef::new_empty();
         let _val = format!("{}{:?}", v, v); // calls Format and Debug on StringRef
+    }
     #[test]
     fn test_string_just_fits() {
         let large = "0".repeat(SLAB_SIZE);
         let mut pool = StringPool::new();
         let interned = pool.intern(large.as_bytes());
         assert_eq!(interned.as_str(), large);
+    }
     #[test]
     #[should_panic]
     fn test_string_too_large() {
         let large = "0".repeat(SLAB_SIZE + 1);
         let mut pool = StringPool::new();
         let _interned = pool.intern(large.as_bytes());
+    }
     #[test]
     fn test_lots_of_small_allocations() {
         const NUM_PER_SLAB: usize = 32;
         const NUM_SLABS: usize = 4;
         let to_intern = "0".repeat(SLAB_SIZE / NUM_PER_SLAB);
         let mut pool = StringPool::new();
         let mut last_slab = pool.last;
         let mut all_refs = Vec::new();
         // Fill up first slab
         for _alloc_idx in 0..NUM_PER_SLAB {
             let interned = pool.intern(to_intern.as_bytes());
             all_refs.push(interned);
             assert!(std::ptr::eq(last_slab, pool.last));
+        }
         for _slab_idx in 0..NUM_SLABS-1 {
             for alloc_idx in 0..NUM_PER_SLAB {
                 let interned = pool.intern(to_intern.as_bytes());
                 all_refs.push(interned);
                 if alloc_idx == 0 {
                     // First allocation produces a new slab
                     assert!(!std::ptr::eq(last_slab, pool.last));
                     last_slab = pool.last;
                 } else {
                     assert!(std::ptr::eq(last_slab, pool.last));
+                }
+            }
+        }
         // All strings are still correct
         for string_ref in all_refs {
             assert_eq!(string_ref.as_str(), to_intern);
+        }
+    }
+}
@@ \ No newline at end of file @@

src/common.rs

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deleted file

src/lib.rs

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 #[macro_use]
 mod macros;
 // mod common;
 mod protocol;
 pub mod runtime;
 pub mod runtime2;
 mod collections;
 mod random;
 pub use protocol::{ProtocolDescription, ProtocolDescriptionBuilder, ComponentCreationError};
@@ \ No newline at end of file @@

src/macros.rs

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 // Utility for performing debug printing within a particular module. Still
 // requires some extra macros to be defined to be ergonomic.
 macro_rules! enabled_debug_print {
     (false, $name:literal, $format:literal) => {};
     (false, $name:literal, $format:literal, $($args:expr),*) => {};
     (true, $name:literal, $format:literal) => {
         println!("[{}] {}", $name, $format)
     };
     (true, $name:literal, $format:literal, $($args:expr),*) => {
         println!("[{}] {}", $name, format!($format, $($args),*))
     };
+}
 // Utility for inserting code only executed in debug mode. Because writing the
 // conditional cfg is tedious and looks ugly. Still doesn't work for struct
 // fields, though.
 macro_rules! dbg_code {
     ($code:stmt) => {
         #[cfg(debug_assertions)] $code
+    }
+}
 // Given a function name, return type and variant, will generate the all-so
 // common `union_value.as_variant()` method. The return value is the reference
 // to the embedded union type.
 macro_rules! union_cast_to_ref_method_impl {
     ($func_name:ident, $ret_type:ty, $variant:path) => {
         fn $func_name(&self) -> &$ret_type {
             match self {
                 $variant(content) => return content,
                 _ => unreachable!(),
+            }
+        }
+    }
+}
 // Another union cast, but now returning a copy of the value
 macro_rules! union_cast_to_value_method_impl {
     ($func_name:ident, $ret_type:ty, $variant:path) => {
         impl Value {
             pub(crate) fn $func_name(&self) -> $ret_type {
                 match self {
                     $variant(v) => *v,
                     _ => unreachable!(),
+                }
+            }
+        }
+    }
+}
@@ \ No newline at end of file @@

src/protocol/ast.rs

➞

Show inline comments

 use std::fmt;
 use std::fmt::{Debug, Display, Formatter};
 use std::ops::{Index, IndexMut};
 use super::arena::{Arena, Id};
 use crate::collections::StringRef;
 use crate::protocol::input_source::InputSpan;
 use crate::protocol::TypeId;
 /// Helper macro that defines a type alias for a AST element ID. In this case
 /// only used to alias the `Id<T>` types.
 macro_rules! define_aliased_ast_id {
     // Variant where we just defined the alias, without any indexing
     ($name:ident, $parent:ty) => {
         pub type $name = $parent;
     };
     // Variant where we define the type, and the Index and IndexMut traits
+    (
         $name:ident, $parent:ty,
         index($indexed_type:ty, $indexed_arena:ident)
     ) => {
         define_aliased_ast_id!($name, $parent);
         impl Index<$name> for Heap {
             type Output = $indexed_type;
             fn index(&self, index: $name) -> &Self::Output {
                 &self.$indexed_arena[index]
+            }
+        }
         impl IndexMut<$name> for Heap {
             fn index_mut(&mut self, index: $name) -> &mut Self::Output {
                 &mut self.$indexed_arena[index]
+            }
+        }
     };
     // Variant where we define type, Index(Mut) traits and an allocation function
+    (
         $name:ident, $parent:ty,
         index($indexed_type:ty, $indexed_arena:ident),
         alloc($fn_name:ident)
     ) => {
         define_aliased_ast_id!($name, $parent, index($indexed_type, $indexed_arena));
         impl Heap {
             pub fn $fn_name(&mut self, f: impl FnOnce($name) -> $indexed_type) -> $name {
                 self.$indexed_arena.alloc_with_id(|id| f(id))
+            }
+        }
     };
+}
 /// Helper macro that defines a wrapper type for a particular variant of an AST
 /// element ID. Only used to define single-wrapping IDs.
 macro_rules! define_new_ast_id {
     // Variant where we just defined the new type, without any indexing
     ($name:ident, $parent:ty) => {
         #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
         pub struct $name (pub(crate) $parent);
         #[allow(dead_code)]
         impl $name {
             pub(crate) fn new_invalid() -> Self     { Self(<$parent>::new_invalid()) }
             pub(crate) fn is_invalid(&self) -> bool { self.0.is_invalid() }
             pub fn upcast(self) -> $parent          { self.0 }
+        }
     };
     // Variant where we define the type, and the Index and IndexMut traits
+    (
         $name:ident, $parent:ty,
         index($indexed_type:ty, $wrapper_type:path, $indexed_arena:ident)
     ) => {
         define_new_ast_id!($name, $parent);
         impl Index<$name> for Heap {
             type Output = $indexed_type;
             fn index(&self, index: $name) -> &Self::Output {
                 if let $wrapper_type(v) = &self.$indexed_arena[index.0] {
+                    v
                 } else {
                     unreachable!()
+                }
+            }
+        }
         impl IndexMut<$name> for Heap {
             fn index_mut(&mut self, index: $name) -> &mut Self::Output {
                 if let $wrapper_type(v) = &mut self.$indexed_arena[index.0] {
+                    v
                 } else {
                     unreachable!()
+                }
+            }
+        }
     };
     // Variant where we define the type, the Index and IndexMut traits, and an allocation function
+    (
         $name:ident, $parent:ty,
         index($indexed_type:ty, $wrapper_type:path, $indexed_arena:ident),
         alloc($fn_name:ident)
     ) => {
         define_new_ast_id!($name, $parent, index($indexed_type, $wrapper_type, $indexed_arena));
         impl Heap {
             pub fn $fn_name(&mut self, f: impl FnOnce($name) -> $indexed_type) -> $name {
                 $name(
                     self.$indexed_arena.alloc_with_id(|id| {
                         $wrapper_type(f($name(id)))
                     })
+                )
+            }
+        }
+    }
+}
 define_aliased_ast_id!(RootId, Id<Root>, index(Root, protocol_descriptions), alloc(alloc_protocol_description));
 define_aliased_ast_id!(PragmaId, Id<Pragma>, index(Pragma, pragmas), alloc(alloc_pragma));
 define_aliased_ast_id!(ImportId, Id<Import>, index(Import, imports), alloc(alloc_import));
 define_aliased_ast_id!(VariableId, Id<Variable>, index(Variable, variables), alloc(alloc_variable));
 define_aliased_ast_id!(DefinitionId, Id<Definition>, index(Definition, definitions));
 define_new_ast_id!(StructDefinitionId, DefinitionId, index(StructDefinition, Definition::Struct, definitions), alloc(alloc_struct_definition));
 define_new_ast_id!(EnumDefinitionId, DefinitionId, index(EnumDefinition, Definition::Enum, definitions), alloc(alloc_enum_definition));
 define_new_ast_id!(UnionDefinitionId, DefinitionId, index(UnionDefinition, Definition::Union, definitions), alloc(alloc_union_definition));
 define_new_ast_id!(ComponentDefinitionId, DefinitionId, index(ComponentDefinition, Definition::Component, definitions), alloc(alloc_component_definition));
 define_new_ast_id!(FunctionDefinitionId, DefinitionId, index(FunctionDefinition, Definition::Function, definitions), alloc(alloc_function_definition));
 define_new_ast_id!(ProcedureDefinitionId, DefinitionId, index(ProcedureDefinition, Definition::Procedure, definitions), alloc(alloc_procedure_definition));
 define_aliased_ast_id!(StatementId, Id<Statement>, index(Statement, statements));
 define_new_ast_id!(BlockStatementId, StatementId, index(BlockStatement, Statement::Block, statements), alloc(alloc_block_statement));
 define_new_ast_id!(EndBlockStatementId, StatementId, index(EndBlockStatement, Statement::EndBlock, statements), alloc(alloc_end_block_statement));
 define_new_ast_id!(LocalStatementId, StatementId, index(LocalStatement, Statement::Local, statements));
 define_new_ast_id!(MemoryStatementId, LocalStatementId);
 define_new_ast_id!(ChannelStatementId, LocalStatementId);
 define_new_ast_id!(LabeledStatementId, StatementId, index(LabeledStatement, Statement::Labeled, statements), alloc(alloc_labeled_statement));
 define_new_ast_id!(IfStatementId, StatementId, index(IfStatement, Statement::If, statements), alloc(alloc_if_statement));
 define_new_ast_id!(EndIfStatementId, StatementId, index(EndIfStatement, Statement::EndIf, statements), alloc(alloc_end_if_statement));
 define_new_ast_id!(WhileStatementId, StatementId, index(WhileStatement, Statement::While, statements), alloc(alloc_while_statement));
 define_new_ast_id!(EndWhileStatementId, StatementId, index(EndWhileStatement, Statement::EndWhile, statements), alloc(alloc_end_while_statement));
 define_new_ast_id!(BreakStatementId, StatementId, index(BreakStatement, Statement::Break, statements), alloc(alloc_break_statement));
 define_new_ast_id!(ContinueStatementId, StatementId, index(ContinueStatement, Statement::Continue, statements), alloc(alloc_continue_statement));
 define_new_ast_id!(SynchronousStatementId, StatementId, index(SynchronousStatement, Statement::Synchronous, statements), alloc(alloc_synchronous_statement));
 define_new_ast_id!(EndSynchronousStatementId, StatementId, index(EndSynchronousStatement, Statement::EndSynchronous, statements), alloc(alloc_end_synchronous_statement));
 define_new_ast_id!(ForkStatementId, StatementId, index(ForkStatement, Statement::Fork, statements), alloc(alloc_fork_statement));
 define_new_ast_id!(EndForkStatementId, StatementId, index(EndForkStatement, Statement::EndFork, statements), alloc(alloc_end_fork_statement));
 define_new_ast_id!(SelectStatementId, StatementId, index(SelectStatement, Statement::Select, statements), alloc(alloc_select_statement));
 define_new_ast_id!(EndSelectStatementId, StatementId, index(EndSelectStatement, Statement::EndSelect, statements), alloc(alloc_end_select_statement));
 define_new_ast_id!(ReturnStatementId, StatementId, index(ReturnStatement, Statement::Return, statements), alloc(alloc_return_statement));
 define_new_ast_id!(GotoStatementId, StatementId, index(GotoStatement, Statement::Goto, statements), alloc(alloc_goto_statement));
 define_new_ast_id!(NewStatementId, StatementId, index(NewStatement, Statement::New, statements), alloc(alloc_new_statement));
 define_new_ast_id!(ExpressionStatementId, StatementId, index(ExpressionStatement, Statement::Expression, statements), alloc(alloc_expression_statement));
 define_aliased_ast_id!(ExpressionId, Id<Expression>, index(Expression, expressions));
 define_new_ast_id!(AssignmentExpressionId, ExpressionId, index(AssignmentExpression, Expression::Assignment, expressions), alloc(alloc_assignment_expression));
 define_new_ast_id!(BindingExpressionId, ExpressionId, index(BindingExpression, Expression::Binding, expressions), alloc(alloc_binding_expression));
 define_new_ast_id!(ConditionalExpressionId, ExpressionId, index(ConditionalExpression, Expression::Conditional, expressions), alloc(alloc_conditional_expression));
 define_new_ast_id!(BinaryExpressionId, ExpressionId, index(BinaryExpression, Expression::Binary, expressions), alloc(alloc_binary_expression));
 define_new_ast_id!(UnaryExpressionId, ExpressionId, index(UnaryExpression, Expression::Unary, expressions), alloc(alloc_unary_expression));
 define_new_ast_id!(IndexingExpressionId, ExpressionId, index(IndexingExpression, Expression::Indexing, expressions), alloc(alloc_indexing_expression));
 define_new_ast_id!(SlicingExpressionId, ExpressionId, index(SlicingExpression, Expression::Slicing, expressions), alloc(alloc_slicing_expression));
 define_new_ast_id!(SelectExpressionId, ExpressionId, index(SelectExpression, Expression::Select, expressions), alloc(alloc_select_expression));
 define_new_ast_id!(LiteralExpressionId, ExpressionId, index(LiteralExpression, Expression::Literal, expressions), alloc(alloc_literal_expression));
 define_new_ast_id!(CastExpressionId, ExpressionId, index(CastExpression, Expression::Cast, expressions), alloc(alloc_cast_expression));
 define_new_ast_id!(CallExpressionId, ExpressionId, index(CallExpression, Expression::Call, expressions), alloc(alloc_call_expression));
 define_new_ast_id!(VariableExpressionId, ExpressionId, index(VariableExpression, Expression::Variable, expressions), alloc(alloc_variable_expression));
 define_aliased_ast_id!(ScopeId, Id<Scope>, index(Scope, scopes), alloc(alloc_scope));
 #[derive(Debug)]
 pub struct Heap {
     // Root arena, contains the entry point for different modules. Each root
     // contains lists of IDs that correspond to the other arenas.
     pub(crate) protocol_descriptions: Arena<Root>,
     // Contents of a file, these are the elements the `Root` elements refer to
     pragmas: Arena<Pragma>,
     pub(crate) imports: Arena<Import>,
     pub(crate) variables: Arena<Variable>,
     pub(crate) definitions: Arena<Definition>,
     pub(crate) statements: Arena<Statement>,
     pub(crate) expressions: Arena<Expression>,
     pub(crate) scopes: Arena<Scope>,
+}
 impl Heap {
     pub fn new() -> Heap {
         Heap {
             // string_alloc: StringAllocator::new(),
             protocol_descriptions: Arena::new(),
             pragmas: Arena::new(),
             imports: Arena::new(),
             variables: Arena::new(),
             definitions: Arena::new(),
             statements: Arena::new(),
             expressions: Arena::new(),
             scopes: Arena::new(),
+        }
+    }
     pub fn alloc_memory_statement(
         &mut self,
         f: impl FnOnce(MemoryStatementId) -> MemoryStatement,
     ) -> MemoryStatementId {
         MemoryStatementId(LocalStatementId(self.statements.alloc_with_id(|id| {
             Statement::Local(LocalStatement::Memory(
                 f(MemoryStatementId(LocalStatementId(id)))
             ))
         })))
+    }
     pub fn alloc_channel_statement(
         &mut self,
         f: impl FnOnce(ChannelStatementId) -> ChannelStatement,
     ) -> ChannelStatementId {
         ChannelStatementId(LocalStatementId(self.statements.alloc_with_id(|id| {
             Statement::Local(LocalStatement::Channel(
                 f(ChannelStatementId(LocalStatementId(id)))
             ))
         })))
+    }
+}
 impl Index<MemoryStatementId> for Heap {
     type Output = MemoryStatement;
     fn index(&self, index: MemoryStatementId) -> &Self::Output {
         &self.statements[index.0.0].as_memory()
         match &self.statements[index.0.0] {
             Statement::Local(LocalStatement::Memory(v)) => v,
             _ => unreachable!(),
+        }
+    }
+}
 impl Index<ChannelStatementId> for Heap {
     type Output = ChannelStatement;
     fn index(&self, index: ChannelStatementId) -> &Self::Output {
         &self.statements[index.0.0].as_channel()
         match &self.statements[index.0.0] {
             Statement::Local(LocalStatement::Channel(v)) => v,
             _ => unreachable!(),
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub struct Root {
     pub this: RootId,
     // Phase 1: parser
     // pub position: InputPosition,
     pub pragmas: Vec<PragmaId>,
     pub imports: Vec<ImportId>,
     pub definitions: Vec<DefinitionId>,
+}
 impl Root {
     pub fn get_definition_ident(&self, h: &Heap, id: &[u8]) -> Option<DefinitionId> {
         for &def in self.definitions.iter() {
             if h[def].identifier().value.as_bytes() == id {
                 return Some(def);
+            }
+        }
         None
+    }
+}
 #[derive(Debug, Clone)]
 pub enum Pragma {
     Version(PragmaVersion),
     Module(PragmaModule),
+}
 impl Pragma {
     pub(crate) fn as_module(&self) -> &PragmaModule {
         match self {
             Pragma::Module(pragma) => pragma,
             _ => unreachable!("Tried to obtain {:?} as PragmaModule", self),
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub struct PragmaVersion {
     pub this: PragmaId,
     // Phase 1: parser
     pub span: InputSpan, // of full pragma
     pub version: u64,
+}
 #[derive(Debug, Clone)]
 pub struct PragmaModule {
     pub this: PragmaId,
     // Phase 1: parser
     pub span: InputSpan, // of full pragma
     pub value: Identifier,
+}
 #[derive(Debug, Clone)]
 pub enum Import {
     Module(ImportModule),
     Symbols(ImportSymbols)
+}
 impl Import {
     pub(crate) fn span(&self) -> InputSpan {
         match self {
             Import::Module(v) => v.span,
             Import::Symbols(v) => v.span,
+        }
+    }
     pub(crate) fn as_module(&self) -> &ImportModule {
         match self {
             Import::Module(m) => m,
             _ => unreachable!("Unable to cast 'Import' to 'ImportModule'")
+        }
+    }
     pub(crate) fn as_symbols(&self) -> &ImportSymbols {
         match self {
             Import::Symbols(m) => m,
             _ => unreachable!("Unable to cast 'Import' to 'ImportSymbols'")
+        }
+    }
     pub(crate) fn as_symbols_mut(&mut self) -> &mut ImportSymbols {
         match self {
             Import::Symbols(m) => m,
             _ => unreachable!("Unable to cast 'Import' to 'ImportSymbols'")
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub struct ImportModule {
     pub this: ImportId,
     // Phase 1: parser
     pub span: InputSpan,
     pub module: Identifier,
     pub alias: Identifier,
     pub module_id: RootId,
+}
 #[derive(Debug, Clone)]
 pub struct AliasedSymbol {
     pub name: Identifier,
     pub alias: Option<Identifier>,
     pub definition_id: DefinitionId,
+}
 #[derive(Debug, Clone)]
 pub struct ImportSymbols {
     pub this: ImportId,
     // Phase 1: parser
     pub span: InputSpan,
     pub module: Identifier,
     pub module_id: RootId,
     pub symbols: Vec<AliasedSymbol>,
+}
 #[derive(Debug, Clone)]
 pub struct Identifier {
     pub span: InputSpan,
     pub value: StringRef<'static>,
+}
 impl Identifier {
     pub(crate) const fn new_empty(span: InputSpan) -> Identifier {
         return Identifier{
             span,
             value: StringRef::new_empty(),
         };
+    }
+}
 impl PartialEq for Identifier {
     fn eq(&self, other: &Self) -> bool {
         return self.value == other.value
+    }
+}
 impl Display for Identifier {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         write!(f, "{}", self.value.as_str())
+    }
+}
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum ParserTypeVariant {
     // Special builtin, only usable by the compiler and not constructable by the
     // programmer
     Void,
     InputOrOutput,
     ArrayLike,
     IntegerLike,
     // Basic builtin
     Message,
     Bool,
     UInt8, UInt16, UInt32, UInt64,
     SInt8, SInt16, SInt32, SInt64,
     Character, String,
     // Literals (need to get concrete builtin type during typechecking)
     IntegerLiteral,
     // Marker for inference
     Inferred,
     // Builtins expecting one subsequent type
     Array,
     Input,
     Output,
     // Tuple: expecting any number of elements. Note that the parser type can
     // have one-valued tuples, these will be filtered out later during type
     // checking.
     Tuple(u32), // u32 = number of subsequent types
     // User-defined types
     PolymorphicArgument(DefinitionId, u32), // u32 = index into polymorphic variables
     Definition(DefinitionId, u32), // u32 = number of subsequent types in the type tree.
+}
 impl ParserTypeVariant {
     pub(crate) fn num_embedded(&self) -> usize {
         use ParserTypeVariant::*;
         match self {
             Void | IntegerLike |
             Message | Bool |
             UInt8 | UInt16 | UInt32 | UInt64 |
             SInt8 | SInt16 | SInt32 | SInt64 |
             Character | String | IntegerLiteral |
             Inferred | PolymorphicArgument(_, _) =>
 ,
             ArrayLike | InputOrOutput | Array | Input | Output =>
 ,
             Definition(_, num) | Tuple(num) => *num as usize,
+        }
+    }
+}
 /// ParserTypeElement is an element of the type tree. An element may be
 /// implicit, meaning that the user didn't specify the type, but it was set by
 /// the compiler.
 #[derive(Debug, Clone)]
 pub struct ParserTypeElement {
     pub element_span: InputSpan, // span of this element, not including the child types
     pub variant: ParserTypeVariant,
+}
 /// ParserType is a specification of a type during the parsing phase and initial
 /// linker/validator phase of the compilation process. These types may be
 /// (partially) inferred or represent literals (e.g. a integer whose bytesize is
 /// not yet determined).
 ///
 /// Its contents are the depth-first serialization of the type tree. Each node
 /// is a type that may accept polymorphic arguments. The polymorphic arguments
 /// are then the children of the node.
 #[derive(Debug, Clone)]
 pub struct ParserType {
     pub elements: Vec<ParserTypeElement>,
     pub full_span: InputSpan,
+}
 impl ParserType {
     pub(crate) fn iter_embedded(&self, parent_idx: usize) -> ParserTypeIter {
         ParserTypeIter::new(&self.elements, parent_idx)
+    }
+}
 /// Iterator over the embedded elements of a specific element.
 pub struct ParserTypeIter<'a> {
     pub elements: &'a [ParserTypeElement],
     pub cur_embedded_idx: usize,
+}
 impl<'a> ParserTypeIter<'a> {
     fn new(elements: &'a [ParserTypeElement], parent_idx: usize) -> Self {
         debug_assert!(parent_idx < elements.len(), "parent index exceeds number of elements in ParserType");
         if elements[0].variant.num_embedded() == 0 {
             // Parent element does not have any embedded types, place
             // `cur_embedded_idx` at end so we will always return `None`
             Self{ elements, cur_embedded_idx: elements.len() }
         } else {
             // Parent element has an embedded type
             Self{ elements, cur_embedded_idx: parent_idx + 1 }
+        }
+    }
+}
 impl<'a> Iterator for ParserTypeIter<'a> {
     type Item = &'a [ParserTypeElement];
     fn next(&mut self) -> Option<Self::Item> {
         let elements_len = self.elements.len();
         if self.cur_embedded_idx >= elements_len {
             return None;
+        }
         // Seek to the end of the subtree
         let mut depth = 1;
         let start_element = self.cur_embedded_idx;
         while self.cur_embedded_idx < elements_len {
             let cur_element = &self.elements[self.cur_embedded_idx];
             let depth_change = cur_element.variant.num_embedded() as i32 - 1;
             depth += depth_change;
             debug_assert!(depth >= 0, "illegally constructed ParserType: {:?}", self.elements);
             self.cur_embedded_idx += 1;
             if depth == 0 {
                 break;
+            }
+        }
         debug_assert!(depth == 0, "illegally constructed ParserType: {:?}", self.elements);
         return Some(&self.elements[start_element..self.cur_embedded_idx]);
+    }
+}
 /// ConcreteType is the representation of a type after the type inference and
 /// checker is finished. These are fully typed.
 #[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
 pub enum ConcreteTypePart {
     // Special types (cannot be explicitly constructed by the programmer)
     Void,
     // Builtin types without nested types
     Message,
     Bool,
     UInt8, UInt16, UInt32, UInt64,
     SInt8, SInt16, SInt32, SInt64,
     Character, String,
     // Builtin types with one nested type
     Array,
     Slice,
     Input,
     Output,
     Pointer,
     // Tuple: variable number of nested types, will never be 1
     Tuple(u32),
     // User defined type with any number of nested types
     Instance(DefinitionId, u32),    // instance of data type
     Function(DefinitionId, u32),    // instance of function
     Component(DefinitionId, u32),   // instance of a connector
     Function(ProcedureDefinitionId, u32),    // instance of function
     Component(ProcedureDefinitionId, u32),   // instance of a connector
+}
 impl ConcreteTypePart {
     pub(crate) fn num_embedded(&self) -> u32 {
         use ConcreteTypePart::*;
         match self {
             Void | Message | Bool |
             UInt8 | UInt16 | UInt32 | UInt64 |
             SInt8 | SInt16 | SInt32 | SInt64 |
             Character | String =>
 ,
             Array | Slice | Input | Output =>
+            Array | Slice | Input | Output | Pointer =>
 ,
             Tuple(num_embedded) => *num_embedded,
             Instance(_, num_embedded) => *num_embedded,
             Function(_, num_embedded) => *num_embedded,
             Component(_, num_embedded) => *num_embedded,
+        }
+    }
+}
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct ConcreteType {
     pub(crate) parts: Vec<ConcreteTypePart>
+}
 impl Default for ConcreteType {
     fn default() -> Self {
         Self{ parts: Vec::new() }
+    }
+}
 impl ConcreteType {
     /// Returns an iterator over the subtrees that are type arguments (e.g. an
     /// array element's type, or a polymorphic type's arguments) to the
     /// provided parent type (specified by its index in the `parts` array).
     pub(crate) fn embedded_iter(&self, parent_part_idx: usize) -> ConcreteTypeIter {
         return ConcreteTypeIter::new(&self.parts, parent_part_idx);
+    }
     /// Construct a human-readable name for the type. Because this performs
     /// a string allocation don't use it for anything else then displaying the
     /// type to the user.
     pub(crate) fn display_name(&self, heap: &Heap) -> String {
         return Self::type_parts_display_name(self.parts.as_slice(), heap);
+    }
     // --- Utilities that operate on slice of parts
     /// Given the starting position of a type tree, determine the exclusive
     /// ending index.
     pub(crate) fn type_parts_subtree_end_idx(parts: &[ConcreteTypePart], start_idx: usize) -> usize {
         let mut depth = 1;
         let num_parts = parts.len();
         debug_assert!(start_idx < num_parts);
         for part_idx in start_idx..parts.len() {
             let depth_change = parts[part_idx].num_embedded() as i32 - 1;
             depth += depth_change;
             debug_assert!(depth >= 0);
             if depth == 0 {
                 return part_idx + 1;
+            }
+        }
         debug_assert!(false, "incorrectly constructed ConcreteType instance");
         return 0;
+    }
     /// Produces a human-readable representation of the concrete type parts
     fn type_parts_display_name(parts: &[ConcreteTypePart], heap: &Heap) -> String {
         let mut name = String::with_capacity(128);
         let _final_idx = Self::render_type_part_at(parts, heap, 0, &mut name);
         debug_assert_eq!(_final_idx, parts.len());
         return name;
+    }
     /// Produces a human-readable representation of a single type part. Lower
     /// level utility for `type_parts_display_name`.
     fn render_type_part_at(parts: &[ConcreteTypePart], heap: &Heap, mut idx: usize, target: &mut String) -> usize {
         use ConcreteTypePart as CTP;
         use crate::protocol::parser::token_parsing::*;
         let cur_idx = idx;
         idx += 1; // increment by 1, because it always happens
         match parts[cur_idx] {
             CTP::Void => { target.push_str("void"); },
             CTP::Message => { target.push_str(KW_TYPE_MESSAGE_STR); },
             CTP::Bool => { target.push_str(KW_TYPE_BOOL_STR); },
             CTP::UInt8 => { target.push_str(KW_TYPE_UINT8_STR); },
             CTP::UInt16 => { target.push_str(KW_TYPE_UINT16_STR); },
             CTP::UInt32 => { target.push_str(KW_TYPE_UINT32_STR); },
             CTP::UInt64 => { target.push_str(KW_TYPE_UINT64_STR); },
             CTP::SInt8 => { target.push_str(KW_TYPE_SINT8_STR); },
             CTP::SInt16 => { target.push_str(KW_TYPE_SINT16_STR); },
             CTP::SInt32 => { target.push_str(KW_TYPE_SINT32_STR); },
             CTP::SInt64 => { target.push_str(KW_TYPE_SINT64_STR); },
             CTP::Character => { target.push_str(KW_TYPE_CHAR_STR); },
             CTP::String => { target.push_str(KW_TYPE_STRING_STR); },
             CTP::Array | CTP::Slice => {
                 idx = Self::render_type_part_at(parts, heap, idx, target);
                 target.push_str("[]");
             },
             CTP::Input => {
                 target.push_str(KW_TYPE_IN_PORT_STR);
                 target.push('<');
                 idx = Self::render_type_part_at(parts, heap, idx, target);
                 target.push('>');
             },
             CTP::Output => {
                 target.push_str(KW_TYPE_OUT_PORT_STR);
                 target.push('<');
                 idx = Self::render_type_part_at(parts, heap, idx, target);
                 target.push('>');
             },
             CTP::Pointer => {
                 target.push('*');
                 idx = Self::render_type_part_at(parts, heap, idx, target);
+            }
             CTP::Tuple(num_parts) => {
                 target.push('(');
                 if num_parts != 0 {
                     idx = Self::render_type_part_at(parts, heap, idx, target);
                     for _ in 1..num_parts {
                         target.push(',');
                         idx = Self::render_type_part_at(parts, heap, idx, target);
+                    }
+                }
                 target.push(')');
             },
             CTP::Instance(definition_id, num_poly_args) |
             CTP::Instance(definition_id, num_poly_args) => {
                 idx = Self::render_definition_type_parts_at(parts, heap, definition_id, num_poly_args, idx, target);
+            }
             CTP::Function(definition_id, num_poly_args) |
             CTP::Component(definition_id, num_poly_args) => {
                 idx = Self::render_definition_type_parts_at(parts, heap, definition_id.upcast(), num_poly_args, idx, target);
+            }
+        }
         idx
+    }
     fn render_definition_type_parts_at(parts: &[ConcreteTypePart], heap: &Heap, definition_id: DefinitionId, num_poly_args: u32, mut idx: usize, target: &mut String) -> usize {
         let definition = &heap[definition_id];
         target.push_str(definition.identifier().value.as_str());
         if num_poly_args != 0 {
             target.push('<');
             for poly_arg_idx in 0..num_poly_args {
                 if poly_arg_idx != 0 {
                     target.push(',');
+                }
                 idx = Self::render_type_part_at(parts, heap, idx, target);
+            }
             target.push('>');
+        }
+            }
+        }
         idx
+        return idx;
+    }
+}
 #[derive(Debug)]
 pub struct ConcreteTypeIter<'a> {
     parts: &'a [ConcreteTypePart],
     idx_embedded: u32,
     num_embedded: u32,
     part_idx: usize,
+}
 impl<'a> ConcreteTypeIter<'a> {
     pub(crate) fn new(parts: &'a[ConcreteTypePart], parent_idx: usize) -> Self {
         let num_embedded = parts[parent_idx].num_embedded();
         return ConcreteTypeIter{
             parts,
             idx_embedded: 0,
             num_embedded,
             part_idx: parent_idx + 1,
+        }
+    }
+}
 impl<'a> Iterator for ConcreteTypeIter<'a> {
     type Item = &'a [ConcreteTypePart];
     fn next(&mut self) -> Option<Self::Item> {
         if self.idx_embedded == self.num_embedded {
             return None;
+        }
         // Retrieve the subtree of interest
         let start_idx = self.part_idx;
         let end_idx = ConcreteType::type_parts_subtree_end_idx(&self.parts, start_idx);
         self.idx_embedded += 1;
         self.part_idx = end_idx;
         return Some(&self.parts[start_idx..end_idx]);
+    }
+}
 #[derive(Debug, Clone, Copy)]
-pub enum Scope {
+pub enum ScopeAssociation {
     Definition(DefinitionId),
     Regular(BlockStatementId),
     Synchronous(SynchronousStatementId, BlockStatementId),
+}
 impl Scope {
     pub(crate) fn new_invalid() -> Scope {
         return Scope::Definition(DefinitionId::new_invalid());
+    }
     pub(crate) fn is_invalid(&self) -> bool {
         match self {
             Scope::Definition(id) => id.is_invalid(),
             _ => false,
+        }
+    }
     pub fn is_block(&self) -> bool {
         match &self {
             Scope::Definition(_) => false,
             Scope::Regular(_) => true,
             Scope::Synchronous(_, _) => true,
+        }
+    }
     pub fn to_block(&self) -> BlockStatementId {
         match &self {
             Scope::Regular(id) => *id,
             Scope::Synchronous(_, id) => *id,
             _ => panic!("unable to get BlockStatement from Scope")
+        }
+    }
     Block(BlockStatementId),
     If(IfStatementId, bool), // if true, then body of "if", otherwise body of "else"
     While(WhileStatementId),
     Synchronous(SynchronousStatementId),
     SelectCase(SelectStatementId, u32), // index is select case
+}
 /// `ScopeNode` is a helper that links scopes in two directions. It doesn't
 /// actually contain any information associated with the scope, this may be
 /// found on the AST elements that `Scope` points to.
 #[derive(Debug, Clone)]
 pub struct ScopeNode {
     pub parent: Scope,
     pub nested: Vec<Scope>,
 pub struct Scope {
     // Relation to other scopes
     pub this: ScopeId,
     pub parent: Option<ScopeId>,
     pub nested: Vec<ScopeId>,
     // Locally available variables/labels
     pub association: ScopeAssociation,
     pub variables: Vec<VariableId>,
     pub labels: Vec<LabeledStatementId>,
     // Location trackers/counters
     pub relative_pos_in_parent: i32,
     pub first_unique_id_in_scope: i32,
     pub next_unique_id_in_scope: i32,
+}
 impl ScopeNode {
     pub(crate) fn new_invalid() -> Self {
         ScopeNode{
             parent: Scope::new_invalid(),
 impl Scope {
     pub(crate) fn new(id: ScopeId, association: ScopeAssociation) -> Self {
         return Self{
             this: id,
             parent: None,
             nested: Vec::new(),
             association,
             variables: Vec::new(),
             labels: Vec::new(),
             relative_pos_in_parent: -1,
             first_unique_id_in_scope: -1,
             next_unique_id_in_scope: -1,
+        }
+    }
+}
 impl Scope {
     pub(crate) fn new_invalid(this: ScopeId) -> Self {
         return Self{
             this,
             parent: None,
             nested: Vec::new(),
             association: ScopeAssociation::Definition(DefinitionId::new_invalid()),
             variables: Vec::new(),
             labels: Vec::new(),
             relative_pos_in_parent: -1,
             first_unique_id_in_scope: -1,
             next_unique_id_in_scope: -1,
         };
+    }
+}
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum VariableKind {
     Parameter,      // in parameter list of function/component
     Local,          // declared in function/component body
     Binding,        // may be bound to in a binding expression (determined in validator/linker)
+}
 #[derive(Debug, Clone)]
 pub struct Variable {
     pub this: VariableId,
     // Parsing
     pub kind: VariableKind,
     pub parser_type: ParserType,
     pub identifier: Identifier,
     // Validator/linker
-    pub relative_pos_in_block: i32,
+    pub relative_pos_in_parent: i32,
     pub unique_id_in_scope: i32, // Temporary fix until proper bytecode/asm is generated
+}
-#[derive(Debug, Clone)]
 #[derive(Debug)]
 pub enum Definition {
     Struct(StructDefinition),
     Enum(EnumDefinition),
     Union(UnionDefinition),
     Component(ComponentDefinition),
     Function(FunctionDefinition),
     Procedure(ProcedureDefinition),
+}
 impl Definition {
     pub fn is_struct(&self) -> bool {
         match self {
             Definition::Struct(_) => true,
             _ => false
+        }
+    }
     pub(crate) fn as_struct(&self) -> &StructDefinition {
         match self {
             Definition::Struct(result) => result,
             _ => panic!("Unable to cast 'Definition' to 'StructDefinition'"),
+        }
+    }
     pub(crate) fn as_struct_mut(&mut self) -> &mut StructDefinition {
         match self {
             Definition::Struct(result) => result,
             _ => panic!("Unable to cast 'Definition' to 'StructDefinition'"),
+        }
+    }
     pub fn is_enum(&self) -> bool {
         match self {
             Definition::Enum(_) => true,
             _ => false,
+        }
+    }
     pub(crate) fn as_enum(&self) -> &EnumDefinition {
         match self {
             Definition::Enum(result) => result,
             _ => panic!("Unable to cast 'Definition' to 'EnumDefinition'"),
+        }
+    }
     pub(crate) fn as_enum_mut(&mut self) -> &mut EnumDefinition {
         match self {
             Definition::Enum(result) => result,
             _ => panic!("Unable to cast 'Definition' to 'EnumDefinition'"),
+        }
+    }
     pub fn is_union(&self) -> bool {
         match self {
             Definition::Union(_) => true,
             _ => false,
+        }
+    }
     pub(crate) fn as_union(&self) -> &UnionDefinition {
         match self {
             Definition::Union(result) => result,
             _ => panic!("Unable to cast 'Definition' to 'UnionDefinition'"),
+        }
+    }
     pub(crate) fn as_union_mut(&mut self) -> &mut UnionDefinition {
         match self {
             Definition::Union(result) => result,
             _ => panic!("Unable to cast 'Definition' to 'UnionDefinition'"),
+        }
+    }
     pub fn is_component(&self) -> bool {
         match self {
             Definition::Component(_) => true,
             _ => false,
+        }
+    }
     pub(crate) fn as_component(&self) -> &ComponentDefinition {
         match self {
             Definition::Component(result) => result,
             _ => panic!("Unable to cast `Definition` to `Component`"),
+        }
+    }
     pub(crate) fn as_component_mut(&mut self) -> &mut ComponentDefinition {
         match self {
             Definition::Component(result) => result,
             _ => panic!("Unable to cast `Definition` to `Component`"),
+        }
+    }
     pub fn is_function(&self) -> bool {
     pub fn is_procedure(&self) -> bool {
         match self {
-            Definition::Function(_) => true,
+            Definition::Procedure(_) => true,
             _ => false,
+        }
+    }
     pub(crate) fn as_function(&self) -> &FunctionDefinition {
     pub(crate) fn as_procedure(&self) -> &ProcedureDefinition {
         match self {
-            Definition::Function(result) => result,
+            Definition::Procedure(result) => result,
             _ => panic!("Unable to cast `Definition` to `Function`"),
+        }
+    }
     pub(crate) fn as_function_mut(&mut self) -> &mut FunctionDefinition {
     pub(crate) fn as_procedure_mut(&mut self) -> &mut ProcedureDefinition {
         match self {
-            Definition::Function(result) => result,
+            Definition::Procedure(result) => result,
             _ => panic!("Unable to cast `Definition` to `Function`"),
+        }
+    }
     pub fn parameters(&self) -> &Vec<VariableId> {
         match self {
             Definition::Component(def) => &def.parameters,
             Definition::Function(def) => &def.parameters,
             _ => panic!("Called parameters() on {:?}", self)
+        }
+    }
     pub fn defined_in(&self) -> RootId {
         match self {
             Definition::Struct(def) => def.defined_in,
             Definition::Enum(def) => def.defined_in,
             Definition::Union(def) => def.defined_in,
             Definition::Component(def) => def.defined_in,
             Definition::Function(def) => def.defined_in,
             Definition::Procedure(def) => def.defined_in,
+        }
+    }
     pub fn identifier(&self) -> &Identifier {
         match self {
             Definition::Struct(def) => &def.identifier,
             Definition::Enum(def) => &def.identifier,
             Definition::Union(def) => &def.identifier,
             Definition::Component(def) => &def.identifier,
             Definition::Function(def) => &def.identifier,
             Definition::Procedure(def) => &def.identifier,
+        }
+    }
     pub fn poly_vars(&self) -> &Vec<Identifier> {
         match self {
             Definition::Struct(def) => &def.poly_vars,
             Definition::Enum(def) => &def.poly_vars,
             Definition::Union(def) => &def.poly_vars,
             Definition::Component(def) => &def.poly_vars,
             Definition::Function(def) => &def.poly_vars,
             Definition::Procedure(def) => &def.poly_vars,
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub struct StructFieldDefinition {
     pub span: InputSpan,
     pub field: Identifier,
     pub parser_type: ParserType,
+}
 #[derive(Debug, Clone)]
 pub struct StructDefinition {
     pub this: StructDefinitionId,
     pub defined_in: RootId,
     // Symbol scanning
     pub span: InputSpan,
     pub identifier: Identifier,
     pub poly_vars: Vec<Identifier>,
     // Parsing
     pub fields: Vec<StructFieldDefinition>
+}
 impl StructDefinition {
     pub(crate) fn new_empty(
         this: StructDefinitionId, defined_in: RootId, span: InputSpan,
         identifier: Identifier, poly_vars: Vec<Identifier>
     ) -> Self {
         Self{ this, defined_in, span, identifier, poly_vars, fields: Vec::new() }
+    }
+}
 #[derive(Debug, Clone, Copy)]
 pub enum EnumVariantValue {
     None,
     Integer(i64),
+}
 #[derive(Debug, Clone)]
 pub struct EnumVariantDefinition {
     pub identifier: Identifier,
     pub value: EnumVariantValue,
+}
 #[derive(Debug, Clone)]
 pub struct EnumDefinition {
     pub this: EnumDefinitionId,
     pub defined_in: RootId,
     // Symbol scanning
     pub span: InputSpan,
     pub identifier: Identifier,
     pub poly_vars: Vec<Identifier>,
     // Parsing
     pub variants: Vec<EnumVariantDefinition>,
+}
 impl EnumDefinition {
     pub(crate) fn new_empty(
         this: EnumDefinitionId, defined_in: RootId, span: InputSpan,
         identifier: Identifier, poly_vars: Vec<Identifier>
     ) -> Self {
         Self{ this, defined_in, span, identifier, poly_vars, variants: Vec::new() }
+    }
+}
 #[derive(Debug, Clone)]
 pub struct UnionVariantDefinition {
     pub span: InputSpan,
     pub identifier: Identifier,
     pub value: Vec<ParserType>, // if empty, then union variant does not contain any embedded types
+}
 #[derive(Debug, Clone)]
 pub struct UnionDefinition {
     pub this: UnionDefinitionId,
     pub defined_in: RootId,
     // Phase 1: symbol scanning
     pub span: InputSpan,
     pub identifier: Identifier,
     pub poly_vars: Vec<Identifier>,
     // Phase 2: parsing
     pub variants: Vec<UnionVariantDefinition>,
+}
 impl UnionDefinition {
     pub(crate) fn new_empty(
         this: UnionDefinitionId, defined_in: RootId, span: InputSpan,
         identifier: Identifier, poly_vars: Vec<Identifier>
     ) -> Self {
         Self{ this, defined_in, span, identifier, poly_vars, variants: Vec::new() }
+    }
+}
 #[derive(Debug, Clone, Copy)]
 pub enum ComponentVariant {
     Primitive,
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum ProcedureKind {
     Function, // with return type
     Primitive, // without return type
     Composite,
+}
 #[derive(Debug, Clone)]
 pub struct ComponentDefinition {
     pub this: ComponentDefinitionId,
     pub defined_in: RootId,
     // Symbol scanning
     pub span: InputSpan,
     pub variant: ComponentVariant,
     pub identifier: Identifier,
     pub poly_vars: Vec<Identifier>,
     // Parsing
     pub parameters: Vec<VariableId>,
     pub body: BlockStatementId,
     // Validation/linking
     pub num_expressions_in_body: i32,
 /// Monomorphed instantiation of a procedure (or the sole instantiation of a
 /// non-polymorphic procedure).
 #[derive(Debug)]
 pub struct ProcedureDefinitionMonomorph {
     pub argument_types: Vec<TypeId>,
     pub expr_info: Vec<ExpressionInfo>
+}
 impl ComponentDefinition {
     // Used for preallocation during symbol scanning
     pub(crate) fn new_empty(
         this: ComponentDefinitionId, defined_in: RootId, span: InputSpan,
         variant: ComponentVariant, identifier: Identifier, poly_vars: Vec<Identifier>
     ) -> Self {
         Self{
             this, defined_in, span, variant, identifier, poly_vars,
             parameters: Vec::new(),
             body: BlockStatementId::new_invalid(),
             num_expressions_in_body: -1,
 impl ProcedureDefinitionMonomorph {
     pub(crate) fn new_invalid() -> Self {
         return Self{
             argument_types: Vec::new(),
             expr_info: Vec::new(),
+        }
+    }
+}
 #[derive(Debug, Clone, Copy)]
 pub struct ExpressionInfo {
     pub type_id: TypeId,
     pub variant: ExpressionInfoVariant,
+}
 impl ExpressionInfo {
     pub(crate) fn new_invalid() -> Self {
         return Self{
             type_id: TypeId::new_invalid(),
             variant: ExpressionInfoVariant::Generic,
+        }
+    }
+}
 #[derive(Debug, Clone, Copy)]
 pub enum ExpressionInfoVariant {
     Generic,
     Procedure(TypeId, u32), // procedure TypeID and its monomorph index
     Select(i32), // index
+}
 impl ExpressionInfoVariant {
     pub(crate) fn as_select(&self) -> i32 {
         match self {
             ExpressionInfoVariant::Select(v) => *v,
             _ => unreachable!(),
+        }
+    }
     pub(crate) fn as_procedure(&self) -> (TypeId, u32) {
         match self {
             ExpressionInfoVariant::Procedure(type_id, monomorph_index) => (*type_id, *monomorph_index),
             _ => unreachable!(),
+        }
+    }
+}
 /// Generic storage for functions, primitive components and composite
 /// components.
 // Note that we will have function definitions for builtin functions as well. In
 // that case the span, the identifier span and the body are all invalid.
 #[derive(Debug, Clone)]
 pub struct FunctionDefinition {
     pub this: FunctionDefinitionId,
 #[derive(Debug)]
 pub struct ProcedureDefinition {
     pub this: ProcedureDefinitionId,
     pub defined_in: RootId,
     // Symbol scanning
     pub builtin: bool,
     pub kind: ProcedureKind,
     pub span: InputSpan,
     pub identifier: Identifier,
     pub poly_vars: Vec<Identifier>,
     // Parser
-    pub return_types: Vec<ParserType>,
+    pub return_type: Option<ParserType>, // present on functions, not components
     pub parameters: Vec<VariableId>,
     pub scope: ScopeId,
     pub body: BlockStatementId,
     // Validation/linking
     pub num_expressions_in_body: i32,
     // Monomorphization of typed procedures
     pub monomorphs: Vec<ProcedureDefinitionMonomorph>,
+}
-impl FunctionDefinition {
+impl ProcedureDefinition {
     pub(crate) fn new_empty(
         this: FunctionDefinitionId, defined_in: RootId, span: InputSpan,
         identifier: Identifier, poly_vars: Vec<Identifier>
         this: ProcedureDefinitionId, defined_in: RootId, span: InputSpan,
         kind: ProcedureKind, identifier: Identifier, poly_vars: Vec<Identifier>
     ) -> Self {
         Self {
             this, defined_in,
             builtin: false,
             span, identifier, poly_vars,
             return_types: Vec::new(),
             span,
             kind, identifier, poly_vars,
             return_type: None,
             parameters: Vec::new(),
             scope: ScopeId::new_invalid(),
             body: BlockStatementId::new_invalid(),
-            num_expressions_in_body: -1,
+            monomorphs: Vec::new(),
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub enum Statement {
     Block(BlockStatement),
     EndBlock(EndBlockStatement),
     Local(LocalStatement),
     Labeled(LabeledStatement),
     If(IfStatement),
     EndIf(EndIfStatement),
     While(WhileStatement),
     EndWhile(EndWhileStatement),
     Break(BreakStatement),
     Continue(ContinueStatement),
     Synchronous(SynchronousStatement),
     EndSynchronous(EndSynchronousStatement),
     Fork(ForkStatement),
     EndFork(EndForkStatement),
     Select(SelectStatement),
     EndSelect(EndSelectStatement),
     Return(ReturnStatement),
     Goto(GotoStatement),
     New(NewStatement),
     Expression(ExpressionStatement),
+}
 impl Statement {
     pub fn as_block(&self) -> &BlockStatement {
         match self {
             Statement::Block(result) => result,
             _ => panic!("Unable to cast `Statement` to `BlockStatement`"),
+        }
+    }
     pub fn as_local(&self) -> &LocalStatement {
         match self {
             Statement::Local(result) => result,
             _ => panic!("Unable to cast `Statement` to `LocalStatement`"),
+        }
+    }
     pub fn as_memory(&self) -> &MemoryStatement {
         self.as_local().as_memory()
+    }
     pub fn as_channel(&self) -> &ChannelStatement {
         self.as_local().as_channel()
+    }
     pub fn as_new(&self) -> &NewStatement {
         match self {
             Statement::New(result) => result,
             _ => panic!("Unable to cast `Statement` to `NewStatement`"),
+        }
+    }
     pub fn span(&self) -> InputSpan {
         match self {
             Statement::Block(v) => v.span,
             Statement::Local(v) => v.span(),
             Statement::Labeled(v) => v.label.span,
             Statement::If(v) => v.span,
             Statement::While(v) => v.span,
             Statement::Break(v) => v.span,
             Statement::Continue(v) => v.span,
             Statement::Synchronous(v) => v.span,
             Statement::Fork(v) => v.span,
             Statement::Select(v) => v.span,
             Statement::Return(v) => v.span,
             Statement::Goto(v) => v.span,
             Statement::New(v) => v.span,
             Statement::Expression(v) => v.span,
             Statement::EndBlock(_)
             | Statement::EndIf(_)
             | Statement::EndWhile(_)
             | Statement::EndSynchronous(_)
             | Statement::EndFork(_)
             | Statement::EndSelect(_) => unreachable!(),
+        }
+    }
     pub fn link_next(&mut self, next: StatementId) {
         match self {
             Statement::Block(stmt) => stmt.next = next,
             Statement::EndBlock(stmt) => stmt.next = next,
             Statement::Local(stmt) => match stmt {
                 LocalStatement::Channel(stmt) => stmt.next = next,
                 LocalStatement::Memory(stmt) => stmt.next = next,
             },
             Statement::EndIf(stmt) => stmt.next = next,
             Statement::EndWhile(stmt) => stmt.next = next,
             Statement::EndSynchronous(stmt) => stmt.next = next,
             Statement::EndFork(stmt) => stmt.next = next,
             Statement::EndSelect(stmt) => stmt.next = next,
             Statement::New(stmt) => stmt.next = next,
             Statement::Expression(stmt) => stmt.next = next,
             Statement::Return(_)
             | Statement::Break(_)
             | Statement::Continue(_)
             | Statement::Synchronous(_)
             | Statement::Fork(_)
             | Statement::Select(_)
             | Statement::Goto(_)
             | Statement::While(_)
             | Statement::Labeled(_)
             | Statement::If(_) => unreachable!(),
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub struct BlockStatement {
     pub this: BlockStatementId,
     // Phase 1: parser
     pub is_implicit: bool,
     pub span: InputSpan, // of the complete block
     pub statements: Vec<StatementId>,
     pub end_block: EndBlockStatementId,
     // Phase 2: linker
     pub scope_node: ScopeNode,
     pub first_unique_id_in_scope: i32, // Temporary fix until proper bytecode/asm is generated
     pub next_unique_id_in_scope: i32, // Temporary fix until proper bytecode/asm is generated
     pub locals: Vec<VariableId>,
     pub labels: Vec<LabeledStatementId>,
     pub scope: ScopeId,
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct EndBlockStatement {
     pub this: EndBlockStatementId,
     // Parser
     pub start_block: BlockStatementId,
     // Validation/Linking
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub enum LocalStatement {
     Memory(MemoryStatement),
     Channel(ChannelStatement),
+}
 impl LocalStatement {
     pub fn this(&self) -> LocalStatementId {
         match self {
             LocalStatement::Memory(stmt) => stmt.this.upcast(),
             LocalStatement::Channel(stmt) => stmt.this.upcast(),
+        }
+    }
     pub fn as_memory(&self) -> &MemoryStatement {
         match self {
             LocalStatement::Memory(result) => result,
             _ => panic!("Unable to cast `LocalStatement` to `MemoryStatement`"),
+        }
+    }
     pub fn as_channel(&self) -> &ChannelStatement {
         match self {
             LocalStatement::Channel(result) => result,
             _ => panic!("Unable to cast `LocalStatement` to `ChannelStatement`"),
+        }
+    }
     pub fn span(&self) -> InputSpan {
         match self {
             LocalStatement::Channel(v) => v.span,
             LocalStatement::Memory(v) => v.span,
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub struct MemoryStatement {
     pub this: MemoryStatementId,
     // Phase 1: parser
     pub span: InputSpan,
     pub variable: VariableId,
     pub initial_expr: AssignmentExpressionId,
     // Phase 2: linker
     pub next: StatementId,
+}
 /// ChannelStatement is the declaration of an input and output port associated
 /// with the same channel. Note that the polarity of the ports are from the
 /// point of view of the component. So an output port is something that a
 /// component uses to send data over (i.e. it is the "input end" of the
 /// channel), and vice versa.
 #[derive(Debug, Clone)]
 pub struct ChannelStatement {
     pub this: ChannelStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "channel" keyword
     pub from: VariableId, // output
     pub to: VariableId,   // input
     // Phase 2: linker
-    pub relative_pos_in_block: i32,
+    pub relative_pos_in_parent: i32,
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct LabeledStatement {
     pub this: LabeledStatementId,
     // Phase 1: parser
     pub label: Identifier,
     pub body: StatementId,
     // Phase 2: linker
-    pub relative_pos_in_block: i32,
+    pub relative_pos_in_parent: i32,
     pub in_sync: SynchronousStatementId, // may be invalid
+}
 #[derive(Debug, Clone)]
 pub struct IfStatement {
     pub this: IfStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "if" keyword
     pub test: ExpressionId,
     pub true_body: BlockStatementId,
     pub false_body: Option<BlockStatementId>,
     pub true_case: IfStatementCase,
     pub false_case: Option<IfStatementCase>,
     pub end_if: EndIfStatementId,
+}
 #[derive(Debug, Clone, Copy)]
 pub struct IfStatementCase {
     pub body: StatementId,
     pub scope: ScopeId,
+}
 #[derive(Debug, Clone)]
 pub struct EndIfStatement {
     pub this: EndIfStatementId,
     pub start_if: IfStatementId,
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct WhileStatement {
     pub this: WhileStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "while" keyword
     pub test: ExpressionId,
     pub body: BlockStatementId,
     pub scope: ScopeId,
     pub body: StatementId,
     pub end_while: EndWhileStatementId,
     pub in_sync: SynchronousStatementId, // may be invalid
+}
 #[derive(Debug, Clone)]
 pub struct EndWhileStatement {
     pub this: EndWhileStatementId,
     pub start_while: WhileStatementId,
     // Phase 2: linker
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct BreakStatement {
     pub this: BreakStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "break" keyword
     pub label: Option<Identifier>,
     // Phase 2: linker
     pub target: EndWhileStatementId, // invalid if not yet set
+}
 #[derive(Debug, Clone)]
 pub struct ContinueStatement {
     pub this: ContinueStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "continue" keyword
     pub label: Option<Identifier>,
     // Phase 2: linker
     pub target: WhileStatementId, // invalid if not yet set
+}
 #[derive(Debug, Clone)]
 pub struct SynchronousStatement {
     pub this: SynchronousStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "sync" keyword
     pub body: BlockStatementId,
     pub scope: ScopeId,
     pub body: StatementId,
     pub end_sync: EndSynchronousStatementId,
+}
 #[derive(Debug, Clone)]
 pub struct EndSynchronousStatement {
     pub this: EndSynchronousStatementId,
     pub start_sync: SynchronousStatementId,
     // Phase 2: linker
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct ForkStatement {
     pub this: ForkStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "fork" keyword
     pub left_body: BlockStatementId,
     pub right_body: Option<BlockStatementId>,
     pub left_body: StatementId,
     pub right_body: Option<StatementId>,
     pub end_fork: EndForkStatementId,
+}
 #[derive(Debug, Clone)]
 pub struct EndForkStatement {
     pub this: EndForkStatementId,
     pub start_fork: ForkStatementId,
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct SelectStatement {
     pub this: SelectStatementId,
     pub span: InputSpan, // of the "select" keyword
     pub cases: Vec<SelectCase>,
     pub end_select: EndSelectStatementId,
     pub relative_pos_in_parent: i32,
     pub next: StatementId, // note: the select statement will be transformed into other AST elements, this `next` jumps to those replacement statements
+}
 #[derive(Debug, Clone)]
 pub struct SelectCase {
     // The guard statement of a `select` is either a MemoryStatement or an
     // ExpressionStatement. Nothing else is allowed by the initial parsing
     pub guard: StatementId,
     pub block: BlockStatementId,
     pub body: StatementId,
     pub scope: ScopeId,
     // Phase 2: Validation and Linking
     pub involved_ports: Vec<(CallExpressionId, ExpressionId)>, // call to `get` and its port argument
+}
 #[derive(Debug, Clone)]
 pub struct EndSelectStatement {
     pub this: EndSelectStatementId,
     pub start_select: SelectStatementId,
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct ReturnStatement {
     pub this: ReturnStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "return" keyword
     pub expressions: Vec<ExpressionId>,
+}
 #[derive(Debug, Clone)]
 pub struct GotoStatement {
     pub this: GotoStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "goto" keyword
     pub label: Identifier,
     // Phase 2: linker
     pub target: LabeledStatementId, // invalid if not yet set
+}
 #[derive(Debug, Clone)]
 pub struct NewStatement {
     pub this: NewStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "new" keyword
     pub expression: CallExpressionId,
     // Phase 2: linker
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct ExpressionStatement {
     pub this: ExpressionStatementId,
     // Phase 1: parser
     pub span: InputSpan,
     pub expression: ExpressionId,
     // Phase 2: linker
     pub next: StatementId,
+}
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub enum ExpressionParent {
     None, // only set during initial parsing
     Memory(MemoryStatementId),
     If(IfStatementId),
     While(WhileStatementId),
     Return(ReturnStatementId),
     New(NewStatementId),
     ExpressionStmt(ExpressionStatementId),
     Expression(ExpressionId, u32) // index within expression (e.g LHS or RHS of expression)
+    Expression(ExpressionId, u32) // index within expression (e.g LHS or RHS of expression, or index in array literal, etc.)
+}
 impl ExpressionParent {
     pub fn is_new(&self) -> bool {
         match self {
             ExpressionParent::New(_) => true,
             _ => false,
+        }
+    }
     pub fn as_expression(&self) -> ExpressionId {
         match self {
             ExpressionParent::Expression(id, _) => *id,
             _ => panic!("called as_expression() on {:?}", self),
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub enum Expression {
     Assignment(AssignmentExpression),
     Binding(BindingExpression),
     Conditional(ConditionalExpression),
     Binary(BinaryExpression),
     Unary(UnaryExpression),
     Indexing(IndexingExpression),
     Slicing(SlicingExpression),
     Select(SelectExpression),
     Literal(LiteralExpression),
     Cast(CastExpression),
     Call(CallExpression),
     Variable(VariableExpression),
+}
 impl Expression {
     pub fn as_variable(&self) -> &VariableExpression {
         match self {
             Expression::Variable(result) => result,
             _ => panic!("Unable to cast `Expression` to `VariableExpression`"),
+        }
+    }
     /// Returns operator span, function name, a binding's "let" span, etc. An
     /// indicator for the kind of expression that is being applied.
     pub fn operation_span(&self) -> InputSpan {
         match self {
             Expression::Assignment(expr) => expr.operator_span,
             Expression::Binding(expr) => expr.operator_span,
             Expression::Conditional(expr) => expr.operator_span,
             Expression::Binary(expr) => expr.operator_span,
             Expression::Unary(expr) => expr.operator_span,
             Expression::Indexing(expr) => expr.operator_span,
             Expression::Slicing(expr) => expr.slicing_span,
             Expression::Select(expr) => expr.operator_span,
             Expression::Literal(expr) => expr.span,
             Expression::Cast(expr) => expr.cast_span,
             Expression::Call(expr) => expr.func_span,
             Expression::Variable(expr) => expr.identifier.span,
+        }
+    }
     /// Returns the span covering the entire expression (i.e. including the
     /// spans of the arguments as well).
     pub fn full_span(&self) -> InputSpan {
         match self {
             Expression::Assignment(expr) => expr.full_span,
             Expression::Binding(expr) => expr.full_span,
             Expression::Conditional(expr) => expr.full_span,
             Expression::Binary(expr) => expr.full_span,
             Expression::Unary(expr) => expr.full_span,
             Expression::Indexing(expr) => expr.full_span,
             Expression::Slicing(expr) => expr.full_span,
             Expression::Select(expr) => expr.full_span,
             Expression::Literal(expr) => expr.span,
             Expression::Cast(expr) => expr.full_span,
             Expression::Call(expr) => expr.full_span,
             Expression::Variable(expr) => expr.identifier.span,
+        }
+    }
     pub fn parent(&self) -> &ExpressionParent {
         match self {
             Expression::Assignment(expr) => &expr.parent,
             Expression::Binding(expr) => &expr.parent,
             Expression::Conditional(expr) => &expr.parent,
             Expression::Binary(expr) => &expr.parent,
             Expression::Unary(expr) => &expr.parent,
             Expression::Indexing(expr) => &expr.parent,
             Expression::Slicing(expr) => &expr.parent,
             Expression::Select(expr) => &expr.parent,
             Expression::Literal(expr) => &expr.parent,
             Expression::Cast(expr) => &expr.parent,
             Expression::Call(expr) => &expr.parent,
             Expression::Variable(expr) => &expr.parent,
+        }
+    }
     pub fn parent_mut(&mut self) -> &mut ExpressionParent {
         match self {
             Expression::Assignment(expr) => &mut expr.parent,
             Expression::Binding(expr) => &mut expr.parent,
             Expression::Conditional(expr) => &mut expr.parent,
             Expression::Binary(expr) => &mut expr.parent,
             Expression::Unary(expr) => &mut expr.parent,
             Expression::Indexing(expr) => &mut expr.parent,
             Expression::Slicing(expr) => &mut expr.parent,
             Expression::Select(expr) => &mut expr.parent,
             Expression::Literal(expr) => &mut expr.parent,
             Expression::Cast(expr) => &mut expr.parent,
             Expression::Call(expr) => &mut expr.parent,
             Expression::Variable(expr) => &mut expr.parent,
+        }
+    }
     pub fn parent_expr_id(&self) -> Option<ExpressionId> {
         if let ExpressionParent::Expression(id, _) = self.parent() {
             Some(*id)
         } else {
             None
+        }
+    }
     pub fn get_unique_id_in_definition(&self) -> i32 {
     pub fn type_index(&self) -> i32 {
         match self {
             Expression::Assignment(expr) => expr.type_index,
             Expression::Binding(expr) => expr.type_index,
             Expression::Conditional(expr) => expr.type_index,
             Expression::Binary(expr) => expr.type_index,
             Expression::Unary(expr) => expr.type_index,
             Expression::Indexing(expr) => expr.type_index,
             Expression::Slicing(expr) => expr.type_index,
             Expression::Select(expr) => expr.type_index,
             Expression::Literal(expr) => expr.type_index,
             Expression::Cast(expr) => expr.type_index,
             Expression::Call(expr) => expr.type_index,
             Expression::Variable(expr) => expr.type_index,
+        }
+    }
     pub fn type_index_mut(&mut self) -> &mut i32 {
         match self {
             Expression::Assignment(expr) => expr.unique_id_in_definition,
             Expression::Binding(expr) => expr.unique_id_in_definition,
             Expression::Conditional(expr) => expr.unique_id_in_definition,
             Expression::Binary(expr) => expr.unique_id_in_definition,
             Expression::Unary(expr) => expr.unique_id_in_definition,
             Expression::Indexing(expr) => expr.unique_id_in_definition,
             Expression::Slicing(expr) => expr.unique_id_in_definition,
             Expression::Select(expr) => expr.unique_id_in_definition,
             Expression::Literal(expr) => expr.unique_id_in_definition,
             Expression::Cast(expr) => expr.unique_id_in_definition,
             Expression::Call(expr) => expr.unique_id_in_definition,
             Expression::Variable(expr) => expr.unique_id_in_definition,
             Expression::Assignment(expr) => &mut expr.type_index,
             Expression::Binding(expr) => &mut expr.type_index,
             Expression::Conditional(expr) => &mut expr.type_index,
             Expression::Binary(expr) => &mut expr.type_index,
             Expression::Unary(expr) => &mut expr.type_index,
             Expression::Indexing(expr) => &mut expr.type_index,
             Expression::Slicing(expr) => &mut expr.type_index,
             Expression::Select(expr) => &mut expr.type_index,
             Expression::Literal(expr) => &mut expr.type_index,
             Expression::Cast(expr) => &mut expr.type_index,
             Expression::Call(expr) => &mut expr.type_index,
             Expression::Variable(expr) => &mut expr.type_index,
+        }
+    }
+}
 #[derive(Debug, Clone, Copy)]
 pub enum AssignmentOperator {
     Set,
     Concatenated,
     Multiplied,
     Divided,
     Remained,
     Added,
     Subtracted,
     ShiftedLeft,
     ShiftedRight,
     BitwiseAnded,
     BitwiseXored,
     BitwiseOred,
+}
 #[derive(Debug, Clone)]
 pub struct AssignmentExpression {
     pub this: AssignmentExpressionId,
     // Parsing
     pub operator_span: InputSpan,
     pub full_span: InputSpan,
     pub left: ExpressionId,
     pub operation: AssignmentOperator,
     pub right: ExpressionId,
     // Validator/Linker
     pub parent: ExpressionParent,
     pub unique_id_in_definition: i32,
     // Typing
     pub type_index: i32,
+}
 #[derive(Debug, Clone)]
 pub struct BindingExpression {
     pub this: BindingExpressionId,
     // Parsing
     pub operator_span: InputSpan,
     pub full_span: InputSpan,
     pub bound_to: ExpressionId,
     pub bound_from: ExpressionId,
     // Validator/Linker
     pub parent: ExpressionParent,
     pub unique_id_in_definition: i32,
     // Typing
     pub type_index: i32,
+}
 #[derive(Debug, Clone)]
 pub struct ConditionalExpression {
     pub this: ConditionalExpressionId,
     // Parsing
     pub operator_span: InputSpan,
     pub full_span: InputSpan,
     pub test: ExpressionId,
     pub true_expression: ExpressionId,
     pub false_expression: ExpressionId,
     // Validator/Linking
     pub parent: ExpressionParent,
     pub unique_id_in_definition: i32,
     // Typing
     pub type_index: i32,
+}
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum BinaryOperator {
     Concatenate,
     LogicalOr,
     LogicalAnd,
     BitwiseOr,
     BitwiseXor,
     BitwiseAnd,
     Equality,
     Inequality,
     LessThan,
     GreaterThan,
     LessThanEqual,
     GreaterThanEqual,
     ShiftLeft,
     ShiftRight,
     Add,
     Subtract,
     Multiply,
     Divide,
     Remainder,
+}
 #[derive(Debug, Clone)]
 pub struct BinaryExpression {
     pub this: BinaryExpressionId,
     // Parsing
     pub operator_span: InputSpan,
     pub full_span: InputSpan,
     pub left: ExpressionId,
     pub operation: BinaryOperator,
     pub right: ExpressionId,
     // Validator/Linker
     pub parent: ExpressionParent,
     pub unique_id_in_definition: i32,
     // Typing
     pub type_index: i32,
+}
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum UnaryOperator {
     Positive,
     Negative,
     BitwiseNot,
     LogicalNot,
+}
 #[derive(Debug, Clone)]
 pub struct UnaryExpression {
     pub this: UnaryExpressionId,
     // Parsing
     pub operator_span: InputSpan,
     pub full_span: InputSpan,
     pub operation: UnaryOperator,
     pub expression: ExpressionId,
     // Validator/Linker
     pub parent: ExpressionParent,
     pub unique_id_in_definition: i32,
     // Typing
     pub type_index: i32,
+}
 #[derive(Debug, Clone)]
 pub struct IndexingExpression {
     pub this: IndexingExpressionId,
     // Parsing
     pub operator_span: InputSpan,
     pub full_span: InputSpan,
     pub subject: ExpressionId,
     pub index: ExpressionId,
     // Validator/Linker
     pub parent: ExpressionParent,
     pub unique_id_in_definition: i32,
     // Typing
     pub type_index: i32,
+}
 #[derive(Debug, Clone)]
 pub struct SlicingExpression {
     pub this: SlicingExpressionId,
     // Parsing
     pub slicing_span: InputSpan, // from '[' to ']'
     pub full_span: InputSpan, // includes subject
     pub subject: ExpressionId,
     pub from_index: ExpressionId,
     pub to_index: ExpressionId,
     // Validator/Linker
     pub parent: ExpressionParent,
     pub unique_id_in_definition: i32,
     // Typing
     pub type_index: i32,
+}
 #[derive(Debug, Clone)]
 pub enum SelectKind {
     StructField(Identifier),
     TupleMember(u64), // u64 is overkill, but space is taken up by `StructField` variant anyway
+}
 #[derive(Debug, Clone)]
 pub struct SelectExpression {
     pub this: SelectExpressionId,
     // Parsing
     pub operator_span: InputSpan, // of the '.'
     pub full_span: InputSpan, // includes subject and field
     pub subject: ExpressionId,
     pub kind: SelectKind,
     // Validator/Linker
     pub parent: ExpressionParent,
     pub unique_id_in_definition: i32,
     // Typing
     pub type_index: i32,
+}
 #[derive(Debug, Clone)]
 pub struct CastExpression {
     pub this: CastExpressionId,
     // Parsing
     pub cast_span: InputSpan, // of the "cast" keyword,
     pub full_span: InputSpan, // includes the cast subject
     pub to_type: ParserType,
     pub subject: ExpressionId,
     // Validator/linker
     pub parent: ExpressionParent,
     pub unique_id_in_definition: i32,
     // Typing
     pub type_index: i32,
+}
 #[derive(Debug, Clone)]
 pub struct CallExpression {
     pub this: CallExpressionId,
     // Parsing
     pub func_span: InputSpan, // of the function name
     pub full_span: InputSpan, // includes the arguments and parentheses
     pub parser_type: ParserType, // of the function call, not the return type
     pub method: Method,
     pub arguments: Vec<ExpressionId>,
-    pub definition: DefinitionId,
+    pub procedure: ProcedureDefinitionId,
     // Validator/Linker
     pub parent: ExpressionParent,
     pub unique_id_in_definition: i32,
     // Typing
     pub type_index: i32,
+}
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum Method {
     // Builtin
+    // Builtin, accessible by programmer
     Get,
     Put,
     Fires,
     Create,
     Length,
     Assert,
     Print,
     // Builtin, not accessible by programmer
     SelectStart, // SelectStart(total_num_cases, total_num_ports)
     SelectRegisterCasePort, // SelectRegisterCasePort(case_index, port_index, port_id)
     SelectWait, // SelectWait() -> u32
     // User-defined
     UserFunction,
     UserComponent,
+}
 #[derive(Debug, Clone)]
 pub struct MethodSymbolic {
     pub(crate) parser_type: ParserType,
     pub(crate) definition: DefinitionId
 impl Method {
     pub(crate) fn is_public_builtin(&self) -> bool {
         use Method::*;
         match self {
             Get | Put | Fires | Create | Length | Assert | Print => true,
             _ => false,
+        }
+    }
     pub(crate) fn is_user_defined(&self) -> bool {
         use Method::*;
         match self {
             UserFunction | UserComponent => true,
             _ => false,
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub struct LiteralExpression {
     pub this: LiteralExpressionId,
     // Parsing
     pub span: InputSpan,
     pub value: Literal,
     // Validator/Linker
     pub parent: ExpressionParent,
     pub unique_id_in_definition: i32,
     // Typing
     pub type_index: i32,
+}
 #[derive(Debug, Clone)]
 pub enum Literal {
     Null, // message
     True,
     False,
     Character(char),
     String(StringRef<'static>),
     Integer(LiteralInteger),
     Struct(LiteralStruct),
     Enum(LiteralEnum),
     Union(LiteralUnion),
     Array(Vec<ExpressionId>),
     Tuple(Vec<ExpressionId>),
+}
 impl Literal {
     pub(crate) fn as_struct(&self) -> &LiteralStruct {
         if let Literal::Struct(literal) = self{
             literal
         } else {
             unreachable!("Attempted to obtain {:?} as Literal::Struct", self)
+        }
+    }
     pub(crate) fn as_enum(&self) -> &LiteralEnum {
         if let Literal::Enum(literal) = self {
             literal
         } else {
             unreachable!("Attempted to obtain {:?} as Literal::Enum", self)
+        }
+    }
     pub(crate) fn as_union(&self) -> &LiteralUnion {
         if let Literal::Union(literal) = self {
             literal
         } else {
             unreachable!("Attempted to obtain {:?} as Literal::Union", self)
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub struct LiteralInteger {
     pub(crate) unsigned_value: u64,
     pub(crate) negated: bool, // for constant expression evaluation, TODO: @Int
+}
 #[derive(Debug, Clone)]
 pub struct LiteralStructField {
     // Phase 1: parser
     pub(crate) identifier: Identifier,
     pub(crate) value: ExpressionId,
     // Phase 2: linker
     pub(crate) field_idx: usize, // in struct definition
+}
 #[derive(Debug, Clone)]
 pub struct LiteralStruct {
     // Phase 1: parser
     pub(crate) parser_type: ParserType,
     pub(crate) fields: Vec<LiteralStructField>,
     pub(crate) definition: DefinitionId,
+}
 #[derive(Debug, Clone)]
 pub struct LiteralEnum {
     // Phase 1: parser
     pub(crate) parser_type: ParserType,
     pub(crate) variant: Identifier,
     pub(crate) definition: DefinitionId,
     // Phase 2: linker
     pub(crate) variant_idx: usize, // as present in the type table
+}
 #[derive(Debug, Clone)]
 pub struct LiteralUnion {
     // Phase 1: parser
     pub(crate) parser_type: ParserType,
     pub(crate) variant: Identifier,
     pub(crate) values: Vec<ExpressionId>,
     pub(crate) definition: DefinitionId,
     // Phase 2: linker
     pub(crate) variant_idx: usize, // as present in type table
+}
 #[derive(Debug, Clone)]
 pub struct VariableExpression {
     pub this: VariableExpressionId,
     // Parsing
     pub identifier: Identifier,
     // Validator/Linker
     pub declaration: Option<VariableId>,
     pub used_as_binding_target: bool,
     pub parent: ExpressionParent,
     pub unique_id_in_definition: i32,
     // Typing
     pub type_index: i32,
+}
@@ \ No newline at end of file @@

src/protocol/ast_printer.rs

➞

Show inline comments

 #![allow(dead_code)]
 use std::fmt::{Debug, Display};
 use std::io::Write as IOWrite;
 use super::ast::*;
 use super::token_parsing::*;
 const INDENT: usize = 2;
 const PREFIX_EMPTY: &'static str = "    ";
 const PREFIX_ROOT_ID: &'static str = "Root";
 const PREFIX_PRAGMA_ID: &'static str = "Prag";
 const PREFIX_IMPORT_ID: &'static str = "Imp ";
 const PREFIX_TYPE_ANNOT_ID: &'static str = "TyAn";
 const PREFIX_VARIABLE_ID: &'static str = "Var ";
 const PREFIX_DEFINITION_ID: &'static str = "Def ";
 const PREFIX_STRUCT_ID: &'static str = "DefS";
 const PREFIX_ENUM_ID: &'static str = "DefE";
 const PREFIX_UNION_ID: &'static str = "DefU";
 const PREFIX_COMPONENT_ID: &'static str = "DefC";
 const PREFIX_FUNCTION_ID: &'static str = "DefF";
 const PREFIX_STMT_ID: &'static str = "Stmt";
 const PREFIX_BLOCK_STMT_ID: &'static str = "SBl ";
 const PREFIX_ENDBLOCK_STMT_ID: &'static str = "SEBl";
 const PREFIX_LOCAL_STMT_ID: &'static str = "SLoc";
 const PREFIX_MEM_STMT_ID: &'static str = "SMem";
 const PREFIX_CHANNEL_STMT_ID: &'static str = "SCha";
 const PREFIX_SKIP_STMT_ID: &'static str = "SSki";
 const PREFIX_LABELED_STMT_ID: &'static str = "SLab";
 const PREFIX_IF_STMT_ID: &'static str = "SIf ";
 const PREFIX_ENDIF_STMT_ID: &'static str = "SEIf";
 const PREFIX_WHILE_STMT_ID: &'static str = "SWhi";
 const PREFIX_ENDWHILE_STMT_ID: &'static str = "SEWh";
 const PREFIX_BREAK_STMT_ID: &'static str = "SBre";
 const PREFIX_CONTINUE_STMT_ID: &'static str = "SCon";
 const PREFIX_SYNC_STMT_ID: &'static str = "SSyn";
 const PREFIX_ENDSYNC_STMT_ID: &'static str = "SESy";
 const PREFIX_FORK_STMT_ID: &'static str = "SFrk";
 const PREFIX_END_FORK_STMT_ID: &'static str = "SEFk";
 const PREFIX_SELECT_STMT_ID: &'static str = "SSel";
 const PREFIX_END_SELECT_STMT_ID: &'static str = "SESl";
 const PREFIX_RETURN_STMT_ID: &'static str = "SRet";
 const PREFIX_ASSERT_STMT_ID: &'static str = "SAsr";
 const PREFIX_GOTO_STMT_ID: &'static str = "SGot";
 const PREFIX_NEW_STMT_ID: &'static str = "SNew";
 const PREFIX_PUT_STMT_ID: &'static str = "SPut";
 const PREFIX_EXPR_STMT_ID: &'static str = "SExp";
 const PREFIX_ASSIGNMENT_EXPR_ID: &'static str = "EAsi";
 const PREFIX_BINDING_EXPR_ID: &'static str = "EBnd";
 const PREFIX_CONDITIONAL_EXPR_ID: &'static str = "ECnd";
 const PREFIX_BINARY_EXPR_ID: &'static str = "EBin";
 const PREFIX_UNARY_EXPR_ID: &'static str = "EUna";
 const PREFIX_INDEXING_EXPR_ID: &'static str = "EIdx";
 const PREFIX_SLICING_EXPR_ID: &'static str = "ESli";
 const PREFIX_SELECT_EXPR_ID: &'static str = "ESel";
 const PREFIX_LITERAL_EXPR_ID: &'static str = "ELit";
 const PREFIX_CAST_EXPR_ID: &'static str = "ECas";
 const PREFIX_CALL_EXPR_ID: &'static str = "ECll";
 const PREFIX_VARIABLE_EXPR_ID: &'static str = "EVar";
 struct KV<'a> {
     buffer: &'a mut String,
     prefix: Option<(&'static str, i32)>,
     indent: usize,
     temp_key: &'a mut String,
     temp_val: &'a mut String,
+}
 impl<'a> KV<'a> {
     fn new(buffer: &'a mut String, temp_key: &'a mut String, temp_val: &'a mut String, indent: usize) -> Self {
         temp_key.clear();
         temp_val.clear();
         KV{
             buffer,
             prefix: None,
             indent,
             temp_key,
             temp_val
+        }
+    }
     fn with_id(mut self, prefix: &'static str, id: i32) -> Self {
         self.prefix = Some((prefix, id));
         self
+    }
     fn with_s_key(self, key: &str) -> Self {
         self.temp_key.push_str(key);
         self
+    }
     fn with_d_key<D: Display>(self, key: &D) -> Self {
         self.temp_key.push_str(&key.to_string());
         self
+    }
     fn with_s_val(self, val: &str) -> Self {
         self.temp_val.push_str(val);
         self
+    }
     fn with_disp_val<D: Display>(self, val: &D) -> Self {
         self.temp_val.push_str(&format!("{}", val));
         self
+    }
     fn with_debug_val<D: Debug>(self, val: &D) -> Self {
         self.temp_val.push_str(&format!("{:?}", val));
         self
+    }
     fn with_identifier_val(self, val: &Identifier) -> Self {
         self.temp_val.push_str(val.value.as_str());
         self
+    }
     fn with_opt_disp_val<D: Display>(self, val: Option<&D>) -> Self {
         match val {
             Some(v) => { self.temp_val.push_str(&format!("Some({})", v)); },
             None => { self.temp_val.push_str("None"); }
+        }
         self
+    }
     fn with_opt_identifier_val(self, val: Option<&Identifier>) -> Self {
         match val {
             Some(v) => {
                 self.temp_val.push_str("Some(");
                 self.temp_val.push_str(v.value.as_str());
                 self.temp_val.push(')');
             },
             None => {
                 self.temp_val.push_str("None");
+            }
+        }
         self
+    }
     fn with_custom_val<F: Fn(&mut String)>(mut self, val_fn: F) -> Self {
         val_fn(&mut self.temp_val);
         self
+    }
+}
 impl<'a> Drop for KV<'a> {
     fn drop(&mut self) {
         // Prefix and indent
         if let Some((prefix, id)) = &self.prefix {
             self.buffer.push_str(&format!("{}[{:04}]", prefix, id));
         } else {
             self.buffer.push_str("           ");
+        }
         for _ in 0..self.indent * INDENT {
             self.buffer.push(' ');
+        }
         // Leading dash
         self.buffer.push_str("- ");
         // Key and value
         self.buffer.push_str(self.temp_key);
         if self.temp_val.is_empty() {
             self.buffer.push(':');
         } else {
             self.buffer.push_str(": ");
             self.buffer.push_str(&self.temp_val);
+        }
         self.buffer.push('\n');
+    }
+}
 pub(crate) struct ASTWriter {
     cur_definition: Option<DefinitionId>,
     buffer: String,
     temp1: String,
     temp2: String,
+}
 impl ASTWriter {
     pub(crate) fn new() -> Self {
         Self{
             cur_definition: None,
             buffer: String::with_capacity(4096),
             temp1: String::with_capacity(256),
             temp2: String::with_capacity(256),
+        }
+    }
     pub(crate) fn write_ast<W: IOWrite>(&mut self, w: &mut W, heap: &Heap) {
         for root_id in heap.protocol_descriptions.iter().map(|v| v.this) {
             self.write_module(heap, root_id);
             w.write_all(self.buffer.as_bytes()).expect("flush buffer");
             self.buffer.clear();
+        }
+    }
     //--------------------------------------------------------------------------
     // Top-level module writing
     //--------------------------------------------------------------------------
     fn write_module(&mut self, heap: &Heap, root_id: RootId) {
         self.kv(0).with_id(PREFIX_ROOT_ID, root_id.index)
             .with_s_key("Module");
         let root = &heap[root_id];
         self.kv(1).with_s_key("Pragmas");
         for pragma_id in &root.pragmas {
             self.write_pragma(heap, *pragma_id, 2);
+        }
         self.kv(1).with_s_key("Imports");
         for import_id in &root.imports {
             self.write_import(heap, *import_id, 2);
+        }
         self.kv(1).with_s_key("Definitions");
         for def_id in &root.definitions {
             self.write_definition(heap, *def_id, 2);
+        }
+    }
     fn write_pragma(&mut self, heap: &Heap, pragma_id: PragmaId, indent: usize) {
         match &heap[pragma_id] {
             Pragma::Version(pragma) => {
                 self.kv(indent).with_id(PREFIX_PRAGMA_ID, pragma.this.index)
                     .with_s_key("PragmaVersion")
                     .with_disp_val(&pragma.version);
             },
             Pragma::Module(pragma) => {
                 self.kv(indent).with_id(PREFIX_PRAGMA_ID, pragma.this.index)
                     .with_s_key("PragmaModule")
                     .with_identifier_val(&pragma.value);
+            }
+        }
+    }
     fn write_import(&mut self, heap: &Heap, import_id: ImportId, indent: usize) {
         let import = &heap[import_id];
         let indent2 = indent + 1;
         match import {
             Import::Module(import) => {
                 self.kv(indent).with_id(PREFIX_IMPORT_ID, import.this.index)
                     .with_s_key("ImportModule");
                 self.kv(indent2).with_s_key("Name").with_identifier_val(&import.module);
                 self.kv(indent2).with_s_key("Alias").with_identifier_val(&import.alias);
                 self.kv(indent2).with_s_key("Target").with_disp_val(&import.module_id.index);
             },
             Import::Symbols(import) => {
                 self.kv(indent).with_id(PREFIX_IMPORT_ID, import.this.index)
                     .with_s_key("ImportSymbol");
                 self.kv(indent2).with_s_key("Name").with_identifier_val(&import.module);
                 self.kv(indent2).with_s_key("Target").with_disp_val(&import.module_id.index);
                 self.kv(indent2).with_s_key("Symbols");
                 let indent3 = indent2 + 1;
                 let indent4 = indent3 + 1;
                 for symbol in &import.symbols {
                     self.kv(indent3).with_s_key("AliasedSymbol");
                     self.kv(indent4).with_s_key("Name").with_identifier_val(&symbol.name);
                     self.kv(indent4).with_s_key("Alias").with_opt_identifier_val(symbol.alias.as_ref());
                     self.kv(indent4).with_s_key("Definition").with_disp_val(&symbol.definition_id.index);
+                }
+            }
+        }
+    }
     //--------------------------------------------------------------------------
     // Top-level definition writing
     //--------------------------------------------------------------------------
     fn write_definition(&mut self, heap: &Heap, def_id: DefinitionId, indent: usize) {
         self.cur_definition = Some(def_id);
         let indent2 = indent + 1;
         let indent3 = indent2 + 1;
         let indent4 = indent3 + 1;
         match &heap[def_id] {
             Definition::Struct(def) => {
                 self.kv(indent).with_id(PREFIX_STRUCT_ID, def.this.0.index)
                     .with_s_key("DefinitionStruct");
                 self.kv(indent2).with_s_key("Name").with_identifier_val(&def.identifier);
                 for poly_var_id in &def.poly_vars {
                     self.kv(indent3).with_s_key("PolyVar").with_identifier_val(&poly_var_id);
+                }
                 self.kv(indent2).with_s_key("Fields");
                 for field in &def.fields {
                     self.kv(indent3).with_s_key("Field");
                     self.kv(indent4).with_s_key("Name")
                         .with_identifier_val(&field.field);
                     self.kv(indent4).with_s_key("Type")
                         .with_custom_val(|s| write_parser_type(s, heap, &field.parser_type));
+                }
             },
             Definition::Enum(def) => {
                 self.kv(indent).with_id(PREFIX_ENUM_ID, def.this.0.index)
                     .with_s_key("DefinitionEnum");
                 self.kv(indent2).with_s_key("Name").with_identifier_val(&def.identifier);
                 for poly_var_id in &def.poly_vars {
                     self.kv(indent3).with_s_key("PolyVar").with_identifier_val(&poly_var_id);
+                }
                 self.kv(indent2).with_s_key("Variants");
                 for variant in &def.variants {
                     self.kv(indent3).with_s_key("Variant");
                     self.kv(indent4).with_s_key("Name")
                         .with_identifier_val(&variant.identifier);
                     let variant_value = self.kv(indent4).with_s_key("Value");
                     match &variant.value {
                         EnumVariantValue::None => variant_value.with_s_val("None"),
                         EnumVariantValue::Integer(value) => variant_value.with_disp_val(value),
                     };
+                }
             },
             Definition::Union(def) => {
                 self.kv(indent).with_id(PREFIX_UNION_ID, def.this.0.index)
                     .with_s_key("DefinitionUnion");
                 self.kv(indent2).with_s_key("Name").with_identifier_val(&def.identifier);
                 for poly_var_id in &def.poly_vars {
                     self.kv(indent3).with_s_key("PolyVar").with_identifier_val(&poly_var_id);
+                }
                 self.kv(indent2).with_s_key("Variants");
                 for variant in &def.variants {
                     self.kv(indent3).with_s_key("Variant");
                     self.kv(indent4).with_s_key("Name")
                         .with_identifier_val(&variant.identifier);
                     if variant.value.is_empty() {
                         self.kv(indent4).with_s_key("Value").with_s_val("None");
                     } else {
                         self.kv(indent4).with_s_key("Values");
                         for embedded in &variant.value {
                             self.kv(indent4+1).with_s_key("Value")
                                 .with_custom_val(|v| write_parser_type(v, heap, embedded));
+                        }
+                    }
+                }
+            }
-            Definition::Function(def) => {
+            Definition::Procedure(def) => {
                 self.kv(indent).with_id(PREFIX_FUNCTION_ID, def.this.0.index)
                     .with_s_key("DefinitionFunction");
                 self.kv(indent2).with_s_key("Name").with_identifier_val(&def.identifier);
                 for poly_var_id in &def.poly_vars {
                     self.kv(indent3).with_s_key("PolyVar").with_identifier_val(&poly_var_id);
+                }
                 self.kv(indent2).with_s_key("ReturnParserTypes");
                 for return_type in &def.return_types {
                     self.kv(indent3).with_s_key("ReturnParserType")
                         .with_custom_val(|s| write_parser_type(s, heap, return_type));
                 self.kv(indent2).with_s_key("Kind").with_debug_val(&def.kind);
                 if let Some(parser_type) = &def.return_type {
                     self.kv(indent2).with_s_key("ReturnParserType")
                         .with_custom_val(|s| write_parser_type(s, heap, parser_type));
+                }
                 self.kv(indent2).with_s_key("Parameters");
                 for variable_id in &def.parameters {
                     self.write_variable(heap, *variable_id, indent3);
+                }
                 self.kv(indent2).with_s_key("Body");
                 self.write_stmt(heap, def.body.upcast(), indent3);
             },
             Definition::Component(def) => {
                 self.kv(indent).with_id(PREFIX_COMPONENT_ID,def.this.0.index)
                     .with_s_key("DefinitionComponent");
                 self.kv(indent2).with_s_key("Name").with_identifier_val(&def.identifier);
                 self.kv(indent2).with_s_key("Variant").with_debug_val(&def.variant);
                 self.kv(indent2).with_s_key("PolymorphicVariables");
                 for poly_var_id in &def.poly_vars {
                     self.kv(indent3).with_s_key("PolyVar").with_identifier_val(&poly_var_id);
+                }
                 self.kv(indent2).with_s_key("Parameters");
                 for variable_id in &def.parameters {
                     self.write_variable(heap, *variable_id, indent3)
+                }
                 self.kv(indent2).with_s_key("Body");
                 self.write_stmt(heap, def.body.upcast(), indent3);
+            }
+        }
+    }
     fn write_stmt(&mut self, heap: &Heap, stmt_id: StatementId, indent: usize) {
         let stmt = &heap[stmt_id];
         let indent2 = indent + 1;
         let indent3 = indent2 + 1;
         match stmt {
             Statement::Block(stmt) => {
                 self.kv(indent).with_id(PREFIX_BLOCK_STMT_ID, stmt.this.0.index)
                     .with_s_key("Block");
                 self.kv(indent2).with_s_key("EndBlockID").with_disp_val(&stmt.end_block.0.index);
                 self.kv(indent2).with_s_key("FirstUniqueScopeID").with_disp_val(&stmt.first_unique_id_in_scope);
                 self.kv(indent2).with_s_key("NextUniqueScopeID").with_disp_val(&stmt.next_unique_id_in_scope);
                 self.kv(indent2).with_s_key("RelativePos").with_disp_val(&stmt.scope_node.relative_pos_in_parent);
                 self.kv(indent2).with_s_key("ScopeID").with_disp_val(&stmt.scope.index);
                 self.kv(indent2).with_s_key("Statements");
                 for stmt_id in &stmt.statements {
                     self.write_stmt(heap, *stmt_id, indent3);
+                }
             },
             Statement::EndBlock(stmt) => {
                 self.kv(indent).with_id(PREFIX_ENDBLOCK_STMT_ID, stmt.this.0.index)
                     .with_s_key("EndBlock");
                 self.kv(indent2).with_s_key("StartBlockID").with_disp_val(&stmt.start_block.0.index);
+            }
             Statement::Local(stmt) => {
                 match stmt {
                     LocalStatement::Channel(stmt) => {
                         self.kv(indent).with_id(PREFIX_CHANNEL_STMT_ID, stmt.this.0.0.index)
                             .with_s_key("LocalChannel");
                         self.kv(indent2).with_s_key("From");
                         self.write_variable(heap, stmt.from, indent3);
                         self.kv(indent2).with_s_key("To");
                         self.write_variable(heap, stmt.to, indent3);
                         self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
                     },
                     LocalStatement::Memory(stmt) => {
                         self.kv(indent).with_id(PREFIX_MEM_STMT_ID, stmt.this.0.0.index)
                             .with_s_key("LocalMemory");
                         self.kv(indent2).with_s_key("Variable");
                         self.write_variable(heap, stmt.variable, indent3);
                         self.kv(indent2).with_s_key("InitialValue");
                         self.write_expr(heap, stmt.initial_expr.upcast(), indent3);
                         self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
+                    }
+                }
             },
             Statement::Labeled(stmt) => {
                 self.kv(indent).with_id(PREFIX_LABELED_STMT_ID, stmt.this.0.index)
                     .with_s_key("Labeled");
                 self.kv(indent2).with_s_key("Label").with_identifier_val(&stmt.label);
                 self.kv(indent2).with_s_key("Statement");
                 self.write_stmt(heap, stmt.body, indent3);
             },
             Statement::If(stmt) => {
                 self.kv(indent).with_id(PREFIX_IF_STMT_ID, stmt.this.0.index)
                     .with_s_key("If");
                 self.kv(indent2).with_s_key("EndIf").with_disp_val(&stmt.end_if.0.index);
                 self.kv(indent2).with_s_key("Condition");
                 self.write_expr(heap, stmt.test, indent3);
                 self.kv(indent2).with_s_key("TrueBody");
-                self.write_stmt(heap, stmt.true_body.upcast(), indent3);
+                self.write_stmt(heap, stmt.true_case.body, indent3);
-                if let Some(false_body) = stmt.false_body {
+                if let Some(false_body) = stmt.false_case {
                     self.kv(indent2).with_s_key("FalseBody");
-                    self.write_stmt(heap, false_body.upcast(), indent3);
+                    self.write_stmt(heap, false_body.body, indent3);
+                }
             },
             Statement::EndIf(stmt) => {
                 self.kv(indent).with_id(PREFIX_ENDIF_STMT_ID, stmt.this.0.index)
                     .with_s_key("EndIf");
                 self.kv(indent2).with_s_key("StartIf").with_disp_val(&stmt.start_if.0.index);
                 self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
             },
             Statement::While(stmt) => {
                 self.kv(indent).with_id(PREFIX_WHILE_STMT_ID, stmt.this.0.index)
                     .with_s_key("While");
                 self.kv(indent2).with_s_key("EndWhile").with_disp_val(&stmt.end_while.0.index);
                 self.kv(indent2).with_s_key("InSync")
                     .with_disp_val(&stmt.in_sync.0.index);
                 self.kv(indent2).with_s_key("Condition");
                 self.write_expr(heap, stmt.test, indent3);
                 self.kv(indent2).with_s_key("Body");
-                self.write_stmt(heap, stmt.body.upcast(), indent3);
                 self.write_stmt(heap, stmt.body, indent3);
             },
             Statement::EndWhile(stmt) => {
                 self.kv(indent).with_id(PREFIX_ENDWHILE_STMT_ID, stmt.this.0.index)
                     .with_s_key("EndWhile");
                 self.kv(indent2).with_s_key("StartWhile").with_disp_val(&stmt.start_while.0.index);
                 self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
             },
             Statement::Break(stmt) => {
                 self.kv(indent).with_id(PREFIX_BREAK_STMT_ID, stmt.this.0.index)
                     .with_s_key("Break");
                 self.kv(indent2).with_s_key("Label")
                     .with_opt_identifier_val(stmt.label.as_ref());
                 self.kv(indent2).with_s_key("Target")
                     .with_disp_val(&stmt.target.0.index);
             },
             Statement::Continue(stmt) => {
                 self.kv(indent).with_id(PREFIX_CONTINUE_STMT_ID, stmt.this.0.index)
                     .with_s_key("Continue");
                 self.kv(indent2).with_s_key("Label")
                     .with_opt_identifier_val(stmt.label.as_ref());
                 self.kv(indent2).with_s_key("Target")
                     .with_disp_val(&stmt.target.0.index);
             },
             Statement::Synchronous(stmt) => {
                 self.kv(indent).with_id(PREFIX_SYNC_STMT_ID, stmt.this.0.index)
                     .with_s_key("Synchronous");
                 self.kv(indent2).with_s_key("EndSync").with_disp_val(&stmt.end_sync.0.index);
                 self.kv(indent2).with_s_key("Body");
-                self.write_stmt(heap, stmt.body.upcast(), indent3);
                 self.write_stmt(heap, stmt.body, indent3);
             },
             Statement::EndSynchronous(stmt) => {
                 self.kv(indent).with_id(PREFIX_ENDSYNC_STMT_ID, stmt.this.0.index)
                     .with_s_key("EndSynchronous");
                 self.kv(indent2).with_s_key("StartSync").with_disp_val(&stmt.start_sync.0.index);
                 self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
             },
             Statement::Fork(stmt) => {
                 self.kv(indent).with_id(PREFIX_FORK_STMT_ID, stmt.this.0.index)
                     .with_s_key("Fork");
                 self.kv(indent2).with_s_key("EndFork").with_disp_val(&stmt.end_fork.0.index);
                 self.kv(indent2).with_s_key("LeftBody");
-                self.write_stmt(heap, stmt.left_body.upcast(), indent3);
                 self.write_stmt(heap, stmt.left_body, indent3);
                 if let Some(right_body_id) = stmt.right_body {
                     self.kv(indent2).with_s_key("RightBody");
-                    self.write_stmt(heap, right_body_id.upcast(), indent3);
                     self.write_stmt(heap, right_body_id, indent3);
+                }
             },
             Statement::EndFork(stmt) => {
                 self.kv(indent).with_id(PREFIX_END_FORK_STMT_ID, stmt.this.0.index)
                     .with_s_key("EndFork");
                 self.kv(indent2).with_s_key("StartFork").with_disp_val(&stmt.start_fork.0.index);
                 self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
             },
             Statement::Select(stmt) => {
                 self.kv(indent).with_id(PREFIX_SELECT_STMT_ID, stmt.this.0.index)
                     .with_s_key("Select");
                 self.kv(indent2).with_s_key("EndSelect").with_disp_val(&stmt.end_select.0.index);
                 self.kv(indent2).with_s_key("Cases");
                 let indent3 = indent2 + 1;
                 let indent4 = indent3 + 1;
                 for case in &stmt.cases {
                     self.kv(indent3).with_s_key("Guard");
                     self.write_stmt(heap, case.guard, indent4);
                     self.kv(indent3).with_s_key("Block");
-                    self.write_stmt(heap, case.block.upcast(), indent4);
+                    self.write_stmt(heap, case.body, indent4);
+                }
                 self.kv(indent2).with_s_key("Replacement");
                 self.write_stmt(heap, stmt.next, indent3);
             },
             Statement::EndSelect(stmt) => {
                 self.kv(indent).with_id(PREFIX_END_SELECT_STMT_ID, stmt.this.0.index)
                     .with_s_key("EndSelect");
                 self.kv(indent2).with_s_key("StartSelect").with_disp_val(&stmt.start_select.0.index);
                 self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
+            }
             Statement::Return(stmt) => {
                 self.kv(indent).with_id(PREFIX_RETURN_STMT_ID, stmt.this.0.index)
                     .with_s_key("Return");
                 self.kv(indent2).with_s_key("Expressions");
                 for expr_id in &stmt.expressions {
                     self.write_expr(heap, *expr_id, indent3);
+                }
             },
             Statement::Goto(stmt) => {
                 self.kv(indent).with_id(PREFIX_GOTO_STMT_ID, stmt.this.0.index)
                     .with_s_key("Goto");
                 self.kv(indent2).with_s_key("Label").with_identifier_val(&stmt.label);
                 self.kv(indent2).with_s_key("Target")
                     .with_disp_val(&stmt.target.0.index);
             },
             Statement::New(stmt) => {
                 self.kv(indent).with_id(PREFIX_NEW_STMT_ID, stmt.this.0.index)
                     .with_s_key("New");
                 self.kv(indent2).with_s_key("Expression");
                 self.write_expr(heap, stmt.expression.upcast(), indent3);
                 self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
             },
             Statement::Expression(stmt) => {
                 self.kv(indent).with_id(PREFIX_EXPR_STMT_ID, stmt.this.0.index)
                     .with_s_key("ExpressionStatement");
                 self.write_expr(heap, stmt.expression, indent2);
                 self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
+            }
+        }
+    }
     fn write_expr(&mut self, heap: &Heap, expr_id: ExpressionId, indent: usize) {
         let expr = &heap[expr_id];
         let indent2 = indent + 1;
         let indent3 = indent2 + 1;
         match expr {
             Expression::Assignment(expr) => {
                 self.kv(indent).with_id(PREFIX_ASSIGNMENT_EXPR_ID, expr.this.0.index)
                     .with_s_key("AssignmentExpr");
                 self.kv(indent2).with_s_key("TypeIndex").with_disp_val(&expr.type_index);
                 self.kv(indent2).with_s_key("Operation").with_debug_val(&expr.operation);
                 self.kv(indent2).with_s_key("Left");
                 self.write_expr(heap, expr.left, indent3);
                 self.kv(indent2).with_s_key("Right");
                 self.write_expr(heap, expr.right, indent3);
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
             },
             Expression::Binding(expr) => {
                 self.kv(indent).with_id(PREFIX_BINARY_EXPR_ID, expr.this.0.index)
                     .with_s_key("BindingExpr");
                 self.kv(indent2).with_s_key("TypeIndex").with_disp_val(&expr.type_index);
                 self.kv(indent2).with_s_key("BindToExpression");
                 self.write_expr(heap, expr.bound_to, indent3);
                 self.kv(indent2).with_s_key("BindFromExpression");
                 self.write_expr(heap, expr.bound_from, indent3);
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
             },
             Expression::Conditional(expr) => {
                 self.kv(indent).with_id(PREFIX_CONDITIONAL_EXPR_ID, expr.this.0.index)
                     .with_s_key("ConditionalExpr");
                 self.kv(indent2).with_s_key("TypeIndex").with_disp_val(&expr.type_index);
                 self.kv(indent2).with_s_key("Condition");
                 self.write_expr(heap, expr.test, indent3);
                 self.kv(indent2).with_s_key("TrueExpression");
                 self.write_expr(heap, expr.true_expression, indent3);
                 self.kv(indent2).with_s_key("FalseExpression");
                 self.write_expr(heap, expr.false_expression, indent3);
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
             },
             Expression::Binary(expr) => {
                 self.kv(indent).with_id(PREFIX_BINARY_EXPR_ID, expr.this.0.index)
                     .with_s_key("BinaryExpr");
                 self.kv(indent2).with_s_key("TypeIndex").with_disp_val(&expr.type_index);
                 self.kv(indent2).with_s_key("Operation").with_debug_val(&expr.operation);
                 self.kv(indent2).with_s_key("Left");
                 self.write_expr(heap, expr.left, indent3);
                 self.kv(indent2).with_s_key("Right");
                 self.write_expr(heap, expr.right, indent3);
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
             },
             Expression::Unary(expr) => {
                 self.kv(indent).with_id(PREFIX_UNARY_EXPR_ID, expr.this.0.index)
                     .with_s_key("UnaryExpr");
                 self.kv(indent2).with_s_key("TypeIndex").with_disp_val(&expr.type_index);
                 self.kv(indent2).with_s_key("Operation").with_debug_val(&expr.operation);
                 self.kv(indent2).with_s_key("Argument");
                 self.write_expr(heap, expr.expression, indent3);
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
             },
             Expression::Indexing(expr) => {
                 self.kv(indent).with_id(PREFIX_INDEXING_EXPR_ID, expr.this.0.index)
                     .with_s_key("IndexingExpr");
                 self.kv(indent2).with_s_key("TypeIndex").with_disp_val(&expr.type_index);
                 self.kv(indent2).with_s_key("Subject");
                 self.write_expr(heap, expr.subject, indent3);
                 self.kv(indent2).with_s_key("Index");
                 self.write_expr(heap, expr.index, indent3);
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
             },
             Expression::Slicing(expr) => {
                 self.kv(indent).with_id(PREFIX_SLICING_EXPR_ID, expr.this.0.index)
                     .with_s_key("SlicingExpr");
                 self.kv(indent2).with_s_key("TypeIndex").with_disp_val(&expr.type_index);
                 self.kv(indent2).with_s_key("Subject");
                 self.write_expr(heap, expr.subject, indent3);
                 self.kv(indent2).with_s_key("FromIndex");
                 self.write_expr(heap, expr.from_index, indent3);
                 self.kv(indent2).with_s_key("ToIndex");
                 self.write_expr(heap, expr.to_index, indent3);
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
             },
             Expression::Select(expr) => {
                 self.kv(indent).with_id(PREFIX_SELECT_EXPR_ID, expr.this.0.index)
                     .with_s_key("SelectExpr");
                 self.kv(indent2).with_s_key("TypeIndex").with_disp_val(&expr.type_index);
                 self.kv(indent2).with_s_key("Subject");
                 self.write_expr(heap, expr.subject, indent3);
                 match &expr.kind {
                     SelectKind::StructField(field_name) => {
                         self.kv(indent2).with_s_key("StructField").with_identifier_val(field_name);
                     },
                     SelectKind::TupleMember(member_index) => {
                         self.kv(indent2).with_s_key("TupleMember").with_disp_val(member_index);
                     },
+                }
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
             },
             Expression::Literal(expr) => {
                 self.kv(indent).with_id(PREFIX_LITERAL_EXPR_ID, expr.this.0.index)
                     .with_s_key("LiteralExpr");
                 self.kv(indent2).with_s_key("TypeIndex").with_disp_val(&expr.type_index);
                 let val = self.kv(indent2).with_s_key("Value");
                 match &expr.value {
                     Literal::Null => { val.with_s_val("null"); },
                     Literal::True => { val.with_s_val("true"); },
                     Literal::False => { val.with_s_val("false"); },
                     Literal::Character(data) => { val.with_disp_val(data); },
                     Literal::String(data) => {
                         // Stupid hack
                         let string = String::from(data.as_str());
                         val.with_disp_val(&string);
                     },
                     Literal::Integer(data) => { val.with_debug_val(data); },
                     Literal::Struct(data) => {
                         val.with_s_val("Struct");
                         let indent4 = indent3 + 1;
                         self.kv(indent3).with_s_key("ParserType")
                             .with_custom_val(|t| write_parser_type(t, heap, &data.parser_type));
                         self.kv(indent3).with_s_key("Definition").with_disp_val(&data.definition.index);
                         for field in &data.fields {
                             self.kv(indent3).with_s_key("Field");
                             self.kv(indent4).with_s_key("Name").with_identifier_val(&field.identifier);
                             self.kv(indent4).with_s_key("Index").with_disp_val(&field.field_idx);
                             self.kv(indent4).with_s_key("ParserType");
                             self.write_expr(heap, field.value, indent4 + 1);
+                        }
                     },
                     Literal::Enum(data) => {
                         val.with_s_val("Enum");
                         self.kv(indent3).with_s_key("ParserType")
                             .with_custom_val(|t| write_parser_type(t, heap, &data.parser_type));
                         self.kv(indent3).with_s_key("Definition").with_disp_val(&data.definition.index);
                         self.kv(indent3).with_s_key("VariantIdx").with_disp_val(&data.variant_idx);
                     },
                     Literal::Union(data) => {
                         val.with_s_val("Union");
                         let indent4 = indent3 + 1;
                         self.kv(indent3).with_s_key("ParserType")
                             .with_custom_val(|t| write_parser_type(t, heap, &data.parser_type));
                         self.kv(indent3).with_s_key("Definition").with_disp_val(&data.definition.index);
                         self.kv(indent3).with_s_key("VariantIdx").with_disp_val(&data.variant_idx);
                         for value in &data.values {
                             self.kv(indent3).with_s_key("Value");
                             self.write_expr(heap, *value, indent4);
+                        }
                     },
                     Literal::Array(data) => {
                         val.with_s_val("Array");
                         let indent4 = indent3 + 1;
                         self.kv(indent3).with_s_key("Elements");
                         for expr_id in data {
                             self.write_expr(heap, *expr_id, indent4);
+                        }
                     },
                     Literal::Tuple(data) => {
                         val.with_s_val("Tuple");
                         let indent4 = indent3 + 1;
                         self.kv(indent3).with_s_key("Elements");
                         for expr_id in data {
                             self.write_expr(heap, *expr_id, indent4);
+                        }
+                    }
+                }
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
             },
             Expression::Cast(expr) => {
                 self.kv(indent).with_id(PREFIX_CAST_EXPR_ID, expr.this.0.index)
                     .with_s_key("CallExpr");
                 self.kv(indent2).with_s_key("TypeIndex").with_disp_val(&expr.type_index);
                 self.kv(indent2).with_s_key("ToType")
                     .with_custom_val(|t| write_parser_type(t, heap, &expr.to_type));
                 self.kv(indent2).with_s_key("Subject");
                 self.write_expr(heap, expr.subject, indent3);
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
+            }
             Expression::Call(expr) => {
                 self.kv(indent).with_id(PREFIX_CALL_EXPR_ID, expr.this.0.index)
                     .with_s_key("CallExpr");
                 let definition = &heap[expr.definition];
                 match definition {
                     Definition::Component(definition) => {
                         self.kv(indent2).with_s_key("BuiltIn").with_disp_val(&false);
                         self.kv(indent2).with_s_key("Variant").with_debug_val(&definition.variant);
                     },
                     Definition::Function(definition) => {
                 self.kv(indent2).with_s_key("TypeIndex").with_disp_val(&expr.type_index);
                 self.kv(indent2).with_s_key("Method").with_debug_val(&expr.method);
                 if !expr.procedure.is_invalid() {
                     let definition = &heap[expr.procedure];
                     self.kv(indent2).with_s_key("BuiltIn").with_disp_val(&definition.builtin);
                         self.kv(indent2).with_s_key("Variant").with_s_val("Function");
                     },
                     _ => unreachable!()
+                }
                 self.kv(indent2).with_s_key("MethodName").with_identifier_val(definition.identifier());
                     self.kv(indent2).with_s_key("Variant").with_debug_val(&definition.kind);
                     self.kv(indent2).with_s_key("MethodName").with_identifier_val(&definition.identifier);
                     self.kv(indent2).with_s_key("ParserType")
                         .with_custom_val(|t| write_parser_type(t, heap, &expr.parser_type));
+                }
                 // Arguments
                 self.kv(indent2).with_s_key("Arguments");
                 for arg_id in &expr.arguments {
                     self.write_expr(heap, *arg_id, indent3);
+                }
                 // Parent
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
             },
             Expression::Variable(expr) => {
                 self.kv(indent).with_id(PREFIX_VARIABLE_EXPR_ID, expr.this.0.index)
                     .with_s_key("VariableExpr");
                 self.kv(indent2).with_s_key("TypeIndex").with_disp_val(&expr.type_index);
                 self.kv(indent2).with_s_key("Name").with_identifier_val(&expr.identifier);
                 self.kv(indent2).with_s_key("Definition")
                     .with_opt_disp_val(expr.declaration.as_ref().map(|v| &v.index));
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
+            }
+        }
+    }
     fn write_variable(&mut self, heap: &Heap, variable_id: VariableId, indent: usize) {
         let var = &heap[variable_id];
         let indent2 = indent + 1;
         self.kv(indent).with_id(PREFIX_VARIABLE_ID, variable_id.index)
             .with_s_key("Variable");
         self.kv(indent2).with_s_key("Name").with_identifier_val(&var.identifier);
         self.kv(indent2).with_s_key("Kind").with_debug_val(&var.kind);
         self.kv(indent2).with_s_key("ParserType")
             .with_custom_val(|w| write_parser_type(w, heap, &var.parser_type));
-        self.kv(indent2).with_s_key("RelativePos").with_disp_val(&var.relative_pos_in_block);
+        self.kv(indent2).with_s_key("RelativePos").with_disp_val(&var.relative_pos_in_parent);
         self.kv(indent2).with_s_key("UniqueScopeID").with_disp_val(&var.unique_id_in_scope);
+    }
     //--------------------------------------------------------------------------
     // Printing Utilities
     //--------------------------------------------------------------------------
     fn kv(&mut self, indent: usize) -> KV {
         KV::new(&mut self.buffer, &mut self.temp1, &mut self.temp2, indent)
+    }
     fn flush<W: IOWrite>(&mut self, w: &mut W) {
         w.write(self.buffer.as_bytes()).unwrap();
         self.buffer.clear()
+    }
+}
 fn write_option<V: Display>(target: &mut String, value: Option<V>) {
     target.clear();
     match &value {
         Some(v) => target.push_str(&format!("Some({})", v)),
         None => target.push_str("None")
     };
+}
 fn write_parser_type(target: &mut String, heap: &Heap, t: &ParserType) {
     use ParserTypeVariant as PTV;
     if t.elements.is_empty() {
         target.push_str("no elements in ParserType (can happen due to compiler-inserted AST nodes)");
         return;
+    }
     fn write_element(target: &mut String, heap: &Heap, t: &ParserType, mut element_idx: usize) -> usize {
         let element = &t.elements[element_idx];
         match &element.variant {
             PTV::Void => target.push_str("void"),
             PTV::InputOrOutput => {
                 target.push_str("portlike<");
                 element_idx = write_element(target, heap, t, element_idx + 1);
                 target.push('>');
             },
             PTV::ArrayLike => {
                 element_idx = write_element(target, heap, t, element_idx + 1);
                 target.push_str("[???]");
             },
             PTV::IntegerLike => target.push_str("integerlike"),
             PTV::Message => { target.push_str(KW_TYPE_MESSAGE_STR); },
             PTV::Bool => { target.push_str(KW_TYPE_BOOL_STR); },
             PTV::UInt8 => { target.push_str(KW_TYPE_UINT8_STR); },
             PTV::UInt16 => { target.push_str(KW_TYPE_UINT16_STR); },
             PTV::UInt32 => { target.push_str(KW_TYPE_UINT32_STR); },
             PTV::UInt64 => { target.push_str(KW_TYPE_UINT64_STR); },
             PTV::SInt8 => { target.push_str(KW_TYPE_SINT8_STR); },
             PTV::SInt16 => { target.push_str(KW_TYPE_SINT16_STR); },
             PTV::SInt32 => { target.push_str(KW_TYPE_SINT32_STR); },
             PTV::SInt64 => { target.push_str(KW_TYPE_SINT64_STR); },
             PTV::Character => { target.push_str(KW_TYPE_CHAR_STR); },
             PTV::String => { target.push_str(KW_TYPE_STRING_STR); },
             PTV::IntegerLiteral => { target.push_str("int_literal"); },
             PTV::Inferred => { target.push_str(KW_TYPE_INFERRED_STR); },
             PTV::Array => {
                 element_idx = write_element(target, heap, t, element_idx + 1);
                 target.push_str("[]");
             },
             PTV::Input => {
                 target.push_str(KW_TYPE_IN_PORT_STR);
                 target.push('<');
                 element_idx = write_element(target, heap, t, element_idx + 1);
                 target.push('>');
             },
             PTV::Output => {
                 target.push_str(KW_TYPE_OUT_PORT_STR);
                 target.push('<');
                 element_idx = write_element(target, heap, t, element_idx + 1);
                 target.push('>');
             },
             PTV::Tuple(num_embedded) => {
                 target.push('(');
                 let num_embedded = *num_embedded;
                 for embedded_idx in 0..num_embedded {
                     if embedded_idx != 0 {
                         target.push(',');
+                    }
                     element_idx = write_element(target, heap, t, element_idx + 1);
+                }
                 target.push(')');
+            }
             PTV::PolymorphicArgument(definition_id, arg_idx) => {
                 let definition = &heap[*definition_id];
                 let poly_var = &definition.poly_vars()[*arg_idx as usize].value;
                 target.push_str(poly_var.as_str());
             },
             PTV::Definition(definition_id, num_embedded) => {
                 let definition = &heap[*definition_id];
                 let definition_ident = definition.identifier().value.as_str();
                 target.push_str(definition_ident);
                 let num_embedded = *num_embedded;
                 if num_embedded != 0 {
                     target.push('<');
                     for embedded_idx in 0..num_embedded {
                         if embedded_idx != 0 {
                             target.push(',');
+                        }
                         element_idx = write_element(target, heap, t, element_idx + 1);
+                    }
                     target.push('>');
+                }
+            }
+        }
         element_idx
+    }
     write_element(target, heap, t, 0);
+}
 fn write_concrete_type(target: &mut String, heap: &Heap, def_id: DefinitionId, t: &ConcreteType) {
     use ConcreteTypePart as CTP;
     fn write_concrete_part(target: &mut String, heap: &Heap, def_id: DefinitionId, t: &ConcreteType, mut idx: usize) -> usize {
         if idx >= t.parts.len() {
             return idx;
+        }
         match &t.parts[idx] {
             CTP::Void => target.push_str("void"),
             CTP::Message => target.push_str("msg"),
-            CTP::Bool => target.push_str("bool"),
+            CTP::Bool => target.push_str(KW_TYPE_BOOL_STR),
             CTP::UInt8 => target.push_str(KW_TYPE_UINT8_STR),
             CTP::UInt16 => target.push_str(KW_TYPE_UINT16_STR),
             CTP::UInt32 => target.push_str(KW_TYPE_UINT32_STR),
             CTP::UInt64 => target.push_str(KW_TYPE_UINT64_STR),
             CTP::SInt8 => target.push_str(KW_TYPE_SINT8_STR),
             CTP::SInt16 => target.push_str(KW_TYPE_SINT16_STR),
             CTP::SInt32 => target.push_str(KW_TYPE_SINT32_STR),
             CTP::SInt64 => target.push_str(KW_TYPE_SINT64_STR),
             CTP::Character => target.push_str(KW_TYPE_CHAR_STR),
             CTP::String => target.push_str(KW_TYPE_STRING_STR),
             CTP::Pointer => target.push('*'),
             CTP::Array => {
                 idx = write_concrete_part(target, heap, def_id, t, idx + 1);
                 target.push_str("[]");
             },
             CTP::Slice => {
                 idx = write_concrete_part(target, heap, def_id, t, idx + 1);
                 target.push_str("[..]");
+            }
             CTP::Input => {
                 target.push_str("in<");
                 idx = write_concrete_part(target, heap, def_id, t, idx + 1);
                 target.push('>');
             },
             CTP::Output => {
                 target.push_str("out<");
                 idx = write_concrete_part(target, heap, def_id, t, idx + 1);
                 target.push('>')
             },
             CTP::Tuple(num_embedded) => {
                 target.push('(');
                 for idx_embedded in 0..*num_embedded {
                     if idx_embedded != 0 {
                         target.push_str(", ");
+                    }
                     idx = write_concrete_part(target, heap, def_id, t, idx + 1);
+                }
                 target.push(')');
             },
             CTP::Instance(definition_id, num_embedded) => {
                 let identifier = heap[*definition_id].identifier();
                 target.push_str(identifier.value.as_str());
                 target.push('<');
                 for idx_embedded in 0..*num_embedded {
                     if idx_embedded != 0 {
                         target.push_str(", ");
+                    }
                     idx = write_concrete_part(target, heap, def_id, t, idx + 1);
+                }
                 target.push('>');
             },
             CTP::Function(_, _) => todo!("AST printer for ConcreteTypePart::Function"),
             CTP::Component(_, _) => todo!("AST printer for ConcreteTypePart::Component"),
+        }
         idx + 1
+    }
     write_concrete_part(target, heap, def_id, t, 0);
+}
 fn write_expression_parent(target: &mut String, parent: &ExpressionParent) {
     use ExpressionParent as EP;
     *target = match parent {
         EP::None => String::from("None"),
         EP::Memory(id) => format!("MemStmt({})", id.0.0.index),
         EP::If(id) => format!("IfStmt({})", id.0.index),
         EP::While(id) => format!("WhileStmt({})", id.0.index),
         EP::Return(id) => format!("ReturnStmt({})", id.0.index),
         EP::New(id) => format!("NewStmt({})", id.0.index),
         EP::ExpressionStmt(id) => format!("ExprStmt({})", id.0.index),
         EP::Expression(id, idx) => format!("Expr({}, {})", id.index, idx)
     };
+}
@@ \ No newline at end of file @@

src/protocol/eval/error.rs

➞

Show inline comments

 use std::fmt;
 use crate::protocol::{
     ast::*,
     Module,
     input_source::{ErrorStatement, StatementKind}
 };
 use super::executor::*;
 /// Represents a stack frame recorded in an error
 #[derive(Debug)]
 pub struct EvalFrame {
     pub line: u32,
     pub module_name: String,
     pub procedure: String, // function or component
     pub is_func: bool,
+}
 impl fmt::Display for EvalFrame {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let func_or_comp = if self.is_func {
             "function "
         } else {
             "component"
         };
         if self.module_name.is_empty() {
             write!(f, "{} {}:{}", func_or_comp, &self.procedure, self.line)
         } else {
             write!(f, "{} {}:{}:{}", func_or_comp, &self.module_name, &self.procedure, self.line)
+        }
+    }
+}
 /// Represents an error that ocurred during evaluation. Contains error
 /// statements just like in parsing errors. Additionally may display the current
 /// execution state.
 #[derive(Debug)]
 pub struct EvalError {
     pub(crate) statements: Vec<ErrorStatement>,
     pub(crate) frames: Vec<EvalFrame>,
+}
 impl EvalError {
     pub(crate) fn new_error_at_expr(prompt: &Prompt, modules: &[Module], heap: &Heap, expr_id: ExpressionId, msg: String) -> EvalError {
         // Create frames
         debug_assert!(!prompt.frames.is_empty());
         let mut frames = Vec::with_capacity(prompt.frames.len());
         let mut last_module_source = &modules[0].source;
         for frame in prompt.frames.iter() {
             let definition = &heap[frame.definition];
             let statement = &heap[frame.position];
             let statement_span = statement.span();
             let (root_id, procedure, is_func) = match definition {
                 Definition::Function(def) => {
                     (def.defined_in, def.identifier.value.as_str().to_string(), true)
                 },
                 Definition::Component(def) => {
                     (def.defined_in, def.identifier.value.as_str().to_string(), false)
                 },
                 _ => unreachable!("construct stack frame with definition pointing to data type")
             };
             // Lookup module name, if it has one
-            let module = modules.iter().find(|m| m.root_id == root_id).unwrap();
+            let module = modules.iter().find(|m| m.root_id == definition.defined_in).unwrap();
             let module_name = if let Some(name) = &module.name {
                 name.as_str().to_string()
             } else {
                 String::new()
             };
             last_module_source = &module.source;
             frames.push(EvalFrame{
                 line: statement_span.begin.line,
                 module_name,
                 procedure,
                 is_func
                 procedure: definition.identifier.value.as_str().to_string(),
                 is_func: definition.kind == ProcedureKind::Function,
             });
+        }
         let expr = &heap[expr_id];
         let statements = vec![
             ErrorStatement::from_source_at_span(StatementKind::Error, last_module_source, expr.full_span(), msg)
         ];
         EvalError{ statements, frames }
+    }
+}
 impl fmt::Display for EvalError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         // Display error statement(s)
         self.statements[0].fmt(f)?;
         for statement in self.statements.iter().skip(1) {
             writeln!(f)?;
             statement.fmt(f)?;
+        }
         // Display stack trace
         writeln!(f)?;
         writeln!(f, " +-  Stack trace:")?;
         for frame in self.frames.iter().rev() {
             write!(f, " | ")?;
             frame.fmt(f)?;
             writeln!(f)?;
+        }
         Ok(())
+    }
+}
@@ \ No newline at end of file @@

src/protocol/eval/executor.rs

➞

Show inline comments

 use std::collections::VecDeque;
 use super::value::*;
 use super::store::*;
 use super::error::*;
 use crate::protocol::*;
 use crate::protocol::ast::*;
 use crate::protocol::type_table::*;
 macro_rules! debug_enabled { () => { false }; }
 macro_rules! debug_log {
     ($format:literal) => {
         enabled_debug_print!(false, "exec", $format);
     };
     ($format:literal, $($args:expr),*) => {
         enabled_debug_print!(false, "exec", $format, $($args),*);
     };
+}
 #[derive(Debug, Clone)]
 pub(crate) enum ExprInstruction {
     EvalExpr(ExpressionId),
     PushValToFront,
+}
 #[derive(Debug, Clone)]
 pub(crate) struct Frame {
     pub(crate) definition: DefinitionId,
     pub(crate) monomorph_idx: i32,
     pub(crate) definition: ProcedureDefinitionId,
     pub(crate) monomorph_type_id: TypeId,
     pub(crate) monomorph_index: usize,
     pub(crate) position: StatementId,
     pub(crate) expr_stack: VecDeque<ExprInstruction>, // hack for expression evaluation, evaluated by popping from back
     pub(crate) expr_values: VecDeque<Value>, // hack for expression results, evaluated by popping from front/back
     pub(crate) max_stack_size: u32,
+}
 impl Frame {
     /// Creates a new execution frame. Does not modify the stack in any way.
-    pub fn new(heap: &Heap, definition_id: DefinitionId, monomorph_idx: i32) -> Self {
+    pub fn new(heap: &Heap, definition_id: ProcedureDefinitionId, monomorph_type_id: TypeId, monomorph_index: u32) -> Self {
         let definition = &heap[definition_id];
         let first_statement = match definition {
             Definition::Component(definition) => definition.body,
             Definition::Function(definition) => definition.body,
             _ => unreachable!("initializing frame with {:?} instead of a function/component", definition),
         };
         let outer_scope_id = definition.scope;
         let first_statement_id = definition.body;
         // Another not-so-pretty thing that has to be replaced somewhere in the
         // future...
         fn determine_max_stack_size(heap: &Heap, block_id: BlockStatementId, max_size: &mut u32) {
             let block_stmt = &heap[block_id];
             debug_assert!(block_stmt.next_unique_id_in_scope >= 0);
         fn determine_max_stack_size(heap: &Heap, scope_id: ScopeId, max_size: &mut u32) {
             let scope = &heap[scope_id];
             // Check current block
-            let cur_size = block_stmt.next_unique_id_in_scope as u32;
+            let cur_size = scope.next_unique_id_in_scope as u32;
             if cur_size > *max_size { *max_size = cur_size; }
             // And child blocks
             for child_scope in &block_stmt.scope_node.nested {
                 determine_max_stack_size(heap, child_scope.to_block(), max_size);
             for child_scope in &scope.nested {
                 determine_max_stack_size(heap, *child_scope, max_size);
+            }
+        }
         let mut max_stack_size = 0;
-        determine_max_stack_size(heap, first_statement, &mut max_stack_size);
+        determine_max_stack_size(heap, outer_scope_id, &mut max_stack_size);
         Frame{
             definition: definition_id,
             monomorph_idx,
             position: first_statement.upcast(),
             monomorph_type_id,
             monomorph_index: monomorph_index as usize,
             position: first_statement_id.upcast(),
             expr_stack: VecDeque::with_capacity(128),
             expr_values: VecDeque::with_capacity(128),
             max_stack_size,
+        }
+    }
     /// Prepares a single expression for execution. This involves walking the
     /// expression tree and putting them in the `expr_stack` such that
     /// continuously popping from its back will evaluate the expression. The
     /// results of each expression will be stored by pushing onto `expr_values`.
     pub fn prepare_single_expression(&mut self, heap: &Heap, expr_id: ExpressionId) {
         debug_assert!(self.expr_stack.is_empty());
         self.expr_values.clear(); // May not be empty if last expression result(s) were discarded
         self.serialize_expression(heap, expr_id);
+    }
     /// Prepares multiple expressions for execution (i.e. evaluating all
     /// function arguments or all elements of an array/union literal). Per
     /// expression this works the same as `prepare_single_expression`. However
     /// after each expression is evaluated we insert a `PushValToFront`
     /// instruction
     pub fn prepare_multiple_expressions(&mut self, heap: &Heap, expr_ids: &[ExpressionId]) {
         debug_assert!(self.expr_stack.is_empty());
         self.expr_values.clear();
         for expr_id in expr_ids {
             self.expr_stack.push_back(ExprInstruction::PushValToFront);
             self.serialize_expression(heap, *expr_id);
+        }
+    }
     /// Performs depth-first serialization of expression tree. Let's not care
     /// about performance for a temporary runtime implementation
     fn serialize_expression(&mut self, heap: &Heap, id: ExpressionId) {
         self.expr_stack.push_back(ExprInstruction::EvalExpr(id));
         match &heap[id] {
             Expression::Assignment(expr) => {
                 self.serialize_expression(heap, expr.left);
                 self.serialize_expression(heap, expr.right);
             },
             Expression::Binding(expr) => {
                 self.serialize_expression(heap, expr.bound_to);
                 self.serialize_expression(heap, expr.bound_from);
             },
             Expression::Conditional(expr) => {
                 self.serialize_expression(heap, expr.test);
             },
             Expression::Binary(expr) => {
                 self.serialize_expression(heap, expr.left);
                 self.serialize_expression(heap, expr.right);
             },
             Expression::Unary(expr) => {
                 self.serialize_expression(heap, expr.expression);
             },
             Expression::Indexing(expr) => {
                 self.serialize_expression(heap, expr.index);
                 self.serialize_expression(heap, expr.subject);
             },
             Expression::Slicing(expr) => {
                 self.serialize_expression(heap, expr.from_index);
                 self.serialize_expression(heap, expr.to_index);
                 self.serialize_expression(heap, expr.subject);
             },
             Expression::Select(expr) => {
                 self.serialize_expression(heap, expr.subject);
             },
             Expression::Literal(expr) => {
                 // Here we only care about literals that have subexpressions
                 match &expr.value {
                     Literal::Null | Literal::True | Literal::False |
                     Literal::Character(_) | Literal::String(_) |
                     Literal::Integer(_) | Literal::Enum(_) => {
                         // No subexpressions
                     },
                     Literal::Struct(literal) => {
                         // Note: fields expressions are evaluated in programmer-
                         // specified order. But struct construction expects them
                         // in type-defined order. I might want to come back to
                         // this.
                         let mut _num_pushed = 0;
                         for want_field_idx in 0..literal.fields.len() {
                             for field in &literal.fields {
                                 if field.field_idx == want_field_idx {
                                     _num_pushed += 1;
                                     self.expr_stack.push_back(ExprInstruction::PushValToFront);
                                     self.serialize_expression(heap, field.value);
+                                }
+                            }
+                        }
                         debug_assert_eq!(_num_pushed, literal.fields.len())
                     },
                     Literal::Union(literal) => {
                         for value_expr_id in &literal.values {
                             self.expr_stack.push_back(ExprInstruction::PushValToFront);
                             self.serialize_expression(heap, *value_expr_id);
+                        }
                     },
                     Literal::Array(value_expr_ids) => {
                         for value_expr_id in value_expr_ids {
                             self.expr_stack.push_back(ExprInstruction::PushValToFront);
                             self.serialize_expression(heap, *value_expr_id);
+                        }
                     },
                     Literal::Tuple(value_expr_ids) => {
                         for value_expr_id in value_expr_ids {
                             self.expr_stack.push_back(ExprInstruction::PushValToFront);
                             self.serialize_expression(heap, *value_expr_id);
+                        }
+                    }
+                }
             },
             Expression::Cast(expr) => {
                 self.serialize_expression(heap, expr.subject);
+            }
             Expression::Call(expr) => {
                 for arg_expr_id in &expr.arguments {
                     self.expr_stack.push_back(ExprInstruction::PushValToFront);
                     self.serialize_expression(heap, *arg_expr_id);
+                }
             },
             Expression::Variable(_expr) => {
                 // No subexpressions
+            }
+        }
+    }
+}
 pub type EvalResult = Result<EvalContinuation, EvalError>;
 #[derive(Debug)]
 pub enum EvalContinuation {
     // Returned in both sync and non-sync modes
     Stepping,
     // Returned only in sync mode
     BranchInconsistent,
     SyncBlockEnd,
     NewFork,
     BlockFires(PortId),
     BlockGet(PortId),
     Put(PortId, ValueGroup),
     SelectStart(u32, u32), // (num_cases, num_ports_total)
     SelectRegisterPort(u32, u32, PortId), // (case_index, port_index_in_case, port_id)
     SelectWait, // wait until select can continue
     // Returned only in non-sync mode
     ComponentTerminated,
     SyncBlockStart,
-    NewComponent(DefinitionId, i32, ValueGroup),
+    NewComponent(ProcedureDefinitionId, TypeId, ValueGroup),
     NewChannel,
+}
 // Note: cloning is fine, methinks. cloning all values and the heap regions then
 // we end up with valid "pointers" to heap regions.
 #[derive(Debug, Clone)]
 pub struct Prompt {
     pub(crate) frames: Vec<Frame>,
     pub(crate) store: Store,
+}
 impl Prompt {
-    pub fn new(_types: &TypeTable, heap: &Heap, def: DefinitionId, monomorph_idx: i32, args: ValueGroup) -> Self {
+    pub fn new(types: &TypeTable, heap: &Heap, def: ProcedureDefinitionId, type_id: TypeId, args: ValueGroup) -> Self {
         let mut prompt = Self{
             frames: Vec::new(),
             store: Store::new(),
         };
         // Maybe do typechecking in the future?
         let new_frame = Frame::new(heap, def, monomorph_idx);
         let monomorph_index = types.get_monomorph(type_id).variant.as_procedure().monomorph_index;
         let new_frame = Frame::new(heap, def, type_id, monomorph_index);
         let max_stack_size = new_frame.max_stack_size;
         prompt.frames.push(new_frame);
         args.into_store(&mut prompt.store);
         prompt.store.reserve_stack(max_stack_size);
         prompt
+    }
     /// Big 'ol function right here. Didn't want to break it up unnecessarily.
     /// It consists of, in sequence: executing any expressions that should be
     /// executed before the next statement can be evaluated, then a section that
     /// performs debug printing, and finally a section that takes the next
     /// statement and executes it. If the statement requires any expressions to
     /// be evaluated, then they will be added such that the next time `step` is
     /// called, all of these expressions are indeed evaluated.
     pub(crate) fn step(&mut self, types: &TypeTable, heap: &Heap, modules: &[Module], ctx: &mut impl RunContext) -> EvalResult {
         // Helper function to transfer multiple values from the expression value
         // array into a heap region (e.g. constructing arrays or structs).
         fn transfer_expression_values_front_into_heap(cur_frame: &mut Frame, store: &mut Store, num_values: usize) -> HeapPos {
             let heap_pos = store.alloc_heap();
             // Do the transformation first (because Rust...)
             for val_idx in 0..num_values {
                 cur_frame.expr_values[val_idx] = store.read_take_ownership(cur_frame.expr_values[val_idx].clone());
+            }
             // And now transfer to the heap region
             let values = &mut store.heap_regions[heap_pos as usize].values;
             debug_assert!(values.is_empty());
             values.reserve(num_values);
             for _ in 0..num_values {
                 values.push(cur_frame.expr_values.pop_front().unwrap());
+            }
             heap_pos
+        }
         // Helper function to make sure that an index into an aray is valid.
         fn array_inclusive_index_is_invalid(store: &Store, array_heap_pos: u32, idx: i64) -> bool {
             let array_len = store.heap_regions[array_heap_pos as usize].values.len();
             return idx < 0 || idx >= array_len as i64;
+        }
         fn array_exclusive_index_is_invalid(store: &Store, array_heap_pos: u32, idx: i64) -> bool {
             let array_len = store.heap_regions[array_heap_pos as usize].values.len();
             return idx < 0 || idx > array_len as i64;
+        }
         fn construct_array_error(prompt: &Prompt, modules: &[Module], heap: &Heap, expr_id: ExpressionId, heap_pos: u32, idx: i64) -> EvalError {
             let array_len = prompt.store.heap_regions[heap_pos as usize].values.len();
             return EvalError::new_error_at_expr(
                 prompt, modules, heap, expr_id,
                 format!("index {} is out of bounds: array length is {}", idx, array_len)
+            )
+        }
         // Checking if we're at the end of execution
         let cur_frame = self.frames.last_mut().unwrap();
         if cur_frame.position.is_invalid() {
-            if heap[cur_frame.definition].is_function() {
+            if heap[cur_frame.definition].kind == ProcedureKind::Function {
                 todo!("End of function without return, return an evaluation error");
+            }
             return Ok(EvalContinuation::ComponentTerminated);
+        }
-        debug_log!("Taking step in '{}'", heap[cur_frame.definition].identifier().value.as_str());
         debug_log!("Taking step in '{}'", heap[cur_frame.definition].identifier.value.as_str());
         // Execute all pending expressions
         while !cur_frame.expr_stack.is_empty() {
             let next = cur_frame.expr_stack.pop_back().unwrap();
             debug_log!("Expr stack: {:?}", next);
             match next {
                 ExprInstruction::PushValToFront => {
                     cur_frame.expr_values.rotate_right(1);
                 },
                 ExprInstruction::EvalExpr(expr_id) => {
                     let expr = &heap[expr_id];
                     match expr {
                         Expression::Assignment(expr) => {
                             let to = cur_frame.expr_values.pop_back().unwrap().as_ref();
                             let rhs = cur_frame.expr_values.pop_back().unwrap();
                             // Note: although not pretty, the assignment operator takes ownership
                             // of the right-hand side value when possible. So we do not drop the
                             // rhs's optionally owned heap data.
                             let rhs = self.store.read_take_ownership(rhs);
                             apply_assignment_operator(&mut self.store, to, expr.operation, rhs);
                         },
                         Expression::Binding(_expr) => {
                             let bind_to = cur_frame.expr_values.pop_back().unwrap();
                             let bind_from = cur_frame.expr_values.pop_back().unwrap();
                             let bind_to_heap_pos = bind_to.get_heap_pos();
                             let bind_from_heap_pos = bind_from.get_heap_pos();
                             let result = apply_binding_operator(&mut self.store, bind_to, bind_from);
                             self.store.drop_value(bind_to_heap_pos);
                             self.store.drop_value(bind_from_heap_pos);
                             cur_frame.expr_values.push_back(Value::Bool(result));
                         },
                         Expression::Conditional(expr) => {
                             // Evaluate testing expression, then extend the
                             // expression stack with the appropriate expression
                             let test_result = cur_frame.expr_values.pop_back().unwrap().as_bool();
                             if test_result {
                                 cur_frame.serialize_expression(heap, expr.true_expression);
                             } else {
                                 cur_frame.serialize_expression(heap, expr.false_expression);
+                            }
                         },
                         Expression::Binary(expr) => {
                             let lhs = cur_frame.expr_values.pop_back().unwrap();
                             let rhs = cur_frame.expr_values.pop_back().unwrap();
                             let result = apply_binary_operator(&mut self.store, &lhs, expr.operation, &rhs);
                             cur_frame.expr_values.push_back(result);
                             self.store.drop_value(lhs.get_heap_pos());
                             self.store.drop_value(rhs.get_heap_pos());
                         },
                         Expression::Unary(expr) => {
                             let val = cur_frame.expr_values.pop_back().unwrap();
                             let result = apply_unary_operator(&mut self.store, expr.operation, &val);
                             cur_frame.expr_values.push_back(result);
                             self.store.drop_value(val.get_heap_pos());
                         },
                         Expression::Indexing(_expr) => {
                             // Evaluate index. Never heap allocated so we do
                             // not have to drop it.
                             let index = cur_frame.expr_values.pop_back().unwrap();
                             let index = self.store.maybe_read_ref(&index);
                             debug_assert!(index.is_integer());
                             let index = if index.is_signed_integer() {
                                 index.as_signed_integer() as i64
                             } else {
                                 index.as_unsigned_integer() as i64
                             };
                             let subject = cur_frame.expr_values.pop_back().unwrap();
                             let (deallocate_heap_pos, value_to_push) = match subject {
                                 Value::Ref(value_ref) => {
                                     // Our expression stack value is a reference to something that
                                     // exists in the normal stack/heap. We don't want to deallocate
                                     // this thing. Rather we want to return a reference to it.
                                     let subject = self.store.read_ref(value_ref);
                                     let subject_heap_pos = match subject {
                                         Value::String(v) => *v,
                                         Value::Array(v) => *v,
                                         Value::Message(v) => *v,
                                         _ => unreachable!(),
                                     };
                                     if array_inclusive_index_is_invalid(&self.store, subject_heap_pos, index) {
                                         return Err(construct_array_error(self, modules, heap, expr_id, subject_heap_pos, index));
+                                    }
                                     (None, Value::Ref(ValueId::Heap(subject_heap_pos, index as u32)))
                                 },
                                 _ => {
                                     // Our value lives on the expression stack, hence we need to
                                     // clone whatever we're referring to. Then drop the subject.
                                     let subject_heap_pos = match &subject {
                                         Value::String(v) => *v,
                                         Value::Array(v) => *v,
                                         Value::Message(v) => *v,
                                         _ => unreachable!(),
                                     };
                                     if array_inclusive_index_is_invalid(&self.store, subject_heap_pos, index) {
                                         return Err(construct_array_error(self, modules, heap, expr_id, subject_heap_pos, index));
+                                    }
                                     let subject_indexed = Value::Ref(ValueId::Heap(subject_heap_pos, index as u32));
                                     (Some(subject_heap_pos), self.store.clone_value(subject_indexed))
                                 },
                             };
                             cur_frame.expr_values.push_back(value_to_push);
                             self.store.drop_value(deallocate_heap_pos);
                         },
                         Expression::Slicing(expr) => {
                             // Evaluate indices
                             let from_index = cur_frame.expr_values.pop_back().unwrap();
                             let from_index = self.store.maybe_read_ref(&from_index);
                             let to_index = cur_frame.expr_values.pop_back().unwrap();
                             let to_index = self.store.maybe_read_ref(&to_index);
                             debug_assert!(from_index.is_integer() && to_index.is_integer());
                             let from_index = if from_index.is_signed_integer() {
                                 from_index.as_signed_integer()
                             } else {
                                 from_index.as_unsigned_integer() as i64
                             };
                             let to_index = if to_index.is_signed_integer() {
                                 to_index.as_signed_integer()
                             } else {
                                 to_index.as_unsigned_integer() as i64
                             };
                             // Dereference subject if needed
                             let subject = cur_frame.expr_values.pop_back().unwrap();
                             let deref_subject = self.store.maybe_read_ref(&subject);
                             // Slicing needs to produce a copy anyway (with the
                             // current evaluator implementation)
                             enum ValueKind{ Array, String, Message }
                             let (value_kind, array_heap_pos) = match deref_subject {
                                 Value::Array(v) => (ValueKind::Array, *v),
                                 Value::String(v) => (ValueKind::String, *v),
                                 Value::Message(v) => (ValueKind::Message, *v),
                                 _ => unreachable!()
                             };
                             if array_inclusive_index_is_invalid(&self.store, array_heap_pos, from_index) {
                                 return Err(construct_array_error(self, modules, heap, expr.from_index, array_heap_pos, from_index));
+                            }
                             if array_exclusive_index_is_invalid(&self.store, array_heap_pos, to_index) {
                                 return Err(construct_array_error(self, modules, heap, expr.to_index, array_heap_pos, to_index));
+                            }
                             // Again: would love to push directly, but rust...
                             let new_heap_pos = self.store.alloc_heap();
                             debug_assert!(self.store.heap_regions[new_heap_pos as usize].values.is_empty());
                             if to_index > from_index {
                                 let from_index = from_index as usize;
                                 let to_index = to_index as usize;
                                 let mut values = Vec::with_capacity(to_index - from_index);
                                 for idx in from_index..to_index {
                                     let value = self.store.heap_regions[array_heap_pos as usize].values[idx].clone();
                                     values.push(self.store.clone_value(value));
+                                }
                                 self.store.heap_regions[new_heap_pos as usize].values = values;
                             } // else: empty range
                             cur_frame.expr_values.push_back(match value_kind {
                                 ValueKind::Array => Value::Array(new_heap_pos),
                                 ValueKind::String => Value::String(new_heap_pos),
                                 ValueKind::Message => Value::Message(new_heap_pos),
                             });
                             // Dropping the original subject, because we don't
                             // want to drop something on the stack
                             self.store.drop_value(subject.get_heap_pos());
                         },
                         Expression::Select(expr) => {
                             let subject= cur_frame.expr_values.pop_back().unwrap();
                             let mono_data = types.get_procedure_monomorph(cur_frame.monomorph_idx);
                             let field_idx = mono_data.expr_data[expr.unique_id_in_definition as usize].field_or_monomorph_idx as u32;
                             let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
                             let field_idx = mono_data.expr_info[expr.type_index as usize].variant.as_select() as u32;
                             // Note: same as above: clone if value lives on expr stack, simply
                             // refer to it if it already lives on the stack/heap.
                             let (deallocate_heap_pos, value_to_push) = match subject {
                                 Value::Ref(value_ref) => {
                                     let subject = self.store.read_ref(value_ref);
                                     let subject_heap_pos = match expr.kind {
                                         SelectKind::StructField(_) => subject.as_struct(),
                                         SelectKind::TupleMember(_) => subject.as_tuple(),
                                     };
                                     (None, Value::Ref(ValueId::Heap(subject_heap_pos, field_idx)))
                                 },
                                 _ => {
                                     let subject_heap_pos = match expr.kind {
                                         SelectKind::StructField(_) => subject.as_struct(),
                                         SelectKind::TupleMember(_) => subject.as_tuple(),
                                     };
                                     let subject_indexed = Value::Ref(ValueId::Heap(subject_heap_pos, field_idx));
                                     (Some(subject_heap_pos), self.store.clone_value(subject_indexed))
                                 },
                             };
                             cur_frame.expr_values.push_back(value_to_push);
                             self.store.drop_value(deallocate_heap_pos);
                         },
                         Expression::Literal(expr) => {
                             let value = match &expr.value {
                                 Literal::Null => Value::Null,
                                 Literal::True => Value::Bool(true),
                                 Literal::False => Value::Bool(false),
                                 Literal::Character(lit_value) => Value::Char(*lit_value),
                                 Literal::String(lit_value) => {
                                     let heap_pos = self.store.alloc_heap();
                                     let values = &mut self.store.heap_regions[heap_pos as usize].values;
                                     let value = lit_value.as_str();
                                     debug_assert!(values.is_empty());
                                     values.reserve(value.len());
                                     for character in value.as_bytes() {
                                         debug_assert!(character.is_ascii());
                                         values.push(Value::Char(*character as char));
+                                    }
                                     Value::String(heap_pos)
+                                }
                                 Literal::Integer(lit_value) => {
                                     use ConcreteTypePart as CTP;
                                     let def_types = types.get_procedure_monomorph(cur_frame.monomorph_idx);
                                     let concrete_type = &def_types.expr_data[expr.unique_id_in_definition as usize].expr_type;
                                     let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
                                     let type_id = mono_data.expr_info[expr.type_index as usize].type_id;
                                     let concrete_type = &types.get_monomorph(type_id).concrete_type;
                                     debug_assert_eq!(concrete_type.parts.len(), 1);
                                     match concrete_type.parts[0] {
                                         CTP::UInt8  => Value::UInt8(lit_value.unsigned_value as u8),
                                         CTP::UInt16 => Value::UInt16(lit_value.unsigned_value as u16),
                                         CTP::UInt32 => Value::UInt32(lit_value.unsigned_value as u32),
                                         CTP::UInt64 => Value::UInt64(lit_value.unsigned_value as u64),
                                         CTP::SInt8  => Value::SInt8(lit_value.unsigned_value as i8),
                                         CTP::SInt16 => Value::SInt16(lit_value.unsigned_value as i16),
                                         CTP::SInt32 => Value::SInt32(lit_value.unsigned_value as i32),
                                         CTP::SInt64 => Value::SInt64(lit_value.unsigned_value as i64),
                                         _ => unreachable!("got concrete type {:?} for integer literal at expr {:?}", concrete_type, expr_id),
+                                    }
+                                }
                                 Literal::Struct(lit_value) => {
                                     let heap_pos = transfer_expression_values_front_into_heap(
                                         cur_frame, &mut self.store, lit_value.fields.len()
                                     );
                                     Value::Struct(heap_pos)
+                                }
                                 Literal::Enum(lit_value) => {
                                     Value::Enum(lit_value.variant_idx as i64)
+                                }
                                 Literal::Union(lit_value) => {
                                     let heap_pos = transfer_expression_values_front_into_heap(
                                         cur_frame, &mut self.store, lit_value.values.len()
                                     );
                                     Value::Union(lit_value.variant_idx as i64, heap_pos)
+                                }
                                 Literal::Array(lit_value) => {
                                     let heap_pos = transfer_expression_values_front_into_heap(
                                         cur_frame, &mut self.store, lit_value.len()
                                     );
                                     Value::Array(heap_pos)
+                                }
                                 Literal::Tuple(lit_value) => {
                                     let heap_pos = transfer_expression_values_front_into_heap(
                                         cur_frame, &mut self.store, lit_value.len()
                                     );
                                     Value::Tuple(heap_pos)
+                                }
                             };
                             cur_frame.expr_values.push_back(value);
                         },
                         Expression::Cast(expr) => {
                             let mono_data = types.get_procedure_monomorph(cur_frame.monomorph_idx);
                             let output_type = &mono_data.expr_data[expr.unique_id_in_definition as usize].expr_type;
                             let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
                             let type_id = mono_data.expr_info[expr.type_index as usize].type_id;
                             let concrete_type = &types.get_monomorph(type_id).concrete_type;
                             // Typechecking reduced this to two cases: either we
                             // have casting noop (same types), or we're casting
                             // between integer/bool/char types.
                             let subject = cur_frame.expr_values.pop_back().unwrap();
-                            match apply_casting(&mut self.store, output_type, &subject) {
+                            match apply_casting(&mut self.store, concrete_type, &subject) {
                                 Ok(value) => cur_frame.expr_values.push_back(value),
                                 Err(msg) => {
                                     return Err(EvalError::new_error_at_expr(self, modules, heap, expr.this.upcast(), msg));
+                                }
+                            }
                             self.store.drop_value(subject.get_heap_pos());
+                        }
                         Expression::Call(expr) => {
                             // If we're dealing with a builtin we don't do any
                             // fancy shenanigans at all, just push the result.
                             match expr.method {
                                 Method::Get => {
                                     let value = cur_frame.expr_values.pop_front().unwrap();
                                     let value = self.store.maybe_read_ref(&value).clone();
                                     let port_id = if let Value::Input(port_id) = value {
                                         port_id
                                     } else {
                                         unreachable!("executor calling 'get' on value {:?}", value)
                                     };
                                     match ctx.performed_get(port_id) {
                                         Some(result) => {
                                             // We have the result. Merge the `ValueGroup` with the
                                             // stack/heap storage.
                                             debug_assert_eq!(result.values.len(), 1);
                                             result.into_stack(&mut cur_frame.expr_values, &mut self.store);
                                         },
                                         None => {
                                             // Don't have the result yet, prepare the expression to
                                             // get run again after we've received a message.
                                             cur_frame.expr_values.push_front(value.clone());
                                             cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
                                             return Ok(EvalContinuation::BlockGet(port_id));
+                                        }
+                                    }
                                 },
                                 Method::Put => {
                                     let port_value = cur_frame.expr_values.pop_front().unwrap();
                                     let deref_port_value = self.store.maybe_read_ref(&port_value).clone();
                                     let port_id = if let Value::Output(port_id) = deref_port_value {
                                         port_id
                                     } else {
                                         unreachable!("executor calling 'put' on value {:?}", deref_port_value)
                                     };
                                     let msg_value = cur_frame.expr_values.pop_front().unwrap();
                                     let deref_msg_value = self.store.maybe_read_ref(&msg_value).clone();
                                     if ctx.performed_put(port_id) {
                                         // We're fine, deallocate in case the expression value stack
                                         // held an owned value
                                         self.store.drop_value(msg_value.get_heap_pos());
                                     } else {
                                         // Prepare to execute again
                                         cur_frame.expr_values.push_front(msg_value);
                                         cur_frame.expr_values.push_front(port_value);
                                         cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
                                         let value_group = ValueGroup::from_store(&self.store, &[deref_msg_value]);
                                         return Ok(EvalContinuation::Put(port_id, value_group));
+                                    }
                                 },
                                 Method::Fires => {
                                     let port_value = cur_frame.expr_values.pop_front().unwrap();
                                     let port_value_deref = self.store.maybe_read_ref(&port_value).clone();
                                     let port_id = match port_value_deref {
                                         Value::Input(port_id) => port_id,
                                         Value::Output(port_id) => port_id,
                                         _ => unreachable!("executor calling 'fires' on value {:?}", port_value_deref),
                                     };
                                     let port_id = port_value_deref.as_port_id();
                                     match ctx.fires(port_id) {
                                         None => {
                                             cur_frame.expr_values.push_front(port_value);
                                             cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
                                             return Ok(EvalContinuation::BlockFires(port_id));
                                         },
                                         Some(value) => {
                                             cur_frame.expr_values.push_back(value);
+                                        }
+                                    }
                                 },
                                 Method::Create => {
                                     let length_value = cur_frame.expr_values.pop_front().unwrap();
                                     let length_value = self.store.maybe_read_ref(&length_value);
                                     let length = if length_value.is_signed_integer() {
                                         let length_value = length_value.as_signed_integer();
                                         if length_value < 0 {
                                             return Err(EvalError::new_error_at_expr(
                                                 self, modules, heap, expr_id,
                                                 format!("got length '{}', can only create a message with a non-negative length", length_value)
                                             ));
+                                        }
                                         length_value as u64
                                     } else {
                                         debug_assert!(length_value.is_unsigned_integer());
                                         length_value.as_unsigned_integer()
                                     };
                                     let heap_pos = self.store.alloc_heap();
                                     let values = &mut self.store.heap_regions[heap_pos as usize].values;
                                     debug_assert!(values.is_empty());
                                     values.resize(length as usize, Value::UInt8(0));
                                     cur_frame.expr_values.push_back(Value::Message(heap_pos));
                                 },
                                 Method::Length => {
                                     let value = cur_frame.expr_values.pop_front().unwrap();
                                     let value_heap_pos = value.get_heap_pos();
                                     let value = self.store.maybe_read_ref(&value);
                                     let heap_pos = match value {
                                         Value::Array(pos) => *pos,
                                         Value::String(pos) => *pos,
                                         _ => unreachable!("length(...) on {:?}", value),
                                     };
                                     let len = self.store.heap_regions[heap_pos as usize].values.len();
                                     // TODO: @PtrInt
                                     cur_frame.expr_values.push_back(Value::UInt32(len as u32));
                                     self.store.drop_value(value_heap_pos);
                                 },
                                 Method::Assert => {
                                     let value = cur_frame.expr_values.pop_front().unwrap();
                                     let value = self.store.maybe_read_ref(&value).clone();
                                     if !value.as_bool() {
                                         return Ok(EvalContinuation::BranchInconsistent)
+                                    }
                                 },
                                 Method::Print => {
                                     // Convert the runtime-variant of a string
                                     // into an actual string.
                                     let value = cur_frame.expr_values.pop_front().unwrap();
                                     let value_heap_pos = value.as_string();
                                     let elements = &self.store.heap_regions[value_heap_pos as usize].values;
                                     let mut message = String::with_capacity(elements.len());
                                     for element in elements {
                                         message.push(element.as_char());
+                                    }
                                     // Drop the heap-allocated value from the
                                     // store
                                     self.store.drop_heap_pos(value_heap_pos);
                                     println!("{}", message);
                                 },
                                 Method::SelectStart => {
                                     let num_cases = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_uint32();
                                     let num_ports = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_uint32();
                                     return Ok(EvalContinuation::SelectStart(num_cases, num_ports));
                                 },
                                 Method::SelectRegisterCasePort => {
                                     let case_index = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_uint32();
                                     let port_index = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_uint32();
                                     let port_value = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_port_id();
                                     return Ok(EvalContinuation::SelectRegisterPort(case_index, port_index, port_value));
                                 },
                                 Method::SelectWait => {
                                     match ctx.performed_select_wait() {
                                         Some(select_index) => {
                                             cur_frame.expr_values.push_back(Value::UInt32(select_index));
                                         },
                                         None => {
                                             cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr.this.upcast()));
                                             return Ok(EvalContinuation::SelectWait)
                                         },
+                                    }
                                 },
                                 Method::UserComponent => {
                                     // This is actually handled by the evaluation
                                     // of the statement.
-                                    debug_assert_eq!(heap[expr.definition].parameters().len(), cur_frame.expr_values.len());
+                                    debug_assert_eq!(heap[expr.procedure].parameters.len(), cur_frame.expr_values.len());
                                     debug_assert_eq!(heap[cur_frame.position].as_new().expression, expr.this)
                                 },
                                 Method::UserFunction => {
                                     // Push a new frame. Note that all expressions have
                                     // been pushed to the front, so they're in the order
                                     // of the definition.
                                     let num_args = expr.arguments.len();
                                     // Determine stack boundaries
                                     let cur_stack_boundary = self.store.cur_stack_boundary;
                                     let new_stack_boundary = self.store.stack.len();
                                     // Push new boundary and function arguments for new frame
                                     self.store.stack.push(Value::PrevStackBoundary(cur_stack_boundary as isize));
                                     for _ in 0..num_args {
                                         let argument = self.store.read_take_ownership(cur_frame.expr_values.pop_front().unwrap());
                                         self.store.stack.push(argument);
+                                    }
                                     // Determine the monomorph index of the function we're calling
                                     let mono_data = types.get_procedure_monomorph(cur_frame.monomorph_idx);
                                     let call_data = &mono_data.expr_data[expr.unique_id_in_definition as usize];
                                     let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
                                     let (type_id, monomorph_index) = mono_data.expr_info[expr.type_index as usize].variant.as_procedure();
                                     // Push the new frame and reserve its stack size
-                                    let new_frame = Frame::new(heap, expr.definition, call_data.field_or_monomorph_idx);
+                                    let new_frame = Frame::new(heap, expr.procedure, type_id, monomorph_index);
                                     let new_stack_size = new_frame.max_stack_size;
                                     self.frames.push(new_frame);
                                     self.store.cur_stack_boundary = new_stack_boundary;
                                     self.store.reserve_stack(new_stack_size);
                                     // To simplify the logic a little bit we will now
                                     // return and ask our caller to call us again
                                     return Ok(EvalContinuation::Stepping);
-                                },
+                                }
+                            }
                         },
                         Expression::Variable(expr) => {
                             let variable = &heap[expr.declaration.unwrap()];
                             let ref_value = if expr.used_as_binding_target {
                                 Value::Binding(variable.unique_id_in_scope as StackPos)
                             } else {
                                 Value::Ref(ValueId::Stack(variable.unique_id_in_scope as StackPos))
                             };
                             cur_frame.expr_values.push_back(ref_value);
+                        }
+                    }
+                }
+            }
+        }
         debug_log!("Frame [{:?}] at {:?}", cur_frame.definition, cur_frame.position);
         if debug_enabled!() {
             debug_log!("Expression value stack (size = {}):", cur_frame.expr_values.len());
             for (_stack_idx, _stack_val) in cur_frame.expr_values.iter().enumerate() {
                 debug_log!("  [{:03}] {:?}", _stack_idx, _stack_val);
+            }
             debug_log!("Stack (size = {}):", self.store.stack.len());
             for (_stack_idx, _stack_val) in self.store.stack.iter().enumerate() {
                 debug_log!("  [{:03}] {:?}", _stack_idx, _stack_val);
+            }
             debug_log!("Heap:");
             for (_heap_idx, _heap_region) in self.store.heap_regions.iter().enumerate() {
                 let _is_free = self.store.free_regions.iter().any(|idx| *idx as usize == _heap_idx);
                 debug_log!("  [{:03}] in_use: {}, len: {}, vals: {:?}", _heap_idx, !_is_free, _heap_region.values.len(), &_heap_region.values);
+            }
+        }
         // No (more) expressions to evaluate. So evaluate statement (that may
         // depend on the result on the last evaluated expression(s))
         let stmt = &heap[cur_frame.position];
         let return_value = match stmt {
             Statement::Block(stmt) => {
                 debug_assert!(stmt.statements.is_empty() || stmt.next == stmt.statements[0]);
                 cur_frame.position = stmt.next;
                 Ok(EvalContinuation::Stepping)
             },
             Statement::EndBlock(stmt) => {
                 let block = &heap[stmt.start_block];
                 self.store.clear_stack(block.first_unique_id_in_scope as usize);
                 let scope = &heap[block.scope];
                 self.store.clear_stack(scope.first_unique_id_in_scope as usize);
                 cur_frame.position = stmt.next;
                 Ok(EvalContinuation::Stepping)
             },
             Statement::Local(stmt) => {
                 match stmt {
                     LocalStatement::Memory(stmt) => {
-                        if cfg!(debug_assertions) {
+                        dbg_code!({
                             let variable = &heap[stmt.variable];
                             debug_assert!(match self.store.read_ref(ValueId::Stack(variable.unique_id_in_scope as u32)) {
                                 Value::Unassigned => false,
                                 _ => true,
                             });
+                        }
+                        });
                         cur_frame.position = stmt.next;
                         Ok(EvalContinuation::Stepping)
                     },
                     LocalStatement::Channel(stmt) => {
                         // Need to create a new channel by requesting it from
                         // the runtime.
                         match ctx.created_channel() {
                             None => {
                                 // No channel is pending. So request one
                                     Ok(EvalContinuation::NewChannel)
                             },
                             Some((put_port, get_port)) => {
                                 self.store.write(ValueId::Stack(heap[stmt.from].unique_id_in_scope as u32), put_port);
                                 self.store.write(ValueId::Stack(heap[stmt.to].unique_id_in_scope as u32), get_port);
                                 cur_frame.position = stmt.next;
                                 Ok(EvalContinuation::Stepping)
+                            }
+                        }
+                    }
+                }
             },
             Statement::Labeled(stmt) => {
                 cur_frame.position = stmt.body;
                 Ok(EvalContinuation::Stepping)
             },
             Statement::If(stmt) => {
                 debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for if statement");
                 let test_value = cur_frame.expr_values.pop_back().unwrap();
                 let test_value = self.store.maybe_read_ref(&test_value).as_bool();
                 if test_value {
                     cur_frame.position = stmt.true_body.upcast();
                 } else if let Some(false_body) = stmt.false_body {
                     cur_frame.position = false_body.upcast();
                     cur_frame.position = stmt.true_case.body;
                 } else if let Some(false_body) = stmt.false_case {
                     cur_frame.position = false_body.body;
                 } else {
                     // Not true, and no false body
                     cur_frame.position = stmt.end_if.upcast();
+                }
                 Ok(EvalContinuation::Stepping)
             },
             Statement::EndIf(stmt) => {
                 cur_frame.position = stmt.next;
                 let if_stmt = &heap[stmt.start_if];
                 debug_assert_eq!(
                     heap[if_stmt.true_case.scope].first_unique_id_in_scope,
                     heap[if_stmt.false_case.unwrap_or(if_stmt.true_case).scope].first_unique_id_in_scope,
                 );
                 let scope = &heap[if_stmt.true_case.scope];
                 self.store.clear_stack(scope.first_unique_id_in_scope as usize);
                 Ok(EvalContinuation::Stepping)
             },
             Statement::While(stmt) => {
                 debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for while statement");
                 let test_value = cur_frame.expr_values.pop_back().unwrap();
                 let test_value = self.store.maybe_read_ref(&test_value).as_bool();
                 if test_value {
-                    cur_frame.position = stmt.body.upcast();
                     cur_frame.position = stmt.body;
                 } else {
                     cur_frame.position = stmt.end_while.upcast();
+                }
                 Ok(EvalContinuation::Stepping)
             },
             Statement::EndWhile(stmt) => {
                 cur_frame.position = stmt.next;
                 let start_while = &heap[stmt.start_while];
                 let scope = &heap[start_while.scope];
                 self.store.clear_stack(scope.first_unique_id_in_scope as usize);
                 Ok(EvalContinuation::Stepping)
             },
             Statement::Break(stmt) => {
                 cur_frame.position = stmt.target.upcast();
                 Ok(EvalContinuation::Stepping)
             },
             Statement::Continue(stmt) => {
                 cur_frame.position = stmt.target.upcast();
                 Ok(EvalContinuation::Stepping)
             },
             Statement::Synchronous(stmt) => {
-                cur_frame.position = stmt.body.upcast();
                 cur_frame.position = stmt.body;
                 Ok(EvalContinuation::SyncBlockStart)
             },
             Statement::EndSynchronous(stmt) => {
                 cur_frame.position = stmt.next;
                 let start_synchronous = &heap[stmt.start_sync];
                 let scope = &heap[start_synchronous.scope];
                 self.store.clear_stack(scope.first_unique_id_in_scope as usize);
                 Ok(EvalContinuation::SyncBlockEnd)
             },
             Statement::Fork(stmt) => {
                 if stmt.right_body.is_none() {
                     // No reason to fork
-                    cur_frame.position = stmt.left_body.upcast();
                     cur_frame.position = stmt.left_body;
                 } else {
                     // Need to fork
                     if let Some(go_left) = ctx.performed_fork() {
                         // Runtime has created a fork
                         if go_left {
-                            cur_frame.position = stmt.left_body.upcast();
                             cur_frame.position = stmt.left_body;
                         } else {
-                            cur_frame.position = stmt.right_body.unwrap().upcast();
                             cur_frame.position = stmt.right_body.unwrap();
+                        }
                     } else {
                         // Request the runtime to create a fork of the current
                         // branch
                         return Ok(EvalContinuation::NewFork);
+                    }
+                }
                 Ok(EvalContinuation::Stepping)
             },
             Statement::EndFork(stmt) => {
                 cur_frame.position = stmt.next;
                 Ok(EvalContinuation::Stepping)
             },
             Statement::Select(_stmt) => {
                 todo!("implement select evaluation")
             Statement::Select(stmt) => {
                 // This is a trampoline for the statements that were placed by
                 // the AST transformation pass
                 cur_frame.position = stmt.next;
                 Ok(EvalContinuation::Stepping)
             },
             Statement::EndSelect(stmt) => {
                 cur_frame.position = stmt.next;
                 let start_select = &heap[stmt.start_select];
                 if let Some(select_case) = start_select.cases.first() {
                     let scope = &heap[select_case.scope];
                     self.store.clear_stack(scope.first_unique_id_in_scope as usize);
+                }
                 Ok(EvalContinuation::Stepping)
             },
             Statement::Return(_stmt) => {
                 debug_assert!(heap[cur_frame.definition].is_function());
                 debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for return statement");
                 // The preceding frame has executed a call, so is expecting the
                 // return expression on its expression value stack. Note that
                 // we may be returning a reference to something on our stack,
                 // so we need to read that value and clone it.
                 let return_value = cur_frame.expr_values.pop_back().unwrap();
                 let return_value = match return_value {
                     Value::Ref(value_id) => self.store.read_copy(value_id),
                     _ => return_value,
                 };
                 // Pre-emptively pop our stack frame
                 self.frames.pop();
                 // Clean up our section of the stack
                 self.store.clear_stack(0);
                 self.store.stack.truncate(self.store.cur_stack_boundary + 1);
                 let prev_stack_idx = self.store.stack.pop().unwrap().as_stack_boundary();
                 // TODO: Temporary hack for testing, remove at some point
                 if self.frames.is_empty() {
                     debug_assert!(prev_stack_idx == -1);
                     debug_assert!(self.store.stack.len() == 0);
                     self.store.stack.push(return_value);
                     return Ok(EvalContinuation::ComponentTerminated);
+                }
                 debug_assert!(prev_stack_idx >= 0);
                 // Return to original state of stack frame
                 self.store.cur_stack_boundary = prev_stack_idx as usize;
                 let cur_frame = self.frames.last_mut().unwrap();
                 cur_frame.expr_values.push_back(return_value);
                 // We just returned to the previous frame, which might be in
                 // the middle of evaluating expressions for a particular
                 // statement. So we don't want to enter the code below.
                 return Ok(EvalContinuation::Stepping);
             },
             Statement::Goto(stmt) => {
                 cur_frame.position = stmt.target.upcast();
                 Ok(EvalContinuation::Stepping)
             },
             Statement::New(stmt) => {
                 let call_expr = &heap[stmt.expression];
                 debug_assert!(heap[call_expr.definition].is_component());
                 debug_assert_eq!(
-                    cur_frame.expr_values.len(), heap[call_expr.definition].parameters().len(),
+                    cur_frame.expr_values.len(), heap[call_expr.procedure].parameters.len(),
                     "mismatch in expr stack size and number of arguments for new statement"
                 );
                 let mono_data = types.get_procedure_monomorph(cur_frame.monomorph_idx);
                 let expr_data = &mono_data.expr_data[call_expr.unique_id_in_definition as usize];
                 let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
                 let type_id = mono_data.expr_info[call_expr.type_index as usize].variant.as_procedure().0;
                 // Note that due to expression value evaluation they exist in
                 // reverse order on the stack.
                 // TODO: Revise this code, keep it as is to be compatible with current runtime
                 let mut args = Vec::new();
                 while let Some(value) = cur_frame.expr_values.pop_front() {
                     args.push(value);
+                }
                 // Construct argument group, thereby copying heap regions
                 let argument_group = ValueGroup::from_store(&self.store, &args);
                 // println!("Creating {} with\n{:#?}", heap[call_expr.definition].identifier().value.as_str(), argument_group);
                 // Clear any heap regions
                 for arg in &args {
                     self.store.drop_value(arg.get_heap_pos());
+                }
                 cur_frame.position = stmt.next;
-                Ok(EvalContinuation::NewComponent(call_expr.definition, expr_data.field_or_monomorph_idx, argument_group))
+                Ok(EvalContinuation::NewComponent(call_expr.procedure, type_id, argument_group))
             },
             Statement::Expression(stmt) => {
                 // The expression has just been completely evaluated. Some
                 // values might have remained on the expression value stack.
                 // cur_frame.expr_values.clear(); PROPER CLEARING
                 cur_frame.position = stmt.next;
                 Ok(EvalContinuation::Stepping)
             },
         };
         assert!(
             cur_frame.expr_values.is_empty(),
             "This is a debugging assertion that will fail if you perform expressions without \
             assigning to anything. This should be completely valid, and this assertion should be \
             replaced by something that clears the expression values if needed, but I'll keep this \
             in for now for debugging purposes."
         );
         // If the next statement requires evaluating expressions then we push
         // these onto the expression stack. This way we will evaluate this
         // stack in the next loop, then evaluate the statement using the result
         // from the expression evaluation.
         if !cur_frame.position.is_invalid() {
             let stmt = &heap[cur_frame.position];
             match stmt {
                 Statement::Local(stmt) => {
                     if let LocalStatement::Memory(stmt) = stmt {
                         // Setup as unassigned, when we execute the memory
                         // statement (after evaluating expression), it should no
                         // longer be `Unassigned`.
                         let variable = &heap[stmt.variable];
                         self.store.write(ValueId::Stack(variable.unique_id_in_scope as u32), Value::Unassigned);
                         cur_frame.prepare_single_expression(heap, stmt.initial_expr.upcast());
+                    }
                 },
                 Statement::If(stmt) => cur_frame.prepare_single_expression(heap, stmt.test),
                 Statement::While(stmt) => cur_frame.prepare_single_expression(heap, stmt.test),
                 Statement::Return(stmt) => {
                     debug_assert_eq!(stmt.expressions.len(), 1); // TODO: @ReturnValues
                     cur_frame.prepare_single_expression(heap, stmt.expressions[0]);
                 },
                 Statement::New(stmt) => {
                     // Note that we will end up not evaluating the call itself.
                     // Rather we will evaluate its expressions and then
                     // instantiate the component upon reaching the "new" stmt.
                     let call_expr = &heap[stmt.expression];
                     cur_frame.prepare_multiple_expressions(heap, &call_expr.arguments);
                 },
                 Statement::Expression(stmt) => {
                     cur_frame.prepare_single_expression(heap, stmt.expression);
+                }
                 _ => {},
+            }
+        }
         return_value
+    }
     /// Constructs an error at the current expression that lives at the top of
     /// the expression stack. Falls back to constructing an error at the current
     /// statement if there is no expression.
     pub(crate) fn new_error_at_expr(&self, modules: &[Module], heap: &Heap, error_message: String) -> EvalError {
         let last_frame = self.frames.last().unwrap();
         for instruction in last_frame.expr_stack.iter().rev() {
             if let ExprInstruction::EvalExpr(expression_id) = instruction {
                 return EvalError::new_error_at_expr(
                     self, modules, heap, *expression_id, error_message
                 );
+            }
+        }
         // If here then expression stack was empty (cannot have just rotate
         // instructions)
         panic!("attempted to construct evaluation error without any expressions to evaluate in frame");
+    }
+}
@@ \ No newline at end of file @@

src/protocol/eval/value.rs

➞

Show inline comments

 use std::collections::VecDeque;
 use super::store::*;
 use crate::protocol::ast::{
     AssignmentOperator,
     BinaryOperator,
     UnaryOperator,
     ConcreteType,
     ConcreteTypePart,
 };
 use crate::protocol::parser::token_parsing::*;
 pub type StackPos = u32;
 pub type HeapPos = u32;
 #[derive(Debug, Copy, Clone)]
 pub enum ValueId {
     Stack(StackPos), // place on stack
     Heap(HeapPos, u32), // allocated region + values within that region
+}
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub struct PortId{
     pub(crate) id: u32
+}
 impl PortId {
     pub fn new(id: u32) -> Self {
         return Self{ id };
+    }
+}
 /// Represents a value stored on the stack or on the heap. Some values contain
 /// a `HeapPos`, implying that they're stored in the store's `Heap`. Clearing
 /// a `Value` with a `HeapPos` from a stack must also clear the associated
 /// region from the `Heap`.
 #[derive(Debug, Clone)]
 pub enum Value {
     // Special types, never encountered during evaluation if the compiler works correctly
     Unassigned,                 // Marker when variables are first declared, immediately followed by assignment
     PrevStackBoundary(isize),   // Marker for stack frame beginning, so we can pop stack values
     Ref(ValueId),               // Reference to a value, used by expressions producing references
     Binding(StackPos),          // Reference to a binding variable (reserved on the stack)
     // Builtin types
     Input(PortId),
     Output(PortId),
     Message(HeapPos),
     Null,
     Bool(bool),
     Char(char),
     String(HeapPos),
     UInt8(u8),
     UInt16(u16),
     UInt32(u32),
     UInt64(u64),
     SInt8(i8),
     SInt16(i16),
     SInt32(i32),
     SInt64(i64),
     Array(HeapPos),
     Tuple(HeapPos),
     // Instances of user-defined types
     Enum(i64),
     Union(i64, HeapPos),
     Struct(HeapPos),
+}
 macro_rules! impl_union_unpack_as_value {
     ($func_name:ident, $variant_name:path, $return_type:ty) => {
         impl Value {
             pub(crate) fn $func_name(&self) -> $return_type {
                 match self {
                     $variant_name(v) => *v,
                     _ => panic!(concat!("called ", stringify!($func_name()), " on {:?}"), self),
+                }
+            }
+        }
+    }
+}
 impl_union_unpack_as_value!(as_stack_boundary, Value::PrevStackBoundary, isize);
 impl_union_unpack_as_value!(as_ref,     Value::Ref,     ValueId);
 impl_union_unpack_as_value!(as_input,   Value::Input,   PortId);
 impl_union_unpack_as_value!(as_output,  Value::Output,  PortId);
 impl_union_unpack_as_value!(as_message, Value::Message, HeapPos);
 impl_union_unpack_as_value!(as_bool,    Value::Bool,    bool);
 impl_union_unpack_as_value!(as_char,    Value::Char,    char);
 impl_union_unpack_as_value!(as_string,  Value::String,  HeapPos);
 impl_union_unpack_as_value!(as_uint8,   Value::UInt8,   u8);
 impl_union_unpack_as_value!(as_uint16,  Value::UInt16,  u16);
 impl_union_unpack_as_value!(as_uint32,  Value::UInt32,  u32);
 impl_union_unpack_as_value!(as_uint64,  Value::UInt64,  u64);
 impl_union_unpack_as_value!(as_sint8,   Value::SInt8,   i8);
 impl_union_unpack_as_value!(as_sint16,  Value::SInt16,  i16);
 impl_union_unpack_as_value!(as_sint32,  Value::SInt32,  i32);
 impl_union_unpack_as_value!(as_sint64,  Value::SInt64,  i64);
 impl_union_unpack_as_value!(as_array,   Value::Array,   HeapPos);
 impl_union_unpack_as_value!(as_tuple,   Value::Tuple,   HeapPos);
 impl_union_unpack_as_value!(as_enum,    Value::Enum,    i64);
 impl_union_unpack_as_value!(as_struct,  Value::Struct,  HeapPos);
 union_cast_to_value_method_impl!(as_stack_boundary, isize, Value::PrevStackBoundary);
 union_cast_to_value_method_impl!(as_ref, ValueId, Value::Ref);
 union_cast_to_value_method_impl!(as_input, PortId, Value::Input);
 union_cast_to_value_method_impl!(as_output, PortId, Value::Output);
 union_cast_to_value_method_impl!(as_message, HeapPos, Value::Message);
 union_cast_to_value_method_impl!(as_bool, bool, Value::Bool);
 union_cast_to_value_method_impl!(as_char, char, Value::Char);
 union_cast_to_value_method_impl!(as_string, HeapPos, Value::String);
 union_cast_to_value_method_impl!(as_uint8, u8, Value::UInt8);
 union_cast_to_value_method_impl!(as_uint16, u16, Value::UInt16);
 union_cast_to_value_method_impl!(as_uint32, u32, Value::UInt32);
 union_cast_to_value_method_impl!(as_uint64, u64, Value::UInt64);
 union_cast_to_value_method_impl!(as_sint8, i8, Value::SInt8);
 union_cast_to_value_method_impl!(as_sint16, i16, Value::SInt16);
 union_cast_to_value_method_impl!(as_sint32, i32, Value::SInt32);
 union_cast_to_value_method_impl!(as_sint64, i64, Value::SInt64);
 union_cast_to_value_method_impl!(as_array, HeapPos, Value::Array);
 union_cast_to_value_method_impl!(as_tuple, HeapPos, Value::Tuple);
 union_cast_to_value_method_impl!(as_enum, i64, Value::Enum);
 union_cast_to_value_method_impl!(as_struct, HeapPos, Value::Struct);
 impl Value {
     pub(crate) fn as_union(&self) -> (i64, HeapPos) {
         match self {
             Value::Union(tag, v) => (*tag, *v),
             _ => panic!("called as_union on {:?}", self),
+        }
+    }
     pub(crate) fn as_port_id(&self) -> PortId {
         match self {
             Value::Input(v) => *v,
             Value::Output(v) => *v,
             _ => unreachable!(),
+        }
+    }
     pub(crate) fn is_integer(&self) -> bool {
         match self {
             Value::UInt8(_) | Value::UInt16(_) | Value::UInt32(_) | Value::UInt64(_) |
             Value::SInt8(_) | Value::SInt16(_) | Value::SInt32(_) | Value::SInt64(_) => true,
             _ => false
+        }
+    }
     pub(crate) fn is_unsigned_integer(&self) -> bool {
         match self {
             Value::UInt8(_) | Value::UInt16(_) | Value::UInt32(_) | Value::UInt64(_) => true,
             _ => false
+        }
+    }
     pub(crate) fn is_signed_integer(&self) -> bool {
         match self {
             Value::SInt8(_) | Value::SInt16(_) | Value::SInt32(_) | Value::SInt64(_) => true,
             _ => false
+        }
+    }
     pub(crate) fn as_unsigned_integer(&self) -> u64 {
         match self {
             Value::UInt8(v)  => *v as u64,
             Value::UInt16(v) => *v as u64,
             Value::UInt32(v) => *v as u64,
             Value::UInt64(v) => *v as u64,
             _ => unreachable!("called as_unsigned_integer on {:?}", self),
+        }
+    }
     pub(crate) fn as_signed_integer(&self) -> i64 {
         match self {
             Value::SInt8(v)  => *v as i64,
             Value::SInt16(v) => *v as i64,
             Value::SInt32(v) => *v as i64,
             Value::SInt64(v) => *v as i64,
             _ => unreachable!("called as_signed_integer on {:?}", self)
+        }
+    }
     /// Returns the heap position associated with the value. If the value
     /// doesn't store anything in the heap then we return `None`.
     pub(crate) fn get_heap_pos(&self) -> Option<HeapPos> {
         match self {
             Value::Message(v) => Some(*v),
             Value::String(v) => Some(*v),
             Value::Array(v) => Some(*v),
             Value::Tuple(v) => Some(*v),
             Value::Union(_, v) => Some(*v),
             Value::Struct(v) => Some(*v),
             _ => None
+        }
+    }
+}
 /// When providing arguments to a new component, or when transferring values
 /// from one component's store to a newly instantiated component, one has to
 /// transfer stack and heap values. This `ValueGroup` represents such a
 /// temporary group of values with potential heap allocations.
 ///
 /// Constructing such a ValueGroup manually requires some extra care to make
 /// sure all elements of `values` point to valid elements of `regions`.
 ///
 /// Again: this is a temporary thing, hopefully removed once we move to a
 /// bytecode interpreter.
 #[derive(Clone, Debug)]
 pub struct ValueGroup {
     pub(crate) values: Vec<Value>,
     pub(crate) regions: Vec<Vec<Value>>
+}
 impl ValueGroup {
     pub(crate) fn new_stack(values: Vec<Value>) -> Self {
         debug_assert!(values.iter().all(|v| v.get_heap_pos().is_none()));
         Self{
             values,
             regions: Vec::new(),
+        }
+    }
     pub(crate) fn from_store(store: &Store, values: &[Value]) -> Self {
         let mut group = ValueGroup{
             values: Vec::with_capacity(values.len()),
             regions: Vec::with_capacity(values.len()), // estimation
         };
         for value in values {
             let transferred = group.retrieve_value(value, store);
             group.values.push(transferred);
+        }
         group
+    }
     /// Transfers a provided value from a store into a local value with its
     /// heap allocations (if any) stored in the ValueGroup. Calling this
     /// function will not store the returned value in the `values` member.
     fn retrieve_value(&mut self, value: &Value, from_store: &Store) -> Value {
         let value = from_store.maybe_read_ref(value);
         if let Some(heap_pos) = value.get_heap_pos() {
             // Value points to a heap allocation, so transfer the heap values
             // internally.
             let from_region = &from_store.heap_regions[heap_pos as usize].values;
             let mut new_region = Vec::with_capacity(from_region.len());
             for value in from_region {
                 let transferred = self.retrieve_value(value, from_store);
                 new_region.push(transferred);
+            }
             // Region is constructed, store internally and return the new value.
             let new_region_idx = self.regions.len() as HeapPos;
             self.regions.push(new_region);
             return match value {
                 Value::Message(_)    => Value::Message(new_region_idx),
                 Value::String(_)     => Value::String(new_region_idx),
                 Value::Array(_)      => Value::Array(new_region_idx),
                 Value::Tuple(_)      => Value::Tuple(new_region_idx),
                 Value::Union(tag, _) => Value::Union(*tag, new_region_idx),
                 Value::Struct(_)     => Value::Struct(new_region_idx),
                 _ => unreachable!(),
             };
         } else {
             return value.clone();
+        }
+    }
     /// Transfers the heap values and the stack values into the store. Stack
     /// values are pushed onto the Store's stack in the order in which they
     /// appear in the value group.
     pub(crate) fn into_store(self, store: &mut Store) {
         for value in &self.values {
             let transferred = self.provide_value(value, store);
             store.stack.push(transferred);
+        }
+    }
     /// Transfers the heap values into the store, but will put the stack values
     /// into the provided `VecDeque`. This is mainly used to merge `ValueGroup`
     /// instances retrieved by the code by `get` calls into the expression
     /// stack.
     pub(crate) fn into_stack(self, stack: &mut VecDeque<Value>, store: &mut Store) {
         for value in &self.values {
             let transferred = self.provide_value(value, store);
             stack.push_back(transferred);
+        }
+    }
     fn provide_value(&self, value: &Value, to_store: &mut Store) -> Value {
         if let Some(from_heap_pos) = value.get_heap_pos() {
             let from_heap_pos = from_heap_pos as usize;
             let to_heap_pos = to_store.alloc_heap();
             let to_heap_pos_usize = to_heap_pos as usize;
             to_store.heap_regions[to_heap_pos_usize].values.reserve(self.regions[from_heap_pos].len());
             for value in &self.regions[from_heap_pos as usize] {
                 let transferred = self.provide_value(value, to_store);
                 to_store.heap_regions[to_heap_pos_usize].values.push(transferred);
+            }
             return match value {
                 Value::Message(_)    => Value::Message(to_heap_pos),
                 Value::String(_)     => Value::String(to_heap_pos),
                 Value::Array(_)      => Value::Array(to_heap_pos),
                 Value::Tuple(_)      => Value::Tuple(to_heap_pos),
                 Value::Union(tag, _) => Value::Union(*tag, to_heap_pos),
                 Value::Struct(_)     => Value::Struct(to_heap_pos),
                 _ => unreachable!(),
             };
         } else {
             return value.clone();
+        }
+    }
+}
 impl Default for ValueGroup {
     /// Returns an empty ValueGroup
     fn default() -> Self {
         Self { values: Vec::new(), regions: Vec::new() }
+    }
+}
 enum ValueKind { Message, String, Array }
 pub(crate) fn apply_assignment_operator(store: &mut Store, lhs: ValueId, op: AssignmentOperator, rhs: Value) {
     use AssignmentOperator as AO;
     macro_rules! apply_int_op {
         ($lhs:ident, $assignment_tokens:tt, $operator:ident, $rhs:ident) => {
             match $lhs {
                 Value::UInt8(v)  => { *v $assignment_tokens $rhs.as_uint8();  },
                 Value::UInt16(v) => { *v $assignment_tokens $rhs.as_uint16(); },
                 Value::UInt32(v) => { *v $assignment_tokens $rhs.as_uint32(); },
                 Value::UInt64(v) => { *v $assignment_tokens $rhs.as_uint64(); },
                 Value::SInt8(v)  => { *v $assignment_tokens $rhs.as_sint8();  },
                 Value::SInt16(v) => { *v $assignment_tokens $rhs.as_sint16(); },
                 Value::SInt32(v) => { *v $assignment_tokens $rhs.as_sint32(); },
                 Value::SInt64(v) => { *v $assignment_tokens $rhs.as_sint64(); },
                 _ => unreachable!("apply_assignment_operator {:?} on lhs {:?} and rhs {:?}", $operator, $lhs, $rhs),
+            }
+        }
+    }
     let lhs = store.read_mut_ref(lhs);
     let mut to_dealloc = None;
     match op {
         AO::Set => {
             match lhs {
                 Value::Unassigned => { *lhs = rhs; },
                 Value::Input(v)  => { *v = rhs.as_input(); },
                 Value::Output(v) => { *v = rhs.as_output(); },
                 Value::Message(v)  => { to_dealloc = Some(*v); *v = rhs.as_message(); },
                 Value::Bool(v)    => { *v = rhs.as_bool(); },
                 Value::Char(v) => { *v = rhs.as_char(); },
                 Value::String(v) => { *v = rhs.as_string().clone(); },
                 Value::UInt8(v) => { *v = rhs.as_uint8(); },
                 Value::UInt16(v) => { *v = rhs.as_uint16(); },
                 Value::UInt32(v) => { *v = rhs.as_uint32(); },
                 Value::UInt64(v) => { *v = rhs.as_uint64(); },
                 Value::SInt8(v) => { *v = rhs.as_sint8(); },
                 Value::SInt16(v) => { *v = rhs.as_sint16(); },
                 Value::SInt32(v) => { *v = rhs.as_sint32(); },
                 Value::SInt64(v) => { *v = rhs.as_sint64(); },
                 Value::Array(v) => { to_dealloc = Some(*v); *v = rhs.as_array(); },
                 Value::Tuple(v) => { to_dealloc = Some(*v); *v = rhs.as_tuple(); },
                 Value::Enum(v) => { *v = rhs.as_enum(); },
                 Value::Union(lhs_tag, lhs_heap_pos) => {
                     to_dealloc = Some(*lhs_heap_pos);
                     let (rhs_tag, rhs_heap_pos) = rhs.as_union();
                     *lhs_tag = rhs_tag;
                     *lhs_heap_pos = rhs_heap_pos;
+                }
                 Value::Struct(v) => { to_dealloc = Some(*v); *v = rhs.as_struct(); },
                 _ => unreachable!("apply_assignment_operator {:?} on lhs {:?} and rhs {:?}", op, lhs, rhs),
+            }
         },
         AO::Concatenated => {
             let lhs_heap_pos = lhs.get_heap_pos().unwrap() as usize;
             let rhs_heap_pos = rhs.get_heap_pos().unwrap() as usize;
             // To prevent borrowing crap, swap out heap region with a temp empty array
             let mut total = Vec::new();
             std::mem::swap(&mut total, &mut store.heap_regions[lhs_heap_pos].values);
             // Push everything onto the swapped vector
             let rhs_len = store.heap_regions[rhs_heap_pos].values.len();
             total.reserve(rhs_len);
             for value_idx in 0..rhs_len {
                 total.push(store.clone_value(store.heap_regions[rhs_heap_pos].values[value_idx].clone()));
+            }
             // Swap back in place
             std::mem::swap(&mut total, &mut store.heap_regions[lhs_heap_pos].values);
             // We took ownership of the RHS, but we copied it into the LHS, so
             // different form assignment we need to drop the RHS heap pos.
             to_dealloc = Some(rhs_heap_pos as u32);
         },
         AO::Multiplied =>   { apply_int_op!(lhs, *=,  op, rhs) },
         AO::Divided =>      { apply_int_op!(lhs, /=,  op, rhs) },
         AO::Remained =>     { apply_int_op!(lhs, %=,  op, rhs) },
         AO::Added =>        { apply_int_op!(lhs, +=,  op, rhs) },
         AO::Subtracted =>   { apply_int_op!(lhs, -=,  op, rhs) },
         AO::ShiftedLeft =>  { apply_int_op!(lhs, <<=, op, rhs) },
         AO::ShiftedRight => { apply_int_op!(lhs, >>=, op, rhs) },
         AO::BitwiseAnded => { apply_int_op!(lhs, &=,  op, rhs) },
         AO::BitwiseXored => { apply_int_op!(lhs, ^=,  op, rhs) },
         AO::BitwiseOred =>  { apply_int_op!(lhs, |=,  op, rhs) },
+    }
     if let Some(heap_pos) = to_dealloc {
         store.drop_heap_pos(heap_pos);
+    }
+}
 pub(crate) fn apply_binary_operator(store: &mut Store, lhs: &Value, op: BinaryOperator, rhs: &Value) -> Value {
     use BinaryOperator as BO;
     macro_rules! apply_int_op_and_return_self {
         ($lhs:ident, $operator_tokens:tt, $operator:ident, $rhs:ident) => {
             return match $lhs {
                 Value::UInt8(v)  => { Value::UInt8( *v $operator_tokens $rhs.as_uint8() ) },
                 Value::UInt16(v) => { Value::UInt16(*v $operator_tokens $rhs.as_uint16()) },
                 Value::UInt32(v) => { Value::UInt32(*v $operator_tokens $rhs.as_uint32()) },
                 Value::UInt64(v) => { Value::UInt64(*v $operator_tokens $rhs.as_uint64()) },
                 Value::SInt8(v)  => { Value::SInt8( *v $operator_tokens $rhs.as_sint8() ) },
                 Value::SInt16(v) => { Value::SInt16(*v $operator_tokens $rhs.as_sint16()) },
                 Value::SInt32(v) => { Value::SInt32(*v $operator_tokens $rhs.as_sint32()) },
                 Value::SInt64(v) => { Value::SInt64(*v $operator_tokens $rhs.as_sint64()) },
                 _ => unreachable!("apply_binary_operator {:?} on lhs {:?} and rhs {:?}", $operator, $lhs, $rhs)
             };
+        }
+    }
     macro_rules! apply_int_op_and_return_bool {
         ($lhs:ident, $operator_tokens:tt, $operator:ident, $rhs:ident) => {
             return match $lhs {
                 Value::UInt8(v)  => { Value::Bool(*v $operator_tokens $rhs.as_uint8() ) },
                 Value::UInt16(v) => { Value::Bool(*v $operator_tokens $rhs.as_uint16()) },
                 Value::UInt32(v) => { Value::Bool(*v $operator_tokens $rhs.as_uint32()) },
                 Value::UInt64(v) => { Value::Bool(*v $operator_tokens $rhs.as_uint64()) },
                 Value::SInt8(v)  => { Value::Bool(*v $operator_tokens $rhs.as_sint8() ) },
                 Value::SInt16(v) => { Value::Bool(*v $operator_tokens $rhs.as_sint16()) },
                 Value::SInt32(v) => { Value::Bool(*v $operator_tokens $rhs.as_sint32()) },
                 Value::SInt64(v) => { Value::Bool(*v $operator_tokens $rhs.as_sint64()) },
                 _ => unreachable!("apply_binary_operator {:?} on lhs {:?} and rhs {:?}", $operator, $lhs, $rhs)
             };
+        }
+    }
     // We need to handle concatenate in a special way because it needs the store
     // mutably.
     if op == BO::Concatenate {
         let target_heap_pos = store.alloc_heap();
         let lhs_heap_pos;
         let rhs_heap_pos;
         let lhs = store.maybe_read_ref(lhs);
         let rhs = store.maybe_read_ref(rhs);
         let value_kind;
         match lhs {
             Value::Message(lhs_pos) => {
                 lhs_heap_pos = *lhs_pos;
                 rhs_heap_pos = rhs.as_message();
                 value_kind = ValueKind::Message;
             },
             Value::String(lhs_pos) => {
                 lhs_heap_pos = *lhs_pos;
                 rhs_heap_pos = rhs.as_string();
                 value_kind = ValueKind::String;
             },
             Value::Array(lhs_pos) => {
                 lhs_heap_pos = *lhs_pos;
                 rhs_heap_pos = rhs.as_array();
                 value_kind = ValueKind::Array;
             },
             _ => unreachable!("apply_binary_operator {:?} on lhs {:?} and rhs {:?}", op, lhs, rhs)
+        }
         let lhs_heap_pos = lhs_heap_pos as usize;
         let rhs_heap_pos = rhs_heap_pos as usize;
         let mut concatenated = Vec::new();
         let lhs_len = store.heap_regions[lhs_heap_pos].values.len();
         let rhs_len = store.heap_regions[rhs_heap_pos].values.len();
         concatenated.reserve(lhs_len + rhs_len);
         for idx in 0..lhs_len {
             concatenated.push(store.clone_value(store.heap_regions[lhs_heap_pos].values[idx].clone()));
+        }
         for idx in 0..rhs_len {
             concatenated.push(store.clone_value(store.heap_regions[rhs_heap_pos].values[idx].clone()));
+        }
         store.heap_regions[target_heap_pos as usize].values = concatenated;
         return match value_kind{
             ValueKind::Message => Value::Message(target_heap_pos),
             ValueKind::String => Value::String(target_heap_pos),
             ValueKind::Array => Value::Array(target_heap_pos),
         };
+    }
     // If any of the values are references, retrieve the thing they're referring
     // to.
     let lhs = store.maybe_read_ref(lhs);
     let rhs = store.maybe_read_ref(rhs);
     match op {
         BO::Concatenate => unreachable!(),
         BO::LogicalOr => {
             return Value::Bool(lhs.as_bool() || rhs.as_bool());
         },
         BO::LogicalAnd => {
             return Value::Bool(lhs.as_bool() && rhs.as_bool());
         },
         BO::BitwiseOr        => { apply_int_op_and_return_self!(lhs, |,  op, rhs); },
         BO::BitwiseXor       => { apply_int_op_and_return_self!(lhs, ^,  op, rhs); },
         BO::BitwiseAnd       => { apply_int_op_and_return_self!(lhs, &,  op, rhs); },
         BO::Equality         => { Value::Bool(apply_equality_operator(store, lhs, rhs)) },
         BO::Inequality       => { Value::Bool(apply_inequality_operator(store, lhs, rhs)) },
         BO::LessThan         => { apply_int_op_and_return_bool!(lhs, <,  op, rhs); },
         BO::GreaterThan      => { apply_int_op_and_return_bool!(lhs, >,  op, rhs); },
         BO::LessThanEqual    => { apply_int_op_and_return_bool!(lhs, <=, op, rhs); },
         BO::GreaterThanEqual => { apply_int_op_and_return_bool!(lhs, >=, op, rhs); },
         BO::ShiftLeft        => { apply_int_op_and_return_self!(lhs, <<, op, rhs); },
         BO::ShiftRight       => { apply_int_op_and_return_self!(lhs, >>, op, rhs); },
         BO::Add              => { apply_int_op_and_return_self!(lhs, +,  op, rhs); },
         BO::Subtract         => { apply_int_op_and_return_self!(lhs, -,  op, rhs); },
         BO::Multiply         => { apply_int_op_and_return_self!(lhs, *,  op, rhs); },
         BO::Divide           => { apply_int_op_and_return_self!(lhs, /,  op, rhs); },
         BO::Remainder        => { apply_int_op_and_return_self!(lhs, %,  op, rhs); }
+    }
+}
 pub(crate) fn apply_unary_operator(store: &mut Store, op: UnaryOperator, value: &Value) -> Value {
     use UnaryOperator as UO;
     macro_rules! apply_int_expr_and_return {
         ($value:ident, $apply:tt, $op:ident) => {
             return match $value {
                 Value::UInt8(v)  => Value::UInt8($apply *v),
                 Value::UInt16(v) => Value::UInt16($apply *v),
                 Value::UInt32(v) => Value::UInt32($apply *v),
                 Value::UInt64(v) => Value::UInt64($apply *v),
                 Value::SInt8(v)  => Value::SInt8($apply *v),
                 Value::SInt16(v) => Value::SInt16($apply *v),
                 Value::SInt32(v) => Value::SInt32($apply *v),
                 Value::SInt64(v) => Value::SInt64($apply *v),
                 _ => unreachable!("apply_unary_operator {:?} on value {:?}", $op, $value),
-            };
+            }
+        }
+    }
     // If the value is a reference, retrieve the thing it is referring to
     let value = store.maybe_read_ref(value);
     match op {
         UO::Positive => {
             debug_assert!(value.is_integer());
             return value.clone();
         },
         UO::Negative => {
             // TODO: Error on negating unsigned integers
             return match value {
                 Value::SInt8(v) => Value::SInt8(-*v),
                 Value::SInt16(v) => Value::SInt16(-*v),
                 Value::SInt32(v) => Value::SInt32(-*v),
                 Value::SInt64(v) => Value::SInt64(-*v),
                 _ => unreachable!("apply_unary_operator {:?} on value {:?}", op, value),
+            }
         },
         UO::BitwiseNot => { apply_int_expr_and_return!(value, !, op)},
+        UO::BitwiseNot => { apply_int_expr_and_return!(value, !, op); },
         UO::LogicalNot => { return Value::Bool(!value.as_bool()); },
+    }
+}
 pub(crate) fn apply_casting(store: &mut Store, output_type: &ConcreteType, subject: &Value) -> Result<Value, String> {
     // To simplify the casting logic: if the output type is not a simple
     // integer/boolean/character, then the type checker made sure that the two
     // types must be equal, hence we can do a simple clone.
     use ConcreteTypePart as CTP;
     let part = &output_type.parts[0];
     match part {
         CTP::Bool | CTP::Character |
         CTP::UInt8 | CTP::UInt16 | CTP::UInt32 | CTP::UInt64 |
         CTP::SInt8 | CTP::SInt16 | CTP::SInt32 | CTP::SInt64 => {
             // Do the checking of these below
             debug_assert_eq!(output_type.parts.len(), 1);
         },
         _ => {
             return Ok(store.clone_value(subject.clone()));
         },
+    }
     // Note: character is not included, needs per-type checking
     macro_rules! unchecked_cast {
         ($input: expr, $output_part: expr) => {
             return Ok(match $output_part {
                 CTP::UInt8 => Value::UInt8($input as u8),
                 CTP::UInt16 => Value::UInt16($input as u16),
                 CTP::UInt32 => Value::UInt32($input as u32),
                 CTP::UInt64 => Value::UInt64($input as u64),
                 CTP::SInt8 => Value::SInt8($input as i8),
                 CTP::SInt16 => Value::SInt16($input as i16),
                 CTP::SInt32 => Value::SInt32($input as i32),
                 CTP::SInt64 => Value::SInt64($input as i64),
                 _ => unreachable!()
             })
+        }
+    }
     macro_rules! from_unsigned_cast {
         ($input:expr, $input_type:ty, $output_part:expr) => {
+            {
                 let target_type_name = match $output_part {
                     CTP::Bool => return Ok(Value::Bool($input != 0)),
                     CTP::Character => if $input <= u8::MAX as $input_type {
                         return Ok(Value::Char(($input as u8) as char))
                     } else {
                         KW_TYPE_CHAR_STR
                     },
                     CTP::UInt8 => if $input <= u8::MAX as $input_type {
                         return Ok(Value::UInt8($input as u8))
                     } else {
                         KW_TYPE_UINT8_STR
                     },
                     CTP::UInt16 => if $input <= u16::MAX as $input_type {
                         return Ok(Value::UInt16($input as u16))
                     } else {
                         KW_TYPE_UINT16_STR
                     },
                     CTP::UInt32 => if $input <= u32::MAX as $input_type {
                         return Ok(Value::UInt32($input as u32))
                     } else {
                         KW_TYPE_UINT32_STR
                     },
                     CTP::UInt64 => return Ok(Value::UInt64($input as u64)), // any unsigned int to u64 is fine
                     CTP::SInt8 => if $input <= i8::MAX as $input_type {
                         return Ok(Value::SInt8($input as i8))
                     } else {
                         KW_TYPE_SINT8_STR
                     },
                     CTP::SInt16 => if $input <= i16::MAX as $input_type {
                         return Ok(Value::SInt16($input as i16))
                     } else {
                         KW_TYPE_SINT16_STR
                     },
                     CTP::SInt32 => if $input <= i32::MAX as $input_type {
                         return Ok(Value::SInt32($input as i32))
                     } else {
                         KW_TYPE_SINT32_STR
                     },
                     CTP::SInt64 => if $input <= i64::MAX as $input_type {
                         return Ok(Value::SInt64($input as i64))
                     } else {
                         KW_TYPE_SINT64_STR
                     },
                     _ => unreachable!(),
                 };
                 return Err(format!("value is '{}' which doesn't fit in a type '{}'", $input, target_type_name));
+            }
+        }
+    }
     macro_rules! from_signed_cast {
         // Programmer note: for signed checking we cannot do
         //  output_type::MAX as input_type,
         //
         // because if the output type's width is larger than the input type,
         // then the cast results in a negative number. So we mask with the
         // maximum possible value the input type can become. As in:
         //  (output_type::MAX as input_type) & input_type::MAX
         //
         // This way:
         // 1. output width is larger than input width: fine in all cases, we
         //  simply compare against the max input value, which is always true.
         // 2. output width is equal to input width: by masking we "remove the
         //  signed bit from the unsigned number" and again compare against the
         //  maximum input value.
         // 3. output width is smaller than the input width: masking does nothing
         //  because the signed bit is never set, and we simply compare against
         //  the maximum possible output value.
         //
         // A similar kind of mechanism for the minimum value, but here we do
         // a binary OR. We do a:
         //  (output_type::MIN as input_type) & input_type::MIN
         //
         // This way:
         // 1. output width is larger than input width: initial cast truncates to
         //  0, then we OR with the actual minimum value, so we attain the
         //  minimum value of the input type.
         // 2. output width is equal to input width: we OR the minimum value with
         //  itself.
         // 3. output width is smaller than input width: the cast produces the
         //  min value of the output type, the subsequent OR does nothing, as it
         //  essentially just sets the signed bit (which must already be set,
         //  since we're dealing with a signed minimum value)
         //
         // After all of this expanding, we simply hope the compiler does a best
         // effort constant expression evaluation, and presto!
         ($input:expr, $input_type:ty, $output_type:expr) => {
+            {
                 let target_type_name = match $output_type {
                     CTP::Bool => return Ok(Value::Bool($input != 0)),
                     CTP::Character => if $input >= 0 && $input <= (u8::max as $input_type & <$input_type>::MAX) {
                         return Ok(Value::Char(($input as u8) as char))
                     } else {
                         KW_TYPE_CHAR_STR
                     },
                     CTP::UInt8 => if $input >= 0 && $input <= ((u8::MAX as $input_type) & <$input_type>::MAX) {
                         return Ok(Value::UInt8($input as u8));
                     } else {
                         KW_TYPE_UINT8_STR
                     },
                     CTP::UInt16 => if $input >= 0 && $input <= ((u16::MAX as $input_type) & <$input_type>::MAX) {
                         return Ok(Value::UInt16($input as u16));
                     } else {
                         KW_TYPE_UINT16_STR
                     },
                     CTP::UInt32 => if $input >= 0 && $input <= ((u32::MAX as $input_type) & <$input_type>::MAX) {
                         return Ok(Value::UInt32($input as u32));
                     } else {
                         KW_TYPE_UINT32_STR
                     },
                     CTP::UInt64 => if $input >= 0 && $input <= ((u64::MAX as $input_type) & <$input_type>::MAX) {
                         return Ok(Value::UInt64($input as u64));
                     } else {
                         KW_TYPE_UINT64_STR
                     },
                     CTP::SInt8 => if $input >= ((i8::MIN as $input_type) | <$input_type>::MIN) && $input <= ((i8::MAX as $input_type) & <$input_type>::MAX) {
                         return Ok(Value::SInt8($input as i8));
                     } else {
                         KW_TYPE_SINT8_STR
                     },
                     CTP::SInt16 => if $input >= ((i16::MIN as $input_type | <$input_type>::MIN)) && $input <= ((i16::MAX as $input_type) & <$input_type>::MAX) {
                         return Ok(Value::SInt16($input as i16));
                     } else {
                         KW_TYPE_SINT16_STR
                     },
                     CTP::SInt32 => if $input >= ((i32::MIN as $input_type | <$input_type>::MIN)) && $input <= ((i32::MAX as $input_type) & <$input_type>::MAX) {
                         return Ok(Value::SInt32($input as i32));
                     } else {
                         KW_TYPE_SINT32_STR
                     },
                     CTP::SInt64 => return Ok(Value::SInt64($input as i64)),
                     _ => unreachable!(),
                 };
                 return Err(format!("value is '{}' which doesn't fit in a type '{}'", $input, target_type_name));
+            }
+        }
+    }
     // If here, then the types might still be equal, but at least we're dealing
     // with a simple integer/boolean/character input and output type.
     let subject = store.maybe_read_ref(subject);
     match subject {
         Value::Bool(val) => {
             match part {
                 CTP::Bool => return Ok(Value::Bool(*val)),
                 CTP::Character => return Ok(Value::Char(1 as char)),
                 _ => unchecked_cast!(*val, part),
+            }
         },
         Value::Char(val) => {
             match part {
                 CTP::Bool => return Ok(Value::Bool(*val != 0 as char)),
                 CTP::Character => return Ok(Value::Char(*val)),
                 _ => unchecked_cast!(*val, part),
+            }
         },
         Value::UInt8(val) => from_unsigned_cast!(*val, u8, part),
         Value::UInt16(val) => from_unsigned_cast!(*val, u16, part),
         Value::UInt32(val) => from_unsigned_cast!(*val, u32, part),
         Value::UInt64(val) => from_unsigned_cast!(*val, u64, part),
         Value::SInt8(val) => from_signed_cast!(*val, i8, part),
         Value::SInt16(val) => from_signed_cast!(*val, i16, part),
         Value::SInt32(val) => from_signed_cast!(*val, i32, part),
         Value::SInt64(val) => from_signed_cast!(*val, i64, part),
         _ => unreachable!("mismatch between 'cast' type checking and 'cast' evaluation"),
+    }
+}
 /// Recursively checks for equality.
 pub(crate) fn apply_equality_operator(store: &Store, lhs: &Value, rhs: &Value) -> bool {
     let lhs = store.maybe_read_ref(lhs);
     let rhs = store.maybe_read_ref(rhs);
     fn eval_equality_heap(store: &Store, lhs_pos: HeapPos, rhs_pos: HeapPos) -> bool {
         let lhs_vals = &store.heap_regions[lhs_pos as usize].values;
         let rhs_vals = &store.heap_regions[rhs_pos as usize].values;
         let lhs_len = lhs_vals.len();
         if lhs_len != rhs_vals.len() {
             return false;
+        }
         for idx in 0..lhs_len {
             let lhs_val = &lhs_vals[idx];
             let rhs_val = &rhs_vals[idx];
             if !apply_equality_operator(store, lhs_val, rhs_val) {
                 return false;
+            }
+        }
         return true;
+    }
     match lhs {
         Value::Input(v) => *v == rhs.as_input(),
         Value::Output(v) => *v == rhs.as_output(),
         Value::Message(lhs_pos) => eval_equality_heap(store, *lhs_pos, rhs.as_message()),
         Value::Null => todo!("remove null"),
         Value::Bool(v) => *v == rhs.as_bool(),
         Value::Char(v) => *v == rhs.as_char(),
         Value::String(lhs_pos) => eval_equality_heap(store, *lhs_pos, rhs.as_string()),
         Value::UInt8(v) => *v == rhs.as_uint8(),
         Value::UInt16(v) => *v == rhs.as_uint16(),
         Value::UInt32(v) => *v == rhs.as_uint32(),
         Value::UInt64(v) => *v == rhs.as_uint64(),
         Value::SInt8(v) => *v == rhs.as_sint8(),
         Value::SInt16(v) => *v == rhs.as_sint16(),
         Value::SInt32(v) => *v == rhs.as_sint32(),
         Value::SInt64(v) => *v == rhs.as_sint64(),
         Value::Array(lhs_pos) => eval_equality_heap(store, *lhs_pos, rhs.as_array()),
         Value::Tuple(lhs_pos) => eval_equality_heap(store, *lhs_pos, rhs.as_tuple()),
         Value::Enum(v) => *v == rhs.as_enum(),
         Value::Union(lhs_tag, lhs_pos) => {
             let (rhs_tag, rhs_pos) = rhs.as_union();
             if *lhs_tag != rhs_tag {
                 return false;
+            }
             eval_equality_heap(store, *lhs_pos, rhs_pos)
         },
         Value::Struct(lhs_pos) => eval_equality_heap(store, *lhs_pos, rhs.as_struct()),
         _ => unreachable!("apply_equality_operator to lhs {:?}", lhs),
+    }
+}
 /// Recursively checks for inequality
 pub(crate) fn apply_inequality_operator(store: &Store, lhs: &Value, rhs: &Value) -> bool {
     let lhs = store.maybe_read_ref(lhs);
     let rhs = store.maybe_read_ref(rhs);
     fn eval_inequality_heap(store: &Store, lhs_pos: HeapPos, rhs_pos: HeapPos) -> bool {
         let lhs_vals = &store.heap_regions[lhs_pos as usize].values;
         let rhs_vals = &store.heap_regions[rhs_pos as usize].values;
         let lhs_len = lhs_vals.len();
         if lhs_len != rhs_vals.len() {
             return true;
+        }
         for idx in 0..lhs_len {
             let lhs_val = &lhs_vals[idx];
             let rhs_val = &rhs_vals[idx];
             if apply_inequality_operator(store, lhs_val, rhs_val) {
                 return true;
+            }
+        }
         return false;
+    }
     match lhs {
         Value::Input(v) => *v != rhs.as_input(),
         Value::Output(v) => *v != rhs.as_output(),
         Value::Message(lhs_pos) => eval_inequality_heap(store, *lhs_pos, rhs.as_message()),
         Value::Null => todo!("remove null"),
         Value::Bool(v) => *v != rhs.as_bool(),
         Value::Char(v) => *v != rhs.as_char(),
         Value::String(lhs_pos) => eval_inequality_heap(store, *lhs_pos, rhs.as_string()),
         Value::UInt8(v) => *v != rhs.as_uint8(),
         Value::UInt16(v) => *v != rhs.as_uint16(),
         Value::UInt32(v) => *v != rhs.as_uint32(),
         Value::UInt64(v) => *v != rhs.as_uint64(),
         Value::SInt8(v) => *v != rhs.as_sint8(),
         Value::SInt16(v) => *v != rhs.as_sint16(),
         Value::SInt32(v) => *v != rhs.as_sint32(),
         Value::SInt64(v) => *v != rhs.as_sint64(),
         Value::Array(lhs_pos) => eval_inequality_heap(store, *lhs_pos, rhs.as_array()),
         Value::Tuple(lhs_pos) => eval_inequality_heap(store, *lhs_pos, rhs.as_tuple()),
         Value::Enum(v) => *v != rhs.as_enum(),
         Value::Union(lhs_tag, lhs_pos) => {
             let (rhs_tag, rhs_pos) = rhs.as_union();
             if *lhs_tag != rhs_tag {
                 return true;
+            }
             eval_inequality_heap(store, *lhs_pos, rhs_pos)
         },
         Value::Struct(lhs_pos) => eval_inequality_heap(store, *lhs_pos, rhs.as_struct()),
         _ => unreachable!("apply_inequality_operator to lhs {:?}", lhs)
+    }
+}
 /// Recursively applies binding operator. Essentially an equality operator with
 /// special handling if the LHS contains a binding reference to a stack
 /// stack variable.
 // Note: that there is a lot of `Value.clone()` going on here. As always: this
 // is potentially cloning the references to heap values, not actually cloning
 // those heap regions into a new heap region.
 pub(crate) fn apply_binding_operator(store: &mut Store, lhs: Value, rhs: Value) -> bool {
     let lhs = store.maybe_read_ref(&lhs).clone();
     let rhs = store.maybe_read_ref(&rhs).clone();
     fn eval_binding_heap(store: &mut Store, lhs_pos: HeapPos, rhs_pos: HeapPos) -> bool {
         let lhs_len = store.heap_regions[lhs_pos as usize].values.len();
         let rhs_len = store.heap_regions[rhs_pos as usize].values.len();
         if lhs_len != rhs_len {
             return false;
+        }
         for idx in 0..lhs_len {
             // More rust shenanigans... I'm going to calm myself by saying that
             // this is just a temporary evaluator implementation.
             let lhs_val = store.heap_regions[lhs_pos as usize].values[idx].clone();
             let rhs_val = store.heap_regions[rhs_pos as usize].values[idx].clone();
             if !apply_binding_operator(store, lhs_val, rhs_val) {
                 return false;
+            }
+        }
         return true;
+    }
     match lhs {
         Value::Binding(var_pos) => {
             let to_write = store.clone_value(rhs.clone());
             store.write(ValueId::Stack(var_pos), to_write);
             return true;
         },
         Value::Input(v) => v == rhs.as_input(),
         Value::Output(v) => v == rhs.as_output(),
         Value::Message(lhs_pos) => eval_binding_heap(store, lhs_pos, rhs.as_message()),
         Value::Null => todo!("remove null"),
         Value::Bool(v) => v == rhs.as_bool(),
         Value::Char(v) => v == rhs.as_char(),
         Value::String(lhs_pos) => eval_binding_heap(store, lhs_pos, rhs.as_string()),
         Value::UInt8(v) => v == rhs.as_uint8(),
         Value::UInt16(v) => v == rhs.as_uint16(),
         Value::UInt32(v) => v == rhs.as_uint32(),
         Value::UInt64(v) => v == rhs.as_uint64(),
         Value::SInt8(v) => v == rhs.as_sint8(),
         Value::SInt16(v) => v == rhs.as_sint16(),
         Value::SInt32(v) => v == rhs.as_sint32(),
         Value::SInt64(v) => v == rhs.as_sint64(),
         Value::Array(lhs_pos) => eval_binding_heap(store, lhs_pos, rhs.as_array()),
         Value::Tuple(lhs_pos) => eval_binding_heap(store, lhs_pos, rhs.as_tuple()),
         Value::Enum(v) => v == rhs.as_enum(),
         Value::Union(lhs_tag, lhs_pos) => {
             let (rhs_tag, rhs_pos) = rhs.as_union();
             if lhs_tag != rhs_tag {
                 return false;
+            }
             eval_binding_heap(store, lhs_pos, rhs_pos)
         },
         Value::Struct(lhs_pos) => eval_binding_heap(store, lhs_pos, rhs.as_struct()),
         _ => unreachable!("apply_binding_operator to lhs {:?}", lhs),
+    }
+}
@@ \ No newline at end of file @@

src/protocol/input_source.rs

➞

Show inline comments

 use std::fmt;
 use std::sync::{RwLock, RwLockReadGuard};
 use std::fmt::Write;
 #[derive(Debug, Clone, Copy)]
 pub struct InputPosition {
     pub line: u32,
     pub offset: u32,
+}
 impl InputPosition {
     pub(crate) fn with_offset(&self, offset: u32) -> Self {
         InputPosition { line: self.line, offset: self.offset + offset }
+    }
+}
 #[derive(Debug, Clone, Copy)]
 pub struct InputSpan {
     pub begin: InputPosition,
     pub end: InputPosition,
+}
 impl InputSpan {
     // This will only be used for builtin functions
     // This must only be used if you're sure that the span will not be involved
     // in creating an error message.
     #[inline]
     pub fn new() -> InputSpan {
+    pub const fn new() -> InputSpan {
         InputSpan{ begin: InputPosition{ line: 0, offset: 0 }, end: InputPosition{ line: 0, offset: 0 }}
+    }
     #[inline]
     pub fn from_positions(begin: InputPosition, end: InputPosition) -> Self {
         Self { begin, end }
+    }
+}
 /// Wrapper around source file with optional filename. Ensures that the file is
 /// only scanned once.
 pub struct InputSource {
     pub(crate) filename: String,
     pub(crate) input: Vec<u8>,
     // Iteration
     line: u32,
     offset: usize,
     // State tracking
     pub(crate) had_error: Option<ParseError>,
     // The offset_lookup is built on-demand upon attempting to report an error.
     // Only one procedure will actually create the lookup, afterwards only read
     // locks will be held.
     offset_lookup: RwLock<Vec<u32>>,
+}
 impl InputSource {
     pub fn new(filename: String, input: Vec<u8>) -> Self {
         Self{
             filename,
             input,
             line: 1,
             offset: 0,
             had_error: None,
             offset_lookup: RwLock::new(Vec::new()),
+        }
+    }
     #[inline]
     pub fn pos(&self) -> InputPosition {
         InputPosition { line: self.line, offset: self.offset as u32 }
+    }
     pub fn next(&self) -> Option<u8> {
         if self.offset < self.input.len() {
             Some(self.input[self.offset])
         } else {
             None
+        }
+    }
     pub fn lookahead(&self, offset: usize) -> Option<u8> {
         let offset_pos = self.offset + offset;
         if offset_pos < self.input.len() {
             Some(self.input[offset_pos])
         } else {
             None
+        }
+    }
     #[inline]
     pub fn section_at_pos(&self, start: InputPosition, end: InputPosition) -> &[u8] {
         &self.input[start.offset as usize..end.offset as usize]
+    }
     #[inline]
     pub fn section_at_span(&self, span: InputSpan) -> &[u8] {
         &self.input[span.begin.offset as usize..span.end.offset as usize]
+    }
     // Consumes the next character. Will check well-formedness of newlines: \r
     // must be followed by a \n, because this is used for error reporting. Will
     // not check for ascii-ness of the file, better left to a tokenizer.
     pub fn consume(&mut self) {
         match self.next() {
             Some(b'\r') => {
                 if Some(b'\n') == self.lookahead(1) {
                     // Well formed file
                     self.offset += 1;
                 } else {
                     // Not a well-formed file, pretend like we can continue
                     self.offset += 1;
                     self.set_error("Encountered carriage-feed without a following newline");
+                }
             },
             Some(b'\n') => {
                 self.line += 1;
                 self.offset += 1;
             },
             Some(_) => {
                 self.offset += 1;
+            }
             None => {}
+        }
         // Maybe we actually want to check this in release mode. Then again:
         // a 4 gigabyte source file... Really?
         debug_assert!(self.offset < u32::max_value() as usize);
+    }
     fn set_error(&mut self, msg: &str) {
         if self.had_error.is_none() {
             self.had_error = Some(ParseError::new_error_str_at_pos(self, self.pos(), msg));
+        }
+    }
     fn get_lookup(&self) -> RwLockReadGuard<Vec<u32>> {
         // Once constructed the lookup always contains one element. We use this
         // to see if it is constructed already.
+        {
             let lookup = self.offset_lookup.read().unwrap();
             if !lookup.is_empty() {
                 return lookup;
+            }
+        }
         // Lookup was not constructed yet
         let mut lookup = self.offset_lookup.write().unwrap();
         if !lookup.is_empty() {
             // Somebody created it before we had the chance
             drop(lookup);
             let lookup = self.offset_lookup.read().unwrap();
             return lookup;
+        }
         // Build the line number (!) to offset lookup, so offset by 1. We
         // assume the entire source file is scanned (most common case) for
         // preallocation.
         lookup.reserve(self.line as usize + 2);
         lookup.push(0); // line 0: never used
         lookup.push(0); // first line: first character
         for char_idx in 0..self.input.len() {
             if self.input[char_idx] == b'\n' {
                 lookup.push(char_idx as u32 + 1);
+            }
+        }
         lookup.push(self.input.len() as u32 + 1); // for lookup_line_end, intentionally adding one character
         // Return created lookup
         drop(lookup);
         let lookup = self.offset_lookup.read().unwrap();
         return lookup;
+    }
     /// Retrieves offset at which line starts (right after newline)
     fn lookup_line_start_offset(&self, line_number: u32) -> u32 {
         let lookup = self.get_lookup();
         lookup[line_number as usize]
+    }
     /// Retrieves offset at which line ends (at the newline character or the
     /// preceding carriage feed for \r\n-encoded newlines)
     fn lookup_line_end_offset(&self, line_number: u32) -> u32 {
         let lookup = self.get_lookup();
         let offset = lookup[(line_number + 1) as usize] - 1;
         let offset_usize = offset as usize;
         // Compensate for newlines and a potential carriage feed. Note that the
         // end position is exclusive. So we only need to compensate for a
         // "\r\n"
         if offset_usize > 0 && offset_usize < self.input.len() && self.input[offset_usize] == b'\n' && self.input[offset_usize - 1] == b'\r' {
             offset - 1
         } else {
             offset
+        }
+    }
+}
 #[derive(Debug)]
 pub enum StatementKind {
     Info,
     Error
+}
 #[derive(Debug)]
 pub enum ContextKind {
     SingleLine,
     MultiLine,
+}
 #[derive(Debug)]
 pub struct ErrorStatement {
     pub(crate) statement_kind: StatementKind,
     pub(crate) context_kind: ContextKind,
     pub(crate) start_line: u32,
     pub(crate) start_column: u32,
     pub(crate) end_line: u32,
     pub(crate) end_column: u32,
     pub(crate) filename: String,
     pub(crate) context: String,
     pub(crate) message: String,
+}
 impl ErrorStatement {
     fn from_source_at_pos(statement_kind: StatementKind, source: &InputSource, position: InputPosition, message: String) -> Self {
         // Seek line start and end
         let line_start = source.lookup_line_start_offset(position.line);
         let line_end = source.lookup_line_end_offset(position.line);
         let context = Self::create_context(source, line_start as usize, line_end as usize);
         debug_assert!(position.offset >= line_start);
         let column = position.offset - line_start + 1;
         Self{
             statement_kind,
             context_kind: ContextKind::SingleLine,
             start_line: position.line,
             start_column: column,
             end_line: position.line,
             end_column: column + 1,
             filename: source.filename.clone(),
             context,
             message,
+        }
+    }
     pub(crate) fn from_source_at_span(statement_kind: StatementKind, source: &InputSource, span: InputSpan, message: String) -> Self {
         debug_assert!(span.end.line >= span.begin.line);
         debug_assert!(span.end.offset >= span.begin.offset);
         let first_line_start = source.lookup_line_start_offset(span.begin.line);
         let last_line_start = source.lookup_line_start_offset(span.end.line);
         let last_line_end = source.lookup_line_end_offset(span.end.line);
         let context = Self::create_context(source, first_line_start as usize, last_line_end as usize);
         debug_assert!(span.begin.offset >= first_line_start);
         let start_column = span.begin.offset - first_line_start + 1;
         let end_column = span.end.offset - last_line_start + 1;
         let context_kind = if span.begin.line == span.end.line {
             ContextKind::SingleLine
         } else {
             ContextKind::MultiLine
         };
         Self{
             statement_kind,
             context_kind,
             start_line: span.begin.line,
             start_column,
             end_line: span.end.line,
             end_column,
             filename: source.filename.clone(),
             context,
             message,
+        }
+    }
     /// Produces context from source
     fn create_context(source: &InputSource, start: usize, end: usize) -> String {
         let context_raw = &source.input[start..end];
         String::from_utf8_lossy(context_raw).to_string()
+    }
+}
 impl fmt::Display for ErrorStatement {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         // Write kind of statement and message
         match self.statement_kind {
             StatementKind::Info => f.write_str(" INFO: ")?,
             StatementKind::Error => f.write_str("ERROR: ")?,
+        }
         f.write_str(&self.message)?;
         f.write_char('\n')?;
         // Write originating file/line/column
         f.write_str(" +- ")?;
         if !self.filename.is_empty() {
             write!(f, "in {} ", self.filename)?;
+        }
         match self.context_kind {
             ContextKind::SingleLine => writeln!(f, " at {}:{}", self.start_line, self.start_column),
             ContextKind::MultiLine => writeln!(
                 f, " from {}:{} to {}:{}",
                 self.start_line, self.start_column, self.end_line, self.end_column
+            )
         }?;
         // Helper function for writing context: converting tabs into 4 spaces
         // (oh, the controversy!) and creating an annotated line
         fn transform_context(source: &str, target: &mut String) {
             for char in source.chars() {
                 if char == '\t' {
                     target.push_str("    ");
                 } else {
                     target.push(char);
+                }
+            }
+        }
         fn extend_annotation(first_col: u32, last_col: u32, source: &str, target: &mut String, extend_char: char) {
             debug_assert!(first_col > 0 && last_col > first_col);
             // If the first index exceeds the size of the context then we should
             // have a message placed at the newline character
             let first_idx = first_col as usize - 1;
             let last_idx = last_col as usize - 1;
             if first_idx >= source.len() {
                 // If any of these fail then the logic behind reporting errors
                 // is incorrect.
                 debug_assert_eq!(first_idx, source.len());
                 debug_assert_eq!(first_idx + 1, last_idx);
                 target.push(extend_char);
             } else {
                 for (char_idx, char) in source.chars().enumerate().skip(first_idx) {
                     if char_idx == last_idx as usize {
                         break;
+                    }
                     if char == '\t' {
                         for _ in 0..4 { target.push(extend_char); }
                     } else {
                         target.push(extend_char);
+                    }
+                }
+            }
+        }
         // Write source context
         writeln!(f, " | ")?;
         let mut context = String::with_capacity(128);
         let mut annotation = String::with_capacity(128);
         match self.context_kind {
             ContextKind::SingleLine => {
                 // Write single line of context with indicator for the offending
                 // span underneath.
                 context.push_str(" |  ");
                 transform_context(&self.context, &mut context);
                 context.push('\n');
                 f.write_str(&context)?;
                 annotation.push_str(" | ");
                 extend_annotation(1, self.start_column + 1, &self.context, &mut annotation, ' ');
                 extend_annotation(self.start_column, self.end_column, &self.context, &mut annotation, '~');
                 annotation.push('\n');
                 f.write_str(&annotation)?;
             },
             ContextKind::MultiLine => {
                 // Annotate all offending lines
                 // - first line
                 let mut lines = self.context.lines();
                 let first_line = lines.next().unwrap();
                 transform_context(first_line, &mut context);
                 writeln!(f, " |- {}", &context)?;
                 // - remaining lines
                 let mut last_line = first_line;
                 while let Some(cur_line) = lines.next() {
                     context.clear();
                     transform_context(cur_line, &mut context);
                     writeln!(f, " |  {}", &context)?;
                     last_line = cur_line;
+                }
                 // - underline beneath last line
                 annotation.push_str(" \\__");
                 extend_annotation(1, self.end_column, &last_line, &mut annotation, '_');
                 annotation.push_str("/\n");
                 f.write_str(&annotation)?;
+            }
+        }
         Ok(())
+    }
+}
 #[derive(Debug)]
 pub struct ParseError {
     pub(crate) statements: Vec<ErrorStatement>
+}
 impl fmt::Display for ParseError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         if self.statements.is_empty() {
             return Ok(())
+        }
         self.statements[0].fmt(f)?;
         for statement in self.statements.iter().skip(1) {
             writeln!(f)?;
             statement.fmt(f)?;
+        }
         Ok(())
+    }
+}
 impl ParseError {
     pub fn new_error_at_pos(source: &InputSource, position: InputPosition, message: String) -> Self {
         Self{ statements: vec!(ErrorStatement::from_source_at_pos(
             StatementKind::Error, source, position, message
         )) }
+    }
     pub fn new_error_str_at_pos(source: &InputSource, position: InputPosition, message: &str) -> Self {
         Self{ statements: vec!(ErrorStatement::from_source_at_pos(
             StatementKind::Error, source, position, message.to_string()
         )) }
+    }
     pub fn new_error_at_span(source: &InputSource, span: InputSpan, message: String) -> Self {
         Self{ statements: vec!(ErrorStatement::from_source_at_span(
             StatementKind::Error, source, span, message
         )) }
+    }
     pub fn new_error_str_at_span(source: &InputSource, span: InputSpan, message: &str) -> Self {
         Self{ statements: vec!(ErrorStatement::from_source_at_span(
             StatementKind::Error, source, span, message.to_string()
         )) }
+    }
     pub fn with_at_span(mut self, error_type: StatementKind, source: &InputSource, span: InputSpan, message: String) -> Self {
         self.statements.push(ErrorStatement::from_source_at_span(error_type, source, span, message.to_string()));
         self
+    }
     pub fn with_info_at_span(self, source: &InputSource, span: InputSpan, msg: String) -> Self {
         self.with_at_span(StatementKind::Info, source, span, msg)
+    }
     pub fn with_info_str_at_pos(self, source: &InputSource, pos: InputPosition, msg: &str) -> Self {
         self.with_at_span(
             StatementKind::Info, source,
             InputSpan::from_positions(pos, pos.with_offset(1)),
             msg.to_string()
+        )
+    }
     pub fn with_info_str_at_span(self, source: &InputSource, span: InputSpan, msg: &str) -> Self {
         self.with_at_span(StatementKind::Info, source, span, msg.to_string())
+    }
+}

src/protocol/mod.rs

➞

Show inline comments

 mod arena;
 pub(crate) mod eval;
 pub(crate) mod input_source;
 mod parser;
 #[cfg(test)] mod tests;
 pub(crate) mod ast;
 pub(crate) mod ast_printer;
 use std::sync::Mutex;
 use crate::collections::{StringPool, StringRef};
 use crate::protocol::ast::*;
 use crate::protocol::eval::*;
 use crate::protocol::input_source::*;
 use crate::protocol::parser::*;
 use crate::protocol::type_table::*;
 pub use parser::type_table::TypeId;
 /// A protocol description module
 pub struct Module {
     pub(crate) source: InputSource,
     pub(crate) root_id: RootId,
     pub(crate) name: Option<StringRef<'static>>,
+}
 /// Description of a protocol object, used to configure new connectors.
 #[repr(C)]
 pub struct ProtocolDescription {
     pub(crate) modules: Vec<Module>,
     pub(crate) heap: Heap,
     pub(crate) types: TypeTable,
     pub(crate) pool: Mutex<StringPool>,
+}
 #[derive(Debug, Clone)]
 pub(crate) struct ComponentState {
     pub(crate) prompt: Prompt,
+}
 #[derive(Debug)]
 pub enum ComponentCreationError {
     ModuleDoesntExist,
     DefinitionDoesntExist,
     DefinitionNotComponent,
     InvalidNumArguments,
     InvalidArgumentType(usize),
     UnownedPort,
     InSync,
+}
 impl ProtocolDescription {
     pub fn parse(buffer: &[u8]) -> Result<Self, String> {
         let source = InputSource::new(String::new(), Vec::from(buffer));
         let mut parser = Parser::new();
         parser.feed(source).expect("failed to feed source");
         if let Err(err) = parser.parse() {
             println!("ERROR:\n{}", err);
             return Err(format!("{}", err))
+        }
         debug_assert_eq!(parser.modules.len(), 1, "only supporting one module here for now");
         let modules: Vec<Module> = parser.modules.into_iter()
             .map(|module| Module{
                 source: module.source,
                 root_id: module.root_id,
                 name: module.name.map(|(_, name)| name)
             })
             .collect();
         return Ok(ProtocolDescription {
             modules,
             heap: parser.heap,
             types: parser.type_table,
             pool: Mutex::new(parser.string_pool),
         });
+    }
     pub(crate) fn new_component(
         &self, module_name: &[u8], identifier: &[u8], arguments: ValueGroup
     ) -> Result<Prompt, ComponentCreationError> {
         // Find the module in which the definition can be found
         let module_root = self.lookup_module_root(module_name);
         if module_root.is_none() {
             return Err(ComponentCreationError::ModuleDoesntExist);
+        }
         let module_root = module_root.unwrap();
         let root = &self.heap[module_root];
         let definition_id = root.get_definition_ident(&self.heap, identifier);
         if definition_id.is_none() {
             return Err(ComponentCreationError::DefinitionDoesntExist);
+        }
         let definition_id = definition_id.unwrap();
         let ast_definition = &self.heap[definition_id];
-        if !ast_definition.is_component() {
+        if !ast_definition.is_procedure() {
             return Err(ComponentCreationError::DefinitionNotComponent);
+        }
         // Make sure that the types of the provided value group matches that of
         // the expected types.
         let ast_definition = ast_definition.as_component();
         if !ast_definition.poly_vars.is_empty() {
         let ast_definition = ast_definition.as_procedure();
         if !ast_definition.poly_vars.is_empty() || ast_definition.kind == ProcedureKind::Function {
             return Err(ComponentCreationError::DefinitionNotComponent);
+        }
         // - check number of arguments by retrieving the one instantiated
         //   monomorph
         let concrete_type = ConcreteType{ parts: vec![ConcreteTypePart::Component(definition_id, 0)] };
         let mono_index = self.types.get_procedure_monomorph_index(&definition_id, &concrete_type.parts).unwrap();
         let mono_type = self.types.get_procedure_monomorph(mono_index);
         if mono_type.arg_types.len() != arguments.values.len() {
         let concrete_type = ConcreteType{ parts: vec![ConcreteTypePart::Component(ast_definition.this, 0)] };
         let procedure_type_id = self.types.get_procedure_monomorph_type_id(&definition_id, &concrete_type.parts).unwrap();
         let procedure_monomorph_index = self.types.get_monomorph(procedure_type_id).variant.as_procedure().monomorph_index;
         let monomorph_info = &ast_definition.monomorphs[procedure_monomorph_index as usize];
         if monomorph_info.argument_types.len() != arguments.values.len() {
             return Err(ComponentCreationError::InvalidNumArguments);
+        }
         // - for each argument try to make sure the types match
         for arg_idx in 0..arguments.values.len() {
             let expected_type = &mono_type.arg_types[arg_idx];
             let expected_type_id = monomorph_info.argument_types[arg_idx];
             let expected_type = &self.types.get_monomorph(expected_type_id).concrete_type;
             let provided_value = &arguments.values[arg_idx];
             if !self.verify_same_type(expected_type, 0, &arguments, provided_value) {
                 return Err(ComponentCreationError::InvalidArgumentType(arg_idx));
+            }
+        }
         // By now we're sure that all of the arguments are correct. So create
         // the connector.
-        return Ok(Prompt::new(&self.types, &self.heap, definition_id, mono_index, arguments));
+        return Ok(Prompt::new(&self.types, &self.heap, ast_definition.this, procedure_type_id, arguments));
+    }
     fn lookup_module_root(&self, module_name: &[u8]) -> Option<RootId> {
         for module in self.modules.iter() {
             match &module.name {
                 Some(name) => if name.as_bytes() == module_name {
                     return Some(module.root_id);
                 },
                 None => if module_name.is_empty() {
                     return Some(module.root_id);
+                }
+            }
+        }
         return None;
+    }
     fn verify_same_type(&self, expected: &ConcreteType, expected_idx: usize, arguments: &ValueGroup, argument: &Value) -> bool {
         use ConcreteTypePart as CTP;
         match &expected.parts[expected_idx] {
             CTP::Void | CTP::Message | CTP::Slice | CTP::Function(_, _) | CTP::Component(_, _) => unreachable!(),
+            CTP::Void | CTP::Message | CTP::Slice | CTP::Pointer | CTP::Function(_, _) | CTP::Component(_, _) => unreachable!(),
             CTP::Bool => if let Value::Bool(_) = argument { true } else { false },
             CTP::UInt8 => if let Value::UInt8(_) = argument { true } else { false },
             CTP::UInt16 => if let Value::UInt16(_) = argument { true } else { false },
             CTP::UInt32 => if let Value::UInt32(_) = argument { true } else { false },
             CTP::UInt64 => if let Value::UInt64(_) = argument { true } else { false },
             CTP::SInt8 => if let Value::SInt8(_) = argument { true } else { false },
             CTP::SInt16 => if let Value::SInt16(_) = argument { true } else { false },
             CTP::SInt32 => if let Value::SInt32(_) = argument { true } else { false },
             CTP::SInt64 => if let Value::SInt64(_) = argument { true } else { false },
             CTP::Character => if let Value::Char(_) = argument { true } else { false },
             CTP::String => {
                 // Match outer string type and embedded character types
                 if let Value::String(heap_pos) = argument {
                     for element in &arguments.regions[*heap_pos as usize] {
                         if let Value::Char(_) = element {} else {
                             return false;
+                        }
+                    }
                 } else {
                     return false;
+                }
                 return true;
             },
             CTP::Array => {
                 if let Value::Array(heap_pos) = argument {
                     let heap_pos = *heap_pos;
                     for element in &arguments.regions[heap_pos as usize] {
                         if !self.verify_same_type(expected, expected_idx + 1, arguments, element) {
                             return false;
+                        }
+                    }
                     return true;
                 } else {
                     return false;
+                }
             },
             CTP::Input => if let Value::Input(_) = argument { true } else { false },
             CTP::Output => if let Value::Output(_) = argument { true } else { false },
             CTP::Tuple(_) => todo!("implement full type checking on user-supplied arguments"),
             CTP::Instance(definition_id, _num_embedded) => {
                 let definition = self.types.get_base_definition(definition_id).unwrap();
                 match &definition.definition {
                     DefinedTypeVariant::Enum(definition) => {
                         if let Value::Enum(variant_value) = argument {
                             let is_valid = definition.variants.iter()
                                 .any(|v| v.value == *variant_value);
                             return is_valid;
+                        }
                     },
                     _ => todo!("implement full type checking on user-supplied arguments"),
+                }
                 return false;
             },
+        }
+    }
+}
 pub trait RunContext {
     fn performed_put(&mut self, port: PortId) -> bool;
     fn performed_get(&mut self, port: PortId) -> Option<ValueGroup>; // None if still waiting on message
     fn fires(&mut self, port: PortId) -> Option<Value>; // None if not yet branched
     fn performed_fork(&mut self) -> Option<bool>; // None if not yet forked
     fn created_channel(&mut self) -> Option<(Value, Value)>; // None if not yet prepared
     fn performed_select_wait(&mut self) -> Option<u32>; // None if not yet notified runtime of select blocker
+}
 pub struct ProtocolDescriptionBuilder {
     parser: Parser,
+}
 impl ProtocolDescriptionBuilder {
     pub fn new() -> Self {
         return Self{
             parser: Parser::new(),
+        }
+    }
     pub fn add(&mut self, filename: String, buffer: Vec<u8>) -> Result<(), ParseError> {
         let input = InputSource::new(filename, buffer);
         self.parser.feed(input)?;
         return Ok(())
+    }
     pub fn compile(mut self) -> Result<ProtocolDescription, ParseError> {
         self.parser.parse()?;
         let modules: Vec<Module> = self.parser.modules.into_iter()
             .map(|module| Module{
                 source: module.source,
                 root_id: module.root_id,
                 name: module.name.map(|(_, name)| name)
             })
             .collect();
         return Ok(ProtocolDescription {
             modules,
             heap: self.parser.heap,
             types: self.parser.type_table,
             pool: Mutex::new(self.parser.string_pool),
         });
+    }
+}

src/protocol/parser/mod.rs

➞

Show inline comments

 #[macro_use] mod visitor;
 pub(crate) mod symbol_table;
 pub(crate) mod type_table;
 pub(crate) mod tokens;
 pub(crate) mod token_parsing;
 pub(crate) mod pass_tokenizer;
 pub(crate) mod pass_symbols;
 pub(crate) mod pass_imports;
 pub(crate) mod pass_definitions;
 pub(crate) mod pass_definitions_types;
 pub(crate) mod pass_validation_linking;
 pub(crate) mod pass_rewriting;
 pub(crate) mod pass_typing;
-mod visitor;
+pub(crate) mod pass_stack_size;
 use tokens::*;
 use crate::collections::*;
 use visitor::Visitor;
 use pass_tokenizer::PassTokenizer;
 use pass_symbols::PassSymbols;
 use pass_imports::PassImport;
 use pass_definitions::PassDefinitions;
 use pass_validation_linking::PassValidationLinking;
 use pass_typing::{PassTyping, ResolveQueue};
 use pass_rewriting::PassRewriting;
 use pass_stack_size::PassStackSize;
 use symbol_table::*;
-use type_table::TypeTable;
+use type_table::*;
 use crate::protocol::ast::*;
 use crate::protocol::input_source::*;
 use crate::protocol::ast_printer::ASTWriter;
 use crate::protocol::parser::type_table::PolymorphicVariable;
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub enum ModuleCompilationPhase {
     Tokenized,              // source is tokenized
     SymbolsScanned,         // all definitions are linked to their type class
     ImportsResolved,        // all imports are added to the symbol table
     DefinitionsParsed,      // produced the AST for the entire module
     TypesAddedToTable,      // added all definitions to the type table
     ValidatedAndLinked,     // AST is traversed and has linked the required AST nodes
     Typed,                  // Type inference and checking has been performed
     Rewritten,              // Special AST nodes are rewritten into regular AST nodes
     // When we continue with the compiler:
-    // Typed,                  // Type inference and checking has been performed
+    // StackSize
+}
 pub struct Module {
     // Buffers
     pub source: InputSource,
     pub tokens: TokenBuffer,
     // Identifiers
     pub root_id: RootId,
     pub name: Option<(PragmaId, StringRef<'static>)>,
     pub version: Option<(PragmaId, i64)>,
     pub phase: ModuleCompilationPhase,
+}
 // TODO: This is kind of wrong. Because when we're producing bytecode we would
 //       like the bytecode itself to not have the notion of the size of a pointer
 //       type. But until I figure out what we do want I'll just set everything
 //       to a 64-bit architecture.
 pub struct TargetArch {
     pub array_size_alignment: (usize, usize),
     pub slice_size_alignment: (usize, usize),
     pub string_size_alignment: (usize, usize),
     pub port_size_alignment: (usize, usize),
     pub pointer_size_alignment: (usize, usize),
     pub void_type_id: TypeId,
     pub message_type_id: TypeId,
     pub bool_type_id: TypeId,
     pub uint8_type_id: TypeId,
     pub uint16_type_id: TypeId,
     pub uint32_type_id: TypeId,
     pub uint64_type_id: TypeId,
     pub sint8_type_id: TypeId,
     pub sint16_type_id: TypeId,
     pub sint32_type_id: TypeId,
     pub sint64_type_id: TypeId,
     pub char_type_id: TypeId,
     pub string_type_id: TypeId,
     pub array_type_id: TypeId,
     pub slice_type_id: TypeId,
     pub input_type_id: TypeId,
     pub output_type_id: TypeId,
     pub pointer_type_id: TypeId,
+}
 impl TargetArch {
     fn new() -> Self {
         return Self{
             void_type_id: TypeId::new_invalid(),
             bool_type_id: TypeId::new_invalid(),
             message_type_id: TypeId::new_invalid(),
             uint8_type_id: TypeId::new_invalid(),
             uint16_type_id: TypeId::new_invalid(),
             uint32_type_id: TypeId::new_invalid(),
             uint64_type_id: TypeId::new_invalid(),
             sint8_type_id: TypeId::new_invalid(),
             sint16_type_id: TypeId::new_invalid(),
             sint32_type_id: TypeId::new_invalid(),
             sint64_type_id: TypeId::new_invalid(),
             char_type_id: TypeId::new_invalid(),
             string_type_id: TypeId::new_invalid(),
             array_type_id: TypeId::new_invalid(),
             slice_type_id: TypeId::new_invalid(),
             input_type_id: TypeId::new_invalid(),
             output_type_id: TypeId::new_invalid(),
             pointer_type_id: TypeId::new_invalid(),
+        }
+    }
+}
 pub struct PassCtx<'a> {
     heap: &'a mut Heap,
     symbols: &'a mut SymbolTable,
     pool: &'a mut StringPool,
     arch: &'a TargetArch,
+}
 pub struct Parser {
     // Storage of all information created/gathered during compilation.
     pub(crate) heap: Heap,
     pub(crate) string_pool: StringPool, // Do not deallocate, holds all strings
     pub(crate) modules: Vec<Module>,
     pub(crate) symbol_table: SymbolTable,
     pub(crate) type_table: TypeTable,
     // Compiler passes, used as little state machine that keep their memory
     // around.
     pass_tokenizer: PassTokenizer,
     pass_symbols: PassSymbols,
     pass_import: PassImport,
     pass_definitions: PassDefinitions,
     pass_validation: PassValidationLinking,
     pass_typing: PassTyping,
     pass_rewriting: PassRewriting,
     pass_stack_size: PassStackSize,
     // Compiler options
     pub write_ast_to: Option<String>,
     pub(crate) arch: TargetArch,
+}
 impl Parser {
     pub fn new() -> Self {
         let mut parser = Parser{
             heap: Heap::new(),
             string_pool: StringPool::new(),
             modules: Vec::new(),
             symbol_table: SymbolTable::new(),
             type_table: TypeTable::new(),
             pass_tokenizer: PassTokenizer::new(),
             pass_symbols: PassSymbols::new(),
             pass_import: PassImport::new(),
             pass_definitions: PassDefinitions::new(),
             pass_validation: PassValidationLinking::new(),
             pass_typing: PassTyping::new(),
             pass_rewriting: PassRewriting::new(),
             pass_stack_size: PassStackSize::new(),
             write_ast_to: None,
             arch: TargetArch {
                 array_size_alignment: (3*8, 8), // pointer, length, capacity
                 slice_size_alignment: (2*8, 8), // pointer, length
                 string_size_alignment: (3*8, 8), // pointer, length, capacity
                 port_size_alignment: (3*4, 4), // two u32s: connector + port ID
                 pointer_size_alignment: (8, 8),
+            }
             arch: TargetArch::new(),
         };
         parser.symbol_table.insert_scope(None, SymbolScope::Global);
         // Insert builtin types
         // TODO: At some point use correct values for size/alignment
         parser.arch.void_type_id    = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Void], false, 0, 1);
         parser.arch.message_type_id = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Message], false, 24, 8);
         parser.arch.bool_type_id    = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Bool], false, 1, 1);
         parser.arch.uint8_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::UInt8], false, 1, 1);
         parser.arch.uint16_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::UInt16], false, 2, 2);
         parser.arch.uint32_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::UInt32], false, 4, 4);
         parser.arch.uint64_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::UInt64], false, 8, 8);
         parser.arch.sint8_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::SInt8], false, 1, 1);
         parser.arch.sint16_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::SInt16], false, 2, 2);
         parser.arch.sint32_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::SInt32], false, 4, 4);
         parser.arch.sint64_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::SInt64], false, 8, 8);
         parser.arch.char_type_id    = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Character], false, 4, 4);
         parser.arch.string_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::String], false, 24, 8);
         parser.arch.array_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Array, ConcreteTypePart::Void], true, 24, 8);
         parser.arch.slice_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Slice, ConcreteTypePart::Void], true, 16, 4);
         parser.arch.input_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Input, ConcreteTypePart::Void], true, 8, 8);
         parser.arch.output_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Output, ConcreteTypePart::Void], true, 8, 8);
         parser.arch.pointer_type_id = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Pointer, ConcreteTypePart::Void], true, 8, 8);
         // Insert builtin functions
         fn quick_type(variants: &[ParserTypeVariant]) -> ParserType {
             let mut t = ParserType{ elements: Vec::with_capacity(variants.len()), full_span: InputSpan::new() };
             for variant in variants {
                 t.elements.push(ParserTypeElement{ element_span: InputSpan::new(), variant: variant.clone() });
+            }
+            t
+        }
         use ParserTypeVariant as PTV;
         insert_builtin_function(&mut parser, "get", &["T"], |id| (
             vec![
                 ("input", quick_type(&[PTV::Input, PTV::PolymorphicArgument(id.upcast(), 0)]))
             ],
             quick_type(&[PTV::PolymorphicArgument(id.upcast(), 0)])
         ));
         insert_builtin_function(&mut parser, "put", &["T"], |id| (
             vec![
                 ("output", quick_type(&[PTV::Output, PTV::PolymorphicArgument(id.upcast(), 0)])),
                 ("value", quick_type(&[PTV::PolymorphicArgument(id.upcast(), 0)])),
             ],
             quick_type(&[PTV::Void])
         ));
         insert_builtin_function(&mut parser, "fires", &["T"], |id| (
             vec![
                 ("port", quick_type(&[PTV::InputOrOutput, PTV::PolymorphicArgument(id.upcast(), 0)]))
             ],
             quick_type(&[PTV::Bool])
         ));
         insert_builtin_function(&mut parser, "create", &["T"], |id| (
             vec![
                 ("length", quick_type(&[PTV::IntegerLike]))
             ],
             quick_type(&[PTV::ArrayLike, PTV::PolymorphicArgument(id.upcast(), 0)])
         ));
         insert_builtin_function(&mut parser, "length", &["T"], |id| (
             vec![
                 ("array", quick_type(&[PTV::ArrayLike, PTV::PolymorphicArgument(id.upcast(), 0)]))
             ],
             quick_type(&[PTV::UInt32]) // TODO: @PtrInt
         ));
         insert_builtin_function(&mut parser, "assert", &[], |_id| (
             vec![
                 ("condition", quick_type(&[PTV::Bool])),
             ],
             quick_type(&[PTV::Void])
         ));
         insert_builtin_function(&mut parser, "print", &[], |_id| (
             vec![
                 ("message", quick_type(&[PTV::String])),
             ],
             quick_type(&[PTV::Void])
         ));
         parser
+    }
     pub fn feed(&mut self, mut source: InputSource) -> Result<(), ParseError> {
         let mut token_buffer = TokenBuffer::new();
         self.pass_tokenizer.tokenize(&mut source, &mut token_buffer)?;
         let module = Module{
             source,
             tokens: token_buffer,
             root_id: RootId::new_invalid(),
             name: None,
             version: None,
             phase: ModuleCompilationPhase::Tokenized,
         };
         self.modules.push(module);
         Ok(())
+    }
     pub fn parse(&mut self) -> Result<(), ParseError> {
         let mut pass_ctx = PassCtx{
             heap: &mut self.heap,
             symbols: &mut self.symbol_table,
             pool: &mut self.string_pool,
             arch: &self.arch,
         };
         // Advance all modules to the phase where all symbols are scanned
         for module_idx in 0..self.modules.len() {
             self.pass_symbols.parse(&mut self.modules, module_idx, &mut pass_ctx)?;
+        }
         // With all symbols scanned, perform further compilation until we can
         // add all base types to the type table.
         for module_idx in 0..self.modules.len() {
             self.pass_import.parse(&mut self.modules, module_idx, &mut pass_ctx)?;
             self.pass_definitions.parse(&mut self.modules, module_idx, &mut pass_ctx)?;
+        }
         // Add every known type to the type table
         self.type_table.build_base_types(&mut self.modules, &mut pass_ctx)?;
         // Continue compilation with the remaining phases now that the types
         // are all in the type table
         for module_idx in 0..self.modules.len() {
             let mut ctx = visitor::Ctx{
                 heap: &mut self.heap,
                 modules: &mut self.modules,
                 module_idx,
                 symbols: &mut self.symbol_table,
                 types: &mut self.type_table,
                 arch: &self.arch,
             };
             self.pass_validation.visit_module(&mut ctx)?;
+        }
         // Perform typechecking on all modules
         let mut queue = ResolveQueue::new();
         for module_idx in 0..self.modules.len() {
             let mut ctx = visitor::Ctx{
                 heap: &mut self.heap,
                 modules: &mut self.modules,
                 module_idx,
                 symbols: &mut self.symbol_table,
                 types: &mut self.type_table,
                 arch: &self.arch,
             };
-            PassTyping::queue_module_definitions(&mut ctx, &mut queue);
+            self.pass_typing.queue_module_definitions(&mut ctx, &mut queue);
         };
         while !queue.is_empty() {
-            let top = queue.pop().unwrap();
+            let top = queue.pop_front().unwrap();
             let mut ctx = visitor::Ctx{
                 heap: &mut self.heap,
                 modules: &mut self.modules,
                 module_idx: top.root_id.index as usize,
                 symbols: &mut self.symbol_table,
                 types: &mut self.type_table,
                 arch: &self.arch,
             };
             self.pass_typing.handle_module_definition(&mut ctx, &mut queue, top)?;
+        }
         // Rewrite nodes in tree, then prepare for execution of code
         for module_idx in 0..self.modules.len() {
             self.modules[module_idx].phase = ModuleCompilationPhase::Typed;
             let mut ctx = visitor::Ctx{
                 heap: &mut self.heap,
                 modules: &mut self.modules,
                 module_idx,
                 symbols: &mut self.symbol_table,
                 types: &mut self.type_table,
                 arch: &self.arch,
             };
             self.pass_rewriting.visit_module(&mut ctx)?;
             self.pass_stack_size.visit_module(&mut ctx)?;
+        }
         // Write out desired information
         if let Some(filename) = &self.write_ast_to {
             let mut writer = ASTWriter::new();
             let mut file = std::fs::File::create(std::path::Path::new(filename)).unwrap();
             writer.write_ast(&mut file, &self.heap);
+        }
         Ok(())
+    }
+}
 // Note: args and return type need to be a function because we need to know the function ID.
 fn insert_builtin_function<T: Fn(FunctionDefinitionId) -> (Vec<(&'static str, ParserType)>, ParserType)> (
     p: &mut Parser, func_name: &str, polymorphic: &[&str], arg_and_return_fn: T) {
 fn insert_builtin_type(type_table: &mut TypeTable, parts: Vec<ConcreteTypePart>, has_poly_var: bool, size: usize, alignment: usize) -> TypeId {
     const POLY_VARS: [PolymorphicVariable; 1] = [PolymorphicVariable{
         identifier: Identifier::new_empty(InputSpan::new()),
         is_in_use: false,
     }];
     let mut poly_vars = Vec::with_capacity(polymorphic.len());
     let concrete_type = ConcreteType{ parts };
     let poly_var = if has_poly_var {
         POLY_VARS.as_slice()
     } else {
         &[]
     };
     return type_table.add_builtin_data_type(concrete_type, poly_var, size, alignment);
+}
 // Note: args and return type need to be a function because we need to know the function ID.
 fn insert_builtin_function<T: Fn(ProcedureDefinitionId) -> (Vec<(&'static str, ParserType)>, ParserType)> (
     p: &mut Parser, func_name: &str, polymorphic: &[&str], arg_and_return_fn: T
 ) {
     // Insert into AST (to get an ID), also prepare the polymorphic variables
     // we need later for the type table
     let mut ast_poly_vars = Vec::with_capacity(polymorphic.len());
     let mut type_poly_vars = Vec::with_capacity(polymorphic.len());
     for poly_var in polymorphic {
         poly_vars.push(Identifier{ span: InputSpan::new(), value: p.string_pool.intern(poly_var.as_bytes()) });
         let identifier = Identifier{ span: InputSpan::new(), value: p.string_pool.intern(poly_var.as_bytes()) } ;
         ast_poly_vars.push(identifier.clone());
         type_poly_vars.push(PolymorphicVariable{ identifier, is_in_use: false });
+    }
     let func_ident_ref = p.string_pool.intern(func_name.as_bytes());
-    let func_id = p.heap.alloc_function_definition(|this| FunctionDefinition{
+    let procedure_id = p.heap.alloc_procedure_definition(|this| ProcedureDefinition {
         this,
         defined_in: RootId::new_invalid(),
         builtin: true,
         kind: ProcedureKind::Function,
         span: InputSpan::new(),
         identifier: Identifier{ span: InputSpan::new(), value: func_ident_ref.clone() },
         poly_vars,
         return_types: Vec::new(),
         poly_vars: ast_poly_vars,
         return_type: None,
         parameters: Vec::new(),
         scope: ScopeId::new_invalid(),
         body: BlockStatementId::new_invalid(),
-        num_expressions_in_body: -1,
+        monomorphs: Vec::new(),
     });
     let (args, ret) = arg_and_return_fn(func_id);
     // Modify AST with more information about the procedure
     let (arguments, return_type) = arg_and_return_fn(procedure_id);
     let mut parameters = Vec::with_capacity(args.len());
     for (arg_name, arg_type) in args {
     let mut parameters = Vec::with_capacity(arguments.len());
     for (arg_name, arg_type) in arguments {
         let identifier = Identifier{ span: InputSpan::new(), value: p.string_pool.intern(arg_name.as_bytes()) };
         let param_id = p.heap.alloc_variable(|this| Variable{
             this,
             kind: VariableKind::Parameter,
             parser_type: arg_type.clone(),
             identifier,
-            relative_pos_in_block: 0,
+            relative_pos_in_parent: 0,
             unique_id_in_scope: 0
         });
         parameters.push(param_id);
+    }
-    let func = &mut p.heap[func_id];
+    let func = &mut p.heap[procedure_id];
     func.parameters = parameters;
-    func.return_types.push(ret);
+    func.return_type = Some(return_type);
     // Insert into symbol table
     p.symbol_table.insert_symbol(SymbolScope::Global, Symbol{
         name: func_ident_ref,
         variant: SymbolVariant::Definition(SymbolDefinition{
             defined_in_module: RootId::new_invalid(),
             defined_in_scope: SymbolScope::Global,
             definition_span: InputSpan::new(),
             identifier_span: InputSpan::new(),
             imported_at: None,
             class: DefinitionClass::Function,
-            definition_id: func_id.upcast(),
+            definition_id: procedure_id.upcast(),
         })
     }).unwrap();
     // Insert into type table
     // let mut concrete_type = ConcreteType::default();
     // concrete_type.parts.push(ConcreteTypePart::Function(procedure_id, type_poly_vars.len() as u32));
     //
     // for _ in 0..type_poly_vars.len() {
     //     concrete_type.parts.push(ConcreteTypePart::Void); // doesn't matter (I hope...)
     // }
     // p.type_table.add_builtin_procedure_type(concrete_type, &type_poly_vars);
+}
@@ \ No newline at end of file @@

src/protocol/parser/pass_definitions.rs

➞

Show inline comments

 use crate::protocol::ast::*;
 use super::symbol_table::*;
 use super::{Module, ModuleCompilationPhase, PassCtx};
 use super::tokens::*;
 use super::token_parsing::*;
 use super::pass_definitions_types::*;
 use crate::protocol::input_source::{InputSource, InputPosition, InputSpan, ParseError};
 use crate::collections::*;
 /// Parses all the tokenized definitions into actual AST nodes.
 pub(crate) struct PassDefinitions {
     // State associated with the definition currently being processed
     cur_definition: DefinitionId,
     // Itty bitty parsing machines
     type_parser: ParserTypeParser,
     // Temporary buffers of various kinds
     buffer: String,
     struct_fields: ScopedBuffer<StructFieldDefinition>,
     enum_variants: ScopedBuffer<EnumVariantDefinition>,
     union_variants: ScopedBuffer<UnionVariantDefinition>,
     variables: ScopedBuffer<VariableId>,
     expressions: ScopedBuffer<ExpressionId>,
     statements: ScopedBuffer<StatementId>,
     parser_types: ScopedBuffer<ParserType>,
+}
 impl PassDefinitions {
     pub(crate) fn new() -> Self {
         Self{
             cur_definition: DefinitionId::new_invalid(),
             type_parser: ParserTypeParser::new(),
             buffer: String::with_capacity(128),
             struct_fields: ScopedBuffer::with_capacity(128),
             enum_variants: ScopedBuffer::with_capacity(128),
             union_variants: ScopedBuffer::with_capacity(128),
             variables: ScopedBuffer::with_capacity(128),
             expressions: ScopedBuffer::with_capacity(128),
             statements: ScopedBuffer::with_capacity(128),
             parser_types: ScopedBuffer::with_capacity(128),
+        }
+    }
     pub(crate) fn parse(&mut self, modules: &mut [Module], module_idx: usize, ctx: &mut PassCtx) -> Result<(), ParseError> {
         let module = &modules[module_idx];
         let module_range = &module.tokens.ranges[0];
         debug_assert_eq!(module.phase, ModuleCompilationPhase::ImportsResolved);
         debug_assert_eq!(module_range.range_kind, TokenRangeKind::Module);
         // Although we only need to parse the definitions, we want to go through
         // code ranges as well such that we can throw errors if we get
         // unexpected tokens at the module level of the source.
         let mut range_idx = module_range.first_child_idx;
         loop {
             let range_idx_usize = range_idx as usize;
             let cur_range = &module.tokens.ranges[range_idx_usize];
             match cur_range.range_kind {
                 TokenRangeKind::Module => unreachable!(), // should not be reachable
                 TokenRangeKind::Pragma | TokenRangeKind::Import => {
                     // Already fully parsed, fall through and go to next range
                 },
                 TokenRangeKind::Definition | TokenRangeKind::Code => {
                     // Visit range even if it is a "code" range to provide
                     // proper error messages.
                     self.visit_range(modules, module_idx, ctx, range_idx_usize)?;
                 },
+            }
             if cur_range.next_sibling_idx == NO_SIBLING {
                 break;
             } else {
                 range_idx = cur_range.next_sibling_idx;
+            }
+        }
         modules[module_idx].phase = ModuleCompilationPhase::DefinitionsParsed;
         Ok(())
+    }
     fn visit_range(
         &mut self, modules: &[Module], module_idx: usize, ctx: &mut PassCtx, range_idx: usize
     ) -> Result<(), ParseError> {
         let module = &modules[module_idx];
         let cur_range = &module.tokens.ranges[range_idx];
         debug_assert!(cur_range.range_kind == TokenRangeKind::Definition || cur_range.range_kind == TokenRangeKind::Code);
         // Detect which definition we're parsing
         let mut iter = module.tokens.iter_range(cur_range);
         loop {
             let next = iter.next();
             if next.is_none() {
                 return Ok(())
+            }
             // Token was not None, so peek_ident returns None if not an ident
             let ident = peek_ident(&module.source, &mut iter);
             match ident {
                 Some(KW_STRUCT) => self.visit_struct_definition(module, &mut iter, ctx)?,
                 Some(KW_ENUM) => self.visit_enum_definition(module, &mut iter, ctx)?,
                 Some(KW_UNION) => self.visit_union_definition(module, &mut iter, ctx)?,
                 Some(KW_FUNCTION) => self.visit_function_definition(module, &mut iter, ctx)?,
                 Some(KW_PRIMITIVE) | Some(KW_COMPOSITE) => self.visit_component_definition(module, &mut iter, ctx)?,
                 _ => return Err(ParseError::new_error_str_at_pos(
                     &module.source, iter.last_valid_pos(),
                     "unexpected symbol, expected a keyword marking the start of a definition"
                 )),
+            }
+        }
+    }
     fn visit_struct_definition(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<(), ParseError> {
         consume_exact_ident(&module.source, iter, KW_STRUCT)?;
         let (ident_text, _) = consume_ident(&module.source, iter)?;
         // Retrieve preallocated DefinitionId
         let module_scope = SymbolScope::Module(module.root_id);
         let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text)
             .unwrap().variant.as_definition().definition_id;
         self.cur_definition = definition_id;
         // Parse struct definition
         consume_polymorphic_vars_spilled(&module.source, iter, ctx)?;
         let mut fields_section = self.struct_fields.start_section();
         consume_comma_separated(
             TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
             |source, iter, ctx| {
                 let poly_vars = ctx.heap[definition_id].poly_vars();
                 let start_pos = iter.last_valid_pos();
                 let parser_type = self.type_parser.consume_parser_type(
                     iter, &ctx.heap, source, &ctx.symbols, poly_vars, definition_id,
                     module_scope, false, None
                 )?;
                 let field = consume_ident_interned(source, iter, ctx)?;
                 Ok(StructFieldDefinition{
                     span: InputSpan::from_positions(start_pos, field.span.end),
                     field, parser_type
                 })
             },
             &mut fields_section, "a struct field", "a list of struct fields", None
         )?;
         // Transfer to preallocated definition
         let struct_def = ctx.heap[definition_id].as_struct_mut();
         struct_def.fields = fields_section.into_vec();
         Ok(())
+    }
     fn visit_enum_definition(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<(), ParseError> {
         consume_exact_ident(&module.source, iter, KW_ENUM)?;
         let (ident_text, _) = consume_ident(&module.source, iter)?;
         // Retrieve preallocated DefinitionId
         let module_scope = SymbolScope::Module(module.root_id);
         let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text)
             .unwrap().variant.as_definition().definition_id;
         self.cur_definition = definition_id;
         // Parse enum definition
         consume_polymorphic_vars_spilled(&module.source, iter, ctx)?;
         let mut enum_section = self.enum_variants.start_section();
         consume_comma_separated(
             TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
             |source, iter, ctx| {
                 let identifier = consume_ident_interned(source, iter, ctx)?;
                 let value = if iter.next() == Some(TokenKind::Equal) {
                     iter.consume();
                     let (variant_number, _) = consume_integer_literal(source, iter, &mut self.buffer)?;
                     EnumVariantValue::Integer(variant_number as i64) // TODO: @int
                 } else {
                     EnumVariantValue::None
                 };
                 Ok(EnumVariantDefinition{ identifier, value })
             },
             &mut enum_section, "an enum variant", "a list of enum variants", None
         )?;
         // Transfer to definition
         let enum_def = ctx.heap[definition_id].as_enum_mut();
         enum_def.variants = enum_section.into_vec();
         Ok(())
+    }
     fn visit_union_definition(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<(), ParseError> {
         consume_exact_ident(&module.source, iter, KW_UNION)?;
         let (ident_text, _) = consume_ident(&module.source, iter)?;
         // Retrieve preallocated DefinitionId
         let module_scope = SymbolScope::Module(module.root_id);
         let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text)
             .unwrap().variant.as_definition().definition_id;
         self.cur_definition = definition_id;
         // Parse union definition
         consume_polymorphic_vars_spilled(&module.source, iter, ctx)?;
         let mut variants_section = self.union_variants.start_section();
         consume_comma_separated(
             TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
             |source, iter, ctx| {
                 let identifier = consume_ident_interned(source, iter, ctx)?;
                 let mut close_pos = identifier.span.end;
                 let mut types_section = self.parser_types.start_section();
                 let has_embedded = maybe_consume_comma_separated(
                     TokenKind::OpenParen, TokenKind::CloseParen, source, iter, ctx,
                     |source, iter, ctx| {
                         let poly_vars = ctx.heap[definition_id].poly_vars();
                         self.type_parser.consume_parser_type(
                             iter, &ctx.heap, source, &ctx.symbols, poly_vars, definition_id,
                             module_scope, false, None
+                        )
                     },
                     &mut types_section, "an embedded type", Some(&mut close_pos)
                 )?;
                 let value = if has_embedded {
                     types_section.into_vec()
                 } else {
                     types_section.forget();
                     Vec::new()
                 };
                 Ok(UnionVariantDefinition{
                     span: InputSpan::from_positions(identifier.span.begin, close_pos),
                     identifier,
                     value
                 })
             },
             &mut variants_section, "a union variant", "a list of union variants", None
         )?;
         // Transfer to AST
         let union_def = ctx.heap[definition_id].as_union_mut();
         union_def.variants = variants_section.into_vec();
         Ok(())
+    }
     fn visit_function_definition(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<(), ParseError> {
         // Retrieve function name
         consume_exact_ident(&module.source, iter, KW_FUNCTION)?;
         let (ident_text, _) = consume_ident(&module.source, iter)?;
         // Retrieve preallocated DefinitionId
         let module_scope = SymbolScope::Module(module.root_id);
         let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text)
             .unwrap().variant.as_definition().definition_id;
         self.cur_definition = definition_id;
         consume_polymorphic_vars_spilled(&module.source, iter, ctx)?;
         // Parse function's argument list
         let mut parameter_section = self.variables.start_section();
         consume_parameter_list(
             &mut self.type_parser, &module.source, iter, ctx, &mut parameter_section, module_scope, definition_id
         )?;
         let parameters = parameter_section.into_vec();
         // Consume return types
         consume_token(&module.source, iter, TokenKind::ArrowRight)?;
         let mut return_types = self.parser_types.start_section();
         let mut open_curly_pos = iter.last_valid_pos(); // bogus value
         consume_comma_separated_until(
             TokenKind::OpenCurly, &module.source, iter, ctx,
             |source, iter, ctx| {
         let poly_vars = ctx.heap[definition_id].poly_vars();
                 self.type_parser.consume_parser_type(
                     iter, &ctx.heap, source, &ctx.symbols, poly_vars, definition_id,
         let parser_type = self.type_parser.consume_parser_type(
             iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars, definition_id,
             module_scope, false, None
+                )
             },
             &mut return_types, "a return type", Some(&mut open_curly_pos)
         )?;
         let return_types = return_types.into_vec();
         match return_types.len() {
 => return Err(ParseError::new_error_str_at_pos(&module.source, open_curly_pos, "expected a return type")),
 => {},
             _ => return Err(ParseError::new_error_str_at_pos(&module.source, open_curly_pos, "multiple return types are not (yet) allowed")),
+        }
         // Consume block
         let body = self.consume_block_statement_without_leading_curly(module, iter, ctx, open_curly_pos)?;
         // Consume block and the definition's scope
         let body_id = self.consume_block_statement(module, iter, ctx)?;
         let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Definition(definition_id)));
         // Assign everything in the preallocated AST node
         let function = ctx.heap[definition_id].as_function_mut();
         function.return_types = return_types;
         let function = ctx.heap[definition_id].as_procedure_mut();
         function.return_type = Some(parser_type);
         function.parameters = parameters;
         function.body = body;
         function.scope = scope_id;
         function.body = body_id;
         Ok(())
+    }
     fn visit_component_definition(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<(), ParseError> {
         // Consume component variant and name
         let (_variant_text, _) = consume_any_ident(&module.source, iter)?;
         debug_assert!(_variant_text == KW_PRIMITIVE || _variant_text == KW_COMPOSITE);
         let (ident_text, _) = consume_ident(&module.source, iter)?;
         // Retrieve preallocated definition
         let module_scope = SymbolScope::Module(module.root_id);
         let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text)
             .unwrap().variant.as_definition().definition_id;
         self.cur_definition = definition_id;
         consume_polymorphic_vars_spilled(&module.source, iter, ctx)?;
         // Parse component's argument list
         let mut parameter_section = self.variables.start_section();
         consume_parameter_list(
             &mut self.type_parser, &module.source, iter, ctx, &mut parameter_section, module_scope, definition_id
         )?;
         let parameters = parameter_section.into_vec();
         // Consume block
         let body = self.consume_block_statement(module, iter, ctx)?;
         let body_id = self.consume_block_statement(module, iter, ctx)?;
         let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Definition(definition_id)));
         // Assign everything in the AST node
         let component = ctx.heap[definition_id].as_component_mut();
         let component = ctx.heap[definition_id].as_procedure_mut();
         debug_assert!(component.return_type.is_none());
         component.parameters = parameters;
         component.body = body;
         component.scope = scope_id;
         component.body = body_id;
         Ok(())
+    }
     /// Consumes a block statement. If the resulting statement is not a block
     /// (e.g. for a shorthand "if (expr) single_statement") then it will be
     /// wrapped in one
     fn consume_block_or_wrapped_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<BlockStatementId, ParseError> {
         if Some(TokenKind::OpenCurly) == iter.next() {
             // This is a block statement
             self.consume_block_statement(module, iter, ctx)
         } else {
             // Not a block statement, so wrap it in one
             let mut statements = self.statements.start_section();
             let wrap_begin_pos = iter.last_valid_pos();
             self.consume_statement(module, iter, ctx, &mut statements)?;
             let wrap_end_pos = iter.last_valid_pos();
             let statements = statements.into_vec();
             let id = ctx.heap.alloc_block_statement(|this| BlockStatement{
                 this,
                 is_implicit: true,
                 span: InputSpan::from_positions(wrap_begin_pos, wrap_end_pos),
                 statements,
                 end_block: EndBlockStatementId::new_invalid(),
                 scope_node: ScopeNode::new_invalid(),
                 first_unique_id_in_scope: -1,
                 next_unique_id_in_scope: -1,
                 locals: Vec::new(),
                 labels: Vec::new(),
                 next: StatementId::new_invalid(),
             });
             let end_block = ctx.heap.alloc_end_block_statement(|this| EndBlockStatement{
                 this, start_block: id, next: StatementId::new_invalid()
             });
             let block_stmt = &mut ctx.heap[id];
             block_stmt.end_block = end_block;
             Ok(id)
+        }
+    }
     /// Consumes a statement and returns a boolean indicating whether it was a
     /// block or not.
     fn consume_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, section: &mut ScopedSection<StatementId>
     ) -> Result<(), ParseError> {
     fn consume_statement(&mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx) -> Result<StatementId, ParseError> {
         let next = iter.next().expect("consume_statement has a next token");
         if next == TokenKind::OpenCurly {
             let id = self.consume_block_statement(module, iter, ctx)?;
-            section.push(id.upcast());
+            return Ok(id.upcast());
         } else if next == TokenKind::Ident {
             let ident = peek_ident(&module.source, iter).unwrap();
             if ident == KW_STMT_IF {
                 // Consume if statement and place end-if statement directly
                 // after it.
                 let id = self.consume_if_statement(module, iter, ctx)?;
                 section.push(id.upcast());
                 let end_if = ctx.heap.alloc_end_if_statement(|this| EndIfStatement {
                     this,
                     start_if: id,
                     next: StatementId::new_invalid()
                 });
                 section.push(end_if.upcast());
                 let if_stmt = &mut ctx.heap[id];
                 if_stmt.end_if = end_if;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_WHILE {
                 let id = self.consume_while_statement(module, iter, ctx)?;
                 section.push(id.upcast());
                 let end_while = ctx.heap.alloc_end_while_statement(|this| EndWhileStatement {
                     this,
                     start_while: id,
                     next: StatementId::new_invalid()
                 });
                 section.push(end_while.upcast());
                 let while_stmt = &mut ctx.heap[id];
                 while_stmt.end_while = end_while;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_BREAK {
                 let id = self.consume_break_statement(module, iter, ctx)?;
-                section.push(id.upcast());
+                return Ok(id.upcast());
             } else if ident == KW_STMT_CONTINUE {
                 let id = self.consume_continue_statement(module, iter, ctx)?;
-                section.push(id.upcast());
+                return Ok(id.upcast());
             } else if ident == KW_STMT_SYNC {
                 let id = self.consume_synchronous_statement(module, iter, ctx)?;
                 section.push(id.upcast());
                 let end_sync = ctx.heap.alloc_end_synchronous_statement(|this| EndSynchronousStatement {
                     this,
                     start_sync: id,
                     next: StatementId::new_invalid()
                 });
                 section.push(end_sync.upcast());
                 let sync_stmt = &mut ctx.heap[id];
                 sync_stmt.end_sync = end_sync;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_FORK {
                 let id = self.consume_fork_statement(module, iter, ctx)?;
                 section.push(id.upcast());
                 let end_fork = ctx.heap.alloc_end_fork_statement(|this| EndForkStatement {
                     this,
                     start_fork: id,
                     next: StatementId::new_invalid(),
                 });
                 section.push(end_fork.upcast());
                 let fork_stmt = &mut ctx.heap[id];
                 fork_stmt.end_fork = end_fork;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_SELECT {
                 let id = self.consume_select_statement(module, iter, ctx)?;
                 section.push(id.upcast());
                 let end_select = ctx.heap.alloc_end_select_statement(|this| EndSelectStatement{
                     this,
                     start_select: id,
                     next: StatementId::new_invalid(),
                 });
                 section.push(end_select.upcast());
                 let select_stmt = &mut ctx.heap[id];
                 select_stmt.end_select = end_select;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_RETURN {
                 let id = self.consume_return_statement(module, iter, ctx)?;
-                section.push(id.upcast());
+                return Ok(id.upcast());
             } else if ident == KW_STMT_GOTO {
                 let id = self.consume_goto_statement(module, iter, ctx)?;
-                section.push(id.upcast());
+                return Ok(id.upcast());
             } else if ident == KW_STMT_NEW {
                 let id = self.consume_new_statement(module, iter, ctx)?;
-                section.push(id.upcast());
+                return Ok(id.upcast());
             } else if ident == KW_STMT_CHANNEL {
                 let id = self.consume_channel_statement(module, iter, ctx)?;
-                section.push(id.upcast().upcast());
+                return Ok(id.upcast().upcast());
             } else if iter.peek() == Some(TokenKind::Colon) {
                 self.consume_labeled_statement(module, iter, ctx, section)?;
                 let id = self.consume_labeled_statement(module, iter, ctx)?;
                 return Ok(id.upcast());
             } else {
                 // Two fallback possibilities: the first one is a memory
                 // declaration, the other one is to parse it as a normal
                 // expression. This is a bit ugly.
                 if let Some(memory_stmt_id) = self.maybe_consume_memory_statement_without_semicolon(module, iter, ctx)? {
                     consume_token(&module.source, iter, TokenKind::SemiColon)?;
-                    section.push(memory_stmt_id.upcast().upcast());
+                    return Ok(memory_stmt_id.upcast().upcast());
                 } else {
                     let id = self.consume_expression_statement(module, iter, ctx)?;
-                    section.push(id.upcast());
+                    return Ok(id.upcast());
+                }
+            }
         } else if next == TokenKind::OpenParen {
             // Same as above: memory statement or normal expression
             if let Some(memory_stmt_id) = self.maybe_consume_memory_statement_without_semicolon(module, iter, ctx)? {
                 consume_token(&module.source, iter, TokenKind::SemiColon)?;
-                section.push(memory_stmt_id.upcast().upcast());
+                return Ok(memory_stmt_id.upcast().upcast());
             } else {
                 let id = self.consume_expression_statement(module, iter, ctx)?;
-                section.push(id.upcast());
+                return Ok(id.upcast());
+            }
         } else {
             let id = self.consume_expression_statement(module, iter, ctx)?;
-            section.push(id.upcast());
+            return Ok(id.upcast());
+        }
         return Ok(());
+    }
     fn consume_block_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<BlockStatementId, ParseError> {
         let open_span = consume_token(&module.source, iter, TokenKind::OpenCurly)?;
         self.consume_block_statement_without_leading_curly(module, iter, ctx, open_span.begin)
+    }
         let open_curly_span = consume_token(&module.source, iter, TokenKind::OpenCurly)?;
     fn consume_block_statement_without_leading_curly(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, open_curly_pos: InputPosition
     ) -> Result<BlockStatementId, ParseError> {
         let mut stmt_section = self.statements.start_section();
         let mut next = iter.next();
         while next != Some(TokenKind::CloseCurly) {
             if next.is_none() {
                 return Err(ParseError::new_error_str_at_pos(
                     &module.source, iter.last_valid_pos(), "expected a statement or '}'"
                 ));
+            }
             self.consume_statement(module, iter, ctx, &mut stmt_section)?;
             let stmt_id = self.consume_statement(module, iter, ctx)?;
             stmt_section.push(stmt_id);
             next = iter.next();
+        }
         let statements = stmt_section.into_vec();
         let mut block_span = consume_token(&module.source, iter, TokenKind::CloseCurly)?;
-        block_span.begin = open_curly_pos;
+        block_span.begin = open_curly_span.begin;
-        let id = ctx.heap.alloc_block_statement(|this| BlockStatement{
+        let block_id = ctx.heap.alloc_block_statement(|this| BlockStatement{
             this,
             is_implicit: false,
             span: block_span,
             statements,
             end_block: EndBlockStatementId::new_invalid(),
             scope_node: ScopeNode::new_invalid(),
             first_unique_id_in_scope: -1,
             next_unique_id_in_scope: -1,
             locals: Vec::new(),
             labels: Vec::new(),
             scope: ScopeId::new_invalid(),
             next: StatementId::new_invalid(),
         });
         let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Block(block_id)));
         let end_block = ctx.heap.alloc_end_block_statement(|this| EndBlockStatement{
             this, start_block: id, next: StatementId::new_invalid()
         let end_block_id = ctx.heap.alloc_end_block_statement(|this| EndBlockStatement{
             this, start_block: block_id, next: StatementId::new_invalid()
         });
         let block_stmt = &mut ctx.heap[id];
         block_stmt.end_block = end_block;
         let block_stmt = &mut ctx.heap[block_id];
         block_stmt.end_block = end_block_id;
         block_stmt.scope = scope_id;
-        Ok(id)
+        Ok(block_id)
+    }
     fn consume_if_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<IfStatementId, ParseError> {
         let if_span = consume_exact_ident(&module.source, iter, KW_STMT_IF)?;
         consume_token(&module.source, iter, TokenKind::OpenParen)?;
         let test = self.consume_expression(module, iter, ctx)?;
         consume_token(&module.source, iter, TokenKind::CloseParen)?;
         let true_body = self.consume_block_or_wrapped_statement(module, iter, ctx)?;
         // Consume bodies of if-statement
         let true_body = IfStatementCase{
             body: self.consume_statement(module, iter, ctx)?,
             scope: ScopeId::new_invalid(),
         };
         let false_body = if has_ident(&module.source, iter, KW_STMT_ELSE) {
             iter.consume();
             let false_body = self.consume_block_or_wrapped_statement(module, iter, ctx)?;
             let false_body = IfStatementCase{
                 body: self.consume_statement(module, iter, ctx)?,
                 scope: ScopeId::new_invalid(),
             };
             Some(false_body)
         } else {
             None
         };
         Ok(ctx.heap.alloc_if_statement(|this| IfStatement{
         // Construct AST elements
         let if_stmt_id = ctx.heap.alloc_if_statement(|this| IfStatement{
             this,
             span: if_span,
             test,
             true_body,
             false_body,
             true_case: true_body,
             false_case: false_body,
             end_if: EndIfStatementId::new_invalid(),
         }))
         });
         let end_if_stmt_id = ctx.heap.alloc_end_if_statement(|this| EndIfStatement{
             this,
             start_if: if_stmt_id,
             next: StatementId::new_invalid(),
         });
         let true_scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::If(if_stmt_id, true)));
         let false_scope_id = if false_body.is_some() {
             Some(ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::If(if_stmt_id, false))))
         } else {
             None
         };
         let if_stmt = &mut ctx.heap[if_stmt_id];
         if_stmt.end_if = end_if_stmt_id;
         if_stmt.true_case.scope = true_scope_id;
         if let Some(false_case) = &mut if_stmt.false_case {
             false_case.scope = false_scope_id.unwrap();
+        }
         return Ok(if_stmt_id);
+    }
     fn consume_while_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<WhileStatementId, ParseError> {
         let while_span = consume_exact_ident(&module.source, iter, KW_STMT_WHILE)?;
         consume_token(&module.source, iter, TokenKind::OpenParen)?;
         let test = self.consume_expression(module, iter, ctx)?;
         consume_token(&module.source, iter, TokenKind::CloseParen)?;
-        let body = self.consume_block_or_wrapped_statement(module, iter, ctx)?;
+        let body = self.consume_statement(module, iter, ctx)?;
-        Ok(ctx.heap.alloc_while_statement(|this| WhileStatement{
+        let while_stmt_id = ctx.heap.alloc_while_statement(|this| WhileStatement{
             this,
             span: while_span,
             test,
             scope: ScopeId::new_invalid(),
             body,
             end_while: EndWhileStatementId::new_invalid(),
             in_sync: SynchronousStatementId::new_invalid(),
         }))
         });
         let end_while_stmt_id = ctx.heap.alloc_end_while_statement(|this| EndWhileStatement{
             this,
             start_while: while_stmt_id,
             next: StatementId::new_invalid(),
         });
         let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::While(while_stmt_id)));
         let while_stmt = &mut ctx.heap[while_stmt_id];
         while_stmt.scope = scope_id;
         while_stmt.end_while = end_while_stmt_id;
         Ok(while_stmt_id)
+    }
     fn consume_break_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<BreakStatementId, ParseError> {
         let break_span = consume_exact_ident(&module.source, iter, KW_STMT_BREAK)?;
         let label = if Some(TokenKind::Ident) == iter.next() {
             let label = consume_ident_interned(&module.source, iter, ctx)?;
             Some(label)
         } else {
             None
         };
         consume_token(&module.source, iter, TokenKind::SemiColon)?;
         Ok(ctx.heap.alloc_break_statement(|this| BreakStatement{
             this,
             span: break_span,
             label,
             target: EndWhileStatementId::new_invalid(),
         }))
+    }
     fn consume_continue_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ContinueStatementId, ParseError> {
         let continue_span = consume_exact_ident(&module.source, iter, KW_STMT_CONTINUE)?;
         let label=  if Some(TokenKind::Ident) == iter.next() {
             let label = consume_ident_interned(&module.source, iter, ctx)?;
             Some(label)
         } else {
             None
         };
         consume_token(&module.source, iter, TokenKind::SemiColon)?;
         Ok(ctx.heap.alloc_continue_statement(|this| ContinueStatement{
             this,
             span: continue_span,
             label,
             target: WhileStatementId::new_invalid(),
         }))
+    }
     fn consume_synchronous_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<SynchronousStatementId, ParseError> {
         let synchronous_span = consume_exact_ident(&module.source, iter, KW_STMT_SYNC)?;
-        let body = self.consume_block_or_wrapped_statement(module, iter, ctx)?;
+        let body = self.consume_statement(module, iter, ctx)?;
-        Ok(ctx.heap.alloc_synchronous_statement(|this| SynchronousStatement{
+        let sync_stmt_id = ctx.heap.alloc_synchronous_statement(|this| SynchronousStatement{
             this,
             span: synchronous_span,
             scope: ScopeId::new_invalid(),
             body,
             end_sync: EndSynchronousStatementId::new_invalid(),
         }))
         });
         let end_sync_stmt_id = ctx.heap.alloc_end_synchronous_statement(|this| EndSynchronousStatement{
             this,
             start_sync: sync_stmt_id,
             next: StatementId::new_invalid(),
         });
         let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Synchronous(sync_stmt_id)));
         let sync_stmt = &mut ctx.heap[sync_stmt_id];
         sync_stmt.scope = scope_id;
         sync_stmt.end_sync = end_sync_stmt_id;
         return Ok(sync_stmt_id);
+    }
     fn consume_fork_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ForkStatementId, ParseError> {
         let fork_span = consume_exact_ident(&module.source, iter, KW_STMT_FORK)?;
-        let left_body = self.consume_block_or_wrapped_statement(module, iter, ctx)?;
+        let left_body = self.consume_statement(module, iter, ctx)?;
         let right_body = if has_ident(&module.source, iter, KW_STMT_OR) {
             iter.consume();
-            let right_body = self.consume_block_or_wrapped_statement(module, iter, ctx)?;
+            let right_body = self.consume_statement(module, iter, ctx)?;
             Some(right_body)
         } else {
             None
         };
         Ok(ctx.heap.alloc_fork_statement(|this| ForkStatement{
             this,
             span: fork_span,
             left_body,
             right_body,
             end_fork: EndForkStatementId::new_invalid(),
         }))
+    }
     fn consume_select_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<SelectStatementId, ParseError> {
         let select_span = consume_exact_ident(&module.source, iter, KW_STMT_SELECT)?;
         consume_token(&module.source, iter, TokenKind::OpenCurly)?;
         let mut cases = Vec::new();
         let mut next = iter.next();
         while Some(TokenKind::CloseCurly) != next {
             let guard = match self.maybe_consume_memory_statement_without_semicolon(module, iter, ctx)? {
                 Some(guard_mem_stmt) => guard_mem_stmt.upcast().upcast(),
                 None => {
                     let start_pos = iter.last_valid_pos();
                     let expr = self.consume_expression(module, iter, ctx)?;
                     let end_pos = iter.last_valid_pos();
                     let guard_expr_stmt = ctx.heap.alloc_expression_statement(|this| ExpressionStatement{
                         this,
                         span: InputSpan::from_positions(start_pos, end_pos),
                         expression: expr,
                         next: StatementId::new_invalid(),
                     });
                     guard_expr_stmt.upcast()
                 },
             };
             consume_token(&module.source, iter, TokenKind::ArrowRight)?;
-            let block = self.consume_block_or_wrapped_statement(module, iter, ctx)?;
+            let block = self.consume_statement(module, iter, ctx)?;
             cases.push(SelectCase{
                 guard, block,
                 guard,
                 body: block,
                 scope: ScopeId::new_invalid(),
                 involved_ports: Vec::with_capacity(1)
             });
             next = iter.next();
+        }
         consume_token(&module.source, iter, TokenKind::CloseCurly)?;
         Ok(ctx.heap.alloc_select_statement(|this| SelectStatement{
         let num_cases = cases.len();
         let select_stmt_id = ctx.heap.alloc_select_statement(|this| SelectStatement{
             this,
             span: select_span,
             cases,
             end_select: EndSelectStatementId::new_invalid(),
         }))
             relative_pos_in_parent: -1,
             next: StatementId::new_invalid(),
         });
         let end_select_stmt_id = ctx.heap.alloc_end_select_statement(|this| EndSelectStatement{
             this,
             start_select: select_stmt_id,
             next: StatementId::new_invalid(),
         });
         let select_stmt = &mut ctx.heap[select_stmt_id];
         select_stmt.end_select = end_select_stmt_id;
         for case_index in 0..num_cases {
             let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::SelectCase(select_stmt_id, case_index as u32)));
             let select_stmt = &mut ctx.heap[select_stmt_id];
             let select_case = &mut select_stmt.cases[case_index];
             select_case.scope = scope_id;
+        }
         return Ok(select_stmt_id)
+    }
     fn consume_return_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ReturnStatementId, ParseError> {
         let return_span = consume_exact_ident(&module.source, iter, KW_STMT_RETURN)?;
         let mut scoped_section = self.expressions.start_section();
         consume_comma_separated_until(
             TokenKind::SemiColon, &module.source, iter, ctx,
             |_source, iter, ctx| self.consume_expression(module, iter, ctx),
             &mut scoped_section, "an expression", None
         )?;
         let expressions = scoped_section.into_vec();
         if expressions.is_empty() {
             return Err(ParseError::new_error_str_at_span(&module.source, return_span, "expected at least one return value"));
         } else if expressions.len() > 1 {
             return Err(ParseError::new_error_str_at_span(&module.source, return_span, "multiple return values are not (yet) supported"))
+        }
         Ok(ctx.heap.alloc_return_statement(|this| ReturnStatement{
             this,
             span: return_span,
             expressions
         }))
+    }
     fn consume_goto_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<GotoStatementId, ParseError> {
         let goto_span = consume_exact_ident(&module.source, iter, KW_STMT_GOTO)?;
         let label = consume_ident_interned(&module.source, iter, ctx)?;
         consume_token(&module.source, iter, TokenKind::SemiColon)?;
         Ok(ctx.heap.alloc_goto_statement(|this| GotoStatement{
             this,
             span: goto_span,
             label,
             target: LabeledStatementId::new_invalid(),
         }))
+    }
     fn consume_new_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<NewStatementId, ParseError> {
         let new_span = consume_exact_ident(&module.source, iter, KW_STMT_NEW)?;
         let start_pos = iter.last_valid_pos();
         let expression_id = self.consume_primary_expression(module, iter, ctx)?;
         let expression = &ctx.heap[expression_id];
         let mut valid = false;
         let mut call_id = CallExpressionId::new_invalid();
         if let Expression::Call(expression) = expression {
             // Allow both components and functions, as it makes more sense to
             // check their correct use in the validation and linking pass
             if expression.method == Method::UserComponent || expression.method == Method::UserFunction {
                 call_id = expression.this;
                 valid = true;
+            }
+        }
         if !valid {
             return Err(ParseError::new_error_str_at_span(
                 &module.source, InputSpan::from_positions(start_pos, iter.last_valid_pos()), "expected a call expression"
             ));
+        }
         consume_token(&module.source, iter, TokenKind::SemiColon)?;
         debug_assert!(!call_id.is_invalid());
         Ok(ctx.heap.alloc_new_statement(|this| NewStatement{
             this,
             span: new_span,
             expression: call_id,
             next: StatementId::new_invalid(),
         }))
+    }
     fn consume_channel_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ChannelStatementId, ParseError> {
         // Consume channel specification
         let channel_span = consume_exact_ident(&module.source, iter, KW_STMT_CHANNEL)?;
         let (inner_port_type, end_pos) = if Some(TokenKind::OpenAngle) == iter.next() {
             // Retrieve the type of the channel, we're cheating a bit here by
             // consuming the first '<' and setting the initial angle depth to 1
             // such that our final '>' will be consumed as well.
             let angle_start_pos = iter.next_start_position();
             iter.consume();
             let definition_id = self.cur_definition;
             let poly_vars = ctx.heap[definition_id].poly_vars();
             let parser_type = self.type_parser.consume_parser_type(
                 iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars,
                 definition_id, SymbolScope::Module(module.root_id),
                 true, Some(angle_start_pos)
             )?;
             (parser_type.elements, parser_type.full_span.end)
         } else {
             // Assume inferred
+            (
                 vec![ParserTypeElement{
                     element_span: channel_span,
                     variant: ParserTypeVariant::Inferred
                 }],
                 channel_span.end
+            )
         };
         let from_identifier = consume_ident_interned(&module.source, iter, ctx)?;
         consume_token(&module.source, iter, TokenKind::ArrowRight)?;
         let to_identifier = consume_ident_interned(&module.source, iter, ctx)?;
         consume_token(&module.source, iter, TokenKind::SemiColon)?;
         // Construct ports
         let port_type_span = InputSpan::from_positions(channel_span.begin, end_pos);
         let port_type_len = inner_port_type.len() + 1;
         let mut from_port_type = ParserType{ elements: Vec::with_capacity(port_type_len), full_span: port_type_span };
         from_port_type.elements.push(ParserTypeElement{
             element_span: channel_span,
             variant: ParserTypeVariant::Output,
         });
         from_port_type.elements.extend_from_slice(&inner_port_type);
         let from = ctx.heap.alloc_variable(|this| Variable{
             this,
             kind: VariableKind::Local,
             identifier: from_identifier,
             parser_type: from_port_type,
-            relative_pos_in_block: 0,
+            relative_pos_in_parent: 0,
             unique_id_in_scope: -1,
         });
         let mut to_port_type = ParserType{ elements: Vec::with_capacity(port_type_len), full_span: port_type_span };
         to_port_type.elements.push(ParserTypeElement{
             element_span: channel_span,
             variant: ParserTypeVariant::Input
         });
         to_port_type.elements.extend_from_slice(&inner_port_type);
         let to = ctx.heap.alloc_variable(|this|Variable{
             this,
             kind: VariableKind::Local,
             identifier: to_identifier,
             parser_type: to_port_type,
-            relative_pos_in_block: 0,
+            relative_pos_in_parent: 0,
             unique_id_in_scope: -1,
         });
         // Construct the channel
         Ok(ctx.heap.alloc_channel_statement(|this| ChannelStatement{
             this,
             span: channel_span,
             from, to,
-            relative_pos_in_block: 0,
+            relative_pos_in_parent: 0,
             next: StatementId::new_invalid(),
         }))
+    }
     fn consume_labeled_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, section: &mut ScopedSection<StatementId>
     ) -> Result<(), ParseError> {
     fn consume_labeled_statement(&mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx) -> Result<LabeledStatementId, ParseError> {
         let label = consume_ident_interned(&module.source, iter, ctx)?;
         consume_token(&module.source, iter, TokenKind::Colon)?;
         // Not pretty: consume_statement may produce more than one statement.
         // The values in the section need to be in the correct order if some
         // kind of outer block is consumed, so we take another section, push
         // the expressions in that one, and then allocate the labeled statement.
         let mut inner_section = self.statements.start_section();
         self.consume_statement(module, iter, ctx, &mut inner_section)?;
         debug_assert!(inner_section.len() >= 1);
         let inner_stmt_id = self.consume_statement(module, iter, ctx)?;
         let stmt_id = ctx.heap.alloc_labeled_statement(|this| LabeledStatement {
             this,
             label,
             body: inner_section[0],
             relative_pos_in_block: 0,
             body: inner_stmt_id,
             relative_pos_in_parent: 0,
             in_sync: SynchronousStatementId::new_invalid(),
         });
         if inner_section.len() == 1 {
             // Produce the labeled statement pointing to the first statement.
             // This is by far the most common case.
             inner_section.forget();
             section.push(stmt_id.upcast());
         } else {
             // Produce the labeled statement using the first statement, and push
             // the remaining ones at the end.
             let inner_statements = inner_section.into_vec();
             section.push(stmt_id.upcast());
             for idx in 1..inner_statements.len() {
                 section.push(inner_statements[idx])
+            }
+        }
         Ok(())
         return Ok(stmt_id);
+    }
     /// Attempts to consume a memory statement (a statement along the lines of
     /// `type var_name = initial_expr`). Will return `Ok(None)` if it didn't
     /// seem like there was a memory statement, `Ok(Some(...))` if there was
     /// one, and `Err(...)` if its reasonable to assume that there was a memory
     /// statement, but we failed to parse it.
     fn maybe_consume_memory_statement_without_semicolon(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<Option<MemoryStatementId>, ParseError> {
         // This is a bit ugly. It would be nicer if we could somehow
         // consume the expression with a type hint if we do get a valid
         // type, but we don't get an identifier following it
         let iter_state = iter.save();
         let definition_id = self.cur_definition;
         let poly_vars = ctx.heap[definition_id].poly_vars();
         let parser_type = self.type_parser.consume_parser_type(
             iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars,
             definition_id, SymbolScope::Definition(definition_id), true, None
         );
         if let Ok(parser_type) = parser_type {
             if Some(TokenKind::Ident) == iter.next() {
                 // Assume this is a proper memory statement
                 let identifier = consume_ident_interned(&module.source, iter, ctx)?;
                 let memory_span = InputSpan::from_positions(parser_type.full_span.begin, identifier.span.end);
                 let assign_span = consume_token(&module.source, iter, TokenKind::Equal)?;
                 let initial_expr_id = self.consume_expression(module, iter, ctx)?;
                 let initial_expr_end_pos = iter.last_valid_pos();
                 // Create the AST variable
                 let local_id = ctx.heap.alloc_variable(|this| Variable{
                     this,
                     kind: VariableKind::Local,
                     identifier: identifier.clone(),
                     parser_type,
-                    relative_pos_in_block: 0,
+                    relative_pos_in_parent: 0,
                     unique_id_in_scope: -1,
                 });
                 // Create the initial assignment expression
                 // Note: we set the initial variable declaration here
                 let variable_expr_id = ctx.heap.alloc_variable_expression(|this| VariableExpression{
                     this,
                     identifier,
                     declaration: Some(local_id),
                     used_as_binding_target: false,
                     parent: ExpressionParent::None,
-                    unique_id_in_definition: -1,
+                    type_index: -1,
                 });
                 let assignment_expr_id = ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{
                     this,
                     operator_span: assign_span,
                     full_span: InputSpan::from_positions(memory_span.begin, initial_expr_end_pos),
                     left: variable_expr_id.upcast(),
                     operation: AssignmentOperator::Set,
                     right: initial_expr_id,
                     parent: ExpressionParent::None,
-                    unique_id_in_definition: -1,
+                    type_index: -1,
                 });
                 // Put both together in the memory statement
                 let memory_stmt_id = ctx.heap.alloc_memory_statement(|this| MemoryStatement{
                     this,
                     span: memory_span,
                     variable: local_id,
                     initial_expr: assignment_expr_id,
                     next: StatementId::new_invalid()
                 });
                 return Ok(Some(memory_stmt_id));
+            }
+        }
         // If here then one of the preconditions for a memory statement was not
         // met. So recover the iterator and return
         iter.load(iter_state);
         Ok(None)
+    }
     fn consume_expression_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionStatementId, ParseError> {
         let start_pos = iter.last_valid_pos();
         let expression = self.consume_expression(module, iter, ctx)?;
         let end_pos = iter.last_valid_pos();
         consume_token(&module.source, iter, TokenKind::SemiColon)?;
         Ok(ctx.heap.alloc_expression_statement(|this| ExpressionStatement{
             this,
             span: InputSpan::from_positions(start_pos, end_pos),
             expression,
             next: StatementId::new_invalid(),
         }))
+    }
     //--------------------------------------------------------------------------
     // Expression Parsing
     //--------------------------------------------------------------------------
     // TODO: @Cleanup This is fine for now. But I prefer my stacktraces not to
     //  look like enterprise Java code...
     fn consume_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         self.consume_assignment_expression(module, iter, ctx)
+    }
     fn consume_assignment_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         // Utility to convert token into assignment operator
         fn parse_assignment_operator(token: Option<TokenKind>) -> Option<AssignmentOperator> {
             use TokenKind as TK;
             use AssignmentOperator as AO;
             if token.is_none() {
                 return None
+            }
             match token.unwrap() {
                 TK::Equal               => Some(AO::Set),
                 TK::AtEquals            => Some(AO::Concatenated),
                 TK::StarEquals          => Some(AO::Multiplied),
                 TK::SlashEquals         => Some(AO::Divided),
                 TK::PercentEquals       => Some(AO::Remained),
                 TK::PlusEquals          => Some(AO::Added),
                 TK::MinusEquals         => Some(AO::Subtracted),
                 TK::ShiftLeftEquals     => Some(AO::ShiftedLeft),
                 TK::ShiftRightEquals    => Some(AO::ShiftedRight),
                 TK::AndEquals           => Some(AO::BitwiseAnded),
                 TK::CaretEquals         => Some(AO::BitwiseXored),
                 TK::OrEquals            => Some(AO::BitwiseOred),
                 _                       => None
+            }
+        }
         let expr = self.consume_conditional_expression(module, iter, ctx)?;
         if let Some(operation) = parse_assignment_operator(iter.next()) {
             let operator_span = iter.next_span();
             iter.consume();
             let left = expr;
             let right = self.consume_expression(module, iter, ctx)?;
             let full_span = InputSpan::from_positions(
                 ctx.heap[left].full_span().begin,
                 ctx.heap[right].full_span().end,
             );
             Ok(ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{
                 this, operator_span, full_span, left, operation, right,
                 parent: ExpressionParent::None,
-                unique_id_in_definition: -1,
+                type_index: -1,
             }).upcast())
         } else {
             Ok(expr)
+        }
+    }
     fn consume_conditional_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         let result = self.consume_concat_expression(module, iter, ctx)?;
         if let Some(TokenKind::Question) = iter.next() {
             let operator_span = iter.next_span();
             iter.consume();
             let test = result;
             let true_expression = self.consume_expression(module, iter, ctx)?;
             consume_token(&module.source, iter, TokenKind::Colon)?;
             let false_expression = self.consume_expression(module, iter, ctx)?;
             let full_span = InputSpan::from_positions(
                 ctx.heap[test].full_span().begin,
                 ctx.heap[false_expression].full_span().end,
             );
             Ok(ctx.heap.alloc_conditional_expression(|this| ConditionalExpression{
                 this, operator_span, full_span, test, true_expression, false_expression,
                 parent: ExpressionParent::None,
-                unique_id_in_definition: -1,
+                type_index: -1,
             }).upcast())
         } else {
             Ok(result)
+        }
+    }
     fn consume_concat_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         self.consume_generic_binary_expression(
             module, iter, ctx,
             |token| match token {
                 Some(TokenKind::At) => Some(BinaryOperator::Concatenate),
                 _ => None
             },
             Self::consume_logical_or_expression
+        )
+    }
     fn consume_logical_or_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         self.consume_generic_binary_expression(
             module, iter, ctx,
             |token| match token {
                 Some(TokenKind::OrOr) => Some(BinaryOperator::LogicalOr),
                 _ => None
             },
             Self::consume_logical_and_expression
+        )
+    }
     fn consume_logical_and_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         self.consume_generic_binary_expression(
             module, iter, ctx,
             |token| match token {
                 Some(TokenKind::AndAnd) => Some(BinaryOperator::LogicalAnd),
                 _ => None
             },
             Self::consume_bitwise_or_expression
+        )
+    }
     fn consume_bitwise_or_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         self.consume_generic_binary_expression(
             module, iter, ctx,
             |token| match token {
                 Some(TokenKind::Or) => Some(BinaryOperator::BitwiseOr),
                 _ => None
             },
             Self::consume_bitwise_xor_expression
+        )
+    }
     fn consume_bitwise_xor_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         self.consume_generic_binary_expression(
             module, iter, ctx,
             |token| match token {
                 Some(TokenKind::Caret) => Some(BinaryOperator::BitwiseXor),
                 _ => None
             },
             Self::consume_bitwise_and_expression
+        )
+    }
     fn consume_bitwise_and_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         self.consume_generic_binary_expression(
             module, iter, ctx,
             |token| match token {
                 Some(TokenKind::And) => Some(BinaryOperator::BitwiseAnd),
                 _ => None
             },
             Self::consume_equality_expression
+        )
+    }
     fn consume_equality_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         self.consume_generic_binary_expression(
             module, iter, ctx,
             |token| match token {
                 Some(TokenKind::EqualEqual) => Some(BinaryOperator::Equality),
                 Some(TokenKind::NotEqual) => Some(BinaryOperator::Inequality),
                 _ => None
             },
             Self::consume_relational_expression
+        )
+    }
     fn consume_relational_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         self.consume_generic_binary_expression(
             module, iter, ctx,
             |token| match token {
                 Some(TokenKind::OpenAngle) => Some(BinaryOperator::LessThan),
                 Some(TokenKind::CloseAngle) => Some(BinaryOperator::GreaterThan),
                 Some(TokenKind::LessEquals) => Some(BinaryOperator::LessThanEqual),
                 Some(TokenKind::GreaterEquals) => Some(BinaryOperator::GreaterThanEqual),
                 _ => None
             },
             Self::consume_shift_expression
+        )
+    }
     fn consume_shift_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         self.consume_generic_binary_expression(
             module, iter, ctx,
             |token| match token {
                 Some(TokenKind::ShiftLeft) => Some(BinaryOperator::ShiftLeft),
                 Some(TokenKind::ShiftRight) => Some(BinaryOperator::ShiftRight),
                 _ => None
             },
             Self::consume_add_or_subtract_expression
+        )
+    }
     fn consume_add_or_subtract_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         self.consume_generic_binary_expression(
             module, iter, ctx,
             |token| match token {
                 Some(TokenKind::Plus) => Some(BinaryOperator::Add),
                 Some(TokenKind::Minus) => Some(BinaryOperator::Subtract),
                 _ => None,
             },
             Self::consume_multiply_divide_or_modulus_expression
+        )
+    }
     fn consume_multiply_divide_or_modulus_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         self.consume_generic_binary_expression(
             module, iter, ctx,
             |token| match token {
                 Some(TokenKind::Star) => Some(BinaryOperator::Multiply),
                 Some(TokenKind::Slash) => Some(BinaryOperator::Divide),
                 Some(TokenKind::Percent) => Some(BinaryOperator::Remainder),
                 _ => None
             },
             Self::consume_prefix_expression
+        )
+    }
     fn consume_prefix_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         fn parse_prefix_token(token: Option<TokenKind>) -> Option<UnaryOperator> {
             use TokenKind as TK;
             use UnaryOperator as UO;
             match token {
                 Some(TK::Plus) => Some(UO::Positive),
                 Some(TK::Minus) => Some(UO::Negative),
                 Some(TK::Tilde) => Some(UO::BitwiseNot),
                 Some(TK::Exclamation) => Some(UO::LogicalNot),
                 _ => None
+            }
+        }
         let next = iter.next();
         if let Some(operation) = parse_prefix_token(next) {
             let operator_span = iter.next_span();
             iter.consume();
             let expression = self.consume_prefix_expression(module, iter, ctx)?;
             let full_span = InputSpan::from_positions(
                 operator_span.begin, ctx.heap[expression].full_span().end,
             );
             Ok(ctx.heap.alloc_unary_expression(|this| UnaryExpression {
                 this, operator_span, full_span, operation, expression,
                 parent: ExpressionParent::None,
-                unique_id_in_definition: -1,
+                type_index: -1,
             }).upcast())
         } else if next == Some(TokenKind::PlusPlus) {
             return Err(ParseError::new_error_str_at_span(
                 &module.source, iter.next_span(), "prefix increment is not supported in the language"
             ));
         } else if next == Some(TokenKind::MinusMinus) {
             return Err(ParseError::new_error_str_at_span(
                 &module.source, iter.next_span(), "prefix decrement is not supported in this language"
             ));
         } else {
             self.consume_postfix_expression(module, iter, ctx)
+        }
+    }
     fn consume_postfix_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         fn has_matching_postfix_token(token: Option<TokenKind>) -> bool {
             use TokenKind as TK;
             if token.is_none() { return false; }
             match token.unwrap() {
                 TK::PlusPlus | TK::MinusMinus | TK::OpenSquare | TK::Dot => true,
                 _ => false
+            }
+        }
         let mut result = self.consume_primary_expression(module, iter, ctx)?;
         let mut next = iter.next();
         while has_matching_postfix_token(next) {
             let token = next.unwrap();
             let mut operator_span = iter.next_span();
             iter.consume();
             if token == TokenKind::PlusPlus {
                 return Err(ParseError::new_error_str_at_span(
                     &module.source, operator_span, "postfix increment is not supported in this language"
                 ));
             } else if token == TokenKind::MinusMinus {
                 return Err(ParseError::new_error_str_at_span(
                     &module.source, operator_span, "prefix increment is not supported in this language"
                 ));
             } else if token == TokenKind::OpenSquare {
                 let subject = result;
                 let from_index = self.consume_expression(module, iter, ctx)?;
                 // Check if we have an indexing or slicing operation
                 next = iter.next();
                 if Some(TokenKind::DotDot) == next {
                     iter.consume();
                     let to_index = self.consume_expression(module, iter, ctx)?;
                     let end_span = consume_token(&module.source, iter, TokenKind::CloseSquare)?;
                     operator_span.end = end_span.end;
                     let full_span = InputSpan::from_positions(
                         ctx.heap[subject].full_span().begin, operator_span.end
                     );
                     result = ctx.heap.alloc_slicing_expression(|this| SlicingExpression{
                         this,
                         slicing_span: operator_span,
                         full_span, subject, from_index, to_index,
                         parent: ExpressionParent::None,
-                        unique_id_in_definition: -1,
+                        type_index: -1,
                     }).upcast();
                 } else if Some(TokenKind::CloseSquare) == next {
                     let end_span = consume_token(&module.source, iter, TokenKind::CloseSquare)?;
                     operator_span.end = end_span.end;
                     let full_span = InputSpan::from_positions(
                         ctx.heap[subject].full_span().begin, operator_span.end
                     );
                     result = ctx.heap.alloc_indexing_expression(|this| IndexingExpression{
                         this, operator_span, full_span, subject,
                         index: from_index,
                         parent: ExpressionParent::None,
-                        unique_id_in_definition: -1,
+                        type_index: -1,
                     }).upcast();
                 } else {
                     return Err(ParseError::new_error_str_at_pos(
                         &module.source, iter.last_valid_pos(), "unexpected token: expected ']' or '..'"
                     ));
+                }
             } else {
                 // Can be a select expression for struct fields, or a select
                 // for a tuple element.
                 debug_assert_eq!(token, TokenKind::Dot);
                 let subject = result;
                 let next = iter.next();
                 let (select_kind, full_span) = if Some(TokenKind::Integer) == next {
                     // Tuple member
                     let (index, index_span) = consume_integer_literal(&module.source, iter, &mut self.buffer)?;
                     let full_span = InputSpan::from_positions(
                         ctx.heap[subject].full_span().begin, index_span.end
                     );
                     (SelectKind::TupleMember(index), full_span)
                 } else if Some(TokenKind::Ident) == next {
                     // Struct field
                     let field_name = consume_ident_interned(&module.source, iter, ctx)?;
                     let full_span = InputSpan::from_positions(
                         ctx.heap[subject].full_span().begin, field_name.span.end
                     );
                     (SelectKind::StructField(field_name), full_span)
                 } else {
                     return Err(ParseError::new_error_str_at_pos(
                         &module.source, iter.last_valid_pos(), "unexpected token: expected integer or identifier"
                     ));
                 };
                 result = ctx.heap.alloc_select_expression(|this| SelectExpression{
                     this, operator_span, full_span, subject,
                     kind: select_kind,
                     parent: ExpressionParent::None,
-                    unique_id_in_definition: -1,
+                    type_index: -1,
                 }).upcast();
+            }
             next = iter.next();
+        }
         Ok(result)
+    }
     fn consume_primary_expression(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ExpressionId, ParseError> {
         let next = iter.next();
         let result = if next == Some(TokenKind::OpenParen) {
             // Something parenthesized. This can mean several things: we have
             // a parenthesized expression or we have a tuple literal. They are
             // ambiguous when the tuple has one member. But like the tuple type
             // parsing we interpret all one-tuples as parenthesized expressions.
             //
             // Practically (to prevent unnecessary `consume_expression` calls)
             // we distinguish the zero-tuple, the parenthesized expression, and
             // the N-tuple (for N > 1).
             let open_paren_pos = iter.next_start_position();
             iter.consume();
             let result = if Some(TokenKind::CloseParen) == iter.next() {
                 // Zero-tuple
                 let (_, close_paren_pos) = iter.next_positions();
                 iter.consume();
                 let literal_id = ctx.heap.alloc_literal_expression(|this| LiteralExpression{
                     this,
                     span: InputSpan::from_positions(open_paren_pos, close_paren_pos),
                     value: Literal::Tuple(Vec::new()),
                     parent: ExpressionParent::None,
-                    unique_id_in_definition: -1,
+                    type_index: -1,
                 });
                 literal_id.upcast()
             } else {
                 // Start by consuming one expression, then check for a comma
                 let expr_id = self.consume_expression(module, iter, ctx)?;
                 if Some(TokenKind::Comma) == iter.next() && Some(TokenKind::CloseParen) != iter.peek() {
                     // Must be an N-tuple
                     iter.consume(); // the comma
                     let mut scoped_section = self.expressions.start_section();
                     scoped_section.push(expr_id);
                     let mut close_paren_pos = open_paren_pos;
                     consume_comma_separated_until(
                         TokenKind::CloseParen, &module.source, iter, ctx,
                         |_source, iter, ctx| self.consume_expression(module, iter, ctx),
                         &mut scoped_section, "an expression", Some(&mut close_paren_pos)
                     )?;
                     debug_assert!(scoped_section.len() > 1); // peeked token wasn't CloseParen, must be expression
                     let literal_id = ctx.heap.alloc_literal_expression(|this| LiteralExpression{
                         this,
                         span: InputSpan::from_positions(open_paren_pos, close_paren_pos),
                         value: Literal::Tuple(scoped_section.into_vec()),
                         parent: ExpressionParent::None,
-                        unique_id_in_definition: -1,
+                        type_index: -1,
                     });
                     literal_id.upcast()
                 } else {
                     // Assume we're dealing with a normal expression
                     consume_token(&module.source, iter, TokenKind::CloseParen)?;
                     expr_id
+                }
             };
             result
         } else if next == Some(TokenKind::OpenCurly) {
             // Array literal
             let (start_pos, mut end_pos) = iter.next_positions();
             let mut scoped_section = self.expressions.start_section();
             consume_comma_separated(
                 TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
                 |_source, iter, ctx| self.consume_expression(module, iter, ctx),
                 &mut scoped_section, "an expression", "a list of expressions", Some(&mut end_pos)
             )?;
             ctx.heap.alloc_literal_expression(|this| LiteralExpression{
                 this,
                 span: InputSpan::from_positions(start_pos, end_pos),
                 value: Literal::Array(scoped_section.into_vec()),
                 parent: ExpressionParent::None,
-                unique_id_in_definition: -1,
+                type_index: -1,
             }).upcast()
         } else if next == Some(TokenKind::Integer) {
             let (literal, span) = consume_integer_literal(&module.source, iter, &mut self.buffer)?;
             ctx.heap.alloc_literal_expression(|this| LiteralExpression{
                 this, span,
                 value: Literal::Integer(LiteralInteger{ unsigned_value: literal, negated: false }),
                 parent: ExpressionParent::None,
-                unique_id_in_definition: -1,
+                type_index: -1,
             }).upcast()
         } else if next == Some(TokenKind::String) {
             let span = consume_string_literal(&module.source, iter, &mut self.buffer)?;
             let interned = ctx.pool.intern(self.buffer.as_bytes());
             ctx.heap.alloc_literal_expression(|this| LiteralExpression{
                 this, span,
                 value: Literal::String(interned),
                 parent: ExpressionParent::None,
-                unique_id_in_definition: -1,
+                type_index: -1,
             }).upcast()
         } else if next == Some(TokenKind::Character) {
             let (character, span) = consume_character_literal(&module.source, iter)?;
             ctx.heap.alloc_literal_expression(|this| LiteralExpression{
                 this, span,
                 value: Literal::Character(character),
                 parent: ExpressionParent::None,
-                unique_id_in_definition: -1,
+                type_index: -1,
             }).upcast()
         } else if next == Some(TokenKind::Ident) {
             // May be a variable, a type instantiation or a function call. If we
             // have a single identifier that we cannot find in the type table
             // then we're going to assume that we're dealing with a variable.
             let ident_span = iter.next_span();
             let ident_text = module.source.section_at_span(ident_span);
             let symbol = ctx.symbols.get_symbol_by_name(SymbolScope::Module(module.root_id), ident_text);
             if symbol.is_some() {
                 // The first bit looked like a symbol, so we're going to follow
                 // that all the way through, assume we arrive at some kind of
                 // function call or type instantiation
                 use ParserTypeVariant as PTV;
                 let symbol_scope = SymbolScope::Definition(self.cur_definition);
                 let poly_vars = ctx.heap[self.cur_definition].poly_vars();
                 let parser_type = self.type_parser.consume_parser_type(
                     iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars, self.cur_definition,
                     symbol_scope, true, None
                 )?;
                 debug_assert!(!parser_type.elements.is_empty());
                 match parser_type.elements[0].variant {
                     PTV::Definition(target_definition_id, _) => {
                         let definition = &ctx.heap[target_definition_id];
                         match definition {
                             Definition::Struct(_) => {
                                 // Struct literal
                                 let mut last_token = iter.last_valid_pos();
                                 let mut struct_fields = Vec::new();
                                 consume_comma_separated(
                                     TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
                                     |source, iter, ctx| {
                                         let identifier = consume_ident_interned(source, iter, ctx)?;
                                         consume_token(source, iter, TokenKind::Colon)?;
                                         let value = self.consume_expression(module, iter, ctx)?;
                                         Ok(LiteralStructField{ identifier, value, field_idx: 0 })
                                     },
                                     &mut struct_fields, "a struct field", "a list of struct fields", Some(&mut last_token)
                                 )?;
                                 ctx.heap.alloc_literal_expression(|this| LiteralExpression{
                                     this,
                                     span: InputSpan::from_positions(ident_span.begin, last_token),
                                     value: Literal::Struct(LiteralStruct{
                                         parser_type,
                                         fields: struct_fields,
                                         definition: target_definition_id,
                                     }),
                                     parent: ExpressionParent::None,
-                                    unique_id_in_definition: -1,
+                                    type_index: -1,
                                 }).upcast()
                             },
                             Definition::Enum(_) => {
                                 // Enum literal: consume the variant
                                 consume_token(&module.source, iter, TokenKind::ColonColon)?;
                                 let variant = consume_ident_interned(&module.source, iter, ctx)?;
                                 ctx.heap.alloc_literal_expression(|this| LiteralExpression{
                                     this,
                                     span: InputSpan::from_positions(ident_span.begin, variant.span.end),
                                     value: Literal::Enum(LiteralEnum{
                                         parser_type,
                                         variant,
                                         definition: target_definition_id,
                                         variant_idx: 0
                                     }),
                                     parent: ExpressionParent::None,
-                                    unique_id_in_definition: -1,
+                                    type_index: -1,
                                 }).upcast()
                             },
                             Definition::Union(_) => {
                                 // Union literal: consume the variant
                                 consume_token(&module.source, iter, TokenKind::ColonColon)?;
                                 let variant = consume_ident_interned(&module.source, iter, ctx)?;
                                 // Consume any possible embedded values
                                 let mut end_pos = variant.span.end;
                                 let values = if Some(TokenKind::OpenParen) == iter.next() {
                                     self.consume_expression_list(module, iter, ctx, Some(&mut end_pos))?
                                 } else {
                                     Vec::new()
                                 };
                                 ctx.heap.alloc_literal_expression(|this| LiteralExpression{
                                     this,
                                     span: InputSpan::from_positions(ident_span.begin, end_pos),
                                     value: Literal::Union(LiteralUnion{
                                         parser_type, variant, values,
                                         definition: target_definition_id,
                                         variant_idx: 0,
                                     }),
                                     parent: ExpressionParent::None,
                                     unique_id_in_definition: -1,
                                 }).upcast()
                             },
                             Definition::Component(_) => {
                                 // Component instantiation
                                 let func_span = parser_type.full_span;
                                 let mut full_span = func_span;
                                 let arguments = self.consume_expression_list(
                                     module, iter, ctx, Some(&mut full_span.end)
                                 )?;
                                 ctx.heap.alloc_call_expression(|this| CallExpression{
                                     this, func_span, full_span,
                                     parser_type,
                                     method: Method::UserComponent,
                                     arguments,
                                     definition: target_definition_id,
                                     parent: ExpressionParent::None,
                                     unique_id_in_definition: -1,
                                     type_index: -1,
                                 }).upcast()
                             },
-                            Definition::Function(function_definition) => {
+                            Definition::Procedure(proc_def) => {
                                 // Check whether it is a builtin function
                                 let method = if function_definition.builtin {
                                     match function_definition.identifier.value.as_bytes() {
                                 let procedure_id = proc_def.this;
                                 let method = if proc_def.builtin {
                                     match proc_def.identifier.value.as_bytes() {
                                         KW_FUNC_GET => Method::Get,
                                         KW_FUNC_PUT => Method::Put,
                                         KW_FUNC_FIRES => Method::Fires,
                                         KW_FUNC_CREATE => Method::Create,
                                         KW_FUNC_LENGTH => Method::Length,
                                         KW_FUNC_ASSERT => Method::Assert,
                                         KW_FUNC_PRINT => Method::Print,
                                         _ => unreachable!(),
+                                    }
                                 } else {
+                                } else if proc_def.kind == ProcedureKind::Function {
                                     Method::UserFunction
                                 } else {
                                     Method::UserComponent
                                 };
                                 // Function call: consume the arguments
                                 let func_span = parser_type.full_span;
                                 let mut full_span = func_span;
                                 let arguments = self.consume_expression_list(
                                     module, iter, ctx, Some(&mut full_span.end)
                                 )?;
                                 ctx.heap.alloc_call_expression(|this| CallExpression{
                                     this, func_span, full_span, parser_type, method, arguments,
-                                    definition: target_definition_id,
+                                    procedure: procedure_id,
                                     parent: ExpressionParent::None,
-                                    unique_id_in_definition: -1,
+                                    type_index: -1,
                                 }).upcast()
+                            }
+                        }
                     },
                     _ => {
                         return Err(ParseError::new_error_str_at_span(
                             &module.source, parser_type.full_span, "unexpected type in expression"
                         ))
+                    }
+                }
             } else {
                 // Check for builtin keywords or builtin functions
                 if ident_text == KW_LIT_NULL || ident_text == KW_LIT_TRUE || ident_text == KW_LIT_FALSE {
                     iter.consume();
                     // Parse builtin literal
                     let value = match ident_text {
                         KW_LIT_NULL => Literal::Null,
                         KW_LIT_TRUE => Literal::True,
                         KW_LIT_FALSE => Literal::False,
                         _ => unreachable!(),
                     };
                     ctx.heap.alloc_literal_expression(|this| LiteralExpression {
                         this,
                         span: ident_span,
                         value,
                         parent: ExpressionParent::None,
-                        unique_id_in_definition: -1,
+                        type_index: -1,
                     }).upcast()
                 } else if ident_text == KW_LET {
                     // Binding expression
                     let operator_span = iter.next_span();
                     iter.consume();
                     let bound_to = self.consume_prefix_expression(module, iter, ctx)?;
                     consume_token(&module.source, iter, TokenKind::Equal)?;
                     let bound_from = self.consume_prefix_expression(module, iter, ctx)?;
                     let full_span = InputSpan::from_positions(
                         operator_span.begin, ctx.heap[bound_from].full_span().end,
                     );
                     ctx.heap.alloc_binding_expression(|this| BindingExpression{
                         this, operator_span, full_span, bound_to, bound_from,
                         parent: ExpressionParent::None,
-                        unique_id_in_definition: -1,
+                        type_index: -1,
                     }).upcast()
                 } else if ident_text == KW_CAST {
                     // Casting expression
                     iter.consume();
                     let to_type = if Some(TokenKind::OpenAngle) == iter.next() {
                         let angle_start_pos = iter.next_start_position();
                         iter.consume();
                         let definition_id = self.cur_definition;
                         let poly_vars = ctx.heap[definition_id].poly_vars();
                         self.type_parser.consume_parser_type(
                             iter, &ctx.heap, &module.source, &ctx.symbols,
                             poly_vars, definition_id, SymbolScope::Module(module.root_id),
                             true, Some(angle_start_pos)
                         )?
                     } else {
                         // Automatic casting with inferred target type
                         ParserType{
                             elements: vec![ParserTypeElement{
                                 element_span: ident_span,
                                 variant: ParserTypeVariant::Inferred,
                             }],
                             full_span: ident_span
+                        }
                     };
                     consume_token(&module.source, iter, TokenKind::OpenParen)?;
                     let subject = self.consume_expression(module, iter, ctx)?;
                     let mut full_span = iter.next_span();
                     full_span.begin = to_type.full_span.begin;
                     consume_token(&module.source, iter, TokenKind::CloseParen)?;
                     ctx.heap.alloc_cast_expression(|this| CastExpression{
                         this,
                         cast_span: to_type.full_span,
                         full_span, to_type, subject,
                         parent: ExpressionParent::None,
-                        unique_id_in_definition: -1,
+                        type_index: -1,
                     }).upcast()
                 } else {
                     // Not a builtin literal, but also not a known type. So we
                     // assume it is a variable expression. Although if we do,
                     // then if a programmer mistyped a struct/function name the
                     // error messages will be rather cryptic. For polymorphic
                     // arguments we can't really do anything at all (because it
                     // uses the '<' token). In the other cases we try to provide
                     // a better error message.
                     iter.consume();
                     let next = iter.next();
                     if Some(TokenKind::ColonColon) == next {
                         return Err(ParseError::new_error_str_at_span(&module.source, ident_span, "unknown identifier"));
                     } else if Some(TokenKind::OpenParen) == next {
                         return Err(ParseError::new_error_str_at_span(
                             &module.source, ident_span,
                             "unknown identifier, did you mistype a union variant's, component's, or function's name?"
                         ));
                     } else if Some(TokenKind::OpenCurly) == next {
                         return Err(ParseError::new_error_str_at_span(
                             &module.source, ident_span,
                             "unknown identifier, did you mistype a struct type's name?"
                         ))
+                    }
                     let ident_text = ctx.pool.intern(ident_text);
                     let identifier = Identifier { span: ident_span, value: ident_text };
                     ctx.heap.alloc_variable_expression(|this| VariableExpression {
                         this,
                         identifier,
                         declaration: None,
                         used_as_binding_target: false,
                         parent: ExpressionParent::None,
-                        unique_id_in_definition: -1,
+                        type_index: -1,
                     }).upcast()
+                }
+            }
         } else {
             return Err(ParseError::new_error_str_at_pos(
                 &module.source, iter.last_valid_pos(), "expected an expression"
             ));
         };
         Ok(result)
+    }
     //--------------------------------------------------------------------------
     // Expression Utilities
     //--------------------------------------------------------------------------
     #[inline]
     fn consume_generic_binary_expression<
         M: Fn(Option<TokenKind>) -> Option<BinaryOperator>,
         F: Fn(&mut PassDefinitions, &Module, &mut TokenIter, &mut PassCtx) -> Result<ExpressionId, ParseError>
     >(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, match_fn: M, higher_precedence_fn: F
     ) -> Result<ExpressionId, ParseError> {
         let mut result = higher_precedence_fn(self, module, iter, ctx)?;
         while let Some(operation) = match_fn(iter.next()) {
             let operator_span = iter.next_span();
             iter.consume();
             let left = result;
             let right = higher_precedence_fn(self, module, iter, ctx)?;
             let full_span = InputSpan::from_positions(
                 ctx.heap[left].full_span().begin,
                 ctx.heap[right].full_span().end,
             );
             result = ctx.heap.alloc_binary_expression(|this| BinaryExpression{
                 this, operator_span, full_span, left, operation, right,
                 parent: ExpressionParent::None,
-                unique_id_in_definition: -1,
+                type_index: -1,
             }).upcast();
+        }
         Ok(result)
+    }
     #[inline]
     fn consume_expression_list(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, end_pos: Option<&mut InputPosition>
     ) -> Result<Vec<ExpressionId>, ParseError> {
         let mut section = self.expressions.start_section();
         consume_comma_separated(
             TokenKind::OpenParen, TokenKind::CloseParen, &module.source, iter, ctx,
             |_source, iter, ctx| self.consume_expression(module, iter, ctx),
             &mut section, "an expression", "a list of expressions", end_pos
         )?;
         Ok(section.into_vec())
+    }
+}
 /// Consumes polymorphic variables and throws them on the floor.
 fn consume_polymorphic_vars_spilled(source: &InputSource, iter: &mut TokenIter, _ctx: &mut PassCtx) -> Result<(), ParseError> {
     maybe_consume_comma_separated_spilled(
         TokenKind::OpenAngle, TokenKind::CloseAngle, source, iter, _ctx,
         |source, iter, _ctx| {
             consume_ident(source, iter)?;
             Ok(())
         }, "a polymorphic variable"
     )?;
     Ok(())
+}
 /// Consumes the parameter list to functions/components
 fn consume_parameter_list(
     parser: &mut ParserTypeParser, source: &InputSource, iter: &mut TokenIter,
     ctx: &mut PassCtx, target: &mut ScopedSection<VariableId>,
     scope: SymbolScope, definition_id: DefinitionId
 ) -> Result<(), ParseError> {
     consume_comma_separated(
         TokenKind::OpenParen, TokenKind::CloseParen, source, iter, ctx,
         |source, iter, ctx| {
             let poly_vars = ctx.heap[definition_id].poly_vars(); // Rust being rust, multiple lookups
             let parser_type = parser.consume_parser_type(
                 iter, &ctx.heap, source, &ctx.symbols, poly_vars, definition_id,
                 scope, false, None
             )?;
             let identifier = consume_ident_interned(source, iter, ctx)?;
             let parameter_id = ctx.heap.alloc_variable(|this| Variable{
                 this,
                 kind: VariableKind::Parameter,
                 parser_type,
                 identifier,
-                relative_pos_in_block: 0,
+                relative_pos_in_parent: 0,
                 unique_id_in_scope: -1,
             });
             Ok(parameter_id)
         },
         target, "a parameter", "a parameter list", None
+    )
+}
@@ \ No newline at end of file @@

src/protocol/parser/pass_rewriting.rs

➞

Show inline comments

@@ new file 100644 @@
 use crate::collections::*;
 use crate::protocol::*;
 use super::visitor::*;
 pub(crate) struct PassRewriting {
     current_scope: ScopeId,
     current_procedure_id: ProcedureDefinitionId,
     definition_buffer: ScopedBuffer<DefinitionId>,
     statement_buffer: ScopedBuffer<StatementId>,
     call_expr_buffer: ScopedBuffer<CallExpressionId>,
     expression_buffer: ScopedBuffer<ExpressionId>,
     scope_buffer: ScopedBuffer<ScopeId>,
+}
 impl PassRewriting {
     pub(crate) fn new() -> Self {
         Self{
             current_scope: ScopeId::new_invalid(),
             current_procedure_id: ProcedureDefinitionId::new_invalid(),
             definition_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
             statement_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             call_expr_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             expression_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             scope_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
+        }
+    }
+}
 impl Visitor for PassRewriting {
     fn visit_module(&mut self, ctx: &mut Ctx) -> VisitorResult {
         let module = ctx.module();
         debug_assert_eq!(module.phase, ModuleCompilationPhase::Typed);
         let root_id = module.root_id;
         let root = &ctx.heap[root_id];
         let definition_section = self.definition_buffer.start_section_initialized(&root.definitions);
         for definition_index in 0..definition_section.len() {
             let definition_id = definition_section[definition_index];
             self.visit_definition(ctx, definition_id)?;
+        }
         definition_section.forget();
         ctx.module_mut().phase = ModuleCompilationPhase::Rewritten;
         return Ok(())
+    }
     // --- Visiting procedures
     fn visit_procedure_definition(&mut self, ctx: &mut Ctx, id: ProcedureDefinitionId) -> VisitorResult {
         let definition = &ctx.heap[id];
         let body_id = definition.body;
         self.current_scope = definition.scope;
         self.current_procedure_id = id;
         return self.visit_block_stmt(ctx, body_id);
+    }
     // --- Visiting statements (that are not the select statement)
     fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
         let block_stmt = &ctx.heap[id];
         let stmt_section = self.statement_buffer.start_section_initialized(&block_stmt.statements);
         self.current_scope = block_stmt.scope;
         for stmt_idx in 0..stmt_section.len() {
             self.visit_stmt(ctx, stmt_section[stmt_idx])?;
+        }
         stmt_section.forget();
         return Ok(())
+    }
     fn visit_labeled_stmt(&mut self, ctx: &mut Ctx, id: LabeledStatementId) -> VisitorResult {
         let labeled_stmt = &ctx.heap[id];
         let body_id = labeled_stmt.body;
         return self.visit_stmt(ctx, body_id);
+    }
     fn visit_if_stmt(&mut self, ctx: &mut Ctx, id: IfStatementId) -> VisitorResult {
         let if_stmt = &ctx.heap[id];
         let true_case = if_stmt.true_case;
         let false_case = if_stmt.false_case;
         self.current_scope = true_case.scope;
         self.visit_stmt(ctx, true_case.body)?;
         if let Some(false_case) = false_case {
             self.current_scope = false_case.scope;
             self.visit_stmt(ctx, false_case.body)?;
+        }
         return Ok(())
+    }
     fn visit_while_stmt(&mut self, ctx: &mut Ctx, id: WhileStatementId) -> VisitorResult {
         let while_stmt = &ctx.heap[id];
         let body_id = while_stmt.body;
         self.current_scope = while_stmt.scope;
         return self.visit_stmt(ctx, body_id);
+    }
     fn visit_synchronous_stmt(&mut self, ctx: &mut Ctx, id: SynchronousStatementId) -> VisitorResult {
         let sync_stmt = &ctx.heap[id];
         let body_id = sync_stmt.body;
         self.current_scope = sync_stmt.scope;
         return self.visit_stmt(ctx, body_id);
+    }
     // --- Visiting the select statement
     fn visit_select_stmt(&mut self, ctx: &mut Ctx, id: SelectStatementId) -> VisitorResult {
         // Utility for the last stage of rewriting process. Note that caller
         // still needs to point the end of the if-statement to the end of the
         // replacement statement of the select statement.
         fn transform_select_case_code(
             ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId,
             select_id: SelectStatementId, case_index: usize,
             select_var_id: VariableId, select_var_type_id: TypeIdReference
         ) -> (IfStatementId, EndIfStatementId, ScopeId) {
             // Retrieve statement IDs associated with case
             let case = &ctx.heap[select_id].cases[case_index];
             let case_guard_id = case.guard;
             let case_body_id = case.body;
             let case_scope_id = case.scope;
             // Create the if-statement for the result of the select statement
             let compare_expr_id = create_ast_equality_comparison_expr(ctx, containing_procedure_id, select_var_id, select_var_type_id, case_index as u64);
             let true_case = IfStatementCase{
                 body: case_guard_id, // which is linked up to the body
                 scope: case_scope_id,
             };
             let (if_stmt_id, end_if_stmt_id) = create_ast_if_stmt(ctx, compare_expr_id.upcast(), true_case, None);
             // Link up body statement to end-if
             set_ast_statement_next(ctx, case_body_id, end_if_stmt_id.upcast());
             return (if_stmt_id, end_if_stmt_id, case_scope_id);
+        }
         // Precreate the block that will end up containing all of the
         // transformed statements. Also precreate the scope associated with it
         let (outer_block_id, outer_end_block_id, outer_scope_id) =
             create_ast_block_stmt(ctx, Vec::new());
         // The "select" and the "end select" statement will act like trampolines
         // that jump to the replacement block. So set the child/parent
         // relationship already.
         // --- for the statements
         let select_stmt = &mut ctx.heap[id];
         select_stmt.next = outer_block_id.upcast();
         let end_select_stmt_id = select_stmt.end_select;
         let select_stmt_relative_pos = select_stmt.relative_pos_in_parent;
         let outer_end_block_stmt = &mut ctx.heap[outer_end_block_id];
         outer_end_block_stmt.next = end_select_stmt_id.upcast();
         // --- for the scopes
         link_new_child_to_existing_parent_scope(ctx, &mut self.scope_buffer, self.current_scope, outer_scope_id, select_stmt_relative_pos);
         // Create statements that will create temporary variables for all of the
         // ports passed to the "get" calls in the select case guards.
         let select_stmt = &ctx.heap[id];
         let total_num_cases = select_stmt.cases.len();
         let mut total_num_ports = 0;
         let end_select_stmt_id = select_stmt.end_select;
         let _end_select = &ctx.heap[end_select_stmt_id];
         // Put heap IDs into temporary buffers to handle borrowing rules
         let mut call_id_section = self.call_expr_buffer.start_section();
         let mut expr_id_section = self.expression_buffer.start_section();
         for case in select_stmt.cases.iter() {
             total_num_ports += case.involved_ports.len();
             for (call_id, expr_id) in case.involved_ports.iter().copied() {
                 call_id_section.push(call_id);
                 expr_id_section.push(expr_id);
+            }
+        }
         // Transform all of the call expressions by takings its argument (the
         // port from which we `get`) and turning it into a temporary variable.
         let mut transformed_stmts = Vec::with_capacity(total_num_ports); // TODO: Recompute this preallocated length, put assert at the end
         let mut locals = Vec::with_capacity(total_num_ports);
         for port_var_idx in 0..call_id_section.len() {
             let get_call_expr_id = call_id_section[port_var_idx];
             let port_expr_id = expr_id_section[port_var_idx];
             let port_type_index = ctx.heap[port_expr_id].type_index();
             let port_type_ref = TypeIdReference::IndirectSameAsExpr(port_type_index);
             // Move the port expression such that it gets assigned to a temporary variable
             let variable_id = create_ast_variable(ctx, outer_scope_id);
             let variable_decl_stmt_id = create_ast_variable_declaration_stmt(ctx, self.current_procedure_id, variable_id, port_type_ref, port_expr_id);
             // Replace the original port expression in the call with a reference
             // to the replacement variable
             let variable_expr_id = create_ast_variable_expr(ctx, self.current_procedure_id, variable_id, port_type_ref);
             let call_expr = &mut ctx.heap[get_call_expr_id];
             call_expr.arguments[0] = variable_expr_id.upcast();
             transformed_stmts.push(variable_decl_stmt_id.upcast().upcast());
             locals.push((variable_id, port_type_ref));
+        }
         // Insert runtime calls that facilitate the semantics of the select
         // block.
         // Create the call that indicates the start of the select block
+        {
             let num_cases_expression_id = create_ast_literal_integer_expr(ctx, self.current_procedure_id, total_num_cases as u64, ctx.arch.uint32_type_id);
             let num_ports_expression_id = create_ast_literal_integer_expr(ctx, self.current_procedure_id, total_num_ports as u64, ctx.arch.uint32_type_id);
             let arguments = vec![
                 num_cases_expression_id.upcast(),
                 num_ports_expression_id.upcast()
             ];
             let call_expression_id = create_ast_call_expr(ctx, self.current_procedure_id, Method::SelectStart, &mut self.expression_buffer, arguments);
             let call_statement_id = create_ast_expression_stmt(ctx, call_expression_id.upcast());
             transformed_stmts.push(call_statement_id.upcast());
+        }
         // Create calls for each select case that will register the ports that
         // we are waiting on at the runtime.
+        {
             let mut total_port_index = 0;
             for case_index in 0..total_num_cases {
                 let case = &ctx.heap[id].cases[case_index];
                 let case_num_ports = case.involved_ports.len();
                 for case_port_index in 0..case_num_ports {
                     // Arguments to runtime call
                     let (port_variable_id, port_variable_type) = locals[total_port_index]; // so far this variable contains the temporary variables for the port expressions
                     let case_index_expr_id = create_ast_literal_integer_expr(ctx, self.current_procedure_id, case_index as u64, ctx.arch.uint32_type_id);
                     let port_index_expr_id = create_ast_literal_integer_expr(ctx, self.current_procedure_id, case_port_index as u64, ctx.arch.uint32_type_id);
                     let port_variable_expr_id = create_ast_variable_expr(ctx, self.current_procedure_id, port_variable_id, port_variable_type);
                     let runtime_call_arguments = vec![
                         case_index_expr_id.upcast(),
                         port_index_expr_id.upcast(),
                         port_variable_expr_id.upcast()
                     ];
                     // Create runtime call, then store it
                     let runtime_call_expr_id = create_ast_call_expr(ctx, self.current_procedure_id, Method::SelectRegisterCasePort, &mut self.expression_buffer, runtime_call_arguments);
                     let runtime_call_stmt_id = create_ast_expression_stmt(ctx, runtime_call_expr_id.upcast());
                     transformed_stmts.push(runtime_call_stmt_id.upcast());
                     total_port_index += 1;
+                }
+            }
+        }
         // Create the variable that will hold the result of a completed select
         // block. Then create the runtime call that will produce this result
         let select_variable_id = create_ast_variable(ctx, outer_scope_id);
         let select_variable_type = TypeIdReference::DirectTypeId(ctx.arch.uint32_type_id);
         locals.push((select_variable_id, select_variable_type));
+        {
             let runtime_call_expr_id = create_ast_call_expr(ctx, self.current_procedure_id, Method::SelectWait, &mut self.expression_buffer, Vec::new());
             let variable_stmt_id = create_ast_variable_declaration_stmt(ctx, self.current_procedure_id, select_variable_id, select_variable_type, runtime_call_expr_id.upcast());
             transformed_stmts.push(variable_stmt_id.upcast().upcast());
+        }
         call_id_section.forget();
         expr_id_section.forget();
         // Now we transform each of the select block case's guard and code into
         // a chained if-else statement.
         let mut relative_pos = transformed_stmts.len() as i32;
         if total_num_cases > 0 {
             let (if_stmt_id, end_if_stmt_id, scope_id) = transform_select_case_code(ctx, self.current_procedure_id, id, 0, select_variable_id, select_variable_type);
             link_existing_child_to_new_parent_scope(ctx, &mut self.scope_buffer, outer_scope_id, scope_id, relative_pos);
             let first_end_if_stmt = &mut ctx.heap[end_if_stmt_id];
             first_end_if_stmt.next = outer_end_block_id.upcast();
             let mut last_if_stmt_id = if_stmt_id;
             let mut last_end_if_stmt_id = end_if_stmt_id;
             let mut last_parent_scope_id = outer_scope_id;
             let mut last_relative_pos = transformed_stmts.len() as i32 + 1;
             transformed_stmts.push(last_if_stmt_id.upcast());
             for case_index in 1..total_num_cases {
                 let (if_stmt_id, end_if_stmt_id, scope_id) = transform_select_case_code(ctx, self.current_procedure_id, id, case_index, select_variable_id, select_variable_type);
                 let false_case_scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::If(last_if_stmt_id, false)));
                 link_existing_child_to_new_parent_scope(ctx, &mut self.scope_buffer, false_case_scope_id, scope_id, 0);
                 link_new_child_to_existing_parent_scope(ctx, &mut self.scope_buffer, last_parent_scope_id, false_case_scope_id, last_relative_pos);
                 set_ast_if_statement_false_body(ctx, last_if_stmt_id, last_end_if_stmt_id, IfStatementCase{ body: if_stmt_id.upcast(), scope: false_case_scope_id });
                 let end_if_stmt = &mut ctx.heap[end_if_stmt_id];
                 end_if_stmt.next = last_end_if_stmt_id.upcast();
                 last_if_stmt_id = if_stmt_id;
                 last_end_if_stmt_id = end_if_stmt_id;
                 last_parent_scope_id = false_case_scope_id;
                 last_relative_pos = 0;
+            }
+        }
         // Final steps: set the statements of the replacement block statement,
         // link all of those statements together, and update the scopes.
         let first_stmt_id = transformed_stmts[0];
         let mut last_stmt_id = transformed_stmts[0];
         for stmt_id in transformed_stmts.iter().skip(1).copied() {
             set_ast_statement_next(ctx, last_stmt_id, stmt_id);
             last_stmt_id = stmt_id;
+        }
         if total_num_cases == 0 {
             // If we don't have any cases, then we didn't connect the statements
             // up to the end of the outer block, so do that here
             set_ast_statement_next(ctx, last_stmt_id, outer_end_block_id.upcast());
+        }
         let outer_block_stmt = &mut ctx.heap[outer_block_id];
         outer_block_stmt.next = first_stmt_id;
         outer_block_stmt.statements = transformed_stmts;
         return Ok(())
+    }
+}
 // -----------------------------------------------------------------------------
 // Utilities to create compiler-generated AST nodes
 // -----------------------------------------------------------------------------
 #[derive(Clone, Copy)]
 enum TypeIdReference {
     DirectTypeId(TypeId),
     IndirectSameAsExpr(i32), // by type index
+}
 fn create_ast_variable(ctx: &mut Ctx, scope_id: ScopeId) -> VariableId {
     let variable_id = ctx.heap.alloc_variable(|this| Variable{
         this,
         kind: VariableKind::Local,
         parser_type: ParserType{
             elements: Vec::new(),
             full_span: InputSpan::new(),
         },
         identifier: Identifier::new_empty(InputSpan::new()),
         relative_pos_in_parent: -1,
         unique_id_in_scope: -1,
     });
     let scope = &mut ctx.heap[scope_id];
     scope.variables.push(variable_id);
     return variable_id;
+}
 fn create_ast_variable_expr(ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId, variable_id: VariableId, variable_type_id: TypeIdReference) -> VariableExpressionId {
     let variable_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, variable_type_id);
     return ctx.heap.alloc_variable_expression(|this| VariableExpression{
         this,
         identifier: Identifier::new_empty(InputSpan::new()),
         declaration: Some(variable_id),
         used_as_binding_target: false,
         parent: ExpressionParent::None,
         type_index: variable_type_index,
     });
+}
 fn create_ast_call_expr(ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId, method: Method, buffer: &mut ScopedBuffer<ExpressionId>, arguments: Vec<ExpressionId>) -> CallExpressionId {
     let call_type_id = match method {
         Method::SelectStart => ctx.arch.void_type_id,
         Method::SelectRegisterCasePort => ctx.arch.void_type_id,
         Method::SelectWait => ctx.arch.uint32_type_id, // TODO: Not pretty, this. Pretty error prone
         _ => unreachable!(), // if this goes of, add the appropriate method here.
     };
     let expression_ids = buffer.start_section_initialized(&arguments);
     let call_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, TypeIdReference::DirectTypeId(call_type_id));
     let call_expression_id = ctx.heap.alloc_call_expression(|this| CallExpression{
         func_span: InputSpan::new(),
         this,
         full_span: InputSpan::new(),
         parser_type: ParserType{
             elements: Vec::new(),
             full_span: InputSpan::new(),
         },
         method,
         arguments,
         procedure: ProcedureDefinitionId::new_invalid(),
         parent: ExpressionParent::None,
         type_index: call_type_index,
     });
     for argument_index in 0..expression_ids.len() {
         let argument_id = expression_ids[argument_index];
         let argument_expr = &mut ctx.heap[argument_id];
         *argument_expr.parent_mut() = ExpressionParent::Expression(call_expression_id.upcast(), argument_index as u32);
+    }
     return call_expression_id;
+}
 fn create_ast_literal_integer_expr(ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId, unsigned_value: u64, type_id: TypeId) -> LiteralExpressionId {
     let literal_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, TypeIdReference::DirectTypeId(type_id));
     return ctx.heap.alloc_literal_expression(|this| LiteralExpression{
         this,
         span: InputSpan::new(),
         value: Literal::Integer(LiteralInteger{
             unsigned_value,
             negated: false,
         }),
         parent: ExpressionParent::None,
         type_index: literal_type_index,
     });
+}
 fn create_ast_equality_comparison_expr(
     ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId,
     variable_id: VariableId, variable_type: TypeIdReference, value: u64
 ) -> BinaryExpressionId {
     let var_expr_id = create_ast_variable_expr(ctx, containing_procedure_id, variable_id, variable_type);
     let int_expr_id = create_ast_literal_integer_expr(ctx, containing_procedure_id, value, ctx.arch.uint32_type_id);
     let cmp_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, TypeIdReference::DirectTypeId(ctx.arch.bool_type_id));
     let cmp_expr_id = ctx.heap.alloc_binary_expression(|this| BinaryExpression{
         this,
         operator_span: InputSpan::new(),
         full_span: InputSpan::new(),
         left: var_expr_id.upcast(),
         operation: BinaryOperator::Equality,
         right: int_expr_id.upcast(),
         parent: ExpressionParent::None,
         type_index: cmp_type_index,
     });
     let var_expr = &mut ctx.heap[var_expr_id];
     var_expr.parent = ExpressionParent::Expression(cmp_expr_id.upcast(), 0);
     let int_expr = &mut ctx.heap[int_expr_id];
     int_expr.parent = ExpressionParent::Expression(cmp_expr_id.upcast(), 1);
     return cmp_expr_id;
+}
 fn create_ast_expression_stmt(ctx: &mut Ctx, expression_id: ExpressionId) -> ExpressionStatementId {
     let statement_id = ctx.heap.alloc_expression_statement(|this| ExpressionStatement{
         this,
         span: InputSpan::new(),
         expression: expression_id,
         next: StatementId::new_invalid(),
     });
     let expression = &mut ctx.heap[expression_id];
     *expression.parent_mut() = ExpressionParent::ExpressionStmt(statement_id);
     return statement_id;
+}
 fn create_ast_variable_declaration_stmt(
     ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId,
     variable_id: VariableId, variable_type: TypeIdReference, initial_value_expr_id: ExpressionId
 ) -> MemoryStatementId {
     // Create the assignment expression, assigning the initial value to the variable
     let variable_expr_id = create_ast_variable_expr(ctx, containing_procedure_id, variable_id, variable_type);
     let void_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, TypeIdReference::DirectTypeId(ctx.arch.void_type_id));
     let assignment_expr_id = ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{
         this,
         operator_span: InputSpan::new(),
         full_span: InputSpan::new(),
         left: variable_expr_id.upcast(),
         operation: AssignmentOperator::Set,
         right: initial_value_expr_id,
         parent: ExpressionParent::None,
         type_index: void_type_index,
     });
     // Create the memory statement
     let memory_stmt_id = ctx.heap.alloc_memory_statement(|this| MemoryStatement{
         this,
         span: InputSpan::new(),
         variable: variable_id,
         initial_expr: assignment_expr_id,
         next: StatementId::new_invalid(),
     });
     // Set all parents which we can access
     let variable_expr = &mut ctx.heap[variable_expr_id];
     variable_expr.parent = ExpressionParent::Expression(assignment_expr_id.upcast(), 0);
     let value_expr = &mut ctx.heap[initial_value_expr_id];
     *value_expr.parent_mut() = ExpressionParent::Expression(assignment_expr_id.upcast(), 1);
     let assignment_expr = &mut ctx.heap[assignment_expr_id];
     assignment_expr.parent = ExpressionParent::Memory(memory_stmt_id);
     return memory_stmt_id;
+}
 fn create_ast_block_stmt(ctx: &mut Ctx, statements: Vec<StatementId>) -> (BlockStatementId, EndBlockStatementId, ScopeId) {
     let block_stmt_id = ctx.heap.alloc_block_statement(|this| BlockStatement{
         this,
         span: InputSpan::new(),
         statements,
         end_block: EndBlockStatementId::new_invalid(),
         scope: ScopeId::new_invalid(),
         next: StatementId::new_invalid(),
     });
     let end_block_stmt_id = ctx.heap.alloc_end_block_statement(|this| EndBlockStatement{
         this,
         start_block: block_stmt_id,
         next: StatementId::new_invalid(),
     });
     let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Block(block_stmt_id)));
     let block_stmt = &mut ctx.heap[block_stmt_id];
     block_stmt.end_block = end_block_stmt_id;
     block_stmt.scope = scope_id;
     return (block_stmt_id, end_block_stmt_id, scope_id);
+}
 fn create_ast_if_stmt(ctx: &mut Ctx, condition_expression_id: ExpressionId, true_case: IfStatementCase, false_case: Option<IfStatementCase>) -> (IfStatementId, EndIfStatementId) {
     // Create if statement and the end-if statement
     let if_stmt_id = ctx.heap.alloc_if_statement(|this| IfStatement{
         this,
         span: InputSpan::new(),
         test: condition_expression_id,
         true_case,
         false_case,
         end_if: EndIfStatementId::new_invalid()
     });
     let end_if_stmt_id = ctx.heap.alloc_end_if_statement(|this| EndIfStatement{
         this,
         start_if: if_stmt_id,
         next: StatementId::new_invalid(),
     });
     // Link the statements up as much as we can
     let if_stmt = &mut ctx.heap[if_stmt_id];
     if_stmt.end_if = end_if_stmt_id;
     let condition_expr = &mut ctx.heap[condition_expression_id];
     *condition_expr.parent_mut() = ExpressionParent::If(if_stmt_id);
     return (if_stmt_id, end_if_stmt_id);
+}
 /// Sets the false body for a given
 fn set_ast_if_statement_false_body(ctx: &mut Ctx, if_statement_id: IfStatementId, end_if_statement_id: EndIfStatementId, false_case: IfStatementCase) {
     // Point if-statement to "false body"
     let if_stmt = &mut ctx.heap[if_statement_id];
     debug_assert!(if_stmt.false_case.is_none()); // simplifies logic, not necessary
     if_stmt.false_case = Some(false_case);
     // Point end of false body to the end of the if statement
     set_ast_statement_next(ctx, false_case.body, end_if_statement_id.upcast());
+}
 /// Sets the specified AST statement's control flow such that it will be
 /// followed by the target statement. This may seem obvious, but may imply that
 /// a statement associated with, but different from, the source statement is
 /// modified.
 fn set_ast_statement_next(ctx: &mut Ctx, source_stmt_id: StatementId, target_stmt_id: StatementId) {
     let source_stmt = &mut ctx.heap[source_stmt_id];
     match source_stmt {
         Statement::Block(stmt) => {
             let end_id = stmt.end_block;
             ctx.heap[end_id].next = target_stmt_id
         },
         Statement::EndBlock(stmt) => stmt.next = target_stmt_id,
         Statement::Local(stmt) => {
             match stmt {
                 LocalStatement::Memory(stmt) => stmt.next = target_stmt_id,
                 LocalStatement::Channel(stmt) => stmt.next = target_stmt_id,
+            }
         },
         Statement::Labeled(stmt) => {
             let body_id = stmt.body;
             set_ast_statement_next(ctx, body_id, target_stmt_id);
         },
         Statement::If(stmt) => {
             let end_id = stmt.end_if;
             ctx.heap[end_id].next = target_stmt_id;
         },
         Statement::EndIf(stmt) => stmt.next = target_stmt_id,
         Statement::While(stmt) => {
             let end_id = stmt.end_while;
             ctx.heap[end_id].next = target_stmt_id;
         },
         Statement::EndWhile(stmt) => stmt.next = target_stmt_id,
         Statement::Break(_stmt) => {},
         Statement::Continue(_stmt) => {},
         Statement::Synchronous(stmt) => {
             let end_id = stmt.end_sync;
             ctx.heap[end_id].next = target_stmt_id;
         },
         Statement::EndSynchronous(stmt) => {
             stmt.next = target_stmt_id;
         },
         Statement::Fork(_) | Statement::EndFork(_) => {
             todo!("remove fork from language");
         },
         Statement::Select(stmt) => {
             let end_id = stmt.end_select;
             ctx.heap[end_id].next = target_stmt_id;
         },
         Statement::EndSelect(stmt) => stmt.next = target_stmt_id,
         Statement::Return(_stmt) => {},
         Statement::Goto(_stmt) => {},
         Statement::New(stmt) => stmt.next = target_stmt_id,
         Statement::Expression(stmt) => stmt.next = target_stmt_id,
+    }
+}
 /// Links a new scope to an existing scope as its child.
 fn link_new_child_to_existing_parent_scope(ctx: &mut Ctx, scope_buffer: &mut ScopedBuffer<ScopeId>, parent_scope_id: ScopeId, child_scope_id: ScopeId, relative_pos_hint: i32) {
     let child_scope = &mut ctx.heap[child_scope_id];
     debug_assert!(child_scope.parent.is_none());
     child_scope.parent = Some(parent_scope_id);
     child_scope.relative_pos_in_parent = relative_pos_hint;
     add_child_scope_to_parent(ctx, scope_buffer, parent_scope_id, child_scope_id, relative_pos_hint);
+}
 /// Relinks an existing scope to a new scope as its child. Will also break the
 /// link of the child scope's old parent.
 fn link_existing_child_to_new_parent_scope(ctx: &mut Ctx, scope_buffer: &mut ScopedBuffer<ScopeId>, new_parent_scope_id: ScopeId, child_scope_id: ScopeId, new_relative_pos_in_parent: i32) {
     let child_scope = &mut ctx.heap[child_scope_id];
     let old_parent_scope_id = child_scope.parent.unwrap();
     child_scope.parent = Some(new_parent_scope_id);
     child_scope.relative_pos_in_parent = new_relative_pos_in_parent;
     // Remove from old parent
     let old_parent = &mut ctx.heap[old_parent_scope_id];
     let scope_index = old_parent.nested.iter()
         .position(|v| *v == child_scope_id)
         .unwrap();
     old_parent.nested.remove(scope_index);
     // Add to new parent
     add_child_scope_to_parent(ctx, scope_buffer, new_parent_scope_id, child_scope_id, new_relative_pos_in_parent);
+}
 /// Will add a child scope to a parent scope using the relative position hint.
 fn add_child_scope_to_parent(ctx: &mut Ctx, scope_buffer: &mut ScopedBuffer<ScopeId>, parent_scope_id: ScopeId, child_scope_id: ScopeId, relative_pos_hint: i32) {
     let parent_scope = &ctx.heap[parent_scope_id];
     let existing_scope_ids = scope_buffer.start_section_initialized(&parent_scope.nested);
     let mut insert_pos = existing_scope_ids.len();
     for index in 0..existing_scope_ids.len() {
         let existing_scope_id = existing_scope_ids[index];
         let existing_scope = &ctx.heap[existing_scope_id];
         if relative_pos_hint <= existing_scope.relative_pos_in_parent {
             insert_pos = index;
             break;
+        }
+    }
     existing_scope_ids.forget();
     let parent_scope = &mut ctx.heap[parent_scope_id];
     parent_scope.nested.insert(insert_pos, child_scope_id);
+}
 fn add_new_procedure_expression_type(ctx: &mut Ctx, procedure_id: ProcedureDefinitionId, type_id: TypeIdReference) -> i32 {
     let procedure = &mut ctx.heap[procedure_id];
     let type_index = procedure.monomorphs[0].expr_info.len();
     match type_id {
         TypeIdReference::DirectTypeId(type_id) => {
             for monomorph in procedure.monomorphs.iter_mut() {
                 debug_assert_eq!(monomorph.expr_info.len(), type_index);
                 monomorph.expr_info.push(ExpressionInfo{
                     type_id,
                     variant: ExpressionInfoVariant::Generic
                 });
+            }
         },
         TypeIdReference::IndirectSameAsExpr(source_type_index) => {
             for monomorph in procedure.monomorphs.iter_mut() {
                 debug_assert_eq!(monomorph.expr_info.len(), type_index);
                 let copied_expr_info = monomorph.expr_info[source_type_index as usize];
                 monomorph.expr_info.push(copied_expr_info)
+            }
+        }
+    }
     return type_index as i32;
+}
@@ \ No newline at end of file @@

src/protocol/parser/pass_stack_size.rs

➞

Show inline comments

@@ new file 100644 @@
 use crate::collections::*;
 use crate::protocol::*;
 use super::visitor::*;
 // Will get a rename. Will probably become bytecode emitter or something. For
 // now it just scans the scopes and assigns a unique number for each variable
 // such that, at any point in the program's execution, all accessible in-scope
 // variables will have a unique position "on the stack".
 pub(crate) struct PassStackSize {
     definition_buffer: ScopedBuffer<DefinitionId>,
     variable_buffer: ScopedBuffer<VariableId>,
     scope_buffer: ScopedBuffer<ScopeId>,
+}
 impl PassStackSize {
     pub(crate) fn new() -> Self {
         return Self{
             definition_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
             variable_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             scope_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
+        }
+    }
+}
 impl Visitor for PassStackSize {
     // Top level visitors
     fn visit_module(&mut self, ctx: &mut Ctx) -> VisitorResult {
         let module = ctx.module();
         debug_assert_eq!(module.phase, ModuleCompilationPhase::Rewritten);
         let root_id = module.root_id;
         let root = &ctx.heap[root_id];
         let definition_section = self.definition_buffer.start_section_initialized(&root.definitions);
         for definition_index in 0..definition_section.len() {
             let definition_id = definition_section[definition_index];
             self.visit_definition(ctx, definition_id)?
+        }
         definition_section.forget();
         // ctx.module_mut().phase = ModuleCompilationPhase::StackSizeStuffAndStuff;
         return Ok(())
+    }
     fn visit_procedure_definition(&mut self, ctx: &mut Ctx, id: ProcedureDefinitionId) -> VisitorResult {
         let definition = &ctx.heap[id];
         let scope_id = definition.scope;
         self.visit_scope_and_assign_local_ids(ctx, scope_id, 0);
         return Ok(());
+    }
+}
 impl PassStackSize {
     fn visit_scope_and_assign_local_ids(&mut self, ctx: &mut Ctx, scope_id: ScopeId, mut variable_counter: i32) {
         let scope = &mut ctx.heap[scope_id];
         scope.first_unique_id_in_scope = variable_counter;
         let variable_section = self.variable_buffer.start_section_initialized(&scope.variables);
         let child_scope_section = self.scope_buffer.start_section_initialized(&scope.nested);
         let mut variable_index = 0;
         let mut child_scope_index = 0;
         loop {
             // Determine relative positions of variable and scope to determine
             // which one occurs first within the current scope.
             let variable_relative_pos;
             if variable_index < variable_section.len() {
                 let variable_id = variable_section[variable_index];
                 let variable = &ctx.heap[variable_id];
                 variable_relative_pos = variable.relative_pos_in_parent;
             } else {
                 variable_relative_pos = i32::MAX;
+            }
             let child_scope_relative_pos;
             if child_scope_index < child_scope_section.len() {
                 let child_scope_id = child_scope_section[child_scope_index];
                 let child_scope = &ctx.heap[child_scope_id];
                 child_scope_relative_pos = child_scope.relative_pos_in_parent;
             } else {
                 child_scope_relative_pos = i32::MAX;
+            }
             if variable_relative_pos == i32::MAX && child_scope_relative_pos == i32::MAX {
                 // Done, no more elements in the scope to consider
                 break;
+            }
             // Label the variable/scope, whichever comes first.
             if variable_relative_pos <= child_scope_relative_pos {
                 debug_assert_ne!(variable_relative_pos, child_scope_relative_pos, "checking if this ever happens");
                 let variable = &mut ctx.heap[variable_section[variable_index]];
                 variable.unique_id_in_scope = variable_counter;
                 variable_counter += 1;
                 variable_index += 1;
             } else {
                 let child_scope_id = child_scope_section[child_scope_index];
                 self.visit_scope_and_assign_local_ids(ctx, child_scope_id, variable_counter);
                 child_scope_index += 1;
+            }
+        }
         variable_section.forget();
         child_scope_section.forget();
         let scope = &mut ctx.heap[scope_id];
         scope.next_unique_id_in_scope = variable_counter;
+    }
+}
@@ \ No newline at end of file @@

src/protocol/parser/pass_symbols.rs

➞

Show inline comments

 use crate::protocol::ast::*;
 use super::symbol_table::*;
 use crate::protocol::input_source::{ParseError, InputSpan};
 use super::tokens::*;
 use super::token_parsing::*;
 use super::{Module, ModuleCompilationPhase, PassCtx};
 /// Scans the module and finds all module-level type definitions. These will be
 /// added to the symbol table such that during AST-construction we know which
 /// identifiers point to types. Will also parse all pragmas to determine module
 /// names.
 pub(crate) struct PassSymbols {
     symbols: Vec<Symbol>,
     pragmas: Vec<PragmaId>,
     imports: Vec<ImportId>,
     definitions: Vec<DefinitionId>,
     buffer: String,
     has_pragma_version: bool,
     has_pragma_module: bool,
+}
 impl PassSymbols {
     pub(crate) fn new() -> Self {
         Self{
             symbols: Vec::with_capacity(128),
             pragmas: Vec::with_capacity(8),
             imports: Vec::with_capacity(32),
             definitions: Vec::with_capacity(128),
             buffer: String::with_capacity(128),
             has_pragma_version: false,
             has_pragma_module: false,
+        }
+    }
     fn reset(&mut self) {
         self.symbols.clear();
         self.pragmas.clear();
         self.imports.clear();
         self.definitions.clear();
         self.has_pragma_version = false;
         self.has_pragma_module = false;
+    }
     pub(crate) fn parse(&mut self, modules: &mut [Module], module_idx: usize, ctx: &mut PassCtx) -> Result<(), ParseError> {
         self.reset();
         let module = &mut modules[module_idx];
         let module_range = &module.tokens.ranges[0];
         debug_assert_eq!(module.phase, ModuleCompilationPhase::Tokenized);
         debug_assert_eq!(module_range.range_kind, TokenRangeKind::Module);
         debug_assert!(module.root_id.is_invalid()); // not set yet,
         // Preallocate root in the heap
         let root_id = ctx.heap.alloc_protocol_description(|this| {
             Root{
                 this,
                 pragmas: Vec::new(),
                 imports: Vec::new(),
                 definitions: Vec::new(),
+            }
         });
         module.root_id = root_id;
         // Retrieve first range index, then make immutable borrow
         let mut range_idx = module_range.first_child_idx;
         // Visit token ranges to detect definitions and pragmas
         loop {
             let module = &modules[module_idx];
             let range_idx_usize = range_idx as usize;
             let cur_range = &module.tokens.ranges[range_idx_usize];
             let next_sibling_idx = cur_range.next_sibling_idx;
             let range_kind = cur_range.range_kind;
             // Parse if it is a definition or a pragma
             if range_kind == TokenRangeKind::Definition {
                 self.visit_definition_range(modules, module_idx, ctx, range_idx_usize)?;
             } else if range_kind == TokenRangeKind::Pragma {
                 self.visit_pragma_range(modules, module_idx, ctx, range_idx_usize)?;
+            }
             if next_sibling_idx == NO_SIBLING {
                 break;
             } else {
                 range_idx = next_sibling_idx;
+            }
+        }
         // Add the module's symbol scope and the symbols we just parsed
         let module_scope = SymbolScope::Module(root_id);
         ctx.symbols.insert_scope(Some(SymbolScope::Global), module_scope);
         for symbol in self.symbols.drain(..) {
             ctx.symbols.insert_scope(Some(module_scope), SymbolScope::Definition(symbol.variant.as_definition().definition_id));
             if let Err((new_symbol, old_symbol)) = ctx.symbols.insert_symbol(module_scope, symbol) {
                 return Err(construct_symbol_conflict_error(modules, module_idx, ctx, &new_symbol, &old_symbol))
+            }
+        }
         // Modify the preallocated root
         let root = &mut ctx.heap[root_id];
         root.pragmas.extend(self.pragmas.drain(..));
         root.definitions.extend(self.definitions.drain(..));
         // Modify module
         let module = &mut modules[module_idx];
         module.phase = ModuleCompilationPhase::SymbolsScanned;
         Ok(())
+    }
     fn visit_pragma_range(&mut self, modules: &mut [Module], module_idx: usize, ctx: &mut PassCtx, range_idx: usize) -> Result<(), ParseError> {
         let module = &mut modules[module_idx];
         let range = &module.tokens.ranges[range_idx];
         let mut iter = module.tokens.iter_range(range);
         // Consume pragma name
         let (pragma_section, pragma_start, _) = consume_pragma(&module.source, &mut iter)?;
         // Consume pragma values
         if pragma_section == b"#module" {
             // Check if name is defined twice within the same file
             if self.has_pragma_module {
                 return Err(ParseError::new_error_str_at_pos(&module.source, pragma_start, "module name is defined twice"));
+            }
             // Consume the domain-name
             let (module_name, module_span) = consume_domain_ident(&module.source, &mut iter)?;
             if iter.next().is_some() {
                 return Err(ParseError::new_error_str_at_pos(&module.source, iter.last_valid_pos(), "expected end of #module pragma after module name"));
+            }
             // Add to heap and symbol table
             let pragma_span = InputSpan::from_positions(pragma_start, module_span.end);
             let module_name = ctx.pool.intern(module_name);
             let pragma_id = ctx.heap.alloc_pragma(|this| Pragma::Module(PragmaModule{
                 this,
                 span: pragma_span,
                 value: Identifier{ span: module_span, value: module_name.clone() },
             }));
             self.pragmas.push(pragma_id);
             if let Err(other_module_root_id) = ctx.symbols.insert_module(module_name.clone(), module.root_id) {
                 // Naming conflict
                 let this_module = &modules[module_idx];
                 let other_module = seek_module(modules, other_module_root_id).unwrap();
                 let other_module_pragma_id = other_module.name.as_ref().map(|v| (*v).0).unwrap();
                 let other_pragma = ctx.heap[other_module_pragma_id].as_module();
                 return Err(ParseError::new_error_str_at_span(
                     &this_module.source, pragma_span, "conflict in module name"
                 ).with_info_str_at_span(
                     &other_module.source, other_pragma.span, "other module is defined here"
                 ));
+            }
             module.name = Some((pragma_id, module_name));
             self.has_pragma_module = true;
         } else if pragma_section == b"#version" {
             // Check if version is defined twice within the same file
             if self.has_pragma_version {
                 return Err(ParseError::new_error_str_at_pos(&module.source, pragma_start, "module version is defined twice"));
+            }
             // Consume the version pragma
             let (version, version_span) = consume_integer_literal(&module.source, &mut iter, &mut self.buffer)?;
             let pragma_id = ctx.heap.alloc_pragma(|this| Pragma::Version(PragmaVersion{
                 this,
                 span: InputSpan::from_positions(pragma_start, version_span.end),
                 version,
             }));
             self.pragmas.push(pragma_id);
             module.version = Some((pragma_id, version as i64));
             self.has_pragma_version = true;
         } else {
             // Custom pragma, maybe we support this in the future, but for now
             // we don't.
             return Err(ParseError::new_error_str_at_pos(&module.source, pragma_start, "illegal pragma name"));
+        }
         Ok(())
+    }
     fn visit_definition_range(&mut self, modules: &[Module], module_idx: usize, ctx: &mut PassCtx, range_idx: usize) -> Result<(), ParseError> {
         let module = &modules[module_idx];
         let range = &module.tokens.ranges[range_idx];
         let definition_span = InputSpan::from_positions(
             module.tokens.start_pos(range),
             module.tokens.end_pos(range)
         );
         let mut iter = module.tokens.iter_range(range);
         // First ident must be type of symbol
         let (kw_text, _) = consume_any_ident(&module.source, &mut iter).unwrap();
         // Retrieve identifier of definition
         let identifier = consume_ident_interned(&module.source, &mut iter, ctx)?;
         let mut poly_vars = Vec::new();
         maybe_consume_comma_separated(
             TokenKind::OpenAngle, TokenKind::CloseAngle, &module.source, &mut iter, ctx,
             |source, iter, ctx| consume_ident_interned(source, iter, ctx),
             &mut poly_vars, "a polymorphic variable", None
         )?;
         let ident_text = identifier.value.clone(); // because we need it later
         let ident_span = identifier.span.clone();
         // Reserve space in AST for definition and add it to the symbol table
         let definition_class;
         let ast_definition_id;
         match kw_text {
             KW_STRUCT => {
                 let struct_def_id = ctx.heap.alloc_struct_definition(|this| {
                     StructDefinition::new_empty(this, module.root_id, definition_span, identifier, poly_vars)
                 });
                 definition_class = DefinitionClass::Struct;
                 ast_definition_id = struct_def_id.upcast();
             },
             KW_ENUM => {
                 let enum_def_id = ctx.heap.alloc_enum_definition(|this| {
                     EnumDefinition::new_empty(this, module.root_id, definition_span, identifier, poly_vars)
                 });
                 definition_class = DefinitionClass::Enum;
                 ast_definition_id = enum_def_id.upcast();
             },
             KW_UNION => {
                 let union_def_id = ctx.heap.alloc_union_definition(|this| {
                     UnionDefinition::new_empty(this, module.root_id, definition_span, identifier, poly_vars)
                 });
                 definition_class = DefinitionClass::Union;
                 ast_definition_id = union_def_id.upcast()
             },
             KW_FUNCTION => {
                 let func_def_id = ctx.heap.alloc_function_definition(|this| {
                     FunctionDefinition::new_empty(this, module.root_id, definition_span, identifier, poly_vars)
                 let proc_def_id = ctx.heap.alloc_procedure_definition(|this| {
                     ProcedureDefinition::new_empty(this, module.root_id, definition_span, ProcedureKind::Function, identifier, poly_vars)
                 });
                 definition_class = DefinitionClass::Function;
-                ast_definition_id = func_def_id.upcast();
+                ast_definition_id = proc_def_id.upcast();
             },
             KW_PRIMITIVE | KW_COMPOSITE => {
                 let component_variant = if kw_text == KW_PRIMITIVE {
                     ComponentVariant::Primitive
                 let procedure_kind = if kw_text == KW_PRIMITIVE {
                     ProcedureKind::Primitive
                 } else {
-                    ComponentVariant::Composite
+                    ProcedureKind::Composite
                 };
                 let comp_def_id = ctx.heap.alloc_component_definition(|this| {
                     ComponentDefinition::new_empty(this, module.root_id, definition_span, component_variant, identifier, poly_vars)
                 let proc_def_id = ctx.heap.alloc_procedure_definition(|this| {
                     ProcedureDefinition::new_empty(this, module.root_id, definition_span, procedure_kind, identifier, poly_vars)
                 });
                 definition_class = DefinitionClass::Component;
-                ast_definition_id = comp_def_id.upcast();
+                ast_definition_id = proc_def_id.upcast();
             },
             _ => unreachable!("encountered keyword '{}' in definition range", String::from_utf8_lossy(kw_text)),
+        }
         let symbol = Symbol{
             name: ident_text,
             variant: SymbolVariant::Definition(SymbolDefinition{
                 defined_in_module: module.root_id,
                 defined_in_scope: SymbolScope::Module(module.root_id),
                 definition_span,
                 identifier_span: ident_span,
                 imported_at: None,
                 class: definition_class,
                 definition_id: ast_definition_id,
             }),
         };
         self.symbols.push(symbol);
         self.definitions.push(ast_definition_id);
         Ok(())
+    }
+}
@@ \ No newline at end of file @@

src/protocol/parser/pass_typing.rs

➞

Show inline comments

 /// pass_typing
 ///
 /// Performs type inference and type checking. Type inference is implemented by
 /// applying constraints on (sub)trees of types. During this process the
 /// resolver takes the `ParserType` structs (the representation of the types
 /// written by the programmer), converts them to `InferenceType` structs (the
 /// temporary data structure used during type inference) and attempts to arrive
 /// at `ConcreteType` structs (the representation of a fully checked and
 /// validated type).
 ///
 /// The resolver will visit every statement and expression relevant to the
 /// procedure and insert and determine its initial type based on context (e.g. a
 /// return statement's expression must match the function's return type, an
 /// if statement's test expression must evaluate to a boolean). When all are
 /// visited we attempt to make progress in evaluating the types. Whenever a type
 /// is progressed we queue the related expressions for further type progression.
 /// Once no more expressions are in the queue the algorithm is finished. At this
 /// point either all types are inferred (or can be trivially implicitly
 /// determined), or we have incomplete types. In the latter case we return an
 /// error.
 ///
 /// TODO: Needs a thorough rewrite:
 ///  0. polymorph_progress is intentionally broken at the moment. Make it work
 ///     again and use a normal VecSomething.
 ///  1. The foundation for doing all of the work with predetermined indices
 ///     instead of with HashMaps is there, but it is not really used because of
 ///     time constraints. When time is available, rewrite the system such that
 ///     AST IDs are not needed, and only indices into arrays are used.
 ///  2. We're doing a lot of extra work. It seems better to apply the initial
 ///     type based on expression parents, and immediately apply forced
 ///     constraints (arg to a fires() call must be port-like). All of the \
 ///     progress_xxx calls should then only be concerned with "transmitting"
 ///     type inference across their parent/child expressions.
 ///  3. Remove the `msg` type?
 ///  4. Disallow certain types in certain operations (e.g. `Void`).
 ///  2. Remove the `msg` type?
 ///  3. Disallow certain types in certain operations (e.g. `Void`).
 macro_rules! debug_log_enabled {
     () => { false };
+}
 macro_rules! debug_log {
     ($format:literal) => {
         enabled_debug_print!(false, "types", $format);
     };
     ($format:literal, $($args:expr),*) => {
         enabled_debug_print!(false, "types", $format, $($args),*);
     };
+}
-use std::collections::{HashMap, HashSet};
+use std::collections::VecDeque;
 use crate::collections::{ScopedBuffer, ScopedSection, DequeSet};
 use crate::protocol::ast::*;
 use crate::protocol::input_source::ParseError;
 use crate::protocol::parser::ModuleCompilationPhase;
 use crate::protocol::parser::type_table::*;
 use crate::protocol::parser::token_parsing::*;
 use super::visitor::{
     BUFFER_INIT_CAPACITY,
     BUFFER_INIT_CAP_LARGE,
     BUFFER_INIT_CAP_SMALL,
     Ctx,
     Visitor,
     VisitorResult
 };
 // -----------------------------------------------------------------------------
 // Inference type
 // -----------------------------------------------------------------------------
 const VOID_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::Void ];
 const MESSAGE_TEMPLATE: [InferenceTypePart; 2] = [ InferenceTypePart::Message, InferenceTypePart::UInt8 ];
 const BOOL_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::Bool ];
 const CHARACTER_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::Character ];
 const STRING_TEMPLATE: [InferenceTypePart; 2] = [ InferenceTypePart::String, InferenceTypePart::Character ];
 const NUMBERLIKE_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::NumberLike ];
 const INTEGERLIKE_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::IntegerLike ];
 const ARRAY_TEMPLATE: [InferenceTypePart; 2] = [ InferenceTypePart::Array, InferenceTypePart::Unknown ];
 const SLICE_TEMPLATE: [InferenceTypePart; 2] = [ InferenceTypePart::Slice, InferenceTypePart::Unknown ];
 const ARRAYLIKE_TEMPLATE: [InferenceTypePart; 2] = [ InferenceTypePart::ArrayLike, InferenceTypePart::Unknown ];
 /// TODO: @performance Turn into PartialOrd+Ord to simplify checks
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub(crate) enum InferenceTypePart {
     // When we infer types of AST elements that support polymorphic arguments,
     // then we might have the case that multiple embedded types depend on the
     // polymorphic type (e.g. func bla(T a, T[] b) -> T[][]). If we can infer
     // the type in one place (e.g. argument a), then we may propagate this
     // information to other types (e.g. argument b and the return type). For
     // this reason we place markers in the `InferenceType` instances such that
     // we know which part of the type was originally a polymorphic argument.
     Marker(u32),
     // Completely unknown type, needs to be inferred
     Unknown,
     // Partially known type, may be inferred to to be the appropriate related
     // type.
     // IndexLike,      // index into array/slice
     NumberLike,     // any kind of integer/float
     IntegerLike,    // any kind of integer
     ArrayLike,      // array or slice. Note that this must have a subtype
     PortLike,       // input or output port
     // Special types that cannot be instantiated by the user
     Void, // For builtin functions that do not return anything
     // Concrete types without subtypes
     Bool,
     UInt8,
     UInt16,
     UInt32,
     UInt64,
     SInt8,
     SInt16,
     SInt32,
     SInt64,
     Character,
     String,
     // One subtype
     Message,
     Array,
     Slice,
     Input,
     Output,
     // Tuple with any number of subtypes (for practical reasons 1 element is impossible)
     Tuple(u32),
     // A user-defined type with any number of subtypes
     Instance(DefinitionId, u32)
+}
 impl InferenceTypePart {
     fn is_marker(&self) -> bool {
         match self {
             InferenceTypePart::Marker(_) => true,
             _ => false,
+        }
+    }
     /// Checks if the type is concrete, markers are interpreted as concrete
     /// types.
     fn is_concrete(&self) -> bool {
         use InferenceTypePart as ITP;
         match self {
             ITP::Unknown | ITP::NumberLike |
             ITP::IntegerLike | ITP::ArrayLike | ITP::PortLike => false,
             _ => true
+        }
+    }
     fn is_concrete_number(&self) -> bool {
         use InferenceTypePart as ITP;
         match self {
             ITP::UInt8 | ITP::UInt16 | ITP::UInt32 | ITP::UInt64 |
             ITP::SInt8 | ITP::SInt16 | ITP::SInt32 | ITP::SInt64 => true,
             _ => false,
+        }
+    }
     fn is_concrete_integer(&self) -> bool {
         use InferenceTypePart as ITP;
         match self {
             ITP::UInt8 | ITP::UInt16 | ITP::UInt32 | ITP::UInt64 |
             ITP::SInt8 | ITP::SInt16 | ITP::SInt32 | ITP::SInt64 => true,
             _ => false,
+        }
+    }
     fn is_concrete_arraylike(&self) -> bool {
         use InferenceTypePart as ITP;
         match self {
             ITP::Array | ITP::Slice | ITP::String | ITP::Message => true,
             _ => false,
+        }
+    }
     fn is_concrete_port(&self) -> bool {
         use InferenceTypePart as ITP;
         match self {
             ITP::Input | ITP::Output => true,
             _ => false,
+        }
+    }
     /// Checks if a part is less specific than the argument. Only checks for
     /// single-part inference (i.e. not the replacement of an `Unknown` variant
     /// with the argument)
     fn may_be_inferred_from(&self, arg: &InferenceTypePart) -> bool {
         use InferenceTypePart as ITP;
         (*self == ITP::IntegerLike && arg.is_concrete_integer()) ||
         (*self == ITP::NumberLike && (arg.is_concrete_number() || *arg == ITP::IntegerLike)) ||
         (*self == ITP::ArrayLike && arg.is_concrete_arraylike()) ||
         (*self == ITP::PortLike && arg.is_concrete_port())
+    }
     /// Checks if a part is more specific
     /// Returns the change in "iteration depth" when traversing this particular
     /// part. The iteration depth is used to traverse the tree in a linear
     /// fashion. It is basically `number_of_subtypes - 1`
     fn depth_change(&self) -> i32 {
         use InferenceTypePart as ITP;
         match &self {
             ITP::Unknown | ITP::NumberLike | ITP::IntegerLike |
             ITP::Void | ITP::Bool |
             ITP::UInt8 | ITP::UInt16 | ITP::UInt32 | ITP::UInt64 |
             ITP::SInt8 | ITP::SInt16 | ITP::SInt32 | ITP::SInt64 |
             ITP::Character => {
                 -1
             },
             ITP::Marker(_) |
             ITP::ArrayLike | ITP::Message | ITP::Array | ITP::Slice |
             ITP::PortLike | ITP::Input | ITP::Output | ITP::String => {
                 // One subtype, so do not modify depth
             },
             ITP::Tuple(num) | ITP::Instance(_, num) => {
                 (*num as i32) - 1
+            }
+        }
+    }
+}
 #[derive(Debug, Clone)]
 struct InferenceType {
     has_marker: bool,
     is_done: bool,
     parts: Vec<InferenceTypePart>,
+}
 impl InferenceType {
     /// Generates a new InferenceType. The two boolean flags will be checked in
     /// debug mode.
     fn new(has_marker: bool, is_done: bool, parts: Vec<InferenceTypePart>) -> Self {
-        if cfg!(debug_assertions) {
+        dbg_code!({
             debug_assert!(!parts.is_empty());
             let parts_body_marker = parts.iter().any(|v| v.is_marker());
             debug_assert_eq!(has_marker, parts_body_marker);
             let parts_done = parts.iter().all(|v| v.is_concrete());
             debug_assert_eq!(is_done, parts_done, "{:?}", parts);
+        }
+        });
         Self{ has_marker, is_done, parts }
+    }
     /// Replaces a type subtree with the provided subtree. The caller must make
     /// sure the the replacement is a well formed type subtree.
     fn replace_subtree(&mut self, start_idx: usize, with: &[InferenceTypePart]) {
         let end_idx = Self::find_subtree_end_idx(&self.parts, start_idx);
         debug_assert_eq!(with.len(), Self::find_subtree_end_idx(with, 0));
         self.parts.splice(start_idx..end_idx, with.iter().cloned());
         self.recompute_is_done();
+    }
     // TODO: @performance, might all be done inline in the type inference methods
     fn recompute_is_done(&mut self) {
         self.is_done = self.parts.iter().all(|v| v.is_concrete());
+    }
     /// Seeks a body marker starting at the specified position. If a marker is
     /// found then its value and the index of the type subtree that follows it
     /// is returned.
     fn find_marker(&self, mut start_idx: usize) -> Option<(u32, usize)> {
         while start_idx < self.parts.len() {
             if let InferenceTypePart::Marker(marker) = &self.parts[start_idx] {
                 return Some((*marker, start_idx + 1))
+            }
             start_idx += 1;
+        }
         None
+    }
     /// Returns an iterator over all body markers and the partial type tree that
     /// follows those markers. If it is a problem that `InferenceType` is
     /// borrowed by the iterator, then use `find_body_marker`.
     fn marker_iter(&self) -> InferenceTypeMarkerIter {
         InferenceTypeMarkerIter::new(&self.parts)
+    }
     /// Given that the `parts` are a depth-first serialized tree of types, this
     /// function finds the subtree anchored at a specific node. The returned
     /// index is exclusive.
     fn find_subtree_end_idx(parts: &[InferenceTypePart], start_idx: usize) -> usize {
         let mut depth = 1;
         let mut idx = start_idx;
         while idx < parts.len() {
             depth += parts[idx].depth_change();
             if depth == 0 {
                 return idx + 1;
+            }
             idx += 1;
+        }
         // If here, then the inference type is malformed
         unreachable!("Malformed type: {:?}", parts);
+    }
     /// Call that attempts to infer the part at `to_infer.parts[to_infer_idx]`
     /// using the subtree at `template.parts[template_idx]`. Will return
     /// `Some(depth_change_due_to_traversal)` if type inference has been
     /// applied. In this case the indices will also be modified to point to the
     /// next part in both templates. If type inference has not (or: could not)
     /// be applied then `None` will be returned. Note that this might mean that
     /// the types are incompatible.
     ///
     /// As this is a helper functions, some assumptions: the parts are not
     /// exactly equal, and neither of them contains a marker. Also: only the
     /// `to_infer` parts are checked for inference. It might be that this
     /// function returns `None`, but that that `template` is still compatible
     /// with `to_infer`, e.g. when `template` has an `Unknown` part.
     fn infer_part_for_single_type(
         to_infer: &mut InferenceType, to_infer_idx: &mut usize,
         template_parts: &[InferenceTypePart], template_idx: &mut usize,
     ) -> Option<i32> {
         use InferenceTypePart as ITP;
         let to_infer_part = &to_infer.parts[*to_infer_idx];
         let template_part = &template_parts[*template_idx];
         // Check for programmer mistakes
         debug_assert_ne!(to_infer_part, template_part);
         debug_assert!(!to_infer_part.is_marker(), "marker encountered in 'infer part'");
         debug_assert!(!template_part.is_marker(), "marker encountered in 'template part'");
         // Inference of a somewhat-specified type
         if to_infer_part.may_be_inferred_from(template_part) {
             let depth_change = to_infer_part.depth_change();
             debug_assert_eq!(depth_change, template_part.depth_change());
             to_infer.parts[*to_infer_idx] = template_part.clone();
             *to_infer_idx += 1;
             *template_idx += 1;
             return Some(depth_change);
+        }
         // Inference of a completely unknown type
         if *to_infer_part == ITP::Unknown {
             // template part is different, so cannot be unknown, hence copy the
             // entire subtree. Make sure not to copy markers.
             let template_end_idx = Self::find_subtree_end_idx(template_parts, *template_idx);
             to_infer.parts[*to_infer_idx] = template_parts[*template_idx].clone(); // first element
             *to_infer_idx += 1;
             for template_idx in *template_idx + 1..template_end_idx {
                 let template_part = &template_parts[template_idx];
                 if !template_part.is_marker() {
                     to_infer.parts.insert(*to_infer_idx, template_part.clone());
                     *to_infer_idx += 1;
+                }
+            }
             *template_idx = template_end_idx;
             // Note: by definition the LHS was Unknown and the RHS traversed a
             // full subtree.
             return Some(-1);
+        }
         None
+    }
     /// Call that checks if the `to_check` part is compatible with the `infer`
     /// part. This is essentially a copy of `infer_part_for_single_type`, but
     /// without actually copying the type parts.
     fn check_part_for_single_type(
         to_check_parts: &[InferenceTypePart], to_check_idx: &mut usize,
         template_parts: &[InferenceTypePart], template_idx: &mut usize
     ) -> Option<i32> {
         use InferenceTypePart as ITP;
         let to_check_part = &to_check_parts[*to_check_idx];
         let template_part = &template_parts[*template_idx];
         // Checking programmer errors
         debug_assert_ne!(to_check_part, template_part);
         debug_assert!(!to_check_part.is_marker(), "marker encountered in 'to_check part'");
         debug_assert!(!template_part.is_marker(), "marker encountered in 'template part'");
         if to_check_part.may_be_inferred_from(template_part) {
             let depth_change = to_check_part.depth_change();
             debug_assert_eq!(depth_change, template_part.depth_change());
             *to_check_idx += 1;
             *template_idx += 1;
             return Some(depth_change);
+        }
         if *to_check_part == ITP::Unknown {
             *to_check_idx += 1;
             *template_idx = Self::find_subtree_end_idx(template_parts, *template_idx);
             // By definition LHS and RHS had depth change of -1
             return Some(-1);
+        }
         None
+    }
     /// Attempts to infer types between two `InferenceType` instances. This
     /// function is unsafe as it accepts pointers to work around Rust's
     /// borrowing rules. The caller must ensure that the pointers are distinct.
     unsafe fn infer_subtrees_for_both_types(
         type_a: *mut InferenceType, start_idx_a: usize,
         type_b: *mut InferenceType, start_idx_b: usize
     ) -> DualInferenceResult {
         debug_assert!(!std::ptr::eq(type_a, type_b), "encountered pointers to the same inference type");
         let type_a = &mut *type_a;
         let type_b = &mut *type_b;
         let mut modified_a = false;
         let mut modified_b = false;
         let mut idx_a = start_idx_a;
         let mut idx_b = start_idx_b;
         let mut depth = 1;
         while depth > 0 {
             // Advance indices if we encounter markers or equal parts
             let part_a = &type_a.parts[idx_a];
             let part_b = &type_b.parts[idx_b];
             if part_a == part_b {
                 let depth_change = part_a.depth_change();
                 depth += depth_change;
                 debug_assert_eq!(depth_change, part_b.depth_change());
                 idx_a += 1;
                 idx_b += 1;
                 continue;
+            }
             if part_a.is_marker() { idx_a += 1; continue; }
             if part_b.is_marker() { idx_b += 1; continue; }
             // Types are not equal and are both not markers
             if let Some(depth_change) = Self::infer_part_for_single_type(type_a, &mut idx_a, &type_b.parts, &mut idx_b) {
                 depth += depth_change;
                 modified_a = true;
                 continue;
+            }
             if let Some(depth_change) = Self::infer_part_for_single_type(type_b, &mut idx_b, &type_a.parts, &mut idx_a) {
                 depth += depth_change;
                 modified_b = true;
                 continue;
+            }
             // Types can not be inferred in any way: types must be incompatible
             return DualInferenceResult::Incompatible;
+        }
         if modified_a { type_a.recompute_is_done(); }
         if modified_b { type_b.recompute_is_done(); }
         // If here then we completely inferred the subtrees.
         match (modified_a, modified_b) {
             (false, false) => DualInferenceResult::Neither,
             (false, true) => DualInferenceResult::Second,
             (true, false) => DualInferenceResult::First,
             (true, true) => DualInferenceResult::Both
+        }
+    }
     /// Attempts to infer the first subtree based on the template. Like
     /// `infer_subtrees_for_both_types`, but now only applying inference to
     /// `to_infer` based on the type information in `template`.
     ///
     /// The `forced_template` flag controls whether `to_infer` is considered
     /// valid if it is more specific then the template. When `forced_template`
     /// is false, then as long as the `to_infer` and `template` types are
     /// compatible the inference will succeed. If `forced_template` is true,
     /// then `to_infer` MUST be less specific than `template` (e.g.
     /// `IntegerLike` is less specific than `UInt32`)
     fn infer_subtree_for_single_type(
         to_infer: &mut InferenceType, mut to_infer_idx: usize,
         template: &[InferenceTypePart], mut template_idx: usize,
         forced_template: bool,
     ) -> SingleInferenceResult {
         let mut modified = false;
         let mut depth = 1;
         while depth > 0 {
             let to_infer_part = &to_infer.parts[to_infer_idx];
             let template_part = &template[template_idx];
             if to_infer_part == template_part {
                 let depth_change = to_infer_part.depth_change();
                 depth += depth_change;
                 debug_assert_eq!(depth_change, template_part.depth_change());
                 to_infer_idx += 1;
                 template_idx += 1;
                 continue;
+            }
             if to_infer_part.is_marker() { to_infer_idx += 1; continue; }
             if template_part.is_marker() { template_idx += 1; continue; }
             // Types are not equal and not markers. So check if we can infer
             // anything
             if let Some(depth_change) = Self::infer_part_for_single_type(
                 to_infer, &mut to_infer_idx, template, &mut template_idx
             ) {
                 depth += depth_change;
                 modified = true;
                 continue;
+            }
             if !forced_template {
                 // We cannot infer anything, but the template may still be
                 // compatible with the type we're inferring
                 if let Some(depth_change) = Self::check_part_for_single_type(
                     template, &mut template_idx, &to_infer.parts, &mut to_infer_idx
                 ) {
                     depth += depth_change;
                     continue;
+                }
+            }
             return SingleInferenceResult::Incompatible
+        }
         if modified {
             to_infer.recompute_is_done();
             return SingleInferenceResult::Modified;
         } else {
             return SingleInferenceResult::Unmodified;
+        }
+    }
     /// Checks if both types are compatible, doesn't perform any inference
     fn check_subtrees(
         type_parts_a: &[InferenceTypePart], start_idx_a: usize,
         type_parts_b: &[InferenceTypePart], start_idx_b: usize
     ) -> bool {
         let mut depth = 1;
         let mut idx_a = start_idx_a;
         let mut idx_b = start_idx_b;
         while depth > 0 {
             let part_a = &type_parts_a[idx_a];
             let part_b = &type_parts_b[idx_b];
             if part_a == part_b {
                 let depth_change = part_a.depth_change();
                 depth += depth_change;
                 debug_assert_eq!(depth_change, part_b.depth_change());
                 idx_a += 1;
                 idx_b += 1;
                 continue;
+            }
             if part_a.is_marker() { idx_a += 1; continue; }
             if part_b.is_marker() { idx_b += 1; continue; }
             if let Some(depth_change) = Self::check_part_for_single_type(
                 type_parts_a, &mut idx_a, type_parts_b, &mut idx_b
             ) {
                 depth += depth_change;
                 continue;
+            }
             if let Some(depth_change) = Self::check_part_for_single_type(
                 type_parts_b, &mut idx_b, type_parts_a, &mut idx_a
             ) {
                 depth += depth_change;
                 continue;
+            }
             return false;
+        }
         true
+    }
     /// Performs the conversion of the inference type into a concrete type.
     /// By calling this function you must make sure that no unspecified types
     /// (e.g. Unknown or IntegerLike) exist in the type. Will not clear or check
     /// if the supplied `ConcreteType` is empty, will simply append to the parts
     /// vector.
     fn write_concrete_type(&self, concrete_type: &mut ConcreteType) {
         use InferenceTypePart as ITP;
         use ConcreteTypePart as CTP;
         // Make sure inference type is specified but concrete type is not yet specified
         debug_assert!(!self.parts.is_empty());
         concrete_type.parts.reserve(self.parts.len());
         let mut idx = 0;
         while idx < self.parts.len() {
             let part = &self.parts[idx];
             let converted_part = match part {
                 ITP::Marker(_) => {
                     // Markers are removed when writing to the concrete type.
                     idx += 1;
                     continue;
                 },
                 ITP::Unknown | ITP::NumberLike |
                 ITP::IntegerLike | ITP::ArrayLike | ITP::PortLike => {
                     // Should not happen if type inferencing works correctly: we
                     // should have returned a programmer-readable error or have
                     // inferred all types.
                     unreachable!("attempted to convert inference type part {:?} into concrete type", part);
                 },
                 ITP::Void => CTP::Void,
                 ITP::Message => CTP::Message,
                 ITP::Bool => CTP::Bool,
                 ITP::UInt8 => CTP::UInt8,
                 ITP::UInt16 => CTP::UInt16,
                 ITP::UInt32 => CTP::UInt32,
                 ITP::UInt64 => CTP::UInt64,
                 ITP::SInt8 => CTP::SInt8,
                 ITP::SInt16 => CTP::SInt16,
                 ITP::SInt32 => CTP::SInt32,
                 ITP::SInt64 => CTP::SInt64,
                 ITP::Character => CTP::Character,
                 ITP::String => {
                     // Inferred type has a 'char' subtype to simplify array
                     // checking, we remove it here.
                     debug_assert_eq!(self.parts[idx + 1], InferenceTypePart::Character);
                     idx += 1;
                     CTP::String
                 },
                 ITP::Array => CTP::Array,
                 ITP::Slice => CTP::Slice,
                 ITP::Input => CTP::Input,
                 ITP::Output => CTP::Output,
                 ITP::Tuple(num) => CTP::Tuple(*num),
                 ITP::Instance(id, num) => CTP::Instance(*id, *num),
             };
             concrete_type.parts.push(converted_part);
             idx += 1;
+        }
+    }
     /// Writes a human-readable version of the type to a string. This is used
     /// to display error messages
     fn write_display_name(
         buffer: &mut String, heap: &Heap, parts: &[InferenceTypePart], mut idx: usize
     ) -> usize {
         use InferenceTypePart as ITP;
         match &parts[idx] {
             ITP::Marker(_marker_idx) => {
                 if debug_log_enabled!() {
                     buffer.push_str(&format!("{{Marker:{}}}", *_marker_idx));
+                }
                 idx = Self::write_display_name(buffer, heap, parts, idx + 1);
             },
             ITP::Unknown => buffer.push_str("?"),
             ITP::NumberLike => buffer.push_str("numberlike"),
             ITP::IntegerLike => buffer.push_str("integerlike"),
             ITP::ArrayLike => {
                 idx = Self::write_display_name(buffer, heap, parts, idx + 1);
                 buffer.push_str("[?]");
             },
             ITP::PortLike => {
                 buffer.push_str("portlike<");
                 idx = Self::write_display_name(buffer, heap, parts, idx + 1);
                 buffer.push('>');
+            }
             ITP::Void => buffer.push_str("void"),
             ITP::Bool => buffer.push_str(KW_TYPE_BOOL_STR),
             ITP::UInt8 => buffer.push_str(KW_TYPE_UINT8_STR),
             ITP::UInt16 => buffer.push_str(KW_TYPE_UINT16_STR),
             ITP::UInt32 => buffer.push_str(KW_TYPE_UINT32_STR),
             ITP::UInt64 => buffer.push_str(KW_TYPE_UINT64_STR),
             ITP::SInt8 => buffer.push_str(KW_TYPE_SINT8_STR),
             ITP::SInt16 => buffer.push_str(KW_TYPE_SINT16_STR),
             ITP::SInt32 => buffer.push_str(KW_TYPE_SINT32_STR),
             ITP::SInt64 => buffer.push_str(KW_TYPE_SINT64_STR),
             ITP::Character => buffer.push_str(KW_TYPE_CHAR_STR),
             ITP::String => {
                 buffer.push_str(KW_TYPE_STRING_STR);
                 idx += 1; // skip the 'char' subtype
             },
             ITP::Message => {
                 buffer.push_str(KW_TYPE_MESSAGE_STR);
                 buffer.push('<');
                 idx = Self::write_display_name(buffer, heap, parts, idx + 1);
                 buffer.push('>');
             },
             ITP::Array => {
                 idx = Self::write_display_name(buffer, heap, parts, idx + 1);
                 buffer.push_str("[]");
             },
             ITP::Slice => {
                 idx = Self::write_display_name(buffer, heap, parts, idx + 1);
                 buffer.push_str("[..]");
             },
             ITP::Input => {
                 buffer.push_str(KW_TYPE_IN_PORT_STR);
                 buffer.push('<');
                 idx = Self::write_display_name(buffer, heap, parts, idx + 1);
                 buffer.push('>');
             },
             ITP::Output => {
                 buffer.push_str(KW_TYPE_OUT_PORT_STR);
                 buffer.push('<');
                 idx = Self::write_display_name(buffer, heap, parts, idx + 1);
                 buffer.push('>');
             },
             ITP::Tuple(num_sub) => {
                 buffer.push('(');
                 if *num_sub > 0 {
                     idx = Self::write_display_name(buffer, heap, parts, idx + 1);
                     for _sub_idx in 1..*num_sub {
                         buffer.push_str(", ");
                         idx = Self::write_display_name(buffer, heap, parts, idx + 1);
+                    }
+                }
                 buffer.push(')');
+            }
             ITP::Instance(definition_id, num_sub) => {
                 let definition = &heap[*definition_id];
                 buffer.push_str(definition.identifier().value.as_str());
                 if *num_sub > 0 {
                     buffer.push('<');
                     idx = Self::write_display_name(buffer, heap, parts, idx + 1);
                     for _sub_idx in 1..*num_sub {
                         buffer.push_str(", ");
                         idx = Self::write_display_name(buffer, heap, parts, idx + 1);
+                    }
                     buffer.push('>');
+                }
             },
+        }
         idx
+    }
     /// Returns the display name of a (part of) the type tree. Will allocate a
     /// string.
     fn partial_display_name(heap: &Heap, parts: &[InferenceTypePart]) -> String {
         let mut buffer = String::with_capacity(parts.len() * 6);
         Self::write_display_name(&mut buffer, heap, parts, 0);
         buffer
+    }
     /// Returns the display name of the full type tree. Will allocate a string.
     fn display_name(&self, heap: &Heap) -> String {
         Self::partial_display_name(heap, &self.parts)
+    }
+}
 impl Default for InferenceType {
     fn default() -> Self {
         Self{
             has_marker: false,
             is_done: false,
             parts: Vec::new(),
+        }
+    }
+}
 /// Iterator over the subtrees that follow a marker in an `InferenceType`
 /// instance. Returns immutable slices over the internal parts
 struct InferenceTypeMarkerIter<'a> {
     parts: &'a [InferenceTypePart],
     idx: usize,
+}
 impl<'a> InferenceTypeMarkerIter<'a> {
     fn new(parts: &'a [InferenceTypePart]) -> Self {
         Self{ parts, idx: 0 }
+    }
+}
 impl<'a> Iterator for InferenceTypeMarkerIter<'a> {
     type Item = (u32, &'a [InferenceTypePart]);
     fn next(&mut self) -> Option<Self::Item> {
         // Iterate until we find a marker
         while self.idx < self.parts.len() {
             if let InferenceTypePart::Marker(marker) = self.parts[self.idx] {
                 // Found a marker, find the subtree end
                 let start_idx = self.idx + 1;
                 let end_idx = InferenceType::find_subtree_end_idx(self.parts, start_idx);
                 // Modify internal index, then return items
                 self.idx = end_idx;
                 return Some((marker, &self.parts[start_idx..end_idx]));
+            }
             self.idx += 1;
+        }
         None
+    }
+}
 #[derive(Debug, PartialEq, Eq)]
 enum DualInferenceResult {
     Neither,        // neither argument is clarified
     First,          // first argument is clarified using the second one
     Second,         // second argument is clarified using the first one
     Both,           // both arguments are clarified
     Incompatible,   // types are incompatible: programmer error
+}
 impl DualInferenceResult {
     fn modified_lhs(&self) -> bool {
         match self {
             DualInferenceResult::First | DualInferenceResult::Both => true,
             _ => false
+        }
+    }
     fn modified_rhs(&self) -> bool {
         match self {
             DualInferenceResult::Second | DualInferenceResult::Both => true,
             _ => false
+        }
+    }
+}
 #[derive(Debug, PartialEq, Eq)]
 enum SingleInferenceResult {
     Unmodified,
     Modified,
     Incompatible
+}
 enum DefinitionType{
     Component(ComponentDefinitionId),
     Function(FunctionDefinitionId),
+}
 // -----------------------------------------------------------------------------
 // PassTyping - Public Interface
 // -----------------------------------------------------------------------------
 impl DefinitionType {
     fn definition_id(&self) -> DefinitionId {
         match self {
             DefinitionType::Component(v) => v.upcast(),
             DefinitionType::Function(v) => v.upcast(),
+        }
+    }
+}
 type InferNodeIndex = usize;
 type PolyDataIndex = isize;
 type VarDataIndex = usize;
 pub(crate) struct ResolveQueueElement {
     // Note that using the `definition_id` and the `monomorph_idx` one may
     // query the type table for the full procedure type, thereby retrieving
     // the polymorphic arguments to the procedure.
     pub(crate) root_id: RootId,
     pub(crate) definition_id: DefinitionId,
     pub(crate) reserved_monomorph_idx: i32,
     pub(crate) reserved_type_id: TypeId,
     pub(crate) reserved_monomorph_index: u32,
+}
-pub(crate) type ResolveQueue = Vec<ResolveQueueElement>;
+pub(crate) type ResolveQueue = VecDeque<ResolveQueueElement>;
 #[derive(Clone)]
 struct InferenceExpression {
 struct InferenceNode {
     // filled in during type inference
     expr_type: InferenceType,               // result type from expression
     expr_id: ExpressionId,                  // expression that is evaluated
     field_or_monomorph_idx: i32,    // index of field, of index of monomorph array in type table
     extra_data_idx: i32,            // index of extra data needed for inference
     inference_rule: InferenceRule,          // rule used to infer node type
     parent_index: Option<InferNodeIndex>,   // parent of inference node
     field_index: i32,                       // index of struct field or tuple member
     poly_data_index: PolyDataIndex,         // index to inference data for polymorphic types
     // filled in once type inference is done
     info_type_id: TypeId,
     info_variant: ExpressionInfoVariant,
+}
 impl InferenceNode {
     #[inline]
     fn as_expression_info(&self) -> ExpressionInfo {
         return ExpressionInfo {
             type_id: self.info_type_id,
             variant: self.info_variant
+        }
+    }
+}
 /// Inferencing rule to apply. Some of these are reasonably generic. Other ones
 /// require so much custom logic that we'll not try to come up with an
 /// abstraction.
 enum InferenceRule {
     Noop,
     MonoTemplate(InferenceRuleTemplate),
     BiEqual(InferenceRuleBiEqual),
     TriEqualArgs(InferenceRuleTriEqualArgs),
     TriEqualAll(InferenceRuleTriEqualAll),
     Concatenate(InferenceRuleTwoArgs),
     IndexingExpr(InferenceRuleIndexingExpr),
     SlicingExpr(InferenceRuleSlicingExpr),
     SelectStructField(InferenceRuleSelectStructField),
     SelectTupleMember(InferenceRuleSelectTupleMember),
     LiteralStruct(InferenceRuleLiteralStruct),
     LiteralEnum,
     LiteralUnion(InferenceRuleLiteralUnion),
     LiteralArray(InferenceRuleLiteralArray),
     LiteralTuple(InferenceRuleLiteralTuple),
     CastExpr(InferenceRuleCastExpr),
     CallExpr(InferenceRuleCallExpr),
     VariableExpr(InferenceRuleVariableExpr),
+}
 impl InferenceRule {
     union_cast_to_ref_method_impl!(as_mono_template, InferenceRuleTemplate, InferenceRule::MonoTemplate);
     union_cast_to_ref_method_impl!(as_bi_equal, InferenceRuleBiEqual, InferenceRule::BiEqual);
     union_cast_to_ref_method_impl!(as_tri_equal_args, InferenceRuleTriEqualArgs, InferenceRule::TriEqualArgs);
     union_cast_to_ref_method_impl!(as_tri_equal_all, InferenceRuleTriEqualAll, InferenceRule::TriEqualAll);
     union_cast_to_ref_method_impl!(as_concatenate, InferenceRuleTwoArgs, InferenceRule::Concatenate);
     union_cast_to_ref_method_impl!(as_indexing_expr, InferenceRuleIndexingExpr, InferenceRule::IndexingExpr);
     union_cast_to_ref_method_impl!(as_slicing_expr, InferenceRuleSlicingExpr, InferenceRule::SlicingExpr);
     union_cast_to_ref_method_impl!(as_select_struct_field, InferenceRuleSelectStructField, InferenceRule::SelectStructField);
     union_cast_to_ref_method_impl!(as_select_tuple_member, InferenceRuleSelectTupleMember, InferenceRule::SelectTupleMember);
     union_cast_to_ref_method_impl!(as_literal_struct, InferenceRuleLiteralStruct, InferenceRule::LiteralStruct);
     union_cast_to_ref_method_impl!(as_literal_union, InferenceRuleLiteralUnion, InferenceRule::LiteralUnion);
     union_cast_to_ref_method_impl!(as_literal_array, InferenceRuleLiteralArray, InferenceRule::LiteralArray);
     union_cast_to_ref_method_impl!(as_literal_tuple, InferenceRuleLiteralTuple, InferenceRule::LiteralTuple);
     union_cast_to_ref_method_impl!(as_cast_expr, InferenceRuleCastExpr, InferenceRule::CastExpr);
     union_cast_to_ref_method_impl!(as_call_expr, InferenceRuleCallExpr, InferenceRule::CallExpr);
     union_cast_to_ref_method_impl!(as_variable_expr, InferenceRuleVariableExpr, InferenceRule::VariableExpr);
+}
 // Note: InferenceRuleTemplate is `Copy`, so don't add dynamically allocated
 // members in the future (or review places where this struct is copied)
 #[derive(Clone, Copy)]
 struct InferenceRuleTemplate {
     template: &'static [InferenceTypePart],
     application: InferenceRuleTemplateApplication,
+}
 impl InferenceRuleTemplate {
     fn new_none() -> Self {
         return Self{
             template: &[],
             application: InferenceRuleTemplateApplication::None,
         };
+    }
 impl Default for InferenceExpression {
     fn default() -> Self {
         Self{
             expr_type: InferenceType::default(),
             expr_id: ExpressionId::new_invalid(),
             field_or_monomorph_idx: -1,
             extra_data_idx: -1,
     fn new_forced(template: &'static [InferenceTypePart]) -> Self {
         return Self{
             template,
             application: InferenceRuleTemplateApplication::Forced,
         };
+    }
     fn new_template(template: &'static [InferenceTypePart]) -> Self {
         return Self{
             template,
             application: InferenceRuleTemplateApplication::Template,
+        }
+    }
+}
 #[derive(Clone, Copy)]
 enum InferenceRuleTemplateApplication {
     None, // do not apply template, silly, but saves some bytes
     Forced,
     Template,
+}
 /// Type equality applied to 'self' and the argument. An optional template will
 /// be applied to 'self' first. Example: "bitwise not"
 struct InferenceRuleBiEqual {
     template: InferenceRuleTemplate,
     argument_index: InferNodeIndex,
+}
 /// Type equality applied to two arguments. Template can be applied to 'self'
 /// (generally forced, since this rule does not apply a type equality constraint
 /// to 'self') and the two arguments. Example: "equality operator"
 struct InferenceRuleTriEqualArgs {
     argument_template: InferenceRuleTemplate,
     result_template: InferenceRuleTemplate,
     argument1_index: InferNodeIndex,
     argument2_index: InferNodeIndex,
+}
 /// Type equality applied to 'self' and two arguments. Template may be
 /// optionally applied to 'self'. Example: "addition operator"
 struct InferenceRuleTriEqualAll {
     template: InferenceRuleTemplate,
     argument1_index: InferNodeIndex,
     argument2_index: InferNodeIndex,
+}
 /// Information for an inference rule that is applied to 'self' and two
 /// arguments, see `InferenceRule` for its meaning.
 struct InferenceRuleTwoArgs {
     argument1_index: InferNodeIndex,
     argument2_index: InferNodeIndex,
+}
 struct InferenceRuleIndexingExpr {
     subject_index: InferNodeIndex,
     index_index: InferNodeIndex,
+}
 struct InferenceRuleSlicingExpr {
     subject_index: InferNodeIndex,
     from_index: InferNodeIndex,
     to_index: InferNodeIndex,
+}
 struct InferenceRuleSelectStructField {
     subject_index: InferNodeIndex,
     selected_field: Identifier,
+}
 struct InferenceRuleSelectTupleMember {
     subject_index: InferNodeIndex,
     selected_index: u64,
+}
 struct InferenceRuleLiteralStruct {
     element_indices: Vec<InferNodeIndex>,
+}
 struct InferenceRuleLiteralUnion {
     element_indices: Vec<InferNodeIndex>
+}
 struct InferenceRuleLiteralArray {
     element_indices: Vec<InferNodeIndex>
+}
 struct InferenceRuleLiteralTuple {
     element_indices: Vec<InferNodeIndex>
+}
 struct InferenceRuleCastExpr {
     subject_index: InferNodeIndex,
+}
 struct InferenceRuleCallExpr {
     argument_indices: Vec<InferNodeIndex>
+}
 /// Data associated with a variable expression: an expression that reads the
 /// value from a variable.
 struct InferenceRuleVariableExpr {
     var_data_index: VarDataIndex, // shared variable information
+}
 /// This particular visitor will recurse depth-first into the AST and ensures
 /// that all expressions have the appropriate types.
 pub(crate) struct PassTyping {
     // Current definition we're typechecking.
     reserved_idx: i32,
     definition_type: DefinitionType,
     reserved_type_id: TypeId,
     reserved_monomorph_index: u32,
     procedure_id: ProcedureDefinitionId,
     procedure_kind: ProcedureKind,
     poly_vars: Vec<ConcreteType>,
     // Temporary variables during construction of inference rulesr
     parent_index: Option<InferNodeIndex>,
     // Buffers for iteration over various types
     var_buffer: ScopedBuffer<VariableId>,
     expr_buffer: ScopedBuffer<ExpressionId>,
     stmt_buffer: ScopedBuffer<StatementId>,
     bool_buffer: ScopedBuffer<bool>,
     index_buffer: ScopedBuffer<usize>,
     definition_buffer: ScopedBuffer<DefinitionId>,
     poly_progress_buffer: ScopedBuffer<u32>,
     // Mapping from parser type to inferred type. We attempt to continue to
     // specify these types until we're stuck or we've fully determined the type.
     var_types: HashMap<VariableId, VarData>,            // types of variables
     expr_types: Vec<InferenceExpression>,                     // will be transferred to type table at end
     extra_data: Vec<ExtraData>,       // data for polymorph inference
     infer_nodes: Vec<InferenceNode>,                     // will be transferred to type table at end
     poly_data: Vec<PolyData>,       // data for polymorph inference
     var_data: Vec<VarData>,
     // Keeping track of which expressions need to be reinferred because the
     // expressions they're linked to made progression on an associated type
-    expr_queued: DequeSet<i32>,
+    node_queued: DequeSet<InferNodeIndex>,
+}
 // TODO: @Rename, this is used for a lot of type inferencing. It seems like
 //  there is a different underlying architecture waiting to surface.
 struct ExtraData {
     expr_id: ExpressionId, // the expression with which this data is associated
 /// Generic struct that is used to store inferred types associated with
 /// polymorphic types.
 struct PolyData {
     first_rule_application: bool,
     definition_id: DefinitionId, // the definition, only used for user feedback
     /// Progression of polymorphic variables (if any)
     /// Inferred types of the polymorphic variables as they are written down
     /// at the type's definition.
     poly_vars: Vec<InferenceType>,
     /// Progression of types of call arguments or struct members
     embedded: Vec<InferenceType>,
     expr_types: PolyDataTypes,
+}
 // silly structure, just so we can use `PolyDataTypeIndex` ergonomically while
 // making sure we're still capable of borrowing from `poly_vars`.
 struct PolyDataTypes {
     /// Inferred types of associated types (e.g. struct fields, tuple members,
     /// function arguments). These types may depend on the polymorphic variables
     /// defined above.
     associated: Vec<InferenceType>,
     /// Inferred "returned" type (e.g. if a struct field is selected, then this
     /// contains the type of the selected field, for a function call it contains
     /// the return type). May depend on the polymorphic variables defined above.
     returned: InferenceType,
+}
 impl Default for ExtraData {
     fn default() -> Self {
         Self{
             expr_id: ExpressionId::new_invalid(),
             definition_id: DefinitionId::new_invalid(),
             poly_vars: Vec::new(),
             embedded: Vec::new(),
             returned: InferenceType::default(),
 #[derive(Clone, Copy)]
 enum PolyDataTypeIndex {
     Associated(usize), // indexes into `PolyData.associated`
     Returned,
+}
 impl PolyDataTypes {
     fn get_type(&self, index: PolyDataTypeIndex) -> &InferenceType {
         match index {
             PolyDataTypeIndex::Associated(index) => return &self.associated[index],
             PolyDataTypeIndex::Returned => return &self.returned,
+        }
+    }
 struct VarData {
     /// Type of the variable
     var_type: InferenceType,
     /// VariableExpressions that use the variable
     used_at: Vec<ExpressionId>,
     /// For channel statements we link to the other variable such that when one
     /// channel's interior type is resolved, we can also resolve the other one.
     linked_var: Option<VariableId>,
     fn get_type_mut(&mut self, index: PolyDataTypeIndex) -> &mut InferenceType {
         match index {
             PolyDataTypeIndex::Associated(index) => return &mut self.associated[index],
             PolyDataTypeIndex::Returned => return &mut self.returned,
+        }
 impl VarData {
     fn new_channel(var_type: InferenceType, other_port: VariableId) -> Self {
         Self{ var_type, used_at: Vec::new(), linked_var: Some(other_port) }
+    }
     fn new_local(var_type: InferenceType) -> Self {
         Self{ var_type, used_at: Vec::new(), linked_var: None }
+}
 struct VarData {
     var_id: VariableId,
     var_type: InferenceType,
     used_at: Vec<InferNodeIndex>, // of variable expressions
     linked_var: Option<VarDataIndex>,
+}
 impl PassTyping {
     pub(crate) fn new() -> Self {
         PassTyping {
             reserved_idx: -1,
             definition_type: DefinitionType::Function(FunctionDefinitionId::new_invalid()),
             reserved_type_id: TypeId::new_invalid(),
             reserved_monomorph_index: u32::MAX,
             procedure_id: ProcedureDefinitionId::new_invalid(),
             procedure_kind: ProcedureKind::Function,
             poly_vars: Vec::new(),
             var_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAPACITY),
             expr_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAPACITY),
             stmt_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAPACITY),
             bool_buffer: ScopedBuffer::with_capacity(16),
             var_types: HashMap::new(),
             expr_types: Vec::new(),
             extra_data: Vec::new(),
             expr_queued: DequeSet::new(),
+        }
+    }
     pub(crate) fn queue_module_definitions(ctx: &mut Ctx, queue: &mut ResolveQueue) {
             parent_index: None,
             var_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
             expr_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
             stmt_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
             bool_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             index_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             definition_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
             poly_progress_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             infer_nodes: Vec::with_capacity(BUFFER_INIT_CAP_LARGE),
             poly_data: Vec::with_capacity(BUFFER_INIT_CAP_SMALL),
             var_data: Vec::with_capacity(BUFFER_INIT_CAP_SMALL),
             node_queued: DequeSet::new(),
+        }
+    }
     pub(crate) fn queue_module_definitions(&mut self, ctx: &mut Ctx, queue: &mut ResolveQueue) {
         debug_assert_eq!(ctx.module().phase, ModuleCompilationPhase::ValidatedAndLinked);
         let root_id = ctx.module().root_id;
         let root = &ctx.heap.protocol_descriptions[root_id];
         for definition_id in &root.definitions {
             let definition = &ctx.heap[*definition_id];
         let definitions_section = self.definition_buffer.start_section_initialized(&root.definitions);
         for definition_id in definitions_section.iter_copied() {
             let definition = &ctx.heap[definition_id];
             let first_concrete_part = match definition {
                 Definition::Function(definition) => {
             let first_concrete_part_and_procedure_id = match definition {
                 Definition::Procedure(definition) => {
                     if definition.poly_vars.is_empty() {
                         Some(ConcreteTypePart::Function(*definition_id, 0))
                         if definition.kind == ProcedureKind::Function {
                             Some((ConcreteTypePart::Function(definition.this, 0), definition.this))
                         } else {
-                        None
+                            Some((ConcreteTypePart::Component(definition.this, 0), definition.this))
+                        }
+                }
                 Definition::Component(definition) => {
                     if definition.poly_vars.is_empty() {
                         Some(ConcreteTypePart::Component(*definition_id, 0))
                     } else {
                         None
+                    }
-                },
+                }
                 Definition::Enum(_) | Definition::Struct(_) | Definition::Union(_) => None,
             };
             if let Some(first_concrete_part) = first_concrete_part {
             if let Some((first_concrete_part, procedure_id)) = first_concrete_part_and_procedure_id {
                 let procedure = &mut ctx.heap[procedure_id];
                 let monomorph_index = procedure.monomorphs.len() as u32;
                 procedure.monomorphs.push(ProcedureDefinitionMonomorph::new_invalid());
                 let concrete_type = ConcreteType{ parts: vec![first_concrete_part] };
                 let reserved_idx = ctx.types.reserve_procedure_monomorph_index(definition_id, concrete_type);
                 queue.push(ResolveQueueElement{
                 let type_id = ctx.types.reserve_procedure_monomorph_type_id(&definition_id, concrete_type, monomorph_index);
                 queue.push_back(ResolveQueueElement{
                     root_id,
                     definition_id: *definition_id,
                     reserved_monomorph_idx: reserved_idx,
                     definition_id,
                     reserved_type_id: type_id,
                     reserved_monomorph_index: monomorph_index,
                 })
+            }
+        }
         definitions_section.forget();
+    }
     pub(crate) fn handle_module_definition(
         &mut self, ctx: &mut Ctx, queue: &mut ResolveQueue, element: ResolveQueueElement
     ) -> VisitorResult {
         self.reset();
         debug_assert_eq!(ctx.module().root_id, element.root_id);
         debug_assert!(self.poly_vars.is_empty());
         // Prepare for visiting the definition
         self.reserved_idx = element.reserved_monomorph_idx;
         self.reserved_type_id = element.reserved_type_id;
         self.reserved_monomorph_index = element.reserved_monomorph_index;
         let proc_base = ctx.types.get_base_definition(&element.definition_id).unwrap();
         if proc_base.is_polymorph {
-            let monomorph = ctx.types.get_monomorph(element.reserved_monomorph_idx);
+            let monomorph = ctx.types.get_monomorph(element.reserved_type_id);
             for poly_arg in monomorph.concrete_type.embedded_iter(0) {
                 self.poly_vars.push(ConcreteType{ parts: Vec::from(poly_arg) });
+            }
+        }
         // Visit the definition, setting up the type resolving process, then
         // (attempt to) resolve all types
         self.visit_definition(ctx, element.definition_id)?;
         self.resolve_types(ctx, queue)?;
         Ok(())
+    }
     fn reset(&mut self) {
         self.reserved_idx = -1;
         self.definition_type = DefinitionType::Function(FunctionDefinitionId::new_invalid());
         self.reserved_type_id = TypeId::new_invalid();
         self.procedure_id = ProcedureDefinitionId::new_invalid();
         self.procedure_kind = ProcedureKind::Function;
         self.poly_vars.clear();
         self.var_types.clear();
         self.expr_types.clear();
         self.extra_data.clear();
         self.expr_queued.clear();
         self.parent_index = None;
         self.infer_nodes.clear();
         self.poly_data.clear();
         self.var_data.clear();
         self.node_queued.clear();
+    }
+}
 impl Visitor for PassTyping {
     // Definitions
     fn visit_component_definition(&mut self, ctx: &mut Ctx, id: ComponentDefinitionId) -> VisitorResult {
         self.definition_type = DefinitionType::Component(id);
 // -----------------------------------------------------------------------------
 // PassTyping - Visitor-like implementation
 // -----------------------------------------------------------------------------
         let comp_def = &ctx.heap[id];
         debug_assert_eq!(comp_def.poly_vars.len(), self.poly_vars.len(), "component polyvars do not match imposed polyvars");
 type VisitorResult = Result<(), ParseError>;
 type VisitExprResult = Result<InferNodeIndex, ParseError>;
         debug_log!("{}", "-".repeat(50));
         debug_log!("Visiting component '{}': {}", comp_def.identifier.value.as_str(), id.0.index);
         debug_log!("{}", "-".repeat(50));
         // Reserve data for expression types
         debug_assert!(self.expr_types.is_empty());
         self.expr_types.resize(comp_def.num_expressions_in_body as usize, Default::default());
 impl PassTyping {
     // Definitions
         // Visit parameters
         let section = self.var_buffer.start_section_initialized(comp_def.parameters.as_slice());
         for param_id in section.iter_copied() {
             let param = &ctx.heap[param_id];
             let var_type = self.determine_inference_type_from_parser_type_elements(&param.parser_type.elements, true);
             debug_assert!(var_type.is_done, "expected component arguments to be concrete types");
             self.var_types.insert(param_id, VarData::new_local(var_type));
     fn visit_definition(&mut self, ctx: &mut Ctx, id: DefinitionId) -> VisitorResult {
         return visitor_recursive_definition_impl!(self, &ctx.heap[id], ctx);
+    }
         section.forget();
         // Visit the body and all of its expressions
         let body_stmt_id = ctx.heap[id].body;
         self.visit_block_stmt(ctx, body_stmt_id)
+    }
     fn visit_enum_definition(&mut self, _: &mut Ctx, _: EnumDefinitionId) -> VisitorResult { return Ok(()) }
     fn visit_struct_definition(&mut self, _: &mut Ctx, _: StructDefinitionId) -> VisitorResult { return Ok(()) }
     fn visit_union_definition(&mut self, _: &mut Ctx, _: UnionDefinitionId) -> VisitorResult { return Ok(()) }
     fn visit_function_definition(&mut self, ctx: &mut Ctx, id: FunctionDefinitionId) -> VisitorResult {
         self.definition_type = DefinitionType::Function(id);
     fn visit_procedure_definition(&mut self, ctx: &mut Ctx, id: ProcedureDefinitionId) -> VisitorResult {
         let procedure_def = &ctx.heap[id];
         let func_def = &ctx.heap[id];
         debug_assert_eq!(func_def.poly_vars.len(), self.poly_vars.len(), "function polyvars do not match imposed polyvars");
         self.procedure_id = id;
         self.procedure_kind = procedure_def.kind;
         let body_id = procedure_def.body;
         debug_log!("{}", "-".repeat(50));
         debug_log!("Visiting function '{}': {}", func_def.identifier.value.as_str(), id.0.index);
         if debug_log_enabled!() {
             debug_log!("Polymorphic variables:");
             for (_idx, poly_var) in self.poly_vars.iter().enumerate() {
                 let mut infer_type_parts = Vec::new();
                 Self::determine_inference_type_from_concrete_type(
                     &mut infer_type_parts, &poly_var.parts
                 );
                 let _infer_type = InferenceType::new(false, true, infer_type_parts);
                 debug_log!(" - [{:03}] {:?}", _idx, _infer_type.display_name(&ctx.heap));
+            }
+        }
         debug_log!("Visiting procedure: '{}' (id: {}, kind: {:?})", procedure_def.identifier.value.as_str(), id.0.index, procedure_def.kind);
         debug_log!("{}", "-".repeat(50));
         // Reserve data for expression types
         debug_assert!(self.expr_types.is_empty());
         self.expr_types.resize(func_def.num_expressions_in_body as usize, Default::default());
         // Visit parameters
-        let section = self.var_buffer.start_section_initialized(func_def.parameters.as_slice());
+        let section = self.var_buffer.start_section_initialized(procedure_def.parameters.as_slice());
         for param_id in section.iter_copied() {
             let param = &ctx.heap[param_id];
             let var_type = self.determine_inference_type_from_parser_type_elements(&param.parser_type.elements, true);
             debug_assert!(var_type.is_done, "expected function arguments to be concrete types");
             self.var_types.insert(param_id, VarData::new_local(var_type));
             self.var_data.push(VarData{
                 var_id: param_id,
                 var_type,
                 used_at: Vec::new(),
                 linked_var: None
             })
+        }
         section.forget();
         // Visit all of the expressions within the body
         let body_stmt_id = ctx.heap[id].body;
         self.visit_block_stmt(ctx, body_stmt_id)
         self.parent_index = None;
         return self.visit_block_stmt(ctx, body_id);
+    }
     // Statements
     fn visit_stmt(&mut self, ctx: &mut Ctx, id: StatementId) -> VisitorResult {
         return visitor_recursive_statement_impl!(self, &ctx.heap[id], ctx, Ok(()));
+    }
     fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
         // Transfer statements for traversal
         let block = &ctx.heap[id];
         let section = self.stmt_buffer.start_section_initialized(block.statements.as_slice());
         for stmt_id in section.iter_copied() {
             self.visit_stmt(ctx, stmt_id)?;
+        }
         section.forget();
         Ok(())
+    }
     fn visit_local_stmt(&mut self, ctx: &mut Ctx, id: LocalStatementId) -> VisitorResult {
         return visitor_recursive_local_impl!(self, &ctx.heap[id], ctx);
+    }
     fn visit_local_memory_stmt(&mut self, ctx: &mut Ctx, id: MemoryStatementId) -> VisitorResult {
         let memory_stmt = &ctx.heap[id];
         let initial_expr_id = memory_stmt.initial_expr;
         // Setup memory statement inference
         let local = &ctx.heap[memory_stmt.variable];
         let var_type = self.determine_inference_type_from_parser_type_elements(&local.parser_type.elements, true);
         self.var_types.insert(memory_stmt.variable, VarData::new_local(var_type));
         self.var_data.push(VarData{
             var_id: memory_stmt.variable,
             var_type,
             used_at: Vec::new(),
             linked_var: None,
         });
         // Process the initial value
         self.visit_assignment_expr(ctx, initial_expr_id)?;
         Ok(())
+    }
     fn visit_local_channel_stmt(&mut self, ctx: &mut Ctx, id: ChannelStatementId) -> VisitorResult {
         let channel_stmt = &ctx.heap[id];
         let from_var_index = self.var_data.len() as VarDataIndex;
         let to_var_index = from_var_index + 1;
         let from_local = &ctx.heap[channel_stmt.from];
         let from_var_type = self.determine_inference_type_from_parser_type_elements(&from_local.parser_type.elements, true);
         self.var_types.insert(from_local.this, VarData::new_channel(from_var_type, channel_stmt.to));
         self.var_data.push(VarData{
             var_id: channel_stmt.from,
             var_type: from_var_type,
             used_at: Vec::new(),
             linked_var: Some(to_var_index),
         });
         let to_local = &ctx.heap[channel_stmt.to];
         let to_var_type = self.determine_inference_type_from_parser_type_elements(&to_local.parser_type.elements, true);
         self.var_types.insert(to_local.this, VarData::new_channel(to_var_type, channel_stmt.from));
         self.var_data.push(VarData{
             var_id: channel_stmt.to,
             var_type: to_var_type,
             used_at: Vec::new(),
             linked_var: Some(from_var_index),
         });
         Ok(())
+    }
     fn visit_labeled_stmt(&mut self, ctx: &mut Ctx, id: LabeledStatementId) -> VisitorResult {
         let labeled_stmt = &ctx.heap[id];
         let substmt_id = labeled_stmt.body;
         self.visit_stmt(ctx, substmt_id)
+    }
     fn visit_if_stmt(&mut self, ctx: &mut Ctx, id: IfStatementId) -> VisitorResult {
         let if_stmt = &ctx.heap[id];
         let true_body_id = if_stmt.true_body;
         let false_body_id = if_stmt.false_body;
         let true_body_case = if_stmt.true_case;
         let false_body_case = if_stmt.false_case;
         let test_expr_id = if_stmt.test;
         self.visit_expr(ctx, test_expr_id)?;
         self.visit_block_stmt(ctx, true_body_id)?;
         if let Some(false_body_id) = false_body_id {
             self.visit_block_stmt(ctx, false_body_id)?;
         self.visit_stmt(ctx, true_body_case.body)?;
         if let Some(false_body_case) = false_body_case {
             self.visit_stmt(ctx, false_body_case.body)?;
+        }
         Ok(())
+    }
     fn visit_while_stmt(&mut self, ctx: &mut Ctx, id: WhileStatementId) -> VisitorResult {
         let while_stmt = &ctx.heap[id];
         let body_id = while_stmt.body;
         let test_expr_id = while_stmt.test;
         self.visit_expr(ctx, test_expr_id)?;
-        self.visit_block_stmt(ctx, body_id)?;
+        self.visit_stmt(ctx, body_id)?;
         Ok(())
+    }
     fn visit_break_stmt(&mut self, _: &mut Ctx, _: BreakStatementId) -> VisitorResult { return Ok(()) }
     fn visit_continue_stmt(&mut self, _: &mut Ctx, _: ContinueStatementId) -> VisitorResult { return Ok(()) }
     fn visit_synchronous_stmt(&mut self, ctx: &mut Ctx, id: SynchronousStatementId) -> VisitorResult {
         let sync_stmt = &ctx.heap[id];
         let body_id = sync_stmt.body;
-        self.visit_block_stmt(ctx, body_id)
+        self.visit_stmt(ctx, body_id)
+    }
     fn visit_fork_stmt(&mut self, ctx: &mut Ctx, id: ForkStatementId) -> VisitorResult {
         let fork_stmt = &ctx.heap[id];
         let left_body_id = fork_stmt.left_body;
         let right_body_id = fork_stmt.right_body;
-        self.visit_block_stmt(ctx, left_body_id)?;
+        self.visit_stmt(ctx, left_body_id)?;
         if let Some(right_body_id) = right_body_id {
-            self.visit_block_stmt(ctx, right_body_id)?;
+            self.visit_stmt(ctx, right_body_id)?;
+        }
         Ok(())
+    }
     fn visit_select_stmt(&mut self, ctx: &mut Ctx, id: SelectStatementId) -> VisitorResult {
         let select_stmt = &ctx.heap[id];
         let mut section = self.stmt_buffer.start_section();
         let num_cases = select_stmt.cases.len();
         for case in &select_stmt.cases {
             section.push(case.guard);
-            section.push(case.block.upcast());
+            section.push(case.body);
+        }
         for case_index in 0..num_cases {
             let base_index = 2 * case_index;
             let guard_stmt_id = section[base_index    ];
             let block_stmt_id = section[base_index + 1];
             self.visit_stmt(ctx, guard_stmt_id)?;
             self.visit_stmt(ctx, block_stmt_id)?;
+        }
         section.forget();
         Ok(())
+    }
     fn visit_return_stmt(&mut self, ctx: &mut Ctx, id: ReturnStatementId) -> VisitorResult {
         let return_stmt = &ctx.heap[id];
         debug_assert_eq!(return_stmt.expressions.len(), 1);
         let expr_id = return_stmt.expressions[0];
         self.visit_expr(ctx, expr_id)
         self.visit_expr(ctx, expr_id)?;
         return Ok(());
+    }
     fn visit_goto_stmt(&mut self, _: &mut Ctx, _: GotoStatementId) -> VisitorResult { return Ok(()) }
     fn visit_new_stmt(&mut self, ctx: &mut Ctx, id: NewStatementId) -> VisitorResult {
         let new_stmt = &ctx.heap[id];
         let call_expr_id = new_stmt.expression;
         self.visit_call_expr(ctx, call_expr_id)
         self.visit_call_expr(ctx, call_expr_id)?;
         return Ok(());
+    }
     fn visit_expr_stmt(&mut self, ctx: &mut Ctx, id: ExpressionStatementId) -> VisitorResult {
         let expr_stmt = &ctx.heap[id];
         let subexpr_id = expr_stmt.expression;
         self.visit_expr(ctx, subexpr_id)
         self.visit_expr(ctx, subexpr_id)?;
         return Ok(());
+    }
     // Expressions
     fn visit_assignment_expr(&mut self, ctx: &mut Ctx, id: AssignmentExpressionId) -> VisitorResult {
     fn visit_expr(&mut self, ctx: &mut Ctx, id: ExpressionId) -> VisitExprResult {
         return visitor_recursive_expression_impl!(self, &ctx.heap[id], ctx);
+    }
     fn visit_assignment_expr(&mut self, ctx: &mut Ctx, id: AssignmentExpressionId) -> VisitExprResult {
         use AssignmentOperator as AO;
         let upcast_id = id.upcast();
-        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
+        let self_index = self.insert_initial_inference_node(ctx, upcast_id)?;
         let assign_expr = &ctx.heap[id];
         let assign_op = assign_expr.operation;
         let left_expr_id = assign_expr.left;
         let right_expr_id = assign_expr.right;
         self.visit_expr(ctx, left_expr_id)?;
         self.visit_expr(ctx, right_expr_id)?;
         let old_parent = self.parent_index.replace(self_index);
         let left_index = self.visit_expr(ctx, left_expr_id)?;
         let right_index = self.visit_expr(ctx, right_expr_id)?;
         let node = &mut self.infer_nodes[self_index];
         let argument_template = match assign_op {
             AO::Set =>
                 InferenceRuleTemplate::new_none(),
             AO::Concatenated =>
                 InferenceRuleTemplate::new_template(&ARRAYLIKE_TEMPLATE),
             AO::Multiplied | AO::Divided | AO::Added | AO::Subtracted =>
                 InferenceRuleTemplate::new_template(&NUMBERLIKE_TEMPLATE),
             AO::Remained | AO::ShiftedLeft | AO::ShiftedRight |
             AO::BitwiseAnded | AO::BitwiseXored | AO::BitwiseOred =>
                 InferenceRuleTemplate::new_template(&INTEGERLIKE_TEMPLATE),
         };
         node.inference_rule = InferenceRule::TriEqualArgs(InferenceRuleTriEqualArgs{
             argument_template,
             result_template: InferenceRuleTemplate::new_forced(&VOID_TEMPLATE),
             argument1_index: left_index,
             argument2_index: right_index,
         });
         self.progress_assignment_expr(ctx, id)
         self.parent_index = old_parent;
         self.progress_inference_rule_tri_equal_args(ctx, self_index)?;
         return Ok(self_index);
+    }
-    fn visit_binding_expr(&mut self, ctx: &mut Ctx, id: BindingExpressionId) -> VisitorResult {
+    fn visit_binding_expr(&mut self, ctx: &mut Ctx, id: BindingExpressionId) -> VisitExprResult {
         let upcast_id = id.upcast();
-        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
+        let self_index = self.insert_initial_inference_node(ctx, upcast_id)?;
         let binding_expr = &ctx.heap[id];
         let bound_to_id = binding_expr.bound_to;
         let bound_from_id = binding_expr.bound_from;
         self.visit_expr(ctx, bound_to_id)?;
         self.visit_expr(ctx, bound_from_id)?;
         let old_parent = self.parent_index.replace(self_index);
         let arg_to_index = self.visit_expr(ctx, bound_to_id)?;
         let arg_from_index = self.visit_expr(ctx, bound_from_id)?;
         self.progress_binding_expr(ctx, id)
         let node = &mut self.infer_nodes[self_index];
         node.inference_rule = InferenceRule::TriEqualArgs(InferenceRuleTriEqualArgs{
             argument_template: InferenceRuleTemplate::new_none(),
             result_template: InferenceRuleTemplate::new_forced(&BOOL_TEMPLATE),
             argument1_index: arg_to_index,
             argument2_index: arg_from_index,
         });
         self.parent_index = old_parent;
         self.progress_inference_rule_tri_equal_args(ctx, self_index)?;
         return Ok(self_index);
+    }
-    fn visit_conditional_expr(&mut self, ctx: &mut Ctx, id: ConditionalExpressionId) -> VisitorResult {
+    fn visit_conditional_expr(&mut self, ctx: &mut Ctx, id: ConditionalExpressionId) -> VisitExprResult {
         let upcast_id = id.upcast();
-        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
+        let self_index = self.insert_initial_inference_node(ctx, upcast_id)?;
         let conditional_expr = &ctx.heap[id];
         let test_expr_id = conditional_expr.test;
         let true_expr_id = conditional_expr.true_expression;
         let false_expr_id = conditional_expr.false_expression;
         let old_parent = self.parent_index.replace(self_index);
         self.visit_expr(ctx, test_expr_id)?;
         self.visit_expr(ctx, true_expr_id)?;
         self.visit_expr(ctx, false_expr_id)?;
         let true_index = self.visit_expr(ctx, true_expr_id)?;
         let false_index = self.visit_expr(ctx, false_expr_id)?;
         // Note: the test to the conditional expression has already been forced
         // to the boolean type. So the only thing we need to do while progressing
         // is to apply an equal3 constraint to the arguments and the result of
         // the expression.
         let node = &mut self.infer_nodes[self_index];
         node.inference_rule = InferenceRule::TriEqualAll(InferenceRuleTriEqualAll{
             template: InferenceRuleTemplate::new_none(),
             argument1_index: true_index,
             argument2_index: false_index,
         });
         self.progress_conditional_expr(ctx, id)
         self.parent_index = old_parent;
         self.progress_inference_rule_tri_equal_all(ctx, self_index)?;
         return Ok(self_index);
+    }
     fn visit_binary_expr(&mut self, ctx: &mut Ctx, id: BinaryExpressionId) -> VisitorResult {
     fn visit_binary_expr(&mut self, ctx: &mut Ctx, id: BinaryExpressionId) -> VisitExprResult {
         use BinaryOperator as BO;
         let upcast_id = id.upcast();
-        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
+        let self_index = self.insert_initial_inference_node(ctx, upcast_id)?;
         let binary_expr = &ctx.heap[id];
         let binary_op = binary_expr.operation;
         let lhs_expr_id = binary_expr.left;
         let rhs_expr_id = binary_expr.right;
         self.visit_expr(ctx, lhs_expr_id)?;
         self.visit_expr(ctx, rhs_expr_id)?;
         let old_parent = self.parent_index.replace(self_index);
         let left_index = self.visit_expr(ctx, lhs_expr_id)?;
         let right_index = self.visit_expr(ctx, rhs_expr_id)?;
         let inference_rule = match binary_op {
             BO::Concatenate =>
                 InferenceRule::Concatenate(InferenceRuleTwoArgs{
                     argument1_index: left_index,
                     argument2_index: right_index,
                 }),
             BO::LogicalAnd | BO::LogicalOr =>
                 InferenceRule::TriEqualAll(InferenceRuleTriEqualAll{
                     template: InferenceRuleTemplate::new_forced(&BOOL_TEMPLATE),
                     argument1_index: left_index,
                     argument2_index: right_index,
                 }),
             BO::BitwiseOr | BO::BitwiseXor | BO::BitwiseAnd | BO::Remainder | BO::ShiftLeft | BO::ShiftRight =>
                 InferenceRule::TriEqualAll(InferenceRuleTriEqualAll{
                     template: InferenceRuleTemplate::new_template(&INTEGERLIKE_TEMPLATE),
                     argument1_index: left_index,
                     argument2_index: right_index,
                 }),
             BO::Equality | BO::Inequality =>
                 InferenceRule::TriEqualArgs(InferenceRuleTriEqualArgs{
                     argument_template: InferenceRuleTemplate::new_none(),
                     result_template: InferenceRuleTemplate::new_forced(&BOOL_TEMPLATE),
                     argument1_index: left_index,
                     argument2_index: right_index,
                 }),
             BO::LessThan | BO::GreaterThan | BO::LessThanEqual | BO::GreaterThanEqual =>
                 InferenceRule::TriEqualArgs(InferenceRuleTriEqualArgs{
                     argument_template: InferenceRuleTemplate::new_template(&NUMBERLIKE_TEMPLATE),
                     result_template: InferenceRuleTemplate::new_forced(&BOOL_TEMPLATE),
                     argument1_index: left_index,
                     argument2_index: right_index,
                 }),
             BO::Add | BO::Subtract | BO::Multiply | BO::Divide =>
                 InferenceRule::TriEqualAll(InferenceRuleTriEqualAll{
                     template: InferenceRuleTemplate::new_template(&NUMBERLIKE_TEMPLATE),
                     argument1_index: left_index,
                     argument2_index: right_index,
                 }),
         };
         let node = &mut self.infer_nodes[self_index];
         node.inference_rule = inference_rule;
         self.progress_binary_expr(ctx, id)
         self.parent_index = old_parent;
         self.progress_inference_rule(ctx, self_index)?;
         return Ok(self_index);
+    }
     fn visit_unary_expr(&mut self, ctx: &mut Ctx, id: UnaryExpressionId) -> VisitorResult {
     fn visit_unary_expr(&mut self, ctx: &mut Ctx, id: UnaryExpressionId) -> VisitExprResult {
         use UnaryOperator as UO;
         let upcast_id = id.upcast();
-        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
+        let self_index = self.insert_initial_inference_node(ctx, upcast_id)?;
         let unary_expr = &ctx.heap[id];
         let operation = unary_expr.operation;
         let arg_expr_id = unary_expr.expression;
         self.visit_expr(ctx, arg_expr_id)?;
         let old_parent = self.parent_index.replace(self_index);
         let argument_index = self.visit_expr(ctx, arg_expr_id)?;
         let template = match operation {
             UO::Positive | UO::Negative =>
                 InferenceRuleTemplate::new_template(&NUMBERLIKE_TEMPLATE),
             UO::BitwiseNot =>
                 InferenceRuleTemplate::new_template(&INTEGERLIKE_TEMPLATE),
             UO::LogicalNot =>
                 InferenceRuleTemplate::new_forced(&BOOL_TEMPLATE),
         };
         let node = &mut self.infer_nodes[self_index];
         node.inference_rule = InferenceRule::BiEqual(InferenceRuleBiEqual{
             template, argument_index,
         });
         self.progress_unary_expr(ctx, id)
         self.parent_index = old_parent;
         self.progress_inference_rule_bi_equal(ctx, self_index)?;
         return Ok(self_index);
+    }
-    fn visit_indexing_expr(&mut self, ctx: &mut Ctx, id: IndexingExpressionId) -> VisitorResult {
+    fn visit_indexing_expr(&mut self, ctx: &mut Ctx, id: IndexingExpressionId) -> VisitExprResult {
         let upcast_id = id.upcast();
-        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
+        let self_index = self.insert_initial_inference_node(ctx, upcast_id)?;
         let indexing_expr = &ctx.heap[id];
         let subject_expr_id = indexing_expr.subject;
         let index_expr_id = indexing_expr.index;
         self.visit_expr(ctx, subject_expr_id)?;
         self.visit_expr(ctx, index_expr_id)?;
         let old_parent = self.parent_index.replace(self_index);
         let subject_index = self.visit_expr(ctx, subject_expr_id)?;
         let index_index = self.visit_expr(ctx, index_expr_id)?; // cool name, bro
         let node = &mut self.infer_nodes[self_index];
         node.inference_rule = InferenceRule::IndexingExpr(InferenceRuleIndexingExpr{
             subject_index, index_index,
         });
         self.progress_indexing_expr(ctx, id)
         self.parent_index = old_parent;
         self.progress_inference_rule_indexing_expr(ctx, self_index)?;
         return Ok(self_index);
+    }
-    fn visit_slicing_expr(&mut self, ctx: &mut Ctx, id: SlicingExpressionId) -> VisitorResult {
+    fn visit_slicing_expr(&mut self, ctx: &mut Ctx, id: SlicingExpressionId) -> VisitExprResult {
         let upcast_id = id.upcast();
-        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
+        let self_index = self.insert_initial_inference_node(ctx, upcast_id)?;
         let slicing_expr = &ctx.heap[id];
         let subject_expr_id = slicing_expr.subject;
         let from_expr_id = slicing_expr.from_index;
         let to_expr_id = slicing_expr.to_index;
         self.visit_expr(ctx, subject_expr_id)?;
         self.visit_expr(ctx, from_expr_id)?;
         self.visit_expr(ctx, to_expr_id)?;
         let old_parent = self.parent_index.replace(self_index);
         let subject_index = self.visit_expr(ctx, subject_expr_id)?;
         let from_index = self.visit_expr(ctx, from_expr_id)?;
         let to_index = self.visit_expr(ctx, to_expr_id)?;
         let node = &mut self.infer_nodes[self_index];
         node.inference_rule = InferenceRule::SlicingExpr(InferenceRuleSlicingExpr{
             subject_index, from_index, to_index,
         });
         self.progress_slicing_expr(ctx, id)
         self.parent_index = old_parent;
         self.progress_inference_rule_slicing_expr(ctx, self_index)?;
         return Ok(self_index);
+    }
-    fn visit_select_expr(&mut self, ctx: &mut Ctx, id: SelectExpressionId) -> VisitorResult {
+    fn visit_select_expr(&mut self, ctx: &mut Ctx, id: SelectExpressionId) -> VisitExprResult {
         let upcast_id = id.upcast();
-        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
+        let self_index = self.insert_initial_inference_node(ctx, upcast_id)?;
         let select_expr = &ctx.heap[id];
         let subject_expr_id = select_expr.subject;
         self.visit_expr(ctx, subject_expr_id)?;
         let old_parent = self.parent_index.replace(self_index);
         let subject_index = self.visit_expr(ctx, subject_expr_id)?;
         let node = &mut self.infer_nodes[self_index];
         let inference_rule = match &ctx.heap[id].kind {
             SelectKind::StructField(field_identifier) =>
                 InferenceRule::SelectStructField(InferenceRuleSelectStructField{
                     subject_index,
                     selected_field: field_identifier.clone(),
                 }),
             SelectKind::TupleMember(member_index) =>
                 InferenceRule::SelectTupleMember(InferenceRuleSelectTupleMember{
                     subject_index,
                     selected_index: *member_index,
                 }),
         };
         node.inference_rule = inference_rule;
         self.progress_select_expr(ctx, id)
         self.parent_index = old_parent;
         self.progress_inference_rule(ctx, self_index)?;
         return Ok(self_index);
+    }
-    fn visit_literal_expr(&mut self, ctx: &mut Ctx, id: LiteralExpressionId) -> VisitorResult {
+    fn visit_literal_expr(&mut self, ctx: &mut Ctx, id: LiteralExpressionId) -> VisitExprResult {
         let upcast_id = id.upcast();
         self.insert_initial_expr_inference_type(ctx, upcast_id)?;
         let self_index = self.insert_initial_inference_node(ctx, upcast_id)?;
         let old_parent = self.parent_index.replace(self_index);
         let literal_expr = &ctx.heap[id];
         match &literal_expr.value {
             Literal::Null | Literal::False | Literal::True |
             Literal::Integer(_) | Literal::Character(_) | Literal::String(_) => {
                 // No subexpressions
             Literal::Null => {
                 let node = &mut self.infer_nodes[self_index];
                 node.inference_rule = InferenceRule::MonoTemplate(InferenceRuleTemplate::new_template(&MESSAGE_TEMPLATE));
             },
             Literal::Integer(_) => {
                 let node = &mut self.infer_nodes[self_index];
                 node.inference_rule = InferenceRule::MonoTemplate(InferenceRuleTemplate::new_template(&INTEGERLIKE_TEMPLATE));
             },
             Literal::True | Literal::False => {
                 let node = &mut self.infer_nodes[self_index];
                 node.inference_rule = InferenceRule::MonoTemplate(InferenceRuleTemplate::new_forced(&BOOL_TEMPLATE));
             },
             Literal::Character(_) => {
                 let node = &mut self.infer_nodes[self_index];
                 node.inference_rule = InferenceRule::MonoTemplate(InferenceRuleTemplate::new_forced(&CHARACTER_TEMPLATE));
             },
             Literal::String(_) => {
                 let node = &mut self.infer_nodes[self_index];
                 node.inference_rule = InferenceRule::MonoTemplate(InferenceRuleTemplate::new_forced(&STRING_TEMPLATE));
             },
             Literal::Struct(literal) => {
                 // Visit field expressions
                 let mut expr_ids = self.expr_buffer.start_section();
                 for field in &literal.fields {
                     expr_ids.push(field.value);
+                }
                 self.insert_initial_struct_polymorph_data(ctx, id);
                 let mut expr_indices = self.index_buffer.start_section();
                 for expr_id in expr_ids.iter_copied() {
                     self.visit_expr(ctx, expr_id)?;
                     let expr_index = self.visit_expr(ctx, expr_id)?;
                     expr_indices.push(expr_index);
+                }
                 expr_ids.forget();
                 let element_indices = expr_indices.into_vec();
                 // Assign rule and extra data index to inference node
                 let poly_data_index = self.insert_initial_struct_polymorph_data(ctx, id);
                 let node = &mut self.infer_nodes[self_index];
                 node.poly_data_index = poly_data_index;
                 node.inference_rule = InferenceRule::LiteralStruct(InferenceRuleLiteralStruct{
                     element_indices,
                 });
             },
             Literal::Enum(_) => {
                 // Enumerations do not carry any subexpressions, but may still
                 // have a user-defined polymorphic marker variable. For this
                 // reason we may still have to apply inference to this
                 // polymorphic variable
                 self.insert_initial_enum_polymorph_data(ctx, id);
                 let poly_data_index = self.insert_initial_enum_polymorph_data(ctx, id);
                 let node = &mut self.infer_nodes[self_index];
                 node.poly_data_index = poly_data_index;
                 node.inference_rule = InferenceRule::LiteralEnum;
             },
             Literal::Union(literal) => {
                 // May carry subexpressions and polymorphic arguments
                 let expr_ids = self.expr_buffer.start_section_initialized(literal.values.as_slice());
                 self.insert_initial_union_polymorph_data(ctx, id);
+                let poly_data_index = self.insert_initial_union_polymorph_data(ctx, id);
                 let mut expr_indices = self.index_buffer.start_section();
                 for expr_id in expr_ids.iter_copied() {
                     self.visit_expr(ctx, expr_id)?;
                     let expr_index = self.visit_expr(ctx, expr_id)?;
                     expr_indices.push(expr_index);
+                }
                 expr_ids.forget();
                 let element_indices = expr_indices.into_vec();
                 let node = &mut self.infer_nodes[self_index];
                 node.poly_data_index = poly_data_index;
                 node.inference_rule = InferenceRule::LiteralUnion(InferenceRuleLiteralUnion{
                     element_indices,
                 });
             },
-            Literal::Array(expressions) | Literal::Tuple(expressions) => {
             Literal::Array(expressions) => {
                 let expr_ids = self.expr_buffer.start_section_initialized(expressions.as_slice());
                 let mut expr_indices = self.index_buffer.start_section();
                 for expr_id in expr_ids.iter_copied() {
                     self.visit_expr(ctx, expr_id)?;
                     let expr_index = self.visit_expr(ctx, expr_id)?;
                     expr_indices.push(expr_index);
+                }
                 expr_ids.forget();
                 let element_indices = expr_indices.into_vec();
                 let node = &mut self.infer_nodes[self_index];
                 node.inference_rule = InferenceRule::LiteralArray(InferenceRuleLiteralArray{
                     element_indices,
                 });
             },
             Literal::Tuple(expressions) => {
                 let expr_ids = self.expr_buffer.start_section_initialized(expressions.as_slice());
                 let mut expr_indices = self.index_buffer.start_section();
                 for expr_id in expr_ids.iter_copied() {
                     let expr_index = self.visit_expr(ctx, expr_id)?;
                     expr_indices.push(expr_index);
+                }
                 expr_ids.forget();
                 let element_indices = expr_indices.into_vec();
                 let node = &mut self.infer_nodes[self_index];
                 node.inference_rule = InferenceRule::LiteralTuple(InferenceRuleLiteralTuple{
                     element_indices,
                 })
+            }
+        }
         self.progress_literal_expr(ctx, id)
         self.parent_index = old_parent;
         self.progress_inference_rule(ctx, self_index)?;
         return Ok(self_index);
+    }
-    fn visit_cast_expr(&mut self, ctx: &mut Ctx, id: CastExpressionId) -> VisitorResult {
+    fn visit_cast_expr(&mut self, ctx: &mut Ctx, id: CastExpressionId) -> VisitExprResult {
         let upcast_id = id.upcast();
-        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
+        let self_index = self.insert_initial_inference_node(ctx, upcast_id)?;
         let cast_expr = &ctx.heap[id];
         let subject_expr_id = cast_expr.subject;
         self.visit_expr(ctx, subject_expr_id)?;
         let old_parent = self.parent_index.replace(self_index);
         let subject_index = self.visit_expr(ctx, subject_expr_id)?;
         let node = &mut self.infer_nodes[self_index];
         node.inference_rule = InferenceRule::CastExpr(InferenceRuleCastExpr{
             subject_index,
         });
         self.parent_index = old_parent;
         self.progress_cast_expr(ctx, id)
         // The cast expression is a bit special at this point: the progression
         // function simply makes sure input/output types are compatible. But if
         // the programmer explicitly specified the output type, then we can
         // already perform that inference rule here.
+        {
             let cast_expr = &ctx.heap[id];
             let specified_type = self.determine_inference_type_from_parser_type_elements(&cast_expr.to_type.elements, true);
             let _progress = self.apply_template_constraint(ctx, self_index, &specified_type.parts)?;
+        }
         self.progress_inference_rule_cast_expr(ctx, self_index)?;
         return Ok(self_index);
+    }
-    fn visit_call_expr(&mut self, ctx: &mut Ctx, id: CallExpressionId) -> VisitorResult {
+    fn visit_call_expr(&mut self, ctx: &mut Ctx, id: CallExpressionId) -> VisitExprResult {
         let upcast_id = id.upcast();
         self.insert_initial_expr_inference_type(ctx, upcast_id)?;
         self.insert_initial_call_polymorph_data(ctx, id);
         let self_index = self.insert_initial_inference_node(ctx, upcast_id)?;
         let extra_index = self.insert_initial_call_polymorph_data(ctx, id);
         // By default we set the polymorph idx for calls to 0. If the call ends
         // up not being a polymorphic one, then we will select the default
         // expression types in the type table
         let call_expr = &ctx.heap[id];
         self.expr_types[call_expr.unique_id_in_definition as usize].field_or_monomorph_idx = 0;
         // By default we set the polymorph idx for calls to 0. If the call
         // refers to a non-polymorphic function, then it will be "monomorphed"
         // once, hence we end up pointing to the correct instance.
         self.infer_nodes[self_index].field_index = 0;
         // Visit all arguments
         let old_parent = self.parent_index.replace(self_index);
         let call_expr = &ctx.heap[id];
         let expr_ids = self.expr_buffer.start_section_initialized(call_expr.arguments.as_slice());
         let mut expr_indices = self.index_buffer.start_section();
         for arg_expr_id in expr_ids.iter_copied() {
             self.visit_expr(ctx, arg_expr_id)?;
             let expr_index = self.visit_expr(ctx, arg_expr_id)?;
             expr_indices.push(expr_index);
+        }
         expr_ids.forget();
         let argument_indices = expr_indices.into_vec();
         let node = &mut self.infer_nodes[self_index];
         node.poly_data_index = extra_index;
         node.inference_rule = InferenceRule::CallExpr(InferenceRuleCallExpr{
             argument_indices,
         });
         self.progress_call_expr(ctx, id)
         self.parent_index = old_parent;
         self.progress_inference_rule_call_expr(ctx, self_index)?;
         return Ok(self_index);
+    }
-    fn visit_variable_expr(&mut self, ctx: &mut Ctx, id: VariableExpressionId) -> VisitorResult {
+    fn visit_variable_expr(&mut self, ctx: &mut Ctx, id: VariableExpressionId) -> VisitExprResult {
         let upcast_id = id.upcast();
-        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
+        let self_index = self.insert_initial_inference_node(ctx, upcast_id)?;
         let var_expr = &ctx.heap[id];
         debug_assert!(var_expr.declaration.is_some());
         let old_parent = self.parent_index.replace(self_index);
         // Not pretty: if a binding expression, then this is the first time we
         // encounter the variable, so we still need to insert the variable data.
         let declaration = &ctx.heap[var_expr.declaration.unwrap()];
         if !self.var_types.contains_key(&declaration.this)  {
             debug_assert!(declaration.kind == VariableKind::Binding);
         let mut var_data_index = None;
         for (index, var_data) in self.var_data.iter().enumerate() {
             if var_data.var_id == declaration.this {
                 var_data_index = Some(index);
                 break;
+            }
+        }
         let var_data_index = if let Some(var_data_index) = var_data_index {
             let var_data = &mut self.var_data[var_data_index];
             var_data.used_at.push(self_index);
             var_data_index
         } else {
             // If we're in a binding expression then it might the first time we
             // encounter the variable, so add a `VarData` entry.
             debug_assert_eq!(declaration.kind, VariableKind::Binding);
             let var_type = self.determine_inference_type_from_parser_type_elements(
                 &declaration.parser_type.elements, true
             );
             self.var_types.insert(declaration.this, VarData{
             let var_data_index = self.var_data.len();
             self.var_data.push(VarData{
                 var_id: declaration.this,
                 var_type,
                 used_at: vec![upcast_id],
                 linked_var: None
                 used_at: vec![self_index],
                 linked_var: None,
             });
         } else {
             let var_data = self.var_types.get_mut(&declaration.this).unwrap();
             var_data.used_at.push(upcast_id);
+        }
         self.progress_variable_expr(ctx, id)
             var_data_index
         };
         let node = &mut self.infer_nodes[self_index];
         node.inference_rule = InferenceRule::VariableExpr(InferenceRuleVariableExpr{
             var_data_index,
         });
         self.parent_index = old_parent;
         self.progress_inference_rule_variable_expr(ctx, self_index)?;
         return Ok(self_index);
+    }
+}
 // -----------------------------------------------------------------------------
 // PassTyping - Type-inference progression
 // -----------------------------------------------------------------------------
 impl PassTyping {
     #[allow(dead_code)] // used when debug flag at the top of this file is true.
     fn debug_get_display_name(&self, ctx: &Ctx, expr_id: ExpressionId) -> String {
         let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition();
         let expr_type = &self.expr_types[expr_idx as usize].expr_type;
     fn debug_get_display_name(&self, ctx: &Ctx, node_index: InferNodeIndex) -> String {
         let expr_type = &self.infer_nodes[node_index].expr_type;
         expr_type.display_name(&ctx.heap)
+    }
     fn resolve_types(&mut self, ctx: &mut Ctx, queue: &mut ResolveQueue) -> Result<(), ParseError> {
         // Keep inferring until we can no longer make any progress
         while !self.expr_queued.is_empty() {
             // Make as much progress as possible without forced integer
             // inference.
             while !self.expr_queued.is_empty() {
                 let next_expr_idx = self.expr_queued.pop_front().unwrap();
                 self.progress_expr(ctx, next_expr_idx)?;
         while !self.node_queued.is_empty() {
             while !self.node_queued.is_empty() {
                 let node_index = self.node_queued.pop_front().unwrap();
                 self.progress_inference_rule(ctx, node_index)?;
+            }
             // Nothing is queued anymore. However we might have integer literals
             // whose type cannot be inferred. For convenience's sake we'll
             // infer these to be s32.
             for (infer_expr_idx, infer_expr) in self.expr_types.iter_mut().enumerate() {
                 let expr_type = &mut infer_expr.expr_type;
             for (infer_node_index, infer_node) in self.infer_nodes.iter_mut().enumerate() {
                 let expr_type = &mut infer_node.expr_type;
                 if !expr_type.is_done && expr_type.parts.len() == 1 && expr_type.parts[0] == InferenceTypePart::IntegerLike {
                     // Force integer type to s32
                     expr_type.parts[0] = InferenceTypePart::SInt32;
                     expr_type.is_done = true;
                     // Requeue expression (and its parent, if it exists)
                     self.expr_queued.push_back(infer_expr_idx as i32);
                     if let Some(parent_expr) = ctx.heap[infer_expr.expr_id].parent_expr_id() {
                         let parent_idx = ctx.heap[parent_expr].get_unique_id_in_definition();
                         self.expr_queued.push_back(parent_idx);
                     self.node_queued.push_back(infer_node_index);
                     if let Some(node_parent_index) = infer_node.parent_index {
                         self.node_queued.push_back(node_parent_index);
+                    }
+                }
+            }
+        }
         // Helper for transferring polymorphic variables to concrete types and
         // checking if they're completely specified
         fn inference_type_to_concrete_type(
             ctx: &Ctx, expr_id: ExpressionId, inference: &Vec<InferenceType>,
         fn poly_data_type_to_concrete_type(
             ctx: &Ctx, expr_id: ExpressionId, inference_poly_args: &Vec<InferenceType>,
             first_concrete_part: ConcreteTypePart,
         ) -> Result<ConcreteType, ParseError> {
             // Prepare storage vector
             let mut num_inference_parts = 0;
-            for inference_type in inference {
+            for inference_type in inference_poly_args {
                 num_inference_parts += inference_type.parts.len();
+            }
             let mut concrete_type = ConcreteType{
                 parts: Vec::with_capacity(1 + num_inference_parts),
             };
             concrete_type.parts.push(first_concrete_part);
             // Go through all polymorphic arguments and add them to the concrete
             // types.
-            for (poly_idx, poly_type) in inference.iter().enumerate() {
+            for (poly_idx, poly_type) in inference_poly_args.iter().enumerate() {
                 if !poly_type.is_done {
                     let expr = &ctx.heap[expr_id];
                     let definition = match expr {
-                        Expression::Call(expr) => expr.definition,
+                        Expression::Call(expr) => expr.procedure.upcast(),
                         Expression::Literal(expr) => match &expr.value {
                             Literal::Enum(lit) => lit.definition,
                             Literal::Union(lit) => lit.definition,
                             Literal::Struct(lit) => lit.definition,
                             _ => unreachable!()
                         },
                         _ => unreachable!(),
                     };
                     let poly_vars = ctx.heap[definition].poly_vars();
                     return Err(ParseError::new_error_at_span(
                         &ctx.module().source, expr.operation_span(), format!(
                             "could not fully infer the type of polymorphic variable '{}' of this expression (got '{}')",
                             poly_vars[poly_idx].value.as_str(), poly_type.display_name(&ctx.heap)
+                        )
                     ));
+                }
                 poly_type.write_concrete_type(&mut concrete_type);
+            }
             Ok(concrete_type)
+        }
         // Inference is now done. But we may still have uninferred types. So we
         // check for these.
         for infer_expr in self.expr_types.iter_mut() {
             if !infer_expr.expr_type.is_done {
                 let expr = &ctx.heap[infer_expr.expr_id];
                 return Err(ParseError::new_error_at_span(
                     &ctx.module().source, expr.full_span(), format!(
                         "could not fully infer the type of this expression (got '{}')",
                         infer_expr.expr_type.display_name(&ctx.heap)
+                    )
                 ));
+            }
             // Expression is fine, check if any extra data is attached
             if infer_expr.extra_data_idx < 0 { continue; }
             // Extra data is attached, perform typechecking and transfer
             // resolved information to the expression
             let extra_data = &self.extra_data[infer_expr.extra_data_idx as usize];
         // Every expression checked, and new monomorphs are queued. Transfer the
         // expression information to the AST. If this is the first time we're
         // visiting this procedure then we assign expression indices as well.
         let procedure = &ctx.heap[self.procedure_id];
         let num_infer_nodes = self.infer_nodes.len();
         let mut monomorph = ProcedureDefinitionMonomorph{
             argument_types: Vec::with_capacity(procedure.parameters.len()),
             expr_info: Vec::with_capacity(num_infer_nodes),
         };
             // Note that only call and literal expressions need full inference.
             // Select expressions also use `extra_data`, but only for temporary
             // storage of the struct type whose field it is selecting.
             match &ctx.heap[extra_data.expr_id] {
                 Expression::Call(expr) => {
                     // Check if it is not a builtin function. If not, then
                     // construct the first part of the concrete type.
                     let first_concrete_part = if expr.method == Method::UserFunction {
                         ConcreteTypePart::Function(expr.definition, extra_data.poly_vars.len() as u32)
                     } else if expr.method == Method::UserComponent {
                         ConcreteTypePart::Component(expr.definition, extra_data.poly_vars.len() as u32)
                     } else {
                         // Builtin function
                         continue;
         // For all of the expressions look up the TypeId (or create a new one).
         // For function calls and component instantiations figure out if they
         // need to be typechecked
         for infer_node in self.infer_nodes.iter_mut() {
             // Determine type ID
             let expr = &ctx.heap[infer_node.expr_id];
             // TODO: Maybe optimize? Split insertion up into lookup, then clone
             //  if needed?
             let mut concrete_type = ConcreteType::default();
             infer_node.expr_type.write_concrete_type(&mut concrete_type);
             let info_type_id = ctx.types.add_monomorphed_type(ctx.modules, ctx.heap, ctx.arch, concrete_type)?;
             // Determine procedure type ID, i.e. a called/instantiated
             // procedure's signature.
             let info_variant = if let Expression::Call(expr) = expr {
                 // Construct full function type. If not yet typechecked then
                 // queue it for typechecking.
                 let poly_data = &self.poly_data[infer_node.poly_data_index as usize];
                 debug_assert!(expr.method.is_user_defined() || expr.method.is_public_builtin());
                 let procedure_id = expr.procedure;
                 let num_poly_vars = poly_data.poly_vars.len() as u32;
                 let first_part = match expr.method {
                     Method::UserFunction => ConcreteTypePart::Function(procedure_id, num_poly_vars),
                     Method::UserComponent => ConcreteTypePart::Component(procedure_id, num_poly_vars),
                     _ => ConcreteTypePart::Function(procedure_id, num_poly_vars),
                 };
                     let definition_id = expr.definition;
                     let concrete_type = inference_type_to_concrete_type(
                         ctx, extra_data.expr_id, &extra_data.poly_vars, first_concrete_part
                 let definition_id = procedure_id.upcast();
                 let signature_type = poly_data_type_to_concrete_type(
                     ctx, infer_node.expr_id, &poly_data.poly_vars, first_part
                 )?;
                     match ctx.types.get_procedure_monomorph_index(&definition_id, &concrete_type.parts) {
                         Some(reserved_idx) => {
                             // Already typechecked, or already put into the resolve queue
                             infer_expr.field_or_monomorph_idx = reserved_idx;
                         },
                         None => {
                             // Not typechecked yet, so add an entry in the queue
                             let reserved_idx = ctx.types.reserve_procedure_monomorph_index(&definition_id, concrete_type);
                             infer_expr.field_or_monomorph_idx = reserved_idx;
                             queue.push(ResolveQueueElement {
                 let (type_id, monomorph_index) = if let Some(type_id) = ctx.types.get_procedure_monomorph_type_id(&definition_id, &signature_type.parts) {
                     // Procedure is already typechecked
                     let monomorph_index = ctx.types.get_monomorph(type_id).variant.as_procedure().monomorph_index;
                     (type_id, monomorph_index)
                 } else {
                     // Procedure is not yet typechecked, reserve a TypeID and a monomorph index
                     let procedure_to_check = &mut ctx.heap[procedure_id];
                     let monomorph_index = procedure_to_check.monomorphs.len() as u32;
                     procedure_to_check.monomorphs.push(ProcedureDefinitionMonomorph::new_invalid());
                     let type_id = ctx.types.reserve_procedure_monomorph_type_id(&definition_id, signature_type, monomorph_index);
                     if !procedure_to_check.builtin {
                         // Only perform typechecking on the user-defined
                         // procedures
                         queue.push_back(ResolveQueueElement{
                             root_id: ctx.heap[definition_id].defined_in(),
                             definition_id,
                                 reserved_monomorph_idx: reserved_idx,
                             reserved_type_id: type_id,
                             reserved_monomorph_index: monomorph_index,
                         });
+                    }
+                    }
                 },
                 Expression::Literal(expr) => {
                     let definition_id = match &expr.value {
                         Literal::Enum(lit) => lit.definition,
                         Literal::Union(lit) => lit.definition,
                         Literal::Struct(lit) => lit.definition,
                         _ => unreachable!(),
                     };
                     let first_concrete_part = ConcreteTypePart::Instance(definition_id, extra_data.poly_vars.len() as u32);
                     let concrete_type = inference_type_to_concrete_type(
                         ctx, extra_data.expr_id, &extra_data.poly_vars, first_concrete_part
                     )?;
                     let mono_index = ctx.types.add_data_monomorph(ctx.modules, ctx.heap, ctx.arch, definition_id, concrete_type)?;
                     infer_expr.field_or_monomorph_idx = mono_index;
                 },
                 Expression::Select(_) => {
                     debug_assert!(infer_expr.field_or_monomorph_idx >= 0);
                 },
                 _ => {
                     unreachable!("handling extra data for expression {:?}", &ctx.heap[extra_data.expr_id]);
+                }
+            }
+        }
         // Every expression checked, and new monomorphs are queued. Transfer the
         // expression information to the type table.
         let procedure_arguments = match &self.definition_type {
             DefinitionType::Component(id) => {
                 let definition = &ctx.heap[*id];
                 &definition.parameters
             },
             DefinitionType::Function(id) => {
                 let definition = &ctx.heap[*id];
                 &definition.parameters
             },
                     (type_id, monomorph_index)
                 };
         let target = ctx.types.get_procedure_monomorph_mut(self.reserved_idx);
         debug_assert!(target.arg_types.is_empty()); // makes sure we never queue a procedure's type inferencing twice
         debug_assert!(target.expr_data.is_empty());
                 ExpressionInfoVariant::Procedure(type_id, monomorph_index)
             } else if let Expression::Select(_expr) = expr {
                 ExpressionInfoVariant::Select(infer_node.field_index)
             } else {
                 ExpressionInfoVariant::Generic
             };
         // - Write the arguments to the procedure
         target.arg_types.reserve(procedure_arguments.len());
         for argument_id in procedure_arguments {
             let mut concrete = ConcreteType::default();
             let argument_type = self.var_types.get(argument_id).unwrap();
             argument_type.var_type.write_concrete_type(&mut concrete);
             target.arg_types.push(concrete);
             infer_node.info_type_id = info_type_id;
             infer_node.info_variant = info_variant;
+        }
         // - Write the expression data
         target.expr_data.reserve(self.expr_types.len());
         for infer_expr in self.expr_types.iter() {
         // Write the types of the arguments
         let procedure = &ctx.heap[self.procedure_id];
         for parameter_id in procedure.parameters.iter().copied() {
             let mut concrete = ConcreteType::default();
             infer_expr.expr_type.write_concrete_type(&mut concrete);
             target.expr_data.push(MonomorphExpression{
                 expr_type: concrete,
                 field_or_monomorph_idx: infer_expr.field_or_monomorph_idx
             });
             let var_data = self.var_data.iter().find(|v| v.var_id == parameter_id).unwrap();
             var_data.var_type.write_concrete_type(&mut concrete);
             let type_id = ctx.types.add_monomorphed_type(ctx.modules, ctx.heap, ctx.arch, concrete)?;
             monomorph.argument_types.push(type_id)
+        }
         // Determine if we have already assigned type indices to the expressions
         // before (the indices that, for a monomorph, can retrieve the type of
         // the expression).
         let has_type_indices = self.reserved_monomorph_index > 0;
         if has_type_indices {
             // already have indices, so resize and then index into it
             debug_assert!(monomorph.expr_info.is_empty());
             monomorph.expr_info.resize(num_infer_nodes, ExpressionInfo::new_invalid());
             for infer_node in self.infer_nodes.iter() {
                 let type_index = ctx.heap[infer_node.expr_id].type_index();
                 monomorph.expr_info[type_index as usize] = infer_node.as_expression_info();
+            }
         } else {
             // no indices yet, need to be assigned in AST
             for infer_node in self.infer_nodes.iter() {
                 let type_index = monomorph.expr_info.len();
                 monomorph.expr_info.push(infer_node.as_expression_info());
                 *ctx.heap[infer_node.expr_id].type_index_mut() = type_index as i32;
+            }
+        }
         // Push the information into the AST
         let procedure = &mut ctx.heap[self.procedure_id];
         procedure.monomorphs[self.reserved_monomorph_index as usize] = monomorph;
         Ok(())
+    }
     fn progress_expr(&mut self, ctx: &mut Ctx, idx: i32) -> Result<(), ParseError> {
         let id = self.expr_types[idx as usize].expr_id;
         match &ctx.heap[id] {
             Expression::Assignment(expr) => {
                 let id = expr.this;
                 self.progress_assignment_expr(ctx, id)
             },
             Expression::Binding(expr) => {
                 let id = expr.this;
                 self.progress_binding_expr(ctx, id)
             },
             Expression::Conditional(expr) => {
                 let id = expr.this;
                 self.progress_conditional_expr(ctx, id)
             },
             Expression::Binary(expr) => {
                 let id = expr.this;
                 self.progress_binary_expr(ctx, id)
             },
             Expression::Unary(expr) => {
                 let id = expr.this;
                 self.progress_unary_expr(ctx, id)
             },
             Expression::Indexing(expr) => {
                 let id = expr.this;
                 self.progress_indexing_expr(ctx, id)
             },
             Expression::Slicing(expr) => {
                 let id = expr.this;
                 self.progress_slicing_expr(ctx, id)
             },
             Expression::Select(expr) => {
                 let id = expr.this;
                 self.progress_select_expr(ctx, id)
             },
             Expression::Literal(expr) => {
                 let id = expr.this;
                 self.progress_literal_expr(ctx, id)
             },
             Expression::Cast(expr) => {
                 let id = expr.this;
                 self.progress_cast_expr(ctx, id)
             },
             Expression::Call(expr) => {
                 let id = expr.this;
                 self.progress_call_expr(ctx, id)
             },
             Expression::Variable(expr) => {
                 let id = expr.this;
                 self.progress_variable_expr(ctx, id)
+            }
+        }
+    }
     fn progress_inference_rule(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         use InferenceRule as IR;
     fn progress_assignment_expr(&mut self, ctx: &mut Ctx, id: AssignmentExpressionId) -> Result<(), ParseError> {
         use AssignmentOperator as AO;
         let node = &self.infer_nodes[node_index];
         match &node.inference_rule {
             IR::Noop =>
                 unreachable!(),
             IR::MonoTemplate(_) =>
                 self.progress_inference_rule_mono_template(ctx, node_index),
             IR::BiEqual(_) =>
                 self.progress_inference_rule_bi_equal(ctx, node_index),
             IR::TriEqualArgs(_) =>
                 self.progress_inference_rule_tri_equal_args(ctx, node_index),
             IR::TriEqualAll(_) =>
                 self.progress_inference_rule_tri_equal_all(ctx, node_index),
             IR::Concatenate(_) =>
                 self.progress_inference_rule_concatenate(ctx, node_index),
             IR::IndexingExpr(_) =>
                 self.progress_inference_rule_indexing_expr(ctx, node_index),
             IR::SlicingExpr(_) =>
                 self.progress_inference_rule_slicing_expr(ctx, node_index),
             IR::SelectStructField(_) =>
                 self.progress_inference_rule_select_struct_field(ctx, node_index),
             IR::SelectTupleMember(_) =>
                 self.progress_inference_rule_select_tuple_member(ctx, node_index),
             IR::LiteralStruct(_) =>
                 self.progress_inference_rule_literal_struct(ctx, node_index),
             IR::LiteralEnum =>
                 self.progress_inference_rule_literal_enum(ctx, node_index),
             IR::LiteralUnion(_) =>
                 self.progress_inference_rule_literal_union(ctx, node_index),
             IR::LiteralArray(_) =>
                 self.progress_inference_rule_literal_array(ctx, node_index),
             IR::LiteralTuple(_) =>
                 self.progress_inference_rule_literal_tuple(ctx, node_index),
             IR::CastExpr(_) =>
                 self.progress_inference_rule_cast_expr(ctx, node_index),
             IR::CallExpr(_) =>
                 self.progress_inference_rule_call_expr(ctx, node_index),
             IR::VariableExpr(_) =>
                 self.progress_inference_rule_variable_expr(ctx, node_index),
+        }
+    }
     fn progress_inference_rule_mono_template(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let rule = *node.inference_rule.as_mono_template();
         let progress = self.progress_template(ctx, node_index, rule.application, rule.template)?;
         if progress { self.queue_node_parent(node_index); }
         let upcast_id = id.upcast();
         return Ok(());
+    }
         let expr = &ctx.heap[id];
         let arg1_expr_id = expr.left;
         let arg2_expr_id = expr.right;
     fn progress_inference_rule_bi_equal(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let rule = node.inference_rule.as_bi_equal();
         let template = rule.template;
         let arg_index = rule.argument_index;
         debug_log!("Assignment expr '{:?}': {}", expr.operation, upcast_id.index);
         debug_log!(" * Before:");
         debug_log!("   - Arg1 type: {}", self.debug_get_display_name(ctx, arg1_expr_id));
         debug_log!("   - Arg2 type: {}", self.debug_get_display_name(ctx, arg2_expr_id));
         debug_log!("   - Expr type: {}", self.debug_get_display_name(ctx, upcast_id));
         let base_progress = self.progress_template(ctx, node_index, template.application, template.template)?;
         let (node_progress, arg_progress) = self.apply_equal2_constraint(ctx, node_index, node_index, 0, arg_index, 0)?;
         // Assignment does not return anything (it operates like a statement)
         let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &VOID_TEMPLATE)?;
         if base_progress || node_progress { self.queue_node_parent(node_index); }
         if arg_progress { self.queue_node(arg_index); }
         // Apply forced constraint to LHS value
         let progress_forced = match expr.operation {
             AO::Set =>
                 false,
             AO::Concatenated =>
                 self.apply_template_constraint(ctx, arg1_expr_id, &ARRAYLIKE_TEMPLATE)?,
             AO::Multiplied | AO::Divided | AO::Added | AO::Subtracted =>
                 self.apply_template_constraint(ctx, arg1_expr_id, &NUMBERLIKE_TEMPLATE)?,
             AO::Remained | AO::ShiftedLeft | AO::ShiftedRight |
             AO::BitwiseAnded | AO::BitwiseXored | AO::BitwiseOred =>
                 self.apply_template_constraint(ctx, arg1_expr_id, &INTEGERLIKE_TEMPLATE)?,
         };
         return Ok(())
+    }
         let (progress_arg1, progress_arg2) = self.apply_equal2_constraint(
             ctx, upcast_id, arg1_expr_id, 0, arg2_expr_id, 0
         )?;
     fn progress_inference_rule_tri_equal_args(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let rule = node.inference_rule.as_tri_equal_args();
         debug_log!(" * After:");
         debug_log!("   - Arg1 type [{}]: {}", progress_forced || progress_arg1, self.debug_get_display_name(ctx, arg1_expr_id));
         debug_log!("   - Arg2 type [{}]: {}", progress_arg2, self.debug_get_display_name(ctx, arg2_expr_id));
         debug_log!("   - Expr type [{}]: {}", progress_expr, self.debug_get_display_name(ctx, upcast_id));
         let result_template = rule.result_template;
         let argument_template = rule.argument_template;
         let arg1_index = rule.argument1_index;
         let arg2_index = rule.argument2_index;
         let self_template_progress = self.progress_template(ctx, node_index, result_template.application, result_template.template)?;
         let arg1_template_progress = self.progress_template(ctx, arg1_index, argument_template.application, argument_template.template)?;
         let (arg1_progress, arg2_progress) = self.apply_equal2_constraint(ctx, node_index, arg1_index, 0, arg2_index, 0)?;
         if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
         if progress_forced || progress_arg1 { self.queue_expr(ctx, arg1_expr_id); }
         if progress_arg2 { self.queue_expr(ctx, arg2_expr_id); }
         if self_template_progress { self.queue_node_parent(node_index); }
         if arg1_template_progress || arg1_progress { self.queue_node(arg1_index); }
         if arg2_progress { self.queue_node(arg2_index); }
         Ok(())
+        return Ok(());
+    }
     fn progress_binding_expr(&mut self, ctx: &mut Ctx, id: BindingExpressionId) -> Result<(), ParseError> {
         let upcast_id = id.upcast();
         let binding_expr = &ctx.heap[id];
         let bound_from_id = binding_expr.bound_from;
         let bound_to_id = binding_expr.bound_to;
         // Output is always a boolean. The two arguments should be of equal
         // type.
         let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
         let (progress_from, progress_to) = self.apply_equal2_constraint(ctx, upcast_id, bound_from_id, 0, bound_to_id, 0)?;
         if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
         if progress_from { self.queue_expr(ctx, bound_from_id); }
         if progress_to { self.queue_expr(ctx, bound_to_id); }
         Ok(())
+    }
     fn progress_inference_rule_tri_equal_all(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let rule = node.inference_rule.as_tri_equal_all();
     fn progress_conditional_expr(&mut self, ctx: &mut Ctx, id: ConditionalExpressionId) -> Result<(), ParseError> {
         // Note: test expression type is already enforced
         let upcast_id = id.upcast();
         let expr = &ctx.heap[id];
         let arg1_expr_id = expr.true_expression;
         let arg2_expr_id = expr.false_expression;
         debug_log!("Conditional expr: {}", upcast_id.index);
         debug_log!(" * Before:");
         debug_log!("   - Arg1 type: {}", self.debug_get_display_name(ctx, arg1_expr_id));
         debug_log!("   - Arg2 type: {}", self.debug_get_display_name(ctx, arg2_expr_id));
         debug_log!("   - Expr type: {}", self.debug_get_display_name(ctx, upcast_id));
         // I keep confusing myself: this applies equality of types between the
         // condition branches' types, and the result from the conditional
         // expression, because the result from the conditional is one of the
         // branches.
         let (progress_expr, progress_arg1, progress_arg2) = self.apply_equal3_constraint(
             ctx, upcast_id, arg1_expr_id, arg2_expr_id, 0
         )?;
         let template = rule.template;
         let arg1_index = rule.argument1_index;
         let arg2_index = rule.argument2_index;
         debug_log!(" * After:");
         debug_log!("   - Arg1 type [{}]: {}", progress_arg1, self.debug_get_display_name(ctx, arg1_expr_id));
         debug_log!("   - Arg2 type [{}]: {}", progress_arg2, self.debug_get_display_name(ctx, arg2_expr_id));
         debug_log!("   - Expr type [{}]: {}", progress_expr, self.debug_get_display_name(ctx, upcast_id));
         let template_progress = self.progress_template(ctx, node_index, template.application, template.template)?;
         let (node_progress, arg1_progress, arg2_progress) =
             self.apply_equal3_constraint(ctx, node_index, arg1_index, arg2_index, 0)?;
         if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
         if progress_arg1 { self.queue_expr(ctx, arg1_expr_id); }
         if progress_arg2 { self.queue_expr(ctx, arg2_expr_id); }
         if template_progress || node_progress { self.queue_node_parent(node_index); }
         if arg1_progress { self.queue_node(arg1_index); }
         if arg2_progress { self.queue_node(arg2_index); }
         Ok(())
+        return Ok(());
+    }
     fn progress_binary_expr(&mut self, ctx: &mut Ctx, id: BinaryExpressionId) -> Result<(), ParseError> {
         // Note: our expression type might be fixed by our parent, but we still
         // need to make sure it matches the type associated with our operation.
         use BinaryOperator as BO;
     fn progress_inference_rule_concatenate(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let rule = node.inference_rule.as_concatenate();
         let arg1_index = rule.argument1_index;
         let arg2_index = rule.argument2_index;
         let upcast_id = id.upcast();
         let expr = &ctx.heap[id];
         let arg1_id = expr.left;
         let arg2_id = expr.right;
         debug_log!("Binary expr '{:?}': {}", expr.operation, upcast_id.index);
         debug_log!(" * Before:");
         debug_log!("   - Arg1 type: {}", self.debug_get_display_name(ctx, arg1_id));
         debug_log!("   - Arg2 type: {}", self.debug_get_display_name(ctx, arg2_id));
         debug_log!("   - Expr type: {}", self.debug_get_display_name(ctx, upcast_id));
         let (progress_expr, progress_arg1, progress_arg2) = match expr.operation {
             BO::Concatenate => {
                 // Two cases: if one of the arguments or the output type is a
                 // string, then all must be strings. Otherwise the arguments
                 // must be arraylike and the output will be a array.
                 let (expr_is_str, expr_is_not_str) = self.type_is_certainly_or_certainly_not_string(ctx, upcast_id);
                 let (arg1_is_str, arg1_is_not_str) = self.type_is_certainly_or_certainly_not_string(ctx, arg1_id);
                 let (arg2_is_str, arg2_is_not_str) = self.type_is_certainly_or_certainly_not_string(ctx, arg2_id);
         // Two cases: one of the arguments is a string (then all must be), or
         // one of the arguments is an array (and all must be arrays).
         let (expr_is_str, expr_is_not_str) = self.type_is_certainly_or_certainly_not_string(node_index);
         let (arg1_is_str, arg1_is_not_str) = self.type_is_certainly_or_certainly_not_string(arg1_index);
         let (arg2_is_str, arg2_is_not_str) = self.type_is_certainly_or_certainly_not_string(arg2_index);
         let someone_is_str = expr_is_str || arg1_is_str || arg2_is_str;
         let someone_is_not_str = expr_is_not_str || arg1_is_not_str || arg2_is_not_str;
         // Note: this statement is an expression returning the progression bools
-                if someone_is_str {
+        let (node_progress, arg1_progress, arg2_progress) = if someone_is_str {
             // One of the arguments is a string, then all must be strings
-                    self.apply_equal3_constraint(ctx, upcast_id, arg1_id, arg2_id, 0)?
+            self.apply_equal3_constraint(ctx, node_index, arg1_index, arg2_index, 0)?
         } else {
             let progress_expr = if someone_is_not_str {
                 // Output must be a normal array
-                        self.apply_template_constraint(ctx, upcast_id, &ARRAY_TEMPLATE)?
+                self.apply_template_constraint(ctx, node_index, &ARRAY_TEMPLATE)?
             } else {
                 // Output may still be anything
-                        self.apply_template_constraint(ctx, upcast_id, &ARRAYLIKE_TEMPLATE)?
+                self.apply_template_constraint(ctx, node_index, &ARRAYLIKE_TEMPLATE)?
             };
                     let progress_arg1 = self.apply_template_constraint(ctx, arg1_id, &ARRAYLIKE_TEMPLATE)?;
                     let progress_arg2 = self.apply_template_constraint(ctx, arg2_id, &ARRAYLIKE_TEMPLATE)?;
             let progress_arg1 = self.apply_template_constraint(ctx, arg1_index, &ARRAYLIKE_TEMPLATE)?;
             let progress_arg2 = self.apply_template_constraint(ctx, arg2_index, &ARRAYLIKE_TEMPLATE)?;
             // If they're all arraylike, then we want the subtype to match
             let (subtype_expr, subtype_arg1, subtype_arg2) =
-                        self.apply_equal3_constraint(ctx, upcast_id, arg1_id, arg2_id, 1)?;
+                self.apply_equal3_constraint(ctx, node_index, arg1_index, arg2_index, 1)?;
             (progress_expr || subtype_expr, progress_arg1 || subtype_arg1, progress_arg2 || subtype_arg2)
+                }
             },
             BO::LogicalAnd => {
                 // Forced boolean on all
                 let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
                 let progress_arg1 = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
                 let progress_arg2 = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
                 (progress_expr, progress_arg1, progress_arg2)
             },
             BO::LogicalOr => {
                 // Forced boolean on all
                 let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
                 let progress_arg1 = self.apply_forced_constraint(ctx, arg1_id, &BOOL_TEMPLATE)?;
                 let progress_arg2 = self.apply_forced_constraint(ctx, arg2_id, &BOOL_TEMPLATE)?;
                 (progress_expr, progress_arg1, progress_arg2)
             },
             BO::BitwiseOr | BO::BitwiseXor | BO::BitwiseAnd | BO::Remainder | BO::ShiftLeft | BO::ShiftRight => {
                 // All equal of integer type
                 let progress_base = self.apply_template_constraint(ctx, upcast_id, &INTEGERLIKE_TEMPLATE)?;
                 let (progress_expr, progress_arg1, progress_arg2) =
                     self.apply_equal3_constraint(ctx, upcast_id, arg1_id, arg2_id, 0)?;
                 (progress_base || progress_expr, progress_base || progress_arg1, progress_base || progress_arg2)
             },
             BO::Equality | BO::Inequality => {
                 // Equal2 on args, forced boolean output
                 let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
                 let (progress_arg1, progress_arg2) =
                     self.apply_equal2_constraint(ctx, upcast_id, arg1_id, 0, arg2_id, 0)?;
                 (progress_expr, progress_arg1, progress_arg2)
             },
             BO::LessThan | BO::GreaterThan | BO::LessThanEqual | BO::GreaterThanEqual => {
                 // Equal2 on args with numberlike type, forced boolean output
                 let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
                 let progress_arg_base = self.apply_template_constraint(ctx, arg1_id, &NUMBERLIKE_TEMPLATE)?;
                 let (progress_arg1, progress_arg2) =
                     self.apply_equal2_constraint(ctx, upcast_id, arg1_id, 0, arg2_id, 0)?;
                 (progress_expr, progress_arg_base || progress_arg1, progress_arg_base || progress_arg2)
             },
             BO::Add | BO::Subtract | BO::Multiply | BO::Divide => {
                 // All equal of number type
                 let progress_base = self.apply_template_constraint(ctx, upcast_id, &NUMBERLIKE_TEMPLATE)?;
                 let (progress_expr, progress_arg1, progress_arg2) =
                     self.apply_equal3_constraint(ctx, upcast_id, arg1_id, arg2_id, 0)?;
                 (progress_base || progress_expr, progress_base || progress_arg1, progress_base || progress_arg2)
             },
         };
         debug_log!(" * After:");
         debug_log!("   - Arg1 type [{}]: {}", progress_arg1, self.debug_get_display_name(ctx, arg1_id));
         debug_log!("   - Arg2 type [{}]: {}", progress_arg2, self.debug_get_display_name(ctx, arg2_id));
         debug_log!("   - Expr type [{}]: {}", progress_expr, self.debug_get_display_name(ctx, upcast_id));
         if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
         if progress_arg1 { self.queue_expr(ctx, arg1_id); }
         if progress_arg2 { self.queue_expr(ctx, arg2_id); }
         if node_progress { self.queue_node_parent(node_index); }
         if arg1_progress { self.queue_node(arg1_index); }
         if arg2_progress { self.queue_node(arg2_index); }
         Ok(())
+        return Ok(())
+    }
     fn progress_unary_expr(&mut self, ctx: &mut Ctx, id: UnaryExpressionId) -> Result<(), ParseError> {
         use UnaryOperator as UO;
     fn progress_inference_rule_indexing_expr(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let rule = node.inference_rule.as_indexing_expr();
         let subject_index = rule.subject_index;
         let index_index = rule.index_index; // which one?
         let upcast_id = id.upcast();
         let expr = &ctx.heap[id];
         let arg_id = expr.expression;
         debug_log!("Unary expr '{:?}': {}", expr.operation, upcast_id.index);
         debug_log!(" * Before:");
         debug_log!("   - Arg  type: {}", self.debug_get_display_name(ctx, arg_id));
         debug_log!("   - Expr type: {}", self.debug_get_display_name(ctx, upcast_id));
         let (progress_expr, progress_arg) = match expr.operation {
             UO::Positive | UO::Negative => {
                 // Equal types of numeric class
                 let progress_base = self.apply_template_constraint(ctx, upcast_id, &NUMBERLIKE_TEMPLATE)?;
                 let (progress_expr, progress_arg) =
                     self.apply_equal2_constraint(ctx, upcast_id, upcast_id, 0, arg_id, 0)?;
                 (progress_base || progress_expr, progress_base || progress_arg)
             },
             UO::BitwiseNot => {
                 // Equal types of integer class
                 let progress_base = self.apply_template_constraint(ctx, upcast_id, &INTEGERLIKE_TEMPLATE)?;
                 let (progress_expr, progress_arg) =
                     self.apply_equal2_constraint(ctx, upcast_id, upcast_id, 0, arg_id, 0)?;
         // Subject is arraylike, index in integerlike
         let subject_template_progress = self.apply_template_constraint(ctx, subject_index, &ARRAYLIKE_TEMPLATE)?;
         let index_template_progress = self.apply_template_constraint(ctx, index_index, &INTEGERLIKE_TEMPLATE)?;
                 (progress_base || progress_expr, progress_base || progress_arg)
             },
             UO::LogicalNot => {
                 // Both bools
                 let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
                 let progress_arg = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
                 (progress_expr, progress_arg)
+            }
         };
         debug_log!(" * After:");
         debug_log!("   - Arg  type [{}]: {}", progress_arg, self.debug_get_display_name(ctx, arg_id));
         debug_log!("   - Expr type [{}]: {}", progress_expr, self.debug_get_display_name(ctx, upcast_id));
         // If subject is type `Array<T>`, then expr type is `T`
         let (node_progress, subject_progress) =
             self.apply_equal2_constraint(ctx, node_index, node_index, 0, subject_index, 1)?;
         if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
         if progress_arg { self.queue_expr(ctx, arg_id); }
         if node_progress { self.queue_node_parent(node_index); }
         if subject_template_progress || subject_progress { self.queue_node(subject_index); }
         if index_template_progress { self.queue_node(index_index); }
         Ok(())
+        return Ok(());
+    }
     fn progress_indexing_expr(&mut self, ctx: &mut Ctx, id: IndexingExpressionId) -> Result<(), ParseError> {
         let upcast_id = id.upcast();
         let expr = &ctx.heap[id];
         let subject_id = expr.subject;
         let index_id = expr.index;
         debug_log!("Indexing expr: {}", upcast_id.index);
         debug_log!(" * Before:");
         debug_log!("   - Subject type: {}", self.debug_get_display_name(ctx, subject_id));
         debug_log!("   - Index   type: {}", self.debug_get_display_name(ctx, index_id));
         debug_log!("   - Expr    type: {}", self.debug_get_display_name(ctx, upcast_id));
     fn progress_inference_rule_slicing_expr(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let rule = node.inference_rule.as_slicing_expr();
         let subject_index = rule.subject_index;
         let from_index_index = rule.from_index;
         let to_index_index = rule.to_index;
         // Make sure subject is arraylike and index is integerlike
         let progress_subject_base = self.apply_template_constraint(ctx, subject_id, &ARRAYLIKE_TEMPLATE)?;
         let progress_index = self.apply_template_constraint(ctx, index_id, &INTEGERLIKE_TEMPLATE)?;
         debug_log!("Rule slicing [node: {}, expr: {}]", node_index, node.expr_id.index);
         // Make sure if output is of T then subject is Array<T>
         let (progress_expr, progress_subject) =
             self.apply_equal2_constraint(ctx, upcast_id, upcast_id, 0, subject_id, 1)?;
         // Subject is arraylike, indices are integerlike
         let subject_template_progress = self.apply_template_constraint(ctx, subject_index, &ARRAYLIKE_TEMPLATE)?;
         let from_template_progress = self.apply_template_constraint(ctx, from_index_index, &INTEGERLIKE_TEMPLATE)?;
         let to_template_progress = self.apply_template_constraint(ctx, to_index_index, &INTEGERLIKE_TEMPLATE)?;
         let (from_index_progress, to_index_progress) =
             self.apply_equal2_constraint(ctx, node_index, from_index_index, 0, to_index_index, 0)?;
         debug_log!(" * After:");
         debug_log!("   - Subject type [{}]: {}", progress_subject_base || progress_subject, self.debug_get_display_name(ctx, subject_id));
         debug_log!("   - Index   type [{}]: {}", progress_index, self.debug_get_display_name(ctx, index_id));
         debug_log!("   - Expr    type [{}]: {}", progress_expr, self.debug_get_display_name(ctx, upcast_id));
         if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
         if progress_subject_base || progress_subject { self.queue_expr(ctx, subject_id); }
         if progress_index { self.queue_expr(ctx, index_id); }
         Ok(())
+    }
     fn progress_slicing_expr(&mut self, ctx: &mut Ctx, id: SlicingExpressionId) -> Result<(), ParseError> {
         let upcast_id = id.upcast();
         let expr = &ctx.heap[id];
         let subject_id = expr.subject;
         let from_id = expr.from_index;
         let to_id = expr.to_index;
         debug_log!("Slicing expr: {}", upcast_id.index);
         debug_log!(" * Before:");
         debug_log!("   - Subject type: {}", self.debug_get_display_name(ctx, subject_id));
         debug_log!("   - FromIdx type: {}", self.debug_get_display_name(ctx, from_id));
         debug_log!("   - ToIdx   type: {}", self.debug_get_display_name(ctx, to_id));
         debug_log!("   - Expr    type: {}", self.debug_get_display_name(ctx, upcast_id));
         // Make sure subject is arraylike and indices are of equal integerlike
         let progress_subject_base = self.apply_template_constraint(ctx, subject_id, &ARRAYLIKE_TEMPLATE)?;
         let progress_idx_base = self.apply_template_constraint(ctx, from_id, &INTEGERLIKE_TEMPLATE)?;
         let (progress_from, progress_to) = self.apply_equal2_constraint(ctx, upcast_id, from_id, 0, to_id, 0)?;
         let (progress_expr, progress_subject) = match self.type_is_certainly_or_certainly_not_string(ctx, subject_id) {
             (true, _) => {
         // Same as array indexing: result depends on whether subject is string
         // or array
         let (is_string, is_not_string) = self.type_is_certainly_or_certainly_not_string(node_index);
         let (node_progress, subject_progress) = if is_string {
             // Certainly a string
                 (self.apply_forced_constraint(ctx, upcast_id, &STRING_TEMPLATE)?, false)
             },
             (_, true) => {
                 // Certainly not a string
                 let progress_expr_base = self.apply_template_constraint(ctx, upcast_id, &SLICE_TEMPLATE)?;
                 let (progress_expr, progress_subject) =
                     self.apply_equal2_constraint(ctx, upcast_id, upcast_id, 1, subject_id, 1)?;
+            (
                 self.apply_forced_constraint(ctx, node_index, &STRING_TEMPLATE)?,
                 false
+            )
         } else if is_not_string {
             // Certainly not a string, apply template constraint. Then make sure
             // that if we have an `Array<T>`, that the slice produces `Slice<T>`
             let node_template_progress = self.apply_template_constraint(ctx, node_index, &SLICE_TEMPLATE)?;
             let (node_progress, subject_progress) =
                 self.apply_equal2_constraint(ctx, node_index, node_index, 1, subject_index, 1)?;
                 (progress_expr_base || progress_expr, progress_subject)
             },
             _ => {
                 // Could be anything, at least attempt to progress subtype
                 let progress_expr_base = self.apply_template_constraint(ctx, upcast_id, &ARRAYLIKE_TEMPLATE)?;
                 let (progress_expr, progress_subject) =
                     self.apply_equal2_constraint(ctx, upcast_id, upcast_id, 1, subject_id, 1)?;
+            (
                 node_template_progress || node_progress,
                 subject_progress
+            )
         } else {
             // Not sure yet
             let node_template_progress = self.apply_template_constraint(ctx, node_index, &ARRAYLIKE_TEMPLATE)?;
             let (node_progress, subject_progress) =
                 self.apply_equal2_constraint(ctx, node_index, node_index, 1, subject_index, 1)?;
                 (progress_expr_base || progress_expr, progress_subject)
+            }
+            (
                 node_template_progress || node_progress,
                 subject_progress
+            )
         };
         debug_log!(" * After:");
         debug_log!("   - Subject type [{}]: {}", progress_subject_base || progress_subject, self.debug_get_display_name(ctx, subject_id));
         debug_log!("   - FromIdx type [{}]: {}", progress_idx_base || progress_from, self.debug_get_display_name(ctx, from_id));
         debug_log!("   - ToIdx   type [{}]: {}", progress_idx_base || progress_to, self.debug_get_display_name(ctx, to_id));
         debug_log!("   - Expr    type [{}]: {}", progress_expr, self.debug_get_display_name(ctx, upcast_id));
         if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
         if progress_subject_base || progress_subject { self.queue_expr(ctx, subject_id); }
         if progress_idx_base || progress_from { self.queue_expr(ctx, from_id); }
         if progress_idx_base || progress_to { self.queue_expr(ctx, to_id); }
         if node_progress { self.queue_node_parent(node_index); }
         if subject_template_progress || subject_progress { self.queue_node(subject_index); }
         if from_template_progress || from_index_progress { self.queue_node(from_index_index); }
         if to_template_progress || to_index_progress { self.queue_node(to_index_index); }
         Ok(())
+        return Ok(());
+    }
     fn progress_select_expr(&mut self, ctx: &mut Ctx, id: SelectExpressionId) -> Result<(), ParseError> {
         let upcast_id = id.upcast();
         debug_log!("Select expr: {}", upcast_id.index);
         debug_log!(" * Before:");
         debug_log!("   - Subject type: {}", self.debug_get_display_name(ctx, ctx.heap[id].subject));
         debug_log!("   - Expr    type: {}", self.debug_get_display_name(ctx, upcast_id));
         let subject_id = ctx.heap[id].subject;
         let subject_expr_idx = ctx.heap[subject_id].get_unique_id_in_definition();
         let select_expr = &ctx.heap[id];
         let expr_idx = select_expr.unique_id_in_definition;
         let infer_expr = &self.expr_types[expr_idx as usize];
         let extra_idx = infer_expr.extra_data_idx;
     fn progress_inference_rule_select_struct_field(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let rule = node.inference_rule.as_select_struct_field();
         fn try_get_definition_id_from_inference_type<'a>(types: &'a TypeTable, infer_type: &InferenceType) -> Result<Option<&'a DefinedType>, ()> {
             for part in &infer_type.parts {
                 if part.is_marker() || !part.is_concrete() {
                     continue;
+                }
         let subject_index = rule.subject_index;
         let selected_field = rule.selected_field.clone();
                 // Part is concrete, check if it is an instance of something
                 if let InferenceTypePart::Instance(definition_id, _num_sub) = part {
                     // Lookup type definition and ensure the specified field
                     // name exists on the struct
                     let definition = types.get_base_definition(definition_id);
                     debug_assert!(definition.is_some());
                     let definition = definition.unwrap();
         fn get_definition_id_from_inference_type(inference_type: &InferenceType) -> Result<Option<DefinitionId>, ()> {
             for part in inference_type.parts.iter() {
                 if part.is_marker() { continue; }
                 if !part.is_concrete() { break; }
                     return Ok(Some(definition))
                 if let InferenceTypePart::Instance(definition_id, _) = part {
                     return Ok(Some(*definition_id));
                 } else {
                     // Expected an instance of something
                     return Err(())
+                }
+            }
             // Nothing is concrete yet
             Ok(None)
+        }
         fn try_get_tuple_size_from_inference_type(infer_type: &InferenceType) -> Result<Option<u32>, ()> {
             for part in &infer_type.parts {
                 if part.is_marker() || !part.is_concrete() {
                     continue;
             // Nothing is known yet
             return Ok(None);
+        }
                 if let InferenceTypePart::Tuple(size) = part {
                     return Ok(Some(*size));
                 } else {
                     // Expected a tuple
                     return Err(());
+                }
+            }
             // Type is not "defined enough" yet
             Ok(None)
+        }
         let (progress_subject, progress_expr) = match &select_expr.kind {
             SelectKind::StructField(field_name) => {
                 // Handle select of a struct's field
                 if infer_expr.field_or_monomorph_idx < 0 {
                     // We don't know the field or the definition it is pointing to yet
                     // Not yet known, check if we can determine it
                     let subject_type = &self.expr_types[subject_expr_idx as usize].expr_type;
                     let type_def = try_get_definition_id_from_inference_type(&ctx.types, subject_type);
                     match type_def {
                         Ok(Some(type_def)) => {
                             // Subject type is known, check if it is a
                             // struct and the field exists on the struct
                             let struct_def = if let DefinedTypeVariant::Struct(struct_def) = &type_def.definition {
                                 struct_def
         if node.field_index < 0 {
             // Don't know the subject definition, hence the field yet. Try to
             // determine it.
             let subject_node = &self.infer_nodes[subject_index];
             match get_definition_id_from_inference_type(&subject_node.expr_type) {
                 Ok(Some(definition_id)) => {
                     // Determined definition of subject for the first time.
                     let base_definition = ctx.types.get_base_definition(&definition_id).unwrap();
                     let struct_definition = if let DefinedTypeVariant::Struct(struct_definition) = &base_definition.definition {
                         struct_definition
                     } else {
                         return Err(ParseError::new_error_at_span(
-                                    &ctx.module().source, field_name.span, format!(
+                            &ctx.module().source, selected_field.span, format!(
                                 "Can only apply field access to structs, got a subject of type '{}'",
-                                        subject_type.display_name(&ctx.heap)
+                                subject_node.expr_type.display_name(&ctx.heap)
+                            )
                         ));
                     };
                             let mut struct_def_id = None;
                             for (field_def_idx, field_def) in struct_def.fields.iter().enumerate() {
                                 if field_def.identifier == *field_name {
                                     // Set field definition and index
                                     let infer_expr = &mut self.expr_types[expr_idx as usize];
                                     infer_expr.field_or_monomorph_idx = field_def_idx as i32;
                                     struct_def_id = Some(type_def.ast_definition);
                     // Seek the field that is referenced by the select
                     // expression
                     let mut field_found = false;
                     for (field_index, field) in struct_definition.fields.iter().enumerate() {
                         if field.identifier.value == selected_field.value {
                             // Found the field of interest
                             field_found = true;
                             let node = &mut self.infer_nodes[node_index];
                             node.field_index = field_index as i32;
                             break;
+                        }
+                    }
                             if struct_def_id.is_none() {
                                 let ast_struct_def = ctx.heap[type_def.ast_definition].as_struct();
                     if !field_found {
                         let struct_definition = ctx.heap[definition_id].as_struct();
                         return Err(ParseError::new_error_at_span(
-                                    &ctx.module().source, field_name.span, format!(
+                            &ctx.module().source, selected_field.span, format!(
                                 "this field does not exist on the struct '{}'",
-                                        ast_struct_def.identifier.value.as_str()
+                                struct_definition.identifier.value.as_str()
+                            )
-                                ))
+                        ));
+                    }
                             // Encountered definition and field index for the
                             // first time
                             self.insert_initial_select_polymorph_data(ctx, id, struct_def_id.unwrap());
                     // Insert the initial data needed to infer polymorphic
                     // fields
                     let extra_index = self.insert_initial_select_polymorph_data(ctx, node_index, definition_id);
                     let node = &mut self.infer_nodes[node_index];
                     node.poly_data_index = extra_index;
                 },
                 Ok(None) => {
                             // Type of subject is not yet known, so we
                             // cannot make any progress yet
                     // We don't know what to do yet, because we don't know the
                     // subject type yet.
                     return Ok(())
                 },
                 Err(()) => {
                     return Err(ParseError::new_error_at_span(
-                                &ctx.module().source, field_name.span, format!(
+                        &ctx.module().source, rule.selected_field.span, format!(
                             "Can only apply field access to structs, got a subject of type '{}'",
-                                    subject_type.display_name(&ctx.heap)
+                            subject_node.expr_type.display_name(&ctx.heap)
+                        )
                     ));
                 },
+            }
+        }
+                }
                 // If here then field index is known, and the referenced struct type
                 // information is inserted into `extra_data`. Check to see if we can
                 // do some mutual inference.
                 let poly_data = &mut self.extra_data[extra_idx as usize];
                 let mut poly_progress = HashSet::new(); // TODO: @Performance
                 // Apply to struct's type
                 let signature_type: *mut _ = &mut poly_data.embedded[0];
                 let subject_type: *mut _ = &mut self.expr_types[subject_expr_idx as usize].expr_type;
         // If here then the field index is known, hence we can start inferring
         // the type of the selected field
         let field_expr_id = self.infer_nodes[node_index].expr_id;
         let subject_expr_id = self.infer_nodes[subject_index].expr_id;
         let mut poly_progress_section = self.poly_progress_buffer.start_section();
                 let (_, progress_subject) = Self::apply_equal2_signature_constraint(
                     ctx, upcast_id, Some(subject_id), poly_data, &mut poly_progress,
                     signature_type, 0, subject_type, 0
         let (_, progress_subject_1) = self.apply_polydata_equal2_constraint(
             ctx, node_index, subject_expr_id, "selected struct's",
             PolyDataTypeIndex::Associated(0), 0, subject_index, 0, &mut poly_progress_section
         )?;
                 if progress_subject {
                     self.expr_queued.push_back(subject_expr_idx);
+                }
                 // Apply to field's type
                 let signature_type: *mut _ = &mut poly_data.returned;
                 let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
                 let (_, progress_expr) = Self::apply_equal2_signature_constraint(
                     ctx, upcast_id, None, poly_data, &mut poly_progress,
                     signature_type, 0, expr_type, 0
         let (_, progress_field_1) = self.apply_polydata_equal2_constraint(
             ctx, node_index, field_expr_id, "selected field's",
             PolyDataTypeIndex::Returned, 0, node_index, 0, &mut poly_progress_section
         )?;
                 if progress_expr {
                     if let Some(parent_id) = ctx.heap[upcast_id].parent_expr_id() {
                         let parent_idx = ctx.heap[parent_id].get_unique_id_in_definition();
                         self.expr_queued.push_back(parent_idx);
+                    }
+                }
                 // Reapply progress in polymorphic variables to struct's type
                 let signature_type: *mut _ = &mut poly_data.embedded[0];
                 let subject_type: *mut _ = &mut self.expr_types[subject_expr_idx as usize].expr_type;
                 let progress_subject = Self::apply_equal2_polyvar_constraint(
                     poly_data, &poly_progress, signature_type, subject_type
         // Maybe make progress on types due to inferred polymorphic variables
         let progress_subject_2 = self.apply_polydata_polyvar_constraint(
             ctx, node_index, PolyDataTypeIndex::Associated(0), subject_index, &poly_progress_section
         );
                 let signature_type: *mut _ = &mut poly_data.returned;
                 let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
                 let progress_expr = Self::apply_equal2_polyvar_constraint(
                     poly_data, &poly_progress, signature_type, expr_type
         let progress_field_2 = self.apply_polydata_polyvar_constraint(
             ctx, node_index, PolyDataTypeIndex::Returned, node_index, &poly_progress_section
         );
                 (progress_subject, progress_expr)
             },
             SelectKind::TupleMember(member_index) => {
                 let member_index = *member_index;
                 if infer_expr.field_or_monomorph_idx < 0 {
                     // We don't know what kind of tuple we're accessing yet
                     let subject_type = &self.expr_types[subject_expr_idx as usize].expr_type;
                     let tuple_size = try_get_tuple_size_from_inference_type(subject_type);
                     match tuple_size {
                         Ok(Some(enum_size)) => {
                             // Make sure we don't access an element outside of
                             // the tuple's bounds
                             if member_index >= enum_size as u64 {
                                 return Err(ParseError::new_error_at_span(
                                     &ctx.module().source, select_expr.full_span, format!(
                                         "element index {} is out of bounds, tuple has {} elements",
                                         member_index, enum_size
+                                    )
                                 ));
         if progress_subject_1 || progress_subject_2 { self.queue_node(subject_index); }
         if progress_field_1 || progress_field_2 { self.queue_node_parent(node_index); }
         poly_progress_section.forget();
         self.finish_polydata_constraint(node_index);
         return Ok(())
+    }
                             // Within bounds, so set the index (such that we
                             // will not perform this lookup again)
                             let infer_expr = &mut self.expr_types[expr_idx as usize];
                             infer_expr.field_or_monomorph_idx = member_index as i32;
     fn progress_inference_rule_select_tuple_member(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let rule = node.inference_rule.as_select_tuple_member();
         let subject_index = rule.subject_index;
         let tuple_member_index = rule.selected_index;
         if node.field_index < 0 {
             let subject_type = &self.infer_nodes[subject_index].expr_type;
             let tuple_size = get_tuple_size_from_inference_type(subject_type);
             let tuple_size = match tuple_size {
                 Ok(Some(tuple_size)) => {
                     tuple_size
                 },
                 Ok(None) => {
                             // Nothing is known about the tuple yet
                             return Ok(());
                     // We can't infer anything yet
                     return Ok(())
                 },
                 Err(()) => {
                     let select_expr_span = ctx.heap[node.expr_id].full_span();
                     return Err(ParseError::new_error_at_span(
                                 &ctx.module().source, select_expr.full_span, format!(
                                     "Can only apply tuple element selection to tuples, got a subject of type '{}'",
                         &ctx.module().source, select_expr_span, format!(
                             "tuple element select cannot be applied to a subject of type '{}'",
                             subject_type.display_name(&ctx.heap)
+                        )
                     ));
+                }
             };
             // If here then we at least have the tuple size. Now check if the
             // index doesn't exceed that size.
             if tuple_member_index >= tuple_size as u64 {
                 let select_expr_span = ctx.heap[node.expr_id].full_span();
                 return Err(ParseError::new_error_at_span(
                     &ctx.module().source, select_expr_span, format!(
                         "element index {} is out of bounds, tuple has {} elements",
                         tuple_member_index, tuple_size
+                    )
                 ));
+            }
             // Within bounds, set index on the type inference node
             let node = &mut self.infer_nodes[node_index];
             node.field_index = tuple_member_index as i32;
+        }
                 // If here then we know which member we're accessing. So seek
                 // that member in the subject type and apply inference.
                 let subject_type = &self.expr_types[subject_expr_idx as usize].expr_type;
                 let mut member_start_idx = 1;
                 for _ in 0..member_index {
                     member_start_idx = InferenceType::find_subtree_end_idx(&subject_type.parts, member_start_idx);
         // If here then we know we can use `tuple_member_index`. We need to keep
         // computing the offset to the subtype, as its value changes during
         // inference
         let subject_type = &self.infer_nodes[subject_index].expr_type;
         let mut selected_member_start_index = 1; // start just after the InferenceTypeElement::Tuple
         for _ in 0..tuple_member_index {
             selected_member_start_index = InferenceType::find_subtree_end_idx(&subject_type.parts, selected_member_start_index);
+        }
                 let (progress_expr, progress_subject) = self.apply_equal2_constraint(
                     ctx, upcast_id, upcast_id, 0, subject_id, member_start_idx
         let (progress_member, progress_subject) = self.apply_equal2_constraint(
             ctx, node_index, node_index, 0, subject_index, selected_member_start_index
         )?;
                 (progress_subject, progress_expr)
             },
         };
         if progress_subject { self.queue_expr(ctx, subject_id); }
         if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
         debug_log!(" * After:");
         debug_log!("   - Subject type [{}]: {}", progress_subject, self.debug_get_display_name(ctx, subject_id));
         debug_log!("   - Expr    type [{}]: {}", progress_expr, self.debug_get_display_name(ctx, upcast_id));
         if progress_member { self.queue_node_parent(node_index); }
         if progress_subject { self.queue_node(subject_index); }
         Ok(())
+        return Ok(());
+    }
     fn progress_literal_expr(&mut self, ctx: &mut Ctx, id: LiteralExpressionId) -> Result<(), ParseError> {
         let upcast_id = id.upcast();
         let expr = &ctx.heap[id];
         let expr_idx = expr.unique_id_in_definition;
         let extra_idx = self.expr_types[expr_idx as usize].extra_data_idx;
     fn progress_inference_rule_literal_struct(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let node_expr_id = node.expr_id;
         let rule = node.inference_rule.as_literal_struct();
         // For each of the fields in the literal struct, apply the type equality
         // constraint. If the literal is polymorphic, then we try to progress
         // their types during this process
         let element_indices_section = self.index_buffer.start_section_initialized(&rule.element_indices);
         let mut poly_progress_section = self.poly_progress_buffer.start_section();
         for (field_index, field_node_index) in element_indices_section.iter_copied().enumerate() {
             let field_expr_id = self.infer_nodes[field_node_index].expr_id;
             let (_, progress_field) = self.apply_polydata_equal2_constraint(
                 ctx, node_index, field_expr_id, "struct field's",
                 PolyDataTypeIndex::Associated(field_index), 0,
                 field_node_index, 0, &mut poly_progress_section
             )?;
         debug_log!("Literal expr: {}", upcast_id.index);
         debug_log!(" * Before:");
         debug_log!("   - Expr type: {}", self.debug_get_display_name(ctx, upcast_id));
             if progress_field { self.queue_node(field_node_index); }
+        }
         let progress_expr = match &expr.value {
             Literal::Null => {
                 self.apply_template_constraint(ctx, upcast_id, &MESSAGE_TEMPLATE)?
             },
             Literal::Integer(_) => {
                 self.apply_template_constraint(ctx, upcast_id, &INTEGERLIKE_TEMPLATE)?
             },
             Literal::True | Literal::False => {
                 self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?
             },
             Literal::Character(_) => {
                 self.apply_forced_constraint(ctx, upcast_id, &CHARACTER_TEMPLATE)?
             },
             Literal::String(_) => {
                 self.apply_forced_constraint(ctx, upcast_id, &STRING_TEMPLATE)?
             },
             Literal::Struct(data) => {
                 let extra = &mut self.extra_data[extra_idx as usize];
                 for _poly in &extra.poly_vars {
                     debug_log!(" * Poly: {}", _poly.display_name(&ctx.heap));
+                }
                 let mut poly_progress = HashSet::new();
                 debug_assert_eq!(extra.embedded.len(), data.fields.len());
                 debug_log!(" * During (inferring types from fields and struct type):");
                 // Mutually infer field signature/expression types
                 for (field_idx, field) in data.fields.iter().enumerate() {
                     let field_expr_id = field.value;
                     let field_expr_idx = ctx.heap[field_expr_id].get_unique_id_in_definition();
                     let signature_type: *mut _ = &mut extra.embedded[field_idx];
                     let field_type: *mut _ = &mut self.expr_types[field_expr_idx as usize].expr_type;
                     let (_, progress_arg) = Self::apply_equal2_signature_constraint(
                         ctx, upcast_id, Some(field_expr_id), extra, &mut poly_progress,
                         signature_type, 0, field_type, 0
         // Now we do the same thing for the struct literal expression (the type
         // of the struct itself).
         let (_, progress_literal_1) = self.apply_polydata_equal2_constraint(
             ctx, node_index, node_expr_id, "struct literal's",
             PolyDataTypeIndex::Returned, 0, node_index, 0, &mut poly_progress_section
         )?;
                     debug_log!(
                         "   - Field {} type | sig: {}, field: {}", field_idx,
                         unsafe{&*signature_type}.display_name(&ctx.heap),
                         unsafe{&*field_type}.display_name(&ctx.heap)
         // And the other way around: if any of our polymorphic variables are
         // more specific then they were before, then we forward that information
         // back to our struct/fields.
         for (field_index, field_node_index) in element_indices_section.iter_copied().enumerate() {
             let progress_field = self.apply_polydata_polyvar_constraint(
                 ctx, node_index, PolyDataTypeIndex::Associated(field_index),
                 field_node_index, &poly_progress_section
             );
                     if progress_arg {
                         self.expr_queued.push_back(field_expr_idx);
             if progress_field { self.queue_node(field_node_index); }
+        }
         let progress_literal_2 = self.apply_polydata_polyvar_constraint(
             ctx, node_index, PolyDataTypeIndex::Returned,
             node_index, &poly_progress_section
         );
         if progress_literal_1 || progress_literal_2 { self.queue_node_parent(node_index); }
         poly_progress_section.forget();
         element_indices_section.forget();
         self.finish_polydata_constraint(node_index);
         return Ok(())
+    }
                 debug_log!("   - Field poly progress | {:?}", poly_progress);
     fn progress_inference_rule_literal_enum(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let node_expr_id = node.expr_id;
         let mut poly_progress_section = self.poly_progress_buffer.start_section();
                 // Same for the type of the struct itself
                 let signature_type: *mut _ = &mut extra.returned;
                 let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
                 let (_, progress_expr) = Self::apply_equal2_signature_constraint(
                     ctx, upcast_id, None, extra, &mut poly_progress,
                     signature_type, 0, expr_type, 0
         // An enum literal type is simply, well, the enum's type. However, it
         // might still have polymorphic variables, hence the use of `PolyData`.
         let (_, progress_literal_1) = self.apply_polydata_equal2_constraint(
             ctx, node_index, node_expr_id, "enum literal's",
             PolyDataTypeIndex::Returned, 0, node_index, 0, &mut poly_progress_section
         )?;
                 debug_log!(
                     "   - Ret type | sig: {}, expr: {}",
                     unsafe{&*signature_type}.display_name(&ctx.heap),
                     unsafe{&*expr_type}.display_name(&ctx.heap)
                 );
                 debug_log!("   - Ret poly progress | {:?}", poly_progress);
                 if progress_expr {
                     // TODO: @cleanup, cannot call utility self.queue_parent thingo
                     if let Some(parent_id) = ctx.heap[upcast_id].parent_expr_id() {
                         let parent_idx = ctx.heap[parent_id].get_unique_id_in_definition();
                         self.expr_queued.push_back(parent_idx);
+                    }
+                }
                 // Check which expressions use the polymorphic arguments. If the
                 // polymorphic variables have been progressed then we try to
                 // progress them inside the expression as well.
                 debug_log!(" * During (reinferring from progressed polyvars):");
                 // For all field expressions
                 for field_idx in 0..extra.embedded.len() {
                     // Note: fields in extra.embedded are in the same order as
                     // they are specified in the literal. Whereas
                     // `data.fields[...].field_idx` points to the field in the
                     // struct definition.
                     let signature_type: *mut _ = &mut extra.embedded[field_idx];
                     let field_expr_id = data.fields[field_idx].value;
                     let field_expr_idx = ctx.heap[field_expr_id].get_unique_id_in_definition();
                     let field_type: *mut _ = &mut self.expr_types[field_expr_idx as usize].expr_type;
                     let progress_arg = Self::apply_equal2_polyvar_constraint(
                         extra, &poly_progress, signature_type, field_type
         let progress_literal_2 = self.apply_polydata_polyvar_constraint(
             ctx, node_index, PolyDataTypeIndex::Returned, node_index, &poly_progress_section
         );
                     debug_log!(
                         "   - Field {} type | sig: {}, field: {}", field_idx,
                         unsafe{&*signature_type}.display_name(&ctx.heap),
                         unsafe{&*field_type}.display_name(&ctx.heap)
                     );
                     if progress_arg {
                         self.expr_queued.push_back(field_expr_idx);
+                    }
         if progress_literal_1 || progress_literal_2 { self.queue_node_parent(node_index); }
         poly_progress_section.forget();
         self.finish_polydata_constraint(node_index);
         return Ok(());
+    }
                 // For the return type
                 let signature_type: *mut _ = &mut extra.returned;
                 let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
     fn progress_inference_rule_literal_union(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let node_expr_id = node.expr_id;
         let rule = node.inference_rule.as_literal_union();
                 let progress_expr = Self::apply_equal2_polyvar_constraint(
                     extra, &poly_progress, signature_type, expr_type
                 );
         // Infer type of any embedded values in the union variant. At the same
         // time progress the polymorphic variables associated with the union.
         let element_indices_section = self.index_buffer.start_section_initialized(&rule.element_indices);
         let mut poly_progress_section = self.poly_progress_buffer.start_section();
                 progress_expr
             },
             Literal::Enum(_) => {
                 let extra = &mut self.extra_data[extra_idx as usize];
                 for _poly in &extra.poly_vars {
                     debug_log!(" * Poly: {}", _poly.display_name(&ctx.heap));
+                }
                 let mut poly_progress = HashSet::new();
         for (embedded_index, embedded_node_index) in element_indices_section.iter_copied().enumerate() {
             let embedded_node_expr_id = self.infer_nodes[embedded_node_index].expr_id;
             let (_, progress_embedded) = self.apply_polydata_equal2_constraint(
                 ctx, node_index, embedded_node_expr_id, "embedded value's",
                 PolyDataTypeIndex::Associated(embedded_index), 0,
                 embedded_node_index, 0, &mut poly_progress_section
             )?;
                 debug_log!(" * During (inferring types from return type)");
             if progress_embedded { self.queue_node(embedded_node_index); }
+        }
                 let signature_type: *mut _ = &mut extra.returned;
                 let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
                 let (_, progress_expr) = Self::apply_equal2_signature_constraint(
                     ctx, upcast_id, None, extra, &mut poly_progress,
                     signature_type, 0, expr_type, 0
         let (_, progress_literal_1) = self.apply_polydata_equal2_constraint(
             ctx, node_index, node_expr_id, "union's",
             PolyDataTypeIndex::Returned, 0, node_index, 0, &mut poly_progress_section
         )?;
                 debug_log!(
                     "   - Ret type | sig: {}, expr: {}",
                     unsafe{&*signature_type}.display_name(&ctx.heap),
                     unsafe{&*expr_type}.display_name(&ctx.heap)
         // Propagate progress in the polymorphic variables to the expressions
         // that constitute the union literal.
         for (embedded_index, embedded_node_index) in element_indices_section.iter_copied().enumerate() {
             let progress_embedded = self.apply_polydata_polyvar_constraint(
                 ctx, node_index, PolyDataTypeIndex::Associated(embedded_index),
                 embedded_node_index, &poly_progress_section
             );
                 if progress_expr {
                     // TODO: @cleanup
                     if let Some(parent_id) = ctx.heap[upcast_id].parent_expr_id() {
                         let parent_idx = ctx.heap[parent_id].get_unique_id_in_definition();
                         self.expr_queued.push_back(parent_idx);
+                    }
             if progress_embedded { self.queue_node(embedded_node_index); }
+        }
                 debug_log!(" * During (reinferring from progress polyvars):");
                 let progress_expr = Self::apply_equal2_polyvar_constraint(
                     extra, &poly_progress, signature_type, expr_type
         let progress_literal_2 = self.apply_polydata_polyvar_constraint(
             ctx, node_index, PolyDataTypeIndex::Returned, node_index, &poly_progress_section
         );
                 progress_expr
             },
             Literal::Union(data) => {
                 let extra = &mut self.extra_data[extra_idx as usize];
                 for _poly in &extra.poly_vars {
                     debug_log!(" * Poly: {}", _poly.display_name(&ctx.heap));
+                }
                 let mut poly_progress = HashSet::new();
                 debug_assert_eq!(extra.embedded.len(), data.values.len());
                 debug_log!(" * During (inferring types from variant values and union type):");
                 // Mutually infer union variant values
                 for (value_idx, value_expr_id) in data.values.iter().enumerate() {
                     let value_expr_id = *value_expr_id;
                     let value_expr_idx = ctx.heap[value_expr_id].get_unique_id_in_definition();
                     let signature_type: *mut _ = &mut extra.embedded[value_idx];
                     let value_type: *mut _ = &mut self.expr_types[value_expr_idx as usize].expr_type;
                     let (_, progress_arg) = Self::apply_equal2_signature_constraint(
                         ctx, upcast_id, Some(value_expr_id), extra, &mut poly_progress,
                         signature_type, 0, value_type, 0
                     )?;
         if progress_literal_1 || progress_literal_2 { self.queue_node_parent(node_index); }
                     debug_log!(
                         "   - Value {} type | sig: {}, field: {}", value_idx,
                         unsafe{&*signature_type}.display_name(&ctx.heap),
                         unsafe{&*value_type}.display_name(&ctx.heap)
                     );
                     if progress_arg {
                         self.expr_queued.push_back(value_expr_idx);
+                    }
         poly_progress_section.forget();
         self.finish_polydata_constraint(node_index);
         return Ok(());
+    }
                 debug_log!("   - Field poly progress | {:?}", poly_progress);
     fn progress_inference_rule_literal_array(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let rule = node.inference_rule.as_literal_array();
                 // Infer type of union itself
                 let signature_type: *mut _ = &mut extra.returned;
                 let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
                 let (_, progress_expr) = Self::apply_equal2_signature_constraint(
                     ctx, upcast_id, None, extra, &mut poly_progress,
                     signature_type, 0, expr_type, 0
                 )?;
         // Apply equality rule to all of the elements that form the array
         let argument_node_indices = self.index_buffer.start_section_initialized(&rule.element_indices);
         let mut argument_progress_section = self.bool_buffer.start_section();
         self.apply_equal_n_constraint(ctx, node_index, &argument_node_indices, &mut argument_progress_section)?;
                 debug_log!(
                     "   - Ret type | sig: {}, expr: {}",
                     unsafe{&*signature_type}.display_name(&ctx.heap),
                     unsafe{&*expr_type}.display_name(&ctx.heap)
                 );
                 debug_log!("   - Ret poly progress | {:?}", poly_progress);
         debug_assert_eq!(argument_node_indices.len(), argument_progress_section.len());
         for argument_index in 0..argument_node_indices.len() {
             let argument_node_index = argument_node_indices[argument_index];
             let progress = argument_progress_section[argument_index];
                 if progress_expr {
                     // TODO: @cleanup, borrowing rules
                     if let Some(parent_id) = ctx.heap[upcast_id].parent_expr_id() {
                         let parent_idx = ctx.heap[parent_id].get_unique_id_in_definition();
                         self.expr_queued.push_back(parent_idx);
             if progress { self.queue_node(argument_node_index); }
+        }
+                }
                 debug_log!(" * During (reinferring from progress polyvars):");
                 // For all embedded values of the union variant
                 for value_idx in 0..extra.embedded.len() {
                     let signature_type: *mut _ = &mut extra.embedded[value_idx];
                     let value_expr_id = data.values[value_idx];
                     let value_expr_idx = ctx.heap[value_expr_id].get_unique_id_in_definition();
                     let value_type: *mut _ = &mut self.expr_types[value_expr_idx as usize].expr_type;
         // If elements are of type `T`, then the array is of type `Array<T>`, so:
         let mut progress_literal = self.apply_template_constraint(ctx, node_index, &ARRAY_TEMPLATE)?;
         if argument_node_indices.len() != 0 {
             let argument_node_index = argument_node_indices[0];
             let (progress_literal_inner, progress_argument) = self.apply_equal2_constraint(
                 ctx, node_index, node_index, 1, argument_node_index, 0
             )?;
                     let progress_arg = Self::apply_equal2_polyvar_constraint(
                         extra, &poly_progress, signature_type, value_type
                     );
             progress_literal = progress_literal || progress_literal_inner;
                     debug_log!(
                         "   - Value {} type | sig: {}, value: {}", value_idx,
                         unsafe{&*signature_type}.display_name(&ctx.heap),
                         unsafe{&*value_type}.display_name(&ctx.heap)
                     );
                     if progress_arg {
                         self.expr_queued.push_back(value_expr_idx);
+                    }
             // It is possible that the `Array<T>` has a more progress `T` then
             // the arguments. So in the case we progress our argument type we
             // simply queue this rule again
             if progress_argument { self.queue_node(node_index); }
+        }
                 // And for the union type itself
                 let signature_type: *mut _ = &mut extra.returned;
                 let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
         argument_node_indices.forget();
         argument_progress_section.forget();
                 let progress_expr = Self::apply_equal2_polyvar_constraint(
                     extra, &poly_progress, signature_type, expr_type
                 );
         if progress_literal { self.queue_node_parent(node_index); }
         return Ok(());
+    }
                 progress_expr
             },
             Literal::Array(data) => {
                 let expr_elements = self.expr_buffer.start_section_initialized(data.as_slice());
                 debug_log!("Array expr ({} elements): {}", expr_elements.len(), upcast_id.index);
                 debug_log!(" * Before:");
                 debug_log!("   - Expr type: {}", self.debug_get_display_name(ctx, upcast_id));
                 // All elements should have an equal type
                 let mut bool_buffer = self.bool_buffer.start_section();
                 self.apply_equal_n_constraint(ctx, upcast_id, &expr_elements, &mut bool_buffer)?;
                 for (progress_arg, arg_id) in bool_buffer.iter_copied().zip(expr_elements.iter_copied()) {
                     if progress_arg {
                         self.queue_expr(ctx, arg_id);
+                    }
+                }
                 // And the output should be an array of the element types
                 let mut progress_expr = self.apply_template_constraint(ctx, upcast_id, &ARRAY_TEMPLATE)?;
                 if expr_elements.len() != 0 {
                     let first_arg_id = expr_elements[0];
                     let (inner_expr_progress, arg_progress) = self.apply_equal2_constraint(
                         ctx, upcast_id, upcast_id, 1, first_arg_id, 0
                     )?;
     fn progress_inference_rule_literal_tuple(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let rule = node.inference_rule.as_literal_tuple();
-                    progress_expr = progress_expr || inner_expr_progress;
+        let element_indices = self.index_buffer.start_section_initialized(&rule.element_indices);
                     // Note that if the array type progressed the type of the arguments,
                     // then we should enqueue this progression function again
                     // TODO: @fix Make apply_equal_n accept a start idx as well
                     if arg_progress { self.queue_expr(ctx, upcast_id); }
         // Check if we need to apply the initial tuple template type. Note that
         // this is a hacky check.
         let num_tuple_elements = rule.element_indices.len();
         let mut template_type = Vec::with_capacity(num_tuple_elements + 1); // TODO: @performance
         template_type.push(InferenceTypePart::Tuple(num_tuple_elements as u32));
         for _ in 0..num_tuple_elements {
             template_type.push(InferenceTypePart::Unknown);
+        }
                 debug_log!(" * After:");
                 debug_log!("   - Expr type [{}]: {}", progress_expr, self.debug_get_display_name(ctx, upcast_id));
         let mut progress_literal = self.apply_template_constraint(ctx, node_index, &template_type)?;
                 expr_elements.forget();
                 progress_expr
             },
             Literal::Tuple(data) => {
                 let expr_elements = self.expr_buffer.start_section_initialized(data.as_slice());
                 debug_log!("Tuple expr ({} elements): {}", expr_elements.len(), upcast_id.index);
                 debug_log!(" * Before:");
                 debug_log!("   - Expr type: {}", self.debug_get_display_name(ctx, upcast_id));
                 // Initial tuple constraint
                 let num_members = expr_elements.len();
                 let mut initial_type = Vec::with_capacity(num_members + 1); // TODO: @performance
                 initial_type.push(InferenceTypePart::Tuple(num_members as u32));
                 for _ in 0..num_members {
                     initial_type.push(InferenceTypePart::Unknown);
+                }
                 let mut progress_expr = self.apply_template_constraint(ctx, upcast_id, &initial_type)?;
                 // The elements of the tuple can have any type, but they must
                 // end up as arguments to the output tuple type.
                 debug_log!(" * During (checking expressions constituting tuple):");
                 for (member_expr_index, member_expr_id) in expr_elements.iter_copied().enumerate() {
                     // For the current expression index, (re)compute the
                     // position in the tuple type where the types should match.
                     let mut start_index = 1; // first element is Tuple type, second is the first child
                     for _ in 0..member_expr_index {
                         let tuple_expr_index = ctx.heap[id].unique_id_in_definition;
                         let tuple_type = &self.expr_types[tuple_expr_index as usize].expr_type;
                         start_index = InferenceType::find_subtree_end_idx(&tuple_type.parts, start_index);
                         debug_assert_ne!(start_index, tuple_type.parts.len()); // would imply less tuple type children than member expressions
+                    }
                     // Apply the constraint
                     let (member_progress_expr, member_progress) = self.apply_equal2_constraint(
                         ctx, upcast_id, upcast_id, start_index, member_expr_id, 0
         // Because of the (early returning error) check above, we're certain
         // that the tuple has the correct number of elements. Now match each
         // element expression type to the tuple subtype.
         let mut element_subtree_start_index = 1; // first element is InferenceTypePart::Tuple
         for element_node_index in element_indices.iter_copied() {
             let (progress_literal_element, progress_element) = self.apply_equal2_constraint(
                 ctx, node_index, node_index, element_subtree_start_index, element_node_index, 0
             )?;
                     debug_log!("   - Member {} type | {}", member_expr_index, self.debug_get_display_name(ctx, *member_expr_id));
                     progress_expr = progress_expr || member_progress_expr;
                     if member_progress {
                         self.queue_expr(ctx, member_expr_id);
+                    }
             progress_literal = progress_literal || progress_literal_element;
             if progress_element {
                 self.queue_node(element_node_index);
+            }
                 expr_elements.forget();
                 progress_expr
             // Prepare for next element
             let node = &self.infer_nodes[node_index];
             let subtree_end_index = InferenceType::find_subtree_end_idx(&node.expr_type.parts, element_subtree_start_index);
             element_subtree_start_index = subtree_end_index;
+        }
         };
         debug_log!(" * After:");
         debug_log!("   - Expr type [{}]: {}", progress_expr, self.debug_get_display_name(ctx, upcast_id));
         debug_assert_eq!(element_subtree_start_index, self.infer_nodes[node_index].expr_type.parts.len());
-        if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
+        if progress_literal { self.queue_node_parent(node_index); }
         Ok(())
         element_indices.forget();
         return Ok(());
+    }
     fn progress_cast_expr(&mut self, ctx: &mut Ctx, id: CastExpressionId) -> Result<(), ParseError> {
         let upcast_id = id.upcast();
         let expr = &ctx.heap[id];
         let expr_idx = expr.unique_id_in_definition;
         debug_log!("Casting expr: {}", upcast_id.index);
         debug_log!(" * Before:");
         debug_log!("   - Expr type:    {}", self.debug_get_display_name(ctx, upcast_id));
         debug_log!("   - Subject type: {}", self.debug_get_display_name(ctx, expr.subject));
         // The cast expression might have its output type fixed by the
         // programmer, so apply that type to the output. Apart from that casting
         // acts like a blocker for two-way inference. So we'll just have to wait
         // until we know if the cast is valid.
         // TODO: Another thing that has to be updated the moment the type
         //  inferencer is fully index/job-based
         let infer_type = self.determine_inference_type_from_parser_type_elements(&expr.to_type.elements, true);
         let expr_progress = self.apply_template_constraint(ctx, upcast_id, &infer_type.parts)?;
         if expr_progress {
             self.queue_expr_parent(ctx, upcast_id);
+        }
         // Check if the two types are compatible
         debug_log!(" * After:");
         debug_log!("   - Expr type [{}]: {}", expr_progress, self.debug_get_display_name(ctx, upcast_id));
         debug_log!("   - Note that the subject type can never be inferred");
         debug_log!(" * Decision:");
         let subject_idx = ctx.heap[expr.subject].get_unique_id_in_definition();
         let expr_type = &self.expr_types[expr_idx as usize].expr_type;
         let subject_type = &self.expr_types[subject_idx as usize].expr_type;
         if !expr_type.is_done || !subject_type.is_done {
             // Not yet done
             debug_log!("   - Casting is valid: unknown as the types are not yet complete");
             return Ok(())
     fn progress_inference_rule_cast_expr(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let rule = node.inference_rule.as_cast_expr();
         let subject_index = rule.subject_index;
         let subject = &self.infer_nodes[subject_index];
         // Make sure that both types are completely done. Note: a cast
         // expression cannot really infer anything between the subject and the
         // output type, we can only make sure that, at the end, the cast is
         // correct.
         if !node.expr_type.is_done || !subject.expr_type.is_done {
             return Ok(());
+        }
         // Valid casts: (bool, integer, character) can always be cast to one
         // another. A cast from a type to itself is also valid.
         // Both types are known, currently the only valid casts are bool,
         // integer and character casts.
         fn is_bool_int_or_char(parts: &[InferenceTypePart]) -> bool {
             return parts.len() == 1 && (
                 parts[0] == InferenceTypePart::Bool ||
                 parts[0] == InferenceTypePart::Character ||
                 parts[0].is_concrete_integer()
             );
             let mut index = 0;
             while index < parts.len() {
                 let part = &parts[index];
                 if !part.is_marker() { break; }
                 index += 1;
+            }
             debug_assert!(index != parts.len());
             let part = &parts[index];
             if *part == InferenceTypePart::Bool || *part == InferenceTypePart::Character || part.is_concrete_integer() {
                 debug_assert!(index + 1 == parts.len()); // type is done, first part does not have children -> must be at end
                 return true;
             } else {
                 return false;
+            }
+        }
-        let is_valid = if is_bool_int_or_char(&expr_type.parts) && is_bool_int_or_char(&subject_type.parts) {
+        let is_valid = if is_bool_int_or_char(&node.expr_type.parts) && is_bool_int_or_char(&subject.expr_type.parts) {
             true
         } else if expr_type.parts == subject_type.parts {
         } else if InferenceType::check_subtrees(&node.expr_type.parts, 0, &subject.expr_type.parts, 0) {
             // again: check_subtrees is sufficient since both types are done
             true
         } else {
             false
         };
         debug_log!("   - Casting is valid: {}", is_valid);
         if !is_valid {
             let cast_expr = &ctx.heap[id];
             let subject_expr = &ctx.heap[cast_expr.subject];
             let cast_expr = &ctx.heap[node.expr_id];
             let subject_expr = &ctx.heap[subject.expr_id];
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, cast_expr.full_span, "invalid casting operation"
+                &ctx.module().source, cast_expr.full_span(), "invalid casting operation"
             ).with_info_at_span(
                 &ctx.module().source, subject_expr.full_span(), format!(
                     "cannot cast the argument type '{}' to the cast type '{}'",
                     subject_type.display_name(&ctx.heap),
                     expr_type.display_name(&ctx.heap)
                     "cannot cast the argument type '{}' to the type '{}'",
                     subject.expr_type.display_name(&ctx.heap),
                     node.expr_type.display_name(&ctx.heap)
+                )
             ));
+        }
         Ok(())
+        return Ok(())
+    }
     // TODO: @cleanup, see how this can be cleaned up once I implement
     //  polymorphic struct/enum/union literals. These likely follow the same
     //  pattern as here.
     fn progress_call_expr(&mut self, ctx: &mut Ctx, id: CallExpressionId) -> Result<(), ParseError> {
         let upcast_id = id.upcast();
         let expr = &ctx.heap[id];
         let expr_idx = expr.unique_id_in_definition;
         let extra_idx = self.expr_types[expr_idx as usize].extra_data_idx;
         debug_log!("Call expr '{}': {}", ctx.heap[expr.definition].identifier().value.as_str(), upcast_id.index);
         debug_log!(" * Before:");
         debug_log!("   - Expr type: {}", self.debug_get_display_name(ctx, upcast_id));
         debug_log!(" * During (inferring types from arguments and return type):");
         let extra = &mut self.extra_data[extra_idx as usize];
         // Check if we can make progress using the arguments and/or return types
         // while keeping track of the polyvars we've extended
         let mut poly_progress = HashSet::new();
         debug_assert_eq!(extra.embedded.len(), expr.arguments.len());
         for (call_arg_idx, arg_id) in expr.arguments.clone().into_iter().enumerate() {
             let arg_expr_idx = ctx.heap[arg_id].get_unique_id_in_definition();
             let signature_type: *mut _ = &mut extra.embedded[call_arg_idx];
             let argument_type: *mut _ = &mut self.expr_types[arg_expr_idx as usize].expr_type;
             let (_, progress_arg) = Self::apply_equal2_signature_constraint(
                 ctx, upcast_id, Some(arg_id), extra, &mut poly_progress,
                 signature_type, 0, argument_type, 0
             )?;
     fn progress_inference_rule_call_expr(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &self.infer_nodes[node_index];
         let node_expr_id = node.expr_id;
         let rule = node.inference_rule.as_call_expr();
             debug_log!(
                 "   - Arg {} type | sig: {}, arg: {}", call_arg_idx,
                 unsafe{&*signature_type}.display_name(&ctx.heap),
                 unsafe{&*argument_type}.display_name(&ctx.heap));
         let mut poly_progress_section = self.poly_progress_buffer.start_section();
         let argument_node_indices = self.index_buffer.start_section_initialized(&rule.argument_indices);
             if progress_arg {
                 // Progressed argument expression
                 self.expr_queued.push_back(arg_expr_idx);
+            }
         // Perform inference on arguments to function, while trying to figure
         // out the polymorphic variables
         for (argument_index, argument_node_index) in argument_node_indices.iter_copied().enumerate() {
             let argument_expr_id = self.infer_nodes[argument_node_index].expr_id;
             let (_, progress_argument) = self.apply_polydata_equal2_constraint(
                 ctx, node_index, argument_expr_id, "argument's",
                 PolyDataTypeIndex::Associated(argument_index), 0,
                 argument_node_index, 0, &mut poly_progress_section
             )?;
             if progress_argument { self.queue_node(argument_node_index); }
+        }
         // Do the same for the return type
         let signature_type: *mut _ = &mut extra.returned;
         let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
         let (_, progress_expr) = Self::apply_equal2_signature_constraint(
             ctx, upcast_id, None, extra, &mut poly_progress,
             signature_type, 0, expr_type, 0
         // Same for the return type.
         let (_, progress_call_1) = self.apply_polydata_equal2_constraint(
             ctx, node_index, node_expr_id, "return",
             PolyDataTypeIndex::Returned, 0,
             node_index, 0, &mut poly_progress_section
         )?;
         debug_log!(
             "   - Ret type | sig: {}, expr: {}",
             unsafe{&*signature_type}.display_name(&ctx.heap),
             unsafe{&*expr_type}.display_name(&ctx.heap)
         // We will now apply any progression in the polymorphic variable type
         // back to the arguments.
         for (argument_index, argument_node_index) in argument_node_indices.iter_copied().enumerate() {
             let progress_argument = self.apply_polydata_polyvar_constraint(
                 ctx, node_index, PolyDataTypeIndex::Associated(argument_index),
                 argument_node_index, &poly_progress_section
             );
         if progress_expr {
             // TODO: @cleanup, cannot call utility self.queue_parent thingo
             if let Some(parent_id) = ctx.heap[upcast_id].parent_expr_id() {
                 let parent_idx = ctx.heap[parent_id].get_unique_id_in_definition();
                 self.expr_queued.push_back(parent_idx);
+            }
+        }
         // If we did not have an error in the polymorph inference above, then
         // reapplying the polymorph type to each argument type and the return
         // type should always succeed.
         debug_log!(" * During (reinferring from progressed polyvars):");
         for (_poly_idx, _poly_var) in extra.poly_vars.iter().enumerate() {
             debug_log!("   - Poly {} | sig: {}", _poly_idx, _poly_var.display_name(&ctx.heap));
+        }
         // TODO: @performance If the algorithm is changed to be more "on demand
         //  argument re-evaluation", instead of "all-argument re-evaluation",
         //  then this is no longer true
         for arg_idx in 0..extra.embedded.len() {
             let signature_type: *mut _ = &mut extra.embedded[arg_idx];
             let arg_expr_id = expr.arguments[arg_idx];
             let arg_expr_idx = ctx.heap[arg_expr_id].get_unique_id_in_definition();
             let arg_type: *mut _ = &mut self.expr_types[arg_expr_idx as usize].expr_type;
             let progress_arg = Self::apply_equal2_polyvar_constraint(
                 extra, &poly_progress,
                 signature_type, arg_type
             );
             debug_log!(
                 "   - Arg {} type | sig: {}, arg: {}", arg_idx,
                 unsafe{&*signature_type}.display_name(&ctx.heap),
                 unsafe{&*arg_type}.display_name(&ctx.heap)
             );
             if progress_arg {
                 self.expr_queued.push_back(arg_expr_idx);
             if progress_argument { self.queue_node(argument_node_index); }
+        }
+        }
         // Once more for the return type
         let signature_type: *mut _ = &mut extra.returned;
         let ret_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
         let progress_ret = Self::apply_equal2_polyvar_constraint(
             extra, &poly_progress, signature_type, ret_type
         );
         debug_log!(
             "   - Ret type | sig: {}, arg: {}",
             unsafe{&*signature_type}.display_name(&ctx.heap),
             unsafe{&*ret_type}.display_name(&ctx.heap)
         // And back to the return type.
         let progress_call_2 = self.apply_polydata_polyvar_constraint(
             ctx, node_index, PolyDataTypeIndex::Returned,
             node_index, &poly_progress_section
         );
         if progress_ret {
             self.queue_expr_parent(ctx, upcast_id);
+        }
         debug_log!(" * After:");
         debug_log!("   - Expr type: {}", self.debug_get_display_name(ctx, upcast_id));
         if progress_call_1 || progress_call_2 { self.queue_node_parent(node_index); }
         Ok(())
         poly_progress_section.forget();
         argument_node_indices.forget();
         self.finish_polydata_constraint(node_index);
         return Ok(())
+    }
     fn progress_variable_expr(&mut self, ctx: &mut Ctx, id: VariableExpressionId) -> Result<(), ParseError> {
         let upcast_id = id.upcast();
         let var_expr = &ctx.heap[id];
         let var_expr_idx = var_expr.unique_id_in_definition;
         let var_id = var_expr.declaration.unwrap();
     fn progress_inference_rule_variable_expr(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
         let node = &mut self.infer_nodes[node_index];
         let rule = node.inference_rule.as_variable_expr();
         let var_data_index = rule.var_data_index;
         debug_log!("Variable expr '{}': {}", ctx.heap[var_id].identifier.value.as_str(), upcast_id.index);
         debug_log!(" * Before:");
         debug_log!("   - Var  type: {}", self.var_types.get(&var_id).unwrap().var_type.display_name(&ctx.heap));
         debug_log!("   - Expr type: {}", self.debug_get_display_name(ctx, upcast_id));
         let var_data = &mut self.var_data[var_data_index];
         // Apply inference to the shared variable type and the expression type
         let shared_type: *mut _ = &mut var_data.var_type;
         let expr_type: *mut _ = &mut node.expr_type;
         // Retrieve shared variable type and expression type and apply inference
         let var_data = self.var_types.get_mut(&var_id).unwrap();
         let expr_type = &mut self.expr_types[var_expr_idx as usize].expr_type;
         let inference_result = unsafe {
             // safety: vectors exist in different storage vectors, so cannot alias
             InferenceType::infer_subtrees_for_both_types(shared_type, 0, expr_type, 0)
         };
         let infer_res = unsafe{ InferenceType::infer_subtrees_for_both_types(
             &mut var_data.var_type as *mut _, 0, expr_type, 0
         ) };
         if infer_res == DualInferenceResult::Incompatible {
             let var_decl = &ctx.heap[var_id];
             return Err(ParseError::new_error_at_span(
                 &ctx.module().source, var_decl.identifier.span, format!(
                     "Conflicting types for this variable, previously assigned the type '{}'",
                     var_data.var_type.display_name(&ctx.heap)
+                )
             ).with_info_at_span(
                 &ctx.module().source, var_expr.identifier.span, format!(
                     "But inferred to have incompatible type '{}' here",
                     expr_type.display_name(&ctx.heap)
+                )
             ))
         if inference_result == DualInferenceResult::Incompatible {
             return Err(self.construct_variable_type_error(ctx, node_index));
+        }
         let progress_var = infer_res.modified_lhs();
         let progress_expr = infer_res.modified_rhs();
         let progress_var_data = inference_result.modified_lhs();
         let progress_expr = inference_result.modified_rhs();
         if progress_var {
             // Let other variable expressions using this type progress as well
             for other_expr in var_data.used_at.iter() {
                 if *other_expr != upcast_id {
                     let other_expr_idx = ctx.heap[*other_expr].get_unique_id_in_definition();
                     self.expr_queued.push_back(other_expr_idx);
         if progress_var_data {
             // We progressed the type of the shared variable, so propagate this
             // to all associated variable expressions (and relatived variables).
             for other_node_index in var_data.used_at.iter().copied() {
                 if other_node_index != node_index {
                     self.node_queued.push_back(other_node_index);
+                }
+            }
             // Let a linked port know that our type has updated
             if let Some(linked_id) = var_data.linked_var {
                 // Only perform one-way inference to prevent updating our type,
                 // this would lead to an inconsistency in the type inference
                 // algorithm otherwise.
                 let var_type: *mut _ = &mut var_data.var_type;
                 let link_data = self.var_types.get_mut(&linked_id).unwrap();
             if let Some(linked_var_data_index) = var_data.linked_var {
                 // Only perform one-way inference, progressing the linked
                 // variable.
                 // note: because this "linking" is used only for channels, we
                 // will start inference one level below the top-level in the
                 // type tree (i.e. ensure `T` in `in<T>` and `out<T>` is equal).
                 debug_assert!(
                     unsafe{&*var_type}.parts[0] == InferenceTypePart::Input ||
                     unsafe{&*var_type}.parts[0] == InferenceTypePart::Output
                     var_data.var_type.parts[0] == InferenceTypePart::Input ||
                     var_data.var_type.parts[0] == InferenceTypePart::Output
                 );
                 let this_var_type: *const _ = &var_data.var_type;
                 let linked_var_data = &mut self.var_data[linked_var_data_index];
                 debug_assert!(
                     link_data.var_type.parts[0] == InferenceTypePart::Input ||
                     link_data.var_type.parts[0] == InferenceTypePart::Output
                     linked_var_data.var_type.parts[0] == InferenceTypePart::Input ||
                     linked_var_data.var_type.parts[0] == InferenceTypePart::Output
                 );
                 match InferenceType::infer_subtree_for_single_type(&mut link_data.var_type, 1, &unsafe{&*var_type}.parts, 1, false) {
                 // safety: by construction var_data_index and linked_var_data_index cannot be the
                 // same, hence we're not aliasing here.
                 let inference_result = InferenceType::infer_subtree_for_single_type(
                     &mut linked_var_data.var_type, 1,
                     unsafe{ &(*this_var_type).parts }, 1, false
                 );
                 match inference_result {
                     SingleInferenceResult::Modified => {
                         for other_expr in &link_data.used_at {
                             let other_expr_idx = ctx.heap[*other_expr].get_unique_id_in_definition();
                             self.expr_queued.push_back(other_expr_idx);
                         for used_at in linked_var_data.used_at.iter().copied() {
                             self.node_queued.push_back(used_at);
+                        }
                     },
                     SingleInferenceResult::Unmodified => {},
                     SingleInferenceResult::Incompatible => {
                         let var_data = self.var_types.get(&var_id).unwrap();
                         let link_data = self.var_types.get(&linked_id).unwrap();
                         let var_decl = &ctx.heap[var_id];
                         let link_decl = &ctx.heap[linked_id];
                         let var_data_this = &self.var_data[var_data_index];
                         let var_decl_this = &ctx.heap[var_data_this.var_id];
                         let var_data_linked = &self.var_data[linked_var_data_index];
                         let var_decl_linked = &ctx.heap[var_data_linked.var_id];
                         return Err(ParseError::new_error_at_span(
                             &ctx.module().source, var_decl.identifier.span, format!(
                                 "Conflicting types for this variable, assigned the type '{}'",
                                 var_data.var_type.display_name(&ctx.heap)
                             &ctx.module().source, var_decl_this.identifier.span, format!(
                                 "conflicting types for this channel, this port has type '{}'",
                                 var_data_this.var_type.display_name(&ctx.heap)
+                            )
                         ).with_info_at_span(
                             &ctx.module().source, link_decl.identifier.span, format!(
                                 "Because it is incompatible with this variable, assigned the type '{}'",
                                 link_data.var_type.display_name(&ctx.heap)
                             &ctx.module().source, var_decl_linked.identifier.span, format!(
                                 "while this port has type '{}'",
                                 var_data_linked.var_type.display_name(&ctx.heap)
+                            )
                         ));
+                    }
+                }
+            }
+        }
         if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
         debug_log!(" * After:");
         debug_log!("   - Var  type [{}]: {}", progress_var, self.var_types.get(&var_id).unwrap().var_type.display_name(&ctx.heap));
         debug_log!("   - Expr type [{}]: {}", progress_expr, self.debug_get_display_name(ctx, upcast_id));
         if progress_expr { self.queue_node_parent(node_index); }
         return Ok(());
+    }
     fn progress_template(&mut self, ctx: &Ctx, node_index: InferNodeIndex, application: InferenceRuleTemplateApplication, template: &[InferenceTypePart]) -> Result<bool, ParseError> {
         use InferenceRuleTemplateApplication as TA;
         Ok(())
         match application {
             TA::None => Ok(false),
             TA::Template => self.apply_template_constraint(ctx, node_index, template),
             TA::Forced => self.apply_forced_constraint(ctx, node_index, template),
+        }
+    }
     fn queue_expr_parent(&mut self, ctx: &Ctx, expr_id: ExpressionId) {
         if let ExpressionParent::Expression(parent_expr_id, _) = &ctx.heap[expr_id].parent() {
             let expr_idx = ctx.heap[*parent_expr_id].get_unique_id_in_definition();
             self.expr_queued.push_back(expr_idx);
     fn queue_node_parent(&mut self, node_index: InferNodeIndex) {
         let node = &self.infer_nodes[node_index];
         if let Some(parent_node_index) = node.parent_index {
             self.node_queued.push_back(parent_node_index);
+        }
+    }
     fn queue_expr(&mut self, ctx: &Ctx, expr_id: ExpressionId) {
         let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition();
         self.expr_queued.push_back(expr_idx);
     #[inline]
     fn queue_node(&mut self, node_index: InferNodeIndex) {
         self.node_queued.push_back(node_index);
+    }
     /// Returns whether the type is certainly a string (true, false), certainly
     /// not a string (false, true), or still unknown (false, false).
     fn type_is_certainly_or_certainly_not_string(&self, node_index: InferNodeIndex) -> (bool, bool) {
         let expr_type = &self.infer_nodes[node_index].expr_type;
         let mut part_index = 0;
         while part_index < expr_type.parts.len() {
             let part = &expr_type.parts[part_index];
             if part.is_marker() {
                 part_index += 1;
                 continue;
+            }
             if !part.is_concrete() { break; }
     // first returned is certainly string, second is certainly not
     fn type_is_certainly_or_certainly_not_string(&self, ctx: &Ctx, expr_id: ExpressionId) -> (bool, bool) {
         let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition();
         let expr_type = &self.expr_types[expr_idx as usize].expr_type;
         if expr_type.is_done {
             if expr_type.parts[0] == InferenceTypePart::String {
             if *part == InferenceTypePart::String {
                 // First part is a string
                 return (true, false);
             } else {
                 return (false, true);
+            }
+        }
         // If here then first non-marker type is not concrete
         if part_index == expr_type.parts.len() {
             // nothing known at all
             return (false, false);
+        }
         // Special case: array-like where its argument is not a character
         if part_index + 1 < expr_type.parts.len() {
             if expr_type.parts[part_index] == InferenceTypePart::ArrayLike && expr_type.parts[part_index + 1] != InferenceTypePart::Character {
                 return (false, true);
+            }
+        }
         (false, false)
+    }
     /// Applies a template type constraint: the type associated with the
     /// supplied expression will be molded into the provided `template`. But
     /// will be considered valid if the template could've been molded into the
     /// expression type as well. Hence the template may be fully specified (e.g.
     /// a bool) or contain "inference" variables (e.g. an array of T)
     fn apply_template_constraint(
-        &mut self, ctx: &Ctx, expr_id: ExpressionId, template: &[InferenceTypePart]
+        &mut self, ctx: &Ctx, node_index: InferNodeIndex, template: &[InferenceTypePart]
     ) -> Result<bool, ParseError> {
         let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition(); // TODO: @Temp
         let expr_type = &mut self.expr_types[expr_idx as usize].expr_type;
         let expr_type = &mut self.infer_nodes[node_index].expr_type;
         match InferenceType::infer_subtree_for_single_type(expr_type, 0, template, 0, false) {
             SingleInferenceResult::Modified => Ok(true),
             SingleInferenceResult::Unmodified => Ok(false),
             SingleInferenceResult::Incompatible => Err(
-                self.construct_template_type_error(ctx, expr_id, template)
+                self.construct_template_type_error(ctx, node_index, template)
+            )
+        }
+    }
     fn apply_template_constraint_to_types(
         to_infer: *mut InferenceType, to_infer_start_idx: usize,
         template: &[InferenceTypePart], template_start_idx: usize
     ) -> Result<bool, ()> {
         match InferenceType::infer_subtree_for_single_type(
             unsafe{ &mut *to_infer }, to_infer_start_idx,
             template, template_start_idx, false
         ) {
             SingleInferenceResult::Modified => Ok(true),
             SingleInferenceResult::Unmodified => Ok(false),
             SingleInferenceResult::Incompatible => Err(()),
+        }
+    }
     /// Applies a forced constraint: the supplied expression's type MUST be
     /// inferred from the template, the other way around is considered invalid.
     fn apply_forced_constraint(
-        &mut self, ctx: &Ctx, expr_id: ExpressionId, template: &[InferenceTypePart]
+        &mut self, ctx: &Ctx, node_index: InferNodeIndex, template: &[InferenceTypePart]
     ) -> Result<bool, ParseError> {
         let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition();
         let expr_type = &mut self.expr_types[expr_idx as usize].expr_type;
         let expr_type = &mut self.infer_nodes[node_index].expr_type;
         match InferenceType::infer_subtree_for_single_type(expr_type, 0, template, 0, true) {
             SingleInferenceResult::Modified => Ok(true),
             SingleInferenceResult::Unmodified => Ok(false),
             SingleInferenceResult::Incompatible => Err(
-                self.construct_template_type_error(ctx, expr_id, template)
+                self.construct_template_type_error(ctx, node_index, template)
+            )
+        }
+    }
     /// Applies a type constraint that expects the two provided types to be
     /// equal. We attempt to make progress in inferring the types. If the call
     /// is successful then the composition of all types are made equal.
     /// The "parent" `expr_id` is provided to construct errors.
     fn apply_equal2_constraint(
         &mut self, ctx: &Ctx, expr_id: ExpressionId,
         arg1_id: ExpressionId, arg1_start_idx: usize,
         arg2_id: ExpressionId, arg2_start_idx: usize
         &mut self, ctx: &Ctx, node_index: InferNodeIndex,
         arg1_index: InferNodeIndex, arg1_start_idx: usize,
         arg2_index: InferNodeIndex, arg2_start_idx: usize
     ) -> Result<(bool, bool), ParseError> {
         let arg1_expr_idx = ctx.heap[arg1_id].get_unique_id_in_definition(); // TODO: @Temp
         let arg2_expr_idx = ctx.heap[arg2_id].get_unique_id_in_definition();
         let arg1_type: *mut _ = &mut self.expr_types[arg1_expr_idx as usize].expr_type;
         let arg2_type: *mut _ = &mut self.expr_types[arg2_expr_idx as usize].expr_type;
         let arg1_type: *mut _ = &mut self.infer_nodes[arg1_index].expr_type;
         let arg2_type: *mut _ = &mut self.infer_nodes[arg2_index].expr_type;
         let infer_res = unsafe{ InferenceType::infer_subtrees_for_both_types(
             arg1_type, arg1_start_idx,
             arg2_type, arg2_start_idx
         ) };
         if infer_res == DualInferenceResult::Incompatible {
-            return Err(self.construct_arg_type_error(ctx, expr_id, arg1_id, arg2_id));
+            return Err(self.construct_arg_type_error(ctx, node_index, arg1_index, arg2_index));
+        }
         Ok((infer_res.modified_lhs(), infer_res.modified_rhs()))
+    }
     /// Applies an equal2 constraint between a signature type (e.g. a function
     /// argument or struct field) and an expression whose type should match that
     /// expression. If we make progress on the signature, then we try to see if
     /// any of the embedded polymorphic types can be progressed.
     /// Applies an equal2 constraint between a member of the `PolyData` struct,
     /// and another inferred type. If any progress is made in the `PolyData`
     /// struct then the affected polymorphic variables are updated as well.
     ///
     /// Because a lot of types/expressions are involved in polymorphic typFe
     /// inference, some explanation: "outer_node" refers to the main expression
     /// that is the root cause of type inference (e.g. a struct literal
     /// expression, or a tuple member select expression). Associated with that
     /// outer node is `PolyData`, so that is what the "poly_data" variables
     /// are referring to. We are applying equality between a "poly_data" type
     /// and an associated expression (not necessarily the "outer_node", e.g.
     /// the expression that constructs the value of a struct field). Hence the
     /// "associated" variables.
     ///
     /// `outer_expr_id` is the main expression we're progressing (e.g. a
     /// function call), while `expr_id` is the embedded expression we're
     /// matching against the signature. `expression_type` and
     /// `expression_start_idx` belong to `expr_id`.
     fn apply_equal2_signature_constraint(
         ctx: &Ctx, outer_expr_id: ExpressionId, expr_id: Option<ExpressionId>,
         polymorph_data: &mut ExtraData, polymorph_progress: &mut HashSet<u32>,
         signature_type: *mut InferenceType, signature_start_idx: usize,
         expression_type: *mut InferenceType, expression_start_idx: usize
     /// Finally, when an error occurs we'll first show the outer node's
     /// location. As info, the `error_location_expr_id` span is shown,
     /// indicating that the "`error_type_name` type has been resolved to
     /// `outer_node_type`, but this expression has been resolved to
     /// `associated_node_type`".
     fn apply_polydata_equal2_constraint(
         &mut self, ctx: &Ctx,
         outer_node_index: InferNodeIndex, error_location_expr_id: ExpressionId, error_type_name: &str,
         poly_data_type_index: PolyDataTypeIndex, poly_data_start_index: usize,
         associated_node_index: InferNodeIndex, associated_node_start_index: usize,
         poly_progress_section: &mut ScopedSection<u32>,
     ) -> Result<(bool, bool), ParseError> {
         // Safety: all pointers distinct
         // Infer the signature and expression type
         let infer_res = unsafe {
         let poly_data_index = self.infer_nodes[outer_node_index].poly_data_index;
         let poly_data = &mut self.poly_data[poly_data_index as usize];
         let poly_data_type = poly_data.expr_types.get_type_mut(poly_data_type_index);
         let associated_type: *mut _ = &mut self.infer_nodes[associated_node_index].expr_type;
         let inference_result = unsafe{
             // Safety: pointers originate from different vectors, so cannot
             // alias.
             let poly_data_type: *mut _ = poly_data_type;
             InferenceType::infer_subtrees_for_both_types(
                 signature_type, signature_start_idx,
                 expression_type, expression_start_idx
                 poly_data_type, poly_data_start_index,
                 associated_type, associated_node_start_index
+            )
         };
         if infer_res == DualInferenceResult::Incompatible {
             // TODO: Check if I still need to use this
             let outer_span = ctx.heap[outer_expr_id].full_span();
             let (span_name, span) = match expr_id {
                 Some(expr_id) => ("argument's", ctx.heap[expr_id].full_span()),
                 None => ("type's", outer_span)
             };
             let (signature_display_type, expression_display_type) = unsafe { (
                 (&*signature_type).display_name(&ctx.heap),
                 (&*expression_type).display_name(&ctx.heap)
             ) };
         let modified_poly_data = inference_result.modified_lhs();
         let modified_associated = inference_result.modified_rhs();
         if inference_result == DualInferenceResult::Incompatible {
             let outer_node_expr_id = self.infer_nodes[outer_node_index].expr_id;
             let outer_node_span = ctx.heap[outer_node_expr_id].full_span();
             let detailed_span = ctx.heap[error_location_expr_id].full_span();
             let outer_node_type = poly_data_type.display_name(&ctx.heap);
             let associated_type = self.infer_nodes[associated_node_index].expr_type.display_name(&ctx.heap);
             let source = &ctx.module().source;
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, outer_span,
                 "failed to fully resolve the types of this expression"
             ).with_info_at_span(
                 &ctx.module().source, span, format!(
                     "because the {} signature has been resolved to '{}', but the expression has been resolved to '{}'",
                     span_name, signature_display_type, expression_display_type
                 source, outer_node_span, "failed to resolve the types of this expression"
             ).with_info_str_at_span(
                 source, detailed_span, &format!(
                     "because the {} type has been resolved to '{}', but this expression has been resolved to '{}'",
                     error_type_name, outer_node_type, associated_type
+                )
             ));
+        }
         // Try to see if we can progress any of the polymorphic variables
         let progress_sig = infer_res.modified_lhs();
         let progress_expr = infer_res.modified_rhs();
         if modified_poly_data {
             debug_assert!(poly_data_type.has_marker);
         if progress_sig {
             let signature_type = unsafe{&mut *signature_type};
             debug_assert!(
                 signature_type.has_marker,
                 "made progress on signature type, but it doesn't have a marker"
             );
             for (poly_idx, poly_section) in signature_type.marker_iter() {
                 let polymorph_type = &mut polymorph_data.poly_vars[poly_idx as usize];
                 match Self::apply_template_constraint_to_types(
                     polymorph_type, 0, poly_section, 0
                 ) {
                     Ok(true) => { polymorph_progress.insert(poly_idx); },
                     Ok(false) => {},
                     Err(()) => { return Err(Self::construct_poly_arg_error(ctx, polymorph_data, outer_expr_id))}
             // Go through markers for polymorphic variables and use the
             // (hopefully) more specific types to update their representation
             // in the PolyData struct
             for (poly_var_index, poly_var_section) in poly_data_type.marker_iter() {
                 let poly_var_type = &mut poly_data.poly_vars[poly_var_index as usize];
                 match InferenceType::infer_subtree_for_single_type(poly_var_type, 0, poly_var_section, 0, false) {
                     SingleInferenceResult::Modified => {
                         poly_progress_section.push_unique(poly_var_index);
                     },
                     SingleInferenceResult::Unmodified => {
                         // nothing to do
                     },
                     SingleInferenceResult::Incompatible => {
                         return Err(Self::construct_poly_arg_error(
                             ctx, &self.poly_data[poly_data_index as usize],
                             self.infer_nodes[outer_node_index].expr_id
                         ));
+                    }
+                }
+            }
+        }
         Ok((progress_sig, progress_expr))
         return Ok((modified_poly_data, modified_associated));
+    }
     /// Applies equal2 constraints on the signature type for each of the
     /// polymorphic variables. If the signature type is progressed then we
     /// progress the expression type as well.
     /// After calling `apply_polydata_equal2_constraint` on several expressions
     /// that are associated with some kind of polymorphic expression, several of
     /// the polymorphic variables might have been inferred to more specific
     /// types than before.
     ///
     /// This function assumes that the polymorphic variables have already been
     /// progressed as far as possible by calling
     /// `apply_equal2_signature_constraint`. As such, we expect to not encounter
     /// any errors.
     /// At this point one should call this function to apply the progress in
     /// these polymorphic variables back onto the types that are functions of
     /// these polymorphic variables.
     ///
     /// This function returns true if the expression's type has been progressed
     fn apply_equal2_polyvar_constraint(
         polymorph_data: &ExtraData, _polymorph_progress: &HashSet<u32>,
         signature_type: *mut InferenceType, expr_type: *mut InferenceType
     /// An example: a struct literal with a polymorphic variable `T` may have
     /// two fields `foo` and `bar` each with different types that are a function
     /// of the polymorhic variable `T`. If the expressions constructing the
     /// value for the field `foo` causes the type `T` to progress, then we can
     /// also progress the type of the expression that constructs `bar`.
     ///
     /// And so we have `outer_node_index` + `poly_data_type_index` pointing to
     /// the appropriate type in the `PolyData` struct. Which will be updated
     /// first using the polymorphic variables. If we happen to have updated that
     /// type, then we should also progress the associated expression, hence the
     /// `associated_node_index`.
     fn apply_polydata_polyvar_constraint(
         &mut self, _ctx: &Ctx,
         outer_node_index: InferNodeIndex, poly_data_type_index: PolyDataTypeIndex,
         associated_node_index: InferNodeIndex, poly_progress_section: &ScopedSection<u32>
     ) -> bool {
         // Safety: all pointers should be distinct
         //         polymorph_data containers may not be modified
         let signature_type = unsafe{&mut *signature_type};
         let expr_type = unsafe{&mut *expr_type};
         // Iterate through markers in signature type to try and make progress
         // on the polymorphic variable
         let mut seek_idx = 0;
         let mut modified_sig = false;
         while let Some((poly_idx, start_idx)) = signature_type.find_marker(seek_idx) {
             let end_idx = InferenceType::find_subtree_end_idx(&signature_type.parts, start_idx);
             // if polymorph_progress.contains(&poly_idx) {
                 // Need to match subtrees
                 let polymorph_type = &polymorph_data.poly_vars[poly_idx as usize];
                 let modified_at_marker = Self::apply_template_constraint_to_types(
                     signature_type, start_idx,
                     &polymorph_type.parts, 0
                 ).expect("no failure when applying polyvar constraints");
                 modified_sig = modified_sig || modified_at_marker;
             // }
             seek_idx = end_idx;
+        }
         // If we made any progress on the signature's type, then we also need to
         // apply it to the expression that is supposed to match the signature.
         if modified_sig {
             match InferenceType::infer_subtree_for_single_type(
                 expr_type, 0, &signature_type.parts, 0, true
         let poly_data_index = self.infer_nodes[outer_node_index].poly_data_index;
         let poly_data = &mut self.poly_data[poly_data_index as usize];
         // Early exit, most common case (literals or functions calls which are
         // actually not polymorphic)
         if !poly_data.first_rule_application && poly_progress_section.len() == 0 {
             return false;
+        }
         // safety: we're borrowing from two distinct fields, so should be fine
         let poly_data_type = poly_data.expr_types.get_type_mut(poly_data_type_index);
         let mut last_start_index = 0;
         let mut modified_poly_type = false;
         while let Some((poly_var_index, poly_var_start_index)) = poly_data_type.find_marker(last_start_index) {
             let poly_var_end_index = InferenceType::find_subtree_end_idx(&poly_data_type.parts, poly_var_start_index);
             if poly_data.first_rule_application || poly_progress_section.contains(&poly_var_index) {
                 // We have updated this polymorphic variable, so try updating it
                 // in the PolyData type
                 let modified_in_poly_data = match InferenceType::infer_subtree_for_single_type(
                     poly_data_type, poly_var_start_index, &poly_data.poly_vars[poly_var_index as usize].parts, 0, false
                 ) {
                     SingleInferenceResult::Modified => true,
                     SingleInferenceResult::Unmodified => false,
                 SingleInferenceResult::Incompatible =>
                     unreachable!("encountered failure while reapplying modified signature to expression after polyvar inference")
                     SingleInferenceResult::Incompatible => {
                         // practically impossible: before calling this function we gather all the
                         // data on the polymorphic variables from the associated expressions. So if
                         // the polymorphic variables in those expressions were not mutually
                         // compatible, we must have encountered that error already.
                         unreachable!()
                     },
                 };
                 modified_poly_type = modified_poly_type || modified_in_poly_data;
+            }
             last_start_index = poly_var_end_index;
+        }
         if modified_poly_type {
             let associated_type = &mut self.infer_nodes[associated_node_index].expr_type;
             match InferenceType::infer_subtree_for_single_type(
                 associated_type, 0, &poly_data_type.parts, 0, true
             ) {
                 SingleInferenceResult::Modified => return true,
                 SingleInferenceResult::Unmodified => return false,
                 SingleInferenceResult::Incompatible => unreachable!(), // same as above
+            }
         } else {
             false
             // Did not update associated type
             return false;
+        }
+    }
     /// Should be called after completing one full round of applying polydata
     /// constraints.
     fn finish_polydata_constraint(&mut self, outer_node_index: InferNodeIndex) {
         let poly_data_index = self.infer_nodes[outer_node_index].poly_data_index;
         let poly_data = &mut self.poly_data[poly_data_index as usize];
         poly_data.first_rule_application = false;
+    }
     /// Applies a type constraint that expects all three provided types to be
     /// equal. In case we can make progress in inferring the types then we
     /// attempt to do so. If the call is successful then the composition of all
     /// types is made equal.
     fn apply_equal3_constraint(
         &mut self, ctx: &Ctx, expr_id: ExpressionId,
         arg1_id: ExpressionId, arg2_id: ExpressionId,
         &mut self, ctx: &Ctx, node_index: InferNodeIndex,
         arg1_index: InferNodeIndex, arg2_index: InferNodeIndex,
         start_idx: usize
     ) -> Result<(bool, bool, bool), ParseError> {
-        // Safety: all points are unique
+        // Safety: all indices are unique
         //         containers may not be modified
         let expr_expr_idx = ctx.heap[expr_id].get_unique_id_in_definition(); // TODO: @Temp
         let arg1_expr_idx = ctx.heap[arg1_id].get_unique_id_in_definition();
         let arg2_expr_idx = ctx.heap[arg2_id].get_unique_id_in_definition();
         let expr_type: *mut _ = &mut self.expr_types[expr_expr_idx as usize].expr_type;
         let arg1_type: *mut _ = &mut self.expr_types[arg1_expr_idx as usize].expr_type;
         let arg2_type: *mut _ = &mut self.expr_types[arg2_expr_idx as usize].expr_type;
         let expr_type: *mut _ = &mut self.infer_nodes[node_index].expr_type;
         let arg1_type: *mut _ = &mut self.infer_nodes[arg1_index].expr_type;
         let arg2_type: *mut _ = &mut self.infer_nodes[arg2_index].expr_type;
         let expr_res = unsafe{
             InferenceType::infer_subtrees_for_both_types(expr_type, start_idx, arg1_type, start_idx)
         };
         if expr_res == DualInferenceResult::Incompatible {
-            return Err(self.construct_expr_type_error(ctx, expr_id, arg1_id));
+            return Err(self.construct_expr_type_error(ctx, node_index, arg1_index));
+        }
         let args_res = unsafe{
             InferenceType::infer_subtrees_for_both_types(arg1_type, start_idx, arg2_type, start_idx) };
         if args_res == DualInferenceResult::Incompatible {
-            return Err(self.construct_arg_type_error(ctx, expr_id, arg1_id, arg2_id));
+            return Err(self.construct_arg_type_error(ctx, node_index, arg1_index, arg2_index));
+        }
         // If all types are compatible, but the second call caused the arg1_type
         // to be expanded, then we must also assign this to expr_type.
         let mut progress_expr = expr_res.modified_lhs();
         let mut progress_arg1 = expr_res.modified_rhs();
         let progress_arg2 = args_res.modified_rhs();
         if args_res.modified_lhs() {
             unsafe {
                 let end_idx = InferenceType::find_subtree_end_idx(&(*arg2_type).parts, start_idx);
                 let subtree = &((*arg2_type).parts[start_idx..end_idx]);
                 (*expr_type).replace_subtree(start_idx, subtree);
+            }
             progress_expr = true;
             progress_arg1 = true;
+        }
         Ok((progress_expr, progress_arg1, progress_arg2))
+    }
     /// Applies equal constraint to N consecutive expressions. The returned
     /// `progress` vec will contain which expressions were progressed and will
     /// have length N
     // If you ever
     /// have length N.
     fn apply_equal_n_constraint(
         &mut self, ctx: &Ctx, expr_id: ExpressionId,
         args: &ScopedSection<ExpressionId>, progress: &mut ScopedSection<bool>
         &mut self, ctx: &Ctx, outer_node_index: InferNodeIndex,
         arguments: &ScopedSection<InferNodeIndex>, progress: &mut ScopedSection<bool>
     ) -> Result<(), ParseError> {
         // Early exit
         // Depending on the argument perform an early exit. This simplifies
         // later logic
         debug_assert_eq!(progress.len(), 0);
-        match args.len() {
+        match arguments.len() {
 => {
                 // nothing to progress
                 return Ok(())
             },
 => {
                 // only one type, so nothing to infer
                 progress.push(false);
                 return Ok(())
             },
             n => {
                 for _ in 0..n {
                     progress.push(false);
+                }
+            }
+        }
         // Do pairwise inference, keep track of the last entry we made progress
         // on. Once done we need to update everything to the most-inferred type.
         let mut arg_iter = args.iter_copied();
         let mut last_arg_id = arg_iter.next().unwrap();
         let mut last_lhs_progressed = 0;
         let mut lhs_arg_idx = 0;
         // We'll start doing pairwise inference for all of the inference nodes
         // (node[0] with node[1], then node[1] with node[2], then node[2] ...,
         // etc.), so when we're at the end we have `node[N-1]` as the most
         // progressed type.
         let mut last_index_requiring_inference = 0;
         while let Some(next_arg_id) = arg_iter.next() {
             let last_expr_idx = ctx.heap[last_arg_id].get_unique_id_in_definition(); // TODO: @Temp
             let next_expr_idx = ctx.heap[next_arg_id].get_unique_id_in_definition();
             let last_type: *mut _ = &mut self.expr_types[last_expr_idx as usize].expr_type;
             let next_type: *mut _ = &mut self.expr_types[next_expr_idx as usize].expr_type;
         for prev_argument_index in 0..arguments.len() - 1 {
             let next_argument_index = prev_argument_index + 1;
             let res = unsafe {
                 InferenceType::infer_subtrees_for_both_types(last_type, 0, next_type, 0)
             };
             let prev_node_index = arguments[prev_argument_index];
             let next_node_index = arguments[next_argument_index];
             let (prev_progress, next_progress) = self.apply_equal2_constraint(
                 ctx, outer_node_index, prev_node_index, 0, next_node_index, 0
             )?;
             if res == DualInferenceResult::Incompatible {
                 return Err(self.construct_arg_type_error(ctx, expr_id, last_arg_id, next_arg_id));
             if prev_progress {
                 // Previous node is progress, so every type in front of it needs
                 // to be reinferred.
                 progress[prev_argument_index] = true;
                 last_index_requiring_inference = prev_argument_index;
+            }
             if res.modified_lhs() {
                 // We re-inferred something on the left hand side, so everything
                 // up until now should be re-inferred.
                 progress[lhs_arg_idx] = true;
                 last_lhs_progressed = lhs_arg_idx;
             progress[next_argument_index] = next_progress;
+        }
             progress[lhs_arg_idx + 1] = res.modified_rhs();
             last_arg_id = next_arg_id;
             lhs_arg_idx += 1;
+        }
         // Apply inference using the most progressed type (the last one) to the
         // ones that did not obtain this information during the inference
         // process.
         let last_argument_node_index = arguments[arguments.len() - 1];
         let last_argument_type: *mut _ = &mut self.infer_nodes[last_argument_node_index].expr_type;
         // Re-infer everything. Note that we do not need to re-infer the type
         // exactly at `last_lhs_progressed`, but only everything up to it.
         let last_arg_expr_idx = ctx.heap[last_arg_id].get_unique_id_in_definition();
         let last_type: *mut _ = &mut self.expr_types[last_arg_expr_idx as usize].expr_type;
         for arg_idx in 0..last_lhs_progressed {
             let other_arg_expr_idx = ctx.heap[args[arg_idx]].get_unique_id_in_definition();
             let arg_type: *mut _ = &mut self.expr_types[other_arg_expr_idx as usize].expr_type;
         for argument_index in 0..last_index_requiring_inference {
             // We can cheat, we know the LHS is less specific than the right
             // hand side, so:
             let argument_node_index = arguments[argument_index];
             let argument_type = &mut self.infer_nodes[argument_node_index].expr_type;
             unsafe {
                 (*arg_type).replace_subtree(0, &(*last_type).parts);
                 // safety: we're dealing with different vectors, so cannot alias
                 argument_type.replace_subtree(0, &(*last_argument_type).parts);
+            }
-            progress[arg_idx] = true;
+            progress[argument_index] = true;
+        }
         return Ok(());
+    }
     /// Determines the `InferenceType` for the expression based on the
     /// expression parent. Note that if the parent is another expression, we do
     /// not take special action, instead we let parent expressions fix the type
     /// of subexpressions before they have a chance to call this function.
     fn insert_initial_expr_inference_type(
     /// expression parent (this is not done if the parent is a regular 'ol
     /// expression). Expects `parent_index` to be set to the parent of the
     /// inference node that is created here.
     fn insert_initial_inference_node(
         &mut self, ctx: &mut Ctx, expr_id: ExpressionId
-    ) -> Result<(), ParseError> {
+    ) -> Result<InferNodeIndex, ParseError> {
         use ExpressionParent as EP;
         use InferenceTypePart as ITP;
         // Set the initial inference type based on the expression parent.
         let expr = &ctx.heap[expr_id];
         let inference_type = match expr.parent() {
             EP::None =>
                 // Should have been set by linker
                 unreachable!(),
             EP::Memory(_) | EP::ExpressionStmt(_) =>
                 // Determined during type inference
                 InferenceType::new(false, false, vec![ITP::Unknown]),
             EP::Expression(parent_id, idx_in_parent) => {
                 // If we are the test expression of a conditional expression,
                 // then we must resolve to a boolean
                 let is_conditional = if let Expression::Conditional(_) = &ctx.heap[*parent_id] {
                     true
                 } else {
                     false
                 };
                 if is_conditional && *idx_in_parent == 0 {
                     InferenceType::new(false, true, vec![ITP::Bool])
                 } else {
                     InferenceType::new(false, false, vec![ITP::Unknown])
+                }
             },
             EP::If(_) | EP::While(_) =>
                 // Must be a boolean
                 InferenceType::new(false, true, vec![ITP::Bool]),
             EP::Return(_) =>
+            EP::Return(_) => {
                 // Must match the return type of the function
                 if let DefinitionType::Function(func_id) = self.definition_type {
                     debug_assert_eq!(ctx.heap[func_id].return_types.len(), 1);
                     let returned = &ctx.heap[func_id].return_types[0];
                 debug_assert_eq!(self.procedure_kind, ProcedureKind::Function);
                 let returned = &ctx.heap[self.procedure_id].return_type.as_ref().unwrap();
                 self.determine_inference_type_from_parser_type_elements(&returned.elements, true)
                 } else {
                     // Cannot happen: definition always set upon body traversal
                     // and "return" calls in components are illegal.
                     unreachable!();
             },
             EP::New(_) =>
                 // Must be a component call, which we assign a "Void" return
                 // type
                 InferenceType::new(false, true, vec![ITP::Void]),
         };
         let infer_expr = &mut self.expr_types[expr.get_unique_id_in_definition() as usize];
         let needs_extra_data = match expr {
             Expression::Call(_) => true,
             Expression::Literal(expr) => match expr.value {
                 Literal::Enum(_) | Literal::Union(_) | Literal::Struct(_) => true,
                 _ => false,
             },
             Expression::Select(expr) => match expr.kind {
                 SelectKind::StructField(_) => true,
                 SelectKind::TupleMember(_) => false,
             },
             _ => false,
         };
         if infer_expr.expr_id.is_invalid() {
             // Nothing is set yet
             infer_expr.expr_type = inference_type;
             infer_expr.expr_id = expr_id;
             if needs_extra_data {
                 let extra_idx = self.extra_data.len() as i32;
                 self.extra_data.push(ExtraData::default());
                 infer_expr.extra_data_idx = extra_idx;
+            }
         } else {
             // We already have an entry
             debug_assert!(false, "does this ever happen?");
             if let SingleInferenceResult::Incompatible = InferenceType::infer_subtree_for_single_type(
                 &mut infer_expr.expr_type, 0, &inference_type.parts, 0, false
             ) {
                 return Err(self.construct_expr_type_error(ctx, expr_id, expr_id));
+            }
             debug_assert!((infer_expr.extra_data_idx != -1) == needs_extra_data);
+        }
         let infer_index = self.infer_nodes.len() as InferNodeIndex;
         self.infer_nodes.push(InferenceNode {
             expr_type: inference_type,
             expr_id,
             inference_rule: InferenceRule::Noop,
             parent_index: self.parent_index,
             field_index: -1,
             poly_data_index: -1,
             info_type_id: TypeId::new_invalid(),
             info_variant: ExpressionInfoVariant::Generic,
         });
-        Ok(())
+        return Ok(infer_index);
+    }
     fn insert_initial_call_polymorph_data(
         &mut self, ctx: &mut Ctx, call_id: CallExpressionId
     ) {
+    ) -> PolyDataIndex {
         // Note: the polymorph variables may be partially specified and may
         // contain references to the wrapping definition's (i.e. the proctype
         // we are currently visiting) polymorphic arguments.
         //
         // The arguments of the call may refer to polymorphic variables in the
         // definition of the function we're calling, not of the wrapping
         // definition. We insert markers in these inferred types to be able to
         // map them back and forth to the polymorphic arguments of the function
         // we are calling.
         let call = &ctx.heap[call_id];
         let extra_data_idx = self.expr_types[call.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
         debug_assert!(extra_data_idx != -1, "insert initial call polymorph data, no preallocated ExtraData");
         // Handle the polymorphic arguments (if there are any)
         let num_poly_args = call.parser_type.elements[0].variant.num_embedded();
         let mut poly_args = Vec::with_capacity(num_poly_args);
         for embedded_elements in call.parser_type.iter_embedded(0) {
             poly_args.push(self.determine_inference_type_from_parser_type_elements(embedded_elements, true));
+        }
         // Handle the arguments and return types
         let definition = &ctx.heap[call.definition];
         let (parameters, returned) = match definition {
             Definition::Component(definition) => {
         let definition = &ctx.heap[call.procedure];
         debug_assert_eq!(poly_args.len(), definition.poly_vars.len());
                 (&definition.parameters, None)
             },
             Definition::Function(definition) => {
                 debug_assert_eq!(poly_args.len(), definition.poly_vars.len());
                 (&definition.parameters, Some(&definition.return_types))
             },
             Definition::Struct(_) | Definition::Enum(_) | Definition::Union(_) => {
                 unreachable!("insert_initial_call_polymorph data for non-procedure type");
             },
         };
         let mut parameter_types = Vec::with_capacity(parameters.len());
         for parameter_id in parameters.clone().into_iter() { // TODO: @Performance @Now
         let mut parameter_types = Vec::with_capacity(definition.parameters.len());
         let parameter_section = self.var_buffer.start_section_initialized(&definition.parameters);
         for parameter_id in parameter_section.iter_copied() {
             let param = &ctx.heap[parameter_id];
             parameter_types.push(self.determine_inference_type_from_parser_type_elements(&param.parser_type.elements, false));
+        }
         parameter_section.forget();
-        let return_type = match returned {
+        let return_type = match &definition.return_type {
             None => {
                 // Component, so returns a "Void"
                 debug_assert_ne!(definition.kind, ProcedureKind::Function);
                 InferenceType::new(false, true, vec![InferenceTypePart::Void])
             },
             Some(returned) => {
                 debug_assert_eq!(returned.len(), 1); // TODO: @ReturnTypes
                 let returned = &returned[0];
                 debug_assert_eq!(definition.kind, ProcedureKind::Function);
                 self.determine_inference_type_from_parser_type_elements(&returned.elements, false)
+            }
         };
         self.extra_data[extra_data_idx as usize] = ExtraData{
             expr_id: call_id.upcast(),
             definition_id: call.definition,
         let extra_data_idx = self.poly_data.len() as PolyDataIndex;
         self.poly_data.push(PolyData {
             first_rule_application: true,
             definition_id: call.procedure.upcast(),
             poly_vars: poly_args,
             embedded: parameter_types,
             expr_types: PolyDataTypes {
                 associated: parameter_types,
                 returned: return_type
         };
+            }
         });
         return extra_data_idx
+    }
     fn insert_initial_struct_polymorph_data(
         &mut self, ctx: &mut Ctx, lit_id: LiteralExpressionId,
     ) {
+    ) -> PolyDataIndex {
         use InferenceTypePart as ITP;
         let literal = &ctx.heap[lit_id];
         let extra_data_idx = self.expr_types[literal.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
         debug_assert!(extra_data_idx != -1, "initial struct polymorph data, but no preallocated ExtraData");
         let literal = ctx.heap[lit_id].value.as_struct();
         // Handle polymorphic arguments
         let num_embedded = literal.parser_type.elements[0].variant.num_embedded();
         let mut total_num_poly_parts = 0;
         let mut poly_args = Vec::with_capacity(num_embedded);
         for embedded_elements in literal.parser_type.iter_embedded(0) {
             let poly_type = self.determine_inference_type_from_parser_type_elements(embedded_elements, true);
             total_num_poly_parts += poly_type.parts.len();
             poly_args.push(poly_type);
+        }
         // Handle parser types on struct definition
         let defined_type = ctx.types.get_base_definition(&literal.definition).unwrap();
         let struct_type = defined_type.definition.as_struct();
         debug_assert_eq!(poly_args.len(), defined_type.poly_vars.len());
         // Note: programmer is capable of specifying fields in a struct literal
         // in a different order than on the definition. We take the literal-
         // specified order to be leading.
         let mut embedded_types = Vec::with_capacity(struct_type.fields.len());
         for lit_field in literal.fields.iter() {
             let def_field = &struct_type.fields[lit_field.field_idx];
             let inference_type = self.determine_inference_type_from_parser_type_elements(&def_field.parser_type.elements, false);
             embedded_types.push(inference_type);
+        }
         // Return type is the struct type itself, with the appropriate
         // polymorphic variables. So:
         // - 1 part for definition
         // - N_poly_arg marker parts for each polymorphic argument
         // - all the parts for the currently known polymorphic arguments
         let parts_reserved = 1 + poly_args.len() + total_num_poly_parts;
         let mut parts = Vec::with_capacity(parts_reserved);
         parts.push(ITP::Instance(literal.definition, poly_args.len() as u32));
         let mut return_type_done = true;
         for (poly_var_idx, poly_var) in poly_args.iter().enumerate() {
             if !poly_var.is_done { return_type_done = false; }
             parts.push(ITP::Marker(poly_var_idx as u32));
             parts.extend(poly_var.parts.iter().cloned());
+        }
         debug_assert_eq!(parts.len(), parts_reserved);
         let return_type = InferenceType::new(!poly_args.is_empty(), return_type_done, parts);
         self.extra_data[extra_data_idx as usize] = ExtraData{
             expr_id: lit_id.upcast(),
         let extra_data_index = self.poly_data.len() as PolyDataIndex;
         self.poly_data.push(PolyData {
             first_rule_application: true,
             definition_id: literal.definition,
             poly_vars: poly_args,
             embedded: embedded_types,
             expr_types: PolyDataTypes {
                 associated: embedded_types,
                 returned: return_type,
         };
             },
         });
         return extra_data_index
+    }
     /// Inserts the extra polymorphic data struct for enum expressions. These
     /// can never be determined from the enum itself, but may be inferred from
     /// the use of the enum.
     fn insert_initial_enum_polymorph_data(
         &mut self, ctx: &Ctx, lit_id: LiteralExpressionId
     ) {
+    ) -> PolyDataIndex {
         use InferenceTypePart as ITP;
         let literal = &ctx.heap[lit_id];
         let extra_data_idx = self.expr_types[literal.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
         debug_assert!(extra_data_idx != -1, "initial enum polymorph data, but no preallocated ExtraData");
         let literal = ctx.heap[lit_id].value.as_enum();
         // Handle polymorphic arguments to the enum
         let num_poly_args = literal.parser_type.elements[0].variant.num_embedded();
         let mut total_num_poly_parts = 0;
         let mut poly_args = Vec::with_capacity(num_poly_args);
         for embedded_elements in literal.parser_type.iter_embedded(0) {
             let poly_type = self.determine_inference_type_from_parser_type_elements(embedded_elements, true);
             total_num_poly_parts += poly_type.parts.len();
             poly_args.push(poly_type);
+        }
         // Handle enum type itself
         let parts_reserved = 1 + poly_args.len() + total_num_poly_parts;
         let mut parts = Vec::with_capacity(parts_reserved);
         parts.push(ITP::Instance(literal.definition, poly_args.len() as u32));
         let mut enum_type_done = true;
         for (poly_var_idx, poly_var) in poly_args.iter().enumerate() {
             if !poly_var.is_done { enum_type_done = false; }
             parts.push(ITP::Marker(poly_var_idx as u32));
             parts.extend(poly_var.parts.iter().cloned());
+        }
         debug_assert_eq!(parts.len(), parts_reserved);
         let enum_type = InferenceType::new(!poly_args.is_empty(), enum_type_done, parts);
         self.extra_data[extra_data_idx as usize] = ExtraData{
             expr_id: lit_id.upcast(),
         let extra_data_index = self.poly_data.len() as PolyDataIndex;
         self.poly_data.push(PolyData {
             first_rule_application: true,
             definition_id: literal.definition,
             poly_vars: poly_args,
             embedded: Vec::new(),
             expr_types: PolyDataTypes {
                 associated: Vec::new(),
                 returned: enum_type,
         };
             },
         });
         return extra_data_index;
+    }
     /// Inserts the extra polymorphic data struct for unions. The polymorphic
     /// arguments may be partially determined from embedded values in the union.
     fn insert_initial_union_polymorph_data(
         &mut self, ctx: &Ctx, lit_id: LiteralExpressionId
     ) {
+    ) -> PolyDataIndex {
         use InferenceTypePart as ITP;
         let literal = &ctx.heap[lit_id];
         let extra_data_idx = self.expr_types[literal.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
         debug_assert!(extra_data_idx != -1, "initial union polymorph data, but no preallocated ExtraData");
         let literal = ctx.heap[lit_id].value.as_union();
         // Construct the polymorphic variables
         let num_poly_args = literal.parser_type.elements[0].variant.num_embedded();
         let mut total_num_poly_parts = 0;
         let mut poly_args = Vec::with_capacity(num_poly_args);
         for embedded_elements in literal.parser_type.iter_embedded(0) {
             let poly_type = self.determine_inference_type_from_parser_type_elements(embedded_elements, true);
             total_num_poly_parts += poly_type.parts.len();
             poly_args.push(poly_type);
+        }
         // Handle any of the embedded values in the variant, if specified
         let definition_id = literal.definition;
         let type_definition = ctx.types.get_base_definition(&definition_id).unwrap();
         let union_definition = type_definition.definition.as_union();
         debug_assert_eq!(poly_args.len(), type_definition.poly_vars.len());
         let variant_definition = &union_definition.variants[literal.variant_idx];
         debug_assert_eq!(variant_definition.embedded.len(), literal.values.len());
         let mut embedded = Vec::with_capacity(variant_definition.embedded.len());
         for embedded_parser_type in &variant_definition.embedded {
             let inference_type = self.determine_inference_type_from_parser_type_elements(&embedded_parser_type.elements, false);
             embedded.push(inference_type);
+        }
         // Handle the type of the union itself
         let parts_reserved = 1 + poly_args.len() + total_num_poly_parts;
         let mut parts = Vec::with_capacity(parts_reserved);
         parts.push(ITP::Instance(definition_id, poly_args.len() as u32));
         let mut union_type_done = true;
         for (poly_var_idx, poly_var) in poly_args.iter().enumerate() {
             if !poly_var.is_done { union_type_done = false; }
             parts.push(ITP::Marker(poly_var_idx as u32));
             parts.extend(poly_var.parts.iter().cloned());
+        }
         debug_assert_eq!(parts_reserved, parts.len());
         let union_type = InferenceType::new(!poly_args.is_empty(), union_type_done, parts);
         self.extra_data[extra_data_idx as usize] = ExtraData{
             expr_id: lit_id.upcast(),
         let extra_data_index = self.poly_data.len() as isize;
         self.poly_data.push(PolyData {
             first_rule_application: true,
             definition_id: literal.definition,
             poly_vars: poly_args,
             embedded,
             returned: union_type
         };
             expr_types: PolyDataTypes {
                 associated: embedded,
                 returned: union_type,
             },
         });
         return extra_data_index;
+    }
     /// Inserts the extra polymorphic data struct. Assumes that the select
     /// expression's referenced (definition_id, field_idx) has been resolved.
     fn insert_initial_select_polymorph_data(
         &mut self, ctx: &Ctx, select_id: SelectExpressionId, struct_def_id: DefinitionId
     ) {
         &mut self, ctx: &Ctx, node_index: InferNodeIndex, struct_def_id: DefinitionId
     ) -> PolyDataIndex {
         use InferenceTypePart as ITP;
         // Retrieve relevant data
         let expr = &ctx.heap[select_id];
         let expr_type = &self.expr_types[expr.unique_id_in_definition as usize];
         let field_idx = expr_type.field_or_monomorph_idx as usize;
         let extra_data_idx = expr_type.extra_data_idx; // TODO: @Temp
         debug_assert!(extra_data_idx != -1, "initial select polymorph data, but no preallocated ExtraData");
         let definition = ctx.heap[struct_def_id].as_struct();
         let node = &self.infer_nodes[node_index];
         let field_index = node.field_index as usize;
         // Generate initial polyvar types and struct type
         // TODO: @Performance: we can immediately set the polyvars of the subject's struct type
         let num_poly_vars = definition.poly_vars.len();
         let mut poly_vars = Vec::with_capacity(num_poly_vars);
         let struct_parts_reserved = 1 + 2 * num_poly_vars;
         let mut struct_parts = Vec::with_capacity(struct_parts_reserved);
         struct_parts.push(ITP::Instance(struct_def_id, num_poly_vars as u32));
         for poly_idx in 0..num_poly_vars {
             poly_vars.push(InferenceType::new(true, false, vec![
                 ITP::Marker(poly_idx as u32), ITP::Unknown,
             ]));
             struct_parts.push(ITP::Marker(poly_idx as u32));
             struct_parts.push(ITP::Unknown);
+        }
         debug_assert_eq!(struct_parts.len(), struct_parts_reserved);
         // Generate initial field type
         let field_type = self.determine_inference_type_from_parser_type_elements(&definition.fields[field_idx].parser_type.elements, false);
         self.extra_data[extra_data_idx as usize] = ExtraData{
             expr_id: select_id.upcast(),
         let field_type = self.determine_inference_type_from_parser_type_elements(&definition.fields[field_index].parser_type.elements, false);
         let extra_data_index = self.poly_data.len() as PolyDataIndex;
         self.poly_data.push(PolyData {
             first_rule_application: true,
             definition_id: struct_def_id,
             poly_vars,
             embedded: vec![InferenceType::new(num_poly_vars != 0, num_poly_vars == 0, struct_parts)],
             returned: field_type
         };
             expr_types: PolyDataTypes {
                 associated: vec![InferenceType::new(num_poly_vars != 0, num_poly_vars == 0, struct_parts)],
                 returned: field_type,
             },
         });
         return extra_data_index;
+    }
     /// Determines the initial InferenceType from the provided ParserType. This
     /// may be called with two kinds of intentions:
     /// 1. To resolve a ParserType within the body of a function, or on
     ///     polymorphic arguments to calls/instantiations within that body. This
     ///     means that the polymorphic variables are known and can be replaced
     ///     with the monomorph we're instantiating.
     /// 2. To resolve a ParserType on a called function's definition or on
     ///     an instantiated datatype's members. This means that the polymorphic
     ///     arguments inside those ParserTypes refer to the polymorphic
     ///     variables in the called/instantiated type's definition.
     /// In the second case we place InferenceTypePart::Marker instances such
     /// that we can perform type inference on the polymorphic variables.
     fn determine_inference_type_from_parser_type_elements(
         &mut self, elements: &[ParserTypeElement],
         use_definitions_known_poly_args: bool
     ) -> InferenceType {
         use ParserTypeVariant as PTV;
         use InferenceTypePart as ITP;
         let mut infer_type = Vec::with_capacity(elements.len());
         let mut has_inferred = false;
         let mut has_markers = false;
         for element in elements {
             match &element.variant {
                 // Compiler-only types
                 PTV::Void => { infer_type.push(ITP::Void); },
                 PTV::InputOrOutput => { infer_type.push(ITP::PortLike); has_inferred = true },
                 PTV::ArrayLike => { infer_type.push(ITP::ArrayLike); has_inferred = true },
                 PTV::IntegerLike => { infer_type.push(ITP::IntegerLike); has_inferred = true },
                 // Builtins
                 PTV::Message => {
                     // TODO: @types Remove the Message -> Byte hack at some point...
                     infer_type.push(ITP::Message);
                     infer_type.push(ITP::UInt8);
                 },
                 PTV::Bool => { infer_type.push(ITP::Bool); },
                 PTV::UInt8 => { infer_type.push(ITP::UInt8); },
                 PTV::UInt16 => { infer_type.push(ITP::UInt16); },
                 PTV::UInt32 => { infer_type.push(ITP::UInt32); },
                 PTV::UInt64 => { infer_type.push(ITP::UInt64); },
                 PTV::SInt8 => { infer_type.push(ITP::SInt8); },
                 PTV::SInt16 => { infer_type.push(ITP::SInt16); },
                 PTV::SInt32 => { infer_type.push(ITP::SInt32); },
                 PTV::SInt64 => { infer_type.push(ITP::SInt64); },
                 PTV::Character => { infer_type.push(ITP::Character); },
                 PTV::String => {
                     infer_type.push(ITP::String);
                     infer_type.push(ITP::Character);
                 },
                 // Special markers
                 PTV::IntegerLiteral => { unreachable!("integer literal type on variable type"); },
                 PTV::Inferred => {
                     infer_type.push(ITP::Unknown);
                     has_inferred = true;
                 },
                 // With nested types
                 PTV::Array => { infer_type.push(ITP::Array); },
                 PTV::Input => { infer_type.push(ITP::Input); },
                 PTV::Output => { infer_type.push(ITP::Output); },
                 PTV::Tuple(num_embedded) => { infer_type.push(ITP::Tuple(*num_embedded)); },
                 PTV::PolymorphicArgument(belongs_to_definition, poly_arg_idx) => {
                     let poly_arg_idx = *poly_arg_idx;
                     if use_definitions_known_poly_args {
                         // Refers to polymorphic argument on procedure we're currently processing.
                         // This argument is already known.
-                        debug_assert_eq!(*belongs_to_definition, self.definition_type.definition_id());
+                        debug_assert_eq!(*belongs_to_definition, self.procedure_id.upcast());
                         debug_assert!((poly_arg_idx as usize) < self.poly_vars.len());
                         Self::determine_inference_type_from_concrete_type(
                             &mut infer_type, &self.poly_vars[poly_arg_idx as usize].parts
                         );
                     } else {
                         // Polymorphic argument has to be inferred
                         has_markers = true;
                         has_inferred = true;
                         infer_type.push(ITP::Marker(poly_arg_idx));
                         infer_type.push(ITP::Unknown)
+                    }
                 },
                 PTV::Definition(definition_id, num_embedded) => {
                     infer_type.push(ITP::Instance(*definition_id, *num_embedded));
+                }
+            }
+        }
         InferenceType::new(has_markers, !has_inferred, infer_type)
+    }
     /// Determines the inference type from an already concrete type. Applies the
     /// various type "hacks" inside the type inferencer.
     fn determine_inference_type_from_concrete_type(parser_type: &mut Vec<InferenceTypePart>, concrete_type: &[ConcreteTypePart]) {
         use InferenceTypePart as ITP;
         use ConcreteTypePart as CTP;
         for concrete_part in concrete_type {
             match concrete_part {
                 CTP::Void => parser_type.push(ITP::Void),
                 CTP::Message => {
                     parser_type.push(ITP::Message);
                     parser_type.push(ITP::UInt8)
                 },
                 CTP::Bool => parser_type.push(ITP::Bool),
                 CTP::UInt8 => parser_type.push(ITP::UInt8),
                 CTP::UInt16 => parser_type.push(ITP::UInt16),
                 CTP::UInt32 => parser_type.push(ITP::UInt32),
                 CTP::UInt64 => parser_type.push(ITP::UInt64),
                 CTP::SInt8 => parser_type.push(ITP::SInt8),
                 CTP::SInt16 => parser_type.push(ITP::SInt16),
                 CTP::SInt32 => parser_type.push(ITP::SInt32),
                 CTP::SInt64 => parser_type.push(ITP::SInt64),
                 CTP::Character => parser_type.push(ITP::Character),
                 CTP::String => {
                     parser_type.push(ITP::String);
                     parser_type.push(ITP::Character)
                 },
                 CTP::Array => parser_type.push(ITP::Array),
                 CTP::Slice => parser_type.push(ITP::Slice),
                 CTP::Input => parser_type.push(ITP::Input),
                 CTP::Output => parser_type.push(ITP::Output),
                 CTP::Pointer => unreachable!("pointer type during concrete to inference type conversion"),
                 CTP::Tuple(num) => parser_type.push(ITP::Tuple(*num)),
                 CTP::Instance(id, num) => parser_type.push(ITP::Instance(*id, *num)),
                 CTP::Function(_, _) => unreachable!("function type during concrete to inference type conversion"),
                 CTP::Component(_, _) => unreachable!("component type during concrete to inference type conversion"),
+            }
+        }
+    }
     /// Construct an error when an expression's type does not match. This
     /// happens if we infer the expression type from its arguments (e.g. the
     /// expression type of an addition operator is the type of the arguments)
     /// But the expression type was already set due to our parent (e.g. an
     /// "if statement" or a "logical not" always expecting a boolean)
     fn construct_expr_type_error(
-        &self, ctx: &Ctx, expr_id: ExpressionId, arg_id: ExpressionId
+        &self, ctx: &Ctx, expr_index: InferNodeIndex, arg_index: InferNodeIndex
     ) -> ParseError {
         // TODO: Expand and provide more meaningful information for humans
         let expr = &ctx.heap[expr_id];
         let arg_expr = &ctx.heap[arg_id];
         let expr_idx = expr.get_unique_id_in_definition();
         let arg_expr_idx = arg_expr.get_unique_id_in_definition();
         let expr_type = &self.expr_types[expr_idx as usize].expr_type;
         let arg_type = &self.expr_types[arg_expr_idx as usize].expr_type;
         let expr_node = &self.infer_nodes[expr_index];
         let arg_node = &self.infer_nodes[arg_index];
         let expr = &ctx.heap[expr_node.expr_id];
         let arg = &ctx.heap[arg_node.expr_id];
         return ParseError::new_error_at_span(
             &ctx.module().source, expr.operation_span(), format!(
                 "incompatible types: this expression expected a '{}'",
                 expr_type.display_name(&ctx.heap)
+                expr_node.expr_type.display_name(&ctx.heap)
+            )
         ).with_info_at_span(
-            &ctx.module().source, arg_expr.full_span(), format!(
+            &ctx.module().source, arg.full_span(), format!(
                 "but this expression yields a '{}'",
-                arg_type.display_name(&ctx.heap)
+                arg_node.expr_type.display_name(&ctx.heap)
+            )
+        )
+    }
     fn construct_arg_type_error(
         &self, ctx: &Ctx, expr_id: ExpressionId,
         arg1_id: ExpressionId, arg2_id: ExpressionId
         &self, ctx: &Ctx, expr_index: InferNodeIndex,
         arg1_index: InferNodeIndex, arg2_index: InferNodeIndex
     ) -> ParseError {
         let expr = &ctx.heap[expr_id];
         let arg1 = &ctx.heap[arg1_id];
         let arg2 = &ctx.heap[arg2_id];
         let arg1_node = &self.infer_nodes[arg1_index];
         let arg2_node = &self.infer_nodes[arg2_index];
         let arg1_idx = arg1.get_unique_id_in_definition();
         let arg1_type = &self.expr_types[arg1_idx as usize].expr_type;
         let arg2_idx = arg2.get_unique_id_in_definition();
         let arg2_type = &self.expr_types[arg2_idx as usize].expr_type;
         let expr_id = self.infer_nodes[expr_index].expr_id;
         let expr = &ctx.heap[expr_id];
         let arg1 = &ctx.heap[arg1_node.expr_id];
         let arg2 = &ctx.heap[arg2_node.expr_id];
         return ParseError::new_error_str_at_span(
             &ctx.module().source, expr.operation_span(),
             "incompatible types: cannot apply this expression"
         ).with_info_at_span(
             &ctx.module().source, arg1.full_span(), format!(
                 "Because this expression has type '{}'",
-                arg1_type.display_name(&ctx.heap)
+                arg1_node.expr_type.display_name(&ctx.heap)
+            )
         ).with_info_at_span(
             &ctx.module().source, arg2.full_span(), format!(
                 "But this expression has type '{}'",
-                arg2_type.display_name(&ctx.heap)
+                arg2_node.expr_type.display_name(&ctx.heap)
+            )
+        )
+    }
     fn construct_template_type_error(
-        &self, ctx: &Ctx, expr_id: ExpressionId, template: &[InferenceTypePart]
+        &self, ctx: &Ctx, node_index: InferNodeIndex, template: &[InferenceTypePart]
     ) -> ParseError {
         let expr = &ctx.heap[expr_id];
         let expr_idx = expr.get_unique_id_in_definition();
         let expr_type = &self.expr_types[expr_idx as usize].expr_type;
         let node = &self.infer_nodes[node_index];
         let expr = &ctx.heap[node.expr_id];
         let expr_type = &node.expr_type;
         return ParseError::new_error_at_span(
             &ctx.module().source, expr.full_span(), format!(
                 "incompatible types: got a '{}' but expected a '{}'",
                 expr_type.display_name(&ctx.heap),
                 InferenceType::partial_display_name(&ctx.heap, template)
+            )
+        )
+    }
     fn construct_variable_type_error(
         &self, ctx: &Ctx, node_index: InferNodeIndex,
     ) -> ParseError {
         let node = &self.infer_nodes[node_index];
         let rule = node.inference_rule.as_variable_expr();
         let var_data = &self.var_data[rule.var_data_index];
         let var_decl = &ctx.heap[var_data.var_id];
         let var_expr = &ctx.heap[node.expr_id];
         return ParseError::new_error_at_span(
             &ctx.module().source, var_decl.identifier.span, format!(
                 "conflicting types for this variable, previously assigned the type '{}'",
                 var_data.var_type.display_name(&ctx.heap)
+            )
         ).with_info_at_span(
             &ctx.module().source, var_expr.full_span(), format!(
                 "but inferred to have incompatible type '{}' here",
                 node.expr_type.display_name(&ctx.heap)
+            )
         );
+    }
     /// Constructs a human interpretable error in the case that type inference
     /// on a polymorphic variable to a function call or literal construction
     /// failed. This may only be caused by a pair of inference types (which may
     /// come from arguments or the return type) having two different inferred
     /// values for that polymorphic variable.
     ///
     /// So we find this pair and construct the error using it.
     ///
     /// We assume that the expression is a function call or a struct literal,
     /// and that an actual error has occurred.
     fn construct_poly_arg_error(
-        ctx: &Ctx, poly_data: &ExtraData, expr_id: ExpressionId
+        ctx: &Ctx, poly_data: &PolyData, expr_id: ExpressionId
     ) -> ParseError {
         // Helper function to check for polymorph mismatch between two inference
         // types.
         fn has_poly_mismatch<'a>(type_a: &'a InferenceType, type_b: &'a InferenceType) -> Option<(u32, &'a [InferenceTypePart], &'a [InferenceTypePart])> {
             if !type_a.has_marker || !type_b.has_marker {
                 return None
+            }
             for (marker_a, section_a) in type_a.marker_iter() {
                 for (marker_b, section_b) in type_b.marker_iter() {
                     if marker_a != marker_b {
                         // Not the same polymorphic variable
                         continue;
+                    }
                     if !InferenceType::check_subtrees(section_a, 0, section_b, 0) {
                         // Not compatible
                         return Some((marker_a, section_a, section_b))
+                    }
+                }
+            }
             None
+        }
         // Helper function to check for polymorph mismatch between an inference
         // type and the polymorphic variables in the poly_data struct.
         fn has_explicit_poly_mismatch<'a>(
             poly_vars: &'a [InferenceType], arg: &'a InferenceType
         ) -> Option<(u32, &'a [InferenceTypePart], &'a [InferenceTypePart])> {
             for (marker, section) in arg.marker_iter() {
                 debug_assert!((marker as usize) < poly_vars.len());
                 let poly_section = &poly_vars[marker as usize].parts;
                 if !InferenceType::check_subtrees(poly_section, 0, section, 0) {
                     return Some((marker, poly_section, section))
+                }
+            }
             None
+        }
         // Helpers function to retrieve polyvar name and definition name
         fn get_poly_var_and_definition_name<'a>(ctx: &'a Ctx, poly_var_idx: u32, definition_id: DefinitionId) -> (&'a str, &'a str) {
             let definition = &ctx.heap[definition_id];
             let poly_var = definition.poly_vars()[poly_var_idx as usize].value.as_str();
             let func_name = definition.identifier().value.as_str();
             (poly_var, func_name)
+        }
         // Helper function to construct initial error
-        fn construct_main_error(ctx: &Ctx, poly_data: &ExtraData, poly_var_idx: u32, expr: &Expression) -> ParseError {
+        fn construct_main_error(ctx: &Ctx, poly_data: &PolyData, poly_var_idx: u32, expr: &Expression) -> ParseError {
             match expr {
                 Expression::Call(expr) => {
                     let (poly_var, func_name) = get_poly_var_and_definition_name(ctx, poly_var_idx, poly_data.definition_id);
                     return ParseError::new_error_at_span(
                         &ctx.module().source, expr.func_span, format!(
                             "Conflicting type for polymorphic variable '{}' of '{}'",
                             poly_var, func_name
+                        )
+                    )
                 },
                 Expression::Literal(expr) => {
                     let (poly_var, type_name) = get_poly_var_and_definition_name(ctx, poly_var_idx, poly_data.definition_id);
                     return ParseError::new_error_at_span(
                         &ctx.module().source, expr.span, format!(
                             "Conflicting type for polymorphic variable '{}' of instantiation of '{}'",
                             poly_var, type_name
+                        )
                     );
                 },
                 Expression::Select(expr) => {
                     let (poly_var, struct_name) = get_poly_var_and_definition_name(ctx, poly_var_idx, poly_data.definition_id);
                     let field_name = match &expr.kind {
                         SelectKind::StructField(v) => v,
                         SelectKind::TupleMember(_) => unreachable!(), // because we're constructing a polymorph error, and tuple access does not deal with polymorphs
                     };
                     return ParseError::new_error_at_span(
                         &ctx.module().source, expr.full_span, format!(
                             "Conflicting type for polymorphic variable '{}' while accessing field '{}' of '{}'",
                             poly_var, field_name.value.as_str(), struct_name
+                        )
+                    )
+                }
                 _ => unreachable!("called construct_poly_arg_error without an expected expression, got: {:?}", expr)
+            }
+        }
         // Actual checking
         let expr = &ctx.heap[expr_id];
         let (expr_args, expr_return_name) = match expr {
             Expression::Call(expr) =>
+                (
                     expr.arguments.clone(),
                     "return type"
                 ),
             Expression::Literal(expr) => {
                 let expressions = match &expr.value {
                     Literal::Struct(v) => v.fields.iter()
                         .map(|f| f.value)
                         .collect(),
                     Literal::Enum(_) => Vec::new(),
                     Literal::Union(v) => v.values.clone(),
                     _ => unreachable!()
                 };
                 ( expressions, "literal" )
             },
             Expression::Select(expr) =>
                 // Select expression uses the polymorphic variables of the
                 // struct it is accessing, so get the subject expression.
+                (
                     vec![expr.subject],
                     "selected field"
                 ),
             _ => unreachable!(),
         };
         // - check return type with itself
         if let Some((poly_idx, section_a, section_b)) = has_poly_mismatch(
             &poly_data.returned, &poly_data.returned
+            &poly_data.expr_types.returned, &poly_data.expr_types.returned
         ) {
             return construct_main_error(ctx, poly_data, poly_idx, expr)
                 .with_info_at_span(
                     &ctx.module().source, expr.full_span(), format!(
                         "The {} inferred the conflicting types '{}' and '{}'",
                         expr_return_name,
                         InferenceType::partial_display_name(&ctx.heap, section_a),
                         InferenceType::partial_display_name(&ctx.heap, section_b)
+                    )
                 );
+        }
         // - check arguments with each other argument and with return type
         for (arg_a_idx, arg_a) in poly_data.embedded.iter().enumerate() {
             for (arg_b_idx, arg_b) in poly_data.embedded.iter().enumerate() {
         for (arg_a_idx, arg_a) in poly_data.expr_types.associated.iter().enumerate() {
             for (arg_b_idx, arg_b) in poly_data.expr_types.associated.iter().enumerate() {
                 if arg_b_idx > arg_a_idx {
                     break;
+                }
                 if let Some((poly_idx, section_a, section_b)) = has_poly_mismatch(&arg_a, &arg_b) {
                     let error = construct_main_error(ctx, poly_data, poly_idx, expr);
                     if arg_a_idx == arg_b_idx {
                         // Same argument
                         let arg = &ctx.heap[expr_args[arg_a_idx]];
                         return error.with_info_at_span(
                             &ctx.module().source, arg.full_span(), format!(
                                 "This argument inferred the conflicting types '{}' and '{}'",
                                 InferenceType::partial_display_name(&ctx.heap, section_a),
                                 InferenceType::partial_display_name(&ctx.heap, section_b)
+                            )
                         );
                     } else {
                         let arg_a = &ctx.heap[expr_args[arg_a_idx]];
                         let arg_b = &ctx.heap[expr_args[arg_b_idx]];
                         return error.with_info_at_span(
                             &ctx.module().source, arg_a.full_span(), format!(
                                 "This argument inferred it to '{}'",
                                 InferenceType::partial_display_name(&ctx.heap, section_a)
+                            )
                         ).with_info_at_span(
                             &ctx.module().source, arg_b.full_span(), format!(
                                 "While this argument inferred it to '{}'",
                                 InferenceType::partial_display_name(&ctx.heap, section_b)
+                            )
+                        )
+                    }
+                }
+            }
             // Check with return type
             if let Some((poly_idx, section_arg, section_ret)) = has_poly_mismatch(arg_a, &poly_data.returned) {
+            if let Some((poly_idx, section_arg, section_ret)) = has_poly_mismatch(arg_a, &poly_data.expr_types.returned) {
                 let arg = &ctx.heap[expr_args[arg_a_idx]];
                 return construct_main_error(ctx, poly_data, poly_idx, expr)
                     .with_info_at_span(
                         &ctx.module().source, arg.full_span(), format!(
                             "This argument inferred it to '{}'",
                             InferenceType::partial_display_name(&ctx.heap, section_arg)
+                        )
+                    )
                     .with_info_at_span(
                         &ctx.module().source, expr.full_span(), format!(
                             "While the {} inferred it to '{}'",
                             expr_return_name,
                             InferenceType::partial_display_name(&ctx.heap, section_ret)
+                        )
                     );
+            }
+        }
         // Now check against the explicitly specified polymorphic variables (if
         // any).
-        for (arg_idx, arg) in poly_data.embedded.iter().enumerate() {
+        for (arg_idx, arg) in poly_data.expr_types.associated.iter().enumerate() {
             if let Some((poly_idx, poly_section, arg_section)) = has_explicit_poly_mismatch(&poly_data.poly_vars, arg) {
                 let arg = &ctx.heap[expr_args[arg_idx]];
                 return construct_main_error(ctx, poly_data, poly_idx, expr)
                     .with_info_at_span(
                         &ctx.module().source, arg.full_span(), format!(
                             "The polymorphic variable has type '{}' (which might have been partially inferred) while the argument inferred it to '{}'",
                             InferenceType::partial_display_name(&ctx.heap, poly_section),
                             InferenceType::partial_display_name(&ctx.heap, arg_section)
+                        )
                     );
+            }
+        }
         if let Some((poly_idx, poly_section, ret_section)) = has_explicit_poly_mismatch(&poly_data.poly_vars, &poly_data.returned) {
+        if let Some((poly_idx, poly_section, ret_section)) = has_explicit_poly_mismatch(&poly_data.poly_vars, &poly_data.expr_types.returned) {
             return construct_main_error(ctx, poly_data, poly_idx, expr)
                 .with_info_at_span(
                     &ctx.module().source, expr.full_span(), format!(
                         "The polymorphic variable has type '{}' (which might have been partially inferred) while the {} inferred it to '{}'",
                         InferenceType::partial_display_name(&ctx.heap, poly_section),
                         expr_return_name,
                         InferenceType::partial_display_name(&ctx.heap, ret_section)
+                    )
+                )
+        }
         unreachable!("construct_poly_arg_error without actual error found?")
+    }
+}
 fn get_tuple_size_from_inference_type(inference_type: &InferenceType) -> Result<Option<u32>, ()> {
     for part in &inference_type.parts {
         if part.is_marker() { continue; }
         if !part.is_concrete() { break; }
         if let InferenceTypePart::Tuple(size) = part {
             return Ok(Some(*size));
         } else {
             return Err(()); // not a tuple!
+        }
+    }
     return Ok(None);
+}
 #[cfg(test)]
 mod tests {
     use super::*;
     use crate::protocol::arena::Id;
     use InferenceTypePart as ITP;
     use InferenceType as IT;
     #[test]
     fn test_single_part_inference() {
         // lhs argument inferred from rhs
         let pairs = [
             (ITP::NumberLike, ITP::UInt8),
             (ITP::IntegerLike, ITP::SInt32),
             (ITP::Unknown, ITP::UInt64),
             (ITP::Unknown, ITP::Bool)
         ];
         for (lhs, rhs) in pairs.iter() {
             // Using infer-both
             let mut lhs_type = IT::new(false, false, vec![lhs.clone()]);
             let mut rhs_type = IT::new(false, true, vec![rhs.clone()]);
             let result = unsafe{ IT::infer_subtrees_for_both_types(
                 &mut lhs_type, 0, &mut rhs_type, 0
             ) };
             assert_eq!(DualInferenceResult::First, result);
             assert_eq!(lhs_type.parts, rhs_type.parts);
             // Using infer-single
             let mut lhs_type = IT::new(false, false, vec![lhs.clone()]);
             let rhs_type = IT::new(false, true, vec![rhs.clone()]);
             let result = IT::infer_subtree_for_single_type(
                 &mut lhs_type, 0, &rhs_type.parts, 0, false
             );
             assert_eq!(SingleInferenceResult::Modified, result);
             assert_eq!(lhs_type.parts, rhs_type.parts);
+        }
+    }
     #[test]
     fn test_multi_part_inference() {
         let pairs = [
             (vec![ITP::ArrayLike, ITP::NumberLike], vec![ITP::Slice, ITP::SInt8]),
             (vec![ITP::Unknown], vec![ITP::Input, ITP::Array, ITP::String, ITP::Character]),
             (vec![ITP::PortLike, ITP::SInt32], vec![ITP::Input, ITP::SInt32]),
             (vec![ITP::Unknown], vec![ITP::Output, ITP::SInt32]),
+            (
                 vec![ITP::Instance(Id::new(0), 2), ITP::Input, ITP::Unknown, ITP::Output, ITP::Unknown],
                 vec![ITP::Instance(Id::new(0), 2), ITP::Input, ITP::Array, ITP::SInt32, ITP::Output, ITP::SInt32]
+            )
         ];
         for (lhs, rhs) in pairs.iter() {
             let mut lhs_type = IT::new(false, false, lhs.clone());
             let mut rhs_type = IT::new(false, true, rhs.clone());
             let result = unsafe{ IT::infer_subtrees_for_both_types(
                 &mut lhs_type, 0, &mut rhs_type, 0
             ) };
             assert_eq!(DualInferenceResult::First, result);
             assert_eq!(lhs_type.parts, rhs_type.parts);
             let mut lhs_type = IT::new(false, false, lhs.clone());
             let rhs_type = IT::new(false, true, rhs.clone());
             let result = IT::infer_subtree_for_single_type(
                 &mut lhs_type, 0, &rhs_type.parts, 0, false
             );
             assert_eq!(SingleInferenceResult::Modified, result);
             assert_eq!(lhs_type.parts, rhs_type.parts)
+        }
+    }
+}
@@ \ No newline at end of file @@

src/protocol/parser/pass_validation_linking.rs

➞

Show inline comments

 /*
  * pass_validation_linking.rs
+ *
  * The pass that will validate properties of the AST statements (one is not
  * allowed to nest synchronous statements, instantiating components occurs in
  * the right places, etc.) and expressions (assignments may not occur in
  * arbitrary expressions).
+ *
  * Furthermore, this pass will also perform "linking", in the sense of: some AST
  * nodes have something to do with one another, so we link them up in this pass
  * (e.g. setting the parents of expressions, linking the control flow statements
  * like `continue` and `break` up to the respective loop statement, etc.).
+ *
  * There are several "confusing" parts about this pass:
+ *
  * Setting expression parents: this is the simplest one. The pass struct acts
  * like a little state machine. When visiting an expression it will set the
  * "parent expression" field of the pass to itself, then visit its child. The
  * child will look at this "parent expression" field to determine its parent.
+ *
  * Setting the `next` statement: the AST is a tree, but during execution we walk
  * a linear path through all statements. So where appropriate a statement may
  * set the "previous statement" field of the pass to itself. When visiting the
  * subsequent statement it will check this "previous statement", and if set, it
  * will link this previous statement up to itself. Not every statement has a
  * previous statement. Hence there are two patterns that occur: assigning the
  * `next` value, then clearing the "previous statement" field. And assigning the
  * `next` value, and then putting the current statement's ID in the "previous
  * statement" field. Because it is so common, this file contain two macros that
  * perform that operation.
+ *
  * To make storing types for polymorphic procedures simpler and more efficient,
  * we assign to each expression in the procedure a unique ID. This is what the
  * "next expression index" field achieves. Each expression simply takes the
  * current value, and then increments this counter.
  */
 use crate::collections::{ScopedBuffer};
 use crate::protocol::ast::*;
 use crate::protocol::input_source::*;
 use crate::protocol::parser::symbol_table::*;
 use crate::protocol::parser::type_table::*;
 use super::visitor::{
     BUFFER_INIT_CAPACITY,
     BUFFER_INIT_CAP_SMALL,
     BUFFER_INIT_CAP_LARGE,
     Ctx,
     Visitor,
     VisitorResult
 };
 use crate::protocol::parser::ModuleCompilationPhase;
 #[derive(PartialEq, Eq)]
 enum DefinitionType {
     Primitive(ComponentDefinitionId),
     Composite(ComponentDefinitionId),
     Function(FunctionDefinitionId)
+}
 impl DefinitionType {
     fn is_primitive(&self) -> bool { if let Self::Primitive(_) = self { true } else { false } }
     fn is_composite(&self) -> bool { if let Self::Composite(_) = self { true } else { false } }
     fn is_function(&self) -> bool { if let Self::Function(_) = self { true } else { false } }
     fn definition_id(&self) -> DefinitionId {
         match self {
             DefinitionType::Primitive(v) => v.upcast(),
             DefinitionType::Composite(v) => v.upcast(),
             DefinitionType::Function(v) => v.upcast(),
+        }
+    }
+}
 struct ControlFlowStatement {
     in_sync: SynchronousStatementId,
     in_while: WhileStatementId,
-    in_scope: Scope,
+    in_scope: ScopeId,
     statement: StatementId, // of 'break', 'continue' or 'goto'
+}
 /// This particular visitor will go through the entire AST in a recursive manner
 /// and check if all statements and expressions are legal (e.g. no "return"
 /// statements in component definitions), and will link certain AST nodes to
 /// their appropriate targets (e.g. goto statements, or function calls).
 ///
 /// This visitor will not perform control-flow analysis (e.g. making sure that
 /// each function actually returns) and will also not perform type checking. So
 /// the linking of function calls and component instantiations will be checked
 /// and linked to the appropriate definitions, but the return types and/or
 /// arguments will not be checked for validity.
 ///
 /// The main idea is, because we're visiting nodes in a tree, to do as much as
 /// we can while we have the memory in cache.
 pub(crate) struct PassValidationLinking {
     // Traversal state, all valid IDs if inside a certain AST element. Otherwise
     // `id.is_invalid()` returns true.
     in_sync: SynchronousStatementId,
     in_while: WhileStatementId, // to resolve labeled continue/break
     in_select_guard: SelectStatementId, // for detection/rejection of builtin calls
     in_select_arm: u32,
     in_test_expr: StatementId, // wrapping if/while stmt id
     in_binding_expr: BindingExpressionId, // to resolve variable expressions
     in_binding_expr_lhs: bool,
     // Traversal state, current scope (which can be used to find the parent
     // scope) and the definition variant we are considering.
     cur_scope: Scope,
     def_type: DefinitionType,
     cur_scope: ScopeId,
     proc_id: ProcedureDefinitionId,
     proc_kind: ProcedureKind,
     // "Trailing" traversal state, set be child/prev stmt/expr used by next one
     prev_stmt: StatementId,
     expr_parent: ExpressionParent,
     // Set by parent to indicate that child expression must be assignable. The
     // child will throw an error if it is not assignable. The stored span is
     // used for the error's position
     must_be_assignable: Option<InputSpan>,
     // Keeping track of relative positions and unique IDs.
     relative_pos_in_block: i32, // of statements: to determine when variables are visible
     next_expr_index: i32, // to arrive at a unique ID for all expressions within a definition
     relative_pos_in_parent: i32, // of statements: to determine when variables are visible
     // Control flow statements that require label resolving
     control_flow_stmts: Vec<ControlFlowStatement>,
     // Various temporary buffers for traversal. Essentially working around
     // Rust's borrowing rules since it cannot understand we're modifying AST
     // members but not the AST container.
     variable_buffer: ScopedBuffer<VariableId>,
     definition_buffer: ScopedBuffer<DefinitionId>,
     statement_buffer: ScopedBuffer<StatementId>,
     expression_buffer: ScopedBuffer<ExpressionId>,
     scope_buffer: ScopedBuffer<ScopeId>,
+}
 impl PassValidationLinking {
     pub(crate) fn new() -> Self {
         Self{
             in_sync: SynchronousStatementId::new_invalid(),
             in_while: WhileStatementId::new_invalid(),
             in_select_guard: SelectStatementId::new_invalid(),
             in_select_arm: 0,
             in_test_expr: StatementId::new_invalid(),
             in_binding_expr: BindingExpressionId::new_invalid(),
             in_binding_expr_lhs: false,
-            cur_scope: Scope::new_invalid(),
+            cur_scope: ScopeId::new_invalid(),
             prev_stmt: StatementId::new_invalid(),
             expr_parent: ExpressionParent::None,
             def_type: DefinitionType::Function(FunctionDefinitionId::new_invalid()),
             proc_id: ProcedureDefinitionId::new_invalid(),
             proc_kind: ProcedureKind::Function,
             must_be_assignable: None,
             relative_pos_in_block: 0,
             next_expr_index: 0,
             control_flow_stmts: Vec::with_capacity(32),
             variable_buffer: ScopedBuffer::with_capacity(128),
             definition_buffer: ScopedBuffer::with_capacity(128),
             statement_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAPACITY),
             expression_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAPACITY),
             relative_pos_in_parent: 0,
             control_flow_stmts: Vec::with_capacity(BUFFER_INIT_CAP_SMALL),
             variable_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             definition_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             statement_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
             expression_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
             scope_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
+        }
+    }
     fn reset_state(&mut self) {
         self.in_sync = SynchronousStatementId::new_invalid();
         self.in_while = WhileStatementId::new_invalid();
         self.in_select_guard = SelectStatementId::new_invalid();
         self.in_test_expr = StatementId::new_invalid();
         self.in_binding_expr = BindingExpressionId::new_invalid();
         self.in_binding_expr_lhs = false;
         self.cur_scope = Scope::new_invalid();
         self.def_type = DefinitionType::Function(FunctionDefinitionId::new_invalid());
         self.cur_scope = ScopeId::new_invalid();
         self.proc_id = ProcedureDefinitionId::new_invalid();
         self.proc_kind = ProcedureKind::Function;
         self.prev_stmt = StatementId::new_invalid();
         self.expr_parent = ExpressionParent::None;
         self.must_be_assignable = None;
         self.relative_pos_in_block = 0;
         self.next_expr_index = 0;
         self.relative_pos_in_parent = 0;
         self.control_flow_stmts.clear();
+    }
+}
 macro_rules! assign_then_erase_next_stmt {
     ($self:ident, $ctx:ident, $stmt_id:expr) => {
         if !$self.prev_stmt.is_invalid() {
             $ctx.heap[$self.prev_stmt].link_next($stmt_id);
             $self.prev_stmt = StatementId::new_invalid();
+        }
+    }
+}
 macro_rules! assign_and_replace_next_stmt {
     ($self:ident, $ctx:ident, $stmt_id:expr) => {
         if !$self.prev_stmt.is_invalid() {
             $ctx.heap[$self.prev_stmt].link_next($stmt_id);
+        }
         $self.prev_stmt = $stmt_id;
+    }
+}
 impl Visitor for PassValidationLinking {
     fn visit_module(&mut self, ctx: &mut Ctx) -> VisitorResult {
         debug_assert_eq!(ctx.module().phase, ModuleCompilationPhase::TypesAddedToTable);
         let root = &ctx.heap[ctx.module().root_id];
         let section = self.definition_buffer.start_section_initialized(&root.definitions);
         for definition_id in section.iter_copied() {
             self.visit_definition(ctx, definition_id)?;
+        }
         section.forget();
         ctx.module_mut().phase = ModuleCompilationPhase::ValidatedAndLinked;
         Ok(())
+    }
     //--------------------------------------------------------------------------
     // Definition visitors
     //--------------------------------------------------------------------------
-    fn visit_component_definition(&mut self, ctx: &mut Ctx, id: ComponentDefinitionId) -> VisitorResult {
+    fn visit_procedure_definition(&mut self, ctx: &mut Ctx, id: ProcedureDefinitionId) -> VisitorResult {
         self.reset_state();
         self.def_type = match &ctx.heap[id].variant {
             ComponentVariant::Primitive => DefinitionType::Primitive(id),
             ComponentVariant::Composite => DefinitionType::Composite(id),
         };
         self.cur_scope = Scope::Definition(id.upcast());
         self.expr_parent = ExpressionParent::None;
         // Visit parameters and assign a unique scope ID
         let definition = &ctx.heap[id];
         let body_id = definition.body;
         let section = self.variable_buffer.start_section_initialized(&definition.parameters);
         for variable_idx in 0..section.len() {
             let variable_id = section[variable_idx];
             let variable = &mut ctx.heap[variable_id];
             variable.unique_id_in_scope = variable_idx as i32;
+        }
         section.forget();
         // Visit statements in component body
         self.visit_block_stmt(ctx, body_id)?;
         // Assign total number of expressions and assign an in-block unique ID
         // to each of the locals in the procedure.
         ctx.heap[id].num_expressions_in_body = self.next_expr_index;
         self.visit_definition_and_assign_local_ids(ctx, id.upcast());
         self.resolve_pending_control_flow_targets(ctx)?;
         Ok(())
+    }
     fn visit_function_definition(&mut self, ctx: &mut Ctx, id: FunctionDefinitionId) -> VisitorResult {
         self.reset_state();
         // Set internal statement indices
         self.def_type = DefinitionType::Function(id);
         self.cur_scope = Scope::Definition(id.upcast());
         self.proc_id = id;
         self.proc_kind = definition.kind;
         self.expr_parent = ExpressionParent::None;
         // Visit parameters and assign a unique scope ID
         // Visit parameters
         let scope_id = definition.scope;
         let old_scope = self.push_scope(ctx, true, scope_id);
         let definition = &ctx.heap[id];
         let body_id = definition.body;
         let section = self.variable_buffer.start_section_initialized(&definition.parameters);
         for variable_idx in 0..section.len() {
             let variable_id = section[variable_idx];
             let variable = &mut ctx.heap[variable_id];
             variable.unique_id_in_scope = variable_idx as i32;
             self.checked_at_single_scope_add_local(ctx, self.cur_scope, -1, variable_id)?;
+        }
         section.forget();
         // Visit statements in function body
         self.visit_block_stmt(ctx, body_id)?;
         self.pop_scope(old_scope);
         // Assign total number of expressions and assign an in-block unique ID
         // to each of the locals in the procedure.
         ctx.heap[id].num_expressions_in_body = self.next_expr_index;
         self.visit_definition_and_assign_local_ids(ctx, id.upcast());
         self.resolve_pending_control_flow_targets(ctx)?;
         Ok(())
+    }
     //--------------------------------------------------------------------------
     // Statement visitors
     //--------------------------------------------------------------------------
     fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
         let old_scope = self.push_statement_scope(ctx, Scope::Regular(id));
         // Set end of block
         // Get end of block
         let block_stmt = &ctx.heap[id];
         let end_block_id = block_stmt.end_block;
         // Copy statement IDs into buffer
         let scope_id = block_stmt.scope;
         // Traverse statements in block
         let statement_section = self.statement_buffer.start_section_initialized(&block_stmt.statements);
         let old_scope = self.push_scope(ctx, false, scope_id);
         assign_and_replace_next_stmt!(self, ctx, id.upcast());
         for stmt_idx in 0..statement_section.len() {
-            self.relative_pos_in_block = stmt_idx as i32;
+            self.relative_pos_in_parent = stmt_idx as i32;
             self.visit_stmt(ctx, statement_section[stmt_idx])?;
+        }
         statement_section.forget();
         assign_and_replace_next_stmt!(self, ctx, end_block_id.upcast());
-        self.pop_statement_scope(old_scope);
+        self.pop_scope(old_scope);
         Ok(())
+    }
     fn visit_local_memory_stmt(&mut self, ctx: &mut Ctx, id: MemoryStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         let expr_id = stmt.initial_expr;
         let variable_id = stmt.variable;
-        self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_block, variable_id)?;
+        self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_parent, variable_id)?;
         assign_and_replace_next_stmt!(self, ctx, id.upcast().upcast());
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         self.expr_parent = ExpressionParent::Memory(id);
         self.visit_assignment_expr(ctx, expr_id)?;
         self.expr_parent = ExpressionParent::None;
         Ok(())
+    }
     fn visit_local_channel_stmt(&mut self, ctx: &mut Ctx, id: ChannelStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         let from_id = stmt.from;
         let to_id = stmt.to;
         self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_block, from_id)?;
         self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_block, to_id)?;
         self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_parent, from_id)?;
         self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_parent, to_id)?;
         assign_and_replace_next_stmt!(self, ctx, id.upcast().upcast());
         Ok(())
+    }
     fn visit_labeled_stmt(&mut self, ctx: &mut Ctx, id: LabeledStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         let body_id = stmt.body;
-        self.checked_add_label(ctx, self.relative_pos_in_block, self.in_sync, id)?;
+        self.checked_add_label(ctx, self.relative_pos_in_parent, self.in_sync, id)?;
         self.visit_stmt(ctx, body_id)?;
         Ok(())
+    }
     fn visit_if_stmt(&mut self, ctx: &mut Ctx, id: IfStatementId) -> VisitorResult {
         let if_stmt = &ctx.heap[id];
         let end_if_id = if_stmt.end_if;
         let test_expr_id = if_stmt.test;
         let true_stmt_id = if_stmt.true_body;
         let false_stmt_id = if_stmt.false_body;
         let true_case = if_stmt.true_case;
         let false_case = if_stmt.false_case;
         // Visit test expression
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         debug_assert!(self.in_test_expr.is_invalid());
         self.in_test_expr = id.upcast();
         self.expr_parent = ExpressionParent::If(id);
         self.visit_expr(ctx, test_expr_id)?;
         self.in_test_expr = StatementId::new_invalid();
         self.expr_parent = ExpressionParent::None;
         // Visit true and false branch. Executor chooses next statement based on
         // test expression, not on if-statement itself. Hence the if statement
         // does not have a static subsequent statement.
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         self.visit_block_stmt(ctx, true_stmt_id)?;
         let old_scope = self.push_scope(ctx, false, true_case.scope);
         self.visit_stmt(ctx, true_case.body)?;
         self.pop_scope(old_scope);
         assign_then_erase_next_stmt!(self, ctx, end_if_id.upcast());
         if let Some(false_id) = false_stmt_id {
             self.visit_block_stmt(ctx, false_id)?;
         if let Some(false_case) = false_case {
             let old_scope = self.push_scope(ctx, false, false_case.scope);
             self.visit_stmt(ctx, false_case.body)?;
             self.pop_scope(old_scope);
             assign_then_erase_next_stmt!(self, ctx, end_if_id.upcast());
+        }
         self.prev_stmt = end_if_id.upcast();
         Ok(())
+    }
     fn visit_while_stmt(&mut self, ctx: &mut Ctx, id: WhileStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         let end_while_id = stmt.end_while;
         let test_expr_id = stmt.test;
         let body_stmt_id = stmt.body;
         let scope_id = stmt.scope;
         let old_while = self.in_while;
         self.in_while = id;
         // Visit test expression
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         debug_assert!(self.in_test_expr.is_invalid());
         self.in_test_expr = id.upcast();
         self.expr_parent = ExpressionParent::While(id);
         self.visit_expr(ctx, test_expr_id)?;
         self.in_test_expr = StatementId::new_invalid();
         // Link up to body statement
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         self.expr_parent = ExpressionParent::None;
         self.visit_block_stmt(ctx, body_stmt_id)?;
         let old_scope = self.push_scope(ctx, false, scope_id);
         self.visit_stmt(ctx, body_stmt_id)?;
         self.pop_scope(old_scope);
         self.in_while = old_while;
         // Link final entry in while's block statement back to the while. The
         // executor will go to the end-while statement if the test expression
         // is false, so put that in as the new previous stmt
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         self.prev_stmt = end_while_id.upcast();
         Ok(())
+    }
     fn visit_break_stmt(&mut self, ctx: &mut Ctx, id: BreakStatementId) -> VisitorResult {
         self.control_flow_stmts.push(ControlFlowStatement{
             in_sync: self.in_sync,
             in_while: self.in_while,
             in_scope: self.cur_scope,
             statement: id.upcast()
         });
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         Ok(())
+    }
     fn visit_continue_stmt(&mut self, ctx: &mut Ctx, id: ContinueStatementId) -> VisitorResult {
         self.control_flow_stmts.push(ControlFlowStatement{
             in_sync: self.in_sync,
             in_while: self.in_while,
             in_scope: self.cur_scope,
             statement: id.upcast()
         });
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         Ok(())
+    }
     fn visit_synchronous_stmt(&mut self, ctx: &mut Ctx, id: SynchronousStatementId) -> VisitorResult {
         // Check for validity of synchronous statement
         let sync_stmt = &ctx.heap[id];
         let end_sync_id = sync_stmt.end_sync;
         let cur_sync_span = sync_stmt.span;
         let scope_id = sync_stmt.scope;
         if !self.in_sync.is_invalid() {
             // Nested synchronous statement
             let old_sync_span = ctx.heap[self.in_sync].span;
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, cur_sync_span, "Illegal nested synchronous statement"
             ).with_info_str_at_span(
                 &ctx.module().source, old_sync_span, "It is nested in this synchronous statement"
             ));
+        }
-        if !self.def_type.is_primitive() {
+        if self.proc_kind != ProcedureKind::Primitive {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, cur_sync_span,
                 "synchronous statements may only be used in primitive components"
             ));
+        }
         // Synchronous statement implicitly moves to its block
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         // Visit block statement. Note that we explicitly push the scope here
         // (and the `visit_block_stmt` will also push, but without effect) to
         // ensure the scope contains the sync ID.
         let sync_body = ctx.heap[id].body;
         debug_assert!(self.in_sync.is_invalid());
         self.in_sync = id;
         let old_scope = self.push_statement_scope(ctx, Scope::Synchronous(id, sync_body));
         self.visit_block_stmt(ctx, sync_body)?;
         self.pop_statement_scope(old_scope);
         let old_scope = self.push_scope(ctx, false, scope_id);
         self.visit_stmt(ctx, sync_body)?;
         self.pop_scope(old_scope);
         assign_and_replace_next_stmt!(self, ctx, end_sync_id.upcast());
         self.in_sync = SynchronousStatementId::new_invalid();
         Ok(())
+    }
     fn visit_fork_stmt(&mut self, ctx: &mut Ctx, id: ForkStatementId) -> VisitorResult {
         let fork_stmt = &ctx.heap[id];
         let end_fork_id = fork_stmt.end_fork;
         let left_body_id = fork_stmt.left_body;
         let right_body_id = fork_stmt.right_body;
         // Fork statements may only occur inside sync blocks
         if self.in_sync.is_invalid() {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, fork_stmt.span,
                 "Forking may only occur inside sync blocks"
             ));
+        }
         // Visit the respective bodies. Like the if statement, a fork statement
         // does not have a single static subsequent statement. It forks and then
         // each fork has a different next statement.
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
-        self.visit_block_stmt(ctx, left_body_id)?;
+        self.visit_stmt(ctx, left_body_id)?;
         assign_then_erase_next_stmt!(self, ctx, end_fork_id.upcast());
         if let Some(right_body_id) = right_body_id {
-            self.visit_block_stmt(ctx, right_body_id)?;
+            self.visit_stmt(ctx, right_body_id)?;
             assign_then_erase_next_stmt!(self, ctx, end_fork_id.upcast());
+        }
         self.prev_stmt = end_fork_id.upcast();
         Ok(())
+    }
     fn visit_select_stmt(&mut self, ctx: &mut Ctx, id: SelectStatementId) -> VisitorResult {
         let select_stmt = &mut ctx.heap[id];
         select_stmt.relative_pos_in_parent = self.relative_pos_in_parent;
         self.relative_pos_in_parent += 1;
         let select_stmt = &ctx.heap[id];
         let end_select_id = select_stmt.end_select;
         // Select statements may only occur inside sync blocks
         if self.in_sync.is_invalid() {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, select_stmt.span,
                 "select statements may only occur inside sync blocks"
             ));
+        }
-        if !self.def_type.is_primitive() {
+        if self.proc_kind != ProcedureKind::Primitive {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, select_stmt.span,
                 "select statements may only be used in primitive components"
             ));
+        }
         // Visit the various arms in the select block
         let mut case_stmt_ids = self.statement_buffer.start_section();
         let mut case_scope_ids = self.scope_buffer.start_section();
         let num_cases = select_stmt.cases.len();
         for case in &select_stmt.cases {
             // Note: we add both to the buffer, retrieve them later in indexed
             // fashion
             // We add them in pairs, so the subsequent for-loop retrieves in pairs
             case_stmt_ids.push(case.guard);
             case_stmt_ids.push(case.block.upcast());
             case_stmt_ids.push(case.body);
             case_scope_ids.push(case.scope);
+        }
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         for idx in 0..num_cases {
             let base_idx = 2 * idx;
             let guard_id     = case_stmt_ids[base_idx    ];
             let arm_block_id = case_stmt_ids[base_idx + 1];
             debug_assert_eq!(ctx.heap[arm_block_id].as_block().this.upcast(), arm_block_id); // backwards way of saying arm_block_id is a BlockStatementId
             let arm_block_id = BlockStatementId(arm_block_id);
         for index in 0..num_cases {
             let base_index = 2 * index;
             let guard_id     = case_stmt_ids[base_index];
             let case_body_id = case_stmt_ids[base_index + 1];
             let case_scope_id = case_scope_ids[index];
             // The guard statement ends up belonging to the block statement
             // following the arm. The reason we parse it separately is to
             // extract all of the "get" calls.
-            let old_scope = self.push_statement_scope(ctx, Scope::Regular(arm_block_id));
+            let old_scope = self.push_scope(ctx, false, case_scope_id);
             // Visit the guard of this arm
             debug_assert!(self.in_select_guard.is_invalid());
             self.in_select_guard = id;
-            self.in_select_arm = idx as u32;
+            self.in_select_arm = index as u32;
             self.visit_stmt(ctx, guard_id)?;
             self.in_select_guard = SelectStatementId::new_invalid();
             // Visit the code associated with the guard
             self.visit_block_stmt(ctx, arm_block_id)?;
             self.pop_statement_scope(old_scope);
             self.relative_pos_in_parent += 1;
             self.visit_stmt(ctx, case_body_id)?;
             self.pop_scope(old_scope);
             // Link up last statement in block to EndSelect
             assign_then_erase_next_stmt!(self, ctx, end_select_id.upcast());
+        }
         self.in_select_guard = SelectStatementId::new_invalid();
         self.prev_stmt = end_select_id.upcast();
         Ok(())
+    }
     fn visit_return_stmt(&mut self, ctx: &mut Ctx, id: ReturnStatementId) -> VisitorResult {
         // Check if "return" occurs within a function
         let stmt = &ctx.heap[id];
-        if !self.def_type.is_function() {
+        if self.proc_kind != ProcedureKind::Function {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, stmt.span,
                 "return statements may only appear in function bodies"
             ));
+        }
         // If here then we are within a function
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         debug_assert_eq!(ctx.heap[id].expressions.len(), 1);
         self.expr_parent = ExpressionParent::Return(id);
         self.visit_expr(ctx, ctx.heap[id].expressions[0])?;
         self.expr_parent = ExpressionParent::None;
         Ok(())
+    }
     fn visit_goto_stmt(&mut self, ctx: &mut Ctx, id: GotoStatementId) -> VisitorResult {
         self.control_flow_stmts.push(ControlFlowStatement{
             in_sync: self.in_sync,
             in_while: self.in_while,
             in_scope: self.cur_scope,
             statement: id.upcast(),
         });
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         Ok(())
+    }
     fn visit_new_stmt(&mut self, ctx: &mut Ctx, id: NewStatementId) -> VisitorResult {
         // Make sure the new statement occurs inside a composite component
-        if !self.def_type.is_composite() {
+        if self.proc_kind != ProcedureKind::Composite {
             let new_stmt = &ctx.heap[id];
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, new_stmt.span,
                 "instantiating components may only be done in composite components"
             ));
+        }
         // Recurse into call expression (which will check the expression parent
         // to ensure that the "new" statment instantiates a component)
         let call_expr_id = ctx.heap[id].expression;
         assign_and_replace_next_stmt!(self, ctx, id.upcast());
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         self.expr_parent = ExpressionParent::New(id);
         self.visit_call_expr(ctx, call_expr_id)?;
         self.expr_parent = ExpressionParent::None;
         Ok(())
+    }
     fn visit_expr_stmt(&mut self, ctx: &mut Ctx, id: ExpressionStatementId) -> VisitorResult {
         let expr_id = ctx.heap[id].expression;
         assign_and_replace_next_stmt!(self, ctx, id.upcast());
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         self.expr_parent = ExpressionParent::ExpressionStmt(id);
         self.visit_expr(ctx, expr_id)?;
         self.expr_parent = ExpressionParent::None;
         Ok(())
+    }
     //--------------------------------------------------------------------------
     // Expression visitors
     //--------------------------------------------------------------------------
     fn visit_assignment_expr(&mut self, ctx: &mut Ctx, id: AssignmentExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         let assignment_expr = &mut ctx.heap[id];
         // Although we call assignment an expression to simplify the compiler's
         // code (mainly typechecking), we disallow nested use in expressions
         match self.expr_parent {
             // Look at us: lying through our teeth while providing error messages.
             ExpressionParent::Memory(_) => {},
             ExpressionParent::ExpressionStmt(_) => {},
             _ => {
                 let assignment_span = assignment_expr.full_span;
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, assignment_span,
                     "assignments are statements, and cannot be used in expressions"
                 ))
             },
+        }
         let left_expr_id = assignment_expr.left;
         let right_expr_id = assignment_expr.right;
         let old_expr_parent = self.expr_parent;
         assignment_expr.parent = old_expr_parent;
         assignment_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.must_be_assignable = Some(assignment_expr.operator_span);
         self.visit_expr(ctx, left_expr_id)?;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.must_be_assignable = None;
         self.visit_expr(ctx, right_expr_id)?;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_binding_expr(&mut self, ctx: &mut Ctx, id: BindingExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         // Check for valid context of binding expression
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a binding expression"
             ));
+        }
         if self.in_test_expr.is_invalid() {
             let binding_expr = &ctx.heap[id];
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, binding_expr.full_span,
                 "binding expressions can only be used inside the testing expression of 'if' and 'while' statements"
             ));
+        }
         if !self.in_binding_expr.is_invalid() {
             let binding_expr = &ctx.heap[id];
             let previous_expr = &ctx.heap[self.in_binding_expr];
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, binding_expr.full_span,
                 "nested binding expressions are not allowed"
             ).with_info_str_at_span(
                 &ctx.module().source, previous_expr.operator_span,
                 "the outer binding expression is found here"
             ));
+        }
         let mut seeking_parent = self.expr_parent;
         loop {
             // Perform upward search to make sure only LogicalAnd is applied to
             // the binding expression
             let valid = match seeking_parent {
                 ExpressionParent::If(_) | ExpressionParent::While(_) => {
                     // Every parent expression (if any) were LogicalAnd.
                     break;
+                }
                 ExpressionParent::Expression(parent_id, _) => {
                     let parent_expr = &ctx.heap[parent_id];
                     match parent_expr {
                         Expression::Binary(parent_expr) => {
                             // Set new parent to continue the search. Otherwise
                             // halt and provide an error using the current
                             // parent.
                             if parent_expr.operation == BinaryOperator::LogicalAnd {
                                 seeking_parent = parent_expr.parent;
                                 true
                             } else {
                                 false
+                            }
                         },
                         _ => false,
+                    }
                 },
                 _ => unreachable!(), // nested under if/while, so always expressions as parents
             };
             if !valid {
                 let binding_expr = &ctx.heap[id];
                 let parent_expr = &ctx.heap[seeking_parent.as_expression()];
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, binding_expr.full_span,
                     "only the logical-and operator (&&) may be applied to binding expressions"
                 ).with_info_str_at_span(
                     &ctx.module().source, parent_expr.operation_span(),
                     "this was the disallowed operation applied to the result from a binding expression"
                 ));
+            }
+        }
         // Perform all of the index/parent assignment magic
         let binding_expr = &mut ctx.heap[id];
         let old_expr_parent = self.expr_parent;
         binding_expr.parent = old_expr_parent;
         binding_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.in_binding_expr = id;
         // Perform preliminary check on children: binding expressions only make
         // sense if the left hand side is just a variable expression, or if it
         // is a literal of some sort. The typechecker will take care of the rest
         let bound_to_id = binding_expr.bound_to;
         let bound_from_id = binding_expr.bound_from;
         match &ctx.heap[bound_to_id] {
             // Variables may not be binding variables, and literals may
             // actually not contain binding variables. But in that case we just
             // perform an equality check.
             Expression::Variable(_) => {}
             Expression::Literal(_) => {},
             _ => {
                 let binding_expr = &ctx.heap[id];
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, binding_expr.operator_span,
                     "the left hand side of a binding expression may only be a variable or a literal expression"
                 ));
             },
+        }
         // Visit the children themselves
         self.in_binding_expr_lhs = true;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.visit_expr(ctx, bound_to_id)?;
         self.in_binding_expr_lhs = false;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.visit_expr(ctx, bound_from_id)?;
         self.expr_parent = old_expr_parent;
         self.in_binding_expr = BindingExpressionId::new_invalid();
         Ok(())
+    }
     fn visit_conditional_expr(&mut self, ctx: &mut Ctx, id: ConditionalExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         let conditional_expr = &mut ctx.heap[id];
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a conditional expression"
             ))
+        }
         let test_expr_id = conditional_expr.test;
         let true_expr_id = conditional_expr.true_expression;
         let false_expr_id = conditional_expr.false_expression;
         let old_expr_parent = self.expr_parent;
         conditional_expr.parent = old_expr_parent;
         conditional_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.visit_expr(ctx, test_expr_id)?;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.visit_expr(ctx, true_expr_id)?;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 2);
         self.visit_expr(ctx, false_expr_id)?;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_binary_expr(&mut self, ctx: &mut Ctx, id: BinaryExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         let binary_expr = &mut ctx.heap[id];
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a binary expression"
             ))
+        }
         let left_expr_id = binary_expr.left;
         let right_expr_id = binary_expr.right;
         let old_expr_parent = self.expr_parent;
         binary_expr.parent = old_expr_parent;
         binary_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.visit_expr(ctx, left_expr_id)?;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.visit_expr(ctx, right_expr_id)?;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_unary_expr(&mut self, ctx: &mut Ctx, id: UnaryExpressionId) -> VisitorResult {
         let unary_expr = &mut ctx.heap[id];
         let expr_id = unary_expr.expression;
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a unary expression"
             ))
+        }
         let old_expr_parent = self.expr_parent;
         unary_expr.parent = old_expr_parent;
         unary_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(id.upcast(), 0);
         self.visit_expr(ctx, expr_id)?;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_indexing_expr(&mut self, ctx: &mut Ctx, id: IndexingExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         let indexing_expr = &mut ctx.heap[id];
         let subject_expr_id = indexing_expr.subject;
         let index_expr_id = indexing_expr.index;
         let old_expr_parent = self.expr_parent;
         indexing_expr.parent = old_expr_parent;
         indexing_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.visit_expr(ctx, subject_expr_id)?;
         let old_assignable = self.must_be_assignable.take();
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.visit_expr(ctx, index_expr_id)?;
         self.must_be_assignable = old_assignable;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_slicing_expr(&mut self, ctx: &mut Ctx, id: SlicingExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         let slicing_expr = &mut ctx.heap[id];
         if let Some(span) = self.must_be_assignable {
             // TODO: @Slicing
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "assignment to slices should be valid in the final language, but is currently not implemented"
             ));
+        }
         let subject_expr_id = slicing_expr.subject;
         let from_expr_id = slicing_expr.from_index;
         let to_expr_id = slicing_expr.to_index;
         let old_expr_parent = self.expr_parent;
         slicing_expr.parent = old_expr_parent;
         slicing_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.visit_expr(ctx, subject_expr_id)?;
         let old_assignable = self.must_be_assignable.take();
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.visit_expr(ctx, from_expr_id)?;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 2);
         self.visit_expr(ctx, to_expr_id)?;
         self.must_be_assignable = old_assignable;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_select_expr(&mut self, ctx: &mut Ctx, id: SelectExpressionId) -> VisitorResult {
         let select_expr = &mut ctx.heap[id];
         let expr_id = select_expr.subject;
         let old_expr_parent = self.expr_parent;
         select_expr.parent = old_expr_parent;
         select_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(id.upcast(), 0);
         self.visit_expr(ctx, expr_id)?;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_literal_expr(&mut self, ctx: &mut Ctx, id: LiteralExpressionId) -> VisitorResult {
         let literal_expr = &mut ctx.heap[id];
         let old_expr_parent = self.expr_parent;
         literal_expr.parent = old_expr_parent;
         literal_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to a literal expression"
             ))
+        }
         match &mut literal_expr.value {
             Literal::Null | Literal::True | Literal::False |
             Literal::Character(_) | Literal::String(_) | Literal::Integer(_) => {
                 // Just the parent has to be set, done above
             },
             Literal::Struct(literal) => {
                 let upcast_id = id.upcast();
                 // Retrieve type definition
                 let type_definition = ctx.types.get_base_definition(&literal.definition).unwrap();
                 let struct_definition = type_definition.definition.as_struct();
                 // Make sure all fields are specified, none are specified twice
                 // and all fields exist on the struct definition
                 let mut specified = Vec::new(); // TODO: @performance
                 specified.resize(struct_definition.fields.len(), false);
                 for field in &mut literal.fields {
                     // Find field in the struct definition
                     let field_idx = struct_definition.fields.iter().position(|v| v.identifier == field.identifier);
                     if field_idx.is_none() {
                         let field_span = field.identifier.span;
                         let literal = ctx.heap[id].value.as_struct();
                         let ast_definition = &ctx.heap[literal.definition];
                         return Err(ParseError::new_error_at_span(
                             &ctx.module().source, field_span, format!(
                                 "This field does not exist on the struct '{}'",
                                 ast_definition.identifier().value.as_str()
+                            )
                         ));
+                    }
                     field.field_idx = field_idx.unwrap();
                     // Check if specified more than once
                     if specified[field.field_idx] {
                         let field_span = field.identifier.span;
                         return Err(ParseError::new_error_str_at_span(
                             &ctx.module().source, field_span,
                             "This field is specified more than once"
                         ));
+                    }
                     specified[field.field_idx] = true;
+                }
                 if !specified.iter().all(|v| *v) {
                     // Some fields were not specified
                     let mut not_specified = String::new();
                     let mut num_not_specified = 0;
                     for (def_field_idx, is_specified) in specified.iter().enumerate() {
                         if !is_specified {
                             if !not_specified.is_empty() { not_specified.push_str(", ") }
                             let field_ident = &struct_definition.fields[def_field_idx].identifier;
                             not_specified.push_str(field_ident.value.as_str());
                             num_not_specified += 1;
+                        }
+                    }
                     debug_assert!(num_not_specified > 0);
                     let msg = if num_not_specified == 1 {
                         format!("not all fields are specified, '{}' is missing", not_specified)
                     } else {
                         format!("not all fields are specified, [{}] are missing", not_specified)
                     };
                     let literal_span = literal.parser_type.full_span;
                     return Err(ParseError::new_error_at_span(
                         &ctx.module().source, literal_span, msg
                     ));
+                }
                 // Need to traverse fields expressions in struct and evaluate
                 // the poly args
                 let mut expr_section = self.expression_buffer.start_section();
                 for field in &literal.fields {
                     expr_section.push(field.value);
+                }
                 for expr_idx in 0..expr_section.len() {
                     let expr_id = expr_section[expr_idx];
                     self.expr_parent = ExpressionParent::Expression(upcast_id, expr_idx as u32);
                     self.visit_expr(ctx, expr_id)?;
+                }
                 expr_section.forget();
             },
             Literal::Enum(literal) => {
                 // Make sure the variant exists
                 let type_definition = ctx.types.get_base_definition(&literal.definition).unwrap();
                 let enum_definition = type_definition.definition.as_enum();
                 let variant_idx = enum_definition.variants.iter().position(|v| {
                     v.identifier == literal.variant
                 });
                 if variant_idx.is_none() {
                     let literal = ctx.heap[id].value.as_enum();
                     let ast_definition = ctx.heap[literal.definition].as_enum();
                     return Err(ParseError::new_error_at_span(
                         &ctx.module().source, literal.parser_type.full_span, format!(
                             "the variant '{}' does not exist on the enum '{}'",
                             literal.variant.value.as_str(), ast_definition.identifier.value.as_str()
+                        )
                     ));
+                }
                 literal.variant_idx = variant_idx.unwrap();
             },
             Literal::Union(literal) => {
                 // Make sure the variant exists
                 let type_definition = ctx.types.get_base_definition(&literal.definition).unwrap();
                 let union_definition = type_definition.definition.as_union();
                 let variant_idx = union_definition.variants.iter().position(|v| {
                     v.identifier == literal.variant
                 });
                 if variant_idx.is_none() {
                     let literal = ctx.heap[id].value.as_union();
                     let ast_definition = ctx.heap[literal.definition].as_union();
                     return Err(ParseError::new_error_at_span(
                         &ctx.module().source, literal.parser_type.full_span, format!(
                             "the variant '{}' does not exist on the union '{}'",
                             literal.variant.value.as_str(), ast_definition.identifier.value.as_str()
+                        )
                     ));
+                }
                 literal.variant_idx = variant_idx.unwrap();
                 // Make sure the number of specified values matches the expected
                 // number of embedded values in the union variant.
                 let union_variant = &union_definition.variants[literal.variant_idx];
                 if union_variant.embedded.len() != literal.values.len() {
                     let literal = ctx.heap[id].value.as_union();
                     let ast_definition = ctx.heap[literal.definition].as_union();
                     return Err(ParseError::new_error_at_span(
                         &ctx.module().source, literal.parser_type.full_span, format!(
                             "The variant '{}' of union '{}' expects {} embedded values, but {} were specified",
                             literal.variant.value.as_str(), ast_definition.identifier.value.as_str(),
                             union_variant.embedded.len(), literal.values.len()
                         ),
                     ))
+                }
                 // Traverse embedded values of union (if any) and evaluate the
                 // polymorphic arguments
                 let upcast_id = id.upcast();
                 let mut expr_section = self.expression_buffer.start_section();
                 for value in &literal.values {
                     expr_section.push(*value);
+                }
                 for expr_idx in 0..expr_section.len() {
                     let expr_id = expr_section[expr_idx];
                     self.expr_parent = ExpressionParent::Expression(upcast_id, expr_idx as u32);
                     self.visit_expr(ctx, expr_id)?;
+                }
                 expr_section.forget();
             },
             Literal::Array(literal) | Literal::Tuple(literal) => {
                 // Visit all expressions in the array
                 let upcast_id = id.upcast();
                 let expr_section = self.expression_buffer.start_section_initialized(literal);
                 for expr_idx in 0..expr_section.len() {
                     let expr_id = expr_section[expr_idx];
                     self.expr_parent = ExpressionParent::Expression(upcast_id, expr_idx as u32);
                     self.visit_expr(ctx, expr_id)?;
+                }
                 expr_section.forget();
+            }
+        }
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_cast_expr(&mut self, ctx: &mut Ctx, id: CastExpressionId) -> VisitorResult {
         let cast_expr = &mut ctx.heap[id];
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a cast expression"
             ))
+        }
         let upcast_id = id.upcast();
         let old_expr_parent = self.expr_parent;
         cast_expr.parent = old_expr_parent;
         cast_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         // Recurse into the thing that we're casting
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         let subject_id = cast_expr.subject;
         self.visit_expr(ctx, subject_id)?;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_call_expr(&mut self, ctx: &mut Ctx, id: CallExpressionId) -> VisitorResult {
         let call_expr = &ctx.heap[id];
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a call expression"
             ))
+        }
         // Check whether the method is allowed to be called within the code's
         // context (in sync, definition type, etc.)
         let mut expecting_wrapping_new_stmt = false;
         let mut expecting_primitive_def = false;
         let mut expecting_wrapping_sync_stmt = false;
         let mut expecting_no_select_stmt = false;
         match call_expr.method {
             Method::Get => {
                 expecting_primitive_def = true;
                 expecting_wrapping_sync_stmt = true;
                 if !self.in_select_guard.is_invalid() {
                     // In a select guard. Take the argument (i.e. the port we're
                     // retrieving from) and add it to the list of involved ports
                     // of the guard
                     if call_expr.arguments.len() == 1 {
                         // We're checking the number of arguments later, for now
                         // assume it is correct.
                         let argument = call_expr.arguments[0];
                         let select_stmt = &mut ctx.heap[self.in_select_guard];
                         let select_case = &mut select_stmt.cases[self.in_select_arm as usize];
                         select_case.involved_ports.push((id, argument));
+                    }
+                }
             },
             Method::Put => {
                 expecting_primitive_def = true;
                 expecting_wrapping_sync_stmt = true;
                 expecting_no_select_stmt = true;
             },
             Method::Fires => {
                 expecting_primitive_def = true;
                 expecting_wrapping_sync_stmt = true;
             },
             Method::Create => {},
             Method::Length => {},
             Method::Assert => {
                 expecting_wrapping_sync_stmt = true;
                 expecting_no_select_stmt = true;
-                if self.def_type.is_function() {
+                if self.proc_kind == ProcedureKind::Function {
                     let call_span = call_expr.func_span;
                     return Err(ParseError::new_error_str_at_span(
                         &ctx.module().source, call_span,
                         "assert statement may only occur in components"
                     ));
+                }
             },
             Method::Print => {},
             Method::UserFunction => {},
             Method::SelectStart
             | Method::SelectRegisterCasePort
             | Method::SelectWait => unreachable!(), // not usable by programmer directly
             Method::UserFunction => {}
             Method::UserComponent => {
                 expecting_wrapping_new_stmt = true;
             },
+        }
         let call_expr = &mut ctx.heap[id];
         fn get_span_and_name<'a>(ctx: &'a Ctx, id: CallExpressionId) -> (InputSpan, String) {
             let call = &ctx.heap[id];
             let span = call.func_span;
             let name = String::from_utf8_lossy(ctx.module().source.section_at_span(span)).to_string();
             return (span, name);
+        }
         if expecting_primitive_def {
-            if !self.def_type.is_primitive() {
+            if self.proc_kind != ProcedureKind::Primitive {
                 let (call_span, func_name) = get_span_and_name(ctx, id);
                 return Err(ParseError::new_error_at_span(
                     &ctx.module().source, call_span,
                     format!("a call to '{}' may only occur in primitive component definitions", func_name)
                 ));
+            }
+        }
         if expecting_wrapping_sync_stmt {
             if self.in_sync.is_invalid() {
                 let (call_span, func_name) = get_span_and_name(ctx, id);
                 return Err(ParseError::new_error_at_span(
                     &ctx.module().source, call_span,
                     format!("a call to '{}' may only occur inside synchronous blocks", func_name)
                 ))
+            }
+        }
         if expecting_no_select_stmt {
             if !self.in_select_guard.is_invalid() {
                 let (call_span, func_name) = get_span_and_name(ctx, id);
                 return Err(ParseError::new_error_at_span(
                     &ctx.module().source, call_span,
                     format!("a call to '{}' may not occur in a select statement's guard", func_name)
                 ));
+            }
+        }
         if expecting_wrapping_new_stmt {
             if !self.expr_parent.is_new() {
                 let call_span = call_expr.func_span;
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, call_span,
                     "cannot call a component, it can only be instantiated by using 'new'"
                 ));
+            }
         } else {
             if self.expr_parent.is_new() {
                 let call_span = call_expr.func_span;
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, call_span,
                     "only components can be instantiated, this is a function"
                 ));
+            }
+        }
         // Check the number of arguments
-        let call_definition = ctx.types.get_base_definition(&call_expr.definition).unwrap();
+        let call_definition = ctx.types.get_base_definition(&call_expr.procedure.upcast()).unwrap();
         let num_expected_args = match &call_definition.definition {
             DefinedTypeVariant::Function(definition) => definition.arguments.len(),
             DefinedTypeVariant::Component(definition) => definition.arguments.len(),
             v => unreachable!("encountered {} type in call expression", v.type_class()),
             DefinedTypeVariant::Procedure(definition) => definition.arguments.len(),
             _ => unreachable!(),
         };
         let num_provided_args = call_expr.arguments.len();
         if num_provided_args != num_expected_args {
             let argument_text = if num_expected_args == 1 { "argument" } else { "arguments" };
             let call_span = call_expr.full_span;
             return Err(ParseError::new_error_at_span(
                 &ctx.module().source, call_span, format!(
                     "expected {} {}, but {} were provided",
                     num_expected_args, argument_text, num_provided_args
+                )
             ));
+        }
         // Recurse into all of the arguments and set the expression's parent
         let upcast_id = id.upcast();
         let section = self.expression_buffer.start_section_initialized(&call_expr.arguments);
         let old_expr_parent = self.expr_parent;
         call_expr.parent = old_expr_parent;
         call_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         for arg_expr_idx in 0..section.len() {
             let arg_expr_id = section[arg_expr_idx];
             self.expr_parent = ExpressionParent::Expression(upcast_id, arg_expr_idx as u32);
             self.visit_expr(ctx, arg_expr_id)?;
+        }
         section.forget();
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_variable_expr(&mut self, ctx: &mut Ctx, id: VariableExpressionId) -> VisitorResult {
         let var_expr = &ctx.heap[id];
         // Check if declaration was already resolved (this occurs for the
         // variable expr that is on the LHS of the assignment expr that is
         // associated with a variable declaration)
         let mut variable_id = var_expr.declaration;
         let mut is_binding_target = false;
         // Otherwise try to find it
         if variable_id.is_none() {
-            variable_id = self.find_variable(ctx, self.relative_pos_in_block, &var_expr.identifier);
+            variable_id = self.find_variable(ctx, self.relative_pos_in_parent, &var_expr.identifier);
+        }
         // Otherwise try to see if is a variable introduced by a binding expr
         let variable_id = if let Some(variable_id) = variable_id {
             variable_id
         } else {
             if self.in_binding_expr.is_invalid() || !self.in_binding_expr_lhs {
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, var_expr.identifier.span, "unresolved variable"
                 ));
+            }
             // This is a binding variable, but it may only appear in very
             // specific locations.
             let is_valid_binding = match self.expr_parent {
                 ExpressionParent::Expression(expr_id, idx) => {
                     match &ctx.heap[expr_id] {
                         Expression::Binding(_binding_expr) => {
                             // Nested binding is disallowed, and because of
                             // the check above we know we're directly at the
                             // LHS of the binding expression
                             debug_assert_eq!(_binding_expr.this, self.in_binding_expr);
                             debug_assert_eq!(idx, 0);
                             true
+                        }
                         Expression::Literal(lit_expr) => {
                             // Only struct, unions, tuples and arrays can
                             // have subexpressions, so we're always fine
-                            if cfg!(debug_assertions) {
+                            dbg_code!({
                                 match lit_expr.value {
                                     Literal::Struct(_) | Literal::Union(_) | Literal::Array(_) | Literal::Tuple(_) => {},
                                     _ => unreachable!(),
+                                }
+                            }
+                            });
                             true
                         },
                         _ => false,
+                    }
                 },
                 _ => {
                     false
+                }
             };
             if !is_valid_binding {
                 let binding_expr = &ctx.heap[self.in_binding_expr];
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, var_expr.identifier.span,
                     "illegal location for binding variable: binding variables may only be nested under a binding expression, or a struct, union or array literal"
                 ).with_info_at_span(
                     &ctx.module().source, binding_expr.operator_span, format!(
                         "'{}' was interpreted as a binding variable because the variable is not declared and it is nested under this binding expression",
                         var_expr.identifier.value.as_str()
+                    )
                 ));
+            }
             // By now we know that this is a valid binding expression. Given
             // that a binding expression must be nested under an if/while
             // statement, we now add the variable to the (implicit) block
             // statement following the if/while statement.
             // statement, we now add the variable to the scope associated with
             // that statement.
             let bound_identifier = var_expr.identifier.clone();
             let bound_variable_id = ctx.heap.alloc_variable(|this| Variable {
                 this,
                 kind: VariableKind::Binding,
                 parser_type: ParserType {
                     elements: vec![ParserTypeElement {
                         element_span: bound_identifier.span,
                         variant: ParserTypeVariant::Inferred
                     }],
                     full_span: bound_identifier.span
                 },
                 identifier: bound_identifier,
-                relative_pos_in_block: 0,
+                relative_pos_in_parent: 0,
                 unique_id_in_scope: -1,
             });
             let body_stmt_id = match &ctx.heap[self.in_test_expr] {
                 Statement::If(stmt) => stmt.true_body,
                 Statement::While(stmt) => stmt.body,
             let scope_id = match &ctx.heap[self.in_test_expr] {
                 Statement::If(stmt) => stmt.true_case.scope,
                 Statement::While(stmt) => stmt.scope,
                 _ => unreachable!(),
             };
             let body_scope = Scope::Regular(body_stmt_id);
             self.checked_at_single_scope_add_local(ctx, body_scope, -1, bound_variable_id)?; // add at -1 such that first statement can access
             self.checked_at_single_scope_add_local(ctx, scope_id, -1, bound_variable_id)?; // add at -1 such that first statement can find the variable if needed
             is_binding_target = true;
             bound_variable_id
         };
         let var_expr = &mut ctx.heap[id];
         var_expr.declaration = Some(variable_id);
         var_expr.used_as_binding_target = is_binding_target;
         var_expr.parent = self.expr_parent;
         var_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         Ok(())
+    }
+}
 impl PassValidationLinking {
     //--------------------------------------------------------------------------
     // Special traversal
     //--------------------------------------------------------------------------
     /// Pushes a new scope associated with a particular statement. If that
     /// statement already has an associated scope (i.e. scope associated with
     /// sync statement or select statement's arm) then we won't do anything.
     /// In all cases the caller must call `pop_statement_scope` with the scope
     /// and relative scope position returned by this function.
     fn push_statement_scope(&mut self, ctx: &mut Ctx, new_scope: Scope) -> (Scope, i32) {
         let old_scope = self.cur_scope.clone();
         debug_assert!(new_scope.is_block()); // never call for Definition scope
         let is_new_block = if old_scope.is_block() {
             old_scope.to_block() != new_scope.to_block()
         } else {
             true
         };
         if !is_new_block {
             // No need to push, but still return old scope, we pretend like we
             // replaced it.
             debug_assert!(!ctx.heap[new_scope.to_block()].scope_node.parent.is_invalid());
             return (old_scope, self.relative_pos_in_block);
+        }
         // This is a new block, so link it up
         if old_scope.is_block() {
             let parent_block = &mut ctx.heap[old_scope.to_block()];
             parent_block.scope_node.nested.push(new_scope);
+        }
         self.cur_scope = new_scope;
         let cur_block = &mut ctx.heap[new_scope.to_block()];
         cur_block.scope_node.parent = old_scope;
         cur_block.scope_node.relative_pos_in_parent = self.relative_pos_in_block;
         let old_relative_pos = self.relative_pos_in_block;
         self.relative_pos_in_block = -1;
         return (old_scope, old_relative_pos)
+    }
     fn pop_statement_scope(&mut self, scope_to_restore: (Scope, i32)) {
         self.cur_scope = scope_to_restore.0;
         self.relative_pos_in_block = scope_to_restore.1;
+    }
     fn visit_definition_and_assign_local_ids(&mut self, ctx: &mut Ctx, definition_id: DefinitionId) {
         let mut var_counter = 0;
         // Set IDs on parameters
         let (param_section, body_id) = match &ctx.heap[definition_id] {
             Definition::Function(func_def) => (
                 self.variable_buffer.start_section_initialized(&func_def.parameters),
                 func_def.body
             ),
             Definition::Component(comp_def) => (
                 self.variable_buffer.start_section_initialized(&comp_def.parameters),
                 comp_def.body
             ),
             _ => unreachable!(),
         } ;
         for var_id in param_section.iter_copied() {
             let var = &mut ctx.heap[var_id];
             var.unique_id_in_scope = var_counter;
             var_counter += 1;
+        }
         param_section.forget();
     fn push_scope(&mut self, ctx: &mut Ctx, is_top_level_scope: bool, pushed_scope_id: ScopeId) -> (ScopeId, i32) {
         // Set the properties of the pushed scope (it is already created during
         // AST construction, but most values are not yet set to their correct
         // values)
         let old_scope_id = self.cur_scope;
         // Recurse into body
         self.visit_block_and_assign_local_ids(ctx, body_id, var_counter);
         let scope = &mut ctx.heap[pushed_scope_id];
         if !is_top_level_scope {
             scope.parent = Some(old_scope_id);
+        }
     fn visit_block_and_assign_local_ids(&mut self, ctx: &mut Ctx, block_id: BlockStatementId, mut var_counter: i32) {
         let block_stmt = &mut ctx.heap[block_id];
         block_stmt.first_unique_id_in_scope = var_counter;
         scope.relative_pos_in_parent = self.relative_pos_in_parent;
         let old_relative_pos = self.relative_pos_in_parent;
         self.relative_pos_in_parent = 0;
         let var_section = self.variable_buffer.start_section_initialized(&block_stmt.locals);
         let mut scope_section = self.statement_buffer.start_section();
         for child_scope in &block_stmt.scope_node.nested {
             debug_assert!(child_scope.is_block(), "found a child scope that is not a block statement");
             scope_section.push(child_scope.to_block().upcast());
         // Link up scopes
         if !is_top_level_scope {
             let old_scope = &mut ctx.heap[old_scope_id];
             old_scope.nested.push(pushed_scope_id);
+        }
         let mut var_idx = 0;
         let mut scope_idx = 0;
         while var_idx < var_section.len() || scope_idx < scope_section.len() {
             let relative_var_pos = if var_idx < var_section.len() {
                 ctx.heap[var_section[var_idx]].relative_pos_in_block
             } else {
                 i32::MAX
             };
             let relative_scope_pos = if scope_idx < scope_section.len() {
                 ctx.heap[scope_section[scope_idx]].as_block().scope_node.relative_pos_in_parent
             } else {
                 i32::MAX
             };
             debug_assert!(!(relative_var_pos == i32::MAX && relative_scope_pos == i32::MAX));
             // In certain cases the relative variable position is the same as
             // the scope position (insertion of binding variables). In that case
             // the variable should be treated first
             if relative_var_pos <= relative_scope_pos {
                 let var = &mut ctx.heap[var_section[var_idx]];
                 var.unique_id_in_scope = var_counter;
                 var_counter += 1;
                 var_idx += 1;
             } else {
                 // Boy oh boy
                 let block_id = ctx.heap[scope_section[scope_idx]].as_block().this;
                 self.visit_block_and_assign_local_ids(ctx, block_id, var_counter);
                 scope_idx += 1;
+            }
         // Set as current traversal scope, then return old scope
         self.cur_scope = pushed_scope_id;
         return (old_scope_id, old_relative_pos)
+    }
         var_section.forget();
         scope_section.forget();
         // Done assigning all IDs, assign the last ID to the block statement scope
         let block_stmt = &mut ctx.heap[block_id];
         block_stmt.next_unique_id_in_scope = var_counter;
     fn pop_scope(&mut self, scope_to_restore: (ScopeId, i32)) {
         self.cur_scope = scope_to_restore.0;
         self.relative_pos_in_parent = scope_to_restore.1;
+    }
     fn resolve_pending_control_flow_targets(&mut self, ctx: &mut Ctx) -> Result<(), ParseError> {
         for entry in &self.control_flow_stmts {
             let stmt = &ctx.heap[entry.statement];
             match stmt {
                 Statement::Break(stmt) => {
                     let stmt_id = stmt.this;
                     let target_while_id = Self::resolve_break_or_continue_target(ctx, entry, stmt.span, &stmt.label)?;
                     let target_while_stmt = &ctx.heap[target_while_id];
                     let target_end_while_id = target_while_stmt.end_while;
                     debug_assert!(!target_end_while_id.is_invalid());
                     let break_stmt = &mut ctx.heap[stmt_id];
                     break_stmt.target = target_end_while_id;
                 },
                 Statement::Continue(stmt) => {
                     let stmt_id = stmt.this;
                     let target_while_id = Self::resolve_break_or_continue_target(ctx, entry, stmt.span, &stmt.label)?;
                     let continue_stmt = &mut ctx.heap[stmt_id];
                     continue_stmt.target = target_while_id;
                 },
                 Statement::Goto(stmt) => {
                     let stmt_id = stmt.this;
                     let target_id = Self::find_label(entry.in_scope, ctx, &stmt.label)?;
                     let target_stmt = &ctx.heap[target_id];
                     if entry.in_sync != target_stmt.in_sync {
                         // Nested sync not allowed. And goto can only go to
                         // outer scopes, so we must be escaping from a sync.
                         debug_assert!(target_stmt.in_sync.is_invalid());    // target not in sync
                         debug_assert!(!entry.in_sync.is_invalid()); // but the goto is in sync
                         let goto_stmt = &ctx.heap[stmt_id];
                         let sync_stmt = &ctx.heap[entry.in_sync];
                         return Err(
                             ParseError::new_error_str_at_span(&ctx.module().source, goto_stmt.span, "goto may not escape the surrounding synchronous block")
                             .with_info_str_at_span(&ctx.module().source, target_stmt.label.span, "this is the target of the goto statement")
                             .with_info_str_at_span(&ctx.module().source, sync_stmt.span, "which will jump past this statement")
                         );
+                    }
                     let goto_stmt = &mut ctx.heap[stmt_id];
                     goto_stmt.target = target_id;
                 },
                 _ => unreachable!("cannot resolve control flow target for {:?}", stmt),
+            }
+        }
         return Ok(())
+    }
     //--------------------------------------------------------------------------
     // Utilities
     //--------------------------------------------------------------------------
     /// Adds a local variable to the current scope. It will also annotate the
     /// `Local` in the AST with its relative position in the block.
     fn checked_add_local(&mut self, ctx: &mut Ctx, target_scope: Scope, target_relative_pos: i32, id: VariableId) -> Result<(), ParseError> {
         debug_assert!(target_scope.is_block());
         let local = &ctx.heap[id];
     fn checked_add_local(&mut self, ctx: &mut Ctx, target_scope_id: ScopeId, target_relative_pos: i32, new_variable_id: VariableId) -> Result<(), ParseError> {
         let new_variable = &ctx.heap[new_variable_id];
         // We immediately go to the parent scope. We check the target scope
         // in the call at the end. That is also where we check for collisions
         // with symbols.
         let block = &ctx.heap[target_scope.to_block()];
         let mut scope = block.scope_node.parent;
         let mut cur_relative_pos = block.scope_node.relative_pos_in_parent;
         loop {
             if let Scope::Definition(definition_id) = scope {
                 // At outer scope, check parameters of function/component
                 for parameter_id in ctx.heap[definition_id].parameters() {
                     let parameter = &ctx.heap[*parameter_id];
                     if local.identifier == parameter.identifier {
         let mut scope = &ctx.heap[target_scope_id];
         let mut cur_relative_pos = scope.relative_pos_in_parent;
         while let Some(scope_parent_id) = scope.parent {
             scope = &ctx.heap[scope_parent_id];
             // Check for collisions
             for variable_id in scope.variables.iter().copied() {
                 let existing_variable = &ctx.heap[variable_id];
                 if existing_variable.identifier == new_variable.identifier &&
                     existing_variable.this != new_variable_id &&
                     cur_relative_pos >= existing_variable.relative_pos_in_parent {
                     return Err(
                         ParseError::new_error_str_at_span(
-                                &ctx.module().source, local.identifier.span, "Local variable name conflicts with parameter"
+                            &ctx.module().source, new_variable.identifier.span, "Local variable name conflicts with another variable"
                         ).with_info_str_at_span(
-                                &ctx.module().source, parameter.identifier.span, "Parameter definition is found here"
+                            &ctx.module().source, existing_variable.identifier.span, "Previous variable is found here"
+                        )
                     );
+                }
+            }
                 // No collisions
                 break;
+            }
             // If here then the parent scope is a block scope
             let block = &ctx.heap[scope.to_block()];
             for other_local_id in &block.locals {
                 let other_local = &ctx.heap[*other_local_id];
                 // Position check in case another variable with the same name
                 // is defined in a higher-level scope, but later than the scope
                 // in which the current variable resides.
                 if local.this != *other_local_id &&
                     cur_relative_pos >= other_local.relative_pos_in_block &&
                     local.identifier == other_local.identifier {
                     // Collision within this scope
                     return Err(
                         ParseError::new_error_str_at_span(
                             &ctx.module().source, local.identifier.span, "Local variable name conflicts with another variable"
                         ).with_info_str_at_span(
                             &ctx.module().source, other_local.identifier.span, "Previous variable is found here"
+                        )
                     );
+                }
+            }
             scope = block.scope_node.parent;
             cur_relative_pos = block.scope_node.relative_pos_in_parent;
             cur_relative_pos = scope.relative_pos_in_parent;
+        }
         // No collisions in any of the parent scope, attempt to add to scope
-        self.checked_at_single_scope_add_local(ctx, target_scope, target_relative_pos, id)
+        self.checked_at_single_scope_add_local(ctx, target_scope_id, target_relative_pos, new_variable_id)
+    }
     /// Adds a local variable to the specified scope. Will check the specified
     /// scope for variable conflicts and the symbol table for global conflicts.
     /// Will NOT check parent scopes of the specified scope.
     fn checked_at_single_scope_add_local(
-        &mut self, ctx: &mut Ctx, scope: Scope, relative_pos: i32, id: VariableId
+        &mut self, ctx: &mut Ctx, scope_id: ScopeId, relative_pos: i32, new_variable_id: VariableId
     ) -> Result<(), ParseError> {
         // Check the symbol table for conflicts
+        {
             let cur_scope = SymbolScope::Definition(self.def_type.definition_id());
             let ident = &ctx.heap[id].identifier;
             let cur_scope = SymbolScope::Definition(self.proc_id.upcast());
             let ident = &ctx.heap[new_variable_id].identifier;
             if let Some(symbol) = ctx.symbols.get_symbol_by_name(cur_scope, &ident.value.as_bytes()) {
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, ident.span,
                     "local variable declaration conflicts with symbol"
                 ).with_info_str_at_span(
                     &ctx.module().source, symbol.variant.span_of_introduction(&ctx.heap), "the conflicting symbol is introduced here"
                 ));
+            }
+        }
         // Check the specified scope for conflicts
         let local = &ctx.heap[id];
         let new_variable = &ctx.heap[new_variable_id];
         let scope = &ctx.heap[scope_id];
         debug_assert!(scope.is_block());
         let block = &ctx.heap[scope.to_block()];
         for other_local_id in &block.locals {
             let other_local = &ctx.heap[*other_local_id];
             if local.this != other_local.this &&
         for variable_id in scope.variables.iter().copied() {
             let old_variable = &ctx.heap[variable_id];
             if new_variable.this != old_variable.this &&
                 // relative_pos >= other_local.relative_pos_in_block &&
-                local.identifier == other_local.identifier {
+                new_variable.identifier == old_variable.identifier {
                 // Collision
                 return Err(
                     ParseError::new_error_str_at_span(
-                        &ctx.module().source, local.identifier.span, "Local variable name conflicts with another variable"
+                        &ctx.module().source, new_variable.identifier.span, "Local variable name conflicts with another variable"
                     ).with_info_str_at_span(
-                        &ctx.module().source, other_local.identifier.span, "Previous variable is found here"
+                        &ctx.module().source, old_variable.identifier.span, "Previous variable is found here"
+                    )
                 );
+            }
+        }
         // No collisions
         let block = &mut ctx.heap[scope.to_block()];
         block.locals.push(id);
         let scope = &mut ctx.heap[scope_id];
         scope.variables.push(new_variable_id);
         let local = &mut ctx.heap[id];
         local.relative_pos_in_block = relative_pos;
         let variable = &mut ctx.heap[new_variable_id];
         variable.relative_pos_in_parent = relative_pos;
         Ok(())
+    }
     /// Finds a variable in the visitor's scope that must appear before the
     /// specified relative position within that block.
     fn find_variable(&self, ctx: &Ctx, mut relative_pos: i32, identifier: &Identifier) -> Option<VariableId> {
         debug_assert!(self.cur_scope.is_block());
         // No need to use iterator over namespaces if here
         let mut scope = &self.cur_scope;
         let mut scope_id = self.cur_scope;
         loop {
             debug_assert!(scope.is_block());
             let block = &ctx.heap[scope.to_block()];
             // Check if we can find the variable in the current scope
             let scope = &ctx.heap[scope_id];
             for local_id in &block.locals {
                 let local = &ctx.heap[*local_id];
             for variable_id in scope.variables.iter().copied() {
                 let variable = &ctx.heap[variable_id];
                 if local.relative_pos_in_block < relative_pos && identifier == &local.identifier {
                     return Some(*local_id);
                 if variable.relative_pos_in_parent < relative_pos && identifier == &variable.identifier {
                     return Some(variable_id);
+                }
+            }
             scope = &block.scope_node.parent;
             if !scope.is_block() {
                 // Definition scope, need to check arguments to definition
                 match scope {
                     Scope::Definition(definition_id) => {
                         let definition = &ctx.heap[*definition_id];
                         for parameter_id in definition.parameters() {
                             let parameter = &ctx.heap[*parameter_id];
                             if identifier == &parameter.identifier {
                                 return Some(*parameter_id);
+                            }
+                        }
                     },
                     _ => unreachable!(),
             // Could not find variable, move to parent scope and try again
             if scope.parent.is_none() {
                 return None;
+            }
                 // Variable could not be found
                 return None
             } else {
                 relative_pos = block.scope_node.relative_pos_in_parent;
+            }
             scope_id = scope.parent.unwrap();
             relative_pos = scope.relative_pos_in_parent;
+        }
+    }
     /// Adds a particular label to the current scope. Will return an error if
     /// there is another label with the same name visible in the current scope.
     fn checked_add_label(&mut self, ctx: &mut Ctx, relative_pos: i32, in_sync: SynchronousStatementId, id: LabeledStatementId) -> Result<(), ParseError> {
         debug_assert!(self.cur_scope.is_block());
     fn checked_add_label(&mut self, ctx: &mut Ctx, relative_pos: i32, in_sync: SynchronousStatementId, new_label_id: LabeledStatementId) -> Result<(), ParseError> {
         // Make sure label is not defined within the current scope or any of the
         // parent scope.
         let label = &mut ctx.heap[id];
         label.relative_pos_in_block = relative_pos;
         label.in_sync = in_sync;
         let new_label = &mut ctx.heap[new_label_id];
         new_label.relative_pos_in_parent = relative_pos;
         new_label.in_sync = in_sync;
         let label = &ctx.heap[id];
         let mut scope = &self.cur_scope;
         let new_label = &ctx.heap[new_label_id];
         let mut scope_id = self.cur_scope;
         loop {
             debug_assert!(scope.is_block(), "scope is not a block");
             let block = &ctx.heap[scope.to_block()];
             for other_label_id in &block.labels {
                 let other_label = &ctx.heap[*other_label_id];
                 if other_label.label == label.label {
             let scope = &ctx.heap[scope_id];
             for existing_label_id in scope.labels.iter().copied() {
                 let existing_label = &ctx.heap[existing_label_id];
                 if existing_label.label == new_label.label {
                     // Collision
                     return Err(ParseError::new_error_str_at_span(
-                        &ctx.module().source, label.label.span, "label name is used more than once"
+                        &ctx.module().source, new_label.label.span, "label name is used more than once"
                     ).with_info_str_at_span(
-                        &ctx.module().source, other_label.label.span, "the other label is found here"
+                        &ctx.module().source, existing_label.label.span, "the other label is found here"
                     ));
+                }
+            }
             scope = &block.scope_node.parent;
             if !scope.is_block() {
             if scope.parent.is_none() {
                 break;
+            }
             scope_id = scope.parent.unwrap();
+        }
         // No collisions
         let block = &mut ctx.heap[self.cur_scope.to_block()];
         block.labels.push(id);
         let scope = &mut ctx.heap[self.cur_scope];
         scope.labels.push(new_label_id);
         Ok(())
+    }
     /// Finds a particular labeled statement by its identifier. Once found it
     /// will make sure that the target label does not skip over any variable
     /// declarations within the scope in which the label was found.
     fn find_label(mut scope: Scope, ctx: &Ctx, identifier: &Identifier) -> Result<LabeledStatementId, ParseError> {
         debug_assert!(scope.is_block());
     fn find_label(mut scope_id: ScopeId, ctx: &Ctx, identifier: &Identifier) -> Result<LabeledStatementId, ParseError> {
         loop {
             debug_assert!(scope.is_block(), "scope is not a block");
             let relative_scope_pos = ctx.heap[scope.to_block()].scope_node.relative_pos_in_parent;
             let scope = &ctx.heap[scope_id];
             let relative_scope_pos = scope.relative_pos_in_parent;
             let block = &ctx.heap[scope.to_block()];
             for label_id in &block.labels {
                 let label = &ctx.heap[*label_id];
             for label_id in scope.labels.iter().copied() {
                 let label = &ctx.heap[label_id];
                 if label.label == *identifier {
                     for local_id in &block.locals {
                     // Found the target label, now make sure that the jump to
                     // the label doesn't imply a skipped variable declaration
                     for variable_id in scope.variables.iter().copied() {
                         // TODO: Better to do this in control flow analysis, it
                         //  is legal to skip over a variable declaration if it
                         //  is not actually being used. I might be missing
                         //  something here when laying out the bytecode...
                         let local = &ctx.heap[*local_id];
                         if local.relative_pos_in_block > relative_scope_pos && local.relative_pos_in_block < label.relative_pos_in_block {
                         //  is not actually being used.
                         let variable = &ctx.heap[variable_id];
                         if variable.relative_pos_in_parent > relative_scope_pos && variable.relative_pos_in_parent < label.relative_pos_in_parent {
                             return Err(
                                 ParseError::new_error_str_at_span(&ctx.module().source, identifier.span, "this target label skips over a variable declaration")
                                 .with_info_str_at_span(&ctx.module().source, label.label.span, "because it jumps to this label")
-                                .with_info_str_at_span(&ctx.module().source, local.identifier.span, "which skips over this variable")
+                                .with_info_str_at_span(&ctx.module().source, variable.identifier.span, "which skips over this variable")
                             );
+                        }
+                    }
-                    return Ok(*label_id);
                     return Ok(label_id);
+                }
+            }
             scope = block.scope_node.parent;
             if !scope.is_block() {
             if scope.parent.is_none() {
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, identifier.span, "could not find this label"
                 ));
+            }
             scope_id = scope.parent.unwrap();
+        }
+    }
     /// This function will check if the provided while statement ID has a block
     /// statement that is one of our current parents.
     fn has_parent_while_scope(mut scope: Scope, ctx: &Ctx, id: WhileStatementId) -> bool {
         let while_stmt = &ctx.heap[id];
     /// This function will check if the provided scope has a parent that belongs
     /// to a while statement.
     fn scope_is_nested_in_while_statement(mut scope_id: ScopeId, ctx: &Ctx, expected_while_id: WhileStatementId) -> bool {
         let while_stmt = &ctx.heap[expected_while_id];
         loop {
             debug_assert!(scope.is_block());
             let block = scope.to_block();
             if while_stmt.body == block {
             let scope = &ctx.heap[scope_id];
             if scope.this == while_stmt.scope {
                 return true;
+            }
             let block = &ctx.heap[block];
             scope = block.scope_node.parent;
             if !scope.is_block() {
                 return false;
             match scope.parent {
                 Some(new_scope_id) => scope_id = new_scope_id,
                 None => return false, // walked all the way up, not encountering the while statement
+            }
+        }
+    }
     /// This function should be called while dealing with break/continue
     /// statements. It will try to find the targeted while statement, using the
     /// target label if provided. If a valid target is found then the loop's
     /// ID will be returned, otherwise a parsing error is constructed.
     /// The provided input position should be the position of the break/continue
     /// statement.
     fn resolve_break_or_continue_target(ctx: &Ctx, control_flow: &ControlFlowStatement, span: InputSpan, label: &Option<Identifier>) -> Result<WhileStatementId, ParseError> {
         let target = match label {
             Some(label) => {
                 let target_id = Self::find_label(control_flow.in_scope, ctx, label)?;
                 // Make sure break target is a while statement
                 let target = &ctx.heap[target_id];
                 if let Statement::While(target_stmt) = &ctx.heap[target.body] {
                     // Even though we have a target while statement, the break might not be
                     // present underneath this particular labeled while statement
                     if !Self::has_parent_while_scope(control_flow.in_scope, ctx, target_stmt.this) {
                     // Even though we have a target while statement, the control
                     // flow statement might not be present underneath this
                     // particular labeled while statement.
                     if !Self::scope_is_nested_in_while_statement(control_flow.in_scope, ctx, target_stmt.this) {
                         return Err(ParseError::new_error_str_at_span(
                             &ctx.module().source, label.span, "break statement is not nested under the target label's while statement"
                         ).with_info_str_at_span(
                             &ctx.module().source, target.label.span, "the targeted label is found here"
                         ));
+                    }
                     target_stmt.this
                 } else {
                     return Err(ParseError::new_error_str_at_span(
                         &ctx.module().source, label.span, "incorrect break target label, it must target a while loop"
                     ).with_info_str_at_span(
                         &ctx.module().source, target.label.span, "The targeted label is found here"
                     ));
+                }
             },
             None => {
                 // Use the enclosing while statement, the break must be
                 // nested within that while statement
                 if control_flow.in_while.is_invalid() {
                     return Err(ParseError::new_error_str_at_span(
                         &ctx.module().source, span, "Break statement is not nested under a while loop"
                     ));
+                }
                 control_flow.in_while
+            }
         };
         // We have a valid target for the break statement. But we need to
         // make sure we will not break out of a synchronous block
+        {
             let target_while = &ctx.heap[target];
             if target_while.in_sync != control_flow.in_sync {
                 // Break is nested under while statement, so can only escape a
                 // sync block if the sync is nested inside the while statement.
                 debug_assert!(!control_flow.in_sync.is_invalid());
                 let sync_stmt = &ctx.heap[control_flow.in_sync];
                 return Err(
                     ParseError::new_error_str_at_span(&ctx.module().source, span, "break may not escape the surrounding synchronous block")
                         .with_info_str_at_span(&ctx.module().source, target_while.span, "the break escapes out of this loop")
                         .with_info_str_at_span(&ctx.module().source, sync_stmt.span, "And would therefore escape this synchronous block")
                 );
+            }
+        }
         Ok(target)
+    }
+}
@@ \ No newline at end of file @@

src/protocol/parser/type_table.rs

➞

Show inline comments

 /**
  * type_table.rs
+ *
  * The type table is a lookup from AST definition (which contains just what the
  * programmer typed) to a type with additional information computed (e.g. the
  * byte size and offsets of struct members). The type table should be considered
  * the authoritative source of information on types by the compiler (not the
  * AST itself!).
+ *
  * The type table operates in two modes: one is where we just look up the type,
  * check its fields for correctness and mark whether it is polymorphic or not.
  * The second one is where we compute byte sizes, alignment and offsets.
+ *
  * The basic algorithm for type resolving and computing byte sizes is to
  * recursively try to lay out each member type of a particular type. This is
  * done in a stack-like fashion, where each embedded type pushes a breadcrumb
  * unto the stack. We may discover a cycle in embedded types (we call this a
  * "type loop"). After which the type table attempts to break the type loop by
  * making specific types heap-allocated. Upon doing so we know their size
  * because their stack-size is now based on pointers. Hence breaking the type
  * loop required for computing the byte size of types.
+ *
  * The reason for these type shenanigans is because PDL is a value-based
  * language, but we would still like to be able to express recursively defined
  * types like trees or linked lists. Hence we need to insert pointers somewhere
  * to break these cycles.
+ *
  * We will insert these pointers into the variants of unions. However note that
  * we can only compute the stack size of a union until we've looked at *all*
  * variants. Hence we perform an initial pass where we detect type loops, a
  * second pass where we compute the stack sizes of everything, and a third pass
  * where we actually compute the size of the heap allocations for unions.
+ *
  * As a final bit of global documentation: non-polymorphic types will always
  * have one "monomorph" entry. This contains the non-polymorphic type's memory
  * layout.
  */
 use std::fmt::{Formatter, Result as FmtResult};
 // Programmer note: deduplication of types is currently disabled, see the
 // @Deduplication key. Tests might fail when it is re-enabled.
 use std::collections::HashMap;
 use std::hash::{Hash, Hasher};
 use crate::protocol::ast::*;
 use crate::protocol::parser::symbol_table::SymbolScope;
 use crate::protocol::input_source::ParseError;
 use crate::protocol::parser::*;
 //------------------------------------------------------------------------------
 // Defined Types
 //------------------------------------------------------------------------------
 #[derive(Copy, Clone, PartialEq, Eq)]
 pub enum TypeClass {
     Enum,
     Union,
     Struct,
     Function,
     Component
+}
 impl TypeClass {
     pub(crate) fn display_name(&self) -> &'static str {
         match self {
             TypeClass::Enum => "enum",
             TypeClass::Union => "union",
             TypeClass::Struct => "struct",
             TypeClass::Function => "function",
             TypeClass::Component => "component",
+        }
+    }
     pub(crate) fn is_data_type(&self) -> bool {
         match self {
             TypeClass::Enum | TypeClass::Union | TypeClass::Struct => true,
             TypeClass::Function | TypeClass::Component => false,
+        }
+    }
+}
 impl std::fmt::Display for TypeClass {
     fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
         write!(f, "{}", self.display_name())
+    }
+}
 /// Struct wrapping around a potentially polymorphic type. If the type does not
 /// have any polymorphic arguments then it will not have any monomorphs and
 /// `is_polymorph` will be set to `false`. A type with polymorphic arguments
 /// only has `is_polymorph` set to `true` if the polymorphic arguments actually
 /// appear in the types associated types (function return argument, struct
 /// field, enum variant, etc.). Otherwise the polymorphic argument is just a
 /// marker and does not influence the bytesize of the type.
 pub struct DefinedType {
     pub(crate) ast_root: RootId,
     pub(crate) ast_definition: DefinitionId,
     pub(crate) definition: DefinedTypeVariant,
     pub(crate) poly_vars: Vec<PolymorphicVariable>,
     pub(crate) is_polymorph: bool,
+}
 pub enum DefinedTypeVariant {
     Enum(EnumType),
     Union(UnionType),
     Struct(StructType),
     Function(FunctionType),
     Component(ComponentType)
     Procedure(ProcedureType),
+}
 impl DefinedTypeVariant {
     pub(crate) fn type_class(&self) -> TypeClass {
     pub(crate) fn is_data_type(&self) -> bool {
         use DefinedTypeVariant as DTV;
         match self {
             DefinedTypeVariant::Enum(_) => TypeClass::Enum,
             DefinedTypeVariant::Union(_) => TypeClass::Union,
             DefinedTypeVariant::Struct(_) => TypeClass::Struct,
             DefinedTypeVariant::Function(_) => TypeClass::Function,
             DefinedTypeVariant::Component(_) => TypeClass::Component
             DTV::Struct(_) | DTV::Enum(_) | DTV::Union(_) => return true,
             DTV::Procedure(_) => return false,
+        }
+    }
     pub(crate) fn as_struct(&self) -> &StructType {
         match self {
             DefinedTypeVariant::Struct(v) => v,
-            _ => unreachable!("Cannot convert {} to struct variant", self.type_class())
             _ => unreachable!()
+        }
+    }
     pub(crate) fn as_enum(&self) -> &EnumType {
         match self {
             DefinedTypeVariant::Enum(v) => v,
-            _ => unreachable!("Cannot convert {} to enum variant", self.type_class())
             _ => unreachable!()
+        }
+    }
     pub(crate) fn as_union(&self) -> &UnionType {
         match self {
             DefinedTypeVariant::Union(v) => v,
-            _ => unreachable!("Cannot convert {} to union variant", self.type_class())
             _ => unreachable!()
+        }
+    }
+}
 pub struct PolymorphicVariable {
     identifier: Identifier,
     is_in_use: bool, // a polymorphic argument may be defined, but not used by the type definition
     pub(crate) identifier: Identifier,
     pub(crate) is_in_use: bool, // a polymorphic argument may be defined, but not used by the type definition
+}
 /// `EnumType` is the classical C/C++ enum type. It has various variants with
 /// an assigned integer value. The integer values may be user-defined,
 /// compiler-defined, or a mix of the two. If a user assigns the same enum
 /// value multiple times, we assume the user is an expert and we consider both
 /// variants to be equal to one another.
 pub struct EnumType {
     pub variants: Vec<EnumVariant>,
     pub minimum_tag_value: i64,
     pub maximum_tag_value: i64,
     pub tag_type: ConcreteType,
     pub size: usize,
     pub alignment: usize,
+}
 // TODO: Also support maximum u64 value
 pub struct EnumVariant {
     pub identifier: Identifier,
     pub value: i64,
+}
 /// `UnionType` is the algebraic datatype (or sum type, or discriminated union).
 /// A value is an element of the union, identified by its tag, and may contain
 /// a single subtype.
 /// For potentially infinite types (i.e. a tree, or a linked list) only unions
 /// can break the infinite cycle. So when we lay out these unions in memory we
 /// will reserve enough space on the stack for all union variants that do not
 /// cause "type loops" (i.e. a union `A` with a variant containing a struct
 /// `B`). And we will reserve enough space on the heap (and store a pointer in
 /// the union) for all variants which do cause type loops (i.e. a union `A`
 /// with a variant to a struct `B` that contains the union `A` again).
 pub struct UnionType {
     pub variants: Vec<UnionVariant>,
     pub tag_type: ConcreteType,
     pub tag_size: usize,
+}
 pub struct UnionVariant {
     pub identifier: Identifier,
     pub embedded: Vec<ParserType>, // zero-length does not have embedded values
     pub tag_value: i64,
+}
 /// `StructType` is a generic C-like struct type (or record type, or product
 /// type) type.
 pub struct StructType {
     pub fields: Vec<StructField>,
+}
 pub struct StructField {
     pub identifier: Identifier,
     pub parser_type: ParserType,
+}
 /// `FunctionType` is what you expect it to be: a particular function's
 /// signature.
 pub struct FunctionType {
     pub return_types: Vec<ParserType>,
     pub arguments: Vec<FunctionArgument>,
+}
 pub struct ComponentType {
     pub variant: ComponentVariant,
     pub arguments: Vec<FunctionArgument>,
 /// `ProcedureType` is the signature of a procedure/component
 pub struct ProcedureType {
     pub kind: ProcedureKind,
     pub return_type: Option<ParserType>,
     pub arguments: Vec<ProcedureArgument>,
+}
-pub struct FunctionArgument {
+pub struct ProcedureArgument {
     identifier: Identifier,
     parser_type: ParserType,
+}
 /// Represents the data associated with a single expression after type inference
 /// for a monomorph (or just the normal expression types, if dealing with a
 /// non-polymorphic function/component).
 pub struct MonomorphExpression {
     // The output type of the expression. Note that for a function it is not the
     // function's signature but its return type
     pub(crate) expr_type: ConcreteType,
     // Has multiple meanings: the field index for select expressions, the
     // monomorph index for polymorphic function calls or literals. Negative
     // values are never used, but used to catch programming errors.
     pub(crate) field_or_monomorph_idx: i32,
     pub(crate) type_id: TypeId,
+}
 //------------------------------------------------------------------------------
 // Type monomorph storage
 //------------------------------------------------------------------------------
 /// Generic monomorph has a specific concrete type, a size and an alignment.
 /// Extra data is in the `MonomorphVariant` per kind of type.
 pub(crate) struct TypeMonomorph {
     pub concrete_type: ConcreteType,
     pub size: usize,
     pub alignment: usize,
     pub variant: MonomorphVariant,
+}
 pub(crate) enum MonomorphVariant {
 pub(crate) enum MonoTypeVariant {
     Builtin, // no extra data, added manually in compiler initialization code
     Enum, // no extra data
     Struct(StructMonomorph),
     Union(UnionMonomorph),
     Procedure(ProcedureMonomorph), // functions, components
     Tuple(TupleMonomorph),
+}
-impl MonomorphVariant {
+impl MonoTypeVariant {
     fn as_struct_mut(&mut self) -> &mut StructMonomorph {
         match self {
-            MonomorphVariant::Struct(v) => v,
+            MonoTypeVariant::Struct(v) => v,
             _ => unreachable!(),
+        }
+    }
     pub(crate) fn as_union(&self) -> &UnionMonomorph {
         match self {
-            MonomorphVariant::Union(v) => v,
+            MonoTypeVariant::Union(v) => v,
             _ => unreachable!(),
+        }
+    }
     fn as_union_mut(&mut self) -> &mut UnionMonomorph {
         match self {
-            MonomorphVariant::Union(v) => v,
+            MonoTypeVariant::Union(v) => v,
             _ => unreachable!(),
+        }
+    }
     fn as_tuple_mut(&mut self) -> &mut TupleMonomorph {
         match self {
-            MonomorphVariant::Tuple(v) => v,
+            MonoTypeVariant::Tuple(v) => v,
             _ => unreachable!(),
+        }
+    }
     fn as_procedure(&self) -> &ProcedureMonomorph {
+    pub(crate) fn as_procedure(&self) -> &ProcedureMonomorph {
         match self {
-            MonomorphVariant::Procedure(v) => v,
+            MonoTypeVariant::Procedure(v) => v,
             _ => unreachable!(),
+        }
+    }
     fn as_procedure_mut(&mut self) -> &mut ProcedureMonomorph {
         match self {
-            MonomorphVariant::Procedure(v) => v,
+            MonoTypeVariant::Procedure(v) => v,
             _ => unreachable!(),
+        }
+    }
+}
 /// Struct monomorph
 pub struct StructMonomorph {
     pub fields: Vec<StructMonomorphField>,
+}
 pub struct StructMonomorphField {
     pub concrete_type: ConcreteType,
     pub type_id: TypeId,
     concrete_type: ConcreteType,
     pub size: usize,
     pub alignment: usize,
     pub offset: usize,
+}
 /// Union monomorph
 pub struct UnionMonomorph {
     pub variants: Vec<UnionMonomorphVariant>,
     pub tag_size: usize, // copied from `UnionType` upon monomorph construction.
     // note that the stack size is in the `TypeMonomorph` struct. This size and
     // alignment will include the size of the union tag.
     //
     // heap_size contains the allocated size of the union in the case it
     // is used to break a type loop. If it is 0, then it doesn't require
     // allocation and lives entirely on the stack.
     pub heap_size: usize,
     pub heap_alignment: usize,
+}
 pub struct UnionMonomorphVariant {
     pub lives_on_heap: bool,
     pub embedded: Vec<UnionMonomorphEmbedded>,
+}
 pub struct UnionMonomorphEmbedded {
     pub concrete_type: ConcreteType,
     pub type_id: TypeId,
     concrete_type: ConcreteType,
     // Note that the meaning of the offset (and alignment) depend on whether or
     // not the variant lives on the stack/heap. If it lives on the stack then
     // they refer to the offset from the start of the union value (so the first
     // embedded type lives at a non-zero offset, because the union tag sits in
     // the front). If it lives on the heap then it refers to the offset from the
     // allocated memory region (so the first embedded type lives at a 0 offset).
     pub size: usize,
     pub alignment: usize,
     pub offset: usize,
+}
 /// Procedure (functions and components of all possible types) monomorph. Also
 /// stores the expression type data from the typechecking/inferencing pass.
 pub struct ProcedureMonomorph {
     // Expression data for one particular monomorph
     pub arg_types: Vec<ConcreteType>,
     pub expr_data: Vec<MonomorphExpression>,
     pub monomorph_index: u32,
     pub builtin: bool,
+}
 /// Tuple monomorph. Again a kind of exception because one cannot define a named
 /// tuple type containing explicit polymorphic variables. But again: we need to
 /// store size/offset/alignment information, so we do it here.
 pub struct TupleMonomorph {
     pub members: Vec<TupleMonomorphMember>
+}
 pub struct TupleMonomorphMember {
     pub concrete_type: ConcreteType,
     pub type_id: TypeId,
     concrete_type: ConcreteType,
     pub size: usize,
     pub alignment: usize,
     pub offset: usize,
+}
 /// Key used to perform lookups in the monomorph table. It computes a hash of
 /// the type while not taking the unused polymorphic variables of the base type
 /// into account (e.g. `struct Foo<A,B>{ A field }`, here `B` is an unused
 /// polymorphic variable).
 struct MonomorphKey {
     parts: Vec<ConcreteTypePart>,
     in_use: Vec<bool>, // TODO: @Performance, limit num args and use two `u64` as bitflags or something
+}
 /// Generic unique type ID. Every monomorphed type and every non-polymorphic
 /// type will have one of these associated with it.
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub struct TypeId(i64);
 use std::hash::*;
 impl TypeId {
     pub(crate) fn new_invalid() -> Self {
         return Self(-1);
+    }
+}
 impl Hash for MonomorphKey {
     fn hash<H: Hasher>(&self, state: &mut H) {
         // if `in_use` is empty, then we may assume the type is not polymorphic
         // (or all types are in use)
         if self.in_use.is_empty() {
             self.parts.hash(state);
         } else {
             // type is polymorphic
             self.parts[0].hash(state);
 /// A monomorphed type (or non-polymorphic type's) memory layout and information
 /// regarding associated types (like a struct's field type).
 pub struct MonoType {
     pub type_id: TypeId,
     pub concrete_type: ConcreteType,
     pub size: usize,
     pub alignment: usize,
     pub(crate) variant: MonoTypeVariant
+}
             // note: hash is computed in a unique way, because practically
             // speaking `in_use` is fixed per base type. So we cannot have the
             // same base type (hence: a type with the same DefinitionId) with
             // different different polymorphic variables in use.
             let mut in_use_index = 0;
             for section in ConcreteTypeIter::new(self.parts.as_slice(), 0) {
                 if self.in_use[in_use_index] {
                     section.hash(state);
 impl MonoType {
     #[inline]
     fn new_empty(type_id: TypeId, concrete_type: ConcreteType, variant: MonoTypeVariant) -> Self {
         return Self {
             type_id, concrete_type,
             size: 0,
             alignment: 0,
             variant,
+        }
                 in_use_index += 1;
+    }
     /// Little internal helper function as a reminder: if alignment is 0, then
     /// the size/alignment are not actually computed yet!
     #[inline]
     fn get_size_alignment(&self) -> Option<(usize, usize)> {
         if self.alignment == 0 {
             return None
         } else {
             return Some((self.size, self.alignment));
+        }
+    }
+}
 impl PartialEq for MonomorphKey {
     fn eq(&self, other: &Self) -> bool {
         if self.in_use.is_empty() {
             let temp_result = self.parts == other.parts;
             return temp_result;
         } else {
             // Outer type does not match
             if self.parts[0] != other.parts[0] {
                 return false;
 /// Special structure that acts like the lookup key for `ConcreteType` instances
 /// that have already been added to the type table before.
 #[derive(Clone)]
 struct MonoSearchKey {
     // Uses bitflags to denote when parts between search keys should match and
     // whether they should be checked. Needs to have a system like this to
     // accommodate tuples.
     parts: Vec<(u8, ConcreteTypePart)>,
     change_bit: u8,
+}
 impl MonoSearchKey {
     const KEY_IN_USE: u8 = 0x01;
     const KEY_CHANGE_BIT: u8 = 0x02;
     fn with_capacity(capacity: usize) -> Self {
         return MonoSearchKey{
             parts: Vec::with_capacity(capacity),
             change_bit: 0,
         };
+    }
             debug_assert_eq!(self.parts[0].num_embedded() as usize, self.in_use.len());
             let mut iter_self = ConcreteTypeIter::new(self.parts.as_slice(), 0);
             let mut iter_other = ConcreteTypeIter::new(other.parts.as_slice(), 0);
             let mut index = 0;
             while let Some(section_self) = iter_self.next() {
                 let section_other = iter_other.next().unwrap();
                 let in_use = self.in_use[index];
                 index += 1;
     /// Sets the search key based on a single concrete type and its polymorphic
     /// variables.
     fn set(&mut self, concrete_type_parts: &[ConcreteTypePart], poly_var_in_use: &[PolymorphicVariable]) {
         self.set_top_type(concrete_type_parts[0]);
                 if !in_use {
                     continue;
         let mut poly_var_index = 0;
         for subtype in ConcreteTypeIter::new(concrete_type_parts, 0) {
             let in_use = poly_var_in_use[poly_var_index].is_in_use;
             poly_var_index += 1;
             self.push_subtype(subtype, in_use);
+        }
                 if section_self != section_other {
                     return false;
+                }
         debug_assert_eq!(poly_var_index, poly_var_in_use.len());
+    }
             return true;
     /// Starts setting the search key based on an initial top-level type,
     /// programmer must call `push_subtype` the appropriate number of times
     /// after calling this function
     fn set_top_type(&mut self, type_part: ConcreteTypePart) {
         self.parts.clear();
         self.parts.push((Self::KEY_IN_USE, type_part));
         self.change_bit = Self::KEY_CHANGE_BIT;
+    }
     fn push_subtype(&mut self, concrete_type: &[ConcreteTypePart], in_use: bool) {
         let flag = self.change_bit | (if in_use { Self::KEY_IN_USE } else { 0 });
         for part in concrete_type {
             self.parts.push((flag, *part));
+        }
         self.change_bit ^= Self::KEY_CHANGE_BIT;
+    }
 impl Eq for MonomorphKey {}
     fn push_subtree(&mut self, concrete_type: &[ConcreteTypePart], poly_var_in_use: &[PolymorphicVariable]) {
         self.parts.push((self.change_bit | Self::KEY_IN_USE, concrete_type[0]));
         self.change_bit ^= Self::KEY_CHANGE_BIT;
 use std::cell::UnsafeCell;
 /// Lookup table for monomorphs. Wrapped in a special struct because we don't
 /// want to allocate for each lookup (what we really want is a HashMap that
 /// exposes its CompareFn and HashFn, but whatevs).
 pub(crate) struct MonomorphTable {
     lookup: HashMap<MonomorphKey, i32>, // indexes into `monomorphs`
     pub(crate) monomorphs: Vec<TypeMonomorph>,
     // We use an UnsafeCell because this is only used internally per call to
     // `get_monomorph_index` calls. This is safe because `&TypeMonomorph`s
     // retrieved for this class remain valid when the key is mutated and the
     // type table is not multithreaded.
     //
     // I added this because we don't want to allocate for each lookup, hence we
     // need a reusable `key` internal to this class. This in turn makes
     // `get_monomorph_index` a mutable call. Now the code that calls this
     // function (even though we're not mutating the table!) needs a lot of extra
     // boilerplate. I opted for the `UnsafeCell` instead of the boilerplate.
     key: UnsafeCell<MonomorphKey>,
         let mut poly_var_index = 0;
         for subtype in ConcreteTypeIter::new(concrete_type, 0) {
             let in_use = poly_var_in_use[poly_var_index].is_in_use;
             poly_var_index += 1;
             self.push_subtype(subtype, in_use);
+        }
 // TODO: Clean this up: somehow prevent the `key`, but also do not allocate for
 //  each "get_monomorph_index"
 unsafe impl Send for MonomorphTable{}
 unsafe impl Sync for MonomorphTable{}
 impl MonomorphTable {
     fn new() -> Self {
         return Self {
             lookup: HashMap::with_capacity(256),
             monomorphs: Vec::with_capacity(256),
             key: UnsafeCell::new(MonomorphKey{
                 parts: Vec::with_capacity(32),
                 in_use: Vec::with_capacity(32),
             }),
         debug_assert_eq!(poly_var_index, poly_var_in_use.len());
+    }
     // Utilities for hashing and comparison
     fn find_end_index(&self, start_index: usize) -> usize {
         // Check if we're already at the end
         let mut index = start_index;
         if index >= self.parts.len() {
             return index;
+        }
     fn insert_with_zero_size_and_alignment(&mut self, concrete_type: ConcreteType, in_use: &[PolymorphicVariable], variant: MonomorphVariant) -> i32 {
         let key = MonomorphKey{
             parts: Vec::from(concrete_type.parts.as_slice()),
             in_use: in_use.iter().map(|v| v.is_in_use).collect(),
         };
         let index = self.monomorphs.len();
         let _result = self.lookup.insert(key, index as i32);
         debug_assert!(_result.is_none()); // did not exist yet
         self.monomorphs.push(TypeMonomorph{
             concrete_type,
             size: 0,
             alignment: 0,
             variant,
         });
         // Iterate until bit flips, or until at end
         let expected_bit = self.parts[index].0 & Self::KEY_CHANGE_BIT;
         return index as i32;
         index += 1;
         while index < self.parts.len() {
             let current_bit = self.parts[index].0 & Self::KEY_CHANGE_BIT;
             if current_bit != expected_bit {
                 return index;
+            }
     fn get_monomorph_index(&self, parts: &[ConcreteTypePart], in_use: &[PolymorphicVariable]) -> Option<i32> {
         let key = unsafe {
             // Clear-and-extend to, at some point, prevent future allocations
             let key = &mut *self.key.get();
             key.parts.clear();
             key.parts.extend_from_slice(parts);
             key.in_use.clear();
             key.in_use.extend(in_use.iter().map(|v| v.is_in_use));
             index += 1;
+        }
             &*key
         };
         return index;
+    }
+}
         match self.lookup.get(key) {
             Some(index) => return Some(*index),
             None => return None,
 impl Hash for MonoSearchKey {
     fn hash<H: Hasher>(&self, state: &mut H) {
         for index in 0..self.parts.len() {
             let (_flags, part) = self.parts[index];
             // if flags & Self::KEY_IN_USE != 0 { @Deduplication
             part.hash(state);
             // }
+        }
+    }
+}
     #[inline]
     fn get(&self, index: i32) -> &TypeMonomorph {
         debug_assert!(index >= 0);
         return &self.monomorphs[index as usize];
 impl PartialEq for MonoSearchKey {
     fn eq(&self, other: &Self) -> bool {
         let mut self_index = 0;
         let mut other_index = 0;
         while self_index < self.parts.len() && other_index < other.parts.len() {
             // Retrieve part and flags
             let (_self_bits, _) = self.parts[self_index];
             let (_other_bits, _) = other.parts[other_index];
             let self_in_use = true; // (self_bits & Self::KEY_IN_USE) != 0; @Deduplication
             let other_in_use = true; // (other_bits & Self::KEY_IN_USE) != 0; @Deduplication
             // Determine ending indices
             let self_end_index = self.find_end_index(self_index);
             let other_end_index = other.find_end_index(other_index);
             if self_in_use == other_in_use {
                 if self_in_use {
                     // Both are in use, so both parts should be equal
                     let delta_self = self_end_index - self_index;
                     let delta_other = other_end_index - other_index;
                     if delta_self != delta_other {
                         // Both in use, but not of equal length, so the types
                         // cannot match
                         return false;
+                    }
     #[inline]
     fn get_mut(&mut self, index: i32) -> &mut TypeMonomorph {
         debug_assert!(index >= 0);
         return &mut self.monomorphs[index as usize];
                     for _ in 0..delta_self {
                         let (_, self_part) = self.parts[self_index];
                         let (_, other_part) = other.parts[other_index];
                         if self_part != other_part {
                             return false;
+                        }
     fn get_monomorph_size_alignment(&self, index: i32) -> Option<(usize, usize)> {
         let monomorph = self.get(index);
         if monomorph.size == 0 && monomorph.alignment == 0 {
             // If both are zero, then we wish to mean: we haven't actually
             // computed the size and alignment yet. So:
             return None;
                         self_index += 1;
                         other_index += 1;
+                    }
                 } else {
             return Some((monomorph.size, monomorph.alignment));
                     // Both not in use, so skip associated parts
                     self_index = self_end_index;
                     other_index = other_end_index;
+                }
             } else {
                 // No agreement on importance of parts. This is practically
                 // impossible
                 unreachable!();
+            }
+        }
         // Everything matched, so if we're at the end of both arrays then we're
         // certain that the two keys are equal.
         return self_index == self.parts.len() && other_index == other.parts.len();
+    }
+}
 impl Eq for MonoSearchKey{}
 //------------------------------------------------------------------------------
 // Type table
 //------------------------------------------------------------------------------
 const POLY_VARS_IN_USE: [PolymorphicVariable; 1] = [PolymorphicVariable{ identifier: Identifier::new_empty(InputSpan::new()), is_in_use: true }];
 // Programmer note: keep this struct free of dynamically allocated memory
 #[derive(Clone)]
 struct TypeLoopBreadcrumb {
-    monomorph_idx: i32,
+    type_id: TypeId,
     next_member: u32,
     next_embedded: u32, // for unions, the index into the variant's embedded types
+}
 // Programmer note: keep this struct free of dynamically allocated memory
 #[derive(Clone)]
 struct MemoryBreadcrumb {
-    monomorph_idx: i32,
+    type_id: TypeId,
     next_member: u32,
     next_embedded: u32,
     first_size_alignment_idx: u32,
+}
 #[derive(Debug, PartialEq, Eq)]
 enum TypeLoopResult {
     TypeExists,
     PushBreadcrumb(DefinitionId, ConcreteType),
     TypeLoop(usize), // index into vec of breadcrumbs at which the type matched
+}
 enum MemoryLayoutResult {
     TypeExists(usize, usize), // (size, alignment)
     PushBreadcrumb(MemoryBreadcrumb),
+}
 // TODO: @Optimize, initial memory-unoptimized implementation
 struct TypeLoopEntry {
-    monomorph_idx: i32,
+    type_id: TypeId,
     is_union: bool,
+}
 struct TypeLoop {
     members: Vec<TypeLoopEntry>
+    members: Vec<TypeLoopEntry>,
+}
 type DefinitionMap = HashMap<DefinitionId, DefinedType>;
 type MonoTypeMap = HashMap<MonoSearchKey, TypeId>;
 type MonoTypeArray = Vec<MonoType>;
 pub struct TypeTable {
     /// Lookup from AST DefinitionId to a defined type. Also lookups for
     /// concrete type to monomorphs
     pub(crate) type_lookup: HashMap<DefinitionId, DefinedType>,
     pub(crate) mono_lookup: MonomorphTable,
     /// Breadcrumbs left behind while trying to find type loops. Also used to
     /// determine sizes of types when all type loops are detected.
     // Lookup from AST DefinitionId to a defined type. Also lookups for
     // concrete type to monomorphs
     pub(crate) definition_lookup: DefinitionMap,
     mono_type_lookup: MonoTypeMap,
     pub(crate) mono_types: MonoTypeArray,
     mono_search_key: MonoSearchKey,
     // Breadcrumbs left behind while trying to find type loops. Also used to
     // determine sizes of types when all type loops are detected.
     type_loop_breadcrumbs: Vec<TypeLoopBreadcrumb>,
     type_loops: Vec<TypeLoop>,
     /// Stores all encountered types during type loop detection. Used afterwards
     /// to iterate over all types in order to compute size/alignment.
     // Stores all encountered types during type loop detection. Used afterwards
     // to iterate over all types in order to compute size/alignment.
     encountered_types: Vec<TypeLoopEntry>,
-    /// Breadcrumbs and temporary storage during memory layout computation.
     // Breadcrumbs and temporary storage during memory layout computation.
     memory_layout_breadcrumbs: Vec<MemoryBreadcrumb>,
     size_alignment_stack: Vec<(usize, usize)>,
+}
 impl TypeTable {
     /// Construct a new type table without any resolved types.
     pub(crate) fn new() -> Self {
         Self{
             type_lookup: HashMap::with_capacity(128),
             mono_lookup: MonomorphTable::new(),
             definition_lookup: HashMap::with_capacity(128),
             mono_type_lookup: HashMap::with_capacity(128),
             mono_types: Vec::with_capacity(128),
             mono_search_key: MonoSearchKey::with_capacity(32),
             type_loop_breadcrumbs: Vec::with_capacity(32),
             type_loops: Vec::with_capacity(8),
             encountered_types: Vec::with_capacity(32),
             memory_layout_breadcrumbs: Vec::with_capacity(32),
             size_alignment_stack: Vec::with_capacity(64),
+        }
+    }
     /// Iterates over all defined types (polymorphic and non-polymorphic) and
     /// add their types in two passes. In the first pass we will just add the
     /// base types (we will not consider monomorphs, and we will not compute
     /// byte sizes). In the second pass we will compute byte sizes of
     /// non-polymorphic types, and potentially the monomorphs that are embedded
     /// in those types.
     pub(crate) fn build_base_types(&mut self, modules: &mut [Module], ctx: &mut PassCtx) -> Result<(), ParseError> {
         // Make sure we're allowed to cast root_id to index into ctx.modules
         debug_assert!(modules.iter().all(|m| m.phase >= ModuleCompilationPhase::DefinitionsParsed));
-        debug_assert!(self.type_lookup.is_empty());
+        debug_assert!(self.definition_lookup.is_empty());
-        if cfg!(debug_assertions) {
+        dbg_code!({
             for (index, module) in modules.iter().enumerate() {
                 debug_assert_eq!(index, module.root_id.index as usize);
+            }
+        }
+        });
         // Use context to guess hashmap size of the base types
         let reserve_size = ctx.heap.definitions.len();
-        self.type_lookup.reserve(reserve_size);
+        self.definition_lookup.reserve(reserve_size);
         // Resolve all base types
         for definition_idx in 0..ctx.heap.definitions.len() {
             let definition_id = ctx.heap.definitions.get_id(definition_idx);
             let definition = &ctx.heap[definition_id];
             match definition {
                 Definition::Enum(_) => self.build_base_enum_definition(modules, ctx, definition_id)?,
                 Definition::Union(_) => self.build_base_union_definition(modules, ctx, definition_id)?,
                 Definition::Struct(_) => self.build_base_struct_definition(modules, ctx, definition_id)?,
                 Definition::Function(_) => self.build_base_function_definition(modules, ctx, definition_id)?,
                 Definition::Component(_) => self.build_base_component_definition(modules, ctx, definition_id)?,
                 Definition::Procedure(_) => self.build_base_procedure_definition(modules, ctx, definition_id)?,
+            }
+        }
-        debug_assert_eq!(self.type_lookup.len(), reserve_size, "mismatch in reserved size of type table"); // NOTE: Temp fix for builtin functions
+        debug_assert_eq!(self.definition_lookup.len(), reserve_size, "mismatch in reserved size of type table");
         for module in modules.iter_mut() {
             module.phase = ModuleCompilationPhase::TypesAddedToTable;
+        }
         // Go through all types again, lay out all types that are not
         // polymorphic. This might cause us to lay out types that are monomorphs
         // of polymorphic types.
         // polymorphic. This might cause us to lay out monomorphized polymorphs
         // if these were member types of non-polymorphic types.
         for definition_idx in 0..ctx.heap.definitions.len() {
             let definition_id = ctx.heap.definitions.get_id(definition_idx);
-            let poly_type = self.type_lookup.get(&definition_id).unwrap();
+            let poly_type = self.definition_lookup.get(&definition_id).unwrap();
-            if !poly_type.definition.type_class().is_data_type() || !poly_type.poly_vars.is_empty() {
             if !poly_type.definition.is_data_type() || !poly_type.poly_vars.is_empty() {
                 continue;
+            }
             // If here then the type is a data type without polymorphic
             // variables, but we might have instantiated it already, so:
             let concrete_parts = [ConcreteTypePart::Instance(definition_id, 0)];
             let mono_index = self.mono_lookup.get_monomorph_index(&concrete_parts, &[]);
             if mono_index.is_none() {
             self.mono_search_key.set(&concrete_parts, &[]);
             let type_id = self.mono_type_lookup.get(&self.mono_search_key);
             if type_id.is_none() {
                 self.detect_and_resolve_type_loops_for(
                     modules, ctx.heap,
+                    modules, ctx.heap, ctx.arch,
                     ConcreteType{
                         parts: vec![ConcreteTypePart::Instance(definition_id, 0)]
                     },
                 )?;
                 self.lay_out_memory_for_encountered_types(ctx.arch);
+            }
+        }
         Ok(())
+    }
     /// Retrieves base definition from type table. We must be able to retrieve
     /// it as we resolve all base types upon type table construction (for now).
     /// However, in the future we might do on-demand type resolving, so return
     /// an option anyway
     #[inline]
     pub(crate) fn get_base_definition(&self, definition_id: &DefinitionId) -> Option<&DefinedType> {
-        self.type_lookup.get(&definition_id)
+        self.definition_lookup.get(&definition_id)
+    }
     /// Returns the index into the monomorph type array if the procedure type
     /// already has a (reserved) monomorph.
     /// FIXME: This really shouldn't be called from within the runtime. See UnsafeCell in MonomorphTable
     #[inline]
     pub(crate) fn get_procedure_monomorph_index(&self, definition_id: &DefinitionId, type_parts: &[ConcreteTypePart]) -> Option<i32> {
         let base_type = self.type_lookup.get(definition_id).unwrap();
         return self.mono_lookup.get_monomorph_index(type_parts, &base_type.poly_vars);
+    }
     #[inline]
     pub(crate) fn get_monomorph(&self, monomorph_index: i32) -> &TypeMonomorph {
         return self.mono_lookup.get(monomorph_index);
+    }
     pub(crate) fn get_procedure_monomorph_type_id(&self, definition_id: &DefinitionId, type_parts: &[ConcreteTypePart]) -> Option<TypeId> {
         // Cannot use internal search key due to mutability issues. But this
         // method should end up being deprecated at some point anyway.
         debug_assert_eq!(get_concrete_type_definition(type_parts).unwrap(), *definition_id);
         let base_type = self.definition_lookup.get(definition_id).unwrap();
         let mut search_key = MonoSearchKey::with_capacity(type_parts.len());
         search_key.set(type_parts, &base_type.poly_vars);
     /// Returns a mutable reference to a procedure's monomorph expression data.
     /// Used by typechecker to fill in previously reserved type information
     #[inline]
     pub(crate) fn get_procedure_monomorph_mut(&mut self, monomorph_index: i32) -> &mut ProcedureMonomorph {
         debug_assert!(monomorph_index >= 0);
         let monomorph = self.mono_lookup.get_mut(monomorph_index);
         return monomorph.variant.as_procedure_mut();
         return self.mono_type_lookup.get(&search_key).copied();
+    }
     #[inline]
     pub(crate) fn get_procedure_monomorph(&self, monomorph_index: i32) -> &ProcedureMonomorph {
         debug_assert!(monomorph_index >= 0);
         let monomorph = self.mono_lookup.get(monomorph_index);
         return monomorph.variant.as_procedure();
     pub(crate) fn get_monomorph(&self, type_id: TypeId) -> &MonoType {
         return &self.mono_types[type_id.0 as usize];
+    }
     /// Reserves space for a monomorph of a polymorphic procedure. The index
     /// will point into a (reserved) slot of the array of expression types. The
     /// monomorph may NOT exist yet (because the reservation implies that we're
     /// going to be performing typechecking on it, and we don't want to
     /// check the same monomorph twice)
     pub(crate) fn reserve_procedure_monomorph_index(&mut self, definition_id: &DefinitionId, concrete_type: ConcreteType) -> i32 {
         let base_type = self.type_lookup.get_mut(definition_id).unwrap();
         let mono_index = self.mono_lookup.insert_with_zero_size_and_alignment(
             concrete_type, &base_type.poly_vars, MonomorphVariant::Procedure(ProcedureMonomorph{
                 arg_types: Vec::new(),
                 expr_data: Vec::new(),
             })
         );
     pub(crate) fn reserve_procedure_monomorph_type_id(&mut self, definition_id: &DefinitionId, concrete_type: ConcreteType, monomorph_index: u32) -> TypeId {
         debug_assert_eq!(get_concrete_type_definition(&concrete_type.parts).unwrap(), *definition_id);
         let type_id = TypeId(self.mono_types.len() as i64);
         let base_type = self.definition_lookup.get_mut(definition_id).unwrap();
         self.mono_search_key.set(&concrete_type.parts, &base_type.poly_vars);
         debug_assert!(!self.mono_type_lookup.contains_key(&self.mono_search_key));
         self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
         self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Procedure(ProcedureMonomorph{
             monomorph_index,
             builtin: false,
         })));
         return type_id;
+    }
     /// Adds a builtin type to the type table. As this is only called by the
     /// compiler during setup we assume it cannot fail.
     pub(crate) fn add_builtin_data_type(&mut self, concrete_type: ConcreteType, poly_vars: &[PolymorphicVariable], size: usize, alignment: usize) -> TypeId {
         self.mono_search_key.set(&concrete_type.parts, poly_vars);
         debug_assert!(!self.mono_type_lookup.contains_key(&self.mono_search_key));
         debug_assert_ne!(alignment, 0);
         let type_id = TypeId(self.mono_types.len() as i64);
         self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
         self.mono_types.push(MonoType{
             type_id,
             concrete_type,
             size,
             alignment,
             variant: MonoTypeVariant::Builtin,
         });
-        return mono_index;
+        return type_id;
+    }
     /// Adds a datatype polymorph to the type table. Will not add the
     /// monomorph if it is already present, or if the type's polymorphic
     /// variables are all unused.
     /// TODO: Fix signature
     pub(crate) fn add_data_monomorph(
         &mut self, modules: &[Module], heap: &Heap, arch: &TargetArch, definition_id: DefinitionId, concrete_type: ConcreteType
     ) -> Result<i32, ParseError> {
         debug_assert_eq!(definition_id, get_concrete_type_definition(&concrete_type));
     /// Adds a builtin procedure to the type table.
     pub(crate) fn add_builtin_procedure_type(&mut self, concrete_type: ConcreteType, poly_vars: &[PolymorphicVariable]) -> TypeId {
         self.mono_search_key.set(&concrete_type.parts, poly_vars);
         debug_assert!(!self.mono_type_lookup.contains_key(&self.mono_search_key));
         let type_id = TypeId(self.mono_types.len() as i64);
         self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
         self.mono_types.push(MonoType{
             type_id,
             concrete_type,
             size: 0,
             alignment: 0,
             variant: MonoTypeVariant::Procedure(ProcedureMonomorph{
                 monomorph_index: u32::MAX,
                 builtin: true,
             })
         });
         return type_id;
+    }
         // Check if the monomorph already exists
         let poly_type = self.type_lookup.get_mut(&definition_id).unwrap();
         if let Some(idx) = self.mono_lookup.get_monomorph_index(&concrete_type.parts, &poly_type.poly_vars) {
             return Ok(idx);
     /// Adds a monomorphed type to the type table. If it already exists then the
     /// previous entry will be used.
     pub(crate) fn add_monomorphed_type(
         &mut self, modules: &[Module], heap: &Heap, arch: &TargetArch, concrete_type: ConcreteType
     ) -> Result<TypeId, ParseError> {
         // Check if the concrete type was already added
         Self::set_search_key_to_type(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
         if let Some(type_id) = self.mono_type_lookup.get(&self.mono_search_key) {
             return Ok(*type_id);
+        }
         // Doesn't exist, so instantiate a monomorph and determine its memory
         // layout.
         self.detect_and_resolve_type_loops_for(modules, heap, concrete_type)?;
         let mono_idx = self.encountered_types[0].monomorph_idx;
         // Concrete type needs to be added
         self.detect_and_resolve_type_loops_for(modules, heap, arch, concrete_type)?;
         let type_id = self.encountered_types[0].type_id;
         self.lay_out_memory_for_encountered_types(arch);
-        return Ok(mono_idx as i32);
+        return Ok(type_id);
+    }
     //--------------------------------------------------------------------------
     // Building base types
     //--------------------------------------------------------------------------
     /// Builds the base type for an enum. Will not compute byte sizes
     fn build_base_enum_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, definition_id: DefinitionId) -> Result<(), ParseError> {
-        debug_assert!(!self.type_lookup.contains_key(&definition_id), "base enum already built");
+        debug_assert!(!self.definition_lookup.contains_key(&definition_id), "base enum already built");
         let definition = ctx.heap[definition_id].as_enum();
         let root_id = definition.defined_in;
         // Determine enum variants
         let mut enum_value = -1;
         let mut variants = Vec::with_capacity(definition.variants.len());
         for variant in &definition.variants {
             if enum_value == i64::MAX {
                 let source = &modules[definition.defined_in.index as usize].source;
                 return Err(ParseError::new_error_str_at_span(
                     source, variant.identifier.span,
                     "this enum variant has an integer value that is too large"
                 ));
+            }
             enum_value += 1;
             if let EnumVariantValue::Integer(explicit_value) = variant.value {
                 enum_value = explicit_value;
+            }
             variants.push(EnumVariant{
                 identifier: variant.identifier.clone(),
                 value: enum_value,
             });
+        }
         // Determine tag size
         let mut min_enum_value = 0;
         let mut max_enum_value = 0;
         if !variants.is_empty() {
             min_enum_value = variants[0].value;
             max_enum_value = variants[0].value;
             for variant in variants.iter().skip(1) {
                 min_enum_value = min_enum_value.min(variant.value);
                 max_enum_value = max_enum_value.max(variant.value);
+            }
+        }
         let (tag_type, size_and_alignment) = Self::variant_tag_type_from_values(min_enum_value, max_enum_value);
         // Enum names and polymorphic args do not conflict
         Self::check_identifier_collision(
             modules, root_id, &variants, |variant| &variant.identifier, "enum variant"
         )?;
         // Polymorphic arguments cannot appear as embedded types, because
         // they can only consist of integer variants.
         Self::check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
         let poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
-        self.type_lookup.insert(definition_id, DefinedType {
+        self.definition_lookup.insert(definition_id, DefinedType {
             ast_root: root_id,
             ast_definition: definition_id,
             definition: DefinedTypeVariant::Enum(EnumType{
                 variants,
                 minimum_tag_value: min_enum_value,
                 maximum_tag_value: max_enum_value,
                 tag_type,
                 size: size_and_alignment,
                 alignment: size_and_alignment
             }),
             poly_vars,
             is_polymorph: false,
         });
         return Ok(());
+    }
     /// Builds the base type for a union. Will compute byte sizes.
     fn build_base_union_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, definition_id: DefinitionId) -> Result<(), ParseError> {
-        debug_assert!(!self.type_lookup.contains_key(&definition_id), "base union already built");
+        debug_assert!(!self.definition_lookup.contains_key(&definition_id), "base union already built");
         let definition = ctx.heap[definition_id].as_union();
         let root_id = definition.defined_in;
         // Check all variants and their embedded types
         let mut variants = Vec::with_capacity(definition.variants.len());
         let mut tag_counter = 0;
         for variant in &definition.variants {
             for embedded in &variant.value {
                 Self::check_member_parser_type(
                     modules, ctx, root_id, embedded, false
                 )?;
+            }
             variants.push(UnionVariant{
                 identifier: variant.identifier.clone(),
                 embedded: variant.value.clone(),
                 tag_value: tag_counter,
             });
             tag_counter += 1;
+        }
         let mut max_tag_value = 0;
         if tag_counter != 0 {
             max_tag_value = tag_counter - 1
+        }
         let (tag_type, tag_size) = Self::variant_tag_type_from_values(0, max_tag_value);
         // Make sure there are no conflicts in identifiers
         Self::check_identifier_collision(
             modules, root_id, &variants, |variant| &variant.identifier, "union variant"
         )?;
         Self::check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
         // Construct internal representation of union
         let mut poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
         for variant in &definition.variants {
             for embedded in &variant.value {
                 Self::mark_used_polymorphic_variables(&mut poly_vars, embedded);
+            }
+        }
         let is_polymorph = poly_vars.iter().any(|arg| arg.is_in_use);
-        self.type_lookup.insert(definition_id, DefinedType{
+        self.definition_lookup.insert(definition_id, DefinedType{
             ast_root: root_id,
             ast_definition: definition_id,
             definition: DefinedTypeVariant::Union(UnionType{ variants, tag_type, tag_size }),
             poly_vars,
             is_polymorph
         });
         return Ok(());
+    }
     /// Builds base struct type. Will not compute byte sizes.
     fn build_base_struct_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, definition_id: DefinitionId) -> Result<(), ParseError> {
-        debug_assert!(!self.type_lookup.contains_key(&definition_id), "base struct already built");
+        debug_assert!(!self.definition_lookup.contains_key(&definition_id), "base struct already built");
         let definition = ctx.heap[definition_id].as_struct();
         let root_id = definition.defined_in;
         // Check all struct fields and construct internal representation
         let mut fields = Vec::with_capacity(definition.fields.len());
         for field in &definition.fields {
             Self::check_member_parser_type(
                 modules, ctx, root_id, &field.parser_type, false
             )?;
             fields.push(StructField{
                 identifier: field.field.clone(),
                 parser_type: field.parser_type.clone(),
             });
+        }
         // Make sure there are no conflicting variables
         Self::check_identifier_collision(
             modules, root_id, &fields, |field| &field.identifier, "struct field"
         )?;
         Self::check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
         // Construct base type in table
         let mut poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
         for field in &fields {
             Self::mark_used_polymorphic_variables(&mut poly_vars, &field.parser_type);
+        }
         let is_polymorph = poly_vars.iter().any(|arg| arg.is_in_use);
-        self.type_lookup.insert(definition_id, DefinedType{
+        self.definition_lookup.insert(definition_id, DefinedType{
             ast_root: root_id,
             ast_definition: definition_id,
             definition: DefinedTypeVariant::Struct(StructType{ fields }),
             poly_vars,
             is_polymorph
         });
         return Ok(())
+    }
     /// Builds base function type.
     fn build_base_function_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, definition_id: DefinitionId) -> Result<(), ParseError> {
         debug_assert!(!self.type_lookup.contains_key(&definition_id), "base function already built");
         let definition = ctx.heap[definition_id].as_function();
     /// Builds base procedure type.
     fn build_base_procedure_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, definition_id: DefinitionId) -> Result<(), ParseError> {
         debug_assert!(!self.definition_lookup.contains_key(&definition_id), "base function already built");
         let definition = ctx.heap[definition_id].as_procedure();
         let root_id = definition.defined_in;
         // Check and construct return types and argument types.
         debug_assert_eq!(definition.return_types.len(), 1, "not one return type");
         for return_type in &definition.return_types {
         if let Some(return_type) = &definition.return_type {
             Self::check_member_parser_type(
                 modules, ctx, root_id, return_type, definition.builtin
             )?;
+        }
         let mut arguments = Vec::with_capacity(definition.parameters.len());
         for parameter_id in &definition.parameters {
             let parameter = &ctx.heap[*parameter_id];
             Self::check_member_parser_type(
                 modules, ctx, root_id, &parameter.parser_type, definition.builtin
             )?;
-            arguments.push(FunctionArgument{
+            arguments.push(ProcedureArgument{
                 identifier: parameter.identifier.clone(),
                 parser_type: parameter.parser_type.clone(),
             });
+        }
         // Check conflict of identifiers
         Self::check_identifier_collision(
-            modules, root_id, &arguments, |arg| &arg.identifier, "function argument"
+            modules, root_id, &arguments, |arg| &arg.identifier, "procedure argument"
         )?;
         Self::check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
         // Construct internal representation of function type
         // TODO: Marking used polymorphic variables should take statements in
         //  the body into account. But currently we don't. Hence mark them all
         //  as being in-use. Note to self: true condition should be that the
         //  polymorphic variables are used in places where the resulting types
         //  are themselves truly polymorphic types (e.g. not a phantom type).
         let mut poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
         for return_type in &definition.return_types {
             Self::mark_used_polymorphic_variables(&mut poly_vars, return_type);
+        }
         for argument in &arguments {
             Self::mark_used_polymorphic_variables(&mut poly_vars, &argument.parser_type);
+        }
         let is_polymorph = poly_vars.iter().any(|arg| arg.is_in_use);
         self.type_lookup.insert(definition_id, DefinedType{
             ast_root: root_id,
             ast_definition: definition_id,
             definition: DefinedTypeVariant::Function(FunctionType{ return_types: definition.return_types.clone(), arguments }),
             poly_vars,
             is_polymorph
         });
         return Ok(());
+    }
     /// Builds base component type.
     fn build_base_component_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, definition_id: DefinitionId) -> Result<(), ParseError> {
         debug_assert!(!self.type_lookup.contains_key(&definition_id), "base component already built");
         let definition = &ctx.heap[definition_id].as_component();
         let root_id = definition.defined_in;
         // Check the argument types
         let mut arguments = Vec::with_capacity(definition.parameters.len());
         for parameter_id in &definition.parameters {
             let parameter = &ctx.heap[*parameter_id];
             Self::check_member_parser_type(
                 modules, ctx, root_id, &parameter.parser_type, false
             )?;
             arguments.push(FunctionArgument{
                 identifier: parameter.identifier.clone(),
                 parser_type: parameter.parser_type.clone(),
             });
+        }
         // Check conflict of identifiers
         Self::check_identifier_collision(
             modules, root_id, &arguments, |arg| &arg.identifier, "connector argument"
         )?;
         Self::check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
         // Construct internal representation of component
         // TODO: Marking used polymorphic variables on procedures requires
         //  making sure that each is used in the body. For now, mark them all
         //  as required.
         let mut poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
         // for argument in &arguments {
         //     Self::mark_used_polymorphic_variables(&mut poly_vars, &argument.parser_type);
         // }
         for poly_var in &mut poly_vars {
             poly_var.is_in_use = true;
+        }
         let is_polymorph = poly_vars.iter().any(|arg| arg.is_in_use);
-        self.type_lookup.insert(definition_id, DefinedType{
+        self.definition_lookup.insert(definition_id, DefinedType{
             ast_root: root_id,
             ast_definition: definition_id,
             definition: DefinedTypeVariant::Component(ComponentType{ variant: definition.variant, arguments }),
             definition: DefinedTypeVariant::Procedure(ProcedureType{
                 kind: definition.kind,
                 return_type: definition.return_type.clone(),
                 arguments
             }),
             poly_vars,
             is_polymorph
         });
         Ok(())
+        return Ok(());
+    }
     /// Will check if the member type (field of a struct, embedded type in a
     /// union variant) is valid.
     fn check_member_parser_type(
         modules: &[Module], ctx: &PassCtx, base_definition_root_id: RootId,
         member_parser_type: &ParserType, allow_special_compiler_types: bool
     ) -> Result<(), ParseError> {
         use ParserTypeVariant as PTV;
         for element in &member_parser_type.elements {
             match element.variant {
                 // Special cases
                 PTV::Void | PTV::InputOrOutput | PTV::ArrayLike | PTV::IntegerLike => {
                     if !allow_special_compiler_types {
                         unreachable!("compiler-only ParserTypeVariant in member type");
+                    }
                 },
                 // Builtin types, always valid
                 PTV::Message | PTV::Bool |
                 PTV::UInt8 | PTV::UInt16 | PTV::UInt32 | PTV::UInt64 |
                 PTV::SInt8 | PTV::SInt16 | PTV::SInt32 | PTV::SInt64 |
                 PTV::Character | PTV::String |
                 PTV::Array | PTV::Input | PTV::Output | PTV::Tuple(_) |
                 // Likewise, polymorphic variables are always valid
                 PTV::PolymorphicArgument(_, _) => {},
                 // Types that are not constructable, or types that are not
                 // allowed (and checked earlier)
                 PTV::IntegerLiteral | PTV::Inferred => {
                     unreachable!("illegal ParserTypeVariant within type definition");
                 },
                 // Finally, user-defined types
                 PTV::Definition(definition_id, _) => {
                     let definition = &ctx.heap[definition_id];
                     if !(definition.is_struct() || definition.is_enum() || definition.is_union()) {
                         let source = &modules[base_definition_root_id.index as usize].source;
                         return Err(ParseError::new_error_str_at_span(
                             source, element.element_span, "expected a datatype (a struct, enum or union)"
                         ));
+                    }
                     // Otherwise, we're fine
+                }
+            }
+        }
         // If here, then all elements check out
         return Ok(());
+    }
     /// Go through a list of identifiers and ensure that all identifiers have
     /// unique names
     fn check_identifier_collision<T: Sized, F: Fn(&T) -> &Identifier>(
         modules: &[Module], root_id: RootId, items: &[T], getter: F, item_name: &'static str
     ) -> Result<(), ParseError> {
         for (item_idx, item) in items.iter().enumerate() {
             let item_ident = getter(item);
             for other_item in &items[0..item_idx] {
                 let other_item_ident = getter(other_item);
                 if item_ident == other_item_ident {
                     let module_source = &modules[root_id.index as usize].source;
                     return Err(ParseError::new_error_at_span(
                         module_source, item_ident.span, format!("This {} is defined more than once", item_name)
                     ).with_info_at_span(
                         module_source, other_item_ident.span, format!("The other {} is defined here", item_name)
                     ));
+                }
+            }
+        }
         Ok(())
+    }
     /// Go through a list of polymorphic arguments and make sure that the
     /// arguments all have unique names, and the arguments do not conflict with
     /// any symbols defined at the module scope.
     fn check_poly_args_collision(
         modules: &[Module], ctx: &PassCtx, root_id: RootId, poly_args: &[Identifier]
     ) -> Result<(), ParseError> {
         // Make sure polymorphic arguments are unique and none of the
         // identifiers conflict with any imported scopes
         for (arg_idx, poly_arg) in poly_args.iter().enumerate() {
             for other_poly_arg in &poly_args[..arg_idx] {
                 if poly_arg == other_poly_arg {
                     let module_source = &modules[root_id.index as usize].source;
                     return Err(ParseError::new_error_str_at_span(
                         module_source, poly_arg.span,
                         "This polymorphic argument is defined more than once"
                     ).with_info_str_at_span(
                         module_source, other_poly_arg.span,
                         "It conflicts with this polymorphic argument"
                     ));
+                }
+            }
             // Check if identifier conflicts with a symbol defined or imported
             // in the current module
             if let Some(symbol) = ctx.symbols.get_symbol_by_name(SymbolScope::Module(root_id), poly_arg.value.as_bytes()) {
                 // We have a conflict
                 let module_source = &modules[root_id.index as usize].source;
                 let introduction_span = symbol.variant.span_of_introduction(ctx.heap);
                 return Err(ParseError::new_error_str_at_span(
                     module_source, poly_arg.span,
                     "This polymorphic argument conflicts with another symbol"
                 ).with_info_str_at_span(
                     module_source, introduction_span,
                     "It conflicts due to this symbol"
                 ));
+            }
+        }
         // All arguments are fine
         Ok(())
+    }
     //--------------------------------------------------------------------------
     // Detecting type loops
     //--------------------------------------------------------------------------
     /// Internal function that will detect type loops and check if they're
     /// resolvable. If so then the appropriate union variants will be marked as
     /// "living on heap". If not then a `ParseError` will be returned
     fn detect_and_resolve_type_loops_for(&mut self, modules: &[Module], heap: &Heap, concrete_type: ConcreteType) -> Result<(), ParseError> {
+    fn detect_and_resolve_type_loops_for(&mut self, modules: &[Module], heap: &Heap, arch: &TargetArch, concrete_type: ConcreteType) -> Result<(), ParseError> {
         // Programmer notes: what happens here is the we call
         // `check_member_for_type_loops` for a particular type's member, and
         // then take action using the return value:
         // 1. It might already be resolved: in this case it implies we don't
         //  have type loops, or they have been resolved.
         // 2. A new type is encountered. If so then it is added to the type loop
         //  breadcrumbs.
         // 3. A type loop is detected (implying the type is already resolved, or
         //  already exists in the type loop breadcrumbs).
         //
         // Using the breadcrumbs we incrementally check every member type of a
         // particular considered type (e.g. a struct field, tuple member), and
         // do the same as above. Note that when a breadcrumb is added we reserve
         // space in the monomorph storage, initialized to zero-values (i.e.
         // wrong values). The breadcrumbs keep track of how far and along we are
         // with resolving the member types.
         //
         // At the end we may have some type loops. If they're unresolvable then
         // we throw an error). If there are no type loops or they are all
         // resolvable then we end up with a list of `encountered_types`. These
         // are then used by `lay_out_memory_for_encountered_types`.
         debug_assert!(self.type_loop_breadcrumbs.is_empty());
         debug_assert!(self.type_loops.is_empty());
         debug_assert!(self.encountered_types.is_empty());
         // Push the initial breadcrumb
         let initial_breadcrumb = self.check_member_for_type_loops(&concrete_type);
         let initial_breadcrumb = Self::check_member_for_type_loops(
             &self.type_loop_breadcrumbs, &self.definition_lookup, &self.mono_type_lookup,
             &mut self.mono_search_key, &concrete_type
         );
         if let TypeLoopResult::PushBreadcrumb(definition_id, concrete_type) = initial_breadcrumb {
             self.handle_new_breadcrumb_for_type_loops(definition_id, concrete_type);
+            self.handle_new_breadcrumb_for_type_loops(arch, definition_id, concrete_type);
         } else {
             unreachable!();
+        }
             unreachable!()
         };
         // Enter into the main resolving loop
         while !self.type_loop_breadcrumbs.is_empty() {
             // Because we might be modifying the breadcrumb array we need to
             let breadcrumb_idx = self.type_loop_breadcrumbs.len() - 1;
             let mut breadcrumb = self.type_loop_breadcrumbs[breadcrumb_idx].clone();
             let monomorph = self.mono_lookup.get(breadcrumb.monomorph_idx);
             let resolve_result = match &monomorph.variant {
                 MonomorphVariant::Enum => {
             let mono_type = &self.mono_types[breadcrumb.type_id.0 as usize];
             let resolve_result = match &mono_type.variant {
                 MonoTypeVariant::Builtin => {
                     TypeLoopResult::TypeExists
+                }
                 MonoTypeVariant::Enum => {
                     TypeLoopResult::TypeExists
                 },
-                MonomorphVariant::Union(monomorph) => {
+                MonoTypeVariant::Union(monomorph) => {
                     let num_variants = monomorph.variants.len() as u32;
                     let mut union_result = TypeLoopResult::TypeExists;
                     'member_loop: while breadcrumb.next_member < num_variants {
                         let mono_variant = &monomorph.variants[breadcrumb.next_member as usize];
                         let num_embedded = mono_variant.embedded.len() as u32;
                         while breadcrumb.next_embedded < num_embedded {
                             let mono_embedded = &mono_variant.embedded[breadcrumb.next_embedded as usize];
                             union_result = self.check_member_for_type_loops(&mono_embedded.concrete_type);
                             union_result = Self::check_member_for_type_loops(
                                 &self.type_loop_breadcrumbs, &self.definition_lookup, &self.mono_type_lookup,
                                 &mut self.mono_search_key, &mono_embedded.concrete_type
                             );
                             if union_result != TypeLoopResult::TypeExists {
                                 // In type loop or new breadcrumb pushed, so
                                 // break out of the resolving loop
                                 break 'member_loop;
+                            }
                             breadcrumb.next_embedded += 1;
+                        }
                         breadcrumb.next_embedded = 0;
                         breadcrumb.next_member += 1
+                    }
                     union_result
                 },
-                MonomorphVariant::Struct(monomorph) => {
+                MonoTypeVariant::Struct(monomorph) => {
                     let num_fields = monomorph.fields.len() as u32;
                     let mut struct_result = TypeLoopResult::TypeExists;
                     while breadcrumb.next_member < num_fields {
                         let mono_field = &monomorph.fields[breadcrumb.next_member as usize];
                         struct_result = self.check_member_for_type_loops(&mono_field.concrete_type);
                         struct_result = Self::check_member_for_type_loops(
                             &self.type_loop_breadcrumbs, &self.definition_lookup, &self.mono_type_lookup,
                             &mut self.mono_search_key, &mono_field.concrete_type
                         );
                         if struct_result != TypeLoopResult::TypeExists {
                             // Type loop or breadcrumb pushed, so break out of
                             // the resolving loop
                             break;
+                        }
                         breadcrumb.next_member += 1;
+                    }
                     struct_result
                 },
                 MonomorphVariant::Procedure(_) => unreachable!(),
                 MonomorphVariant::Tuple(monomorph) => {
                 MonoTypeVariant::Procedure(_) => unreachable!(),
                 MonoTypeVariant::Tuple(monomorph) => {
                     let num_members = monomorph.members.len() as u32;
                     let mut tuple_result = TypeLoopResult::TypeExists;
                     while breadcrumb.next_member < num_members {
                         let tuple_member = &monomorph.members[breadcrumb.next_member as usize];
                         tuple_result = self.check_member_for_type_loops(&tuple_member.concrete_type);
                         tuple_result = Self::check_member_for_type_loops(
                             &self.type_loop_breadcrumbs, &self.definition_lookup, &self.mono_type_lookup,
                             &mut self.mono_search_key, &tuple_member.concrete_type
                         );
                         if tuple_result != TypeLoopResult::TypeExists {
                             break;
+                        }
                         breadcrumb.next_member += 1;
+                    }
                     tuple_result
+                }
             };
             // Handle the result of attempting to resolve the current breadcrumb
             match resolve_result {
                 TypeLoopResult::TypeExists => {
                     // We finished parsing the type
                     self.type_loop_breadcrumbs.pop();
                 },
                 TypeLoopResult::PushBreadcrumb(definition_id, concrete_type) => {
                     // We recurse into the member type.
                     self.type_loop_breadcrumbs[breadcrumb_idx] = breadcrumb;
                     self.handle_new_breadcrumb_for_type_loops(definition_id, concrete_type);
+                    self.handle_new_breadcrumb_for_type_loops(arch, definition_id, concrete_type);
                 },
                 TypeLoopResult::TypeLoop(first_idx) => {
                     // Because we will be modifying breadcrumbs within the
                     // type-loop handling code, put back the modified breadcrumb
                     self.type_loop_breadcrumbs[breadcrumb_idx] = breadcrumb;
                     // We're in a type loop. Add the type loop
                     let mut loop_members = Vec::with_capacity(self.type_loop_breadcrumbs.len() - first_idx);
                     let mut contains_union = false;
                     for breadcrumb_idx in first_idx..self.type_loop_breadcrumbs.len() {
                         let breadcrumb = &mut self.type_loop_breadcrumbs[breadcrumb_idx];
                         let mut is_union = false;
                         let monomorph = self.mono_lookup.get_mut(breadcrumb.monomorph_idx);
                         // TODO: Match on monomorph directly here
                         match &mut monomorph.variant {
                             MonomorphVariant::Union(monomorph) => {
                                 // Mark the currently processed variant as requiring heap
                                 // allocation, then advance the *embedded* type. The loop above
                                 // will then take care of advancing it to the next *member*.
                                 let variant = &mut monomorph.variants[breadcrumb.next_member as usize];
                         // Check if type loop member is a union that may be
                         // broken up by moving some of its members to the heap.
                         let mono_type = &mut self.mono_types[breadcrumb.type_id.0 as usize];
                         if let MonoTypeVariant::Union(union_type) = &mut mono_type.variant {
                             // Mark the variant that caused the loop as heap
                             // allocated to break the type loop.
                             let variant = &mut union_type.variants[breadcrumb.next_member as usize];
                             variant.lives_on_heap = true;
                             breadcrumb.next_embedded += 1;
                             is_union = true;
                             contains_union = true;
                             },
                             _ => {}, // else: we don't care for now
+                        }
                         } // else: we don't care about the type for now
                         loop_members.push(TypeLoopEntry{
-                            monomorph_idx: breadcrumb.monomorph_idx,
+                            type_id: breadcrumb.type_id,
                             is_union
                         });
+                    }
                     let new_type_loop = TypeLoop{ members: loop_members };
                     if !contains_union {
                         // No way to (potentially) break the union. So return a
                         // type loop error. This is because otherwise our
                         // breadcrumb resolver ends up in an infinite loop.
                         return Err(construct_type_loop_error(
                             self, &new_type_loop, modules, heap
+                            &self.mono_types, &new_type_loop, modules, heap
                         ));
+                    }
                     self.type_loops.push(new_type_loop);
+                }
+            }
+        }
         // All breadcrumbs have been cleared. So now `type_loops` contains all
         // of the encountered type loops, and `encountered_types` contains a
         // list of all unique monomorphs we encountered.
         // The next step is to figure out if all of the type loops can be
         // broken. A type loop can be broken if at least one union exists in the
         // loop and that union ended up having variants that are not part of
         // a type loop.
         fn type_loop_source_span_and_message<'a>(
             modules: &'a [Module], heap: &Heap, mono_lookup: &MonomorphTable,
             definition_id: DefinitionId, monomorph_idx: i32, index_in_loop: usize
             modules: &'a [Module], heap: &Heap, mono_types: &MonoTypeArray,
             definition_id: DefinitionId, mono_type_id: TypeId, index_in_loop: usize
         ) -> (&'a InputSource, InputSpan, String) {
             // Note: because we will discover the type loop the *first* time we
             // instantiate a monomorph with the provided polymorphic arguments
             // (not all arguments are actually used in the type). We don't have
             // to care about a second instantiation where certain unused
             // polymorphic arguments are different.
             let monomorph_type = &mono_lookup.get(monomorph_idx).concrete_type;
             let mono_type = &mono_types[mono_type_id.0 as usize];
             let type_name = mono_type.concrete_type.display_name(heap);
             let type_name = monomorph_type.display_name(&heap);
             let message = if index_in_loop == 0 {
                 format!(
                     "encountered an infinitely large type for '{}' (which can be fixed by \
                     introducing a union type that has a variant whose embedded types are \
                     not part of a type loop, or do not have embedded types)",
                     type_name
+                )
             } else if index_in_loop == 1 {
                 format!("because it depends on the type '{}'", type_name)
             } else {
                 format!("which depends on the type '{}'", type_name)
             };
             let ast_definition = &heap[definition_id];
             let ast_root_id = ast_definition.defined_in();
             return (
                 &modules[ast_root_id.index as usize].source,
                 ast_definition.identifier().span,
                 message
             );
+        }
         fn retrieve_definition_id_if_possible(parts: &[ConcreteTypePart]) -> DefinitionId {
             match &parts[0] {
                 ConcreteTypePart::Instance(v, _) |
                 ConcreteTypePart::Function(v, _) |
                 ConcreteTypePart::Component(v, _) => *v,
                 _ => DefinitionId::new_invalid(),
+            }
+        }
         fn construct_type_loop_error(table: &TypeTable, type_loop: &TypeLoop, modules: &[Module], heap: &Heap) -> ParseError {
         fn construct_type_loop_error(mono_types: &MonoTypeArray, type_loop: &TypeLoop, modules: &[Module], heap: &Heap) -> ParseError {
             // Seek first entry to produce parse error. Then continue builder
             // pattern. This is the error case so efficiency can go home.
             let mut parse_error = None;
             let mut next_member_index = 0;
             while next_member_index < type_loop.members.len() {
                 let first_entry = &type_loop.members[next_member_index];
                 next_member_index += 1;
                 let first_definition_id = retrieve_definition_id_if_possible(&table.mono_lookup.get(first_entry.monomorph_idx).concrete_type.parts);
                 if first_definition_id.is_invalid() {
                 // Retrieve definition of first type in loop
                 let first_mono_type = &mono_types[first_entry.type_id.0 as usize];
                 let first_definition_id = get_concrete_type_definition(&first_mono_type.concrete_type.parts);
                 if first_definition_id.is_none() {
                     continue;
+                }
                 let first_definition_id = first_definition_id.unwrap();
                 // Produce error message for first type in loop
                 let (first_module, first_span, first_message) = type_loop_source_span_and_message(
-                    modules, heap, &table.mono_lookup, first_definition_id, first_entry.monomorph_idx, 0
+                    modules, heap, mono_types, first_definition_id, first_entry.type_id, 0
                 );
                 parse_error = Some(ParseError::new_error_at_span(first_module, first_span, first_message));
                 break;
+            }
             let mut parse_error = parse_error.unwrap(); // Loop above cannot have failed, because we must have a type loop, type loops cannot contain only unnamed types
             let mut error_counter = 1;
             for member_idx in next_member_index..type_loop.members.len() {
                 let entry = &type_loop.members[member_idx];
                 let definition_id = retrieve_definition_id_if_possible(&table.mono_lookup.get(entry.monomorph_idx).concrete_type.parts);
                 if definition_id.is_invalid() {
                     continue; // dont display tuples
                 let mono_type = &mono_types[entry.type_id.0 as usize];
                 let definition_id = get_concrete_type_definition(&mono_type.concrete_type.parts);
                 if definition_id.is_none() {
                     continue;
+                }
                 let definition_id = definition_id.unwrap();
                 let (module, span, message) = type_loop_source_span_and_message(
-                    modules, heap, &table.mono_lookup, definition_id, entry.monomorph_idx, error_counter
+                    modules, heap, mono_types, definition_id, entry.type_id, error_counter
                 );
                 parse_error = parse_error.with_info_at_span(module, span, message);
                 error_counter += 1;
+            }
             parse_error
+        }
         for type_loop in &self.type_loops {
             let mut can_be_broken = false;
             debug_assert!(!type_loop.members.is_empty());
             for entry in &type_loop.members {
                 if entry.is_union {
                     let monomorph = self.mono_lookup.get(entry.monomorph_idx).variant.as_union();
                     debug_assert!(!monomorph.variants.is_empty()); // otherwise it couldn't be part of the type loop
                     let has_stack_variant = monomorph.variants.iter().any(|variant| !variant.lives_on_heap);
                     let mono_type = self.mono_types[entry.type_id.0 as usize].variant.as_union();
                     debug_assert!(!mono_type.variants.is_empty()); // otherwise it couldn't be part of the type loop
                     let has_stack_variant = mono_type.variants.iter().any(|variant| !variant.lives_on_heap);
                     if has_stack_variant {
                         can_be_broken = true;
                         break;
+                    }
+                }
+            }
             if !can_be_broken {
                 // Construct a type loop error
                 return Err(construct_type_loop_error(self, type_loop, modules, heap));
+                return Err(construct_type_loop_error(&self.mono_types, type_loop, modules, heap));
+            }
+        }
         // If here, then all type loops have been resolved and we can lay out
         // all of the members
         self.type_loops.clear();
         return Ok(());
+    }
     /// Checks if the specified type needs to be resolved (i.e. we need to push
     /// a breadcrumb), is already resolved (i.e. we can continue with the next
     /// member of the currently considered type) or is in the process of being
     /// resolved (i.e. we're in a type loop). Because of borrowing rules we
     /// don't do any modifications of internal types here. Hence: if we
     /// return `PushBreadcrumb` then call `handle_new_breadcrumb_for_type_loops`
     /// to take care of storing the appropriate types.
     fn check_member_for_type_loops(&self, definition_type: &ConcreteType) -> TypeLoopResult {
     fn check_member_for_type_loops(
         breadcrumbs: &[TypeLoopBreadcrumb], definition_map: &DefinitionMap, mono_type_map: &MonoTypeMap,
         mono_key: &mut MonoSearchKey, concrete_type: &ConcreteType
     ) -> TypeLoopResult {
         use ConcreteTypePart as CTP;
         // Depending on the type, lookup if the type has already been visited
         // (i.e. either already has its memory layed out, or is part of a type
         // loop because we've already visited the type)
         debug_assert!(!definition_type.parts.is_empty());
         let (definition_id, monomorph_index) = match &definition_type.parts[0] {
             CTP::Tuple(_) => {
                 let monomorph_index = self.mono_lookup.get_monomorph_index(&definition_type.parts, &[]);
                 (DefinitionId::new_invalid(), monomorph_index)
             },
             CTP::Instance(definition_id, _) |
             CTP::Function(definition_id, _) |
             CTP::Component(definition_id, _) => {
                 let base_type = self.type_lookup.get(definition_id).unwrap();
                 let monomorph_index = self.mono_lookup.get_monomorph_index(&definition_type.parts, &base_type.poly_vars);
                 (*definition_id, monomorph_index)
             },
             _ => {
                 return TypeLoopResult::TypeExists
             },
         debug_assert!(!concrete_type.parts.is_empty());
         let definition_id = if let ConcreteTypePart::Instance(definition_id, _) = concrete_type.parts[0] {
             definition_id
         } else {
             DefinitionId::new_invalid()
         };
         if let Some(monomorph_index) = monomorph_index {
             for (breadcrumb_idx, breadcrumb) in self.type_loop_breadcrumbs.iter().enumerate() {
                 if breadcrumb.monomorph_idx == monomorph_index {
         Self::set_search_key_to_type(mono_key, definition_map, &concrete_type.parts);
         if let Some(type_id) = mono_type_map.get(mono_key).copied() {
             for (breadcrumb_idx, breadcrumb) in breadcrumbs.iter().enumerate() {
                 if breadcrumb.type_id == type_id {
                     return TypeLoopResult::TypeLoop(breadcrumb_idx);
+                }
+            }
             return TypeLoopResult::TypeExists;
+        }
         // Type is not yet known, so we need to insert it into the lookup and
         // push a new breadcrumb.
-        return TypeLoopResult::PushBreadcrumb(definition_id, definition_type.clone());
+        return TypeLoopResult::PushBreadcrumb(definition_id, concrete_type.clone());
+    }
     /// Handles the `PushBreadcrumb` result for a `check_member_for_type_loops`
     /// call.
     fn handle_new_breadcrumb_for_type_loops(&mut self, definition_id: DefinitionId, definition_type: ConcreteType) {
     /// call. Will preallocate entries in the monomorphed type storage (with
     /// all memory properties zeroed).
     fn handle_new_breadcrumb_for_type_loops(&mut self, arch: &TargetArch, definition_id: DefinitionId, concrete_type: ConcreteType) {
         use DefinedTypeVariant as DTV;
         use ConcreteTypePart as CTP;
         let mut is_union = false;
         let monomorph_index = match &definition_type.parts[0] {
         let type_id = match &concrete_type.parts[0] {
             // Builtin types
             CTP::Void | CTP::Message | CTP::Bool |
             CTP::UInt8 | CTP::UInt16 | CTP::UInt32 | CTP::UInt64 |
             CTP::SInt8 | CTP::SInt16 | CTP::SInt32 | CTP::SInt64 |
             CTP::Character | CTP::String |
             CTP::Array | CTP::Slice | CTP::Input | CTP::Output | CTP::Pointer => {
                 // Insert the entry for the builtin type, we should be able to
                 // immediately "steal" the size from the preinserted builtins.
                 let base_type_id = match &concrete_type.parts[0] {
                     CTP::Void => arch.void_type_id,
                     CTP::Message => arch.message_type_id,
                     CTP::Bool => arch.bool_type_id,
                     CTP::UInt8 => arch.uint8_type_id,
                     CTP::UInt16 => arch.uint16_type_id,
                     CTP::UInt32 => arch.uint32_type_id,
                     CTP::UInt64 => arch.uint64_type_id,
                     CTP::SInt8 => arch.sint8_type_id,
                     CTP::SInt16 => arch.sint16_type_id,
                     CTP::SInt32 => arch.sint32_type_id,
                     CTP::SInt64 => arch.sint64_type_id,
                     CTP::Character => arch.char_type_id,
                     CTP::String => arch.string_type_id,
                     CTP::Array => arch.array_type_id,
                     CTP::Slice => arch.slice_type_id,
                     CTP::Input => arch.input_type_id,
                     CTP::Output => arch.output_type_id,
                     CTP::Pointer => arch.pointer_type_id,
                     _ => unreachable!(),
                 };
                 let base_type = &self.mono_types[base_type_id.0 as usize];
                 let base_type_size = base_type.size;
                 let base_type_alignment = base_type.alignment;
                 let type_id = TypeId(self.mono_types.len() as i64);
                 Self::set_search_key_to_type(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
                 self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
                 self.mono_types.push(MonoType{
                     type_id,
                     concrete_type,
                     size: base_type_size,
                     alignment: base_type_alignment,
                     variant: MonoTypeVariant::Builtin
                 });
                 type_id
             },
             // User-defined types
             CTP::Tuple(num_embedded) => {
                 debug_assert!(definition_id.is_invalid()); // because tuples do not have an associated `DefinitionId`
                 let mut members = Vec::with_capacity(*num_embedded as usize);
-                for section in ConcreteTypeIter::new(&definition_type.parts, 0) {
+                for section in ConcreteTypeIter::new(&concrete_type.parts, 0) {
                     members.push(TupleMonomorphMember{
                         type_id: TypeId::new_invalid(),
                         concrete_type: ConcreteType{ parts: Vec::from(section) },
                         size: 0,
                         alignment: 0,
                         offset: 0
                     });
+                }
                 let mono_index = self.mono_lookup.insert_with_zero_size_and_alignment(
                     definition_type, &[],
                     MonomorphVariant::Tuple(TupleMonomorph{
                         members,
                     })
                 );
                 mono_index
                 let type_id = TypeId(self.mono_types.len() as i64);
                 Self::set_search_key_to_tuple(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
                 self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
                 self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Tuple(TupleMonomorph{ members })));
                 type_id
             },
             CTP::Instance(_check_definition_id, _) => {
                 debug_assert_eq!(definition_id, *_check_definition_id); // because this is how `definition_id` was determined
                 let base_type = self.type_lookup.get_mut(&definition_id).unwrap();
                 let monomorph_index = match &mut base_type.definition {
                 Self::set_search_key_to_type(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
                 let base_type = self.definition_lookup.get(&definition_id).unwrap();
                 let type_id = match &base_type.definition {
                     DTV::Enum(definition) => {
                         // The enum is a bit exceptional in that when we insert
                         // it we we will immediately set its size/alignment:
                         // there is nothing to compute here.
                         debug_assert!(definition.size != 0 && definition.alignment != 0);
                         let mono_index = self.mono_lookup.insert_with_zero_size_and_alignment(
                             definition_type, &base_type.poly_vars, MonomorphVariant::Enum
                         );
                         let mono_type = self.mono_lookup.get_mut(mono_index);
                         let type_id = TypeId(self.mono_types.len() as i64);
                         self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
                         self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Enum));
                         let mono_type = &mut self.mono_types[type_id.0 as usize];
                         mono_type.size = definition.size;
                         mono_type.alignment = definition.alignment;
-                        mono_index
+                        type_id
                     },
                     DTV::Union(definition) => {
                         // Create all the variants with their concrete types
                         let mut mono_variants = Vec::with_capacity(definition.variants.len());
                         for poly_variant in &definition.variants {
                             let mut mono_embedded = Vec::with_capacity(poly_variant.embedded.len());
                             for poly_embedded in &poly_variant.embedded {
-                                let mono_concrete = Self::construct_concrete_type(poly_embedded, &definition_type);
+                                let mono_concrete = Self::construct_concrete_type(poly_embedded, &concrete_type);
                                 mono_embedded.push(UnionMonomorphEmbedded{
                                     type_id: TypeId::new_invalid(),
                                     concrete_type: mono_concrete,
                                     size: 0,
                                     alignment: 0,
                                     offset: 0
                                 });
+                            }
                             mono_variants.push(UnionMonomorphVariant{
                                 lives_on_heap: false,
                                 embedded: mono_embedded,
                             })
+                        }
                         let mono_index = self.mono_lookup.insert_with_zero_size_and_alignment(
                             definition_type, &base_type.poly_vars,
                             MonomorphVariant::Union(UnionMonomorph{
                         let type_id = TypeId(self.mono_types.len() as i64);
                         let tag_size = definition.tag_size;
                         Self::set_search_key_to_type(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
                         self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
                         self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Union(UnionMonomorph{
                             variants: mono_variants,
-                                tag_size: definition.tag_size,
                             tag_size,
                             heap_size: 0,
                                 heap_alignment: 0
                             })
                         );
                             heap_alignment: 0,
                         })));
                         is_union = true;
-                        mono_index
+                        type_id
                     },
                     DTV::Struct(definition) => {
                         // Create fields
                         let mut mono_fields = Vec::with_capacity(definition.fields.len());
                         for poly_field in &definition.fields {
-                            let mono_concrete = Self::construct_concrete_type(&poly_field.parser_type, &definition_type);
+                            let mono_concrete = Self::construct_concrete_type(&poly_field.parser_type, &concrete_type);
                             mono_fields.push(StructMonomorphField{
                                 type_id: TypeId::new_invalid(),
                                 concrete_type: mono_concrete,
                                 size: 0,
                                 alignment: 0,
                                 offset: 0
                             })
+                        }
                         let mono_index = self.mono_lookup.insert_with_zero_size_and_alignment(
                             definition_type, &base_type.poly_vars,
                             MonomorphVariant::Struct(StructMonomorph{ fields: mono_fields })
                         );
                         let type_id = TypeId(self.mono_types.len() as i64);
                         Self::set_search_key_to_type(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
                         self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
                         self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Struct(StructMonomorph{
                             fields: mono_fields,
                         })));
-                        mono_index
+                        type_id
                     },
-                    DTV::Function(_) | DTV::Component(_) => {
+                    DTV::Procedure(_) => {
                         unreachable!("pushing type resolving breadcrumb for procedure type")
                     },
                 };
-                monomorph_index
+                type_id
             },
-            _ => unreachable!(),
+            CTP::Function(_, _) | CTP::Component(_, _) => todo!("function pointers"),
         };
         self.encountered_types.push(TypeLoopEntry{
             monomorph_idx: monomorph_index,
             is_union,
         });
         self.encountered_types.push(TypeLoopEntry{ type_id, is_union });
         self.type_loop_breadcrumbs.push(TypeLoopBreadcrumb{
-            monomorph_idx: monomorph_index,
+            type_id,
             next_member: 0,
             next_embedded: 0,
         });
+    }
     /// Constructs a concrete type out of a parser type for a struct field or
     /// union embedded type. It will do this by looking up the polymorphic
     /// variables in the supplied concrete type. The assumption is that the
     /// polymorphic variable's indices correspond to the subtrees in the
     /// concrete type.
     fn construct_concrete_type(member_type: &ParserType, container_type: &ConcreteType) -> ConcreteType {
         use ParserTypeVariant as PTV;
         use ConcreteTypePart as CTP;
         // TODO: Combine with code in pass_typing.rs
         fn parser_to_concrete_part(part: &ParserTypeVariant) -> Option<ConcreteTypePart> {
             match part {
                 PTV::Void      => Some(CTP::Void),
                 PTV::Message   => Some(CTP::Message),
                 PTV::Bool      => Some(CTP::Bool),
                 PTV::UInt8     => Some(CTP::UInt8),
                 PTV::UInt16    => Some(CTP::UInt16),
                 PTV::UInt32    => Some(CTP::UInt32),
                 PTV::UInt64    => Some(CTP::UInt64),
                 PTV::SInt8     => Some(CTP::SInt8),
                 PTV::SInt16    => Some(CTP::SInt16),
                 PTV::SInt32    => Some(CTP::SInt32),
                 PTV::SInt64    => Some(CTP::SInt64),
                 PTV::Character => Some(CTP::Character),
                 PTV::String    => Some(CTP::String),
                 PTV::Array     => Some(CTP::Array),
                 PTV::Input     => Some(CTP::Input),
                 PTV::Output    => Some(CTP::Output),
                 PTV::Tuple(num) => Some(CTP::Tuple(*num)),
                 PTV::Definition(definition_id, num) => Some(CTP::Instance(*definition_id, *num)),
                 _              => None
+            }
+        }
         let mut parts = Vec::with_capacity(member_type.elements.len()); // usually a correct estimation, might not be
         for member_part in &member_type.elements {
             // Check if we have a regular builtin type
             if let Some(part) = parser_to_concrete_part(&member_part.variant) {
                 parts.push(part);
                 continue;
+            }
             // Not builtin, but if all code is working correctly, we only care
             // about the polymorphic argument at this point.
             if let PTV::PolymorphicArgument(_container_definition_id, poly_arg_idx) = member_part.variant {
                 debug_assert_eq!(_container_definition_id, get_concrete_type_definition(container_type));
+                debug_assert_eq!(_container_definition_id, get_concrete_type_definition(&container_type.parts).unwrap());
                 let mut container_iter = container_type.embedded_iter(0);
                 for _ in 0..poly_arg_idx {
                     container_iter.next();
+                }
                 let poly_section = container_iter.next().unwrap();
                 parts.extend(poly_section);
                 continue;
+            }
             unreachable!("unexpected type part {:?} from {:?}", member_part, member_type);
+        }
         return ConcreteType{ parts };
+    }
     //--------------------------------------------------------------------------
     // Determining memory layout for types
     //--------------------------------------------------------------------------
     /// Should be called after type loops are detected (and resolved
     /// successfully). As a result of this call we expect the
     /// `encountered_types` array to be filled. We'll calculate size/alignment/
     /// offset values for those types in this routine.
     fn lay_out_memory_for_encountered_types(&mut self, arch: &TargetArch) {
         // Programmers note: this works like a little stack machine. We have
         // memory layout breadcrumbs which, like the type loop breadcrumbs, keep
         // track of the currently considered member type. This breadcrumb also
         // stores an index into the `size_alignment_stack`, which will be used
         // to store intermediate size/alignment pairs until all members are
         // resolved. Note that this `size_alignment_stack` is NOT an
         // optimization, we're working around borrowing rules here.
         // Just finished type loop detection, so we're left with the encountered
         // types only
         // types only. If we don't have any (a builtin type's monomorph was
         // added to the type table) then this function shouldn't be called at
         // all.
         debug_assert!(self.type_loops.is_empty());
         debug_assert!(!self.encountered_types.is_empty());
         debug_assert!(self.memory_layout_breadcrumbs.is_empty());
         debug_assert!(self.size_alignment_stack.is_empty());
         let (ptr_size, ptr_align) = self.mono_types[arch.pointer_type_id.0 as usize].get_size_alignment().unwrap();
         // Push the first entry (the type we originally started with when we
         // were detecting type loops)
         let first_entry = &self.encountered_types[0];
         self.memory_layout_breadcrumbs.push(MemoryBreadcrumb{
-            monomorph_idx: first_entry.monomorph_idx,
+            type_id: first_entry.type_id,
             next_member: 0,
             next_embedded: 0,
             first_size_alignment_idx: 0,
         });
         // Enter the main resolving loop
         'breadcrumb_loop: while !self.memory_layout_breadcrumbs.is_empty() {
             let cur_breadcrumb_idx = self.memory_layout_breadcrumbs.len() - 1;
             let mut breadcrumb = self.memory_layout_breadcrumbs[cur_breadcrumb_idx].clone();
-            let mono_type = self.mono_lookup.get(breadcrumb.monomorph_idx);
+            let mono_type = &self.mono_types[breadcrumb.type_id.0 as usize];
             match &mono_type.variant {
-                MonomorphVariant::Enum => {
+                MonoTypeVariant::Builtin | MonoTypeVariant::Enum => {
                     // Size should already be computed
                     if cfg!(debug_assertions) {
                         let mono_type = self.mono_lookup.get(breadcrumb.monomorph_idx);
                     dbg_code!({
                         let mono_type = &self.mono_types[breadcrumb.type_id.0 as usize];
                         debug_assert!(mono_type.size != 0 && mono_type.alignment != 0);
+                    }
+                    });
                 },
-                MonomorphVariant::Union(mono_type) => {
+                MonoTypeVariant::Union(mono_type) => {
                     // Retrieve size/alignment of each embedded type. We do not
                     // compute the offsets or total type sizes yet.
                     let num_variants = mono_type.variants.len() as u32;
                     while breadcrumb.next_member < num_variants {
                         let mono_variant = &mono_type.variants[breadcrumb.next_member as usize];
                         if mono_variant.lives_on_heap {
                             // To prevent type loops we made this a heap-
                             // allocated variant. This implies we cannot
                             // compute sizes of members at this point.
                         } else {
                             let num_embedded = mono_variant.embedded.len() as u32;
                             while breadcrumb.next_embedded < num_embedded {
                                 let mono_embedded = &mono_variant.embedded[breadcrumb.next_embedded as usize];
                                 match self.get_memory_layout_or_breadcrumb(arch, &mono_embedded.concrete_type.parts) {
                                 let layout_result = Self::get_memory_layout_or_breadcrumb(
                                     &self.definition_lookup, &self.mono_type_lookup, &self.mono_types,
                                     &mut self.mono_search_key, arch, &mono_embedded.concrete_type.parts,
                                     self.size_alignment_stack.len()
                                 );
                                 match layout_result {
                                     MemoryLayoutResult::TypeExists(size, alignment) => {
                                         self.size_alignment_stack.push((size, alignment));
                                     },
                                     MemoryLayoutResult::PushBreadcrumb(new_breadcrumb) => {
                                         self.memory_layout_breadcrumbs[cur_breadcrumb_idx] = breadcrumb;
                                         self.memory_layout_breadcrumbs.push(new_breadcrumb);
                                         continue 'breadcrumb_loop;
+                                    }
+                                }
                                 breadcrumb.next_embedded += 1;
+                            }
+                        }
                         breadcrumb.next_member += 1;
                         breadcrumb.next_embedded = 0;
+                    }
                     // If here then we can at least compute the stack size of
                     // the type, we'll have to come back at the very end to
                     // fill in the heap size/alignment/offset of each heap-
                     // allocated variant.
                     let mut max_size = mono_type.tag_size;
                     let mut max_alignment = mono_type.tag_size;
                     let mono_info = self.mono_lookup.get_mut(breadcrumb.monomorph_idx);
                     let mono_type = mono_info.variant.as_union_mut();
                     let mono_type = &mut self.mono_types[breadcrumb.type_id.0 as usize];
                     let union_type = mono_type.variant.as_union_mut();
                     let mut size_alignment_idx = breadcrumb.first_size_alignment_idx as usize;
-                    for variant in &mut mono_type.variants {
+                    for variant in &mut union_type.variants {
                         // We're doing stack computations, so always start with
                         // the tag size/alignment.
                         let mut variant_offset = mono_type.tag_size;
                         let mut variant_alignment = mono_type.tag_size;
                         let mut variant_offset = union_type.tag_size;
                         let mut variant_alignment = union_type.tag_size;
                         if variant.lives_on_heap {
                             // Variant lives on heap, so just a pointer
                             let (ptr_size, ptr_align) = arch.pointer_size_alignment;
                             align_offset_to(&mut variant_offset, ptr_align);
                             variant_offset += ptr_size;
                             variant_alignment = variant_alignment.max(ptr_align);
                         } else {
                             // Variant lives on stack, so walk all embedded
                             // types.
                             for embedded in &mut variant.embedded {
                                 let (size, alignment) = self.size_alignment_stack[size_alignment_idx];
                                 embedded.size = size;
                                 embedded.alignment = alignment;
                                 size_alignment_idx += 1;
                                 align_offset_to(&mut variant_offset, alignment);
                                 embedded.offset = variant_offset;
                                 variant_offset += size;
                                 variant_alignment = variant_alignment.max(alignment);
+                            }
                         };
                         max_size = max_size.max(variant_offset);
                         max_alignment = max_alignment.max(variant_alignment);
+                    }
                     mono_info.size = max_size;
                     mono_info.alignment = max_alignment;
                     mono_type.size = max_size;
                     mono_type.alignment = max_alignment;
                     self.size_alignment_stack.truncate(breadcrumb.first_size_alignment_idx as usize);
                 },
-                MonomorphVariant::Struct(mono_type) => {
+                MonoTypeVariant::Struct(mono_type) => {
                     // Retrieve size and alignment of each struct member. We'll
                     // compute the offsets once all of those are known
                     let num_fields = mono_type.fields.len() as u32;
                     while breadcrumb.next_member < num_fields {
                         let mono_field = &mono_type.fields[breadcrumb.next_member as usize];
                         match self.get_memory_layout_or_breadcrumb(arch, &mono_field.concrete_type.parts) {
                         let layout_result = Self::get_memory_layout_or_breadcrumb(
                             &self.definition_lookup, &self.mono_type_lookup, &self.mono_types,
                             &mut self.mono_search_key, arch, &mono_field.concrete_type.parts,
                             self.size_alignment_stack.len()
                         );
                         match layout_result {
                             MemoryLayoutResult::TypeExists(size, alignment) => {
                                 self.size_alignment_stack.push((size, alignment))
                             },
                             MemoryLayoutResult::PushBreadcrumb(new_breadcrumb) => {
                                 self.memory_layout_breadcrumbs[cur_breadcrumb_idx] = breadcrumb;
                                 self.memory_layout_breadcrumbs.push(new_breadcrumb);
                                 continue 'breadcrumb_loop;
                             },
+                        }
                         breadcrumb.next_member += 1;
+                    }
                     // Compute offsets and size of total type
                     let mut cur_offset = 0;
                     let mut max_alignment = 1;
                     let mono_info = self.mono_lookup.get_mut(breadcrumb.monomorph_idx);
                     let mono_type = mono_info.variant.as_struct_mut();
                     let mono_type = &mut self.mono_types[breadcrumb.type_id.0 as usize];
                     let struct_type = mono_type.variant.as_struct_mut();
                     let mut size_alignment_idx = breadcrumb.first_size_alignment_idx as usize;
-                    for field in &mut mono_type.fields {
+                    for field in &mut struct_type.fields {
                         let (size, alignment) = self.size_alignment_stack[size_alignment_idx];
                         field.size = size;
                         field.alignment = alignment;
                         size_alignment_idx += 1;
                         align_offset_to(&mut cur_offset, alignment);
                         field.offset = cur_offset;
                         cur_offset += size;
                         max_alignment = max_alignment.max(alignment);
+                    }
                     mono_info.size = cur_offset;
                     mono_info.alignment = max_alignment;
                     mono_type.size = cur_offset;
                     mono_type.alignment = max_alignment;
                     self.size_alignment_stack.truncate(breadcrumb.first_size_alignment_idx as usize);
                 },
-                MonomorphVariant::Procedure(_) => {
+                MonoTypeVariant::Procedure(_) => {
                     unreachable!();
                 },
-                MonomorphVariant::Tuple(mono_type) => {
+                MonoTypeVariant::Tuple(mono_type) => {
                     let num_members = mono_type.members.len() as u32;
                     while breadcrumb.next_member < num_members {
                         let mono_member = &mono_type.members[breadcrumb.next_member as usize];
                         match self.get_memory_layout_or_breadcrumb(arch, &mono_member.concrete_type.parts) {
                         let layout_result = Self::get_memory_layout_or_breadcrumb(
                             &self.definition_lookup, &self.mono_type_lookup, &self.mono_types,
                             &mut self.mono_search_key, arch, &mono_member.concrete_type.parts,
                             self.size_alignment_stack.len()
                         );
                         match layout_result {
                             MemoryLayoutResult::TypeExists(size, alignment) => {
                                 self.size_alignment_stack.push((size, alignment));
                             },
                             MemoryLayoutResult::PushBreadcrumb(new_breadcrumb) => {
                                 self.memory_layout_breadcrumbs[cur_breadcrumb_idx] = breadcrumb;
                                 self.memory_layout_breadcrumbs.push(new_breadcrumb);
                                 continue 'breadcrumb_loop;
                             },
+                        }
                         breadcrumb.next_member += 1;
+                    }
                     // If here then we can compute the memory layout of the tuple.
                     let mut cur_offset = 0;
                     let mut max_alignment = 1;
                     let mono_info = self.mono_lookup.get_mut(breadcrumb.monomorph_idx);
                     let mono_type = mono_info.variant.as_tuple_mut();
                     let mono_type = &mut self.mono_types[breadcrumb.type_id.0 as usize];
                     let mono_tuple = mono_type.variant.as_tuple_mut();
                     let mut size_alignment_index = breadcrumb.first_size_alignment_idx as usize;
                     for member_index in 0..num_members {
                         let (member_size, member_alignment) = self.size_alignment_stack[size_alignment_index];
                         align_offset_to(&mut cur_offset, member_alignment);
                         size_alignment_index += 1;
-                        let member = &mut mono_type.members[member_index as usize];
+                        let member = &mut mono_tuple.members[member_index as usize];
                         member.size = member_size;
                         member.alignment = member_alignment;
                         member.offset = cur_offset;
                         cur_offset += member_size;
                         max_alignment = max_alignment.max(member_alignment);
+                    }
                     mono_info.size = cur_offset;
                     mono_info.alignment = max_alignment;
                     mono_type.size = cur_offset;
                     mono_type.alignment = max_alignment;
                     self.size_alignment_stack.truncate(breadcrumb.first_size_alignment_idx as usize);
                 },
+            }
             // If here, then we completely layed out the current type. So move
             // to the next breadcrumb
             self.memory_layout_breadcrumbs.pop();
+        }
         debug_assert!(self.size_alignment_stack.is_empty());
         // If here then all types have been layed out. What remains is to
         // compute the sizes/alignment/offsets of the heap variants of the
         // unions we have encountered.
         for entry in &self.encountered_types {
             if !entry.is_union {
                 continue;
+            }
             // First pass, use buffer to store size/alignment to prevent
             // borrowing issues.
-            let mono_type = self.mono_lookup.get(entry.monomorph_idx).variant.as_union();
+            let mono_type = self.mono_types[entry.type_id.0 as usize].variant.as_union();
             for variant in &mono_type.variants {
                 if !variant.lives_on_heap {
                     continue;
+                }
                 debug_assert!(!variant.embedded.is_empty());
                 for embedded in &variant.embedded {
                     match self.get_memory_layout_or_breadcrumb(arch, &embedded.concrete_type.parts) {
                     let layout_result = Self::get_memory_layout_or_breadcrumb(
                         &self.definition_lookup, &self.mono_type_lookup, &self.mono_types,
                         &mut self.mono_search_key, arch, &embedded.concrete_type.parts,
                         self.size_alignment_stack.len()
                     );
                     match layout_result {
                         MemoryLayoutResult::TypeExists(size, alignment) => {
                             self.size_alignment_stack.push((size, alignment));
                         },
                         _ => unreachable!(),
+                        _ => unreachable!(), // type was not truly infinite, so type must have been found
+                    }
+                }
+            }
             // Second pass, apply the size/alignment values in our buffer
-            let mono_type = self.mono_lookup.get_mut(entry.monomorph_idx).variant.as_union_mut();
+            let mono_type = self.mono_types[entry.type_id.0 as usize].variant.as_union_mut();
             let mut max_size = 0;
             let mut max_alignment = 1;
             let mut size_alignment_idx = 0;
             for variant in &mut mono_type.variants {
                 if !variant.lives_on_heap {
                     continue;
+                }
                 let mut variant_offset = 0;
                 let mut variant_alignment = 1;
                 for embedded in &mut variant.embedded {
                     let (size, alignment) = self.size_alignment_stack[size_alignment_idx];
                     embedded.size = size;
                     embedded.alignment = alignment;
                     size_alignment_idx += 1;
                     align_offset_to(&mut variant_offset, alignment);
                     embedded.alignment = variant_offset;
                     variant_offset += size;
                     variant_alignment = variant_alignment.max(alignment);
+                }
                 max_size = max_size.max(variant_offset);
                 max_alignment = max_alignment.max(variant_alignment);
+            }
             if max_size != 0 {
                 // At least one entry lives on the heap
                 mono_type.heap_size = max_size;
                 mono_type.heap_alignment = max_alignment;
+            }
+        }
         // And now, we're actually, properly, done
         self.encountered_types.clear();
+    }
     /// Attempts to compute size/alignment for the provided type. Note that this
     /// is called *after* type loops have been succesfully resolved. Hence we
     /// may assume that all monomorph entries exist, but we may not assume that
     /// those entries already have their size/alignment computed.
     fn get_memory_layout_or_breadcrumb(&self, arch: &TargetArch, parts: &[ConcreteTypePart]) -> MemoryLayoutResult {
     // Passed parameters are messy. But need to strike balance between borrowing
     // and allocations in hot loops. So it is what it is.
     fn get_memory_layout_or_breadcrumb(
         definition_map: &DefinitionMap, mono_type_map: &MonoTypeMap, mono_types: &MonoTypeArray,
         search_key: &mut MonoSearchKey, arch: &TargetArch, parts: &[ConcreteTypePart],
         size_alignment_stack_len: usize,
     ) -> MemoryLayoutResult {
         use ConcreteTypePart as CTP;
         debug_assert!(!parts.is_empty());
         let (builtin_size, builtin_alignment) = match parts[0] {
             CTP::Void   => (0, 1),
             CTP::Message => arch.array_size_alignment,
             CTP::Bool   => (1, 1),
             CTP::UInt8  => (1, 1),
             CTP::UInt16 => (2, 2),
             CTP::UInt32 => (4, 4),
             CTP::UInt64 => (8, 8),
             CTP::SInt8  => (1, 1),
             CTP::SInt16 => (2, 2),
             CTP::SInt32 => (4, 4),
             CTP::SInt64 => (8, 8),
             CTP::Character => (4, 4),
             CTP::String => arch.string_size_alignment,
             CTP::Array => arch.array_size_alignment,
             CTP::Slice => arch.array_size_alignment,
             CTP::Input => arch.port_size_alignment,
             CTP::Output => arch.port_size_alignment,
         let type_id = match parts[0] {
             CTP::Void      => arch.void_type_id,
             CTP::Message   => arch.message_type_id,
             CTP::Bool      => arch.bool_type_id,
             CTP::UInt8     => arch.uint8_type_id,
             CTP::UInt16    => arch.uint16_type_id,
             CTP::UInt32    => arch.uint32_type_id,
             CTP::UInt64    => arch.uint64_type_id,
             CTP::SInt8     => arch.sint8_type_id,
             CTP::SInt16    => arch.sint16_type_id,
             CTP::SInt32    => arch.sint32_type_id,
             CTP::SInt64    => arch.sint64_type_id,
             CTP::Character => arch.char_type_id,
             CTP::String    => arch.string_type_id,
             CTP::Array     => arch.array_type_id,
             CTP::Slice     => arch.slice_type_id,
             CTP::Input     => arch.input_type_id,
             CTP::Output    => arch.output_type_id,
             CTP::Pointer   => arch.pointer_type_id,
             CTP::Tuple(_) => {
                 let mono_index = self.mono_lookup.get_monomorph_index(parts, &[]).unwrap();
                 if let Some((size, alignment)) = self.mono_lookup.get_monomorph_size_alignment(mono_index) {
                     return MemoryLayoutResult::TypeExists(size, alignment);
                 } else {
                     return MemoryLayoutResult::PushBreadcrumb(MemoryBreadcrumb{
                         monomorph_idx: mono_index,
                         next_member: 0,
                         next_embedded: 0,
                         first_size_alignment_idx: self.size_alignment_stack.len() as u32,
                     })
+                }
                 Self::set_search_key_to_tuple(search_key, definition_map, parts);
                 let type_id = mono_type_map.get(&search_key).copied().unwrap();
                 type_id
             },
             CTP::Instance(definition_id, _) => {
                 // Retrieve entry and the specific monomorph index by applying
                 // the full concrete type.
                 let entry = self.type_lookup.get(&definition_id).unwrap();
                 let mono_index = self.mono_lookup.get_monomorph_index(parts, &entry.poly_vars).unwrap();
                 let definition_type = definition_map.get(&definition_id).unwrap();
                 search_key.set(parts, &definition_type.poly_vars);
                 let type_id = mono_type_map.get(&search_key).copied().unwrap();
                 type_id
             },
             CTP::Function(_, _) | CTP::Component(_, _) => {
                 todo!("storage for 'function pointers'");
+            }
         };
                 if let Some((size, alignment)) = self.mono_lookup.get_monomorph_size_alignment(mono_index) {
         let mono_type = &mono_types[type_id.0 as usize];
         if let Some((size, alignment)) = mono_type.get_size_alignment() {
             return MemoryLayoutResult::TypeExists(size, alignment);
         } else {
             return MemoryLayoutResult::PushBreadcrumb(MemoryBreadcrumb{
-                        monomorph_idx: mono_index,
+                type_id,
                 next_member: 0,
                 next_embedded: 0,
-                        first_size_alignment_idx: self.size_alignment_stack.len() as u32,
+                first_size_alignment_idx: size_alignment_stack_len as u32,
             });
+        }
             },
             CTP::Function(_, _) | CTP::Component(_, _) => {
                 todo!("storage for 'function pointers'");
+            }
         };
         return MemoryLayoutResult::TypeExists(builtin_size, builtin_alignment);
+    }
     /// Returns tag concrete type (always a builtin integer type), the size of
     /// that type in bytes (and implicitly, its alignment)
     fn variant_tag_type_from_values(min_val: i64, max_val: i64) -> (ConcreteType, usize) {
         debug_assert!(min_val <= max_val);
         let (part, size) = if min_val >= 0 {
             // Can be an unsigned integer
             if max_val <= (u8::MAX as i64) {
                 (ConcreteTypePart::UInt8, 1)
             } else if max_val <= (u16::MAX as i64) {
                 (ConcreteTypePart::UInt16, 2)
             } else if max_val <= (u32::MAX as i64) {
                 (ConcreteTypePart::UInt32, 4)
             } else {
                 (ConcreteTypePart::UInt64, 8)
+            }
         } else {
             // Must be a signed integer
             if min_val >= (i8::MIN as i64) && max_val <= (i8::MAX as i64) {
                 (ConcreteTypePart::SInt8, 1)
             } else if min_val >= (i16::MIN as i64) && max_val <= (i16::MAX as i64) {
                 (ConcreteTypePart::SInt16, 2)
             } else if min_val >= (i32::MIN as i64) && max_val <= (i32::MAX as i64) {
                 (ConcreteTypePart::SInt32, 4)
             } else {
                 (ConcreteTypePart::SInt64, 8)
+            }
         };
         return (ConcreteType{ parts: vec![part] }, size);
+    }
     //--------------------------------------------------------------------------
     // Small utilities
     //--------------------------------------------------------------------------
     fn create_polymorphic_variables(variables: &[Identifier]) -> Vec<PolymorphicVariable> {
         let mut result = Vec::with_capacity(variables.len());
         for variable in variables.iter() {
             result.push(PolymorphicVariable{ identifier: variable.clone(), is_in_use: false });
+        }
         result
+    }
     fn mark_used_polymorphic_variables(poly_vars: &mut Vec<PolymorphicVariable>, parser_type: &ParserType) {
         for element in &parser_type.elements {
             if let ParserTypeVariant::PolymorphicArgument(_, idx) = &element.variant {
                 poly_vars[*idx as usize].is_in_use = true;
+            }
+        }
+    }
     /// Sets the search key to a specific type.
     fn set_search_key_to_type(search_key: &mut MonoSearchKey, definition_map: &DefinitionMap, type_parts: &[ConcreteTypePart]) {
         use ConcreteTypePart as CTP;
         match type_parts[0] {
             // Builtin types without any embedded types
             CTP::Void | CTP::Message | CTP::Bool |
             CTP::UInt8 | CTP::UInt16 | CTP::UInt32 | CTP::UInt64 |
             CTP::SInt8 | CTP::SInt16 | CTP::SInt32 | CTP::SInt64 |
             CTP::Character | CTP::String => {
                 debug_assert_eq!(type_parts.len(), 1);
                 search_key.set_top_type(type_parts[0]);
             },
             // Builtin types with a single nested type
             CTP::Array | CTP::Slice | CTP::Input | CTP::Output | CTP::Pointer => {
                 debug_assert_eq!(type_parts[0].num_embedded(), 1);
                 search_key.set(type_parts, &POLY_VARS_IN_USE[..1])
             },
             // User-defined types
             CTP::Tuple(_) => {
                 Self::set_search_key_to_tuple(search_key, definition_map, type_parts);
             },
             CTP::Instance(definition_id, _) => {
                 let definition_type = definition_map.get(&definition_id).unwrap();
                 search_key.set(type_parts, &definition_type.poly_vars);
             },
             CTP::Function(_, _) | CTP::Component(_, _) => {
                 todo!("implement function pointers")
             },
+        }
+    }
     fn set_search_key_to_tuple(search_key: &mut MonoSearchKey, definition_map: &DefinitionMap, type_parts: &[ConcreteTypePart]) {
         dbg_code!({
             let is_tuple = if let ConcreteTypePart::Tuple(_) = type_parts[0] { true } else { false };
             assert!(is_tuple);
         });
         search_key.set_top_type(type_parts[0]);
         for subtree in ConcreteTypeIter::new(type_parts, 0) {
             if let Some(definition_id) = get_concrete_type_definition(subtree) {
                 // A definition, so retrieve poly var usage info
                 let definition_type = definition_map.get(&definition_id).unwrap();
                 search_key.push_subtree(subtree, &definition_type.poly_vars);
             } else {
                 // Not a definition, so all type information is important
                 search_key.push_subtype(subtree, true);
+            }
+        }
+    }
+}
 #[inline]
 fn align_offset_to(offset: &mut usize, alignment: usize) {
     debug_assert!(alignment > 0);
     let alignment_min_1 = alignment - 1;
     *offset += alignment_min_1;
     *offset &= !(alignment_min_1);
+}
 #[inline]
 fn get_concrete_type_definition(concrete: &ConcreteType) -> DefinitionId {
     if let ConcreteTypePart::Instance(definition_id, _) = concrete.parts[0] {
         return definition_id;
     } else {
         debug_assert!(false, "passed {:?} to the type table", concrete);
         return DefinitionId::new_invalid()
 fn get_concrete_type_definition(concrete_parts: &[ConcreteTypePart]) -> Option<DefinitionId> {
     match concrete_parts[0] {
         ConcreteTypePart::Instance(definition_id, _) => {
             return Some(definition_id)
         },
         ConcreteTypePart::Function(definition_id, _) |
         ConcreteTypePart::Component(definition_id, _) => {
             return Some(definition_id.upcast());
         },
         _ => {
             return None;
         },
+    }
+}
@@ \ No newline at end of file @@

src/protocol/parser/visitor.rs

➞

Show inline comments

 use crate::protocol::ast::*;
 use crate::protocol::input_source::ParseError;
 use crate::protocol::parser::{type_table::*, Module};
 use crate::protocol::symbol_table::{SymbolTable};
 type Unit = ();
 pub(crate) type VisitorResult = Result<Unit, ParseError>;
 /// Globally configured vector capacity for buffers in visitor implementations
 pub(crate) const BUFFER_INIT_CAPACITY: usize = 256;
 /// Globally configured capacity for large-ish buffers in visitor impls
 pub(crate) const BUFFER_INIT_CAP_LARGE: usize = 256;
 /// Globally configured capacity for small-ish buffers in visitor impls
 pub(crate) const BUFFER_INIT_CAP_SMALL: usize = 64;
 /// General context structure that is used while traversing the AST.
 pub(crate) struct Ctx<'p> {
     pub heap: &'p mut Heap,
     pub modules: &'p mut [Module],
     pub module_idx: usize, // currently considered module
     pub symbols: &'p mut SymbolTable,
     pub types: &'p mut TypeTable,
     pub arch: &'p crate::protocol::TargetArch,
+}
 impl<'p> Ctx<'p> {
     /// Returns module `modules[module_idx]`
     pub(crate) fn module(&self) -> &Module {
         &self.modules[self.module_idx]
+    }
     pub(crate) fn module_mut(&mut self) -> &mut Module {
         &mut self.modules[self.module_idx]
+    }
+}
 /// Visitor is a generic trait that will fully walk the AST. The default
 /// implementation of the visitors is to not recurse. The exception is the
 /// top-level `visit_definition`, `visit_stmt` and `visit_expr` methods, which
 /// call the appropriate visitor function.
 pub(crate) trait Visitor {
     // Entry point
     fn visit_module(&mut self, ctx: &mut Ctx) -> VisitorResult {
         let mut def_index = 0;
         let module_root_id = ctx.modules[ctx.module_idx].root_id;
         loop {
             let definition_id = {
                 let root = &ctx.heap[module_root_id];
                 if def_index >= root.definitions.len() {
                     return Ok(())
+                }
                 root.definitions[def_index]
             };
             self.visit_definition(ctx, definition_id)?;
             def_index += 1;
+        }
+    }
     // Definitions
     // --- enum matching
     fn visit_definition(&mut self, ctx: &mut Ctx, id: DefinitionId) -> VisitorResult {
         match &ctx.heap[id] {
             Definition::Enum(def) => {
                 let def = def.this;
                 self.visit_enum_definition(ctx, def)
             },
             Definition::Union(def) => {
                 let def = def.this;
                 self.visit_union_definition(ctx, def)
+            }
             Definition::Struct(def) => {
                 let def = def.this;
                 self.visit_struct_definition(ctx, def)
             },
             Definition::Component(def) => {
                 let def = def.this;
                 self.visit_component_definition(ctx, def)
             },
             Definition::Function(def) => {
                 let def = def.this;
                 self.visit_function_definition(ctx, def)
+            }
+        }
+    }
     // --- enum variant handling
     fn visit_enum_definition(&mut self, _ctx: &mut Ctx, _id: EnumDefinitionId) -> VisitorResult { Ok(()) }
     fn visit_union_definition(&mut self, _ctx: &mut Ctx, _id: UnionDefinitionId) -> VisitorResult{ Ok(()) }
     fn visit_struct_definition(&mut self, _ctx: &mut Ctx, _id: StructDefinitionId) -> VisitorResult { Ok(()) }
     fn visit_component_definition(&mut self, _ctx: &mut Ctx, _id: ComponentDefinitionId) -> VisitorResult { Ok(()) }
     fn visit_function_definition(&mut self, _ctx: &mut Ctx, _id: FunctionDefinitionId) -> VisitorResult { Ok(()) }
     // Statements
     // --- enum matching
     fn visit_stmt(&mut self, ctx: &mut Ctx, id: StatementId) -> VisitorResult {
         match &ctx.heap[id] {
 /// Implements the logic that checks the statement union retrieved from the
 /// AST and calls the appropriate visit function. This entire macro assumes that
 /// `$this` points to `self`, `$stmt` is the statement of type `Statement`,
 /// `$ctx` is the context passed to all the visitor calls (of the form
 /// `visit_x_stmt(context, id)`) and `$default_return` is the default return
 /// value for the statements that will not be visited.
 macro_rules! visitor_recursive_statement_impl {
     ($this:expr, $stmt:expr, $ctx:expr, $default_return:expr) => {
         match $stmt {
             Statement::Block(stmt) => {
                 let this = stmt.this;
-                self.visit_block_stmt(ctx, this)
+                $this.visit_block_stmt($ctx, this)
             },
-            Statement::EndBlock(_stmt) => Ok(()),
+            Statement::EndBlock(_stmt) => $default_return,
             Statement::Local(stmt) => {
                 let this = stmt.this();
-                self.visit_local_stmt(ctx, this)
+                $this.visit_local_stmt($ctx, this)
             },
             Statement::Labeled(stmt) => {
                 let this = stmt.this;
-                self.visit_labeled_stmt(ctx, this)
+                $this.visit_labeled_stmt($ctx, this)
             },
             Statement::If(stmt) => {
                 let this = stmt.this;
-                self.visit_if_stmt(ctx, this)
+                $this.visit_if_stmt($ctx, this)
             },
-            Statement::EndIf(_stmt) => Ok(()),
+            Statement::EndIf(_stmt) => $default_return,
             Statement::While(stmt) => {
                 let this = stmt.this;
-                self.visit_while_stmt(ctx, this)
+                $this.visit_while_stmt($ctx, this)
             },
-            Statement::EndWhile(_stmt) => Ok(()),
+            Statement::EndWhile(_stmt) => $default_return,
             Statement::Break(stmt) => {
                 let this = stmt.this;
-                self.visit_break_stmt(ctx, this)
+                $this.visit_break_stmt($ctx, this)
             },
             Statement::Continue(stmt) => {
                 let this = stmt.this;
-                self.visit_continue_stmt(ctx, this)
+                $this.visit_continue_stmt($ctx, this)
             },
             Statement::Synchronous(stmt) => {
                 let this = stmt.this;
-                self.visit_synchronous_stmt(ctx, this)
+                $this.visit_synchronous_stmt($ctx, this)
             },
-            Statement::EndSynchronous(_stmt) => Ok(()),
+            Statement::EndSynchronous(_stmt) => $default_return,
             Statement::Fork(stmt) => {
                 let this = stmt.this;
-                self.visit_fork_stmt(ctx, this)
+                $this.visit_fork_stmt($ctx, this)
             },
-            Statement::EndFork(_stmt) => Ok(()),
+            Statement::EndFork(_stmt) => $default_return,
             Statement::Select(stmt) => {
                 let this = stmt.this;
-                self.visit_select_stmt(ctx, this)
+                $this.visit_select_stmt($ctx, this)
             },
-            Statement::EndSelect(_stmt) => Ok(()),
+            Statement::EndSelect(_stmt) => $default_return,
             Statement::Return(stmt) => {
                 let this = stmt.this;
-                self.visit_return_stmt(ctx, this)
+                $this.visit_return_stmt($ctx, this)
             },
             Statement::Goto(stmt) => {
                 let this = stmt.this;
-                self.visit_goto_stmt(ctx, this)
+                $this.visit_goto_stmt($ctx, this)
             },
             Statement::New(stmt) => {
                 let this = stmt.this;
-                self.visit_new_stmt(ctx, this)
+                $this.visit_new_stmt($ctx, this)
             },
             Statement::Expression(stmt) => {
                 let this = stmt.this;
-                self.visit_expr_stmt(ctx, this)
+                $this.visit_expr_stmt($ctx, this)
+            }
+        }
     };
+}
     fn visit_local_stmt(&mut self, ctx: &mut Ctx, id: LocalStatementId) -> VisitorResult {
         match &ctx.heap[id] {
             LocalStatement::Channel(stmt) => {
                 let this = stmt.this;
                 self.visit_local_channel_stmt(ctx, this)
             },
             LocalStatement::Memory(stmt) => {
                 let this = stmt.this;
                 self.visit_local_memory_stmt(ctx, this)
 macro_rules! visitor_recursive_local_impl {
     ($this:expr, $local:expr, $ctx:expr) => {
         match $local {
             LocalStatement::Channel(local) => {
                 let this = local.this;
                 $this.visit_local_channel_stmt($ctx, this)
             },
             LocalStatement::Memory(local) => {
                 let this = local.this;
                 $this.visit_local_memory_stmt($ctx, this)
+            }
+        }
+    }
+}
     // --- enum variant handling
     fn visit_block_stmt(&mut self, _ctx: &mut Ctx, _id: BlockStatementId) -> VisitorResult { Ok(()) }
     fn visit_local_memory_stmt(&mut self, _ctx: &mut Ctx, _id: MemoryStatementId) -> VisitorResult { Ok(()) }
     fn visit_local_channel_stmt(&mut self, _ctx: &mut Ctx, _id: ChannelStatementId) -> VisitorResult { Ok(()) }
     fn visit_labeled_stmt(&mut self, _ctx: &mut Ctx, _id: LabeledStatementId) -> VisitorResult { Ok(()) }
     fn visit_if_stmt(&mut self, _ctx: &mut Ctx, _id: IfStatementId) -> VisitorResult { Ok(()) }
     fn visit_while_stmt(&mut self, _ctx: &mut Ctx, _id: WhileStatementId) -> VisitorResult { Ok(()) }
     fn visit_break_stmt(&mut self, _ctx: &mut Ctx, _id: BreakStatementId) -> VisitorResult { Ok(()) }
     fn visit_continue_stmt(&mut self, _ctx: &mut Ctx, _id: ContinueStatementId) -> VisitorResult { Ok(()) }
     fn visit_synchronous_stmt(&mut self, _ctx: &mut Ctx, _id: SynchronousStatementId) -> VisitorResult { Ok(()) }
     fn visit_fork_stmt(&mut self, _ctx: &mut Ctx, _id: ForkStatementId) -> VisitorResult { Ok(()) }
     fn visit_select_stmt(&mut self, _ctx: &mut Ctx, _id: SelectStatementId) -> VisitorResult { Ok(()) }
     fn visit_return_stmt(&mut self, _ctx: &mut Ctx, _id: ReturnStatementId) -> VisitorResult { Ok(()) }
     fn visit_goto_stmt(&mut self, _ctx: &mut Ctx, _id: GotoStatementId) -> VisitorResult { Ok(()) }
     fn visit_new_stmt(&mut self, _ctx: &mut Ctx, _id: NewStatementId) -> VisitorResult { Ok(()) }
     fn visit_expr_stmt(&mut self, _ctx: &mut Ctx, _id: ExpressionStatementId) -> VisitorResult { Ok(()) }
 macro_rules! visitor_recursive_definition_impl {
     ($this:expr, $definition:expr, $ctx:expr) => {
         match $definition {
             Definition::Enum(def) => {
                 let def = def.this;
                 $this.visit_enum_definition($ctx, def)
             },
             Definition::Union(def) => {
                 let def = def.this;
                 $this.visit_union_definition($ctx, def)
             },
             Definition::Struct(def) => {
                 let def = def.this;
                 $this.visit_struct_definition($ctx, def)
             },
             Definition::Procedure(def) => {
                 let def = def.this;
                 $this.visit_procedure_definition($ctx, def)
             },
+        }
+    }
+}
     // Expressions
     // --- enum matching
     fn visit_expr(&mut self, ctx: &mut Ctx, id: ExpressionId) -> VisitorResult {
         match &ctx.heap[id] {
 macro_rules! visitor_recursive_expression_impl {
     ($this:expr, $expression:expr, $ctx:expr) => {
         match $expression {
             Expression::Assignment(expr) => {
                 let this = expr.this;
-                self.visit_assignment_expr(ctx, this)
+                $this.visit_assignment_expr($ctx, this)
             },
             Expression::Binding(expr) => {
                 let this = expr.this;
                 self.visit_binding_expr(ctx, this)
+            }
                 $this.visit_binding_expr($ctx, this)
             },
             Expression::Conditional(expr) => {
                 let this = expr.this;
                 self.visit_conditional_expr(ctx, this)
+            }
                 $this.visit_conditional_expr($ctx, this)
             },
             Expression::Binary(expr) => {
                 let this = expr.this;
                 self.visit_binary_expr(ctx, this)
+            }
                 $this.visit_binary_expr($ctx, this)
             },
             Expression::Unary(expr) => {
                 let this = expr.this;
                 self.visit_unary_expr(ctx, this)
+            }
                 $this.visit_unary_expr($ctx, this)
             },
             Expression::Indexing(expr) => {
                 let this = expr.this;
                 self.visit_indexing_expr(ctx, this)
+            }
                 $this.visit_indexing_expr($ctx, this)
             },
             Expression::Slicing(expr) => {
                 let this = expr.this;
                 self.visit_slicing_expr(ctx, this)
+            }
                 $this.visit_slicing_expr($ctx, this)
             },
             Expression::Select(expr) => {
                 let this = expr.this;
                 self.visit_select_expr(ctx, this)
+            }
                 $this.visit_select_expr($ctx, this)
             },
             Expression::Literal(expr) => {
                 let this = expr.this;
                 self.visit_literal_expr(ctx, this)
+            }
                 $this.visit_literal_expr($ctx, this)
             },
             Expression::Cast(expr) => {
                 let this = expr.this;
                 self.visit_cast_expr(ctx, this)
+            }
                 $this.visit_cast_expr($ctx, this)
             },
             Expression::Call(expr) => {
                 let this = expr.this;
                 self.visit_call_expr(ctx, this)
+            }
                 $this.visit_call_expr($ctx, this)
             },
             Expression::Variable(expr) => {
                 let this = expr.this;
                 self.visit_variable_expr(ctx, this)
                 $this.visit_variable_expr($ctx, this)
             },
+        }
     };
+}
 /// Visitor is a generic trait that will fully walk the AST. The default
 /// implementation of the visitors is to not recurse. The exception is the
 /// top-level `visit_definition`, `visit_stmt` and `visit_expr` methods, which
 /// call the appropriate visitor function.
 pub(crate) trait Visitor {
     // Entry point
     fn visit_module(&mut self, ctx: &mut Ctx) -> VisitorResult {
         let mut def_index = 0;
         let module_root_id = ctx.modules[ctx.module_idx].root_id;
         loop {
             let definition_id = {
                 let root = &ctx.heap[module_root_id];
                 if def_index >= root.definitions.len() {
                     return Ok(())
+                }
                 root.definitions[def_index]
             };
             self.visit_definition(ctx, definition_id)?;
             def_index += 1;
+        }
+    }
     // Definitions
     // --- enum matching
     fn visit_definition(&mut self, ctx: &mut Ctx, id: DefinitionId) -> VisitorResult {
         return visitor_recursive_definition_impl!(self, &ctx.heap[id], ctx);
+    }
     // --- enum variant handling
     fn visit_enum_definition(&mut self, _ctx: &mut Ctx, _id: EnumDefinitionId) -> VisitorResult { Ok(()) }
     fn visit_union_definition(&mut self, _ctx: &mut Ctx, _id: UnionDefinitionId) -> VisitorResult{ Ok(()) }
     fn visit_struct_definition(&mut self, _ctx: &mut Ctx, _id: StructDefinitionId) -> VisitorResult { Ok(()) }
     fn visit_procedure_definition(&mut self, _ctx: &mut Ctx, _id: ProcedureDefinitionId) -> VisitorResult { Ok(()) }
     // Statements
     // --- enum matching
     fn visit_stmt(&mut self, ctx: &mut Ctx, id: StatementId) -> VisitorResult {
         return visitor_recursive_statement_impl!(self, &ctx.heap[id], ctx, Ok(()));
+    }
     fn visit_local_stmt(&mut self, ctx: &mut Ctx, id: LocalStatementId) -> VisitorResult {
         return visitor_recursive_local_impl!(self, &ctx.heap[id], ctx);
+    }
     // --- enum variant handling
     fn visit_block_stmt(&mut self, _ctx: &mut Ctx, _id: BlockStatementId) -> VisitorResult { Ok(()) }
     fn visit_local_memory_stmt(&mut self, _ctx: &mut Ctx, _id: MemoryStatementId) -> VisitorResult { Ok(()) }
     fn visit_local_channel_stmt(&mut self, _ctx: &mut Ctx, _id: ChannelStatementId) -> VisitorResult { Ok(()) }
     fn visit_labeled_stmt(&mut self, _ctx: &mut Ctx, _id: LabeledStatementId) -> VisitorResult { Ok(()) }
     fn visit_if_stmt(&mut self, _ctx: &mut Ctx, _id: IfStatementId) -> VisitorResult { Ok(()) }
     fn visit_while_stmt(&mut self, _ctx: &mut Ctx, _id: WhileStatementId) -> VisitorResult { Ok(()) }
     fn visit_break_stmt(&mut self, _ctx: &mut Ctx, _id: BreakStatementId) -> VisitorResult { Ok(()) }
     fn visit_continue_stmt(&mut self, _ctx: &mut Ctx, _id: ContinueStatementId) -> VisitorResult { Ok(()) }
     fn visit_synchronous_stmt(&mut self, _ctx: &mut Ctx, _id: SynchronousStatementId) -> VisitorResult { Ok(()) }
     fn visit_fork_stmt(&mut self, _ctx: &mut Ctx, _id: ForkStatementId) -> VisitorResult { Ok(()) }
     fn visit_select_stmt(&mut self, _ctx: &mut Ctx, _id: SelectStatementId) -> VisitorResult { Ok(()) }
     fn visit_return_stmt(&mut self, _ctx: &mut Ctx, _id: ReturnStatementId) -> VisitorResult { Ok(()) }
     fn visit_goto_stmt(&mut self, _ctx: &mut Ctx, _id: GotoStatementId) -> VisitorResult { Ok(()) }
     fn visit_new_stmt(&mut self, _ctx: &mut Ctx, _id: NewStatementId) -> VisitorResult { Ok(()) }
     fn visit_expr_stmt(&mut self, _ctx: &mut Ctx, _id: ExpressionStatementId) -> VisitorResult { Ok(()) }
     // Expressions
     // --- enum matching
     fn visit_expr(&mut self, ctx: &mut Ctx, id: ExpressionId) -> VisitorResult {
         return visitor_recursive_expression_impl!(self, &ctx.heap[id], ctx);
+    }
     fn visit_assignment_expr(&mut self, _ctx: &mut Ctx, _id: AssignmentExpressionId) -> VisitorResult { Ok(()) }
     fn visit_binding_expr(&mut self, _ctx: &mut Ctx, _id: BindingExpressionId) -> VisitorResult { Ok(()) }
     fn visit_conditional_expr(&mut self, _ctx: &mut Ctx, _id: ConditionalExpressionId) -> VisitorResult { Ok(()) }
     fn visit_binary_expr(&mut self, _ctx: &mut Ctx, _id: BinaryExpressionId) -> VisitorResult { Ok(()) }
     fn visit_unary_expr(&mut self, _ctx: &mut Ctx, _id: UnaryExpressionId) -> VisitorResult { Ok(()) }
     fn visit_indexing_expr(&mut self, _ctx: &mut Ctx, _id: IndexingExpressionId) -> VisitorResult { Ok(()) }
     fn visit_slicing_expr(&mut self, _ctx: &mut Ctx, _id: SlicingExpressionId) -> VisitorResult { Ok(()) }
     fn visit_select_expr(&mut self, _ctx: &mut Ctx, _id: SelectExpressionId) -> VisitorResult { Ok(()) }
     fn visit_literal_expr(&mut self, _ctx: &mut Ctx, _id: LiteralExpressionId) -> VisitorResult { Ok(()) }
     fn visit_cast_expr(&mut self, _ctx: &mut Ctx, _id: CastExpressionId) -> VisitorResult { Ok(()) }
     fn visit_call_expr(&mut self, _ctx: &mut Ctx, _id: CallExpressionId) -> VisitorResult { Ok(()) }
     fn visit_variable_expr(&mut self, _ctx: &mut Ctx, _id: VariableExpressionId) -> VisitorResult { Ok(()) }
+}
@@ \ No newline at end of file @@

src/protocol/tests/parser_monomorphs.rs

➞

Show inline comments

 /// parser_monomorphs.rs
 ///
 /// Simple tests to make sure that all of the appropriate monomorphs are
 /// instantiated
 use super::*;
 #[test]
 fn test_struct_monomorphs() {
     Tester::new_single_source_expect_ok(
         "no polymorph",
         "struct Integer{ s32 field }"
     ).for_struct("Integer", |s| { s
         .assert_num_monomorphs(1)
         .assert_has_monomorph("Integer");
     });
     Tester::new_single_source_expect_ok(
         "single polymorph",
+        "
         struct Number<T>{ T number }
         func instantiator() -> s32 {
             auto a = Number<s8>{ number: 0 };
             auto b = Number<s8>{ number: 1 };
             auto c = Number<s32>{ number: 2 };
             auto d = Number<s64>{ number: 3 };
             auto e = Number<Number<s16>>{ number: Number{ number: 4 }};
             return 0;
+        }
+        "
     ).for_struct("Number", |s| { s
         .assert_has_monomorph("Number<s8>")
         .assert_has_monomorph("Number<s16>")
         .assert_has_monomorph("Number<s32>")
         .assert_has_monomorph("Number<s64>")
         .assert_has_monomorph("Number<Number<s16>>")
         .assert_num_monomorphs(5);
     }).for_function("instantiator", |f| { f
         .for_variable("a", |v| {v.assert_concrete_type("Number<s8>");} )
         .for_variable("e", |v| {v.assert_concrete_type("Number<Number<s16>>");} );
     });
+}
 #[test]
 fn test_enum_monomorphs() {
     Tester::new_single_source_expect_ok(
         "no polymorph",
+        "
         enum Answer{ Yes, No }
         func do_it() -> s32 { auto a = Answer::Yes; return 0; }
+        "
     ).for_enum("Answer", |e| { e
         .assert_num_monomorphs(1)
         .assert_has_monomorph("Answer")
         .assert_size_alignment("Answer", 1, 1);
     });
     // Note for reader: because the enum doesn't actually use the polymorphic
     // variable, we expect to have 1 monomorph: the type only has to be laid
     // out once.
+    // out once. @Deduplication
     Tester::new_single_source_expect_ok(
         "single polymorph",
+        "
         enum Answer<T> { Yes, No }
         func instantiator() -> s32 {
             auto a = Answer<s8>::Yes;
             auto b = Answer<s8>::No;
             auto c = Answer<s32>::Yes;
             auto d = Answer<Answer<Answer<s64>>>::No;
             return 0;
+        }
+        "
     ).for_enum("Answer", |e| { e
         .assert_num_monomorphs(1)
         .assert_has_monomorph("Answer<s8>");
         .assert_num_monomorphs(3)
         .assert_has_monomorph("Answer<s8>")
         .assert_has_monomorph("Answer<s32>")
         .assert_has_monomorph("Answer<Answer<Answer<s64>>>");
     });
+}
 #[test]
 fn test_union_monomorphs() {
     Tester::new_single_source_expect_ok(
         "no polymorph",
+        "
         union Trinary { Undefined, Value(bool) }
         func do_it() -> s32 { auto a = Trinary::Value(true); return 0; }
+        "
     ).for_union("Trinary", |e| { e
         .assert_num_monomorphs(1)
         .assert_has_monomorph("Trinary");
     });
     Tester::new_single_source_expect_ok(
         "polymorphs",
+        "
         union Result<T, E>{ Ok(T), Err(E) }
         func instantiator() -> s32 {
             s16 a_s16 = 5;
             auto a = Result<s8, bool>::Ok(0);
             auto b = Result<bool, s8>::Ok(true);
             auto c = Result<Result<s8, s32>, Result<s16, s64>>::Err(Result::Ok(5));
             auto d = Result<Result<s8, s32>, auto>::Err(Result<auto, s64>::Ok(a_s16));
             return 0;
+        }
+        "
     ).for_union("Result", |e| { e
         .assert_num_monomorphs(5)
         .assert_has_monomorph("Result<s8,bool>")
         .assert_has_monomorph("Result<bool,s8>")
         .assert_has_monomorph("Result<Result<s8,s32>,Result<s16,s64>>")
         .assert_has_monomorph("Result<s8,s32>")
         .assert_has_monomorph("Result<s16,s64>");
     }).for_function("instantiator", |f| { f
         .for_variable("d", |v| { v
             .assert_parser_type("auto")
             .assert_concrete_type("Result<Result<s8,s32>,Result<s16,s64>>");
         });
     });
+}
@@ \ No newline at end of file @@

src/protocol/tests/parser_validation.rs

➞

Show inline comments

 /// parser_validation.rs
 ///
 /// Simple tests for the validation phase
 use super::*;
 #[test]
 fn test_correct_struct_instance() {
     Tester::new_single_source_expect_ok(
         "single field",
+        "
         struct Foo { s32 a }
         func bar(s32 arg) -> Foo { return Foo{ a: arg }; }
+        "
     );
     Tester::new_single_source_expect_ok(
         "multiple fields",
+        "
         struct Foo { s32 a, s32 b }
         func bar(s32 arg) -> Foo { return Foo{ a: arg, b: arg }; }
+        "
     );
     Tester::new_single_source_expect_ok(
         "single field, explicit polymorph",
+        "
         struct Foo<T>{ T field }
         func bar(s32 arg) -> Foo<s32> { return Foo<s32>{ field: arg }; }
+        "
     );
     Tester::new_single_source_expect_ok(
         "single field, implicit polymorph",
+        "
         struct Foo<T>{ T field }
         func bar(s32 arg) -> s32 {
             auto thingo = Foo{ field: arg };
             return arg;
+        }
+        "
     );
     Tester::new_single_source_expect_ok(
         "multiple fields, same explicit polymorph",
+        "
         struct Pair<T1, T2>{ T1 first, T2 second }
         func bar(s32 arg) -> s32 {
             auto qux = Pair<s32, s32>{ first: arg, second: arg };
             return arg;
+        }
+        "
     );
     Tester::new_single_source_expect_ok(
         "multiple fields, same implicit polymorph",
+        "
         struct Pair<T1, T2>{ T1 first, T2 second }
         func bar(s32 arg) -> s32 {
             auto wup = Pair{ first: arg, second: arg };
             return arg;
+        }
+        "
     );
     Tester::new_single_source_expect_ok(
         "multiple fields, different explicit polymorph",
+        "
         struct Pair<T1, T2>{ T1 first, T2 second }
         func bar(s32 arg1, s8 arg2) -> s32 {
             auto shoo = Pair<s32, s8>{ first: arg1, second: arg2 };
             return arg1;
+        }
+        "
     );
     Tester::new_single_source_expect_ok(
         "multiple fields, different implicit polymorph",
+        "
         struct Pair<T1, T2>{ T1 first, T2 second }
         func bar(s32 arg1, s8 arg2) -> s32 {
             auto shrubbery = Pair{ first: arg1, second: arg2 };
             return arg1;
+        }
+        "
     );
+}
 #[test]
 fn test_incorrect_struct_instance() {
     Tester::new_single_source_expect_err(
         "reused field in definition",
         "struct Foo{ s32 a, s8 a }"
     ).error(|e| { e
         .assert_num(2)
         .assert_occurs_at(0, "a }")
         .assert_msg_has(0, "defined more than once")
         .assert_occurs_at(1, "a, ")
         .assert_msg_has(1, "other struct field");
     });
     Tester::new_single_source_expect_err(
         "reused field in instance",
+        "
         struct Foo{ s32 a, s32 b }
         func bar() -> s32 {
             auto foo = Foo{ a: 5, a: 3 };
             return 0;
+        }
+        "
     ).error(|e| { e
         .assert_occurs_at(0, "a: 3")
         .assert_msg_has(0, "field is specified more than once");
     });
     Tester::new_single_source_expect_err(
         "missing field",
+        "
         struct Foo { s32 a, s32 b }
         func bar() -> s32 {
             auto foo = Foo{ a: 2 };
             return 0;
+        }
+        "
     ).error(|e| { e
         .assert_occurs_at(0, "Foo{")
         .assert_msg_has(0, "'b' is missing");
     });
     Tester::new_single_source_expect_err(
         "missing fields",
+        "
         struct Foo { s32 a, s32 b, s32 c }
         func bar() -> s32 {
             auto foo = Foo{ a: 2 };
             return 0;
+        }
+        "
     ).error(|e| { e
         .assert_occurs_at(0, "Foo{")
         .assert_msg_has(0, "[b, c] are missing");
     });
+}
 #[test]
 fn test_correct_enum_instance() {
     Tester::new_single_source_expect_ok(
         "single variant",
+        "
         enum Foo { A }
         func bar() -> Foo { return Foo::A; }
+        "
     );
     Tester::new_single_source_expect_ok(
         "multiple variants",
+        "
         enum Foo { A=15, B = 0xF }
         func bar() -> Foo { auto a = Foo::A; return Foo::B; }
+        "
     );
     Tester::new_single_source_expect_ok(
         "explicit single polymorph",
+        "
         enum Foo<T>{ A }
         func bar() -> Foo<s32> { return Foo::A; }
+        "
     );
     Tester::new_single_source_expect_ok(
         "explicit multi-polymorph",
+        "
         enum Foo<A, B>{ A, B }
         func bar() -> Foo<s8, s32> { return Foo::B; }
+        "
     );
+}
 #[test]
 fn test_incorrect_enum_instance() {
     Tester::new_single_source_expect_err(
         "variant name reuse",
+        "
         enum Foo { A, A }
         func bar() -> Foo { return Foo::A; }
+        "
     ).error(|e| { e
         .assert_num(2)
         .assert_occurs_at(0, "A }")
         .assert_msg_has(0, "defined more than once")
         .assert_occurs_at(1, "A, ")
         .assert_msg_has(1, "other enum variant is defined here");
     });
     Tester::new_single_source_expect_err(
         "undefined variant",
+        "
         enum Foo { A }
         func bar() -> Foo { return Foo::B; }
+        "
     ).error(|e| { e
         .assert_num(1)
         .assert_msg_has(0, "variant 'B' does not exist on the enum 'Foo'");
     });
+}
 #[test]
 fn test_correct_union_instance() {
     Tester::new_single_source_expect_ok(
         "single tag",
+        "
         union Foo { A }
         func bar() -> Foo { return Foo::A; }
+        "
     );
     Tester::new_single_source_expect_ok(
         "multiple tags",
+        "
         union Foo { A, B }
         func bar() -> Foo { return Foo::B; }
+        "
     );
     Tester::new_single_source_expect_ok(
         "single embedded",
+        "
         union Foo { A(s32) }
         func bar() -> Foo { return Foo::A(5); }
+        "
     );
     Tester::new_single_source_expect_ok(
         "multiple embedded",
+        "
         union Foo { A(s32), B(s8) }
         func bar() -> Foo { return Foo::B(2); }
+        "
     );
     Tester::new_single_source_expect_ok(
         "multiple values in embedded",
+        "
         union Foo { A(s32, s8) }
         func bar() -> Foo { return Foo::A(0, 2); }
+        "
     );
     Tester::new_single_source_expect_ok(
         "mixed tag/embedded",
+        "
         union OptionInt { None, Some(s32) }
         func bar() -> OptionInt { return OptionInt::Some(3); }
+        "
     );
     Tester::new_single_source_expect_ok(
         "single polymorphic var",
+        "
         union Option<T> { None, Some(T) }
         func bar() -> Option<s32> { return Option::Some(3); }"
     );
     Tester::new_single_source_expect_ok(
         "multiple polymorphic vars",
+        "
         union Result<T, E> { Ok(T), Err(E), }
         func bar() -> Result<s32, s8> { return Result::Ok(3); }
+        "
     );
     Tester::new_single_source_expect_ok(
         "multiple polymorphic in one variant",
+        "
         union MaybePair<T1, T2>{ None, Some(T1, T2) }
         func bar() -> MaybePair<s8, s32> { return MaybePair::Some(1, 2); }
+        "
     );
+}
 #[test]
 fn test_incorrect_union_instance() {
     Tester::new_single_source_expect_err(
         "tag-variant name reuse",
+        "
         union Foo{ A, A }
+        "
     ).error(|e| { e
         .assert_num(2)
         .assert_occurs_at(0, "A }")
         .assert_msg_has(0, "union variant is defined more than once")
         .assert_occurs_at(1, "A, ")
         .assert_msg_has(1, "other union variant");
     });
     Tester::new_single_source_expect_err(
         "embedded-variant name reuse",
+        "
         union Foo{ A(s32), A(s8) }
+        "
     ).error(|e| { e
         .assert_num(2)
         .assert_occurs_at(0, "A(s8)")
         .assert_msg_has(0, "union variant is defined more than once")
         .assert_occurs_at(1, "A(s32)")
         .assert_msg_has(1, "other union variant");
     });
     Tester::new_single_source_expect_err(
         "undefined variant",
+        "
         union Silly{ Thing(s8) }
         func bar() -> Silly { return Silly::Undefined(5); }
+        "
     ).error(|e| { e
         .assert_msg_has(0, "variant 'Undefined' does not exist on the union 'Silly'");
     });
     Tester::new_single_source_expect_err(
         "using tag instead of embedded",
+        "
         union Foo{ A(s32) }
         func bar() -> Foo { return Foo::A; }
+        "
     ).error(|e| { e
         .assert_msg_has(0, "variant 'A' of union 'Foo' expects 1 embedded values, but 0 were");
     });
     Tester::new_single_source_expect_err(
         "using embedded instead of tag",
+        "
         union Foo{ A }
         func bar() -> Foo { return Foo::A(3); }
+        "
     ).error(|e| { e
         .assert_msg_has(0, "The variant 'A' of union 'Foo' expects 0");
     });
     Tester::new_single_source_expect_err(
         "wrong embedded value",
+        "
         union Foo{ A(s32) }
         func bar() -> Foo { return Foo::A(false); }
+        "
     ).error(|e| { e
         .assert_occurs_at(0, "Foo::A")
-        .assert_msg_has(0, "failed to fully resolve")
         .assert_msg_has(0, "failed to resolve")
         .assert_occurs_at(1, "false")
         .assert_msg_has(1, "has been resolved to 's32'")
         .assert_msg_has(1, "has been resolved to 'bool'");
     });
+}
 #[test]
 fn test_correct_tuple_members() {
     // Tuples with zero members
     Tester::new_single_source_expect_ok(
         "single zero-tuple",
         "struct Foo{ () bar }"
     ).for_struct("Foo", |s| { s
         .for_field("bar", |f| { f.assert_parser_type("()"); })
         .assert_size_alignment("Foo", 0, 1);
     });
     Tester::new_single_source_expect_ok(
         "triple zero-tuple",
         "struct Foo{ () bar, () baz, () qux }"
     ).for_struct("Foo", |s| { s
         .assert_size_alignment("Foo", 0, 1);
     });
     // Tuples with one member (which are elided, because due to ambiguity
     // between a one-tuple literal and a parenthesized expression, we're not
     // going to be able to construct one-tuples).
     Tester::new_single_source_expect_ok(
         "single elided one-tuple",
         "struct Foo{ (u32) bar }"
     ).for_struct("Foo", |s| { s
         .for_field("bar", |f| { f.assert_parser_type("u32"); })
         .assert_size_alignment("Foo", 4, 4);
     });
     Tester::new_single_source_expect_ok(
         "triple elided one-tuple",
         "struct Foo{ (u8) bar, (u16) baz, (u32) qux }"
     ).for_struct("Foo", |s| { s
         .assert_size_alignment("Foo", 8, 4);
     });
     // Tuples with three members
     Tester::new_single_source_expect_ok(
         "single three-tuple",
         "struct Foo{ (u8, u16, u32) bar }"
     ).for_struct("Foo", |s| { s
         .for_field("bar", |f| { f.assert_parser_type("(u8,u16,u32)"); })
         .assert_size_alignment("Foo", 8, 4);
     });
     Tester::new_single_source_expect_ok(
         "double three-tuple",
         "struct Foo{ (u8,u16,u32,) bar, (s8,s16,s32,) baz }"
     ).for_struct("Foo", |s| { s
         .for_field("bar", |f| { f.assert_parser_type("(u8,u16,u32)"); })
         .for_field("baz", |f| { f.assert_parser_type("(s8,s16,s32)"); })
         .assert_size_alignment("Foo", 16, 4);
     });
+}
 #[test]
 fn test_incorrect_tuple_member() {
     // Test not really necessary, but hey, what's a test between friends
     Tester::new_single_source_expect_err(
         "unknown tuple member",
         "struct Foo{ (u32, u32, u32, YouThirstySchmoo) field }"
     ).error(|e| { e
         .assert_num(1)
         .assert_msg_has(0, "unknown type")
         .assert_occurs_at(0, "YouThirstySchmoo");
     });
+}
 #[test]
 fn test_correct_tuple_polymorph_args() {
     Tester::new_single_source_expect_ok(
         "single tuple arg",
+        "
         union Option<T>{ Some(T), None }
         func thing() -> u32 {
             auto a = Option<()>::None;
             auto b = Option<(u32, u64)>::None;
             auto c = Option<(Option<(u8, s8)>, Option<(s8, u8)>)>::None;
             return 0;
+        }
+        "
     ).for_union("Option", |u| { u
         .assert_has_monomorph("Option<()>")
         .assert_has_monomorph("Option<(u32,u64)>")
         .assert_has_monomorph("Option<(Option<(u8,s8)>,Option<(s8,u8)>)>")
         .assert_size_alignment("Option<()>", 1, 1, 0, 0)
         .assert_size_alignment("Option<(u32,u64)>", 24, 8, 0, 0) // (u32, u64) becomes size 16, alignment 8. Hence union tag is aligned to 8
         .assert_size_alignment("Option<(Option<(u8,s8)>,Option<(s8,u8)>)>", 7, 1, 0, 0); // inner unions are size 3, alignment 1. Two of those with a tag is size 7
     });
+}
 #[test]
 fn test_incorrect_tuple_polymorph_args() {
     // Do some mismatching brackets. I don't know what else to test
     Tester::new_single_source_expect_err(
         "mismatch angle bracket",
+        "
         union Option<T>{ Some(T), None }
         func f() -> u32 {
             auto a = Option<(u32>)::None;
             return 0;
         }"
     ).error(|e| { e
         .assert_num(2)
         .assert_msg_has(0, "closing '>'").assert_occurs_at(0, ">)::None")
         .assert_msg_has(1, "match this '('").assert_occurs_at(1, "(u32>");
     });
     Tester::new_single_source_expect_err(
         "wrongly placed angle",
+        "
         union O<T>{ S(T), N }
         func f() -> u32 {
             auto a = O<(<u32>)>::None;
             return 0;
+        }
+        "
     ).error(|e| { e
         .assert_num(1)
         .assert_msg_has(0, "expected typename")
         .assert_occurs_at(0, "<u32");
     });
+}
 #[test]
 fn test_incorrect_tuple_member_access() {
     Tester::new_single_source_expect_err(
         "zero-tuple",
         "func foo() -> () { () a = (); auto b = a.0; return a; }"
     ).error(|e| { e
         .assert_num(1)
         .assert_msg_has(0, "out of bounds")
         .assert_occurs_at(0, "a.0");
     });
     // Make the type checker do some shenanigans before we can decide the tuple
     // type.
     Tester::new_single_source_expect_err(
         "sized tuple",
+        "
         func determinator<A,B>((A,B,A) v) -> B { return v.1; }
         func tester() -> u64 {
             auto v = (0,1,2);
             u32 a_u32 = 5;
             v.2 = a_u32;
             v.8 = 5;
             return determinator(v);
+        }
+        "
     ).error(|e| { e
         .assert_num(1)
         .assert_msg_has(0, "out of bounds")
         .assert_occurs_at(0, "v.8");
     });
+}
 #[test]
 fn test_polymorph_array_types() {
     Tester::new_single_source_expect_ok(
         "array of polymorph in struct",
+        "
         struct Foo<T> { T[] hello }
         struct Bar { Foo<u32>[] world }
+        "
     ).for_struct("Bar", |s| { s
         .for_field("world", |f| { f.assert_parser_type("Foo<u32>[]"); });
     });
     Tester::new_single_source_expect_ok(
         "array of port in struct",
+        "
         struct Bar { in<u32>[] inputs }
+        "
     ).for_struct("Bar", |s| { s
         .for_field("inputs", |f| { f.assert_parser_type("in<u32>[]"); });
     });
+}
 #[test]
 fn test_correct_modifying_operators() {
     // Not testing the types, just that it parses
     Tester::new_single_source_expect_ok(
         "valid uses",
+        "
         func f() -> u32 {
             auto a = 5;
             a += 2; a -= 2; a *= 2; a /= 2; a %= 2;
             a <<= 2; a >>= 2;
             a |= 2; a &= 2; a ^= 2;
             return a;
+        }
+        "
     );
+}
 #[test]
 fn test_incorrect_modifying_operators() {
     Tester::new_single_source_expect_err(
         "wrong declaration",
         "func f() -> u8 { auto a += 2; return a; }"
     ).error(|e| { e.assert_msg_has(0, "expected '='"); });
     Tester::new_single_source_expect_err(
         "inside function",
         "func f(u32 a) -> u32 { auto b = 0; auto c = f(a += 2); }"
     ).error(|e| { e.assert_msg_has(0, "assignments are statements"); });
     Tester::new_single_source_expect_err(
         "inside tuple",
         "func f(u32 a) -> u32 { auto b = (a += 2, a /= 2); return 0; }"
     ).error(|e| { e.assert_msg_has(0, "assignments are statements"); });
+}
 #[test]
 fn test_variable_introduction_in_scope() {
     Tester::new_single_source_expect_err(
         "variable use before declaration",
         "func f() -> u8 { return thing; auto thing = 5; }"
     ).error(|e| { e.assert_msg_has(0, "unresolved variable"); });
     Tester::new_single_source_expect_err(
         "variable use in declaration",
         "func f() -> u8 { auto thing = 5 + thing; return thing; }"
     ).error(|e| { e.assert_msg_has(0, "unresolved variable"); });
     Tester::new_single_source_expect_ok(
         "variable use after declaration",
         "func f() -> u8 { auto thing = 5; return thing; }"
     );
     Tester::new_single_source_expect_err(
         "variable use of closed scope",
         "func f() -> u8 { { auto thing = 5; } return thing; }"
     ).error(|e| { e.assert_msg_has(0, "unresolved variable"); });
+}
 #[test]
 fn test_correct_select_statement() {
     Tester::new_single_source_expect_ok(
         "guard variable decl",
+        "
         primitive f() {
             channel<u32> unused -> input;
             u32 outer_value = 0;
             sync select {
                 auto in_same_guard = get(input) -> {} // decl A1
                 auto in_same_gaurd = get(input) -> {} // decl A2
                 auto in_guard_and_block = get(input) -> {} // decl B1
                 outer_value = get(input) -> { auto in_guard_and_block = outer_value; } // decl B2
+            }
+        }
+        "
     );
     Tester::new_single_source_expect_ok(
         "empty select",
         "primitive f() { sync select {} }"
     );
     Tester::new_single_source_expect_ok(
         "mixed uses", "
         primitive f() {
             channel unused_output -> input;
             u32 outer_value = 0;
             sync select {
                 outer_value = get(input) -> outer_value = 0;
                 auto new_value = get(input) -> {
                     outer_value = new_value;
+                }
                 get(input) + get(input) ->
                     outer_value = 8;
                 get(input) ->
                     {}
                 outer_value %= get(input) -> {
                     outer_value *= outer_value;
                     auto new_value = get(input);
                     outer_value += new_value;
+                }
+            }
+        }
+        "
     );
+}
 #[test]
 fn test_incorrect_select_statement() {
     Tester::new_single_source_expect_err(
         "outside sync",
         "primitive f() { select {} }"
     ).error(|e| { e
         .assert_num(1)
         .assert_occurs_at(0, "select")
         .assert_msg_has(0, "inside sync blocks");
     });
     Tester::new_single_source_expect_err(
         "variable in previous block",
         "primitive f() {
             channel<u32> tx -> rx;
             u32 a = 0; // this one will be shadowed
             sync select { auto a = get(rx) -> {} }
         }"
     ).error(|e| { e
         .assert_num(2)
         .assert_occurs_at(0, "a = get").assert_msg_has(0, "variable name conflicts")
         .assert_occurs_at(1, "a = 0").assert_msg_has(1, "Previous variable");
     });
     Tester::new_single_source_expect_err(
         "put inside arm",
         "primitive f() {
             channel<u32> a -> b;
             sync select { put(a) -> {} }
         }"
     ).error(|e| { e
         .assert_occurs_at(0, "put")
         .assert_msg_has(0, "may not occur");
     });
+}
 #[test]
 fn test_incorrect_goto_statement() {
     Tester::new_single_source_expect_err(
         "goto missing var in same scope",
         "func f() -> u32 {
             goto exit;
             auto v = 5;
             exit: return 0;
         }"
     ).error(|e| { e
         .assert_num(3)
         .assert_occurs_at(0, "exit;").assert_msg_has(0, "skips over a variable")
         .assert_occurs_at(1, "exit:").assert_msg_has(1, "jumps to this label")
         .assert_occurs_at(2, "v = 5").assert_msg_has(2, "skips over this variable");
     });
     Tester::new_single_source_expect_err(
         "goto missing var in outer scope",
         "func f() -> u32 {
             if (true) {
                 goto exit;
+            }
             auto v = 0;
             exit: return 1;
         }"
     ).error(|e| { e
         .assert_num(3)
         .assert_occurs_at(0, "exit;").assert_msg_has(0, "skips over a variable")
         .assert_occurs_at(1, "exit:").assert_msg_has(1, "jumps to this label")
         .assert_occurs_at(2, "v = 0").assert_msg_has(2, "skips over this variable");
     });
     Tester::new_single_source_expect_err(
         "goto jumping into scope",
         "func f() -> u32 {
             goto nested;
+            {
                 nested: return 0;
+            }
             return 1;
         }"
     ).error(|e| { e
         .assert_num(1)
         .assert_occurs_at(0, "nested;")
         .assert_msg_has(0, "could not find this label");
     });
     Tester::new_single_source_expect_err(
         "goto jumping outside sync",
         "primitive f() {
             sync { goto exit; }
             exit: u32 v = 0;
         }"
     ).error(|e| { e
         .assert_num(3)
         .assert_occurs_at(0, "goto exit;").assert_msg_has(0, "not escape the surrounding sync")
         .assert_occurs_at(1, "exit: u32 v").assert_msg_has(1, "target of the goto")
         .assert_occurs_at(2, "sync {").assert_msg_has(2, "jump past this");
     })
     });
     Tester::new_single_source_expect_err(
         "goto jumping to select case",
         "primitive f(in<u32> i) {
             sync select {
                 hello: auto a = get(i) -> i += 1
+            }
             goto hello;
         }"
     ).error(|e| { e
         .assert_msg_has(0, "expected '->'");
     });
     Tester::new_single_source_expect_err(
         "goto jumping into select case skipping variable",
         "primitive f(in<u32> i) {
             goto waza;
             sync select {
                 auto a = get(i) -> {
                     waza: a += 1;
+                }
+            }
         }"
     ).error(|e| { e
         .assert_num(1)
         .assert_msg_has(0, "not find this label")
         .assert_occurs_at(0, "waza;");
     });
+}
 #[test]
 fn test_incorrect_while_statement() {
     // Just testing the error cases caught at compile-time. Other ones need
     // evaluation testing
     Tester::new_single_source_expect_err(
         "break wrong earlier loop",
         "func f() -> u32 {
             target: while (true) {}
             while (true) { break target; }
             return 0;
         }"
     ).error(|e| { e
         .assert_num(2)
         .assert_occurs_at(0, "target; }").assert_msg_has(0, "not nested under the target")
         .assert_occurs_at(1, "target: while").assert_msg_has(1, "is found here");
     });
     Tester::new_single_source_expect_err(
         "break wrong later loop",
         "func f() -> u32 {
             while (true) { break target; }
             target: while (true) {}
             return 0;
         }"
     ).error(|e| { e
         .assert_num(2)
         .assert_occurs_at(0, "target; }").assert_msg_has(0, "not nested under the target")
         .assert_occurs_at(1, "target: while").assert_msg_has(1, "is found here");
     });
     Tester::new_single_source_expect_err(
         "break outside of sync",
         "primitive f() {
             outer: while (true) { //mark
                 sync while(true) { break outer; }
+            }
         }"
     ).error(|e| { e
         .assert_num(3)
         .assert_occurs_at(0, "break outer;").assert_msg_has(0, "may not escape the surrounding")
         .assert_occurs_at(1, "while (true) { //mark").assert_msg_has(1, "escapes out of this loop")
         .assert_occurs_at(2, "sync while").assert_msg_has(2, "escape this synchronous block");
     });
+}
@@ \ No newline at end of file @@

src/protocol/tests/utils.rs

➞

Show inline comments

 use crate::collections::StringPool;
 use crate::protocol::{Module, ast::*, input_source::*, parser::{
     Parser,
     type_table::*,
     symbol_table::SymbolTable,
     token_parsing::*,
 }, eval::*, RunContext};
 // Carries information about the test into utility structures for builder-like
 // assertions
 #[derive(Clone, Copy)]
 struct TestCtx<'a> {
     test_name: &'a str,
     heap: &'a Heap,
     modules: &'a Vec<Module>,
     types: &'a TypeTable,
     symbols: &'a SymbolTable,
+}
 //------------------------------------------------------------------------------
 // Interface for parsing and compiling
 //------------------------------------------------------------------------------
 pub(crate) struct Tester {
     test_name: String,
     sources: Vec<String>
+}
 impl Tester {
     /// Constructs a new tester, allows adding multiple sources before compiling
     pub(crate) fn new<S: ToString>(test_name: S) -> Self {
         Self{
             test_name: test_name.to_string(),
             sources: Vec::new()
+        }
+    }
     /// Utility for quick tests that use a single source file and expect the
     /// compilation to succeed.
     pub(crate) fn new_single_source_expect_ok<T: ToString, S: ToString>(test_name: T, source: S) -> AstOkTester {
         Self::new(test_name)
             .with_source(source)
             .compile()
             .expect_ok()
+    }
     /// Utility for quick tests that use a single source file and expect the
     /// compilation to fail.
     pub(crate) fn new_single_source_expect_err<T: ToString, S: ToString>(test_name: T, source: S) -> AstErrTester {
         Self::new(test_name)
             .with_source(source)
             .compile()
             .expect_err()
+    }
     pub(crate) fn with_source<S: ToString>(mut self, source: S) -> Self {
         self.sources.push(source.to_string());
         self
+    }
     pub(crate) fn compile(self) -> AstTesterResult {
         let mut parser = Parser::new();
         for source in self.sources.into_iter() {
             let source = source.into_bytes();
             let input_source = InputSource::new(String::from(""), source);
             if let Err(err) = parser.feed(input_source) {
                 return AstTesterResult::Err(AstErrTester::new(self.test_name, err))
+            }
+        }
         if let Err(err) = parser.parse() {
             return AstTesterResult::Err(AstErrTester::new(self.test_name, err))
+        }
         AstTesterResult::Ok(AstOkTester::new(self.test_name, parser))
+    }
+}
 pub(crate) enum AstTesterResult {
     Ok(AstOkTester),
     Err(AstErrTester)
+}
 impl AstTesterResult {
     pub(crate) fn expect_ok(self) -> AstOkTester {
         match self {
             AstTesterResult::Ok(v) => v,
             AstTesterResult::Err(err) => {
                 let wrapped = ErrorTester{ test_name: &err.test_name, error: &err.error };
                 println!("DEBUG: Full error:\n{}", &err.error);
                 assert!(
                     false,
                     "[{}] Expected compilation to succeed, but it failed with {}",
                     err.test_name, wrapped.assert_postfix()
                 );
                 unreachable!();
+            }
+        }
+    }
     pub(crate) fn expect_err(self) -> AstErrTester {
         match self {
             AstTesterResult::Ok(ok) => {
                 assert!(false, "[{}] Expected compilation to fail, but it succeeded", ok.test_name);
                 unreachable!();
             },
             AstTesterResult::Err(err) => err,
+        }
+    }
+}
 //------------------------------------------------------------------------------
 // Interface for successful compilation
 //------------------------------------------------------------------------------
 #[allow(dead_code)]
 pub(crate) struct AstOkTester {
     test_name: String,
     modules: Vec<Module>,
     heap: Heap,
     symbols: SymbolTable,
     types: TypeTable,
     pool: StringPool, // This is stored because if we drop it on the floor, we lose all our `StringRef<'static>`s
+}
 impl AstOkTester {
     fn new(test_name: String, parser: Parser) -> Self {
         Self {
             test_name,
             modules: parser.modules.into_iter().map(|module| Module{
                 source: module.source,
                 root_id: module.root_id,
                 name: module.name.map(|(_, name)| name)
             }).collect(),
             heap: parser.heap,
             symbols: parser.symbol_table,
             types: parser.type_table,
             pool: parser.string_pool,
+        }
+    }
     pub(crate) fn for_struct<F: Fn(StructTester)>(self, name: &str, f: F) -> Self {
         let mut found = false;
         for definition in self.heap.definitions.iter() {
             if let Definition::Struct(ast_definition) = definition {
                 if ast_definition.identifier.value.as_str() != name {
                     continue;
+                }
                 // Found struct with the same name
                 let definition_id = ast_definition.this.upcast();
                 let type_entry = self.types.get_base_definition(&definition_id).unwrap();
                 let type_definition = type_entry.definition.as_struct();
                 let tester = StructTester::new(self.ctx(), ast_definition, type_definition);
                 f(tester);
                 found = true;
                 break
+            }
+        }
         assert!(
             found, "[{}] Failed to find definition for struct '{}'",
             self.test_name, name
         );
         self
+    }
     pub(crate) fn for_enum<F: Fn(EnumTester)>(self, name: &str, f: F) -> Self {
         let mut found = false;
         for definition in self.heap.definitions.iter() {
             if let Definition::Enum(definition) = definition {
                 if definition.identifier.value.as_str() != name {
                     continue;
+                }
                 // Found enum with the same name
                 let tester = EnumTester::new(self.ctx(), definition);
                 f(tester);
                 found = true;
                 break;
+            }
+        }
         assert!(
             found, "[{}] Failed to find definition for enum '{}'",
             self.test_name, name
         );
         self
+    }
     pub(crate) fn for_union<F: Fn(UnionTester)>(self, name: &str, f: F) -> Self {
         let mut found = false;
         for definition in self.heap.definitions.iter() {
             if let Definition::Union(definition) = definition {
                 if definition.identifier.value.as_str() != name {
                     continue;
+                }
                 // Found union with the same name
                 let definition_id = definition.this.upcast();
                 let base_type = self.types.get_base_definition(&definition_id).unwrap();
                 let tester = UnionTester::new(self.ctx(), definition, &base_type.definition.as_union());
                 f(tester);
                 found = true;
                 break;
+            }
+        }
         assert!(
             found, "[{}] Failed to find definition for union '{}'",
             self.test_name, name
         );
         self
+    }
     pub(crate) fn for_function<F: FnOnce(FunctionTester)>(self, name: &str, f: F) -> Self {
         let mut found = false;
         for definition in self.heap.definitions.iter() {
-            if let Definition::Function(definition) = definition {
+            if let Definition::Procedure(definition) = definition {
                 if definition.identifier.value.as_str() != name {
                     continue;
+                }
                 // Found function
                 let tester = FunctionTester::new(self.ctx(), definition);
                 f(tester);
                 found = true;
                 break;
+            }
+        }
         if found { return self }
         assert!(
             false, "[{}] failed to find definition for function '{}'",
             self.test_name, name
         );
         unreachable!();
+    }
     fn ctx(&self) -> TestCtx {
         TestCtx{
             test_name: &self.test_name,
             modules: &self.modules,
             heap: &self.heap,
             types: &self.types,
             symbols: &self.symbols,
+        }
+    }
+}
 //------------------------------------------------------------------------------
 // Utilities for successful compilation
 //------------------------------------------------------------------------------
 pub(crate) struct StructTester<'a> {
     ctx: TestCtx<'a>,
     ast_def: &'a StructDefinition,
     type_def: &'a StructType,
+}
 impl<'a> StructTester<'a> {
     fn new(ctx: TestCtx<'a>, ast_def: &'a StructDefinition, type_def: &'a StructType) -> Self {
         Self{ ctx, ast_def, type_def }
+    }
     pub(crate) fn assert_num_fields(self, num: usize) -> Self {
         assert_eq!(
             num, self.ast_def.fields.len(),
             "[{}] Expected {} struct fields, but found {} for {}",
             self.ctx.test_name, num, self.ast_def.fields.len(), self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
         let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.ast_def.this.upcast());
         assert!(
             is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
             self.ctx.test_name, num, num_encountered, self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
         let (has_monomorph, serialized) = has_monomorph(self.ctx, self.ast_def.this.upcast(), serialized_monomorph);
         assert!(
             has_monomorph.is_some(), "[{}] Expected to find monomorph {}, but got {} for {}",
             self.ctx.test_name, serialized_monomorph, &serialized, self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_size_alignment(mut self, monomorph: &str, size: usize, alignment: usize) -> Self {
         self = self.assert_has_monomorph(monomorph);
         let (mono_idx, _) = has_monomorph(self.ctx, self.ast_def.this.upcast(), monomorph);
         let mono_idx = mono_idx.unwrap();
         let mono = self.ctx.types.get_monomorph(mono_idx);
         let type_id = mono_idx.unwrap();
         let mono = self.ctx.types.get_monomorph(type_id);
         assert!(
             mono.size == size && mono.alignment == alignment,
             "[{}] Expected (size,alignment) of ({}, {}), but got ({}, {}) for {}",
             self.ctx.test_name, size, alignment, mono.size, mono.alignment, self.assert_postfix()
         );
         self
+    }
     pub(crate) fn for_field<F: Fn(StructFieldTester)>(self, name: &str, f: F) -> Self {
         // Find field with specified name
         for field in &self.ast_def.fields {
             if field.field.value.as_str() == name {
                 let tester = StructFieldTester::new(self.ctx, field);
                 f(tester);
                 return self;
+            }
+        }
         assert!(
             false, "[{}] Could not find struct field '{}' for {}",
             self.ctx.test_name, name, self.assert_postfix()
         );
         unreachable!();
+    }
     fn assert_postfix(&self) -> String {
         let mut v = String::new();
         v.push_str("Struct{ name: ");
         v.push_str(self.ast_def.identifier.value.as_str());
         v.push_str(", fields: [");
         for (field_idx, field) in self.ast_def.fields.iter().enumerate() {
             if field_idx != 0 { v.push_str(", "); }
             v.push_str(field.field.value.as_str());
+        }
         v.push_str("] }");
+        v
+    }
+}
 pub(crate) struct StructFieldTester<'a> {
     ctx: TestCtx<'a>,
     def: &'a StructFieldDefinition,
+}
 impl<'a> StructFieldTester<'a> {
     fn new(ctx: TestCtx<'a>, def: &'a StructFieldDefinition) -> Self {
         Self{ ctx, def }
+    }
     pub(crate) fn assert_parser_type(self, expected: &str) -> Self {
         let mut serialized_type = String::new();
         serialize_parser_type(&mut serialized_type, &self.ctx.heap, &self.def.parser_type);
         assert_eq!(
             expected, &serialized_type,
             "[{}] Expected type '{}', but got '{}' for {}",
             self.ctx.test_name, expected, &serialized_type, self.assert_postfix()
         );
         self
+    }
     fn assert_postfix(&self) -> String {
         let mut serialized_type = String::new();
         serialize_parser_type(&mut serialized_type, &self.ctx.heap, &self.def.parser_type);
         format!("StructField{{ name: {}, parser_type: {} }}", self.def.field.value.as_str(), serialized_type)
+    }
+}
 pub(crate) struct EnumTester<'a> {
     ctx: TestCtx<'a>,
     def: &'a EnumDefinition,
+}
 impl<'a> EnumTester<'a> {
     fn new(ctx: TestCtx<'a>, def: &'a EnumDefinition) -> Self {
         Self{ ctx, def }
+    }
     pub(crate) fn assert_num_variants(self, num: usize) -> Self {
         assert_eq!(
             num, self.def.variants.len(),
             "[{}] Expected {} enum variants, but found {} for {}",
             self.ctx.test_name, num, self.def.variants.len(), self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
         let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.def.this.upcast());
         assert!(
             is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
             self.ctx.test_name, num, num_encountered, self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
         let (has_monomorph, serialized) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
         assert!(
             has_monomorph.is_some(), "[{}] Expected to find monomorph {}, but got {} for {}",
             self.ctx.test_name, serialized_monomorph, serialized, self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_size_alignment(mut self, serialized_monomorph: &str, size: usize, alignment: usize) -> Self {
         self = self.assert_has_monomorph(serialized_monomorph);
         let (has_monomorph, _) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
         let mono_index = has_monomorph.unwrap();
         let mono = self.ctx.types.get_monomorph(mono_index);
         assert!(
             mono.size == size && mono.alignment == alignment,
             "[{}] Expected (size,alignment) of ({}, {}), but got ({}, {}) for {}",
             self.ctx.test_name, size, alignment, mono.size, mono.alignment, self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_postfix(&self) -> String {
         let mut v = String::new();
         v.push_str("Enum{ name: ");
         v.push_str(self.def.identifier.value.as_str());
         v.push_str(", variants: [");
         for (variant_idx, variant) in self.def.variants.iter().enumerate() {
             if variant_idx != 0 { v.push_str(", "); }
             v.push_str(variant.identifier.value.as_str());
+        }
         v.push_str("] }");
+        v
+    }
+}
 pub(crate) struct UnionTester<'a> {
     ctx: TestCtx<'a>,
     ast_def: &'a UnionDefinition,
     type_def: &'a UnionType,
+}
 impl<'a> UnionTester<'a> {
     fn new(ctx: TestCtx<'a>, ast_def: &'a UnionDefinition, type_def: &'a UnionType) -> Self {
         Self{ ctx, ast_def, type_def }
+    }
     pub(crate) fn assert_num_variants(self, num: usize) -> Self {
         assert_eq!(
             num, self.ast_def.variants.len(),
             "[{}] Expected {} union variants, but found {} for {}",
             self.ctx.test_name, num, self.ast_def.variants.len(), self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
         let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.ast_def.this.upcast());
         assert!(
             is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
             self.ctx.test_name, num, num_encountered, self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
         let (has_monomorph, serialized) = has_monomorph(self.ctx, self.ast_def.this.upcast(), serialized_monomorph);
         assert!(
             has_monomorph.is_some(), "[{}] Expected to find monomorph {}, but got {} for {}",
             self.ctx.test_name, serialized_monomorph, serialized, self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_size_alignment(
         mut self, serialized_monomorph: &str,
         stack_size: usize, stack_alignment: usize, heap_size: usize, heap_alignment: usize
     ) -> Self {
         self = self.assert_has_monomorph(serialized_monomorph);
         let (mono_idx, _) = has_monomorph(self.ctx, self.ast_def.this.upcast(), serialized_monomorph);
         let mono_idx = mono_idx.unwrap();
         let mono_base = self.ctx.types.get_monomorph(mono_idx);
         let mono_union = mono_base.variant.as_union();
         assert!(
             stack_size == mono_base.size && stack_alignment == mono_base.alignment &&
                 heap_size == mono_union.heap_size && heap_alignment == mono_union.heap_alignment,
             "[{}] Expected (stack | heap) (size, alignment) of ({}, {} | {}, {}), but got ({}, {} | {}, {}) for {}",
             self.ctx.test_name,
             stack_size, stack_alignment, heap_size, heap_alignment,
             mono_base.size, mono_base.alignment, mono_union.heap_size, mono_union.heap_alignment,
             self.assert_postfix()
         );
         self
+    }
     fn assert_postfix(&self) -> String {
         let mut v = String::new();
         v.push_str("Union{ name: ");
         v.push_str(self.ast_def.identifier.value.as_str());
         v.push_str(", variants: [");
         for (variant_idx, variant) in self.ast_def.variants.iter().enumerate() {
             if variant_idx != 0 { v.push_str(", "); }
             v.push_str(variant.identifier.value.as_str());
+        }
         v.push_str("] }");
+        v
+    }
+}
 pub(crate) struct FunctionTester<'a> {
     ctx: TestCtx<'a>,
-    def: &'a FunctionDefinition,
+    def: &'a ProcedureDefinition,
+}
 impl<'a> FunctionTester<'a> {
-    fn new(ctx: TestCtx<'a>, def: &'a FunctionDefinition) -> Self {
+    fn new(ctx: TestCtx<'a>, def: &'a ProcedureDefinition) -> Self {
         Self{ ctx, def }
+    }
     pub(crate) fn for_variable<F: Fn(VariableTester)>(self, name: &str, f: F) -> Self {
         // Seek through the blocks in order to find the variable
         let wrapping_block_id = seek_stmt(
             self.ctx.heap, self.def.body.upcast(),
             &|stmt| {
                 if let Statement::Block(block) = stmt {
                     for local_id in &block.locals {
                         let var = &self.ctx.heap[*local_id];
         let wrapping_scope = seek_scope(
             self.ctx.heap, self.def.scope,
             &|scope| {
                 for variable_id in scope.variables.iter().copied() {
                     let var = &self.ctx.heap[variable_id];
                     if var.identifier.value.as_str() == name {
                         return true;
+                    }
+                }
+                }
                 false
+            }
         );
         let mut found_local_id = None;
         if let Some(block_id) = wrapping_block_id {
             // Found the right block, find the variable inside the block again
             let block_stmt = self.ctx.heap[block_id].as_block();
             for local_id in &block_stmt.locals {
                 let var = &self.ctx.heap[*local_id];
                 if var.identifier.value.as_str() == name {
                     found_local_id = Some(*local_id);
         if let Some(scope_id) = wrapping_scope {
             // Found the right scope, find the variable inside the block again
             let scope = &self.ctx.heap[scope_id];
             for variable_id in scope.variables.iter().copied() {
                 let variable = &self.ctx.heap[variable_id];
                 if variable.identifier.value.as_str() == name {
                     found_local_id = Some(variable_id);
+                }
+            }
+        }
         assert!(
             found_local_id.is_some(), "[{}] Failed to find variable '{}' in {}",
             self.ctx.test_name, name, self.assert_postfix()
         );
         let local = &self.ctx.heap[found_local_id.unwrap()];
         // Find an instance of the variable expression so we can determine its
         // type.
         let var_expr = seek_expr_in_stmt(
             self.ctx.heap, self.def.body.upcast(),
             &|expr| {
                 if let Expression::Variable(variable_expr) = expr {
                     if variable_expr.identifier.value.as_str() == name {
                         return true;
+                    }
+                }
                 false
+            }
         );
         assert!(
             var_expr.is_some(), "[{}] Failed to find variable expression of '{}' in {}",
             self.ctx.test_name, name, self.assert_postfix()
         );
         let var_expr = &self.ctx.heap[var_expr.unwrap()];
         // Construct tester and pass to tester function
         let tester = VariableTester::new(
             self.ctx, self.def.this.upcast(), local,
             var_expr.as_variable()
         );
         f(tester);
         self
+    }
     /// Finds a specific expression within a function. There are two matchers:
     /// one outer matcher (to find a rough indication of the expression) and an
     /// inner matcher to find the exact expression.
     ///
     /// The reason being that, for example, a function's body might be littered
     /// with addition symbols, so we first match on "some_var + some_other_var",
     /// and then match exactly on "+".
     pub(crate) fn for_expression_by_source<F: Fn(ExpressionTester)>(self, outer_match: &str, inner_match: &str, f: F) -> Self {
         // Seek the expression in the source code
         assert!(outer_match.contains(inner_match), "improper testing code");
         let module = seek_def_in_modules(
             &self.ctx.heap, &self.ctx.modules, self.def.this.upcast()
         ).unwrap();
         // Find the first occurrence of the expression after the definition of
         // the function, we'll check that it is included in the body later.
         let mut outer_match_idx = self.def.span.begin.offset as usize;
         while outer_match_idx < module.source.input.len() {
             if module.source.input[outer_match_idx..].starts_with(outer_match.as_bytes()) {
                 break;
+            }
             outer_match_idx += 1
+        }
         assert!(
             outer_match_idx < module.source.input.len(),
             "[{}] Failed to find '{}' within the source that contains {}",
             self.ctx.test_name, outer_match, self.assert_postfix()
         );
         let inner_match_idx = outer_match_idx + outer_match.find(inner_match).unwrap();
         // Use the inner match index to find the expression
         let expr_id = seek_expr_in_stmt(
             &self.ctx.heap, self.def.body.upcast(),
             &|expr| expr.operation_span().begin.offset as usize == inner_match_idx
         );
         assert!(
             expr_id.is_some(),
             "[{}] Failed to find '{}' within the source that contains {} \
             (note: expression was found, but not within the specified function",
             self.ctx.test_name, outer_match, self.assert_postfix()
         );
         let expr_id = expr_id.unwrap();
         // We have the expression, call the testing function
         let tester = ExpressionTester::new(
             self.ctx, self.def.this.upcast(), &self.ctx.heap[expr_id]
         );
         f(tester);
         self
+    }
     pub(crate) fn call_ok(self, expected_result: Option<Value>) -> Self {
         use crate::protocol::*;
         let (prompt, result) = self.eval_until_end();
         match result {
             Ok(_) => {
                 assert!(
                     prompt.store.stack.len() > 0, // note: stack never shrinks
                     "[{}] No value on stack after calling function for {}",
                     self.ctx.test_name, self.assert_postfix()
                 );
             },
             Err(err) => {
                 println!("DEBUG: Formatted evaluation error:\n{}", err);
                 assert!(
                     false,
                     "[{}] Expected call to succeed, but got {:?} for {}",
                     self.ctx.test_name, err, self.assert_postfix()
+                )
+            }
+        }
         if let Some(expected_result) = expected_result {
             debug_assert!(expected_result.get_heap_pos().is_none(), "comparing against heap thingamajigs is not yet implemented");
             assert!(
                 value::apply_equality_operator(&prompt.store, &prompt.store.stack[0], &expected_result),
                 "[{}] Result from call was {:?}, but expected {:?} for {}",
                 self.ctx.test_name, &prompt.store.stack[0], &expected_result, self.assert_postfix()
+            )
+        }
         self
+    }
     // Keeping this simple for now, will likely change
     pub(crate) fn call_err(self, expected_result: &str) -> Self {
         let (_, result) = self.eval_until_end();
         match result {
             Ok(_) => {
                 assert!(
                     false,
                     "[{}] Expected an error, but evaluation finished successfully for {}",
                     self.ctx.test_name, self.assert_postfix()
                 );
             },
             Err(err) => {
                 println!("DEBUG: Formatted evaluation error:\n{}", err);
                 debug_assert_eq!(err.statements.len(), 1);
                 assert!(
                     err.statements[0].message.contains(&expected_result),
                     "[{}] Expected error message to contain '{}', but it was '{}' for {}",
                     self.ctx.test_name, expected_result, err.statements[0].message, self.assert_postfix()
                 );
+            }
+        }
         self
+    }
     fn eval_until_end(&self) -> (Prompt, Result<EvalContinuation, EvalError>) {
         use crate::protocol::*;
         // Assuming the function is not polymorphic
-        let definition_id = self.def.this.upcast();
         let definition_id = self.def.this;
         let func_type = [ConcreteTypePart::Function(definition_id, 0)];
-        let mono_index = self.ctx.types.get_procedure_monomorph_index(&definition_id, &func_type).unwrap();
+        let mono_index = self.ctx.types.get_procedure_monomorph_type_id(&definition_id.upcast(), &func_type).unwrap();
-        let mut prompt = Prompt::new(&self.ctx.types, &self.ctx.heap, self.def.this.upcast(), mono_index, ValueGroup::new_stack(Vec::new()));
+        let mut prompt = Prompt::new(&self.ctx.types, &self.ctx.heap, definition_id, mono_index, ValueGroup::new_stack(Vec::new()));
         let mut call_context = FakeRunContext{};
         loop {
             let result = prompt.step(&self.ctx.types, &self.ctx.heap, &self.ctx.modules, &mut call_context);
             match result {
                 Ok(EvalContinuation::Stepping) => {},
                 _ => return (prompt, result),
+            }
+        }
+    }
     fn assert_postfix(&self) -> String {
         format!("Function{{ name: {} }}", self.def.identifier.value.as_str())
+    }
+}
 pub(crate) struct VariableTester<'a> {
     ctx: TestCtx<'a>,
     definition_id: DefinitionId,
     variable: &'a Variable,
     var_expr: &'a VariableExpression,
+}
 impl<'a> VariableTester<'a> {
     fn new(
         ctx: TestCtx<'a>, definition_id: DefinitionId, variable: &'a Variable, var_expr: &'a VariableExpression
     ) -> Self {
         Self{ ctx, definition_id, variable, var_expr }
+    }
     pub(crate) fn assert_parser_type(self, expected: &str) -> Self {
         let mut serialized = String::new();
         serialize_parser_type(&mut serialized, self.ctx.heap, &self.variable.parser_type);
         assert_eq!(
             expected, &serialized,
             "[{}] Expected parser type '{}', but got '{}' for {}",
             self.ctx.test_name, expected, &serialized, self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_concrete_type(self, expected: &str) -> Self {
         // Lookup concrete type in type table
         let mono_data = get_procedure_monomorph(&self.ctx.heap, &self.ctx.types, self.definition_id);
         let concrete_type = &mono_data.expr_data[self.var_expr.unique_id_in_definition as usize].expr_type;
         let mono_proc = get_procedure_monomorph(&self.ctx.heap, &self.ctx.types, self.definition_id);
         let mono_index = mono_proc.monomorph_index;
         let mono_data = &self.ctx.heap[self.definition_id].as_procedure().monomorphs[mono_index as usize];
         let expr_info = &mono_data.expr_info[self.var_expr.type_index as usize];
         let concrete_type = &self.ctx.types.get_monomorph(expr_info.type_id).concrete_type;
         // Serialize and check
         let serialized = concrete_type.display_name(self.ctx.heap);
         assert_eq!(
             expected, &serialized,
             "[{}] Expected concrete type '{}', but got '{}' for {}",
             self.ctx.test_name, expected, &serialized, self.assert_postfix()
         );
         self
+    }
     fn assert_postfix(&self) -> String {
         format!("Variable{{ name: {} }}", self.variable.identifier.value.as_str())
+    }
+}
 pub(crate) struct ExpressionTester<'a> {
     ctx: TestCtx<'a>,
     definition_id: DefinitionId, // of the enclosing function/component
     expr: &'a Expression
+}
 impl<'a> ExpressionTester<'a> {
     fn new(
         ctx: TestCtx<'a>, definition_id: DefinitionId, expr: &'a Expression
     ) -> Self {
         Self{ ctx, definition_id, expr }
+    }
     pub(crate) fn assert_concrete_type(self, expected: &str) -> Self {
         // Lookup concrete type
         let mono_data = get_procedure_monomorph(&self.ctx.heap, &self.ctx.types, self.definition_id);
         let expr_index = self.expr.get_unique_id_in_definition();
         let concrete_type = &mono_data.expr_data[expr_index as usize].expr_type;
         let mono_proc = get_procedure_monomorph(&self.ctx.heap, &self.ctx.types, self.definition_id);
         let mono_index = mono_proc.monomorph_index;
         let mono_data = &self.ctx.heap[self.definition_id].as_procedure().monomorphs[mono_index as usize];
         let expr_info = &mono_data.expr_info[self.expr.type_index() as usize];
         let concrete_type = &self.ctx.types.get_monomorph(expr_info.type_id).concrete_type;
         // Serialize and check type
         let serialized = concrete_type.display_name(self.ctx.heap);
         assert_eq!(
             expected, &serialized,
             "[{}] Expected concrete type '{}', but got '{}' for {}",
             self.ctx.test_name, expected, &serialized, self.assert_postfix()
         );
         self
+    }
     fn assert_postfix(&self) -> String {
         format!(
             "Expression{{ debug: {:?} }}",
             self.expr
+        )
+    }
+}
 fn get_procedure_monomorph<'a>(heap: &Heap, types: &'a TypeTable, definition_id: DefinitionId) -> &'a ProcedureMonomorph {
     let ast_definition = &heap[definition_id];
     let func_type = if ast_definition.is_function() {
         [ConcreteTypePart::Function(definition_id, 0)]
     } else if ast_definition.is_component() {
         [ConcreteTypePart::Component(definition_id, 0)]
     let ast_definition = heap[definition_id].as_procedure();
     let func_type = if ast_definition.kind == ProcedureKind::Function {
         [ConcreteTypePart::Function(ast_definition.this, 0)]
     } else {
         assert!(false);
         unreachable!()
         [ConcreteTypePart::Component(ast_definition.this, 0)]
     };
     let mono_index = types.get_procedure_monomorph_index(&definition_id, &func_type).unwrap();
     let mono_data = types.get_procedure_monomorph(mono_index);
     let mono_index = types.get_procedure_monomorph_type_id(&definition_id, &func_type).unwrap();
     let mono_data = types.get_monomorph(mono_index).variant.as_procedure();
     mono_data
+}
 //------------------------------------------------------------------------------
 // Interface for failed compilation
 //------------------------------------------------------------------------------
 pub(crate) struct AstErrTester {
     test_name: String,
     error: ParseError,
+}
 impl AstErrTester {
     fn new(test_name: String, error: ParseError) -> Self {
         Self{ test_name, error }
+    }
     pub(crate) fn error<F: Fn(ErrorTester)>(&self, f: F) {
         // Maybe multiple errors will be supported in the future
         let tester = ErrorTester{ test_name: &self.test_name, error: &self.error };
         f(tester)
+    }
+}
 //------------------------------------------------------------------------------
 // Utilities for failed compilation
 //------------------------------------------------------------------------------
 pub(crate) struct ErrorTester<'a> {
     test_name: &'a str,
     error: &'a ParseError,
+}
 impl<'a> ErrorTester<'a> {
     pub(crate) fn assert_num(self, num: usize) -> Self {
         assert_eq!(
             num, self.error.statements.len(),
             "[{}] expected error to consist of '{}' parts, but encountered '{}' for {}",
             self.test_name, num, self.error.statements.len(), self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_ctx_has(self, idx: usize, msg: &str) -> Self {
         assert!(
             self.error.statements[idx].context.contains(msg),
             "[{}] expected error statement {}'s context to contain '{}' for {}",
             self.test_name, idx, msg, self.assert_postfix()
         );
         self
+    }
     pub(crate) fn assert_msg_has(self, idx: usize, msg: &str) -> Self {
         assert!(
             self.error.statements[idx].message.contains(msg),
             "[{}] expected error statement {}'s message to contain '{}' for {}",
             self.test_name, idx, msg, self.assert_postfix()
         );
         self
+    }
     /// Seeks the index of the pattern in the context message, then checks if
     /// the input position corresponds to that index.
     pub (crate) fn assert_occurs_at(self, idx: usize, pattern: &str) -> Self {
         let pos = self.error.statements[idx].context.find(pattern);
         assert!(
             pos.is_some(),
             "[{}] incorrect occurs_at: '{}' could not be found in the context for {}",
             self.test_name, pattern, self.assert_postfix()
         );
         let pos = pos.unwrap();
         let col = self.error.statements[idx].start_column as usize;
         assert_eq!(
             pos + 1, col,
             "[{}] Expected error to occur at column {}, but found it at {} for {}",
             self.test_name, pos + 1, col, self.assert_postfix()
         );
         self
+    }
     fn assert_postfix(&self) -> String {
         let mut v = String::new();
         v.push_str("error: [");
         for (idx, stmt) in self.error.statements.iter().enumerate() {
             if idx != 0 {
                 v.push_str(", ");
+            }
             v.push_str(&format!("{{ context: {}, message: {} }}", &stmt.context, stmt.message));
+        }
         v.push(']');
+        v
+    }
+}
 //------------------------------------------------------------------------------
 // Generic utilities
 //------------------------------------------------------------------------------
 fn has_equal_num_monomorphs(ctx: TestCtx, num: usize, definition_id: DefinitionId) -> (bool, usize) {
     // Again: inefficient, but its testing code
     let mut num_on_type = 0;
-    for mono in &ctx.types.mono_lookup.monomorphs {
+    for mono in &ctx.types.mono_types {
         match &mono.concrete_type.parts[0] {
             ConcreteTypePart::Instance(def_id, _) |
             ConcreteTypePart::Instance(def_id, _) => {
                 if *def_id == definition_id {
                     num_on_type += 1;
+                }
+            }
             ConcreteTypePart::Function(def_id, _) |
             ConcreteTypePart::Component(def_id, _) => {
-                if *def_id == definition_id {
+                if def_id.upcast() == definition_id {
                     num_on_type += 1;
+                }
             },
             _ => {},
         };
+    }
     (num_on_type == num, num_on_type)
+}
-fn has_monomorph(ctx: TestCtx, definition_id: DefinitionId, serialized_monomorph: &str) -> (Option<i32>, String) {
+fn has_monomorph(ctx: TestCtx, definition_id: DefinitionId, serialized_monomorph: &str) -> (Option<TypeId>, String) {
     // Note: full_buffer is just for error reporting
     let mut full_buffer = String::new();
     let mut has_match = None;
     full_buffer.push('[');
-    let mut append_to_full_buffer = |concrete_type: &ConcreteType, mono_idx: usize| {
+    let mut append_to_full_buffer = |concrete_type: &ConcreteType, type_id: TypeId| {
         if full_buffer.len() != 1 {
             full_buffer.push_str(", ");
+        }
         full_buffer.push('"');
         let first_idx = full_buffer.len();
         full_buffer.push_str(concrete_type.display_name(ctx.heap).as_str());
         if &full_buffer[first_idx..] == serialized_monomorph {
-            has_match = Some(mono_idx as i32);
+            has_match = Some(type_id);
+        }
         full_buffer.push('"');
     };
     // Bit wasteful, but this is (temporary?) testing code:
-    for (mono_idx, mono) in ctx.types.mono_lookup.monomorphs.iter().enumerate() {
+    for (_mono_idx, mono) in ctx.types.mono_types.iter().enumerate() {
         let got_definition_id = match &mono.concrete_type.parts[0] {
-            ConcreteTypePart::Instance(v, _) |
+            ConcreteTypePart::Instance(v, _) => *v,
             ConcreteTypePart::Function(v, _) |
-            ConcreteTypePart::Component(v, _) => *v,
+            ConcreteTypePart::Component(v, _) => v.upcast(),
             _ => DefinitionId::new_invalid(),
         };
         if got_definition_id == definition_id {
-            append_to_full_buffer(&mono.concrete_type, mono_idx);
+            append_to_full_buffer(&mono.concrete_type, mono.type_id);
+        }
+    }
     full_buffer.push(']');
     (has_match, full_buffer)
+}
 fn serialize_parser_type(buffer: &mut String, heap: &Heap, parser_type: &ParserType) {
     use ParserTypeVariant as PTV;
     fn serialize_variant(buffer: &mut String, heap: &Heap, parser_type: &ParserType, mut idx: usize) -> usize {
         match &parser_type.elements[idx].variant {
             PTV::Void => buffer.push_str("void"),
             PTV::InputOrOutput => {
                 buffer.push_str("portlike<");
                 idx = serialize_variant(buffer, heap, parser_type, idx + 1);
                 buffer.push('>');
             },
             PTV::ArrayLike => {
                 idx = serialize_variant(buffer, heap, parser_type, idx + 1);
                 buffer.push_str("[???]");
             },
             PTV::IntegerLike => buffer.push_str("integerlike"),
             PTV::Message => buffer.push_str(KW_TYPE_MESSAGE_STR),
             PTV::Bool => buffer.push_str(KW_TYPE_BOOL_STR),
             PTV::UInt8 => buffer.push_str(KW_TYPE_UINT8_STR),
             PTV::UInt16 => buffer.push_str(KW_TYPE_UINT16_STR),
             PTV::UInt32 => buffer.push_str(KW_TYPE_UINT32_STR),
             PTV::UInt64 => buffer.push_str(KW_TYPE_UINT64_STR),
             PTV::SInt8 => buffer.push_str(KW_TYPE_SINT8_STR),
             PTV::SInt16 => buffer.push_str(KW_TYPE_SINT16_STR),
             PTV::SInt32 => buffer.push_str(KW_TYPE_SINT32_STR),
             PTV::SInt64 => buffer.push_str(KW_TYPE_SINT64_STR),
             PTV::Character => buffer.push_str(KW_TYPE_CHAR_STR),
             PTV::String => buffer.push_str(KW_TYPE_STRING_STR),
             PTV::IntegerLiteral => buffer.push_str("int_literal"),
             PTV::Inferred => buffer.push_str(KW_TYPE_INFERRED_STR),
             PTV::Array => {
                 idx = serialize_variant(buffer, heap, parser_type, idx + 1);
                 buffer.push_str("[]");
             },
             PTV::Input => {
                 buffer.push_str(KW_TYPE_IN_PORT_STR);
                 buffer.push('<');
                 idx = serialize_variant(buffer, heap, parser_type, idx + 1);
                 buffer.push('>');
             },
             PTV::Output => {
                 buffer.push_str(KW_TYPE_OUT_PORT_STR);
                 buffer.push('<');
                 idx = serialize_variant(buffer, heap, parser_type, idx + 1);
                 buffer.push('>');
             },
             PTV::Tuple(num_embedded) => {
                 buffer.push('(');
                 for embedded_idx in 0..*num_embedded {
                     if embedded_idx != 0 {
                         buffer.push(',');
+                    }
                     idx = serialize_variant(buffer, heap, parser_type, idx + 1);
+                }
                 buffer.push(')');
             },
             PTV::PolymorphicArgument(definition_id, poly_idx) => {
                 let definition = &heap[*definition_id];
                 let poly_arg = &definition.poly_vars()[*poly_idx as usize];
                 buffer.push_str(poly_arg.value.as_str());
             },
             PTV::Definition(definition_id, num_embedded) => {
                 let definition = &heap[*definition_id];
                 buffer.push_str(definition.identifier().value.as_str());
                 let num_embedded = *num_embedded;
                 if num_embedded != 0 {
                     buffer.push('<');
                     for embedded_idx in 0..num_embedded {
                         if embedded_idx != 0 {
                             buffer.push(',');
+                        }
                         idx = serialize_variant(buffer, heap, parser_type, idx + 1);
+                    }
                     buffer.push('>');
+                }
+            }
+        }
         idx
+    }
     serialize_variant(buffer, heap, parser_type, 0);
+}
 fn seek_def_in_modules<'a>(heap: &Heap, modules: &'a [Module], def_id: DefinitionId) -> Option<&'a Module> {
     for module in modules {
         let root = &heap.protocol_descriptions[module.root_id];
         for definition in &root.definitions {
             if *definition == def_id {
                 return Some(module)
+            }
+        }
+    }
     None
+}
 fn seek_stmt<F: Fn(&Statement) -> bool>(heap: &Heap, start: StatementId, f: &F) -> Option<StatementId> {
     let stmt = &heap[start];
     if f(stmt) { return Some(start); }
     // This statement wasn't it, try to recurse
     let matched = match stmt {
         Statement::Block(block) => {
             for sub_id in &block.statements {
                 if let Some(id) = seek_stmt(heap, *sub_id, f) {
                     return Some(id);
+                }
+            }
             None
         },
         Statement::Labeled(stmt) => seek_stmt(heap, stmt.body, f),
         Statement::If(stmt) => {
-            if let Some(id) = seek_stmt(heap, stmt.true_body.upcast(), f) {
+            if let Some(id) = seek_stmt(heap, stmt.true_case.body, f) {
                 return Some(id);
             } else if let Some(false_body) = stmt.false_body {
                 if let Some(id) = seek_stmt(heap, false_body.upcast(), f) {
             } else if let Some(false_body) = stmt.false_case {
                 if let Some(id) = seek_stmt(heap, false_body.body, f) {
                     return Some(id);
+                }
+            }
             None
         },
         Statement::While(stmt) => seek_stmt(heap, stmt.body.upcast(), f),
         Statement::Synchronous(stmt) => seek_stmt(heap, stmt.body.upcast(), f),
         Statement::While(stmt) => seek_stmt(heap, stmt.body, f),
         Statement::Synchronous(stmt) => seek_stmt(heap, stmt.body, f),
         _ => None
     };
     matched
+}
 fn seek_scope<F: Fn(&Scope) -> bool>(heap: &Heap, start: ScopeId, f: &F) -> Option<ScopeId> {
     let scope = &heap[start];
     if f(scope) { return Some(start); }
     for child_scope_id in scope.nested.iter().copied() {
         if let Some(result) = seek_scope(heap, child_scope_id, f) {
             return Some(result);
+        }
+    }
     return None;
+}
 fn seek_expr_in_expr<F: Fn(&Expression) -> bool>(heap: &Heap, start: ExpressionId, f: &F) -> Option<ExpressionId> {
     let expr = &heap[start];
     if f(expr) { return Some(start); }
     match expr {
         Expression::Assignment(expr) => {
             None
             .or_else(|| seek_expr_in_expr(heap, expr.left, f))
             .or_else(|| seek_expr_in_expr(heap, expr.right, f))
         },
         Expression::Binding(expr) => {
             None
             .or_else(|| seek_expr_in_expr(heap, expr.bound_to, f))
             .or_else(|| seek_expr_in_expr(heap, expr.bound_from, f))
+        }
         Expression::Conditional(expr) => {
             None
             .or_else(|| seek_expr_in_expr(heap, expr.test, f))
             .or_else(|| seek_expr_in_expr(heap, expr.true_expression, f))
             .or_else(|| seek_expr_in_expr(heap, expr.false_expression, f))
         },
         Expression::Binary(expr) => {
             None
             .or_else(|| seek_expr_in_expr(heap, expr.left, f))
             .or_else(|| seek_expr_in_expr(heap, expr.right, f))
         },
         Expression::Unary(expr) => {
             seek_expr_in_expr(heap, expr.expression, f)
         },
         Expression::Indexing(expr) => {
             None
             .or_else(|| seek_expr_in_expr(heap, expr.subject, f))
             .or_else(|| seek_expr_in_expr(heap, expr.index, f))
         },
         Expression::Slicing(expr) => {
             None
             .or_else(|| seek_expr_in_expr(heap, expr.subject, f))
             .or_else(|| seek_expr_in_expr(heap, expr.from_index, f))
             .or_else(|| seek_expr_in_expr(heap, expr.to_index, f))
         },
         Expression::Select(expr) => {
             seek_expr_in_expr(heap, expr.subject, f)
         },
         Expression::Literal(expr) => {
             if let Literal::Struct(lit) = &expr.value {
                 for field in &lit.fields {
                     if let Some(id) = seek_expr_in_expr(heap, field.value, f) {
                         return Some(id)
+                    }
+                }
             } else if let Literal::Array(elements) = &expr.value {
                 for element in elements {
                     if let Some(id) = seek_expr_in_expr(heap, *element, f) {
                         return Some(id)
+                    }
+                }
+            }
             None
         },
         Expression::Cast(expr) => {
             seek_expr_in_expr(heap, expr.subject, f)
+        }
         Expression::Call(expr) => {
             for arg in &expr.arguments {
                 if let Some(id) = seek_expr_in_expr(heap, *arg, f) {
                     return Some(id)
+                }
+            }
             None
         },
         Expression::Variable(_expr) => {
             None
+        }
+    }
+}
 fn seek_expr_in_stmt<F: Fn(&Expression) -> bool>(heap: &Heap, start: StatementId, f: &F) -> Option<ExpressionId> {
     let stmt = &heap[start];
     match stmt {
         Statement::Local(stmt) => {
             match stmt {
                 LocalStatement::Memory(stmt) => seek_expr_in_expr(heap, stmt.initial_expr.upcast(), f),
                 LocalStatement::Channel(_) => None
+            }
+        }
         Statement::Block(stmt) => {
             for stmt_id in &stmt.statements {
                 if let Some(id) = seek_expr_in_stmt(heap, *stmt_id, f) {
                     return Some(id)
+                }
+            }
             None
         },
         Statement::Labeled(stmt) => {
             seek_expr_in_stmt(heap, stmt.body, f)
         },
         Statement::If(stmt) => {
             None
             .or_else(|| seek_expr_in_expr(heap, stmt.test, f))
             .or_else(|| seek_expr_in_stmt(heap, stmt.true_body.upcast(), f))
             .or_else(|| if let Some(false_body) = stmt.false_body {
                 seek_expr_in_stmt(heap, false_body.upcast(), f)
             .or_else(|| seek_expr_in_stmt(heap, stmt.true_case.body, f))
             .or_else(|| if let Some(false_body) = stmt.false_case {
                 seek_expr_in_stmt(heap, false_body.body, f)
             } else {
                 None
             })
         },
         Statement::While(stmt) => {
             None
             .or_else(|| seek_expr_in_expr(heap, stmt.test, f))
-            .or_else(|| seek_expr_in_stmt(heap, stmt.body.upcast(), f))
             .or_else(|| seek_expr_in_stmt(heap, stmt.body, f))
         },
         Statement::Synchronous(stmt) => {
-            seek_expr_in_stmt(heap, stmt.body.upcast(), f)
             seek_expr_in_stmt(heap, stmt.body, f)
         },
         Statement::Return(stmt) => {
             for expr_id in &stmt.expressions {
                 if let Some(id) = seek_expr_in_expr(heap, *expr_id, f) {
                     return Some(id);
+                }
+            }
             None
         },
         Statement::New(stmt) => {
             seek_expr_in_expr(heap, stmt.expression.upcast(), f)
         },
         Statement::Expression(stmt) => {
             seek_expr_in_expr(heap, stmt.expression, f)
         },
         _ => None
+    }
+}
 struct FakeRunContext{}
 impl RunContext for FakeRunContext {
     fn performed_put(&mut self, _port: PortId) -> bool {
         unreachable!("'put' called in compiler testing code")
+    }
     fn performed_get(&mut self, _port: PortId) -> Option<ValueGroup> {
         unreachable!("'get' called in compiler testing code")
+    }
     fn fires(&mut self, _port: PortId) -> Option<Value> {
         unreachable!("'fires' called in compiler testing code")
+    }
     fn performed_fork(&mut self) -> Option<bool> {
         unreachable!("'fork' called in compiler testing code")
+    }
     fn created_channel(&mut self) -> Option<(Value, Value)> {
         unreachable!("channel created in compiler testing code")
+    }
     fn performed_put(&mut self, _port: PortId) -> bool { unreachable!() }
     fn performed_get(&mut self, _port: PortId) -> Option<ValueGroup> { unreachable!() }
     fn fires(&mut self, _port: PortId) -> Option<Value> { unreachable!() }
     fn performed_fork(&mut self) -> Option<bool> { unreachable!() }
     fn created_channel(&mut self) -> Option<(Value, Value)> { unreachable!() }
     fn performed_select_wait(&mut self) -> Option<u32> { unreachable!() }
+}
@@ \ No newline at end of file @@

src/random.rs

➞

Show inline comments

@@ new file 100644 @@
 /**
  * random.rs
+ *
  * Simple wrapper over a random number generator. Put here so that we can have
  * a feature flag for particular forms of randomness. For now we'll use pseudo-
  * randomness since that will help debugging.
  */
 use rand::{RngCore, SeedableRng};
 use rand_pcg;
 pub(crate) struct Random {
     rng: rand_pcg::Lcg64Xsh32,
+}
 impl Random {
     pub(crate) fn new() -> Self {
         use std::time::SystemTime;
         let now = SystemTime::now();
         let elapsed = match now.duration_since(SystemTime::UNIX_EPOCH) {
             Ok(elapsed) => elapsed,
             Err(err) => err.duration(),
         };
         let elapsed = elapsed.as_nanos();
         let seed = elapsed.to_le_bytes();
         return Self::new_seeded(seed);
+    }
     pub(crate) fn new_seeded(seed: [u8; 16]) -> Self {
         return Self{ rng: rand_pcg::Pcg32::from_seed(seed) }
+    }
     pub(crate) fn get_u64(&mut self) -> u64 {
         return self.rng.next_u64();
+    }
+}
@@ \ No newline at end of file @@

src/runtime/connector.rs

➞

Show inline comments

 // connector.rs
 //
 // Represents a component. A component (and the scheduler that is running it)
 // has many properties that are not easy to subdivide into aspects that are
 // conceptually handled by particular data structures. That is to say: the code
 // that we run governs: running PDL code, keeping track of ports, instantiating
 // new components and transports (i.e. interacting with the runtime), running
 // a consensus algorithm, etc. But on the other hand, our data is rather
 // simple: we have a speculative execution tree, a set of ports that we own,
 // and a bit of code that we should run.
 //
 // So currently the code is organized as following:
 // - The scheduler that is running the component is the authoritative source on
 //     ports during *non-sync* mode. The consensus algorithm is the
 //     authoritative source during *sync* mode. They retrieve each other's
 //     state during the transitions. Hence port data exists duplicated between
 //     these two datastructures.
 // - The execution tree is where executed branches reside. But the execution
 //     tree is only aware of the tree shape itself (and keeps track of some
 //     queues of branches that are in a particular state), and tends to store
 //     the PDL program state. The consensus algorithm is also somewhat aware
 //     of the execution tree, but only in terms of what is needed to complete
 //     a sync round (for now, that means the port mapping in each branch).
 //     Hence once more we have properties conceptually associated with branches
 //     in two places.
 // - TODO: Write about handling messages, consensus wrapping data
 // - TODO: Write about way information is exchanged between PDL/component and scheduler through ctx
 use std::sync::atomic::AtomicBool;
 use crate::ProtocolDescription;
 use crate::protocol::eval::{EvalContinuation, EvalError, Prompt, Value, PortId, ValueGroup};
 use crate::protocol::RunContext;
 use super::branch::{BranchId, ExecTree, QueueKind, SpeculativeState, PreparedStatement};
 use super::consensus::{Consensus, Consistency, RoundConclusion, find_ports_in_value_group};
 use super::inbox::{DataMessage, Message, SyncCompMessage, SyncPortMessage, SyncControlMessage, PublicInbox};
 use super::native::Connector;
 use super::port::{PortKind, PortIdLocal};
 use super::scheduler::{ComponentCtx, SchedulerCtx, MessageTicket};
 pub(crate) struct ConnectorPublic {
     pub inbox: PublicInbox,
     pub sleeping: AtomicBool,
+}
 impl ConnectorPublic {
     pub fn new(initialize_as_sleeping: bool) -> Self {
         ConnectorPublic{
             inbox: PublicInbox::new(),
             sleeping: AtomicBool::new(initialize_as_sleeping),
+        }
+    }
+}
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 enum Mode {
     NonSync,    // running non-sync code
     Sync,       // running sync code (in potentially multiple branches)
     SyncError,  // encountered an unrecoverable error in sync mode
     Error,      // encountered an error in non-sync mode (or finished handling the sync mode error).
+}
 #[derive(Debug)]
 pub(crate) enum ConnectorScheduling {
     Immediate,          // Run again, immediately
     Later,              // Schedule for running, at some later point in time
     NotNow,             // Do not reschedule for running
     Exit,               // Connector has exited
+}
 pub(crate) struct ConnectorPDL {
     mode: Mode,
     eval_error: Option<EvalError>,
     tree: ExecTree,
     consensus: Consensus,
     last_finished_handled: Option<BranchId>,
+}
 struct ConnectorRunContext<'a> {
     branch_id: BranchId,
     consensus: &'a Consensus,
     prepared: PreparedStatement,
+}
 impl<'a> RunContext for ConnectorRunContext<'a>{
     fn performed_put(&mut self, _port: PortId) -> bool {
         return match self.prepared.take() {
             PreparedStatement::None => false,
             PreparedStatement::PerformedPut => true,
             taken => unreachable!("prepared statement is '{:?}' during 'performed_put()'", taken)
         };
+    }
     fn performed_get(&mut self, _port: PortId) -> Option<ValueGroup> {
         return match self.prepared.take() {
             PreparedStatement::None => None,
             PreparedStatement::PerformedGet(value) => Some(value),
             taken => unreachable!("prepared statement is '{:?}' during 'performed_get()'", taken),
         };
+    }
     fn fires(&mut self, _port: PortId) -> Option<Value> {
         todo!("Remove fires() now")
         // let port_id = PortIdLocal::new(port.id);
         // let annotation = self.consensus.get_annotation(self.branch_id, port_id);
         // return annotation.expected_firing.map(|v| Value::Bool(v));
+    }
     fn created_channel(&mut self) -> Option<(Value, Value)> {
         return match self.prepared.take() {
             PreparedStatement::None => None,
             PreparedStatement::CreatedChannel(ports) => Some(ports),
             taken => unreachable!("prepared statement is '{:?}' during 'created_channel()'", taken),
         };
+    }
     fn performed_fork(&mut self) -> Option<bool> {
         return match self.prepared.take() {
             PreparedStatement::None => None,
             PreparedStatement::ForkedExecution(path) => Some(path),
             taken => unreachable!("prepared statement is '{:?}' during 'performed_fork()'", taken),
         };
+    }
     fn performed_select_wait(&mut self) -> Option<u32> { unreachable!() }
+}
 impl Connector for ConnectorPDL {
     fn run(&mut self, sched_ctx: SchedulerCtx, comp_ctx: &mut ComponentCtx) -> ConnectorScheduling {
         if let Some(scheduling) = self.handle_new_messages(comp_ctx) {
             return scheduling;
+        }
         match self.mode {
             Mode::Sync => {
                 // Run in sync mode
                 let scheduling = self.run_in_sync_mode(sched_ctx, comp_ctx);
                 // Handle any new finished branches
                 let mut iter_id = self.last_finished_handled.or(self.tree.get_queue_first(QueueKind::FinishedSync));
                 while let Some(branch_id) = iter_id {
                     iter_id = self.tree.get_queue_next(branch_id);
                     self.last_finished_handled = Some(branch_id);
                     if let Some(round_conclusion) = self.consensus.handle_new_finished_sync_branch(branch_id, comp_ctx) {
                         // Actually found a solution
                         return self.enter_non_sync_mode(round_conclusion, comp_ctx);
+                    }
                     self.last_finished_handled = Some(branch_id);
+                }
                 return scheduling;
             },
             Mode::NonSync => {
                 let scheduling = self.run_in_deterministic_mode(sched_ctx, comp_ctx);
                 return scheduling;
             },
             Mode::SyncError => {
                 let scheduling = self.run_in_sync_mode(sched_ctx, comp_ctx);
                 return scheduling;
             },
             Mode::Error => {
                 // This shouldn't really be called. Because when we reach exit
                 // mode the scheduler should not run the component anymore
                 unreachable!("called component run() during error-mode");
             },
+        }
+    }
+}
 impl ConnectorPDL {
     pub fn new(initial: Prompt) -> Self {
         Self{
             mode: Mode::NonSync,
             eval_error: None,
             tree: ExecTree::new(initial),
             consensus: Consensus::new(),
             last_finished_handled: None,
+        }
+    }
     // --- Handling messages
     pub fn handle_new_messages(&mut self, ctx: &mut ComponentCtx) -> Option<ConnectorScheduling> {
         while let Some(ticket) = ctx.get_next_message_ticket() {
             let message = ctx.read_message_using_ticket(ticket);
             let immediate_result = if let Message::Data(_) = message {
                 self.handle_new_data_message(ticket, ctx);
                 None
             } else {
                 match ctx.take_message_using_ticket(ticket) {
                     Message::Data(_) => unreachable!(),
                     Message::SyncComp(message) => {
                         self.handle_new_sync_comp_message(message, ctx)
                     },
                     Message::SyncPort(message) => {
                         self.handle_new_sync_port_message(message, ctx);
                         None
                     },
                     Message::SyncControl(message) => {
                         self.handle_new_sync_control_message(message, ctx)
                     },
                     Message::Control(_) => unreachable!("control message in component"),
+                }
             };
             if let Some(result) = immediate_result {
                 return Some(result);
+            }
+        }
         return None;
+    }
     pub fn handle_new_data_message(&mut self, ticket: MessageTicket, ctx: &mut ComponentCtx) {
         // Go through all branches that are awaiting new messages and see if
         // there is one that can receive this message.
         if !self.consensus.handle_new_data_message(ticket, ctx) {
             // Message should not be handled now
             return;
+        }
         let message = ctx.read_message_using_ticket(ticket).as_data();
         let mut iter_id = self.tree.get_queue_first(QueueKind::AwaitingMessage);
         while let Some(branch_id) = iter_id {
             iter_id = self.tree.get_queue_next(branch_id);
             let branch = &self.tree[branch_id];
             if branch.awaiting_port != message.data_header.target_port { continue; }
             if !self.consensus.branch_can_receive(branch_id, &message) { continue; }
             // This branch can receive, so fork and given it the message
             let receiving_branch_id = self.tree.fork_branch(branch_id);
             self.consensus.notify_of_new_branch(branch_id, receiving_branch_id);
             let receiving_branch = &mut self.tree[receiving_branch_id];
             debug_assert!(receiving_branch.awaiting_port == message.data_header.target_port);
             receiving_branch.awaiting_port = PortIdLocal::new_invalid();
             receiving_branch.prepared = PreparedStatement::PerformedGet(message.content.clone());
             self.consensus.notify_of_received_message(receiving_branch_id, &message, ctx);
             // And prepare the branch for running
             self.tree.push_into_queue(QueueKind::Runnable, receiving_branch_id);
+        }
+    }
     pub fn handle_new_sync_comp_message(&mut self, message: SyncCompMessage, ctx: &mut ComponentCtx) -> Option<ConnectorScheduling> {
         if let Some(round_conclusion) = self.consensus.handle_new_sync_comp_message(message, ctx) {
             return Some(self.enter_non_sync_mode(round_conclusion, ctx));
+        }
         return None;
+    }
     pub fn handle_new_sync_port_message(&mut self, message: SyncPortMessage, ctx: &mut ComponentCtx) {
         self.consensus.handle_new_sync_port_message(message, ctx);
+    }
     pub fn handle_new_sync_control_message(&mut self, message: SyncControlMessage, ctx: &mut ComponentCtx) -> Option<ConnectorScheduling> {
         if let Some(round_conclusion) = self.consensus.handle_new_sync_control_message(message, ctx) {
             return Some(self.enter_non_sync_mode(round_conclusion, ctx));
+        }
         return None;
+    }
     // --- Running code
     pub fn run_in_sync_mode(&mut self, sched_ctx: SchedulerCtx, comp_ctx: &mut ComponentCtx) -> ConnectorScheduling {
         // Check if we have any branch that needs running
         debug_assert!(self.tree.is_in_sync() && self.consensus.is_in_sync());
         let branch_id = self.tree.pop_from_queue(QueueKind::Runnable);
         if branch_id.is_none() {
             return ConnectorScheduling::NotNow;
+        }
         // Retrieve the branch and run it
         let branch_id = branch_id.unwrap();
         let branch = &mut self.tree[branch_id];
         let mut run_context = ConnectorRunContext{
             branch_id,
             consensus: &self.consensus,
             prepared: branch.prepared.take(),
         };
         let run_result = Self::run_prompt(&mut branch.code_state, &sched_ctx.runtime.protocol_description, &mut run_context);
         if let Err(eval_error) = run_result {
             self.eval_error = Some(eval_error);
             self.mode = Mode::SyncError;
             if let Some(conclusion) = self.consensus.notify_of_fatal_branch(branch_id, comp_ctx) {
                 // We can exit immediately
                 return self.enter_non_sync_mode(conclusion, comp_ctx);
             } else {
                 // Current branch failed. But we may have other things that are
                 // running.
                 return ConnectorScheduling::Immediate;
+            }
+        }
         let run_result = run_result.unwrap();
         // Handle the returned result. Note that this match statement contains
         // explicit returns in case the run result requires that the component's
         // code is ran again immediately
         match run_result {
             EvalContinuation::BranchInconsistent => {
                 // Branch became inconsistent
                 branch.sync_state = SpeculativeState::Inconsistent;
             },
             EvalContinuation::BlockFires(port_id) => {
                 // Branch called `fires()` on a port that has not been used yet.
                 let port_id = PortIdLocal::new(port_id.id);
                 // Create two forks, one that assumes the port will fire, and
                 // one that assumes the port remains silent
                 branch.sync_state = SpeculativeState::HaltedAtBranchPoint;
                 let firing_branch_id = self.tree.fork_branch(branch_id);
                 let silent_branch_id = self.tree.fork_branch(branch_id);
                 self.consensus.notify_of_new_branch(branch_id, firing_branch_id);
                 let _result = self.consensus.notify_of_speculative_mapping(firing_branch_id, port_id, true, comp_ctx);
                 debug_assert_eq!(_result, Consistency::Valid);
                 self.consensus.notify_of_new_branch(branch_id, silent_branch_id);
                 let _result = self.consensus.notify_of_speculative_mapping(silent_branch_id, port_id, false, comp_ctx);
                 debug_assert_eq!(_result, Consistency::Valid);
                 // Somewhat important: we push the firing one first, such that
                 // that branch is ran again immediately.
                 self.tree.push_into_queue(QueueKind::Runnable, firing_branch_id);
                 self.tree.push_into_queue(QueueKind::Runnable, silent_branch_id);
                 return ConnectorScheduling::Immediate;
             },
             EvalContinuation::BlockGet(port_id) => {
                 // Branch performed a `get()` on a port that does not have a
                 // received message on that port.
                 let port_id = PortIdLocal::new(port_id.id);
                 branch.sync_state = SpeculativeState::HaltedAtBranchPoint;
                 branch.awaiting_port = port_id;
                 self.tree.push_into_queue(QueueKind::AwaitingMessage, branch_id);
                 // Note: we only know that a branch is waiting on a message when
                 // it reaches the `get` call. But we might have already received
                 // a message that targets this branch, so check now.
                 let mut any_message_received = false;
                 for message in comp_ctx.get_read_data_messages(port_id) {
                     if self.consensus.branch_can_receive(branch_id, &message) {
                         // This branch can receive the message, so we do the
                         // fork-and-receive dance
                         let receiving_branch_id = self.tree.fork_branch(branch_id);
                         let branch = &mut self.tree[receiving_branch_id];
                         branch.awaiting_port = PortIdLocal::new_invalid();
                         branch.prepared = PreparedStatement::PerformedGet(message.content.clone());
                         self.consensus.notify_of_new_branch(branch_id, receiving_branch_id);
                         self.consensus.notify_of_received_message(receiving_branch_id, &message, comp_ctx);
                         self.tree.push_into_queue(QueueKind::Runnable, receiving_branch_id);
                         any_message_received = true;
+                    }
+                }
                 if any_message_received {
                     return ConnectorScheduling::Immediate;
+                }
+            }
             EvalContinuation::SyncBlockEnd => {
                 let consistency = self.consensus.notify_of_finished_branch(branch_id);
                 if consistency == Consistency::Valid {
                     branch.sync_state = SpeculativeState::ReachedSyncEnd;
                     self.tree.push_into_queue(QueueKind::FinishedSync, branch_id);
                 } else {
                     branch.sync_state = SpeculativeState::Inconsistent;
+                }
             },
             EvalContinuation::NewFork => {
                 // Like the `NewChannel` result. This means we're setting up
                 // a branch and putting a marker inside the RunContext for the
                 // next time we run the PDL code
                 let left_id = branch_id;
                 let right_id = self.tree.fork_branch(left_id);
                 self.consensus.notify_of_new_branch(left_id, right_id);
                 self.tree.push_into_queue(QueueKind::Runnable, left_id);
                 self.tree.push_into_queue(QueueKind::Runnable, right_id);
                 let left_branch = &mut self.tree[left_id];
                 left_branch.prepared = PreparedStatement::ForkedExecution(true);
                 let right_branch = &mut self.tree[right_id];
                 right_branch.prepared = PreparedStatement::ForkedExecution(false);
+            }
             EvalContinuation::Put(port_id, content) => {
                 // Branch is attempting to send data
                 let port_id = PortIdLocal::new(port_id.id);
                 let (sync_header, data_header) = self.consensus.handle_message_to_send(branch_id, port_id, &content, comp_ctx);
                 let message = DataMessage{ sync_header, data_header, content };
                 match comp_ctx.submit_message(Message::Data(message)) {
                     Ok(_) => {
                         // Message is underway
                         branch.prepared = PreparedStatement::PerformedPut;
                         self.tree.push_into_queue(QueueKind::Runnable, branch_id);
                         return ConnectorScheduling::Immediate;
                     },
                     Err(_) => {
                         // We don't own the port
                         let pd = &sched_ctx.runtime.protocol_description;
                         let eval_error = branch.code_state.new_error_at_expr(
                             &pd.modules, &pd.heap,
                             String::from("attempted to 'put' on port that is no longer owned")
                         );
                         self.eval_error = Some(eval_error);
                         self.mode = Mode::SyncError;
                         if let Some(conclusion) = self.consensus.notify_of_fatal_branch(branch_id, comp_ctx) {
                             return self.enter_non_sync_mode(conclusion, comp_ctx);
+                        }
+                    }
+                }
             },
             _ => unreachable!("unexpected run result {:?} in sync mode", run_result),
+        }
         // If here then the run result did not require a particular action. We
         // return whether we have more active branches to run or not.
         if self.tree.queue_is_empty(QueueKind::Runnable) {
             return ConnectorScheduling::NotNow;
         } else {
             return ConnectorScheduling::Later;
+        }
+    }
     pub fn run_in_deterministic_mode(&mut self, sched_ctx: SchedulerCtx, comp_ctx: &mut ComponentCtx) -> ConnectorScheduling {
         debug_assert!(!self.tree.is_in_sync() && !self.consensus.is_in_sync());
         let branch = self.tree.base_branch_mut();
         debug_assert!(branch.sync_state == SpeculativeState::RunningNonSync);
         let mut run_context = ConnectorRunContext{
             branch_id: branch.id,
             consensus: &self.consensus,
             prepared: branch.prepared.take(),
         };
         let run_result = Self::run_prompt(&mut branch.code_state, &sched_ctx.runtime.protocol_description, &mut run_context);
         if let Err(eval_error) = run_result {
             comp_ctx.push_error(eval_error);
             return ConnectorScheduling::Exit
+        }
         let run_result = run_result.unwrap();
         match run_result {
             EvalContinuation::ComponentTerminated => {
                 branch.sync_state = SpeculativeState::Finished;
                 return ConnectorScheduling::Exit;
             },
             EvalContinuation::SyncBlockStart => {
                 comp_ctx.notify_sync_start();
                 let sync_branch_id = self.tree.start_sync();
                 debug_assert!(self.last_finished_handled.is_none());
                 self.consensus.start_sync(comp_ctx);
                 self.consensus.notify_of_new_branch(BranchId::new_invalid(), sync_branch_id);
                 self.tree.push_into_queue(QueueKind::Runnable, sync_branch_id);
                 self.mode = Mode::Sync;
                 return ConnectorScheduling::Immediate;
             },
-            EvalContinuation::NewComponent(definition_id, monomorph_idx, arguments) => {
+            EvalContinuation::NewComponent(definition_id, type_id, arguments) => {
                 // Note: we're relinquishing ownership of ports. But because
                 // we are in non-sync mode the scheduler will handle and check
                 // port ownership transfer.
                 debug_assert!(comp_ctx.workspace_ports.is_empty());
                 find_ports_in_value_group(&arguments, &mut comp_ctx.workspace_ports);
                 let new_prompt = Prompt::new(
                     &sched_ctx.runtime.protocol_description.types,
                     &sched_ctx.runtime.protocol_description.heap,
-                    definition_id, monomorph_idx, arguments
+                    definition_id, type_id, arguments
                 );
                 let new_component = ConnectorPDL::new(new_prompt);
                 comp_ctx.push_component(new_component, comp_ctx.workspace_ports.clone());
                 comp_ctx.workspace_ports.clear();
                 return ConnectorScheduling::Later;
             },
             EvalContinuation::NewChannel => {
                 let (getter, putter) = sched_ctx.runtime.create_channel(comp_ctx.id);
                 debug_assert!(getter.kind == PortKind::Getter && putter.kind == PortKind::Putter);
                 branch.prepared = PreparedStatement::CreatedChannel((
                     Value::Output(PortId::new(putter.self_id.index)),
                     Value::Input(PortId::new(getter.self_id.index)),
                 ));
                 comp_ctx.push_port(putter);
                 comp_ctx.push_port(getter);
                 return ConnectorScheduling::Immediate;
             },
             _ => unreachable!("unexpected run result '{:?}' while running in non-sync mode", run_result),
+        }
+    }
     /// Helper that moves the component's state back into non-sync mode, using
     /// the provided solution branch ID as the branch that should be comitted to
     /// memory. If this function returns false, then the component is supposed
     /// to exit.
     fn enter_non_sync_mode(&mut self, conclusion: RoundConclusion, ctx: &mut ComponentCtx) -> ConnectorScheduling {
         debug_assert!(self.mode == Mode::Sync || self.mode == Mode::SyncError);
         // Depending on local state decide what to do
         let final_branch_id = match conclusion {
             RoundConclusion::Success(branch_id) => Some(branch_id),
             RoundConclusion::Failure => None,
         };
         if let Some(solution_branch_id) = final_branch_id {
             let mut fake_vec = Vec::new();
             self.tree.end_sync(solution_branch_id);
             self.consensus.end_sync(solution_branch_id, &mut fake_vec);
             debug_assert!(fake_vec.is_empty());
             ctx.notify_sync_end(&[]);
             self.last_finished_handled = None;
             self.eval_error = None; // in case we came from the SyncError mode
             self.mode = Mode::NonSync;
             return ConnectorScheduling::Immediate;
         } else {
             // No final branch, because we're supposed to exit!
             self.last_finished_handled = None;
             self.mode = Mode::Error;
             if let Some(eval_error) = self.eval_error.take() {
                 ctx.push_error(eval_error);
+            }
             return ConnectorScheduling::Exit;
+        }
+    }
     /// Runs the prompt repeatedly until some kind of execution-blocking
     /// condition appears.
     #[inline]
     fn run_prompt(prompt: &mut Prompt, pd: &ProtocolDescription, ctx: &mut ConnectorRunContext) -> Result<EvalContinuation, EvalError> {
         loop {
             let result = prompt.step(&pd.types, &pd.heap, &pd.modules, ctx);
             if let Ok(EvalContinuation::Stepping) = result {
                 continue;
+            }
             return result;
+        }
+    }
+}
@@ \ No newline at end of file @@

src/runtime/consensus.rs

➞

Show inline comments

 use crate::collections::VecSet;
 use crate::protocol::eval::ValueGroup;
 use super::ConnectorId;
 use super::branch::BranchId;
 use super::port::{ChannelId, PortIdLocal, PortState};
 use super::inbox::{
     Message, DataHeader, SyncHeader, ChannelAnnotation, BranchMarker,
     DataMessage,
     SyncCompMessage, SyncCompContent,
     SyncPortMessage, SyncPortContent,
     SyncControlMessage, SyncControlContent
 };
 use super::scheduler::{ComponentCtx, ComponentPortChange, MessageTicket};
 struct BranchAnnotation {
     channel_mapping: Vec<ChannelAnnotation>,
     cur_marker: BranchMarker,
+}
 #[derive(Debug)]
 pub(crate) struct LocalSolution {
     component: ConnectorId,
     final_branch_id: BranchId,
     sync_round_number: u32,
     port_mapping: Vec<(ChannelId, BranchMarker)>,
+}
 #[derive(Debug, Clone)]
 pub(crate) struct GlobalSolution {
     component_branches: Vec<(ConnectorId, BranchId, u32)>,
     channel_mapping: Vec<(ChannelId, BranchMarker)>, // TODO: This can go, is debugging info
+}
 #[derive(Debug, PartialEq, Eq)]
 pub enum RoundConclusion {
     Failure,
     Success(BranchId),
+}
 // -----------------------------------------------------------------------------
 // Consensus
 // -----------------------------------------------------------------------------
 #[derive(Debug)]
 struct Peer {
     id: ConnectorId,
     encountered_this_round: bool,
     expected_sync_round: u32,
+}
 /// The consensus algorithm. Currently only implemented to find the component
 /// with the highest ID within the sync region and letting it handle all the
 /// local solutions.
 ///
 /// The type itself serves as an experiment to see how code should be organized.
 // TODO: Flatten all datastructures
 // TODO: Have a "branch+port position hint" in case multiple operations are
 //  performed on the same port to prevent repeated lookups
 // TODO: A lot of stuff should be batched. Like checking all the sync headers
 //  and sending "I have a higher ID" messages. Should reduce locking by quite a
 //  bit.
 // TODO: Needs a refactor. Firstly we have cases where we don't have a branch ID
 //  but we do want to enumerate all current ports. So put that somewhere in a
 //  central place. Secondly. Error handling and regular message handling is
 //  becoming a mess.
 pub(crate) struct Consensus {
     // --- State that is cleared after each round
     // Local component's state
     highest_connector_id: ConnectorId,
     branch_annotations: Vec<BranchAnnotation>, // index is branch ID
     branch_markers: Vec<BranchId>, // index is branch marker, maps to branch
     // Gathered state from communication
     encountered_ports: VecSet<PortIdLocal>, // to determine if we should send "port remains silent" messages.
     solution_combiner: SolutionCombiner,
     handled_wave: bool, // encountered notification wave in this round
     conclusion: Option<RoundConclusion>,
     ack_remaining: u32,
     // --- Persistent state
     peers: Vec<Peer>,
     sync_round: u32,
     // --- Workspaces
     workspace_ports: Vec<PortIdLocal>,
+}
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub(crate) enum Consistency {
     Valid,
     Inconsistent,
+}
 #[derive(Debug, PartialEq, Eq)]
 pub(crate) enum MessageOrigin {
     Past,
     Present,
     Future
+}
 impl Consensus {
     pub fn new() -> Self {
         return Self {
             highest_connector_id: ConnectorId::new_invalid(),
             branch_annotations: Vec::new(),
             branch_markers: Vec::new(),
             encountered_ports: VecSet::new(),
             solution_combiner: SolutionCombiner::new(),
             handled_wave: false,
             conclusion: None,
             ack_remaining: 0,
             peers: Vec::new(),
             sync_round: 0,
             workspace_ports: Vec::new(),
+        }
+    }
     // --- Controlling sync round and branches
     /// Returns whether the consensus algorithm is running in sync mode
     pub fn is_in_sync(&self) -> bool {
         return !self.branch_annotations.is_empty();
+    }
     /// Sets up the consensus algorithm for a new synchronous round. The
     /// provided ports should be the ports the component owns at the start of
     /// the sync round.
     pub fn start_sync(&mut self, ctx: &ComponentCtx) {
         debug_assert!(!self.highest_connector_id.is_valid());
         debug_assert!(self.branch_annotations.is_empty());
         debug_assert!(self.solution_combiner.local.is_empty());
         // We'll use the first "branch" (the non-sync one) to store our ports,
         // this allows cloning if we created a new branch.
         self.branch_annotations.push(BranchAnnotation{
             channel_mapping: ctx.get_ports().iter()
                 .map(|v| ChannelAnnotation {
                     channel_id: v.channel_id,
                     registered_id: None,
                     expected_firing: None,
                 })
                 .collect(),
             cur_marker: BranchMarker::new_invalid(),
         });
         self.branch_markers.push(BranchId::new_invalid());
         self.highest_connector_id = ctx.id;
+    }
     /// Notifies the consensus algorithm that a new branch has appeared. Must be
     /// called for each forked branch in the execution tree.
     pub fn notify_of_new_branch(&mut self, parent_branch_id: BranchId, new_branch_id: BranchId) {
         // If called correctly. Then each time we are notified the new branch's
         // index is the length in `branch_annotations`.
         debug_assert!(self.branch_annotations.len() == new_branch_id.index as usize);
         let parent_branch_annotations = &self.branch_annotations[parent_branch_id.index as usize];
         let new_marker = BranchMarker::new(self.branch_markers.len() as u32);
         let new_branch_annotations = BranchAnnotation{
             channel_mapping: parent_branch_annotations.channel_mapping.clone(),
             cur_marker: new_marker,
         };
         self.branch_annotations.push(new_branch_annotations);
         self.branch_markers.push(new_branch_id);
+    }
     /// Notifies the consensus algorithm that a particular branch has
     /// encountered an unrecoverable error.
     pub fn notify_of_fatal_branch(&mut self, failed_branch_id: BranchId, ctx: &mut ComponentCtx) -> Option<RoundConclusion> {
         debug_assert!(self.is_in_sync());
         // Check for trivial case, where branch has not yet communicated within
         // the consensus algorithm
         let branch = &self.branch_annotations[failed_branch_id.index as usize];
         if branch.channel_mapping.iter().all(|v| v.registered_id.is_none()) {
             return Some(RoundConclusion::Failure);
+        }
         // We're not in the trivial case: since we've communicated we need to
         // let everyone know that this round is probably not going to end well.
         return self.initiate_sync_failure(ctx);
+    }
     /// Notifies the consensus algorithm that a branch has reached the end of
     /// the sync block. A final check for consistency will be performed that the
     /// caller has to handle. Note that
     pub fn notify_of_finished_branch(&self, branch_id: BranchId) -> Consistency {
         debug_assert!(self.is_in_sync());
         let branch = &self.branch_annotations[branch_id.index as usize];
         for mapping in &branch.channel_mapping {
             match mapping.expected_firing {
                 Some(expected) => {
                     if expected != mapping.registered_id.is_some() {
                         // Inconsistent speculative state and actual state
                         debug_assert!(mapping.registered_id.is_none()); // because if we did fire on a silent port, we should've caught that earlier
                         return Consistency::Inconsistent;
+                    }
                 },
                 None => {},
+            }
+        }
         return Consistency::Valid;
+    }
     /// Notifies the consensus algorithm that a particular branch has assumed
     /// a speculative value for its port mapping.
     pub fn notify_of_speculative_mapping(&mut self, branch_id: BranchId, port_id: PortIdLocal, does_fire: bool, ctx: &ComponentCtx) -> Consistency {
         debug_assert!(self.is_in_sync());
         let port_desc = ctx.get_port_by_id(port_id).unwrap();
         let channel_id = port_desc.channel_id;
         let branch = &mut self.branch_annotations[branch_id.index as usize];
         for mapping in &mut branch.channel_mapping {
             if mapping.channel_id == channel_id {
                 match mapping.expected_firing {
                     None => {
                         // Not yet mapped, perform speculative mapping
                         mapping.expected_firing = Some(does_fire);
                         return Consistency::Valid;
                     },
                     Some(current) => {
                         // Already mapped
                         if current == does_fire {
                             return Consistency::Valid;
                         } else {
                             return Consistency::Inconsistent;
+                        }
+                    }
+                }
+            }
+        }
         unreachable!("notify_of_speculative_mapping called with unowned port");
+    }
     /// Generates a new local solution from a finished branch. If the component
     /// is not the leader of the sync region then it will be sent to the
     /// appropriate component. If it is the leader then there is a chance that
     /// this solution completes a global solution. In that case the solution
     /// branch ID will be returned.
     pub(crate) fn handle_new_finished_sync_branch(&mut self, branch_id: BranchId, ctx: &mut ComponentCtx) -> Option<RoundConclusion> {
         // Turn the port mapping into a local solution
         let source_mapping = &self.branch_annotations[branch_id.index as usize].channel_mapping;
         let mut target_mapping = Vec::with_capacity(source_mapping.len());
         for port in source_mapping {
             // Note: if the port is silent, and we've never communicated
             // over the port, then we need to do so now, to let the peer
             // component know about our sync leader state.
             let port_desc = ctx.get_port_by_channel_id(port.channel_id).unwrap();
             let self_port_id = port_desc.self_id;
             let peer_port_id = port_desc.peer_id;
             let channel_id = port_desc.channel_id;
             if !self.encountered_ports.contains(&self_port_id) {
                 let message = SyncPortMessage {
                     sync_header: SyncHeader{
                         sending_component_id: ctx.id,
                         highest_component_id: self.highest_connector_id,
                         sync_round: self.sync_round
                     },
                     source_port: self_port_id,
                     target_port: peer_port_id,
                     content: SyncPortContent::SilentPortNotification,
                 };
                 match ctx.submit_message(Message::SyncPort(message)) {
                     Ok(_) => {
                         self.encountered_ports.push(self_port_id);
                     },
                     Err(_) => {
                         // Seems like we were done with this branch, but one of
                         // the silent ports (in scope) is actually closed
                         return self.notify_of_fatal_branch(branch_id, ctx);
+                    }
+                }
+            }
             target_mapping.push((
                 channel_id,
                 port.registered_id.unwrap_or(BranchMarker::new_invalid())
             ));
+        }
         let local_solution = LocalSolution{
             component: ctx.id,
             sync_round_number: self.sync_round,
             final_branch_id: branch_id,
             port_mapping: target_mapping,
         };
         let maybe_conclusion = self.send_to_leader_or_handle_as_leader(SyncCompContent::LocalSolution(local_solution), ctx);
         return maybe_conclusion;
+    }
     /// Notifies the consensus algorithm about the chosen branch to commit to
     /// memory (may be the invalid "start" branch)
     pub fn end_sync(&mut self, branch_id: BranchId, _final_ports: &mut Vec<ComponentPortChange>) {
         debug_assert!(self.is_in_sync());
         // TODO: Handle sending and receiving ports
         // Set final ports
         let _branch = &self.branch_annotations[branch_id.index as usize];
         // Clear out internal storage to defaults
         self.highest_connector_id = ConnectorId::new_invalid();
         self.branch_annotations.clear();
         self.branch_markers.clear();
         self.encountered_ports.clear();
         self.solution_combiner.clear();
         self.handled_wave = false;
         self.conclusion = None;
         self.ack_remaining = 0;
         // And modify persistent storage
         self.sync_round += 1;
         for peer in self.peers.iter_mut() {
             peer.encountered_this_round = false;
             peer.expected_sync_round += 1;
+        }
+    }
     // --- Handling messages
     /// Prepares a message for sending. Caller should have made sure that
     /// sending the message is consistent with the speculative state.
     pub fn handle_message_to_send(&mut self, branch_id: BranchId, source_port_id: PortIdLocal, content: &ValueGroup, ctx: &mut ComponentCtx) -> (SyncHeader, DataHeader) {
         debug_assert!(self.is_in_sync());
         let branch = &mut self.branch_annotations[branch_id.index as usize];
         let port_info = ctx.get_port_by_id(source_port_id).unwrap();
-        if cfg!(debug_assertions) {
+        dbg_code!({
             // Check for consistent mapping
             let port = branch.channel_mapping.iter()
                 .find(|v| v.channel_id == port_info.channel_id)
                 .unwrap();
             debug_assert!(port.expected_firing == None || port.expected_firing == Some(true));
+        }
+        });
         // Check for ports that are being sent
         debug_assert!(self.workspace_ports.is_empty());
         find_ports_in_value_group(content, &mut self.workspace_ports);
         if !self.workspace_ports.is_empty() {
             todo!("handle sending ports");
             // self.workspace_ports.clear();
+        }
         // Construct data header
         let data_header = DataHeader{
             expected_mapping: branch.channel_mapping.iter()
                 .filter(|v| v.registered_id.is_some() || v.channel_id == port_info.channel_id)
                 .copied()
                 .collect(),
             sending_port: port_info.self_id,
             target_port: port_info.peer_id,
             new_mapping: branch.cur_marker,
         };
         // Update port mapping
         for mapping in &mut branch.channel_mapping {
             if mapping.channel_id == port_info.channel_id {
                 mapping.expected_firing = Some(true);
                 mapping.registered_id = Some(branch.cur_marker);
+            }
+        }
         // Update branch marker
         let new_marker = BranchMarker::new(self.branch_markers.len() as u32);
         branch.cur_marker = new_marker;
         self.branch_markers.push(branch_id);
         self.encountered_ports.push(source_port_id);
         return (self.create_sync_header(ctx), data_header);
+    }
     /// Handles a new data message by handling the sync header. The caller is
     /// responsible for checking for branches that might be able to receive
     /// the message.
     pub fn handle_new_data_message(&mut self, ticket: MessageTicket, ctx: &mut ComponentCtx) -> bool {
         let message = ctx.read_message_using_ticket(ticket).as_data();
         let target_port = message.data_header.target_port;
         match self.handle_received_sync_header(message.sync_header, ctx) {
             MessageOrigin::Past => return false,
             MessageOrigin::Present => {
                 self.encountered_ports.push(target_port);
                 return true;
             },
             MessageOrigin::Future => {
                 let message = ctx.take_message_using_ticket(ticket);
                 ctx.put_back_message(message);
                 return false;
+            }
+        }
+    }
     /// Handles a new sync message by handling the sync header and the contents
     /// of the message. Returns `Some` with the branch ID of the global solution
     /// if the sync solution has been found.
     pub fn handle_new_sync_comp_message(&mut self, message: SyncCompMessage, ctx: &mut ComponentCtx) -> Option<RoundConclusion> {
         match self.handle_received_sync_header(message.sync_header, ctx) {
             MessageOrigin::Past => return None,
             MessageOrigin::Present => {},
             MessageOrigin::Future => {
                 ctx.put_back_message(Message::SyncComp(message));
                 return None
+            }
+        }
         // And handle the contents
         debug_assert_eq!(message.target_component_id, ctx.id);
         match &message.content {
             SyncCompContent::LocalFailure |
             SyncCompContent::LocalSolution(_) |
             SyncCompContent::PartialSolution(_) |
             SyncCompContent::AckFailure |
             SyncCompContent::Presence(_) => {
                 // Needs to be handled by the leader
                 return self.send_to_leader_or_handle_as_leader(message.content, ctx);
             },
             SyncCompContent::GlobalSolution(solution) => {
                 // Found a global solution
                 debug_assert_ne!(self.highest_connector_id, ctx.id); // not the leader
                 let (_, branch_id, _) = solution.component_branches.iter()
                     .find(|(component_id, _, _)| *component_id == ctx.id)
                     .unwrap();
                 return Some(RoundConclusion::Success(*branch_id));
             },
             SyncCompContent::GlobalFailure => {
                 // Global failure of round, send Ack to leader
                 debug_assert_ne!(self.highest_connector_id, ctx.id); // not the leader
                 let _result = self.send_to_leader_or_handle_as_leader(SyncCompContent::AckFailure, ctx);
                 debug_assert!(_result.is_none());
                 return Some(RoundConclusion::Failure);
             },
             SyncCompContent::Notification => {
                 // We were just interested in the sync header we handled above
                 return None;
+            }
+        }
+    }
     pub fn handle_new_sync_port_message(&mut self, message: SyncPortMessage, ctx: &mut ComponentCtx) -> Option<RoundConclusion> {
         match self.handle_received_sync_header(message.sync_header, ctx) {
             MessageOrigin::Past => return None,
             MessageOrigin::Present => {},
             MessageOrigin::Future => {
                 ctx.put_back_message(Message::SyncPort(message));
                 return None;
+            }
+        }
         debug_assert!(self.is_in_sync());
         debug_assert!(ctx.get_port_by_id(message.target_port).is_some());
         match message.content {
             SyncPortContent::SilentPortNotification => {
                 // The point here is to let us become part of the sync round and
                 // take note of the leader in case all of our ports are silent.
                 self.encountered_ports.push(message.target_port);
                 return None
+            }
             SyncPortContent::NotificationWave => {
                 // Wave to discover everyone in the network, handling sync
                 // header takes care of leader discovery, here we need to make
                 // sure we propagate the wave
                 if self.handled_wave {
                     return None;
+                }
                 self.handled_wave = true;
                 // Propagate wave to all peers except the one that has sent us
                 // the wave.
                 for mapping in &self.branch_annotations[0].channel_mapping {
                     let channel_id = mapping.channel_id;
                     let port_desc = ctx.get_port_by_channel_id(channel_id).unwrap();
                     if port_desc.self_id == message.target_port {
                         // Wave came from this port, no need to send one back
                         continue;
+                    }
                     let message = SyncPortMessage{
                         sync_header: self.create_sync_header(ctx),
                         source_port: port_desc.self_id,
                         target_port: port_desc.peer_id,
                         content: SyncPortContent::NotificationWave,
                     };
                     // As with the other SyncPort where we throw away the
                     // result: we're dealing with an error here anyway
                     let _unused = ctx.submit_message(Message::SyncPort(message));
+                }
                 // And let the leader know about our port state
                 let annotations = &self.branch_annotations[0];
                 let mut channels = Vec::with_capacity(annotations.channel_mapping.len());
                 for mapping in &annotations.channel_mapping {
                     let port_info = ctx.get_port_by_channel_id(mapping.channel_id).unwrap();
                     channels.push(LocalChannelPresence{
                         channel_id: mapping.channel_id,
                         is_closed: port_info.state == PortState::Closed,
                     });
+                }
                 let maybe_conclusion = self.send_to_leader_or_handle_as_leader(SyncCompContent::Presence(ComponentPresence{
                     component_id: ctx.id,
                     channels,
                 }), ctx);
                 return maybe_conclusion;
+            }
+        }
+    }
     pub fn handle_new_sync_control_message(&mut self, message: SyncControlMessage, ctx: &mut ComponentCtx) -> Option<RoundConclusion> {
         if message.in_response_to_sync_round < self.sync_round {
             // Old message
             return None
+        }
         // Because the message is always sent in response to a message
         // originating here, the sync round number can never be larger than the
         // currently stored one.
         debug_assert_eq!(message.in_response_to_sync_round, self.sync_round);
         match message.content {
             SyncControlContent::ChannelIsClosed(_) => {
                 return self.initiate_sync_failure(ctx);
+            }
+        }
+    }
     pub fn notify_of_received_message(&mut self, branch_id: BranchId, message: &DataMessage, ctx: &ComponentCtx) {
         debug_assert!(self.branch_can_receive(branch_id, message));
         let target_port = ctx.get_port_by_id(message.data_header.target_port).unwrap();
         let branch = &mut self.branch_annotations[branch_id.index as usize];
         for mapping in &mut branch.channel_mapping {
             if mapping.channel_id == target_port.channel_id {
                 // Found the port in which the message should be inserted
                 mapping.registered_id = Some(message.data_header.new_mapping);
                 // Check for sent ports
                 debug_assert!(self.workspace_ports.is_empty());
                 find_ports_in_value_group(&message.content, &mut self.workspace_ports);
                 if !self.workspace_ports.is_empty() {
                     todo!("handle received ports");
                     // self.workspace_ports.clear();
+                }
                 return;
+            }
+        }
         // If here, then the branch didn't actually own the port? Means the
         // caller made a mistake
         unreachable!("incorrect notify_of_received_message");
+    }
     /// Matches the mapping between the branch and the data message. If they
     /// match then the branch can receive the message.
     pub fn branch_can_receive(&self, branch_id: BranchId, message: &DataMessage) -> bool {
         if let Some(peer) = self.peers.iter().find(|v| v.id == message.sync_header.sending_component_id) {
             if message.sync_header.sync_round < peer.expected_sync_round {
                 return false;
+            }
+        }
         let annotation = &self.branch_annotations[branch_id.index as usize];
         for expected in &message.data_header.expected_mapping {
             // If we own the port, then we have an entry in the
             // annotation, check if the current mapping matches
             for current in &annotation.channel_mapping {
                 if expected.channel_id == current.channel_id {
                     if expected.registered_id != current.registered_id {
                         // IDs do not match, we cannot receive the
                         // message in this branch
                         return false;
+                    }
+                }
+            }
+        }
         return true;
+    }
     // --- Internal helpers
     fn handle_received_sync_header(&mut self, sync_header: SyncHeader, ctx: &mut ComponentCtx) -> MessageOrigin {
         debug_assert!(sync_header.sending_component_id != ctx.id); // not sending to ourselves
         let origin = self.handle_peer(&sync_header);
         if origin != MessageOrigin::Present {
             // We do not have to handle it now
             return origin;
+        }
         if sync_header.highest_component_id > self.highest_connector_id {
             // Sender has higher component ID. So should be the target of our
             // messages. We should also let all of our peers know
             self.highest_connector_id = sync_header.highest_component_id;
             for peer in self.peers.iter() {
                 if peer.id == sync_header.sending_component_id || !peer.encountered_this_round {
                     // Don't need to send it to this one
                     continue
+                }
                 let message = SyncCompMessage {
                     sync_header: self.create_sync_header(ctx),
                     target_component_id: peer.id,
                     content: SyncCompContent::Notification,
                 };
                 ctx.submit_message(Message::SyncComp(message)).unwrap(); // unwrap: sending to component instead of through channel
+            }
             // But also send our locally combined solution
             self.forward_local_data_to_new_leader(ctx);
         } else if sync_header.highest_component_id < self.highest_connector_id {
             // Sender has lower leader ID, so it should know about our higher
             // one.
             let message = SyncCompMessage {
                 sync_header: self.create_sync_header(ctx),
                 target_component_id: sync_header.sending_component_id,
                 content: SyncCompContent::Notification
             };
             ctx.submit_message(Message::SyncComp(message)).unwrap(); // unwrap: sending to component instead of through channel
         } // else: exactly equal, so do nothing
         return MessageOrigin::Present;
+    }
     /// Handles a (potentially new) peer. Returns `false` if the provided sync
     /// number is different then the expected one.
     fn handle_peer(&mut self, sync_header: &SyncHeader) -> MessageOrigin {
         let position = self.peers.iter().position(|v| v.id == sync_header.sending_component_id);
         match position {
             Some(index) => {
                 let entry = &mut self.peers[index];
                 if entry.encountered_this_round {
                     // Already encountered this round
                     if sync_header.sync_round < entry.expected_sync_round {
                         return MessageOrigin::Past;
                     } else if sync_header.sync_round == entry.expected_sync_round {
                         return MessageOrigin::Present;
                     } else {
                         return MessageOrigin::Future;
+                    }
                 } else {
                     // TODO: Proper handling of potential overflow
                     entry.encountered_this_round = true;
                     if sync_header.sync_round >= entry.expected_sync_round {
                         entry.expected_sync_round = sync_header.sync_round;
                         return MessageOrigin::Present;
                     } else {
                         return MessageOrigin::Past;
+                    }
+                }
             },
             None => {
                 self.peers.push(Peer{
                     id: sync_header.sending_component_id,
                     encountered_this_round: true,
                     expected_sync_round: sync_header.sync_round,
                 });
                 return MessageOrigin::Present;
+            }
+        }
+    }
     /// Sends a message towards the leader, if already the leader then the
     /// message will be handled immediately.
     fn send_to_leader_or_handle_as_leader(&mut self, content: SyncCompContent, ctx: &mut ComponentCtx) -> Option<RoundConclusion> {
         if self.highest_connector_id == ctx.id {
             // We are the leader
             match content {
                 SyncCompContent::LocalFailure => {
                     if self.solution_combiner.mark_failure_and_check_for_global_failure() {
                         return self.handle_global_failure_as_leader(ctx);
+                    }
                 },
                 SyncCompContent::LocalSolution(local_solution) => {
                     if let Some(global_solution) = self.solution_combiner.add_solution_and_check_for_global_solution(local_solution) {
                         return self.handle_global_solution_as_leader(global_solution, ctx);
+                    }
                 },
                 SyncCompContent::PartialSolution(partial_solution) => {
                     if let Some(conclusion) = self.solution_combiner.combine(partial_solution) {
                         match conclusion {
                             LeaderConclusion::Solution(global_solution) => {
                                 return self.handle_global_solution_as_leader(global_solution, ctx);
                             },
                             LeaderConclusion::Failure => {
                                 return self.handle_global_failure_as_leader(ctx);
+                            }
+                        }
+                    }
                 },
                 SyncCompContent::Presence(component_presence) => {
                     if self.solution_combiner.add_presence_and_check_for_global_failure(component_presence.component_id, &component_presence.channels) {
                         return self.handle_global_failure_as_leader(ctx);
+                    }
                 },
                 SyncCompContent::AckFailure => {
                     debug_assert_eq!(Some(RoundConclusion::Failure), self.conclusion);
                     debug_assert!(self.ack_remaining > 0);
                     self.ack_remaining -= 1;
                     if self.ack_remaining == 0 {
                         return Some(RoundConclusion::Failure);
+                    }
+                }
                 SyncCompContent::Notification | SyncCompContent::GlobalSolution(_) |
                 SyncCompContent::GlobalFailure => {
                     unreachable!("unexpected message content for leader");
                 },
+            }
         } else {
             // Someone else is the leader
             let message = SyncCompMessage {
                 sync_header: self.create_sync_header(ctx),
                 target_component_id: self.highest_connector_id,
                 content,
             };
             ctx.submit_message(Message::SyncComp(message)).unwrap(); // unwrap: sending to component instead of through channel
+        }
         return None;
+    }
     fn handle_global_solution_as_leader(&mut self, global_solution: GlobalSolution, ctx: &mut ComponentCtx) -> Option<RoundConclusion> {
         if self.conclusion.is_some() {
             return None;
+        }
         // Handle the global solution
         let mut my_final_branch_id = BranchId::new_invalid();
         for (connector_id, branch_id, sync_round) in global_solution.component_branches.iter().copied() {
             if connector_id == ctx.id {
                 // This is our solution branch
                 my_final_branch_id = branch_id;
                 continue;
+            }
             // Send solution message
             let message = SyncCompMessage {
                 sync_header: self.create_sync_header(ctx),
                 target_component_id: connector_id,
                 content: SyncCompContent::GlobalSolution(global_solution.clone()),
             };
             ctx.submit_message(Message::SyncComp(message)).unwrap(); // unwrap: sending to component instead of through channel
             // Update peers as leader. Subsequent call to `end_sync` will update
             // the round numbers
             match self.peers.iter_mut().find(|v| v.id == connector_id) {
                 Some(peer) => {
                     peer.expected_sync_round = sync_round;
                 },
                 None => {
                     self.peers.push(Peer{
                         id: connector_id,
                         expected_sync_round: sync_round,
                         encountered_this_round: true,
                     });
+                }
+            }
+        }
         debug_assert!(my_final_branch_id.is_valid());
         self.conclusion = Some(RoundConclusion::Success(my_final_branch_id));
         return Some(RoundConclusion::Success(my_final_branch_id));
+    }
     fn handle_global_failure_as_leader(&mut self, ctx: &mut ComponentCtx) -> Option<RoundConclusion> {
         debug_assert!(self.solution_combiner.failure_reported && self.solution_combiner.check_for_global_failure());
         if self.conclusion.is_some() {
             // Already sent out a failure
             return None;
+        }
         // TODO: Performance
         let mut encountered = VecSet::new();
         for presence in &self.solution_combiner.presence {
             if presence.owner_a != ctx.id {
                 // Did not add it ourselves
                 if encountered.push(presence.owner_a) {
                     // Not yet sent a message
                     let message = SyncCompMessage{
                         sync_header: self.create_sync_header(ctx),
                         target_component_id: presence.owner_a,
                         content: SyncCompContent::GlobalFailure,
                     };
                     ctx.submit_message(Message::SyncComp(message)).unwrap(); // unwrap: sending to component instead of through channel
+                }
+            }
             if let Some(owner_b) = presence.owner_b {
                 if owner_b != ctx.id {
                     if encountered.push(owner_b) {
                         let message = SyncCompMessage{
                             sync_header: self.create_sync_header(ctx),
                             target_component_id: owner_b,
                             content: SyncCompContent::GlobalFailure,
                         };
                         ctx.submit_message(Message::SyncComp(message)).unwrap();
+                    }
+                }
+            }
+        }
         self.conclusion = Some(RoundConclusion::Failure);
         if encountered.is_empty() {
             // We don't have to wait on Acks
             return Some(RoundConclusion::Failure);
         } else {
             self.ack_remaining = encountered.len() as u32;
             return None;
+        }
+    }
     fn initiate_sync_failure(&mut self, ctx: &mut ComponentCtx) -> Option<RoundConclusion> {
         debug_assert!(self.is_in_sync());
         // Notify leader of our channels and the fact that we just failed
         let channel_mapping = &self.branch_annotations[0].channel_mapping;
         let mut channel_presence = Vec::with_capacity(channel_mapping.len());
         for mapping in channel_mapping {
             let port = ctx.get_port_by_channel_id(mapping.channel_id).unwrap();
             channel_presence.push(LocalChannelPresence{
                 channel_id: mapping.channel_id,
                 is_closed: port.state == PortState::Closed,
             });
+        }
         let maybe_already = self.send_to_leader_or_handle_as_leader(SyncCompContent::Presence(ComponentPresence{
             component_id: ctx.id,
             channels: channel_presence,
         }), ctx);
         if self.handled_wave {
             // Someone (or us) has already initiated a sync failure.
             return maybe_already;
+        }
         let maybe_conclusion = self.send_to_leader_or_handle_as_leader(SyncCompContent::LocalFailure, ctx);
         debug_assert!(if maybe_already.is_some() { maybe_conclusion.is_some() } else { true });
         // Initiate a discovery wave so peers can do the same
         self.handled_wave = true;
         for mapping in &self.branch_annotations[0].channel_mapping {
             let channel_id = mapping.channel_id;
             let port_info = ctx.get_port_by_channel_id(channel_id).unwrap();
             let message = SyncPortMessage{
                 sync_header: self.create_sync_header(ctx),
                 source_port: port_info.self_id,
                 target_port: port_info.peer_id,
                 content: SyncPortContent::NotificationWave,
             };
             // Note: submitting the message might fail. But we're attempting to
             // handle the error anyway.
             // TODO: Think about this a second time: how do we make sure the
             //  entire network will fail if we reach this condition
             let _unused = ctx.submit_message(Message::SyncPort(message));
+        }
         return maybe_conclusion;
+    }
     #[inline]
     fn create_sync_header(&self, ctx: &ComponentCtx) -> SyncHeader {
         return SyncHeader{
             sending_component_id: ctx.id,
             highest_component_id: self.highest_connector_id,
             sync_round: self.sync_round,
+        }
+    }
     fn forward_local_data_to_new_leader(&mut self, ctx: &mut ComponentCtx) {
         debug_assert_ne!(self.highest_connector_id, ctx.id);
         if let Some(partial_solution) = self.solution_combiner.drain() {
             let message = SyncCompMessage {
                 sync_header: self.create_sync_header(ctx),
                 target_component_id: self.highest_connector_id,
                 content: SyncCompContent::PartialSolution(partial_solution),
             };
             ctx.submit_message(Message::SyncComp(message)).unwrap(); // unwrap: sending to component instead of through channel
+        }
+    }
+}
 // -----------------------------------------------------------------------------
 // Solution storage and algorithms
 // -----------------------------------------------------------------------------
 // TODO: Remove all debug derives
 #[derive(Debug, Clone)]
 struct MatchedLocalSolution {
     final_branch_id: BranchId,
     channel_mapping: Vec<(ChannelId, BranchMarker)>,
     matches: Vec<ComponentMatches>,
+}
 #[derive(Debug, Clone)]
 struct ComponentMatches {
     target_id: ConnectorId,
     target_index: usize,
     match_indices: Vec<usize>, // of local solution in connector
+}
 #[derive(Debug, Clone)]
 struct ComponentPeer {
     target_id: ConnectorId,
     target_index: usize, // in array of global solution components
     involved_channels: Vec<ChannelId>,
+}
 #[derive(Debug, Clone)]
 struct ComponentLocalSolutions {
     component: ConnectorId,
     sync_round: u32,
     peers: Vec<ComponentPeer>,
     solutions: Vec<MatchedLocalSolution>,
     all_peers_present: bool,
+}
 #[derive(Debug, Clone)]
 pub(crate) struct ComponentPresence {
     component_id: ConnectorId,
     channels: Vec<LocalChannelPresence>,
+}
 #[derive(Debug, Clone)]
 pub(crate) struct LocalChannelPresence {
     channel_id: ChannelId,
     is_closed: bool,
+}
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 enum PresenceState {
     OnePresent, // one component reported the channel being open
     BothPresent, // two components reported the channel being open
     Closed, // one component reported the channel being closed
+}
 /// Record to hold channel state during the error-resolving mode of the leader.
 /// This is used to determine when the sync region has grown to its largest
 /// size. The structure is eventually consistent in the sense that a component
 /// might initially presume a channel is open, only to figure out later it is
 /// actually closed.
 #[derive(Debug, Clone)]
 struct ChannelPresence {
     owner_a: ConnectorId,
     owner_b: Option<ConnectorId>,
     id: ChannelId,
     state: PresenceState,
+}
 // TODO: Flatten? Flatten. Flatten everything.
 #[derive(Debug)]
 pub(crate) struct SolutionCombiner {
     local: Vec<ComponentLocalSolutions>, // used for finding solution
     presence: Vec<ChannelPresence>, // used to detect all channels present in case of failure
     failure_reported: bool,
+}
 struct CheckEntry {
     component_index: usize,         // component index in combiner's vector
     solution_index: usize,          // solution entry in the above component entry
     parent_entry_index: usize,      // parent that caused the creation of this checking entry
     match_index_in_parent: usize,   // index in the matches array of the parent
     solution_index_in_parent: usize,// index in the solution array of the match entry in the parent
+}
 enum LeaderConclusion {
     Solution(GlobalSolution),
     Failure,
+}
 impl SolutionCombiner {
     fn new() -> Self {
         return Self{
             local: Vec::new(),
             presence: Vec::new(),
             failure_reported: false,
         };
+    }
     /// Adds a new local solution to the global solution storage. Will check the
     /// new local solutions for matching against already stored local solutions
     /// of peer connectors.
     fn add_solution_and_check_for_global_solution(&mut self, solution: LocalSolution) -> Option<GlobalSolution> {
         let component_id = solution.component;
         let sync_round = solution.sync_round_number;
         let solution = MatchedLocalSolution{
             final_branch_id: solution.final_branch_id,
             channel_mapping: solution.port_mapping,
             matches: Vec::new(),
         };
         // Create an entry for the solution for the particular component
         let component_exists = self.local.iter_mut()
             .enumerate()
             .find(|(_, v)| v.component == component_id);
         let (component_index, solution_index, new_component) = match component_exists {
             Some((component_index, storage)) => {
                 // Entry for component exists, so add to solutions
                 let solution_index = storage.solutions.len();
                 storage.solutions.push(solution);
                 (component_index, solution_index, false)
+            }
             None => {
                 // Entry for component does not exist yet
                 let component_index = self.local.len();
                 self.local.push(ComponentLocalSolutions{
                     component: component_id,
                     sync_round,
                     peers: Vec::new(),
                     solutions: vec![solution],
                     all_peers_present: false,
                 });
                 (component_index, 0, true)
+            }
         };
         // If this is a solution of a component that is new to us, then we check
         // in the stored solutions which other components are peers of the new
         // one.
         if new_component {
             let cur_ports = &self.local[component_index].solutions[0].channel_mapping;
             let mut component_peers = Vec::new();
             // Find the matching components
             for (other_index, other_component) in self.local.iter().enumerate() {
                 if other_index == component_index {
                     // Don't match against ourselves
                     continue;
+                }
                 let mut matching_channels = Vec::new();
                 for (cur_channel_id, _) in cur_ports {
                     for (other_channel_id, _) in &other_component.solutions[0].channel_mapping {
                         if cur_channel_id == other_channel_id {
                             // We have a shared port
                             matching_channels.push(*cur_channel_id);
+                        }
+                    }
+                }
                 if !matching_channels.is_empty() {
                     // We share some ports
                     component_peers.push(ComponentPeer{
                         target_id: other_component.component,
                         target_index: other_index,
                         involved_channels: matching_channels,
                     });
+                }
+            }
             let mut num_ports_in_peers = 0;
             for peer in &component_peers {
                 num_ports_in_peers += peer.involved_channels.len();
+            }
             if num_ports_in_peers == cur_ports.len() {
                 // Newly added component has all required peers present
                 self.local[component_index].all_peers_present = true;
+            }
             // Add the found component pairing entries to the solution entries
             // for the two involved components
             for component_match in component_peers {
                 // Check the other component for having all peers present
                 let mut num_ports_in_peers = component_match.involved_channels.len();
                 let other_component = &mut self.local[component_match.target_index];
                 for existing_peer in &other_component.peers {
                     num_ports_in_peers += existing_peer.involved_channels.len();
+                }
                 if num_ports_in_peers == other_component.solutions[0].channel_mapping.len() {
                     other_component.all_peers_present = true;
+                }
                 other_component.peers.push(ComponentPeer{
                     target_id: component_id,
                     target_index: component_index,
                     involved_channels: component_match.involved_channels.clone(),
                 });
                 let new_component = &mut self.local[component_index];
                 new_component.peers.push(component_match);
+            }
+        }
         // We're now sure that we know which other components the currently
         // considered component is linked up to. Now we need to check those
         // entries (if any) to see if any pair of local solutions match
         let mut new_component_matches = Vec::new();
         let cur_component = &self.local[component_index];
         let cur_solution = &cur_component.solutions[solution_index];
         for peer in &cur_component.peers {
             let mut new_solution_matches = Vec::new();
             let other_component = &self.local[peer.target_index];
             for (other_solution_index, other_solution) in other_component.solutions.iter().enumerate() {
                 // Check the port mappings between the pair of solutions.
                 let mut all_matched = true;

src/runtime2/component/component_context.rs

➞

Show inline comments

 use crate::runtime2::scheduler::*;
 use crate::runtime2::runtime::*;
 use crate::runtime2::communication::*;
 #[derive(Debug)]
 pub struct Port {
     pub self_id: PortId,
     pub peer_comp_id: CompId, // eventually consistent
     pub peer_port_id: PortId, // eventually consistent
     pub kind: PortKind,
     pub state: PortState,
     #[cfg(debug_assertions)] pub(crate) associated_with_peer: bool,
 }
 pub struct Peer {
     pub id: CompId,
     pub num_associated_ports: u32,
     pub(crate) handle: CompHandle,
 }
 /// Port and peer management structure. Will keep a local reference counter to
 /// the ports associate with peers, additionally manages the atomic reference
 /// counter associated with the peers' component handles.
 pub struct CompCtx {
     pub id: CompId,
     ports: Vec<Port>,
     peers: Vec<Peer>,
     port_id_counter: u32,
 }
 #[derive(Copy, Clone)]
+#[derive(Copy, Clone, PartialEq, Eq)]
 pub struct LocalPortHandle(PortId);
 #[derive(Copy, Clone)]
 pub struct LocalPeerHandle(CompId);
 impl CompCtx {
     /// Creates a new component context based on a reserved entry in the
     /// component store. This reservation is used such that we already know our
     /// assigned ID.
     pub(crate) fn new(reservation: &CompReserved) -> Self {
         return Self{
             id: reservation.id(),
             ports: Vec::new(),
             peers: Vec::new(),
             port_id_counter: 0,
         }
     }
     /// Creates a new channel that is fully owned by the component associated
     /// with this context.
     pub(crate) fn create_channel(&mut self) -> Channel {
         let putter_id = PortId(self.take_port_id());
         let getter_id = PortId(self.take_port_id());
         self.ports.push(Port{
             self_id: putter_id,
             peer_port_id: getter_id,
             kind: PortKind::Putter,
             state: PortState::Open,
             peer_comp_id: self.id,
             associated_with_peer: false,
         });
         self.ports.push(Port{
             self_id: getter_id,
             peer_port_id: putter_id,
             kind: PortKind::Getter,
             state: PortState::Open,
             peer_comp_id: self.id,
             associated_with_peer: false,
         });
         return Channel{ putter_id, getter_id };
     }
     /// Adds a new port. Make sure to call `add_peer` afterwards.
     pub(crate) fn add_port(&mut self, peer_comp_id: CompId, peer_port_id: PortId, kind: PortKind, state: PortState) -> LocalPortHandle {
         let self_id = PortId(self.take_port_id());
         self.ports.push(Port{
             self_id, peer_comp_id, peer_port_id, kind, state,
             #[cfg(debug_assertions)] associated_with_peer: false,
         });
         return LocalPortHandle(self_id);
     }
     /// Removes a port. Make sure you called `remove_peer` first.
     pub(crate) fn remove_port(&mut self, port_handle: LocalPortHandle) -> Port {
         let port_index = self.must_get_port_index(port_handle);
         let port = self.ports.remove(port_index);
         debug_assert!(!port.associated_with_peer);
         return port;
     }
     /// Adds a new peer. This must be called for every port, no matter the
     /// component the channel is connected to. If a `CompHandle` is supplied,
     /// then it will be used to add the peer. Otherwise it will be retrieved
     /// from the runtime using its ID.
     pub(crate) fn add_peer(&mut self, port_handle: LocalPortHandle, sched_ctx: &SchedulerCtx, peer_comp_id: CompId, handle: Option<&CompHandle>) {
         let self_id = self.id;
         let port = self.get_port_mut(port_handle);
         debug_assert_eq!(port.peer_comp_id, peer_comp_id);
         debug_assert!(!port.associated_with_peer);
         if !Self::requires_peer_reference(port, self_id, false) {
             return;
         }
         dbg_code!(port.associated_with_peer = true);
         match self.get_peer_index_by_id(peer_comp_id) {
             Some(peer_index) => {
                 let peer = &mut self.peers[peer_index];
                 peer.num_associated_ports += 1;
             },
             None => {
                 let handle = match handle {
                     Some(handle) => handle.clone(),
                     None => sched_ctx.runtime.get_component_public(peer_comp_id)
                 };
                 self.peers.push(Peer{
                     id: peer_comp_id,
                     num_associated_ports: 1,
                     handle,
                 });
             }
         }
     }
     /// Removes a peer associated with a port.
     pub(crate) fn remove_peer(&mut self, sched_ctx: &SchedulerCtx, port_handle: LocalPortHandle, peer_id: CompId, also_remove_if_closed: bool) {
         let self_id = self.id;
         let port = self.get_port_mut(port_handle);
         debug_assert_eq!(port.peer_comp_id, peer_id);
         if !Self::requires_peer_reference(port, self_id, also_remove_if_closed) {
             return;
         }
         debug_assert!(port.associated_with_peer);
         dbg_code!(port.associated_with_peer = false);
         let peer_index = self.get_peer_index_by_id(peer_id).unwrap();
         let peer = &mut self.peers[peer_index];
         peer.num_associated_ports -= 1;
         if peer.num_associated_ports == 0 {
             let mut peer = self.peers.remove(peer_index);
             if let Some(key) = peer.handle.decrement_users() {
                 debug_assert_ne!(key.downgrade(), self.id); // should be upheld by the code that shuts down a component
                 sched_ctx.runtime.destroy_component(key);
             }
         }
     }
     pub(crate) fn set_port_state(&mut self, port_handle: LocalPortHandle, new_state: PortState) {
         let port_info = self.get_port_mut(port_handle);
         debug_assert_ne!(port_info.state, PortState::Closed); // because then we do not expect to change the state
         port_info.state = new_state;
     }
     pub(crate) fn get_port_handle(&self, port_id: PortId) -> LocalPortHandle {
         return LocalPortHandle(port_id);
     }
     // should perhaps be revised, used in main inbox
     pub(crate) fn get_port_index(&self, port_handle: LocalPortHandle) -> usize {
         return self.must_get_port_index(port_handle);
     }
     pub(crate) fn get_peer_handle(&self, peer_id: CompId) -> LocalPeerHandle {
         return LocalPeerHandle(peer_id);
     }
     pub(crate) fn get_port(&self, port_handle: LocalPortHandle) -> &Port {
         let index = self.must_get_port_index(port_handle);
         return &self.ports[index];
     }
     pub(crate) fn get_port_mut(&mut self, port_handle: LocalPortHandle) -> &mut Port {
         let index = self.must_get_port_index(port_handle);
         return &mut self.ports[index];
     }
     pub(crate) fn get_port_by_index_mut(&mut self, index: usize) -> &mut Port {
         return &mut self.ports[index];
     }
     pub(crate) fn get_peer(&self, peer_handle: LocalPeerHandle) -> &Peer {
         let index = self.must_get_peer_index(peer_handle);
         return &self.peers[index];
     }
     pub(crate) fn get_peer_mut(&mut self, peer_handle: LocalPeerHandle) -> &mut Peer {
         let index = self.must_get_peer_index(peer_handle);
         return &mut self.peers[index];
     }
     #[inline]
     pub(crate) fn iter_ports(&self) -> impl Iterator<Item=&Port> {
         return self.ports.iter();
     }
     #[inline]
     pub(crate) fn iter_ports_mut(&mut self) -> impl Iterator<Item=&mut Port> {
         return self.ports.iter_mut();
     }
     #[inline]
     pub(crate) fn iter_peers(&self) -> impl Iterator<Item=&Peer> {
         return self.peers.iter();
     }
     #[inline]
     pub(crate) fn num_ports(&self) -> usize {
         return self.ports.len();
     }
     // -------------------------------------------------------------------------
     // Local utilities
     // -------------------------------------------------------------------------
     #[inline]
     fn requires_peer_reference(port: &Port, self_id: CompId, required_if_closed: bool) -> bool {
         return (port.state != PortState::Closed || required_if_closed) && port.peer_comp_id != self_id;
     }
     fn must_get_port_index(&self, handle: LocalPortHandle) -> usize {
         for (index, port) in self.ports.iter().enumerate() {
             if port.self_id == handle.0 {
                 return index;
             }
         }
         unreachable!()
     }
     fn must_get_peer_index(&self, handle: LocalPeerHandle) -> usize {
         for (index, peer) in self.peers.iter().enumerate() {
             if peer.id == handle.0 {
                 return index;
             }
         }
         unreachable!()
     }
     fn get_peer_index_by_id(&self, comp_id: CompId) -> Option<usize> {
         for (index, peer) in self.peers.iter().enumerate() {
             if peer.id == comp_id {
                 return Some(index);
             }
         }
         return None;
     }
     fn take_port_id(&mut self) -> u32 {
         let port_id = self.port_id_counter;
         self.port_id_counter = self.port_id_counter.wrapping_add(1);
         return port_id;
     }
 }
@@ \ No newline at end of file @@

src/runtime2/component/component_pdl.rs

➞

Show inline comments

 use crate::random::Random;
 use crate::protocol::*;
-use crate::protocol::ast::DefinitionId;
+use crate::protocol::ast::ProcedureDefinitionId;
 use crate::protocol::eval::{
     PortId as EvalPortId, Prompt,
     ValueGroup, Value,
     EvalContinuation, EvalResult, EvalError
 };
 use crate::runtime2::scheduler::SchedulerCtx;
 use crate::runtime2::communication::*;
 use super::component_context::*;
 use super::control_layer::*;
 use super::consensus::Consensus;
 pub enum CompScheduling {
     Immediate,
     Requeue,
     Sleep,
     Exit,
+}
 pub enum ExecStmt {
     CreatedChannel((Value, Value)),
     PerformedPut,
     PerformedGet(ValueGroup),
     PerformedSelectWait(u32),
     None,
+}
 impl ExecStmt {
     fn take(&mut self) -> ExecStmt {
         let mut value = ExecStmt::None;
         std::mem::swap(self, &mut value);
         return value;
+    }
     fn is_none(&self) -> bool {
         match self {
             ExecStmt::None => return true,
             _ => return false,
+        }
+    }
+}
 pub struct ExecCtx {
     stmt: ExecStmt,
+}
 impl RunContext for ExecCtx {
     fn performed_put(&mut self, _port: EvalPortId) -> bool {
         match self.stmt.take() {
             ExecStmt::None => return false,
             ExecStmt::PerformedPut => return true,
             _ => unreachable!(),
+        }
+    }
     fn performed_get(&mut self, _port: EvalPortId) -> Option<ValueGroup> {
         match self.stmt.take() {
             ExecStmt::None => return None,
             ExecStmt::PerformedGet(value) => return Some(value),
             _ => unreachable!(),
+        }
+    }
     fn fires(&mut self, _port: EvalPortId) -> Option<Value> {
         todo!("remove fires")
+    }
     fn performed_fork(&mut self) -> Option<bool> {
         todo!("remove fork")
+    }
     fn created_channel(&mut self) -> Option<(Value, Value)> {
         match self.stmt.take() {
             ExecStmt::None => return None,
             ExecStmt::CreatedChannel(ports) => return Some(ports),
             _ => unreachable!(),
+        }
+    }
     fn performed_select_wait(&mut self) -> Option<u32> {
         match self.stmt.take() {
             ExecStmt::None => return None,
             ExecStmt::PerformedSelectWait(selected_case) => Some(selected_case),
             _v => unreachable!(),
+        }
+    }
+}
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub(crate) enum Mode {
     NonSync, // not in sync mode
     Sync, // in sync mode, can interact with other components
     SyncEnd, // awaiting a solution, i.e. encountered the end of the sync block
     BlockedGet,
     BlockedPut,
     BlockedGet, // blocked because we need to receive a message on a particular port
     BlockedPut, // component is blocked because the port is blocked
     BlockedSelect, // waiting on message to complete the select statement
     StartExit, // temporary state: if encountered then we start the shutdown process
     BusyExit, // temporary state: waiting for Acks for all the closed ports
     Exit, // exiting: shutdown process started, now waiting until the reference count drops to 0
+}
 struct SelectCase {
     involved_ports: Vec<LocalPortHandle>,
+}
 // TODO: @Optimize, flatten cases into single array, have index-pointers to next case
 struct SelectState {
     cases: Vec<SelectCase>,
     next_case: u32,
     num_cases: u32,
     random: Random,
     candidates_workspace: Vec<usize>,
+}
 enum SelectDecision {
     None,
     Case(u32), // contains case index, should be passed along to PDL code
+}
 type InboxMain = Vec<Option<DataMessage>>;
 impl SelectState {
     fn new() -> Self {
         return Self{
             cases: Vec::new(),
             next_case: 0,
             num_cases: 0,
             random: Random::new(),
             candidates_workspace: Vec::new(),
+        }
+    }
     fn handle_select_start(&mut self, num_cases: u32) {
         self.cases.clear();
         self.next_case = 0;
         self.num_cases = num_cases;
+    }
     /// Register a port as belonging to a particular case. As for correctness of
     /// PDL code one cannot register the same port twice, this function might
     /// return an error
     fn register_select_case_port(&mut self, comp_ctx: &CompCtx, case_index: u32, _port_index: u32, port_id: PortId) -> Result<(), PortId> {
         // Retrieve case and port handle
         self.ensure_at_case(case_index);
         let cur_case = &mut self.cases[case_index as usize];
         let port_handle = comp_ctx.get_port_handle(port_id);
         debug_assert_eq!(cur_case.involved_ports.len(), _port_index as usize);
         // Make sure port wasn't added before, we disallow having the same port
         // in the same select guard twice.
         if cur_case.involved_ports.contains(&port_handle) {
             return Err(port_id);
+        }
         cur_case.involved_ports.push(port_handle);
         return Ok(());
+    }
     /// Notification that all ports have been registered and we should now wait
     /// until the appropriate messages have come in.
     fn handle_select_waiting_point(&mut self, inbox: &InboxMain, comp_ctx: &CompCtx) -> SelectDecision {
         if self.num_cases != self.next_case {
             // This happens when there are >=1 select cases written at the end
             // of the select block.
             self.ensure_at_case(self.num_cases - 1);
+        }
         return self.has_decision(inbox, comp_ctx);
+    }
     fn handle_updated_inbox(&mut self, inbox: &InboxMain, comp_ctx: &CompCtx) -> SelectDecision {
         return self.has_decision(inbox, comp_ctx);
+    }
     /// Internal helper, pushes empty cases inbetween last case and provided new
     /// case index.
     fn ensure_at_case(&mut self, new_case_index: u32) {
         // Push an empty case for all intermediate cases that were not
         // registered with a port.
         debug_assert!(new_case_index >= self.next_case && new_case_index < self.num_cases);
         for _ in self.next_case..new_case_index + 1 {
             self.cases.push(SelectCase{ involved_ports: Vec::new() });
+        }
         self.next_case = new_case_index + 1;
+    }
     /// Checks if a decision can be reached
     fn has_decision(&mut self, inbox: &InboxMain, comp_ctx: &CompCtx) -> SelectDecision {
         self.candidates_workspace.clear();
         if self.cases.is_empty() {
             // If there are no cases then we can immediately reach a "bogus
             // decision".
             return SelectDecision::Case(0);
+        }
         // Need to check for valid case
         'case_loop: for (case_index, case) in self.cases.iter().enumerate() {
             for port_handle in case.involved_ports.iter().copied() {
                 let port_index = comp_ctx.get_port_index(port_handle);
                 if inbox[port_index].is_none() {
                     // Condition not satisfied
                     continue 'case_loop;
+                }
+            }
             // If here then the case guard is satisfied
             self.candidates_workspace.push(case_index);
+        }
         if self.candidates_workspace.is_empty() {
             return SelectDecision::None;
         } else {
             let candidate_index = self.random.get_u64() as usize % self.candidates_workspace.len();
             return SelectDecision::Case(self.candidates_workspace[candidate_index] as u32);
+        }
+    }
+}
 pub(crate) struct CompPDL {
     pub mode: Mode,
     pub mode_port: PortId, // when blocked on a port
     pub mode_value: ValueGroup, // when blocked on a put
     select: SelectState,
     pub prompt: Prompt,
     pub control: ControlLayer,
     pub consensus: Consensus,
     pub sync_counter: u32,
     pub exec_ctx: ExecCtx,
     // TODO: Temporary field, simulates future plans of having one storage place
     //  reserved per port.
     // Should be same length as the number of ports. Corresponding indices imply
     // message is intended for that port.
-    pub inbox_main: Vec<Option<DataMessage>>,
+    pub inbox_main: InboxMain,
     pub inbox_backup: Vec<DataMessage>,
+}
 impl CompPDL {
     pub(crate) fn new(initial_state: Prompt, num_ports: usize) -> Self {
         let mut inbox_main = Vec::new();
         inbox_main.reserve(num_ports);
         for _ in 0..num_ports {
             inbox_main.push(None);
+        }
         return Self{
             mode: Mode::NonSync,
             mode_port: PortId::new_invalid(),
             mode_value: ValueGroup::default(),
             select: SelectState::new(),
             prompt: initial_state,
             control: ControlLayer::default(),
             consensus: Consensus::new(),
             sync_counter: 0,
             exec_ctx: ExecCtx{
                 stmt: ExecStmt::None,
             },
             inbox_main,
             inbox_backup: Vec::new(),
+        }
+    }
     pub(crate) fn handle_message(&mut self, sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx, mut message: Message) {
         sched_ctx.log(&format!("handling message: {:#?}", message));
         if let Some(new_target) = self.control.should_reroute(&mut message) {
             let mut target = sched_ctx.runtime.get_component_public(new_target);
             target.send_message(sched_ctx, message, false); // not waking up: we schedule once we've received all PortPeerChanged Acks
             let _should_remove = target.decrement_users();
             debug_assert!(_should_remove.is_none());
             return;
+        }
         match message {
             Message::Data(message) => {
                 self.handle_incoming_data_message(sched_ctx, comp_ctx, message);
             },
             Message::Control(message) => {
                 self.handle_incoming_control_message(sched_ctx, comp_ctx, message);
             },
             Message::Sync(message) => {
                 self.handle_incoming_sync_message(sched_ctx, comp_ctx, message);
+            }
+        }
+    }
     // -------------------------------------------------------------------------
     // Running component and handling changes in global component state
     // -------------------------------------------------------------------------
     pub(crate) fn run(&mut self, sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx) -> Result<CompScheduling, EvalError> {
         use EvalContinuation as EC;
         sched_ctx.log(&format!("Running component (mode: {:?})", self.mode));
         // Depending on the mode don't do anything at all, take some special
         // actions, or fall through and run the PDL code.
         match self.mode {
             Mode::NonSync | Mode::Sync => {},
             Mode::NonSync | Mode::Sync | Mode::BlockedSelect => {
                 // continue and run PDL code
             },
             Mode::SyncEnd | Mode::BlockedGet | Mode::BlockedPut => {
                 return Ok(CompScheduling::Sleep);
+            }
             Mode::StartExit => {
                 self.handle_component_exit(sched_ctx, comp_ctx);
                 return Ok(CompScheduling::Immediate);
             },
             Mode::BusyExit => {
                 if self.control.has_acks_remaining() {
                     return Ok(CompScheduling::Sleep);
                 } else {
                     self.mode = Mode::Exit;
                     return Ok(CompScheduling::Exit);
+                }
             },
             Mode::Exit => {
                 return Ok(CompScheduling::Exit);
+            }
+        }
         let run_result = self.execute_prompt(&sched_ctx)?;
         match run_result {
             EC::Stepping => unreachable!(), // execute_prompt runs until this is no longer returned
             EC::BranchInconsistent | EC::NewFork | EC::BlockFires(_) => todo!("remove these"),
             // Results that can be returned in sync mode
             EC::SyncBlockEnd => {
                 debug_assert_eq!(self.mode, Mode::Sync);
                 self.handle_sync_end(sched_ctx, comp_ctx);
                 return Ok(CompScheduling::Immediate);
             },
             EC::BlockGet(port_id) => {
                 debug_assert_eq!(self.mode, Mode::Sync);
                 debug_assert!(self.exec_ctx.stmt.is_none());
                 let port_id = port_id_from_eval(port_id);
                 let port_handle = comp_ctx.get_port_handle(port_id);
                 let port_index = comp_ctx.get_port_index(port_handle);
                 if let Some(message) = &self.inbox_main[port_index] {
                     // Check if we can actually receive the message
                     if self.consensus.try_receive_data_message(sched_ctx, comp_ctx, message) {
                         // Message was received. Make sure any blocked peers and
                         // pending messages are handled.
                         let message = self.inbox_main[port_index].take().unwrap();
                         self.handle_received_data_message(sched_ctx, comp_ctx, port_handle);
                         self.exec_ctx.stmt = ExecStmt::PerformedGet(message.content);
                         return Ok(CompScheduling::Immediate);
                     } else {
                         todo!("handle sync failure due to message deadlock");
                         return Ok(CompScheduling::Sleep);
+                    }
                 } else {
                     // We need to wait
                     self.mode = Mode::BlockedGet;
                     self.mode_port = port_id;
                     return Ok(CompScheduling::Sleep);
+                }
             },
             EC::Put(port_id, value) => {
                 debug_assert_eq!(self.mode, Mode::Sync);
                 sched_ctx.log(&format!("Putting value {:?}", value));
                 let port_id = port_id_from_eval(port_id);
                 let port_handle = comp_ctx.get_port_handle(port_id);
                 let port_info = comp_ctx.get_port(port_handle);
                 if port_info.state.is_blocked() {
                     self.mode = Mode::BlockedPut;
                     self.mode_port = port_id;
                     self.mode_value = value;
                     self.exec_ctx.stmt = ExecStmt::PerformedPut; // prepare for when we become unblocked
                     return Ok(CompScheduling::Sleep);
                 } else {
                     self.send_data_message_and_wake_up(sched_ctx, comp_ctx, port_handle, value);
                     self.exec_ctx.stmt = ExecStmt::PerformedPut;
                     return Ok(CompScheduling::Immediate);
+                }
             },
             EC::SelectStart(num_cases, _num_ports) => {
                 debug_assert_eq!(self.mode, Mode::Sync);
                 self.select.handle_select_start(num_cases);
                 return Ok(CompScheduling::Requeue);
             },
             EC::SelectRegisterPort(case_index, port_index, port_id) => {
                 debug_assert_eq!(self.mode, Mode::Sync);
                 let port_id = port_id_from_eval(port_id);
                 if let Err(_err) = self.select.register_select_case_port(comp_ctx, case_index, port_index, port_id) {
                     todo!("handle registering a port multiple times");
+                }
                 return Ok(CompScheduling::Immediate);
             },
             EC::SelectWait => {
                 debug_assert_eq!(self.mode, Mode::Sync);
                 let select_decision = self.select.handle_select_waiting_point(&self.inbox_main, comp_ctx);
                 if let SelectDecision::Case(case_index) = select_decision {
                     // Reached a conclusion, so we can continue immediately
                     self.exec_ctx.stmt = ExecStmt::PerformedSelectWait(case_index);
                     self.mode = Mode::Sync;
                     return Ok(CompScheduling::Immediate);
                 } else {
                     // No decision yet
                     self.mode = Mode::BlockedSelect;
                     return Ok(CompScheduling::Sleep);
+                }
             },
             // Results that can be returned outside of sync mode
             EC::ComponentTerminated => {
                 self.mode = Mode::StartExit; // next call we'll take care of the exit
                 return Ok(CompScheduling::Immediate);
             },
             EC::SyncBlockStart => {
                 debug_assert_eq!(self.mode, Mode::NonSync);
                 self.handle_sync_start(sched_ctx, comp_ctx);
                 return Ok(CompScheduling::Immediate);
             },
-            EC::NewComponent(definition_id, monomorph_idx, arguments) => {
+            EC::NewComponent(definition_id, type_id, arguments) => {
                 debug_assert_eq!(self.mode, Mode::NonSync);
                 self.create_component_and_transfer_ports(
                     sched_ctx, comp_ctx,
-                    definition_id, monomorph_idx, arguments
+                    definition_id, type_id, arguments
                 );
                 return Ok(CompScheduling::Requeue);
             },
             EC::NewChannel => {
                 debug_assert_eq!(self.mode, Mode::NonSync);
                 debug_assert!(self.exec_ctx.stmt.is_none());
                 let channel = comp_ctx.create_channel();
                 self.exec_ctx.stmt = ExecStmt::CreatedChannel((
                     Value::Output(port_id_to_eval(channel.putter_id)),
                     Value::Input(port_id_to_eval(channel.getter_id))
                 ));
                 self.inbox_main.push(None);
                 self.inbox_main.push(None);
                 return Ok(CompScheduling::Immediate);
+            }
+        }
+    }
     fn execute_prompt(&mut self, sched_ctx: &SchedulerCtx) -> EvalResult {
         let mut step_result = EvalContinuation::Stepping;
         while let EvalContinuation::Stepping = step_result {
             step_result = self.prompt.step(
                 &sched_ctx.runtime.protocol.types, &sched_ctx.runtime.protocol.heap,
                 &sched_ctx.runtime.protocol.modules, &mut self.exec_ctx,
             )?;
+        }
         return Ok(step_result)
+    }
     fn handle_sync_start(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx) {
         sched_ctx.log("Component starting sync mode");
         self.consensus.notify_sync_start(comp_ctx);
         debug_assert_eq!(self.mode, Mode::NonSync);
         self.mode = Mode::Sync;
+    }
     /// Handles end of sync. The conclusion to the sync round might arise
     /// immediately (and be handled immediately), or might come later through
     /// messaging. In any case the component should be scheduled again
     /// immediately
     fn handle_sync_end(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx) {
         sched_ctx.log("Component ending sync mode (now waiting for solution)");
         let decision = self.consensus.notify_sync_end(sched_ctx, comp_ctx);
         self.mode = Mode::SyncEnd;
         self.handle_sync_decision(sched_ctx, comp_ctx, decision);
+    }
     /// Handles decision from the consensus round. This will cause a change in
     /// the internal `Mode`, such that the next call to `run` can take the
     /// appropriate next steps.
-    fn handle_sync_decision(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, decision: SyncRoundDecision) {
+    fn handle_sync_decision(&mut self, sched_ctx: &SchedulerCtx, _comp_ctx: &mut CompCtx, decision: SyncRoundDecision) {
         sched_ctx.log(&format!("Handling sync decision: {:?} (in mode {:?})", decision, self.mode));
         let is_success = match decision {
             SyncRoundDecision::None => {
                 // No decision yet
                 return;
             },
             SyncRoundDecision::Solution => true,
             SyncRoundDecision::Failure => false,
         };
         // If here then we've reached a decision
         debug_assert_eq!(self.mode, Mode::SyncEnd);
         if is_success {
             self.mode = Mode::NonSync;
             self.consensus.notify_sync_decision(decision);
         } else {
             self.mode = Mode::StartExit;
+        }
+    }
     fn handle_component_exit(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx) {
         sched_ctx.log("Component exiting");
         debug_assert_eq!(self.mode, Mode::StartExit);
         self.mode = Mode::BusyExit;
         // Doing this by index, then retrieving the handle is a bit rediculous,
         // but Rust is being Rust with its borrowing rules.
         for port_index in 0..comp_ctx.num_ports() {
             let port = comp_ctx.get_port_by_index_mut(port_index);
             if port.state == PortState::Closed {
                 // Already closed, or in the process of being closed
                 continue;
+            }
             // Mark as closed
             let port_id = port.self_id;
             port.state = PortState::Closed;
             // Notify peer of closing
             let port_handle = comp_ctx.get_port_handle(port_id);
             let (peer, message) = self.control.initiate_port_closing(port_handle, comp_ctx);
             let peer_info = comp_ctx.get_peer(peer);
             peer_info.handle.send_message(sched_ctx, Message::Control(message), true);
+        }
+    }
     // -------------------------------------------------------------------------
     // Handling messages
     // -------------------------------------------------------------------------
     fn send_data_message_and_wake_up(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &CompCtx, source_port_handle: LocalPortHandle, value: ValueGroup) {
         let port_info = comp_ctx.get_port(source_port_handle);
         let peer_handle = comp_ctx.get_peer_handle(port_info.peer_comp_id);
         let peer_info = comp_ctx.get_peer(peer_handle);
         let annotated_message = self.consensus.annotate_data_message(comp_ctx, port_info, value);
         peer_info.handle.send_message(sched_ctx, Message::Data(annotated_message), true);
+    }
     /// Handles a message that came in through the public inbox. This function
     /// will handle putting it in the correct place, and potentially blocking
     /// the port in case too many messages are being received.
     fn handle_incoming_data_message(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, message: DataMessage) {
         // Check if we can insert it directly into the storage associated with
         // the port
         let target_port_id = message.data_header.target_port;
         let port_handle = comp_ctx.get_port_handle(target_port_id);
         let port_index = comp_ctx.get_port_index(port_handle);
         if self.inbox_main[port_index].is_none() {
             self.inbox_main[port_index] = Some(message);
             // After direct insertion, check if this component's execution is
             // blocked on receiving a message on that port
             debug_assert!(!comp_ctx.get_port(port_handle).state.is_blocked()); // because we could insert directly
             if self.mode == Mode::BlockedGet && self.mode_port == target_port_id {
                 // We were indeed blocked
                 self.mode = Mode::Sync;
                 self.mode_port = PortId::new_invalid();
             } else if self.mode == Mode::BlockedSelect {
                 let select_decision = self.select.handle_updated_inbox(&self.inbox_main, comp_ctx);
                 if let SelectDecision::Case(case_index) = select_decision {
                     self.exec_ctx.stmt = ExecStmt::PerformedSelectWait(case_index);
                     self.mode = Mode::Sync;
+                }
+            }
             return;
+        }
         // The direct inbox is full, so the port will become (or was already) blocked
         let port_info = comp_ctx.get_port_mut(port_handle);
         debug_assert!(port_info.state == PortState::Open || port_info.state.is_blocked());
         if port_info.state == PortState::Open {
             comp_ctx.set_port_state(port_handle, PortState::BlockedDueToFullBuffers);
             let (peer_handle, message) =
                 self.control.initiate_port_blocking(comp_ctx, port_handle);
             let peer = comp_ctx.get_peer(peer_handle);
             peer.handle.send_message(sched_ctx, Message::Control(message), true);
+        }
         // But we still need to remember the message, so:
         self.inbox_backup.push(message);
+    }
     /// Handles when a message has been handed off from the inbox to the PDL
     /// code. We check to see if there are more messages waiting and, if not,
     /// then we handle the case where the port might have been blocked
     /// previously.
     fn handle_received_data_message(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, port_handle: LocalPortHandle) {
         let port_index = comp_ctx.get_port_index(port_handle);
         debug_assert!(self.inbox_main[port_index].is_none()); // this function should be called after the message is taken out
         // Check for any more messages
         let port_info = comp_ctx.get_port(port_handle);
         for message_index in 0..self.inbox_backup.len() {
             let message = &self.inbox_backup[message_index];
             if message.data_header.target_port == port_info.self_id {
                 // One more message for this port
                 let message = self.inbox_backup.remove(message_index);
                 debug_assert!(comp_ctx.get_port(port_handle).state.is_blocked()); // since we had >1 message on the port
                 self.inbox_main[port_index] = Some(message);
                 return;
+            }
+        }
         // Did not have any more messages. So if we were blocked, then we need
         // to send the "unblock" message.
         if port_info.state == PortState::BlockedDueToFullBuffers {
             comp_ctx.set_port_state(port_handle, PortState::Open);
             let (peer_handle, message) = self.control.cancel_port_blocking(comp_ctx, port_handle);
             let peer_info = comp_ctx.get_peer(peer_handle);
             peer_info.handle.send_message(sched_ctx, Message::Control(message), true);
+        }
+    }
     fn handle_incoming_control_message(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, message: ControlMessage) {
         // Little local utility to send an Ack
         fn send_control_ack_message(sched_ctx: &SchedulerCtx, comp_ctx: &CompCtx, causer_id: ControlId, peer_handle: LocalPeerHandle) {
             let peer_info = comp_ctx.get_peer(peer_handle);
             peer_info.handle.send_message(sched_ctx, Message::Control(ControlMessage{
                 id: causer_id,
                 sender_comp_id: comp_ctx.id,
                 target_port_id: None,
                 content: ControlMessageContent::Ack,
             }), true);
+        }
         // Handle the content of the control message, and optionally Ack it
         match message.content {
             ControlMessageContent::Ack => {
                 self.handle_ack(sched_ctx, comp_ctx, message.id);
             },
             ControlMessageContent::BlockPort(port_id) => {
                 // On of our messages was accepted, but the port should be
                 // blocked.
                 let port_handle = comp_ctx.get_port_handle(port_id);
                 let port_info = comp_ctx.get_port(port_handle);
                 debug_assert_eq!(port_info.kind, PortKind::Putter);
                 if port_info.state == PortState::Open {
                     // only when open: we don't do this when closed, and we we don't do this if we're blocked due to peer changes
                     comp_ctx.set_port_state(port_handle, PortState::BlockedDueToFullBuffers);
+                }
             },
             ControlMessageContent::ClosePort(port_id) => {
                 // Request to close the port. We immediately comply and remove
                 // the component handle as well
                 let port_handle = comp_ctx.get_port_handle(port_id);
                 let peer_comp_id = comp_ctx.get_port(port_handle).peer_comp_id;
                 let peer_handle = comp_ctx.get_peer_handle(peer_comp_id);
                 // One exception to sending an `Ack` is if we just closed the
                 // port ourselves, meaning that the `ClosePort` messages got
                 // sent to one another.
                 if let Some(control_id) = self.control.has_close_port_entry(port_handle, comp_ctx) {
                     self.handle_ack(sched_ctx, comp_ctx, control_id);
                 } else {
                     send_control_ack_message(sched_ctx, comp_ctx, message.id, peer_handle);
                     comp_ctx.remove_peer(sched_ctx, port_handle, peer_comp_id, false); // do not remove if closed
                     comp_ctx.set_port_state(port_handle, PortState::Closed); // now set to closed
+                }
             },
             ControlMessageContent::UnblockPort(port_id) => {
                 // We were previously blocked (or already closed)
                 let port_handle = comp_ctx.get_port_handle(port_id);
                 let port_info = comp_ctx.get_port(port_handle);
                 debug_assert_eq!(port_info.kind, PortKind::Putter);
                 if port_info.state == PortState::BlockedDueToFullBuffers {
                     self.handle_unblock_port_instruction(sched_ctx, comp_ctx, port_handle);
+                }
             },
             ControlMessageContent::PortPeerChangedBlock(port_id) => {
                 // The peer of our port has just changed. So we are asked to
                 // temporarily block the port (while our original recipient is
                 // potentially rerouting some of the in-flight messages) and
                 // Ack. Then we wait for the `unblock` call.
                 debug_assert_eq!(message.target_port_id, Some(port_id));
                 let port_handle = comp_ctx.get_port_handle(port_id);
                 comp_ctx.set_port_state(port_handle, PortState::BlockedDueToPeerChange);
                 let port_info = comp_ctx.get_port(port_handle);
                 let peer_handle = comp_ctx.get_peer_handle(port_info.peer_comp_id);
                 send_control_ack_message(sched_ctx, comp_ctx, message.id, peer_handle);
             },
             ControlMessageContent::PortPeerChangedUnblock(new_port_id, new_comp_id) => {
                 let port_handle = comp_ctx.get_port_handle(message.target_port_id.unwrap());
                 let port_info = comp_ctx.get_port(port_handle);
                 debug_assert!(port_info.state == PortState::BlockedDueToPeerChange);
                 let old_peer_id = port_info.peer_comp_id;
                 comp_ctx.remove_peer(sched_ctx, port_handle, old_peer_id, false);
                 let port_info = comp_ctx.get_port_mut(port_handle);
                 port_info.peer_comp_id = new_comp_id;
                 port_info.peer_port_id = new_port_id;
                 comp_ctx.add_peer(port_handle, sched_ctx, new_comp_id, None);
                 self.handle_unblock_port_instruction(sched_ctx, comp_ctx, port_handle);
+            }
+        }
+    }
     fn handle_incoming_sync_message(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, message: SyncMessage) {
         let decision = self.consensus.receive_sync_message(sched_ctx, comp_ctx, message);
         self.handle_sync_decision(sched_ctx, comp_ctx, decision);
+    }
     /// Little helper that notifies the control layer of an `Ack`, and takes the
     /// appropriate subsequent action
     fn handle_ack(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, control_id: ControlId) {
         let mut to_ack = control_id;
         loop {
             let (action, new_to_ack) = self.control.handle_ack(to_ack, sched_ctx, comp_ctx);
             match action {
                 AckAction::SendMessage(target_comp, message) => {
                     // FIX @NoDirectHandle
                     let mut handle = sched_ctx.runtime.get_component_public(target_comp);
                     handle.send_message(sched_ctx, Message::Control(message), true);
                     let _should_remove = handle.decrement_users();
                     debug_assert!(_should_remove.is_none());
                 },
                 AckAction::ScheduleComponent(to_schedule) => {
                     // FIX @NoDirectHandle
                     let mut handle = sched_ctx.runtime.get_component_public(to_schedule);
                     // Note that the component is intentionally not
                     // sleeping, so we just wake it up
                     debug_assert!(!handle.sleeping.load(std::sync::atomic::Ordering::Acquire));
                     let key = unsafe{ to_schedule.upgrade() };
                     sched_ctx.runtime.enqueue_work(key);
                     let _should_remove = handle.decrement_users();
                     debug_assert!(_should_remove.is_none());
                 },
                 AckAction::None => {}
+            }
             match new_to_ack {
                 Some(new_to_ack) => to_ack = new_to_ack,
                 None => break,
+            }
+        }
+    }
     // -------------------------------------------------------------------------
     // Handling ports
     // -------------------------------------------------------------------------
     /// Unblocks a port, potentially continuing execution of the component, in
     /// response to a message that told us to unblock a previously blocked
     fn handle_unblock_port_instruction(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, port_handle: LocalPortHandle) {
         let port_info = comp_ctx.get_port_mut(port_handle);
         let port_id = port_info.self_id;
         debug_assert!(port_info.state.is_blocked());
         port_info.state = PortState::Open;
         if self.mode == Mode::BlockedPut && port_id == self.mode_port {
             // We were blocked on the port that just became unblocked, so
             // send the message.
             debug_assert_eq!(port_info.kind, PortKind::Putter);
             let mut replacement = ValueGroup::default();
             std::mem::swap(&mut replacement, &mut self.mode_value);
             self.send_data_message_and_wake_up(sched_ctx, comp_ctx, port_handle, replacement);
             self.mode = Mode::Sync;
             self.mode_port = PortId::new_invalid();
+        }
+    }
     fn create_component_and_transfer_ports(
         &mut self,
         sched_ctx: &SchedulerCtx, creator_ctx: &mut CompCtx,
-        definition_id: DefinitionId, monomorph_index: i32, mut arguments: ValueGroup
+        definition_id: ProcedureDefinitionId, type_id: TypeId, mut arguments: ValueGroup
     ) {
         struct PortPair{
             creator_handle: LocalPortHandle,
             creator_id: PortId,
             created_handle: LocalPortHandle,
             created_id: PortId,
+        }
         let mut port_id_pairs = Vec::new();
         let reservation = sched_ctx.runtime.start_create_pdl_component();
         let mut created_ctx = CompCtx::new(&reservation);
         // Take all the ports ID that are in the `args` (and currently belong to
         // the creator component) and translate them into new IDs that are
         // associated with the component we're about to create
         let mut arg_iter = ValueGroupIter::new(&mut arguments);
         while let Some(port_reference) = arg_iter.next() {
             // Create port entry for new component
             let creator_port_id = port_reference.id;
             let creator_port_handle = creator_ctx.get_port_handle(creator_port_id);
             let creator_port = creator_ctx.get_port(creator_port_handle);
             let created_port_handle = created_ctx.add_port(
                 creator_port.peer_comp_id, creator_port.peer_port_id,
                 creator_port.kind, creator_port.state
             );
             let created_port = created_ctx.get_port(created_port_handle);
             let created_port_id = created_port.self_id;
             port_id_pairs.push(PortPair{
                 creator_handle: creator_port_handle,
                 creator_id: creator_port_id,
                 created_handle: created_port_handle,
                 created_id: created_port_id,
             });
             // Modify value in arguments (bit dirty, but double vec in ValueGroup causes lifetime issues)
             let arg_value = if let Some(heap_pos) = port_reference.heap_pos {
                 &mut arg_iter.group.regions[heap_pos][port_reference.index]
             } else {
                 &mut arg_iter.group.values[port_reference.index]
             };
             match arg_value {
                 Value::Input(id) => *id = port_id_to_eval(created_port_id),
                 Value::Output(id) => *id = port_id_to_eval(created_port_id),
                 _ => unreachable!(),
+            }
+        }
         // For each transferred port pair set their peer components to the
         // correct values. This will only change the values for the ports of
         // the new component.
         let mut created_component_has_remote_peers = false;
         for pair in port_id_pairs.iter() {
             let creator_port_info = creator_ctx.get_port(pair.creator_handle);
             let created_port_info = created_ctx.get_port_mut(pair.created_handle);
             if created_port_info.peer_comp_id == creator_ctx.id {
                 // Port peer is owned by the creator as well
                 let created_peer_port_index = port_id_pairs
                     .iter()
                     .position(|v| v.creator_id == creator_port_info.peer_port_id);
                 match created_peer_port_index {
                     Some(created_peer_port_index) => {
                         // Peer port moved to the new component as well. So
                         // adjust IDs appropriately.
                         let peer_pair = &port_id_pairs[created_peer_port_index];
                         created_port_info.peer_port_id = peer_pair.created_id;
                         created_port_info.peer_comp_id = reservation.id();
                         todo!("either add 'self peer', or remove that idea from Ctx altogether")
                     },
                     None => {
                         // Peer port remains with creator component.
                         created_port_info.peer_comp_id = creator_ctx.id;
                         created_ctx.add_peer(pair.created_handle, sched_ctx, creator_ctx.id, None);
+                    }
+                }
             } else {
                 // Peer is a different component. We'll deal with sending the
                 // appropriate messages later
                 let peer_handle = creator_ctx.get_peer_handle(created_port_info.peer_comp_id);
                 let peer_info = creator_ctx.get_peer(peer_handle);
                 created_ctx.add_peer(pair.created_handle, sched_ctx, peer_info.id, Some(&peer_info.handle));
                 created_component_has_remote_peers = true;
+            }
+        }
         // We'll now actually turn our reservation for a new component into an
         // actual component. Note that we initialize it as "not sleeping" as
         // its initial scheduling might be performed based on `Ack`s in response
         // to message exchanges between remote peers.
         let prompt = Prompt::new(
             &sched_ctx.runtime.protocol.types, &sched_ctx.runtime.protocol.heap,
-            definition_id, monomorph_index, arguments,
+            definition_id, type_id, arguments,
         );
         let component = CompPDL::new(prompt, port_id_pairs.len());
         let (created_key, component) = sched_ctx.runtime.finish_create_pdl_component(
             reservation, component, created_ctx, false,
         );
         let created_ctx = &component.ctx;
         // Now modify the creator's ports: remove every transferred port and
         // potentially remove the peer component. Here is also where we will
         // transfer messages in the main inbox.
         for pair in port_id_pairs.iter() {
             // Remove peer if appropriate
             let creator_port_info = creator_ctx.get_port(pair.creator_handle);
             let creator_port_index = creator_ctx.get_port_index(pair.creator_handle);
             let creator_peer_comp_id = creator_port_info.peer_comp_id;
             creator_ctx.remove_peer(sched_ctx, pair.creator_handle, creator_peer_comp_id, false);
             creator_ctx.remove_port(pair.creator_handle);
             // Transfer any messages
             let created_port_index = created_ctx.get_port_index(pair.created_handle);
             let created_port_info = created_ctx.get_port(pair.created_handle);
             debug_assert!(component.code.inbox_main[created_port_index].is_none());
             if let Some(mut message) = self.inbox_main.remove(creator_port_index) {
                 message.data_header.target_port = pair.created_id;
                 component.code.inbox_main[created_port_index] = Some(message);
+            }
             let mut message_index = 0;
             while message_index < self.inbox_backup.len() {
                 let message = &self.inbox_backup[message_index];
                 if message.data_header.target_port == pair.creator_id {
                     // transfer message
                     let mut message = self.inbox_backup.remove(message_index);
                     message.data_header.target_port = pair.created_id;
                     component.code.inbox_backup.push(message);
                 } else {
                     message_index += 1;
+                }
+            }
             // Handle potential channel between creator and created component
             if created_port_info.peer_comp_id == creator_ctx.id {
                 let peer_port_handle = creator_ctx.get_port_handle(created_port_info.peer_port_id);
                 let peer_port_info = creator_ctx.get_port_mut(peer_port_handle);
                 peer_port_info.peer_comp_id = created_ctx.id;
                 peer_port_info.peer_port_id = created_port_info.self_id;
                 creator_ctx.add_peer(peer_port_handle, sched_ctx, created_ctx.id, None);
+            }
+        }
         // By now all ports have been transferred. We'll now do any of the setup
         // for rerouting/messaging
         if created_component_has_remote_peers {
             let schedule_entry_id = self.control.add_schedule_entry(created_ctx.id);
             for pair in port_id_pairs.iter() {
                 let port_info = created_ctx.get_port(pair.created_handle);
                 if port_info.peer_comp_id != creator_ctx.id && port_info.peer_comp_id != created_ctx.id {
                     let message = self.control.add_reroute_entry(
                         creator_ctx.id, port_info.peer_port_id, port_info.peer_comp_id,
                         pair.creator_id, pair.created_id, created_ctx.id,
                         schedule_entry_id
                     );
                     let peer_handle = created_ctx.get_peer_handle(port_info.peer_comp_id);
                     let peer_info = created_ctx.get_peer(peer_handle);
                     peer_info.handle.send_message(sched_ctx, message, true);
+                }
+            }
         } else {
             // Peer can be scheduled immediately
             sched_ctx.runtime.enqueue_work(created_key);
+        }
+    }
+}
 #[inline]
 fn port_id_from_eval(port_id: EvalPortId) -> PortId {
     return PortId(port_id.id);
+}
 #[inline]
 fn port_id_to_eval(port_id: PortId) -> EvalPortId {
     return EvalPortId{ id: port_id.0 };
+}
 /// Recursively goes through the value group, attempting to find ports.
 /// Duplicates will only be added once.
 pub(crate) fn find_ports_in_value_group(value_group: &ValueGroup, ports: &mut Vec<PortId>) {
     // Helper to check a value for a port and recurse if needed.
     fn find_port_in_value(group: &ValueGroup, value: &Value, ports: &mut Vec<PortId>) {
         match value {
             Value::Input(port_id) | Value::Output(port_id) => {
                 // This is an actual port
                 let cur_port = PortId(port_id.id);
                 for prev_port in ports.iter() {
                     if *prev_port == cur_port {
                         // Already added
                         return;
+                    }
+                }
                 ports.push(cur_port);
             },
             Value::Array(heap_pos) |
             Value::Message(heap_pos) |
             Value::String(heap_pos) |
             Value::Struct(heap_pos) |
             Value::Union(_, heap_pos) => {
                 // Reference to some dynamic thing which might contain ports,
                 // so recurse
                 let heap_region = &group.regions[*heap_pos as usize];
                 for embedded_value in heap_region {
                     find_port_in_value(group, embedded_value, ports);
+                }
             },
             _ => {}, // values we don't care about
+        }
+    }
     // Clear the ports, then scan all the available values
     ports.clear();
     for value in &value_group.values {
         find_port_in_value(value_group, value, ports);
+    }
+}
 struct ValueGroupIter<'a> {
     group: &'a mut ValueGroup,
     heap_stack: Vec<(usize, usize)>,
     index: usize,
+}
 impl<'a> ValueGroupIter<'a> {
     fn new(group: &'a mut ValueGroup) -> Self {
         return Self{ group, heap_stack: Vec::new(), index: 0 }
+    }
+}
 struct ValueGroupPortRef {
     id: PortId,
     heap_pos: Option<usize>, // otherwise: on stack
     index: usize,
+}
 impl<'a> Iterator for ValueGroupIter<'a> {
     type Item = ValueGroupPortRef;
     fn next(&mut self) -> Option<Self::Item> {
         // Enter loop that keeps iterating until a port is found
         loop {
             if let Some(pos) = self.heap_stack.last() {
                 let (heap_pos, region_index) = *pos;
                 if region_index >= self.group.regions[heap_pos].len() {
                     self.heap_stack.pop();
                     continue;
+                }
                 let value = &self.group.regions[heap_pos][region_index];
                 self.heap_stack.last_mut().unwrap().1 += 1;
                 match value {
                     Value::Input(id) | Value::Output(id) => {
                         let id = PortId(id.id);
                         return Some(ValueGroupPortRef{
                             id,
                             heap_pos: Some(heap_pos),
                             index: region_index,
                         });
                     },
                     _ => {},
+                }
                 if let Some(heap_pos) = value.get_heap_pos() {
                     self.heap_stack.push((heap_pos as usize, 0));
+                }
             } else {
                 if self.index >= self.group.values.len() {
                     return None;
+                }
                 let value = &mut self.group.values[self.index];
                 self.index += 1;
                 match value {
                     Value::Input(id) | Value::Output(id) => {
                         let id = PortId(id.id);
                         return Some(ValueGroupPortRef{
                             id,
                             heap_pos: None,
                             index: self.index - 1
                         });
                     },
                     _ => {},
+                }
                 // Not a port, check if we need to enter a heap region
                 if let Some(heap_pos) = value.get_heap_pos() {
                     self.heap_stack.push((heap_pos as usize, 0));
                 } // else: just consider the next value
+            }
+        }
+    }
+}
@@ \ No newline at end of file @@

src/runtime2/component/consensus.rs

➞

Show inline comments

 use crate::protocol::eval::ValueGroup;
 use crate::runtime2::scheduler::*;
 use crate::runtime2::runtime::*;
 use crate::runtime2::communication::*;
 use super::component_context::*;
 pub struct PortAnnotation {
     self_comp_id: CompId,
     self_port_id: PortId,
     peer_comp_id: CompId, // only valid for getter ports
     peer_port_id: PortId, // only valid for getter ports
     mapping: Option<u32>,
+}
 impl PortAnnotation {
     fn new(comp_id: CompId, port_id: PortId) -> Self {
         return Self{
             self_comp_id: comp_id,
             self_port_id: port_id,
             peer_comp_id: CompId::new_invalid(),
             peer_port_id: PortId::new_invalid(),
             mapping: None
+        }
+    }
+}
 #[derive(Debug, Eq, PartialEq)]
 enum Mode {
     NonSync,
     SyncBusy,
     SyncAwaitingSolution,
     SelectBusy,
     SelectWait,
+}
 struct SolutionCombiner {
     solution: SyncPartialSolution,
     matched_channels: usize,
+}
 impl SolutionCombiner {
     fn new() -> Self {
         return Self {
             solution: SyncPartialSolution::default(),
             matched_channels: 0,
+        }
+    }
     #[inline]
     fn has_contributions(&self) -> bool {
         return !self.solution.channel_mapping.is_empty();
+    }
     /// Returns a decision for the current round. If there is no decision (yet)
     /// then `RoundDecision::None` is returned.
     fn get_decision(&self) -> SyncRoundDecision {
         if self.matched_channels == self.solution.channel_mapping.len() {
             debug_assert_ne!(self.solution.decision, SyncRoundDecision::None);
             return self.solution.decision;
+        }
         return SyncRoundDecision::None; // even in case of failure: wait for everyone.
+    }
     fn combine_with_partial_solution(&mut self, partial: SyncPartialSolution) {
         debug_assert_ne!(self.solution.decision, SyncRoundDecision::Solution);
         debug_assert_ne!(partial.decision, SyncRoundDecision::Solution);
         if partial.decision == SyncRoundDecision::Failure {
             self.solution.decision = SyncRoundDecision::Failure;
+        }
         for entry in partial.channel_mapping {
             let channel_index = if entry.getter.is_some() && entry.putter.is_some() {
                 let channel_index = self.solution.channel_mapping.len();
                 self.solution.channel_mapping.push(entry);
                 self.matched_channels += 1;
                 channel_index
             } else if let Some(putter) = entry.putter {
                 self.combine_with_putter_port(putter)
             } else if let Some(getter) = entry.getter {
                 self.combine_with_getter_port(getter)
             } else {
                 unreachable!(); // both putter and getter are None
             };
             let channel = &self.solution.channel_mapping[channel_index];
             if let Some(consistent) = Self::channel_is_consistent(channel) {
                 if !consistent {
                     self.solution.decision = SyncRoundDecision::Failure;
+                }
                 self.matched_channels += 1;
+            }
+        }
         self.update_solution();
+    }
     /// Combines the currently stored global solution (if any) with the newly
     /// provided local solution. Make sure to check the `has_decision` return
     /// value afterwards.
-    fn combine_with_local_solution(&mut self, comp_id: CompId, solution: SyncLocalSolution) {
+    fn combine_with_local_solution(&mut self, _comp_id: CompId, solution: SyncLocalSolution) {
         debug_assert_ne!(self.solution.decision, SyncRoundDecision::Solution);
         // Combine partial solution with the local solution entries
         for entry in solution {
             // Match the current entry up with its peer endpoint, or add a new
             // entry.
             let channel_index = match entry {
                 SyncLocalSolutionEntry::Putter(putter) => {
                     self.combine_with_putter_port(putter)
                 },
                 SyncLocalSolutionEntry::Getter(getter) => {
                     self.combine_with_getter_port(getter)
+                }
             };
             // Check if channel is now consistent
             let channel = &self.solution.channel_mapping[channel_index];
             if let Some(consistent) = Self::channel_is_consistent(channel) {
                 if !consistent {
                     self.solution.decision = SyncRoundDecision::Failure;
+                }
                 self.matched_channels += 1;
+            }
+        }
         self.update_solution();
+    }
     /// Takes whatever partial solution is present in the solution combiner and
     /// returns it. The solution combiner's solution will end up being empty.
     /// This is used when a new leader is found and we need to pass along our
     /// partial results.
     fn take_partial_solution(&mut self) -> SyncPartialSolution {
         let mut partial_solution = SyncPartialSolution::default();
         std::mem::swap(&mut partial_solution, &mut self.solution);
         self.clear();
         return partial_solution;
+    }
     fn clear(&mut self) {
         self.solution.channel_mapping.clear();
         self.solution.decision = SyncRoundDecision::None;
         self.matched_channels = 0;
+    }
     // --- Small utilities for combining solutions
     fn combine_with_putter_port(&mut self, putter: SyncSolutionPutterPort) -> usize {
         let channel_index = self.get_channel_index_for_putter(putter.self_comp_id, putter.self_port_id);
         if let Some(channel_index) = channel_index {
             let channel = &mut self.solution.channel_mapping[channel_index];
             debug_assert!(channel.putter.is_none());
             channel.putter = Some(putter);
             return channel_index;
         } else {
             let channel_index = self.solution.channel_mapping.len();
             self.solution.channel_mapping.push(SyncSolutionChannel{
                 putter: Some(putter),
                 getter: None,
             });
             return channel_index;
+        }
+    }
     fn combine_with_getter_port(&mut self, getter: SyncSolutionGetterPort) -> usize {
         let channel_index = self.get_channel_index_for_getter(getter.peer_comp_id, getter.peer_port_id);
         if let Some(channel_index) = channel_index {
             let channel = &mut self.solution.channel_mapping[channel_index];
             debug_assert!(channel.getter.is_none());
             channel.getter = Some(getter);
             return channel_index;
         } else {
             let channel_index = self.solution.channel_mapping.len();
             self.solution.channel_mapping.push(SyncSolutionChannel{
                 putter: None,
                 getter: Some(getter)
             });
             return channel_index;
+        }
+    }
     /// Retrieve index of the channel containing a getter port that has received
     /// from the specified putter port.
     fn get_channel_index_for_putter(&self, putter_comp_id: CompId, putter_port_id: PortId) -> Option<usize> {
         for (channel_index, channel) in self.solution.channel_mapping.iter().enumerate() {
             if let Some(getter) = &channel.getter {
                 if getter.peer_comp_id == putter_comp_id && getter.peer_port_id == putter_port_id {
                     return Some(channel_index);
+                }
+            }
+        }
         return None;
+    }
     /// Retrieve index of the channel for a getter port. To find this channel
     /// the **peer** component/port IDs of the getter port are used.
     fn get_channel_index_for_getter(&self, peer_comp_id: CompId, peer_port_id: PortId) -> Option<usize> {
         for (channel_index, channel) in self.solution.channel_mapping.iter().enumerate() {
             if let Some(putter) = &channel.putter {
                 if putter.self_comp_id == peer_comp_id && putter.self_port_id == peer_port_id {
                     return Some(channel_index);
+                }
+            }
+        }
         return None;
+    }
     fn channel_is_consistent(channel: &SyncSolutionChannel) -> Option<bool> {
         if channel.putter.is_none() || channel.getter.is_none() {
             return None;
+        }
         let putter = channel.putter.as_ref().unwrap();
         let getter = channel.getter.as_ref().unwrap();
         return Some(putter.mapping == getter.mapping);
+    }
     /// Determines the global solution if all components have contributed their
     /// local solutions.
     fn update_solution(&mut self) {
         if self.matched_channels == self.solution.channel_mapping.len() {
             if self.solution.decision != SyncRoundDecision::Failure {
                 self.solution.decision = SyncRoundDecision::Solution;
+            }
+        }
+    }
+}
 /// Tracking consensus state
 pub struct Consensus {
     // General state of consensus manager
     mapping_counter: u32,
     mode: Mode,
     // State associated with sync round
     round_index: u32,
     highest_id: CompId,
     ports: Vec<PortAnnotation>,
     // State associated with arriving at a solution and being a (temporary)
     // leader in the consensus round
     solution: SolutionCombiner,
+}
 impl Consensus {
     pub(crate) fn new() -> Self {
         return Self{
             round_index: 0,
             highest_id: CompId::new_invalid(),
             ports: Vec::new(),
             mapping_counter: 0,
             mode: Mode::NonSync,
             solution: SolutionCombiner::new(),
+        }
+    }
     // -------------------------------------------------------------------------
     // Managing sync state
     // -------------------------------------------------------------------------
     /// Notifies the consensus management that the PDL code has reached the
     /// start of a sync block.
     pub(crate) fn notify_sync_start(&mut self, comp_ctx: &CompCtx) {
         debug_assert_eq!(self.mode, Mode::NonSync);
         self.highest_id = comp_ctx.id;
         self.mapping_counter = 0;
         self.mode = Mode::SyncBusy;
         self.make_ports_consistent_with_ctx(comp_ctx);
+    }
     /// Notifies the consensus management that the PDL code has reached the end
     /// of a sync block. A local solution will be submitted, after which we wait
     /// until the participants in the round (hopefully) reach a conclusion.
     pub(crate) fn notify_sync_end(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &CompCtx) -> SyncRoundDecision {
         debug_assert_eq!(self.mode, Mode::SyncBusy);
         self.mode = Mode::SyncAwaitingSolution;
         // Submit our port mapping as a solution
         let mut local_solution = Vec::with_capacity(self.ports.len());
         for port in &self.ports {
             if let Some(mapping) = port.mapping {
                 let port_handle = comp_ctx.get_port_handle(port.self_port_id);
                 let port_info = comp_ctx.get_port(port_handle);
                 let new_entry = match port_info.kind {
                     PortKind::Putter => SyncLocalSolutionEntry::Putter(SyncSolutionPutterPort{
                         self_comp_id: comp_ctx.id,
                         self_port_id: port_info.self_id,
                         mapping
                     }),
                     PortKind::Getter => SyncLocalSolutionEntry::Getter(SyncSolutionGetterPort{
                         self_comp_id: comp_ctx.id,
                         self_port_id: port_info.self_id,
                         peer_comp_id: port.peer_comp_id,
                         peer_port_id: port.peer_port_id,
                         mapping
                     })
                 };
                 local_solution.push(new_entry);
+            }
+        }
         let decision = self.handle_local_solution(sched_ctx, comp_ctx, comp_ctx.id, local_solution);
         return decision;
+    }
     /// Notifies that a decision has been reached. Note that the caller should
     /// still take the appropriate actions based on the decision it is supplying
     /// to the consensus layer.
     pub(crate) fn notify_sync_decision(&mut self, _decision: SyncRoundDecision) {
         // Reset everything for the next round
         debug_assert_eq!(self.mode, Mode::SyncAwaitingSolution);
         self.mode = Mode::NonSync;
         self.round_index = self.round_index.wrapping_add(1);
         for port in self.ports.iter_mut() {
             port.mapping = None;
+        }
         self.solution.clear();
+    }
     fn make_ports_consistent_with_ctx(&mut self, comp_ctx: &CompCtx) {
         let mut needs_setting_ports = false;
         if comp_ctx.num_ports() != self.ports.len() {
             needs_setting_ports = true;
         } else {
             for (idx, port) in comp_ctx.iter_ports().enumerate() {
                 let comp_port_id = port.self_id;
                 let cons_port_id = self.ports[idx].self_port_id;
                 if comp_port_id != cons_port_id {
                     needs_setting_ports = true;
                     break;
+                }
+            }
+        }
         if needs_setting_ports {
             self.ports.clear();
             self.ports.reserve(comp_ctx.num_ports());
             for port in comp_ctx.iter_ports() {
                 self.ports.push(PortAnnotation::new(comp_ctx.id, port.self_id))
+            }
+        }
+    }
     // -------------------------------------------------------------------------
     // Handling inbound and outbound messages
     // -------------------------------------------------------------------------
     pub(crate) fn annotate_data_message(&mut self, comp_ctx: &CompCtx, port_info: &Port, content: ValueGroup) -> DataMessage {
         debug_assert_eq!(self.mode, Mode::SyncBusy); // can only send between sync start and sync end
         debug_assert!(self.ports.iter().any(|v| v.self_port_id == port_info.self_id));
         let data_header = self.create_data_header_and_update_mapping(port_info);
         let sync_header = self.create_sync_header(comp_ctx);
         return DataMessage{ data_header, sync_header, content };
+    }
     /// Checks if the data message can be received (due to port annotations), if
     /// it can then `true` is returned and the caller is responsible for handing
     /// the message of to the PDL code. Otherwise the message cannot be
     /// received.
     pub(crate) fn try_receive_data_message(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, message: &DataMessage) -> bool {
         debug_assert_eq!(self.mode, Mode::SyncBusy);
         debug_assert!(self.ports.iter().any(|v| v.self_port_id == message.data_header.target_port));
         // Make sure the expected mapping matches the currently stored mapping
         for (expected_id, expected_annotation) in &message.data_header.expected_mapping {
             let got_annotation = self.get_annotation(*expected_id);
             if got_annotation != *expected_annotation {
                 return false;
+            }
+        }
         // Expected mapping matches current mapping, so we will receive the message
         self.set_annotation(message.sync_header.sending_id, &message.data_header);
         // Handle the sync header embedded within the data message
         self.handle_sync_header(sched_ctx, comp_ctx, &message.sync_header);
         return true;
+    }
     /// Receives the sync message and updates the consensus state appropriately.
     pub(crate) fn receive_sync_message(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, message: SyncMessage) -> SyncRoundDecision {
         // Whatever happens: handle the sync header (possibly changing the
         // currently registered leader)
         self.handle_sync_header(sched_ctx, comp_ctx, &message.sync_header);
         match message.content {
             SyncMessageContent::NotificationOfLeader => {
                 return SyncRoundDecision::None;
             },
             SyncMessageContent::LocalSolution(solution_generator_id, local_solution) => {
                 return self.handle_local_solution(sched_ctx, comp_ctx, solution_generator_id, local_solution);
             },
             SyncMessageContent::PartialSolution(partial_solution) => {
                 return self.handle_partial_solution(sched_ctx, comp_ctx, partial_solution);
             },
             SyncMessageContent::GlobalSolution => {
                 debug_assert_eq!(self.mode, Mode::SyncAwaitingSolution); // leader can only find global- if we submitted local solution
                 return SyncRoundDecision::Solution;
             },
             SyncMessageContent::GlobalFailure => {
                 debug_assert_eq!(self.mode, Mode::SyncAwaitingSolution);
                 return SyncRoundDecision::Failure;
+            }
+        }
+    }
     fn handle_sync_header(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, header: &MessageSyncHeader) {
         if header.highest_id.0 > self.highest_id.0 {
             // Sender knows of someone with a higher ID. So store highest ID,
             // notify all peers, and forward local solutions
             self.highest_id = header.highest_id;
             for peer in comp_ctx.iter_peers() {
                 if peer.id == header.sending_id {
                     continue; // do not send to sender: it has the higher ID
+                }
                 // also: only send if we received a message in this round
                 let mut performed_communication = false; // TODO: Revise, temporary fix
                 for port in self.ports.iter() {
                     if port.peer_comp_id == peer.id && port.mapping.is_some() {
                         performed_communication = true;
                         break;
+                    }
+                }
                 if !performed_communication {
                     continue;
+                }
                 let message = SyncMessage{
                     sync_header: self.create_sync_header(comp_ctx),
                     content: SyncMessageContent::NotificationOfLeader,
                 };
                 peer.handle.send_message(sched_ctx, Message::Sync(message), true);
+            }
             self.forward_partial_solution(sched_ctx, comp_ctx);
         } else if header.highest_id.0 < self.highest_id.0 {
             // Sender has a lower ID, so notify it of our higher one
             let message = SyncMessage{
                 sync_header: self.create_sync_header(comp_ctx),
                 content: SyncMessageContent::NotificationOfLeader,
             };
             let peer_handle = comp_ctx.get_peer_handle(header.sending_id);
             let peer_info = comp_ctx.get_peer(peer_handle);
             peer_info.handle.send_message(sched_ctx, Message::Sync(message), true);
         } // else: exactly equal
+    }
     fn get_annotation(&self, port_id: PortId) -> Option<u32> {
         for annotation in self.ports.iter() {
             if annotation.self_port_id == port_id {
                 return annotation.mapping;
+            }
+        }
         debug_assert!(false);
         return None;
+    }
     fn set_annotation(&mut self, source_comp_id: CompId, data_header: &MessageDataHeader) {
         for annotation in self.ports.iter_mut() {
             if annotation.self_port_id == data_header.target_port {
                 annotation.peer_comp_id = source_comp_id;
                 annotation.peer_port_id = data_header.source_port;
                 annotation.mapping = Some(data_header.new_mapping);
+            }
+        }
+    }
     // -------------------------------------------------------------------------
     // Leader-related methods
     // -------------------------------------------------------------------------
     fn forward_partial_solution(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx) {
         debug_assert_ne!(self.highest_id, comp_ctx.id); // not leader
         // Make sure that we have something to send
         if !self.solution.has_contributions() {
             return;
+        }
         // Swap the container with the partial solution and then send it along
         let partial_solution = self.solution.take_partial_solution();
         self.send_to_leader(sched_ctx, comp_ctx, Message::Sync(SyncMessage{
             sync_header: self.create_sync_header(comp_ctx),
             content: SyncMessageContent::PartialSolution(partial_solution),
         }));
+    }
     fn handle_local_solution(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &CompCtx, solution_sender_id: CompId, solution: SyncLocalSolution) -> SyncRoundDecision {
         if self.highest_id == comp_ctx.id {
             // We are the leader
             self.solution.combine_with_local_solution(solution_sender_id, solution);
             let round_decision = self.solution.get_decision();
             if round_decision != SyncRoundDecision::None {
                 self.broadcast_decision(sched_ctx, comp_ctx, round_decision);
+            }
             return round_decision;
         } else {
             // Forward the solution
             let message = SyncMessage{
                 sync_header: self.create_sync_header(comp_ctx),
                 content: SyncMessageContent::LocalSolution(solution_sender_id, solution),
             };
             self.send_to_leader(sched_ctx, comp_ctx, Message::Sync(message));
             return SyncRoundDecision::None;
+        }
+    }
     fn handle_partial_solution(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, solution: SyncPartialSolution) -> SyncRoundDecision {
         if self.highest_id == comp_ctx.id {
             // We are the leader, combine existing and new solution
             self.solution.combine_with_partial_solution(solution);
             let round_decision = self.solution.get_decision();
             if round_decision != SyncRoundDecision::None {
                 self.broadcast_decision(sched_ctx, comp_ctx, round_decision);
+            }
             return round_decision;
         } else {
             // Forward the partial solution
             let message = SyncMessage{
                 sync_header: self.create_sync_header(comp_ctx),
                 content: SyncMessageContent::PartialSolution(solution),
             };
             self.send_to_leader(sched_ctx, comp_ctx, Message::Sync(message));
             return SyncRoundDecision::None;
+        }
+    }
     fn broadcast_decision(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &CompCtx, decision: SyncRoundDecision) {
         debug_assert_eq!(self.highest_id, comp_ctx.id);
         let is_success = match decision {
             SyncRoundDecision::None => unreachable!(),
             SyncRoundDecision::Solution => true,
             SyncRoundDecision::Failure => false,
         };
         let mut peers = Vec::with_capacity(self.solution.solution.channel_mapping.len()); // TODO: @Performance
         for channel in self.solution.solution.channel_mapping.iter() {
             let getter = channel.getter.as_ref().unwrap();
             if getter.self_comp_id != comp_ctx.id && !peers.contains(&getter.self_comp_id) {
                 peers.push(getter.self_comp_id);
+            }
             if getter.peer_comp_id != comp_ctx.id && !peers.contains(&getter.peer_comp_id) {
                 peers.push(getter.peer_comp_id);
+            }
+        }
         for peer in peers {
             let mut handle = sched_ctx.runtime.get_component_public(peer);
             let message = Message::Sync(SyncMessage{
                 sync_header: self.create_sync_header(comp_ctx),
                 content: if is_success { SyncMessageContent::GlobalSolution } else { SyncMessageContent::GlobalFailure },
             });
             handle.send_message(sched_ctx, message, true);
             let _should_remove = handle.decrement_users();
             debug_assert!(_should_remove.is_none());
+        }
+    }
     fn send_to_leader(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &CompCtx, message: Message) {
         debug_assert_ne!(self.highest_id, comp_ctx.id); // we're not the leader
         let mut leader_info = sched_ctx.runtime.get_component_public(self.highest_id);
         leader_info.send_message(sched_ctx, message, true);
         let should_remove = leader_info.decrement_users();
         if let Some(key) = should_remove {
             sched_ctx.runtime.destroy_component(key);
+        }
+    }
     // -------------------------------------------------------------------------
     // Creating message headers
     // -------------------------------------------------------------------------
     fn create_data_header_and_update_mapping(&mut self, port_info: &Port) -> MessageDataHeader {
         let mut expected_mapping = Vec::with_capacity(self.ports.len());
         let mut port_index = usize::MAX;
         for (index, port) in self.ports.iter().enumerate() {
             if port.self_port_id == port_info.self_id {
                 port_index = index;
+            }
             expected_mapping.push((port.self_port_id, port.mapping));
+        }
         let new_mapping = self.take_mapping();
         self.ports[port_index].mapping = Some(new_mapping);
         debug_assert_eq!(port_info.kind, PortKind::Putter);
         return MessageDataHeader{
             expected_mapping,
             new_mapping,
             source_port: port_info.self_id,
             target_port: port_info.peer_port_id,
         };
+    }
     #[inline]
     fn create_sync_header(&self, comp_ctx: &CompCtx) -> MessageSyncHeader {
         return MessageSyncHeader{
             sync_round: self.round_index,
             sending_id: comp_ctx.id,
             highest_id: self.highest_id,
         };
+    }
     #[inline]
     fn take_mapping(&mut self) -> u32 {
         let mapping = self.mapping_counter;
         self.mapping_counter = self.mapping_counter.wrapping_add(1);
         return mapping;
+    }
+}
@@ \ No newline at end of file @@

src/runtime2/store/component.rs

➞

Show inline comments

 /*
  * Component Store
+ *
  * Concurrent datastructure for creating/destroying/retrieving components using
  * their ID. It is essentially a variation on a concurrent freelist. We store an
  * array of (potentially null) pointers to data. Indices into this array that
  * are unused (but may be left allocated) are in a freelist. So creating a new
  * bit of data involves taking an index from this freelist. Destruction involves
  * putting the index back.
+ *
  * This datastructure takes care of the threadsafe implementation of the
  * freelist and calling the data's destructor when needed. Note that it is not
  * completely safe (in Rust's sense of the word) because it is possible to
  * get more than one mutable reference to a piece of data. Likewise it is
  * possible to put back bogus indices into the freelist, which will destroy the
  * integrity of the datastructure.
+ *
  * Some underlying assumptions that led to this design (note that I haven't
  * actually checked these conditions or performed any real profiling, yet):
  *  - Resizing the freelist should be very rare. The datastructure should grow
  *    to some kind of maximum size and stay at that size.
  *  - Creation should (preferably) be faster than deletion of data. Reason being
  *    that creation implies we're creating a component that has code to be
  *    executed. Better to quickly be able to execute code than being able to
  *    quickly tear down finished components.
  *  - Retrieval is much more likely than creation/destruction.
+ *
  * Some obvious flaws with this implementation:
  *  - Because of the freelist implementation we will generally allocate all of
  *    the data pointers that are available (i.e. if we have a buffer of size
  *    64, but we generally use 33 elements, than we'll have 64 elements
  *    allocated), which might be wasteful at larger array sizes (which are
  *    always powers of two).
  *  - A lot of concurrent operations are not necessary: we may move some of the
  *    access to the global concurrent datastructure by an initial access to some
  *    kind of thread-local datastructure.
  */
 use std::mem::transmute;
 use std::alloc::{dealloc, Layout};
 use std::ptr;
 use std::sync::atomic::{AtomicUsize, Ordering};
 use super::unfair_se_lock::{UnfairSeLock, UnfairSeLockSharedGuard};
 /// Generic store of components. Essentially a resizable freelist (implemented
 /// as a ringbuffer) combined with an array of actual elements.
 pub struct ComponentStore<T: Sized> {
     inner: UnfairSeLock<Inner<T>>,
     read_head: AtomicUsize,
     write_head: AtomicUsize,
     limit_head: AtomicUsize,
+}
 unsafe impl<T: Sized> Send for ComponentStore<T>{}
 unsafe impl<T: Sized> Sync for ComponentStore<T>{}
 /// Contents of the `ComponentStore` that require a shared/exclusive locking
 /// mechanism for consistency.
 struct Inner<T: Sized> {
     freelist: Vec<u32>,
     data: Vec<*mut T>,
     size: usize,
     compare_mask: usize,
     index_mask: usize,
+}
 type InnerShared<'a, T> = UnfairSeLockSharedGuard<'a, Inner<T>>;
 /// Reservation of a slot in the component store. Corresponds to the case where
 /// an index has been taken from the freelist, but the element has not yet been
 /// initialized
 pub struct ComponentReservation {
     pub(crate) index: u32,
     #[cfg(debug_assertions)] submitted: bool,
+}
 impl ComponentReservation {
     fn new(index: u32) -> Self {
         return Self{
             index,
             #[cfg(debug_assertions)] submitted: false,
+        }
+    }
+}
 impl Drop for ComponentReservation {
     fn drop(&mut self) {
         debug_assert!(self.submitted);
+    }
+}
 impl<T: Sized> ComponentStore<T> {
     pub fn new(initial_size: usize) -> Self {
         Self::assert_valid_size(initial_size);
         // Fill initial freelist and preallocate data array
         let mut initial_freelist = Vec::with_capacity(initial_size);
         for idx in 0..initial_size {
             initial_freelist.push(idx as u32)
+        }
         let mut initial_data = Vec::new();
         initial_data.resize(initial_size, ptr::null_mut());
         // Return initial store
         return Self{
             inner: UnfairSeLock::new(Inner{
                 freelist: initial_freelist,
                 data: initial_data,
                 size: initial_size,
                 compare_mask: 2*initial_size - 1,
                 index_mask: initial_size - 1,
             }),
             read_head: AtomicUsize::new(0),
             write_head: AtomicUsize::new(initial_size),
             limit_head: AtomicUsize::new(initial_size),
         };
+    }
     /// Creates a new element initialized to the provided `value`. This returns
     /// the index at which the element can be retrieved.
     pub fn create(&self, value: T) -> u32 {
         let lock = self.inner.lock_shared();
         let (lock, index) = self.pop_freelist_index(lock);
         Self::initialize_at_index(lock, index, value);
         return index;
+    }
     pub fn reserve(&self) -> ComponentReservation {
         let lock = self.inner.lock_shared();
         let (_lock, index) = self.pop_freelist_index(lock);
         return ComponentReservation::new(index);
+    }
     pub fn submit(&self, mut reservation: ComponentReservation, value: T) -> u32 {
         dbg_code!({ reservation.submitted = true; });
         let lock = self.inner.lock_shared();
         Self::initialize_at_index(lock, reservation.index, value);
         return reservation.index;
+    }
     /// Destroys an element at the provided `index`. The caller must make sure
     /// that it does not use any previously received references to the data at
     /// this index, and that no more calls to `get` are performed using this
     /// index. This is allowed again if the index has been reacquired using
     /// `create`.
     pub fn destroy(&self, index: u32) {
         let lock = self.inner.lock_shared();
         self.destruct_at_index(&lock, index);
         self.push_freelist_index(&lock, index);
+    }
     /// Retrieves an element by reference
     pub fn get(&self, index: u32) -> &T {
         let lock = self.inner.lock_shared();
         let value = lock.data[index as usize];
         unsafe {
             debug_assert!(!value.is_null());
             return &*value;
+        }
+    }
     /// Retrieves an element by mutable reference. The caller should ensure that
     /// use of that mutability is thread-safe
     pub fn get_mut(&self, index: u32) -> &mut T {
         let lock = self.inner.lock_shared();
         let value = lock.data[index as usize];
         unsafe {
             debug_assert!(!value.is_null());
             return &mut *value;
+        }
+    }
     #[inline]
     fn pop_freelist_index<'a>(&'a self, mut shared_lock: InnerShared<'a, T>) -> (InnerShared<'a, T>, u32) {
         'attempt_read: loop {
             // Load indices and check for reallocation condition
             let current_size = shared_lock.size;
             let mut read_index = self.read_head.load(Ordering::Relaxed);
             let limit_index = self.limit_head.load(Ordering::Acquire);
             if read_index == limit_index {
                 shared_lock = self.reallocate(current_size, shared_lock);
                 continue 'attempt_read;
+            }
             loop {
                 let preemptive_read = shared_lock.freelist[read_index & shared_lock.index_mask];
                 if let Err(actual_read_index) = self.read_head.compare_exchange(
                     read_index, (read_index + 1) & shared_lock.compare_mask,
                     Ordering::AcqRel, Ordering::Acquire
                 ) {
                     // We need to try again
                     read_index = actual_read_index;
                     continue 'attempt_read;
+                }
                 // If here then we performed the read
                 return (shared_lock, preemptive_read);
+            }
+        }
+    }
     #[inline]
     fn initialize_at_index(read_lock: InnerShared<T>, index: u32, value: T) {
         let mut target_ptr = read_lock.data[index as usize];
         unsafe {
             if target_ptr.is_null() {
                 let layout = Layout::for_value(&value);
                 target_ptr = std::alloc::alloc(layout).cast();
                 let rewrite: *mut *mut T = transmute(read_lock.data.as_ptr());
                 *rewrite.add(index as usize) = target_ptr;
+            }
             std::ptr::write(target_ptr, value);
+        }
+    }
     #[inline]
     fn push_freelist_index(&self, read_lock: &InnerShared<T>, index_to_put_back: u32) {
         // Acquire an index in the freelist to which we can write
         let mut cur_write_index = self.write_head.load(Ordering::Relaxed);
         let mut new_write_index = (cur_write_index + 1) & read_lock.compare_mask;
         while let Err(actual_write_index) = self.write_head.compare_exchange(
             cur_write_index, new_write_index,
             Ordering::AcqRel, Ordering::Acquire
         ) {
             cur_write_index = actual_write_index;
             new_write_index = (cur_write_index + 1) & read_lock.compare_mask;
+        }
         // We own the data at the index, write to it and notify reader through
         // limit_head that it can be read from. Note that we cheat around the
         // rust mutability system here :)
         unsafe {
             let target: *mut u32 = transmute(read_lock.freelist.as_ptr());
             *(target.add(cur_write_index & read_lock.index_mask)) = index_to_put_back;
+        }
         // Essentially spinlocking, relaxed failure ordering because the logic
         // is that a write first moves the `write_head`, then the `limit_head`.
         while let Err(_) = self.limit_head.compare_exchange(
             cur_write_index, new_write_index,
             Ordering::AcqRel, Ordering::Relaxed
         ) {};
+    }
     #[inline]
     fn destruct_at_index(&self, read_lock: &InnerShared<T>, index: u32) {
         let target_ptr = read_lock.data[index as usize];
         unsafe{ ptr::drop_in_place(target_ptr); }
+    }
     // NOTE: Bit of a mess, and could have a cleanup with better logic for the
     // resizing. Maybe even a different indexing scheme...
     fn reallocate(&self, old_size: usize, inner: InnerShared<T>) -> InnerShared<T> {
         drop(inner);
+        {
             // After dropping read lock, acquire write lock
             let mut lock = self.inner.lock_exclusive();
             if old_size == lock.size {
                 // We are the thread that is supposed to reallocate
                 let new_size = old_size * 2;
                 Self::assert_valid_size(new_size);
                 // Note that the atomic indices are in the range [0, new_size)
                 // already, so we need to be careful
                 let new_index_mask = new_size - 1;
                 let new_compare_mask = (2 * new_size) - 1;
                 lock.data.resize(new_size, ptr::null_mut());
                 lock.freelist.resize(new_size, 0);
                 for idx in 0..old_size {
                     lock.freelist[old_size + idx] = lock.freelist[idx];
+                }
                 // We need to fill the freelist with the indices of all of the
                 // new elements that we have just created.
                 debug_assert_eq!(self.limit_head.load(Ordering::SeqCst), self.write_head.load(Ordering::SeqCst));
                 let old_read_index = self.read_head.load(Ordering::SeqCst);
                 let old_write_index = self.write_head.load(Ordering::SeqCst);
                 if old_read_index > old_write_index {
                     // Read index wraps, so keep it as-is and fill
                     let new_read_index = old_read_index + old_size;
                     for index in 0..old_size {
                         let target_idx = (new_read_index + index) & new_index_mask;
                         lock.freelist[target_idx] = (old_size + index) as u32;
+                    }
                     self.read_head.store(new_read_index, Ordering::SeqCst);
                     debug_assert!(new_read_index < 2*new_size);
                     debug_assert!(old_write_index.wrapping_sub(new_read_index) & new_compare_mask <= new_size);
                 } else {
                     // No wrapping, so increment write index
                     let new_write_index = old_write_index + old_size;
                     for index in 0..old_size {
                         let target_idx = (old_write_index + index) & new_index_mask;
                         lock.freelist[target_idx] = (old_size + index) as u32;
+                    }
                     // Update write/limit heads
                     self.write_head.store(new_write_index, Ordering::SeqCst);
                     self.limit_head.store(new_write_index, Ordering::SeqCst);
                     debug_assert!(new_write_index < 2*new_size);
                     debug_assert!(new_write_index.wrapping_sub(old_read_index) & new_compare_mask <= new_size);
+                }
                 // Update sizes and masks
                 lock.size = new_size;
                 lock.compare_mask = new_compare_mask;
                 lock.index_mask = new_index_mask;
             } // else: someone else allocated, so we don't have to
+        }
         // We've dropped the write lock, acquire the read lock again
         return self.inner.lock_shared();
+    }
     #[inline]
     fn assert_valid_size(size: usize) {
         // Condition the size needs to adhere to. Some are a bit excessive, but
         // we don't hit this check very often
         assert!(
             size.is_power_of_two() &&
                 size >= 4 &&
                 size <= usize::MAX / 2 &&
                 size <= u32::MAX as usize
         );
+    }
+}
 impl<T: Sized> Drop for ComponentStore<T> {
     fn drop(&mut self) {
         let value_layout = Layout::from_size_align(
             std::mem::size_of::<T>(), std::mem::align_of::<T>()
         ).unwrap();
         // Note that if the indices exist in the freelist then the destructor
         // has already been called. So handle them first
         let mut lock = self.inner.lock_exclusive();
         let read_index = self.read_head.load(Ordering::Acquire);
         let write_index = self.write_head.load(Ordering::Acquire);
         debug_assert_eq!(write_index, self.limit_head.load(Ordering::Acquire));
         let mut index = read_index;
         while index != write_index {
             let dealloc_index = lock.freelist[index & lock.index_mask] as usize;
             let target_ptr = lock.data[dealloc_index];
             unsafe {
                 dealloc(target_ptr.cast(), value_layout);
                 lock.data[dealloc_index] = ptr::null_mut();
+            }
             index += 1;
             index &= lock.compare_mask;
+        }
         // With all of those set to null, we'll just iterate through all
         // pointers and destruct+deallocate the ones not set to null yet
         for target_ptr in lock.data.iter().copied() {
             if !target_ptr.is_null() {
                 unsafe {
                     ptr::drop_in_place(target_ptr);
                     dealloc(target_ptr.cast(), value_layout);
+                }
+            }
+        }
+    }
+}
 #[cfg(test)]
 mod tests {
     use super::*;
     use super::super::tests::*;
     use rand::prelude::*;
     use rand_pcg::Pcg32;
     fn seeds() -> Vec<[u8;16]> {
         return vec![
             [241, 47, 70, 87, 240, 246, 20, 173, 219, 143, 74, 23, 158, 58, 205, 172],
             [178, 112, 230, 205, 230, 178, 2, 90, 162, 218, 49, 196, 224, 222, 208, 43],
             [245, 42, 35, 167, 153, 205, 221, 144, 200, 253, 144, 117, 176, 231, 17, 70],
             [143, 39, 177, 216, 124, 96, 225, 39, 30, 82, 239, 193, 133, 58, 255, 193],
             [25, 105, 10, 52, 161, 212, 190, 112, 178, 193, 68, 249, 167, 153, 172, 144],
+        ]
+    }
     #[test]
     fn test_ctor_dtor_simple_unthreaded() {
         const NUM_ROUNDS: usize = 5;
         const NUM_ELEMENTS: usize = 1024;
         let store = ComponentStore::new(32);
         let counters = Counters::new();
         let mut indices = Vec::with_capacity(NUM_ELEMENTS);
         for _round_index in 0..NUM_ROUNDS {
             // Creation round
             for value in 0..NUM_ELEMENTS {
                 let new_resource = Resource::new(&counters, value as u64);
                 let new_index = store.create(new_resource);
                 indices.push(new_index);
+            }
             // Checking round
             for el_index in indices.iter().copied() {
                 let element = store.get(el_index);
                 assert_eq!(element.val, el_index as u64);
+            }
             // Destruction round
             for el_index in indices.iter().copied() {
                 store.destroy(el_index);
+            }
             indices.clear();
+        }
         let num_expected = (NUM_ROUNDS * NUM_ELEMENTS) as u64;
         assert_ctor_eq!(counters, num_expected);
         assert_dtor_eq!(counters, num_expected);
+    }
     #[test]
     fn test_ctor_dtor_simple_threaded() {
         const MAX_SIZE: usize = 1024;
         const NUM_THREADS: usize = 4;
         const NUM_PER_THREAD: usize = MAX_SIZE / NUM_THREADS;
         const NUM_ROUNDS: usize = 4;
         assert!(MAX_SIZE % NUM_THREADS == 0);
         let store = Arc::new(ComponentStore::new(16));
         let counters = Counters::new();
         let mut threads = Vec::with_capacity(NUM_THREADS);
         for thread_index in 0..NUM_THREADS {
             // Setup local clones to move into the thread
             let store = store.clone();
             let first_index = thread_index * NUM_PER_THREAD;
             let last_index = (thread_index + 1) * NUM_PER_THREAD;
             let counters = counters.clone();
             let handle = std::thread::spawn(move || {
                 let mut indices = Vec::with_capacity(last_index - first_index);
                 for _round_index in 0..NUM_ROUNDS {
                     // Creation round
                     for value in first_index..last_index {
                         let el_index = store.create(Resource::new(&counters, value as u64));
                         indices.push(el_index);
+                    }
                     // Checking round
                     for (value_offset, el_index) in indices.iter().copied().enumerate() {
                         let element = store.get(el_index);
                         assert_eq!(element.val, (first_index + value_offset) as u64);
+                    }
                     // Destruction round
                     for el_index in indices.iter().copied() {
                         store.destroy(el_index);
+                    }
                     indices.clear();
+                }
             });
             threads.push(handle);
+        }
         for thread in threads {
             thread.join().expect("clean exit");
+        }
         let num_expected = (NUM_ROUNDS * MAX_SIZE) as u64;
         assert_ctor_eq!(counters, num_expected);
         assert_dtor_eq!(counters, num_expected);
+    }
     #[test]
     fn test_ctor_dtor_random_threaded() {
         const NUM_ROUNDS: usize = 4;
         const NUM_THREADS: usize = 4;
         const NUM_OPERATIONS: usize = 1024;
         const NUM_OPS_PER_THREAD: usize = NUM_OPERATIONS / NUM_THREADS;
         const NUM_OPS_PER_ROUND: usize = NUM_OPS_PER_THREAD / NUM_ROUNDS;
         const NUM_STORED_PER_THREAD: usize = 32;
         assert!(NUM_OPERATIONS % NUM_THREADS == 0);
         assert!(NUM_OPS_PER_THREAD / 2 > NUM_STORED_PER_THREAD);
         let seeds = seeds();
         for seed_index in 0..seeds.len() {
             // Setup store, counters and threads
             let store = Arc::new(ComponentStore::new(16));
             let counters = Counters::new();
             let mut threads = Vec::with_capacity(NUM_THREADS);
             for thread_index in 0..NUM_THREADS {
                 // Setup local clones to move into the thread
                 let store = store.clone();
                 let counters = counters.clone();
                 // Setup local rng
                 let mut seed = seeds[seed_index];
                 for seed_val_idx in 0..16 {
                     seed[seed_val_idx] ^= thread_index as u8; // blegh
+                }
                 let mut rng = Pcg32::from_seed(seed);
                 let handle = std::thread::spawn(move || {
                     let mut stored = Vec::with_capacity(NUM_STORED_PER_THREAD);
                     for _round_index in 0..NUM_ROUNDS {
                         // Modify store elements in the store randomly, for some
                         // silly definition of random
                         for _op_index in 0..NUM_OPS_PER_ROUND {
                             // Perform a single operation, depending on current
                             // size of the number of values owned by this thread
                             let new_value = rng.next_u64();
                             let should_create = rng.next_u32() % 2 == 0;
                             let is_empty = stored.is_empty();
                             let is_full = stored.len() == NUM_STORED_PER_THREAD;
                             if is_empty || (!is_full && should_create) {
                                 // Must create
                                 let el_index = store.create(Resource::new(&counters, new_value));
                                 stored.push((el_index, new_value));
                             } else {
                                 // Must destroy
                                 let stored_index = new_value as usize % stored.len();
-                                let (el_index, el_value) = stored.remove(stored_index);
+                                let (el_index, _el_value) = stored.remove(stored_index);
                                 store.destroy(el_index);
+                            }
+                        }
                         // Checking if the values we own still make sense
                         for (el_index, value) in stored.iter().copied() {
                             let gotten = store.get(el_index);
                             assert_eq!(value, gotten.val, "failed at thread {} value {}", thread_index, el_index);
+                        }
+                    }
                     return stored.len(); // return number of remaining elements
                 });
                 threads.push(handle);
+            }
             // Done with the current round
             let mut total_left_allocated = 0;
             for thread in threads {
                 let num_still_stored = thread.join().unwrap();
                 total_left_allocated += num_still_stored as u64;
+            }
             // Before store is dropped
             // note: cannot determine number of creations, creation/destructor
             // is random
             let num_ctor = counters.ctor.load(Ordering::Acquire);
             assert_dtor_eq!(counters, num_ctor - total_left_allocated);
             // After store is dropped
             drop(store);
             assert_dtor_eq!(counters, num_ctor);
+        }
+    }
+}
@@ \ No newline at end of file @@

src/runtime2/tests/mod.rs

➞

Show inline comments

 use crate::protocol::*;
 use crate::protocol::eval::*;
 use crate::runtime2::runtime::*;
 use crate::runtime2::component::{CompCtx, CompPDL};
 fn create_component(rt: &Runtime, module_name: &str, routine_name: &str, args: ValueGroup) {
     let prompt = rt.inner.protocol.new_component(
         module_name.as_bytes(), routine_name.as_bytes(), args
     ).expect("create prompt");
     let reserved = rt.inner.start_create_pdl_component();
     let ctx = CompCtx::new(&reserved);
     let (key, _) = rt.inner.finish_create_pdl_component(reserved, CompPDL::new(prompt, 0), ctx, false);
     rt.inner.enqueue_work(key);
+}
 fn no_args() -> ValueGroup { ValueGroup::new_stack(Vec::new()) }
 #[test]
 fn test_component_creation() {
     let pd = ProtocolDescription::parse(b"
     primitive nothing_at_all() {
         s32 a = 5;
         auto b = 5 + a;
+    }
     ").expect("compilation");
     let rt = Runtime::new(1, true, pd);
-    for i in 0..20 {
+    for _i in 0..20 {
         create_component(&rt, "", "nothing_at_all", no_args());
+    }
+}
 #[test]
 fn test_component_communication() {
     let pd = ProtocolDescription::parse(b"
     primitive sender(out<u32> o, u32 outside_loops, u32 inside_loops) {
         u32 outside_index = 0;
         while (outside_index < outside_loops) {
             u32 inside_index = 0;
             sync while (inside_index < inside_loops) {
                 put(o, inside_index);
                 inside_index += 1;
+            }
             outside_index += 1;
+        }
+    }
     primitive receiver(in<u32> i, u32 outside_loops, u32 inside_loops) {
         u32 outside_index = 0;
         while (outside_index < outside_loops) {
             u32 inside_index = 0;
             sync while (inside_index < inside_loops) {
                 auto val = get(i);
                 while (val != inside_index) {} // infinite loop if incorrect value is received
                 inside_index += 1;
+            }
             outside_index += 1;
+        }
+    }
     composite constructor() {
         channel o_orom -> i_orom;
         channel o_mrom -> i_mrom;
         channel o_ormm -> i_ormm;
         channel o_mrmm -> i_mrmm;
         // one round, one message per round
         new sender(o_orom, 1, 1);
         new receiver(i_orom, 1, 1);
         // multiple rounds, one message per round
         new sender(o_mrom, 5, 1);
         new receiver(i_mrom, 5, 1);
         // one round, multiple messages per round
         new sender(o_ormm, 1, 5);
         new receiver(i_ormm, 1, 5);
         // multiple rounds, multiple messages per round
         new sender(o_mrmm, 5, 5);
         new receiver(i_mrmm, 5, 5);
     }").expect("compilation");
     let rt = Runtime::new(3, true, pd);
     create_component(&rt, "", "constructor", no_args());
+}
 #[test]
 fn test_simple_select() {
     let pd = ProtocolDescription::parse(b"
     func infinite_assert<T>(T val, T expected) -> () {
         while (val != expected) { print(\"nope!\"); }
         return ();
+    }
     primitive receiver(in<u32> in_a, in<u32> in_b, u32 num_sends) {
         auto num_from_a = 0;
         auto num_from_b = 0;
         while (num_from_a + num_from_b < 2 * num_sends) {
             sync select {
                 auto v = get(in_a) -> {
                     print(\"got something from A\");
                     auto _ = infinite_assert(v, num_from_a);
                     num_from_a += 1;
+                }
                 auto v = get(in_b) -> {
                     print(\"got something from B\");
                     auto _ = infinite_assert(v, num_from_b);
                     num_from_b += 1;
+                }
+            }
+        }
+    }
     primitive sender(out<u32> tx, u32 num_sends) {
         auto index = 0;
         while (index < num_sends) {
             sync {
                 put(tx, index);
                 index += 1;
+            }
+        }
+    }
     composite constructor() {
         auto num_sends = 15;
         channel tx_a -> rx_a;
         channel tx_b -> rx_b;
         new sender(tx_a, num_sends);
         new receiver(rx_a, rx_b, num_sends);
         new sender(tx_b, num_sends);
+    }
     ").expect("compilation");
     let rt = Runtime::new(3, false, pd);
     create_component(&rt, "", "constructor", no_args());
+}
 #[test]
 fn test_unguarded_select() {
     let pd = ProtocolDescription::parse(b"
     primitive constructor_outside_select() {
         u32 index = 0;
         while (index < 5) {
             sync select { auto v = () -> print(\"hello\"); }
             index += 1;
+        }
+    }
     primitive constructor_inside_select() {
         u32 index = 0;
         while (index < 5) {
             sync select { auto v = () -> index += 1; }
+        }
+    }
     ").expect("compilation");
     let rt = Runtime::new(3, false, pd);
     create_component(&rt, "", "constructor_outside_select", no_args());
     create_component(&rt, "", "constructor_inside_select", no_args());
+}
 #[test]
 fn test_empty_select() {
     let pd = ProtocolDescription::parse(b"
     primitive constructor() {
         u32 index = 0;
         while (index < 5) {
             sync select {}
             index += 1;
+        }
+    }
     ").expect("compilation");
     let rt = Runtime::new(3, false, pd);
     create_component(&rt, "", "constructor", no_args());
+}
@@ \ No newline at end of file @@

0 comments (0 inline, 0 general)