Changeset - c6a9e4f128f2
[Not reviewed]
src/collections/raw_vec.rs
Show inline comments
 
use std::{mem, ptr, cmp};
 
use std::alloc::{Layout, alloc, dealloc};
 

	
 
#[derive(Debug)]
 
enum AllocError {
 
    CapacityOverflow,
 
}
 

	
 
/// Generic raw vector. It has a base pointer, a capacity and a length. Basic
 
/// operations are supported, but the user of the structure is responsible for
 
/// ensuring that no illegal mutable access occurs.
 
/// A lot of the logic is simply stolen from the std lib. The destructor will
 
/// free the backing memory, but will not run any destructors.
 
/// Try to use functions to modify the length. But feel free if you know what
 
/// you're doing
 
pub struct RawVec<T: Sized> {
 
    base: *mut T,
 
    cap: usize,
 
    pub len: usize,
 
}
 

	
 
impl<T: Sized> RawVec<T> {
 
    const T_ALIGNMENT: usize = mem::align_of::<T>();
 
    const T_SIZE: usize = mem::size_of::<T>();
 
    
 
    const GROWTH_RATE: usize = 2;
 

	
 
    pub fn new() -> Self {
 
        Self{
 
            base: ptr::null_mut(),
 
            cap: 0,
 
            len: 0,
 
        }
 
    }
 

	
 
    pub fn with_capacity(capacity: usize) -> Self {
 
        // Could be done a bit more efficiently
 
        let mut result = Self::new();
 
        result.ensure_space(capacity).unwrap();
 
        return result;
 
    }
 

	
 
    #[inline]
 
    pub unsafe fn get(&self, idx: usize) -> *const T {
 
        debug_assert!(idx < self.len);
 
        return self.base.add(idx);
 
    }
 

	
 
    #[inline]
 
    pub unsafe fn get_mut(&self, idx: usize) -> *mut T {
 
        debug_assert!(idx < self.len);
 
        return self.base.add(idx);
 
    }
 

	
 
    /// Pushes a new element to the end of the list.
 
    pub fn push(&mut self, item: T) {
 
        self.ensure_space(1).unwrap();
 
        unsafe {
 
            let target = self.base.add(self.len);
 
            std::ptr::write(target, item);
 
            self.len += 1;
 
        }
 
    }
 

	
 
    /// Moves the elements in the range [from_idx, from_idx + num_to_move) to
 
    /// the range [to_idx, to_idx + num_to_move). Caller must make sure that all
 
    /// non-overlapping elements of the second range had their destructor called
 
    /// in case those elements were used.
 
    pub fn move_range(&mut self, from_idx: usize, to_idx: usize, num_to_move: usize) {
 
        debug_assert!(from_idx + num_to_move <= self.len);
 
        debug_assert!(to_idx + num_to_move <= self.len); // maybe not in future, for now this is fine
 
        unsafe {
 
            let source = self.base.add(from_idx);
 
            let target = self.base.add(to_idx);
 
            std::ptr::copy(source, target, num_to_move);
 
        }
 
    }
 

	
 
    pub fn len(&self) -> usize {
 
        return self.len;
 
    }
 

	
 
    pub fn as_slice(&self) -> &[T] {
 
        return unsafe{
 
            std::slice::from_raw_parts(self.base, self.len)
 
        };
 
    }
 

	
 
    fn ensure_space(&mut self, additional: usize) -> Result<(), AllocError>{
 
        debug_assert!(Self::T_SIZE != 0);
 
        debug_assert!(self.cap >= self.len);
 
        if self.cap - self.len < additional {
 
            // Need to resize. Note that due to all checked conditions we have
 
            // that new_cap >= 1.
 
            debug_assert!(additional > 0);
 
            let new_cap = self.len.checked_add(additional).unwrap();
 
            let new_cap = cmp::max(new_cap, self.cap * Self::GROWTH_RATE);
 

	
 
            let layout = Layout::array::<T>(new_cap)
 
                .map_err(|_| AllocError::CapacityOverflow)?;
 
            debug_assert_eq!(new_cap * Self::T_SIZE, layout.size());
 

	
 
            unsafe {
 
                // Allocate new storage, transfer bits, deallocate old store
 
                let new_base = alloc(layout);
 

	
 
                if self.cap > 0 {
 
                    let old_base = self.base as *mut u8;
 
                    let (old_size, old_layout) = self.current_layout();
 

	
 
                    ptr::copy_nonoverlapping(old_base, new_base, old_size);
 
                    dealloc(old_base, old_layout);
 
                }
 

	
 
                self.base = new_base as *mut T;
 
                self.cap = new_cap;
 
            }
 
        } // else: still enough space
 

	
 
        return Ok(());
 
    }
 

	
 
    #[inline]
 
    fn current_layout(&self) -> (usize, Layout) {
 
        debug_assert!(Self::T_SIZE > 0);
 
        let old_size = self.cap * Self::T_SIZE;
 
        unsafe {
 
            return (
 
                old_size,
 
                Layout::from_size_align_unchecked(old_size, Self::T_ALIGNMENT)
 
            );
 
        }
 
    }
 
}
 

	
 
impl<T: Sized> Drop for RawVec<T> {
 
    fn drop(&mut self) {
 
        if self.cap > 0 {
 
            debug_assert!(!self.base.is_null());
 
            let (_, layout) = self.current_layout();
 
            unsafe {
 
                dealloc(self.base as *mut u8, layout);
 
                dbg_code!({ self.base = ptr::null_mut(); });
 
            }
 
        }
 
    }
 
}
 
\ No newline at end of file
src/protocol/ast.rs
Show inline comments
 
@@ -24,297 +24,302 @@ macro_rules! define_aliased_ast_id {
 
            fn index(&self, index: $name) -> &Self::Output {
 
                &self.$indexed_arena[index]
 
            }
 
        }
 

	
 
        impl IndexMut<$name> for Heap {
 
            fn index_mut(&mut self, index: $name) -> &mut Self::Output {
 
                &mut self.$indexed_arena[index]
 
            }
 
        }
 
    };
 
    // Variant where we define type, Index(Mut) traits and an allocation function
 
    (
 
        $name:ident, $parent:ty,
 
        index($indexed_type:ty, $indexed_arena:ident),
 
        alloc($fn_name:ident)
 
    ) => {
 
        define_aliased_ast_id!($name, $parent, index($indexed_type, $indexed_arena));
 
        impl Heap {
 
            pub fn $fn_name(&mut self, f: impl FnOnce($name) -> $indexed_type) -> $name {
 
                self.$indexed_arena.alloc_with_id(|id| f(id))
 
            }
 
        }
 
    };
 
}
 

	
 
/// Helper macro that defines a wrapper type for a particular variant of an AST
 
/// element ID. Only used to define single-wrapping IDs.
 
macro_rules! define_new_ast_id {
 
    // Variant where we just defined the new type, without any indexing
 
    ($name:ident, $parent:ty) => {
 
        #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 
        pub struct $name (pub(crate) $parent);
 

	
 
        #[allow(dead_code)]
 
        impl $name {
 
            pub(crate) fn new_invalid() -> Self     { Self(<$parent>::new_invalid()) }
 
            pub(crate) fn is_invalid(&self) -> bool { self.0.is_invalid() }
 
            pub fn upcast(self) -> $parent          { self.0 }
 
        }
 
    };
 
    // Variant where we define the type, and the Index and IndexMut traits
 
    (
 
        $name:ident, $parent:ty, 
 
        index($indexed_type:ty, $wrapper_type:path, $indexed_arena:ident)
 
    ) => {
 
        define_new_ast_id!($name, $parent);
 
        impl Index<$name> for Heap {
 
            type Output = $indexed_type;
 
            fn index(&self, index: $name) -> &Self::Output {
 
                if let $wrapper_type(v) = &self.$indexed_arena[index.0] {
 
                    v
 
                } else {
 
                    unreachable!()
 
                }
 
            }
 
        }
 

	
 
        impl IndexMut<$name> for Heap {
 
            fn index_mut(&mut self, index: $name) -> &mut Self::Output {
 
                if let $wrapper_type(v) = &mut self.$indexed_arena[index.0] {
 
                    v
 
                } else {
 
                    unreachable!()
 
                }
 
            }
 
        }
 
    };
 
    // Variant where we define the type, the Index and IndexMut traits, and an allocation function
 
    (
 
        $name:ident, $parent:ty, 
 
        index($indexed_type:ty, $wrapper_type:path, $indexed_arena:ident),
 
        alloc($fn_name:ident)
 
    ) => {
 
        define_new_ast_id!($name, $parent, index($indexed_type, $wrapper_type, $indexed_arena));
 
        impl Heap {
 
            pub fn $fn_name(&mut self, f: impl FnOnce($name) -> $indexed_type) -> $name {
 
                $name(
 
                    self.$indexed_arena.alloc_with_id(|id| {
 
                        $wrapper_type(f($name(id)))
 
                    })
 
                )
 
            }
 
        }
 
    }
 
}
 

	
 
define_aliased_ast_id!(RootId, Id<Root>, index(Root, protocol_descriptions), alloc(alloc_protocol_description));
 
define_aliased_ast_id!(PragmaId, Id<Pragma>, index(Pragma, pragmas), alloc(alloc_pragma));
 
define_aliased_ast_id!(ImportId, Id<Import>, index(Import, imports), alloc(alloc_import));
 
define_aliased_ast_id!(VariableId, Id<Variable>, index(Variable, variables), alloc(alloc_variable));
 

	
 
define_aliased_ast_id!(DefinitionId, Id<Definition>, index(Definition, definitions));
 
define_new_ast_id!(StructDefinitionId, DefinitionId, index(StructDefinition, Definition::Struct, definitions), alloc(alloc_struct_definition));
 
define_new_ast_id!(EnumDefinitionId, DefinitionId, index(EnumDefinition, Definition::Enum, definitions), alloc(alloc_enum_definition));
 
define_new_ast_id!(UnionDefinitionId, DefinitionId, index(UnionDefinition, Definition::Union, definitions), alloc(alloc_union_definition));
 
define_new_ast_id!(ComponentDefinitionId, DefinitionId, index(ComponentDefinition, Definition::Component, definitions), alloc(alloc_component_definition));
 
define_new_ast_id!(FunctionDefinitionId, DefinitionId, index(FunctionDefinition, Definition::Function, definitions), alloc(alloc_function_definition));
 
define_new_ast_id!(ProcedureDefinitionId, DefinitionId, index(ProcedureDefinition, Definition::Procedure, definitions), alloc(alloc_procedure_definition));
 

	
 
define_aliased_ast_id!(StatementId, Id<Statement>, index(Statement, statements));
 
define_new_ast_id!(BlockStatementId, StatementId, index(BlockStatement, Statement::Block, statements), alloc(alloc_block_statement));
 
define_new_ast_id!(EndBlockStatementId, StatementId, index(EndBlockStatement, Statement::EndBlock, statements), alloc(alloc_end_block_statement));
 
define_new_ast_id!(LocalStatementId, StatementId, index(LocalStatement, Statement::Local, statements));
 
define_new_ast_id!(MemoryStatementId, LocalStatementId);
 
define_new_ast_id!(ChannelStatementId, LocalStatementId);
 
define_new_ast_id!(LabeledStatementId, StatementId, index(LabeledStatement, Statement::Labeled, statements), alloc(alloc_labeled_statement));
 
define_new_ast_id!(IfStatementId, StatementId, index(IfStatement, Statement::If, statements), alloc(alloc_if_statement));
 
define_new_ast_id!(EndIfStatementId, StatementId, index(EndIfStatement, Statement::EndIf, statements), alloc(alloc_end_if_statement));
 
define_new_ast_id!(WhileStatementId, StatementId, index(WhileStatement, Statement::While, statements), alloc(alloc_while_statement));
 
define_new_ast_id!(EndWhileStatementId, StatementId, index(EndWhileStatement, Statement::EndWhile, statements), alloc(alloc_end_while_statement));
 
define_new_ast_id!(BreakStatementId, StatementId, index(BreakStatement, Statement::Break, statements), alloc(alloc_break_statement));
 
define_new_ast_id!(ContinueStatementId, StatementId, index(ContinueStatement, Statement::Continue, statements), alloc(alloc_continue_statement));
 
define_new_ast_id!(SynchronousStatementId, StatementId, index(SynchronousStatement, Statement::Synchronous, statements), alloc(alloc_synchronous_statement));
 
define_new_ast_id!(EndSynchronousStatementId, StatementId, index(EndSynchronousStatement, Statement::EndSynchronous, statements), alloc(alloc_end_synchronous_statement));
 
define_new_ast_id!(ForkStatementId, StatementId, index(ForkStatement, Statement::Fork, statements), alloc(alloc_fork_statement));
 
define_new_ast_id!(EndForkStatementId, StatementId, index(EndForkStatement, Statement::EndFork, statements), alloc(alloc_end_fork_statement));
 
define_new_ast_id!(SelectStatementId, StatementId, index(SelectStatement, Statement::Select, statements), alloc(alloc_select_statement));
 
define_new_ast_id!(EndSelectStatementId, StatementId, index(EndSelectStatement, Statement::EndSelect, statements), alloc(alloc_end_select_statement));
 
define_new_ast_id!(ReturnStatementId, StatementId, index(ReturnStatement, Statement::Return, statements), alloc(alloc_return_statement));
 
define_new_ast_id!(GotoStatementId, StatementId, index(GotoStatement, Statement::Goto, statements), alloc(alloc_goto_statement));
 
define_new_ast_id!(NewStatementId, StatementId, index(NewStatement, Statement::New, statements), alloc(alloc_new_statement));
 
define_new_ast_id!(ExpressionStatementId, StatementId, index(ExpressionStatement, Statement::Expression, statements), alloc(alloc_expression_statement));
 

	
 
define_aliased_ast_id!(ExpressionId, Id<Expression>, index(Expression, expressions));
 
define_new_ast_id!(AssignmentExpressionId, ExpressionId, index(AssignmentExpression, Expression::Assignment, expressions), alloc(alloc_assignment_expression));
 
define_new_ast_id!(BindingExpressionId, ExpressionId, index(BindingExpression, Expression::Binding, expressions), alloc(alloc_binding_expression));
 
define_new_ast_id!(ConditionalExpressionId, ExpressionId, index(ConditionalExpression, Expression::Conditional, expressions), alloc(alloc_conditional_expression));
 
define_new_ast_id!(BinaryExpressionId, ExpressionId, index(BinaryExpression, Expression::Binary, expressions), alloc(alloc_binary_expression));
 
define_new_ast_id!(UnaryExpressionId, ExpressionId, index(UnaryExpression, Expression::Unary, expressions), alloc(alloc_unary_expression));
 
define_new_ast_id!(IndexingExpressionId, ExpressionId, index(IndexingExpression, Expression::Indexing, expressions), alloc(alloc_indexing_expression));
 
define_new_ast_id!(SlicingExpressionId, ExpressionId, index(SlicingExpression, Expression::Slicing, expressions), alloc(alloc_slicing_expression));
 
define_new_ast_id!(SelectExpressionId, ExpressionId, index(SelectExpression, Expression::Select, expressions), alloc(alloc_select_expression));
 
define_new_ast_id!(LiteralExpressionId, ExpressionId, index(LiteralExpression, Expression::Literal, expressions), alloc(alloc_literal_expression));
 
define_new_ast_id!(CastExpressionId, ExpressionId, index(CastExpression, Expression::Cast, expressions), alloc(alloc_cast_expression));
 
define_new_ast_id!(CallExpressionId, ExpressionId, index(CallExpression, Expression::Call, expressions), alloc(alloc_call_expression));
 
define_new_ast_id!(VariableExpressionId, ExpressionId, index(VariableExpression, Expression::Variable, expressions), alloc(alloc_variable_expression));
 

	
 
define_aliased_ast_id!(ScopeId, Id<Scope>, index(Scope, scopes), alloc(alloc_scope));
 

	
 
#[derive(Debug)]
 
pub struct Heap {
 
    // Root arena, contains the entry point for different modules. Each root
 
    // contains lists of IDs that correspond to the other arenas.
 
    pub(crate) protocol_descriptions: Arena<Root>,
 
    // Contents of a file, these are the elements the `Root` elements refer to
 
    pragmas: Arena<Pragma>,
 
    pub(crate) imports: Arena<Import>,
 
    pub(crate) variables: Arena<Variable>,
 
    pub(crate) definitions: Arena<Definition>,
 
    pub(crate) statements: Arena<Statement>,
 
    pub(crate) expressions: Arena<Expression>,
 
    pub(crate) scopes: Arena<Scope>,
 
}
 

	
 
impl Heap {
 
    pub fn new() -> Heap {
 
        Heap {
 
            // string_alloc: StringAllocator::new(),
 
            protocol_descriptions: Arena::new(),
 
            pragmas: Arena::new(),
 
            imports: Arena::new(),
 
            variables: Arena::new(),
 
            definitions: Arena::new(),
 
            statements: Arena::new(),
 
            expressions: Arena::new(),
 
            scopes: Arena::new(),
 
        }
 
    }
 
    pub fn alloc_memory_statement(
 
        &mut self,
 
        f: impl FnOnce(MemoryStatementId) -> MemoryStatement,
 
    ) -> MemoryStatementId {
 
        MemoryStatementId(LocalStatementId(self.statements.alloc_with_id(|id| {
 
            Statement::Local(LocalStatement::Memory(
 
                f(MemoryStatementId(LocalStatementId(id)))
 
            ))
 
        })))
 
    }
 
    pub fn alloc_channel_statement(
 
        &mut self,
 
        f: impl FnOnce(ChannelStatementId) -> ChannelStatement,
 
    ) -> ChannelStatementId {
 
        ChannelStatementId(LocalStatementId(self.statements.alloc_with_id(|id| {
 
            Statement::Local(LocalStatement::Channel(
 
                f(ChannelStatementId(LocalStatementId(id)))
 
            ))
 
        })))
 
    }
 
}
 

	
 
impl Index<MemoryStatementId> for Heap {
 
    type Output = MemoryStatement;
 
    fn index(&self, index: MemoryStatementId) -> &Self::Output {
 
        &self.statements[index.0.0].as_memory()
 
        match &self.statements[index.0.0] {
 
            Statement::Local(LocalStatement::Memory(v)) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 
}
 

	
 
impl Index<ChannelStatementId> for Heap {
 
    type Output = ChannelStatement;
 
    fn index(&self, index: ChannelStatementId) -> &Self::Output {
 
        &self.statements[index.0.0].as_channel()
 
        match &self.statements[index.0.0] {
 
            Statement::Local(LocalStatement::Channel(v)) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct Root {
 
    pub this: RootId,
 
    // Phase 1: parser
 
    // pub position: InputPosition,
 
    pub pragmas: Vec<PragmaId>,
 
    pub imports: Vec<ImportId>,
 
    pub definitions: Vec<DefinitionId>,
 
}
 

	
 
impl Root {
 
    pub fn get_definition_ident(&self, h: &Heap, id: &[u8]) -> Option<DefinitionId> {
 
        for &def in self.definitions.iter() {
 
            if h[def].identifier().value.as_bytes() == id {
 
                return Some(def);
 
            }
 
        }
 
        None
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub enum Pragma {
 
    Version(PragmaVersion),
 
    Module(PragmaModule),
 
}
 

	
 
impl Pragma {
 
    pub(crate) fn as_module(&self) -> &PragmaModule {
 
        match self {
 
            Pragma::Module(pragma) => pragma,
 
            _ => unreachable!("Tried to obtain {:?} as PragmaModule", self),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct PragmaVersion {
 
    pub this: PragmaId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of full pragma
 
    pub version: u64,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct PragmaModule {
 
    pub this: PragmaId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of full pragma
 
    pub value: Identifier,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub enum Import {
 
    Module(ImportModule),
 
    Symbols(ImportSymbols)
 
}
 

	
 
impl Import {
 
    pub(crate) fn span(&self) -> InputSpan {
 
        match self {
 
            Import::Module(v) => v.span,
 
            Import::Symbols(v) => v.span,
 
        }
 
    }
 

	
 
    pub(crate) fn as_module(&self) -> &ImportModule {
 
        match self {
 
            Import::Module(m) => m,
 
            _ => unreachable!("Unable to cast 'Import' to 'ImportModule'")
 
        }
 
    }
 
    pub(crate) fn as_symbols(&self) -> &ImportSymbols {
 
        match self {
 
            Import::Symbols(m) => m,
 
            _ => unreachable!("Unable to cast 'Import' to 'ImportSymbols'")
 
        }
 
    }
 
    pub(crate) fn as_symbols_mut(&mut self) -> &mut ImportSymbols {
 
        match self {
 
            Import::Symbols(m) => m,
 
            _ => unreachable!("Unable to cast 'Import' to 'ImportSymbols'")
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ImportModule {
 
    pub this: ImportId,
 
    // Phase 1: parser
 
    pub span: InputSpan,
 
    pub module: Identifier,
 
    pub alias: Identifier,
 
@@ -422,923 +427,851 @@ impl ParserTypeVariant {
 
pub struct ParserTypeElement {
 
    pub element_span: InputSpan, // span of this element, not including the child types
 
    pub variant: ParserTypeVariant,
 
}
 

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

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

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

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

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

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

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

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

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

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

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

	
 
        match self {
 
            Void | Message | Bool |
 
            UInt8 | UInt16 | UInt32 | UInt64 |
 
            SInt8 | SInt16 | SInt32 | SInt64 |
 
            Character | String =>
 
                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) |
 
            CTP::Instance(definition_id, num_poly_args) => {
 
                idx = Self::render_definition_type_parts_at(parts, heap, definition_id, num_poly_args, idx, target);
 
            }
 
            CTP::Function(definition_id, num_poly_args) |
 
            CTP::Component(definition_id, num_poly_args) => {
 
                idx = Self::render_definition_type_parts_at(parts, heap, definition_id.upcast(), num_poly_args, idx, target);
 
            }
 
        }
 

	
 
        idx
 
    }
 

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

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

	
 
        idx
 
        return idx;
 
    }
 
}
 

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

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

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

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

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

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

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

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

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

	
 
    pub(crate) fn as_union_mut(&mut self) -> &mut UnionDefinition {
 
        match self {
 
            Definition::Union(result) => result,
 
            _ => panic!("Unable to cast 'Definition' to 'UnionDefinition'"),
 
        }
 
    }
 
    pub fn is_component(&self) -> bool {
 
        match self {
 
            Definition::Component(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub(crate) fn as_component(&self) -> &ComponentDefinition {
 
        match self {
 
            Definition::Component(result) => result,
 
            _ => panic!("Unable to cast `Definition` to `Component`"),
 
        }
 
    }
 
    pub(crate) fn as_component_mut(&mut self) -> &mut ComponentDefinition {
 
        match self {
 
            Definition::Component(result) => result,
 
            _ => panic!("Unable to cast `Definition` to `Component`"),
 
        }
 
    }
 
    pub fn is_function(&self) -> bool {
 

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

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

	
 
    pub(crate) fn as_procedure_mut(&mut self) -> &mut ProcedureDefinition {
 
        match self {
 
            Definition::Function(result) => result,
 
            Definition::Procedure(result) => result,
 
            _ => panic!("Unable to cast `Definition` to `Function`"),
 
        }
 
    }
 
    pub fn parameters(&self) -> &Vec<VariableId> {
 
        match self {
 
            Definition::Component(def) => &def.parameters,
 
            Definition::Function(def) => &def.parameters,
 
            _ => panic!("Called parameters() on {:?}", self)
 
        }
 
    }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
#[derive(Debug, Clone)]
 
pub struct ComponentDefinition {
 
    pub this: ComponentDefinitionId,
 
    pub defined_in: RootId,
 
    // Symbol scanning
 
    pub span: InputSpan,
 
    pub variant: ComponentVariant,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    // Parsing
 
    pub parameters: Vec<VariableId>,
 
    pub scope: ScopeId,
 
    pub body: BlockStatementId,
 
    // Validation/linking
 
    pub num_expressions_in_body: i32,
 
}
 

	
 
impl ComponentDefinition {
 
    // Used for preallocation during symbol scanning
 
    pub(crate) fn new_empty(
 
        this: ComponentDefinitionId, defined_in: RootId, span: InputSpan,
 
        variant: ComponentVariant, identifier: Identifier, poly_vars: Vec<Identifier>
 
    ) -> Self {
 
        Self{ 
 
            this, defined_in, span, variant, identifier, poly_vars,
 
            parameters: Vec::new(),
 
            scope: ScopeId::new_invalid(),
 
            body: BlockStatementId::new_invalid(),
 
            num_expressions_in_body: -1,
 
        }
 
    }
 
}
 

	
 
/// Generic storage for functions, primitive components and composite
 
/// components.
 
// Note that we will have function definitions for builtin functions as well. In
 
// that case the span, the identifier span and the body are all invalid.
 
#[derive(Debug, Clone)]
 
pub struct FunctionDefinition {
 
    pub this: FunctionDefinitionId,
 
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: ParserType,
 
    pub return_type: Option<ParserType>, // present on functions, not components
 
    pub parameters: Vec<VariableId>,
 
    pub scope: ScopeId,
 
    pub body: BlockStatementId,
 
    // Monomorphization of typed procedures
 

	
 
    // Validation/linking
 
    pub num_expressions_in_body: i32,
 
}
 

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

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

	
 
impl Statement {
 
    pub fn as_block(&self) -> &BlockStatement {
 
        match self {
 
            Statement::Block(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `BlockStatement`"),
 
        }
 
    }
 
    pub fn as_local(&self) -> &LocalStatement {
 
        match self {
 
            Statement::Local(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `LocalStatement`"),
 
        }
 
    }
 
    pub fn as_memory(&self) -> &MemoryStatement {
 
        self.as_local().as_memory()
 
    }
 
    pub fn as_channel(&self) -> &ChannelStatement {
 
        self.as_local().as_channel()
 
    }
 

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

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

	
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct BlockStatement {
 
    pub this: BlockStatementId,
 
    // Phase 1: parser
 
    pub 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 as_memory(&self) -> &MemoryStatement {
 
        match self {
 
            LocalStatement::Memory(result) => result,
 
            _ => panic!("Unable to cast `LocalStatement` to `MemoryStatement`"),
 
        }
 
    }
 
    pub fn as_channel(&self) -> &ChannelStatement {
 
        match self {
 
            LocalStatement::Channel(result) => result,
 
            _ => panic!("Unable to cast `LocalStatement` to `ChannelStatement`"),
 
        }
 
    }
 
    pub fn span(&self) -> InputSpan {
 
        match self {
 
            LocalStatement::Channel(v) => v.span,
 
            LocalStatement::Memory(v) => v.span,
 
        }
 
    }
 
}
 

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

	
 
/// ChannelStatement is the declaration of an input and output port associated
 
/// with the same channel. Note that the polarity of the ports are from the
 
/// point of view of the component. So an output port is something that a
 
/// component uses to send data over (i.e. it is the "input end" of the
 
/// channel), and vice versa.
 
#[derive(Debug, Clone)]
 
pub struct ChannelStatement {
 
    pub this: ChannelStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "channel" keyword
 
    pub from: VariableId, // output
 
    pub to: VariableId,   // input
 
    // Phase 2: linker
 
    pub relative_pos_in_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
 
@@ -1698,214 +1631,214 @@ pub struct BinaryExpression {
 
    pub operation: BinaryOperator,
 
    pub right: ExpressionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 
pub enum UnaryOperator {
 
    Positive,
 
    Negative,
 
    BitwiseNot,
 
    LogicalNot,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct UnaryExpression {
 
    pub this: UnaryExpressionId,
 
    // Parsing
 
    pub operator_span: InputSpan,
 
    pub full_span: InputSpan,
 
    pub operation: UnaryOperator,
 
    pub expression: ExpressionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct IndexingExpression {
 
    pub this: IndexingExpressionId,
 
    // Parsing
 
    pub operator_span: InputSpan,
 
    pub full_span: InputSpan,
 
    pub subject: ExpressionId,
 
    pub index: ExpressionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct SlicingExpression {
 
    pub this: SlicingExpressionId,
 
    // Parsing
 
    pub slicing_span: InputSpan, // from '[' to ']'
 
    pub full_span: InputSpan, // includes subject
 
    pub subject: ExpressionId,
 
    pub from_index: ExpressionId,
 
    pub to_index: ExpressionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub enum SelectKind {
 
    StructField(Identifier),
 
    TupleMember(u64), // u64 is overkill, but space is taken up by `StructField` variant anyway
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct SelectExpression {
 
    pub this: SelectExpressionId,
 
    // Parsing
 
    pub operator_span: InputSpan, // of the '.'
 
    pub full_span: InputSpan, // includes subject and field
 
    pub subject: ExpressionId,
 
    pub kind: SelectKind,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct CastExpression {
 
    pub this: CastExpressionId,
 
    // Parsing
 
    pub cast_span: InputSpan, // of the "cast" keyword,
 
    pub full_span: InputSpan, // includes the cast subject
 
    pub to_type: ParserType,
 
    pub subject: ExpressionId,
 
    // Validator/linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct CallExpression {
 
    pub this: CallExpressionId,
 
    // Parsing
 
    pub func_span: InputSpan, // of the function name
 
    pub full_span: InputSpan, // includes the arguments and parentheses
 
    pub parser_type: ParserType, // of the function call, not the return type
 
    pub method: Method,
 
    pub arguments: Vec<ExpressionId>,
 
    pub definition: DefinitionId,
 
    pub procedure: ProcedureDefinitionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone, PartialEq, Eq)]
 
pub enum Method {
 
    // Builtin, accessible by programmer
 
    Get,
 
    Put,
 
    Fires,
 
    Create,
 
    Length,
 
    Assert,
 
    Print,
 
    // Builtin, not accessible by programmer
 
    SelectStart, // SelectStart(total_num_cases, total_num_ports)
 
    SelectRegisterCasePort, // SelectRegisterCasePort(case_index, port_index, port_id)
 
    SelectWait, // SelectWait() -> u32
 
    // User-defined
 
    UserFunction,
 
    UserProcedure,
 
    UserComponent,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct MethodSymbolic {
 
    pub(crate) parser_type: ParserType,
 
    pub(crate) definition: DefinitionId
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct LiteralExpression {
 
    pub this: LiteralExpressionId,
 
    // Parsing
 
    pub span: InputSpan,
 
    pub value: Literal,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub enum Literal {
 
    Null, // message
 
    True,
 
    False,
 
    Character(char),
 
    String(StringRef<'static>),
 
    Integer(LiteralInteger),
 
    Struct(LiteralStruct),
 
    Enum(LiteralEnum),
 
    Union(LiteralUnion),
 
    Array(Vec<ExpressionId>),
 
    Tuple(Vec<ExpressionId>),
 
}
 

	
 
impl Literal {
 
    pub(crate) fn as_struct(&self) -> &LiteralStruct {
 
        if let Literal::Struct(literal) = self{
 
            literal
 
        } else {
 
            unreachable!("Attempted to obtain {:?} as Literal::Struct", self)
 
        }
 
    }
 

	
 
    pub(crate) fn as_enum(&self) -> &LiteralEnum {
 
        if let Literal::Enum(literal) = self {
 
            literal
 
        } else {
 
            unreachable!("Attempted to obtain {:?} as Literal::Enum", self)
 
        }
 
    }
 

	
 
    pub(crate) fn as_union(&self) -> &LiteralUnion {
 
        if let Literal::Union(literal) = self {
 
            literal
 
        } else {
 
            unreachable!("Attempted to obtain {:?} as Literal::Union", self)
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct LiteralInteger {
 
    pub(crate) unsigned_value: u64,
 
    pub(crate) negated: bool, // for constant expression evaluation, TODO: @Int
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct LiteralStructField {
 
    // Phase 1: parser
 
    pub(crate) identifier: Identifier,
 
    pub(crate) value: ExpressionId,
 
    // Phase 2: linker
 
    pub(crate) field_idx: usize, // in struct definition
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct LiteralStruct {
 
    // Phase 1: parser
 
    pub(crate) parser_type: ParserType,
 
    pub(crate) fields: Vec<LiteralStructField>,
 
    pub(crate) definition: DefinitionId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct LiteralEnum {
 
    // Phase 1: parser
 
    pub(crate) parser_type: ParserType,
 
    pub(crate) variant: Identifier,
 
    pub(crate) definition: DefinitionId,
 
    // Phase 2: linker
 
    pub(crate) variant_idx: usize, // as present in the type table
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct LiteralUnion {
src/protocol/ast_printer.rs
Show inline comments
 
@@ -252,232 +252,215 @@ impl ASTWriter {
 
                self.kv(indent).with_id(PREFIX_IMPORT_ID, import.this.index)
 
                    .with_s_key("ImportSymbol");
 

	
 
                self.kv(indent2).with_s_key("Name").with_identifier_val(&import.module);
 
                self.kv(indent2).with_s_key("Target").with_disp_val(&import.module_id.index);
 

	
 
                self.kv(indent2).with_s_key("Symbols");
 

	
 
                let indent3 = indent2 + 1;
 
                let indent4 = indent3 + 1;
 
                for symbol in &import.symbols {
 
                    self.kv(indent3).with_s_key("AliasedSymbol");
 
                    self.kv(indent4).with_s_key("Name").with_identifier_val(&symbol.name);
 
                    self.kv(indent4).with_s_key("Alias").with_opt_identifier_val(symbol.alias.as_ref());
 
                    self.kv(indent4).with_s_key("Definition").with_disp_val(&symbol.definition_id.index);
 
                }
 
            }
 
        }
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // Top-level definition writing
 
    //--------------------------------------------------------------------------
 

	
 
    fn write_definition(&mut self, heap: &Heap, def_id: DefinitionId, indent: usize) {
 
        self.cur_definition = Some(def_id);
 
        let indent2 = indent + 1;
 
        let indent3 = indent2 + 1;
 
        let indent4 = indent3 + 1;
 

	
 
        match &heap[def_id] {
 
            Definition::Struct(def) => {
 
                self.kv(indent).with_id(PREFIX_STRUCT_ID, def.this.0.index)
 
                    .with_s_key("DefinitionStruct");
 

	
 
                self.kv(indent2).with_s_key("Name").with_identifier_val(&def.identifier);
 
                for poly_var_id in &def.poly_vars {
 
                    self.kv(indent3).with_s_key("PolyVar").with_identifier_val(&poly_var_id);
 
                }
 

	
 
                self.kv(indent2).with_s_key("Fields");
 
                for field in &def.fields {
 
                    self.kv(indent3).with_s_key("Field");
 
                    self.kv(indent4).with_s_key("Name")
 
                        .with_identifier_val(&field.field);
 
                    self.kv(indent4).with_s_key("Type")
 
                        .with_custom_val(|s| write_parser_type(s, heap, &field.parser_type));
 
                }
 
            },
 
            Definition::Enum(def) => {
 
                self.kv(indent).with_id(PREFIX_ENUM_ID, def.this.0.index)
 
                    .with_s_key("DefinitionEnum");
 

	
 
                self.kv(indent2).with_s_key("Name").with_identifier_val(&def.identifier);
 
                for poly_var_id in &def.poly_vars {
 
                    self.kv(indent3).with_s_key("PolyVar").with_identifier_val(&poly_var_id);
 
                }
 

	
 
                self.kv(indent2).with_s_key("Variants");
 
                for variant in &def.variants {
 
                    self.kv(indent3).with_s_key("Variant");
 
                    self.kv(indent4).with_s_key("Name")
 
                        .with_identifier_val(&variant.identifier);
 
                    let variant_value = self.kv(indent4).with_s_key("Value");
 
                    match &variant.value {
 
                        EnumVariantValue::None => variant_value.with_s_val("None"),
 
                        EnumVariantValue::Integer(value) => variant_value.with_disp_val(value),
 
                    };
 
                }
 
            },
 
            Definition::Union(def) => {
 
                self.kv(indent).with_id(PREFIX_UNION_ID, def.this.0.index)
 
                    .with_s_key("DefinitionUnion");
 

	
 
                self.kv(indent2).with_s_key("Name").with_identifier_val(&def.identifier);
 
                for poly_var_id in &def.poly_vars {
 
                    self.kv(indent3).with_s_key("PolyVar").with_identifier_val(&poly_var_id);
 
                }
 

	
 
                self.kv(indent2).with_s_key("Variants");
 
                for variant in &def.variants {
 
                    self.kv(indent3).with_s_key("Variant");
 
                    self.kv(indent4).with_s_key("Name")
 
                        .with_identifier_val(&variant.identifier);
 
                        
 
                    if variant.value.is_empty() {
 
                        self.kv(indent4).with_s_key("Value").with_s_val("None");
 
                    } else {
 
                        self.kv(indent4).with_s_key("Values");
 
                        for embedded in &variant.value {
 
                            self.kv(indent4+1).with_s_key("Value")
 
                                .with_custom_val(|v| write_parser_type(v, heap, embedded));
 
                        }
 
                    }
 
                }
 
            }
 
            Definition::Function(def) => {
 
            Definition::Procedure(def) => {
 
                self.kv(indent).with_id(PREFIX_FUNCTION_ID, def.this.0.index)
 
                    .with_s_key("DefinitionFunction");
 

	
 
                self.kv(indent2).with_s_key("Name").with_identifier_val(&def.identifier);
 
                for poly_var_id in &def.poly_vars {
 
                    self.kv(indent3).with_s_key("PolyVar").with_identifier_val(&poly_var_id);
 
                }
 

	
 
                self.kv(indent2).with_s_key("Kind").with_debug_val(&def.kind);
 
                if let Some(parser_type) = &def.return_type {
 
                    self.kv(indent2).with_s_key("ReturnParserType")
 
                    .with_custom_val(|s| write_parser_type(s, heap, &def.return_type));
 
                        .with_custom_val(|s| write_parser_type(s, heap, parser_type));
 
                }
 

	
 
                self.kv(indent2).with_s_key("Parameters");
 
                for variable_id in &def.parameters {
 
                    self.write_variable(heap, *variable_id, indent3);
 
                }
 

	
 
                self.kv(indent2).with_s_key("Body");
 
                self.write_stmt(heap, def.body.upcast(), indent3);
 
            },
 
            Definition::Component(def) => {
 
                self.kv(indent).with_id(PREFIX_COMPONENT_ID,def.this.0.index)
 
                    .with_s_key("DefinitionComponent");
 

	
 
                self.kv(indent2).with_s_key("Name").with_identifier_val(&def.identifier);
 
                self.kv(indent2).with_s_key("Variant").with_debug_val(&def.variant);
 

	
 
                self.kv(indent2).with_s_key("PolymorphicVariables");
 
                for poly_var_id in &def.poly_vars {
 
                    self.kv(indent3).with_s_key("PolyVar").with_identifier_val(&poly_var_id);
 
                }
 

	
 
                self.kv(indent2).with_s_key("Parameters");
 
                for variable_id in &def.parameters {
 
                    self.write_variable(heap, *variable_id, indent3)
 
                }
 

	
 
                self.kv(indent2).with_s_key("Body");
 
                self.write_stmt(heap, def.body.upcast(), indent3);
 
            }
 
        }
 
    }
 

	
 
    fn write_stmt(&mut self, heap: &Heap, stmt_id: StatementId, indent: usize) {
 
        let stmt = &heap[stmt_id];
 
        let indent2 = indent + 1;
 
        let indent3 = indent2 + 1;
 

	
 
        match stmt {
 
            Statement::Block(stmt) => {
 
                self.kv(indent).with_id(PREFIX_BLOCK_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Block");
 
                self.kv(indent2).with_s_key("EndBlockID").with_disp_val(&stmt.end_block.0.index);
 
                self.kv(indent2).with_s_key("ScopeID").with_disp_val(&stmt.scope.index);
 

	
 
                self.kv(indent2).with_s_key("Statements");
 
                for stmt_id in &stmt.statements {
 
                    self.write_stmt(heap, *stmt_id, indent3);
 
                }
 
            },
 
            Statement::EndBlock(stmt) => {
 
                self.kv(indent).with_id(PREFIX_ENDBLOCK_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("EndBlock");
 
                self.kv(indent2).with_s_key("StartBlockID").with_disp_val(&stmt.start_block.0.index);
 
            }
 
            Statement::Local(stmt) => {
 
                match stmt {
 
                    LocalStatement::Channel(stmt) => {
 
                        self.kv(indent).with_id(PREFIX_CHANNEL_STMT_ID, stmt.this.0.0.index)
 
                            .with_s_key("LocalChannel");
 

	
 
                        self.kv(indent2).with_s_key("From");
 
                        self.write_variable(heap, stmt.from, indent3);
 
                        self.kv(indent2).with_s_key("To");
 
                        self.write_variable(heap, stmt.to, indent3);
 
                        self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
 
                    },
 
                    LocalStatement::Memory(stmt) => {
 
                        self.kv(indent).with_id(PREFIX_MEM_STMT_ID, stmt.this.0.0.index)
 
                            .with_s_key("LocalMemory");
 

	
 
                        self.kv(indent2).with_s_key("Variable");
 
                        self.write_variable(heap, stmt.variable, indent3);
 
                        self.kv(indent2).with_s_key("InitialValue");
 
                        self.write_expr(heap, stmt.initial_expr.upcast(), indent3);
 
                        self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
 
                    }
 
                }
 
            },
 
            Statement::Labeled(stmt) => {
 
                self.kv(indent).with_id(PREFIX_LABELED_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Labeled");
 

	
 
                self.kv(indent2).with_s_key("Label").with_identifier_val(&stmt.label);
 
                self.kv(indent2).with_s_key("Statement");
 
                self.write_stmt(heap, stmt.body, indent3);
 
            },
 
            Statement::If(stmt) => {
 
                self.kv(indent).with_id(PREFIX_IF_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("If");
 

	
 
                self.kv(indent2).with_s_key("EndIf").with_disp_val(&stmt.end_if.0.index);
 

	
 
                self.kv(indent2).with_s_key("Condition");
 
                self.write_expr(heap, stmt.test, indent3);
 

	
 
                self.kv(indent2).with_s_key("TrueBody");
 
                self.write_stmt(heap, stmt.true_case.body, indent3);
 

	
 
                if let Some(false_body) = stmt.false_case {
 
                    self.kv(indent2).with_s_key("FalseBody");
 
                    self.write_stmt(heap, false_body.body, indent3);
 
                }
 
            },
 
            Statement::EndIf(stmt) => {
 
                self.kv(indent).with_id(PREFIX_ENDIF_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("EndIf");
 
                self.kv(indent2).with_s_key("StartIf").with_disp_val(&stmt.start_if.0.index);
 
                self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
 
            },
 
            Statement::While(stmt) => {
 
                self.kv(indent).with_id(PREFIX_WHILE_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("While");
 

	
 
                self.kv(indent2).with_s_key("EndWhile").with_disp_val(&stmt.end_while.0.index);
 
                self.kv(indent2).with_s_key("InSync")
 
                    .with_disp_val(&stmt.in_sync.0.index);
 
                self.kv(indent2).with_s_key("Condition");
 
                self.write_expr(heap, stmt.test, indent3);
 
                self.kv(indent2).with_s_key("Body");
 
                self.write_stmt(heap, stmt.body, indent3);
 
            },
 
            Statement::EndWhile(stmt) => {
 
                self.kv(indent).with_id(PREFIX_ENDWHILE_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("EndWhile");
 
                self.kv(indent2).with_s_key("StartWhile").with_disp_val(&stmt.start_while.0.index);
 
@@ -689,205 +672,197 @@ impl ASTWriter {
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            },
 
            Expression::Literal(expr) => {
 
                self.kv(indent).with_id(PREFIX_LITERAL_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("LiteralExpr");
 

	
 
                self.kv(indent2).with_s_key("UniqueId").with_disp_val(&expr.unique_id_in_definition);
 
                let val = self.kv(indent2).with_s_key("Value");
 
                match &expr.value {
 
                    Literal::Null => { val.with_s_val("null"); },
 
                    Literal::True => { val.with_s_val("true"); },
 
                    Literal::False => { val.with_s_val("false"); },
 
                    Literal::Character(data) => { val.with_disp_val(data); },
 
                    Literal::String(data) => {
 
                        // Stupid hack
 
                        let string = String::from(data.as_str());
 
                        val.with_disp_val(&string);
 
                    },
 
                    Literal::Integer(data) => { val.with_debug_val(data); },
 
                    Literal::Struct(data) => {
 
                        val.with_s_val("Struct");
 
                        let indent4 = indent3 + 1;
 

	
 
                        self.kv(indent3).with_s_key("ParserType")
 
                            .with_custom_val(|t| write_parser_type(t, heap, &data.parser_type));
 
                        self.kv(indent3).with_s_key("Definition").with_disp_val(&data.definition.index);
 

	
 
                        for field in &data.fields {
 
                            self.kv(indent3).with_s_key("Field");
 
                            self.kv(indent4).with_s_key("Name").with_identifier_val(&field.identifier);
 
                            self.kv(indent4).with_s_key("Index").with_disp_val(&field.field_idx);
 
                            self.kv(indent4).with_s_key("ParserType");
 
                            self.write_expr(heap, field.value, indent4 + 1);
 
                        }
 
                    },
 
                    Literal::Enum(data) => {
 
                        val.with_s_val("Enum");
 

	
 
                        self.kv(indent3).with_s_key("ParserType")
 
                            .with_custom_val(|t| write_parser_type(t, heap, &data.parser_type));
 
                        self.kv(indent3).with_s_key("Definition").with_disp_val(&data.definition.index);
 
                        self.kv(indent3).with_s_key("VariantIdx").with_disp_val(&data.variant_idx);
 
                    },
 
                    Literal::Union(data) => {
 
                        val.with_s_val("Union");
 
                        let indent4 = indent3 + 1;
 

	
 
                        self.kv(indent3).with_s_key("ParserType")
 
                            .with_custom_val(|t| write_parser_type(t, heap, &data.parser_type));
 
                        self.kv(indent3).with_s_key("Definition").with_disp_val(&data.definition.index);
 
                        self.kv(indent3).with_s_key("VariantIdx").with_disp_val(&data.variant_idx);
 

	
 
                        for value in &data.values {
 
                            self.kv(indent3).with_s_key("Value");
 
                            self.write_expr(heap, *value, indent4);
 
                        }
 
                    },
 
                    Literal::Array(data) => {
 
                        val.with_s_val("Array");
 
                        let indent4 = indent3 + 1;
 

	
 
                        self.kv(indent3).with_s_key("Elements");
 
                        for expr_id in data {
 
                            self.write_expr(heap, *expr_id, indent4);
 
                        }
 
                    },
 
                    Literal::Tuple(data) => {
 
                        val.with_s_val("Tuple");
 
                        let indent4 = indent3 + 1;
 
                        self.kv(indent3).with_s_key("Elements");
 
                        for expr_id in data {
 
                            self.write_expr(heap, *expr_id, indent4);
 
                        }
 
                    }
 
                }
 

	
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            },
 
            Expression::Cast(expr) => {
 
                self.kv(indent).with_id(PREFIX_CAST_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("CallExpr");
 
                self.kv(indent2).with_s_key("UniqueId").with_disp_val(&expr.unique_id_in_definition);
 
                self.kv(indent2).with_s_key("ToType")
 
                    .with_custom_val(|t| write_parser_type(t, heap, &expr.to_type));
 
                self.kv(indent2).with_s_key("Subject");
 
                self.write_expr(heap, expr.subject, indent3);
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            }
 
            Expression::Call(expr) => {
 
                self.kv(indent).with_id(PREFIX_CALL_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("CallExpr");
 

	
 
                self.kv(indent2).with_s_key("UniqueId").with_disp_val(&expr.unique_id_in_definition);
 
                let definition = &heap[expr.definition];
 
                match definition {
 
                    Definition::Component(definition) => {
 

	
 
                let definition = &heap[expr.procedure];
 
                self.kv(indent2).with_s_key("BuiltIn").with_disp_val(&false);
 
                        self.kv(indent2).with_s_key("Variant").with_debug_val(&definition.variant);
 
                    },
 
                    Definition::Function(definition) => {
 
                        self.kv(indent2).with_s_key("BuiltIn").with_disp_val(&definition.builtin);
 
                        self.kv(indent2).with_s_key("Variant").with_s_val("Function");
 
                    },
 
                    _ => unreachable!()
 
                }
 
                self.kv(indent2).with_s_key("MethodName").with_identifier_val(definition.identifier());
 
                self.kv(indent2).with_s_key("Variant").with_debug_val(&definition.kind);
 
                self.kv(indent2).with_s_key("MethodName").with_identifier_val(&definition.identifier);
 
                self.kv(indent2).with_s_key("ParserType")
 
                    .with_custom_val(|t| write_parser_type(t, heap, &expr.parser_type));
 

	
 
                // Arguments
 
                self.kv(indent2).with_s_key("Arguments");
 
                for arg_id in &expr.arguments {
 
                    self.write_expr(heap, *arg_id, indent3);
 
                }
 

	
 
                // Parent
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            },
 
            Expression::Variable(expr) => {
 
                self.kv(indent).with_id(PREFIX_VARIABLE_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("VariableExpr");
 
                self.kv(indent2).with_s_key("UniqueId").with_disp_val(&expr.unique_id_in_definition);
 
                self.kv(indent2).with_s_key("Name").with_identifier_val(&expr.identifier);
 
                self.kv(indent2).with_s_key("Definition")
 
                    .with_opt_disp_val(expr.declaration.as_ref().map(|v| &v.index));
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            }
 
        }
 
    }
 

	
 
    fn write_variable(&mut self, heap: &Heap, variable_id: VariableId, indent: usize) {
 
        let var = &heap[variable_id];
 
        let indent2 = indent + 1;
 

	
 
        self.kv(indent).with_id(PREFIX_VARIABLE_ID, variable_id.index)
 
            .with_s_key("Variable");
 

	
 
        self.kv(indent2).with_s_key("Name").with_identifier_val(&var.identifier);
 
        self.kv(indent2).with_s_key("Kind").with_debug_val(&var.kind);
 
        self.kv(indent2).with_s_key("ParserType")
 
            .with_custom_val(|w| write_parser_type(w, heap, &var.parser_type));
 
        self.kv(indent2).with_s_key("RelativePos").with_disp_val(&var.relative_pos_in_parent);
 
        self.kv(indent2).with_s_key("UniqueScopeID").with_disp_val(&var.unique_id_in_scope);
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // Printing Utilities
 
    //--------------------------------------------------------------------------
 

	
 
    fn kv(&mut self, indent: usize) -> KV {
 
        KV::new(&mut self.buffer, &mut self.temp1, &mut self.temp2, indent)
 
    }
 

	
 
    fn flush<W: IOWrite>(&mut self, w: &mut W) {
 
        w.write(self.buffer.as_bytes()).unwrap();
 
        self.buffer.clear()
 
    }
 
}
 

	
 
fn write_option<V: Display>(target: &mut String, value: Option<V>) {
 
    target.clear();
 
    match &value {
 
        Some(v) => target.push_str(&format!("Some({})", v)),
 
        None => target.push_str("None")
 
    };
 
}
 

	
 
fn write_parser_type(target: &mut String, heap: &Heap, t: &ParserType) {
 
    use ParserTypeVariant as PTV;
 

	
 
    fn write_element(target: &mut String, heap: &Heap, t: &ParserType, mut element_idx: usize) -> usize {
 
        let element = &t.elements[element_idx];
 
        match &element.variant {
 
            PTV::Void => target.push_str("void"),
 
            PTV::InputOrOutput => {
 
                target.push_str("portlike<");
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push('>');
 
            },
 
            PTV::ArrayLike => {
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push_str("[???]");
 
            },
 
            PTV::IntegerLike => target.push_str("integerlike"),
 
            PTV::Message => { target.push_str(KW_TYPE_MESSAGE_STR); },
 
            PTV::Bool => { target.push_str(KW_TYPE_BOOL_STR); },
 
            PTV::UInt8 => { target.push_str(KW_TYPE_UINT8_STR); },
 
            PTV::UInt16 => { target.push_str(KW_TYPE_UINT16_STR); },
 
            PTV::UInt32 => { target.push_str(KW_TYPE_UINT32_STR); },
 
            PTV::UInt64 => { target.push_str(KW_TYPE_UINT64_STR); },
 
            PTV::SInt8 => { target.push_str(KW_TYPE_SINT8_STR); },
 
            PTV::SInt16 => { target.push_str(KW_TYPE_SINT16_STR); },
 
            PTV::SInt32 => { target.push_str(KW_TYPE_SINT32_STR); },
 
            PTV::SInt64 => { target.push_str(KW_TYPE_SINT64_STR); },
 
            PTV::Character => { target.push_str(KW_TYPE_CHAR_STR); },
 
            PTV::String => { target.push_str(KW_TYPE_STRING_STR); },
 
            PTV::IntegerLiteral => { target.push_str("int_literal"); },
 
            PTV::Inferred => { target.push_str(KW_TYPE_INFERRED_STR); },
 
            PTV::Array => {
 
                element_idx = write_element(target, heap, t, element_idx + 1);
src/protocol/eval/error.rs
Show inline comments
 
use std::fmt;
 

	
 
use crate::protocol::{
 
    ast::*,
 
    Module,
 
    input_source::{ErrorStatement, StatementKind}
 
};
 
use super::executor::*;
 

	
 
/// Represents a stack frame recorded in an error
 
#[derive(Debug)]
 
pub struct EvalFrame {
 
    pub line: u32,
 
    pub module_name: String,
 
    pub procedure: String, // function or component
 
    pub is_func: bool,
 
}
 

	
 
impl fmt::Display for EvalFrame {
 
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 
        let func_or_comp = if self.is_func {
 
            "function "
 
        } else {
 
            "component"
 
        };
 

	
 
        if self.module_name.is_empty() {
 
            write!(f, "{} {}:{}", func_or_comp, &self.procedure, self.line)
 
        } else {
 
            write!(f, "{} {}:{}:{}", func_or_comp, &self.module_name, &self.procedure, self.line)
 
        }
 
    }
 
}
 

	
 
/// Represents an error that ocurred during evaluation. Contains error
 
/// statements just like in parsing errors. Additionally may display the current
 
/// execution state.
 
#[derive(Debug)]
 
pub struct EvalError {
 
    pub(crate) statements: Vec<ErrorStatement>,
 
    pub(crate) frames: Vec<EvalFrame>,
 
}
 

	
 
impl EvalError {
 
    pub(crate) fn new_error_at_expr(prompt: &Prompt, modules: &[Module], heap: &Heap, expr_id: ExpressionId, msg: String) -> EvalError {
 
        // Create frames
 
        debug_assert!(!prompt.frames.is_empty());
 
        let mut frames = Vec::with_capacity(prompt.frames.len());
 
        let mut last_module_source = &modules[0].source;
 
        for frame in prompt.frames.iter() {
 
            let definition = &heap[frame.definition];
 
            let statement = &heap[frame.position];
 
            let statement_span = statement.span();
 

	
 
            let (root_id, procedure, is_func) = match definition {
 
                Definition::Function(def) => {
 
                    (def.defined_in, def.identifier.value.as_str().to_string(), true)
 
                },
 
                Definition::Component(def) => {
 
                    (def.defined_in, def.identifier.value.as_str().to_string(), false)
 
                },
 
                _ => unreachable!("construct stack frame with definition pointing to data type")
 
            };
 

	
 
            // Lookup module name, if it has one
 
            let module = modules.iter().find(|m| m.root_id == root_id).unwrap();
 
            let module = modules.iter().find(|m| m.root_id == definition.defined_in).unwrap();
 
            let module_name = if let Some(name) = &module.name {
 
                name.as_str().to_string()
 
            } else {
 
                String::new()
 
            };
 

	
 
            last_module_source = &module.source;
 
            frames.push(EvalFrame{
 
                line: statement_span.begin.line,
 
                module_name,
 
                procedure,
 
                is_func
 
                procedure: definition.identifier.value.as_str().to_string(),
 
                is_func: definition.kind == ProcedureKind::Function,
 
            });
 
        }
 

	
 
        let expr = &heap[expr_id];
 
        let statements = vec![
 
            ErrorStatement::from_source_at_span(StatementKind::Error, last_module_source, expr.full_span(), msg)
 
        ];
 

	
 
        EvalError{ statements, frames }
 
    }
 
}
 

	
 
impl fmt::Display for EvalError {
 
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 
        // Display error statement(s)
 
        self.statements[0].fmt(f)?;
 
        for statement in self.statements.iter().skip(1) {
 
            writeln!(f)?;
 
            statement.fmt(f)?;
 
        }
 

	
 
        // Display stack trace
 
        writeln!(f)?;
 
        writeln!(f, " +-  Stack trace:")?;
 
        for frame in self.frames.iter().rev() {
 
            write!(f, " | ")?;
 
            frame.fmt(f)?;
 
            writeln!(f)?;
 
        }
 

	
 
        Ok(())
 
    }
 
}
 
\ No newline at end of file
src/protocol/eval/executor.rs
Show inline comments
 

	
 
use std::collections::VecDeque;
 

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

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

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

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

	
 
impl Frame {
 
    /// Creates a new execution frame. Does not modify the stack in any way.
 
    pub fn new(heap: &Heap, definition_id: DefinitionId, monomorph_type_id: TypeId) -> Self {
 
    pub fn new(heap: &Heap, definition_id: ProcedureDefinitionId, monomorph_type_id: TypeId) -> Self {
 
        let definition = &heap[definition_id];
 
        let (outer_scope_id, first_statement_id) = match definition {
 
            Definition::Component(definition) => (definition.scope, definition.body),
 
            Definition::Function(definition) => (definition.scope, definition.body),
 
            _ => unreachable!("initializing frame with {:?} instead of a function/component", definition),
 
        };
 
        let outer_scope_id = definition.scope;
 
        let first_statement_id = definition.body;
 

	
 
        // Another not-so-pretty thing that has to be replaced somewhere in the
 
        // future...
 
        fn determine_max_stack_size(heap: &Heap, 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,
 
            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(DefinitionId, TypeId, ValueGroup),
 
    NewComponent(ProcedureDefinitionId, TypeId, ValueGroup),
 
    NewChannel,
 
}
 

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

	
 
impl Prompt {
 
    pub fn new(_types: &TypeTable, heap: &Heap, def: DefinitionId, 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 max_stack_size = new_frame.max_stack_size;
 
        prompt.frames.push(new_frame);
 
        args.into_store(&mut prompt.store);
 
        prompt.store.reserve_stack(max_stack_size);
 

	
 
        prompt
 
    }
 

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

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

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

	
 
            heap_pos
 
        }
 

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

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

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

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

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

	
 
        // 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)))
 
@@ -652,227 +649,227 @@ impl Prompt {
 
                                    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.definition].parameters().len(), cur_frame.expr_values.len());
 
                                    debug_assert_eq!(heap[expr.procedure].parameters.len(), cur_frame.expr_values.len());
 
                                    debug_assert_eq!(heap[cur_frame.position].as_new().expression, expr.this)
 
                                },
 
                                Method::UserFunction => {
 
                                Method::UserProcedure => {
 
                                    // Push a new frame. Note that all expressions have
 
                                    // been pushed to the front, so they're in the order
 
                                    // of the definition.
 
                                    let num_args = expr.arguments.len();
 

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

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

	
 
                                    // Determine the monomorph index of the function we're calling
 
                                    let mono_data = types.get_procedure_monomorph(cur_frame.monomorph_type_id);
 
                                    let call_data = &mono_data.expr_data[expr.unique_id_in_definition as usize];
 

	
 
                                    // Push the new frame and reserve its stack size
 
                                    let new_frame = Frame::new(heap, expr.definition, call_data.type_id);
 
                                    let new_frame = Frame::new(heap, expr.procedure, call_data.type_id);
 
                                    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;
 
@@ -884,250 +881,248 @@ impl Prompt {
 
                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!(heap[cur_frame.definition].is_function());
 
                debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for return statement");
 

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

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

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

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

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

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

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

	
 
                let mono_data = types.get_procedure_monomorph(cur_frame.monomorph_type_id);
 
                let expr_data = &mono_data.expr_data[call_expr.unique_id_in_definition as usize];
 

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

	
 
                // Construct argument group, thereby copying heap regions
 
                let argument_group = ValueGroup::from_store(&self.store, &args);
 
                // println!("Creating {} with\n{:#?}", heap[call_expr.definition].identifier().value.as_str(), argument_group);
 

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

	
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::NewComponent(call_expr.definition, expr_data.type_id, argument_group))
 
                Ok(EvalContinuation::NewComponent(call_expr.procedure, expr_data.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_component() {
 
        if !ast_definition.is_procedure() {
 
            return Err(ComponentCreationError::DefinitionNotComponent);
 
        }
 

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

	
 
        // - check number of arguments by retrieving the one instantiated
 
        //   monomorph
 
        let concrete_type = ConcreteType{ parts: vec![ConcreteTypePart::Component(definition_id, 0)] };
 
        let 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() {
 
            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 provided_value = &arguments.values[arg_idx];
 
            if !self.verify_same_type(expected_type, 0, &arguments, provided_value) {
 
                return Err(ComponentCreationError::InvalidArgumentType(arg_idx));
 
            }
 
        }
 

	
 
        // By now we're sure that all of the arguments are correct. So create
 
        // the connector.
 
        return Ok(Prompt::new(&self.types, &self.heap, definition_id, mono_index, arguments));
 
        return Ok(Prompt::new(&self.types, &self.heap, ast_definition.this, mono_index, 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{
src/protocol/parser/mod.rs
Show inline comments
 
@@ -231,184 +231,185 @@ impl Parser {
 
        ));
 

	
 
        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);
 
        };
 
        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);
 
            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);
 
}
 

	
 
// Note: args and return type need to be a function because we need to know the function ID.
 
fn insert_builtin_function<T: Fn(FunctionDefinitionId) -> (Vec<(&'static str, ParserType)>, ParserType)> (
 
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());
 
    for poly_var in polymorphic {
 
        poly_vars.push(Identifier{ span: InputSpan::new(), value: p.string_pool.intern(poly_var.as_bytes()) });
 
    }
 

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

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

	
 
    p.symbol_table.insert_symbol(SymbolScope::Global, Symbol{
 
        name: func_ident_ref,
 
        variant: SymbolVariant::Definition(SymbolDefinition{
 
            defined_in_module: RootId::new_invalid(),
 
            defined_in_scope: SymbolScope::Global,
 
            definition_span: InputSpan::new(),
 
            identifier_span: InputSpan::new(),
 
            imported_at: None,
 
            class: DefinitionClass::Function,
 
            definition_id: func_id.upcast(),
 
            definition_id: procedure_id.upcast(),
 
        })
 
    }).unwrap();
 
}
 
\ No newline at end of file
src/protocol/parser/pass_definitions.rs
Show inline comments
 
@@ -191,230 +191,231 @@ impl PassDefinitions {
 
        Ok(())
 
    }
 

	
 
    fn visit_union_definition(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<(), ParseError> {
 
        consume_exact_ident(&module.source, iter, KW_UNION)?;
 
        let (ident_text, _) = consume_ident(&module.source, iter)?;
 

	
 
        // Retrieve preallocated DefinitionId
 
        let module_scope = SymbolScope::Module(module.root_id);
 
        let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text)
 
            .unwrap().variant.as_definition().definition_id;
 
        self.cur_definition = definition_id;
 

	
 
        // Parse union definition
 
        consume_polymorphic_vars_spilled(&module.source, iter, ctx)?;
 

	
 
        let mut variants_section = self.union_variants.start_section();
 
        consume_comma_separated(
 
            TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
 
            |source, iter, ctx| {
 
                let identifier = consume_ident_interned(source, iter, ctx)?;
 
                let mut close_pos = identifier.span.end;
 

	
 
                let mut types_section = self.parser_types.start_section();
 

	
 
                let has_embedded = maybe_consume_comma_separated(
 
                    TokenKind::OpenParen, TokenKind::CloseParen, source, iter, ctx,
 
                    |source, iter, ctx| {
 
                        let poly_vars = ctx.heap[definition_id].poly_vars();
 
                        self.type_parser.consume_parser_type(
 
                            iter, &ctx.heap, source, &ctx.symbols, poly_vars, definition_id,
 
                            module_scope, false, None
 
                        )
 
                    },
 
                    &mut types_section, "an embedded type", Some(&mut close_pos)
 
                )?;
 
                let value = if has_embedded {
 
                    types_section.into_vec()
 
                } else {
 
                    types_section.forget();
 
                    Vec::new()
 
                };
 

	
 
                Ok(UnionVariantDefinition{
 
                    span: InputSpan::from_positions(identifier.span.begin, close_pos),
 
                    identifier,
 
                    value
 
                })
 
            },
 
            &mut variants_section, "a union variant", "a list of union variants", None
 
        )?;
 

	
 
        // Transfer to AST
 
        let union_def = ctx.heap[definition_id].as_union_mut();
 
        union_def.variants = variants_section.into_vec();
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_function_definition(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<(), ParseError> {
 
        // Retrieve function name
 
        consume_exact_ident(&module.source, iter, KW_FUNCTION)?;
 
        let (ident_text, _) = consume_ident(&module.source, iter)?;
 

	
 
        // Retrieve preallocated DefinitionId
 
        let module_scope = SymbolScope::Module(module.root_id);
 
        let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text)
 
            .unwrap().variant.as_definition().definition_id;
 
        self.cur_definition = definition_id;
 

	
 
        consume_polymorphic_vars_spilled(&module.source, iter, ctx)?;
 

	
 
        // Parse function's argument list
 
        let mut parameter_section = self.variables.start_section();
 
        consume_parameter_list(
 
            &mut self.type_parser, &module.source, iter, ctx, &mut parameter_section, module_scope, definition_id
 
        )?;
 
        let parameters = parameter_section.into_vec();
 

	
 
        // Consume return types
 
        consume_token(&module.source, iter, TokenKind::ArrowRight)?;
 
        let poly_vars = ctx.heap[definition_id].poly_vars();
 
        let parser_type = self.type_parser.consume_parser_type(
 
            iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars, definition_id,
 
            module_scope, false, None
 
        )?;
 

	
 
        // Consume block and the definition's scope
 
        let body_id = self.consume_block_statement(module, iter, ctx)?;
 
        let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Definition(definition_id)));
 

	
 
        // Assign everything in the preallocated AST node
 
        let function = ctx.heap[definition_id].as_function_mut();
 
        function.return_type = parser_type;
 
        let function = ctx.heap[definition_id].as_procedure_mut();
 
        function.return_type = Some(parser_type);
 
        function.parameters = parameters;
 
        function.scope = scope_id;
 
        function.body = body_id;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_component_definition(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<(), ParseError> {
 
        // Consume component variant and name
 
        let (_variant_text, _) = consume_any_ident(&module.source, iter)?;
 
        debug_assert!(_variant_text == KW_PRIMITIVE || _variant_text == KW_COMPOSITE);
 
        let (ident_text, _) = consume_ident(&module.source, iter)?;
 

	
 
        // Retrieve preallocated definition
 
        let module_scope = SymbolScope::Module(module.root_id);
 
        let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text)
 
            .unwrap().variant.as_definition().definition_id;
 
        self.cur_definition = definition_id;
 

	
 
        consume_polymorphic_vars_spilled(&module.source, iter, ctx)?;
 

	
 
        // Parse component's argument list
 
        let mut parameter_section = self.variables.start_section();
 
        consume_parameter_list(
 
            &mut self.type_parser, &module.source, iter, ctx, &mut parameter_section, module_scope, definition_id
 
        )?;
 
        let parameters = parameter_section.into_vec();
 

	
 
        // Consume block
 
        let body_id = self.consume_block_statement(module, iter, ctx)?;
 
        let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Definition(definition_id)));
 

	
 
        // Assign everything in the AST node
 
        let component = ctx.heap[definition_id].as_component_mut();
 
        let component = ctx.heap[definition_id].as_procedure_mut();
 
        debug_assert!(component.return_type.is_none());
 
        component.parameters = parameters;
 
        component.scope = scope_id;
 
        component.body = body_id;
 

	
 
        Ok(())
 
    }
 

	
 
    /// Consumes a statement and returns a boolean indicating whether it was a
 
    /// block or not.
 
    fn consume_statement(&mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx) -> Result<StatementId, ParseError> {
 
        let next = iter.next().expect("consume_statement has a next token");
 

	
 
        if next == TokenKind::OpenCurly {
 
            let id = self.consume_block_statement(module, iter, ctx)?;
 
            return Ok(id.upcast());
 
        } else if next == TokenKind::Ident {
 
            let ident = peek_ident(&module.source, iter).unwrap();
 
            if ident == KW_STMT_IF {
 
                // Consume if statement and place end-if statement directly
 
                // after it.
 
                let id = self.consume_if_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_WHILE {
 
                let id = self.consume_while_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_BREAK {
 
                let id = self.consume_break_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_CONTINUE {
 
                let id = self.consume_continue_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_SYNC {
 
                let id = self.consume_synchronous_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_FORK {
 
                let id = self.consume_fork_statement(module, iter, ctx)?;
 

	
 
                let end_fork = ctx.heap.alloc_end_fork_statement(|this| EndForkStatement {
 
                    this,
 
                    start_fork: id,
 
                    next: StatementId::new_invalid(),
 
                });
 

	
 
                let fork_stmt = &mut ctx.heap[id];
 
                fork_stmt.end_fork = end_fork;
 

	
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_SELECT {
 
                let id = self.consume_select_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_RETURN {
 
                let id = self.consume_return_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_GOTO {
 
                let id = self.consume_goto_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_NEW {
 
                let id = self.consume_new_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_CHANNEL {
 
                let id = self.consume_channel_statement(module, iter, ctx)?;
 
                return Ok(id.upcast().upcast());
 
            } else if iter.peek() == Some(TokenKind::Colon) {
 
                let id = self.consume_labeled_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else {
 
                // Two fallback possibilities: the first one is a memory
 
                // declaration, the other one is to parse it as a normal
 
                // expression. This is a bit ugly.
 
                if let Some(memory_stmt_id) = self.maybe_consume_memory_statement_without_semicolon(module, iter, ctx)? {
 
                    consume_token(&module.source, iter, TokenKind::SemiColon)?;
 
                    return Ok(memory_stmt_id.upcast().upcast());
 
                } else {
 
                    let id = self.consume_expression_statement(module, iter, ctx)?;
 
                    return Ok(id.upcast());
 
                }
 
            }
 
        } else if next == TokenKind::OpenParen {
 
            // Same as above: memory statement or normal expression
 
            if let Some(memory_stmt_id) = self.maybe_consume_memory_statement_without_semicolon(module, iter, ctx)? {
 
                consume_token(&module.source, iter, TokenKind::SemiColon)?;
 
                return Ok(memory_stmt_id.upcast().upcast());
 
            } else {
 
                let id = self.consume_expression_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            }
 
        } else {
 
            let id = self.consume_expression_statement(module, iter, ctx)?;
 
            return Ok(id.upcast());
 
        }
 
    }
 

	
 
    fn consume_block_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<BlockStatementId, ParseError> {
 
        let open_curly_span = consume_token(&module.source, iter, TokenKind::OpenCurly)?;
 
@@ -665,193 +666,193 @@ impl PassDefinitions {
 
            let block = self.consume_statement(module, iter, ctx)?;
 
            cases.push(SelectCase{
 
                guard,
 
                body: block,
 
                scope: ScopeId::new_invalid(),
 
                involved_ports: Vec::with_capacity(1)
 
            });
 

	
 
            next = iter.next();
 
        }
 

	
 
        consume_token(&module.source, iter, TokenKind::CloseCurly)?;
 

	
 
        let num_cases = cases.len();
 
        let select_stmt_id = ctx.heap.alloc_select_statement(|this| SelectStatement{
 
            this,
 
            span: select_span,
 
            cases,
 
            end_select: EndSelectStatementId::new_invalid(),
 
            relative_pos_in_parent: -1,
 
            next: StatementId::new_invalid(),
 
        });
 

	
 
        let end_select_stmt_id = ctx.heap.alloc_end_select_statement(|this| EndSelectStatement{
 
            this,
 
            start_select: select_stmt_id,
 
            next: StatementId::new_invalid(),
 
        });
 

	
 
        let select_stmt = &mut ctx.heap[select_stmt_id];
 
        select_stmt.end_select = end_select_stmt_id;
 

	
 
        for case_index in 0..num_cases {
 
            let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::SelectCase(select_stmt_id, case_index as u32)));
 
            let select_stmt = &mut ctx.heap[select_stmt_id];
 
            let select_case = &mut select_stmt.cases[case_index];
 
            select_case.scope = scope_id;
 
        }
 

	
 
        return Ok(select_stmt_id)
 
    }
 

	
 
    fn consume_return_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ReturnStatementId, ParseError> {
 
        let return_span = consume_exact_ident(&module.source, iter, KW_STMT_RETURN)?;
 
        let mut scoped_section = self.expressions.start_section();
 

	
 
        consume_comma_separated_until(
 
            TokenKind::SemiColon, &module.source, iter, ctx,
 
            |_source, iter, ctx| self.consume_expression(module, iter, ctx),
 
            &mut scoped_section, "an expression", None
 
        )?;
 
        let expressions = scoped_section.into_vec();
 

	
 
        if expressions.is_empty() {
 
            return Err(ParseError::new_error_str_at_span(&module.source, return_span, "expected at least one return value"));
 
        } else if expressions.len() > 1 {
 
            return Err(ParseError::new_error_str_at_span(&module.source, return_span, "multiple return values are not (yet) supported"))
 
        }
 

	
 
        Ok(ctx.heap.alloc_return_statement(|this| ReturnStatement{
 
            this,
 
            span: return_span,
 
            expressions
 
        }))
 
    }
 

	
 
    fn consume_goto_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<GotoStatementId, ParseError> {
 
        let goto_span = consume_exact_ident(&module.source, iter, KW_STMT_GOTO)?;
 
        let label = consume_ident_interned(&module.source, iter, ctx)?;
 
        consume_token(&module.source, iter, TokenKind::SemiColon)?;
 
        Ok(ctx.heap.alloc_goto_statement(|this| GotoStatement{
 
            this,
 
            span: goto_span,
 
            label,
 
            target: LabeledStatementId::new_invalid(),
 
        }))
 
    }
 

	
 
    fn consume_new_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<NewStatementId, ParseError> {
 
        let new_span = consume_exact_ident(&module.source, iter, KW_STMT_NEW)?;
 

	
 
        let start_pos = iter.last_valid_pos();
 
        let expression_id = self.consume_primary_expression(module, iter, ctx)?;
 
        let expression = &ctx.heap[expression_id];
 
        let mut valid = false;
 

	
 
        let mut call_id = CallExpressionId::new_invalid();
 
        if let Expression::Call(expression) = expression {
 
            // Allow both components and functions, as it makes more sense to
 
            // check their correct use in the validation and linking pass
 
            if expression.method == Method::UserComponent || expression.method == Method::UserFunction {
 
            if expression.method == Method::UserComponent || expression.method == Method::UserProcedure {
 
                call_id = expression.this;
 
                valid = true;
 
            }
 
        }
 

	
 
        if !valid {
 
            return Err(ParseError::new_error_str_at_span(
 
                &module.source, InputSpan::from_positions(start_pos, iter.last_valid_pos()), "expected a call expression"
 
            ));
 
        }
 
        consume_token(&module.source, iter, TokenKind::SemiColon)?;
 

	
 
        debug_assert!(!call_id.is_invalid());
 
        Ok(ctx.heap.alloc_new_statement(|this| NewStatement{
 
            this,
 
            span: new_span,
 
            expression: call_id,
 
            next: StatementId::new_invalid(),
 
        }))
 
    }
 

	
 
    fn consume_channel_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ChannelStatementId, ParseError> {
 
        // Consume channel specification
 
        let channel_span = consume_exact_ident(&module.source, iter, KW_STMT_CHANNEL)?;
 
        let (inner_port_type, end_pos) = if Some(TokenKind::OpenAngle) == iter.next() {
 
            // Retrieve the type of the channel, we're cheating a bit here by
 
            // consuming the first '<' and setting the initial angle depth to 1
 
            // such that our final '>' will be consumed as well.
 
            let angle_start_pos = iter.next_start_position();
 
            iter.consume();
 
            let definition_id = self.cur_definition;
 
            let poly_vars = ctx.heap[definition_id].poly_vars();
 
            let parser_type = self.type_parser.consume_parser_type(
 
                iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars,
 
                definition_id, SymbolScope::Module(module.root_id),
 
                true, Some(angle_start_pos)
 
            )?;
 

	
 
            (parser_type.elements, parser_type.full_span.end)
 
        } else {
 
            // Assume inferred
 
            (
 
                vec![ParserTypeElement{
 
                    element_span: channel_span,
 
                    variant: ParserTypeVariant::Inferred
 
                }],
 
                channel_span.end
 
            )
 
        };
 

	
 
        let from_identifier = consume_ident_interned(&module.source, iter, ctx)?;
 
        consume_token(&module.source, iter, TokenKind::ArrowRight)?;
 
        let to_identifier = consume_ident_interned(&module.source, iter, ctx)?;
 
        consume_token(&module.source, iter, TokenKind::SemiColon)?;
 

	
 
        // Construct ports
 
        let port_type_span = InputSpan::from_positions(channel_span.begin, end_pos);
 
        let port_type_len = inner_port_type.len() + 1;
 
        let mut from_port_type = ParserType{ elements: Vec::with_capacity(port_type_len), full_span: port_type_span };
 
        from_port_type.elements.push(ParserTypeElement{
 
            element_span: channel_span,
 
            variant: ParserTypeVariant::Output,
 
        });
 
        from_port_type.elements.extend_from_slice(&inner_port_type);
 
        let from = ctx.heap.alloc_variable(|this| Variable{
 
            this,
 
            kind: VariableKind::Local,
 
            identifier: from_identifier,
 
            parser_type: from_port_type,
 
            relative_pos_in_parent: 0,
 
            unique_id_in_scope: -1,
 
        });
 

	
 
        let mut to_port_type = ParserType{ elements: Vec::with_capacity(port_type_len), full_span: port_type_span };
 
        to_port_type.elements.push(ParserTypeElement{
 
            element_span: channel_span,
 
            variant: ParserTypeVariant::Input
 
        });
 
        to_port_type.elements.extend_from_slice(&inner_port_type);
 
        let to = ctx.heap.alloc_variable(|this|Variable{
 
            this,
 
            kind: VariableKind::Local,
 
            identifier: to_identifier,
 
            parser_type: to_port_type,
 
            relative_pos_in_parent: 0,
 
            unique_id_in_scope: -1,
 
        });
 

	
 
        // Construct the channel
 
        Ok(ctx.heap.alloc_channel_statement(|this| ChannelStatement{
 
            this,
 
            span: channel_span,
 
            from, to,
 
            relative_pos_in_parent: 0,
 
@@ -1483,237 +1484,222 @@ impl PassDefinitions {
 
        } else if next == Some(TokenKind::Ident) {
 
            // May be a variable, a type instantiation or a function call. If we
 
            // have a single identifier that we cannot find in the type table
 
            // then we're going to assume that we're dealing with a variable.
 

	
 
            let ident_span = iter.next_span();
 
            let ident_text = module.source.section_at_span(ident_span);
 
            let symbol = ctx.symbols.get_symbol_by_name(SymbolScope::Module(module.root_id), ident_text);
 

	
 
            if symbol.is_some() {
 
                // The first bit looked like a symbol, so we're going to follow
 
                // that all the way through, assume we arrive at some kind of
 
                // function call or type instantiation
 
                use ParserTypeVariant as PTV;
 

	
 
                let symbol_scope = SymbolScope::Definition(self.cur_definition);
 
                let poly_vars = ctx.heap[self.cur_definition].poly_vars();
 
                let parser_type = self.type_parser.consume_parser_type(
 
                    iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars, self.cur_definition,
 
                    symbol_scope, true, None
 
                )?;
 
                debug_assert!(!parser_type.elements.is_empty());
 
                match parser_type.elements[0].variant {
 
                    PTV::Definition(target_definition_id, _) => {
 
                        let definition = &ctx.heap[target_definition_id];
 
                        match definition {
 
                            Definition::Struct(_) => {
 
                                // Struct literal
 
                                let mut last_token = iter.last_valid_pos();
 
                                let mut struct_fields = Vec::new();
 
                                consume_comma_separated(
 
                                    TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
 
                                    |source, iter, ctx| {
 
                                        let identifier = consume_ident_interned(source, iter, ctx)?;
 
                                        consume_token(source, iter, TokenKind::Colon)?;
 
                                        let value = self.consume_expression(module, iter, ctx)?;
 
                                        Ok(LiteralStructField{ identifier, value, field_idx: 0 })
 
                                    },
 
                                    &mut struct_fields, "a struct field", "a list of struct fields", Some(&mut last_token)
 
                                )?;
 

	
 
                                ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                                    this,
 
                                    span: InputSpan::from_positions(ident_span.begin, last_token),
 
                                    value: Literal::Struct(LiteralStruct{
 
                                        parser_type,
 
                                        fields: struct_fields,
 
                                        definition: target_definition_id,
 
                                    }),
 
                                    parent: ExpressionParent::None,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            },
 
                            Definition::Enum(_) => {
 
                                // Enum literal: consume the variant
 
                                consume_token(&module.source, iter, TokenKind::ColonColon)?;
 
                                let variant = consume_ident_interned(&module.source, iter, ctx)?;
 

	
 
                                ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                                    this,
 
                                    span: InputSpan::from_positions(ident_span.begin, variant.span.end),
 
                                    value: Literal::Enum(LiteralEnum{
 
                                        parser_type,
 
                                        variant,
 
                                        definition: target_definition_id,
 
                                        variant_idx: 0
 
                                    }),
 
                                    parent: ExpressionParent::None,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            },
 
                            Definition::Union(_) => {
 
                                // Union literal: consume the variant
 
                                consume_token(&module.source, iter, TokenKind::ColonColon)?;
 
                                let variant = consume_ident_interned(&module.source, iter, ctx)?;
 

	
 
                                // Consume any possible embedded values
 
                                let mut end_pos = variant.span.end;
 
                                let values = if Some(TokenKind::OpenParen) == iter.next() {
 
                                    self.consume_expression_list(module, iter, ctx, Some(&mut end_pos))?
 
                                } else {
 
                                    Vec::new()
 
                                };
 

	
 
                                ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                                    this,
 
                                    span: InputSpan::from_positions(ident_span.begin, end_pos),
 
                                    value: Literal::Union(LiteralUnion{
 
                                        parser_type, variant, values,
 
                                        definition: target_definition_id,
 
                                        variant_idx: 0,
 
                                    }),
 
                                    parent: ExpressionParent::None,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            },
 
                            Definition::Component(_) => {
 
                                // Component instantiation
 
                                let func_span = parser_type.full_span;
 
                                let mut full_span = func_span;
 
                                let arguments = self.consume_expression_list(
 
                                    module, iter, ctx, Some(&mut full_span.end)
 
                                )?;
 

	
 
                                ctx.heap.alloc_call_expression(|this| CallExpression{
 
                                    this, func_span, full_span,
 
                                    parser_type,
 
                                    method: Method::UserComponent,
 
                                    arguments,
 
                                    definition: target_definition_id,
 
                                    parent: ExpressionParent::None,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            },
 
                            Definition::Function(function_definition) => {
 
                            Definition::Procedure(proc_def) => {
 
                                // Check whether it is a builtin function
 
                                let method = if function_definition.builtin {
 
                                    match function_definition.identifier.value.as_bytes() {
 
                                let procedure_id = proc_def.this;
 
                                let method = if proc_def.builtin {
 
                                    match proc_def.identifier.value.as_bytes() {
 
                                        KW_FUNC_GET => Method::Get,
 
                                        KW_FUNC_PUT => Method::Put,
 
                                        KW_FUNC_FIRES => Method::Fires,
 
                                        KW_FUNC_CREATE => Method::Create,
 
                                        KW_FUNC_LENGTH => Method::Length,
 
                                        KW_FUNC_ASSERT => Method::Assert,
 
                                        KW_FUNC_PRINT => Method::Print,
 
                                        _ => unreachable!(),
 
                                    }
 
                                } else if proc_def.kind == ProcedureKind::Function {
 
                                    Method::UserProcedure
 
                                } else {
 
                                    Method::UserFunction
 
                                    Method::UserComponent
 
                                };
 

	
 
                                // Function call: consume the arguments
 
                                let func_span = parser_type.full_span;
 
                                let mut full_span = func_span;
 
                                let arguments = self.consume_expression_list(
 
                                    module, iter, ctx, Some(&mut full_span.end)
 
                                )?;
 

	
 
                                ctx.heap.alloc_call_expression(|this| CallExpression{
 
                                    this, func_span, full_span, parser_type, method, arguments,
 
                                    definition: target_definition_id,
 
                                    procedure: procedure_id,
 
                                    parent: ExpressionParent::None,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            }
 
                        }
 
                    },
 
                    _ => {
 
                        return Err(ParseError::new_error_str_at_span(
 
                            &module.source, parser_type.full_span, "unexpected type in expression"
 
                        ))
 
                    }
 
                }
 
            } else {
 
                // Check for builtin keywords or builtin functions
 
                if ident_text == KW_LIT_NULL || ident_text == KW_LIT_TRUE || ident_text == KW_LIT_FALSE {
 
                    iter.consume();
 

	
 
                    // Parse builtin literal
 
                    let value = match ident_text {
 
                        KW_LIT_NULL => Literal::Null,
 
                        KW_LIT_TRUE => Literal::True,
 
                        KW_LIT_FALSE => Literal::False,
 
                        _ => unreachable!(),
 
                    };
 

	
 
                    ctx.heap.alloc_literal_expression(|this| LiteralExpression {
 
                        this,
 
                        span: ident_span,
 
                        value,
 
                        parent: ExpressionParent::None,
 
                        unique_id_in_definition: -1,
 
                    }).upcast()
 
                } else if ident_text == KW_LET {
 
                    // Binding expression
 
                    let operator_span = iter.next_span();
 
                    iter.consume();
 

	
 
                    let bound_to = self.consume_prefix_expression(module, iter, ctx)?;
 
                    consume_token(&module.source, iter, TokenKind::Equal)?;
 
                    let bound_from = self.consume_prefix_expression(module, iter, ctx)?;
 

	
 
                    let full_span = InputSpan::from_positions(
 
                        operator_span.begin, ctx.heap[bound_from].full_span().end,
 
                    );
 

	
 
                    ctx.heap.alloc_binding_expression(|this| BindingExpression{
 
                        this, operator_span, full_span, bound_to, bound_from,
 
                        parent: ExpressionParent::None,
 
                        unique_id_in_definition: -1,
 
                    }).upcast()
 
                } else if ident_text == KW_CAST {
 
                    // Casting expression
 
                    iter.consume();
 
                    let to_type = if Some(TokenKind::OpenAngle) == iter.next() {
 
                        let angle_start_pos = iter.next_start_position();
 
                        iter.consume();
 
                        let definition_id = self.cur_definition;
 
                        let poly_vars = ctx.heap[definition_id].poly_vars();
 
                        self.type_parser.consume_parser_type(
 
                            iter, &ctx.heap, &module.source, &ctx.symbols,
 
                            poly_vars, definition_id, SymbolScope::Module(module.root_id),
 
                            true, Some(angle_start_pos)
 
                        )?
 
                    } else {
 
                        // Automatic casting with inferred target type
 
                        ParserType{
 
                            elements: vec![ParserTypeElement{
 
                                element_span: ident_span,
 
                                variant: ParserTypeVariant::Inferred,
 
                            }],
 
                            full_span: ident_span
 
                        }
 
                    };
 

	
 
                    consume_token(&module.source, iter, TokenKind::OpenParen)?;
 
                    let subject = self.consume_expression(module, iter, ctx)?;
 
                    let mut full_span = iter.next_span();
 
                    full_span.begin = to_type.full_span.begin;
 
                    consume_token(&module.source, iter, TokenKind::CloseParen)?;
 

	
 
                    ctx.heap.alloc_cast_expression(|this| CastExpression{
 
                        this,
 
                        cast_span: to_type.full_span,
 
                        full_span, to_type, subject,
 
                        parent: ExpressionParent::None,
 
                        unique_id_in_definition: -1,
 
                    }).upcast()
 
                } else {
 
                    // Not a builtin literal, but also not a known type. So we
 
                    // assume it is a variable expression. Although if we do,
 
                    // then if a programmer mistyped a struct/function name the
 
                    // error messages will be rather cryptic. For polymorphic
 
                    // arguments we can't really do anything at all (because it
 
                    // uses the '<' token). In the other cases we try to provide
 
                    // a better error message.
 
                    iter.consume();
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_component_definition(&mut self, ctx: &mut Ctx, id: ComponentDefinitionId) -> VisitorResult {
 
        let def = &ctx.heap[id];
 
        let body_id = def.body;
 
        self.current_scope = def.scope;
 
        return self.visit_block_stmt(ctx, body_id);
 
    }
 

	
 
    fn visit_function_definition(&mut self, ctx: &mut Ctx, id: FunctionDefinitionId) -> VisitorResult {
 
        let def = &ctx.heap[id];
 
        let body_id = def.body;
 
        self.current_scope = def.scope;
 
    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];
 
        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,
 
            definition: DefinitionId::new_invalid(),
 
            procedure: ProcedureDefinitionId::new_invalid(),
 
            parent: ExpressionParent::None,
 
            unique_id_in_definition: -1,
 
        });
 
        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,
 
        unique_id_in_definition: -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,
 
        definition: DefinitionId::new_invalid(),
 
        procedure: ProcedureDefinitionId::new_invalid(),
 
        parent: ExpressionParent::None,
 
        unique_id_in_definition: -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,
 
        unique_id_in_definition: -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,
 
        unique_id_in_definition: -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,
 
        unique_id_in_definition: -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;
 
}
 

	
src/protocol/parser/pass_stack_size.rs
Show inline comments
 
use crate::collections::*;
 
use crate::protocol::*;
 

	
 
use super::visitor::*;
 

	
 
// Will get a rename. Will probably become bytecode emitter or something. For
 
// now it just scans the scopes and assigns a unique number for each variable
 
// such that, at any point in the program's execution, all accessible in-scope
 
// variables will have a unique position "on the stack".
 
pub(crate) struct PassStackSize {
 
    definition_buffer: ScopedBuffer<DefinitionId>,
 
    variable_buffer: ScopedBuffer<VariableId>,
 
    scope_buffer: ScopedBuffer<ScopeId>,
 
}
 

	
 
impl PassStackSize {
 
    pub(crate) fn new() -> Self {
 
        return Self{
 
            definition_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            variable_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            scope_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
        }
 
    }
 
}
 

	
 
impl Visitor for PassStackSize {
 
    // Top level visitors
 

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

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

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

	
 
    fn visit_function_definition(&mut self, ctx: &mut Ctx, id: FunctionDefinitionId) -> VisitorResult {
 
    fn visit_procedure_definition(&mut self, ctx: &mut Ctx, id: ProcedureDefinitionId) -> VisitorResult {
 
        let definition = &ctx.heap[id];
 
        let scope_id = definition.scope;
 

	
 
        self.visit_scope_and_assign_local_ids(ctx, scope_id, 0);
 
        return Ok(())
 
    }
 

	
 
    fn visit_component_definition(&mut self, ctx: &mut Ctx, id: ComponentDefinitionId) -> VisitorResult {
 
        let definition = &ctx.heap[id];
 
        let scope_id = definition.scope;
 

	
 
        self.visit_scope_and_assign_local_ids(ctx, scope_id, 0);
 
        return Ok(())
 
        return Ok(());
 
    }
 
}
 

	
 
impl PassStackSize {
 
    fn visit_scope_and_assign_local_ids(&mut self, ctx: &mut Ctx, scope_id: ScopeId, mut variable_counter: i32) {
 
        let scope = &mut ctx.heap[scope_id];
 
        scope.first_unique_id_in_scope = variable_counter;
 

	
 
        let variable_section = self.variable_buffer.start_section_initialized(&scope.variables);
 
        let child_scope_section = self.scope_buffer.start_section_initialized(&scope.nested);
 

	
 
        let mut variable_index = 0;
 
        let mut child_scope_index = 0;
 

	
 
        loop {
 
            // Determine relative positions of variable and scope to determine
 
            // which one occurs first within the current scope.
 
            let variable_relative_pos;
 
            if variable_index < variable_section.len() {
 
                let variable_id = variable_section[variable_index];
 
                let variable = &ctx.heap[variable_id];
 
                variable_relative_pos = variable.relative_pos_in_parent;
 
            } else {
 
                variable_relative_pos = i32::MAX;
 
            }
 

	
 
            let child_scope_relative_pos;
 
            if child_scope_index < child_scope_section.len() {
 
                let child_scope_id = child_scope_section[child_scope_index];
 
                let child_scope = &ctx.heap[child_scope_id];
 
                child_scope_relative_pos = child_scope.relative_pos_in_parent;
 
            } else {
 
                child_scope_relative_pos = i32::MAX;
 
            }
 

	
 
            if variable_relative_pos == i32::MAX && child_scope_relative_pos == i32::MAX {
 
                // Done, no more elements in the scope to consider
 
                break;
 
            }
 

	
 
            // Label the variable/scope, whichever comes first.
 
            if variable_relative_pos <= child_scope_relative_pos {
 
                debug_assert_ne!(variable_relative_pos, child_scope_relative_pos, "checking if this ever happens");
 
                let variable = &mut ctx.heap[variable_section[variable_index]];
 
                variable.unique_id_in_scope = variable_counter;
 
                variable_counter += 1;
 
                variable_index += 1;
 
            } else {
 
                let child_scope_id = child_scope_section[child_scope_index];
 
                self.visit_scope_and_assign_local_ids(ctx, child_scope_id, variable_counter);
 
                child_scope_index += 1;
 
            }
 
        }
 

	
 
        variable_section.forget();
 
        child_scope_section.forget();
 

	
 
        let scope = &mut ctx.heap[scope_id];
 
        scope.next_unique_id_in_scope = variable_counter;
 
    }
 
}
 
\ No newline at end of file
src/protocol/parser/pass_symbols.rs
Show inline comments
 
@@ -137,135 +137,135 @@ impl PassSymbols {
 
                this,
 
                span: pragma_span,
 
                value: Identifier{ span: module_span, value: module_name.clone() },
 
            }));
 
            self.pragmas.push(pragma_id);
 

	
 
            if let Err(other_module_root_id) = ctx.symbols.insert_module(module_name.clone(), module.root_id) {
 
                // Naming conflict
 
                let this_module = &modules[module_idx];
 
                let other_module = seek_module(modules, other_module_root_id).unwrap();
 
                let other_module_pragma_id = other_module.name.as_ref().map(|v| (*v).0).unwrap();
 
                let other_pragma = ctx.heap[other_module_pragma_id].as_module();
 
                return Err(ParseError::new_error_str_at_span(
 
                    &this_module.source, pragma_span, "conflict in module name"
 
                ).with_info_str_at_span(
 
                    &other_module.source, other_pragma.span, "other module is defined here"
 
                ));
 
            }
 

	
 
            module.name = Some((pragma_id, module_name));
 
            self.has_pragma_module = true;
 
        } else if pragma_section == b"#version" {
 
            // Check if version is defined twice within the same file
 
            if self.has_pragma_version {
 
                return Err(ParseError::new_error_str_at_pos(&module.source, pragma_start, "module version is defined twice"));
 
            }
 

	
 
            // Consume the version pragma
 
            let (version, version_span) = consume_integer_literal(&module.source, &mut iter, &mut self.buffer)?;
 
            let pragma_id = ctx.heap.alloc_pragma(|this| Pragma::Version(PragmaVersion{
 
                this,
 
                span: InputSpan::from_positions(pragma_start, version_span.end),
 
                version,
 
            }));
 
            self.pragmas.push(pragma_id);
 

	
 
            module.version = Some((pragma_id, version as i64));
 
            self.has_pragma_version = true;
 
        } else {
 
            // Custom pragma, maybe we support this in the future, but for now
 
            // we don't.
 
            return Err(ParseError::new_error_str_at_pos(&module.source, pragma_start, "illegal pragma name"));
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_definition_range(&mut self, modules: &[Module], module_idx: usize, ctx: &mut PassCtx, range_idx: usize) -> Result<(), ParseError> {
 
        let module = &modules[module_idx];
 
        let range = &module.tokens.ranges[range_idx];
 
        let definition_span = InputSpan::from_positions(
 
            module.tokens.start_pos(range),
 
            module.tokens.end_pos(range)
 
        );
 
        let mut iter = module.tokens.iter_range(range);
 

	
 
        // First ident must be type of symbol
 
        let (kw_text, _) = consume_any_ident(&module.source, &mut iter).unwrap();
 

	
 
        // Retrieve identifier of definition
 
        let identifier = consume_ident_interned(&module.source, &mut iter, ctx)?;
 
        let mut poly_vars = Vec::new();
 
        maybe_consume_comma_separated(
 
            TokenKind::OpenAngle, TokenKind::CloseAngle, &module.source, &mut iter, ctx,
 
            |source, iter, ctx| consume_ident_interned(source, iter, ctx),
 
            &mut poly_vars, "a polymorphic variable", None
 
        )?;
 
        let ident_text = identifier.value.clone(); // because we need it later
 
        let ident_span = identifier.span.clone();
 

	
 
        // Reserve space in AST for definition and add it to the symbol table
 
        let definition_class;
 
        let ast_definition_id;
 
        match kw_text {
 
            KW_STRUCT => {
 
                let struct_def_id = ctx.heap.alloc_struct_definition(|this| {
 
                    StructDefinition::new_empty(this, module.root_id, definition_span, identifier, poly_vars)
 
                });
 
                definition_class = DefinitionClass::Struct;
 
                ast_definition_id = struct_def_id.upcast();
 
            },
 
            KW_ENUM => {
 
                let enum_def_id = ctx.heap.alloc_enum_definition(|this| {
 
                    EnumDefinition::new_empty(this, module.root_id, definition_span, identifier, poly_vars)
 
                });
 
                definition_class = DefinitionClass::Enum;
 
                ast_definition_id = enum_def_id.upcast();
 
            },
 
            KW_UNION => {
 
                let union_def_id = ctx.heap.alloc_union_definition(|this| {
 
                    UnionDefinition::new_empty(this, module.root_id, definition_span, identifier, poly_vars)
 
                });
 
                definition_class = DefinitionClass::Union;
 
                ast_definition_id = union_def_id.upcast()
 
            },
 
            KW_FUNCTION => {
 
                let func_def_id = ctx.heap.alloc_function_definition(|this| {
 
                    FunctionDefinition::new_empty(this, module.root_id, definition_span, identifier, poly_vars)
 
                let proc_def_id = ctx.heap.alloc_procedure_definition(|this| {
 
                    ProcedureDefinition::new_empty(this, module.root_id, definition_span, ProcedureKind::Function, identifier, poly_vars)
 
                });
 
                definition_class = DefinitionClass::Function;
 
                ast_definition_id = func_def_id.upcast();
 
                ast_definition_id = proc_def_id.upcast();
 
            },
 
            KW_PRIMITIVE | KW_COMPOSITE => {
 
                let component_variant = if kw_text == KW_PRIMITIVE {
 
                    ComponentVariant::Primitive
 
                let procedure_kind = if kw_text == KW_PRIMITIVE {
 
                    ProcedureKind::Primitive
 
                } else {
 
                    ComponentVariant::Composite
 
                    ProcedureKind::Composite
 
                };
 
                let comp_def_id = ctx.heap.alloc_component_definition(|this| {
 
                    ComponentDefinition::new_empty(this, module.root_id, definition_span, component_variant, identifier, poly_vars)
 
                let proc_def_id = ctx.heap.alloc_procedure_definition(|this| {
 
                    ProcedureDefinition::new_empty(this, module.root_id, definition_span, procedure_kind, identifier, poly_vars)
 
                });
 
                definition_class = DefinitionClass::Component;
 
                ast_definition_id = comp_def_id.upcast();
 
                ast_definition_id = proc_def_id.upcast();
 
            },
 
            _ => unreachable!("encountered keyword '{}' in definition range", String::from_utf8_lossy(kw_text)),
 
        }
 

	
 
        let symbol = Symbol{
 
            name: ident_text,
 
            variant: SymbolVariant::Definition(SymbolDefinition{
 
                defined_in_module: module.root_id,
 
                defined_in_scope: SymbolScope::Module(module.root_id),
 
                definition_span,
 
                identifier_span: ident_span,
 
                imported_at: None,
 
                class: definition_class,
 
                definition_id: ast_definition_id,
 
            }),
 
        };
 
        self.symbols.push(symbol);
 
        self.definitions.push(ast_definition_id);
 

	
 
        Ok(())
 
    }
 
}
 
\ No newline at end of file
src/protocol/parser/pass_typing.rs
Show inline comments
 
@@ -717,654 +717,598 @@ impl InferenceType {
 
        let mut buffer = String::with_capacity(parts.len() * 6);
 
        Self::write_display_name(&mut buffer, heap, parts, 0);
 
        buffer
 
    }
 

	
 
    /// Returns the display name of the full type tree. Will allocate a string.
 
    fn display_name(&self, heap: &Heap) -> String {
 
        Self::partial_display_name(heap, &self.parts)
 
    }
 
}
 

	
 
impl Default for InferenceType {
 
    fn default() -> Self {
 
        Self{
 
            has_marker: false,
 
            is_done: false,
 
            parts: Vec::new(),
 
        }
 
    }
 
}
 

	
 
/// Iterator over the subtrees that follow a marker in an `InferenceType`
 
/// instance. Returns immutable slices over the internal parts
 
struct InferenceTypeMarkerIter<'a> {
 
    parts: &'a [InferenceTypePart],
 
    idx: usize,
 
}
 

	
 
impl<'a> InferenceTypeMarkerIter<'a> {
 
    fn new(parts: &'a [InferenceTypePart]) -> Self {
 
        Self{ parts, idx: 0 }
 
    }
 
}
 

	
 
impl<'a> Iterator for InferenceTypeMarkerIter<'a> {
 
    type Item = (u32, &'a [InferenceTypePart]);
 

	
 
    fn next(&mut self) -> Option<Self::Item> {
 
        // Iterate until we find a marker
 
        while self.idx < self.parts.len() {
 
            if let InferenceTypePart::Marker(marker) = self.parts[self.idx] {
 
                // Found a marker, find the subtree end
 
                let start_idx = self.idx + 1;
 
                let end_idx = InferenceType::find_subtree_end_idx(self.parts, start_idx);
 

	
 
                // Modify internal index, then return items
 
                self.idx = end_idx;
 
                return Some((marker, &self.parts[start_idx..end_idx]));
 
            }
 

	
 
            self.idx += 1;
 
        }
 

	
 
        None
 
    }
 
}
 

	
 
#[derive(Debug, PartialEq, Eq)]
 
enum DualInferenceResult {
 
    Neither,        // neither argument is clarified
 
    First,          // first argument is clarified using the second one
 
    Second,         // second argument is clarified using the first one
 
    Both,           // both arguments are clarified
 
    Incompatible,   // types are incompatible: programmer error
 
}
 

	
 
impl DualInferenceResult {
 
    fn modified_lhs(&self) -> bool {
 
        match self {
 
            DualInferenceResult::First | DualInferenceResult::Both => true,
 
            _ => false
 
        }
 
    }
 
    fn modified_rhs(&self) -> bool {
 
        match self {
 
            DualInferenceResult::Second | DualInferenceResult::Both => true,
 
            _ => false
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, PartialEq, Eq)]
 
enum SingleInferenceResult {
 
    Unmodified,
 
    Modified,
 
    Incompatible
 
}
 

	
 
// -----------------------------------------------------------------------------
 
// PassTyping - Public Interface
 
// -----------------------------------------------------------------------------
 

	
 
type InferNodeIndex = usize;
 
type PolyDataIndex = isize;
 
type VarDataIndex = usize;
 

	
 
enum DefinitionType{
 
    Component(ComponentDefinitionId),
 
    Function(FunctionDefinitionId),
 
}
 

	
 
impl DefinitionType {
 
    fn definition_id(&self) -> DefinitionId {
 
        match self {
 
            DefinitionType::Component(v) => v.upcast(),
 
            DefinitionType::Function(v) => v.upcast(),
 
        }
 
    }
 
}
 

	
 
pub(crate) struct ResolveQueueElement {
 
    // Note that using the `definition_id` and the `monomorph_idx` one may
 
    // query the type table for the full procedure type, thereby retrieving
 
    // the polymorphic arguments to the procedure.
 
    pub(crate) root_id: RootId,
 
    pub(crate) definition_id: DefinitionId,
 
    pub(crate) reserved_type_id: TypeId,
 
}
 

	
 
pub(crate) type ResolveQueue = Vec<ResolveQueueElement>;
 

	
 
struct InferenceNode {
 
    expr_type: InferenceType,       // result type from expression
 
    expr_id: ExpressionId,          // expression that is evaluated
 
    inference_rule: InferenceRule,
 
    parent_index: Option<InferNodeIndex>,
 
    field_or_monomorph_index: i32,    // index of field
 
    poly_data_index: PolyDataIndex,            // index of extra data needed for inference
 
    type_id: TypeId,                // when applicable indexes into type table
 
}
 

	
 
/// Inferencing rule to apply. Some of these are reasonably generic. Other ones
 
/// require so much custom logic that we'll not try to come up with an
 
/// abstraction.
 
enum InferenceRule {
 
    Noop,
 
    MonoTemplate(InferenceRuleTemplate),
 
    BiEqual(InferenceRuleBiEqual),
 
    TriEqualArgs(InferenceRuleTriEqualArgs),
 
    TriEqualAll(InferenceRuleTriEqualAll),
 
    Concatenate(InferenceRuleTwoArgs),
 
    IndexingExpr(InferenceRuleIndexingExpr),
 
    SlicingExpr(InferenceRuleSlicingExpr),
 
    SelectStructField(InferenceRuleSelectStructField),
 
    SelectTupleMember(InferenceRuleSelectTupleMember),
 
    LiteralStruct(InferenceRuleLiteralStruct),
 
    LiteralEnum,
 
    LiteralUnion(InferenceRuleLiteralUnion),
 
    LiteralArray(InferenceRuleLiteralArray),
 
    LiteralTuple(InferenceRuleLiteralTuple),
 
    CastExpr(InferenceRuleCastExpr),
 
    CallExpr(InferenceRuleCallExpr),
 
    VariableExpr(InferenceRuleVariableExpr),
 
}
 

	
 
impl InferenceRule {
 
    union_cast_method_impl!(as_mono_template, InferenceRuleTemplate, InferenceRule::MonoTemplate);
 
    union_cast_method_impl!(as_bi_equal, InferenceRuleBiEqual, InferenceRule::BiEqual);
 
    union_cast_method_impl!(as_tri_equal_args, InferenceRuleTriEqualArgs, InferenceRule::TriEqualArgs);
 
    union_cast_method_impl!(as_tri_equal_all, InferenceRuleTriEqualAll, InferenceRule::TriEqualAll);
 
    union_cast_method_impl!(as_concatenate, InferenceRuleTwoArgs, InferenceRule::Concatenate);
 
    union_cast_method_impl!(as_indexing_expr, InferenceRuleIndexingExpr, InferenceRule::IndexingExpr);
 
    union_cast_method_impl!(as_slicing_expr, InferenceRuleSlicingExpr, InferenceRule::SlicingExpr);
 
    union_cast_method_impl!(as_select_struct_field, InferenceRuleSelectStructField, InferenceRule::SelectStructField);
 
    union_cast_method_impl!(as_select_tuple_member, InferenceRuleSelectTupleMember, InferenceRule::SelectTupleMember);
 
    union_cast_method_impl!(as_literal_struct, InferenceRuleLiteralStruct, InferenceRule::LiteralStruct);
 
    union_cast_method_impl!(as_literal_union, InferenceRuleLiteralUnion, InferenceRule::LiteralUnion);
 
    union_cast_method_impl!(as_literal_array, InferenceRuleLiteralArray, InferenceRule::LiteralArray);
 
    union_cast_method_impl!(as_literal_tuple, InferenceRuleLiteralTuple, InferenceRule::LiteralTuple);
 
    union_cast_method_impl!(as_cast_expr, InferenceRuleCastExpr, InferenceRule::CastExpr);
 
    union_cast_method_impl!(as_call_expr, InferenceRuleCallExpr, InferenceRule::CallExpr);
 
    union_cast_method_impl!(as_variable_expr, InferenceRuleVariableExpr, InferenceRule::VariableExpr);
 
}
 

	
 
// Note: InferenceRuleTemplate is `Copy`, so don't add dynamically allocated
 
// members in the future (or review places where this struct is copied)
 
#[derive(Clone, Copy)]
 
struct InferenceRuleTemplate {
 
    template: &'static [InferenceTypePart],
 
    application: InferenceRuleTemplateApplication,
 
}
 

	
 
impl InferenceRuleTemplate {
 
    fn new_none() -> Self {
 
        return Self{
 
            template: &[],
 
            application: InferenceRuleTemplateApplication::None,
 
        };
 
    }
 

	
 
    fn new_forced(template: &'static [InferenceTypePart]) -> Self {
 
        return Self{
 
            template,
 
            application: InferenceRuleTemplateApplication::Forced,
 
        };
 
    }
 

	
 
    fn new_template(template: &'static [InferenceTypePart]) -> Self {
 
        return Self{
 
            template,
 
            application: InferenceRuleTemplateApplication::Template,
 
        }
 
    }
 
}
 

	
 
#[derive(Clone, Copy)]
 
enum InferenceRuleTemplateApplication {
 
    None, // do not apply template, silly, but saves some bytes
 
    Forced,
 
    Template,
 
}
 

	
 
/// Type equality applied to 'self' and the argument. An optional template will
 
/// be applied to 'self' first. Example: "bitwise not"
 
struct InferenceRuleBiEqual {
 
    template: InferenceRuleTemplate,
 
    argument_index: InferNodeIndex,
 
}
 

	
 
/// Type equality applied to two arguments. Template can be applied to 'self'
 
/// (generally forced, since this rule does not apply a type equality constraint
 
/// to 'self') and the two arguments. Example: "equality operator"
 
struct InferenceRuleTriEqualArgs {
 
    argument_template: InferenceRuleTemplate,
 
    result_template: InferenceRuleTemplate,
 
    argument1_index: InferNodeIndex,
 
    argument2_index: InferNodeIndex,
 
}
 

	
 
/// Type equality applied to 'self' and two arguments. Template may be
 
/// optionally applied to 'self'. Example: "addition operator"
 
struct InferenceRuleTriEqualAll {
 
    template: InferenceRuleTemplate,
 
    argument1_index: InferNodeIndex,
 
    argument2_index: InferNodeIndex,
 
}
 

	
 
/// Information for an inference rule that is applied to 'self' and two
 
/// arguments, see `InferenceRule` for its meaning.
 
struct InferenceRuleTwoArgs {
 
    argument1_index: InferNodeIndex,
 
    argument2_index: InferNodeIndex,
 
}
 

	
 
struct InferenceRuleIndexingExpr {
 
    subject_index: InferNodeIndex,
 
    index_index: InferNodeIndex,
 
}
 

	
 
struct InferenceRuleSlicingExpr {
 
    subject_index: InferNodeIndex,
 
    from_index: InferNodeIndex,
 
    to_index: InferNodeIndex,
 
}
 

	
 
struct InferenceRuleSelectStructField {
 
    subject_index: InferNodeIndex,
 
    selected_field: Identifier,
 
}
 

	
 
struct InferenceRuleSelectTupleMember {
 
    subject_index: InferNodeIndex,
 
    selected_index: u64,
 
}
 

	
 
struct InferenceRuleLiteralStruct {
 
    element_indices: Vec<InferNodeIndex>,
 
}
 

	
 
struct InferenceRuleLiteralUnion {
 
    element_indices: Vec<InferNodeIndex>
 
}
 

	
 
struct InferenceRuleLiteralArray {
 
    element_indices: Vec<InferNodeIndex>
 
}
 

	
 
struct InferenceRuleLiteralTuple {
 
    element_indices: Vec<InferNodeIndex>
 
}
 

	
 
struct InferenceRuleCastExpr {
 
    subject_index: InferNodeIndex,
 
}
 

	
 
struct InferenceRuleCallExpr {
 
    argument_indices: Vec<InferNodeIndex>
 
}
 

	
 
/// Data associated with a variable expression: an expression that reads the
 
/// value from a variable.
 
struct InferenceRuleVariableExpr {
 
    var_data_index: VarDataIndex, // shared variable information
 
}
 

	
 
/// This particular visitor will recurse depth-first into the AST and ensures
 
/// that all expressions have the appropriate types.
 
pub(crate) struct PassTyping {
 
    // Current definition we're typechecking.
 
    reserved_type_id: TypeId,
 
    definition_type: DefinitionType,
 
    procedure_id: ProcedureDefinitionId,
 
    procedure_kind: ProcedureKind,
 
    poly_vars: Vec<ConcreteType>,
 
    // Temporary variables during construction of inference rulesr
 
    parent_index: Option<InferNodeIndex>,
 
    // Buffers for iteration over various types
 
    var_buffer: ScopedBuffer<VariableId>,
 
    expr_buffer: ScopedBuffer<ExpressionId>,
 
    stmt_buffer: ScopedBuffer<StatementId>,
 
    bool_buffer: ScopedBuffer<bool>,
 
    index_buffer: ScopedBuffer<usize>,
 
    poly_progress_buffer: ScopedBuffer<u32>,
 
    // Mapping from parser type to inferred type. We attempt to continue to
 
    // specify these types until we're stuck or we've fully determined the type.
 
    infer_nodes: Vec<InferenceNode>,                     // will be transferred to type table at end
 
    poly_data: Vec<PolyData>,       // data for polymorph inference
 
    var_data: Vec<VarData>,
 
    // Keeping track of which expressions need to be reinferred because the
 
    // expressions they're linked to made progression on an associated type
 
    node_queued: DequeSet<InferNodeIndex>,
 
}
 

	
 
/// Generic struct that is used to store inferred types associated with
 
/// polymorphic types.
 
struct PolyData {
 
    first_rule_application: bool,
 
    definition_id: DefinitionId, // the definition, only used for user feedback
 
    /// Inferred types of the polymorphic variables as they are written down
 
    /// at the type's definition.
 
    poly_vars: Vec<InferenceType>,
 
    expr_types: PolyDataTypes,
 
}
 

	
 
// silly structure, just so we can use `PolyDataTypeIndex` ergonomically while
 
// making sure we're still capable of borrowing from `poly_vars`.
 
struct PolyDataTypes {
 
    /// Inferred types of associated types (e.g. struct fields, tuple members,
 
    /// function arguments). These types may depend on the polymorphic variables
 
    /// defined above.
 
    associated: Vec<InferenceType>,
 
    /// Inferred "returned" type (e.g. if a struct field is selected, then this
 
    /// contains the type of the selected field, for a function call it contains
 
    /// the return type). May depend on the polymorphic variables defined above.
 
    returned: InferenceType,
 
}
 

	
 
#[derive(Clone, Copy)]
 
enum PolyDataTypeIndex {
 
    Associated(usize), // indexes into `PolyData.associated`
 
    Returned,
 
}
 

	
 
impl PolyDataTypes {
 
    fn get_type(&self, index: PolyDataTypeIndex) -> &InferenceType {
 
        match index {
 
            PolyDataTypeIndex::Associated(index) => return &self.associated[index],
 
            PolyDataTypeIndex::Returned => return &self.returned,
 
        }
 
    }
 

	
 
    fn get_type_mut(&mut self, index: PolyDataTypeIndex) -> &mut InferenceType {
 
        match index {
 
            PolyDataTypeIndex::Associated(index) => return &mut self.associated[index],
 
            PolyDataTypeIndex::Returned => return &mut self.returned,
 
        }
 
    }
 
}
 

	
 
struct VarData {
 
    var_id: VariableId,
 
    var_type: InferenceType,
 
    used_at: Vec<InferNodeIndex>, // of variable expressions
 
    linked_var: Option<VarDataIndex>,
 
}
 

	
 
impl PassTyping {
 
    pub(crate) fn new() -> Self {
 
        PassTyping {
 
            reserved_type_id: TypeId::new_invalid(),
 
            definition_type: DefinitionType::Function(FunctionDefinitionId::new_invalid()),
 
            procedure_id: ProcedureDefinitionId::new_invalid(),
 
            procedure_kind: ProcedureKind::Function,
 
            poly_vars: Vec::new(),
 
            parent_index: None,
 
            var_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            expr_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            stmt_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            bool_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            index_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            poly_progress_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            infer_nodes: Vec::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            poly_data: Vec::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            var_data: Vec::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            node_queued: DequeSet::new(),
 
        }
 
    }
 

	
 
    pub(crate) fn queue_module_definitions(ctx: &mut Ctx, queue: &mut ResolveQueue) {
 
        debug_assert_eq!(ctx.module().phase, ModuleCompilationPhase::ValidatedAndLinked);
 
        let root_id = ctx.module().root_id;
 
        let root = &ctx.heap.protocol_descriptions[root_id];
 
        for definition_id in &root.definitions {
 
            let definition = &ctx.heap[*definition_id];
 

	
 
            let first_concrete_part = match definition {
 
                Definition::Function(definition) => {
 
                Definition::Procedure(definition) => {
 
                    if definition.poly_vars.is_empty() {
 
                        Some(ConcreteTypePart::Function(*definition_id, 0))
 
                        if definition.kind == ProcedureKind::Function {
 
                            Some(ConcreteTypePart::Function(definition.this, 0))
 
                        } else {
 
                        None
 
                    }
 
                            Some(ConcreteTypePart::Component(definition.this, 0))
 
                        }
 
                Definition::Component(definition) => {
 
                    if definition.poly_vars.is_empty() {
 
                        Some(ConcreteTypePart::Component(*definition_id, 0))
 
                    } else {
 
                        None
 
                    }
 
                },
 
                }
 
                Definition::Enum(_) | Definition::Struct(_) | Definition::Union(_) => None,
 
            };
 

	
 
            if let Some(first_concrete_part) = first_concrete_part {
 
                let concrete_type = ConcreteType{ parts: vec![first_concrete_part] };
 
                let type_id = ctx.types.reserve_procedure_monomorph_type_id(definition_id, concrete_type);
 
                queue.push(ResolveQueueElement{
 
                    root_id,
 
                    definition_id: *definition_id,
 
                    reserved_type_id: type_id,
 
                })
 
            }
 
        }
 
    }
 

	
 
    pub(crate) fn handle_module_definition(
 
        &mut self, ctx: &mut Ctx, queue: &mut ResolveQueue, element: ResolveQueueElement
 
    ) -> VisitorResult {
 
        self.reset();
 
        debug_assert_eq!(ctx.module().root_id, element.root_id);
 
        debug_assert!(self.poly_vars.is_empty());
 

	
 
        // Prepare for visiting the definition
 
        self.reserved_type_id = element.reserved_type_id;
 

	
 
        let proc_base = ctx.types.get_base_definition(&element.definition_id).unwrap();
 
        if proc_base.is_polymorph {
 
            let monomorph = ctx.types.get_monomorph(element.reserved_type_id);
 
            for poly_arg in monomorph.concrete_type.embedded_iter(0) {
 
                self.poly_vars.push(ConcreteType{ parts: Vec::from(poly_arg) });
 
            }
 
        }
 

	
 
        // Visit the definition, setting up the type resolving process, then
 
        // (attempt to) resolve all types
 
        self.visit_definition(ctx, element.definition_id)?;
 
        self.resolve_types(ctx, queue)?;
 
        Ok(())
 
    }
 

	
 
    fn reset(&mut self) {
 
        self.reserved_type_id = TypeId::new_invalid();
 
        self.definition_type = DefinitionType::Function(FunctionDefinitionId::new_invalid());
 
        self.procedure_id = ProcedureDefinitionId::new_invalid();
 
        self.procedure_kind = ProcedureKind::Function;
 
        self.poly_vars.clear();
 
        self.parent_index = None;
 

	
 
        self.infer_nodes.clear();
 
        self.poly_data.clear();
 
        self.var_data.clear();
 
        self.node_queued.clear();
 
    }
 
}
 

	
 
// -----------------------------------------------------------------------------
 
// PassTyping - Visitor-like implementation
 
// -----------------------------------------------------------------------------
 

	
 
type VisitorResult = Result<(), ParseError>;
 
type VisitExprResult = Result<InferNodeIndex, ParseError>;
 

	
 
impl PassTyping {
 
    // Definitions
 

	
 
    fn visit_definition(&mut self, ctx: &mut Ctx, id: DefinitionId) -> VisitorResult {
 
        return visitor_recursive_definition_impl!(self, &ctx.heap[id], ctx);
 
    }
 

	
 
    fn visit_enum_definition(&mut self, _: &mut Ctx, _: EnumDefinitionId) -> VisitorResult { return Ok(()) }
 
    fn visit_struct_definition(&mut self, _: &mut Ctx, _: StructDefinitionId) -> VisitorResult { return Ok(()) }
 
    fn visit_union_definition(&mut self, _: &mut Ctx, _: UnionDefinitionId) -> VisitorResult { return Ok(()) }
 

	
 
    fn visit_component_definition(&mut self, ctx: &mut Ctx, id: ComponentDefinitionId) -> VisitorResult {
 
        self.definition_type = DefinitionType::Component(id);
 
    fn visit_procedure_definition(&mut self, ctx: &mut Ctx, id: ProcedureDefinitionId) -> VisitorResult {
 
        let procedure_def = &ctx.heap[id];
 

	
 
        let comp_def = &ctx.heap[id];
 
        debug_assert_eq!(comp_def.poly_vars.len(), self.poly_vars.len(), "component polyvars do not match imposed polyvars");
 
        self.procedure_id = id;
 
        self.procedure_kind = procedure_def.kind;
 
        let body_id = procedure_def.body;
 

	
 
        debug_log!("{}", "-".repeat(50));
 
        debug_log!("Visiting component '{}': {}", comp_def.identifier.value.as_str(), id.0.index);
 
        debug_log!("Visiting procedure: '{}' (id: {}, kind: {:?})", procedure_def.identifier.value.as_str(), id.0.index, procedure_def.kind);
 
        debug_log!("{}", "-".repeat(50));
 

	
 
        // Visit parameters
 
        let section = self.var_buffer.start_section_initialized(comp_def.parameters.as_slice());
 
        for param_id in section.iter_copied() {
 
            let param = &ctx.heap[param_id];
 
            let var_type = self.determine_inference_type_from_parser_type_elements(&param.parser_type.elements, true);
 
            debug_assert!(var_type.is_done, "expected component arguments to be concrete types");
 
            self.var_data.push(VarData{
 
                var_id: param_id,
 
                var_type,
 
                used_at: Vec::new(),
 
                linked_var: None
 
            });
 
        }
 
        section.forget();
 

	
 
        // Visit the body and all of its expressions
 
        let body_stmt_id = ctx.heap[id].body;
 
        self.parent_index = None;
 
        self.visit_block_stmt(ctx, body_stmt_id)
 
    }
 

	
 
    fn visit_function_definition(&mut self, ctx: &mut Ctx, id: FunctionDefinitionId) -> VisitorResult {
 
        self.definition_type = DefinitionType::Function(id);
 

	
 
        let func_def = &ctx.heap[id];
 
        debug_assert_eq!(func_def.poly_vars.len(), self.poly_vars.len(), "function polyvars do not match imposed polyvars");
 

	
 
        debug_log!("{}", "-".repeat(50));
 
        debug_log!("Visiting function '{}': {}", func_def.identifier.value.as_str(), id.0.index);
 
        if debug_log_enabled!() {
 
            debug_log!("Polymorphic variables:");
 
            for (_idx, poly_var) in self.poly_vars.iter().enumerate() {
 
                let mut infer_type_parts = Vec::new();
 
                Self::determine_inference_type_from_concrete_type(
 
                    &mut infer_type_parts, &poly_var.parts
 
                );
 
                let _infer_type = InferenceType::new(false, true, infer_type_parts);
 
                debug_log!(" - [{:03}] {:?}", _idx, _infer_type.display_name(&ctx.heap));
 
            }
 
        }
 
        debug_log!("{}", "-".repeat(50));
 

	
 
        // Visit parameters
 
        let section = self.var_buffer.start_section_initialized(func_def.parameters.as_slice());
 
        let section = self.var_buffer.start_section_initialized(procedure_def.parameters.as_slice());
 
        for param_id in section.iter_copied() {
 
            let param = &ctx.heap[param_id];
 
            let var_type = self.determine_inference_type_from_parser_type_elements(&param.parser_type.elements, true);
 
            debug_assert!(var_type.is_done, "expected function arguments to be concrete types");
 
            self.var_data.push(VarData{
 
                var_id: param_id,
 
                var_type,
 
                used_at: Vec::new(),
 
                linked_var: None
 
            })
 
        }
 
        section.forget();
 

	
 
        // Visit all of the expressions within the body
 
        let body_stmt_id = ctx.heap[id].body;
 
        self.parent_index = None;
 
        self.visit_block_stmt(ctx, body_stmt_id)
 
        return self.visit_block_stmt(ctx, body_id);
 
    }
 

	
 
    // Statements
 

	
 
    fn visit_stmt(&mut self, ctx: &mut Ctx, id: StatementId) -> VisitorResult {
 
        return visitor_recursive_statement_impl!(self, &ctx.heap[id], ctx, Ok(()));
 
    }
 

	
 
    fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
 
        // Transfer statements for traversal
 
        let block = &ctx.heap[id];
 

	
 
        let section = self.stmt_buffer.start_section_initialized(block.statements.as_slice());
 
        for stmt_id in section.iter_copied() {
 
            self.visit_stmt(ctx, stmt_id)?;
 
        }
 
        section.forget();
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_local_stmt(&mut self, ctx: &mut Ctx, id: LocalStatementId) -> VisitorResult {
 
        return visitor_recursive_local_impl!(self, &ctx.heap[id], ctx);
 
    }
 

	
 
    fn visit_local_memory_stmt(&mut self, ctx: &mut Ctx, id: MemoryStatementId) -> VisitorResult {
 
        let memory_stmt = &ctx.heap[id];
 
        let initial_expr_id = memory_stmt.initial_expr;
 

	
 
        let local = &ctx.heap[memory_stmt.variable];
 
        let var_type = self.determine_inference_type_from_parser_type_elements(&local.parser_type.elements, true);
 
        self.var_data.push(VarData{
 
            var_id: memory_stmt.variable,
 
            var_type,
 
            used_at: Vec::new(),
 
            linked_var: None,
 
        });
 

	
 
        // Process the initial value
 
        self.visit_assignment_expr(ctx, initial_expr_id)?;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_local_channel_stmt(&mut self, ctx: &mut Ctx, id: ChannelStatementId) -> VisitorResult {
 
        let channel_stmt = &ctx.heap[id];
 

	
 
        let from_var_index = self.var_data.len() as VarDataIndex;
 
        let to_var_index = from_var_index + 1;
 

	
 
        let from_local = &ctx.heap[channel_stmt.from];
 
        let from_var_type = self.determine_inference_type_from_parser_type_elements(&from_local.parser_type.elements, true);
 
        self.var_data.push(VarData{
 
            var_id: channel_stmt.from,
 
            var_type: from_var_type,
 
            used_at: Vec::new(),
 
            linked_var: Some(to_var_index),
 
        });
 

	
 
        let to_local = &ctx.heap[channel_stmt.to];
 
        let to_var_type = self.determine_inference_type_from_parser_type_elements(&to_local.parser_type.elements, true);
 
        self.var_data.push(VarData{
 
            var_id: channel_stmt.to,
 
            var_type: to_var_type,
 
            used_at: Vec::new(),
 
            linked_var: Some(from_var_index),
 
        });
 

	
 
        Ok(())
 
    }
 

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

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

	
 
        let true_body_case = if_stmt.true_case;
 
        let false_body_case = if_stmt.false_case;
 
        let test_expr_id = if_stmt.test;
 

	
 
        self.visit_expr(ctx, test_expr_id)?;
 
        self.visit_stmt(ctx, true_body_case.body)?;
 
        if let Some(false_body_case) = false_body_case {
 
            self.visit_stmt(ctx, false_body_case.body)?;
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_while_stmt(&mut self, ctx: &mut Ctx, id: WhileStatementId) -> VisitorResult {
 
        let while_stmt = &ctx.heap[id];
 

	
 
@@ -1928,309 +1872,300 @@ impl PassTyping {
 
        let var_data_index = if let Some(var_data_index) = var_data_index {
 
            let var_data = &mut self.var_data[var_data_index];
 
            var_data.used_at.push(self_index);
 

	
 
            var_data_index
 
        } else {
 
            // If we're in a binding expression then it might the first time we
 
            // encounter the variable, so add a `VarData` entry.
 
            debug_assert_eq!(declaration.kind, VariableKind::Binding);
 
            let var_type = self.determine_inference_type_from_parser_type_elements(
 
                &declaration.parser_type.elements, true
 
            );
 
            let var_data_index = self.var_data.len();
 
            self.var_data.push(VarData{
 
                var_id: declaration.this,
 
                var_type,
 
                used_at: vec![self_index],
 
                linked_var: None,
 
            });
 

	
 
            var_data_index
 
        };
 

	
 
        let node = &mut self.infer_nodes[self_index];
 
        node.inference_rule = InferenceRule::VariableExpr(InferenceRuleVariableExpr{
 
            var_data_index,
 
        });
 

	
 
        self.parent_index = old_parent;
 
        self.progress_inference_rule_variable_expr(ctx, self_index)?;
 
        return Ok(self_index);
 
    }
 
}
 

	
 
// -----------------------------------------------------------------------------
 
// PassTyping - Type-inference progression
 
// -----------------------------------------------------------------------------
 

	
 
impl PassTyping {
 
    #[allow(dead_code)] // used when debug flag at the top of this file is true.
 
    fn debug_get_display_name(&self, ctx: &Ctx, expr_id: ExpressionId) -> String {
 
        let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition();
 
        let expr_type = &self.infer_nodes[expr_idx as usize].expr_type;
 
        expr_type.display_name(&ctx.heap)
 
    }
 

	
 
    fn resolve_types(&mut self, ctx: &mut Ctx, queue: &mut ResolveQueue) -> Result<(), ParseError> {
 
        // Keep inferring until we can no longer make any progress
 
        while !self.node_queued.is_empty() {
 
            while !self.node_queued.is_empty() {
 
                let node_index = self.node_queued.pop_front().unwrap();
 
                self.progress_inference_rule(ctx, node_index)?;
 
            }
 

	
 
            // Nothing is queued anymore. However we might have integer literals
 
            // whose type cannot be inferred. For convenience's sake we'll
 
            // infer these to be s32.
 
            for (infer_node_index, infer_node) in self.infer_nodes.iter_mut().enumerate() {
 
                let expr_type = &mut infer_node.expr_type;
 
                if !expr_type.is_done && expr_type.parts.len() == 1 && expr_type.parts[0] == InferenceTypePart::IntegerLike {
 
                    // Force integer type to s32
 
                    expr_type.parts[0] = InferenceTypePart::SInt32;
 
                    expr_type.is_done = true;
 

	
 
                    // Requeue expression (and its parent, if it exists)
 
                    self.node_queued.push_back(infer_node_index);
 
                    if let Some(node_parent_index) = infer_node.parent_index {
 
                        self.node_queued.push_back(node_parent_index);
 
                    }
 
                }
 
            }
 
        }
 

	
 
        // Helper for transferring polymorphic variables to concrete types and
 
        // checking if they're completely specified
 
        fn inference_type_to_concrete_type(
 
            ctx: &Ctx, expr_id: ExpressionId, inference: &Vec<InferenceType>,
 
            first_concrete_part: ConcreteTypePart,
 
        ) -> Result<ConcreteType, ParseError> {
 
            // Prepare storage vector
 
            let mut num_inference_parts = 0;
 
            for inference_type in inference {
 
                num_inference_parts += inference_type.parts.len();
 
            }
 

	
 
            let mut concrete_type = ConcreteType{
 
                parts: Vec::with_capacity(1 + num_inference_parts),
 
            };
 
            concrete_type.parts.push(first_concrete_part);
 

	
 
            // Go through all polymorphic arguments and add them to the concrete
 
            // types.
 
            for (poly_idx, poly_type) in inference.iter().enumerate() {
 
                if !poly_type.is_done {
 
                    let expr = &ctx.heap[expr_id];
 
                    let definition = match expr {
 
                        Expression::Call(expr) => expr.definition,
 
                        Expression::Call(expr) => expr.procedure.upcast(),
 
                        Expression::Literal(expr) => match &expr.value {
 
                            Literal::Enum(lit) => lit.definition,
 
                            Literal::Union(lit) => lit.definition,
 
                            Literal::Struct(lit) => lit.definition,
 
                            _ => unreachable!()
 
                        },
 
                        _ => unreachable!(),
 
                    };
 
                    let poly_vars = ctx.heap[definition].poly_vars();
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module().source, expr.operation_span(), format!(
 
                            "could not fully infer the type of polymorphic variable '{}' of this expression (got '{}')",
 
                            poly_vars[poly_idx].value.as_str(), poly_type.display_name(&ctx.heap)
 
                        )
 
                    ));
 
                }
 

	
 
                poly_type.write_concrete_type(&mut concrete_type);
 
            }
 

	
 
            Ok(concrete_type)
 
        }
 

	
 
        // Inference is now done. But we may still have uninferred types. So we
 
        // check for these.
 
        for infer_expr in self.infer_nodes.iter_mut() {
 
            if !infer_expr.expr_type.is_done {
 
                let expr = &ctx.heap[infer_expr.expr_id];
 
                return Err(ParseError::new_error_at_span(
 
                    &ctx.module().source, expr.full_span(), format!(
 
                        "could not fully infer the type of this expression (got '{}')",
 
                        infer_expr.expr_type.display_name(&ctx.heap)
 
                    )
 
                ));
 
            }
 

	
 
            // Expression is fine, check if any extra data is attached
 
            if infer_expr.poly_data_index < 0 { continue; }
 

	
 
            // Extra data is attached, perform typechecking and transfer
 
            // resolved information to the expression
 
            let poly_data = &self.poly_data[infer_expr.poly_data_index as usize];
 

	
 
            // Note that only call and literal expressions need full inference.
 
            // Select expressions also use `extra_data`, but only for temporary
 
            // storage of the struct type whose field it is selecting.
 
            match &ctx.heap[infer_expr.expr_id] {
 
                Expression::Call(expr) => {
 
                    // Check if it is not a builtin function. If not, then
 
                    // construct the first part of the concrete type.
 
                    let first_concrete_part = if expr.method == Method::UserFunction {
 
                        ConcreteTypePart::Function(expr.definition, poly_data.poly_vars.len() as u32)
 
                    let first_concrete_part = if expr.method == Method::UserProcedure {
 
                        ConcreteTypePart::Function(expr.procedure, poly_data.poly_vars.len() as u32)
 
                    } else if expr.method == Method::UserComponent {
 
                        ConcreteTypePart::Component(expr.definition, poly_data.poly_vars.len() as u32)
 
                        ConcreteTypePart::Component(expr.procedure, poly_data.poly_vars.len() as u32)
 
                    } else {
 
                        // Builtin function
 
                        continue;
 
                    };
 

	
 
                    let definition_id = expr.definition;
 
                    let definition_id = expr.procedure.upcast();
 
                    let concrete_type = inference_type_to_concrete_type(
 
                        ctx, infer_expr.expr_id, &poly_data.poly_vars, first_concrete_part
 
                    )?;
 

	
 
                    match ctx.types.get_procedure_monomorph_type_id(&definition_id, &concrete_type.parts) {
 
                        Some(type_id) => {
 
                            // Already typechecked, or already put into the resolve queue
 
                            infer_expr.type_id = type_id;
 
                        },
 
                        None => {
 
                            // Not typechecked yet, so add an entry in the queue
 
                            let reserved_type_id = ctx.types.reserve_procedure_monomorph_type_id(&definition_id, concrete_type);
 
                            infer_expr.type_id = reserved_type_id;
 
                            queue.push(ResolveQueueElement {
 
                                root_id: ctx.heap[definition_id].defined_in(),
 
                                definition_id,
 
                                reserved_type_id,
 
                            });
 
                        }
 
                    }
 
                },
 
                Expression::Literal(expr) => {
 
                    let definition_id = match &expr.value {
 
                        Literal::Enum(lit) => lit.definition,
 
                        Literal::Union(lit) => lit.definition,
 
                        Literal::Struct(lit) => lit.definition,
 
                        _ => unreachable!(),
 
                    };
 
                    let first_concrete_part = ConcreteTypePart::Instance(definition_id, poly_data.poly_vars.len() as u32);
 
                    let concrete_type = inference_type_to_concrete_type(
 
                        ctx, infer_expr.expr_id, &poly_data.poly_vars, first_concrete_part
 
                    )?;
 
                    let type_id = ctx.types.add_monomorphed_type(ctx.modules, ctx.heap, ctx.arch, definition_id, concrete_type)?;
 
                    infer_expr.type_id = type_id;
 
                },
 
                Expression::Select(_) => {
 
                    debug_assert!(infer_expr.field_or_monomorph_index >= 0);
 
                },
 
                _ => {
 
                    unreachable!("handling extra data for expression {:?}", &ctx.heap[infer_expr.expr_id]);
 
                }
 
            }
 
        }
 

	
 
        // Every expression checked, and new monomorphs are queued. Transfer the
 
        // expression information to the type table.
 
        let procedure_arguments = match &self.definition_type {
 
            DefinitionType::Component(id) => {
 
                let definition = &ctx.heap[*id];
 
                &definition.parameters
 
            },
 
            DefinitionType::Function(id) => {
 
                let definition = &ctx.heap[*id];
 
                &definition.parameters
 
            },
 
        };
 
        let procedure_arguments = &ctx.heap[self.procedure_id].parameters;
 

	
 
        let target = ctx.types.get_procedure_monomorph_mut(self.reserved_type_id);
 
        debug_assert!(target.arg_types.is_empty()); // makes sure we never queue a procedure's type inferencing twice
 
        debug_assert!(target.expr_data.is_empty());
 

	
 
        // - Write the arguments to the procedure
 
        target.arg_types.reserve(procedure_arguments.len());
 
        for argument_id in procedure_arguments {
 
            let mut concrete = ConcreteType::default();
 
            let var_data = self.var_data.iter().find(|v| v.var_id == *argument_id).unwrap();
 
            var_data.var_type.write_concrete_type(&mut concrete);
 
            target.arg_types.push(concrete);
 
        }
 

	
 
        // - Write the expression data
 
        target.expr_data.reserve(self.infer_nodes.len());
 
        for infer_expr in self.infer_nodes.iter() {
 
            let mut concrete = ConcreteType::default();
 
            infer_expr.expr_type.write_concrete_type(&mut concrete);
 
            target.expr_data.push(MonomorphExpression{
 
                expr_type: concrete,
 
                field_or_monomorph_idx: infer_expr.field_or_monomorph_index,
 
                type_id: infer_expr.type_id,
 
            });
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    fn progress_inference_rule(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
 
        use InferenceRule as IR;
 

	
 
        let node = &self.infer_nodes[node_index];
 
        match &node.inference_rule {
 
            IR::Noop =>
 
                unreachable!(),
 
            IR::MonoTemplate(_) =>
 
                self.progress_inference_rule_mono_template(ctx, node_index),
 
            IR::BiEqual(_) =>
 
                self.progress_inference_rule_bi_equal(ctx, node_index),
 
            IR::TriEqualArgs(_) =>
 
                self.progress_inference_rule_tri_equal_args(ctx, node_index),
 
            IR::TriEqualAll(_) =>
 
                self.progress_inference_rule_tri_equal_all(ctx, node_index),
 
            IR::Concatenate(_) =>
 
                self.progress_inference_rule_concatenate(ctx, node_index),
 
            IR::IndexingExpr(_) =>
 
                self.progress_inference_rule_indexing_expr(ctx, node_index),
 
            IR::SlicingExpr(_) =>
 
                self.progress_inference_rule_slicing_expr(ctx, node_index),
 
            IR::SelectStructField(_) =>
 
                self.progress_inference_rule_select_struct_field(ctx, node_index),
 
            IR::SelectTupleMember(_) =>
 
                self.progress_inference_rule_select_tuple_member(ctx, node_index),
 
            IR::LiteralStruct(_) =>
 
                self.progress_inference_rule_literal_struct(ctx, node_index),
 
            IR::LiteralEnum =>
 
                self.progress_inference_rule_literal_enum(ctx, node_index),
 
            IR::LiteralUnion(_) =>
 
                self.progress_inference_rule_literal_union(ctx, node_index),
 
            IR::LiteralArray(_) =>
 
                self.progress_inference_rule_literal_array(ctx, node_index),
 
            IR::LiteralTuple(_) =>
 
                self.progress_inference_rule_literal_tuple(ctx, node_index),
 
            IR::CastExpr(_) =>
 
                self.progress_inference_rule_cast_expr(ctx, node_index),
 
            IR::CallExpr(_) =>
 
                self.progress_inference_rule_call_expr(ctx, node_index),
 
            IR::VariableExpr(_) =>
 
                self.progress_inference_rule_variable_expr(ctx, node_index),
 
        }
 
    }
 

	
 
    fn progress_inference_rule_mono_template(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
 
        let node = &self.infer_nodes[node_index];
 
        let rule = *node.inference_rule.as_mono_template();
 

	
 
        let progress = self.progress_template(ctx, node_index, rule.application, rule.template)?;
 
        if progress { self.queue_node_parent(node_index); }
 

	
 
        return Ok(());
 
    }
 

	
 
    fn progress_inference_rule_bi_equal(&mut self, ctx: &Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
 
        let node = &self.infer_nodes[node_index];
 
        let rule = node.inference_rule.as_bi_equal();
 
        let template = rule.template;
 
        let arg_index = rule.argument_index;
 

	
 
        let base_progress = self.progress_template(ctx, node_index, template.application, template.template)?;
 
        let (node_progress, arg_progress) = self.apply_equal2_constraint(ctx, node_index, node_index, 0, arg_index, 0)?;
 

	
 
        if base_progress || node_progress { self.queue_node_parent(node_index); }
 
        if arg_progress { self.queue_node(arg_index); }
 

	
 
        return Ok(())
 
@@ -2929,193 +2864,196 @@ impl PassTyping {
 
            // We progressed the type of the shared variable, so propagate this
 
            // to all associated variable expressions (and relatived variables).
 
            for other_node_index in var_data.used_at.iter().copied() {
 
                if other_node_index != node_index {
 
                    self.node_queued.push_back(other_node_index);
 
                }
 
            }
 

	
 
            if let Some(linked_var_data_index) = var_data.linked_var {
 
                // Only perform one-way inference, progressing the linked
 
                // variable.
 
                // note: because this "linking" is used only for channels, we
 
                // will start inference one level below the top-level in the
 
                // type tree (i.e. ensure `T` in `in<T>` and `out<T>` is equal).
 
                debug_assert!(
 
                    var_data.var_type.parts[0] == InferenceTypePart::Input ||
 
                    var_data.var_type.parts[0] == InferenceTypePart::Output
 
                );
 
                let this_var_type: *const _ = &var_data.var_type;
 
                let linked_var_data = &mut self.var_data[linked_var_data_index];
 
                debug_assert!(
 
                    linked_var_data.var_type.parts[0] == InferenceTypePart::Input ||
 
                    linked_var_data.var_type.parts[0] == InferenceTypePart::Output
 
                );
 

	
 
                // safety: by construction var_data_index and linked_var_data_index cannot be the
 
                // same, hence we're not aliasing here.
 
                let inference_result = InferenceType::infer_subtree_for_single_type(
 
                    &mut linked_var_data.var_type, 1,
 
                    unsafe{ &(*this_var_type).parts }, 1, false
 
                );
 
                match inference_result {
 
                    SingleInferenceResult::Modified => {
 
                        for used_at in linked_var_data.used_at.iter().copied() {
 
                            self.node_queued.push_back(used_at);
 
                        }
 
                    },
 
                    SingleInferenceResult::Unmodified => {},
 
                    SingleInferenceResult::Incompatible => {
 
                        let var_data_this = &self.var_data[var_data_index];
 
                        let var_decl_this = &ctx.heap[var_data_this.var_id];
 
                        let var_data_linked = &self.var_data[linked_var_data_index];
 
                        let var_decl_linked = &ctx.heap[var_data_linked.var_id];
 

	
 
                        return Err(ParseError::new_error_at_span(
 
                            &ctx.module().source, var_decl_this.identifier.span, format!(
 
                                "conflicting types for this channel, this port has type '{}'",
 
                                var_data_this.var_type.display_name(&ctx.heap)
 
                            )
 
                        ).with_info_at_span(
 
                            &ctx.module().source, var_decl_linked.identifier.span, format!(
 
                                "while this port has type '{}'",
 
                                var_data_linked.var_type.display_name(&ctx.heap)
 
                            )
 
                        ));
 
                    }
 
                }
 
            }
 
        }
 

	
 
        if progress_expr { self.queue_node_parent(node_index); }
 

	
 
        return Ok(());
 
    }
 

	
 
    fn progress_template(&mut self, ctx: &Ctx, node_index: InferNodeIndex, application: InferenceRuleTemplateApplication, template: &[InferenceTypePart]) -> Result<bool, ParseError> {
 
        use InferenceRuleTemplateApplication as TA;
 

	
 
        match application {
 
            TA::None => Ok(false),
 
            TA::Template => self.apply_template_constraint(ctx, node_index, template),
 
            TA::Forced => self.apply_forced_constraint(ctx, node_index, template),
 
        }
 
    }
 

	
 
    fn queue_node_parent(&mut self, node_index: InferNodeIndex) {
 
        let node = &self.infer_nodes[node_index];
 
        if let Some(parent_node_index) = node.parent_index {
 
            self.node_queued.push_back(parent_node_index);
 
        }
 
    }
 

	
 
    #[inline]
 
    fn queue_node(&mut self, node_index: InferNodeIndex) {
 
        self.node_queued.push_back(node_index);
 
    }
 

	
 
    /// Returns whether the type is certainly a string (true, false), certainly
 
    /// not a string (false, true), or still unknown (false, false).
 
    fn type_is_certainly_or_certainly_not_string(&self, node_index: InferNodeIndex) -> (bool, bool) {
 
        let expr_type = &self.infer_nodes[node_index].expr_type;
 
        println!("DEBUG: Running test on {:?}", expr_type.parts);
 
        let mut part_index = 0;
 
        while part_index < expr_type.parts.len() {
 
            let part = &expr_type.parts[part_index];
 

	
 
            if part.is_marker() { continue; }
 
            if part.is_marker() {
 
                part_index += 1;
 
                continue;
 
            }
 
            if !part.is_concrete() { break; }
 

	
 
            if *part == InferenceTypePart::String {
 
                // First part is a string
 
                return (true, false);
 
            } else {
 
                return (false, true);
 
            }
 
        }
 

	
 
        // If here then first non-marker type is not concrete
 
        if part_index == expr_type.parts.len() {
 
            // nothing known at all
 
            return (false, false);
 
        }
 

	
 
        // Special case: array-like where its argument is not a character
 
        if part_index + 1 < expr_type.parts.len() {
 
            if expr_type.parts[part_index] == InferenceTypePart::ArrayLike && expr_type.parts[part_index + 1] != InferenceTypePart::Character {
 
                return (false, true);
 
            }
 
        }
 

	
 

	
 
        (false, false)
 
    }
 

	
 
    /// Applies a template type constraint: the type associated with the
 
    /// supplied expression will be molded into the provided `template`. But
 
    /// will be considered valid if the template could've been molded into the
 
    /// expression type as well. Hence the template may be fully specified (e.g.
 
    /// a bool) or contain "inference" variables (e.g. an array of T)
 
    fn apply_template_constraint(
 
        &mut self, ctx: &Ctx, node_index: InferNodeIndex, template: &[InferenceTypePart]
 
    ) -> Result<bool, ParseError> {
 
        let expr_type = &mut self.infer_nodes[node_index].expr_type;
 
        match InferenceType::infer_subtree_for_single_type(expr_type, 0, template, 0, false) {
 
            SingleInferenceResult::Modified => Ok(true),
 
            SingleInferenceResult::Unmodified => Ok(false),
 
            SingleInferenceResult::Incompatible => Err(
 
                self.construct_template_type_error(ctx, node_index, template)
 
            )
 
        }
 
    }
 

	
 
    /// Applies a forced constraint: the supplied expression's type MUST be
 
    /// inferred from the template, the other way around is considered invalid.
 
    fn apply_forced_constraint(
 
        &mut self, ctx: &Ctx, node_index: InferNodeIndex, template: &[InferenceTypePart]
 
    ) -> Result<bool, ParseError> {
 
        let expr_type = &mut self.infer_nodes[node_index].expr_type;
 

	
 
        match InferenceType::infer_subtree_for_single_type(expr_type, 0, template, 0, true) {
 
            SingleInferenceResult::Modified => Ok(true),
 
            SingleInferenceResult::Unmodified => Ok(false),
 
            SingleInferenceResult::Incompatible => Err(
 
                self.construct_template_type_error(ctx, node_index, template)
 
            )
 
        }
 
    }
 

	
 
    /// Applies a type constraint that expects the two provided types to be
 
    /// equal. We attempt to make progress in inferring the types. If the call
 
    /// is successful then the composition of all types are made equal.
 
    /// The "parent" `expr_id` is provided to construct errors.
 
    fn apply_equal2_constraint(
 
        &mut self, ctx: &Ctx, node_index: InferNodeIndex,
 
        arg1_index: InferNodeIndex, arg1_start_idx: usize,
 
        arg2_index: InferNodeIndex, arg2_start_idx: usize
 
    ) -> Result<(bool, bool), ParseError> {
 
        let arg1_type: *mut _ = &mut self.infer_nodes[arg1_index].expr_type;
 
        let arg2_type: *mut _ = &mut self.infer_nodes[arg2_index].expr_type;
 

	
 
        let infer_res = unsafe{ InferenceType::infer_subtrees_for_both_types(
 
            arg1_type, arg1_start_idx,
 
            arg2_type, arg2_start_idx
 
        ) };
 
        if infer_res == DualInferenceResult::Incompatible {
 
            return Err(self.construct_arg_type_error(ctx, node_index, arg1_index, arg2_index));
 
        }
 

	
 
        Ok((infer_res.modified_lhs(), infer_res.modified_rhs()))
 
    }
 

	
 
    /// Applies an equal2 constraint between a member of the `PolyData` struct,
 
    /// and another inferred type. If any progress is made in the `PolyData`
 
    /// struct then the affected polymorphic variables are updated as well.
 
    ///
 
    /// Because a lot of types/expressions are involved in polymorphic typFe
 
    /// inference, some explanation: "outer_node" refers to the main expression
 
    /// that is the root cause of type inference (e.g. a struct literal
 
    /// expression, or a tuple member select expression). Associated with that
 
    /// outer node is `PolyData`, so that is what the "poly_data" variables
 
    /// are referring to. We are applying equality between a "poly_data" type
 
    /// and an associated expression (not necessarily the "outer_node", e.g.
 
    /// the expression that constructs the value of a struct field). Hence the
 
@@ -3125,193 +3063,193 @@ impl PassTyping {
 
    /// location. As info, the `error_location_expr_id` span is shown,
 
    /// indicating that the "`error_type_name` type has been resolved to
 
    /// `outer_node_type`, but this expression has been resolved to
 
    /// `associated_node_type`".
 
    fn apply_polydata_equal2_constraint(
 
        &mut self, ctx: &Ctx,
 
        outer_node_index: InferNodeIndex, error_location_expr_id: ExpressionId, error_type_name: &str,
 
        poly_data_type_index: PolyDataTypeIndex, poly_data_start_index: usize,
 
        associated_node_index: InferNodeIndex, associated_node_start_index: usize,
 
        poly_progress_section: &mut ScopedSection<u32>,
 
    ) -> Result<(bool, bool), ParseError> {
 
        let poly_data_index = self.infer_nodes[outer_node_index].poly_data_index;
 
        let poly_data = &mut self.poly_data[poly_data_index as usize];
 
        let poly_data_type = poly_data.expr_types.get_type_mut(poly_data_type_index);
 
        let associated_type: *mut _ = &mut self.infer_nodes[associated_node_index].expr_type;
 

	
 
        let inference_result = unsafe{
 
            // Safety: pointers originate from different vectors, so cannot
 
            // alias.
 
            let poly_data_type: *mut _ = poly_data_type;
 
            InferenceType::infer_subtrees_for_both_types(
 
                poly_data_type, poly_data_start_index,
 
                associated_type, associated_node_start_index
 
            )
 
        };
 

	
 
        let modified_poly_data = inference_result.modified_lhs();
 
        let modified_associated = inference_result.modified_rhs();
 
        if inference_result == DualInferenceResult::Incompatible {
 
            let outer_node_expr_id = self.infer_nodes[outer_node_index].expr_id;
 
            let outer_node_span = ctx.heap[outer_node_expr_id].full_span();
 
            let detailed_span = ctx.heap[error_location_expr_id].full_span();
 

	
 
            let outer_node_type = poly_data_type.display_name(&ctx.heap);
 
            let associated_type = self.infer_nodes[associated_node_index].expr_type.display_name(&ctx.heap);
 

	
 
            let source = &ctx.module().source;
 
            return Err(ParseError::new_error_str_at_span(
 
                source, outer_node_span, "failed to resolve the types of this expression"
 
            ).with_info_str_at_span(
 
                source, detailed_span, &format!(
 
                    "because the {} type has been resolved to '{}', but this expression has been resolved to '{}'",
 
                    error_type_name, outer_node_type, associated_type
 
                )
 
            ));
 
        }
 

	
 
        if modified_poly_data {
 
            debug_assert!(poly_data_type.has_marker);
 

	
 
            // Go through markers for polymorphic variables and use the
 
            // (hopefully) more specific types to update their representation
 
            // in the PolyData struct
 
            for (poly_var_index, poly_var_section) in poly_data_type.marker_iter() {
 
                let poly_var_type = &mut poly_data.poly_vars[poly_var_index as usize];
 
                match InferenceType::infer_subtree_for_single_type(poly_var_type, 0, poly_var_section, 0, false) {
 
                    SingleInferenceResult::Modified => {
 
                        poly_progress_section.push_unique(poly_var_index);
 
                    },
 
                    SingleInferenceResult::Unmodified => {
 
                        // nothing to do
 
                    },
 
                    SingleInferenceResult::Incompatible => {
 
                        return Err(Self::construct_poly_arg_error(
 
                            ctx, &self.poly_data[poly_data_index as usize],
 
                            self.infer_nodes[outer_node_index].expr_id
 
                        ));
 
                    }
 
                }
 
            }
 
        }
 

	
 
        return Ok((modified_poly_data, modified_associated));
 
    }
 

	
 
    /// After calling `apply_polydata_equal2_constraint` on several expressions
 
    /// that are associated with some kind of polymorphic expression, several of
 
    /// the polymorphic variables might have been inferred to more specific
 
    /// types than before.
 
    ///
 
    /// At this point one should call this function to apply the progress in
 
    /// these polymorphic variables back onto the types that are functions of
 
    /// these polymorphic variables.
 
    ///
 
    /// An example: a struct literal with a polymorphic variable `T` may have
 
    /// two fields `foo` and `bar` each with different types that are a function
 
    /// of the polymorhic variable `T`. If the expressions constructing the
 
    /// value for the field `foo` causes the type `T` to progress, then we can
 
    /// also progress the type of the expression that constructs `bar`.
 
    ///
 
    /// And so we have `outer_node_index` + `poly_data_type_index` pointing to
 
    /// the appropriate type in the `PolyData` struct. Which will be updated
 
    /// first using the polymorphic variables. If we happen to have updated that
 
    /// type, then we should also progress the associated expression, hence the
 
    /// `associated_node_index`.
 
    fn apply_polydata_polyvar_constraint(
 
        &mut self, ctx: &Ctx,
 
        &mut self, _ctx: &Ctx,
 
        outer_node_index: InferNodeIndex, poly_data_type_index: PolyDataTypeIndex,
 
        associated_node_index: InferNodeIndex, poly_progress_section: &ScopedSection<u32>
 
    ) -> bool {
 
        let poly_data_index = self.infer_nodes[outer_node_index].poly_data_index;
 
        let poly_data = &mut self.poly_data[poly_data_index as usize];
 

	
 
        // Early exit, most common case (literals or functions calls which are
 
        // actually not polymorphic)
 
        if !poly_data.first_rule_application && poly_progress_section.len() == 0 {
 
            return false;
 
        }
 

	
 
        // safety: we're borrowing from two distinct fields, so should be fine
 
        let poly_data_type = poly_data.expr_types.get_type_mut(poly_data_type_index);
 
        let mut last_start_index = 0;
 
        let mut modified_poly_type = false;
 

	
 
        while let Some((poly_var_index, poly_var_start_index)) = poly_data_type.find_marker(last_start_index) {
 
            let poly_var_end_index = InferenceType::find_subtree_end_idx(&poly_data_type.parts, poly_var_start_index);
 

	
 
            if poly_data.first_rule_application || poly_progress_section.contains(&poly_var_index) {
 
                // We have updated this polymorphic variable, so try updating it
 
                // in the PolyData type
 
                let modified_in_poly_data = match InferenceType::infer_subtree_for_single_type(
 
                    poly_data_type, poly_var_start_index, &poly_data.poly_vars[poly_var_index as usize].parts, 0, false
 
                ) {
 
                    SingleInferenceResult::Modified => true,
 
                    SingleInferenceResult::Unmodified => false,
 
                    SingleInferenceResult::Incompatible => {
 
                        // practically impossible: before calling this function we gather all the
 
                        // data on the polymorphic variables from the associated expressions. So if
 
                        // the polymorphic variables in those expressions were not mutually
 
                        // compatible, we must have encountered that error already.
 
                        unreachable!()
 
                    },
 
                };
 

	
 
                modified_poly_type = modified_poly_type || modified_in_poly_data;
 
            }
 

	
 
            last_start_index = poly_var_end_index;
 
        }
 

	
 
        if modified_poly_type {
 
            let associated_type = &mut self.infer_nodes[associated_node_index].expr_type;
 
            match InferenceType::infer_subtree_for_single_type(
 
                associated_type, 0, &poly_data_type.parts, 0, true
 
            ) {
 
                SingleInferenceResult::Modified => return true,
 
                SingleInferenceResult::Unmodified => return false,
 
                SingleInferenceResult::Incompatible => unreachable!(), // same as above
 
            }
 
        } else {
 
            // Did not update associated type
 
            return false;
 
        }
 
    }
 

	
 
    /// Should be called after completing one full round of applying polydata
 
    /// constraints.
 
    fn finish_polydata_constraint(&mut self, outer_node_index: InferNodeIndex) {
 
        let poly_data_index = self.infer_nodes[outer_node_index].poly_data_index;
 
        let poly_data = &mut self.poly_data[poly_data_index as usize];
 
        poly_data.first_rule_application = false;
 
    }
 

	
 
    /// Applies a type constraint that expects all three provided types to be
 
    /// equal. In case we can make progress in inferring the types then we
 
    /// attempt to do so. If the call is successful then the composition of all
 
    /// types is made equal.
 
    fn apply_equal3_constraint(
 
        &mut self, ctx: &Ctx, node_index: InferNodeIndex,
 
        arg1_index: InferNodeIndex, arg2_index: InferNodeIndex,
 
        start_idx: usize
 
    ) -> Result<(bool, bool, bool), ParseError> {
 
        // Safety: all indices are unique
 
        //         containers may not be modified
 
        let expr_type: *mut _ = &mut self.infer_nodes[node_index].expr_type;
 
        let arg1_type: *mut _ = &mut self.infer_nodes[arg1_index].expr_type;
 
        let arg2_type: *mut _ = &mut self.infer_nodes[arg2_index].expr_type;
 

	
 
        let expr_res = unsafe{
 
            InferenceType::infer_subtrees_for_both_types(expr_type, start_idx, arg1_type, start_idx)
 
        };
 
        if expr_res == DualInferenceResult::Incompatible {
 
            return Err(self.construct_expr_type_error(ctx, node_index, arg1_index));
 
        }
 

	
 
        let args_res = unsafe{
 
            InferenceType::infer_subtrees_for_both_types(arg1_type, start_idx, arg2_type, start_idx) };
 
        if args_res == DualInferenceResult::Incompatible {
 
            return Err(self.construct_arg_type_error(ctx, node_index, arg1_index, arg2_index));
 
        }
 

	
 
        // If all types are compatible, but the second call caused the arg1_type
 
        // to be expanded, then we must also assign this to expr_type.
 
@@ -3348,279 +3286,267 @@ impl PassTyping {
 
                return Ok(())
 
            },
 
            1 => {
 
                // only one type, so nothing to infer
 
                progress.push(false);
 
                return Ok(())
 
            },
 
            n => {
 
                for _ in 0..n {
 
                    progress.push(false);
 
                }
 
            }
 
        }
 

	
 
        // We'll start doing pairwise inference for all of the inference nodes
 
        // (node[0] with node[1], then node[1] with node[2], then node[2] ...,
 
        // etc.), so when we're at the end we have `node[N-1]` as the most
 
        // progressed type.
 
        let mut last_index_requiring_inference = 0;
 

	
 
        for prev_argument_index in 0..arguments.len() - 1 {
 
            let next_argument_index = prev_argument_index + 1;
 

	
 
            let prev_node_index = arguments[prev_argument_index];
 
            let next_node_index = arguments[next_argument_index];
 
            let (prev_progress, next_progress) = self.apply_equal2_constraint(
 
                ctx, outer_node_index, prev_node_index, 0, next_node_index, 0
 
            )?;
 

	
 
            if prev_progress {
 
                // Previous node is progress, so every type in front of it needs
 
                // to be reinferred.
 
                progress[prev_argument_index] = true;
 
                last_index_requiring_inference = prev_argument_index;
 
            }
 
            progress[next_argument_index] = next_progress;
 
        }
 

	
 
        // Apply inference using the most progressed type (the last one) to the
 
        // ones that did not obtain this information during the inference
 
        // process.
 
        let last_argument_node_index = arguments[arguments.len() - 1];
 
        let last_argument_type: *mut _ = &mut self.infer_nodes[last_argument_node_index].expr_type;
 

	
 
        for argument_index in 0..last_index_requiring_inference {
 
            // We can cheat, we know the LHS is less specific than the right
 
            // hand side, so:
 
            let argument_node_index = arguments[argument_index];
 
            let argument_type = &mut self.infer_nodes[argument_node_index].expr_type;
 
            unsafe {
 
                // safety: we're dealing with different vectors, so cannot alias
 
                argument_type.replace_subtree(0, &(*last_argument_type).parts);
 
            }
 
            progress[argument_index] = true;
 
        }
 

	
 
        return Ok(());
 
    }
 

	
 
    /// Determines the `InferenceType` for the expression based on the
 
    /// expression parent (this is not done if the parent is a regular 'ol
 
    /// expression). Expects `parent_index` to be set to the parent of the
 
    /// inference node that is created here.
 
    fn insert_initial_inference_node(
 
        &mut self, ctx: &mut Ctx, expr_id: ExpressionId
 
    ) -> Result<InferNodeIndex, ParseError> {
 
        use ExpressionParent as EP;
 
        use InferenceTypePart as ITP;
 

	
 
        // Set the initial inference type based on the expression parent.
 
        let expr = &ctx.heap[expr_id];
 
        let inference_type = match expr.parent() {
 
            EP::None =>
 
                // Should have been set by linker
 
                unreachable!(),
 
            EP::Memory(_) | EP::ExpressionStmt(_) =>
 
                // Determined during type inference
 
                InferenceType::new(false, false, vec![ITP::Unknown]),
 
            EP::Expression(parent_id, idx_in_parent) => {
 
                // If we are the test expression of a conditional expression,
 
                // then we must resolve to a boolean
 
                let is_conditional = if let Expression::Conditional(_) = &ctx.heap[*parent_id] {
 
                    true
 
                } else {
 
                    false
 
                };
 

	
 
                if is_conditional && *idx_in_parent == 0 {
 
                    InferenceType::new(false, true, vec![ITP::Bool])
 
                } else {
 
                    InferenceType::new(false, false, vec![ITP::Unknown])
 
                }
 
            },
 
            EP::If(_) | EP::While(_) =>
 
                // Must be a boolean
 
                InferenceType::new(false, true, vec![ITP::Bool]),
 
            EP::Return(_) =>
 
            EP::Return(_) => {
 
                // Must match the return type of the function
 
                if let DefinitionType::Function(func_id) = self.definition_type {
 
                    let returned = &ctx.heap[func_id].return_type;
 
                debug_assert_eq!(self.procedure_kind, ProcedureKind::Function);
 
                let returned = &ctx.heap[self.procedure_id].return_type.as_ref().unwrap();
 
                self.determine_inference_type_from_parser_type_elements(&returned.elements, true)
 
                } else {
 
                    // Cannot happen: definition always set upon body traversal
 
                    // and "return" calls in components are illegal.
 
                    unreachable!();
 
            },
 
            EP::New(_) =>
 
                // Must be a component call, which we assign a "Void" return
 
                // type
 
                InferenceType::new(false, true, vec![ITP::Void]),
 
        };
 

	
 
        let infer_index = self.infer_nodes.len() as InferNodeIndex;
 
        self.infer_nodes.push(InferenceNode {
 
            expr_type: inference_type,
 
            expr_id,
 
            inference_rule: InferenceRule::Noop,
 
            parent_index: self.parent_index,
 
            field_or_monomorph_index: -1,
 
            poly_data_index: -1,
 
            type_id: TypeId::new_invalid(),
 
        });
 

	
 
        return Ok(infer_index);
 
    }
 

	
 
    fn insert_initial_call_polymorph_data(
 
        &mut self, ctx: &mut Ctx, call_id: CallExpressionId
 
    ) -> PolyDataIndex {
 
        // Note: the polymorph variables may be partially specified and may
 
        // contain references to the wrapping definition's (i.e. the proctype
 
        // we are currently visiting) polymorphic arguments.
 
        //
 
        // The arguments of the call may refer to polymorphic variables in the
 
        // definition of the function we're calling, not of the wrapping
 
        // definition. We insert markers in these inferred types to be able to
 
        // map them back and forth to the polymorphic arguments of the function
 
        // we are calling.
 
        let call = &ctx.heap[call_id];
 

	
 
        // Handle the polymorphic arguments (if there are any)
 
        let num_poly_args = call.parser_type.elements[0].variant.num_embedded();
 
        let mut poly_args = Vec::with_capacity(num_poly_args);
 
        for embedded_elements in call.parser_type.iter_embedded(0) {
 
            poly_args.push(self.determine_inference_type_from_parser_type_elements(embedded_elements, true));
 
        }
 

	
 
        // Handle the arguments and return types
 
        let definition = &ctx.heap[call.definition];
 
        let (parameters, returned) = match definition {
 
            Definition::Component(definition) => {
 
                debug_assert_eq!(poly_args.len(), definition.poly_vars.len());
 
                (&definition.parameters, None)
 
            },
 
            Definition::Function(definition) => {
 
        let definition = &ctx.heap[call.procedure];
 
        debug_assert_eq!(poly_args.len(), definition.poly_vars.len());
 
                (&definition.parameters, Some(&definition.return_type))
 
            },
 
            Definition::Struct(_) | Definition::Enum(_) | Definition::Union(_) => {
 
                unreachable!("insert_initial_call_polymorph data for non-procedure type");
 
            },
 
        };
 

	
 
        let mut parameter_types = Vec::with_capacity(parameters.len());
 
        for parameter_id in parameters.clone().into_iter() { // TODO: @Performance @Now
 
        let mut parameter_types = Vec::with_capacity(definition.parameters.len());
 
        let parameter_section = self.var_buffer.start_section_initialized(&definition.parameters);
 
        for parameter_id in parameter_section.iter_copied() {
 
            let param = &ctx.heap[parameter_id];
 
            parameter_types.push(self.determine_inference_type_from_parser_type_elements(&param.parser_type.elements, false));
 
        }
 
        parameter_section.forget();
 

	
 
        let return_type = match returned {
 
        let return_type = match &definition.return_type {
 
            None => {
 
                // Component, so returns a "Void"
 
                debug_assert_ne!(definition.kind, ProcedureKind::Function);
 
                InferenceType::new(false, true, vec![InferenceTypePart::Void])
 
            },
 
            Some(returned) => {
 
                debug_assert_eq!(definition.kind, ProcedureKind::Function);
 
                self.determine_inference_type_from_parser_type_elements(&returned.elements, false)
 
            }
 
        };
 

	
 
        let extra_data_idx = self.poly_data.len() as PolyDataIndex;
 
        self.poly_data.push(PolyData {
 
            first_rule_application: true,
 
            definition_id: call.definition,
 
            definition_id: call.procedure.upcast(),
 
            poly_vars: poly_args,
 
            expr_types: PolyDataTypes {
 
                associated: parameter_types,
 
                returned: return_type
 
            }
 
        });
 
        return extra_data_idx
 
    }
 

	
 
    fn insert_initial_struct_polymorph_data(
 
        &mut self, ctx: &mut Ctx, lit_id: LiteralExpressionId,
 
    ) -> PolyDataIndex {
 
        use InferenceTypePart as ITP;
 
        let literal = ctx.heap[lit_id].value.as_struct();
 

	
 
        // Handle polymorphic arguments
 
        let num_embedded = literal.parser_type.elements[0].variant.num_embedded();
 
        let mut total_num_poly_parts = 0;
 
        let mut poly_args = Vec::with_capacity(num_embedded);
 

	
 
        for embedded_elements in literal.parser_type.iter_embedded(0) {
 
            let poly_type = self.determine_inference_type_from_parser_type_elements(embedded_elements, true);
 
            total_num_poly_parts += poly_type.parts.len();
 
            poly_args.push(poly_type);
 
        }
 

	
 
        // Handle parser types on struct definition
 
        let defined_type = ctx.types.get_base_definition(&literal.definition).unwrap();
 
        let struct_type = defined_type.definition.as_struct();
 
        debug_assert_eq!(poly_args.len(), defined_type.poly_vars.len());
 

	
 
        // Note: programmer is capable of specifying fields in a struct literal
 
        // in a different order than on the definition. We take the literal-
 
        // specified order to be leading.
 
        let mut embedded_types = Vec::with_capacity(struct_type.fields.len());
 
        for lit_field in literal.fields.iter() {
 
            let def_field = &struct_type.fields[lit_field.field_idx];
 
            let inference_type = self.determine_inference_type_from_parser_type_elements(&def_field.parser_type.elements, false);
 
            embedded_types.push(inference_type);
 
        }
 

	
 
        // Return type is the struct type itself, with the appropriate 
 
        // polymorphic variables. So:
 
        // - 1 part for definition
 
        // - N_poly_arg marker parts for each polymorphic argument
 
        // - all the parts for the currently known polymorphic arguments 
 
        let parts_reserved = 1 + poly_args.len() + total_num_poly_parts;
 
        let mut parts = Vec::with_capacity(parts_reserved);
 
        parts.push(ITP::Instance(literal.definition, poly_args.len() as u32));
 
        let mut return_type_done = true;
 
        for (poly_var_idx, poly_var) in poly_args.iter().enumerate() {
 
            if !poly_var.is_done { return_type_done = false; }
 

	
 
            parts.push(ITP::Marker(poly_var_idx as u32));
 
            parts.extend(poly_var.parts.iter().cloned());
 
        }
 

	
 
        debug_assert_eq!(parts.len(), parts_reserved);
 
        let return_type = InferenceType::new(!poly_args.is_empty(), return_type_done, parts);
 

	
 
        let extra_data_index = self.poly_data.len() as PolyDataIndex;
 
        self.poly_data.push(PolyData {
 
            first_rule_application: true,
 
            definition_id: literal.definition,
 
            poly_vars: poly_args,
 
            expr_types: PolyDataTypes {
 
                associated: embedded_types,
 
                returned: return_type,
 
            },
 
        });
 

	
 
        return extra_data_index
 
    }
 

	
 
    /// Inserts the extra polymorphic data struct for enum expressions. These
 
    /// can never be determined from the enum itself, but may be inferred from
 
    /// the use of the enum.
 
    fn insert_initial_enum_polymorph_data(
 
        &mut self, ctx: &Ctx, lit_id: LiteralExpressionId
 
    ) -> PolyDataIndex {
 
        use InferenceTypePart as ITP;
 
        let literal = ctx.heap[lit_id].value.as_enum();
 

	
 
        // Handle polymorphic arguments to the enum
 
        let num_poly_args = literal.parser_type.elements[0].variant.num_embedded();
 
        let mut total_num_poly_parts = 0;
 
        let mut poly_args = Vec::with_capacity(num_poly_args);
 

	
 
        for embedded_elements in literal.parser_type.iter_embedded(0) {
 
            let poly_type = self.determine_inference_type_from_parser_type_elements(embedded_elements, true);
 
            total_num_poly_parts += poly_type.parts.len();
 
            poly_args.push(poly_type);
 
        }
 

	
 
        // Handle enum type itself
 
        let parts_reserved = 1 + poly_args.len() + total_num_poly_parts;
 
@@ -3732,193 +3658,193 @@ impl PassTyping {
 
        let struct_parts_reserved = 1 + 2 * num_poly_vars;
 
        let mut struct_parts = Vec::with_capacity(struct_parts_reserved);
 
        struct_parts.push(ITP::Instance(struct_def_id, num_poly_vars as u32));
 

	
 
        for poly_idx in 0..num_poly_vars {
 
            poly_vars.push(InferenceType::new(true, false, vec![
 
                ITP::Marker(poly_idx as u32), ITP::Unknown,
 
            ]));
 
            struct_parts.push(ITP::Marker(poly_idx as u32));
 
            struct_parts.push(ITP::Unknown);
 
        }
 
        debug_assert_eq!(struct_parts.len(), struct_parts_reserved);
 

	
 
        // Generate initial field type
 
        let field_type = self.determine_inference_type_from_parser_type_elements(&definition.fields[field_index].parser_type.elements, false);
 

	
 
        let extra_data_index = self.poly_data.len() as PolyDataIndex;
 
        self.poly_data.push(PolyData {
 
            first_rule_application: true,
 
            definition_id: struct_def_id,
 
            poly_vars,
 
            expr_types: PolyDataTypes {
 
                associated: vec![InferenceType::new(num_poly_vars != 0, num_poly_vars == 0, struct_parts)],
 
                returned: field_type,
 
            },
 
        });
 

	
 
        return extra_data_index;
 
    }
 

	
 
    /// Determines the initial InferenceType from the provided ParserType. This
 
    /// may be called with two kinds of intentions:
 
    /// 1. To resolve a ParserType within the body of a function, or on
 
    ///     polymorphic arguments to calls/instantiations within that body. This
 
    ///     means that the polymorphic variables are known and can be replaced
 
    ///     with the monomorph we're instantiating.
 
    /// 2. To resolve a ParserType on a called function's definition or on
 
    ///     an instantiated datatype's members. This means that the polymorphic
 
    ///     arguments inside those ParserTypes refer to the polymorphic
 
    ///     variables in the called/instantiated type's definition.
 
    /// In the second case we place InferenceTypePart::Marker instances such
 
    /// that we can perform type inference on the polymorphic variables.
 
    fn determine_inference_type_from_parser_type_elements(
 
        &mut self, elements: &[ParserTypeElement],
 
        use_definitions_known_poly_args: bool
 
    ) -> InferenceType {
 
        use ParserTypeVariant as PTV;
 
        use InferenceTypePart as ITP;
 

	
 
        let mut infer_type = Vec::with_capacity(elements.len());
 
        let mut has_inferred = false;
 
        let mut has_markers = false;
 

	
 
        for element in elements {
 
            match &element.variant {
 
                // Compiler-only types
 
                PTV::Void => { infer_type.push(ITP::Void); },
 
                PTV::InputOrOutput => { infer_type.push(ITP::PortLike); has_inferred = true },
 
                PTV::ArrayLike => { infer_type.push(ITP::ArrayLike); has_inferred = true },
 
                PTV::IntegerLike => { infer_type.push(ITP::IntegerLike); has_inferred = true },
 
                // Builtins
 
                PTV::Message => {
 
                    // TODO: @types Remove the Message -> Byte hack at some point...
 
                    infer_type.push(ITP::Message);
 
                    infer_type.push(ITP::UInt8);
 
                },
 
                PTV::Bool => { infer_type.push(ITP::Bool); },
 
                PTV::UInt8 => { infer_type.push(ITP::UInt8); },
 
                PTV::UInt16 => { infer_type.push(ITP::UInt16); },
 
                PTV::UInt32 => { infer_type.push(ITP::UInt32); },
 
                PTV::UInt64 => { infer_type.push(ITP::UInt64); },
 
                PTV::SInt8 => { infer_type.push(ITP::SInt8); },
 
                PTV::SInt16 => { infer_type.push(ITP::SInt16); },
 
                PTV::SInt32 => { infer_type.push(ITP::SInt32); },
 
                PTV::SInt64 => { infer_type.push(ITP::SInt64); },
 
                PTV::Character => { infer_type.push(ITP::Character); },
 
                PTV::String => {
 
                    infer_type.push(ITP::String);
 
                    infer_type.push(ITP::Character);
 
                },
 
                // Special markers
 
                PTV::IntegerLiteral => { unreachable!("integer literal type on variable type"); },
 
                PTV::Inferred => {
 
                    infer_type.push(ITP::Unknown);
 
                    has_inferred = true;
 
                },
 
                // With nested types
 
                PTV::Array => { infer_type.push(ITP::Array); },
 
                PTV::Input => { infer_type.push(ITP::Input); },
 
                PTV::Output => { infer_type.push(ITP::Output); },
 
                PTV::Tuple(num_embedded) => { infer_type.push(ITP::Tuple(*num_embedded)); },
 
                PTV::PolymorphicArgument(belongs_to_definition, poly_arg_idx) => {
 
                    let poly_arg_idx = *poly_arg_idx;
 
                    if use_definitions_known_poly_args {
 
                        // Refers to polymorphic argument on procedure we're currently processing.
 
                        // This argument is already known.
 
                        debug_assert_eq!(*belongs_to_definition, self.definition_type.definition_id());
 
                        debug_assert_eq!(*belongs_to_definition, self.procedure_id.upcast());
 
                        debug_assert!((poly_arg_idx as usize) < self.poly_vars.len());
 

	
 
                        Self::determine_inference_type_from_concrete_type(
 
                            &mut infer_type, &self.poly_vars[poly_arg_idx as usize].parts
 
                        );
 
                    } else {
 
                        // Polymorphic argument has to be inferred
 
                        has_markers = true;
 
                        has_inferred = true;
 
                        infer_type.push(ITP::Marker(poly_arg_idx));
 
                        infer_type.push(ITP::Unknown)
 
                    }
 
                },
 
                PTV::Definition(definition_id, num_embedded) => {
 
                    infer_type.push(ITP::Instance(*definition_id, *num_embedded));
 
                }
 
            }
 
        }
 

	
 
        InferenceType::new(has_markers, !has_inferred, infer_type)
 
    }
 

	
 
    /// Determines the inference type from an already concrete type. Applies the
 
    /// various type "hacks" inside the type inferencer.
 
    fn determine_inference_type_from_concrete_type(parser_type: &mut Vec<InferenceTypePart>, concrete_type: &[ConcreteTypePart]) {
 
        use InferenceTypePart as ITP;
 
        use ConcreteTypePart as CTP;
 

	
 
        for concrete_part in concrete_type {
 
            match concrete_part {
 
                CTP::Void => parser_type.push(ITP::Void),
 
                CTP::Message => {
 
                    parser_type.push(ITP::Message);
 
                    parser_type.push(ITP::UInt8)
 
                },
 
                CTP::Bool => parser_type.push(ITP::Bool),
 
                CTP::UInt8 => parser_type.push(ITP::UInt8),
 
                CTP::UInt16 => parser_type.push(ITP::UInt16),
 
                CTP::UInt32 => parser_type.push(ITP::UInt32),
 
                CTP::UInt64 => parser_type.push(ITP::UInt64),
 
                CTP::SInt8 => parser_type.push(ITP::SInt8),
 
                CTP::SInt16 => parser_type.push(ITP::SInt16),
 
                CTP::SInt32 => parser_type.push(ITP::SInt32),
 
                CTP::SInt64 => parser_type.push(ITP::SInt64),
 
                CTP::Character => parser_type.push(ITP::Character),
 
                CTP::String => {
 
                    parser_type.push(ITP::String);
 
                    parser_type.push(ITP::Character)
 
                },
 
                CTP::Array => parser_type.push(ITP::Array),
 
                CTP::Slice => parser_type.push(ITP::Slice),
 
                CTP::Input => parser_type.push(ITP::Input),
 
                CTP::Output => parser_type.push(ITP::Output),
 
                CTP::Pointer => unreachable!("pointer type during concrete to inference type conversion"),
 
                CTP::Tuple(num) => parser_type.push(ITP::Tuple(*num)),
 
                CTP::Instance(id, num) => parser_type.push(ITP::Instance(*id, *num)),
 
                CTP::Function(_, _) => unreachable!("function type during concrete to inference type conversion"),
 
                CTP::Component(_, _) => unreachable!("component type during concrete to inference type conversion"),
 
            }
 
        }
 
    }
 

	
 
    /// Construct an error when an expression's type does not match. This
 
    /// happens if we infer the expression type from its arguments (e.g. the
 
    /// expression type of an addition operator is the type of the arguments)
 
    /// But the expression type was already set due to our parent (e.g. an
 
    /// "if statement" or a "logical not" always expecting a boolean)
 
    fn construct_expr_type_error(
 
        &self, ctx: &Ctx, expr_index: InferNodeIndex, arg_index: InferNodeIndex
 
    ) -> ParseError {
 
        // TODO: Expand and provide more meaningful information for humans
 
        let expr_node = &self.infer_nodes[expr_index];
 
        let arg_node = &self.infer_nodes[arg_index];
 

	
 
        let expr = &ctx.heap[expr_node.expr_id];
 
        let arg = &ctx.heap[arg_node.expr_id];
 

	
 
        return ParseError::new_error_at_span(
 
            &ctx.module().source, expr.operation_span(), format!(
 
                "incompatible types: this expression expected a '{}'",
 
                expr_node.expr_type.display_name(&ctx.heap)
 
            )
 
        ).with_info_at_span(
 
            &ctx.module().source, arg.full_span(), format!(
 
                "but this expression yields a '{}'",
 
                arg_node.expr_type.display_name(&ctx.heap)
 
            )
 
        )
 
    }
 

	
 
    fn construct_arg_type_error(
 
        &self, ctx: &Ctx, expr_index: InferNodeIndex,
 
        arg1_index: InferNodeIndex, arg2_index: InferNodeIndex
 
    ) -> ParseError {
 
        let arg1_node = &self.infer_nodes[arg1_index];
 
        let arg2_node = &self.infer_nodes[arg2_index];
src/protocol/parser/pass_validation_linking.rs
Show inline comments
 
/*
 
 * pass_validation_linking.rs
 
 *
 
 * The pass that will validate properties of the AST statements (one is not
 
 * allowed to nest synchronous statements, instantiating components occurs in
 
 * the right places, etc.) and expressions (assignments may not occur in
 
 * arbitrary expressions).
 
 *
 
 * Furthermore, this pass will also perform "linking", in the sense of: some AST
 
 * nodes have something to do with one another, so we link them up in this pass
 
 * (e.g. setting the parents of expressions, linking the control flow statements
 
 * like `continue` and `break` up to the respective loop statement, etc.).
 
 *
 
 * There are several "confusing" parts about this pass:
 
 *
 
 * Setting expression parents: this is the simplest one. The pass struct acts
 
 * like a little state machine. When visiting an expression it will set the
 
 * "parent expression" field of the pass to itself, then visit its child. The
 
 * child will look at this "parent expression" field to determine its parent.
 
 *
 
 * Setting the `next` statement: the AST is a tree, but during execution we walk
 
 * a linear path through all statements. So where appropriate a statement may
 
 * set the "previous statement" field of the pass to itself. When visiting the
 
 * subsequent statement it will check this "previous statement", and if set, it
 
 * will link this previous statement up to itself. Not every statement has a
 
 * previous statement. Hence there are two patterns that occur: assigning the
 
 * `next` value, then clearing the "previous statement" field. And assigning the
 
 * `next` value, and then putting the current statement's ID in the "previous
 
 * statement" field. Because it is so common, this file contain two macros that
 
 * perform that operation.
 
 *
 
 * To make storing types for polymorphic procedures simpler and more efficient,
 
 * we assign to each expression in the procedure a unique ID. This is what the
 
 * "next expression index" field achieves. Each expression simply takes the
 
 * current value, and then increments this counter.
 
 */
 

	
 
use crate::collections::{ScopedBuffer};
 
use crate::protocol::ast::*;
 
use crate::protocol::input_source::*;
 
use crate::protocol::parser::symbol_table::*;
 
use crate::protocol::parser::type_table::*;
 

	
 
use super::visitor::{
 
    BUFFER_INIT_CAP_SMALL,
 
    BUFFER_INIT_CAP_LARGE,
 
    Ctx,
 
    Visitor,
 
    VisitorResult
 
};
 
use crate::protocol::parser::ModuleCompilationPhase;
 

	
 
#[derive(PartialEq, Eq)]
 
enum DefinitionType {
 
    Primitive(ComponentDefinitionId),
 
    Composite(ComponentDefinitionId),
 
    Function(FunctionDefinitionId)
 
}
 

	
 
impl DefinitionType {
 
    fn is_primitive(&self) -> bool { if let Self::Primitive(_) = self { true } else { false } }
 
    fn is_composite(&self) -> bool { if let Self::Composite(_) = self { true } else { false } }
 
    fn is_function(&self) -> bool { if let Self::Function(_) = self { true } else { false } }
 
    fn definition_id(&self) -> DefinitionId {
 
        match self {
 
            DefinitionType::Primitive(v) => v.upcast(),
 
            DefinitionType::Composite(v) => v.upcast(),
 
            DefinitionType::Function(v) => v.upcast(),
 
        }
 
    }
 
}
 

	
 
struct ControlFlowStatement {
 
    in_sync: SynchronousStatementId,
 
    in_while: WhileStatementId,
 
    in_scope: ScopeId,
 
    statement: StatementId, // of 'break', 'continue' or 'goto'
 
}
 

	
 
/// This particular visitor will go through the entire AST in a recursive manner
 
/// and check if all statements and expressions are legal (e.g. no "return"
 
/// statements in component definitions), and will link certain AST nodes to
 
/// their appropriate targets (e.g. goto statements, or function calls).
 
///
 
/// This visitor will not perform control-flow analysis (e.g. making sure that
 
/// each function actually returns) and will also not perform type checking. So
 
/// the linking of function calls and component instantiations will be checked
 
/// and linked to the appropriate definitions, but the return types and/or
 
/// arguments will not be checked for validity.
 
///
 
/// The main idea is, because we're visiting nodes in a tree, to do as much as
 
/// we can while we have the memory in cache.
 
pub(crate) struct PassValidationLinking {
 
    // Traversal state, all valid IDs if inside a certain AST element. Otherwise
 
    // `id.is_invalid()` returns true.
 
    in_sync: SynchronousStatementId,
 
    in_while: WhileStatementId, // to resolve labeled continue/break
 
    in_select_guard: SelectStatementId, // for detection/rejection of builtin calls
 
    in_select_arm: u32,
 
    in_test_expr: StatementId, // wrapping if/while stmt id
 
    in_binding_expr: BindingExpressionId, // to resolve variable expressions
 
    in_binding_expr_lhs: bool,
 
    // Traversal state, current scope (which can be used to find the parent
 
    // scope) and the definition variant we are considering.
 
    cur_scope: ScopeId,
 
    def_type: DefinitionType,
 
    proc_id: ProcedureDefinitionId,
 
    proc_kind: ProcedureKind,
 
    // "Trailing" traversal state, set be child/prev stmt/expr used by next one
 
    prev_stmt: StatementId,
 
    expr_parent: ExpressionParent,
 
    // Set by parent to indicate that child expression must be assignable. The
 
    // child will throw an error if it is not assignable. The stored span is
 
    // used for the error's position
 
    must_be_assignable: Option<InputSpan>,
 
    // Keeping track of relative positions and unique IDs.
 
    relative_pos_in_parent: i32, // of statements: to determine when variables are visible
 
    next_expr_index: i32, // to arrive at a unique ID for all expressions within a definition
 
    // Control flow statements that require label resolving
 
    control_flow_stmts: Vec<ControlFlowStatement>,
 
    // Various temporary buffers for traversal. Essentially working around
 
    // Rust's borrowing rules since it cannot understand we're modifying AST
 
    // members but not the AST container.
 
    variable_buffer: ScopedBuffer<VariableId>,
 
    definition_buffer: ScopedBuffer<DefinitionId>,
 
    statement_buffer: ScopedBuffer<StatementId>,
 
    expression_buffer: ScopedBuffer<ExpressionId>,
 
    scope_buffer: ScopedBuffer<ScopeId>,
 
}
 

	
 
impl PassValidationLinking {
 
    pub(crate) fn new() -> Self {
 
        Self{
 
            in_sync: SynchronousStatementId::new_invalid(),
 
            in_while: WhileStatementId::new_invalid(),
 
            in_select_guard: SelectStatementId::new_invalid(),
 
            in_select_arm: 0,
 
            in_test_expr: StatementId::new_invalid(),
 
            in_binding_expr: BindingExpressionId::new_invalid(),
 
            in_binding_expr_lhs: false,
 
            cur_scope: ScopeId::new_invalid(),
 
            prev_stmt: StatementId::new_invalid(),
 
            expr_parent: ExpressionParent::None,
 
            def_type: DefinitionType::Function(FunctionDefinitionId::new_invalid()),
 
            proc_id: ProcedureDefinitionId::new_invalid(),
 
            proc_kind: ProcedureKind::Function,
 
            must_be_assignable: None,
 
            relative_pos_in_parent: 0,
 
            next_expr_index: 0,
 
            control_flow_stmts: Vec::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            variable_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            definition_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            statement_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            expression_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            scope_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
        }
 
    }
 

	
 
    fn reset_state(&mut self) {
 
        self.in_sync = SynchronousStatementId::new_invalid();
 
        self.in_while = WhileStatementId::new_invalid();
 
        self.in_select_guard = SelectStatementId::new_invalid();
 
        self.in_test_expr = StatementId::new_invalid();
 
        self.in_binding_expr = BindingExpressionId::new_invalid();
 
        self.in_binding_expr_lhs = false;
 
        self.cur_scope = ScopeId::new_invalid();
 
        self.def_type = DefinitionType::Function(FunctionDefinitionId::new_invalid());
 
        self.proc_id = ProcedureDefinitionId::new_invalid();
 
        self.proc_kind = ProcedureKind::Function;
 
        self.prev_stmt = StatementId::new_invalid();
 
        self.expr_parent = ExpressionParent::None;
 
        self.must_be_assignable = None;
 
        self.relative_pos_in_parent = 0;
 
        self.next_expr_index = 0;
 
        self.control_flow_stmts.clear();
 
    }
 
}
 

	
 
macro_rules! assign_then_erase_next_stmt {
 
    ($self:ident, $ctx:ident, $stmt_id:expr) => {
 
        if !$self.prev_stmt.is_invalid() {
 
            $ctx.heap[$self.prev_stmt].link_next($stmt_id);
 
            $self.prev_stmt = StatementId::new_invalid();
 
        }
 
    }
 
}
 

	
 
macro_rules! assign_and_replace_next_stmt {
 
    ($self:ident, $ctx:ident, $stmt_id:expr) => {
 
        if !$self.prev_stmt.is_invalid() {
 
            $ctx.heap[$self.prev_stmt].link_next($stmt_id);
 
        }
 
        $self.prev_stmt = $stmt_id;
 
    }
 
}
 

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

	
 
        let root = &ctx.heap[ctx.module().root_id];
 
        let section = self.definition_buffer.start_section_initialized(&root.definitions);
 
        for definition_id in section.iter_copied() {
 
            self.visit_definition(ctx, definition_id)?;
 
        }
 
        section.forget();
 

	
 
        ctx.module_mut().phase = ModuleCompilationPhase::ValidatedAndLinked;
 
        Ok(())
 
    }
 
    //--------------------------------------------------------------------------
 
    // Definition visitors
 
    //--------------------------------------------------------------------------
 

	
 
    fn visit_component_definition(&mut self, ctx: &mut Ctx, id: ComponentDefinitionId) -> VisitorResult {
 
    fn visit_procedure_definition(&mut self, ctx: &mut Ctx, id: ProcedureDefinitionId) -> VisitorResult {
 
        self.reset_state();
 

	
 
        let definition = &ctx.heap[id];
 
        self.def_type = match &definition.variant {
 
            ComponentVariant::Primitive => DefinitionType::Primitive(id),
 
            ComponentVariant::Composite => DefinitionType::Composite(id),
 
        };
 
        self.proc_id = id;
 
        self.proc_kind = definition.kind;
 
        self.expr_parent = ExpressionParent::None;
 

	
 
        // Visit parameters and assign a unique scope ID
 
        let definition_scope_id = definition.scope;
 
        let old_scope = self.push_scope(ctx, true, definition_scope_id);
 

	
 
        let definition = &ctx.heap[id];
 
        let body_id = definition.body;
 
        let section = self.variable_buffer.start_section_initialized(&definition.parameters);
 
        for variable_idx in 0..section.len() {
 
            let variable_id = section[variable_idx];
 
            self.checked_at_single_scope_add_local(ctx, self.cur_scope, -1, variable_id)?;
 
        }
 
        self.relative_pos_in_parent = section.len() as i32;
 

	
 
        section.forget();
 

	
 
        // Visit statements in component body
 
        self.visit_block_stmt(ctx, body_id)?;
 
        self.pop_scope(old_scope);
 

	
 
        // Assign total number of expressions and assign an in-block unique ID
 
        // to each of the locals in the procedure.
 
        let definition = &mut ctx.heap[id];
 
        definition.num_expressions_in_body = self.next_expr_index;
 

	
 
        self.resolve_pending_control_flow_targets(ctx)?;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_function_definition(&mut self, ctx: &mut Ctx, id: FunctionDefinitionId) -> VisitorResult {
 
        self.reset_state();
 

	
 
        // Set internal statement indices
 
        self.def_type = DefinitionType::Function(id);
 
        self.expr_parent = ExpressionParent::None;
 

	
 
        // Visit parameters and assign a unique scope ID
 
        let definition = &ctx.heap[id];
 
        let definition_scope_id = definition.scope;
 
        let old_scope = self.push_scope(ctx, true, definition_scope_id);
 
        // Visit parameters
 
        let scope_id = definition.scope;
 
        let old_scope = self.push_scope(ctx, true, scope_id);
 

	
 
        let definition = &ctx.heap[id];
 
        let body_id = definition.body;
 
        let section = self.variable_buffer.start_section_initialized(&definition.parameters);
 
        for variable_idx in 0..section.len() {
 
            let variable_id = section[variable_idx];
 
            self.checked_at_single_scope_add_local(ctx, self.cur_scope, -1, variable_id)?;
 
        }
 
        section.forget();
 

	
 
        // Visit statements in function body
 
        self.visit_block_stmt(ctx, body_id)?;
 
        self.pop_scope(old_scope);
 

	
 
        // Assign total number of expressions and assign an in-block unique ID
 
        // to each of the locals in the procedure.
 
        let definition = &mut ctx.heap[id];
 
        definition.num_expressions_in_body = self.next_expr_index;
 

	
 
        self.resolve_pending_control_flow_targets(ctx)?;
 

	
 
        Ok(())
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // Statement visitors
 
    //--------------------------------------------------------------------------
 

	
 
    fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
 
        // Get end of block
 
        let block_stmt = &ctx.heap[id];
 
        let end_block_id = block_stmt.end_block;
 
        let scope_id = block_stmt.scope;
 

	
 
        // Traverse statements in block
 
        let statement_section = self.statement_buffer.start_section_initialized(&block_stmt.statements);
 
        let old_scope = self.push_scope(ctx, false, scope_id);
 
        assign_and_replace_next_stmt!(self, ctx, id.upcast());
 

	
 
        for stmt_idx in 0..statement_section.len() {
 
            self.relative_pos_in_parent = stmt_idx as i32;
 
            self.visit_stmt(ctx, statement_section[stmt_idx])?;
 
        }
 

	
 
        statement_section.forget();
 
        assign_and_replace_next_stmt!(self, ctx, end_block_id.upcast());
 

	
 
        self.pop_scope(old_scope);
 
        Ok(())
 
    }
 

	
 
    fn visit_local_memory_stmt(&mut self, ctx: &mut Ctx, id: MemoryStatementId) -> VisitorResult {
 
        let stmt = &ctx.heap[id];
 
        let expr_id = stmt.initial_expr;
 
        let variable_id = stmt.variable;
 

	
 
        self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_parent, variable_id)?;
 

	
 
        assign_and_replace_next_stmt!(self, ctx, id.upcast().upcast());
 
        debug_assert_eq!(self.expr_parent, ExpressionParent::None);
 
        self.expr_parent = ExpressionParent::Memory(id);
 
        self.visit_assignment_expr(ctx, expr_id)?;
 
        self.expr_parent = ExpressionParent::None;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_local_channel_stmt(&mut self, ctx: &mut Ctx, id: ChannelStatementId) -> VisitorResult {
 
        let stmt = &ctx.heap[id];
 
        let from_id = stmt.from;
 
        let to_id = stmt.to;
 

	
 
        self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_parent, from_id)?;
 
        self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_parent, to_id)?;
 

	
 
        assign_and_replace_next_stmt!(self, ctx, id.upcast().upcast());
 
        Ok(())
 
    }
 

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

	
 
        self.checked_add_label(ctx, self.relative_pos_in_parent, self.in_sync, id)?;
 

	
 
        self.visit_stmt(ctx, body_id)?;
 
        Ok(())
 
    }
 

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

	
 
@@ -367,352 +311,352 @@ impl Visitor for PassValidationLinking {
 
        // test expression, not on if-statement itself. Hence the if statement
 
        // does not have a static subsequent statement.
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 
        let old_scope = self.push_scope(ctx, false, true_case.scope);
 
        self.visit_stmt(ctx, true_case.body)?;
 
        self.pop_scope(old_scope);
 
        assign_then_erase_next_stmt!(self, ctx, end_if_id.upcast());
 

	
 
        if let Some(false_case) = false_case {
 
            let old_scope = self.push_scope(ctx, false, false_case.scope);
 
            self.visit_stmt(ctx, false_case.body)?;
 
            self.pop_scope(old_scope);
 
            assign_then_erase_next_stmt!(self, ctx, end_if_id.upcast());
 
        }
 

	
 
        self.prev_stmt = end_if_id.upcast();
 
        Ok(())
 
    }
 

	
 
    fn visit_while_stmt(&mut self, ctx: &mut Ctx, id: WhileStatementId) -> VisitorResult {
 
        let stmt = &ctx.heap[id];
 
        let end_while_id = stmt.end_while;
 
        let test_expr_id = stmt.test;
 
        let body_stmt_id = stmt.body;
 
        let scope_id = stmt.scope;
 

	
 
        let old_while = self.in_while;
 
        self.in_while = id;
 

	
 
        // Visit test expression
 
        debug_assert_eq!(self.expr_parent, ExpressionParent::None);
 
        debug_assert!(self.in_test_expr.is_invalid());
 
        self.in_test_expr = id.upcast();
 
        self.expr_parent = ExpressionParent::While(id);
 
        self.visit_expr(ctx, test_expr_id)?;
 
        self.in_test_expr = StatementId::new_invalid();
 

	
 
        // Link up to body statement
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 

	
 
        self.expr_parent = ExpressionParent::None;
 
        let old_scope = self.push_scope(ctx, false, scope_id);
 
        self.visit_stmt(ctx, body_stmt_id)?;
 
        self.pop_scope(old_scope);
 
        self.in_while = old_while;
 

	
 
        // Link final entry in while's block statement back to the while. The
 
        // executor will go to the end-while statement if the test expression
 
        // is false, so put that in as the new previous stmt
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 
        self.prev_stmt = end_while_id.upcast();
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_break_stmt(&mut self, ctx: &mut Ctx, id: BreakStatementId) -> VisitorResult {
 
        self.control_flow_stmts.push(ControlFlowStatement{
 
            in_sync: self.in_sync,
 
            in_while: self.in_while,
 
            in_scope: self.cur_scope,
 
            statement: id.upcast()
 
        });
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_continue_stmt(&mut self, ctx: &mut Ctx, id: ContinueStatementId) -> VisitorResult {
 
        self.control_flow_stmts.push(ControlFlowStatement{
 
            in_sync: self.in_sync,
 
            in_while: self.in_while,
 
            in_scope: self.cur_scope,
 
            statement: id.upcast()
 
        });
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_synchronous_stmt(&mut self, ctx: &mut Ctx, id: SynchronousStatementId) -> VisitorResult {
 
        // Check for validity of synchronous statement
 
        let sync_stmt = &ctx.heap[id];
 
        let end_sync_id = sync_stmt.end_sync;
 
        let cur_sync_span = sync_stmt.span;
 
        let scope_id = sync_stmt.scope;
 

	
 
        if !self.in_sync.is_invalid() {
 
            // Nested synchronous statement
 
            let old_sync_span = ctx.heap[self.in_sync].span;
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, cur_sync_span, "Illegal nested synchronous statement"
 
            ).with_info_str_at_span(
 
                &ctx.module().source, old_sync_span, "It is nested in this synchronous statement"
 
            ));
 
        }
 

	
 
        if !self.def_type.is_primitive() {
 
        if self.proc_kind != ProcedureKind::Primitive {
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, cur_sync_span,
 
                "synchronous statements may only be used in primitive components"
 
            ));
 
        }
 

	
 
        // Synchronous statement implicitly moves to its block
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 

	
 
        // Visit block statement. Note that we explicitly push the scope here
 
        // (and the `visit_block_stmt` will also push, but without effect) to
 
        // ensure the scope contains the sync ID.
 
        let sync_body = ctx.heap[id].body;
 
        debug_assert!(self.in_sync.is_invalid());
 
        self.in_sync = id;
 
        let old_scope = self.push_scope(ctx, false, scope_id);
 
        self.visit_stmt(ctx, sync_body)?;
 
        self.pop_scope(old_scope);
 
        assign_and_replace_next_stmt!(self, ctx, end_sync_id.upcast());
 

	
 
        self.in_sync = SynchronousStatementId::new_invalid();
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_fork_stmt(&mut self, ctx: &mut Ctx, id: ForkStatementId) -> VisitorResult {
 
        let fork_stmt = &ctx.heap[id];
 
        let end_fork_id = fork_stmt.end_fork;
 
        let left_body_id = fork_stmt.left_body;
 
        let right_body_id = fork_stmt.right_body;
 

	
 
        // Fork statements may only occur inside sync blocks
 
        if self.in_sync.is_invalid() {
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, fork_stmt.span,
 
                "Forking may only occur inside sync blocks"
 
            ));
 
        }
 

	
 
        // Visit the respective bodies. Like the if statement, a fork statement
 
        // does not have a single static subsequent statement. It forks and then
 
        // each fork has a different next statement.
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 
        self.visit_stmt(ctx, left_body_id)?;
 
        assign_then_erase_next_stmt!(self, ctx, end_fork_id.upcast());
 

	
 
        if let Some(right_body_id) = right_body_id {
 
            self.visit_stmt(ctx, right_body_id)?;
 
            assign_then_erase_next_stmt!(self, ctx, end_fork_id.upcast());
 
        }
 

	
 
        self.prev_stmt = end_fork_id.upcast();
 
        Ok(())
 
    }
 

	
 
    fn visit_select_stmt(&mut self, ctx: &mut Ctx, id: SelectStatementId) -> VisitorResult {
 
        let select_stmt = &mut ctx.heap[id];
 
        select_stmt.relative_pos_in_parent = self.relative_pos_in_parent;
 
        self.relative_pos_in_parent += 1;
 

	
 
        let select_stmt = &ctx.heap[id];
 
        let end_select_id = select_stmt.end_select;
 

	
 
        // Select statements may only occur inside sync blocks
 
        if self.in_sync.is_invalid() {
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, select_stmt.span,
 
                "select statements may only occur inside sync blocks"
 
            ));
 
        }
 

	
 
        if !self.def_type.is_primitive() {
 
        if self.proc_kind != ProcedureKind::Primitive {
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, select_stmt.span,
 
                "select statements may only be used in primitive components"
 
            ));
 
        }
 

	
 
        // Visit the various arms in the select block
 
        let mut case_stmt_ids = self.statement_buffer.start_section();
 
        let mut case_scope_ids = self.scope_buffer.start_section();
 
        let num_cases = select_stmt.cases.len();
 
        for case in &select_stmt.cases {
 
            // We add them in pairs, so the subsequent for-loop retrieves in pairs
 
            case_stmt_ids.push(case.guard);
 
            case_stmt_ids.push(case.body);
 
            case_scope_ids.push(case.scope);
 
        }
 

	
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 

	
 
        for index in 0..num_cases {
 
            let base_index = 2 * index;
 
            let guard_id     = case_stmt_ids[base_index];
 
            let case_body_id = case_stmt_ids[base_index + 1];
 
            let case_scope_id = case_scope_ids[index];
 

	
 
            // The guard statement ends up belonging to the block statement
 
            // following the arm. The reason we parse it separately is to
 
            // extract all of the "get" calls.
 
            let old_scope = self.push_scope(ctx, false, case_scope_id);
 

	
 
            // Visit the guard of this arm
 
            debug_assert!(self.in_select_guard.is_invalid());
 
            self.in_select_guard = id;
 
            self.in_select_arm = index as u32;
 
            self.visit_stmt(ctx, guard_id)?;
 
            self.in_select_guard = SelectStatementId::new_invalid();
 

	
 
            // Visit the code associated with the guard
 
            self.relative_pos_in_parent += 1;
 
            self.visit_stmt(ctx, case_body_id)?;
 
            self.pop_scope(old_scope);
 

	
 
            // Link up last statement in block to EndSelect
 
            assign_then_erase_next_stmt!(self, ctx, end_select_id.upcast());
 
        }
 

	
 
        self.in_select_guard = SelectStatementId::new_invalid();
 
        self.prev_stmt = end_select_id.upcast();
 
        Ok(())
 
    }
 

	
 
    fn visit_return_stmt(&mut self, ctx: &mut Ctx, id: ReturnStatementId) -> VisitorResult {
 
        // Check if "return" occurs within a function
 
        let stmt = &ctx.heap[id];
 
        if !self.def_type.is_function() {
 
        if self.proc_kind != ProcedureKind::Function {
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, stmt.span,
 
                "return statements may only appear in function bodies"
 
            ));
 
        }
 

	
 
        // If here then we are within a function
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 
        debug_assert_eq!(self.expr_parent, ExpressionParent::None);
 
        debug_assert_eq!(ctx.heap[id].expressions.len(), 1);
 
        self.expr_parent = ExpressionParent::Return(id);
 
        self.visit_expr(ctx, ctx.heap[id].expressions[0])?;
 
        self.expr_parent = ExpressionParent::None;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_goto_stmt(&mut self, ctx: &mut Ctx, id: GotoStatementId) -> VisitorResult {
 
        self.control_flow_stmts.push(ControlFlowStatement{
 
            in_sync: self.in_sync,
 
            in_while: self.in_while,
 
            in_scope: self.cur_scope,
 
            statement: id.upcast(),
 
        });
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_new_stmt(&mut self, ctx: &mut Ctx, id: NewStatementId) -> VisitorResult {
 
        // Make sure the new statement occurs inside a composite component
 
        if !self.def_type.is_composite() {
 
        if self.proc_kind != ProcedureKind::Composite {
 
            let new_stmt = &ctx.heap[id];
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, new_stmt.span,
 
                "instantiating components may only be done in composite components"
 
            ));
 
        }
 

	
 
        // Recurse into call expression (which will check the expression parent
 
        // to ensure that the "new" statment instantiates a component)
 
        let call_expr_id = ctx.heap[id].expression;
 

	
 
        assign_and_replace_next_stmt!(self, ctx, id.upcast());
 
        debug_assert_eq!(self.expr_parent, ExpressionParent::None);
 
        self.expr_parent = ExpressionParent::New(id);
 
        self.visit_call_expr(ctx, call_expr_id)?;
 
        self.expr_parent = ExpressionParent::None;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_expr_stmt(&mut self, ctx: &mut Ctx, id: ExpressionStatementId) -> VisitorResult {
 
        let expr_id = ctx.heap[id].expression;
 

	
 
        assign_and_replace_next_stmt!(self, ctx, id.upcast());
 
        debug_assert_eq!(self.expr_parent, ExpressionParent::None);
 
        self.expr_parent = ExpressionParent::ExpressionStmt(id);
 
        self.visit_expr(ctx, expr_id)?;
 
        self.expr_parent = ExpressionParent::None;
 

	
 
        Ok(())
 
    }
 

	
 

	
 
    //--------------------------------------------------------------------------
 
    // Expression visitors
 
    //--------------------------------------------------------------------------
 

	
 
    fn visit_assignment_expr(&mut self, ctx: &mut Ctx, id: AssignmentExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 

	
 
        let assignment_expr = &mut ctx.heap[id];
 

	
 
        // Although we call assignment an expression to simplify the compiler's
 
        // code (mainly typechecking), we disallow nested use in expressions
 
        match self.expr_parent {
 
            // Look at us: lying through our teeth while providing error messages.
 
            ExpressionParent::Memory(_) => {},
 
            ExpressionParent::ExpressionStmt(_) => {},
 
            _ => {
 
                let assignment_span = assignment_expr.full_span;
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, assignment_span,
 
                    "assignments are statements, and cannot be used in expressions"
 
                ))
 
            },
 
        }
 

	
 
        let left_expr_id = assignment_expr.left;
 
        let right_expr_id = assignment_expr.right;
 
        let old_expr_parent = self.expr_parent;
 
        assignment_expr.parent = old_expr_parent;
 
        assignment_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
 
        self.must_be_assignable = Some(assignment_expr.operator_span);
 
        self.visit_expr(ctx, left_expr_id)?;
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
 
        self.must_be_assignable = None;
 
        self.visit_expr(ctx, right_expr_id)?;
 
        self.expr_parent = old_expr_parent;
 
        Ok(())
 
    }
 

	
 
    fn visit_binding_expr(&mut self, ctx: &mut Ctx, id: BindingExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 

	
 
        // Check for valid context of binding expression
 
        if let Some(span) = self.must_be_assignable {
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, span, "cannot assign to the result from a binding expression"
 
            ));
 
        }
 

	
 
        if self.in_test_expr.is_invalid() {
 
            let binding_expr = &ctx.heap[id];
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, binding_expr.full_span,
 
                "binding expressions can only be used inside the testing expression of 'if' and 'while' statements"
 
            ));
 
        }
 

	
 
        if !self.in_binding_expr.is_invalid() {
 
            let binding_expr = &ctx.heap[id];
 
            let previous_expr = &ctx.heap[self.in_binding_expr];
 
            return Err(ParseError::new_error_str_at_span(
 
@@ -1135,272 +1079,271 @@ impl Visitor for PassValidationLinking {
 
                    self.visit_expr(ctx, expr_id)?;
 
                }
 

	
 
                expr_section.forget();
 
            },
 
            Literal::Array(literal) | Literal::Tuple(literal) => {
 
                // Visit all expressions in the array
 
                let upcast_id = id.upcast();
 
                let expr_section = self.expression_buffer.start_section_initialized(literal);
 
                for expr_idx in 0..expr_section.len() {
 
                    let expr_id = expr_section[expr_idx];
 
                    self.expr_parent = ExpressionParent::Expression(upcast_id, expr_idx as u32);
 
                    self.visit_expr(ctx, expr_id)?;
 
                }
 

	
 
                expr_section.forget();
 
            }
 
        }
 

	
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_cast_expr(&mut self, ctx: &mut Ctx, id: CastExpressionId) -> VisitorResult {
 
        let cast_expr = &mut ctx.heap[id];
 

	
 
        if let Some(span) = self.must_be_assignable {
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, span, "cannot assign to the result from a cast expression"
 
            ))
 
        }
 

	
 
        let upcast_id = id.upcast();
 
        let old_expr_parent = self.expr_parent;
 
        cast_expr.parent = old_expr_parent;
 
        cast_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        // Recurse into the thing that we're casting
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
 
        let subject_id = cast_expr.subject;
 
        self.visit_expr(ctx, subject_id)?;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_call_expr(&mut self, ctx: &mut Ctx, id: CallExpressionId) -> VisitorResult {
 
        let call_expr = &ctx.heap[id];
 

	
 
        if let Some(span) = self.must_be_assignable {
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, span, "cannot assign to the result from a call expression"
 
            ))
 
        }
 

	
 
        // Check whether the method is allowed to be called within the code's
 
        // context (in sync, definition type, etc.)
 
        let mut expecting_wrapping_new_stmt = false;
 
        let mut expecting_primitive_def = false;
 
        let mut expecting_wrapping_sync_stmt = false;
 
        let mut expecting_no_select_stmt = false;
 

	
 
        match call_expr.method {
 
            Method::Get => {
 
                expecting_primitive_def = true;
 
                expecting_wrapping_sync_stmt = true;
 
                if !self.in_select_guard.is_invalid() {
 
                    // In a select guard. Take the argument (i.e. the port we're
 
                    // retrieving from) and add it to the list of involved ports
 
                    // of the guard
 
                    if call_expr.arguments.len() == 1 {
 
                        // We're checking the number of arguments later, for now
 
                        // assume it is correct.
 
                        let argument = call_expr.arguments[0];
 
                        let select_stmt = &mut ctx.heap[self.in_select_guard];
 
                        let select_case = &mut select_stmt.cases[self.in_select_arm as usize];
 
                        select_case.involved_ports.push((id, argument));
 
                    }
 
                }
 
            },
 
            Method::Put => {
 
                expecting_primitive_def = true;
 
                expecting_wrapping_sync_stmt = true;
 
                expecting_no_select_stmt = true;
 
            },
 
            Method::Fires => {
 
                expecting_primitive_def = true;
 
                expecting_wrapping_sync_stmt = true;
 
            },
 
            Method::Create => {},
 
            Method::Length => {},
 
            Method::Assert => {
 
                expecting_wrapping_sync_stmt = true;
 
                expecting_no_select_stmt = true;
 
                if self.def_type.is_function() {
 
                if self.proc_kind == ProcedureKind::Function {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "assert statement may only occur in components"
 
                    ));
 
                }
 
            },
 
            Method::Print => {},
 
            Method::SelectStart
 
            | Method::SelectRegisterCasePort
 
            | Method::SelectWait => unreachable!(), // not usable by programmer directly
 
            Method::UserFunction => {},
 
            Method::UserProcedure => {}
 
            Method::UserComponent => {
 
                expecting_wrapping_new_stmt = true;
 
            },
 
        }
 

	
 
        let call_expr = &mut ctx.heap[id];
 

	
 
        fn get_span_and_name<'a>(ctx: &'a Ctx, id: CallExpressionId) -> (InputSpan, String) {
 
            let call = &ctx.heap[id];
 
            let span = call.func_span;
 
            let name = String::from_utf8_lossy(ctx.module().source.section_at_span(span)).to_string();
 
            return (span, name);
 
        }
 
        if expecting_primitive_def {
 
            if !self.def_type.is_primitive() {
 
            if self.proc_kind != ProcedureKind::Primitive {
 
                let (call_span, func_name) = get_span_and_name(ctx, id);
 
                return Err(ParseError::new_error_at_span(
 
                    &ctx.module().source, call_span,
 
                    format!("a call to '{}' may only occur in primitive component definitions", func_name)
 
                ));
 
            }
 
        }
 

	
 
        if expecting_wrapping_sync_stmt {
 
            if self.in_sync.is_invalid() {
 
                let (call_span, func_name) = get_span_and_name(ctx, id);
 
                return Err(ParseError::new_error_at_span(
 
                    &ctx.module().source, call_span,
 
                    format!("a call to '{}' may only occur inside synchronous blocks", func_name)
 
                ))
 
            }
 
        }
 

	
 
        if expecting_no_select_stmt {
 
            if !self.in_select_guard.is_invalid() {
 
                let (call_span, func_name) = get_span_and_name(ctx, id);
 
                return Err(ParseError::new_error_at_span(
 
                    &ctx.module().source, call_span,
 
                    format!("a call to '{}' may not occur in a select statement's guard", func_name)
 
                ));
 
            }
 
        }
 

	
 
        if expecting_wrapping_new_stmt {
 
            if !self.expr_parent.is_new() {
 
                let call_span = call_expr.func_span;
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, call_span,
 
                    "cannot call a component, it can only be instantiated by using 'new'"
 
                ));
 
            }
 
        } else {
 
            if self.expr_parent.is_new() {
 
                let call_span = call_expr.func_span;
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, call_span,
 
                    "only components can be instantiated, this is a function"
 
                ));
 
            }
 
        }
 

	
 
        // Check the number of arguments
 
        let call_definition = ctx.types.get_base_definition(&call_expr.definition).unwrap();
 
        let call_definition = ctx.types.get_base_definition(&call_expr.procedure.upcast()).unwrap();
 
        let num_expected_args = match &call_definition.definition {
 
            DefinedTypeVariant::Function(definition) => definition.arguments.len(),
 
            DefinedTypeVariant::Component(definition) => definition.arguments.len(),
 
            v => unreachable!("encountered {} type in call expression", v.type_class()),
 
            DefinedTypeVariant::Procedure(definition) => definition.arguments.len(),
 
            _ => unreachable!(),
 
        };
 

	
 
        let num_provided_args = call_expr.arguments.len();
 
        if num_provided_args != num_expected_args {
 
            let argument_text = if num_expected_args == 1 { "argument" } else { "arguments" };
 
            let call_span = call_expr.full_span;
 
            return Err(ParseError::new_error_at_span(
 
                &ctx.module().source, call_span, format!(
 
                    "expected {} {}, but {} were provided",
 
                    num_expected_args, argument_text, num_provided_args
 
                )
 
            ));
 
        }
 

	
 
        // Recurse into all of the arguments and set the expression's parent
 
        let upcast_id = id.upcast();
 

	
 
        let section = self.expression_buffer.start_section_initialized(&call_expr.arguments);
 
        let old_expr_parent = self.expr_parent;
 
        call_expr.parent = old_expr_parent;
 
        call_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        for arg_expr_idx in 0..section.len() {
 
            let arg_expr_id = section[arg_expr_idx];
 
            self.expr_parent = ExpressionParent::Expression(upcast_id, arg_expr_idx as u32);
 
            self.visit_expr(ctx, arg_expr_id)?;
 
        }
 

	
 
        section.forget();
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_variable_expr(&mut self, ctx: &mut Ctx, id: VariableExpressionId) -> VisitorResult {
 
        let var_expr = &ctx.heap[id];
 

	
 
        // Check if declaration was already resolved (this occurs for the
 
        // variable expr that is on the LHS of the assignment expr that is
 
        // associated with a variable declaration)
 
        let mut variable_id = var_expr.declaration;
 
        let mut is_binding_target = false;
 

	
 
        // Otherwise try to find it
 
        if variable_id.is_none() {
 
            variable_id = self.find_variable(ctx, self.relative_pos_in_parent, &var_expr.identifier);
 
        }
 

	
 
        // Otherwise try to see if is a variable introduced by a binding expr
 
        let variable_id = if let Some(variable_id) = variable_id {
 
            variable_id
 
        } else {
 
            if self.in_binding_expr.is_invalid() || !self.in_binding_expr_lhs {
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, var_expr.identifier.span, "unresolved variable"
 
                ));
 
            }
 

	
 
            // This is a binding variable, but it may only appear in very
 
            // specific locations.
 
            let is_valid_binding = match self.expr_parent {
 
                ExpressionParent::Expression(expr_id, idx) => {
 
                    match &ctx.heap[expr_id] {
 
                        Expression::Binding(_binding_expr) => {
 
                            // Nested binding is disallowed, and because of
 
                            // the check above we know we're directly at the
 
                            // LHS of the binding expression
 
                            debug_assert_eq!(_binding_expr.this, self.in_binding_expr);
 
                            debug_assert_eq!(idx, 0);
 
                            true
 
                        }
 
                        Expression::Literal(lit_expr) => {
 
                            // Only struct, unions, tuples and arrays can
 
                            // have subexpressions, so we're always fine
 
                            dbg_code!({
 
                                match lit_expr.value {
 
                                    Literal::Struct(_) | Literal::Union(_) | Literal::Array(_) | Literal::Tuple(_) => {},
 
                                    _ => unreachable!(),
 
                                }
 
                            });
 

	
 
                            true
 
                        },
 
                        _ => false,
 
                    }
 
                },
 
                _ => {
 
                    false
 
                }
 
            };
 

	
 
            if !is_valid_binding {
 
                let binding_expr = &ctx.heap[self.in_binding_expr];
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, var_expr.identifier.span,
 
@@ -1502,193 +1445,193 @@ impl PassValidationLinking {
 
            let stmt = &ctx.heap[entry.statement];
 

	
 
            match stmt {
 
                Statement::Break(stmt) => {
 
                    let stmt_id = stmt.this;
 
                    let target_while_id = Self::resolve_break_or_continue_target(ctx, entry, stmt.span, &stmt.label)?;
 
                    let target_while_stmt = &ctx.heap[target_while_id];
 
                    let target_end_while_id = target_while_stmt.end_while;
 
                    debug_assert!(!target_end_while_id.is_invalid());
 

	
 
                    let break_stmt = &mut ctx.heap[stmt_id];
 
                    break_stmt.target = target_end_while_id;
 
                },
 
                Statement::Continue(stmt) => {
 
                    let stmt_id = stmt.this;
 
                    let target_while_id = Self::resolve_break_or_continue_target(ctx, entry, stmt.span, &stmt.label)?;
 

	
 
                    let continue_stmt = &mut ctx.heap[stmt_id];
 
                    continue_stmt.target = target_while_id;
 
                },
 
                Statement::Goto(stmt) => {
 
                    let stmt_id = stmt.this;
 
                    let target_id = Self::find_label(entry.in_scope, ctx, &stmt.label)?;
 
                    let target_stmt = &ctx.heap[target_id];
 
                    if entry.in_sync != target_stmt.in_sync {
 
                        // Nested sync not allowed. And goto can only go to
 
                        // outer scopes, so we must be escaping from a sync.
 
                        debug_assert!(target_stmt.in_sync.is_invalid());    // target not in sync
 
                        debug_assert!(!entry.in_sync.is_invalid()); // but the goto is in sync
 
                        let goto_stmt = &ctx.heap[stmt_id];
 
                        let sync_stmt = &ctx.heap[entry.in_sync];
 
                        return Err(
 
                            ParseError::new_error_str_at_span(&ctx.module().source, goto_stmt.span, "goto may not escape the surrounding synchronous block")
 
                            .with_info_str_at_span(&ctx.module().source, target_stmt.label.span, "this is the target of the goto statement")
 
                            .with_info_str_at_span(&ctx.module().source, sync_stmt.span, "which will jump past this statement")
 
                        );
 
                    }
 

	
 
                    let goto_stmt = &mut ctx.heap[stmt_id];
 
                    goto_stmt.target = target_id;
 
                },
 
                _ => unreachable!("cannot resolve control flow target for {:?}", stmt),
 
            }
 
        }
 

	
 
        return Ok(())
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // Utilities
 
    //--------------------------------------------------------------------------
 

	
 
    /// Adds a local variable to the current scope. It will also annotate the
 
    /// `Local` in the AST with its relative position in the block.
 
    fn checked_add_local(&mut self, ctx: &mut Ctx, target_scope_id: ScopeId, target_relative_pos: i32, new_variable_id: VariableId) -> Result<(), ParseError> {
 
        let new_variable = &ctx.heap[new_variable_id];
 

	
 
        // We immediately go to the parent scope. We check the target scope
 
        // in the call at the end. That is also where we check for collisions
 
        // with symbols.
 
        let mut scope = &ctx.heap[target_scope_id];
 
        let mut cur_relative_pos = scope.relative_pos_in_parent;
 
        while let Some(scope_parent_id) = scope.parent {
 
            scope = &ctx.heap[scope_parent_id];
 

	
 
            // Check for collisions
 
            for variable_id in scope.variables.iter().copied() {
 
                let existing_variable = &ctx.heap[variable_id];
 
                if existing_variable.identifier == new_variable.identifier &&
 
                    existing_variable.this != new_variable_id &&
 
                    cur_relative_pos >= existing_variable.relative_pos_in_parent {
 
                    return Err(
 
                        ParseError::new_error_str_at_span(
 
                            &ctx.module().source, new_variable.identifier.span, "Local variable name conflicts with another variable"
 
                        ).with_info_str_at_span(
 
                            &ctx.module().source, existing_variable.identifier.span, "Previous variable is found here"
 
                        )
 
                    );
 
                }
 
            }
 

	
 
            cur_relative_pos = scope.relative_pos_in_parent;
 
        }
 

	
 
        // No collisions in any of the parent scope, attempt to add to scope
 
        self.checked_at_single_scope_add_local(ctx, target_scope_id, target_relative_pos, new_variable_id)
 
    }
 

	
 
    /// Adds a local variable to the specified scope. Will check the specified
 
    /// scope for variable conflicts and the symbol table for global conflicts.
 
    /// Will NOT check parent scopes of the specified scope.
 
    fn checked_at_single_scope_add_local(
 
        &mut self, ctx: &mut Ctx, scope_id: ScopeId, relative_pos: i32, new_variable_id: VariableId
 
    ) -> Result<(), ParseError> {
 
        // Check the symbol table for conflicts
 
        {
 
            let cur_scope = SymbolScope::Definition(self.def_type.definition_id());
 
            let cur_scope = SymbolScope::Definition(self.proc_id.upcast());
 
            let ident = &ctx.heap[new_variable_id].identifier;
 
            if let Some(symbol) = ctx.symbols.get_symbol_by_name(cur_scope, &ident.value.as_bytes()) {
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, ident.span,
 
                    "local variable declaration conflicts with symbol"
 
                ).with_info_str_at_span(
 
                    &ctx.module().source, symbol.variant.span_of_introduction(&ctx.heap), "the conflicting symbol is introduced here"
 
                ));
 
            }
 
        }
 

	
 
        // Check the specified scope for conflicts
 
        let new_variable = &ctx.heap[new_variable_id];
 
        let scope = &ctx.heap[scope_id];
 

	
 
        for variable_id in scope.variables.iter().copied() {
 
            let old_variable = &ctx.heap[variable_id];
 
            if new_variable.this != old_variable.this &&
 
                // relative_pos >= other_local.relative_pos_in_block &&
 
                new_variable.identifier == old_variable.identifier {
 
                // Collision
 
                return Err(
 
                    ParseError::new_error_str_at_span(
 
                        &ctx.module().source, new_variable.identifier.span, "Local variable name conflicts with another variable"
 
                    ).with_info_str_at_span(
 
                        &ctx.module().source, old_variable.identifier.span, "Previous variable is found here"
 
                    )
 
                );
 
            }
 
        }
 

	
 
        // No collisions
 
        let scope = &mut ctx.heap[scope_id];
 
        scope.variables.push(new_variable_id);
 

	
 
        let variable = &mut ctx.heap[new_variable_id];
 
        variable.relative_pos_in_parent = relative_pos;
 

	
 
        Ok(())
 
    }
 

	
 
    /// Finds a variable in the visitor's scope that must appear before the
 
    /// specified relative position within that block.
 
    fn find_variable(&self, ctx: &Ctx, mut relative_pos: i32, identifier: &Identifier) -> Option<VariableId> {
 
        let mut scope_id = self.cur_scope;
 

	
 
        loop {
 
            // Check if we can find the variable in the current scope
 
            let scope = &ctx.heap[scope_id];
 
            
 
            for variable_id in scope.variables.iter().copied() {
 
                let variable = &ctx.heap[variable_id];
 
                
 
                if variable.relative_pos_in_parent < relative_pos && identifier == &variable.identifier {
 
                    return Some(variable_id);
 
                }
 
            }
 

	
 
            // Could not find variable, move to parent scope and try again
 
            if scope.parent.is_none() {
 
                return None;
 
            }
 

	
 
            scope_id = scope.parent.unwrap();
 
            relative_pos = scope.relative_pos_in_parent;
 
        }
 
    }
 

	
 
    /// Adds a particular label to the current scope. Will return an error if
 
    /// there is another label with the same name visible in the current scope.
 
    fn checked_add_label(&mut self, ctx: &mut Ctx, relative_pos: i32, in_sync: SynchronousStatementId, new_label_id: LabeledStatementId) -> Result<(), ParseError> {
 
        // Make sure label is not defined within the current scope or any of the
 
        // parent scope.
 
        let new_label = &mut ctx.heap[new_label_id];
 
        new_label.relative_pos_in_parent = relative_pos;
 
        new_label.in_sync = in_sync;
 

	
 
        let new_label = &ctx.heap[new_label_id];
 
        let mut scope_id = self.cur_scope;
 

	
 
        loop {
 
            let scope = &ctx.heap[scope_id];
 
            for existing_label_id in scope.labels.iter().copied() {
 
                let existing_label = &ctx.heap[existing_label_id];
 
                if existing_label.label == new_label.label {
 
                    // Collision
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, new_label.label.span, "label name is used more than once"
 
                    ).with_info_str_at_span(
 
                        &ctx.module().source, existing_label.label.span, "the other label is found here"
 
                    ));
 
                }
 
            }
 

	
 
            if scope.parent.is_none() {
 
                break;
src/protocol/parser/type_table.rs
Show inline comments
 
/**
 
 * type_table.rs
 
 *
 
 * The type table is a lookup from AST definition (which contains just what the
 
 * programmer typed) to a type with additional information computed (e.g. the
 
 * byte size and offsets of struct members). The type table should be considered
 
 * the authoritative source of information on types by the compiler (not the
 
 * AST itself!).
 
 *
 
 * The type table operates in two modes: one is where we just look up the type,
 
 * check its fields for correctness and mark whether it is polymorphic or not.
 
 * The second one is where we compute byte sizes, alignment and offsets.
 
 *
 
 * The basic algorithm for type resolving and computing byte sizes is to
 
 * recursively try to lay out each member type of a particular type. This is
 
 * done in a stack-like fashion, where each embedded type pushes a breadcrumb
 
 * unto the stack. We may discover a cycle in embedded types (we call this a
 
 * "type loop"). After which the type table attempts to break the type loop by
 
 * making specific types heap-allocated. Upon doing so we know their size
 
 * because their stack-size is now based on pointers. Hence breaking the type
 
 * loop required for computing the byte size of types.
 
 *
 
 * The reason for these type shenanigans is because PDL is a value-based
 
 * language, but we would still like to be able to express recursively defined
 
 * types like trees or linked lists. Hence we need to insert pointers somewhere
 
 * to break these cycles.
 
 *
 
 * We will insert these pointers into the variants of unions. However note that
 
 * we can only compute the stack size of a union until we've looked at *all*
 
 * variants. Hence we perform an initial pass where we detect type loops, a
 
 * second pass where we compute the stack sizes of everything, and a third pass
 
 * where we actually compute the size of the heap allocations for unions.
 
 *
 
 * As a final bit of global documentation: non-polymorphic types will always
 
 * have one "monomorph" entry. This contains the non-polymorphic type's memory
 
 * layout.
 
 */
 

	
 
use std::fmt::{Formatter, Result as FmtResult};
 
use std::collections::HashMap;
 
use std::hash::{Hash, Hasher};
 

	
 
use crate::protocol::ast::*;
 
use crate::protocol::parser::symbol_table::SymbolScope;
 
use crate::protocol::input_source::ParseError;
 
use crate::protocol::parser::*;
 

	
 
//------------------------------------------------------------------------------
 
// Defined Types
 
//------------------------------------------------------------------------------
 

	
 
#[derive(Copy, Clone, PartialEq, Eq)]
 
pub enum TypeClass {
 
    Enum,
 
    Union,
 
    Struct,
 
    Function,
 
    Component
 
}
 

	
 
impl TypeClass {
 
    pub(crate) fn display_name(&self) -> &'static str {
 
        match self {
 
            TypeClass::Enum => "enum",
 
            TypeClass::Union => "union",
 
            TypeClass::Struct => "struct",
 
            TypeClass::Function => "function",
 
            TypeClass::Component => "component",
 
        }
 
    }
 

	
 
    pub(crate) fn is_data_type(&self) -> bool {
 
        match self {
 
            TypeClass::Enum | TypeClass::Union | TypeClass::Struct => true,
 
            TypeClass::Function | TypeClass::Component => false,
 
        }
 
    }
 
}
 

	
 
impl std::fmt::Display for TypeClass {
 
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
 
        write!(f, "{}", self.display_name())
 
    }
 
}
 

	
 
/// Struct wrapping around a potentially polymorphic type. If the type does not
 
/// have any polymorphic arguments then it will not have any monomorphs and
 
/// `is_polymorph` will be set to `false`. A type with polymorphic arguments
 
/// only has `is_polymorph` set to `true` if the polymorphic arguments actually
 
/// appear in the types associated types (function return argument, struct
 
/// field, enum variant, etc.). Otherwise the polymorphic argument is just a
 
/// marker and does not influence the bytesize of the type.
 
pub struct DefinedType {
 
    pub(crate) ast_root: RootId,
 
    pub(crate) ast_definition: DefinitionId,
 
    pub(crate) definition: DefinedTypeVariant,
 
    pub(crate) poly_vars: Vec<PolymorphicVariable>,
 
    pub(crate) is_polymorph: bool,
 
}
 

	
 
pub enum DefinedTypeVariant {
 
    Enum(EnumType),
 
    Union(UnionType),
 
    Struct(StructType),
 
    Function(FunctionType),
 
    Component(ComponentType)
 
    Procedure(ProcedureType),
 
}
 

	
 
impl DefinedTypeVariant {
 
    pub(crate) fn type_class(&self) -> TypeClass {
 
    pub(crate) fn is_data_type(&self) -> bool {
 
        use DefinedTypeVariant as DTV;
 

	
 
        match self {
 
            DefinedTypeVariant::Enum(_) => TypeClass::Enum,
 
            DefinedTypeVariant::Union(_) => TypeClass::Union,
 
            DefinedTypeVariant::Struct(_) => TypeClass::Struct,
 
            DefinedTypeVariant::Function(_) => TypeClass::Function,
 
            DefinedTypeVariant::Component(_) => TypeClass::Component
 
            DTV::Struct(_) | DTV::Enum(_) | DTV::Union(_) => return true,
 
            DTV::Procedure(_) => return false,
 
        }
 
    }
 

	
 
    pub(crate) fn as_struct(&self) -> &StructType {
 
        match self {
 
            DefinedTypeVariant::Struct(v) => v,
 
            _ => unreachable!("Cannot convert {} to struct variant", self.type_class())
 
            _ => unreachable!()
 
        }
 
    }
 

	
 
    pub(crate) fn as_enum(&self) -> &EnumType {
 
        match self {
 
            DefinedTypeVariant::Enum(v) => v,
 
            _ => unreachable!("Cannot convert {} to enum variant", self.type_class())
 
            _ => unreachable!()
 
        }
 
    }
 

	
 
    pub(crate) fn as_union(&self) -> &UnionType {
 
        match self {
 
            DefinedTypeVariant::Union(v) => v,
 
            _ => unreachable!("Cannot convert {} to union variant", self.type_class())
 
            _ => unreachable!()
 
        }
 
    }
 
}
 

	
 
pub struct PolymorphicVariable {
 
    pub(crate) identifier: Identifier,
 
    pub(crate) is_in_use: bool, // a polymorphic argument may be defined, but not used by the type definition
 
}
 

	
 
/// `EnumType` is the classical C/C++ enum type. It has various variants with
 
/// an assigned integer value. The integer values may be user-defined,
 
/// compiler-defined, or a mix of the two. If a user assigns the same enum
 
/// value multiple times, we assume the user is an expert and we consider both
 
/// variants to be equal to one another.
 
pub struct EnumType {
 
    pub variants: Vec<EnumVariant>,
 
    pub minimum_tag_value: i64,
 
    pub maximum_tag_value: i64,
 
    pub tag_type: ConcreteType,
 
    pub size: usize,
 
    pub alignment: usize,
 
}
 

	
 
// TODO: Also support maximum u64 value
 
pub struct EnumVariant {
 
    pub identifier: Identifier,
 
    pub value: i64,
 
}
 

	
 
/// `UnionType` is the algebraic datatype (or sum type, or discriminated union).
 
/// A value is an element of the union, identified by its tag, and may contain
 
/// a single subtype.
 
/// For potentially infinite types (i.e. a tree, or a linked list) only unions
 
/// can break the infinite cycle. So when we lay out these unions in memory we
 
/// will reserve enough space on the stack for all union variants that do not
 
/// cause "type loops" (i.e. a union `A` with a variant containing a struct
 
/// `B`). And we will reserve enough space on the heap (and store a pointer in
 
/// the union) for all variants which do cause type loops (i.e. a union `A`
 
/// with a variant to a struct `B` that contains the union `A` again).
 
pub struct UnionType {
 
    pub variants: Vec<UnionVariant>,
 
    pub tag_type: ConcreteType,
 
    pub tag_size: usize,
 
}
 

	
 
pub struct UnionVariant {
 
    pub identifier: Identifier,
 
    pub embedded: Vec<ParserType>, // zero-length does not have embedded values
 
    pub tag_value: i64,
 
}
 

	
 
/// `StructType` is a generic C-like struct type (or record type, or product
 
/// type) type.
 
pub struct StructType {
 
    pub fields: Vec<StructField>,
 
}
 

	
 
pub struct StructField {
 
    pub identifier: Identifier,
 
    pub parser_type: ParserType,
 
}
 

	
 
/// `FunctionType` is what you expect it to be: a particular function's
 
/// signature.
 
pub struct FunctionType {
 
    pub return_type: ParserType,
 
    pub arguments: Vec<FunctionArgument>,
 
}
 

	
 
pub struct ComponentType {
 
    pub variant: ComponentVariant,
 
    pub arguments: Vec<FunctionArgument>,
 
/// `ProcedureType` is the signature of a procedure/component
 
pub struct ProcedureType {
 
    pub kind: ProcedureKind,
 
    pub return_type: Option<ParserType>,
 
    pub arguments: Vec<ProcedureArgument>,
 
}
 

	
 
pub struct FunctionArgument {
 
pub struct ProcedureArgument {
 
    identifier: Identifier,
 
    parser_type: ParserType,
 
}
 

	
 
/// Represents the data associated with a single expression after type inference
 
/// for a monomorph (or just the normal expression types, if dealing with a
 
/// non-polymorphic function/component).
 
pub struct MonomorphExpression {
 
    // The output type of the expression. Note that for a function it is not the
 
    // function's signature but its return type
 
    pub(crate) expr_type: ConcreteType,
 
    // Has multiple meanings: the field index for select expressions, the
 
    // monomorph index for polymorphic function calls or literals. Negative
 
    // values are never used, but used to catch programming errors.
 
    pub(crate) field_or_monomorph_idx: i32,
 
    pub(crate) type_id: TypeId,
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Type monomorph storage
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) enum MonoTypeVariant {
 
    Builtin, // no extra data, added manually in compiler initialization code
 
    Enum, // no extra data
 
    Struct(StructMonomorph),
 
    Union(UnionMonomorph),
 
    Procedure(ProcedureMonomorph), // functions, components
 
    Tuple(TupleMonomorph),
 
}
 

	
 
impl MonoTypeVariant {
 
    fn as_struct_mut(&mut self) -> &mut StructMonomorph {
 
        match self {
 
            MonoTypeVariant::Struct(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    pub(crate) fn as_union(&self) -> &UnionMonomorph {
 
        match self {
 
            MonoTypeVariant::Union(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn as_union_mut(&mut self) -> &mut UnionMonomorph {
 
        match self {
 
            MonoTypeVariant::Union(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn as_tuple_mut(&mut self) -> &mut TupleMonomorph {
 
        match self {
 
            MonoTypeVariant::Tuple(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn as_procedure(&self) -> &ProcedureMonomorph {
 
        match self {
 
            MonoTypeVariant::Procedure(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn as_procedure_mut(&mut self) -> &mut ProcedureMonomorph {
 
        match self {
 
            MonoTypeVariant::Procedure(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 
}
 

	
 
/// Struct monomorph
 
pub struct StructMonomorph {
 
    pub fields: Vec<StructMonomorphField>,
 
}
 

	
 
pub struct StructMonomorphField {
 
    pub type_id: TypeId,
 
    concrete_type: ConcreteType,
 
    pub size: usize,
 
    pub alignment: usize,
 
    pub offset: usize,
 
}
 

	
 
/// Union monomorph
 
pub struct UnionMonomorph {
 
    pub variants: Vec<UnionMonomorphVariant>,
 
    pub tag_size: usize, // copied from `UnionType` upon monomorph construction.
 
    // note that the stack size is in the `TypeMonomorph` struct. This size and
 
    // alignment will include the size of the union tag.
 
    //
 
    // heap_size contains the allocated size of the union in the case it
 
@@ -581,210 +539,209 @@ struct MemoryBreadcrumb {
 
    next_member: u32,
 
    next_embedded: u32,
 
    first_size_alignment_idx: u32,
 
}
 

	
 
#[derive(Debug, PartialEq, Eq)]
 
enum TypeLoopResult {
 
    TypeExists,
 
    PushBreadcrumb(DefinitionId, ConcreteType),
 
    TypeLoop(usize), // index into vec of breadcrumbs at which the type matched
 
}
 

	
 
enum MemoryLayoutResult {
 
    TypeExists(usize, usize), // (size, alignment)
 
    PushBreadcrumb(MemoryBreadcrumb),
 
}
 

	
 
// TODO: @Optimize, initial memory-unoptimized implementation
 
struct TypeLoopEntry {
 
    type_id: TypeId,
 
    is_union: bool,
 
}
 

	
 
struct TypeLoop {
 
    members: Vec<TypeLoopEntry>,
 
}
 

	
 
type DefinitionMap = HashMap<DefinitionId, DefinedType>;
 
type MonoTypeMap = HashMap<MonoSearchKey, TypeId>;
 
type MonoTypeArray = Vec<MonoType>;
 

	
 
pub struct TypeTable {
 
    // Lookup from AST DefinitionId to a defined type. Also lookups for
 
    // concrete type to monomorphs
 
    pub(crate) definition_lookup: DefinitionMap,
 
    mono_type_lookup: MonoTypeMap,
 
    pub(crate) mono_types: MonoTypeArray,
 
    mono_search_key: MonoSearchKey,
 
    // Breadcrumbs left behind while trying to find type loops. Also used to
 
    // determine sizes of types when all type loops are detected.
 
    type_loop_breadcrumbs: Vec<TypeLoopBreadcrumb>,
 
    type_loops: Vec<TypeLoop>,
 
    // Stores all encountered types during type loop detection. Used afterwards
 
    // to iterate over all types in order to compute size/alignment.
 
    encountered_types: Vec<TypeLoopEntry>,
 
    // Breadcrumbs and temporary storage during memory layout computation.
 
    memory_layout_breadcrumbs: Vec<MemoryBreadcrumb>,
 
    size_alignment_stack: Vec<(usize, usize)>,
 
}
 

	
 
impl TypeTable {
 
    /// Construct a new type table without any resolved types.
 
    pub(crate) fn new() -> Self {
 
        Self{ 
 
            definition_lookup: HashMap::with_capacity(128),
 
            mono_type_lookup: HashMap::with_capacity(128),
 
            mono_types: Vec::with_capacity(128),
 
            mono_search_key: MonoSearchKey::with_capacity(32),
 
            type_loop_breadcrumbs: Vec::with_capacity(32),
 
            type_loops: Vec::with_capacity(8),
 
            encountered_types: Vec::with_capacity(32),
 
            memory_layout_breadcrumbs: Vec::with_capacity(32),
 
            size_alignment_stack: Vec::with_capacity(64),
 
        }
 
    }
 

	
 
    /// Iterates over all defined types (polymorphic and non-polymorphic) and
 
    /// add their types in two passes. In the first pass we will just add the
 
    /// base types (we will not consider monomorphs, and we will not compute
 
    /// byte sizes). In the second pass we will compute byte sizes of
 
    /// non-polymorphic types, and potentially the monomorphs that are embedded
 
    /// in those types.
 
    pub(crate) fn build_base_types(&mut self, modules: &mut [Module], ctx: &mut PassCtx) -> Result<(), ParseError> {
 
        // Make sure we're allowed to cast root_id to index into ctx.modules
 
        debug_assert!(modules.iter().all(|m| m.phase >= ModuleCompilationPhase::DefinitionsParsed));
 
        debug_assert!(self.definition_lookup.is_empty());
 

	
 
        dbg_code!({
 
            for (index, module) in modules.iter().enumerate() {
 
                debug_assert_eq!(index, module.root_id.index as usize);
 
            }
 
        });
 

	
 
        // Use context to guess hashmap size of the base types
 
        let reserve_size = ctx.heap.definitions.len();
 
        self.definition_lookup.reserve(reserve_size);
 

	
 
        // Resolve all base types
 
        for definition_idx in 0..ctx.heap.definitions.len() {
 
            let definition_id = ctx.heap.definitions.get_id(definition_idx);
 
            let definition = &ctx.heap[definition_id];
 

	
 
            match definition {
 
                Definition::Enum(_) => self.build_base_enum_definition(modules, ctx, definition_id)?,
 
                Definition::Union(_) => self.build_base_union_definition(modules, ctx, definition_id)?,
 
                Definition::Struct(_) => self.build_base_struct_definition(modules, ctx, definition_id)?,
 
                Definition::Function(_) => self.build_base_function_definition(modules, ctx, definition_id)?,
 
                Definition::Component(_) => self.build_base_component_definition(modules, ctx, definition_id)?,
 
                Definition::Procedure(_) => self.build_base_procedure_definition(modules, ctx, definition_id)?,
 
            }
 
        }
 

	
 
        debug_assert_eq!(self.definition_lookup.len(), reserve_size, "mismatch in reserved size of type table");
 
        for module in modules.iter_mut() {
 
            module.phase = ModuleCompilationPhase::TypesAddedToTable;
 
        }
 

	
 
        // Go through all types again, lay out all types that are not
 
        // polymorphic. This might cause us to lay out monomorphized polymorphs
 
        // if these were member types of non-polymorphic types.
 
        for definition_idx in 0..ctx.heap.definitions.len() {
 
            let definition_id = ctx.heap.definitions.get_id(definition_idx);
 
            let poly_type = self.definition_lookup.get(&definition_id).unwrap();
 

	
 
            if !poly_type.definition.type_class().is_data_type() || !poly_type.poly_vars.is_empty() {
 
            if !poly_type.definition.is_data_type() || !poly_type.poly_vars.is_empty() {
 
                continue;
 
            }
 

	
 
            // If here then the type is a data type without polymorphic
 
            // variables, but we might have instantiated it already, so:
 
            let concrete_parts = [ConcreteTypePart::Instance(definition_id, 0)];
 
            self.mono_search_key.set(&concrete_parts, &[]);
 
            let type_id = self.mono_type_lookup.get(&self.mono_search_key);
 
            if type_id.is_none() {
 
                self.detect_and_resolve_type_loops_for(
 
                    modules, ctx.heap,
 
                    ConcreteType{
 
                        parts: vec![ConcreteTypePart::Instance(definition_id, 0)]
 
                    },
 
                )?;
 
                self.lay_out_memory_for_encountered_types(ctx.arch);
 
            }
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    /// Retrieves base definition from type table. We must be able to retrieve
 
    /// it as we resolve all base types upon type table construction (for now).
 
    /// However, in the future we might do on-demand type resolving, so return
 
    /// an option anyway
 
    #[inline]
 
    pub(crate) fn get_base_definition(&self, definition_id: &DefinitionId) -> Option<&DefinedType> {
 
        self.definition_lookup.get(&definition_id)
 
    }
 

	
 
    /// Returns the index into the monomorph type array if the procedure type
 
    /// already has a (reserved) monomorph.
 
    #[inline]
 
    pub(crate) fn get_procedure_monomorph_type_id(&self, definition_id: &DefinitionId, type_parts: &[ConcreteTypePart]) -> Option<TypeId> {
 
        // Cannot use internal search key due to mutability issues. But this
 
        // method should end up being deprecated at some point anyway.
 
        debug_assert_eq!(get_concrete_type_definition(type_parts).unwrap(), *definition_id);
 
        let base_type = self.definition_lookup.get(definition_id).unwrap();
 
        let mut search_key = MonoSearchKey::with_capacity(type_parts.len());
 
        search_key.set(type_parts, &base_type.poly_vars);
 

	
 
        return self.mono_type_lookup.get(&search_key).copied();
 
    }
 

	
 
    #[inline]
 
    pub(crate) fn get_monomorph(&self, type_id: TypeId) -> &MonoType {
 
        return &self.mono_types[type_id.0 as usize];
 
    }
 

	
 
    /// Returns a mutable reference to a procedure's monomorph expression data.
 
    /// Used by typechecker to fill in previously reserved type information
 
    #[inline]
 
    pub(crate) fn get_procedure_monomorph_mut(&mut self, type_id: TypeId) -> &mut ProcedureMonomorph {
 
        let mono_type = &mut self.mono_types[type_id.0 as usize];
 
        return mono_type.variant.as_procedure_mut();
 
    }
 

	
 
    #[inline]
 
    pub(crate) fn get_procedure_monomorph(&self, type_id: TypeId) -> &ProcedureMonomorph {
 
        let mono_type = &self.mono_types[type_id.0 as usize];
 
        return mono_type.variant.as_procedure();
 
    }
 

	
 
    /// Reserves space for a monomorph of a polymorphic procedure. The index
 
    /// will point into a (reserved) slot of the array of expression types. The
 
    /// monomorph may NOT exist yet (because the reservation implies that we're
 
    /// going to be performing typechecking on it, and we don't want to
 
    /// check the same monomorph twice)
 
    pub(crate) fn reserve_procedure_monomorph_type_id(&mut self, definition_id: &DefinitionId, concrete_type: ConcreteType) -> TypeId {
 
        debug_assert_eq!(get_concrete_type_definition(&concrete_type.parts).unwrap(), *definition_id);
 
        let type_id = TypeId(self.mono_types.len() as i64);
 
        let base_type = self.definition_lookup.get_mut(definition_id).unwrap();
 
        self.mono_search_key.set(&concrete_type.parts, &base_type.poly_vars);
 

	
 
        debug_assert!(!self.mono_type_lookup.contains_key(&self.mono_search_key));
 
        self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
 
        self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Procedure(ProcedureMonomorph{
 
            arg_types: Vec::new(),
 
            expr_data: Vec::new(),
 
        })));
 

	
 
        return type_id;
 
    }
 

	
 
    /// Adds a builtin type to the type table. As this is only called by the
 
    /// compiler during setup we assume it cannot fail.
 
    // TODO: Finish this train of thought, requires a little bit of design work
 
    pub(crate) fn add_builtin_type(&mut self, concrete_type: ConcreteType, poly_vars: &[PolymorphicVariable], size: usize, alignment: usize) -> TypeId {
 
        self.mono_search_key.set(&concrete_type.parts, poly_vars);
 
        debug_assert!(!self.mono_type_lookup.contains_key(&self.mono_search_key));
 
        debug_assert_ne!(alignment, 0);
 
        let type_id = TypeId(self.mono_types.len() as i64);
 
        self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
 
        self.mono_types.push(MonoType{
 
            type_id,
 
@@ -907,293 +864,250 @@ impl TypeTable {
 
        let mut variants = Vec::with_capacity(definition.variants.len());
 
        let mut tag_counter = 0;
 
        for variant in &definition.variants {
 
            for embedded in &variant.value {
 
                Self::check_member_parser_type(
 
                    modules, ctx, root_id, embedded, false
 
                )?;
 
            }
 

	
 
            variants.push(UnionVariant{
 
                identifier: variant.identifier.clone(),
 
                embedded: variant.value.clone(),
 
                tag_value: tag_counter,
 
            });
 
            tag_counter += 1;
 
        }
 

	
 
        let mut max_tag_value = 0;
 
        if tag_counter != 0 {
 
            max_tag_value = tag_counter - 1
 
        }
 

	
 
        let (tag_type, tag_size) = Self::variant_tag_type_from_values(0, max_tag_value);
 

	
 
        // Make sure there are no conflicts in identifiers
 
        Self::check_identifier_collision(
 
            modules, root_id, &variants, |variant| &variant.identifier, "union variant"
 
        )?;
 
        Self::check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
 

	
 
        // Construct internal representation of union
 
        let mut poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
 
        for variant in &definition.variants {
 
            for embedded in &variant.value {
 
                Self::mark_used_polymorphic_variables(&mut poly_vars, embedded);
 
            }
 
        }
 

	
 
        let is_polymorph = poly_vars.iter().any(|arg| arg.is_in_use);
 

	
 
        self.definition_lookup.insert(definition_id, DefinedType{
 
            ast_root: root_id,
 
            ast_definition: definition_id,
 
            definition: DefinedTypeVariant::Union(UnionType{ variants, tag_type, tag_size }),
 
            poly_vars,
 
            is_polymorph
 
        });
 

	
 
        return Ok(());
 
    }
 

	
 
    /// Builds base struct type. Will not compute byte sizes.
 
    fn build_base_struct_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, definition_id: DefinitionId) -> Result<(), ParseError> {
 
        debug_assert!(!self.definition_lookup.contains_key(&definition_id), "base struct already built");
 
        let definition = ctx.heap[definition_id].as_struct();
 
        let root_id = definition.defined_in;
 

	
 
        // Check all struct fields and construct internal representation
 
        let mut fields = Vec::with_capacity(definition.fields.len());
 

	
 
        for field in &definition.fields {
 
            Self::check_member_parser_type(
 
                modules, ctx, root_id, &field.parser_type, false
 
            )?;
 

	
 
            fields.push(StructField{
 
                identifier: field.field.clone(),
 
                parser_type: field.parser_type.clone(),
 
            });
 
        }
 

	
 
        // Make sure there are no conflicting variables
 
        Self::check_identifier_collision(
 
            modules, root_id, &fields, |field| &field.identifier, "struct field"
 
        )?;
 
        Self::check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
 

	
 
        // Construct base type in table
 
        let mut poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
 
        for field in &fields {
 
            Self::mark_used_polymorphic_variables(&mut poly_vars, &field.parser_type);
 
        }
 

	
 
        let is_polymorph = poly_vars.iter().any(|arg| arg.is_in_use);
 

	
 
        self.definition_lookup.insert(definition_id, DefinedType{
 
            ast_root: root_id,
 
            ast_definition: definition_id,
 
            definition: DefinedTypeVariant::Struct(StructType{ fields }),
 
            poly_vars,
 
            is_polymorph
 
        });
 

	
 
        return Ok(())
 
    }
 

	
 
    /// Builds base function type.
 
    fn build_base_function_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, definition_id: DefinitionId) -> Result<(), ParseError> {
 
    /// Builds base procedure type.
 
    fn build_base_procedure_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, definition_id: DefinitionId) -> Result<(), ParseError> {
 
        debug_assert!(!self.definition_lookup.contains_key(&definition_id), "base function already built");
 
        let definition = ctx.heap[definition_id].as_function();
 
        let definition = ctx.heap[definition_id].as_procedure();
 
        let root_id = definition.defined_in;
 

	
 
        // Check and construct return types and argument types.
 
        if let Some(return_type) = &definition.return_type {
 
            Self::check_member_parser_type(
 
            modules, ctx, root_id, &definition.return_type, definition.builtin
 
                modules, ctx, root_id, return_type, definition.builtin
 
            )?;
 
        }
 

	
 
        let mut arguments = Vec::with_capacity(definition.parameters.len());
 
        for parameter_id in &definition.parameters {
 
            let parameter = &ctx.heap[*parameter_id];
 
            Self::check_member_parser_type(
 
                modules, ctx, root_id, &parameter.parser_type, definition.builtin
 
            )?;
 

	
 
            arguments.push(FunctionArgument{
 
            arguments.push(ProcedureArgument{
 
                identifier: parameter.identifier.clone(),
 
                parser_type: parameter.parser_type.clone(),
 
            });
 
        }
 

	
 
        // Check conflict of identifiers
 
        Self::check_identifier_collision(
 
            modules, root_id, &arguments, |arg| &arg.identifier, "function argument"
 
            modules, root_id, &arguments, |arg| &arg.identifier, "procedure argument"
 
        )?;
 
        Self::check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
 

	
 
        // Construct internal representation of function type
 
        // TODO: Marking used polymorphic variables should take statements in
 
        //  the body into account. But currently we don't. Hence mark them all
 
        //  as being in-use. Note to self: true condition should be that the
 
        //  polymorphic variables are used in places where the resulting types
 
        //  are themselves truly polymorphic types (e.g. not a phantom type).
 
        let mut poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
 

	
 
        Self::mark_used_polymorphic_variables(&mut poly_vars, &definition.return_type);
 
        for argument in &arguments {
 
            Self::mark_used_polymorphic_variables(&mut poly_vars, &argument.parser_type);
 
        }
 

	
 
        let is_polymorph = poly_vars.iter().any(|arg| arg.is_in_use);
 

	
 
        self.definition_lookup.insert(definition_id, DefinedType{
 
            ast_root: root_id,
 
            ast_definition: definition_id,
 
            definition: DefinedTypeVariant::Function(FunctionType{ return_type: definition.return_type.clone(), arguments }),
 
            poly_vars,
 
            is_polymorph
 
        });
 

	
 
        return Ok(());
 
    }
 

	
 
    /// Builds base component type.
 
    fn build_base_component_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, definition_id: DefinitionId) -> Result<(), ParseError> {
 
        debug_assert!(!self.definition_lookup.contains_key(&definition_id), "base component already built");
 

	
 
        let definition = &ctx.heap[definition_id].as_component();
 
        let root_id = definition.defined_in;
 

	
 
        // Check the argument types
 
        let mut arguments = Vec::with_capacity(definition.parameters.len());
 
        for parameter_id in &definition.parameters {
 
            let parameter = &ctx.heap[*parameter_id];
 
            Self::check_member_parser_type(
 
                modules, ctx, root_id, &parameter.parser_type, false
 
            )?;
 

	
 
            arguments.push(FunctionArgument{
 
                identifier: parameter.identifier.clone(),
 
                parser_type: parameter.parser_type.clone(),
 
            });
 
        }
 

	
 
        // Check conflict of identifiers
 
        Self::check_identifier_collision(
 
            modules, root_id, &arguments, |arg| &arg.identifier, "connector argument"
 
        )?;
 
        Self::check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
 

	
 
        // Construct internal representation of component
 
        // TODO: Marking used polymorphic variables on procedures requires
 
        //  making sure that each is used in the body. For now, mark them all
 
        //  as required.
 
        let mut poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
 
        // for argument in &arguments {
 
        //     Self::mark_used_polymorphic_variables(&mut poly_vars, &argument.parser_type);
 
        // }
 
        for poly_var in &mut poly_vars {
 
            poly_var.is_in_use = true;
 
        }
 

	
 
        let is_polymorph = poly_vars.iter().any(|arg| arg.is_in_use);
 

	
 
        self.definition_lookup.insert(definition_id, DefinedType{
 
            ast_root: root_id,
 
            ast_definition: definition_id,
 
            definition: DefinedTypeVariant::Component(ComponentType{ variant: definition.variant, arguments }),
 
            definition: DefinedTypeVariant::Procedure(ProcedureType{
 
                kind: definition.kind,
 
                return_type: definition.return_type.clone(),
 
                arguments
 
            }),
 
            poly_vars,
 
            is_polymorph
 
        });
 

	
 
        Ok(())
 
        return Ok(());
 
    }
 

	
 
    /// Will check if the member type (field of a struct, embedded type in a
 
    /// union variant) is valid.
 
    fn check_member_parser_type(
 
        modules: &[Module], ctx: &PassCtx, base_definition_root_id: RootId,
 
        member_parser_type: &ParserType, allow_special_compiler_types: bool
 
    ) -> Result<(), ParseError> {
 
        use ParserTypeVariant as PTV;
 

	
 
        for element in &member_parser_type.elements {
 
            match element.variant {
 
                // Special cases
 
                PTV::Void | PTV::InputOrOutput | PTV::ArrayLike | PTV::IntegerLike => {
 
                    if !allow_special_compiler_types {
 
                        unreachable!("compiler-only ParserTypeVariant in member type");
 
                    }
 
                },
 
                // Builtin types, always valid
 
                PTV::Message | PTV::Bool |
 
                PTV::UInt8 | PTV::UInt16 | PTV::UInt32 | PTV::UInt64 |
 
                PTV::SInt8 | PTV::SInt16 | PTV::SInt32 | PTV::SInt64 |
 
                PTV::Character | PTV::String |
 
                PTV::Array | PTV::Input | PTV::Output | PTV::Tuple(_) |
 
                // Likewise, polymorphic variables are always valid
 
                PTV::PolymorphicArgument(_, _) => {},
 
                // Types that are not constructable, or types that are not
 
                // allowed (and checked earlier)
 
                PTV::IntegerLiteral | PTV::Inferred => {
 
                    unreachable!("illegal ParserTypeVariant within type definition");
 
                },
 
                // Finally, user-defined types
 
                PTV::Definition(definition_id, _) => {
 
                    let definition = &ctx.heap[definition_id];
 
                    if !(definition.is_struct() || definition.is_enum() || definition.is_union()) {
 
                        let source = &modules[base_definition_root_id.index as usize].source;
 
                        return Err(ParseError::new_error_str_at_span(
 
                            source, element.element_span, "expected a datatype (a struct, enum or union)"
 
                        ));
 
                    }
 

	
 
                    // Otherwise, we're fine
 
                }
 
            }
 
        }
 

	
 
        // If here, then all elements check out
 
        return Ok(());
 
    }
 

	
 
    /// Go through a list of identifiers and ensure that all identifiers have
 
    /// unique names
 
    fn check_identifier_collision<T: Sized, F: Fn(&T) -> &Identifier>(
 
        modules: &[Module], root_id: RootId, items: &[T], getter: F, item_name: &'static str
 
    ) -> Result<(), ParseError> {
 
        for (item_idx, item) in items.iter().enumerate() {
 
            let item_ident = getter(item);
 
            for other_item in &items[0..item_idx] {
 
                let other_item_ident = getter(other_item);
 
                if item_ident == other_item_ident {
 
                    let module_source = &modules[root_id.index as usize].source;
 
                    return Err(ParseError::new_error_at_span(
 
                        module_source, item_ident.span, format!("This {} is defined more than once", item_name)
 
                    ).with_info_at_span(
 
                        module_source, other_item_ident.span, format!("The other {} is defined here", item_name)
 
                    ));
 
                }
 
            }
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    /// Go through a list of polymorphic arguments and make sure that the
 
    /// arguments all have unique names, and the arguments do not conflict with
 
    /// any symbols defined at the module scope.
 
    fn check_poly_args_collision(
 
        modules: &[Module], ctx: &PassCtx, root_id: RootId, poly_args: &[Identifier]
 
    ) -> Result<(), ParseError> {
 
        // Make sure polymorphic arguments are unique and none of the
 
        // identifiers conflict with any imported scopes
 
        for (arg_idx, poly_arg) in poly_args.iter().enumerate() {
 
            for other_poly_arg in &poly_args[..arg_idx] {
 
                if poly_arg == other_poly_arg {
 
                    let module_source = &modules[root_id.index as usize].source;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        module_source, poly_arg.span,
 
                        "This polymorphic argument is defined more than once"
 
                    ).with_info_str_at_span(
 
                        module_source, other_poly_arg.span,
 
                        "It conflicts with this polymorphic argument"
 
                    ));
 
                }
 
            }
 

	
 
            // Check if identifier conflicts with a symbol defined or imported
 
@@ -1457,332 +1371,334 @@ impl TypeTable {
 
            let mut parse_error = None;
 
            let mut next_member_index = 0;
 
            while next_member_index < type_loop.members.len() {
 
                let first_entry = &type_loop.members[next_member_index];
 
                next_member_index += 1;
 

	
 
                // Retrieve definition of first type in loop
 
                let first_mono_type = &mono_types[first_entry.type_id.0 as usize];
 
                let first_definition_id = get_concrete_type_definition(&first_mono_type.concrete_type.parts);
 
                if first_definition_id.is_none() {
 
                    continue;
 
                }
 
                let first_definition_id = first_definition_id.unwrap();
 

	
 
                // Produce error message for first type in loop
 
                let (first_module, first_span, first_message) = type_loop_source_span_and_message(
 
                    modules, heap, mono_types, first_definition_id, first_entry.type_id, 0
 
                );
 
                parse_error = Some(ParseError::new_error_at_span(first_module, first_span, first_message));
 
                break;
 
            }
 

	
 
            let mut parse_error = parse_error.unwrap(); // Loop above cannot have failed, because we must have a type loop, type loops cannot contain only unnamed types
 

	
 
            let mut error_counter = 1;
 
            for member_idx in next_member_index..type_loop.members.len() {
 
                let entry = &type_loop.members[member_idx];
 
                let mono_type = &mono_types[entry.type_id.0 as usize];
 
                let definition_id = get_concrete_type_definition(&mono_type.concrete_type.parts);
 
                if definition_id.is_none() {
 
                    continue;
 
                }
 
                let definition_id = definition_id.unwrap();
 

	
 
                let (module, span, message) = type_loop_source_span_and_message(
 
                    modules, heap, mono_types, definition_id, entry.type_id, error_counter
 
                );
 
                parse_error = parse_error.with_info_at_span(module, span, message);
 
                error_counter += 1;
 
            }
 

	
 
            parse_error
 
        }
 

	
 
        for type_loop in &self.type_loops {
 
            let mut can_be_broken = false;
 
            debug_assert!(!type_loop.members.is_empty());
 

	
 
            for entry in &type_loop.members {
 
                if entry.is_union {
 
                    let mono_type = self.mono_types[entry.type_id.0 as usize].variant.as_union();
 
                    debug_assert!(!mono_type.variants.is_empty()); // otherwise it couldn't be part of the type loop
 
                    let has_stack_variant = mono_type.variants.iter().any(|variant| !variant.lives_on_heap);
 
                    if has_stack_variant {
 
                        can_be_broken = true;
 
                        break;
 
                    }
 
                }
 
            }
 

	
 
            if !can_be_broken {
 
                // Construct a type loop error
 
                return Err(construct_type_loop_error(&self.mono_types, type_loop, modules, heap));
 
            }
 
        }
 

	
 
        // If here, then all type loops have been resolved and we can lay out
 
        // all of the members
 
        self.type_loops.clear();
 

	
 
        return Ok(());
 
    }
 

	
 
    /// Checks if the specified type needs to be resolved (i.e. we need to push
 
    /// a breadcrumb), is already resolved (i.e. we can continue with the next
 
    /// member of the currently considered type) or is in the process of being
 
    /// resolved (i.e. we're in a type loop). Because of borrowing rules we
 
    /// don't do any modifications of internal types here. Hence: if we
 
    /// return `PushBreadcrumb` then call `handle_new_breadcrumb_for_type_loops`
 
    /// to take care of storing the appropriate types.
 
    fn check_member_for_type_loops(
 
        breadcrumbs: &[TypeLoopBreadcrumb], definition_map: &DefinitionMap, mono_type_map: &MonoTypeMap,
 
        mono_key: &mut MonoSearchKey, concrete_type: &ConcreteType
 
    ) -> TypeLoopResult {
 
        use ConcreteTypePart as CTP;
 

	
 
        // Depending on the type, lookup if the type has already been visited
 
        // (i.e. either already has its memory layed out, or is part of a type
 
        // loop because we've already visited the type)
 
        debug_assert!(!concrete_type.parts.is_empty());
 
        let (definition_id, type_id) = match &concrete_type.parts[0] {
 
            CTP::Tuple(_) => {
 
                Self::set_search_key_to_tuple(mono_key, definition_map, &concrete_type.parts);
 
                let type_id = mono_type_map.get(&mono_key).copied();
 
                (DefinitionId::new_invalid(), type_id)
 
            },
 
            CTP::Instance(definition_id, _) |
 
            CTP::Function(definition_id, _) |
 
            CTP::Component(definition_id, _) => {
 
            CTP::Instance(definition_id, _) => {
 
                let definition_type = definition_map.get(definition_id).unwrap();
 
                mono_key.set(&concrete_type.parts, &definition_type.poly_vars);
 
                let type_id = mono_type_map.get(&mono_key).copied();
 

	
 
                (*definition_id, type_id)
 
            },
 
            CTP::Function(_, _) |
 
            CTP::Component(_, _) => {
 
                todo!("function pointers")
 
            },
 
            _ => {
 
                return TypeLoopResult::TypeExists
 
            },
 
        };
 

	
 
        if let Some(type_id) = type_id {
 
            for (breadcrumb_idx, breadcrumb) in breadcrumbs.iter().enumerate() {
 
                if breadcrumb.type_id == type_id {
 
                    return TypeLoopResult::TypeLoop(breadcrumb_idx);
 
                }
 
            }
 

	
 
            return TypeLoopResult::TypeExists;
 
        }
 

	
 
        // Type is not yet known, so we need to insert it into the lookup and
 
        // push a new breadcrumb.
 
        return TypeLoopResult::PushBreadcrumb(definition_id, concrete_type.clone());
 
    }
 

	
 
    /// Handles the `PushBreadcrumb` result for a `check_member_for_type_loops`
 
    /// call. Will preallocate entries in the monomorphed type storage (with
 
    /// all memory properties zeroed).
 
    fn handle_new_breadcrumb_for_type_loops(&mut self, definition_id: DefinitionId, concrete_type: ConcreteType) {
 
        use DefinedTypeVariant as DTV;
 
        use ConcreteTypePart as CTP;
 

	
 
        let mut is_union = false;
 

	
 
        let type_id = match &concrete_type.parts[0] {
 
            CTP::Tuple(num_embedded) => {
 
                debug_assert!(definition_id.is_invalid()); // because tuples do not have an associated `DefinitionId`
 
                let mut members = Vec::with_capacity(*num_embedded as usize);
 
                for section in ConcreteTypeIter::new(&concrete_type.parts, 0) {
 
                    members.push(TupleMonomorphMember{
 
                        type_id: TypeId::new_invalid(),
 
                        concrete_type: ConcreteType{ parts: Vec::from(section) },
 
                        size: 0,
 
                        alignment: 0,
 
                        offset: 0
 
                    });
 
                }
 

	
 
                let type_id = TypeId(self.mono_types.len() as i64);
 
                Self::set_search_key_to_tuple(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
 
                self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
 
                self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Tuple(TupleMonomorph{ members })));
 

	
 
                type_id
 
            },
 
            CTP::Instance(_check_definition_id, _) => {
 
                debug_assert_eq!(definition_id, *_check_definition_id); // because this is how `definition_id` was determined
 

	
 
                Self::set_search_key_to_type(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
 
                let base_type = self.definition_lookup.get(&definition_id).unwrap();
 
                let type_id = match &base_type.definition {
 
                    DTV::Enum(definition) => {
 
                        // The enum is a bit exceptional in that when we insert
 
                        // it we we will immediately set its size/alignment:
 
                        // there is nothing to compute here.
 
                        debug_assert!(definition.size != 0 && definition.alignment != 0);
 
                        let type_id = TypeId(self.mono_types.len() as i64);
 
                        self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
 
                        self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Enum));
 

	
 
                        let mono_type = &mut self.mono_types[type_id.0 as usize];
 
                        mono_type.size = definition.size;
 
                        mono_type.alignment = definition.alignment;
 

	
 
                        type_id
 
                    },
 
                    DTV::Union(definition) => {
 
                        // Create all the variants with their concrete types
 
                        let mut mono_variants = Vec::with_capacity(definition.variants.len());
 
                        for poly_variant in &definition.variants {
 
                            let mut mono_embedded = Vec::with_capacity(poly_variant.embedded.len());
 
                            for poly_embedded in &poly_variant.embedded {
 
                                let mono_concrete = Self::construct_concrete_type(poly_embedded, &concrete_type);
 
                                mono_embedded.push(UnionMonomorphEmbedded{
 
                                    type_id: TypeId::new_invalid(),
 
                                    concrete_type: mono_concrete,
 
                                    size: 0,
 
                                    alignment: 0,
 
                                    offset: 0
 
                                });
 
                            }
 

	
 
                            mono_variants.push(UnionMonomorphVariant{
 
                                lives_on_heap: false,
 
                                embedded: mono_embedded,
 
                            })
 
                        }
 

	
 
                        let type_id = TypeId(self.mono_types.len() as i64);
 
                        let tag_size = definition.tag_size;
 
                        Self::set_search_key_to_type(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
 
                        self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
 
                        self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Union(UnionMonomorph{
 
                            variants: mono_variants,
 
                            tag_size,
 
                            heap_size: 0,
 
                            heap_alignment: 0,
 
                        })));
 

	
 
                        is_union = true;
 
                        type_id
 
                    },
 
                    DTV::Struct(definition) => {
 
                        // Create fields
 
                        let mut mono_fields = Vec::with_capacity(definition.fields.len());
 
                        for poly_field in &definition.fields {
 
                            let mono_concrete = Self::construct_concrete_type(&poly_field.parser_type, &concrete_type);
 
                            mono_fields.push(StructMonomorphField{
 
                                type_id: TypeId::new_invalid(),
 
                                concrete_type: mono_concrete,
 
                                size: 0,
 
                                alignment: 0,
 
                                offset: 0
 
                            })
 
                        }
 

	
 
                        let type_id = TypeId(self.mono_types.len() as i64);
 
                        Self::set_search_key_to_type(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
 
                        self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
 
                        self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Struct(StructMonomorph{
 
                            fields: mono_fields,
 
                        })));
 

	
 
                        type_id
 
                    },
 
                    DTV::Function(_) | DTV::Component(_) => {
 
                    DTV::Procedure(_) => {
 
                        unreachable!("pushing type resolving breadcrumb for procedure type")
 
                    },
 
                };
 

	
 
                type_id
 
            },
 
            _ => unreachable!(),
 
        };
 

	
 
        self.encountered_types.push(TypeLoopEntry{ type_id, is_union });
 
        self.type_loop_breadcrumbs.push(TypeLoopBreadcrumb{
 
            type_id,
 
            next_member: 0,
 
            next_embedded: 0,
 
        });
 
    }
 

	
 
    /// Constructs a concrete type out of a parser type for a struct field or
 
    /// union embedded type. It will do this by looking up the polymorphic
 
    /// variables in the supplied concrete type. The assumption is that the
 
    /// polymorphic variable's indices correspond to the subtrees in the
 
    /// concrete type.
 
    fn construct_concrete_type(member_type: &ParserType, container_type: &ConcreteType) -> ConcreteType {
 
        use ParserTypeVariant as PTV;
 
        use ConcreteTypePart as CTP;
 

	
 
        // TODO: Combine with code in pass_typing.rs
 
        fn parser_to_concrete_part(part: &ParserTypeVariant) -> Option<ConcreteTypePart> {
 
            match part {
 
                PTV::Void      => Some(CTP::Void),
 
                PTV::Message   => Some(CTP::Message),
 
                PTV::Bool      => Some(CTP::Bool),
 
                PTV::UInt8     => Some(CTP::UInt8),
 
                PTV::UInt16    => Some(CTP::UInt16),
 
                PTV::UInt32    => Some(CTP::UInt32),
 
                PTV::UInt64    => Some(CTP::UInt64),
 
                PTV::SInt8     => Some(CTP::SInt8),
 
                PTV::SInt16    => Some(CTP::SInt16),
 
                PTV::SInt32    => Some(CTP::SInt32),
 
                PTV::SInt64    => Some(CTP::SInt64),
 
                PTV::Character => Some(CTP::Character),
 
                PTV::String    => Some(CTP::String),
 
                PTV::Array     => Some(CTP::Array),
 
                PTV::Input     => Some(CTP::Input),
 
                PTV::Output    => Some(CTP::Output),
 
                PTV::Tuple(num) => Some(CTP::Tuple(*num)),
 
                PTV::Definition(definition_id, num) => Some(CTP::Instance(*definition_id, *num)),
 
                _              => None
 
            }
 
        }
 

	
 
        let mut parts = Vec::with_capacity(member_type.elements.len()); // usually a correct estimation, might not be
 
        for member_part in &member_type.elements {
 
            // Check if we have a regular builtin type
 
            if let Some(part) = parser_to_concrete_part(&member_part.variant) {
 
                parts.push(part);
 
                continue;
 
            }
 

	
 
            // Not builtin, but if all code is working correctly, we only care
 
            // about the polymorphic argument at this point.
 
            if let PTV::PolymorphicArgument(_container_definition_id, poly_arg_idx) = member_part.variant {
 
                debug_assert_eq!(_container_definition_id, get_concrete_type_definition(&container_type.parts).unwrap());
 

	
 
                let mut container_iter = container_type.embedded_iter(0);
 
                for _ in 0..poly_arg_idx {
 
                    container_iter.next();
 
                }
 

	
 
                let poly_section = container_iter.next().unwrap();
 
                parts.extend(poly_section);
 

	
 
                continue;
 
            }
 

	
 
            unreachable!("unexpected type part {:?} from {:?}", member_part, member_type);
 
        }
 

	
 
        return ConcreteType{ parts };
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // Determining memory layout for types
 
    //--------------------------------------------------------------------------
 

	
 
    /// Should be called after type loops are detected (and resolved
 
    /// successfully). As a result of this call we expect the
 
    /// `encountered_types` array to be filled. We'll calculate size/alignment/
 
    /// offset values for those types in this routine.
 
    fn lay_out_memory_for_encountered_types(&mut self, arch: &TargetArch) {
 
        // Programmers note: this works like a little stack machine. We have
 
        // memory layout breadcrumbs which, like the type loop breadcrumbs, keep
 
        // track of the currently considered member type. This breadcrumb also
 
        // stores an index into the `size_alignment_stack`, which will be used
 
        // to store intermediate size/alignment pairs until all members are
 
        // resolved. Note that this `size_alignment_stack` is NOT an
 
@@ -2172,106 +2088,108 @@ impl TypeTable {
 
                (ConcreteTypePart::UInt8, 1)
 
            } else if max_val <= (u16::MAX as i64) {
 
                (ConcreteTypePart::UInt16, 2)
 
            } else if max_val <= (u32::MAX as i64) {
 
                (ConcreteTypePart::UInt32, 4)
 
            } else {
 
                (ConcreteTypePart::UInt64, 8)
 
            }
 
        } else {
 
            // Must be a signed integer
 
            if min_val >= (i8::MIN as i64) && max_val <= (i8::MAX as i64) {
 
                (ConcreteTypePart::SInt8, 1)
 
            } else if min_val >= (i16::MIN as i64) && max_val <= (i16::MAX as i64) {
 
                (ConcreteTypePart::SInt16, 2)
 
            } else if min_val >= (i32::MIN as i64) && max_val <= (i32::MAX as i64) {
 
                (ConcreteTypePart::SInt32, 4)
 
            } else {
 
                (ConcreteTypePart::SInt64, 8)
 
            }
 
        };
 

	
 
        return (ConcreteType{ parts: vec![part] }, size);
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // Small utilities
 
    //--------------------------------------------------------------------------
 

	
 
    fn create_polymorphic_variables(variables: &[Identifier]) -> Vec<PolymorphicVariable> {
 
        let mut result = Vec::with_capacity(variables.len());
 
        for variable in variables.iter() {
 
            result.push(PolymorphicVariable{ identifier: variable.clone(), is_in_use: false });
 
        }
 

	
 
        result
 
    }
 

	
 
    fn mark_used_polymorphic_variables(poly_vars: &mut Vec<PolymorphicVariable>, parser_type: &ParserType) {
 
        for element in &parser_type.elements {
 
            if let ParserTypeVariant::PolymorphicArgument(_, idx) = &element.variant {
 
                poly_vars[*idx as usize].is_in_use = true;
 
            }
 
        }
 
    }
 

	
 
    /// Sets the search key. If `false` is returned then the provided type is a
 
    /// builtin type. If `true` is returned then we're dealing with a user-
 
    /// defined type.
 
    fn set_search_key_to_type(search_key: &mut MonoSearchKey, definition_map: &DefinitionMap, type_parts: &[ConcreteTypePart]) -> bool {
 
        match type_parts[0] {
 
            ConcreteTypePart::Tuple(_) => {
 
                Self::set_search_key_to_tuple(search_key, definition_map, type_parts);
 
                return true;
 
            },
 
            ConcreteTypePart::Instance(definition_id, _) => {
 
                let definition_type = definition_map.get(&definition_id).unwrap();
 
                search_key.set(type_parts, &definition_type.poly_vars);
 
                return true;
 
            },
 
            ConcreteTypePart::Function(_, _) | ConcreteTypePart::Component(_, _) => {
 
                todo!("implement function pointers")
 
            },
 
            _ => return false,
 
        }
 
    }
 

	
 
    fn set_search_key_to_tuple(search_key: &mut MonoSearchKey, definition_map: &DefinitionMap, type_parts: &[ConcreteTypePart]) {
 
        dbg_code!({
 
            let is_tuple = if let ConcreteTypePart::Tuple(_) = type_parts[0] { true } else { false };
 
            assert!(is_tuple);
 
        });
 
        search_key.set_top_type(type_parts[0]);
 
        for subtree in ConcreteTypeIter::new(type_parts, 0) {
 
            if let Some(definition_id) = get_concrete_type_definition(subtree) {
 
                // A definition, so retrieve poly var usage info
 
                let definition_type = definition_map.get(&definition_id).unwrap();
 
                search_key.push_subtree(subtree, &definition_type.poly_vars);
 
            } else {
 
                // Not a definition, so all type information is important
 
                search_key.push_subtype(subtree, true);
 
            }
 
        }
 
    }
 
}
 

	
 
#[inline]
 
fn align_offset_to(offset: &mut usize, alignment: usize) {
 
    debug_assert!(alignment > 0);
 
    let alignment_min_1 = alignment - 1;
 
    *offset += alignment_min_1;
 
    *offset &= !(alignment_min_1);
 
}
 

	
 
#[inline]
 
fn get_concrete_type_definition(concrete_parts: &[ConcreteTypePart]) -> Option<DefinitionId> {
 
    match concrete_parts[0] {
 
        ConcreteTypePart::Instance(definition_id, _) |
 
        ConcreteTypePart::Instance(definition_id, _) => {
 
            return Some(definition_id)
 
        },
 
        ConcreteTypePart::Function(definition_id, _) |
 
        ConcreteTypePart::Component(definition_id, _) => {
 
            return Some(definition_id);
 
            return Some(definition_id.upcast());
 
        },
 
        _ => {
 
            return None;
 
        },
 
    }
 
}
 
\ No newline at end of file
src/protocol/parser/visitor.rs
Show inline comments
 
@@ -44,246 +44,241 @@ macro_rules! visitor_recursive_statement_impl {
 
            Statement::Block(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_block_stmt($ctx, this)
 
            },
 
            Statement::EndBlock(_stmt) => $default_return,
 
            Statement::Local(stmt) => {
 
                let this = stmt.this();
 
                $this.visit_local_stmt($ctx, this)
 
            },
 
            Statement::Labeled(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_labeled_stmt($ctx, this)
 
            },
 
            Statement::If(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_if_stmt($ctx, this)
 
            },
 
            Statement::EndIf(_stmt) => $default_return,
 
            Statement::While(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_while_stmt($ctx, this)
 
            },
 
            Statement::EndWhile(_stmt) => $default_return,
 
            Statement::Break(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_break_stmt($ctx, this)
 
            },
 
            Statement::Continue(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_continue_stmt($ctx, this)
 
            },
 
            Statement::Synchronous(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_synchronous_stmt($ctx, this)
 
            },
 
            Statement::EndSynchronous(_stmt) => $default_return,
 
            Statement::Fork(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_fork_stmt($ctx, this)
 
            },
 
            Statement::EndFork(_stmt) => $default_return,
 
            Statement::Select(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_select_stmt($ctx, this)
 
            },
 
            Statement::EndSelect(_stmt) => $default_return,
 
            Statement::Return(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_return_stmt($ctx, this)
 
            },
 
            Statement::Goto(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_goto_stmt($ctx, this)
 
            },
 
            Statement::New(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_new_stmt($ctx, this)
 
            },
 
            Statement::Expression(stmt) => {
 
                let this = stmt.this;
 
                $this.visit_expr_stmt($ctx, this)
 
            }
 
        }
 
    };
 
}
 

	
 
macro_rules! visitor_recursive_local_impl {
 
    ($this:expr, $local:expr, $ctx:expr) => {
 
        match $local {
 
            LocalStatement::Channel(local) => {
 
                let this = local.this;
 
                $this.visit_local_channel_stmt($ctx, this)
 
            },
 
            LocalStatement::Memory(local) => {
 
                let this = local.this;
 
                $this.visit_local_memory_stmt($ctx, this)
 
            }
 
        }
 
    }
 
}
 

	
 
macro_rules! visitor_recursive_definition_impl {
 
    ($this:expr, $definition:expr, $ctx:expr) => {
 
        match $definition {
 
            Definition::Enum(def) => {
 
                let def = def.this;
 
                $this.visit_enum_definition($ctx, def)
 
            },
 
            Definition::Union(def) => {
 
                let def = def.this;
 
                $this.visit_union_definition($ctx, def)
 
            },
 
            Definition::Struct(def) => {
 
                let def = def.this;
 
                $this.visit_struct_definition($ctx, def)
 
            },
 
            Definition::Component(def) => {
 
            Definition::Procedure(def) => {
 
                let def = def.this;
 
                $this.visit_component_definition($ctx, def)
 
            },
 
            Definition::Function(def) => {
 
                let def = def.this;
 
                $this.visit_function_definition($ctx, def)
 
                $this.visit_procedure_definition($ctx, def)
 
            },
 
        }
 
    }
 
}
 

	
 
macro_rules! visitor_recursive_expression_impl {
 
    ($this:expr, $expression:expr, $ctx:expr) => {
 
        match $expression {
 
            Expression::Assignment(expr) => {
 
                let this = expr.this;
 
                $this.visit_assignment_expr($ctx, this)
 
            },
 
            Expression::Binding(expr) => {
 
                let this = expr.this;
 
                $this.visit_binding_expr($ctx, this)
 
            },
 
            Expression::Conditional(expr) => {
 
                let this = expr.this;
 
                $this.visit_conditional_expr($ctx, this)
 
            },
 
            Expression::Binary(expr) => {
 
                let this = expr.this;
 
                $this.visit_binary_expr($ctx, this)
 
            },
 
            Expression::Unary(expr) => {
 
                let this = expr.this;
 
                $this.visit_unary_expr($ctx, this)
 
            },
 
            Expression::Indexing(expr) => {
 
                let this = expr.this;
 
                $this.visit_indexing_expr($ctx, this)
 
            },
 
            Expression::Slicing(expr) => {
 
                let this = expr.this;
 
                $this.visit_slicing_expr($ctx, this)
 
            },
 
            Expression::Select(expr) => {
 
                let this = expr.this;
 
                $this.visit_select_expr($ctx, this)
 
            },
 
            Expression::Literal(expr) => {
 
                let this = expr.this;
 
                $this.visit_literal_expr($ctx, this)
 
            },
 
            Expression::Cast(expr) => {
 
                let this = expr.this;
 
                $this.visit_cast_expr($ctx, this)
 
            },
 
            Expression::Call(expr) => {
 
                let this = expr.this;
 
                $this.visit_call_expr($ctx, this)
 
            },
 
            Expression::Variable(expr) => {
 
                let this = expr.this;
 
                $this.visit_variable_expr($ctx, this)
 
            },
 
        }
 
    };
 
}
 

	
 
/// Visitor is a generic trait that will fully walk the AST. The default
 
/// implementation of the visitors is to not recurse. The exception is the
 
/// top-level `visit_definition`, `visit_stmt` and `visit_expr` methods, which
 
/// call the appropriate visitor function.
 
pub(crate) trait Visitor {
 
    // Entry point
 
    fn visit_module(&mut self, ctx: &mut Ctx) -> VisitorResult {
 
        let mut def_index = 0;
 
        let module_root_id = ctx.modules[ctx.module_idx].root_id;
 
        loop {
 
            let definition_id = {
 
                let root = &ctx.heap[module_root_id];
 
                if def_index >= root.definitions.len() {
 
                    return Ok(())
 
                }
 

	
 
                root.definitions[def_index]
 
            };
 

	
 
            self.visit_definition(ctx, definition_id)?;
 
            def_index += 1;
 
        }
 
    }
 

	
 
    // Definitions
 
    // --- enum matching
 
    fn visit_definition(&mut self, ctx: &mut Ctx, id: DefinitionId) -> VisitorResult {
 
        return visitor_recursive_definition_impl!(self, &ctx.heap[id], ctx);
 
    }
 

	
 
    // --- enum variant handling
 
    fn visit_enum_definition(&mut self, _ctx: &mut Ctx, _id: EnumDefinitionId) -> VisitorResult { Ok(()) }
 
    fn visit_union_definition(&mut self, _ctx: &mut Ctx, _id: UnionDefinitionId) -> VisitorResult{ Ok(()) }
 
    fn visit_struct_definition(&mut self, _ctx: &mut Ctx, _id: StructDefinitionId) -> VisitorResult { Ok(()) }
 
    fn visit_component_definition(&mut self, _ctx: &mut Ctx, _id: ComponentDefinitionId) -> VisitorResult { Ok(()) }
 
    fn visit_function_definition(&mut self, _ctx: &mut Ctx, _id: FunctionDefinitionId) -> VisitorResult { Ok(()) }
 
    fn visit_procedure_definition(&mut self, _ctx: &mut Ctx, _id: ProcedureDefinitionId) -> VisitorResult { Ok(()) }
 

	
 
    // Statements
 
    // --- enum matching
 
    fn visit_stmt(&mut self, ctx: &mut Ctx, id: StatementId) -> VisitorResult {
 
        return visitor_recursive_statement_impl!(self, &ctx.heap[id], ctx, Ok(()));
 
    }
 

	
 
    fn visit_local_stmt(&mut self, ctx: &mut Ctx, id: LocalStatementId) -> VisitorResult {
 
        return visitor_recursive_local_impl!(self, &ctx.heap[id], ctx);
 
    }
 

	
 
    // --- enum variant handling
 
    fn visit_block_stmt(&mut self, _ctx: &mut Ctx, _id: BlockStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_local_memory_stmt(&mut self, _ctx: &mut Ctx, _id: MemoryStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_local_channel_stmt(&mut self, _ctx: &mut Ctx, _id: ChannelStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_labeled_stmt(&mut self, _ctx: &mut Ctx, _id: LabeledStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_if_stmt(&mut self, _ctx: &mut Ctx, _id: IfStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_while_stmt(&mut self, _ctx: &mut Ctx, _id: WhileStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_break_stmt(&mut self, _ctx: &mut Ctx, _id: BreakStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_continue_stmt(&mut self, _ctx: &mut Ctx, _id: ContinueStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_synchronous_stmt(&mut self, _ctx: &mut Ctx, _id: SynchronousStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_fork_stmt(&mut self, _ctx: &mut Ctx, _id: ForkStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_select_stmt(&mut self, _ctx: &mut Ctx, _id: SelectStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_return_stmt(&mut self, _ctx: &mut Ctx, _id: ReturnStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_goto_stmt(&mut self, _ctx: &mut Ctx, _id: GotoStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_new_stmt(&mut self, _ctx: &mut Ctx, _id: NewStatementId) -> VisitorResult { Ok(()) }
 
    fn visit_expr_stmt(&mut self, _ctx: &mut Ctx, _id: ExpressionStatementId) -> VisitorResult { Ok(()) }
 

	
 
    // Expressions
 
    // --- enum matching
 
    fn visit_expr(&mut self, ctx: &mut Ctx, id: ExpressionId) -> VisitorResult {
 
        return visitor_recursive_expression_impl!(self, &ctx.heap[id], ctx);
 
    }
 

	
 
    fn visit_assignment_expr(&mut self, _ctx: &mut Ctx, _id: AssignmentExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_binding_expr(&mut self, _ctx: &mut Ctx, _id: BindingExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_conditional_expr(&mut self, _ctx: &mut Ctx, _id: ConditionalExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_binary_expr(&mut self, _ctx: &mut Ctx, _id: BinaryExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_unary_expr(&mut self, _ctx: &mut Ctx, _id: UnaryExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_indexing_expr(&mut self, _ctx: &mut Ctx, _id: IndexingExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_slicing_expr(&mut self, _ctx: &mut Ctx, _id: SlicingExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_select_expr(&mut self, _ctx: &mut Ctx, _id: SelectExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_literal_expr(&mut self, _ctx: &mut Ctx, _id: LiteralExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_cast_expr(&mut self, _ctx: &mut Ctx, _id: CastExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_call_expr(&mut self, _ctx: &mut Ctx, _id: CallExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_variable_expr(&mut self, _ctx: &mut Ctx, _id: VariableExpressionId) -> VisitorResult { Ok(()) }
 
}
 
\ No newline at end of file
src/protocol/tests/utils.rs
Show inline comments
 
@@ -125,193 +125,193 @@ pub(crate) struct AstOkTester {
 
}
 

	
 
impl AstOkTester {
 
    fn new(test_name: String, parser: Parser) -> Self {
 
        Self {
 
            test_name,
 
            modules: parser.modules.into_iter().map(|module| Module{
 
                source: module.source,
 
                root_id: module.root_id,
 
                name: module.name.map(|(_, name)| name)
 
            }).collect(),
 
            heap: parser.heap,
 
            symbols: parser.symbol_table,
 
            types: parser.type_table,
 
            pool: parser.string_pool,
 
        }
 
    }
 

	
 
    pub(crate) fn for_struct<F: Fn(StructTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Struct(ast_definition) = definition {
 
                if ast_definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found struct with the same name
 
                let definition_id = ast_definition.this.upcast();
 
                let type_entry = self.types.get_base_definition(&definition_id).unwrap();
 
                let type_definition = type_entry.definition.as_struct();
 

	
 
                let tester = StructTester::new(self.ctx(), ast_definition, type_definition);
 
                f(tester);
 
                found = true;
 
                break
 
            }
 
        }
 

	
 
        assert!(
 
            found, "[{}] Failed to find definition for struct '{}'",
 
            self.test_name, name
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn for_enum<F: Fn(EnumTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Enum(definition) = definition {
 
                if definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found enum with the same name
 
                let tester = EnumTester::new(self.ctx(), definition);
 
                f(tester);
 
                found = true;
 
                break;
 
            }
 
        }
 

	
 
        assert!(
 
            found, "[{}] Failed to find definition for enum '{}'",
 
            self.test_name, name
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn for_union<F: Fn(UnionTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Union(definition) = definition {
 
                if definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found union with the same name
 
                let definition_id = definition.this.upcast();
 
                let base_type = self.types.get_base_definition(&definition_id).unwrap();
 
                let tester = UnionTester::new(self.ctx(), definition, &base_type.definition.as_union());
 
                f(tester);
 
                found = true;
 
                break;
 
            }
 
        }
 

	
 
        assert!(
 
            found, "[{}] Failed to find definition for union '{}'",
 
            self.test_name, name
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn for_function<F: FnOnce(FunctionTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Function(definition) = definition {
 
            if let Definition::Procedure(definition) = definition {
 
                if definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found function
 
                let tester = FunctionTester::new(self.ctx(), definition);
 
                f(tester);
 
                found = true;
 
                break;
 
            }
 
        }
 

	
 
        if found { return self }
 

	
 
        assert!(
 
            false, "[{}] failed to find definition for function '{}'",
 
            self.test_name, name
 
        );
 
        unreachable!();
 
    }
 

	
 
    fn ctx(&self) -> TestCtx {
 
        TestCtx{
 
            test_name: &self.test_name,
 
            modules: &self.modules,
 
            heap: &self.heap,
 
            types: &self.types,
 
            symbols: &self.symbols,
 
        }
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Utilities for successful compilation
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct StructTester<'a> {
 
    ctx: TestCtx<'a>,
 
    ast_def: &'a StructDefinition,
 
    type_def: &'a StructType,
 
}
 

	
 
impl<'a> StructTester<'a> {
 
    fn new(ctx: TestCtx<'a>, ast_def: &'a StructDefinition, type_def: &'a StructType) -> Self {
 
        Self{ ctx, ast_def, type_def }
 
    }
 

	
 
    pub(crate) fn assert_num_fields(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.ast_def.fields.len(),
 
            "[{}] Expected {} struct fields, but found {} for {}",
 
            self.ctx.test_name, num, self.ast_def.fields.len(), self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
 
        let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.ast_def.this.upcast());
 
        assert!(
 
            is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
 
            self.ctx.test_name, num, num_encountered, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
 
        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.ast_def.this.upcast(), serialized_monomorph);
 
        assert!(
 
            has_monomorph.is_some(), "[{}] Expected to find monomorph {}, but got {} for {}",
 
            self.ctx.test_name, serialized_monomorph, &serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_size_alignment(mut self, monomorph: &str, size: usize, alignment: usize) -> Self {
 
        self = self.assert_has_monomorph(monomorph);
 
        let (mono_idx, _) = has_monomorph(self.ctx, self.ast_def.this.upcast(), monomorph);
 
        let type_id = mono_idx.unwrap();
 
        let mono = self.ctx.types.get_monomorph(type_id);
 

	
 
        assert!(
 
            mono.size == size && mono.alignment == alignment,
 
            "[{}] Expected (size,alignment) of ({}, {}), but got ({}, {}) for {}",
 
            self.ctx.test_name, size, alignment, mono.size, mono.alignment, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn for_field<F: Fn(StructFieldTester)>(self, name: &str, f: F) -> Self {
 
        // Find field with specified name
 
        for field in &self.ast_def.fields {
 
            if field.field.value.as_str() == name {
 
                let tester = StructFieldTester::new(self.ctx, field);
 
                f(tester);
 
                return self;
 
            }
 
@@ -414,654 +414,655 @@ impl<'a> EnumTester<'a> {
 
            "[{}] Expected (size,alignment) of ({}, {}), but got ({}, {}) for {}",
 
            self.ctx.test_name, size, alignment, mono.size, mono.alignment, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("Enum{ name: ");
 
        v.push_str(self.def.identifier.value.as_str());
 
        v.push_str(", variants: [");
 
        for (variant_idx, variant) in self.def.variants.iter().enumerate() {
 
            if variant_idx != 0 { v.push_str(", "); }
 
            v.push_str(variant.identifier.value.as_str());
 
        }
 
        v.push_str("] }");
 
        v
 
    }
 
}
 

	
 
pub(crate) struct UnionTester<'a> {
 
    ctx: TestCtx<'a>,
 
    ast_def: &'a UnionDefinition,
 
    type_def: &'a UnionType,
 
}
 

	
 
impl<'a> UnionTester<'a> {
 
    fn new(ctx: TestCtx<'a>, ast_def: &'a UnionDefinition, type_def: &'a UnionType) -> Self {
 
        Self{ ctx, ast_def, type_def }
 
    }
 

	
 
    pub(crate) fn assert_num_variants(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.ast_def.variants.len(),
 
            "[{}] Expected {} union variants, but found {} for {}",
 
            self.ctx.test_name, num, self.ast_def.variants.len(), self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
 
        let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.ast_def.this.upcast());
 
        assert!(
 
            is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
 
            self.ctx.test_name, num, num_encountered, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
 
        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.ast_def.this.upcast(), serialized_monomorph);
 
        assert!(
 
            has_monomorph.is_some(), "[{}] Expected to find monomorph {}, but got {} for {}",
 
            self.ctx.test_name, serialized_monomorph, serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_size_alignment(
 
        mut self, serialized_monomorph: &str,
 
        stack_size: usize, stack_alignment: usize, heap_size: usize, heap_alignment: usize
 
    ) -> Self {
 
        self = self.assert_has_monomorph(serialized_monomorph);
 
        let (mono_idx, _) = has_monomorph(self.ctx, self.ast_def.this.upcast(), serialized_monomorph);
 
        let mono_idx = mono_idx.unwrap();
 
        let mono_base = self.ctx.types.get_monomorph(mono_idx);
 
        let mono_union = mono_base.variant.as_union();
 

	
 
        assert!(
 
            stack_size == mono_base.size && stack_alignment == mono_base.alignment &&
 
                heap_size == mono_union.heap_size && heap_alignment == mono_union.heap_alignment,
 
            "[{}] Expected (stack | heap) (size, alignment) of ({}, {} | {}, {}), but got ({}, {} | {}, {}) for {}",
 
            self.ctx.test_name,
 
            stack_size, stack_alignment, heap_size, heap_alignment,
 
            mono_base.size, mono_base.alignment, mono_union.heap_size, mono_union.heap_alignment,
 
            self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("Union{ name: ");
 
        v.push_str(self.ast_def.identifier.value.as_str());
 
        v.push_str(", variants: [");
 
        for (variant_idx, variant) in self.ast_def.variants.iter().enumerate() {
 
            if variant_idx != 0 { v.push_str(", "); }
 
            v.push_str(variant.identifier.value.as_str());
 
        }
 
        v.push_str("] }");
 
        v
 
    }
 
}
 

	
 
pub(crate) struct FunctionTester<'a> {
 
    ctx: TestCtx<'a>,
 
    def: &'a FunctionDefinition,
 
    def: &'a ProcedureDefinition,
 
}
 

	
 
impl<'a> FunctionTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a FunctionDefinition) -> Self {
 
    fn new(ctx: TestCtx<'a>, def: &'a ProcedureDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn for_variable<F: Fn(VariableTester)>(self, name: &str, f: F) -> Self {
 
        // Seek through the blocks in order to find the variable
 
        let wrapping_scope = seek_scope(
 
            self.ctx.heap, self.def.scope,
 
            &|scope| {
 
                for variable_id in scope.variables.iter().copied() {
 
                    let var = &self.ctx.heap[variable_id];
 
                    if var.identifier.value.as_str() == name {
 
                        return true;
 
                    }
 
                }
 

	
 
                false
 
            }
 
        );
 

	
 
        let mut found_local_id = None;
 
        if let Some(scope_id) = wrapping_scope {
 
            // Found the right scope, find the variable inside the block again
 
            let scope = &self.ctx.heap[scope_id];
 
            for variable_id in scope.variables.iter().copied() {
 
                let variable = &self.ctx.heap[variable_id];
 
                if variable.identifier.value.as_str() == name {
 
                    found_local_id = Some(variable_id);
 
                }
 
            }
 
        }
 

	
 
        assert!(
 
            found_local_id.is_some(), "[{}] Failed to find variable '{}' in {}",
 
            self.ctx.test_name, name, self.assert_postfix()
 
        );
 

	
 
        let local = &self.ctx.heap[found_local_id.unwrap()];
 

	
 
        // Find an instance of the variable expression so we can determine its
 
        // type.
 
        let var_expr = seek_expr_in_stmt(
 
            self.ctx.heap, self.def.body.upcast(),
 
            &|expr| {
 
                if let Expression::Variable(variable_expr) = expr {
 
                    if variable_expr.identifier.value.as_str() == name {
 
                        return true;
 
                    }
 
                }
 

	
 
                false
 
            }
 
        );
 

	
 
        assert!(
 
            var_expr.is_some(), "[{}] Failed to find variable expression of '{}' in {}",
 
            self.ctx.test_name, name, self.assert_postfix()
 
        );
 

	
 
        let var_expr = &self.ctx.heap[var_expr.unwrap()];
 

	
 
        // Construct tester and pass to tester function
 
        let tester = VariableTester::new(
 
            self.ctx, self.def.this.upcast(), local,
 
            var_expr.as_variable()
 
        );
 

	
 
        f(tester);
 

	
 
        self
 
    }
 

	
 
    /// Finds a specific expression within a function. There are two matchers:
 
    /// one outer matcher (to find a rough indication of the expression) and an
 
    /// inner matcher to find the exact expression. 
 
    ///
 
    /// The reason being that, for example, a function's body might be littered
 
    /// with addition symbols, so we first match on "some_var + some_other_var",
 
    /// and then match exactly on "+".
 
    pub(crate) fn for_expression_by_source<F: Fn(ExpressionTester)>(self, outer_match: &str, inner_match: &str, f: F) -> Self {
 
        // Seek the expression in the source code
 
        assert!(outer_match.contains(inner_match), "improper testing code");
 

	
 
        let module = seek_def_in_modules(
 
            &self.ctx.heap, &self.ctx.modules, self.def.this.upcast()
 
        ).unwrap();
 

	
 
        // Find the first occurrence of the expression after the definition of
 
        // the function, we'll check that it is included in the body later.
 
        let mut outer_match_idx = self.def.span.begin.offset as usize;
 
        while outer_match_idx < module.source.input.len() {
 
            if module.source.input[outer_match_idx..].starts_with(outer_match.as_bytes()) {
 
                break;
 
            }
 
            outer_match_idx += 1
 
        }
 

	
 
        assert!(
 
            outer_match_idx < module.source.input.len(),
 
            "[{}] Failed to find '{}' within the source that contains {}",
 
            self.ctx.test_name, outer_match, self.assert_postfix()
 
        );
 
        let inner_match_idx = outer_match_idx + outer_match.find(inner_match).unwrap();
 

	
 
        // Use the inner match index to find the expression
 
        let expr_id = seek_expr_in_stmt(
 
            &self.ctx.heap, self.def.body.upcast(),
 
            &|expr| expr.operation_span().begin.offset as usize == inner_match_idx
 
        );
 
        assert!(
 
            expr_id.is_some(),
 
            "[{}] Failed to find '{}' within the source that contains {} \
 
            (note: expression was found, but not within the specified function",
 
            self.ctx.test_name, outer_match, self.assert_postfix()
 
        );
 
        let expr_id = expr_id.unwrap();
 

	
 
        // We have the expression, call the testing function
 
        let tester = ExpressionTester::new(
 
            self.ctx, self.def.this.upcast(), &self.ctx.heap[expr_id]
 
        );
 
        f(tester);
 

	
 
        self
 
    }
 

	
 
    pub(crate) fn call_ok(self, expected_result: Option<Value>) -> Self {
 
        use crate::protocol::*;
 

	
 
        let (prompt, result) = self.eval_until_end();
 
        match result {
 
            Ok(_) => {
 
                assert!(
 
                    prompt.store.stack.len() > 0, // note: stack never shrinks
 
                    "[{}] No value on stack after calling function for {}",
 
                    self.ctx.test_name, self.assert_postfix()
 
                );
 
            },
 
            Err(err) => {
 
                println!("DEBUG: Formatted evaluation error:\n{}", err);
 
                assert!(
 
                    false,
 
                    "[{}] Expected call to succeed, but got {:?} for {}",
 
                    self.ctx.test_name, err, self.assert_postfix()
 
                )
 
            }
 
        }
 

	
 
        if let Some(expected_result) = expected_result {
 
            debug_assert!(expected_result.get_heap_pos().is_none(), "comparing against heap thingamajigs is not yet implemented");
 
            assert!(
 
                value::apply_equality_operator(&prompt.store, &prompt.store.stack[0], &expected_result),
 
                "[{}] Result from call was {:?}, but expected {:?} for {}",
 
                self.ctx.test_name, &prompt.store.stack[0], &expected_result, self.assert_postfix()
 
            )
 
        }
 

	
 
        self
 
    }
 

	
 
    // Keeping this simple for now, will likely change
 
    pub(crate) fn call_err(self, expected_result: &str) -> Self {
 
        let (_, result) = self.eval_until_end();
 
        match result {
 
            Ok(_) => {
 
                assert!(
 
                    false,
 
                    "[{}] Expected an error, but evaluation finished successfully for {}",
 
                    self.ctx.test_name, self.assert_postfix()
 
                );
 
            },
 
            Err(err) => {
 
                println!("DEBUG: Formatted evaluation error:\n{}", err);
 
                debug_assert_eq!(err.statements.len(), 1);
 
                assert!(
 
                    err.statements[0].message.contains(&expected_result),
 
                    "[{}] Expected error message to contain '{}', but it was '{}' for {}",
 
                    self.ctx.test_name, expected_result, err.statements[0].message, self.assert_postfix()
 
                );
 
            }
 
        }
 

	
 
        self
 
    }
 

	
 
    fn eval_until_end(&self) -> (Prompt, Result<EvalContinuation, EvalError>) {
 
        use crate::protocol::*;
 

	
 
        // Assuming the function is not polymorphic
 
        let definition_id = self.def.this.upcast();
 
        let definition_id = self.def.this;
 
        let func_type = [ConcreteTypePart::Function(definition_id, 0)];
 
        let mono_index = self.ctx.types.get_procedure_monomorph_type_id(&definition_id, &func_type).unwrap();
 
        let mono_index = self.ctx.types.get_procedure_monomorph_type_id(&definition_id.upcast(), &func_type).unwrap();
 

	
 
        let mut prompt = Prompt::new(&self.ctx.types, &self.ctx.heap, self.def.this.upcast(), mono_index, ValueGroup::new_stack(Vec::new()));
 
        let mut prompt = Prompt::new(&self.ctx.types, &self.ctx.heap, definition_id, mono_index, ValueGroup::new_stack(Vec::new()));
 
        let mut call_context = FakeRunContext{};
 
        loop {
 
            let result = prompt.step(&self.ctx.types, &self.ctx.heap, &self.ctx.modules, &mut call_context);
 
            match result {
 
                Ok(EvalContinuation::Stepping) => {},
 
                _ => return (prompt, result),
 
            }
 
        }
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        format!("Function{{ name: {} }}", self.def.identifier.value.as_str())
 
    }
 
}
 

	
 
pub(crate) struct VariableTester<'a> {
 
    ctx: TestCtx<'a>,
 
    definition_id: DefinitionId,
 
    variable: &'a Variable,
 
    var_expr: &'a VariableExpression,
 
}
 

	
 
impl<'a> VariableTester<'a> {
 
    fn new(
 
        ctx: TestCtx<'a>, definition_id: DefinitionId, variable: &'a Variable, var_expr: &'a VariableExpression
 
    ) -> Self {
 
        Self{ ctx, definition_id, variable, var_expr }
 
    }
 

	
 
    pub(crate) fn assert_parser_type(self, expected: &str) -> Self {
 
        let mut serialized = String::new();
 
        serialize_parser_type(&mut serialized, self.ctx.heap, &self.variable.parser_type);
 

	
 
        assert_eq!(
 
            expected, &serialized,
 
            "[{}] Expected parser type '{}', but got '{}' for {}",
 
            self.ctx.test_name, expected, &serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_concrete_type(self, expected: &str) -> Self {
 
        // Lookup concrete type in type table
 
        let mono_data = get_procedure_monomorph(&self.ctx.heap, &self.ctx.types, self.definition_id);
 
        let concrete_type = &mono_data.expr_data[self.var_expr.unique_id_in_definition as usize].expr_type;
 

	
 
        // Serialize and check
 
        let serialized = concrete_type.display_name(self.ctx.heap);
 

	
 
        assert_eq!(
 
            expected, &serialized,
 
            "[{}] Expected concrete type '{}', but got '{}' for {}",
 
            self.ctx.test_name, expected, &serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        format!("Variable{{ name: {} }}", self.variable.identifier.value.as_str())
 
    }
 
}
 

	
 
pub(crate) struct ExpressionTester<'a> {
 
    ctx: TestCtx<'a>,
 
    definition_id: DefinitionId, // of the enclosing function/component
 
    expr: &'a Expression
 
}
 

	
 
impl<'a> ExpressionTester<'a> {
 
    fn new(
 
        ctx: TestCtx<'a>, definition_id: DefinitionId, expr: &'a Expression
 
    ) -> Self {
 
        Self{ ctx, definition_id, expr }
 
    }
 

	
 
    pub(crate) fn assert_concrete_type(self, expected: &str) -> Self {
 
        // Lookup concrete type
 
        let mono_data = get_procedure_monomorph(&self.ctx.heap, &self.ctx.types, self.definition_id);
 
        let expr_index = self.expr.get_unique_id_in_definition();
 
        let concrete_type = &mono_data.expr_data[expr_index as usize].expr_type;
 

	
 
        // Serialize and check type
 
        let serialized = concrete_type.display_name(self.ctx.heap);
 

	
 
        assert_eq!(
 
            expected, &serialized,
 
            "[{}] Expected concrete type '{}', but got '{}' for {}",
 
            self.ctx.test_name, expected, &serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        format!(
 
            "Expression{{ debug: {:?} }}",
 
            self.expr
 
        )
 
    }
 
}
 

	
 
fn get_procedure_monomorph<'a>(heap: &Heap, types: &'a TypeTable, definition_id: DefinitionId) -> &'a ProcedureMonomorph {
 
    let ast_definition = &heap[definition_id];
 
    let func_type = if ast_definition.is_function() {
 
        [ConcreteTypePart::Function(definition_id, 0)]
 
    } else if ast_definition.is_component() {
 
        [ConcreteTypePart::Component(definition_id, 0)]
 
    let ast_definition = heap[definition_id].as_procedure();
 
    let func_type = if ast_definition.kind == ProcedureKind::Function {
 
        [ConcreteTypePart::Function(ast_definition.this, 0)]
 
    } else {
 
        assert!(false);
 
        unreachable!()
 
        [ConcreteTypePart::Component(ast_definition.this, 0)]
 
    };
 

	
 
    let mono_index = types.get_procedure_monomorph_type_id(&definition_id, &func_type).unwrap();
 
    let mono_data = types.get_procedure_monomorph(mono_index);
 

	
 
    mono_data
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Interface for failed compilation
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct AstErrTester {
 
    test_name: String,
 
    error: ParseError,
 
}
 

	
 
impl AstErrTester {
 
    fn new(test_name: String, error: ParseError) -> Self {
 
        Self{ test_name, error }
 
    }
 

	
 
    pub(crate) fn error<F: Fn(ErrorTester)>(&self, f: F) {
 
        // Maybe multiple errors will be supported in the future
 
        let tester = ErrorTester{ test_name: &self.test_name, error: &self.error };
 
        f(tester)
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Utilities for failed compilation
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct ErrorTester<'a> {
 
    test_name: &'a str,
 
    error: &'a ParseError,
 
}
 

	
 
impl<'a> ErrorTester<'a> {
 
    pub(crate) fn assert_num(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.error.statements.len(),
 
            "[{}] expected error to consist of '{}' parts, but encountered '{}' for {}",
 
            self.test_name, num, self.error.statements.len(), self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    pub(crate) fn assert_ctx_has(self, idx: usize, msg: &str) -> Self {
 
        assert!(
 
            self.error.statements[idx].context.contains(msg),
 
            "[{}] expected error statement {}'s context to contain '{}' for {}",
 
            self.test_name, idx, msg, self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    pub(crate) fn assert_msg_has(self, idx: usize, msg: &str) -> Self {
 
        assert!(
 
            self.error.statements[idx].message.contains(msg),
 
            "[{}] expected error statement {}'s message to contain '{}' for {}",
 
            self.test_name, idx, msg, self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    /// Seeks the index of the pattern in the context message, then checks if
 
    /// the input position corresponds to that index.
 
    pub (crate) fn assert_occurs_at(self, idx: usize, pattern: &str) -> Self {
 
        let pos = self.error.statements[idx].context.find(pattern);
 
        assert!(
 
            pos.is_some(),
 
            "[{}] incorrect occurs_at: '{}' could not be found in the context for {}",
 
            self.test_name, pattern, self.assert_postfix()
 
        );
 
        let pos = pos.unwrap();
 
        let col = self.error.statements[idx].start_column as usize;
 
        assert_eq!(
 
            pos + 1, col,
 
            "[{}] Expected error to occur at column {}, but found it at {} for {}",
 
            self.test_name, pos + 1, col, self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("error: [");
 
        for (idx, stmt) in self.error.statements.iter().enumerate() {
 
            if idx != 0 {
 
                v.push_str(", ");
 
            }
 

	
 
            v.push_str(&format!("{{ context: {}, message: {} }}", &stmt.context, stmt.message));
 
        }
 
        v.push(']');
 
        v
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Generic utilities
 
//------------------------------------------------------------------------------
 

	
 
fn has_equal_num_monomorphs(ctx: TestCtx, num: usize, definition_id: DefinitionId) -> (bool, usize) {
 
    // Again: inefficient, but its testing code
 
    let mut num_on_type = 0;
 

	
 
    for mono in &ctx.types.mono_types {
 
        match &mono.concrete_type.parts[0] {
 
            ConcreteTypePart::Instance(def_id, _) |
 
            ConcreteTypePart::Instance(def_id, _) => {
 
                if *def_id == definition_id {
 
                    num_on_type += 1;
 
                }
 
            }
 
            ConcreteTypePart::Function(def_id, _) |
 
            ConcreteTypePart::Component(def_id, _) => {
 
                if *def_id == definition_id {
 
                if def_id.upcast() == definition_id {
 
                    num_on_type += 1;
 
                }
 
            },
 
            _ => {},
 
        };
 
    }
 

	
 
    (num_on_type == num, num_on_type)
 
}
 

	
 
fn has_monomorph(ctx: TestCtx, definition_id: DefinitionId, serialized_monomorph: &str) -> (Option<TypeId>, String) {
 
    // Note: full_buffer is just for error reporting
 
    let mut full_buffer = String::new();
 
    let mut has_match = None;
 

	
 
    full_buffer.push('[');
 
    let mut append_to_full_buffer = |concrete_type: &ConcreteType, type_id: TypeId| {
 
        if full_buffer.len() != 1 {
 
            full_buffer.push_str(", ");
 
        }
 
        full_buffer.push('"');
 

	
 
        let first_idx = full_buffer.len();
 
        full_buffer.push_str(concrete_type.display_name(ctx.heap).as_str());
 
        if &full_buffer[first_idx..] == serialized_monomorph {
 
            has_match = Some(type_id);
 
        }
 

	
 
        full_buffer.push('"');
 
    };
 

	
 
    // Bit wasteful, but this is (temporary?) testing code:
 
    for (mono_idx, mono) in ctx.types.mono_types.iter().enumerate() {
 
    for (_mono_idx, mono) in ctx.types.mono_types.iter().enumerate() {
 
        let got_definition_id = match &mono.concrete_type.parts[0] {
 
            ConcreteTypePart::Instance(v, _) |
 
            ConcreteTypePart::Instance(v, _) => *v,
 
            ConcreteTypePart::Function(v, _) |
 
            ConcreteTypePart::Component(v, _) => *v,
 
            ConcreteTypePart::Component(v, _) => v.upcast(),
 
            _ => DefinitionId::new_invalid(),
 
        };
 
        if got_definition_id == definition_id {
 
            append_to_full_buffer(&mono.concrete_type, mono.type_id);
 
        }
 
    }
 

	
 
    full_buffer.push(']');
 

	
 
    (has_match, full_buffer)
 
}
 

	
 
fn serialize_parser_type(buffer: &mut String, heap: &Heap, parser_type: &ParserType) {
 
    use ParserTypeVariant as PTV;
 

	
 
    fn serialize_variant(buffer: &mut String, heap: &Heap, parser_type: &ParserType, mut idx: usize) -> usize {
 
        match &parser_type.elements[idx].variant {
 
            PTV::Void => buffer.push_str("void"),
 
            PTV::InputOrOutput => {
 
                buffer.push_str("portlike<");
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push('>');
 
            },
 
            PTV::ArrayLike => {
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push_str("[???]");
 
            },
 
            PTV::IntegerLike => buffer.push_str("integerlike"),
 
            PTV::Message => buffer.push_str(KW_TYPE_MESSAGE_STR),
 
            PTV::Bool => buffer.push_str(KW_TYPE_BOOL_STR),
 
            PTV::UInt8 => buffer.push_str(KW_TYPE_UINT8_STR),
 
            PTV::UInt16 => buffer.push_str(KW_TYPE_UINT16_STR),
 
            PTV::UInt32 => buffer.push_str(KW_TYPE_UINT32_STR),
 
            PTV::UInt64 => buffer.push_str(KW_TYPE_UINT64_STR),
 
            PTV::SInt8 => buffer.push_str(KW_TYPE_SINT8_STR),
 
            PTV::SInt16 => buffer.push_str(KW_TYPE_SINT16_STR),
 
            PTV::SInt32 => buffer.push_str(KW_TYPE_SINT32_STR),
 
            PTV::SInt64 => buffer.push_str(KW_TYPE_SINT64_STR),
 
            PTV::Character => buffer.push_str(KW_TYPE_CHAR_STR),
 
            PTV::String => buffer.push_str(KW_TYPE_STRING_STR),
 
            PTV::IntegerLiteral => buffer.push_str("int_literal"),
 
            PTV::Inferred => buffer.push_str(KW_TYPE_INFERRED_STR),
 
            PTV::Array => {
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push_str("[]");
 
            },
 
            PTV::Input => {
 
                buffer.push_str(KW_TYPE_IN_PORT_STR);
 
                buffer.push('<');
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push('>');
 
            },
 
            PTV::Output => {
 
                buffer.push_str(KW_TYPE_OUT_PORT_STR);
 
                buffer.push('<');
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push('>');
 
            },
 
            PTV::Tuple(num_embedded) => {
 
                buffer.push('(');
 
                for embedded_idx in 0..*num_embedded {
 
                    if embedded_idx != 0 {
 
                        buffer.push(',');
 
                    }
 
                    idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                }
 
                buffer.push(')');
 
            },
 
            PTV::PolymorphicArgument(definition_id, poly_idx) => {
 
                let definition = &heap[*definition_id];
 
                let poly_arg = &definition.poly_vars()[*poly_idx as usize];
 
                buffer.push_str(poly_arg.value.as_str());
 
            },
 
            PTV::Definition(definition_id, num_embedded) => {
 
                let definition = &heap[*definition_id];
 
                buffer.push_str(definition.identifier().value.as_str());
 

	
 
                let num_embedded = *num_embedded;
 
                if num_embedded != 0 {
 
                    buffer.push('<');
 
                    for embedded_idx in 0..num_embedded {
 
                        if embedded_idx != 0 {
 
                            buffer.push(',');
 
                        }
 
                        idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                    }
 
                    buffer.push('>');
 
                }
 
            }
 
        }
 

	
 
        idx
 
    }
 

	
 
    serialize_variant(buffer, heap, parser_type, 0);
 
}
src/runtime2/component/component_pdl.rs
Show inline comments
 
use crate::protocol::*;
 
use crate::protocol::ast::DefinitionId;
 
use crate::protocol::ast::ProcedureDefinitionId;
 
use crate::protocol::eval::{
 
    PortId as EvalPortId, Prompt,
 
    ValueGroup, Value,
 
    EvalContinuation, EvalResult, EvalError
 
};
 

	
 
use crate::runtime2::scheduler::SchedulerCtx;
 
use crate::runtime2::communication::*;
 

	
 
use super::component_context::*;
 
use super::control_layer::*;
 
use super::consensus::Consensus;
 

	
 
pub enum CompScheduling {
 
    Immediate,
 
    Requeue,
 
    Sleep,
 
    Exit,
 
}
 

	
 
pub enum ExecStmt {
 
    CreatedChannel((Value, Value)),
 
    PerformedPut,
 
    PerformedGet(ValueGroup),
 
    None,
 
}
 

	
 
impl ExecStmt {
 
    fn take(&mut self) -> ExecStmt {
 
        let mut value = ExecStmt::None;
 
        std::mem::swap(self, &mut value);
 
        return value;
 
    }
 

	
 
    fn is_none(&self) -> bool {
 
        match self {
 
            ExecStmt::None => return true,
 
            _ => return false,
 
        }
 
    }
 
}
 

	
 
pub struct ExecCtx {
 
    stmt: ExecStmt,
 
}
 

	
 
impl RunContext for ExecCtx {
 
    fn performed_put(&mut self, _port: EvalPortId) -> bool {
 
        match self.stmt.take() {
 
            ExecStmt::None => return false,
 
            ExecStmt::PerformedPut => return true,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn performed_get(&mut self, _port: EvalPortId) -> Option<ValueGroup> {
 
        match self.stmt.take() {
 
            ExecStmt::None => return None,
 
            ExecStmt::PerformedGet(value) => return Some(value),
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn fires(&mut self, _port: EvalPortId) -> Option<Value> {
 
        todo!("remove fires")
 
    }
 

	
 
    fn performed_fork(&mut self) -> Option<bool> {
 
        todo!("remove fork")
 
    }
 

	
 
    fn created_channel(&mut self) -> Option<(Value, Value)> {
 
        match self.stmt.take() {
 
            ExecStmt::None => return None,
 
            ExecStmt::CreatedChannel(ports) => return Some(ports),
 
            _ => unreachable!(),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 
pub(crate) enum Mode {
 
    NonSync, // not in sync mode
 
    Sync, // in sync mode, can interact with other components
 
    SyncEnd, // awaiting a solution, i.e. encountered the end of the sync block
 
    BlockedGet,
 
    BlockedPut,
 
    StartExit, // temporary state: if encountered then we start the shutdown process
 
    BusyExit, // temporary state: waiting for Acks for all the closed ports
 
    Exit, // exiting: shutdown process started, now waiting until the reference count drops to 0
 
}
 

	
 
pub(crate) struct CompPDL {
 
    pub mode: Mode,
 
    pub mode_port: PortId, // when blocked on a port
 
    pub mode_value: ValueGroup, // when blocked on a put
 
@@ -505,193 +505,193 @@ impl CompPDL {
 
                // Ack. Then we wait for the `unblock` call.
 
                debug_assert_eq!(message.target_port_id, Some(port_id));
 
                let port_handle = comp_ctx.get_port_handle(port_id);
 
                comp_ctx.set_port_state(port_handle, PortState::BlockedDueToPeerChange);
 

	
 
                let port_info = comp_ctx.get_port(port_handle);
 
                let peer_handle = comp_ctx.get_peer_handle(port_info.peer_comp_id);
 

	
 
                send_control_ack_message(sched_ctx, comp_ctx, message.id, peer_handle);
 
            },
 
            ControlMessageContent::PortPeerChangedUnblock(new_port_id, new_comp_id) => {
 
                let port_handle = comp_ctx.get_port_handle(message.target_port_id.unwrap());
 
                let port_info = comp_ctx.get_port(port_handle);
 
                debug_assert!(port_info.state == PortState::BlockedDueToPeerChange);
 
                let old_peer_id = port_info.peer_comp_id;
 

	
 
                comp_ctx.remove_peer(sched_ctx, port_handle, old_peer_id, false);
 

	
 
                let port_info = comp_ctx.get_port_mut(port_handle);
 
                port_info.peer_comp_id = new_comp_id;
 
                port_info.peer_port_id = new_port_id;
 
                comp_ctx.add_peer(port_handle, sched_ctx, new_comp_id, None);
 
                self.handle_unblock_port_instruction(sched_ctx, comp_ctx, port_handle);
 
            }
 
        }
 
    }
 

	
 
    fn handle_incoming_sync_message(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, message: SyncMessage) {
 
        let decision = self.consensus.receive_sync_message(sched_ctx, comp_ctx, message);
 
        self.handle_sync_decision(sched_ctx, comp_ctx, decision);
 
    }
 

	
 
    /// Little helper that notifies the control layer of an `Ack`, and takes the
 
    /// appropriate subsequent action
 
    fn handle_ack(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, control_id: ControlId) {
 
        let mut to_ack = control_id;
 
        loop {
 
            let (action, new_to_ack) = self.control.handle_ack(to_ack, sched_ctx, comp_ctx);
 
            match action {
 
                AckAction::SendMessage(target_comp, message) => {
 
                    // FIX @NoDirectHandle
 
                    let mut handle = sched_ctx.runtime.get_component_public(target_comp);
 
                    handle.send_message(sched_ctx, Message::Control(message), true);
 
                    let _should_remove = handle.decrement_users();
 
                    debug_assert!(_should_remove.is_none());
 
                },
 
                AckAction::ScheduleComponent(to_schedule) => {
 
                    // FIX @NoDirectHandle
 
                    let mut handle = sched_ctx.runtime.get_component_public(to_schedule);
 

	
 
                    // Note that the component is intentionally not
 
                    // sleeping, so we just wake it up
 
                    debug_assert!(!handle.sleeping.load(std::sync::atomic::Ordering::Acquire));
 
                    let key = unsafe{ to_schedule.upgrade() };
 
                    sched_ctx.runtime.enqueue_work(key);
 
                    let _should_remove = handle.decrement_users();
 
                    debug_assert!(_should_remove.is_none());
 
                },
 
                AckAction::None => {}
 
            }
 

	
 
            match new_to_ack {
 
                Some(new_to_ack) => to_ack = new_to_ack,
 
                None => break,
 
            }
 
        }
 
    }
 

	
 
    // -------------------------------------------------------------------------
 
    // Handling ports
 
    // -------------------------------------------------------------------------
 

	
 
    /// Unblocks a port, potentially continuing execution of the component, in
 
    /// response to a message that told us to unblock a previously blocked
 
    fn handle_unblock_port_instruction(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, port_handle: LocalPortHandle) {
 
        let port_info = comp_ctx.get_port_mut(port_handle);
 
        let port_id = port_info.self_id;
 
        debug_assert!(port_info.state.is_blocked());
 
        port_info.state = PortState::Open;
 

	
 
        if self.mode == Mode::BlockedPut && port_id == self.mode_port {
 
            // We were blocked on the port that just became unblocked, so
 
            // send the message.
 
            debug_assert_eq!(port_info.kind, PortKind::Putter);
 
            let mut replacement = ValueGroup::default();
 
            std::mem::swap(&mut replacement, &mut self.mode_value);
 
            self.send_data_message_and_wake_up(sched_ctx, comp_ctx, port_handle, replacement);
 

	
 
            self.mode = Mode::Sync;
 
            self.mode_port = PortId::new_invalid();
 
        }
 
    }
 

	
 
    fn create_component_and_transfer_ports(
 
        &mut self,
 
        sched_ctx: &SchedulerCtx, creator_ctx: &mut CompCtx,
 
        definition_id: DefinitionId, type_id: TypeId, mut arguments: ValueGroup
 
        definition_id: ProcedureDefinitionId, type_id: TypeId, mut arguments: ValueGroup
 
    ) {
 
        struct PortPair{
 
            creator_handle: LocalPortHandle,
 
            creator_id: PortId,
 
            created_handle: LocalPortHandle,
 
            created_id: PortId,
 
        }
 
        let mut port_id_pairs = Vec::new();
 

	
 
        let reservation = sched_ctx.runtime.start_create_pdl_component();
 
        let mut created_ctx = CompCtx::new(&reservation);
 

	
 
        // Take all the ports ID that are in the `args` (and currently belong to
 
        // the creator component) and translate them into new IDs that are
 
        // associated with the component we're about to create
 
        let mut arg_iter = ValueGroupIter::new(&mut arguments);
 
        while let Some(port_reference) = arg_iter.next() {
 
            // Create port entry for new component
 
            let creator_port_id = port_reference.id;
 
            let creator_port_handle = creator_ctx.get_port_handle(creator_port_id);
 
            let creator_port = creator_ctx.get_port(creator_port_handle);
 
            let created_port_handle = created_ctx.add_port(
 
                creator_port.peer_comp_id, creator_port.peer_port_id,
 
                creator_port.kind, creator_port.state
 
            );
 
            let created_port = created_ctx.get_port(created_port_handle);
 
            let created_port_id = created_port.self_id;
 

	
 
            port_id_pairs.push(PortPair{
 
                creator_handle: creator_port_handle,
 
                creator_id: creator_port_id,
 
                created_handle: created_port_handle,
 
                created_id: created_port_id,
 
            });
 

	
 
            // Modify value in arguments (bit dirty, but double vec in ValueGroup causes lifetime issues)
 
            let arg_value = if let Some(heap_pos) = port_reference.heap_pos {
 
                &mut arg_iter.group.regions[heap_pos][port_reference.index]
 
            } else {
 
                &mut arg_iter.group.values[port_reference.index]
 
            };
 
            match arg_value {
 
                Value::Input(id) => *id = port_id_to_eval(created_port_id),
 
                Value::Output(id) => *id = port_id_to_eval(created_port_id),
 
                _ => unreachable!(),
 
            }
 
        }
 

	
 
        // For each transferred port pair set their peer components to the
 
        // correct values. This will only change the values for the ports of
 
        // the new component.
 
        let mut created_component_has_remote_peers = false;
 

	
 
        for pair in port_id_pairs.iter() {
 
            let creator_port_info = creator_ctx.get_port(pair.creator_handle);
 
            let created_port_info = created_ctx.get_port_mut(pair.created_handle);
 

	
 
            if created_port_info.peer_comp_id == creator_ctx.id {
 
                // Port peer is owned by the creator as well
 
                let created_peer_port_index = port_id_pairs
 
                    .iter()
 
                    .position(|v| v.creator_id == creator_port_info.peer_port_id);
 
                match created_peer_port_index {
 
                    Some(created_peer_port_index) => {
 
                        // Peer port moved to the new component as well. So
 
                        // adjust IDs appropriately.
 
                        let peer_pair = &port_id_pairs[created_peer_port_index];
 
                        created_port_info.peer_port_id = peer_pair.created_id;
 
                        created_port_info.peer_comp_id = reservation.id();
 
                        todo!("either add 'self peer', or remove that idea from Ctx altogether")
 
                    },
 
                    None => {
 
                        // Peer port remains with creator component.
 
                        created_port_info.peer_comp_id = creator_ctx.id;
 
                        created_ctx.add_peer(pair.created_handle, sched_ctx, creator_ctx.id, None);
 
                    }
 
                }
 
            } else {
 
                // Peer is a different component. We'll deal with sending the
 
                // appropriate messages later
 
                let peer_handle = creator_ctx.get_peer_handle(created_port_info.peer_comp_id);
 
                let peer_info = creator_ctx.get_peer(peer_handle);
 
                created_ctx.add_peer(pair.created_handle, sched_ctx, peer_info.id, Some(&peer_info.handle));
 
                created_component_has_remote_peers = true;
 
            }
 
        }
 

	
 
        // We'll now actually turn our reservation for a new component into an
 
        // actual component. Note that we initialize it as "not sleeping" as
 
        // its initial scheduling might be performed based on `Ack`s in response
 
        // to message exchanges between remote peers.
 
        let prompt = Prompt::new(
 
            &sched_ctx.runtime.protocol.types, &sched_ctx.runtime.protocol.heap,
 
            definition_id, type_id, arguments,
 
        );
 
        let component = CompPDL::new(prompt, port_id_pairs.len());
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