CSY/reowolf Changeset - fc2d65a1b906 · Centrum Wiskunde & Informatica (CWI)

Changeset - fc2d65a1b906

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0 18 0

MH - 4 years ago 2021-05-04 14:56:16
contact@maxhenger.nl

WIP on fixing all newly introduced bugs

8 files changed:

src/collections/scoped_buffer.rs

src/protocol/input_source.rs

src/protocol/parser/mod.rs

src/protocol/parser/pass_definitions.rs

src/protocol/parser/pass_imports.rs

src/protocol/parser/pass_symbols.rs

src/protocol/parser/pass_tokenizer.rs

src/protocol/parser/pass_typing.rs

Changeset was too big and was cut off... Show full diff anyway

0 comments (0 inline, 0 general)

src/collections/scoped_buffer.rs

➞

Show inline comments

 use std::iter::FromIterator;
 /// 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.
 use std::iter::FromIterator;
 pub(crate) struct ScopedBuffer<T: Sized> {
     pub inner: Vec<T>,
+}
 /// 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.
 /// 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> ScopedBuffer<T> {
     pub(crate) fn new_reserved(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,
             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,
             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");
+    }
+}
 impl<T: Sized> ScopedSection<T> {
     #[inline]
     pub(crate) fn push(&mut self, value: T) {
         let vec = unsafe{&mut *self.inner};
         debug_assert_eq!(vec.len(), self.cur_size as usize, "trying to push onto section, but size is larger than expected");
         vec.push(value);
         if cfg!(debug_assertions) { self.cur_size += 1; }
+    }
     pub(crate) fn len(&self) -> usize {
         let vec = unsafe{&mut *self.inner};
         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]
     pub(crate) fn forget(self) {
+    pub(crate) fn forget(mut self) {
         let vec = unsafe{&mut *self.inner};
         debug_assert_eq!(vec.len(), self.cur_size as usize, "trying to forget section, but size is larger than expected");
         if cfg!(debug_assertions) {
             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;
+        }
         vec.truncate(self.start_size as usize);
+    }
     #[inline]
     pub(crate) fn into_vec(self) -> Vec<T> {
+    pub(crate) fn into_vec(mut self) -> Vec<T> {
         let vec = unsafe{&mut *self.inner};
         debug_assert_eq!(vec.len(), self.cur_size as usize, "trying to turn section into vec, but size is larger than expected");
         if cfg!(debug_assertions) {
             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
+    }
+}
 impl<T: Sized> std::ops::Index<usize> for ScopedSection<T> {
     type Output = T;
     fn index(&self, idx: usize) -> &Self::Output {
         let vec = unsafe{&*self.inner};
         return &vec[self.start_size as usize + idx]
+    }
+}
 #[cfg(debug_assertions)]
 impl<T: Sized> Drop for ScopedSection<T> {
     fn drop(&mut self) {
         // Make sure that the data was actually taken out of the scoped section
         let vec = unsafe{&*self.inner};
         debug_assert_eq!(vec.len(), self.start_size as usize);
         let mut vec = unsafe{&mut *self.inner};
         debug_assert_eq!(vec.len(), self.cur_size as usize);
         vec.truncate(self.start_size as usize);
+    }
+}
@@ \ 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 {
     #[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()),
+        }
+    }
     #[cfg(test)]
     pub fn new_test(input: &str) -> Self {
         let bytes = Vec::from(input.as_bytes());
         return Self::new(String::from("test"), bytes)
+    }
     #[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); // for lookup_line_end
         debug_assert_eq!(self.line as usize + 2, lookup.len(), "remove me: i am a testing assert and sometimes invalid");
         // 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
         if self.input[offset_usize] == b'\n' {
             if offset_usize > 0 && self.input[offset_usize] == b'\r' {
                 offset - 2
             } else {
                 offset - 1
+            }
         } else {
             offset
+        }
+    }
+}
 #[derive(Debug)]
 pub enum StatementKind {
     Info,
     Error
+}
 #[derive(Debug)]
 pub enum ContextKind {
     SingleLine,
     MultiLine,
+}
 #[derive(Debug)]
 pub struct ParseErrorStatement {
     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 ParseErrorStatement {
     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,
+        }
+    }
     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: first_line_start,
+            start_line: span.begin.line,
             start_column,
-            end_line: last_line_start,
+            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 ParseErrorStatement {
     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);
             for (char_idx, char) in source.chars().enumerate().skip(first_col as usize - 1) {
                 if char_idx == last_col as usize {
             let first_idx = first_col as usize - 1;
             let last_idx = last_col as usize - 1;
             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, &self.context, &mut annotation, ' ');
+                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<ParseErrorStatement>
+}
 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!(ParseErrorStatement::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!(ParseErrorStatement::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!(ParseErrorStatement::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!(ParseErrorStatement::from_source_at_span(
             StatementKind::Error, source, span, message.to_string()
         )) }
+    }
     pub fn with_at_pos(mut self, error_type: StatementKind, source: &InputSource, position: InputPosition, message: String) -> Self {
         self.statements.push(ParseErrorStatement::from_source_at_pos(error_type, source, position, message));
         self
+    }
     pub fn with_at_span(mut self, error_type: StatementKind, source: &InputSource, span: InputSpan, message: String) -> Self {
         self.statements.push(ParseErrorStatement::from_source_at_span(error_type, source, span, message.to_string()));
         self
+    }
     pub fn with_info_at_pos(self, source: &InputSource, position: InputPosition, msg: String) -> Self {
         self.with_at_pos(StatementKind::Info, source, position, msg)
+    }
     pub fn with_info_str_at_pos(self, source: &InputSource, position: InputPosition, msg: &str) -> Self {
         self.with_at_pos(StatementKind::Info, source, position, msg.to_string())
+    }
     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_span(self, source: &InputSource, span: InputSpan, msg: &str) -> Self {
         self.with_at_span(StatementKind::Info, source, span, msg.to_string())
+    }
+}

src/protocol/parser/mod.rs

➞

Show inline comments

 mod depth_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_validation_linking;
 pub(crate) mod pass_typing;
 mod visitor;
 use depth_visitor::*;
 use tokens::*;
 use crate::collections::*;
 use symbol_table::SymbolTable;
 use visitor::Visitor2;
 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 type_table::TypeTable;
 use crate::protocol::ast::*;
 use crate::protocol::input_source::*;
 use crate::protocol::ast_printer::ASTWriter;
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub enum ModuleCompilationPhase {
     Source,                 // only source is set
     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
+}
 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,
+}
 pub struct PassCtx<'a> {
     heap: &'a mut Heap,
     symbols: &'a mut SymbolTable,
     pool: &'a mut StringPool,
+}
 pub struct Parser {
     pub(crate) heap: Heap,
     pub(crate) string_pool: StringPool,
     pub(crate) modules: Vec<Module>,
     pub(crate) symbol_table: SymbolTable,
     pub(crate) type_table: TypeTable,
     // Compiler passes
     pass_tokenizer: PassTokenizer,
     pass_symbols: PassSymbols,
     pass_import: PassImport,
     pass_definitions: PassDefinitions,
     pass_validation: PassValidationLinking,
     pass_typing: PassTyping,
+}
 impl Parser {
     pub fn new() -> Self {
         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(),
+        }
+    }
     pub fn feed(&mut self, mut source: InputSource) -> Result<(), ParseError> {
         // TODO: @Optimize
         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,
         };
         // 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() {
             // TODO: Remove the entire Visitor abstraction. It really doesn't
             //  make sense considering the amount of special handling we do
             //  in each pass.
             let mut ctx = visitor::Ctx{
                 heap: &mut self.heap,
                 module: &self.modules[module_idx],
+                module: &mut self.modules[module_idx],
                 symbols: &mut self.symbol_table,
                 types: &mut self.type_table,
             };
             self.pass_validation.visit_module(&mut ctx)?;
+        }
         // Perform typechecking on all modules
         let mut queue = ResolveQueue::new();
         for module in &self.modules {
+        for module in &mut self.modules {
             let ctx = visitor::Ctx{
                 heap: &mut self.heap,
                 module,
                 symbols: &mut self.symbol_table,
                 types: &mut self.type_table,
             };
             PassTyping::queue_module_definitions(&ctx, &mut queue);
         };
         while !queue.is_empty() {
             let top = queue.pop().unwrap();
             let mut ctx = visitor::Ctx{
                 heap: &mut self.heap,
                 module: &self.modules[top.root_id.index as usize],
+                module: &mut self.modules[top.root_id.index as usize],
                 symbols: &mut self.symbol_table,
                 types: &mut self.type_table,
             };
             self.pass_typing.handle_module_definition(&mut ctx, &mut queue, top)?;
+        }
         // Perform remaining steps
         // TODO: Phase out at some point
         for module in &self.modules {
             let root_id = module.root_id;
             if let Err((position, message)) = Self::parse_inner(&mut self.heap, root_id) {
                 return Err(ParseError::new_error_str_at_pos(&self.modules[0].source, position, &message))
+            }
+        }
         // let mut writer = ASTWriter::new();
         // let mut file = std::fs::File::create(std::path::Path::new("ast.txt")).unwrap();
         // writer.write_ast(&mut file, &self.heap);
         Ok(())
+    }
     pub fn parse_inner(h: &mut Heap, pd: RootId) -> VisitorResult {
         // TODO: @cleanup, slowly phasing out old compiler
         // NestedSynchronousStatements::new().visit_protocol_description(h, pd)?;
         // ChannelStatementOccurrences::new().visit_protocol_description(h, pd)?;
         // FunctionStatementReturns::new().visit_protocol_description(h, pd)?;
         // ComponentStatementReturnNew::new().visit_protocol_description(h, pd)?;
         // CheckBuiltinOccurrences::new().visit_protocol_description(h, pd)?;
         // BuildSymbolDeclarations::new().visit_protocol_description(h, pd)?;
         // LinkCallExpressions::new().visit_protocol_description(h, pd)?;
         // BuildScope::new().visit_protocol_description(h, pd)?;
         // ResolveVariables::new().visit_protocol_description(h, pd)?;
         LinkStatements::new().visit_protocol_description(h, pd)?;
         // BuildLabels::new().visit_protocol_description(h, pd)?;
         // ResolveLabels::new().visit_protocol_description(h, pd)?;
         AssignableExpressions::new().visit_protocol_description(h, pd)?;
         IndexableExpressions::new().visit_protocol_description(h, pd)?;
         SelectableExpressions::new().visit_protocol_description(h, pd)?;
         Ok(())
+    }
+}
@@ \ 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 crate::protocol::input_source::{InputSource as InputSource, InputPosition as InputPosition, InputSpan, ParseError};
 use crate::collections::*;
 /// Parses all the tokenized definitions into actual AST nodes.
 pub(crate) struct PassDefinitions {
     // State
     cur_definition: DefinitionId,
     // Temporary buffers of various kinds
     buffer: String,
     struct_fields: ScopedBuffer<StructFieldDefinition>,
     enum_variants: ScopedBuffer<EnumVariantDefinition>,
     union_variants: ScopedBuffer<UnionVariantDefinition>,
     parameters: ScopedBuffer<ParameterId>,
     expressions: ScopedBuffer<ExpressionId>,
     statements: ScopedBuffer<StatementId>,
     parser_types: Vec<ParserType>,
+}
 impl PassDefinitions {
     pub(crate) fn new() -> Self {
         Self{
             cur_definition: DefinitionId::new_invalid(),
             buffer: String::with_capacity(128),
             struct_fields: ScopedBuffer::new_reserved(128),
             enum_variants: ScopedBuffer::new_reserved(128),
             union_variants: ScopedBuffer::new_reserved(128),
             parameters: ScopedBuffer::new_reserved(128),
             expressions: ScopedBuffer::new_reserved(128),
             statements: ScopedBuffer::new_reserved(128),
             parser_types: Vec::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 => continue, // already fully parsed
                 TokenRangeKind::Definition | TokenRangeKind::Code => {}
+            }
             self.visit_range(modules, module_idx, ctx, range_idx_usize)?;
             match cur_range.next_sibling_idx {
                 Some(idx) => { range_idx = idx; },
                 None => { break; },
             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 some kind of type or procedure definition"
+                    "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(); // TODO: @Cleanup, this is really ugly. But rust...
                 let start_pos = iter.last_valid_pos();
                 let parser_type = consume_parser_type(
                     source, iter, &ctx.symbols, &ctx.heap, poly_vars, module_scope,
                     definition_id, false, 0
                 )?;
                 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 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(); // TODO: @Cleanup, this is really ugly. But rust...
                         consume_parser_type(
                             source, iter, &ctx.symbols, &ctx.heap, poly_vars,
                             module_scope, definition_id, false, 0
+                        )
                     },
                     &mut self.parser_types, "an embedded type", Some(&mut close_pos)
                 )?;
                 let value = if has_embedded {
                     UnionVariantValue::Embedded(self.parser_types.clone())
                 } else {
                     UnionVariantValue::None
                 };
                 self.parser_types.clear();
                 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> {
         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.parameters.start_section();
         consume_parameter_list(
             &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 open_curly_pos = iter.last_valid_pos();
         consume_comma_separated_until(
             TokenKind::OpenCurly, &module.source, iter, ctx,
             |source, iter, ctx| {
                 let poly_vars = ctx.heap[definition_id].poly_vars(); // TODO: @Cleanup, this is really ugly. But rust...
                 consume_parser_type(source, iter, &ctx.symbols, &ctx.heap, poly_vars, module_scope, definition_id, false, 0)
             },
             &mut self.parser_types, "a return type", Some(&mut open_curly_pos)
         )?;
         let return_types = self.parser_types.clone();
         // TODO: @ReturnValues
         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)?;
         // Assign everything in the preallocated AST node
         let function = ctx.heap[definition_id].as_function_mut();
         function.return_types = return_types;
         function.parameters = parameters;
         function.body = body;
         Ok(())
+    }
     fn visit_component_definition(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<(), ParseError> {
         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.parameters.start_section();
         consume_parameter_list(
             &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)?;
         // Assign everything in the AST node
         let component = ctx.heap[definition_id].as_component_mut();
         component.parameters = parameters;
         component.body = body;
         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();
             debug_assert_eq!(statements.len(), 1);
             let statements = statements.into_vec();
             Ok(ctx.heap.alloc_block_statement(|this| BlockStatement{
                 this,
                 is_implicit: true,
                 span: InputSpan::from_positions(wrap_begin_pos, wrap_end_pos), // TODO: @Span
                 statements,
                 parent_scope: None,
                 relative_pos_in_parent: 0,
                 locals: Vec::new(),
                 labels: Vec::new()
             }))
+        }
+    }
     /// 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> {
         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());
         } else if next == TokenKind::Ident {
-            let (ident, _) = consume_any_ident(&module.source, iter)?;
+            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: None
                 });
                 section.push(id.upcast());
                 let if_stmt = &mut ctx.heap[id];
                 if_stmt.end_if = Some(end_if);
             } 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: None
                 });
                 section.push(id.upcast());
                 let while_stmt = &mut ctx.heap[id];
                 while_stmt.end_while = Some(end_while);
             } else if ident == KW_STMT_BREAK {
                 let id = self.consume_break_statement(module, iter, ctx)?;
                 section.push(id.upcast());
             } else if ident == KW_STMT_CONTINUE {
                 let id = self.consume_continue_statement(module, iter, ctx)?;
                 section.push(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: None
                 });
                 let sync_stmt = &mut ctx.heap[id];
                 sync_stmt.end_sync = Some(end_sync);
             } else if ident == KW_STMT_RETURN {
                 let id = self.consume_return_statement(module, iter, ctx)?;
                 section.push(id.upcast());
             } else if ident == KW_STMT_GOTO {
                 let id = self.consume_goto_statement(module, iter, ctx)?;
                 section.push(id.upcast());
             } else if ident == KW_STMT_NEW {
                 let id = self.consume_new_statement(module, iter, ctx)?;
                 section.push(id.upcast());
             } else if ident == KW_STMT_CHANNEL {
                 let id = self.consume_channel_statement(module, iter, ctx)?;
                 section.push(id.upcast().upcast());
             } else if iter.peek() == Some(TokenKind::Colon) {
                 self.consume_labeled_statement(module, iter, ctx, section)?;
             } else {
                 // Two fallback possibilities: the first one is a memory
                 // declaration, the other one is to parse it as a regular
                 // expression. This is a bit ugly
                 if let Some((memory_stmt_id, assignment_stmt_id)) = self.maybe_consume_memory_statement(module, iter, ctx)? {
                     section.push(memory_stmt_id.upcast().upcast());
                     section.push(assignment_stmt_id.upcast());
                 } else {
                     let id = self.consume_expression_statement(module, iter, ctx)?;
                     section.push(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)
+    }
     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)?;
             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;
         Ok(ctx.heap.alloc_block_statement(|this| BlockStatement{
             this,
             is_implicit: false,
             span: block_span,
             statements,
             parent_scope: None,
             relative_pos_in_parent: 0,
             locals: Vec::new(),
             labels: Vec::new(),
         }))
+    }
     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)?;
         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)?;
             Some(false_body)
         } else {
             None
         };
         Ok(ctx.heap.alloc_if_statement(|this| IfStatement{
             this,
             span: if_span,
             test,
             true_body,
             false_body,
             end_if: None,
         }))
+    }
     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)?;
         Ok(ctx.heap.alloc_while_statement(|this| WhileStatement{
             this,
             span: while_span,
             test,
             body,
             end_while: None,
             in_sync: None,
         }))
+    }
     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: None,
         }))
+    }
     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: None
         }))
+    }
     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)?;
         Ok(ctx.heap.alloc_synchronous_statement(|this| SynchronousStatement{
             this,
             span: synchronous_span,
             body,
             end_sync: None,
             parent_scope: None,
         }))
+    }
     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, "a return 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: None
         }))
+    }
     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)?;
         // TODO: @Cleanup, should just call something like consume_component_expression-ish
         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: None
         }))
+    }
     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 channel_type = 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.
             iter.consume();
             let definition_id = self.cur_definition;
             let poly_vars = ctx.heap[definition_id].poly_vars();
             consume_parser_type(
                 &module.source, iter, &ctx.symbols, &ctx.heap,
                 &poly_vars, SymbolScope::Module(module.root_id), definition_id,
                 true, 1
             )?
         } else {
             // Assume inferred
             ParserType{ elements: vec![ParserTypeElement{
                 full_span: channel_span, // TODO: @Span fix
                 variant: ParserTypeVariant::Inferred
             }]}
         };
         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 from = ctx.heap.alloc_local(|this| Local{
             this,
             identifier: from_identifier,
             parser_type: channel_type.clone(),
             relative_pos_in_block: 0,
         });
         let to = ctx.heap.alloc_local(|this| Local{
             this,
             identifier: to_identifier,
             parser_type: channel_type,
             relative_pos_in_block: 0,
         });
         // Construct the channel
         Ok(ctx.heap.alloc_channel_statement(|this| ChannelStatement{
             this,
             span: channel_span,
             from, to,
             relative_pos_in_block: 0,
             next: None,
         }))
+    }
     fn consume_labeled_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, section: &mut ScopedSection<StatementId>
     ) -> Result<(), 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 stmt_id = ctx.heap.alloc_labeled_statement(|this| LabeledStatement {
             this,
             label,
             body: inner_section[0],
             relative_pos_in_block: 0,
             in_sync: None,
         });
         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(())
+    }
     fn maybe_consume_memory_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<Option<(MemoryStatementId, ExpressionStatementId)>, 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 = consume_parser_type(
             &module.source, iter, &ctx.symbols, &ctx.heap, poly_vars,
             SymbolScope::Definition(definition_id), definition_id, true, 0
         );
         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.elements[0].full_span.begin, identifier.span.end);
                 let assign_span = consume_token(&module.source, iter, TokenKind::Equal)?;
                 let initial_expr_begin_pos = iter.last_valid_pos();
                 let initial_expr_id = self.consume_expression(module, iter, ctx)?;
                 let initial_expr_end_pos = iter.last_valid_pos();
                 consume_token(&module.source, iter, TokenKind::SemiColon)?;
                 // Allocate the memory statement with the variable
                 let local_id = ctx.heap.alloc_local(|this| Local{
                     this,
                     identifier: identifier.clone(),
                     parser_type,
                     relative_pos_in_block: 0,
                 });
                 let memory_stmt_id = ctx.heap.alloc_memory_statement(|this| MemoryStatement{
                     this,
                     span: memory_span,
                     variable: local_id,
                     next: None
                 });
                 // Allocate the initial assignment
                 let variable_expr_id = ctx.heap.alloc_variable_expression(|this| VariableExpression{
                     this,
                     identifier,
                     declaration: None,
                     parent: ExpressionParent::None,
                     concrete_type: Default::default()
                 });
                 let assignment_expr_id = ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{
                     this,
                     span: assign_span,
                     left: variable_expr_id.upcast(),
                     operation: AssignmentOperator::Set,
                     right: initial_expr_id,
                     parent: ExpressionParent::None,
                     concrete_type: Default::default(),
                 });
                 let assignment_stmt_id = ctx.heap.alloc_expression_statement(|this| ExpressionStatement{
                     this,
                     span: InputSpan::from_positions(initial_expr_begin_pos, initial_expr_end_pos),
                     expression: assignment_expr_id.upcast(),
                     next: None,
                 });
                 return Ok(Some((memory_stmt_id, assignment_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: None,
         }))
+    }
     //--------------------------------------------------------------------------
     // Expression Parsing
     //--------------------------------------------------------------------------
     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::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 span = iter.next_span();
             iter.consume();
             let left = expr;
             let right = self.consume_expression(module, iter, ctx)?;
             Ok(ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{
                 this, span, left, operation, right,
                 parent: ExpressionParent::None,
                 concrete_type: ConcreteType::default(),
             }).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 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)?;
             Ok(ctx.heap.alloc_conditional_expression(|this| ConditionalExpression{
                 this, span, test, true_expression, false_expression,
                 parent: ExpressionParent::None,
                 concrete_type: ConcreteType::default(),
             }).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<UnaryOperation> {
             use TokenKind as TK;
             use UnaryOperation as UO;
             match token {
                 Some(TK::Plus) => Some(UO::Positive),
                 Some(TK::Minus) => Some(UO::Negative),
                 Some(TK::PlusPlus) => Some(UO::PreIncrement),
                 Some(TK::MinusMinus) => Some(UO::PreDecrement),
                 Some(TK::Tilde) => Some(UO::BitwiseNot),
                 Some(TK::Exclamation) => Some(UO::LogicalNot),
                 _ => None
+            }
+        }
         if let Some(operation) = parse_prefix_token(iter.next()) {
             let span = iter.next_span();
             iter.consume();
             let expression = self.consume_prefix_expression(module, iter, ctx)?;
             Ok(ctx.heap.alloc_unary_expression(|this| UnaryExpression {
                 this, span, operation, expression,
                 parent: ExpressionParent::None,
                 concrete_type: ConcreteType::default()
             }).upcast())
         } 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 span = iter.next_span();
             iter.consume();
             if token == TokenKind::PlusPlus {
                 result = ctx.heap.alloc_unary_expression(|this| UnaryExpression{
                     this, span,
                     operation: UnaryOperation::PostIncrement,
                     expression: result,
                     parent: ExpressionParent::None,
                     concrete_type: ConcreteType::default()
                 }).upcast();
             } else if token == TokenKind::MinusMinus {
                 result = ctx.heap.alloc_unary_expression(|this| UnaryExpression{
                     this, span,
                     operation: UnaryOperation::PostDecrement,
                     expression: result,
                     parent: ExpressionParent::None,
                     concrete_type: ConcreteType::default()
                 }).upcast();
             } 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)?;
                     span.end = end_span.end;
                     result = ctx.heap.alloc_slicing_expression(|this| SlicingExpression{
                         this, span, subject, from_index, to_index,
                         parent: ExpressionParent::None,
                         concrete_type: ConcreteType::default()
                     }).upcast();
                 } else if Some(TokenKind::CloseSquare) == next {
                     let end_span = consume_token(&module.source, iter, TokenKind::CloseSquare)?;
                     span.end = end_span.end;
                     result = ctx.heap.alloc_indexing_expression(|this| IndexingExpression{
                         this, span, subject,
                         index: from_index,
                         parent: ExpressionParent::None,
                         concrete_type: ConcreteType::default()
                     }).upcast();
                 } else {
                     return Err(ParseError::new_error_str_at_pos(
                         &module.source, iter.last_valid_pos(), "unexpected token: expected ']' or '..'"
                     ));
+                }
             } else {
                 debug_assert_eq!(token, TokenKind::Dot);
                 let subject = result;
                 let (field_text, field_span) = consume_ident(&module.source, iter)?;
                 let field = if field_text == b"length" {
                     Field::Length
                 } else {
                     let value = ctx.pool.intern(field_text);
                     let identifier = Identifier{ value, span: field_span };
                     Field::Symbolic(FieldSymbolic{ identifier, definition: None, field_idx: 0 })
                 };
                 result = ctx.heap.alloc_select_expression(|this| SelectExpression{
                     this, span, subject, field,
                     parent: ExpressionParent::None,
                     concrete_type: ConcreteType::default()
                 }).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) {
             // Expression between parentheses
             iter.consume();
             let result = self.consume_expression(module, iter, ctx)?;
             consume_token(&module.source, iter, TokenKind::CloseParen)?;
             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,
                 concrete_type: ConcreteType::default(),
             }).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,
                 concrete_type: ConcreteType::default(),
             }).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,
                 concrete_type: ConcreteType::default(),
             }).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,
                 concrete_type: ConcreteType::default(),
             }).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 = consume_parser_type(
                     &module.source, iter, &ctx.symbols, &ctx.heap, poly_vars, symbol_scope,
                     self.cur_definition, true, 0
                 )?;
                 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 field", 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,
                                     concrete_type: ConcreteType::default(),
                                 }).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,
                                     concrete_type: ConcreteType::default()
                                 }).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 = iter.last_valid_pos();
                                 let values = self.consume_expression_list(module, iter, ctx, Some(&mut end_pos))?;
                                 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,
                                     concrete_type: ConcreteType::default()
                                 }).upcast()
                             },
                             Definition::Component(_) => {
                                 // Component instantiation
                                 let arguments = self.consume_expression_list(module, iter, ctx, None)?;
                                 ctx.heap.alloc_call_expression(|this| CallExpression{
                                     this,
                                     span: parser_type.elements[0].full_span, // TODO: @Span fix
                                     parser_type,
                                     method: Method::UserComponent,
                                     arguments,
                                     definition: target_definition_id,
                                     parent: ExpressionParent::None,
                                     concrete_type: ConcreteType::default(),
                                 }).upcast()
                             },
                             Definition::Function(function_definition) => {
                                 // Check whether it is a builtin function
                                 let method = if function_definition.builtin {
                                     match function_definition.identifier.value.as_str() {
                                         "get" => Method::Get,
                                         "put" => Method::Put,
                                         "fires" => Method::Fires,
                                         "create" => Method::Create,
                                         "length" => Method::Length,
                                         "assert" => Method::Assert,
                                         _ => unreachable!(),
+                                    }
                                 } else {
                                     Method::UserFunction
                                 };
                                 // Function call: consume the arguments
                                 let arguments = self.consume_expression_list(module, iter, ctx, None)?;
                                 ctx.heap.alloc_call_expression(|this| CallExpression{
                                     this,
                                     span: parser_type.elements[0].full_span, // TODO: @Span fix
                                     parser_type,
                                     method,
                                     arguments,
                                     definition: target_definition_id,
                                     parent: ExpressionParent::None,
                                     concrete_type: ConcreteType::default(),
                                 }).upcast()
+                            }
+                        }
                     },
                     _ => {
                         // TODO: Casting expressions
                         return Err(ParseError::new_error_str_at_span(
                             &module.source, parser_type.elements[0].full_span,
                             "unexpected type in expression, note that casting expressions are not yet implemented"
                         ))
+                    }
+                }
             } else {
                 // Check for builtin keywords or builtin functions
                 if ident_text == KW_LIT_NULL || ident_text == KW_LIT_TRUE || ident_text == KW_LIT_FALSE {
                     // 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,
                         concrete_type: ConcreteType::default(),
                     }).upcast()
                 } else {
                     // I'm a bit unsure about this. One may as well have wrongfully
                     // typed `TypeWithTypo<Subtype>::`, then we assume that
                     // `TypeWithTypo` is a variable. So might want to come back to
                     // this later to do some silly heuristics.
                     iter.consume();
                     if Some(TokenKind::ColonColon) == iter.next() {
                         return Err(ParseError::new_error_str_at_span(&module.source, ident_span, "unknown identifier"));
+                    }
                     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,
                         parent: ExpressionParent::None,
                         concrete_type: ConcreteType::default()
                     }).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 span = iter.next_span();
             iter.consume();
             let left = result;
             let right = higher_precedence_fn(self, module, iter, ctx)?;
             result = ctx.heap.alloc_binary_expression(|this| BinaryExpression{
                 this, span, left, operation, right,
                 parent: ExpressionParent::None,
                 concrete_type: ConcreteType::default()
             }).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 a type. A type always starts with an identifier which may indicate
 /// a builtin type or a user-defined type. The fact that it may contain
 /// polymorphic arguments makes it a tree-like structure. Because we cannot rely
 /// on knowing the exact number of polymorphic arguments we do not check for
 /// these.
 ///
 /// Note that the first depth index is used as a hack.
 // TODO: @Optimize, @Span fix
 fn consume_parser_type(
     source: &InputSource, iter: &mut TokenIter, symbols: &SymbolTable, heap: &Heap, poly_vars: &[Identifier],
     cur_scope: SymbolScope, wrapping_definition: DefinitionId, allow_inference: bool, first_angle_depth: i32,
 ) -> Result<ParserType, ParseError> {
     struct Entry{
         element: ParserTypeElement,
         depth: i32,
+    }
     fn insert_array_before(elements: &mut Vec<Entry>, depth: i32, span: InputSpan) {
         let index = elements.iter().rposition(|e| e.depth == depth).unwrap();
         elements.insert(index, Entry{
             element: ParserTypeElement{ full_span: span, variant: ParserTypeVariant::Array },
             depth,
         });
+    }
     // Most common case we just have one type, perhaps with some array
     // annotations.
     let element = consume_parser_type_ident(source, iter, symbols, heap, poly_vars, cur_scope, wrapping_definition, allow_inference)?;
     if iter.next() != Some(TokenKind::OpenAngle) {
         let mut num_array = 0;
         while iter.next() == Some(TokenKind::OpenSquare) {
             iter.consume();
             consume_token(source, iter, TokenKind::CloseSquare)?;
             num_array += 1;
+        }
         let array_span = element.full_span;
         let mut elements = Vec::with_capacity(num_array + 1);
         for _ in 0..num_array {
             elements.push(ParserTypeElement{ full_span: array_span, variant: ParserTypeVariant::Array });
+        }
         elements.push(element);
         return Ok(ParserType{ elements });
     };
     // We have a polymorphic specification. So we start by pushing the item onto
     // our stack, then start adding entries together with the angle-brace depth
     // at which they're found.
     let mut elements = Vec::new();
     elements.push(Entry{ element, depth: 0 });
     // Start out with the first '<' consumed.
     iter.consume();
     enum State { Ident, Open, Close, Comma }
     let mut state = State::Open;
     let mut angle_depth = first_angle_depth + 1;
     loop {
         let next = iter.next();
         match state {
             State::Ident => {
                 // Just parsed an identifier, may expect comma, angled braces,
                 // or the tokens indicating an array
                 if Some(TokenKind::OpenAngle) == next {
                     angle_depth += 1;
                     state = State::Open;
                 } else if Some(TokenKind::CloseAngle) == next {
                     angle_depth -= 1;
                     state = State::Close;
                 } else if Some(TokenKind::ShiftRight) == next {
                     angle_depth -= 2;
                     state = State::Close;
                 } else if Some(TokenKind::Comma) == next {
                     state = State::Comma;
                 } else if Some(TokenKind::OpenSquare) == next {
                     let (start_pos, _) = iter.next_positions();
                     iter.consume(); // consume opening square
                     if iter.next() != Some(TokenKind::CloseSquare) {
                         return Err(ParseError::new_error_str_at_pos(
                             source, iter.last_valid_pos(),
                             "unexpected token: expected ']'"
                         ));
+                    }
                     let (_, end_pos) = iter.next_positions();
                     let array_span = InputSpan::from_positions(start_pos, end_pos);
                     insert_array_before(&mut elements, angle_depth, array_span);
                 } else {
                     return Err(ParseError::new_error_str_at_pos(
                         source, iter.last_valid_pos(),
                         "unexpected token: expected '<', '>', ',' or '['")
                     );
+                }
                 iter.consume();
             },
             State::Open => {
                 // Just parsed an opening angle bracket, expecting an identifier
                 let element = consume_parser_type_ident(source, iter, symbols, heap, poly_vars, cur_scope, wrapping_definition, allow_inference)?;
                 elements.push(Entry{ element, depth: angle_depth });
                 state = State::Ident;
             },
             State::Close => {
                 // Just parsed 1 or 2 closing angle brackets, expecting comma,
                 // more closing brackets or the tokens indicating an array
                 if Some(TokenKind::Comma) == next {
                     state = State::Comma;
                 } else if Some(TokenKind::CloseAngle) == next {
                     angle_depth -= 1;
                     state = State::Close;
                 } else if Some(TokenKind::ShiftRight) == next {
                     angle_depth -= 2;
                     state = State::Close;
                 } else if Some(TokenKind::OpenSquare) == next {
                     let (start_pos, _) = iter.next_positions();
                     iter.consume();
                     if iter.next() != Some(TokenKind::CloseSquare) {
                         return Err(ParseError::new_error_str_at_pos(
                             source, iter.last_valid_pos(),
                             "unexpected token: expected ']'"
                         ));
+                    }
                     let (_, end_pos) = iter.next_positions();
                     let array_span = InputSpan::from_positions(start_pos, end_pos);
                     insert_array_before(&mut elements, angle_depth, array_span);
                 } else {
                     return Err(ParseError::new_error_str_at_pos(
                         source, iter.last_valid_pos(),
                         "unexpected token: expected ',', '>', or '['")
                     );
+                }
                 iter.consume();
             },
             State::Comma => {
                 // Just parsed a comma, expecting an identifier or more closing
                 // braces
                 if Some(TokenKind::Ident) == next {
                     let element = consume_parser_type_ident(source, iter, symbols, heap, poly_vars, cur_scope, wrapping_definition, allow_inference)?;
                     elements.push(Entry{ element, depth: angle_depth });
                     state = State::Ident;
                 } else if Some(TokenKind::CloseAngle) == next {
                     iter.consume();
                     angle_depth -= 1;
                     state = State::Close;
                 } else if Some(TokenKind::ShiftRight) == next {
                     iter.consume();
                     angle_depth -= 2;
                     state = State::Close;
                 } else {
                     return Err(ParseError::new_error_str_at_pos(
                         source, iter.last_valid_pos(),
                         "unexpected token: expected '>' or a type name"
                     ));
+                }
+            }
+        }
         if angle_depth < 0 {
             return Err(ParseError::new_error_str_at_pos(source, iter.last_valid_pos(), "unmatched '>'"));
         } else if angle_depth == 0 {
             break;
+        }
+    }
     // If here then we found the correct number of angle braces. But we still
     // need to make sure that each encountered type has the correct number of
     // embedded types.
     let mut idx = 0;
     while idx < elements.len() {
         let cur_element = &elements[idx];
         let expected_subtypes = cur_element.element.variant.num_embedded();
         let mut encountered_subtypes = 0;
         for peek_idx in idx + 1..elements.len() {
             let peek_element = &elements[peek_idx];
             if peek_element.depth == cur_element.depth + 1 {
                 encountered_subtypes += 1;
             } else if peek_element.depth <= cur_element.depth {
                 break;
+            }
+        }
         if expected_subtypes != encountered_subtypes {
             if encountered_subtypes == 0 {
                 // Case where we have elided the embedded types, all of them
                 // should be inferred.
                 if !allow_inference {
                     return Err(ParseError::new_error_str_at_span(
                         source, cur_element.element.full_span,
                         "type inference is not allowed here"
                     ));
+                }
                 // Insert the missing types
                 let inserted_span = cur_element.element.full_span;
                 let inserted_depth = cur_element.depth + 1;
                 elements.reserve(expected_subtypes);
                 for _ in 0..expected_subtypes {
                     elements.insert(idx + 1, Entry{
                         element: ParserTypeElement{ full_span: inserted_span, variant: ParserTypeVariant::Inferred },
                         depth: inserted_depth,
                     });
+                }
             } else {
                 // Mismatch in number of embedded types
                 let expected_args_text = if expected_subtypes == 1 {
                     "polymorphic argument"
                 } else {
                     "polymorphic arguments"
                 };
                 let maybe_infer_text = if allow_inference {
                     " (or none, to perform implicit type inference)"
                 } else {
                     ""
                 };
                 return Err(ParseError::new_error_at_span(
                     source, cur_element.element.full_span,
                     format!(
                         "expected {} {}{}, but {} were provided",
                         expected_subtypes, expected_args_text, maybe_infer_text, encountered_subtypes
+                    )
                 ));
+            }
+        }
         idx += 1;
+    }
     let mut constructed_elements = Vec::with_capacity(elements.len());
     for element in elements.into_iter() {
         constructed_elements.push(element.element);
+    }
     Ok(ParserType{ elements: constructed_elements })
+}
 /// Consumes an identifier for which we assume that it resolves to some kind of
 /// type. Once we actually arrive at a type we will stop parsing. Hence there
 /// may be trailing '::' tokens in the iterator.
 fn consume_parser_type_ident(
     source: &InputSource, iter: &mut TokenIter, symbols: &SymbolTable, heap: &Heap, poly_vars: &[Identifier],
     mut scope: SymbolScope, wrapping_definition: DefinitionId, allow_inference: bool,
 ) -> Result<ParserTypeElement, ParseError> {
     use ParserTypeVariant as PTV;
     let (mut type_text, mut type_span) = consume_any_ident(source, iter)?;
     let variant = match type_text {
         KW_TYPE_MESSAGE => PTV::Message,
         KW_TYPE_BOOL => PTV::Bool,
         KW_TYPE_UINT8 => PTV::UInt8,
         KW_TYPE_UINT16 => PTV::UInt16,
         KW_TYPE_UINT32 => PTV::UInt32,
         KW_TYPE_UINT64 => PTV::UInt64,
         KW_TYPE_SINT8 => PTV::SInt8,
         KW_TYPE_SINT16 => PTV::SInt16,
         KW_TYPE_SINT32 => PTV::SInt32,
         KW_TYPE_SINT64 => PTV::SInt64,
         KW_TYPE_IN_PORT => PTV::Input,
         KW_TYPE_OUT_PORT => PTV::Output,
         KW_TYPE_CHAR => PTV::Character,
         KW_TYPE_STRING => PTV::String,
         KW_TYPE_INFERRED => {
             if !allow_inference {
                 return Err(ParseError::new_error_str_at_span(source, type_span, "type inference is not allowed here"));
+            }
             PTV::Inferred
         },
         _ => {
             // Must be some kind of symbolic type
             let mut type_kind = None;
             for (poly_idx, poly_var) in poly_vars.iter().enumerate() {
                 if poly_var.value.as_bytes() == type_text {
                     type_kind = Some(PTV::PolymorphicArgument(wrapping_definition, poly_idx));
+                }
+            }
             if type_kind.is_none() {
                 // Check symbol table for definition. To be fair, the language
                 // only allows a single namespace for now. That said:
                 let last_symbol = symbols.get_symbol_by_name(scope, type_text);
                 if last_symbol.is_none() {
                     return Err(ParseError::new_error_str_at_span(source, type_span, "unknown type"));
+                }
                 let mut last_symbol = last_symbol.unwrap();
                 loop {
                     match &last_symbol.variant {
                         SymbolVariant::Module(symbol_module) => {
                             // Expecting more identifiers
                             if Some(TokenKind::ColonColon) != iter.next() {
                                 return Err(ParseError::new_error_str_at_span(source, type_span, "expected type but got module"));
+                            }
                             consume_token(source, iter, TokenKind::ColonColon)?;
                             // Consume next part of type and prepare for next
                             // lookup loop
                             let (next_text, next_span) = consume_any_ident(source, iter)?;
                             let old_text = type_text;
                             type_text = next_text;
                             type_span.end = next_span.end;
                             scope = SymbolScope::Module(symbol_module.root_id);
                             let new_symbol = symbols.get_symbol_by_name_defined_in_scope(scope, type_text);
                             if new_symbol.is_none() {
                                 return Err(ParseError::new_error_at_span(
                                     source, next_span,
                                     format!(
                                         "unknown type '{}' in module '{}'",
                                         String::from_utf8_lossy(type_text),
                                         String::from_utf8_lossy(old_text)
+                                    )
                                 ));
+                            }
                             last_symbol = new_symbol.unwrap();
                         },
                         SymbolVariant::Definition(symbol_definition) => {
                             let num_poly_vars = heap[symbol_definition.definition_id].poly_vars().len();
                             type_kind = Some(PTV::Definition(symbol_definition.definition_id, num_poly_vars));
                             break;
+                        }
+                    }
+                }
+            }
             debug_assert!(type_kind.is_some());
             type_kind.unwrap()
         },
     };
     Ok(ParserTypeElement{ full_span: type_span, variant })
+}
 /// 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(
     source: &InputSource, iter: &mut TokenIter, ctx: &mut PassCtx,
     target: &mut ScopedSection<ParameterId>, 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(); // TODO: @Cleanup, this is really ugly. But rust...
             let (start_pos, _) = iter.next_positions();
             let parser_type = consume_parser_type(
                 source, iter, &ctx.symbols, &ctx.heap, poly_vars, scope,
                 definition_id, false, 0
             )?;
             let identifier = consume_ident_interned(source, iter, ctx)?;
             let parameter_id = ctx.heap.alloc_parameter(|this| Parameter{
                 this,
                 span: InputSpan::from_positions(start_pos, identifier.span.end),
                 parser_type,
                 identifier
             });
             Ok(parameter_id)
         },
         target, "a parameter", "a parameter list", None
+    )
+}
@@ \ No newline at end of file @@

src/protocol/parser/pass_imports.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 crate::protocol::input_source::{InputSource as InputSource, InputSpan, ParseError};
 use crate::collections::*;
 /// Parses all the imports in the module tokens. Is applied after the
 /// definitions and name of modules are resolved. Hence we should be able to
 /// resolve all symbols to their appropriate module/definition.
 pub(crate) struct PassImport {
     imports: Vec<ImportId>,
     found_symbols: Vec<(AliasedSymbol, SymbolDefinition)>,
     scoped_symbols: Vec<Symbol>,
+}
 impl PassImport {
     pub(crate) fn new() -> Self {
         Self{
             imports: Vec::with_capacity(32),
             found_symbols: Vec::with_capacity(32),
             scoped_symbols: Vec::with_capacity(32),
+        }
+    }
     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!(modules.iter().all(|m| m.phase >= ModuleCompilationPhase::SymbolsScanned));
         debug_assert_eq!(module.phase, ModuleCompilationPhase::SymbolsScanned);
         debug_assert_eq!(module_range.range_kind, TokenRangeKind::Module);
         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];
             if cur_range.range_kind == TokenRangeKind::Import {
                 self.visit_import_range(modules, module_idx, ctx, range_idx_usize)?;
+            }
             match cur_range.next_sibling_idx {
                 Some(idx) => { range_idx = idx; },
                 None => { break; }
             if cur_range.next_sibling_idx == NO_SIBLING {
                 break;
             } else {
                 range_idx = cur_range.next_sibling_idx;
+            }
+        }
         let root = &mut ctx.heap[module.root_id];
         root.imports.extend(self.imports.drain(..));
         let module = &mut modules[module_idx];
         module.phase = ModuleCompilationPhase::ImportsResolved;
         Ok(())
+    }
     pub(crate) fn visit_import_range(
         &mut self, modules: &[Module], module_idx: usize, ctx: &mut PassCtx, range_idx: usize
     ) -> Result<(), ParseError> {
         let module = &modules[module_idx];
         let import_range = &module.tokens.ranges[range_idx];
         debug_assert_eq!(import_range.range_kind, TokenRangeKind::Import);
         let mut iter = module.tokens.iter_range(import_range);
         // Consume "import"
         let (_import_ident, import_span) =
             consume_any_ident(&module.source, &mut iter)?;
         debug_assert_eq!(_import_ident, KW_IMPORT);
         // Consume module name
         let (module_name, module_name_span) = consume_domain_ident(&module.source, &mut iter)?;
         let target_root_id = ctx.symbols.get_module_by_name(module_name);
         if target_root_id.is_none() {
             return Err(ParseError::new_error_at_span(
                 &module.source, module_name_span,
                 format!("could not resolve module '{}'", String::from_utf8_lossy(module_name))
             ));
+        }
         let module_name = ctx.pool.intern(module_name);
         let module_identifier = Identifier{ span: module_name_span, value: module_name };
         let target_root_id = target_root_id.unwrap();
         // Check for subsequent characters (alias, multiple imported symbols)
         let next = iter.next();
         let import_id;
         if has_ident(&module.source, &mut iter, b"as") {
             // Alias for module
             iter.consume();
             let alias_identifier = consume_ident_interned(&module.source, &mut iter, ctx)?;
             let alias_name = alias_identifier.value.clone();
             import_id = ctx.heap.alloc_import(|this| Import::Module(ImportModule{
                 this,
                 span: import_span,
                 module: module_identifier,
                 alias: alias_identifier,
                 module_id: target_root_id
             }));
             ctx.symbols.insert_symbol(SymbolScope::Module(module.root_id), Symbol{
                 name: alias_name,
                 variant: SymbolVariant::Module(SymbolModule{
                     root_id: target_root_id,
                     introduced_at: import_id,
                 }),
             });
         } else if Some(TokenKind::ColonColon) == next {
             iter.consume();
             // Helper function to consume symbols, their alias, and the
             // definition the symbol is pointing to.
             fn consume_symbol_and_maybe_alias<'a>(
                 source: &'a InputSource, iter: &mut TokenIter, ctx: &mut PassCtx,
                 module_name: &StringRef<'static>, module_root_id: RootId,
             ) -> Result<(AliasedSymbol, SymbolDefinition), ParseError> {
                 // Consume symbol name and make sure it points to an existing definition
                 let symbol_identifier = consume_ident_interned(source, iter, ctx)?;
                 // Consume alias text if specified
                 let alias_identifier = if peek_ident(source, iter) == Some(b"as") {
                     // Consume alias
                     iter.consume();
                     Some(consume_ident_interned(source, iter, ctx)?)
                 } else {
                     None
                 };
                 let target = ctx.symbols.get_symbol_by_name_defined_in_scope(
                     SymbolScope::Module(module_root_id), symbol_identifier.value.as_bytes()
                 );
                 if target.is_none() {
                     return Err(ParseError::new_error_at_span(
                         source, symbol_identifier.span,
                         format!(
                             "could not find symbol '{}' within module '{}'",
                             symbol_identifier.value.as_str(), module_name.as_str()
+                        )
                     ));
+                }
                 let target = target.unwrap();
                 debug_assert_ne!(target.class(), SymbolClass::Module);
                 let target_definition = target.variant.as_definition();
                 Ok((
                     AliasedSymbol{
                         name: symbol_identifier,
                         alias: alias_identifier,
                         definition_id: target_definition.definition_id,
                     },
                     target_definition.clone()
                 ))
+            }
             let next = iter.next();
             if Some(TokenKind::Ident) == next {
                 // Importing a single symbol
                 iter.consume();
                 let (imported_symbol, symbol_definition) = consume_symbol_and_maybe_alias(
                     &module.source, &mut iter, ctx, &module_identifier.value, target_root_id
                 )?;
                 let alias_identifier = match imported_symbol.alias.as_ref() {
                     Some(alias) => alias.clone(),
                     None => imported_symbol.name.clone(),
                 };
                 import_id = ctx.heap.alloc_import(|this| Import::Symbols(ImportSymbols{
                     this,
                     span: InputSpan::from_positions(import_span.begin, alias_identifier.span.end),
                     module: module_identifier,
                     module_id: target_root_id,
                     symbols: vec![imported_symbol],
                 }));
                 if let Err((new_symbol, old_symbol)) = ctx.symbols.insert_symbol(
                     SymbolScope::Module(module.root_id),
                     Symbol{
                         name: alias_identifier.value,
                         variant: SymbolVariant::Definition(symbol_definition.into_imported(import_id))
+                    }
                 ) {
                     return Err(construct_symbol_conflict_error(
                         modules, module_idx, ctx, &new_symbol, &old_symbol
                     ));
+                }
             } else if Some(TokenKind::OpenCurly) == next {
                 // Importing multiple symbols
                 let mut end_of_list = iter.last_valid_pos();
                 consume_comma_separated(
                     TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, &mut iter, ctx,
                     |source, iter, ctx| consume_symbol_and_maybe_alias(
                         source, iter, ctx, &module_identifier.value, target_root_id
                     ),
                     &mut self.found_symbols, "a symbol", "a list of symbols to import", Some(&mut end_of_list)
                 )?;
                 // Preallocate import
                 import_id = ctx.heap.alloc_import(|this| Import::Symbols(ImportSymbols {
                     this,
                     span: InputSpan::from_positions(import_span.begin, end_of_list),
                     module: module_identifier,
                     module_id: target_root_id,
                     symbols: Vec::with_capacity(self.found_symbols.len()),
                 }));
                 // Fill import symbols while inserting symbols in the
                 // appropriate scope in the symbol table.
                 let import = ctx.heap[import_id].as_symbols_mut();
                 for (imported_symbol, symbol_definition) in self.found_symbols.drain(..) {
                     let import_name = match imported_symbol.alias.as_ref() {
                         Some(import) => import.value.clone(),
                         None => imported_symbol.name.value.clone()
                     };
                     import.symbols.push(imported_symbol);
                     if let Err((new_symbol, old_symbol)) = ctx.symbols.insert_symbol(
                         SymbolScope::Module(module.root_id), Symbol{
                             name: import_name,
                             variant: SymbolVariant::Definition(symbol_definition.into_imported(import_id))
+                        }
                     ) {
                         return Err(construct_symbol_conflict_error(modules, module_idx, ctx, &new_symbol, &old_symbol));
+                    }
+                }
             } else if Some(TokenKind::Star) == next {
                 // Import all symbols from the module
                 let star_span = iter.next_span();
                 iter.consume();
                 self.scoped_symbols.clear();
                 let _found = ctx.symbols.get_all_symbols_defined_in_scope(
                     SymbolScope::Module(target_root_id),
                     &mut self.scoped_symbols
                 );
                 debug_assert!(_found); // even modules without symbols should have a scope
                 // Preallocate import
                 import_id = ctx.heap.alloc_import(|this| Import::Symbols(ImportSymbols{
                     this,
                     span: InputSpan::from_positions(import_span.begin, star_span.end),
                     module: module_identifier,
                     module_id: target_root_id,
                     symbols: Vec::with_capacity(self.scoped_symbols.len())
                 }));
                 // Fill import AST node and symbol table
                 let import = ctx.heap[import_id].as_symbols_mut();
                 for symbol in self.scoped_symbols.drain(..) {
                     let symbol_name = symbol.name;
                     match symbol.variant {
                         SymbolVariant::Definition(symbol_definition) => {
                             import.symbols.push(AliasedSymbol{
                                 name: Identifier{ span: star_span, value: symbol_name.clone() },
                                 alias: None,
                                 definition_id: symbol_definition.definition_id,
                             });
                             if let Err((new_symbol, old_symbol)) = ctx.symbols.insert_symbol(
                                 SymbolScope::Module(module.root_id),
                                 Symbol{
                                     name: symbol_name,
                                     variant: SymbolVariant::Definition(symbol_definition.into_imported(import_id))
+                                }
                             ) {
                                 return Err(construct_symbol_conflict_error(modules, module_idx, ctx, &new_symbol, &old_symbol));
+                            }
                         },
                         _ => unreachable!(),
+                    }
+                }
             } else {
                 return Err(ParseError::new_error_str_at_pos(
                     &module.source, iter.last_valid_pos(), "expected symbol name, '{' or '*'"
                 ));
+            }
         } else {
             // Assume implicit alias
             let module_name_str = module_identifier.value.clone();
             let last_ident_start = module_name_str.as_str().rfind('.').map_or(0, |v| v + 1);
             let alias_text = &module_name_str.as_bytes()[last_ident_start..];
             let alias = ctx.pool.intern(alias_text);
             let alias_span = InputSpan::from_positions(
                 module_name_span.begin.with_offset(last_ident_start as u32),
                 module_name_span.end
             );
             let alias_identifier = Identifier{ span: alias_span, value: alias.clone() };
             import_id = ctx.heap.alloc_import(|this| Import::Module(ImportModule{
                 this,
                 span: InputSpan::from_positions(import_span.begin, module_identifier.span.end),
                 module: module_identifier,
                 alias: alias_identifier,
                 module_id: target_root_id,
             }));
             if let Err((new_symbol, old_symbol)) = ctx.symbols.insert_symbol(SymbolScope::Module(module.root_id), Symbol{
                 name: alias,
                 variant: SymbolVariant::Module(SymbolModule{
                     root_id: target_root_id,
                     introduced_at: import_id
                 })
             }) {
                 return Err(construct_symbol_conflict_error(modules, module_idx, ctx, &new_symbol, &old_symbol));
+            }
+        }
         // By now the `import_id` is set, just need to make sure that the import
         // properly ends with a semicolon
         consume_token(&module.source, &mut iter, TokenKind::SemiColon)?;
         self.imports.push(import_id);
         Ok(())
+    }
+}

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;
         let module = &modules[module_idx];
         // Visit token ranges to detect definitions and pragmas
         loop {
             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)?;
+            }
             match next_sibling_idx {
                 Some(idx) => { range_idx = idx; },
                 None => { break; },
             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(None, module_scope);
         for symbol in self.symbols.drain(..) {
             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(..));
         let module = &mut modules[module_idx];
         module.phase = ModuleCompilationPhase::SymbolsScanned;
         Ok(())
+    }
     fn visit_pragma_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 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, 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"
                 ));
+            }
             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);
             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)
                 });
                 definition_class = DefinitionClass::Function;
                 ast_definition_id = func_def_id.upcast();
             },
             KW_PRIMITIVE | KW_COMPOSITE => {
                 let component_variant = if kw_text == KW_PRIMITIVE {
                     ComponentVariant::Primitive
                 } else {
                     ComponentVariant::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)
                 });
                 definition_class = DefinitionClass::Component;
                 ast_definition_id = comp_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_tokenizer.rs

➞

Show inline comments

 use crate::protocol::input_source::{
     InputSource as InputSource,
     ParseError,
     InputPosition as InputPosition,
 };
 use super::tokens::*;
 use super::token_parsing::*;
 /// Tokenizer is a reusable parser to tokenize multiple source files using the
 /// same allocated buffers. In a well-formed program, we produce a consistent
 /// tree of token ranges such that we may identify tokens that represent a
 /// defintion or an import before producing the entire AST.
 ///
 /// If the program is not well-formed then the tree may be inconsistent, but we
 /// will detect this once we transform the tokens into the AST. To ensure a
 /// consistent AST-producing phase we will require the import to have balanced
 /// curly braces
 pub(crate) struct PassTokenizer {
     // Stack of input positions of opening curly braces, used to detect
     // unmatched opening braces, unmatched closing braces are detected
     // immediately.
     curly_stack: Vec<InputPosition>,
     // Points to an element in the `TokenBuffer.ranges` variable.
     stack_idx: usize,
+}
 impl PassTokenizer {
     pub(crate) fn new() -> Self {
         Self{
             curly_stack: Vec::with_capacity(32),
             stack_idx: 0
+        }
+    }
     pub(crate) fn tokenize(&mut self, source: &mut InputSource, target: &mut TokenBuffer) -> Result<(), ParseError> {
         // Assert source and buffer are at start
         debug_assert_eq!(source.pos().offset, 0);
         debug_assert!(target.tokens.is_empty());
         debug_assert!(target.ranges.is_empty());
         // Set up for tokenization by pushing the first range onto the stack.
         // This range may get transformed into the appropriate range kind later,
         // see `push_range` and `pop_range`.
         self.stack_idx = 0;
         target.ranges.push(TokenRange{
-            parent_idx: 0,
+            parent_idx: NO_RELATION,
             range_kind: TokenRangeKind::Module,
             curly_depth: 0,
             start: 0,
             end: 0,
             num_child_ranges: 0,
             first_child_idx: 0,
             last_child_idx: 0,
             next_sibling_idx: None,
             first_child_idx: NO_RELATION,
             last_child_idx: NO_RELATION,
             next_sibling_idx: NO_RELATION,
         });
         // Main tokenization loop
         while let Some(c) = source.next() {
             let token_index = target.tokens.len() as u32;
             if is_char_literal_start(c) {
                 self.consume_char_literal(source, target)?;
             } else if is_string_literal_start(c) {
                 self.consume_string_literal(source, target)?;
             } else if is_identifier_start(c) {
                 let ident = self.consume_identifier(source, target)?;
                 if demarks_definition(ident) {
                     self.push_range(target, TokenRangeKind::Definition, token_index);
                 } else if demarks_import(ident) {
                     self.push_range(target, TokenRangeKind::Import, token_index);
+                }
             } else if is_integer_literal_start(c) {
                 self.consume_number(source, target)?;
             } else if is_pragma_start_or_pound(c) {
                 let was_pragma = self.consume_pragma_or_pound(c, source, target)?;
                 if was_pragma {
                     self.push_range(target, TokenRangeKind::Pragma, token_index);
+                }
             } else if self.is_line_comment_start(c, source) {
                 self.consume_line_comment(source, target)?;
             } else if self.is_block_comment_start(c, source) {
                 self.consume_block_comment(source, target)?;
             } else if is_whitespace(c) {
                 let contained_newline = self.consume_whitespace(source);
                 if contained_newline {
                     let range = &target.ranges[self.stack_idx];
                     if range.range_kind == TokenRangeKind::Pragma {
                         self.pop_range(target, target.tokens.len() as u32);
+                    }
+                }
             } else {
                 let was_punctuation = self.maybe_parse_punctuation(c, source, target)?;
                 if let Some((token, token_pos)) = was_punctuation {
                     if token == TokenKind::OpenCurly {
                         self.curly_stack.push(token_pos);
                     } else if token == TokenKind::CloseCurly {
                         // Check if this marks the end of a range we're
                         // currently processing
                         if self.curly_stack.is_empty() {
                             return Err(ParseError::new_error_str_at_pos(
                                 source, token_pos, "unmatched closing curly brace '}'"
                             ));
+                        }
                         self.curly_stack.pop();
                         let range = &target.ranges[self.stack_idx];
                         if range.range_kind == TokenRangeKind::Definition && range.curly_depth == self.curly_stack.len() as u32 {
                             self.pop_range(target, target.tokens.len() as u32);
+                        }
                         // Exit early if we have more closing curly braces than
                         // opening curly braces
                     } else if token == TokenKind::SemiColon {
                         // Check if this marks the end of an import
                         let range = &target.ranges[self.stack_idx];
                         if range.range_kind == TokenRangeKind::Import {
                             self.pop_range(target, target.tokens.len() as u32);
+                        }
+                    }
                 } else {
                     return Err(ParseError::new_error_str_at_pos(
                         source, source.pos(), "unexpected character"
                     ));
+                }
+            }
+        }
         // End of file, check if our state is correct
         if let Some(error) = source.had_error.take() {
             return Err(error);
+        }
         if !self.curly_stack.is_empty() {
             // Let's not add a lot of heuristics and just tell the programmer
             // that something is wrong
             let last_unmatched_open = self.curly_stack.pop().unwrap();
             return Err(ParseError::new_error_str_at_pos(
                 source, last_unmatched_open, "unmatched opening curly brace '{'"
             ));
+        }
         // Ranges that did not depend on curly braces may have missing tokens.
         // So close all of the active tokens
         while self.stack_idx != 0 {
             self.pop_range(target, target.tokens.len() as u32);
+        }
         // And finally, we may have a token range at the end that doesn't belong
         // to a range yet, so insert a "code" range if this is the case.
         debug_assert_eq!(self.stack_idx, 0);
         let last_token_idx = target.tokens.len() as u32;
         if target.ranges[0].end != last_token_idx {
+        }
         // TODO: @remove once I'm sure the algorithm works. For now it is better
         //  if the debugging is a little more expedient
         if cfg!(debug_assertions) {
             // For each range make sure its children make sense
             for parent_idx in 0..target.ranges.len() {
                 let cur_range = &target.ranges[parent_idx];
                 if cur_range.num_child_ranges == 0 {
                     assert_eq!(cur_range.first_child_idx, parent_idx as u32);
                     assert_eq!(cur_range.last_child_idx, parent_idx as u32);
                     assert_eq!(cur_range.first_child_idx, NO_RELATION);
                     assert_eq!(cur_range.last_child_idx, NO_RELATION);
                 } else {
                     assert_ne!(cur_range.first_child_idx, parent_idx as u32);
                     assert_ne!(cur_range.last_child_idx, parent_idx as u32);
                     assert_ne!(cur_range.first_child_idx, NO_RELATION);
                     assert_ne!(cur_range.last_child_idx, NO_RELATION);
                     let mut child_counter = 0u32;
                     let last_child_idx = cur_range.first_child_idx;
                     let mut child_idx = Some(cur_range.first_child_idx);
                     while let Some(cur_child_idx) = child_idx {
                         let child_range = &target.ranges[cur_child_idx as usize];
                         assert_eq!(child_range.parent_idx, parent_idx);
                     let mut last_valid_child_idx = cur_range.first_child_idx;
                     let mut child_idx = cur_range.first_child_idx;
                     while child_idx != NO_RELATION {
                         let child_range = &target.ranges[child_idx as usize];
                         assert_eq!(child_range.parent_idx, parent_idx as i32);
                         last_valid_child_idx = child_idx;
                         child_idx = child_range.next_sibling_idx;
                         child_counter += 1;
+                    }
-                    assert_eq!(cur_range.last_child_idx, last_child_idx);
+                    assert_eq!(cur_range.last_child_idx, last_valid_child_idx);
                     assert_eq!(cur_range.num_child_ranges, child_counter);
+                }
+            }
+        }
         Ok(())
+    }
     fn is_line_comment_start(&self, first_char: u8, source: &InputSource) -> bool {
         return first_char == b'/' && Some(b'/') == source.lookahead(1);
+    }
     fn is_block_comment_start(&self, first_char: u8, source: &InputSource) -> bool {
         return first_char == b'/' && Some(b'*') == source.lookahead(1);
+    }
     fn maybe_parse_punctuation(
         &mut self, first_char: u8, source: &mut InputSource, target: &mut TokenBuffer
     ) -> Result<Option<(TokenKind, InputPosition)>, ParseError> {
         debug_assert!(first_char != b'#', "'#' needs special handling");
         debug_assert!(first_char != b'\'', "'\'' needs special handling");
         debug_assert!(first_char != b'"', "'\"' needs special handling");
         let pos = source.pos();
         let token_kind;
         if first_char == b'!' {
             source.consume();
             if Some(b'=') == source.next() {
                 source.consume();
                 token_kind = TokenKind::NotEqual;
             } else {
                 token_kind = TokenKind::Exclamation;
+            }
         } else if first_char == b'%' {
             source.consume();
             if Some(b'=') == source.next() {
                 source.consume();
                 token_kind = TokenKind::PercentEquals;
             } else {
                 token_kind = TokenKind::Percent;
+            }
         } else if first_char == b'&' {
             source.consume();
             let next = source.next();
             if Some(b'&') == next {
                 source.consume();
                 token_kind = TokenKind::AndAnd;
             } else if Some(b'=') == next {
                 source.consume();
                 token_kind = TokenKind::AndEquals;
             } else {
                 token_kind = TokenKind::And;
+            }
         } else if first_char == b'(' {
             source.consume();
             token_kind = TokenKind::OpenParen;
         } else if first_char == b')' {
             source.consume();
             token_kind = TokenKind::CloseParen;
         } else if first_char == b'*' {
             source.consume();
             if let Some(b'=') = source.next() {
                 source.consume();
                 token_kind = TokenKind::StarEquals;
             } else {
                 token_kind = TokenKind::Star;
+            }
         } else if first_char == b'+' {
             source.consume();
             let next = source.next();
             if Some(b'+') == next {
                 source.consume();
                 token_kind = TokenKind::PlusPlus;
             } else if Some(b'=') == next {
                 source.consume();
                 token_kind = TokenKind::PlusEquals;
             } else {
                 token_kind = TokenKind::Plus;
+            }
         } else if first_char == b',' {
             source.consume();
             token_kind = TokenKind::Comma;
         } else if first_char == b'-' {
             source.consume();
             let next = source.next();
             if Some(b'-') == next {
                 source.consume();
                 token_kind = TokenKind::MinusMinus;
             } else if Some(b'>') == next {
                 source.consume();
                 token_kind = TokenKind::ArrowRight;
             } else if Some(b'=') == next {
                 source.consume();
                 token_kind = TokenKind::MinusEquals;
             } else {
                 token_kind = TokenKind::Minus;
+            }
         } else if first_char == b'.' {
             source.consume();
             if let Some(b'.') = source.next() {
                 source.consume();
                 token_kind = TokenKind::DotDot;
             } else {
                 token_kind = TokenKind::Dot
+            }
         } else if first_char == b'/' {
             source.consume();
             debug_assert_ne!(Some(b'/'), source.next());
             debug_assert_ne!(Some(b'*'), source.next());
             if let Some(b'=') = source.next() {
                 source.consume();
                 token_kind = TokenKind::SlashEquals;
             } else {
                 token_kind = TokenKind::Slash;
+            }
         } else if first_char == b':' {
             source.consume();
             if let Some(b':') = source.next() {
                 source.consume();
                 token_kind = TokenKind::ColonColon;
             } else {
                 token_kind = TokenKind::Colon;
+            }
         } else if first_char == b';' {
             source.consume();
             token_kind = TokenKind::SemiColon;
         } else if first_char == b'<' {
             source.consume();
             let next = source.next();
             if let Some(b'<') = next {
                 source.consume();
                 if let Some(b'=') = source.next() {
                     source.consume();
                     token_kind = TokenKind::ShiftLeftEquals;
                 } else {
                     token_kind = TokenKind::ShiftLeft;
+                }
             } else if let Some(b'=') = next {
                 source.consume();
                 token_kind = TokenKind::LessEquals;
             } else {
                 token_kind = TokenKind::OpenAngle;
+            }
         } else if first_char == b'=' {
             source.consume();
             if let Some(b'=') = source.next() {
                 source.consume();
                 token_kind = TokenKind::EqualEqual;
             } else {
                 token_kind = TokenKind::Equal;
+            }
         } else if first_char == b'>' {
             source.consume();
             let next = source.next();
             if Some(b'>') == next {
                 source.consume();
                 if Some(b'=') == source.next() {
                     source.consume();
                     token_kind = TokenKind::ShiftRightEquals;
                 } else {
                     token_kind = TokenKind::ShiftRight;
+                }
             } else if Some(b'=') == next {
                 source.consume();
                 token_kind = TokenKind::GreaterEquals;
             } else {
                 token_kind = TokenKind::CloseAngle;
+            }
         } else if first_char == b'?' {
             source.consume();
             token_kind = TokenKind::Question;
         } else if first_char == b'@' {
             source.consume();
             token_kind = TokenKind::At;
         } else if first_char == b'[' {
             source.consume();
             token_kind = TokenKind::OpenSquare;
         } else if first_char == b']' {
             source.consume();
             token_kind = TokenKind::CloseSquare;
         } else if first_char == b'^' {
             source.consume();
             if let Some(b'=') = source.next() {
                 source.consume();
                 token_kind = TokenKind::CaretEquals;
             } else {
                 token_kind = TokenKind::Caret;
+            }
         } else if first_char == b'{' {
             source.consume();
             token_kind = TokenKind::OpenCurly;
         } else if first_char == b'|' {
             source.consume();
             let next = source.next();
             if Some(b'|') == next {
                 source.consume();
                 token_kind = TokenKind::OrOr;
             } else if Some(b'=') == next {
                 source.consume();
                 token_kind = TokenKind::OrEquals;
             } else {
                 token_kind = TokenKind::Or;
+            }
         } else if first_char == b'}' {
             source.consume();
             token_kind = TokenKind::CloseCurly;
         } else if first_char == b'~' {
             source.consume();
             token_kind = TokenKind::Tilde;
         } else {
             self.check_ascii(source)?;
             return Ok(None);
+        }
         target.tokens.push(Token::new(token_kind, pos));
         Ok(Some((token_kind, pos)))
+    }
     fn consume_char_literal(&mut self, source: &mut InputSource, target: &mut TokenBuffer) -> Result<(), ParseError> {
         let begin_pos = source.pos();
         // Consume the leading quote
         debug_assert!(source.next().unwrap() == b'\'');
         source.consume();
         let mut prev_char = b'\'';
         while let Some(c) = source.next() {
             if !c.is_ascii() {
                 return Err(ParseError::new_error_str_at_pos(source, source.pos(), "non-ASCII character in char literal"));
+            }
             source.consume();
             // Make sure ending quote was not escaped
             if c == b'\'' && prev_char != b'\\' {
                 prev_char = c;
                 break;
+            }
             prev_char = c;
+        }
         if prev_char != b'\'' {
             // Unterminated character literal, reached end of file.
             return Err(ParseError::new_error_str_at_pos(source, begin_pos, "encountered unterminated character literal"));
+        }
         let end_pos = source.pos();
         target.tokens.push(Token::new(TokenKind::Character, begin_pos));
         target.tokens.push(Token::new(TokenKind::SpanEnd, end_pos));
         Ok(())
+    }
     fn consume_string_literal(&mut self, source: &mut InputSource, target: &mut TokenBuffer) -> Result<(), ParseError> {
         let begin_pos = source.pos();
         // Consume the leading double quotes
         debug_assert!(source.next().unwrap() == b'"');
         source.consume();
         let mut prev_char = b'"';
         while let Some(c) = source.next() {
             if !c.is_ascii() {
                 return Err(ParseError::new_error_str_at_pos(source, source.pos(), "non-ASCII character in string literal"));
+            }
             source.consume();
             if c == b'"' && prev_char != b'\\' {
                 prev_char = c;
                 break;
+            }
             prev_char = c;
+        }
         if prev_char != b'"' {
             // Unterminated string literal
             return Err(ParseError::new_error_str_at_pos(source, begin_pos, "encountered unterminated string literal"));
+        }
         let end_pos = source.pos();
         target.tokens.push(Token::new(TokenKind::String, begin_pos));
         target.tokens.push(Token::new(TokenKind::SpanEnd, end_pos));
         Ok(())
+    }
     fn consume_pragma_or_pound(&mut self, first_char: u8, source: &mut InputSource, target: &mut TokenBuffer) -> Result<bool, ParseError> {
         let start_pos = source.pos();
         debug_assert_eq!(first_char, b'#');
         source.consume();
         let next = source.next();
         if next.is_none() || !is_identifier_start(next.unwrap()) {
             // Just a pound sign
             target.tokens.push(Token::new(TokenKind::Pound, start_pos));
             Ok(false)
         } else {
             // Pound sign followed by identifier
             source.consume();
             while let Some(c) = source.next() {
                 if !is_identifier_remaining(c) {
                     break;
+                }
                 source.consume();
+            }
             self.check_ascii(source)?;
             let end_pos = source.pos();
             target.tokens.push(Token::new(TokenKind::Pragma, start_pos));
             target.tokens.push(Token::new(TokenKind::SpanEnd, end_pos));
             Ok(true)
+        }
+    }
     fn consume_line_comment(&mut self, source: &mut InputSource, target: &mut TokenBuffer) -> Result<(), ParseError> {
         let begin_pos = source.pos();
         // Consume the leading "//"
         debug_assert!(source.next().unwrap() == b'/' && source.lookahead(1).unwrap() == b'/');
         source.consume();
         source.consume();
         let mut prev_char = b'/';
         let mut cur_char = b'/';
         while let Some(c) = source.next() {
             prev_char = cur_char;
             cur_char = c;
             if c == b'\n' {
                 // End of line, note that the newline is not consumed
                 break;
+            }
             source.consume();
+        }
         let mut end_pos = source.pos();
         debug_assert_eq!(begin_pos.line, end_pos.line);
         // Modify offset to not include the newline characters
         if cur_char == b'\n' {
             if prev_char == b'\r' {
                 end_pos.offset -= 2;
             } else {
                 end_pos.offset -= 1;
+            }
             // Consume final newline
             source.consume();
         } else {
             // End of comment was due to EOF
             debug_assert!(source.next().is_none())
+        }
         target.tokens.push(Token::new(TokenKind::LineComment, begin_pos));
         target.tokens.push(Token::new(TokenKind::SpanEnd, end_pos));
         Ok(())
+    }
     fn consume_block_comment(&mut self, source: &mut InputSource, target: &mut TokenBuffer) -> Result<(), ParseError> {
         let begin_pos = source.pos();
         // Consume the leading "/*"
         debug_assert!(source.next().unwrap() == b'/' && source.lookahead(1).unwrap() == b'*');
         source.consume();
         source.consume();
         // Explicitly do not put prev_char at "*", because then "/*/" would
         // represent a valid and closed block comment
         let mut prev_char = b' ';
         let mut is_closed = false;
         while let Some(c) = source.next() {
             source.consume();
             if prev_char == b'*' && c == b'/' {
                 // End of block comment
                 is_closed = true;
                 break;
+            }
             prev_char = c;
+        }
         if !is_closed {
             return Err(ParseError::new_error_str_at_pos(
                 source, source.pos(), "encountered unterminated block comment")
             );
+        }
         let end_pos = source.pos();
         target.tokens.push(Token::new(TokenKind::BlockComment, begin_pos));
         target.tokens.push(Token::new(TokenKind::SpanEnd, end_pos));
         Ok(())
+    }
     fn consume_identifier<'a>(&mut self, source: &'a mut InputSource, target: &mut TokenBuffer) -> Result<&'a [u8], ParseError> {
         let begin_pos = source.pos();
         debug_assert!(is_identifier_start(source.next().unwrap()));
         source.consume();
         // Keep reading until no more identifier
         while let Some(c) = source.next() {
             if !is_identifier_remaining(c) {
                 break;
+            }
             source.consume();
+        }
         self.check_ascii(source)?;
         let end_pos = source.pos();
         target.tokens.push(Token::new(TokenKind::Ident, begin_pos));
         target.tokens.push(Token::new(TokenKind::SpanEnd, end_pos));
         Ok(source.section_at_pos(begin_pos, end_pos))
+    }
     fn consume_number(&mut self, source: &mut InputSource, target: &mut TokenBuffer) -> Result<(), ParseError> {
         let begin_pos = source.pos();
         debug_assert!(is_integer_literal_start(source.next().unwrap()));
         source.consume();
         // Keep reading until it doesn't look like a number anymore
         while let Some(c) = source.next() {
             if !maybe_number_remaining(c) {
                 break;
+            }
             source.consume();
+        }
         self.check_ascii(source)?;
         let end_pos = source.pos();
         target.tokens.push(Token::new(TokenKind::Integer, begin_pos));
         target.tokens.push(Token::new(TokenKind::SpanEnd, end_pos));
         Ok(())
+    }
     // Consumes whitespace and returns whether or not the whitespace contained
     // a newline.
     fn consume_whitespace(&self, source: &mut InputSource) -> bool {
         debug_assert!(is_whitespace(source.next().unwrap()));
         let mut has_newline = false;
         while let Some(c) = source.next() {
             if !is_whitespace(c) {
                 break;
+            }
             if c == b'\n' {
                 has_newline = true;
+            }
             source.consume();
+        }
         has_newline
+    }
     /// Pushes a new token range onto the stack in the buffers.
     fn push_range(&mut self, target: &mut TokenBuffer, range_kind: TokenRangeKind, first_token: u32) {
         let new_range_idx = target.ranges.len() as u32;
         let cur_range = &mut target.ranges[self.stack_idx];
         // If we have just popped a range and then push a new range, then the
         // first token is equal to the last token registered on the current
         // range. If not, then we had some intermediate tokens that did not
         // belong to a particular kind of token range: hence we insert an
         // intermediate "code" range.
         if cur_range.end != first_token {
             let code_start = cur_range.end;
     fn push_range(&mut self, target: &mut TokenBuffer, range_kind: TokenRangeKind, first_token_idx: u32) {
         let new_range_idx = target.ranges.len() as i32;
         let parent_idx = self.stack_idx as i32;
         let parent_range = &mut target.ranges[self.stack_idx];
         let curly_depth = self.curly_stack.len() as u32;
             if cur_range.first_child_idx == self.stack_idx as u32 {
                 // The parent of the new "code" range we're going to push does
                 // not have any registered children yet.
                 cur_range.first_child_idx = new_range_idx;
         if parent_range.first_child_idx == NO_RELATION {
             parent_range.first_child_idx = new_range_idx;
+        }
             cur_range.last_child_idx = new_range_idx + 1;
             cur_range.end = first_token;
             cur_range.num_child_ranges += 1;
         if parent_range.end != first_token_idx {
             // We popped a range, processed some intermediate tokens and now
             // enter a new range. Those intermediate tokens do not belong to a
             // particular range yet. So we put them in a "code" range.
             // Remember last sibling from parent (if any)
             let sibling_idx = parent_range.last_child_idx;
             // Push the code range
             let code_start_idx = parent_range.end;
             let code_end_idx = first_token_idx;
             parent_range.last_child_idx = new_range_idx;
             parent_range.end = code_end_idx;
             parent_range.num_child_ranges += 1;
             target.ranges.push(TokenRange{
-                parent_idx: self.stack_idx,
                 parent_idx,
                 range_kind: TokenRangeKind::Code,
                 curly_depth: self.curly_stack.len() as u32,
                 start: code_start,
                 end: first_token,
                 curly_depth,
                 start: code_start_idx,
                 end: code_end_idx,
                 num_child_ranges: 0,
                 first_child_idx: new_range_idx,
                 last_child_idx: new_range_idx,
                 next_sibling_idx: Some(new_range_idx + 1), // we're going to push this thing next
                 first_child_idx: NO_RELATION,
                 last_child_idx: NO_RELATION,
                 next_sibling_idx: new_range_idx + 1, // we're going to push this range below
             });
         } else {
             // We're going to push the range in the code below, but while we
             // have the `cur_range` borrowed mutably, we fix up its children
             // indices.
             if cur_range.first_child_idx == self.stack_idx as u32 {
                 cur_range.first_child_idx = new_range_idx;
             // Fix up the sibling indices
             if sibling_idx != NO_RELATION {
                 let sibling_range = &mut target.ranges[sibling_idx as usize];
                 sibling_range.next_sibling_idx = new_range_idx;
+            }
             cur_range.last_child_idx = new_range_idx;
+        }
         // Insert a new range
         let parent_idx = self.stack_idx;
         // Push the new range
         self.stack_idx = target.ranges.len();
         let new_range_idx = self.stack_idx as u32;
         target.ranges.push(TokenRange{
             parent_idx,
             range_kind,
             curly_depth: self.curly_stack.len() as u32,
             start: first_token,
             end: first_token,
             curly_depth,
             start: first_token_idx,
             end: first_token_idx, // modified when popped
             num_child_ranges: 0,
             first_child_idx: new_range_idx,
             last_child_idx: new_range_idx,
             next_sibling_idx: None,
         });
             first_child_idx: NO_RELATION,
             last_child_idx: NO_RELATION,
             next_sibling_idx: NO_RELATION
         })
+    }
     fn pop_range(&mut self, target: &mut TokenBuffer, end_index: u32) {
         let last = &mut target.ranges[self.stack_idx];
         debug_assert!(self.stack_idx != last.parent_idx, "attempting to pop top-level range");
     fn pop_range(&mut self, target: &mut TokenBuffer, end_token_idx: u32) {
         let popped_idx = self.stack_idx as i32;
         let popped_range = &mut target.ranges[self.stack_idx];
         debug_assert!(self.stack_idx != 0, "attempting to pop top-level range");
         // Fix up the current range before going back to parent
         last.end = end_index;
         debug_assert_ne!(last.start, end_index);
         popped_range.end = end_token_idx;
         debug_assert_ne!(popped_range.start, end_token_idx);
         // Go back to parent
         self.stack_idx = last.parent_idx;
         // Go back to parent and fix up its child pointers, but remember the
         // last child, so we can link it to the newly popped range.
         self.stack_idx = popped_range.parent_idx as usize;
         let parent = &mut target.ranges[self.stack_idx];
         parent.end = end_index;
         if parent.first_child_idx == NO_RELATION {
             parent.first_child_idx = popped_idx;
+        }
         let prev_sibling_idx = parent.last_child_idx;
         parent.last_child_idx = popped_idx;
         parent.end = end_token_idx;
         parent.num_child_ranges += 1;
         // Fix up the sibling (if it exists)
         if prev_sibling_idx != NO_RELATION {
             let sibling = &mut target.ranges[prev_sibling_idx as usize];
             sibling.next_sibling_idx = popped_idx;
+        }
+    }
     fn check_ascii(&self, source: &InputSource) -> Result<(), ParseError> {
         match source.next() {
             Some(c) if !c.is_ascii() => {
                 Err(ParseError::new_error_str_at_pos(source, source.pos(), "encountered a non-ASCII character"))
             },
             _else => {
                 Ok(())
             },
+        }
+    }
+}
 // Helpers for characters
 fn demarks_definition(ident: &[u8]) -> bool {
     return
         ident == KW_STRUCT ||
             ident == KW_ENUM ||
             ident == KW_UNION ||
             ident == KW_FUNCTION ||
             ident == KW_PRIMITIVE ||
             ident == KW_COMPOSITE
+}
 fn demarks_import(ident: &[u8]) -> bool {
     return ident == KW_IMPORT;
+}
 fn is_whitespace(c: u8) -> bool {
     c.is_ascii_whitespace()
+}
 fn is_char_literal_start(c: u8) -> bool {
     return c == b'\'';
+}
 fn is_string_literal_start(c: u8) -> bool {
     return c == b'"';
+}
 fn is_pragma_start_or_pound(c: u8) -> bool {
     return c == b'#';
+}
 fn is_identifier_start(c: u8) -> bool {
     return
         (c >= b'a' && c <= b'z') ||
             (c >= b'A' && c <= b'Z') ||
             c == b'_'
+}
 fn is_identifier_remaining(c: u8) -> bool {
     return
         (c >= b'0' && c <= b'9') ||
             (c >= b'a' && c <= b'z') ||
             (c >= b'A' && c <= b'Z') ||
             c == b'_'
+}
 fn is_integer_literal_start(c: u8) -> bool {
     return c >= b'0' && c <= b'9';
+}
 fn maybe_number_remaining(c: u8) -> bool {
     return
         (c == b'b' || c == b'B' || c == b'o' || c == b'O' || c == b'x' || c == b'X') ||
             (c >= b'0' && c <= b'9') ||
             c == b'_';
+}
 #[cfg(test)]
 mod tests {
     use super::*;
     // TODO: Remove at some point
     #[test]
     fn test_tokenizer() {
         let mut source = InputSource::new_test("
         #version 500
         # hello 2
         import std.reo::*;
         struct Thing {
             int a: 5,
+        }
         enum Hello {
             A,
+            B
+        }
         // Hello hello, is it me you are looking for?
         // I can seee it in your eeeyes
         func something(int a, int b, int c) -> byte {
             int a = 5;
             struct Inner {
                 int a
+            }
             struct City {
                 int b
+            }
             /* Waza
             How are you doing
             Things in here yo
             /* */ */
             a = a + 5 * 2;
             struct Pressure {
                 int d
+            }
+        }
         ");
         let mut t = PassTokenizer::new();
         let mut buffer = TokenBuffer::new();
         t.tokenize(&mut source, &mut buffer).expect("tokenize");
         println!("Ranges:\n");
         for (idx, range) in buffer.ranges.iter().enumerate() {
             println!("[{}] {:?}", idx, range)
+        }
         println!("Tokens:\n");
         let mut iter = buffer.tokens.iter().enumerate();
         while let Some((idx, token)) = iter.next() {
             match token.kind {
                 TokenKind::Ident | TokenKind::Pragma | TokenKind::Integer |
                 TokenKind::String | TokenKind::Character | TokenKind::LineComment |
                 TokenKind::BlockComment => {
                     let (_, end) = iter.next().unwrap();
                     println!("[{}] {:?} ......", idx, token.kind);
                     assert_eq!(end.kind, TokenKind::SpanEnd);
                     let text = source.section_at_pos(token.pos, end.pos);
                     println!("{}", String::from_utf8_lossy(text));
                 },
                 _ => {
                     println!("[{}] {:?}", idx, token.kind);
+                }
+            }
+        }
+    }
+}
@@ \ 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 casee we return an
 /// error.
 ///
 /// Inference may be applied on non-polymorphic procedures and on polymorphic
 /// procedures. When dealing with a non-polymorphic procedure we apply the type
 /// resolver and annotate the AST with the `ConcreteType`s. When dealing with
 /// polymorphic procedures we will only annotate the AST once, preserving
 /// references to polymorphic variables. Any later pass will perform just the
 /// type checking.
 ///
 /// TODO: Needs a thorough rewrite:
 ///  0. polymorph_progress is intentionally broken at the moment.
 ///  1. For polymorphic type inference we need to have an extra datastructure
 ///     for progressing the polymorphic variables and mapping them back to each
 ///     signature type that uses that polymorphic type. The two types of markers
 ///     became somewhat of a mess.
 ///  2. We're doing a lot of extra work. It seems better to apply the initial
 ///     type based on expression parents, then to apply forced constraints (arg
 ///     to a fires() call must be port-like), only then to start progressing the
 ///     types.
 ///     Furthermore, queueing of expressions can be more intelligent, currently
 ///     every child/parent of an expression is inferred again when queued. Hence
 ///     we need to queue only specific children/parents of expressions.
 ///  3. Remove the `msg` type?
 ///  4. Disallow certain types in certain operations (e.g. `Void`).
 ///  5. Implement implicit and explicit casting.
 ///  6. Investigate different ways of performing the type-on-type inference,
 ///     maybe there is a better way then flattened trees + markers?
 macro_rules! debug_log {
     ($format:literal) => {
-        enabled_debug_print!(true, "types", $format);
+        enabled_debug_print!(false, "types", $format);
     };
     ($format:literal, $($args:expr),*) => {
-        enabled_debug_print!(true, "types", $format, $($args),*);
+        enabled_debug_print!(false, "types", $format, $($args),*);
     };
+}
 use std::collections::{HashMap, HashSet};
 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::{
     STMT_BUFFER_INIT_CAPACITY,
     EXPR_BUFFER_INIT_CAPACITY,
     Ctx,
     Visitor2,
     VisitorResult
 };
 use std::collections::hash_map::Entry;
 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; 1] = [ InferenceTypePart::String ];
 const NUMBERLIKE_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::NumberLike ];
 const INTEGERLIKE_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::IntegerLike ];
 const ARRAY_TEMPLATE: [InferenceTypePart; 2] = [ InferenceTypePart::Array, InferenceTypePart::Unknown ];
 const ARRAYLIKE_TEMPLATE: [InferenceTypePart; 2] = [ InferenceTypePart::ArrayLike, InferenceTypePart::Unknown ];
 /// TODO: @performance Turn into PartialOrd+Ord to simplify checks
 /// TODO: @types Remove the Message -> Byte hack at some point...
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub(crate) enum InferenceTypePart {
     // A marker with an identifier which we can use to retrieve the type subtree
     // that follows the marker. This is used to perform type inference on
     // polymorphs: an expression may determine the polymorphs type, after we
     // need to apply that information to all other places where the polymorph is
     // used.
     MarkerDefinition(usize), // marker for polymorph types on a procedure's definition
     MarkerBody(usize), // marker for polymorph types within a procedure body
     // 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,
     // A user-defined type with any number of subtypes
     Instance(DefinitionId, usize)
+}
 impl InferenceTypePart {
     fn is_marker(&self) -> bool {
         use InferenceTypePart as ITP;
         match self {
             ITP::MarkerDefinition(_) | ITP::MarkerBody(_) => 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 {
         // TODO: @float
         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_msg_array_or_slice(&self) -> bool {
         use InferenceTypePart as ITP;
         match self {
             ITP::Array | ITP::Slice | 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_msg_array_or_slice()) ||
         (*self == ITP::PortLike && arg.is_concrete_port())
+    }
     /// 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 | ITP::String => {
                 -1
             },
             ITP::MarkerDefinition(_) | ITP::MarkerBody(_) |
             ITP::ArrayLike | ITP::Message | ITP::Array | ITP::Slice |
             ITP::PortLike | ITP::Input | ITP::Output => {
                 // One subtype, so do not modify depth
             },
             ITP::Instance(_, num_args) => {
                 (*num_args as i32) - 1
+            }
+        }
+    }
+}
 impl From<ConcreteTypePart> for InferenceTypePart {
     fn from(v: ConcreteTypePart) -> InferenceTypePart {
         use ConcreteTypePart as CTP;
         use InferenceTypePart as ITP;
         match v {
             CTP::Marker(_) => {
                 unreachable!("encountered marker while converting concrete type to inferred type");
+            }
             CTP::Void => ITP::Void,
             CTP::Message => ITP::Message,
             CTP::Bool => ITP::Bool,
             CTP::UInt8 => ITP::UInt8,
             CTP::UInt16 => ITP::UInt16,
             CTP::UInt32 => ITP::UInt32,
             CTP::UInt64 => ITP::UInt64,
             CTP::SInt8 => ITP::SInt8,
             CTP::SInt16 => ITP::SInt16,
             CTP::SInt32 => ITP::SInt32,
             CTP::SInt64 => ITP::SInt64,
             CTP::Character => ITP::Character,
             CTP::String => ITP::String,
             CTP::Array => ITP::Array,
             CTP::Slice => ITP::Slice,
             CTP::Input => ITP::Input,
             CTP::Output => ITP::Output,
             CTP::Instance(id, num) => ITP::Instance(id, num),
+        }
+    }
+}
 #[derive(Debug)]
 struct InferenceType {
     has_body_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_body_marker: bool, is_done: bool, parts: Vec<InferenceTypePart>) -> Self {
         if cfg!(debug_assertions) {
             debug_assert!(!parts.is_empty());
             let parts_body_marker = parts.iter().any(|v| {
                 if let InferenceTypePart::MarkerBody(_) = v { true } else { false }
             });
             debug_assert_eq!(has_body_marker, parts_body_marker);
             let parts_done = parts.iter().all(|v| v.is_concrete());
             debug_assert_eq!(is_done, parts_done, "{:?}", parts);
+        }
         Self{ has_body_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_body_marker(&self, mut start_idx: usize) -> Option<(usize, usize)> {
         while start_idx < self.parts.len() {
             if let InferenceTypePart::MarkerBody(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 body_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!();
+    }
     /// 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];
         // TODO: Maybe do this differently?
         let mut template_definition_marker = None;
         if *template_idx > 0 {
             if let ITP::MarkerDefinition(marker) = &template_parts[*template_idx - 1] {
                 template_definition_marker = Some(*marker)
+            }
+        }
         // 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());
             if let Some(marker) = template_definition_marker {
                 to_infer.parts.insert(*to_infer_idx, ITP::MarkerDefinition(marker));
                 *to_infer_idx += 1;
+            }
             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 to copy definition markers, but not to
             // transfer polymorph markers.
             let template_end_idx = Self::find_subtree_end_idx(template_parts, *template_idx);
             let template_start_idx = if let Some(marker) = template_definition_marker {
                 to_infer.parts[*to_infer_idx] = ITP::MarkerDefinition(marker);
                 *template_idx
             } else {
                 to_infer.parts[*to_infer_idx] = template_parts[*template_idx].clone();
                 *template_idx + 1
             };
             *to_infer_idx += 1;
             for template_idx in template_start_idx..template_end_idx {
                 let template_part = &template_parts[template_idx];
                 if let ITP::MarkerBody(_) = template_part {
                     // Do not copy this one
                 } else {
                     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;
+            }
             // And can also 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`.
     /// Secondary use is to make sure that a type follows a certain template.
     fn infer_subtree_for_single_type(
         to_infer: &mut InferenceType, mut to_infer_idx: usize,
         template: &[InferenceTypePart], mut template_idx: usize,
     ) -> 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;
+            }
             // 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
+        }
         return if modified {
             to_infer.recompute_is_done();
             SingleInferenceResult::Modified
         } else {
             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.
     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());
         debug_assert!(concrete_type.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::MarkerDefinition(marker) => {
                     // Outer markers are converted to regular markers, we
                     // completely remove the type subtree that follows it
                     idx = InferenceType::find_subtree_end_idx(&self.parts, idx + 1);
                     concrete_type.parts.push(CTP::Marker(*marker));
                     continue;
                 },
                 ITP::MarkerBody(_) => {
                     // Inner markers are removed when writing to the concrete
                     // type.
                     idx += 1;
                     continue;
                 },
                 ITP::Unknown | ITP::NumberLike | ITP::IntegerLike | ITP::ArrayLike | ITP::PortLike => {
                     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 => CTP::String,
                 ITP::Array => CTP::Array,
                 ITP::Slice => CTP::Slice,
                 ITP::Input => CTP::Input,
                 ITP::Output => CTP::Output,
                 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::MarkerDefinition(thing) => {
                 buffer.push_str(&format!("{{D:{}}}", *thing));
                 idx = Self::write_display_name(buffer, heap, parts, idx + 1);
             },
             ITP::MarkerBody(thing) => {
                 buffer.push_str(&format!("{{B:{}}}", *thing));
                 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),
             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::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)
+    }
+}
 /// 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 = (usize, &'a [InferenceTypePart]);
     fn next(&mut self) -> Option<Self::Item> {
         // Iterate until we find a marker
         while self.idx < self.parts.len() {
             if let InferenceTypePart::MarkerBody(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),
+}
 impl DefinitionType {
     fn definition_id(&self) -> DefinitionId {
         match self {
             DefinitionType::Component(v) => v.upcast(),
             DefinitionType::Function(v) => v.upcast(),
+        }
+    }
+}
 #[derive(PartialEq, Eq)]
 pub(crate) struct ResolveQueueElement {
     pub(crate) root_id: RootId,
     pub(crate) definition_id: DefinitionId,
     pub(crate) monomorph_types: Vec<ConcreteType>,
+}
 pub(crate) type ResolveQueue = Vec<ResolveQueueElement>;
 /// 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.
     definition_type: DefinitionType,
     poly_vars: Vec<ConcreteType>,
     // Buffers for iteration over substatements and subexpressions
     stmt_buffer: Vec<StatementId>,
     expr_buffer: Vec<ExpressionId>,
     // 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: HashMap<ExpressionId, InferenceType>,   // types of expressions
     extra_data: HashMap<ExpressionId, ExtraData>,       // data for polymorph inference
     // Keeping track of which expressions need to be reinferred because the
     // expressions they're linked to made progression on an associated type
     expr_queued: HashSet<ExpressionId>,
+}
 // TODO: @rename used for calls and struct literals, maybe union literals?
 struct ExtraData {
     /// Progression of polymorphic variables (if any)
     poly_vars: Vec<InferenceType>,
     /// Progression of types of call arguments or struct members
     embedded: Vec<InferenceType>,
     returned: InferenceType,
+}
 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>,
+}
 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 }
+    }
+}
 impl PassTyping {
     pub(crate) fn new() -> Self {
         PassTyping {
             definition_type: DefinitionType::Function(FunctionDefinitionId::new_invalid()),
             poly_vars: Vec::new(),
             stmt_buffer: Vec::with_capacity(STMT_BUFFER_INIT_CAPACITY),
             expr_buffer: Vec::with_capacity(EXPR_BUFFER_INIT_CAPACITY),
             var_types: HashMap::new(),
             expr_types: HashMap::new(),
             extra_data: HashMap::new(),
             expr_queued: HashSet::new(),
+        }
+    }
     // TODO: @cleanup Unsure about this, maybe a pattern will arise after
     //  a while.
     pub(crate) fn queue_module_definitions(ctx: &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];
             match definition {
                 Definition::Function(definition) => {
                     if definition.poly_vars.is_empty() {
                         queue.push(ResolveQueueElement{
                             root_id,
                             definition_id: *definition_id,
                             monomorph_types: Vec::new(),
                         })
+                    }
                 },
                 Definition::Component(definition) => {
                     if definition.poly_vars.is_empty() {
                         queue.push(ResolveQueueElement{
                             root_id,
                             definition_id: *definition_id,
                             monomorph_types: Vec::new(),
                         })
+                    }
                 },
                 Definition::Enum(_) | Definition::Struct(_) | Definition::Union(_) => {},
+            }
+        }
+    }
     pub(crate) fn handle_module_definition(
         &mut self, ctx: &mut Ctx, queue: &mut ResolveQueue, element: ResolveQueueElement
     ) -> VisitorResult {
         // Visit the definition
         debug_assert_eq!(ctx.module.root_id, element.root_id);
         self.reset();
         self.poly_vars.clear();
         self.poly_vars.extend(element.monomorph_types.iter().cloned());
         self.visit_definition(ctx, element.definition_id)?;
         // Keep resolving types
         self.resolve_types(ctx, queue)?;
         Ok(())
+    }
     fn reset(&mut self) {
         self.definition_type = DefinitionType::Function(FunctionDefinitionId::new_invalid());
         self.poly_vars.clear();
         self.stmt_buffer.clear();
         self.expr_buffer.clear();
         self.var_types.clear();
         self.expr_types.clear();
         self.extra_data.clear();
         self.expr_queued.clear();
+    }
+}
 impl Visitor2 for PassTyping {
     // Definitions
     fn visit_component_definition(&mut self, ctx: &mut Ctx, id: ComponentDefinitionId) -> VisitorResult {
         self.definition_type = DefinitionType::Component(id);
         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");
         debug_log!("{}", "-".repeat(50));
         debug_log!("Visiting component '{}': {}", comp_def.identifier.value.as_str(), id.0.index);
         debug_log!("{}", "-".repeat(50));
         for param_id in comp_def.parameters.clone() {
             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.upcast(), VarData::new_local(var_type));
+        }
         let body_stmt_id = ctx.heap[id].body;
         self.visit_block_stmt(ctx, body_stmt_id)
+    }
     fn visit_function_definition(&mut self, ctx: &mut Ctx, id: FunctionDefinitionId) -> VisitorResult {
         self.definition_type = DefinitionType::Function(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");
         debug_log!("{}", "-".repeat(50));
         debug_log!("Visiting function '{}': {}", func_def.identifier.value.as_str(), id.0.index);
         debug_log!("{}", "-".repeat(50));
         for param_id in func_def.parameters.clone() {
             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.upcast(), VarData::new_local(var_type));
+        }
         let body_stmt_id = ctx.heap[id].body;
         self.visit_block_stmt(ctx, body_stmt_id)
+    }
     // Statements
     fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
         // Transfer statements for traversal
         let block = &ctx.heap[id];
         for stmt_id in block.statements.clone() {
             self.visit_stmt(ctx, stmt_id)?;
+        }
         Ok(())
+    }
     fn visit_local_memory_stmt(&mut self, ctx: &mut Ctx, id: MemoryStatementId) -> VisitorResult {
         let memory_stmt = &ctx.heap[id];
         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.upcast(), VarData::new_local(var_type));
         Ok(())
+    }
     fn visit_local_channel_stmt(&mut self, ctx: &mut Ctx, id: ChannelStatementId) -> VisitorResult {
         let channel_stmt = &ctx.heap[id];
         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.upcast(), VarData::new_channel(from_var_type, channel_stmt.to.upcast()));
         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.upcast(), VarData::new_channel(to_var_type, channel_stmt.from.upcast()));
         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 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)?;
+        }
         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)?;
         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)
+    }
     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)
+    }
     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)
+    }
     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)
+    }
     // Expressions
     fn visit_assignment_expr(&mut self, ctx: &mut Ctx, id: AssignmentExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         self.insert_initial_expr_inference_type(ctx, upcast_id)?;
         let assign_expr = &ctx.heap[id];
         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)?;
         self.progress_assignment_expr(ctx, id)
+    }
     fn visit_conditional_expr(&mut self, ctx: &mut Ctx, id: ConditionalExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         self.insert_initial_expr_inference_type(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;
         self.expr_types.insert(test_expr_id, InferenceType::new(false, true, vec![InferenceTypePart::Bool]));
         self.visit_expr(ctx, test_expr_id)?;
         self.visit_expr(ctx, true_expr_id)?;
         self.visit_expr(ctx, false_expr_id)?;
         self.progress_conditional_expr(ctx, id)
+    }
     fn visit_binary_expr(&mut self, ctx: &mut Ctx, id: BinaryExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         self.insert_initial_expr_inference_type(ctx, upcast_id)?;
         let binary_expr = &ctx.heap[id];
         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)?;
         self.progress_binary_expr(ctx, id)
+    }
     fn visit_unary_expr(&mut self, ctx: &mut Ctx, id: UnaryExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         self.insert_initial_expr_inference_type(ctx, upcast_id)?;
         let unary_expr = &ctx.heap[id];
         let arg_expr_id = unary_expr.expression;
         self.visit_expr(ctx, arg_expr_id)?;
         self.progress_unary_expr(ctx, id)
+    }
     fn visit_indexing_expr(&mut self, ctx: &mut Ctx, id: IndexingExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         self.insert_initial_expr_inference_type(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)?;
         self.progress_indexing_expr(ctx, id)
+    }
     fn visit_slicing_expr(&mut self, ctx: &mut Ctx, id: SlicingExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         self.insert_initial_expr_inference_type(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)?;
         self.progress_slicing_expr(ctx, id)
+    }
     fn visit_select_expr(&mut self, ctx: &mut Ctx, id: SelectExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         self.insert_initial_expr_inference_type(ctx, upcast_id)?;
         let select_expr = &ctx.heap[id];
         let subject_expr_id = select_expr.subject;
         self.visit_expr(ctx, subject_expr_id)?;
         self.progress_select_expr(ctx, id)
+    }
     fn visit_literal_expr(&mut self, ctx: &mut Ctx, id: LiteralExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         self.insert_initial_expr_inference_type(ctx, upcast_id)?;
         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::Struct(literal) => {
                 // TODO: @performance
                 let expr_ids: Vec<_> = literal.fields
                     .iter()
                     .map(|f| f.value)
                     .collect();
                 self.insert_initial_struct_polymorph_data(ctx, id);
                 for expr_id in expr_ids {
                     self.visit_expr(ctx, expr_id)?;
+                }
             },
             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);
             },
             Literal::Union(literal) => {
                 // May carry subexpressions and polymorphic arguments
                 // TODO: @performance
                 let expr_ids = literal.values.clone();
                 self.insert_initial_union_polymorph_data(ctx, id);
                 for expr_id in expr_ids {
                     self.visit_expr(ctx, expr_id)?;
+                }
             },
             Literal::Array(expressions) => {
                 // TODO: @performance
                 let expr_ids = expressions.clone();
                 for expr_id in expr_ids {
                     self.visit_expr(ctx, expr_id)?;
+                }
+            }
+        }
         self.progress_literal_expr(ctx, id)
+    }
     fn visit_call_expr(&mut self, ctx: &mut Ctx, id: CallExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         self.insert_initial_expr_inference_type(ctx, upcast_id)?;
         self.insert_initial_call_polymorph_data(ctx, id);
         // TODO: @performance
         let call_expr = &ctx.heap[id];
         for arg_expr_id in call_expr.arguments.clone() {
             self.visit_expr(ctx, arg_expr_id)?;
+        }
         self.progress_call_expr(ctx, id)
+    }
     fn visit_variable_expr(&mut self, ctx: &mut Ctx, id: VariableExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         self.insert_initial_expr_inference_type(ctx, upcast_id)?;
         let var_expr = &ctx.heap[id];
         debug_assert!(var_expr.declaration.is_some());
         let var_data = self.var_types.get_mut(var_expr.declaration.as_ref().unwrap()).unwrap();
         var_data.used_at.push(upcast_id);
         self.progress_variable_expr(ctx, id)
+    }
+}
 macro_rules! debug_assert_expr_ids_unique_and_known {
     // Base case for a single expression ID
     ($resolver:ident, $id:ident) => {
         if cfg!(debug_assertions) {
             $resolver.expr_types.contains_key(&$id);
+        }
     };
     // Base case for two expression IDs
     ($resolver:ident, $id1:ident, $id2:ident) => {
         debug_assert_ne!($id1, $id2);
         debug_assert_expr_ids_unique_and_known!($resolver, $id1);
         debug_assert_expr_ids_unique_and_known!($resolver, $id2);
     };
     // Generic case
     ($resolver:ident, $id1:ident, $id2:ident, $($tail:ident),+) => {
         debug_assert_ne!($id1, $id2);
         debug_assert_expr_ids_unique_and_known!($resolver, $id1);
         debug_assert_expr_ids_unique_and_known!($resolver, $id2, $($tail),+);
     };
+}
 macro_rules! debug_assert_ptrs_distinct {
     // Base case
     ($ptr1:ident, $ptr2:ident) => {
         debug_assert!(!std::ptr::eq($ptr1, $ptr2));
     };
     // Generic case
     ($ptr1:ident, $ptr2:ident, $($tail:ident),+) => {
         debug_assert_ptrs_distinct!($ptr1, $ptr2);
         debug_assert_ptrs_distinct!($ptr2, $($tail),+);
     };
+}
 impl PassTyping {
     fn resolve_types(&mut self, ctx: &mut Ctx, queue: &mut ResolveQueue) -> Result<(), ParseError> {
         // Keep inferring until we can no longer make any progress
         while let Some(next_expr_id) = self.expr_queued.iter().next() {
             let next_expr_id = *next_expr_id;
             self.expr_queued.remove(&next_expr_id);
             self.progress_expr(ctx, next_expr_id)?;
+        }
         // We check if we have all the types we need. If we're typechecking a
         // polymorphic procedure more than once, then we have already annotated
         // the AST and have now performed typechecking for a different
         // monomorph. In that case we just need to perform typechecking, no need
         // to annotate the AST again.
         let definition_id = match &self.definition_type {
             DefinitionType::Component(id) => id.upcast(),
             DefinitionType::Function(id) => id.upcast(),
         };
         let already_checked = ctx.types.get_base_definition(&definition_id).unwrap().has_any_monomorph();
         for (expr_id, expr_type) in self.expr_types.iter_mut() {
             if !expr_type.is_done {
                 // Auto-infer numberlike/integerlike types to a regular int
                 if expr_type.parts.len() == 1 && expr_type.parts[0] == InferenceTypePart::IntegerLike {
                     expr_type.parts[0] = InferenceTypePart::SInt32;
                 } else {
                     let expr = &ctx.heap[*expr_id];
                     return Err(ParseError::new_error_at_span(
                         &ctx.module.source, expr.span(), format!(
                             "could not fully infer the type of this expression (got '{}')",
                             expr_type.display_name(&ctx.heap)
+                        )
                     ));
+                }
+            }
             if !already_checked {
                 let concrete_type = ctx.heap[*expr_id].get_type_mut();
                 expr_type.write_concrete_type(concrete_type);
             } else {
                 if cfg!(debug_assertions) {
                     let mut concrete_type = ConcreteType::default();
                     expr_type.write_concrete_type(&mut concrete_type);
                     debug_assert_eq!(*ctx.heap[*expr_id].get_type(), concrete_type);
+                }
+            }
+        }
         // All types are fine
         ctx.types.add_monomorph(&definition_id, self.poly_vars.clone());
         // Check all things we need to monomorphize
         // TODO: Struct/enum/union monomorphization
         for (expr_id, extra_data) in self.extra_data.iter() {
             if extra_data.poly_vars.is_empty() { continue; }
             // Retrieve polymorph variable specification. Those of struct
             // literals and those of procedure calls need to be fully inferred.
             // The remaining ones (e.g. select expressions) allow partial
             // inference of types, as long as the accessed field's type is
             // fully inferred.
             let needs_full_inference = match &ctx.heap[*expr_id] {
                 Expression::Call(_) => true,
                 Expression::Literal(_) => true,
                 _ => false
             };
             if needs_full_inference {
                 let mut monomorph_types = Vec::with_capacity(extra_data.poly_vars.len());
                 for (poly_idx, poly_type) in extra_data.poly_vars.iter().enumerate() {
                     if !poly_type.is_done {
                         // TODO: Single clean function for function signatures and polyvars.
                         // TODO: Better error message
                         let expr = &ctx.heap[*expr_id];
                         return Err(ParseError::new_error_at_span(
                             &ctx.module.source, expr.span(), format!(
                                 "could not fully infer the type of polymorphic variable {} of this expression (got '{}')",
                                 poly_idx, poly_type.display_name(&ctx.heap)
+                            )
                         ))
+                    }
                     let mut concrete_type = ConcreteType::default();
                     poly_type.write_concrete_type(&mut concrete_type);
                     monomorph_types.insert(poly_idx, concrete_type);
+                }
                 // Resolve to the appropriate expression and instantiate
                 // monomorphs.
                 match &ctx.heap[*expr_id] {
                     Expression::Call(call_expr) => {
                         // Add to type table if not yet typechecked
                         if call_expr.method == Method::UserFunction {
                             let definition_id = call_expr.definition;
                             if !ctx.types.has_monomorph(&definition_id, &monomorph_types) {
                                 let root_id = ctx.types
                                     .get_base_definition(&definition_id)
                                     .unwrap()
                                     .ast_root;
                                 // Pre-emptively add the monomorph to the type table, but
                                 // we still need to perform typechecking on it
                                 // TODO: Unsure about this, performance wise
                                 let queue_element = ResolveQueueElement{
                                     root_id,
                                     definition_id,
                                     monomorph_types,
                                 };
                                 if !queue.contains(&queue_element) {
                                     queue.push(queue_element);
+                                }
+                            }
+                        }
                     },
                     Expression::Literal(lit_expr) => {
                         let definition_id = match &lit_expr.value {
                             Literal::Struct(literal) => &literal.definition,
                             Literal::Enum(literal) => &literal.definition,
                             Literal::Union(literal) => &literal.definition,
                             _ => unreachable!("post-inference monomorph for non-struct, non-enum literal")
                         };
                         if !ctx.types.has_monomorph(definition_id, &monomorph_types) {
                             ctx.types.add_monomorph(definition_id, monomorph_types);
+                        }
                     },
                     _ => unreachable!("needs fully inference, but not a struct literal or call expression")
+                }
             } // else: was just a helper structure...
+        }
         Ok(())
+    }
     fn progress_expr(&mut self, ctx: &mut Ctx, id: ExpressionId) -> Result<(), ParseError> {
         match &ctx.heap[id] {
             Expression::Assignment(expr) => {
                 let id = expr.this;
                 self.progress_assignment_expr(ctx, id)
             },
             Expression::Binding(_expr) => {
                 unimplemented!("progress binding expression");
             },
             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::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_assignment_expr(&mut self, ctx: &mut Ctx, id: AssignmentExpressionId) -> Result<(), ParseError> {
         use AssignmentOperator as AO;
         // TODO: Assignable check
         let upcast_id = id.upcast();
         let expr = &ctx.heap[id];
         let arg1_expr_id = expr.left;
         let arg2_expr_id = expr.right;
         debug_log!("Assignment expr '{:?}': {}", expr.operation, upcast_id.index);
         debug_log!(" * Before:");
         debug_log!("   - Arg1 type: {}", self.expr_types.get(&arg1_expr_id).unwrap().display_name(&ctx.heap));
         debug_log!("   - Arg2 type: {}", self.expr_types.get(&arg2_expr_id).unwrap().display_name(&ctx.heap));
         debug_log!("   - Expr type: {}", self.expr_types.get(&upcast_id).unwrap().display_name(&ctx.heap));
         let progress_base = match expr.operation {
             AO::Set =>
                 false,
             AO::Multiplied | AO::Divided | AO::Added | AO::Subtracted =>
                 self.apply_forced_constraint(ctx, upcast_id, &NUMBERLIKE_TEMPLATE)?,
             AO::Remained | AO::ShiftedLeft | AO::ShiftedRight |
             AO::BitwiseAnded | AO::BitwiseXored | AO::BitwiseOred =>
                 self.apply_forced_constraint(ctx, upcast_id, &INTEGERLIKE_TEMPLATE)?,
         };
         let (progress_expr, progress_arg1, progress_arg2) = self.apply_equal3_constraint(
             ctx, upcast_id, arg1_expr_id, arg2_expr_id, 0
         )?;
         debug_log!(" * After:");
         debug_log!("   - Arg1 type [{}]: {}", progress_arg1, self.expr_types.get(&arg1_expr_id).unwrap().display_name(&ctx.heap));
         debug_log!("   - Arg2 type [{}]: {}", progress_arg2, self.expr_types.get(&arg2_expr_id).unwrap().display_name(&ctx.heap));
         debug_log!("   - Expr type [{}]: {}", progress_base || progress_expr, self.expr_types.get(&upcast_id).unwrap().display_name(&ctx.heap));
         if progress_base || progress_expr { self.queue_expr_parent(ctx, upcast_id); }
         if progress_arg1 { self.queue_expr(arg1_expr_id); }
         if progress_arg2 { self.queue_expr(arg2_expr_id); }
         Ok(())
+    }
     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.expr_types.get(&arg1_expr_id).unwrap().display_name(&ctx.heap));
         debug_log!("   - Arg2 type: {}", self.expr_types.get(&arg2_expr_id).unwrap().display_name(&ctx.heap));
         debug_log!("   - Expr type: {}", self.expr_types.get(&upcast_id).unwrap().display_name(&ctx.heap));
         let (progress_expr, progress_arg1, progress_arg2) = self.apply_equal3_constraint(
             ctx, upcast_id, arg1_expr_id, arg2_expr_id, 0
         )?;
         debug_log!(" * After:");
         debug_log!("   - Arg1 type [{}]: {}", progress_arg1, self.expr_types.get(&arg1_expr_id).unwrap().display_name(&ctx.heap));
         debug_log!("   - Arg2 type [{}]: {}", progress_arg2, self.expr_types.get(&arg2_expr_id).unwrap().display_name(&ctx.heap));
         debug_log!("   - Expr type [{}]: {}", progress_expr, self.expr_types.get(&upcast_id).unwrap().display_name(&ctx.heap));
         if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
         if progress_arg1 { self.queue_expr(arg1_expr_id); }
         if progress_arg2 { self.queue_expr(arg2_expr_id); }
         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

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