Changeset - 979f0c33417c
[Not reviewed]
0 12 0
MH - 3 years ago 2022-02-24 18:21:06
contact@maxhenger.nl
WIP: Use monomorph index lookup, prepare builtin procedures
6 files changed:
0 comments (0 inline, 0 general)
src/collections/string_pool.rs
Show inline comments
 
use std::ptr::{null_mut, null};
 
use std::hash::{Hash, Hasher};
 
use std::marker::PhantomData;
 
use std::fmt::{Debug, Display, Formatter, Result as FmtResult};
 

	
 
const SLAB_SIZE: usize = u16::MAX as usize;
 

	
 
#[derive(Clone)]
 
pub struct StringRef<'a> {
 
    data: *const u8,
 
    length: usize,
 
    _phantom: PhantomData<&'a [u8]>,
 
}
 

	
 
// As the StringRef is an immutable thing:
 
unsafe impl Sync for StringRef<'_> {}
 
unsafe impl Send for StringRef<'_> {}
 

	
 
impl<'a> StringRef<'a> {
 
    /// `new` constructs a new StringRef whose data is not owned by the
 
    /// `StringPool`, hence cannot have a `'static` lifetime.
 
    pub(crate) fn new(data: &'a [u8]) -> StringRef<'a> {
 
        // This is an internal (compiler) function: so debug_assert that the
 
        // string is valid ascii. Most commonly the input will come from the
 
        // code's source file, which is checked for ASCII-ness anyway.
 
        debug_assert!(data.is_ascii());
 
        let length = data.len();
 
        let data = data.as_ptr();
 
        StringRef{ data, length, _phantom: PhantomData }
 
    }
 

	
 
    /// `new_empty` creates a empty StringRef. It is a null pointer with a
 
    /// length of zero.
 
    pub(crate) const fn new_empty() -> StringRef<'static> {
 
        StringRef{ data: null(), length: 0, _phantom: PhantomData }
 
    }
 

	
 
    pub fn as_str(&self) -> &'a str {
 
        unsafe {
 
            let slice = std::slice::from_raw_parts::<'a, u8>(self.data, self.length);
 
            std::str::from_utf8_unchecked(slice)
 
        }
 
    }
 

	
 
    pub fn as_bytes(&self) -> &'a [u8] {
 
        unsafe {
 
            std::slice::from_raw_parts::<'a, u8>(self.data, self.length)
 
        }
 
    }
 
}
 

	
 
impl<'a> Debug for StringRef<'a> {
 
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
 
        f.write_str("StringRef{ value: ")?;
 
        f.write_str(self.as_str())?;
 
        f.write_str(" }")
 
    }
 
}
 

	
 
impl<'a> Display for StringRef<'a> {
 
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
 
        f.write_str(self.as_str())
 
    }
 
}
 

	
 
impl PartialEq for StringRef<'_> {
 
    fn eq(&self, other: &StringRef) -> bool {
 
        self.as_str() == other.as_str()
 
    }
 
}
 

	
 
impl Eq for StringRef<'_> {}
 

	
 
impl Hash for StringRef<'_> {
 
    fn hash<H: Hasher>(&self, state: &mut H) {
 
        state.write(self.as_bytes());
 
    }
 
}
 

	
 
struct StringPoolSlab {
 
    prev: *mut StringPoolSlab,
 
    data: Vec<u8>,
 
    remaining: usize,
 
}
 

	
 
impl StringPoolSlab {
 
    fn new(prev: *mut StringPoolSlab) -> Self {
 
        Self{ prev, data: Vec::with_capacity(SLAB_SIZE), remaining: SLAB_SIZE }
 
    }
 
}
 

	
 
/// StringPool is a ever-growing pool of strings. Strings have a maximum size
 
/// equal to the slab size. The slabs are essentially a linked list to maintain
 
/// pointer-stability of the strings themselves.
 
/// All `StringRef` instances are invalidated when the string pool is dropped
 
pub(crate) struct StringPool {
 
    last: *mut StringPoolSlab,
 
}
 

	
 
impl StringPool {
 
    pub(crate) fn new() -> Self {
 
        // To have some stability we just turn a box into a raw ptr.
 
        let initial_slab = Box::new(StringPoolSlab::new(null_mut()));
 
        let initial_slab = Box::into_raw(initial_slab);
 
        StringPool{
 
            last: initial_slab,
 
        }
 
    }
 

	
 
    /// Interns a string to the `StringPool`, returning a reference to it. The
 
    /// pointer owned by `StringRef` is `'static` as the `StringPool` doesn't
 
    /// reallocate/deallocate until dropped (which only happens at the end of
 
    /// the program.)
 
    pub(crate) fn intern(&mut self, data: &[u8]) -> StringRef<'static> {
 
        let data_len = data.len();
 
        assert!(data_len <= SLAB_SIZE, "string is too large for slab"); // if you hit this, create logic for large-string allocations
 
        debug_assert!(std::str::from_utf8(data).is_ok(), "string to intern is not valid UTF-8 encoded");
 
        
 
        let mut last = unsafe{&mut *self.last};
 
        if data.len() > last.remaining {
 
            // Doesn't fit: allocate new slab
 
            self.alloc_new_slab();
 
            last = unsafe{&mut *self.last};
 
        }
 

	
 
        // Must fit now, compute hash and put in buffer
 
        debug_assert!(data_len <= last.remaining);
 
        let range_start = last.data.len();
 
        last.data.extend_from_slice(data);
 
        last.remaining -= data_len;
 
        debug_assert_eq!(range_start + data_len, last.data.len());
 

	
 
        unsafe {
 
            let start = last.data.as_ptr().offset(range_start as isize);
 
            StringRef{ data: start, length: data_len, _phantom: PhantomData }
 
        }
 
    }
 

	
 
    fn alloc_new_slab(&mut self) {
 
        let new_slab = Box::new(StringPoolSlab::new(self.last));
 
        let new_slab = Box::into_raw(new_slab);
 
        self.last = new_slab;
 
    }
 
}
 

	
 
impl Drop for StringPool {
 
    fn drop(&mut self) {
 
        let mut new_slab = self.last;
 
        while !new_slab.is_null() {
 
            let cur_slab = new_slab;
 
            unsafe {
 
                new_slab = (*cur_slab).prev;
 
                Box::from_raw(cur_slab); // consume and deallocate
 
            }
 
        }
 
    }
 
}
 

	
 
// String pool cannot be cloned, and the created `StringRef` instances remain
 
// allocated until the end of the program, so it is always safe to send. It is
 
// also sync in the sense that it becomes an immutable thing after compilation,
 
// but lets not derive that if we would ever become a multithreaded compiler in
 
// the future.
 
unsafe impl Send for StringPool {}
 

	
 
#[cfg(test)]
 
mod tests {
 
    use super::*;
 

	
 
    #[test]
 
    fn display_empty_string_ref() {
 
        // Makes sure that null pointer inside StringRef will not cause issues
 
        let v = StringRef::new_empty();
 
        let val = format!("{}{:?}", v, v);
 
        let _val = format!("{}{:?}", v, v); // calls Format and Debug on StringRef
 
    }
 

	
 
    #[test]
 
    fn test_string_just_fits() {
 
        let large = "0".repeat(SLAB_SIZE);
 
        let mut pool = StringPool::new();
 
        let interned = pool.intern(large.as_bytes());
 
        assert_eq!(interned.as_str(), large);
 
    }
 

	
 
    #[test]
 
    #[should_panic]
 
    fn test_string_too_large() {
 
        let large = "0".repeat(SLAB_SIZE + 1);
 
        let mut pool = StringPool::new();
 
        let _interned = pool.intern(large.as_bytes());
 
    }
 

	
 
    #[test]
 
    fn test_lots_of_small_allocations() {
 
        const NUM_PER_SLAB: usize = 32;
 
        const NUM_SLABS: usize = 4;
 

	
 
        let to_intern = "0".repeat(SLAB_SIZE / NUM_PER_SLAB);
 
        let mut pool = StringPool::new();
 

	
 
        let mut last_slab = pool.last;
 
        let mut all_refs = Vec::new();
 

	
 
        // Fill up first slab
 
        for _alloc_idx in 0..NUM_PER_SLAB {
 
            let interned = pool.intern(to_intern.as_bytes());
 
            all_refs.push(interned);
 
            assert!(std::ptr::eq(last_slab, pool.last));
 
        }
 

	
 
        for _slab_idx in 0..NUM_SLABS-1 {
 
            for alloc_idx in 0..NUM_PER_SLAB {
 
                let interned = pool.intern(to_intern.as_bytes());
 
                all_refs.push(interned);
 

	
 
                if alloc_idx == 0 {
 
                    // First allocation produces a new slab
 
                    assert!(!std::ptr::eq(last_slab, pool.last));
 
                    last_slab = pool.last;
 
                } else {
 
                    assert!(std::ptr::eq(last_slab, pool.last));
 
                }
 
            }
 
        }
 

	
 
        // All strings are still correct
 
        for string_ref in all_refs {
 
            assert_eq!(string_ref.as_str(), to_intern);
 
        }
 
    }
 
}
 
\ No newline at end of file
src/protocol/ast.rs
Show inline comments
 
@@ -426,1071 +426,1070 @@ impl ParserTypeVariant {
 
/// the compiler.
 
#[derive(Debug, Clone)]
 
pub struct ParserTypeElement {
 
    pub element_span: InputSpan, // span of this element, not including the child types
 
    pub variant: ParserTypeVariant,
 
}
 

	
 
/// ParserType is a specification of a type during the parsing phase and initial
 
/// linker/validator phase of the compilation process. These types may be
 
/// (partially) inferred or represent literals (e.g. a integer whose bytesize is
 
/// not yet determined).
 
///
 
/// Its contents are the depth-first serialization of the type tree. Each node
 
/// is a type that may accept polymorphic arguments. The polymorphic arguments
 
/// are then the children of the node.
 
#[derive(Debug, Clone)]
 
pub struct ParserType {
 
    pub elements: Vec<ParserTypeElement>,
 
    pub full_span: InputSpan,
 
}
 

	
 
impl ParserType {
 
    pub(crate) fn iter_embedded(&self, parent_idx: usize) -> ParserTypeIter {
 
        ParserTypeIter::new(&self.elements, parent_idx)
 
    }
 
}
 

	
 
/// Iterator over the embedded elements of a specific element.
 
pub struct ParserTypeIter<'a> {
 
    pub elements: &'a [ParserTypeElement],
 
    pub cur_embedded_idx: usize,
 
}
 

	
 
impl<'a> ParserTypeIter<'a> {
 
    fn new(elements: &'a [ParserTypeElement], parent_idx: usize) -> Self {
 
        debug_assert!(parent_idx < elements.len(), "parent index exceeds number of elements in ParserType");
 
        if elements[0].variant.num_embedded() == 0 {
 
            // Parent element does not have any embedded types, place
 
            // `cur_embedded_idx` at end so we will always return `None`
 
            Self{ elements, cur_embedded_idx: elements.len() }
 
        } else {
 
            // Parent element has an embedded type
 
            Self{ elements, cur_embedded_idx: parent_idx + 1 }
 
        }
 
    }
 
}
 

	
 
impl<'a> Iterator for ParserTypeIter<'a> {
 
    type Item = &'a [ParserTypeElement];
 

	
 
    fn next(&mut self) -> Option<Self::Item> {
 
        let elements_len = self.elements.len();
 
        if self.cur_embedded_idx >= elements_len {
 
            return None;
 
        }
 

	
 
        // Seek to the end of the subtree
 
        let mut depth = 1;
 
        let start_element = self.cur_embedded_idx;
 
        while self.cur_embedded_idx < elements_len {
 
            let cur_element = &self.elements[self.cur_embedded_idx];
 
            let depth_change = cur_element.variant.num_embedded() as i32 - 1;
 
            depth += depth_change;
 
            debug_assert!(depth >= 0, "illegally constructed ParserType: {:?}", self.elements);
 

	
 
            self.cur_embedded_idx += 1;
 
            if depth == 0 {
 
                break;
 
            }
 
        }
 

	
 
        debug_assert!(depth == 0, "illegally constructed ParserType: {:?}", self.elements);
 
        return Some(&self.elements[start_element..self.cur_embedded_idx]);
 
    }
 
}
 

	
 
/// ConcreteType is the representation of a type after the type inference and
 
/// checker is finished. These are fully typed.
 
#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
 
pub enum ConcreteTypePart {
 
    // Special types (cannot be explicitly constructed by the programmer)
 
    Void,
 
    // Builtin types without nested types
 
    Message,
 
    Bool,
 
    UInt8, UInt16, UInt32, UInt64,
 
    SInt8, SInt16, SInt32, SInt64,
 
    Character, String,
 
    // Builtin types with one nested type
 
    Array,
 
    Slice,
 
    Input,
 
    Output,
 
    Pointer,
 
    // Tuple: variable number of nested types, will never be 1
 
    Tuple(u32),
 
    // User defined type with any number of nested types
 
    Instance(DefinitionId, u32),    // instance of data type
 
    Function(ProcedureDefinitionId, u32),    // instance of function
 
    Component(ProcedureDefinitionId, u32),   // instance of a connector
 
}
 

	
 
impl ConcreteTypePart {
 
    pub(crate) fn num_embedded(&self) -> u32 {
 
        use ConcreteTypePart::*;
 

	
 
        match self {
 
            Void | Message | Bool |
 
            UInt8 | UInt16 | UInt32 | UInt64 |
 
            SInt8 | SInt16 | SInt32 | SInt64 |
 
            Character | String =>
 
                0,
 
            Array | Slice | Input | Output | Pointer =>
 
                1,
 
            Tuple(num_embedded) => *num_embedded,
 
            Instance(_, num_embedded) => *num_embedded,
 
            Function(_, num_embedded) => *num_embedded,
 
            Component(_, num_embedded) => *num_embedded,
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, Eq, PartialEq)]
 
pub struct ConcreteType {
 
    pub(crate) parts: Vec<ConcreteTypePart>
 
}
 

	
 
impl Default for ConcreteType {
 
    fn default() -> Self {
 
        Self{ parts: Vec::new() }
 
    }
 
}
 

	
 
impl ConcreteType {
 
    /// Returns an iterator over the subtrees that are type arguments (e.g. an
 
    /// array element's type, or a polymorphic type's arguments) to the
 
    /// provided parent type (specified by its index in the `parts` array).
 
    pub(crate) fn embedded_iter(&self, parent_part_idx: usize) -> ConcreteTypeIter {
 
        return ConcreteTypeIter::new(&self.parts, parent_part_idx);
 
    }
 

	
 
    /// Construct a human-readable name for the type. Because this performs
 
    /// a string allocation don't use it for anything else then displaying the
 
    /// type to the user.
 
    pub(crate) fn display_name(&self, heap: &Heap) -> String {
 
        return Self::type_parts_display_name(self.parts.as_slice(), heap);
 
    }
 

	
 
    // --- Utilities that operate on slice of parts
 

	
 
    /// Given the starting position of a type tree, determine the exclusive
 
    /// ending index.
 
    pub(crate) fn type_parts_subtree_end_idx(parts: &[ConcreteTypePart], start_idx: usize) -> usize {
 
        let mut depth = 1;
 
        let num_parts = parts.len();
 
        debug_assert!(start_idx < num_parts);
 

	
 
        for part_idx in start_idx..parts.len() {
 
            let depth_change = parts[part_idx].num_embedded() as i32 - 1;
 
            depth += depth_change;
 
            debug_assert!(depth >= 0);
 

	
 
            if depth == 0 {
 
                return part_idx + 1;
 
            }
 
        }
 

	
 
        debug_assert!(false, "incorrectly constructed ConcreteType instance");
 
        return 0;
 
    }
 

	
 
    /// Produces a human-readable representation of the concrete type parts
 
    fn type_parts_display_name(parts: &[ConcreteTypePart], heap: &Heap) -> String {
 
        let mut name = String::with_capacity(128);
 
        let _final_idx = Self::render_type_part_at(parts, heap, 0, &mut name);
 
        debug_assert_eq!(_final_idx, parts.len());
 

	
 
        return name;
 
    }
 

	
 
    /// Produces a human-readable representation of a single type part. Lower
 
    /// level utility for `type_parts_display_name`.
 
    fn render_type_part_at(parts: &[ConcreteTypePart], heap: &Heap, mut idx: usize, target: &mut String) -> usize {
 
        use ConcreteTypePart as CTP;
 
        use crate::protocol::parser::token_parsing::*;
 

	
 
        let cur_idx = idx;
 
        idx += 1; // increment by 1, because it always happens
 

	
 
        match parts[cur_idx] {
 
            CTP::Void => { target.push_str("void"); },
 
            CTP::Message => { target.push_str(KW_TYPE_MESSAGE_STR); },
 
            CTP::Bool => { target.push_str(KW_TYPE_BOOL_STR); },
 
            CTP::UInt8 => { target.push_str(KW_TYPE_UINT8_STR); },
 
            CTP::UInt16 => { target.push_str(KW_TYPE_UINT16_STR); },
 
            CTP::UInt32 => { target.push_str(KW_TYPE_UINT32_STR); },
 
            CTP::UInt64 => { target.push_str(KW_TYPE_UINT64_STR); },
 
            CTP::SInt8 => { target.push_str(KW_TYPE_SINT8_STR); },
 
            CTP::SInt16 => { target.push_str(KW_TYPE_SINT16_STR); },
 
            CTP::SInt32 => { target.push_str(KW_TYPE_SINT32_STR); },
 
            CTP::SInt64 => { target.push_str(KW_TYPE_SINT64_STR); },
 
            CTP::Character => { target.push_str(KW_TYPE_CHAR_STR); },
 
            CTP::String => { target.push_str(KW_TYPE_STRING_STR); },
 
            CTP::Array | CTP::Slice => {
 
                idx = Self::render_type_part_at(parts, heap, idx, target);
 
                target.push_str("[]");
 
            },
 
            CTP::Input => {
 
                target.push_str(KW_TYPE_IN_PORT_STR);
 
                target.push('<');
 
                idx = Self::render_type_part_at(parts, heap, idx, target);
 
                target.push('>');
 
            },
 
            CTP::Output => {
 
                target.push_str(KW_TYPE_OUT_PORT_STR);
 
                target.push('<');
 
                idx = Self::render_type_part_at(parts, heap, idx, target);
 
                target.push('>');
 
            },
 
            CTP::Pointer => {
 
                target.push('*');
 
                idx = Self::render_type_part_at(parts, heap, idx, target);
 
            }
 
            CTP::Tuple(num_parts) => {
 
                target.push('(');
 
                if num_parts != 0 {
 
                    idx = Self::render_type_part_at(parts, heap, idx, target);
 
                    for _ in 1..num_parts {
 
                        target.push(',');
 
                        idx = Self::render_type_part_at(parts, heap, idx, target);
 
                    }
 
                }
 
                target.push(')');
 
            },
 
            CTP::Instance(definition_id, num_poly_args) => {
 
                idx = Self::render_definition_type_parts_at(parts, heap, definition_id, num_poly_args, idx, target);
 
            }
 
            CTP::Function(definition_id, num_poly_args) |
 
            CTP::Component(definition_id, num_poly_args) => {
 
                idx = Self::render_definition_type_parts_at(parts, heap, definition_id.upcast(), num_poly_args, idx, target);
 
            }
 
        }
 

	
 
        idx
 
    }
 

	
 
    fn render_definition_type_parts_at(parts: &[ConcreteTypePart], heap: &Heap, definition_id: DefinitionId, num_poly_args: u32, mut idx: usize, target: &mut String) -> usize {
 
        let definition = &heap[definition_id];
 
        target.push_str(definition.identifier().value.as_str());
 

	
 
        if num_poly_args != 0 {
 
            target.push('<');
 
            for poly_arg_idx in 0..num_poly_args {
 
                if poly_arg_idx != 0 {
 
                    target.push(',');
 
                }
 
                idx = Self::render_type_part_at(parts, heap, idx, target);
 
            }
 
            target.push('>');
 
        }
 

	
 
        return idx;
 
    }
 
}
 

	
 
#[derive(Debug)]
 
pub struct ConcreteTypeIter<'a> {
 
    parts: &'a [ConcreteTypePart],
 
    idx_embedded: u32,
 
    num_embedded: u32,
 
    part_idx: usize,
 
}
 

	
 
impl<'a> ConcreteTypeIter<'a> {
 
    pub(crate) fn new(parts: &'a[ConcreteTypePart], parent_idx: usize) -> Self {
 
        let num_embedded = parts[parent_idx].num_embedded();
 
        return ConcreteTypeIter{
 
            parts,
 
            idx_embedded: 0,
 
            num_embedded,
 
            part_idx: parent_idx + 1,
 
        }
 
    }
 
}
 

	
 
impl<'a> Iterator for ConcreteTypeIter<'a> {
 
    type Item = &'a [ConcreteTypePart];
 

	
 
    fn next(&mut self) -> Option<Self::Item> {
 
        if self.idx_embedded == self.num_embedded {
 
            return None;
 
        }
 

	
 
        // Retrieve the subtree of interest
 
        let start_idx = self.part_idx;
 
        let end_idx = ConcreteType::type_parts_subtree_end_idx(&self.parts, start_idx);
 

	
 
        self.idx_embedded += 1;
 
        self.part_idx = end_idx;
 

	
 
        return Some(&self.parts[start_idx..end_idx]);
 
    }
 
}
 

	
 
#[derive(Debug, Clone, Copy)]
 
pub enum ScopeAssociation {
 
    Definition(DefinitionId),
 
    Block(BlockStatementId),
 
    If(IfStatementId, bool), // if true, then body of "if", otherwise body of "else"
 
    While(WhileStatementId),
 
    Synchronous(SynchronousStatementId),
 
    SelectCase(SelectStatementId, u32), // index is select case
 
}
 

	
 
/// `ScopeNode` is a helper that links scopes in two directions. It doesn't
 
/// actually contain any information associated with the scope, this may be
 
/// found on the AST elements that `Scope` points to.
 
#[derive(Debug, Clone)]
 
pub struct Scope {
 
    // Relation to other scopes
 
    pub this: ScopeId,
 
    pub parent: Option<ScopeId>,
 
    pub nested: Vec<ScopeId>,
 
    // Locally available variables/labels
 
    pub association: ScopeAssociation,
 
    pub variables: Vec<VariableId>,
 
    pub labels: Vec<LabeledStatementId>,
 
    // Location trackers/counters
 
    pub relative_pos_in_parent: i32,
 
    pub first_unique_id_in_scope: i32,
 
    pub next_unique_id_in_scope: i32,
 
}
 

	
 
impl Scope {
 
    pub(crate) fn new(id: ScopeId, association: ScopeAssociation) -> Self {
 
        return Self{
 
            this: id,
 
            parent: None,
 
            nested: Vec::new(),
 
            association,
 
            variables: Vec::new(),
 
            labels: Vec::new(),
 
            relative_pos_in_parent: -1,
 
            first_unique_id_in_scope: -1,
 
            next_unique_id_in_scope: -1,
 
        }
 
    }
 
}
 

	
 
impl Scope {
 
    pub(crate) fn new_invalid(this: ScopeId) -> Self {
 
        return Self{
 
            this,
 
            parent: None,
 
            nested: Vec::new(),
 
            association: ScopeAssociation::Definition(DefinitionId::new_invalid()),
 
            variables: Vec::new(),
 
            labels: Vec::new(),
 
            relative_pos_in_parent: -1,
 
            first_unique_id_in_scope: -1,
 
            next_unique_id_in_scope: -1,
 
        };
 
    }
 
}
 

	
 
#[derive(Debug, Clone, PartialEq, Eq)]
 
pub enum VariableKind {
 
    Parameter,      // in parameter list of function/component
 
    Local,          // declared in function/component body
 
    Binding,        // may be bound to in a binding expression (determined in validator/linker)
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct Variable {
 
    pub this: VariableId,
 
    // Parsing
 
    pub kind: VariableKind,
 
    pub parser_type: ParserType,
 
    pub identifier: Identifier,
 
    // Validator/linker
 
    pub relative_pos_in_parent: i32,
 
    pub unique_id_in_scope: i32, // Temporary fix until proper bytecode/asm is generated
 
}
 

	
 
#[derive(Debug, Clone)]
 
#[derive(Debug)]
 
pub enum Definition {
 
    Struct(StructDefinition),
 
    Enum(EnumDefinition),
 
    Union(UnionDefinition),
 
    Procedure(ProcedureDefinition),
 
}
 

	
 
impl Definition {
 
    pub fn is_struct(&self) -> bool {
 
        match self {
 
            Definition::Struct(_) => true,
 
            _ => false
 
        }
 
    }
 
    pub(crate) fn as_struct(&self) -> &StructDefinition {
 
        match self {
 
            Definition::Struct(result) => result,
 
            _ => panic!("Unable to cast 'Definition' to 'StructDefinition'"),
 
        }
 
    }
 
    pub(crate) fn as_struct_mut(&mut self) -> &mut StructDefinition {
 
        match self {
 
            Definition::Struct(result) => result,
 
            _ => panic!("Unable to cast 'Definition' to 'StructDefinition'"),
 
        }
 
    }
 
    pub fn is_enum(&self) -> bool {
 
        match self {
 
            Definition::Enum(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub(crate) fn as_enum(&self) -> &EnumDefinition {
 
        match self {
 
            Definition::Enum(result) => result,
 
            _ => panic!("Unable to cast 'Definition' to 'EnumDefinition'"),
 
        }
 
    }
 
    pub(crate) fn as_enum_mut(&mut self) -> &mut EnumDefinition {
 
        match self {
 
            Definition::Enum(result) => result,
 
            _ => panic!("Unable to cast 'Definition' to 'EnumDefinition'"),
 
        }
 
    }
 
    pub fn is_union(&self) -> bool {
 
        match self {
 
            Definition::Union(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub(crate) fn as_union(&self) -> &UnionDefinition {
 
        match self {
 
            Definition::Union(result) => result, 
 
            _ => panic!("Unable to cast 'Definition' to 'UnionDefinition'"),
 
        }
 
    }
 

	
 
    pub(crate) fn as_union_mut(&mut self) -> &mut UnionDefinition {
 
        match self {
 
            Definition::Union(result) => result,
 
            _ => panic!("Unable to cast 'Definition' to 'UnionDefinition'"),
 
        }
 
    }
 

	
 
    pub fn is_procedure(&self) -> bool {
 
        match self {
 
            Definition::Procedure(_) => true,
 
            _ => false,
 
        }
 
    }
 

	
 
    pub(crate) fn as_procedure(&self) -> &ProcedureDefinition {
 
        match self {
 
            Definition::Procedure(result) => result,
 
            _ => panic!("Unable to cast `Definition` to `Function`"),
 
        }
 
    }
 

	
 
    pub(crate) fn as_procedure_mut(&mut self) -> &mut ProcedureDefinition {
 
        match self {
 
            Definition::Procedure(result) => result,
 
            _ => panic!("Unable to cast `Definition` to `Function`"),
 
        }
 
    }
 

	
 
    pub fn defined_in(&self) -> RootId {
 
        match self {
 
            Definition::Struct(def) => def.defined_in,
 
            Definition::Enum(def) => def.defined_in,
 
            Definition::Union(def) => def.defined_in,
 
            Definition::Procedure(def) => def.defined_in,
 
        }
 
    }
 

	
 
    pub fn identifier(&self) -> &Identifier {
 
        match self {
 
            Definition::Struct(def) => &def.identifier,
 
            Definition::Enum(def) => &def.identifier,
 
            Definition::Union(def) => &def.identifier,
 
            Definition::Procedure(def) => &def.identifier,
 
        }
 
    }
 
    pub fn poly_vars(&self) -> &Vec<Identifier> {
 
        match self {
 
            Definition::Struct(def) => &def.poly_vars,
 
            Definition::Enum(def) => &def.poly_vars,
 
            Definition::Union(def) => &def.poly_vars,
 
            Definition::Procedure(def) => &def.poly_vars,
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct StructFieldDefinition {
 
    pub span: InputSpan,
 
    pub field: Identifier,
 
    pub parser_type: ParserType,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct StructDefinition {
 
    pub this: StructDefinitionId,
 
    pub defined_in: RootId,
 
    // Symbol scanning
 
    pub span: InputSpan,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    // Parsing
 
    pub fields: Vec<StructFieldDefinition>
 
}
 

	
 
impl StructDefinition {
 
    pub(crate) fn new_empty(
 
        this: StructDefinitionId, defined_in: RootId, span: InputSpan,
 
        identifier: Identifier, poly_vars: Vec<Identifier>
 
    ) -> Self {
 
        Self{ this, defined_in, span, identifier, poly_vars, fields: Vec::new() }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, Copy)]
 
pub enum EnumVariantValue {
 
    None,
 
    Integer(i64),
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EnumVariantDefinition {
 
    pub identifier: Identifier,
 
    pub value: EnumVariantValue,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EnumDefinition {
 
    pub this: EnumDefinitionId,
 
    pub defined_in: RootId,
 
    // Symbol scanning
 
    pub span: InputSpan,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    // Parsing
 
    pub variants: Vec<EnumVariantDefinition>,
 
}
 

	
 
impl EnumDefinition {
 
    pub(crate) fn new_empty(
 
        this: EnumDefinitionId, defined_in: RootId, span: InputSpan,
 
        identifier: Identifier, poly_vars: Vec<Identifier>
 
    ) -> Self {
 
        Self{ this, defined_in, span, identifier, poly_vars, variants: Vec::new() }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct UnionVariantDefinition {
 
    pub span: InputSpan,
 
    pub identifier: Identifier,
 
    pub value: Vec<ParserType>, // if empty, then union variant does not contain any embedded types
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct UnionDefinition {
 
    pub this: UnionDefinitionId,
 
    pub defined_in: RootId,
 
    // Phase 1: symbol scanning
 
    pub span: InputSpan,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    // Phase 2: parsing
 
    pub variants: Vec<UnionVariantDefinition>,
 
}
 

	
 
impl UnionDefinition {
 
    pub(crate) fn new_empty(
 
        this: UnionDefinitionId, defined_in: RootId, span: InputSpan,
 
        identifier: Identifier, poly_vars: Vec<Identifier>
 
    ) -> Self {
 
        Self{ this, defined_in, span, identifier, poly_vars, variants: Vec::new() }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 
pub enum ProcedureKind {
 
    Function, // with return type
 
    Primitive, // without return type
 
    Composite,
 
}
 

	
 
/// Monomorphed instantiation of a procedure (or the sole instantiation of a
 
/// non-polymorphic procedure).
 
#[derive(Debug)]
 
pub struct ProcedureDefinitionMonomorph {
 
    pub argument_types: Vec<TypeId>,
 
    pub expr_info: Vec<ExpressionInfo>
 
}
 

	
 
impl ProcedureDefinitionMonomorph {
 
    pub(crate) fn new_invalid() -> Self {
 
        return Self{
 
            argument_types: Vec::new(),
 
            expr_info: Vec::new(),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, Copy)]
 
pub struct ExpressionInfo {
 
    pub type_id: TypeId,
 
    pub variant: ExpressionInfoVariant,
 
}
 

	
 
impl ExpressionInfo {
 
    pub(crate) fn new_invalid() -> Self {
 
        return Self{
 
            type_id: TypeId::new_invalid(),
 
            variant: ExpressionInfoVariant::Generic,
 
        }
 
    }
 
}
 

	
 
#[derive(Clone, Copy)]
 
#[derive(Debug, Clone, Copy)]
 
pub enum ExpressionInfoVariant {
 
    Generic,
 
    Procedure(TypeId, u32), // procedure TypeID and its monomorph index
 
    Select(i32), // index
 
}
 

	
 
impl ExpressionInfoVariant {
 
    pub(crate) fn as_select(&self) -> i32 {
 
        match self {
 
            ExpressionInfoVariant::Select(v) => *v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    pub(crate) fn as_procedure(&self) -> (TypeId, u32) {
 
        match self {
 
            ExpressionInfoVariant::Procedure(type_id, monomorph_index) => (*type_id, *monomorph_index),
 
            _ => unreachable!(),
 
        }
 
    }
 
}
 

	
 
/// Generic storage for functions, primitive components and composite
 
/// components.
 
// Note that we will have function definitions for builtin functions as well. In
 
// that case the span, the identifier span and the body are all invalid.
 
#[derive(Debug, Clone)]
 
#[derive(Debug)]
 
pub struct ProcedureDefinition {
 
    pub this: ProcedureDefinitionId,
 
    pub defined_in: RootId,
 
    // Symbol scanning
 
    pub builtin: bool,
 
    pub kind: ProcedureKind,
 
    pub span: InputSpan,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    // Parser
 
    pub return_type: Option<ParserType>, // present on functions, not components
 
    pub parameters: Vec<VariableId>,
 
    pub scope: ScopeId,
 
    pub body: BlockStatementId,
 
    // Monomorphization of typed procedures
 
    pub monomorphs: Vec<ProcedureDefinitionMonomorph>,
 
    // Validation/linking
 
    pub num_expressions_in_body: i32,
 
}
 

	
 
impl ProcedureDefinition {
 
    pub(crate) fn new_empty(
 
        this: ProcedureDefinitionId, defined_in: RootId, span: InputSpan,
 
        kind: ProcedureKind, identifier: Identifier, poly_vars: Vec<Identifier>
 
    ) -> Self {
 
        Self {
 
            this, defined_in,
 
            builtin: false,
 
            span,
 
            kind, identifier, poly_vars,
 
            return_type: None,
 
            parameters: Vec::new(),
 
            scope: ScopeId::new_invalid(),
 
            body: BlockStatementId::new_invalid(),
 
            monomorphs: Vec::new(),
 
            num_expressions_in_body: -1,
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub enum Statement {
 
    Block(BlockStatement),
 
    EndBlock(EndBlockStatement),
 
    Local(LocalStatement),
 
    Labeled(LabeledStatement),
 
    If(IfStatement),
 
    EndIf(EndIfStatement),
 
    While(WhileStatement),
 
    EndWhile(EndWhileStatement),
 
    Break(BreakStatement),
 
    Continue(ContinueStatement),
 
    Synchronous(SynchronousStatement),
 
    EndSynchronous(EndSynchronousStatement),
 
    Fork(ForkStatement),
 
    EndFork(EndForkStatement),
 
    Select(SelectStatement),
 
    EndSelect(EndSelectStatement),
 
    Return(ReturnStatement),
 
    Goto(GotoStatement),
 
    New(NewStatement),
 
    Expression(ExpressionStatement),
 
}
 

	
 
impl Statement {
 
    pub fn as_new(&self) -> &NewStatement {
 
        match self {
 
            Statement::New(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `NewStatement`"),
 
        }
 
    }
 

	
 
    pub fn span(&self) -> InputSpan {
 
        match self {
 
            Statement::Block(v) => v.span,
 
            Statement::Local(v) => v.span(),
 
            Statement::Labeled(v) => v.label.span,
 
            Statement::If(v) => v.span,
 
            Statement::While(v) => v.span,
 
            Statement::Break(v) => v.span,
 
            Statement::Continue(v) => v.span,
 
            Statement::Synchronous(v) => v.span,
 
            Statement::Fork(v) => v.span,
 
            Statement::Select(v) => v.span,
 
            Statement::Return(v) => v.span,
 
            Statement::Goto(v) => v.span,
 
            Statement::New(v) => v.span,
 
            Statement::Expression(v) => v.span,
 
            Statement::EndBlock(_)
 
            | Statement::EndIf(_)
 
            | Statement::EndWhile(_)
 
            | Statement::EndSynchronous(_)
 
            | Statement::EndFork(_)
 
            | Statement::EndSelect(_) => unreachable!(),
 
        }
 
    }
 
    pub fn link_next(&mut self, next: StatementId) {
 
        match self {
 
            Statement::Block(stmt) => stmt.next = next,
 
            Statement::EndBlock(stmt) => stmt.next = next,
 
            Statement::Local(stmt) => match stmt {
 
                LocalStatement::Channel(stmt) => stmt.next = next,
 
                LocalStatement::Memory(stmt) => stmt.next = next,
 
            },
 
            Statement::EndIf(stmt) => stmt.next = next,
 
            Statement::EndWhile(stmt) => stmt.next = next,
 
            Statement::EndSynchronous(stmt) => stmt.next = next,
 
            Statement::EndFork(stmt) => stmt.next = next,
 
            Statement::EndSelect(stmt) => stmt.next = next,
 
            Statement::New(stmt) => stmt.next = next,
 
            Statement::Expression(stmt) => stmt.next = next,
 
            Statement::Return(_)
 
            | Statement::Break(_)
 
            | Statement::Continue(_)
 
            | Statement::Synchronous(_)
 
            | Statement::Fork(_)
 
            | Statement::Select(_)
 
            | Statement::Goto(_)
 
            | Statement::While(_)
 
            | Statement::Labeled(_)
 
            | Statement::If(_) => unreachable!(),
 
        }
 
    }
 

	
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct BlockStatement {
 
    pub this: BlockStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the complete block
 
    pub statements: Vec<StatementId>,
 
    pub end_block: EndBlockStatementId,
 
    // Phase 2: linker
 
    pub scope: ScopeId,
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndBlockStatement {
 
    pub this: EndBlockStatementId,
 
    // Parser
 
    pub start_block: BlockStatementId,
 
    // Validation/Linking
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub enum LocalStatement {
 
    Memory(MemoryStatement),
 
    Channel(ChannelStatement),
 
}
 

	
 
impl LocalStatement {
 
    pub fn this(&self) -> LocalStatementId {
 
        match self {
 
            LocalStatement::Memory(stmt) => stmt.this.upcast(),
 
            LocalStatement::Channel(stmt) => stmt.this.upcast(),
 
        }
 
    }
 
    pub fn span(&self) -> InputSpan {
 
        match self {
 
            LocalStatement::Channel(v) => v.span,
 
            LocalStatement::Memory(v) => v.span,
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct MemoryStatement {
 
    pub this: MemoryStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan,
 
    pub variable: VariableId,
 
    pub initial_expr: AssignmentExpressionId,
 
    // Phase 2: linker
 
    pub next: StatementId,
 
}
 

	
 
/// ChannelStatement is the declaration of an input and output port associated
 
/// with the same channel. Note that the polarity of the ports are from the
 
/// point of view of the component. So an output port is something that a
 
/// component uses to send data over (i.e. it is the "input end" of the
 
/// channel), and vice versa.
 
#[derive(Debug, Clone)]
 
pub struct ChannelStatement {
 
    pub this: ChannelStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "channel" keyword
 
    pub from: VariableId, // output
 
    pub to: VariableId,   // input
 
    // Phase 2: linker
 
    pub relative_pos_in_parent: i32,
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct LabeledStatement {
 
    pub this: LabeledStatementId,
 
    // Phase 1: parser
 
    pub label: Identifier,
 
    pub body: StatementId,
 
    // Phase 2: linker
 
    pub relative_pos_in_parent: i32,
 
    pub in_sync: SynchronousStatementId, // may be invalid
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct IfStatement {
 
    pub this: IfStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "if" keyword
 
    pub test: ExpressionId,
 
    pub true_case: IfStatementCase,
 
    pub false_case: Option<IfStatementCase>,
 
    pub end_if: EndIfStatementId,
 
}
 

	
 
#[derive(Debug, Clone, Copy)]
 
pub struct IfStatementCase {
 
    pub body: StatementId,
 
    pub scope: ScopeId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndIfStatement {
 
    pub this: EndIfStatementId,
 
    pub start_if: IfStatementId,
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct WhileStatement {
 
    pub this: WhileStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "while" keyword
 
    pub test: ExpressionId,
 
    pub scope: ScopeId,
 
    pub body: StatementId,
 
    pub end_while: EndWhileStatementId,
 
    pub in_sync: SynchronousStatementId, // may be invalid
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndWhileStatement {
 
    pub this: EndWhileStatementId,
 
    pub start_while: WhileStatementId,
 
    // Phase 2: linker
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct BreakStatement {
 
    pub this: BreakStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "break" keyword
 
    pub label: Option<Identifier>,
 
    // Phase 2: linker
 
    pub target: EndWhileStatementId, // invalid if not yet set
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ContinueStatement {
 
    pub this: ContinueStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "continue" keyword
 
    pub label: Option<Identifier>,
 
    // Phase 2: linker
 
    pub target: WhileStatementId, // invalid if not yet set
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct SynchronousStatement {
 
    pub this: SynchronousStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "sync" keyword
 
    pub scope: ScopeId,
 
    pub body: StatementId,
 
    pub end_sync: EndSynchronousStatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndSynchronousStatement {
 
    pub this: EndSynchronousStatementId,
 
    pub start_sync: SynchronousStatementId,
 
    // Phase 2: linker
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ForkStatement {
 
    pub this: ForkStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "fork" keyword
 
    pub left_body: StatementId,
 
    pub right_body: Option<StatementId>,
 
    pub end_fork: EndForkStatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndForkStatement {
 
    pub this: EndForkStatementId,
 
    pub start_fork: ForkStatementId,
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct SelectStatement {
 
    pub this: SelectStatementId,
 
    pub span: InputSpan, // of the "select" keyword
 
    pub cases: Vec<SelectCase>,
 
    pub end_select: EndSelectStatementId,
 
    pub relative_pos_in_parent: i32,
 
    pub next: StatementId, // note: the select statement will be transformed into other AST elements, this `next` jumps to those replacement statements
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct SelectCase {
 
    // The guard statement of a `select` is either a MemoryStatement or an
 
    // ExpressionStatement. Nothing else is allowed by the initial parsing
 
    pub guard: StatementId,
 
    pub body: StatementId,
 
    pub scope: ScopeId,
 
    // Phase 2: Validation and Linking
 
    pub involved_ports: Vec<(CallExpressionId, ExpressionId)>, // call to `get` and its port argument
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndSelectStatement {
 
    pub this: EndSelectStatementId,
 
    pub start_select: SelectStatementId,
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ReturnStatement {
 
    pub this: ReturnStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "return" keyword
 
    pub expressions: Vec<ExpressionId>,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct GotoStatement {
 
    pub this: GotoStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "goto" keyword
 
    pub label: Identifier,
 
    // Phase 2: linker
 
    pub target: LabeledStatementId, // invalid if not yet set
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct NewStatement {
 
    pub this: NewStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "new" keyword
 
    pub expression: CallExpressionId,
 
    // Phase 2: linker
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ExpressionStatement {
 
    pub this: ExpressionStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan,
 
    pub expression: ExpressionId,
 
    // Phase 2: linker
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
 
pub enum ExpressionParent {
 
    None, // only set during initial parsing
 
    Memory(MemoryStatementId),
 
    If(IfStatementId),
 
    While(WhileStatementId),
 
    Return(ReturnStatementId),
 
    New(NewStatementId),
 
    ExpressionStmt(ExpressionStatementId),
 
    Expression(ExpressionId, u32) // index within expression (e.g LHS or RHS of expression, or index in array literal, etc.)
 
}
 

	
 
impl ExpressionParent {
 
    pub fn is_new(&self) -> bool {
 
        match self {
 
            ExpressionParent::New(_) => true,
 
            _ => false,
 
        }
 
    }
 

	
 
    pub fn as_expression(&self) -> ExpressionId {
 
        match self {
 
            ExpressionParent::Expression(id, _) => *id,
 
            _ => panic!("called as_expression() on {:?}", self),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub enum Expression {
 
    Assignment(AssignmentExpression),
 
    Binding(BindingExpression),
 
    Conditional(ConditionalExpression),
 
    Binary(BinaryExpression),
 
    Unary(UnaryExpression),
 
    Indexing(IndexingExpression),
 
    Slicing(SlicingExpression),
 
    Select(SelectExpression),
 
    Literal(LiteralExpression),
 
    Cast(CastExpression),
 
    Call(CallExpression),
 
    Variable(VariableExpression),
 
}
 

	
 
impl Expression {
 
    pub fn as_variable(&self) -> &VariableExpression {
 
        match self {
 
            Expression::Variable(result) => result,
src/protocol/eval/executor.rs
Show inline comments
 

	
 
use std::collections::VecDeque;
 

	
 
use super::value::*;
 
use super::store::*;
 
use super::error::*;
 
use crate::protocol::*;
 
use crate::protocol::ast::*;
 
use crate::protocol::type_table::*;
 

	
 
macro_rules! debug_enabled { () => { false }; }
 
macro_rules! debug_log {
 
    ($format:literal) => {
 
        enabled_debug_print!(false, "exec", $format);
 
    };
 
    ($format:literal, $($args:expr),*) => {
 
        enabled_debug_print!(false, "exec", $format, $($args),*);
 
    };
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub(crate) enum ExprInstruction {
 
    EvalExpr(ExpressionId),
 
    PushValToFront,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub(crate) struct Frame {
 
    pub(crate) definition: ProcedureDefinitionId,
 
    pub(crate) monomorph_type_id: TypeId,
 
    pub(crate) monomorph_index: usize,
 
    pub(crate) position: StatementId,
 
    pub(crate) expr_stack: VecDeque<ExprInstruction>, // hack for expression evaluation, evaluated by popping from back
 
    pub(crate) expr_values: VecDeque<Value>, // hack for expression results, evaluated by popping from front/back
 
    pub(crate) max_stack_size: u32,
 
}
 

	
 
impl Frame {
 
    /// Creates a new execution frame. Does not modify the stack in any way.
 
    pub fn new(heap: &Heap, definition_id: ProcedureDefinitionId, monomorph_type_id: TypeId) -> Self {
 
    pub fn new(heap: &Heap, definition_id: ProcedureDefinitionId, monomorph_type_id: TypeId, monomorph_index: u32) -> Self {
 
        let definition = &heap[definition_id];
 
        let outer_scope_id = definition.scope;
 
        let first_statement_id = definition.body;
 

	
 
        // Another not-so-pretty thing that has to be replaced somewhere in the
 
        // future...
 
        fn determine_max_stack_size(heap: &Heap, scope_id: ScopeId, max_size: &mut u32) {
 
            let scope = &heap[scope_id];
 

	
 
            // Check current block
 
            let cur_size = scope.next_unique_id_in_scope as u32;
 
            if cur_size > *max_size { *max_size = cur_size; }
 

	
 
            // And child blocks
 
            for child_scope in &scope.nested {
 
                determine_max_stack_size(heap, *child_scope, max_size);
 
            }
 
        }
 

	
 
        let mut max_stack_size = 0;
 
        determine_max_stack_size(heap, outer_scope_id, &mut max_stack_size);
 

	
 
        Frame{
 
            definition: definition_id,
 
            monomorph_type_id,
 
            monomorph_index: monomorph_index as usize,
 
            position: first_statement_id.upcast(),
 
            expr_stack: VecDeque::with_capacity(128),
 
            expr_values: VecDeque::with_capacity(128),
 
            max_stack_size,
 
        }
 
    }
 

	
 
    /// Prepares a single expression for execution. This involves walking the
 
    /// expression tree and putting them in the `expr_stack` such that
 
    /// continuously popping from its back will evaluate the expression. The
 
    /// results of each expression will be stored by pushing onto `expr_values`.
 
    pub fn prepare_single_expression(&mut self, heap: &Heap, expr_id: ExpressionId) {
 
        debug_assert!(self.expr_stack.is_empty());
 
        self.expr_values.clear(); // May not be empty if last expression result(s) were discarded
 

	
 
        self.serialize_expression(heap, expr_id);
 
    }
 

	
 
    /// Prepares multiple expressions for execution (i.e. evaluating all
 
    /// function arguments or all elements of an array/union literal). Per
 
    /// expression this works the same as `prepare_single_expression`. However
 
    /// after each expression is evaluated we insert a `PushValToFront`
 
    /// instruction
 
    pub fn prepare_multiple_expressions(&mut self, heap: &Heap, expr_ids: &[ExpressionId]) {
 
        debug_assert!(self.expr_stack.is_empty());
 
        self.expr_values.clear();
 

	
 
        for expr_id in expr_ids {
 
            self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
            self.serialize_expression(heap, *expr_id);
 
        }
 
    }
 

	
 
    /// Performs depth-first serialization of expression tree. Let's not care
 
    /// about performance for a temporary runtime implementation
 
    fn serialize_expression(&mut self, heap: &Heap, id: ExpressionId) {
 
        self.expr_stack.push_back(ExprInstruction::EvalExpr(id));
 

	
 
        match &heap[id] {
 
            Expression::Assignment(expr) => {
 
                self.serialize_expression(heap, expr.left);
 
                self.serialize_expression(heap, expr.right);
 
            },
 
            Expression::Binding(expr) => {
 
                self.serialize_expression(heap, expr.bound_to);
 
                self.serialize_expression(heap, expr.bound_from);
 
            },
 
            Expression::Conditional(expr) => {
 
                self.serialize_expression(heap, expr.test);
 
            },
 
            Expression::Binary(expr) => {
 
                self.serialize_expression(heap, expr.left);
 
                self.serialize_expression(heap, expr.right);
 
            },
 
            Expression::Unary(expr) => {
 
                self.serialize_expression(heap, expr.expression);
 
            },
 
            Expression::Indexing(expr) => {
 
                self.serialize_expression(heap, expr.index);
 
                self.serialize_expression(heap, expr.subject);
 
            },
 
            Expression::Slicing(expr) => {
 
                self.serialize_expression(heap, expr.from_index);
 
                self.serialize_expression(heap, expr.to_index);
 
                self.serialize_expression(heap, expr.subject);
 
            },
 
            Expression::Select(expr) => {
 
                self.serialize_expression(heap, expr.subject);
 
            },
 
            Expression::Literal(expr) => {
 
                // Here we only care about literals that have subexpressions
 
                match &expr.value {
 
                    Literal::Null | Literal::True | Literal::False |
 
                    Literal::Character(_) | Literal::String(_) |
 
                    Literal::Integer(_) | Literal::Enum(_) => {
 
                        // No subexpressions
 
                    },
 
                    Literal::Struct(literal) => {
 
                        // Note: fields expressions are evaluated in programmer-
 
                        // specified order. But struct construction expects them
 
                        // in type-defined order. I might want to come back to
 
                        // this.
 
                        let mut _num_pushed = 0;
 
                        for want_field_idx in 0..literal.fields.len() {
 
                            for field in &literal.fields {
 
                                if field.field_idx == want_field_idx {
 
                                    _num_pushed += 1;
 
                                    self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                                    self.serialize_expression(heap, field.value);
 
                                }
 
                            }
 
                        }
 
                        debug_assert_eq!(_num_pushed, literal.fields.len())
 
                    },
 
                    Literal::Union(literal) => {
 
                        for value_expr_id in &literal.values {
 
                            self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                            self.serialize_expression(heap, *value_expr_id);
 
                        }
 
                    },
 
                    Literal::Array(value_expr_ids) => {
 
                        for value_expr_id in value_expr_ids {
 
                            self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                            self.serialize_expression(heap, *value_expr_id);
 
                        }
 
                    },
 
                    Literal::Tuple(value_expr_ids) => {
 
                        for value_expr_id in value_expr_ids {
 
                            self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                            self.serialize_expression(heap, *value_expr_id);
 
                        }
 
                    }
 
                }
 
            },
 
            Expression::Cast(expr) => {
 
                self.serialize_expression(heap, expr.subject);
 
            }
 
            Expression::Call(expr) => {
 
                for arg_expr_id in &expr.arguments {
 
                    self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                    self.serialize_expression(heap, *arg_expr_id);
 
                }
 
            },
 
            Expression::Variable(_expr) => {
 
                // No subexpressions
 
            }
 
        }
 
    }
 
}
 

	
 
pub type EvalResult = Result<EvalContinuation, EvalError>;
 

	
 
#[derive(Debug)]
 
pub enum EvalContinuation {
 
    // Returned in both sync and non-sync modes
 
    Stepping,
 
    // Returned only in sync mode
 
    BranchInconsistent,
 
    SyncBlockEnd,
 
    NewFork,
 
    BlockFires(PortId),
 
    BlockGet(PortId),
 
    Put(PortId, ValueGroup),
 
    // Returned only in non-sync mode
 
    ComponentTerminated,
 
    SyncBlockStart,
 
    NewComponent(ProcedureDefinitionId, TypeId, ValueGroup),
 
    NewChannel,
 
}
 

	
 
// Note: cloning is fine, methinks. cloning all values and the heap regions then
 
// we end up with valid "pointers" to heap regions.
 
#[derive(Debug, Clone)]
 
pub struct Prompt {
 
    pub(crate) frames: Vec<Frame>,
 
    pub(crate) store: Store,
 
}
 

	
 
impl Prompt {
 
    pub fn new(_types: &TypeTable, heap: &Heap, def: ProcedureDefinitionId, type_id: TypeId, args: ValueGroup) -> Self {
 
    pub fn new(types: &TypeTable, heap: &Heap, def: ProcedureDefinitionId, type_id: TypeId, args: ValueGroup) -> Self {
 
        let mut prompt = Self{
 
            frames: Vec::new(),
 
            store: Store::new(),
 
        };
 

	
 
        // Maybe do typechecking in the future?
 
        let new_frame = Frame::new(heap, def, type_id);
 
        let monomorph_index = types.get_monomorph(type_id).variant.as_procedure().monomorph_index;
 
        let new_frame = Frame::new(heap, def, type_id, monomorph_index);
 
        let max_stack_size = new_frame.max_stack_size;
 
        prompt.frames.push(new_frame);
 
        args.into_store(&mut prompt.store);
 
        prompt.store.reserve_stack(max_stack_size);
 

	
 
        prompt
 
    }
 

	
 
    /// Big 'ol function right here. Didn't want to break it up unnecessarily.
 
    /// It consists of, in sequence: executing any expressions that should be
 
    /// executed before the next statement can be evaluated, then a section that
 
    /// performs debug printing, and finally a section that takes the next
 
    /// statement and executes it. If the statement requires any expressions to
 
    /// be evaluated, then they will be added such that the next time `step` is
 
    /// called, all of these expressions are indeed evaluated.
 
    pub(crate) fn step(&mut self, types: &TypeTable, heap: &Heap, modules: &[Module], ctx: &mut impl RunContext) -> EvalResult {
 
        // Helper function to transfer multiple values from the expression value
 
        // array into a heap region (e.g. constructing arrays or structs).
 
        fn transfer_expression_values_front_into_heap(cur_frame: &mut Frame, store: &mut Store, num_values: usize) -> HeapPos {
 
            let heap_pos = store.alloc_heap();
 

	
 
            // Do the transformation first (because Rust...)
 
            for val_idx in 0..num_values {
 
                cur_frame.expr_values[val_idx] = store.read_take_ownership(cur_frame.expr_values[val_idx].clone());
 
            }
 

	
 
            // And now transfer to the heap region
 
            let values = &mut store.heap_regions[heap_pos as usize].values;
 
            debug_assert!(values.is_empty());
 
            values.reserve(num_values);
 
            for _ in 0..num_values {
 
                values.push(cur_frame.expr_values.pop_front().unwrap());
 
            }
 

	
 
            heap_pos
 
        }
 

	
 
        // Helper function to make sure that an index into an aray is valid.
 
        fn array_inclusive_index_is_invalid(store: &Store, array_heap_pos: u32, idx: i64) -> bool {
 
            let array_len = store.heap_regions[array_heap_pos as usize].values.len();
 
            return idx < 0 || idx >= array_len as i64;
 
        }
 

	
 
        fn array_exclusive_index_is_invalid(store: &Store, array_heap_pos: u32, idx: i64) -> bool {
 
            let array_len = store.heap_regions[array_heap_pos as usize].values.len();
 
            return idx < 0 || idx > array_len as i64;
 
        }
 

	
 
        fn construct_array_error(prompt: &Prompt, modules: &[Module], heap: &Heap, expr_id: ExpressionId, heap_pos: u32, idx: i64) -> EvalError {
 
            let array_len = prompt.store.heap_regions[heap_pos as usize].values.len();
 
            return EvalError::new_error_at_expr(
 
                prompt, modules, heap, expr_id,
 
                format!("index {} is out of bounds: array length is {}", idx, array_len)
 
            )
 
        }
 

	
 
        // Checking if we're at the end of execution
 
        let cur_frame = self.frames.last_mut().unwrap();
 
        if cur_frame.position.is_invalid() {
 
            if heap[cur_frame.definition].kind == ProcedureKind::Function {
 
                todo!("End of function without return, return an evaluation error");
 
            }
 
            return Ok(EvalContinuation::ComponentTerminated);
 
        }
 

	
 
        debug_log!("Taking step in '{}'", heap[cur_frame.definition].identifier().value.as_str());
 

	
 
        // Execute all pending expressions
 
        while !cur_frame.expr_stack.is_empty() {
 
            let next = cur_frame.expr_stack.pop_back().unwrap();
 
            debug_log!("Expr stack: {:?}", next);
 
            match next {
 
                ExprInstruction::PushValToFront => {
 
                    cur_frame.expr_values.rotate_right(1);
 
                },
 
                ExprInstruction::EvalExpr(expr_id) => {
 
                    let expr = &heap[expr_id];
 
                    match expr {
 
                        Expression::Assignment(expr) => {
 
                            let to = cur_frame.expr_values.pop_back().unwrap().as_ref();
 
                            let rhs = cur_frame.expr_values.pop_back().unwrap();
 

	
 
                            // Note: although not pretty, the assignment operator takes ownership
 
                            // of the right-hand side value when possible. So we do not drop the
 
                            // rhs's optionally owned heap data.
 
                            let rhs = self.store.read_take_ownership(rhs);
 
                            apply_assignment_operator(&mut self.store, to, expr.operation, rhs);
 
                        },
 
                        Expression::Binding(_expr) => {
 
                            let bind_to = cur_frame.expr_values.pop_back().unwrap();
 
                            let bind_from = cur_frame.expr_values.pop_back().unwrap();
 
                            let bind_to_heap_pos = bind_to.get_heap_pos();
 
                            let bind_from_heap_pos = bind_from.get_heap_pos();
 

	
 
                            let result = apply_binding_operator(&mut self.store, bind_to, bind_from);
 
                            self.store.drop_value(bind_to_heap_pos);
 
                            self.store.drop_value(bind_from_heap_pos);
 
                            cur_frame.expr_values.push_back(Value::Bool(result));
 
                        },
 
                        Expression::Conditional(expr) => {
 
                            // Evaluate testing expression, then extend the
 
                            // expression stack with the appropriate expression
 
                            let test_result = cur_frame.expr_values.pop_back().unwrap().as_bool();
 
                            if test_result {
 
                                cur_frame.serialize_expression(heap, expr.true_expression);
 
                            } else {
 
                                cur_frame.serialize_expression(heap, expr.false_expression);
 
                            }
 
                        },
 
                        Expression::Binary(expr) => {
 
                            let lhs = cur_frame.expr_values.pop_back().unwrap();
 
                            let rhs = cur_frame.expr_values.pop_back().unwrap();
 
                            let result = apply_binary_operator(&mut self.store, &lhs, expr.operation, &rhs);
 
                            cur_frame.expr_values.push_back(result);
 
                            self.store.drop_value(lhs.get_heap_pos());
 
                            self.store.drop_value(rhs.get_heap_pos());
 
                        },
 
                        Expression::Unary(expr) => {
 
                            let val = cur_frame.expr_values.pop_back().unwrap();
 
                            let result = apply_unary_operator(&mut self.store, expr.operation, &val);
 
                            cur_frame.expr_values.push_back(result);
 
                            self.store.drop_value(val.get_heap_pos());
 
                        },
 
                        Expression::Indexing(_expr) => {
 
                            // Evaluate index. Never heap allocated so we do
 
                            // not have to drop it.
 
                            let index = cur_frame.expr_values.pop_back().unwrap();
 
                            let index = self.store.maybe_read_ref(&index);
 

	
 
                            debug_assert!(index.is_integer());
 
                            let index = if index.is_signed_integer() {
 
                                index.as_signed_integer() as i64
 
                            } else {
 
                                index.as_unsigned_integer() as i64
 
                            };
 

	
 
                            let subject = cur_frame.expr_values.pop_back().unwrap();
 

	
 
                            let (deallocate_heap_pos, value_to_push) = match subject {
 
                                Value::Ref(value_ref) => {
 
                                    // Our expression stack value is a reference to something that
 
                                    // exists in the normal stack/heap. We don't want to deallocate
 
                                    // this thing. Rather we want to return a reference to it.
 
                                    let subject = self.store.read_ref(value_ref);
 
                                    let subject_heap_pos = match subject {
 
                                        Value::String(v) => *v,
 
                                        Value::Array(v) => *v,
 
                                        Value::Message(v) => *v,
 
                                        _ => unreachable!(),
 
                                    };
 

	
 
                                    if array_inclusive_index_is_invalid(&self.store, subject_heap_pos, index) {
 
                                        return Err(construct_array_error(self, modules, heap, expr_id, subject_heap_pos, index));
 
                                    }
 

	
 
                                    (None, Value::Ref(ValueId::Heap(subject_heap_pos, index as u32)))
 
                                },
 
                                _ => {
 
                                    // Our value lives on the expression stack, hence we need to
 
                                    // clone whatever we're referring to. Then drop the subject.
 
                                    let subject_heap_pos = match &subject {
 
                                        Value::String(v) => *v,
 
                                        Value::Array(v) => *v,
 
                                        Value::Message(v) => *v,
 
                                        _ => unreachable!(),
 
                                    };
 

	
 
                                    if array_inclusive_index_is_invalid(&self.store, subject_heap_pos, index) {
 
                                        return Err(construct_array_error(self, modules, heap, expr_id, subject_heap_pos, index));
 
                                    }
 

	
 
                                    let subject_indexed = Value::Ref(ValueId::Heap(subject_heap_pos, index as u32));
 
                                    (Some(subject_heap_pos), self.store.clone_value(subject_indexed))
 
                                },
 
                            };
 

	
 
                            cur_frame.expr_values.push_back(value_to_push);
 
                            self.store.drop_value(deallocate_heap_pos);
 
                        },
 
                        Expression::Slicing(expr) => {
 
                            // Evaluate indices
 
                            let from_index = cur_frame.expr_values.pop_back().unwrap();
 
                            let from_index = self.store.maybe_read_ref(&from_index);
 
                            let to_index = cur_frame.expr_values.pop_back().unwrap();
 
                            let to_index = self.store.maybe_read_ref(&to_index);
 

	
 
                            debug_assert!(from_index.is_integer() && to_index.is_integer());
 
                            let from_index = if from_index.is_signed_integer() {
 
                                from_index.as_signed_integer()
 
                            } else {
 
                                from_index.as_unsigned_integer() as i64
 
                            };
 
                            let to_index = if to_index.is_signed_integer() {
 
                                to_index.as_signed_integer()
 
                            } else {
 
                                to_index.as_unsigned_integer() as i64
 
                            };
 

	
 
                            // Dereference subject if needed
 
                            let subject = cur_frame.expr_values.pop_back().unwrap();
 
                            let deref_subject = self.store.maybe_read_ref(&subject);
 

	
 
                            // Slicing needs to produce a copy anyway (with the
 
                            // current evaluator implementation)
 
                            enum ValueKind{ Array, String, Message }
 
                            let (value_kind, array_heap_pos) = match deref_subject {
 
                                Value::Array(v) => (ValueKind::Array, *v),
 
                                Value::String(v) => (ValueKind::String, *v),
 
                                Value::Message(v) => (ValueKind::Message, *v),
 
                                _ => unreachable!()
 
                            };
 

	
 
                            if array_inclusive_index_is_invalid(&self.store, array_heap_pos, from_index) {
 
                                return Err(construct_array_error(self, modules, heap, expr.from_index, array_heap_pos, from_index));
 
                            }
 
                            if array_exclusive_index_is_invalid(&self.store, array_heap_pos, to_index) {
 
                                return Err(construct_array_error(self, modules, heap, expr.to_index, array_heap_pos, to_index));
 
                            }
 

	
 
                            // Again: would love to push directly, but rust...
 
                            let new_heap_pos = self.store.alloc_heap();
 
                            debug_assert!(self.store.heap_regions[new_heap_pos as usize].values.is_empty());
 
                            if to_index > from_index {
 
                                let from_index = from_index as usize;
 
                                let to_index = to_index as usize;
 
                                let mut values = Vec::with_capacity(to_index - from_index);
 
                                for idx in from_index..to_index {
 
                                    let value = self.store.heap_regions[array_heap_pos as usize].values[idx].clone();
 
                                    values.push(self.store.clone_value(value));
 
                                }
 

	
 
                                self.store.heap_regions[new_heap_pos as usize].values = values;
 

	
 
                            } // else: empty range
 

	
 
                            cur_frame.expr_values.push_back(match value_kind {
 
                                ValueKind::Array => Value::Array(new_heap_pos),
 
                                ValueKind::String => Value::String(new_heap_pos),
 
                                ValueKind::Message => Value::Message(new_heap_pos),
 
                            });
 

	
 
                            // Dropping the original subject, because we don't
 
                            // want to drop something on the stack
 
                            self.store.drop_value(subject.get_heap_pos());
 
                        },
 
                        Expression::Select(expr) => {
 
                            let subject= cur_frame.expr_values.pop_back().unwrap();
 
                            let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                            let field_idx = mono_data.expr_info[expr.type_index as usize].variant.as_select() as u32;
 

	
 
                            // Note: same as above: clone if value lives on expr stack, simply
 
                            // refer to it if it already lives on the stack/heap.
 
                            let (deallocate_heap_pos, value_to_push) = match subject {
 
                                Value::Ref(value_ref) => {
 
                                    let subject = self.store.read_ref(value_ref);
 
                                    let subject_heap_pos = match expr.kind {
 
                                        SelectKind::StructField(_) => subject.as_struct(),
 
                                        SelectKind::TupleMember(_) => subject.as_tuple(),
 
                                    };
 

	
 
                                    (None, Value::Ref(ValueId::Heap(subject_heap_pos, field_idx)))
 
                                },
 
                                _ => {
 
                                    let subject_heap_pos = match expr.kind {
 
                                        SelectKind::StructField(_) => subject.as_struct(),
 
                                        SelectKind::TupleMember(_) => subject.as_tuple(),
 
                                    };
 
                                    let subject_indexed = Value::Ref(ValueId::Heap(subject_heap_pos, field_idx));
 
                                    (Some(subject_heap_pos), self.store.clone_value(subject_indexed))
 
                                },
 
                            };
 

	
 
                            cur_frame.expr_values.push_back(value_to_push);
 
                            self.store.drop_value(deallocate_heap_pos);
 
                        },
 
                        Expression::Literal(expr) => {
 
                            let value = match &expr.value {
 
                                Literal::Null => Value::Null,
 
                                Literal::True => Value::Bool(true),
 
                                Literal::False => Value::Bool(false),
 
                                Literal::Character(lit_value) => Value::Char(*lit_value),
 
                                Literal::String(lit_value) => {
 
                                    let heap_pos = self.store.alloc_heap();
 
                                    let values = &mut self.store.heap_regions[heap_pos as usize].values;
 
                                    let value = lit_value.as_str();
 
                                    debug_assert!(values.is_empty());
 
                                    values.reserve(value.len());
 
                                    for character in value.as_bytes() {
 
                                        debug_assert!(character.is_ascii());
 
                                        values.push(Value::Char(*character as char));
 
                                    }
 
                                    Value::String(heap_pos)
 
                                }
 
                                Literal::Integer(lit_value) => {
 
                                    use ConcreteTypePart as CTP;
 
                                    let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                                    let type_id = mono_data.expr_info[expr.type_index as usize].type_id;
 
                                    let concrete_type = &types.get_monomorph(type_id).concrete_type;
 

	
 
                                    debug_assert_eq!(concrete_type.parts.len(), 1);
 
                                    match concrete_type.parts[0] {
 
                                        CTP::UInt8  => Value::UInt8(lit_value.unsigned_value as u8),
 
                                        CTP::UInt16 => Value::UInt16(lit_value.unsigned_value as u16),
 
                                        CTP::UInt32 => Value::UInt32(lit_value.unsigned_value as u32),
 
                                        CTP::UInt64 => Value::UInt64(lit_value.unsigned_value as u64),
 
                                        CTP::SInt8  => Value::SInt8(lit_value.unsigned_value as i8),
 
                                        CTP::SInt16 => Value::SInt16(lit_value.unsigned_value as i16),
 
                                        CTP::SInt32 => Value::SInt32(lit_value.unsigned_value as i32),
 
                                        CTP::SInt64 => Value::SInt64(lit_value.unsigned_value as i64),
 
                                        _ => unreachable!("got concrete type {:?} for integer literal at expr {:?}", concrete_type, expr_id),
 
                                    }
 
                                }
 
                                Literal::Struct(lit_value) => {
 
                                    let heap_pos = transfer_expression_values_front_into_heap(
 
                                        cur_frame, &mut self.store, lit_value.fields.len()
 
                                    );
 
                                    Value::Struct(heap_pos)
 
                                }
 
                                Literal::Enum(lit_value) => {
 
                                    Value::Enum(lit_value.variant_idx as i64)
 
                                }
 
                                Literal::Union(lit_value) => {
 
                                    let heap_pos = transfer_expression_values_front_into_heap(
 
                                        cur_frame, &mut self.store, lit_value.values.len()
 
                                    );
 
                                    Value::Union(lit_value.variant_idx as i64, heap_pos)
 
                                }
 
                                Literal::Array(lit_value) => {
 
                                    let heap_pos = transfer_expression_values_front_into_heap(
 
                                        cur_frame, &mut self.store, lit_value.len()
 
                                    );
 
                                    Value::Array(heap_pos)
 
                                }
 
                                Literal::Tuple(lit_value) => {
 
                                    let heap_pos = transfer_expression_values_front_into_heap(
 
                                        cur_frame, &mut self.store, lit_value.len()
 
                                    );
 
                                    Value::Tuple(heap_pos)
 
                                }
 
                            };
 

	
 
                            cur_frame.expr_values.push_back(value);
 
                        },
 
                        Expression::Cast(expr) => {
 
                            let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                            let type_id = mono_data.expr_info[expr.type_index as usize].type_id;
 
                            let concrete_type = &types.get_monomorph(type_id).concrete_type;
 

	
 
                            // Typechecking reduced this to two cases: either we
 
                            // have casting noop (same types), or we're casting
 
                            // between integer/bool/char types.
 
                            let subject = cur_frame.expr_values.pop_back().unwrap();
 
                            match apply_casting(&mut self.store, concrete_type, &subject) {
 
                                Ok(value) => cur_frame.expr_values.push_back(value),
 
                                Err(msg) => {
 
                                    return Err(EvalError::new_error_at_expr(self, modules, heap, expr.this.upcast(), msg));
 
                                }
 
                            }
 

	
 
                            self.store.drop_value(subject.get_heap_pos());
 
                        }
 
                        Expression::Call(expr) => {
 
                            // If we're dealing with a builtin we don't do any
 
                            // fancy shenanigans at all, just push the result.
 
                            match expr.method {
 
                                Method::Get => {
 
                                    let value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let value = self.store.maybe_read_ref(&value).clone();
 

	
 
                                    let port_id = if let Value::Input(port_id) = value {
 
                                        port_id
 
                                    } else {
 
                                        unreachable!("executor calling 'get' on value {:?}", value)
 
                                    };
 

	
 
                                    match ctx.performed_get(port_id) {
 
                                        Some(result) => {
 
                                            // We have the result. Merge the `ValueGroup` with the
 
                                            // stack/heap storage.
 
                                            debug_assert_eq!(result.values.len(), 1);
 
                                            result.into_stack(&mut cur_frame.expr_values, &mut self.store);
 
                                        },
 
                                        None => {
 
                                            // Don't have the result yet, prepare the expression to
 
                                            // get run again after we've received a message.
 
                                            cur_frame.expr_values.push_front(value.clone());
 
                                            cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
 
                                            return Ok(EvalContinuation::BlockGet(port_id));
 
                                        }
 
                                    }
 
                                },
 
                                Method::Put => {
 
                                    let port_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let deref_port_value = self.store.maybe_read_ref(&port_value).clone();
 

	
 
                                    let port_id = if let Value::Output(port_id) = deref_port_value {
 
                                        port_id
 
                                    } else {
 
                                        unreachable!("executor calling 'put' on value {:?}", deref_port_value)
 
                                    };
 

	
 
                                    let msg_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let deref_msg_value = self.store.maybe_read_ref(&msg_value).clone();
 

	
 
                                    if ctx.performed_put(port_id) {
 
                                        // We're fine, deallocate in case the expression value stack
 
                                        // held an owned value
 
                                        self.store.drop_value(msg_value.get_heap_pos());
 
                                    } else {
 
                                        // Prepare to execute again
 
                                        cur_frame.expr_values.push_front(msg_value);
 
                                        cur_frame.expr_values.push_front(port_value);
 
                                        cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
 
                                        let value_group = ValueGroup::from_store(&self.store, &[deref_msg_value]);
 
                                        return Ok(EvalContinuation::Put(port_id, value_group));
 
                                    }
 
                                },
 
                                Method::Fires => {
 
                                    let port_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let port_value_deref = self.store.maybe_read_ref(&port_value).clone();
 

	
 
                                    let port_id = match port_value_deref {
 
                                        Value::Input(port_id) => port_id,
 
                                        Value::Output(port_id) => port_id,
 
                                        _ => unreachable!("executor calling 'fires' on value {:?}", port_value_deref),
 
                                    };
 

	
 
                                    match ctx.fires(port_id) {
 
                                        None => {
 
                                            cur_frame.expr_values.push_front(port_value);
 
                                            cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
 
                                            return Ok(EvalContinuation::BlockFires(port_id));
 
                                        },
 
                                        Some(value) => {
 
                                            cur_frame.expr_values.push_back(value);
 
                                        }
 
                                    }
 
                                },
 
                                Method::Create => {
 
                                    let length_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let length_value = self.store.maybe_read_ref(&length_value);
 
                                    let length = if length_value.is_signed_integer() {
 
                                        let length_value = length_value.as_signed_integer();
 
                                        if length_value < 0 {
 
                                            return Err(EvalError::new_error_at_expr(
 
                                                self, modules, heap, expr_id,
 
                                                format!("got length '{}', can only create a message with a non-negative length", length_value)
 
                                            ));
 
                                        }
 

	
 
                                        length_value as u64
 
                                    } else {
 
                                        debug_assert!(length_value.is_unsigned_integer());
 
                                        length_value.as_unsigned_integer()
 
                                    };
 

	
 
                                    let heap_pos = self.store.alloc_heap();
 
                                    let values = &mut self.store.heap_regions[heap_pos as usize].values;
 
                                    debug_assert!(values.is_empty());
 
                                    values.resize(length as usize, Value::UInt8(0));
 
                                    cur_frame.expr_values.push_back(Value::Message(heap_pos));
 
                                },
 
                                Method::Length => {
 
                                    let value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let value_heap_pos = value.get_heap_pos();
 
                                    let value = self.store.maybe_read_ref(&value);
 

	
 
                                    let heap_pos = match value {
 
                                        Value::Array(pos) => *pos,
 
                                        Value::String(pos) => *pos,
 
                                        _ => unreachable!("length(...) on {:?}", value),
 
                                    };
 

	
 
                                    let len = self.store.heap_regions[heap_pos as usize].values.len();
 

	
 
                                    // TODO: @PtrInt
 
                                    cur_frame.expr_values.push_back(Value::UInt32(len as u32));
 
                                    self.store.drop_value(value_heap_pos);
 
                                },
 
                                Method::Assert => {
 
                                    let value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let value = self.store.maybe_read_ref(&value).clone();
 
                                    if !value.as_bool() {
 
                                        return Ok(EvalContinuation::BranchInconsistent)
 
                                    }
 
                                },
 
                                Method::Print => {
 
                                    // Convert the runtime-variant of a string
 
                                    // into an actual string.
 
                                    let value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let value_heap_pos = value.as_string();
 
                                    let elements = &self.store.heap_regions[value_heap_pos as usize].values;
 

	
 
                                    let mut message = String::with_capacity(elements.len());
 
                                    for element in elements {
 
                                        message.push(element.as_char());
 
                                    }
 

	
 
                                    // Drop the heap-allocated value from the
 
                                    // store
 
                                    self.store.drop_heap_pos(value_heap_pos);
 
                                    println!("{}", message);
 
                                },
 
                                Method::SelectStart => {
 
                                    todo!("select start");
 
                                },
 
                                Method::SelectRegisterCasePort => {
 
                                    todo!("select register");
 
                                },
 
                                Method::SelectWait => {
 
                                    todo!("select wait");
 
                                },
 
                                Method::UserComponent => {
 
                                    // This is actually handled by the evaluation
 
                                    // of the statement.
 
                                    debug_assert_eq!(heap[expr.procedure].parameters.len(), cur_frame.expr_values.len());
 
                                    debug_assert_eq!(heap[cur_frame.position].as_new().expression, expr.this)
 
                                },
 
                                Method::UserFunction => {
 
                                    // Push a new frame. Note that all expressions have
 
                                    // been pushed to the front, so they're in the order
 
                                    // of the definition.
 
                                    let num_args = expr.arguments.len();
 

	
 
                                    // Determine stack boundaries
 
                                    let cur_stack_boundary = self.store.cur_stack_boundary;
 
                                    let new_stack_boundary = self.store.stack.len();
 

	
 
                                    // Push new boundary and function arguments for new frame
 
                                    self.store.stack.push(Value::PrevStackBoundary(cur_stack_boundary as isize));
 
                                    for _ in 0..num_args {
 
                                        let argument = self.store.read_take_ownership(cur_frame.expr_values.pop_front().unwrap());
 
                                        self.store.stack.push(argument);
 
                                    }
 

	
 
                                    // Determine the monomorph index of the function we're calling
 
                                    let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                                    let type_id = mono_data.expr_info[expr.type_index as usize].variant.as_procedure().0;
 
                                    let (type_id, monomorph_index) = mono_data.expr_info[expr.type_index as usize].variant.as_procedure();
 

	
 
                                    // Push the new frame and reserve its stack size
 
                                    let new_frame = Frame::new(heap, expr.procedure, type_id);
 
                                    let new_frame = Frame::new(heap, expr.procedure, type_id, monomorph_index);
 
                                    let new_stack_size = new_frame.max_stack_size;
 
                                    self.frames.push(new_frame);
 
                                    self.store.cur_stack_boundary = new_stack_boundary;
 
                                    self.store.reserve_stack(new_stack_size);
 

	
 
                                    // To simplify the logic a little bit we will now
 
                                    // return and ask our caller to call us again
 
                                    return Ok(EvalContinuation::Stepping);
 
                                }
 
                            }
 
                        },
 
                        Expression::Variable(expr) => {
 
                            let variable = &heap[expr.declaration.unwrap()];
 
                            let ref_value = if expr.used_as_binding_target {
 
                                Value::Binding(variable.unique_id_in_scope as StackPos)
 
                            } else {
 
                                Value::Ref(ValueId::Stack(variable.unique_id_in_scope as StackPos))
 
                            };
 
                            cur_frame.expr_values.push_back(ref_value);
 
                        }
 
                    }
 
                }
 
            }
 
        }
 

	
 
        debug_log!("Frame [{:?}] at {:?}", cur_frame.definition, cur_frame.position);
 
        if debug_enabled!() {
 
            debug_log!("Expression value stack (size = {}):", cur_frame.expr_values.len());
 
            for (_stack_idx, _stack_val) in cur_frame.expr_values.iter().enumerate() {
 
                debug_log!("  [{:03}] {:?}", _stack_idx, _stack_val);
 
            }
 

	
 
            debug_log!("Stack (size = {}):", self.store.stack.len());
 
            for (_stack_idx, _stack_val) in self.store.stack.iter().enumerate() {
 
                debug_log!("  [{:03}] {:?}", _stack_idx, _stack_val);
 
            }
 

	
 
            debug_log!("Heap:");
 
            for (_heap_idx, _heap_region) in self.store.heap_regions.iter().enumerate() {
 
                let _is_free = self.store.free_regions.iter().any(|idx| *idx as usize == _heap_idx);
 
                debug_log!("  [{:03}] in_use: {}, len: {}, vals: {:?}", _heap_idx, !_is_free, _heap_region.values.len(), &_heap_region.values);
 
            }
 
        }
 
        // No (more) expressions to evaluate. So evaluate statement (that may
 
        // depend on the result on the last evaluated expression(s))
 
        let stmt = &heap[cur_frame.position];
 
        let return_value = match stmt {
 
            Statement::Block(stmt) => {
 
                debug_assert!(stmt.statements.is_empty() || stmt.next == stmt.statements[0]);
 
                cur_frame.position = stmt.next;
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndBlock(stmt) => {
 
                let block = &heap[stmt.start_block];
 
                let scope = &heap[block.scope];
 
                self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Local(stmt) => {
 
                match stmt {
 
                    LocalStatement::Memory(stmt) => {
 
                        dbg_code!({
 
                            let variable = &heap[stmt.variable];
 
                            debug_assert!(match self.store.read_ref(ValueId::Stack(variable.unique_id_in_scope as u32)) {
 
                                Value::Unassigned => false,
 
                                _ => true,
 
                            });
 
                        });
 

	
 
                        cur_frame.position = stmt.next;
 
                        Ok(EvalContinuation::Stepping)
 
                    },
 
                    LocalStatement::Channel(stmt) => {
 
                        // Need to create a new channel by requesting it from
 
                        // the runtime.
 
                        match ctx.created_channel() {
 
                            None => {
 
                                // No channel is pending. So request one
 
                                    Ok(EvalContinuation::NewChannel)
 
                            },
 
                            Some((put_port, get_port)) => {
 
                                self.store.write(ValueId::Stack(heap[stmt.from].unique_id_in_scope as u32), put_port);
 
                                self.store.write(ValueId::Stack(heap[stmt.to].unique_id_in_scope as u32), get_port);
 
                                cur_frame.position = stmt.next;
 
                                Ok(EvalContinuation::Stepping)
 
                            }
 
                        }
 
                    }
 
                }
 
            },
 
            Statement::Labeled(stmt) => {
 
                cur_frame.position = stmt.body;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::If(stmt) => {
 
                debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for if statement");
 
                let test_value = cur_frame.expr_values.pop_back().unwrap();
 
                let test_value = self.store.maybe_read_ref(&test_value).as_bool();
 
                if test_value {
 
                    cur_frame.position = stmt.true_case.body;
 
                } else if let Some(false_body) = stmt.false_case {
 
                    cur_frame.position = false_body.body;
 
                } else {
 
                    // Not true, and no false body
 
                    cur_frame.position = stmt.end_if.upcast();
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndIf(stmt) => {
 
                cur_frame.position = stmt.next;
 
                let if_stmt = &heap[stmt.start_if];
 
                debug_assert_eq!(
 
                    heap[if_stmt.true_case.scope].first_unique_id_in_scope,
 
                    heap[if_stmt.false_case.unwrap_or(if_stmt.true_case).scope].first_unique_id_in_scope,
 
                );
 
                let scope = &heap[if_stmt.true_case.scope];
 
                self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::While(stmt) => {
 
                debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for while statement");
 
                let test_value = cur_frame.expr_values.pop_back().unwrap();
 
                let test_value = self.store.maybe_read_ref(&test_value).as_bool();
 
                if test_value {
 
                    cur_frame.position = stmt.body;
 
                } else {
 
                    cur_frame.position = stmt.end_while.upcast();
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndWhile(stmt) => {
 
                cur_frame.position = stmt.next;
 
                let start_while = &heap[stmt.start_while];
 
                let scope = &heap[start_while.scope];
 
                self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Break(stmt) => {
 
                cur_frame.position = stmt.target.upcast();
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Continue(stmt) => {
 
                cur_frame.position = stmt.target.upcast();
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Synchronous(stmt) => {
 
                cur_frame.position = stmt.body;
 

	
 
                Ok(EvalContinuation::SyncBlockStart)
 
            },
 
            Statement::EndSynchronous(stmt) => {
 
                cur_frame.position = stmt.next;
 
                let start_synchronous = &heap[stmt.start_sync];
 
                let scope = &heap[start_synchronous.scope];
 
                self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 

	
 
                Ok(EvalContinuation::SyncBlockEnd)
 
            },
 
            Statement::Fork(stmt) => {
 
                if stmt.right_body.is_none() {
 
                    // No reason to fork
 
                    cur_frame.position = stmt.left_body;
 
                } else {
 
                    // Need to fork
 
                    if let Some(go_left) = ctx.performed_fork() {
 
                        // Runtime has created a fork
 
                        if go_left {
 
                            cur_frame.position = stmt.left_body;
 
                        } else {
 
                            cur_frame.position = stmt.right_body.unwrap();
 
                        }
 
                    } else {
 
                        // Request the runtime to create a fork of the current
 
                        // branch
 
                        return Ok(EvalContinuation::NewFork);
 
                    }
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndFork(stmt) => {
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Select(_stmt) => {
 
                todo!("implement select evaluation")
 
            },
 
            Statement::EndSelect(stmt) => {
 
                cur_frame.position = stmt.next;
 
                let start_select = &heap[stmt.start_select];
 
                if let Some(select_case) = start_select.cases.first() {
 
                    let scope = &heap[select_case.scope];
 
                    self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Return(_stmt) => {
 
                debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for return statement");
 

	
 
                // The preceding frame has executed a call, so is expecting the
 
                // return expression on its expression value stack. Note that
 
                // we may be returning a reference to something on our stack,
 
                // so we need to read that value and clone it.
 
                let return_value = cur_frame.expr_values.pop_back().unwrap();
 
                let return_value = match return_value {
 
                    Value::Ref(value_id) => self.store.read_copy(value_id),
 
                    _ => return_value,
 
                };
 

	
 
                // Pre-emptively pop our stack frame
 
                self.frames.pop();
 

	
 
                // Clean up our section of the stack
 
                self.store.clear_stack(0);
 
                self.store.stack.truncate(self.store.cur_stack_boundary + 1);
 
                let prev_stack_idx = self.store.stack.pop().unwrap().as_stack_boundary();
 

	
 
                // TODO: Temporary hack for testing, remove at some point
 
                if self.frames.is_empty() {
 
                    debug_assert!(prev_stack_idx == -1);
 
                    debug_assert!(self.store.stack.len() == 0);
 
                    self.store.stack.push(return_value);
 
                    return Ok(EvalContinuation::ComponentTerminated);
 
                }
 

	
 
                debug_assert!(prev_stack_idx >= 0);
 
                // Return to original state of stack frame
 
                self.store.cur_stack_boundary = prev_stack_idx as usize;
 
                let cur_frame = self.frames.last_mut().unwrap();
 
                cur_frame.expr_values.push_back(return_value);
 

	
 
                // We just returned to the previous frame, which might be in
 
                // the middle of evaluating expressions for a particular
 
                // statement. So we don't want to enter the code below.
 
                return Ok(EvalContinuation::Stepping);
 
            },
 
            Statement::Goto(stmt) => {
 
                cur_frame.position = stmt.target.upcast();
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::New(stmt) => {
 
                let call_expr = &heap[stmt.expression];
 
                debug_assert_eq!(
 
                    cur_frame.expr_values.len(), heap[call_expr.procedure].parameters.len(),
 
                    "mismatch in expr stack size and number of arguments for new statement"
 
                );
 

	
 
                let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                let type_id = mono_data.expr_info[expr.type_index as usize].variant.as_procedure().0;
 
                let type_id = mono_data.expr_info[call_expr.type_index as usize].variant.as_procedure().0;
 

	
 
                // Note that due to expression value evaluation they exist in
 
                // reverse order on the stack.
 
                // TODO: Revise this code, keep it as is to be compatible with current runtime
 
                let mut args = Vec::new();
 
                while let Some(value) = cur_frame.expr_values.pop_front() {
 
                    args.push(value);
 
                }
 

	
 
                // Construct argument group, thereby copying heap regions
 
                let argument_group = ValueGroup::from_store(&self.store, &args);
 

	
 
                // Clear any heap regions
 
                for arg in &args {
 
                    self.store.drop_value(arg.get_heap_pos());
 
                }
 

	
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::NewComponent(call_expr.procedure, type_id, argument_group))
 
            },
 
            Statement::Expression(stmt) => {
 
                // The expression has just been completely evaluated. Some
 
                // values might have remained on the expression value stack.
 
                // cur_frame.expr_values.clear(); PROPER CLEARING
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
        };
 

	
 
        assert!(
 
            cur_frame.expr_values.is_empty(),
 
            "This is a debugging assertion that will fail if you perform expressions without \
 
            assigning to anything. This should be completely valid, and this assertion should be \
 
            replaced by something that clears the expression values if needed, but I'll keep this \
 
            in for now for debugging purposes."
 
        );
 

	
 
        // If the next statement requires evaluating expressions then we push
 
        // these onto the expression stack. This way we will evaluate this
 
        // stack in the next loop, then evaluate the statement using the result
 
        // from the expression evaluation.
 
        if !cur_frame.position.is_invalid() {
 
            let stmt = &heap[cur_frame.position];
 

	
 
            match stmt {
 
                Statement::Local(stmt) => {
 
                    if let LocalStatement::Memory(stmt) = stmt {
 
                        // Setup as unassigned, when we execute the memory
 
                        // statement (after evaluating expression), it should no
 
                        // longer be `Unassigned`.
 
                        let variable = &heap[stmt.variable];
 
                        self.store.write(ValueId::Stack(variable.unique_id_in_scope as u32), Value::Unassigned);
 
                        cur_frame.prepare_single_expression(heap, stmt.initial_expr.upcast());
 
                    }
 
                },
 
                Statement::If(stmt) => cur_frame.prepare_single_expression(heap, stmt.test),
 
                Statement::While(stmt) => cur_frame.prepare_single_expression(heap, stmt.test),
 
                Statement::Return(stmt) => {
 
                    debug_assert_eq!(stmt.expressions.len(), 1); // TODO: @ReturnValues
 
                    cur_frame.prepare_single_expression(heap, stmt.expressions[0]);
 
                },
 
                Statement::New(stmt) => {
 
                    // Note that we will end up not evaluating the call itself.
 
                    // Rather we will evaluate its expressions and then
 
                    // instantiate the component upon reaching the "new" stmt.
 
                    let call_expr = &heap[stmt.expression];
 
                    cur_frame.prepare_multiple_expressions(heap, &call_expr.arguments);
 
                },
 
                Statement::Expression(stmt) => {
 
                    cur_frame.prepare_single_expression(heap, stmt.expression);
 
                }
 
                _ => {},
 
            }
 
        }
 

	
 
        return_value
 
    }
 

	
 
    /// Constructs an error at the current expression that lives at the top of
 
    /// the expression stack. Falls back to constructing an error at the current
 
    /// statement if there is no expression.
 
    pub(crate) fn new_error_at_expr(&self, modules: &[Module], heap: &Heap, error_message: String) -> EvalError {
 
        let last_frame = self.frames.last().unwrap();
 
        for instruction in last_frame.expr_stack.iter().rev() {
 
            if let ExprInstruction::EvalExpr(expression_id) = instruction {
 
                return EvalError::new_error_at_expr(
 
                    self, modules, heap, *expression_id, error_message
 
                );
 
            }
 
        }
 

	
 
        // If here then expression stack was empty (cannot have just rotate
 
        // instructions)
 
        panic!("attempted to construct evaluation error without any expressions to evaluate in frame");
 
    }
 
}
 
\ No newline at end of file
src/protocol/mod.rs
Show inline comments
 
mod arena;
 
pub(crate) mod eval;
 
pub(crate) mod input_source;
 
mod parser;
 
#[cfg(test)] mod tests;
 

	
 
pub(crate) mod ast;
 
pub(crate) mod ast_printer;
 

	
 
use std::sync::Mutex;
 

	
 
use crate::collections::{StringPool, StringRef};
 
use crate::protocol::ast::*;
 
use crate::protocol::eval::*;
 
use crate::protocol::input_source::*;
 
use crate::protocol::parser::*;
 
use crate::protocol::type_table::*;
 

	
 
pub use parser::type_table::TypeId;
 

	
 
/// A protocol description module
 
pub struct Module {
 
    pub(crate) source: InputSource,
 
    pub(crate) root_id: RootId,
 
    pub(crate) name: Option<StringRef<'static>>,
 
}
 
/// Description of a protocol object, used to configure new connectors.
 
#[repr(C)]
 
pub struct ProtocolDescription {
 
    pub(crate) modules: Vec<Module>,
 
    pub(crate) heap: Heap,
 
    pub(crate) types: TypeTable,
 
    pub(crate) pool: Mutex<StringPool>,
 
}
 
#[derive(Debug, Clone)]
 
pub(crate) struct ComponentState {
 
    pub(crate) prompt: Prompt,
 
}
 

	
 
#[derive(Debug)]
 
pub enum ComponentCreationError {
 
    ModuleDoesntExist,
 
    DefinitionDoesntExist,
 
    DefinitionNotComponent,
 
    InvalidNumArguments,
 
    InvalidArgumentType(usize),
 
    UnownedPort,
 
    InSync,
 
}
 

	
 
impl ProtocolDescription {
 
    pub fn parse(buffer: &[u8]) -> Result<Self, String> {
 
        let source = InputSource::new(String::new(), Vec::from(buffer));
 
        let mut parser = Parser::new();
 
        parser.feed(source).expect("failed to feed source");
 
        
 
        if let Err(err) = parser.parse() {
 
            println!("ERROR:\n{}", err);
 
            return Err(format!("{}", err))
 
        }
 

	
 
        debug_assert_eq!(parser.modules.len(), 1, "only supporting one module here for now");
 
        let modules: Vec<Module> = parser.modules.into_iter()
 
            .map(|module| Module{
 
                source: module.source,
 
                root_id: module.root_id,
 
                name: module.name.map(|(_, name)| name)
 
            })
 
            .collect();
 

	
 
        return Ok(ProtocolDescription {
 
            modules,
 
            heap: parser.heap,
 
            types: parser.type_table,
 
            pool: Mutex::new(parser.string_pool),
 
        });
 
    }
 

	
 
    pub(crate) fn new_component(
 
        &self, module_name: &[u8], identifier: &[u8], arguments: ValueGroup
 
    ) -> Result<Prompt, ComponentCreationError> {
 
        // Find the module in which the definition can be found
 
        let module_root = self.lookup_module_root(module_name);
 
        if module_root.is_none() {
 
            return Err(ComponentCreationError::ModuleDoesntExist);
 
        }
 
        let module_root = module_root.unwrap();
 

	
 
        let root = &self.heap[module_root];
 
        let definition_id = root.get_definition_ident(&self.heap, identifier);
 
        if definition_id.is_none() {
 
            return Err(ComponentCreationError::DefinitionDoesntExist);
 
        }
 
        let definition_id = definition_id.unwrap();
 

	
 
        let ast_definition = &self.heap[definition_id];
 
        if !ast_definition.is_procedure() {
 
            return Err(ComponentCreationError::DefinitionNotComponent);
 
        }
 

	
 
        // Make sure that the types of the provided value group matches that of
 
        // the expected types.
 
        let ast_definition = ast_definition.as_procedure();
 
        if !ast_definition.poly_vars.is_empty() || ast_definition.kind == ProcedureKind::Function {
 
            return Err(ComponentCreationError::DefinitionNotComponent);
 
        }
 

	
 
        // - check number of arguments by retrieving the one instantiated
 
        //   monomorph
 
        let concrete_type = ConcreteType{ parts: vec![ConcreteTypePart::Component(ast_definition.this, 0)] };
 
        let mono_index = self.types.get_procedure_monomorph_type_id(&definition_id, &concrete_type.parts).unwrap();
 
        let mono_type = self.types.get_procedure_monomorph(mono_index);
 
        if mono_type.arg_types.len() != arguments.values.len() {
 
        let procedure_type_id = self.types.get_procedure_monomorph_type_id(&definition_id, &concrete_type.parts).unwrap();
 
        let procedure_monomorph_index = self.types.get_monomorph(procedure_type_id).variant.as_procedure().monomorph_index;
 
        let monomorph_info = &ast_definition.monomorphs[procedure_monomorph_index as usize];
 
        if monomorph_info.argument_types.len() != arguments.values.len() {
 
            return Err(ComponentCreationError::InvalidNumArguments);
 
        }
 

	
 
        // - for each argument try to make sure the types match
 
        for arg_idx in 0..arguments.values.len() {
 
            let expected_type = &mono_type.arg_types[arg_idx];
 
            let expected_type_id = monomorph_info.argument_types[arg_idx];
 
            let expected_type = &self.types.get_monomorph(expected_type_id).concrete_type;
 
            let provided_value = &arguments.values[arg_idx];
 
            if !self.verify_same_type(expected_type, 0, &arguments, provided_value) {
 
                return Err(ComponentCreationError::InvalidArgumentType(arg_idx));
 
            }
 
        }
 

	
 
        // By now we're sure that all of the arguments are correct. So create
 
        // the connector.
 
        return Ok(Prompt::new(&self.types, &self.heap, ast_definition.this, mono_index, arguments));
 
        return Ok(Prompt::new(&self.types, &self.heap, ast_definition.this, procedure_type_id, arguments));
 
    }
 

	
 
    fn lookup_module_root(&self, module_name: &[u8]) -> Option<RootId> {
 
        for module in self.modules.iter() {
 
            match &module.name {
 
                Some(name) => if name.as_bytes() == module_name {
 
                    return Some(module.root_id);
 
                },
 
                None => if module_name.is_empty() {
 
                    return Some(module.root_id);
 
                }
 
            }
 
        }
 

	
 
        return None;
 
    }
 

	
 
    fn verify_same_type(&self, expected: &ConcreteType, expected_idx: usize, arguments: &ValueGroup, argument: &Value) -> bool {
 
        use ConcreteTypePart as CTP;
 

	
 
        match &expected.parts[expected_idx] {
 
            CTP::Void | CTP::Message | CTP::Slice | CTP::Pointer | CTP::Function(_, _) | CTP::Component(_, _) => unreachable!(),
 
            CTP::Bool => if let Value::Bool(_) = argument { true } else { false },
 
            CTP::UInt8 => if let Value::UInt8(_) = argument { true } else { false },
 
            CTP::UInt16 => if let Value::UInt16(_) = argument { true } else { false },
 
            CTP::UInt32 => if let Value::UInt32(_) = argument { true } else { false },
 
            CTP::UInt64 => if let Value::UInt64(_) = argument { true } else { false },
 
            CTP::SInt8 => if let Value::SInt8(_) = argument { true } else { false },
 
            CTP::SInt16 => if let Value::SInt16(_) = argument { true } else { false },
 
            CTP::SInt32 => if let Value::SInt32(_) = argument { true } else { false },
 
            CTP::SInt64 => if let Value::SInt64(_) = argument { true } else { false },
 
            CTP::Character => if let Value::Char(_) = argument { true } else { false },
 
            CTP::String => {
 
                // Match outer string type and embedded character types
 
                if let Value::String(heap_pos) = argument {
 
                    for element in &arguments.regions[*heap_pos as usize] {
 
                        if let Value::Char(_) = element {} else {
 
                            return false;
 
                        }
 
                    }
 
                } else {
 
                    return false;
 
                }
 

	
 
                return true;
 
            },
 
            CTP::Array => {
 
                if let Value::Array(heap_pos) = argument {
 
                    let heap_pos = *heap_pos;
 
                    for element in &arguments.regions[heap_pos as usize] {
 
                        if !self.verify_same_type(expected, expected_idx + 1, arguments, element) {
 
                            return false;
 
                        }
 
                    }
 
                    return true;
 
                } else {
 
                    return false;
 
                }
 
            },
 
            CTP::Input => if let Value::Input(_) = argument { true } else { false },
 
            CTP::Output => if let Value::Output(_) = argument { true } else { false },
 
            CTP::Tuple(_) => todo!("implement full type checking on user-supplied arguments"),
 
            CTP::Instance(definition_id, _num_embedded) => {
 
                let definition = self.types.get_base_definition(definition_id).unwrap();
 
                match &definition.definition {
 
                    DefinedTypeVariant::Enum(definition) => {
 
                        if let Value::Enum(variant_value) = argument {
 
                            let is_valid = definition.variants.iter()
 
                                .any(|v| v.value == *variant_value);
 
                            return is_valid;
 
                        }
 
                    },
 
                    _ => todo!("implement full type checking on user-supplied arguments"),
 
                }
 

	
 
                return false;
 
            },
 
        }
 
    }
 
}
 

	
 
pub trait RunContext {
 
    fn performed_put(&mut self, port: PortId) -> bool;
 
    fn performed_get(&mut self, port: PortId) -> Option<ValueGroup>; // None if still waiting on message
 
    fn fires(&mut self, port: PortId) -> Option<Value>; // None if not yet branched
 
    fn performed_fork(&mut self) -> Option<bool>; // None if not yet forked
 
    fn created_channel(&mut self) -> Option<(Value, Value)>; // None if not yet prepared
 
}
 

	
 
pub struct ProtocolDescriptionBuilder {
 
    parser: Parser,
 
}
 

	
 
impl ProtocolDescriptionBuilder {
 
    pub fn new() -> Self {
 
        return Self{
 
            parser: Parser::new(),
 
        }
 
    }
 

	
 
    pub fn add(&mut self, filename: String, buffer: Vec<u8>) -> Result<(), ParseError> {
 
        let input = InputSource::new(filename, buffer);
 
        self.parser.feed(input)?;
 

	
 
        return Ok(())
 
    }
 

	
 
    pub fn compile(mut self) -> Result<ProtocolDescription, ParseError> {
 
        self.parser.parse()?;
 

	
 
        let modules: Vec<Module> = self.parser.modules.into_iter()
 
            .map(|module| Module{
 
                source: module.source,
 
                root_id: module.root_id,
 
                name: module.name.map(|(_, name)| name)
 
            })
 
            .collect();
 

	
 
        return Ok(ProtocolDescription {
 
            modules,
 
            heap: self.parser.heap,
 
            types: self.parser.type_table,
 
            pool: Mutex::new(self.parser.string_pool),
 
        });
 
    }
 
}
src/protocol/parser/mod.rs
Show inline comments
 
#[macro_use] mod visitor;
 
pub(crate) mod symbol_table;
 
pub(crate) mod type_table;
 
pub(crate) mod tokens;
 
pub(crate) mod token_parsing;
 
pub(crate) mod pass_tokenizer;
 
pub(crate) mod pass_symbols;
 
pub(crate) mod pass_imports;
 
pub(crate) mod pass_definitions;
 
pub(crate) mod pass_definitions_types;
 
pub(crate) mod pass_validation_linking;
 
pub(crate) mod pass_rewriting;
 
pub(crate) mod pass_typing;
 
pub(crate) mod pass_stack_size;
 

	
 
use tokens::*;
 
use crate::collections::*;
 
use visitor::Visitor;
 
use pass_tokenizer::PassTokenizer;
 
use pass_symbols::PassSymbols;
 
use pass_imports::PassImport;
 
use pass_definitions::PassDefinitions;
 
use pass_validation_linking::PassValidationLinking;
 
use pass_typing::{PassTyping, ResolveQueue};
 
use pass_rewriting::PassRewriting;
 
use pass_stack_size::PassStackSize;
 
use symbol_table::*;
 
use type_table::*;
 

	
 
use crate::protocol::ast::*;
 
use crate::protocol::input_source::*;
 

	
 
use crate::protocol::ast_printer::ASTWriter;
 
use crate::protocol::parser::type_table::PolymorphicVariable;
 

	
 
#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
 
pub enum ModuleCompilationPhase {
 
    Tokenized,              // source is tokenized
 
    SymbolsScanned,         // all definitions are linked to their type class
 
    ImportsResolved,        // all imports are added to the symbol table
 
    DefinitionsParsed,      // produced the AST for the entire module
 
    TypesAddedToTable,      // added all definitions to the type table
 
    ValidatedAndLinked,     // AST is traversed and has linked the required AST nodes
 
    Typed,                  // Type inference and checking has been performed
 
    Rewritten,              // Special AST nodes are rewritten into regular AST nodes
 
    // When we continue with the compiler:
 
    // StackSize
 
}
 

	
 
pub struct Module {
 
    // Buffers
 
    pub source: InputSource,
 
    pub tokens: TokenBuffer,
 
    // Identifiers
 
    pub root_id: RootId,
 
    pub name: Option<(PragmaId, StringRef<'static>)>,
 
    pub version: Option<(PragmaId, i64)>,
 
    pub phase: ModuleCompilationPhase,
 
}
 

	
 
pub struct TargetArch {
 
    pub void_type_id: TypeId,
 
    pub message_type_id: TypeId,
 
    pub bool_type_id: TypeId,
 
    pub uint8_type_id: TypeId,
 
    pub uint16_type_id: TypeId,
 
    pub uint32_type_id: TypeId,
 
    pub uint64_type_id: TypeId,
 
    pub sint8_type_id: TypeId,
 
    pub sint16_type_id: TypeId,
 
    pub sint32_type_id: TypeId,
 
    pub sint64_type_id: TypeId,
 
    pub char_type_id: TypeId,
 
    pub string_type_id: TypeId,
 
    pub array_type_id: TypeId,
 
    pub slice_type_id: TypeId,
 
    pub input_type_id: TypeId,
 
    pub output_type_id: TypeId,
 
    pub pointer_type_id: TypeId,
 
}
 

	
 
impl TargetArch {
 
    fn new() -> Self {
 
        return Self{
 
            void_type_id: TypeId::new_invalid(),
 
            bool_type_id: TypeId::new_invalid(),
 
            message_type_id: TypeId::new_invalid(),
 
            uint8_type_id: TypeId::new_invalid(),
 
            uint16_type_id: TypeId::new_invalid(),
 
            uint32_type_id: TypeId::new_invalid(),
 
            uint64_type_id: TypeId::new_invalid(),
 
            sint8_type_id: TypeId::new_invalid(),
 
            sint16_type_id: TypeId::new_invalid(),
 
            sint32_type_id: TypeId::new_invalid(),
 
            sint64_type_id: TypeId::new_invalid(),
 
            char_type_id: TypeId::new_invalid(),
 
            string_type_id: TypeId::new_invalid(),
 
            array_type_id: TypeId::new_invalid(),
 
            slice_type_id: TypeId::new_invalid(),
 
            input_type_id: TypeId::new_invalid(),
 
            output_type_id: TypeId::new_invalid(),
 
            pointer_type_id: TypeId::new_invalid(),
 
        }
 
    }
 
}
 

	
 
pub struct PassCtx<'a> {
 
    heap: &'a mut Heap,
 
    symbols: &'a mut SymbolTable,
 
    pool: &'a mut StringPool,
 
    arch: &'a TargetArch,
 
}
 

	
 
pub struct Parser {
 
    // Storage of all information created/gathered during compilation.
 
    pub(crate) heap: Heap,
 
    pub(crate) string_pool: StringPool, // Do not deallocate, holds all strings
 
    pub(crate) modules: Vec<Module>,
 
    pub(crate) symbol_table: SymbolTable,
 
    pub(crate) type_table: TypeTable,
 
    // Compiler passes, used as little state machine that keep their memory
 
    // around.
 
    pass_tokenizer: PassTokenizer,
 
    pass_symbols: PassSymbols,
 
    pass_import: PassImport,
 
    pass_definitions: PassDefinitions,
 
    pass_validation: PassValidationLinking,
 
    pass_typing: PassTyping,
 
    pass_rewriting: PassRewriting,
 
    pass_stack_size: PassStackSize,
 
    // Compiler options
 
    pub write_ast_to: Option<String>,
 
    pub(crate) arch: TargetArch,
 
}
 

	
 
impl Parser {
 
    pub fn new() -> Self {
 
        let mut parser = Parser{
 
            heap: Heap::new(),
 
            string_pool: StringPool::new(),
 
            modules: Vec::new(),
 
            symbol_table: SymbolTable::new(),
 
            type_table: TypeTable::new(),
 
            pass_tokenizer: PassTokenizer::new(),
 
            pass_symbols: PassSymbols::new(),
 
            pass_import: PassImport::new(),
 
            pass_definitions: PassDefinitions::new(),
 
            pass_validation: PassValidationLinking::new(),
 
            pass_typing: PassTyping::new(),
 
            pass_rewriting: PassRewriting::new(),
 
            pass_stack_size: PassStackSize::new(),
 
            write_ast_to: None,
 
            arch: TargetArch::new(),
 
        };
 

	
 
        parser.symbol_table.insert_scope(None, SymbolScope::Global);
 

	
 
        // Insert builtin types
 
        // TODO: At some point use correct values for size/alignment
 
        parser.arch.void_type_id    = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Void], false, 0, 1);
 
        parser.arch.message_type_id = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Message], false, 24, 8);
 
        parser.arch.bool_type_id    = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Bool], false, 1, 1);
 
        parser.arch.uint8_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::UInt8], false, 1, 1);
 
        parser.arch.uint16_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::UInt16], false, 2, 2);
 
        parser.arch.uint32_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::UInt32], false, 4, 4);
 
        parser.arch.uint64_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::UInt64], false, 8, 8);
 
        parser.arch.sint8_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::SInt8], false, 1, 1);
 
        parser.arch.sint16_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::SInt16], false, 2, 2);
 
        parser.arch.sint32_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::SInt32], false, 4, 4);
 
        parser.arch.sint64_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::SInt64], false, 8, 8);
 
        parser.arch.char_type_id    = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Character], false, 4, 4);
 
        parser.arch.string_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::String], false, 24, 8);
 
        parser.arch.array_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Array, ConcreteTypePart::Void], true, 24, 8);
 
        parser.arch.slice_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Slice, ConcreteTypePart::Void], true, 16, 4);
 
        parser.arch.input_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Input, ConcreteTypePart::Void], true, 8, 8);
 
        parser.arch.output_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Output, ConcreteTypePart::Void], true, 8, 8);
 
        parser.arch.pointer_type_id = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Pointer, ConcreteTypePart::Void], true, 8, 8);
 

	
 
        // Insert builtin functions
 
        fn quick_type(variants: &[ParserTypeVariant]) -> ParserType {
 
            let mut t = ParserType{ elements: Vec::with_capacity(variants.len()), full_span: InputSpan::new() };
 
            for variant in variants {
 
                t.elements.push(ParserTypeElement{ element_span: InputSpan::new(), variant: variant.clone() });
 
            }
 
            t
 
        }
 

	
 
        use ParserTypeVariant as PTV;
 
        insert_builtin_function(&mut parser, "get", &["T"], |id| (
 
            vec![
 
                ("input", quick_type(&[PTV::Input, PTV::PolymorphicArgument(id.upcast(), 0)]))
 
            ],
 
            quick_type(&[PTV::PolymorphicArgument(id.upcast(), 0)])
 
        ));
 
        insert_builtin_function(&mut parser, "put", &["T"], |id| (
 
            vec![
 
                ("output", quick_type(&[PTV::Output, PTV::PolymorphicArgument(id.upcast(), 0)])),
 
                ("value", quick_type(&[PTV::PolymorphicArgument(id.upcast(), 0)])),
 
            ],
 
            quick_type(&[PTV::Void])
 
        ));
 
        insert_builtin_function(&mut parser, "fires", &["T"], |id| (
 
            vec![
 
                ("port", quick_type(&[PTV::InputOrOutput, PTV::PolymorphicArgument(id.upcast(), 0)]))
 
            ],
 
            quick_type(&[PTV::Bool])
 
        ));
 
        insert_builtin_function(&mut parser, "create", &["T"], |id| (
 
            vec![
 
                ("length", quick_type(&[PTV::IntegerLike]))
 
            ],
 
            quick_type(&[PTV::ArrayLike, PTV::PolymorphicArgument(id.upcast(), 0)])
 
        ));
 
        insert_builtin_function(&mut parser, "length", &["T"], |id| (
 
            vec![
 
                ("array", quick_type(&[PTV::ArrayLike, PTV::PolymorphicArgument(id.upcast(), 0)]))
 
            ],
 
            quick_type(&[PTV::UInt32]) // TODO: @PtrInt
 
        ));
 
        insert_builtin_function(&mut parser, "assert", &[], |_id| (
 
            vec![
 
                ("condition", quick_type(&[PTV::Bool])),
 
            ],
 
            quick_type(&[PTV::Void])
 
        ));
 
        insert_builtin_function(&mut parser, "print", &[], |_id| (
 
            vec![
 
                ("message", quick_type(&[PTV::String])),
 
            ],
 
            quick_type(&[PTV::Void])
 
        ));
 

	
 
        parser
 
    }
 

	
 
    pub fn feed(&mut self, mut source: InputSource) -> Result<(), ParseError> {
 
        let mut token_buffer = TokenBuffer::new();
 
        self.pass_tokenizer.tokenize(&mut source, &mut token_buffer)?;
 

	
 
        let module = Module{
 
            source,
 
            tokens: token_buffer,
 
            root_id: RootId::new_invalid(),
 
            name: None,
 
            version: None,
 
            phase: ModuleCompilationPhase::Tokenized,
 
        };
 
        self.modules.push(module);
 

	
 
        Ok(())
 
    }
 

	
 
    pub fn parse(&mut self) -> Result<(), ParseError> {
 
        let mut pass_ctx = PassCtx{
 
            heap: &mut self.heap,
 
            symbols: &mut self.symbol_table,
 
            pool: &mut self.string_pool,
 
            arch: &self.arch,
 
        };
 

	
 
        // Advance all modules to the phase where all symbols are scanned
 
        for module_idx in 0..self.modules.len() {
 
            self.pass_symbols.parse(&mut self.modules, module_idx, &mut pass_ctx)?;
 
        }
 

	
 
        // With all symbols scanned, perform further compilation until we can
 
        // add all base types to the type table.
 
        for module_idx in 0..self.modules.len() {
 
            self.pass_import.parse(&mut self.modules, module_idx, &mut pass_ctx)?;
 
            self.pass_definitions.parse(&mut self.modules, module_idx, &mut pass_ctx)?;
 
        }
 

	
 
        // Add every known type to the type table
 
        self.type_table.build_base_types(&mut self.modules, &mut pass_ctx)?;
 

	
 
        // Continue compilation with the remaining phases now that the types
 
        // are all in the type table
 
        for module_idx in 0..self.modules.len() {
 
            let mut ctx = visitor::Ctx{
 
                heap: &mut self.heap,
 
                modules: &mut self.modules,
 
                module_idx,
 
                symbols: &mut self.symbol_table,
 
                types: &mut self.type_table,
 
                arch: &self.arch,
 
            };
 
            self.pass_validation.visit_module(&mut ctx)?;
 
        }
 

	
 
        // Perform typechecking on all modules
 
        let mut queue = ResolveQueue::new();
 
        for module_idx in 0..self.modules.len() {
 
            let mut ctx = visitor::Ctx{
 
                heap: &mut self.heap,
 
                modules: &mut self.modules,
 
                module_idx,
 
                symbols: &mut self.symbol_table,
 
                types: &mut self.type_table,
 
                arch: &self.arch,
 
            };
 
            PassTyping::queue_module_definitions(&mut ctx, &mut queue);
 
            self.pass_typing.queue_module_definitions(&mut ctx, &mut queue);
 
        };
 
        while !queue.is_empty() {
 
            let top = queue.pop().unwrap();
 
            let mut ctx = visitor::Ctx{
 
                heap: &mut self.heap,
 
                modules: &mut self.modules,
 
                module_idx: top.root_id.index as usize,
 
                symbols: &mut self.symbol_table,
 
                types: &mut self.type_table,
 
                arch: &self.arch,
 
            };
 
            self.pass_typing.handle_module_definition(&mut ctx, &mut queue, top)?;
 
        }
 

	
 
        // Rewrite nodes in tree, then prepare for execution of code
 
        for module_idx in 0..self.modules.len() {
 
            self.modules[module_idx].phase = ModuleCompilationPhase::Typed;
 
            let mut ctx = visitor::Ctx{
 
                heap: &mut self.heap,
 
                modules: &mut self.modules,
 
                module_idx,
 
                symbols: &mut self.symbol_table,
 
                types: &mut self.type_table,
 
                arch: &self.arch,
 
            };
 
            self.pass_rewriting.visit_module(&mut ctx)?;
 
            self.pass_stack_size.visit_module(&mut ctx)?;
 
        }
 

	
 
        // Write out desired information
 
        if let Some(filename) = &self.write_ast_to {
 
            let mut writer = ASTWriter::new();
 
            let mut file = std::fs::File::create(std::path::Path::new(filename)).unwrap();
 
            writer.write_ast(&mut file, &self.heap);
 
        }
 

	
 
        Ok(())
 
    }
 
}
 

	
 
fn insert_builtin_type(type_table: &mut TypeTable, parts: Vec<ConcreteTypePart>, has_poly_var: bool, size: usize, alignment: usize) -> TypeId {
 
    const POLY_VARS: [PolymorphicVariable; 1] = [PolymorphicVariable{
 
        identifier: Identifier::new_empty(InputSpan::new()),
 
        is_in_use: false,
 
    }];
 

	
 
    let concrete_type = ConcreteType{ parts };
 
    let poly_var = if has_poly_var {
 
        POLY_VARS.as_slice()
 
    } else {
 
        &[]
 
    };
 

	
 
    return type_table.add_builtin_type(concrete_type, poly_var, size, alignment);
 
    return type_table.add_builtin_data_type(concrete_type, poly_var, size, alignment);
 
}
 

	
 
// Note: args and return type need to be a function because we need to know the function ID.
 
fn insert_builtin_function<T: Fn(ProcedureDefinitionId) -> (Vec<(&'static str, ParserType)>, ParserType)> (
 
    p: &mut Parser, func_name: &str, polymorphic: &[&str], arg_and_return_fn: T
 
) {
 
    let mut poly_vars = Vec::with_capacity(polymorphic.len());
 
    // Insert into AST (to get an ID), also prepare the polymorphic variables
 
    // we need later for the type table
 
    let mut ast_poly_vars = Vec::with_capacity(polymorphic.len());
 
    let mut type_poly_vars = Vec::with_capacity(polymorphic.len());
 
    for poly_var in polymorphic {
 
        poly_vars.push(Identifier{ span: InputSpan::new(), value: p.string_pool.intern(poly_var.as_bytes()) });
 
        let identifier = Identifier{ span: InputSpan::new(), value: p.string_pool.intern(poly_var.as_bytes()) } ;
 
        ast_poly_vars.push(identifier.clone());
 
        type_poly_vars.push(PolymorphicVariable{ identifier, is_in_use: false });
 
    }
 

	
 
    let func_ident_ref = p.string_pool.intern(func_name.as_bytes());
 
    let procedure_id = p.heap.alloc_procedure_definition(|this| ProcedureDefinition {
 
        this,
 
        defined_in: RootId::new_invalid(),
 
        builtin: true,
 
        kind: ProcedureKind::Function,
 
        span: InputSpan::new(),
 
        identifier: Identifier{ span: InputSpan::new(), value: func_ident_ref.clone() },
 
        poly_vars,
 
        poly_vars: ast_poly_vars,
 
        return_type: None,
 
        parameters: Vec::new(),
 
        scope: ScopeId::new_invalid(),
 
        body: BlockStatementId::new_invalid(),
 
        num_expressions_in_body: -1,
 
        monomorphs: Vec::new(),
 
    });
 

	
 
    // Modify AST with more information about the procedure
 
    let (arguments, return_type) = arg_and_return_fn(procedure_id);
 

	
 
    let mut parameters = Vec::with_capacity(arguments.len());
 
    for (arg_name, arg_type) in arguments {
 
        let identifier = Identifier{ span: InputSpan::new(), value: p.string_pool.intern(arg_name.as_bytes()) };
 
        let param_id = p.heap.alloc_variable(|this| Variable{
 
            this,
 
            kind: VariableKind::Parameter,
 
            parser_type: arg_type.clone(),
 
            identifier,
 
            relative_pos_in_parent: 0,
 
            unique_id_in_scope: 0
 
        });
 
        parameters.push(param_id);
 
    }
 

	
 
    let func = &mut p.heap[procedure_id];
 
    func.parameters = parameters;
 
    func.return_type = Some(return_type);
 

	
 
    // Insert into symbol table
 
    p.symbol_table.insert_symbol(SymbolScope::Global, Symbol{
 
        name: func_ident_ref,
 
        variant: SymbolVariant::Definition(SymbolDefinition{
 
            defined_in_module: RootId::new_invalid(),
 
            defined_in_scope: SymbolScope::Global,
 
            definition_span: InputSpan::new(),
 
            identifier_span: InputSpan::new(),
 
            imported_at: None,
 
            class: DefinitionClass::Function,
 
            definition_id: procedure_id.upcast(),
 
        })
 
    }).unwrap();
 

	
 
    // Insert into type table
 
    let mut concrete_type = ConcreteType::default();
 
    concrete_type.parts.push(ConcreteTypePart::Function(procedure_id, type_poly_vars.len() as u32));
 

	
 
    for _ in 0..type_poly_vars.len() {
 
        concrete_type.parts.push(ConcreteTypePart::Void); // doesn't matter (I hope...)
 
    }
 
    p.type_table.add_builtin_procedure_type(concrete_type, &type_poly_vars);
 
}
 
\ No newline at end of file
src/protocol/parser/pass_rewriting.rs
Show inline comments
 
use crate::collections::*;
 
use crate::protocol::*;
 

	
 
use super::visitor::*;
 

	
 
pub(crate) struct PassRewriting {
 
    current_scope: ScopeId,
 
    definition_buffer: ScopedBuffer<DefinitionId>,
 
    statement_buffer: ScopedBuffer<StatementId>,
 
    call_expr_buffer: ScopedBuffer<CallExpressionId>,
 
    expression_buffer: ScopedBuffer<ExpressionId>,
 
    scope_buffer: ScopedBuffer<ScopeId>,
 
}
 

	
 
impl PassRewriting {
 
    pub(crate) fn new() -> Self {
 
        Self{
 
            current_scope: ScopeId::new_invalid(),
 
            definition_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            statement_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            call_expr_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            expression_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            scope_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
        }
 
    }
 
}
 

	
 
impl Visitor for PassRewriting {
 
    fn visit_module(&mut self, ctx: &mut Ctx) -> VisitorResult {
 
        let module = ctx.module();
 
        debug_assert_eq!(module.phase, ModuleCompilationPhase::Typed);
 

	
 
        let root_id = module.root_id;
 
        let root = &ctx.heap[root_id];
 
        let definition_section = self.definition_buffer.start_section_initialized(&root.definitions);
 
        for definition_index in 0..definition_section.len() {
 
            let definition_id = definition_section[definition_index];
 
            self.visit_definition(ctx, definition_id)?;
 
        }
 

	
 
        definition_section.forget();
 
        ctx.module_mut().phase = ModuleCompilationPhase::Rewritten;
 
        return Ok(())
 
    }
 

	
 
    // --- Visiting procedures
 

	
 
    fn visit_procedure_definition(&mut self, ctx: &mut Ctx, id: ProcedureDefinitionId) -> VisitorResult {
 
        let definition = &ctx.heap[id];
 
        let body_id = definition.body;
 
        self.current_scope = definition.scope;
 
        return self.visit_block_stmt(ctx, body_id);
 
    }
 

	
 
    // --- Visiting statements (that are not the select statement)
 

	
 
    fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
 
        let block_stmt = &ctx.heap[id];
 
        let stmt_section = self.statement_buffer.start_section_initialized(&block_stmt.statements);
 

	
 
        self.current_scope = block_stmt.scope;
 
        for stmt_idx in 0..stmt_section.len() {
 
            self.visit_stmt(ctx, stmt_section[stmt_idx])?;
 
        }
 

	
 
        stmt_section.forget();
 
        return Ok(())
 
    }
 

	
 
    fn visit_labeled_stmt(&mut self, ctx: &mut Ctx, id: LabeledStatementId) -> VisitorResult {
 
        let labeled_stmt = &ctx.heap[id];
 
        let body_id = labeled_stmt.body;
 
        return self.visit_stmt(ctx, body_id);
 
    }
 

	
 
    fn visit_if_stmt(&mut self, ctx: &mut Ctx, id: IfStatementId) -> VisitorResult {
 
        let if_stmt = &ctx.heap[id];
 
        let true_case = if_stmt.true_case;
 
        let false_case = if_stmt.false_case;
 

	
 
        self.current_scope = true_case.scope;
 
        self.visit_stmt(ctx, true_case.body)?;
 
        if let Some(false_case) = false_case {
 
            self.current_scope = false_case.scope;
 
            self.visit_stmt(ctx, false_case.body)?;
 
        }
 

	
 
        return Ok(())
 
    }
 

	
 
    fn visit_while_stmt(&mut self, ctx: &mut Ctx, id: WhileStatementId) -> VisitorResult {
 
        let while_stmt = &ctx.heap[id];
 
        let body_id = while_stmt.body;
 
        self.current_scope = while_stmt.scope;
 
        return self.visit_stmt(ctx, body_id);
 
    }
 

	
 
    fn visit_synchronous_stmt(&mut self, ctx: &mut Ctx, id: SynchronousStatementId) -> VisitorResult {
 
        let sync_stmt = &ctx.heap[id];
 
        let body_id = sync_stmt.body;
 
        self.current_scope = sync_stmt.scope;
 
        return self.visit_stmt(ctx, body_id);
 
    }
 

	
 
    // --- Visiting the select statement
 

	
 
    fn visit_select_stmt(&mut self, ctx: &mut Ctx, id: SelectStatementId) -> VisitorResult {
 
        // Utility for the last stage of rewriting process. Note that caller
 
        // still needs to point the end of the if-statement to the end of the
 
        // replacement statement of the select statement.
 
        fn transform_select_case_code(ctx: &mut Ctx, select_id: SelectStatementId, case_index: usize, select_var_id: VariableId) -> (IfStatementId, EndIfStatementId) {
 
            // Retrieve statement IDs associated with case
 
            let case = &ctx.heap[select_id].cases[case_index];
 
            let case_guard_id = case.guard;
 
            let case_body_id = case.body;
 
            let case_scope_id = case.scope;
 

	
 
            // Create the if-statement for the result of the select statement
 
            let compare_expr_id = create_ast_equality_comparison_expr(ctx, select_var_id, case_index as u64);
 
            let true_case = IfStatementCase{
 
                body: case_guard_id, // which is linked up to the body
 
                scope: case_scope_id,
 
            };
 
            let (if_stmt_id, end_if_stmt_id) = create_ast_if_stmt(ctx, compare_expr_id.upcast(), true_case, None);
 

	
 
            // Link up body statement to end-if
 
            set_ast_statement_next(ctx, case_body_id, end_if_stmt_id.upcast());
 

	
 
            return (if_stmt_id, end_if_stmt_id)
 
        }
 

	
 
        // Precreate the block that will end up containing all of the
 
        // transformed statements. Also precreate the scope associated with it
 
        let (outer_block_id, outer_end_block_id, outer_scope_id) =
 
            create_ast_block_stmt(ctx, Vec::new());
 

	
 
        // The "select" and the "end select" statement will act like trampolines
 
        // that jump to the replacement block. So set the child/parent
 
        // relationship already.
 
        // --- for the statements
 
        let select_stmt = &mut ctx.heap[id];
 
        select_stmt.next = outer_block_id.upcast();
 
        let end_select_stmt_id = select_stmt.end_select;
 
        let select_stmt_relative_pos = select_stmt.relative_pos_in_parent;
 

	
 
        let outer_end_block_stmt = &mut ctx.heap[outer_end_block_id];
 
        outer_end_block_stmt.next = end_select_stmt_id.upcast();
 

	
 
        // --- for the scopes
 
        link_new_child_to_existing_parent_scope(ctx, &mut self.scope_buffer, self.current_scope, outer_scope_id, select_stmt_relative_pos);
 

	
 
        // Create statements that will create temporary variables for all of the
 
        // ports passed to the "get" calls in the select case guards.
 
        let select_stmt = &ctx.heap[id];
 
        let total_num_cases = select_stmt.cases.len();
 
        let mut total_num_ports = 0;
 
        let end_select_stmt_id = select_stmt.end_select;
 
        let _end_select = &ctx.heap[end_select_stmt_id];
 

	
 
        // Put heap IDs into temporary buffers to handle borrowing rules
 
        let mut call_id_section = self.call_expr_buffer.start_section();
 
        let mut expr_id_section = self.expression_buffer.start_section();
 

	
 
        for case in select_stmt.cases.iter() {
 
            total_num_ports += case.involved_ports.len();
 
            for (call_id, expr_id) in case.involved_ports.iter().copied() {
 
                call_id_section.push(call_id);
 
                expr_id_section.push(expr_id);
 
            }
 
        }
 

	
 
        // Transform all of the call expressions by takings its argument (the
 
        // port from which we `get`) and turning it into a temporary variable.
 
        let mut transformed_stmts = Vec::with_capacity(total_num_ports); // TODO: Recompute this preallocated length, put assert at the end
 
        let mut locals = Vec::with_capacity(total_num_ports);
 

	
 
        for port_var_idx in 0..call_id_section.len() {
 
            let get_call_expr_id = call_id_section[port_var_idx];
 
            let port_expr_id = expr_id_section[port_var_idx];
 

	
 
            // Move the port expression such that it gets assigned to a temporary variable
 
            let variable_id = create_ast_variable(ctx, outer_scope_id);
 
            let variable_decl_stmt_id = create_ast_variable_declaration_stmt(ctx, variable_id, port_expr_id);
 

	
 
            // Replace the original port expression in the call with a reference
 
            // to the replacement variable
 
            let variable_expr_id = create_ast_variable_expr(ctx, variable_id);
 
            let call_expr = &mut ctx.heap[get_call_expr_id];
 
            call_expr.arguments[0] = variable_expr_id.upcast();
 

	
 
            transformed_stmts.push(variable_decl_stmt_id.upcast().upcast());
 
            locals.push(variable_id);
 
        }
 

	
 
        // Insert runtime calls that facilitate the semantics of the select
 
        // block.
 

	
 
        // Create the call that indicates the start of the select block
 
        {
 
            let num_cases_expression_id = create_ast_literal_integer_expr(ctx, total_num_cases as u64);
 
            let num_ports_expression_id = create_ast_literal_integer_expr(ctx, total_num_ports as u64);
 
            let arguments = vec![
 
                num_cases_expression_id.upcast(),
 
                num_ports_expression_id.upcast()
 
            ];
 

	
 
            let call_expression_id = create_ast_call_expr(ctx, Method::SelectStart, &mut self.expression_buffer, arguments);
 
            let call_statement_id = create_ast_expression_stmt(ctx, call_expression_id.upcast());
 

	
 
            transformed_stmts.push(call_statement_id.upcast());
 
        }
 

	
 
        // Create calls for each select case that will register the ports that
 
        // we are waiting on at the runtime.
 
        {
 
            let mut total_port_index = 0;
 
            for case_index in 0..total_num_cases {
 
                let case = &ctx.heap[id].cases[case_index];
 
                let case_num_ports = case.involved_ports.len();
 

	
 
                for case_port_index in 0..case_num_ports {
 
                    // Arguments to runtime call
 
                    let port_variable_id = locals[total_port_index]; // so far this variable contains the temporary variables for the port expressions
 
                    let case_index_expr_id = create_ast_literal_integer_expr(ctx, case_index as u64);
 
                    let port_index_expr_id = create_ast_literal_integer_expr(ctx, case_port_index as u64);
 
                    let port_variable_expr_id = create_ast_variable_expr(ctx, port_variable_id);
 
                    let runtime_call_arguments = vec![
 
                        case_index_expr_id.upcast(),
 
                        port_index_expr_id.upcast(),
 
                        port_variable_expr_id.upcast()
 
                    ];
 

	
 
                    // Create runtime call, then store it
 
                    let runtime_call_expr_id = create_ast_call_expr(ctx, Method::SelectRegisterCasePort, &mut self.expression_buffer, runtime_call_arguments);
 
                    let runtime_call_stmt_id = create_ast_expression_stmt(ctx, runtime_call_expr_id.upcast());
 

	
 
                    transformed_stmts.push(runtime_call_stmt_id.upcast());
 

	
 
                    total_port_index += 1;
 
                }
 
            }
 
        }
 

	
 
        // Create the variable that will hold the result of a completed select
 
        // block. Then create the runtime call that will produce this result
 
        let select_variable_id = create_ast_variable(ctx, outer_scope_id);
 
        locals.push(select_variable_id);
 

	
 
        {
 
            let runtime_call_expr_id = create_ast_call_expr(ctx, Method::SelectWait, &mut self.expression_buffer, Vec::new());
 
            let variable_stmt_id = create_ast_variable_declaration_stmt(ctx, select_variable_id, runtime_call_expr_id.upcast());
 
            transformed_stmts.push(variable_stmt_id.upcast().upcast());
 
        }
 

	
 
        call_id_section.forget();
 
        expr_id_section.forget();
 

	
 
        // Now we transform each of the select block case's guard and code into
 
        // a chained if-else statement.
 
        if total_num_cases > 0 {
 
            let (if_stmt_id, end_if_stmt_id) = transform_select_case_code(ctx, id, 0, select_variable_id);
 
            let first_end_if_stmt = &mut ctx.heap[end_if_stmt_id];
 
            first_end_if_stmt.next = outer_end_block_id.upcast();
 

	
 
            let mut last_if_stmt_id = if_stmt_id;
 
            let mut last_end_if_stmt_id = end_if_stmt_id;
 
            transformed_stmts.push(last_if_stmt_id.upcast());
 

	
 
            for case_index in 1..total_num_cases {
 
                let (if_stmt_id, end_if_stmt_id) = transform_select_case_code(ctx, id, case_index, select_variable_id);
 
                let false_case_scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::If(last_if_stmt_id, false)));
 
                set_ast_if_statement_false_body(ctx, last_if_stmt_id, last_end_if_stmt_id, IfStatementCase{ body: if_stmt_id.upcast(), scope: false_case_scope_id });
 

	
 
                let end_if_stmt = &mut ctx.heap[end_if_stmt_id];
 
                end_if_stmt.next = last_end_if_stmt_id.upcast();
 

	
 
                last_if_stmt_id = if_stmt_id;
 
                last_end_if_stmt_id = end_if_stmt_id;
 
            }
 
        }
 

	
 
        // Final steps: set the statements of the replacement block statement,
 
        // and link all of those statements together
 
        let mut last_stmt_id = transformed_stmts[0];
 
        for stmt_id in transformed_stmts.iter().skip(1).copied() {
 
            set_ast_statement_next(ctx, last_stmt_id, stmt_id);
 
            last_stmt_id = stmt_id;
 
        }
 

	
 
        let outer_block_stmt = &mut ctx.heap[outer_block_id];
 
        outer_block_stmt.statements = transformed_stmts;
 

	
 
        return Ok(())
 
    }
 
}
 

	
 
impl PassRewriting {
 
    fn create_runtime_call_statement(&self, ctx: &mut Ctx, method: Method, arguments: Vec<ExpressionId>) -> (CallExpressionId, ExpressionStatementId) {
 
        let call_expr_id = ctx.heap.alloc_call_expression(|this| CallExpression{
 
            this,
 
            func_span: InputSpan::new(),
 
            full_span: InputSpan::new(),
 
            parser_type: ParserType{
 
                elements: Vec::new(),
 
                full_span: InputSpan::new(),
 
            },
 
            method,
 
            arguments,
 
            procedure: ProcedureDefinitionId::new_invalid(),
 
            parent: ExpressionParent::None,
 
        });
 
        let call_stmt_id = ctx.heap.alloc_expression_statement(|this| ExpressionStatement{
 
            this,
 
            span: InputSpan::new(),
 
            expression: call_expr_id.upcast(),
 
            next: StatementId::new_invalid(),
 
        });
 

	
 
        let call_expr = &mut ctx.heap[call_expr_id];
 
        call_expr.parent = ExpressionParent::ExpressionStmt(call_stmt_id);
 

	
 
        return (call_expr_id, call_stmt_id);
 
    }
 
}
 

	
 
// -----------------------------------------------------------------------------
 
// Utilities to create compiler-generated AST nodes
 
// -----------------------------------------------------------------------------
 

	
 
fn create_ast_variable(ctx: &mut Ctx, scope_id: ScopeId) -> VariableId {
 
    let variable_id = ctx.heap.alloc_variable(|this| Variable{
 
        this,
 
        kind: VariableKind::Local,
 
        parser_type: ParserType{
 
            elements: Vec::new(),
 
            full_span: InputSpan::new(),
 
        },
 
        identifier: Identifier::new_empty(InputSpan::new()),
 
        relative_pos_in_parent: -1,
 
        unique_id_in_scope: -1,
 
    });
 
    let scope = &mut ctx.heap[scope_id];
 
    scope.variables.push(variable_id);
 

	
 
    return variable_id;
 
}
 

	
 
fn create_ast_variable_expr(ctx: &mut Ctx, variable_id: VariableId) -> VariableExpressionId {
 
    return ctx.heap.alloc_variable_expression(|this| VariableExpression{
 
        this,
 
        identifier: Identifier::new_empty(InputSpan::new()),
 
        declaration: Some(variable_id),
 
        used_as_binding_target: false,
 
        parent: ExpressionParent::None,
 
        type_index: -1
 
    });
 
}
 

	
 
fn create_ast_call_expr(ctx: &mut Ctx, method: Method, buffer: &mut ScopedBuffer<ExpressionId>, arguments: Vec<ExpressionId>) -> CallExpressionId {
 
    let expression_ids = buffer.start_section_initialized(&arguments);
 
    let call_expression_id = ctx.heap.alloc_call_expression(|this| CallExpression{
 
        this,
 
        func_span: InputSpan::new(),
 
        full_span: InputSpan::new(),
 
        parser_type: ParserType{
 
            elements: Vec::new(),
 
            full_span: InputSpan::new(),
 
        },
 
        method,
 
        arguments,
 
        procedure: ProcedureDefinitionId::new_invalid(),
 
        parent: ExpressionParent::None,
 
        type_index: -1,
 
    });
 

	
 
    for argument_index in 0..expression_ids.len() {
 
        let argument_id = expression_ids[argument_index];
 
        let argument_expr = &mut ctx.heap[argument_id];
 
        *argument_expr.parent_mut() = ExpressionParent::Expression(call_expression_id.upcast(), argument_index as u32);
 
    }
 

	
 
    return call_expression_id;
 
}
 

	
 
fn create_ast_literal_integer_expr(ctx: &mut Ctx, unsigned_value: u64) -> LiteralExpressionId {
 
    return ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
        this,
 
        span: InputSpan::new(),
 
        value: Literal::Integer(LiteralInteger{
 
            unsigned_value,
 
            negated: false,
 
        }),
 
        parent: ExpressionParent::None,
 
        type_index: -1
 
    });
 
}
 

	
 
fn create_ast_equality_comparison_expr(ctx: &mut Ctx, variable_id: VariableId, value: u64) -> BinaryExpressionId {
 
    let var_expr_id = create_ast_variable_expr(ctx, variable_id);
 
    let int_expr_id = create_ast_literal_integer_expr(ctx, value);
 
    let cmp_expr_id = ctx.heap.alloc_binary_expression(|this| BinaryExpression{
 
        this,
 
        operator_span: InputSpan::new(),
 
        full_span: InputSpan::new(),
 
        left: var_expr_id.upcast(),
 
        operation: BinaryOperator::Equality,
 
        right: int_expr_id.upcast(),
 
        parent: ExpressionParent::None,
 
        type_index: -1,
 
    });
 

	
 
    let var_expr = &mut ctx.heap[var_expr_id];
 
    var_expr.parent = ExpressionParent::Expression(cmp_expr_id.upcast(), 0);
 
    let int_expr = &mut ctx.heap[int_expr_id];
 
    int_expr.parent = ExpressionParent::Expression(cmp_expr_id.upcast(), 1);
 

	
 
    return cmp_expr_id;
 
}
 

	
 
fn create_ast_expression_stmt(ctx: &mut Ctx, expression_id: ExpressionId) -> ExpressionStatementId {
 
    let statement_id = ctx.heap.alloc_expression_statement(|this| ExpressionStatement{
 
        this,
 
        span: InputSpan::new(),
 
        expression: expression_id,
 
        next: StatementId::new_invalid(),
 
    });
 

	
 
    let expression = &mut ctx.heap[expression_id];
 
    *expression.parent_mut() = ExpressionParent::ExpressionStmt(statement_id);
 

	
 
    return statement_id;
 
}
 

	
 
fn create_ast_variable_declaration_stmt(ctx: &mut Ctx, variable_id: VariableId, initial_value_expr_id: ExpressionId) -> MemoryStatementId {
 
    // Create the assignment expression, assigning the initial value to the variable
 
    let variable_expr_id = create_ast_variable_expr(ctx, variable_id);
 
    let assignment_expr_id = ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{
 
        this,
 
        operator_span: InputSpan::new(),
 
        full_span: InputSpan::new(),
 
        left: variable_expr_id.upcast(),
 
        operation: AssignmentOperator::Set,
 
        right: initial_value_expr_id,
 
        parent: ExpressionParent::None,
 
        type_index: -1,
 
    });
 

	
 
    // Create the memory statement
 
    let memory_stmt_id = ctx.heap.alloc_memory_statement(|this| MemoryStatement{
 
        this,
 
        span: InputSpan::new(),
 
        variable: variable_id,
 
        initial_expr: assignment_expr_id,
 
        next: StatementId::new_invalid(),
 
    });
 

	
 
    // Set all parents which we can access
 
    let variable_expr = &mut ctx.heap[variable_expr_id];
 
    variable_expr.parent = ExpressionParent::Expression(assignment_expr_id.upcast(), 0);
 
    let value_expr = &mut ctx.heap[initial_value_expr_id];
 
    *value_expr.parent_mut() = ExpressionParent::Expression(assignment_expr_id.upcast(), 1);
 
    let assignment_expr = &mut ctx.heap[assignment_expr_id];
 
    assignment_expr.parent = ExpressionParent::Memory(memory_stmt_id);
 

	
 
    return memory_stmt_id;
 
}
 

	
 
fn create_ast_block_stmt(ctx: &mut Ctx, statements: Vec<StatementId>) -> (BlockStatementId, EndBlockStatementId, ScopeId) {
 
    let block_stmt_id = ctx.heap.alloc_block_statement(|this| BlockStatement{
 
        this,
 
        span: InputSpan::new(),
 
        statements,
 
        end_block: EndBlockStatementId::new_invalid(),
 
        scope: ScopeId::new_invalid(),
 
        next: StatementId::new_invalid(),
 
    });
 
    let end_block_stmt_id = ctx.heap.alloc_end_block_statement(|this| EndBlockStatement{
 
        this,
 
        start_block: block_stmt_id,
 
        next: StatementId::new_invalid(),
 
    });
 
    let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Block(block_stmt_id)));
 

	
 
    let block_stmt = &mut ctx.heap[block_stmt_id];
 
    block_stmt.end_block = end_block_stmt_id;
 
    block_stmt.scope = scope_id;
 

	
 
    return (block_stmt_id, end_block_stmt_id, scope_id);
 
}
 

	
 
fn create_ast_if_stmt(ctx: &mut Ctx, condition_expression_id: ExpressionId, true_case: IfStatementCase, false_case: Option<IfStatementCase>) -> (IfStatementId, EndIfStatementId) {
 
    // Create if statement and the end-if statement
 
    let if_stmt_id = ctx.heap.alloc_if_statement(|this| IfStatement{
 
        this,
 
        span: InputSpan::new(),
 
        test: condition_expression_id,
 
        true_case,
 
        false_case,
 
        end_if: EndIfStatementId::new_invalid()
 
    });
 

	
 
    let end_if_stmt_id = ctx.heap.alloc_end_if_statement(|this| EndIfStatement{
 
        this,
 
        start_if: if_stmt_id,
 
        next: StatementId::new_invalid(),
 
    });
 

	
 
    // Link the statements up as much as we can
 
    let if_stmt = &mut ctx.heap[if_stmt_id];
 
    if_stmt.end_if = end_if_stmt_id;
 

	
 
    let condition_expr = &mut ctx.heap[condition_expression_id];
 
    *condition_expr.parent_mut() = ExpressionParent::If(if_stmt_id);
 

	
 

	
 

	
 
    return (if_stmt_id, end_if_stmt_id);
 
}
 

	
 
/// Sets the false body for a given
 
fn set_ast_if_statement_false_body(ctx: &mut Ctx, if_statement_id: IfStatementId, end_if_statement_id: EndIfStatementId, false_case: IfStatementCase) {
 
    // Point if-statement to "false body"
 
    let if_stmt = &mut ctx.heap[if_statement_id];
 
    debug_assert!(if_stmt.false_case.is_none()); // simplifies logic, not necessary
 
    if_stmt.false_case = Some(false_case);
 

	
 
    // Point end of false body to the end of the if statement
 
    set_ast_statement_next(ctx, false_case.body, end_if_statement_id.upcast());
 
}
 

	
 
/// Sets the specified AST statement's control flow such that it will be
 
/// followed by the target statement. This may seem obvious, but may imply that
 
/// a statement associated with, but different from, the source statement is
 
/// modified.
 
fn set_ast_statement_next(ctx: &mut Ctx, source_stmt_id: StatementId, target_stmt_id: StatementId) {
 
    let source_stmt = &mut ctx.heap[source_stmt_id];
 
    match source_stmt {
 
        Statement::Block(stmt) => {
 
            let end_id = stmt.end_block;
 
            ctx.heap[end_id].next = target_stmt_id
 
        },
 
        Statement::EndBlock(stmt) => stmt.next = target_stmt_id,
 
        Statement::Local(stmt) => {
 
            match stmt {
 
                LocalStatement::Memory(stmt) => stmt.next = target_stmt_id,
 
                LocalStatement::Channel(stmt) => stmt.next = target_stmt_id,
 
            }
 
        },
 
        Statement::Labeled(stmt) => {
 
            let body_id = stmt.body;
 
            set_ast_statement_next(ctx, body_id, target_stmt_id);
 
        },
 
        Statement::If(stmt) => {
 
            let end_id = stmt.end_if;
 
            ctx.heap[end_id].next = target_stmt_id;
 
        },
 
        Statement::EndIf(stmt) => stmt.next = target_stmt_id,
 
        Statement::While(stmt) => {
 
            let end_id = stmt.end_while;
 
            ctx.heap[end_id].next = target_stmt_id;
 
        },
 
        Statement::EndWhile(stmt) => stmt.next = target_stmt_id,
 

	
 
        Statement::Break(_stmt) => {},
 
        Statement::Continue(_stmt) => {},
 
        Statement::Synchronous(stmt) => {
 
            let end_id = stmt.end_sync;
 
            ctx.heap[end_id].next = target_stmt_id;
 
        },
 
        Statement::EndSynchronous(stmt) => {
 
            stmt.next = target_stmt_id;
 
        },
 
        Statement::Fork(_) | Statement::EndFork(_) => {
 
            todo!("remove fork from language");
 
        },
 
        Statement::Select(stmt) => {
 
            let end_id = stmt.end_select;
 
            ctx.heap[end_id].next = target_stmt_id;
 
        },
 
        Statement::EndSelect(stmt) => stmt.next = target_stmt_id,
 
        Statement::Return(_stmt) => {},
 
        Statement::Goto(_stmt) => {},
 
        Statement::New(stmt) => stmt.next = target_stmt_id,
 
        Statement::Expression(stmt) => stmt.next = target_stmt_id,
 
    }
 
}
 

	
 
/// Links a new scope to an existing scope as its child.
 
fn link_new_child_to_existing_parent_scope(ctx: &mut Ctx, scope_buffer: &mut ScopedBuffer<ScopeId>, parent_scope_id: ScopeId, child_scope_id: ScopeId, relative_pos_hint: i32) {
 
    let child_scope = &mut ctx.heap[child_scope_id];
 
    debug_assert!(child_scope.parent.is_none());
 

	
 
    child_scope.parent = Some(parent_scope_id);
 
    child_scope.relative_pos_in_parent = relative_pos_hint;
 

	
 
    add_child_scope_to_parent(ctx, scope_buffer, parent_scope_id, child_scope_id, relative_pos_hint);
 
}
 

	
 
/// Relinks an existing scope to a new scope as its child. Will also break the
 
/// link of the child scope's old parent.
 
fn link_existing_child_to_new_parent_scope(ctx: &mut Ctx, scope_buffer: &mut ScopedBuffer<ScopeId>, new_parent_scope_id: ScopeId, child_scope_id: ScopeId, new_relative_pos_in_parent: i32) {
 
    let child_scope = &mut ctx.heap[child_scope_id];
 
    let old_parent_scope_id = child_scope.parent.unwrap();
 
    child_scope.parent = Some(new_parent_scope_id);
 
    child_scope.relative_pos_in_parent = new_relative_pos_in_parent;
 

	
 
    // Remove from old parent
 
    let old_parent = &mut ctx.heap[old_parent_scope_id];
 
    let scope_index = old_parent.nested.iter()
 
        .position(|v| *v == child_scope_id)
 
        .unwrap();
 
    old_parent.nested.remove(scope_index);
 

	
 
    // Add to new parent
 
    add_child_scope_to_parent(ctx, scope_buffer, new_parent_scope_id, child_scope_id, new_relative_pos_in_parent);
 
}
 

	
 
/// Will add a child scope to a parent scope using the relative position hint.
 
fn add_child_scope_to_parent(ctx: &mut Ctx, scope_buffer: &mut ScopedBuffer<ScopeId>, parent_scope_id: ScopeId, child_scope_id: ScopeId, relative_pos_hint: i32) {
 
    let child_scope = &ctx.heap[child_scope_id];
 

	
 
    let existing_scope_ids = scope_buffer.start_section_initialized(&child_scope.nested);
 
    let mut insert_pos = existing_scope_ids.len();
 
    for index in 0..existing_scope_ids.len() {
 
        let existing_scope_id = existing_scope_ids[index];
 
        let existing_scope = &ctx.heap[existing_scope_id];
 
        if relative_pos_hint <= existing_scope.relative_pos_in_parent {
 
            insert_pos = index;
 
            break;
 
        }
 
    }
 
    existing_scope_ids.forget();
 

	
 
    let parent_scope = &mut ctx.heap[parent_scope_id];
 
    parent_scope.nested.insert(insert_pos, child_scope_id);
 
}

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