Changeset - 3bb9f89521a1
[Not reviewed]
0 9 1
MH - 4 years ago 2021-05-25 18:58:12
contact@maxhenger.nl
Prepare for binding expression inference
10 files changed with 505 insertions and 157 deletions:
0 comments (0 inline, 0 general)
src/protocol/ast.rs
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// TODO: @cleanup, rigorous cleanup of dead code and silly object-oriented
 
//  trait impls where I deem them unfit.
 

	
 
use std::fmt;
 
use std::fmt::{Debug, Display, Formatter};
 
use std::ops::{Index, IndexMut};
 

	
 
use super::arena::{Arena, Id};
 
use crate::collections::StringRef;
 
use crate::protocol::input_source::InputSpan;
 

	
 
/// Helper macro that defines a type alias for a AST element ID. In this case 
 
/// only used to alias the `Id<T>` types.
 
macro_rules! define_aliased_ast_id {
 
    // Variant where we just defined the alias, without any indexing
 
    ($name:ident, $parent:ty) => {
 
        pub type $name = $parent;
 
    };
 
    // Variant where we define the type, and the Index and IndexMut traits
 
    (
 
        $name:ident, $parent:ty, 
 
        index($indexed_type:ty, $indexed_arena:ident)
 
    ) => {
 
        define_aliased_ast_id!($name, $parent);
 
        impl Index<$name> for Heap {
 
            type Output = $indexed_type;
 
            fn index(&self, index: $name) -> &Self::Output {
 
                &self.$indexed_arena[index]
 
            }
 
        }
 

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

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

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

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

	
 
define_aliased_ast_id!(RootId, Id<Root>, index(Root, protocol_descriptions), alloc(alloc_protocol_description));
 
define_aliased_ast_id!(PragmaId, Id<Pragma>, index(Pragma, pragmas), alloc(alloc_pragma));
 
define_aliased_ast_id!(ImportId, Id<Import>, index(Import, imports), alloc(alloc_import));
 
define_aliased_ast_id!(ParserTypeId, Id<ParserType>, index(ParserType, parser_types), alloc(alloc_parser_type));
 
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_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), alloc(alloc_local_statement));
 
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!(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));
 

	
 
// TODO: @cleanup - pub qualifiers can be removed once done
 
#[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) parser_types: Arena<ParserType>,
 
    pub(crate) variables: Arena<Variable>,
 
    pub(crate) definitions: Arena<Definition>,
 
    pub(crate) statements: Arena<Statement>,
 
    pub(crate) expressions: Arena<Expression>,
 
}
 

	
 
impl Heap {
 
    pub fn new() -> Heap {
 
        Heap {
 
            // string_alloc: StringAllocator::new(),
 
            protocol_descriptions: Arena::new(),
 
            pragmas: Arena::new(),
 
            imports: Arena::new(),
 
            parser_types: Arena::new(),
 
            variables: Arena::new(),
 
            definitions: Arena::new(),
 
            statements: Arena::new(),
 
            expressions: 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()
 
    }
 
}
 

	
 
impl Index<ChannelStatementId> for Heap {
 
    type Output = ChannelStatement;
 
    fn index(&self, index: ChannelStatementId) -> &Self::Output {
 
        &self.statements[index.0.0].as_channel()
 
    }
 
}
 

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

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

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

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

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

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

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

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

	
 
#[derive(Debug, Clone)]
 
pub struct ImportModule {
 
    pub this: ImportId,
 
    // Phase 1: parser
 
    pub span: InputSpan,
 
    pub module: Identifier,
 
    pub alias: Identifier,
 
    pub module_id: RootId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct AliasedSymbol {
 
    pub name: Identifier,
 
    pub alias: Option<Identifier>,
 
    pub definition_id: DefinitionId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ImportSymbols {
 
    pub this: ImportId,
 
    // Phase 1: parser
 
    pub span: InputSpan,
 
    pub module: Identifier,
 
    pub module_id: RootId,
 
    pub symbols: Vec<AliasedSymbol>,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct Identifier {
 
    pub span: InputSpan,
 
    pub value: StringRef<'static>,
 
}
 

	
 
impl PartialEq for Identifier {
 
    fn eq(&self, other: &Self) -> bool {
 
        return self.value == other.value
 
    }
 
}
 

	
 
impl Display for Identifier {
 
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
 
        write!(f, "{}", self.value.as_str())
 
    }
 
}
 

	
 
#[derive(Debug, Clone, PartialEq, Eq)]
 
pub enum ParserTypeVariant {
 
    // Special builtin, only usable by the compiler and not constructable by the
 
    // programmer
 
    Void,
 
    InputOrOutput,
 
    ArrayLike,
 
    IntegerLike,
 
    // Basic builtin
 
    Message,
 
    Bool,
 
    UInt8, UInt16, UInt32, UInt64,
 
    SInt8, SInt16, SInt32, SInt64,
 
    Character, String,
 
    // Literals (need to get concrete builtin type during typechecking)
 
    IntegerLiteral,
 
    // Marker for inference
 
    Inferred,
 
    // Builtins expecting one subsequent type
 
    Array,
 
    Input,
 
    Output,
 
    // User-defined types
 
    PolymorphicArgument(DefinitionId, u32), // u32 = index into polymorphic variables
 
    Definition(DefinitionId, u32), // u32 = number of following subtypes
 
}
 

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

	
 
        match self {
 
            Void | IntegerLike |
 
            Message | Bool |
 
            UInt8 | UInt16 | UInt32 | UInt64 |
 
            SInt8 | SInt16 | SInt32 | SInt64 |
 
            Character | String | IntegerLiteral |
 
            Inferred | PolymorphicArgument(_, _) =>
 
                0,
 
            ArrayLike | InputOrOutput | Array | Input | Output =>
 
                1,
 
            Definition(_, num) => *num as usize,
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ParserTypeElement {
 
    // TODO: @cleanup, do we ever need the span of a user-defined type after
 
    //  constructing it?
 
    pub full_span: InputSpan, // full span of type, including any polymorphic arguments
 
    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).
 
#[derive(Debug, Clone)]
 
pub struct ParserType {
 
    pub elements: Vec<ParserTypeElement>
 
}
 

	
 
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]);
 
    }
 
}
 

	
 
/// Specifies whether the symbolic type points to an actual user-defined type,
 
/// or whether it points to a polymorphic argument within the definition (e.g.
 
/// a defined variable `T var` within a function `int func<T>()`
 
#[derive(Debug, Clone)]
 
pub enum SymbolicParserTypeVariant {
 
    Definition(DefinitionId),
 
    // TODO: figure out if I need the DefinitionId here
 
    PolyArg(DefinitionId, usize), // index of polyarg in the definition
 
}
 

	
 
/// ConcreteType is the representation of a type after resolving symbolic types
 
/// and performing type inference
 
#[derive(Debug, Clone, Copy, Eq, PartialEq)]
 
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,
 
    // User defined type with any number of nested types
 
    Instance(DefinitionId, u32),
 
}
 

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

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

	
 
// TODO: Remove at some point
 
#[derive(Debug, Clone, PartialEq, Eq)]
 
pub enum PrimitiveType {
 
    Unassigned,
 
    Input,
 
    Output,
 
    Message,
 
    Boolean,
 
    Byte,
 
    Short,
 
    Int,
 
    Long,
 
}
 

	
 
#[derive(Debug, Clone, PartialEq, Eq)]
 
pub struct Type {
 
    pub primitive: PrimitiveType,
 
    pub array: bool,
 
}
 

	
 
#[allow(dead_code)]
 
impl Type {
 
    pub const UNASSIGNED: Type = Type { primitive: PrimitiveType::Unassigned, array: false };
 

	
 
    pub const INPUT: Type = Type { primitive: PrimitiveType::Input, array: false };
 
    pub const OUTPUT: Type = Type { primitive: PrimitiveType::Output, array: false };
 
    pub const MESSAGE: Type = Type { primitive: PrimitiveType::Message, array: false };
 
    pub const BOOLEAN: Type = Type { primitive: PrimitiveType::Boolean, array: false };
 
    pub const BYTE: Type = Type { primitive: PrimitiveType::Byte, array: false };
 
    pub const SHORT: Type = Type { primitive: PrimitiveType::Short, array: false };
 
    pub const INT: Type = Type { primitive: PrimitiveType::Int, array: false };
 
    pub const LONG: Type = Type { primitive: PrimitiveType::Long, array: false };
 

	
 
    pub const INPUT_ARRAY: Type = Type { primitive: PrimitiveType::Input, array: true };
 
    pub const OUTPUT_ARRAY: Type = Type { primitive: PrimitiveType::Output, array: true };
 
    pub const MESSAGE_ARRAY: Type = Type { primitive: PrimitiveType::Message, array: true };
 
    pub const BOOLEAN_ARRAY: Type = Type { primitive: PrimitiveType::Boolean, array: true };
 
    pub const BYTE_ARRAY: Type = Type { primitive: PrimitiveType::Byte, array: true };
 
    pub const SHORT_ARRAY: Type = Type { primitive: PrimitiveType::Short, array: true };
 
    pub const INT_ARRAY: Type = Type { primitive: PrimitiveType::Int, array: true };
 
    pub const LONG_ARRAY: Type = Type { primitive: PrimitiveType::Long, array: true };
 
}
 

	
 
impl Display for Type {
 
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
 
        match &self.primitive {
 
            PrimitiveType::Unassigned => {
 
                write!(f, "unassigned")?;
 
            }
 
            PrimitiveType::Input => {
 
                write!(f, "in")?;
 
            }
 
            PrimitiveType::Output => {
 
                write!(f, "out")?;
 
            }
 
            PrimitiveType::Message => {
 
                write!(f, "msg")?;
 
            }
 
            PrimitiveType::Boolean => {
 
                write!(f, "boolean")?;
 
            }
 
            PrimitiveType::Byte => {
 
                write!(f, "byte")?;
 
            }
 
            PrimitiveType::Short => {
 
                write!(f, "short")?;
 
            }
 
            PrimitiveType::Int => {
 
                write!(f, "int")?;
 
            }
 
            PrimitiveType::Long => {
 
                write!(f, "long")?;
 
            }
 
        }
 
        if self.array {
 
            write!(f, "[]")
 
        } else {
 
            Ok(())
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, Copy)]
 
pub enum Scope {
 
    Definition(DefinitionId),
 
    Regular(BlockStatementId),
 
    Synchronous((SynchronousStatementId, BlockStatementId)),
 
}
 

	
 
impl Scope {
 
    pub fn is_block(&self) -> bool {
 
        match &self {
 
            Scope::Definition(_) => false,
 
            Scope::Regular(_) => true,
 
            Scope::Synchronous(_) => true,
 
        }
 
    }
 
    pub fn to_block(&self) -> BlockStatementId {
 
        match &self {
 
            Scope::Regular(id) => *id,
 
            Scope::Synchronous((_, id)) => *id,
 
            _ => panic!("unable to get BlockStatement from Scope")
 
        }
 
    }
 
}
 

	
 
/// `ScopeNode` is a helper that links scopes in two directions. It doesn't
 
/// actually contain any information associated with the scope, this may be
 
/// found on the AST elements that `Scope` points to.
 
#[derive(Debug, Clone)]
 
pub struct ScopeNode {
 
    pub parent: Scope,
 
    pub nested: Vec<Scope>,
 
}
 

	
 
impl ScopeNode {
 
    pub(crate) fn new_invalid() -> Self {
 
        ScopeNode{
 
            parent: Scope::Definition(DefinitionId::new_invalid()),
 
            nested: Vec::new(),
 
        }
 
    }
 
}
 

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

	
 
#[derive(Debug, Clone)]
 
pub struct Variable {
 
    pub this: VariableId,
 
    // Parsing
 
    pub kind: VariableKind,
 
    pub parser_type: ParserType,
 
    pub identifier: Identifier,
 
    // Validator/linker
 
    pub relative_pos_in_block: u32,
 
    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),
 
}
 

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

	
 
#[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,
 
    // Phase 1: symbol scanning
 
    pub span: InputSpan,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    // Phase 2: 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)]
 
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,
 
    // Phase 1: symbol scanning
 
    // Symbol scanning
 
    pub span: InputSpan,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    // Phase 2: parsing
 
    // 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 enum UnionVariantValue {
 
    None,
 
    Embedded(Vec<ParserType>),
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct UnionVariantDefinition {
 
    pub span: InputSpan,
 
    pub identifier: Identifier,
 
    pub value: UnionVariantValue,
 
}
 

	
 
#[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,
 
    Composite,
 
}
 

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

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

	
 
// 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 defined_in: RootId,
 
    // Symbol scanning
 
    pub builtin: bool,
 
    pub span: InputSpan,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    // Parser
 
    pub return_types: Vec<ParserType>,
 
    pub parameters: Vec<VariableId>,
 
    pub body: BlockStatementId,
 
    // Validation/linking
 
    pub num_expressions_in_body: i32,
 
}
 

	
 
impl FunctionDefinition {
 
    pub(crate) fn new_empty(
 
        this: FunctionDefinitionId, defined_in: RootId, span: InputSpan,
 
        identifier: Identifier, poly_vars: Vec<Identifier>
 
    ) -> Self {
 
        Self {
 
            this, defined_in,
 
            builtin: false,
 
            span, identifier, poly_vars,
 
            return_types: Vec::new(),
 
            parameters: Vec::new(),
 
            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),
 
    Return(ReturnStatement),
 
    Goto(GotoStatement),
 
    New(NewStatement),
 
    Expression(ExpressionStatement),
 
}
 

	
 
impl Statement {
 
    pub fn is_block(&self) -> bool {
 
        match self {
 
            Statement::Block(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub fn as_block(&self) -> &BlockStatement {
 
        match self {
 
            Statement::Block(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `BlockStatement`"),
 
        }
 
    }
 
    pub fn as_block_mut(&mut self) -> &mut 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_labeled(&self) -> &LabeledStatement {
 
        match self {
 
            Statement::Labeled(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `LabeledStatement`"),
 
        }
 
    }
 
    pub fn as_labeled_mut(&mut self) -> &mut LabeledStatement {
 
        match self {
 
            Statement::Labeled(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `LabeledStatement`"),
 
        }
 
    }
 
    pub fn as_if(&self) -> &IfStatement {
 
        match self {
 
            Statement::If(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `IfStatement`"),
 
        }
 
    }
 
    pub fn as_if_mut(&mut self) -> &mut IfStatement {
 
        match self {
 
            Statement::If(result) => result,
 
            _ => panic!("Unable to cast 'Statement' to 'IfStatement'"),
 
        }
 
    }
 
    pub fn as_end_if(&self) -> &EndIfStatement {
 
        match self {
 
            Statement::EndIf(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `EndIfStatement`"),
 
        }
 
    }
 
    pub fn is_while(&self) -> bool {
 
        match self {
 
            Statement::While(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub fn as_while(&self) -> &WhileStatement {
 
        match self {
 
            Statement::While(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `WhileStatement`"),
 
        }
 
    }
 
    pub fn as_while_mut(&mut self) -> &mut WhileStatement {
 
        match self {
 
            Statement::While(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `WhileStatement`"),
 
        }
 
    }
 
    pub fn as_end_while(&self) -> &EndWhileStatement {
 
        match self {
 
            Statement::EndWhile(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `EndWhileStatement`"),
 
        }
 
    }
 
    pub fn as_break(&self) -> &BreakStatement {
 
        match self {
 
            Statement::Break(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `BreakStatement`"),
 
        }
 
    }
 
    pub fn as_break_mut(&mut self) -> &mut BreakStatement {
 
        match self {
 
            Statement::Break(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `BreakStatement`"),
 
        }
 
    }
 
    pub fn as_continue(&self) -> &ContinueStatement {
 
        match self {
 
            Statement::Continue(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `ContinueStatement`"),
 
        }
 
    }
 
    pub fn as_continue_mut(&mut self) -> &mut ContinueStatement {
 
        match self {
 
            Statement::Continue(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `ContinueStatement`"),
 
        }
 
    }
 
    pub fn as_synchronous(&self) -> &SynchronousStatement {
 
        match self {
 
            Statement::Synchronous(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `SynchronousStatement`"),
 
        }
 
    }
 
    pub fn as_synchronous_mut(&mut self) -> &mut SynchronousStatement {
 
        match self {
 
            Statement::Synchronous(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `SynchronousStatement`"),
 
        }
 
    }
 
    pub fn as_end_synchronous(&self) -> &EndSynchronousStatement {
 
        match self {
 
            Statement::EndSynchronous(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `EndSynchronousStatement`"),
 
        }
 
    }
 
    pub fn as_return(&self) -> &ReturnStatement {
 
        match self {
 
            Statement::Return(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `ReturnStatement`"),
 
        }
 
    }
 
    pub fn as_goto(&self) -> &GotoStatement {
 
        match self {
 
            Statement::Goto(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `GotoStatement`"),
 
        }
 
    }
 
    pub fn as_goto_mut(&mut self) -> &mut GotoStatement {
 
        match self {
 
            Statement::Goto(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `GotoStatement`"),
 
        }
 
    }
 
    pub fn as_new(&self) -> &NewStatement {
 
        match self {
 
            Statement::New(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `NewStatement`"),
 
        }
 
    }
 
    pub fn as_expression(&self) -> &ExpressionStatement {
 
        match self {
 
            Statement::Expression(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `ExpressionStatement`"),
 
        }
 
    }
 
    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::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(_) => unreachable!(),
 
        }
 
    }
 
    pub fn link_next(&mut self, next: StatementId) {
 
        match self {
 
            Statement::Block(_) => todo!(),
 
            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::New(stmt) => stmt.next = next,
 
            Statement::Expression(stmt) => stmt.next = next,
 
            Statement::Return(_)
 
            | Statement::Break(_)
 
            | Statement::Continue(_)
 
            | Statement::Synchronous(_)
 
            | Statement::Goto(_)
 
            | Statement::While(_)
 
            | Statement::Labeled(_)
 
            | Statement::If(_) => unreachable!(),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct BlockStatement {
 
    pub this: BlockStatementId,
 
    // Phase 1: parser
 
    pub is_implicit: bool,
 
    pub span: InputSpan, // of the complete block
 
    pub statements: Vec<StatementId>,
 
    pub end_block: EndBlockStatementId,
 
    // Phase 2: linker
 
    pub parent_scope: Scope,
 
    pub scope_node: ScopeNode,
 
    pub first_unique_id_in_scope: i32, // Temporary fix until proper bytecode/asm is generated
 
    pub next_unique_id_in_scope: i32, // Temporary fix until proper bytecode/asm is generated
 
    pub relative_pos_in_parent: u32,
 
    pub locals: Vec<VariableId>,
 
    pub labels: Vec<LabeledStatementId>,
 
}
 

	
 
#[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,
 
    // Phase 2: linker
 
    pub next: StatementId,
 
}
 

	
 
/// ChannelStatement is the declaration of an input and output port associated
 
/// with the same channel. Note that the polarity of the ports are from the
 
/// point of view of the component. So an output port is something that a
 
/// component uses to send data over (i.e. it is the "input end" of the
 
/// channel), and vice versa.
 
#[derive(Debug, Clone)]
 
pub struct ChannelStatement {
 
    pub this: ChannelStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "channel" keyword
 
    pub from: VariableId, // output
 
    pub to: VariableId,   // input
 
    // Phase 2: linker
 
    pub relative_pos_in_block: u32,
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct LabeledStatement {
 
    pub this: LabeledStatementId,
 
    // Phase 1: parser
 
    pub label: Identifier,
 
    pub body: StatementId,
 
    // Phase 2: linker
 
    pub relative_pos_in_block: u32,
 
    pub in_sync: Option<SynchronousStatementId>,
 
    pub in_sync: SynchronousStatementId, // may be invalid
 
}
 

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

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

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

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

	
 
#[derive(Debug, Clone)]
 
pub struct BreakStatement {
 
    pub this: BreakStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "break" keyword
 
    pub label: Option<Identifier>,
 
    // Phase 2: linker
 
    pub target: Option<EndWhileStatementId>,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ContinueStatement {
 
    pub this: ContinueStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "continue" keyword
 
    pub label: Option<Identifier>,
 
    // Phase 2: linker
 
    pub target: Option<WhileStatementId>,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct SynchronousStatement {
 
    pub this: SynchronousStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "sync" keyword
 
    pub body: BlockStatementId,
 
    // Phase 2: linker
 
    pub end_sync: EndSynchronousStatementId,
 
    pub parent_scope: Option<Scope>,
 
}
 

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

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

	
 
#[derive(Debug, Clone)]
 
pub struct GotoStatement {
 
    pub this: GotoStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "goto" keyword
 
    pub label: Identifier,
 
    // Phase 2: linker
 
    pub target: Option<LabeledStatementId>,
 
}
 

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

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

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

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

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

	
 
impl Expression {
 
    pub fn as_assignment(&self) -> &AssignmentExpression {
 
        match self {
 
            Expression::Assignment(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `AssignmentExpression`"),
 
        }
 
    }
 
    pub fn as_conditional(&self) -> &ConditionalExpression {
 
        match self {
 
            Expression::Conditional(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `ConditionalExpression`"),
 
        }
 
    }
 
    pub fn as_binary(&self) -> &BinaryExpression {
 
        match self {
 
            Expression::Binary(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `BinaryExpression`"),
 
        }
 
    }
 
    pub fn as_unary(&self) -> &UnaryExpression {
 
        match self {
 
            Expression::Unary(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `UnaryExpression`"),
 
        }
 
    }
 
    pub fn as_indexing(&self) -> &IndexingExpression {
 
        match self {
 
            Expression::Indexing(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `IndexingExpression`"),
 
        }
 
    }
 
    pub fn as_slicing(&self) -> &SlicingExpression {
 
        match self {
 
            Expression::Slicing(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `SlicingExpression`"),
 
        }
 
    }
 
    pub fn as_select(&self) -> &SelectExpression {
 
        match self {
 
            Expression::Select(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `SelectExpression`"),
 
        }
 
    }
 
    pub fn as_call(&self) -> &CallExpression {
 
        match self {
 
            Expression::Call(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `CallExpression`"),
 
        }
 
    }
 
    pub fn as_call_mut(&mut self) -> &mut CallExpression {
 
        match self {
 
            Expression::Call(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `CallExpression`"),
 
        }
 
    }
 
    pub fn as_variable(&self) -> &VariableExpression {
 
        match self {
 
            Expression::Variable(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `VariableExpression`"),
 
        }
 
    }
 
    pub fn as_variable_mut(&mut self) -> &mut VariableExpression {
 
        match self {
 
            Expression::Variable(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `VariableExpression`"),
 
        }
 
    }
 
    pub fn span(&self) -> InputSpan {
 
        match self {
 
            Expression::Assignment(expr) => expr.span,
 
            Expression::Binding(expr) => expr.span,
 
            Expression::Conditional(expr) => expr.span,
 
            Expression::Binary(expr) => expr.span,
 
            Expression::Unary(expr) => expr.span,
 
            Expression::Indexing(expr) => expr.span,
 
            Expression::Slicing(expr) => expr.span,
 
            Expression::Select(expr) => expr.span,
 
            Expression::Literal(expr) => expr.span,
 
            Expression::Cast(expr) => expr.span,
 
            Expression::Call(expr) => expr.span,
 
            Expression::Variable(expr) => expr.identifier.span,
 
        }
 
    }
 
    // TODO: @cleanup
 
    pub fn parent(&self) -> &ExpressionParent {
 
        match self {
 
            Expression::Assignment(expr) => &expr.parent,
 
            Expression::Binding(expr) => &expr.parent,
 
            Expression::Conditional(expr) => &expr.parent,
 
            Expression::Binary(expr) => &expr.parent,
 
            Expression::Unary(expr) => &expr.parent,
 
            Expression::Indexing(expr) => &expr.parent,
 
            Expression::Slicing(expr) => &expr.parent,
 
            Expression::Select(expr) => &expr.parent,
 
            Expression::Literal(expr) => &expr.parent,
 
            Expression::Cast(expr) => &expr.parent,
 
            Expression::Call(expr) => &expr.parent,
 
            Expression::Variable(expr) => &expr.parent,
 
        }
 
    }
 
    // TODO: @cleanup
 
    pub fn parent_expr_id(&self) -> Option<ExpressionId> {
 
        if let ExpressionParent::Expression(id, _) = self.parent() {
 
            Some(*id)
 
        } else {
 
            None
 
        }
 
    }
 
    // TODO: @cleanup
 
    pub fn set_parent(&mut self, parent: ExpressionParent) {
 
        match self {
 
            Expression::Assignment(expr) => expr.parent = parent,
 
            Expression::Binding(expr) => expr.parent = parent,
 
            Expression::Conditional(expr) => expr.parent = parent,
 
            Expression::Binary(expr) => expr.parent = parent,
 
            Expression::Unary(expr) => expr.parent = parent,
 
            Expression::Indexing(expr) => expr.parent = parent,
 
            Expression::Slicing(expr) => expr.parent = parent,
 
            Expression::Select(expr) => expr.parent = parent,
 
            Expression::Literal(expr) => expr.parent = parent,
 
            Expression::Cast(expr) => expr.parent = parent,
 
            Expression::Call(expr) => expr.parent = parent,
 
            Expression::Variable(expr) => expr.parent = parent,
 
        }
 
    }
 

	
 
    pub fn get_unique_id_in_definition(&self) -> i32 {
 
        match self {
 
            Expression::Assignment(expr) => expr.unique_id_in_definition,
 
            Expression::Binding(expr) => expr.unique_id_in_definition,
 
            Expression::Conditional(expr) => expr.unique_id_in_definition,
 
            Expression::Binary(expr) => expr.unique_id_in_definition,
 
            Expression::Unary(expr) => expr.unique_id_in_definition,
 
            Expression::Indexing(expr) => expr.unique_id_in_definition,
 
            Expression::Slicing(expr) => expr.unique_id_in_definition,
 
            Expression::Select(expr) => expr.unique_id_in_definition,
 
            Expression::Literal(expr) => expr.unique_id_in_definition,
 
            Expression::Cast(expr) => expr.unique_id_in_definition,
 
            Expression::Call(expr) => expr.unique_id_in_definition,
 
            Expression::Variable(expr) => expr.unique_id_in_definition,
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, Copy)]
 
pub enum AssignmentOperator {
 
    Set,
 
    Multiplied,
 
    Divided,
 
    Remained,
 
    Added,
 
    Subtracted,
 
    ShiftedLeft,
 
    ShiftedRight,
 
    BitwiseAnded,
 
    BitwiseXored,
 
    BitwiseOred,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct AssignmentExpression {
 
    pub this: AssignmentExpressionId,
 
    // Parsing
 
    pub span: InputSpan, // of the operator
 
    pub left: ExpressionId,
 
    pub operation: AssignmentOperator,
 
    pub right: ExpressionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct BindingExpression {
 
    pub this: BindingExpressionId,
 
    // Parsing
 
    pub span: InputSpan,
 
    pub left: LiteralExpressionId,
 
    pub right: ExpressionId,
 
    pub span: InputSpan, // of the binding keyword
 
    pub bound_to: ExpressionId,
 
    pub bound_from: ExpressionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ConditionalExpression {
 
    pub this: ConditionalExpressionId,
 
    // Parsing
 
    pub span: InputSpan, // of question mark operator
 
    pub test: ExpressionId,
 
    pub true_expression: ExpressionId,
 
    pub false_expression: ExpressionId,
 
    // Validator/Linking
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 
pub enum BinaryOperator {
 
    Concatenate,
 
    LogicalOr,
 
    LogicalAnd,
 
    BitwiseOr,
 
    BitwiseXor,
 
    BitwiseAnd,
 
    Equality,
 
    Inequality,
 
    LessThan,
 
    GreaterThan,
 
    LessThanEqual,
 
    GreaterThanEqual,
 
    ShiftLeft,
 
    ShiftRight,
 
    Add,
 
    Subtract,
 
    Multiply,
 
    Divide,
 
    Remainder,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct BinaryExpression {
 
    pub this: BinaryExpressionId,
 
    // Parsing
 
    pub span: InputSpan, // of the operator
 
    pub left: ExpressionId,
 
    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,
 
    PreIncrement,
 
    PreDecrement,
 
    PostIncrement,
 
    PostDecrement,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct UnaryExpression {
 
    pub this: UnaryExpressionId,
 
    // Parsing
 
    pub span: InputSpan, // of the operator
 
    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 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 span: InputSpan, // from '[' to ']';
 
    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 struct SelectExpression {
 
    pub this: SelectExpressionId,
 
    // Parsing
 
    pub span: InputSpan, // of the '.'
 
    pub subject: ExpressionId,
 
    pub field_name: Identifier,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct CastExpression {
 
    pub this: CastExpressionId,
 
    // Parsing
 
    pub span: InputSpan, // of the "cast" keyword,
 
    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 span: InputSpan,
 
    pub parser_type: ParserType, // of the function call, not the return type
 
    pub method: Method,
 
    pub arguments: Vec<ExpressionId>,
 
    pub definition: DefinitionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

	
 
#[derive(Debug, Clone, PartialEq, Eq)]
 
pub enum Method {
 
    // Builtin
 
    Get,
 
    Put,
 
    Fires,
 
    Create,
 
    Length,
 
    Assert,
 
    UserFunction,
 
    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>),
 
}
 

	
 
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_struct_mut(&mut self) -> &mut LiteralStruct {
 
        if let Literal::Struct(literal) = self{
 
            literal
 
        } else {
 
            unreachable!("Attempted to obtain {:?} as Literal::Struct", self)
 
        }
 
    }
 

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

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

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

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

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

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

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

	
 
#[derive(Debug, Clone)]
 
pub struct VariableExpression {
 
    pub this: VariableExpressionId,
 
    // Parsing
 
    pub identifier: Identifier,
 
    // Validator/Linker
 
    pub declaration: Option<VariableId>,
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 
\ No newline at end of file
src/protocol/ast_printer.rs
Show inline comments
 
#![allow(dead_code)]
 

	
 
use std::fmt::{Debug, Display};
 
use std::io::Write as IOWrite;
 

	
 
use super::ast::*;
 
use super::token_parsing::*;
 

	
 
const INDENT: usize = 2;
 

	
 
const PREFIX_EMPTY: &'static str = "    ";
 
const PREFIX_ROOT_ID: &'static str = "Root";
 
const PREFIX_PRAGMA_ID: &'static str = "Prag";
 
const PREFIX_IMPORT_ID: &'static str = "Imp ";
 
const PREFIX_TYPE_ANNOT_ID: &'static str = "TyAn";
 
const PREFIX_VARIABLE_ID: &'static str = "Var ";
 
const PREFIX_DEFINITION_ID: &'static str = "Def ";
 
const PREFIX_STRUCT_ID: &'static str = "DefS";
 
const PREFIX_ENUM_ID: &'static str = "DefE";
 
const PREFIX_UNION_ID: &'static str = "DefU";
 
const PREFIX_COMPONENT_ID: &'static str = "DefC";
 
const PREFIX_FUNCTION_ID: &'static str = "DefF";
 
const PREFIX_STMT_ID: &'static str = "Stmt";
 
const PREFIX_BLOCK_STMT_ID: &'static str = "SBl ";
 
const PREFIX_ENDBLOCK_STMT_ID: &'static str = "SEBl";
 
const PREFIX_LOCAL_STMT_ID: &'static str = "SLoc";
 
const PREFIX_MEM_STMT_ID: &'static str = "SMem";
 
const PREFIX_CHANNEL_STMT_ID: &'static str = "SCha";
 
const PREFIX_SKIP_STMT_ID: &'static str = "SSki";
 
const PREFIX_LABELED_STMT_ID: &'static str = "SLab";
 
const PREFIX_IF_STMT_ID: &'static str = "SIf ";
 
const PREFIX_ENDIF_STMT_ID: &'static str = "SEIf";
 
const PREFIX_WHILE_STMT_ID: &'static str = "SWhi";
 
const PREFIX_ENDWHILE_STMT_ID: &'static str = "SEWh";
 
const PREFIX_BREAK_STMT_ID: &'static str = "SBre";
 
const PREFIX_CONTINUE_STMT_ID: &'static str = "SCon";
 
const PREFIX_SYNC_STMT_ID: &'static str = "SSyn";
 
const PREFIX_ENDSYNC_STMT_ID: &'static str = "SESy";
 
const PREFIX_RETURN_STMT_ID: &'static str = "SRet";
 
const PREFIX_ASSERT_STMT_ID: &'static str = "SAsr";
 
const PREFIX_GOTO_STMT_ID: &'static str = "SGot";
 
const PREFIX_NEW_STMT_ID: &'static str = "SNew";
 
const PREFIX_PUT_STMT_ID: &'static str = "SPut";
 
const PREFIX_EXPR_STMT_ID: &'static str = "SExp";
 
const PREFIX_ASSIGNMENT_EXPR_ID: &'static str = "EAsi";
 
const PREFIX_BINDING_EXPR_ID: &'static str = "EBnd";
 
const PREFIX_CONDITIONAL_EXPR_ID: &'static str = "ECnd";
 
const PREFIX_BINARY_EXPR_ID: &'static str = "EBin";
 
const PREFIX_UNARY_EXPR_ID: &'static str = "EUna";
 
const PREFIX_INDEXING_EXPR_ID: &'static str = "EIdx";
 
const PREFIX_SLICING_EXPR_ID: &'static str = "ESli";
 
const PREFIX_SELECT_EXPR_ID: &'static str = "ESel";
 
const PREFIX_LITERAL_EXPR_ID: &'static str = "ELit";
 
const PREFIX_CALL_EXPR_ID: &'static str = "ECll";
 
const PREFIX_VARIABLE_EXPR_ID: &'static str = "EVar";
 

	
 
struct KV<'a> {
 
    buffer: &'a mut String,
 
    prefix: Option<(&'static str, i32)>,
 
    indent: usize,
 
    temp_key: &'a mut String,
 
    temp_val: &'a mut String,
 
}
 

	
 
impl<'a> KV<'a> {
 
    fn new(buffer: &'a mut String, temp_key: &'a mut String, temp_val: &'a mut String, indent: usize) -> Self {
 
        temp_key.clear();
 
        temp_val.clear();
 
        KV{
 
            buffer,
 
            prefix: None,
 
            indent,
 
            temp_key,
 
            temp_val
 
        }
 
    }
 

	
 
    fn with_id(mut self, prefix: &'static str, id: i32) -> Self {
 
        self.prefix = Some((prefix, id));
 
        self
 
    }
 

	
 
    fn with_s_key(self, key: &str) -> Self {
 
        self.temp_key.push_str(key);
 
        self
 
    }
 

	
 
    fn with_d_key<D: Display>(self, key: &D) -> Self {
 
        self.temp_key.push_str(&key.to_string());
 
        self
 
    }
 

	
 
    fn with_s_val(self, val: &str) -> Self {
 
        self.temp_val.push_str(val);
 
        self
 
    }
 

	
 
    fn with_disp_val<D: Display>(self, val: &D) -> Self {
 
        self.temp_val.push_str(&format!("{}", val));
 
        self
 
    }
 

	
 
    fn with_debug_val<D: Debug>(self, val: &D) -> Self {
 
        self.temp_val.push_str(&format!("{:?}", val));
 
        self
 
    }
 

	
 
    fn with_identifier_val(self, val: &Identifier) -> Self {
 
        self.temp_val.push_str(val.value.as_str());
 
        self
 
    }
 

	
 
    fn with_opt_disp_val<D: Display>(self, val: Option<&D>) -> Self {
 
        match val {
 
            Some(v) => { self.temp_val.push_str(&format!("Some({})", v)); },
 
            None => { self.temp_val.push_str("None"); }
 
        }
 
        self
 
    }
 

	
 
    fn with_opt_identifier_val(self, val: Option<&Identifier>) -> Self {
 
        match val {
 
            Some(v) => {
 
                self.temp_val.push_str("Some(");
 
                self.temp_val.push_str(v.value.as_str());
 
                self.temp_val.push(')');
 
            },
 
            None => {
 
                self.temp_val.push_str("None");
 
            }
 
        }
 
        self
 
    }
 

	
 
    fn with_custom_val<F: Fn(&mut String)>(mut self, val_fn: F) -> Self {
 
        val_fn(&mut self.temp_val);
 
        self
 
    }
 
}
 

	
 
impl<'a> Drop for KV<'a> {
 
    fn drop(&mut self) {
 
        // Prefix and indent
 
        if let Some((prefix, id)) = &self.prefix {
 
            self.buffer.push_str(&format!("{}[{:04}]", prefix, id));
 
        } else {
 
            self.buffer.push_str("           ");
 
        }
 

	
 
        for _ in 0..self.indent * INDENT {
 
            self.buffer.push(' ');
 
        }
 

	
 
        // Leading dash
 
        self.buffer.push_str("- ");
 

	
 
        // Key and value
 
        self.buffer.push_str(self.temp_key);
 
        if self.temp_val.is_empty() {
 
            self.buffer.push(':');
 
        } else {
 
            self.buffer.push_str(": ");
 
            self.buffer.push_str(&self.temp_val);
 
        }
 
        self.buffer.push('\n');
 
    }
 
}
 

	
 
pub(crate) struct ASTWriter {
 
    cur_definition: Option<DefinitionId>,
 
    buffer: String,
 
    temp1: String,
 
    temp2: String,
 
}
 

	
 
impl ASTWriter {
 
    pub(crate) fn new() -> Self {
 
        Self{
 
            cur_definition: None,
 
            buffer: String::with_capacity(4096),
 
            temp1: String::with_capacity(256),
 
            temp2: String::with_capacity(256),
 
        }
 
    }
 
    pub(crate) fn write_ast<W: IOWrite>(&mut self, w: &mut W, heap: &Heap) {
 
        for root_id in heap.protocol_descriptions.iter().map(|v| v.this) {
 
            self.write_module(heap, root_id);
 
            w.write_all(self.buffer.as_bytes()).expect("flush buffer");
 
            self.buffer.clear();
 
        }
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // Top-level module writing
 
    //--------------------------------------------------------------------------
 

	
 
    fn write_module(&mut self, heap: &Heap, root_id: RootId) {
 
        self.kv(0).with_id(PREFIX_ROOT_ID, root_id.index)
 
            .with_s_key("Module");
 

	
 
        let root = &heap[root_id];
 
        self.kv(1).with_s_key("Pragmas");
 
        for pragma_id in &root.pragmas {
 
            self.write_pragma(heap, *pragma_id, 2);
 
        }
 

	
 
        self.kv(1).with_s_key("Imports");
 
        for import_id in &root.imports {
 
            self.write_import(heap, *import_id, 2);
 
        }
 

	
 
        self.kv(1).with_s_key("Definitions");
 
        for def_id in &root.definitions {
 
            self.write_definition(heap, *def_id, 2);
 
        }
 
    }
 

	
 
    fn write_pragma(&mut self, heap: &Heap, pragma_id: PragmaId, indent: usize) {
 
        match &heap[pragma_id] {
 
            Pragma::Version(pragma) => {
 
                self.kv(indent).with_id(PREFIX_PRAGMA_ID, pragma.this.index)
 
                    .with_s_key("PragmaVersion")
 
                    .with_disp_val(&pragma.version);
 
            },
 
            Pragma::Module(pragma) => {
 
                self.kv(indent).with_id(PREFIX_PRAGMA_ID, pragma.this.index)
 
                    .with_s_key("PragmaModule")
 
                    .with_identifier_val(&pragma.value);
 
            }
 
        }
 
    }
 

	
 
    fn write_import(&mut self, heap: &Heap, import_id: ImportId, indent: usize) {
 
        let import = &heap[import_id];
 
        let indent2 = indent + 1;
 

	
 
        match import {
 
            Import::Module(import) => {
 
                self.kv(indent).with_id(PREFIX_IMPORT_ID, import.this.index)
 
                    .with_s_key("ImportModule");
 

	
 
                self.kv(indent2).with_s_key("Name").with_identifier_val(&import.module);
 
                self.kv(indent2).with_s_key("Alias").with_identifier_val(&import.alias);
 
                self.kv(indent2).with_s_key("Target").with_disp_val(&import.module_id.index);
 
            },
 
            Import::Symbols(import) => {
 
                self.kv(indent).with_id(PREFIX_IMPORT_ID, import.this.index)
 
                    .with_s_key("ImportSymbol");
 

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
                self.kv(indent2).with_s_key("ReturnParserTypes");
 
                for return_type in &def.return_types {
 
                    self.kv(indent3).with_s_key("ReturnParserType")
 
                        .with_custom_val(|s| write_parser_type(s, heap, return_type));
 
                }
 

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

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

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

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

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

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

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

	
 
        match stmt {
 
            Statement::Block(stmt) => {
 
                self.kv(indent).with_id(PREFIX_BLOCK_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Block");
 
                self.kv(indent2).with_s_key("EndBlockID").with_disp_val(&stmt.end_block.0.index);
 
                self.kv(indent2).with_s_key("FirstUniqueScopeID").with_disp_val(&stmt.first_unique_id_in_scope);
 
                self.kv(indent2).with_s_key("NextUniqueScopeID").with_disp_val(&stmt.next_unique_id_in_scope);
 
                self.kv(indent2).with_s_key("RelativePos").with_disp_val(&stmt.relative_pos_in_parent);
 

	
 
                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("Next").with_disp_val(&stmt.next.index);
 
                    }
 
                }
 
            },
 
            Statement::Labeled(stmt) => {
 
                self.kv(indent).with_id(PREFIX_LABELED_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Labeled");
 

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

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

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

	
 
                self.kv(indent2).with_s_key("TrueBody");
 
                self.write_stmt(heap, stmt.true_body.upcast(), indent3);
 

	
 
                if let Some(false_body) = stmt.false_body {
 
                    self.kv(indent2).with_s_key("FalseBody");
 
                    self.write_stmt(heap, false_body.upcast(), 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_opt_disp_val(stmt.in_sync.as_ref().map(|v| &v.0.index));
 
                    .with_disp_val(&stmt.in_sync.0.index);
 
                self.kv(indent2).with_s_key("Condition");
 
                self.write_expr(heap, stmt.test, indent3);
 
                self.kv(indent2).with_s_key("Body");
 
                self.write_stmt(heap, stmt.body.upcast(), indent3);
 
            },
 
            Statement::EndWhile(stmt) => {
 
                self.kv(indent).with_id(PREFIX_ENDWHILE_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("EndWhile");
 
                self.kv(indent2).with_s_key("StartWhile").with_disp_val(&stmt.start_while.0.index);
 
                self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
 
            },
 
            Statement::Break(stmt) => {
 
                self.kv(indent).with_id(PREFIX_BREAK_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Break");
 
                self.kv(indent2).with_s_key("Label")
 
                    .with_opt_identifier_val(stmt.label.as_ref());
 
                self.kv(indent2).with_s_key("Target")
 
                    .with_opt_disp_val(stmt.target.as_ref().map(|v| &v.0.index));
 
            },
 
            Statement::Continue(stmt) => {
 
                self.kv(indent).with_id(PREFIX_CONTINUE_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Continue");
 
                self.kv(indent2).with_s_key("Label")
 
                    .with_opt_identifier_val(stmt.label.as_ref());
 
                self.kv(indent2).with_s_key("Target")
 
                    .with_opt_disp_val(stmt.target.as_ref().map(|v| &v.0.index));
 
            },
 
            Statement::Synchronous(stmt) => {
 
                self.kv(indent).with_id(PREFIX_SYNC_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Synchronous");
 
                self.kv(indent2).with_s_key("EndSync").with_disp_val(&stmt.end_sync.0.index);
 
                self.kv(indent2).with_s_key("Body");
 
                self.write_stmt(heap, stmt.body.upcast(), indent3);
 
            },
 
            Statement::EndSynchronous(stmt) => {
 
                self.kv(indent).with_id(PREFIX_ENDSYNC_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("EndSynchronous");
 
                self.kv(indent2).with_s_key("StartSync").with_disp_val(&stmt.start_sync.0.index);
 
                self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
 
            },
 
            Statement::Return(stmt) => {
 
                self.kv(indent).with_id(PREFIX_RETURN_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Return");
 
                self.kv(indent2).with_s_key("Expressions");
 
                for expr_id in &stmt.expressions {
 
                    self.write_expr(heap, *expr_id, indent3);
 
                }
 
            },
 
            Statement::Goto(stmt) => {
 
                self.kv(indent).with_id(PREFIX_GOTO_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Goto");
 
                self.kv(indent2).with_s_key("Label").with_identifier_val(&stmt.label);
 
                self.kv(indent2).with_s_key("Target")
 
                    .with_opt_disp_val(stmt.target.as_ref().map(|v| &v.0.index));
 
            },
 
            Statement::New(stmt) => {
 
                self.kv(indent).with_id(PREFIX_NEW_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("New");
 
                self.kv(indent2).with_s_key("Expression");
 
                self.write_expr(heap, stmt.expression.upcast(), indent3);
 
                self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
 
            },
 
            Statement::Expression(stmt) => {
 
                self.kv(indent).with_id(PREFIX_EXPR_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("ExpressionStatement");
 
                self.write_expr(heap, stmt.expression, indent2);
 
                self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
 
            }
 
        }
 
    }
 

	
 
    fn write_expr(&mut self, heap: &Heap, expr_id: ExpressionId, indent: usize) {
 
        let expr = &heap[expr_id];
 
        let indent2 = indent + 1;
 
        let indent3 = indent2 + 1;
 
        let def_id = self.cur_definition.unwrap();
 

	
 
        match expr {
 
            Expression::Assignment(expr) => {
 
                self.kv(indent).with_id(PREFIX_ASSIGNMENT_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("AssignmentExpr");
 
                self.kv(indent2).with_s_key("Operation").with_debug_val(&expr.operation);
 
                self.kv(indent2).with_s_key("Left");
 
                self.write_expr(heap, expr.left, indent3);
 
                self.kv(indent2).with_s_key("Right");
 
                self.write_expr(heap, expr.right, indent3);
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            },
 
            Expression::Binding(expr) => {
 
                self.kv(indent).with_id(PREFIX_BINARY_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("BindingExpr");
 
                self.kv(indent2).with_s_key("LeftExpression");
 
                self.write_expr(heap, expr.left.upcast(), indent3);
 
                self.kv(indent2).with_s_key("RightExpression");
 
                self.write_expr(heap, expr.right, indent3);
 
                self.kv(indent2).with_s_key("BindToExpression");
 
                self.write_expr(heap, expr.bound_to, indent3);
 
                self.kv(indent2).with_s_key("BindFromExpression");
 
                self.write_expr(heap, expr.bound_from, indent3);
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            },
 
            Expression::Conditional(expr) => {
 
                self.kv(indent).with_id(PREFIX_CONDITIONAL_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("ConditionalExpr");
 
                self.kv(indent2).with_s_key("Condition");
 
                self.write_expr(heap, expr.test, indent3);
 
                self.kv(indent2).with_s_key("TrueExpression");
 
                self.write_expr(heap, expr.true_expression, indent3);
 
                self.kv(indent2).with_s_key("FalseExpression");
 
                self.write_expr(heap, expr.false_expression, indent3);
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            },
 
            Expression::Binary(expr) => {
 
                self.kv(indent).with_id(PREFIX_BINARY_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("BinaryExpr");
 
                self.kv(indent2).with_s_key("Operation").with_debug_val(&expr.operation);
 
                self.kv(indent2).with_s_key("Left");
 
                self.write_expr(heap, expr.left, indent3);
 
                self.kv(indent2).with_s_key("Right");
 
                self.write_expr(heap, expr.right, indent3);
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            },
 
            Expression::Unary(expr) => {
 
                self.kv(indent).with_id(PREFIX_UNARY_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("UnaryExpr");
 
                self.kv(indent2).with_s_key("Operation").with_debug_val(&expr.operation);
 
                self.kv(indent2).with_s_key("Argument");
 
                self.write_expr(heap, expr.expression, indent3);
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            },
 
            Expression::Indexing(expr) => {
 
                self.kv(indent).with_id(PREFIX_INDEXING_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("IndexingExpr");
 
                self.kv(indent2).with_s_key("Subject");
 
                self.write_expr(heap, expr.subject, indent3);
 
                self.kv(indent2).with_s_key("Index");
 
                self.write_expr(heap, expr.index, indent3);
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            },
 
            Expression::Slicing(expr) => {
 
                self.kv(indent).with_id(PREFIX_SLICING_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("SlicingExpr");
 
                self.kv(indent2).with_s_key("Subject");
 
                self.write_expr(heap, expr.subject, indent3);
 
                self.kv(indent2).with_s_key("FromIndex");
 
                self.write_expr(heap, expr.from_index, indent3);
 
                self.kv(indent2).with_s_key("ToIndex");
 
                self.write_expr(heap, expr.to_index, indent3);
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            },
 
            Expression::Select(expr) => {
 
                self.kv(indent).with_id(PREFIX_SELECT_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("SelectExpr");
 
                self.kv(indent2).with_s_key("Subject");
 
                self.write_expr(heap, expr.subject, indent3);
 

	
 
                self.kv(indent2).with_s_key("Field").with_identifier_val(&expr.field_name);
 
                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");
 

	
 
                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);
 
                        }
 
                    }
 
                }
 

	
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            },
 
            Expression::Cast(expr) => {
 
                todo!("print casting expression")
 
            }
 
            Expression::Call(expr) => {
 
                self.kv(indent).with_id(PREFIX_CALL_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("CallExpr");
 

	
 
                let definition = &heap[expr.definition];
 
                match definition {
 
                    Definition::Component(definition) => {
 
                        self.kv(indent2).with_s_key("BuiltIn").with_disp_val(&false);
 
                        self.kv(indent2).with_s_key("Variant").with_debug_val(&definition.variant);
 
                    },
 
                    Definition::Function(definition) => {
 
                        self.kv(indent2).with_s_key("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("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("Name").with_identifier_val(&expr.identifier);
 
                self.kv(indent2).with_s_key("Definition")
 
                    .with_opt_disp_val(expr.declaration.as_ref().map(|v| &v.index));
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            }
 
        }
 
    }
 

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

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

	
 
        self.kv(indent2).with_s_key("Name").with_identifier_val(&var.identifier);
 
        self.kv(indent2).with_s_key("Kind").with_debug_val(&var.kind);
 
        self.kv(indent2).with_s_key("ParserType")
 
            .with_custom_val(|w| write_parser_type(w, heap, &var.parser_type));
 
        self.kv(indent2).with_s_key("RelativePos").with_disp_val(&var.relative_pos_in_block);
 
        self.kv(indent2).with_s_key("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);
 
                target.push_str("[]");
 
            },
 
            PTV::Input => {
 
                target.push_str(KW_TYPE_IN_PORT_STR);
 
                target.push('<');
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push('>');
 
            },
 
            PTV::Output => {
 
                target.push_str(KW_TYPE_OUT_PORT_STR);
 
                target.push('<');
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push('>');
 
            },
 
            PTV::PolymorphicArgument(definition_id, arg_idx) => {
 
                let definition = &heap[*definition_id];
 
                let poly_var = &definition.poly_vars()[*arg_idx as usize].value;
 
                target.push_str(poly_var.as_str());
 
            },
 
            PTV::Definition(definition_id, num_embedded) => {
 
                let definition = &heap[*definition_id];
 
                let definition_ident = definition.identifier().value.as_str();
 
                target.push_str(definition_ident);
 

	
 
                let num_embedded = *num_embedded;
 
                if num_embedded != 0 {
 
                    target.push('<');
 
                    for embedded_idx in 0..num_embedded {
 
                        if embedded_idx != 0 {
 
                            target.push(',');
 
                        }
 
                        element_idx = write_element(target, heap, t, element_idx + 1);
 
                    }
 
                    target.push('>');
 
                }
 
            }
 
        }
 

	
 
        element_idx
 
    }
 

	
 
    write_element(target, heap, t, 0);
 
}
 

	
 
// TODO: @Cleanup, this is littered at three places in the codebase
 
fn write_concrete_type(target: &mut String, heap: &Heap, def_id: DefinitionId, t: &ConcreteType) {
 
    use ConcreteTypePart as CTP;
 

	
 
    fn write_concrete_part(target: &mut String, heap: &Heap, def_id: DefinitionId, t: &ConcreteType, mut idx: usize) -> usize {
 
        if idx >= t.parts.len() {
 
            return idx;
 
        }
 

	
 
        match &t.parts[idx] {
 
            CTP::Void => target.push_str("void"),
 
            CTP::Message => target.push_str("msg"),
 
            CTP::Bool => target.push_str("bool"),
 
            CTP::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 => {
 
                idx = write_concrete_part(target, heap, def_id, t, idx + 1);
 
                target.push_str("[]");
 
            },
 
            CTP::Slice => {
 
                idx = write_concrete_part(target, heap, def_id, t, idx + 1);
 
                target.push_str("[..]");
 
            }
 
            CTP::Input => {
 
                target.push_str("in<");
 
                idx = write_concrete_part(target, heap, def_id, t, idx + 1);
 
                target.push('>');
 
            },
 
            CTP::Output => {
 
                target.push_str("out<");
 
                idx = write_concrete_part(target, heap, def_id, t, idx + 1);
 
                target.push('>')
 
            },
 
            CTP::Instance(definition_id, num_embedded) => {
 
                let identifier = heap[*definition_id].identifier();
 
                target.push_str(identifier.value.as_str());
 
                target.push('<');
 
                for idx_embedded in 0..*num_embedded {
 
                    if idx_embedded != 0 {
 
                        target.push_str(", ");
 
                    }
 
                    idx = write_concrete_part(target, heap, def_id, t, idx + 1);
 
                }
 
                target.push('>');
 
            }
 
        }
 

	
 
        idx + 1
 
    }
 

	
 
    write_concrete_part(target, heap, def_id, t, 0);
 
}
 

	
 
fn write_expression_parent(target: &mut String, parent: &ExpressionParent) {
 
    use ExpressionParent as EP;
 

	
 
    *target = match parent {
 
        EP::None => String::from("None"),
 
        EP::If(id) => format!("IfStmt({})", id.0.index),
 
        EP::While(id) => format!("WhileStmt({})", id.0.index),
 
        EP::Return(id) => format!("ReturnStmt({})", id.0.index),
 
        EP::New(id) => format!("NewStmt({})", id.0.index),
 
        EP::ExpressionStmt(id) => format!("ExprStmt({})", id.0.index),
 
        EP::Expression(id, idx) => format!("Expr({}, {})", id.index, idx)
 
    };
 
}
 
\ No newline at end of file
src/protocol/parser/depth_visitor.rs
Show inline comments
 
use crate::protocol::ast::*;
 
use crate::protocol::input_source::*;
 

	
 
// The following indirection is needed due to a bug in the cbindgen tool.
 
type Unit = ();
 
pub(crate) type VisitorError = (InputPosition, String); // TODO: Revise when multi-file compiling is in place
 
pub(crate) type VisitorResult = Result<Unit, VisitorError>;
 

	
 
pub(crate) trait Visitor: Sized {
 
    fn visit_protocol_description(&mut self, h: &mut Heap, pd: RootId) -> VisitorResult {
 
        recursive_protocol_description(self, h, pd)
 
    }
 
    fn visit_pragma(&mut self, _h: &mut Heap, _pragma: PragmaId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_import(&mut self, _h: &mut Heap, _import: ImportId) -> VisitorResult {
 
        Ok(())
 
    }
 

	
 
    fn visit_symbol_definition(&mut self, h: &mut Heap, def: DefinitionId) -> VisitorResult {
 
        recursive_symbol_definition(self, h, def)
 
    }
 
    fn visit_struct_definition(&mut self, _h: &mut Heap, _def: StructDefinitionId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_enum_definition(&mut self, _h: &mut Heap, _def: EnumDefinitionId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_union_definition(&mut self, _h: &mut Heap, _def: UnionDefinitionId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_component_definition(&mut self, h: &mut Heap, def: ComponentDefinitionId) -> VisitorResult {
 
        recursive_component_definition(self, h, def)
 
    }
 
    fn visit_composite_definition(&mut self, h: &mut Heap, def: ComponentDefinitionId) -> VisitorResult {
 
        recursive_composite_definition(self, h, def)
 
    }
 
    fn visit_primitive_definition(&mut self, h: &mut Heap, def: ComponentDefinitionId) -> VisitorResult {
 
        recursive_primitive_definition(self, h, def)
 
    }
 
    fn visit_function_definition(&mut self, h: &mut Heap, def: FunctionDefinitionId) -> VisitorResult {
 
        recursive_function_definition(self, h, def)
 
    }
 

	
 
    fn visit_variable_declaration(&mut self, h: &mut Heap, decl: VariableId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_statement(&mut self, h: &mut Heap, stmt: StatementId) -> VisitorResult {
 
        recursive_statement(self, h, stmt)
 
    }
 
    fn visit_local_statement(&mut self, h: &mut Heap, stmt: LocalStatementId) -> VisitorResult {
 
        recursive_local_statement(self, h, stmt)
 
    }
 
    fn visit_memory_statement(&mut self, _h: &mut Heap, _stmt: MemoryStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_channel_statement(
 
        &mut self,
 
        _h: &mut Heap,
 
        _stmt: ChannelStatementId,
 
    ) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_block_statement(&mut self, h: &mut Heap, stmt: BlockStatementId) -> VisitorResult {
 
        recursive_block_statement(self, h, stmt)
 
    }
 
    fn visit_end_block_statement(&mut self, h: &mut Heap, stmt: EndBlockStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_labeled_statement(&mut self, h: &mut Heap, stmt: LabeledStatementId) -> VisitorResult {
 
        recursive_labeled_statement(self, h, stmt)
 
    }
 
    fn visit_if_statement(&mut self, h: &mut Heap, stmt: IfStatementId) -> VisitorResult {
 
        recursive_if_statement(self, h, stmt)
 
    }
 
    fn visit_end_if_statement(&mut self, _h: &mut Heap, _stmt: EndIfStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_while_statement(&mut self, h: &mut Heap, stmt: WhileStatementId) -> VisitorResult {
 
        recursive_while_statement(self, h, stmt)
 
    }
 
    fn visit_end_while_statement(&mut self, _h: &mut Heap, _stmt: EndWhileStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_break_statement(&mut self, _h: &mut Heap, _stmt: BreakStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_continue_statement(
 
        &mut self,
 
        _h: &mut Heap,
 
        _stmt: ContinueStatementId,
 
    ) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_synchronous_statement(
 
        &mut self,
 
        h: &mut Heap,
 
        stmt: SynchronousStatementId,
 
    ) -> VisitorResult {
 
        recursive_synchronous_statement(self, h, stmt)
 
    }
 
    fn visit_end_synchronous_statement(&mut self, _h: &mut Heap, _stmt: EndSynchronousStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_return_statement(&mut self, h: &mut Heap, stmt: ReturnStatementId) -> VisitorResult {
 
        recursive_return_statement(self, h, stmt)
 
    }
 
    fn visit_new_statement(&mut self, h: &mut Heap, stmt: NewStatementId) -> VisitorResult {
 
        recursive_new_statement(self, h, stmt)
 
    }
 
    fn visit_goto_statement(&mut self, _h: &mut Heap, _stmt: GotoStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_expression_statement(
 
        &mut self,
 
        h: &mut Heap,
 
        stmt: ExpressionStatementId,
 
    ) -> VisitorResult {
 
        recursive_expression_statement(self, h, stmt)
 
    }
 

	
 
    fn visit_expression(&mut self, h: &mut Heap, expr: ExpressionId) -> VisitorResult {
 
        recursive_expression(self, h, expr)
 
    }
 
    fn visit_assignment_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: AssignmentExpressionId,
 
    ) -> VisitorResult {
 
        recursive_assignment_expression(self, h, expr)
 
    }
 
    fn visit_binding_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: BindingExpressionId
 
    ) -> VisitorResult {
 
        recursive_binding_expression(self, h, expr)
 
    }
 
    fn visit_conditional_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: ConditionalExpressionId,
 
    ) -> VisitorResult {
 
        recursive_conditional_expression(self, h, expr)
 
    }
 
    fn visit_binary_expression(&mut self, h: &mut Heap, expr: BinaryExpressionId) -> VisitorResult {
 
        recursive_binary_expression(self, h, expr)
 
    }
 
    fn visit_unary_expression(&mut self, h: &mut Heap, expr: UnaryExpressionId) -> VisitorResult {
 
        recursive_unary_expression(self, h, expr)
 
    }
 
    fn visit_indexing_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: IndexingExpressionId,
 
    ) -> VisitorResult {
 
        recursive_indexing_expression(self, h, expr)
 
    }
 
    fn visit_slicing_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: SlicingExpressionId,
 
    ) -> VisitorResult {
 
        recursive_slicing_expression(self, h, expr)
 
    }
 
    fn visit_select_expression(&mut self, h: &mut Heap, expr: SelectExpressionId) -> VisitorResult {
 
        recursive_select_expression(self, h, expr)
 
    }
 
    fn visit_cast_expression(&mut self, h: &mut Heap, expr: CastExpressionId) -> VisitorResult {
 
        let subject = h[expr].subject;
 
        self.visit_expression(h, subject)
 
    }
 
    fn visit_call_expression(&mut self, h: &mut Heap, expr: CallExpressionId) -> VisitorResult {
 
        recursive_call_expression(self, h, expr)
 
    }
 
    fn visit_constant_expression(
 
        &mut self,
 
        _h: &mut Heap,
 
        _expr: LiteralExpressionId,
 
    ) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_variable_expression(
 
        &mut self,
 
        _h: &mut Heap,
 
        _expr: VariableExpressionId,
 
    ) -> VisitorResult {
 
        Ok(())
 
    }
 
}
 

	
 
fn recursive_call_expression_as_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    call: CallExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, call.upcast())
 
}
 

	
 
// Recursive procedures
 
fn recursive_protocol_description<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    pd: RootId,
 
) -> VisitorResult {
 
    for &pragma in h[pd].pragmas.clone().iter() {
 
        this.visit_pragma(h, pragma)?;
 
    }
 
    for &import in h[pd].imports.clone().iter() {
 
        this.visit_import(h, import)?;
 
    }
 
    for &def in h[pd].definitions.clone().iter() {
 
        this.visit_symbol_definition(h, def)?;
 
    }
 
    Ok(())
 
}
 

	
 
fn recursive_symbol_definition<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    def: DefinitionId,
 
) -> VisitorResult {
 
    // We clone the definition in case it is modified
 
    // TODO: Fix me
 
    match h[def].clone() {
 
        Definition::Struct(def) => this.visit_struct_definition(h, def.this),
 
        Definition::Enum(def) => this.visit_enum_definition(h, def.this),
 
        Definition::Union(def) => this.visit_union_definition(h, def.this),
 
        Definition::Component(cdef) => this.visit_component_definition(h, cdef.this),
 
        Definition::Function(fdef) => this.visit_function_definition(h, fdef.this),
 
    }
 
}
 

	
 
fn recursive_component_definition<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    def: ComponentDefinitionId,
 
) -> VisitorResult {
 
    let component_variant = h[def].variant;
 
    match component_variant {
 
        ComponentVariant::Primitive => this.visit_primitive_definition(h, def),
 
        ComponentVariant::Composite => this.visit_composite_definition(h, def),
 
    }
 
}
 

	
 
fn recursive_composite_definition<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    def: ComponentDefinitionId,
 
) -> VisitorResult {
 
    for &param in h[def].parameters.clone().iter() {
 
        this.visit_variable_declaration(h, param)?;
 
    }
 
    this.visit_block_statement(h, h[def].body)
 
}
 

	
 
fn recursive_primitive_definition<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    def: ComponentDefinitionId,
 
) -> VisitorResult {
 
    for &param in h[def].parameters.clone().iter() {
 
        this.visit_variable_declaration(h, param)?;
 
    }
 
    this.visit_block_statement(h, h[def].body)
 
}
 

	
 
fn recursive_function_definition<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    def: FunctionDefinitionId,
 
) -> VisitorResult {
 
    for &param in h[def].parameters.clone().iter() {
 
        this.visit_variable_declaration(h, param)?;
 
    }
 
    this.visit_block_statement(h, h[def].body)
 
}
 

	
 
fn recursive_statement<T: Visitor>(this: &mut T, h: &mut Heap, stmt: StatementId) -> VisitorResult {
 
    match h[stmt].clone() {
 
        Statement::Block(stmt) => this.visit_block_statement(h, stmt.this),
 
        Statement::EndBlock(stmt) => this.visit_end_block_statement(h, stmt.this),
 
        Statement::Local(stmt) => this.visit_local_statement(h, stmt.this()),
 
        Statement::Labeled(stmt) => this.visit_labeled_statement(h, stmt.this),
 
        Statement::If(stmt) => this.visit_if_statement(h, stmt.this),
 
        Statement::While(stmt) => this.visit_while_statement(h, stmt.this),
 
        Statement::Break(stmt) => this.visit_break_statement(h, stmt.this),
 
        Statement::Continue(stmt) => this.visit_continue_statement(h, stmt.this),
 
        Statement::Synchronous(stmt) => this.visit_synchronous_statement(h, stmt.this),
 
        Statement::Return(stmt) => this.visit_return_statement(h, stmt.this),
 
        Statement::Goto(stmt) => this.visit_goto_statement(h, stmt.this),
 
        Statement::New(stmt) => this.visit_new_statement(h, stmt.this),
 
        Statement::Expression(stmt) => this.visit_expression_statement(h, stmt.this),
 
        Statement::EndSynchronous(stmt) => this.visit_end_synchronous_statement(h, stmt.this),
 
        Statement::EndWhile(stmt) => this.visit_end_while_statement(h, stmt.this),
 
        Statement::EndIf(stmt) => this.visit_end_if_statement(h, stmt.this),
 
    }
 
}
 

	
 
fn recursive_block_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    block: BlockStatementId,
 
) -> VisitorResult {
 
    for &local in h[block].locals.clone().iter() {
 
        this.visit_variable_declaration(h, local)?;
 
    }
 
    for &stmt in h[block].statements.clone().iter() {
 
        this.visit_statement(h, stmt)?;
 
    }
 
    Ok(())
 
}
 

	
 
fn recursive_local_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: LocalStatementId,
 
) -> VisitorResult {
 
    match h[stmt].clone() {
 
        LocalStatement::Channel(stmt) => this.visit_channel_statement(h, stmt.this),
 
        LocalStatement::Memory(stmt) => this.visit_memory_statement(h, stmt.this),
 
    }
 
}
 

	
 
fn recursive_labeled_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: LabeledStatementId,
 
) -> VisitorResult {
 
    this.visit_statement(h, h[stmt].body)
 
}
 

	
 
fn recursive_if_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: IfStatementId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[stmt].test)?;
 
    this.visit_block_statement(h, h[stmt].true_body)?;
 
    if let Some(false_body) = h[stmt].false_body {
 
        this.visit_block_statement(h, false_body)?;
 
    }
 
    Ok(())
 
}
 

	
 
fn recursive_while_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: WhileStatementId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[stmt].test)?;
 
    this.visit_block_statement(h, h[stmt].body)
 
}
 

	
 
fn recursive_synchronous_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: SynchronousStatementId,
 
) -> VisitorResult {
 
    // TODO: Check where this was used for
 
    // for &param in h[stmt].parameters.clone().iter() {
 
    //     recursive_parameter_as_variable(this, h, param)?;
 
    // }
 
    this.visit_block_statement(h, h[stmt].body)
 
}
 

	
 
fn recursive_return_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: ReturnStatementId,
 
) -> VisitorResult {
 
    debug_assert_eq!(h[stmt].expressions.len(), 1);
 
    this.visit_expression(h, h[stmt].expressions[0])
 
}
 

	
 
fn recursive_new_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: NewStatementId,
 
) -> VisitorResult {
 
    recursive_call_expression_as_expression(this, h, h[stmt].expression)
 
}
 

	
 
fn recursive_expression_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: ExpressionStatementId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[stmt].expression)
 
}
 

	
 
fn recursive_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: ExpressionId,
 
) -> VisitorResult {
 
    match h[expr].clone() {
 
        Expression::Assignment(expr) => this.visit_assignment_expression(h, expr.this),
 
        Expression::Binding(expr) => this.visit_binding_expression(h, expr.this),
 
        Expression::Conditional(expr) => this.visit_conditional_expression(h, expr.this),
 
        Expression::Binary(expr) => this.visit_binary_expression(h, expr.this),
 
        Expression::Unary(expr) => this.visit_unary_expression(h, expr.this),
 
        Expression::Indexing(expr) => this.visit_indexing_expression(h, expr.this),
 
        Expression::Slicing(expr) => this.visit_slicing_expression(h, expr.this),
 
        Expression::Select(expr) => this.visit_select_expression(h, expr.this),
 
        Expression::Literal(expr) => this.visit_constant_expression(h, expr.this),
 
        Expression::Cast(expr) => this.visit_cast_expression(h, expr.this),
 
        Expression::Call(expr) => this.visit_call_expression(h, expr.this),
 
        Expression::Variable(expr) => this.visit_variable_expression(h, expr.this),
 
    }
 
}
 

	
 
fn recursive_assignment_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: AssignmentExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].left)?;
 
    this.visit_expression(h, h[expr].right)
 
}
 

	
 
fn recursive_binding_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: BindingExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].left.upcast())?;
 
    this.visit_expression(h, h[expr].right)
 
    this.visit_expression(h, h[expr].bound_from)?;
 
    this.visit_expression(h, h[expr].bound_to)
 
}
 

	
 
fn recursive_conditional_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: ConditionalExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].test)?;
 
    this.visit_expression(h, h[expr].true_expression)?;
 
    this.visit_expression(h, h[expr].false_expression)
 
}
 

	
 
fn recursive_binary_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: BinaryExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].left)?;
 
    this.visit_expression(h, h[expr].right)
 
}
 

	
 
fn recursive_unary_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: UnaryExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].expression)
 
}
 

	
 
fn recursive_indexing_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: IndexingExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].subject)?;
 
    this.visit_expression(h, h[expr].index)
 
}
 

	
 
fn recursive_slicing_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: SlicingExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].subject)?;
 
    this.visit_expression(h, h[expr].from_index)?;
 
    this.visit_expression(h, h[expr].to_index)
 
}
 

	
 
fn recursive_select_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: SelectExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].subject)
 
}
 

	
 
fn recursive_call_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: CallExpressionId,
 
) -> VisitorResult {
 
    for &expr in h[expr].arguments.clone().iter() {
 
        this.visit_expression(h, expr)?;
 
    }
 
    Ok(())
 
}
 

	
 
// ====================
 
// Grammar Rules
 
// ====================
 

	
 
pub(crate) struct UniqueStatementId(StatementId);
 

	
 
pub(crate) struct LinkStatements {
 
    prev: Option<UniqueStatementId>,
 
}
 

	
 
impl LinkStatements {
 
    pub(crate) fn new() -> Self {
 
        LinkStatements { prev: None }
 
    }
 
}
 

	
 
impl Visitor for LinkStatements {
 
    fn visit_symbol_definition(&mut self, h: &mut Heap, def: DefinitionId) -> VisitorResult {
 
        assert!(self.prev.is_none());
 
        recursive_symbol_definition(self, h, def)?;
 
        // Clear out last statement
 
        self.prev = None;
 
        Ok(())
 
    }
 
    fn visit_statement(&mut self, h: &mut Heap, stmt: StatementId) -> VisitorResult {
 
        if let Some(UniqueStatementId(prev)) = self.prev.take() {
 
            h[prev].link_next(stmt);
 
        }
 
        recursive_statement(self, h, stmt)
 
    }
 
    fn visit_block_statement(&mut self, h: &mut Heap, stmt: BlockStatementId) -> VisitorResult {
 
        if let Some(prev) = self.prev.take() {
 
            h[prev.0].link_next(stmt.upcast());
 
        }
 
        let end_block = h[stmt].end_block;
 
        recursive_block_statement(self, h, stmt)?;
 
        if let Some(prev) = self.prev.take() {
 
            h[prev.0].link_next(end_block.upcast());
 
        }
 
        self.prev = Some(UniqueStatementId(end_block.upcast()));
 
        Ok(())
 
    }
 
    fn visit_local_statement(&mut self, _h: &mut Heap, stmt: LocalStatementId) -> VisitorResult {
 
        self.prev = Some(UniqueStatementId(stmt.upcast()));
 
        Ok(())
 
    }
 
    fn visit_labeled_statement(&mut self, h: &mut Heap, stmt: LabeledStatementId) -> VisitorResult {
 
        recursive_labeled_statement(self, h, stmt)
 
    }
 
    fn visit_if_statement(&mut self, h: &mut Heap, stmt: IfStatementId) -> VisitorResult {
 
        // Link the two branches to the corresponding EndIf pseudo-statement
 
        let end_if_id = h[stmt].end_if;
 
        assert!(!end_if_id.is_invalid());
 

	
 
        assert!(self.prev.is_none());
 
        self.visit_block_statement(h, h[stmt].true_body)?;
 
        if let Some(UniqueStatementId(prev)) = self.prev.take() {
 
            h[prev].link_next(end_if_id.upcast());
 
        }
 

	
 
        assert!(self.prev.is_none());
 
        if let Some(false_body) = h[stmt].false_body {
 
            self.visit_block_statement(h, false_body)?;
 
        }
 
        if let Some(UniqueStatementId(prev)) = self.prev.take() {
 
            h[prev].link_next(end_if_id.upcast());
 
        }
 

	
 
        // Use the pseudo-statement as the statement where to update the next pointer
 
        // self.prev = Some(UniqueStatementId(end_if_id.upcast()));
 
        Ok(())
 
    }
 
    fn visit_end_if_statement(&mut self, _h: &mut Heap, stmt: EndIfStatementId) -> VisitorResult {
 
        assert!(self.prev.is_none());
 
        self.prev = Some(UniqueStatementId(stmt.upcast()));
 
        Ok(())
 
    }
 
    fn visit_while_statement(&mut self, h: &mut Heap, stmt: WhileStatementId) -> VisitorResult {
 
        // We allocate a pseudo-statement, to which the break statement finds its target
 
        // Update the while's next statement to point to the pseudo-statement
 
        let end_while_id = h[stmt].end_while;
 
        assert!(!end_while_id.is_invalid());
 

	
 
        assert!(self.prev.is_none());
 
        self.visit_block_statement(h, h[stmt].body)?;
 
        // The body's next statement loops back to the while statement itself
 
        // Note: continue statements also loop back to the while statement itself
 
        if let Some(UniqueStatementId(prev)) = self.prev.take() {
 
            h[prev].link_next(stmt.upcast());
 
        }
 
        // Use the while statement as the statement where the next pointer is updated
 
        // self.prev = Some(UniqueStatementId(end_while_id.upcast()));
 
        Ok(())
 
    }
 
    fn visit_end_while_statement(&mut self, _h: &mut Heap, stmt: EndWhileStatementId) -> VisitorResult {
 
        assert!(self.prev.is_none());
 
        self.prev = Some(UniqueStatementId(stmt.upcast()));
 
        Ok(())
 
    }
 
    fn visit_break_statement(&mut self, _h: &mut Heap, _stmt: BreakStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_continue_statement(
 
        &mut self,
 
        _h: &mut Heap,
 
        _stmt: ContinueStatementId,
 
    ) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_synchronous_statement(
 
        &mut self,
 
        h: &mut Heap,
 
        stmt: SynchronousStatementId,
 
    ) -> VisitorResult {
 
        // Allocate a pseudo-statement, that is added for helping the evaluator to issue a command
 
        // that marks the end of the synchronous block. Every evaluation has to pause at this
 
        // point, only to resume later when the thread is selected as unique thread to continue.
 
        let end_sync_id = h[stmt].end_sync;
 
        assert!(!end_sync_id.is_invalid());
 

	
 
        assert!(self.prev.is_none());
 
        self.visit_block_statement(h, h[stmt].body)?;
 
        // The body's next statement points to the pseudo element
 
        if let Some(UniqueStatementId(prev)) = self.prev.take() {
 
            h[prev].link_next(end_sync_id.upcast());
 
        }
 
        // Use the pseudo-statement as the statement where the next pointer is updated
 
        // self.prev = Some(UniqueStatementId(end_sync_id.upcast()));
 
        Ok(())
 
    }
 
    fn visit_end_synchronous_statement(&mut self, _h: &mut Heap, stmt: EndSynchronousStatementId) -> VisitorResult {
 
        assert!(self.prev.is_none());
 
        self.prev = Some(UniqueStatementId(stmt.upcast()));
 
        Ok(())
 
    }
 
    fn visit_return_statement(&mut self, _h: &mut Heap, _stmt: ReturnStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_goto_statement(&mut self, _h: &mut Heap, _stmt: GotoStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_new_statement(&mut self, _h: &mut Heap, stmt: NewStatementId) -> VisitorResult {
 
        self.prev = Some(UniqueStatementId(stmt.upcast()));
 
        Ok(())
 
    }
 
    fn visit_expression_statement(
 
        &mut self,
 
        _h: &mut Heap,
 
        stmt: ExpressionStatementId,
 
    ) -> VisitorResult {
 
        self.prev = Some(UniqueStatementId(stmt.upcast()));
 
        Ok(())
 
    }
 
    fn visit_expression(&mut self, _h: &mut Heap, _expr: ExpressionId) -> VisitorResult {
 
        Ok(())
 
    }
 
}
 
\ No newline at end of file
src/protocol/parser/pass_definitions.rs
Show inline comments
 
use crate::protocol::ast::*;
 
use super::symbol_table::*;
 
use super::{Module, ModuleCompilationPhase, PassCtx};
 
use super::tokens::*;
 
use super::token_parsing::*;
 
use crate::protocol::input_source::{InputSource as InputSource, InputPosition as InputPosition, InputSpan, ParseError};
 
use crate::collections::*;
 

	
 
/// Parses all the tokenized definitions into actual AST nodes.
 
pub(crate) struct PassDefinitions {
 
    // State associated with the definition currently being processed
 
    cur_definition: DefinitionId,
 
    // Temporary buffers of various kinds
 
    buffer: String,
 
    struct_fields: ScopedBuffer<StructFieldDefinition>,
 
    enum_variants: ScopedBuffer<EnumVariantDefinition>,
 
    union_variants: ScopedBuffer<UnionVariantDefinition>,
 
    variables: ScopedBuffer<VariableId>,
 
    expressions: ScopedBuffer<ExpressionId>,
 
    statements: ScopedBuffer<StatementId>,
 
    parser_types: ScopedBuffer<ParserType>,
 
}
 

	
 
impl PassDefinitions {
 
    pub(crate) fn new() -> Self {
 
        Self{
 
            cur_definition: DefinitionId::new_invalid(),
 
            buffer: String::with_capacity(128),
 
            struct_fields: ScopedBuffer::new_reserved(128),
 
            enum_variants: ScopedBuffer::new_reserved(128),
 
            union_variants: ScopedBuffer::new_reserved(128),
 
            variables: ScopedBuffer::new_reserved(128),
 
            expressions: ScopedBuffer::new_reserved(128),
 
            statements: ScopedBuffer::new_reserved(128),
 
            parser_types: ScopedBuffer::new_reserved(128),
 
        }
 
    }
 

	
 
    pub(crate) fn parse(&mut self, modules: &mut [Module], module_idx: usize, ctx: &mut PassCtx) -> Result<(), ParseError> {
 
        let module = &modules[module_idx];
 
        let module_range = &module.tokens.ranges[0];
 
        debug_assert_eq!(module.phase, ModuleCompilationPhase::ImportsResolved);
 
        debug_assert_eq!(module_range.range_kind, TokenRangeKind::Module);
 

	
 
        // Although we only need to parse the definitions, we want to go through
 
        // code ranges as well such that we can throw errors if we get
 
        // unexpected tokens at the module level of the source.
 
        let mut range_idx = module_range.first_child_idx;
 
        loop {
 
            let range_idx_usize = range_idx as usize;
 
            let cur_range = &module.tokens.ranges[range_idx_usize];
 

	
 
            match cur_range.range_kind {
 
                TokenRangeKind::Module => unreachable!(), // should not be reachable
 
                TokenRangeKind::Pragma | TokenRangeKind::Import => {
 
                    // Already fully parsed, fall through and go to next range
 
                },
 
                TokenRangeKind::Definition | TokenRangeKind::Code => {
 
                    // Visit range even if it is a "code" range to provide
 
                    // proper error messages.
 
                    self.visit_range(modules, module_idx, ctx, range_idx_usize)?;
 
                },
 
            }
 

	
 
            if cur_range.next_sibling_idx == NO_SIBLING {
 
                break;
 
            } else {
 
                range_idx = cur_range.next_sibling_idx;
 
            }
 
        }
 

	
 
        modules[module_idx].phase = ModuleCompilationPhase::DefinitionsParsed;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_range(
 
        &mut self, modules: &[Module], module_idx: usize, ctx: &mut PassCtx, range_idx: usize
 
    ) -> Result<(), ParseError> {
 
        let module = &modules[module_idx];
 
        let cur_range = &module.tokens.ranges[range_idx];
 
        debug_assert!(cur_range.range_kind == TokenRangeKind::Definition || cur_range.range_kind == TokenRangeKind::Code);
 

	
 
        // Detect which definition we're parsing
 
        let mut iter = module.tokens.iter_range(cur_range);
 
        loop {
 
            let next = iter.next();
 
            if next.is_none() {
 
                return Ok(())
 
            }
 

	
 
            // Token was not None, so peek_ident returns None if not an ident
 
            let ident = peek_ident(&module.source, &mut iter);
 
            match ident {
 
                Some(KW_STRUCT) => self.visit_struct_definition(module, &mut iter, ctx)?,
 
                Some(KW_ENUM) => self.visit_enum_definition(module, &mut iter, ctx)?,
 
                Some(KW_UNION) => self.visit_union_definition(module, &mut iter, ctx)?,
 
                Some(KW_FUNCTION) => self.visit_function_definition(module, &mut iter, ctx)?,
 
                Some(KW_PRIMITIVE) | Some(KW_COMPOSITE) => self.visit_component_definition(module, &mut iter, ctx)?,
 
                _ => return Err(ParseError::new_error_str_at_pos(
 
                    &module.source, iter.last_valid_pos(),
 
                    "unexpected symbol, expected a keyword marking the start of a definition"
 
                )),
 
            }
 
        }
 
    }
 

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

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

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

	
 
        let mut fields_section = self.struct_fields.start_section();
 
        consume_comma_separated(
 
            TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
 
            |source, iter, ctx| {
 
                let poly_vars = ctx.heap[definition_id].poly_vars(); // TODO: @Cleanup, this is really ugly. But rust...
 

	
 
                let start_pos = iter.last_valid_pos();
 
                let parser_type = consume_parser_type(
 
                    source, iter, &ctx.symbols, &ctx.heap, poly_vars, module_scope,
 
                    definition_id, false, 0
 
                )?;
 
                let field = consume_ident_interned(source, iter, ctx)?;
 
                Ok(StructFieldDefinition{
 
                    span: InputSpan::from_positions(start_pos, field.span.end),
 
                    field, parser_type
 
                })
 
            },
 
            &mut fields_section, "a struct field", "a list of struct fields", None
 
        )?;
 

	
 
        // Transfer to preallocated definition
 
        let struct_def = ctx.heap[definition_id].as_struct_mut();
 
        struct_def.fields = fields_section.into_vec();
 

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        let mut enum_section = self.enum_variants.start_section();
 
        consume_comma_separated(
 
            TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
 
            |source, iter, ctx| {
 
                let identifier = consume_ident_interned(source, iter, ctx)?;
 
                let value = if iter.next() == Some(TokenKind::Equal) {
 
                    iter.consume();
 
                    let (variant_number, _) = consume_integer_literal(source, iter, &mut self.buffer)?;
 
                    EnumVariantValue::Integer(variant_number as i64) // TODO: @int
 
                } else {
 
                    EnumVariantValue::None
 
                };
 
                Ok(EnumVariantDefinition{ identifier, value })
 
            },
 
            &mut enum_section, "an enum variant", "a list of enum variants", None
 
        )?;
 

	
 
        // Transfer to definition
 
        let enum_def = ctx.heap[definition_id].as_enum_mut();
 
        enum_def.variants = enum_section.into_vec();
 

	
 
        Ok(())
 
    }
 

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

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

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

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

	
 
                let 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(); // TODO: @Cleanup, this is really ugly. But rust...
 
                        consume_parser_type(
 
                            source, iter, &ctx.symbols, &ctx.heap, poly_vars,
 
                            module_scope, definition_id, false, 0
 
                        )
 
                    },
 
                    &mut types_section, "an embedded type", Some(&mut close_pos)
 
                )?;
 
                let value = if has_embedded {
 
                    UnionVariantValue::Embedded(types_section.into_vec())
 
                } else {
 
                    types_section.forget();
 
                    UnionVariantValue::None
 
                };
 

	
 
                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(
 
            &module.source, iter, ctx, &mut parameter_section, module_scope, definition_id
 
        )?;
 
        let parameters = parameter_section.into_vec();
 

	
 
        // Consume return types
 
        consume_token(&module.source, iter, TokenKind::ArrowRight)?;
 
        let mut return_types = self.parser_types.start_section();
 
        let mut open_curly_pos = iter.last_valid_pos(); // bogus value
 
        consume_comma_separated_until(
 
            TokenKind::OpenCurly, &module.source, iter, ctx,
 
            |source, iter, ctx| {
 
                let poly_vars = ctx.heap[definition_id].poly_vars(); // TODO: @Cleanup, this is really ugly. But rust...
 
                consume_parser_type(source, iter, &ctx.symbols, &ctx.heap, poly_vars, module_scope, definition_id, false, 0)
 
            },
 
            &mut return_types, "a return type", Some(&mut open_curly_pos)
 
        )?;
 
        let return_types = return_types.into_vec();
 

	
 
        // TODO: @ReturnValues
 
        match return_types.len() {
 
            0 => return Err(ParseError::new_error_str_at_pos(&module.source, open_curly_pos, "expected a return type")),
 
            1 => {},
 
            _ => return Err(ParseError::new_error_str_at_pos(&module.source, open_curly_pos, "multiple return types are not (yet) allowed")),
 
        }
 

	
 
        // Consume block
 
        let body = self.consume_block_statement_without_leading_curly(module, iter, ctx, open_curly_pos)?;
 

	
 
        // Assign everything in the preallocated AST node
 
        let function = ctx.heap[definition_id].as_function_mut();
 
        function.return_types = return_types;
 
        function.parameters = parameters;
 
        function.body = body;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_component_definition(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<(), ParseError> {
 
        // 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(
 
            &module.source, iter, ctx, &mut parameter_section, module_scope, definition_id
 
        )?;
 
        let parameters = parameter_section.into_vec();
 

	
 
        // Consume block
 
        let body = self.consume_block_statement(module, iter, ctx)?;
 

	
 
        // Assign everything in the AST node
 
        let component = ctx.heap[definition_id].as_component_mut();
 
        component.parameters = parameters;
 
        component.body = body;
 

	
 
        Ok(())
 
    }
 

	
 
    /// Consumes a block statement. If the resulting statement is not a block
 
    /// (e.g. for a shorthand "if (expr) single_statement") then it will be
 
    /// wrapped in one
 
    fn consume_block_or_wrapped_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<BlockStatementId, ParseError> {
 
        if Some(TokenKind::OpenCurly) == iter.next() {
 
            // This is a block statement
 
            self.consume_block_statement(module, iter, ctx)
 
        } else {
 
            // Not a block statement, so wrap it in one
 
            let mut statements = self.statements.start_section();
 
            let wrap_begin_pos = iter.last_valid_pos();
 
            self.consume_statement(module, iter, ctx, &mut statements)?;
 
            let wrap_end_pos = iter.last_valid_pos();
 

	
 
            debug_assert_eq!(statements.len(), 1);
 
            let statements = statements.into_vec();
 

	
 
            let id = ctx.heap.alloc_block_statement(|this| BlockStatement{
 
                this,
 
                is_implicit: true,
 
                span: InputSpan::from_positions(wrap_begin_pos, wrap_end_pos), // TODO: @Span
 
                statements,
 
                end_block: EndBlockStatementId::new_invalid(),
 
                parent_scope: Scope::Definition(DefinitionId::new_invalid()),
 
                scope_node: ScopeNode::new_invalid(),
 
                first_unique_id_in_scope: -1,
 
                next_unique_id_in_scope: -1,
 
                relative_pos_in_parent: 0,
 
                locals: Vec::new(),
 
                labels: Vec::new()
 
            });
 

	
 
            let end_block = ctx.heap.alloc_end_block_statement(|this| EndBlockStatement{
 
                this, start_block: id, next: StatementId::new_invalid()
 
            });
 

	
 
            let block_stmt = &mut ctx.heap[id];
 
            block_stmt.end_block = end_block;
 

	
 
            Ok(id)
 
        }
 
    }
 

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

	
 
        if next == TokenKind::OpenCurly {
 
            let id = self.consume_block_statement(module, iter, ctx)?;
 
            section.push(id.upcast());
 
        } else if next == TokenKind::Ident {
 
            let ident = peek_ident(&module.source, iter).unwrap();
 
            if ident == KW_STMT_IF {
 
                // Consume if statement and place end-if statement directly
 
                // after it.
 
                let id = self.consume_if_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 

	
 
                let end_if = ctx.heap.alloc_end_if_statement(|this| EndIfStatement{
 
                    this, start_if: id, next: StatementId::new_invalid()
 
                });
 
                section.push(end_if.upcast());
 

	
 
                let if_stmt = &mut ctx.heap[id];
 
                if_stmt.end_if = end_if;
 
            } else if ident == KW_STMT_WHILE {
 
                let id = self.consume_while_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 

	
 
                let end_while = ctx.heap.alloc_end_while_statement(|this| EndWhileStatement{
 
                    this, start_while: id, next: StatementId::new_invalid()
 
                });
 
                section.push(end_while.upcast());
 

	
 
                let while_stmt = &mut ctx.heap[id];
 
                while_stmt.end_while = end_while;
 
            } else if ident == KW_STMT_BREAK {
 
                let id = self.consume_break_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 
            } else if ident == KW_STMT_CONTINUE {
 
                let id = self.consume_continue_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 
            } else if ident == KW_STMT_SYNC {
 
                let id = self.consume_synchronous_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 

	
 
                let end_sync = ctx.heap.alloc_end_synchronous_statement(|this| EndSynchronousStatement{
 
                    this, start_sync: id, next: StatementId::new_invalid()
 
                });
 
                section.push(end_sync.upcast());
 

	
 
                let sync_stmt = &mut ctx.heap[id];
 
                sync_stmt.end_sync = end_sync;
 
            } else if ident == KW_STMT_RETURN {
 
                let id = self.consume_return_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 
            } else if ident == KW_STMT_GOTO {
 
                let id = self.consume_goto_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 
            } else if ident == KW_STMT_NEW {
 
                let id = self.consume_new_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 
            } else if ident == KW_STMT_CHANNEL {
 
                let id = self.consume_channel_statement(module, iter, ctx)?;
 
                section.push(id.upcast().upcast());
 
            } else if iter.peek() == Some(TokenKind::Colon) {
 
                self.consume_labeled_statement(module, iter, ctx, section)?;
 
            } else {
 
                // Two fallback possibilities: the first one is a memory
 
                // declaration, the other one is to parse it as a regular
 
                // expression. This is a bit ugly
 
                if let Some((memory_stmt_id, assignment_stmt_id)) = self.maybe_consume_memory_statement(module, iter, ctx)? {
 
                    section.push(memory_stmt_id.upcast().upcast());
 
                    section.push(assignment_stmt_id.upcast());
 
                } else {
 
                    let id = self.consume_expression_statement(module, iter, ctx)?;
 
                    section.push(id.upcast());
 
                }
 
            }
 
        } else {
 
            let id = self.consume_expression_statement(module, iter, ctx)?;
 
            section.push(id.upcast());
 
        }
 

	
 
        return Ok(());
 
    }
 

	
 
    fn consume_block_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<BlockStatementId, ParseError> {
 
        let open_span = consume_token(&module.source, iter, TokenKind::OpenCurly)?;
 
        self.consume_block_statement_without_leading_curly(module, iter, ctx, open_span.begin)
 
    }
 

	
 
    fn consume_block_statement_without_leading_curly(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, open_curly_pos: InputPosition
 
    ) -> Result<BlockStatementId, ParseError> {
 
        let mut stmt_section = self.statements.start_section();
 
        let mut next = iter.next();
 
        while next != Some(TokenKind::CloseCurly) {
 
            if next.is_none() {
 
                return Err(ParseError::new_error_str_at_pos(
 
                    &module.source, iter.last_valid_pos(), "expected a statement or '}'"
 
                ));
 
            }
 
            self.consume_statement(module, iter, ctx, &mut stmt_section)?;
 
            next = iter.next();
 
        }
 

	
 
        let statements = stmt_section.into_vec();
 
        let mut block_span = consume_token(&module.source, iter, TokenKind::CloseCurly)?;
 
        block_span.begin = open_curly_pos;
 

	
 
        let id = ctx.heap.alloc_block_statement(|this| BlockStatement{
 
            this,
 
            is_implicit: false,
 
            span: block_span,
 
            statements,
 
            end_block: EndBlockStatementId::new_invalid(),
 
            parent_scope: Scope::Definition(DefinitionId::new_invalid()),
 
            scope_node: ScopeNode::new_invalid(),
 
            first_unique_id_in_scope: -1,
 
            next_unique_id_in_scope: -1,
 
            relative_pos_in_parent: 0,
 
            locals: Vec::new(),
 
            labels: Vec::new(),
 
        });
 

	
 
        let end_block = ctx.heap.alloc_end_block_statement(|this| EndBlockStatement{
 
            this, start_block: id, next: StatementId::new_invalid()
 
        });
 

	
 
        let block_stmt = &mut ctx.heap[id];
 
        block_stmt.end_block = end_block;
 

	
 
        Ok(id)
 
    }
 

	
 
    fn consume_if_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<IfStatementId, ParseError> {
 
        let if_span = consume_exact_ident(&module.source, iter, KW_STMT_IF)?;
 
        consume_token(&module.source, iter, TokenKind::OpenParen)?;
 
        let test = self.consume_expression(module, iter, ctx)?;
 
        consume_token(&module.source, iter, TokenKind::CloseParen)?;
 
        let true_body = self.consume_block_or_wrapped_statement(module, iter, ctx)?;
 

	
 
        let false_body = if has_ident(&module.source, iter, KW_STMT_ELSE) {
 
            iter.consume();
 
            let false_body = self.consume_block_or_wrapped_statement(module, iter, ctx)?;
 
            Some(false_body)
 
        } else {
 
            None
 
        };
 

	
 
        Ok(ctx.heap.alloc_if_statement(|this| IfStatement{
 
            this,
 
            span: if_span,
 
            test,
 
            true_body,
 
            false_body,
 
            end_if: EndIfStatementId::new_invalid(),
 
        }))
 
    }
 

	
 
    fn consume_while_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<WhileStatementId, ParseError> {
 
        let while_span = consume_exact_ident(&module.source, iter, KW_STMT_WHILE)?;
 
        consume_token(&module.source, iter, TokenKind::OpenParen)?;
 
        let test = self.consume_expression(module, iter, ctx)?;
 
        consume_token(&module.source, iter, TokenKind::CloseParen)?;
 
        let body = self.consume_block_or_wrapped_statement(module, iter, ctx)?;
 

	
 
        Ok(ctx.heap.alloc_while_statement(|this| WhileStatement{
 
            this,
 
            span: while_span,
 
            test,
 
            body,
 
            end_while: EndWhileStatementId::new_invalid(),
 
            in_sync: None,
 
            in_sync: SynchronousStatementId::new_invalid(),
 
        }))
 
    }
 

	
 
    fn consume_break_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<BreakStatementId, ParseError> {
 
        let break_span = consume_exact_ident(&module.source, iter, KW_STMT_BREAK)?;
 
        let label = if Some(TokenKind::Ident) == iter.next() {
 
            let label = consume_ident_interned(&module.source, iter, ctx)?;
 
            Some(label)
 
        } else {
 
            None
 
        };
 
        consume_token(&module.source, iter, TokenKind::SemiColon)?;
 
        Ok(ctx.heap.alloc_break_statement(|this| BreakStatement{
 
            this,
 
            span: break_span,
 
            label,
 
            target: None,
 
        }))
 
    }
 

	
 
    fn consume_continue_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ContinueStatementId, ParseError> {
 
        let continue_span = consume_exact_ident(&module.source, iter, KW_STMT_CONTINUE)?;
 
        let label=  if Some(TokenKind::Ident) == iter.next() {
 
            let label = consume_ident_interned(&module.source, iter, ctx)?;
 
            Some(label)
 
        } else {
 
            None
 
        };
 
        consume_token(&module.source, iter, TokenKind::SemiColon)?;
 
        Ok(ctx.heap.alloc_continue_statement(|this| ContinueStatement{
 
            this,
 
            span: continue_span,
 
            label,
 
            target: None
 
        }))
 
    }
 

	
 
    fn consume_synchronous_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<SynchronousStatementId, ParseError> {
 
        let synchronous_span = consume_exact_ident(&module.source, iter, KW_STMT_SYNC)?;
 
        let body = self.consume_block_or_wrapped_statement(module, iter, ctx)?;
 

	
 
        Ok(ctx.heap.alloc_synchronous_statement(|this| SynchronousStatement{
 
            this,
 
            span: synchronous_span,
 
            body,
 
            end_sync: EndSynchronousStatementId::new_invalid(),
 
            parent_scope: None,
 
        }))
 
    }
 

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

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

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

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

	
 
    fn consume_goto_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<GotoStatementId, ParseError> {
 
        let goto_span = consume_exact_ident(&module.source, iter, KW_STMT_GOTO)?;
 
        let label = consume_ident_interned(&module.source, iter, ctx)?;
 
        consume_token(&module.source, iter, TokenKind::SemiColon)?;
 
        Ok(ctx.heap.alloc_goto_statement(|this| GotoStatement{
 
            this,
 
            span: goto_span,
 
            label,
 
            target: None
 
        }))
 
    }
 

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

	
 
        // TODO: @Cleanup, should just call something like consume_component_expression-ish
 
        let start_pos = iter.last_valid_pos();
 
        let expression_id = self.consume_primary_expression(module, iter, ctx)?;
 
        let expression = &ctx.heap[expression_id];
 
        let mut valid = false;
 

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

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

	
 
        debug_assert!(!call_id.is_invalid());
 
        Ok(ctx.heap.alloc_new_statement(|this| NewStatement{
 
            this,
 
            span: new_span,
 
            expression: call_id,
 
            next: 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 channel_type = if Some(TokenKind::OpenAngle) == iter.next() {
 
            // Retrieve the type of the channel, we're cheating a bit here by
 
            // consuming the first '<' and setting the initial angle depth to 1
 
            // such that our final '>' will be consumed as well.
 
            iter.consume();
 
            let definition_id = self.cur_definition;
 
            let poly_vars = ctx.heap[definition_id].poly_vars();
 
            consume_parser_type(
 
                &module.source, iter, &ctx.symbols, &ctx.heap,
 
                poly_vars, SymbolScope::Module(module.root_id), definition_id,
 
                true, 1
 
            )?
 
        } else {
 
            // Assume inferred
 
            ParserType{ elements: vec![ParserTypeElement{
 
                full_span: channel_span, // TODO: @Span fix
 
                variant: ParserTypeVariant::Inferred
 
            }]}
 
        };
 

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

	
 
        // Construct ports
 
        let from = ctx.heap.alloc_variable(|this| Variable{
 
            this,
 
            kind: VariableKind::Local,
 
            identifier: from_identifier,
 
            parser_type: channel_type.clone(),
 
            relative_pos_in_block: 0,
 
            unique_id_in_scope: -1,
 
        });
 
        let to = ctx.heap.alloc_variable(|this|Variable{
 
            this,
 
            kind: VariableKind::Local,
 
            identifier: to_identifier,
 
            parser_type: channel_type,
 
            relative_pos_in_block: 0,
 
            unique_id_in_scope: -1,
 
        });
 

	
 
        // Construct the channel
 
        Ok(ctx.heap.alloc_channel_statement(|this| ChannelStatement{
 
            this,
 
            span: channel_span,
 
            from, to,
 
            relative_pos_in_block: 0,
 
            next: StatementId::new_invalid(),
 
        }))
 
    }
 

	
 
    fn consume_labeled_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, section: &mut ScopedSection<StatementId>
 
    ) -> Result<(), ParseError> {
 
        let label = consume_ident_interned(&module.source, iter, ctx)?;
 
        consume_token(&module.source, iter, TokenKind::Colon)?;
 

	
 
        // Not pretty: consume_statement may produce more than one statement.
 
        // The values in the section need to be in the correct order if some
 
        // kind of outer block is consumed, so we take another section, push
 
        // the expressions in that one, and then allocate the labeled statement.
 
        let mut inner_section = self.statements.start_section();
 
        self.consume_statement(module, iter, ctx, &mut inner_section)?;
 
        debug_assert!(inner_section.len() >= 1);
 

	
 
        let stmt_id = ctx.heap.alloc_labeled_statement(|this| LabeledStatement {
 
            this,
 
            label,
 
            body: inner_section[0],
 
            relative_pos_in_block: 0,
 
            in_sync: None,
 
            in_sync: SynchronousStatementId::new_invalid(),
 
        });
 

	
 
        if inner_section.len() == 1 {
 
            // Produce the labeled statement pointing to the first statement.
 
            // This is by far the most common case.
 
            inner_section.forget();
 
            section.push(stmt_id.upcast());
 
        } else {
 
            // Produce the labeled statement using the first statement, and push
 
            // the remaining ones at the end.
 
            let inner_statements = inner_section.into_vec();
 
            section.push(stmt_id.upcast());
 
            for idx in 1..inner_statements.len() {
 
                section.push(inner_statements[idx])
 
            }
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    fn maybe_consume_memory_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<Option<(MemoryStatementId, ExpressionStatementId)>, ParseError> {
 
        // This is a bit ugly. It would be nicer if we could somehow
 
        // consume the expression with a type hint if we do get a valid
 
        // type, but we don't get an identifier following it
 
        let iter_state = iter.save();
 
        let definition_id = self.cur_definition;
 
        let poly_vars = ctx.heap[definition_id].poly_vars();
 

	
 
        let parser_type = consume_parser_type(
 
            &module.source, iter, &ctx.symbols, &ctx.heap, poly_vars,
 
            SymbolScope::Definition(definition_id), definition_id, true, 0
 
        );
 

	
 
        if let Ok(parser_type) = parser_type {
 
            if Some(TokenKind::Ident) == iter.next() {
 
                // Assume this is a proper memory statement
 
                let identifier = consume_ident_interned(&module.source, iter, ctx)?;
 
                let memory_span = InputSpan::from_positions(parser_type.elements[0].full_span.begin, identifier.span.end);
 
                let assign_span = consume_token(&module.source, iter, TokenKind::Equal)?;
 

	
 
                let initial_expr_begin_pos = iter.last_valid_pos();
 
                let initial_expr_id = self.consume_expression(module, iter, ctx)?;
 
                let initial_expr_end_pos = iter.last_valid_pos();
 
                consume_token(&module.source, iter, TokenKind::SemiColon)?;
 

	
 
                // Allocate the memory statement with the variable
 
                let local_id = ctx.heap.alloc_variable(|this| Variable{
 
                    this,
 
                    kind: VariableKind::Local,
 
                    identifier: identifier.clone(),
 
                    parser_type,
 
                    relative_pos_in_block: 0,
 
                    unique_id_in_scope: -1,
 
                });
 
                let memory_stmt_id = ctx.heap.alloc_memory_statement(|this| MemoryStatement{
 
                    this,
 
                    span: memory_span,
 
                    variable: local_id,
 
                    next: StatementId::new_invalid()
 
                });
 

	
 
                // Allocate the initial assignment
 
                let variable_expr_id = ctx.heap.alloc_variable_expression(|this| VariableExpression{
 
                    this,
 
                    identifier,
 
                    declaration: None,
 
                    parent: ExpressionParent::None,
 
                    unique_id_in_definition: -1,
 
                });
 
                let assignment_expr_id = ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{
 
                    this,
 
                    span: assign_span,
 
                    left: variable_expr_id.upcast(),
 
                    operation: AssignmentOperator::Set,
 
                    right: initial_expr_id,
 
                    parent: ExpressionParent::None,
 
                    unique_id_in_definition: -1,
 
                });
 
                let assignment_stmt_id = ctx.heap.alloc_expression_statement(|this| ExpressionStatement{
 
                    this,
 
                    span: InputSpan::from_positions(initial_expr_begin_pos, initial_expr_end_pos),
 
                    expression: assignment_expr_id.upcast(),
 
                    next: StatementId::new_invalid(),
 
                });
 

	
 
                return Ok(Some((memory_stmt_id, assignment_stmt_id)))
 
            }
 
        }
 

	
 
        // If here then one of the preconditions for a memory statement was not
 
        // met. So recover the iterator and return
 
        iter.load(iter_state);
 
        Ok(None)
 
    }
 

	
 
    fn consume_expression_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionStatementId, ParseError> {
 
        let start_pos = iter.last_valid_pos();
 
        let expression = self.consume_expression(module, iter, ctx)?;
 
        let end_pos = iter.last_valid_pos();
 
        consume_token(&module.source, iter, TokenKind::SemiColon)?;
 

	
 
        Ok(ctx.heap.alloc_expression_statement(|this| ExpressionStatement{
 
            this,
 
            span: InputSpan::from_positions(start_pos, end_pos),
 
            expression,
 
            next: StatementId::new_invalid(),
 
        }))
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // Expression Parsing
 
    //--------------------------------------------------------------------------
 

	
 
    // TODO: @Cleanup This is fine for now. But I prefer my stacktraces not to
 
    //  look like enterprise Java code...
 
    fn consume_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_assignment_expression(module, iter, ctx)
 
    }
 

	
 
    fn consume_assignment_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        // Utility to convert token into assignment operator
 
        fn parse_assignment_operator(token: Option<TokenKind>) -> Option<AssignmentOperator> {
 
            use TokenKind as TK;
 
            use AssignmentOperator as AO;
 

	
 
            if token.is_none() {
 
                return None
 
            }
 

	
 
            match token.unwrap() {
 
                TK::Equal               => Some(AO::Set),
 
                TK::StarEquals          => Some(AO::Multiplied),
 
                TK::SlashEquals         => Some(AO::Divided),
 
                TK::PercentEquals       => Some(AO::Remained),
 
                TK::PlusEquals          => Some(AO::Added),
 
                TK::MinusEquals         => Some(AO::Subtracted),
 
                TK::ShiftLeftEquals     => Some(AO::ShiftedLeft),
 
                TK::ShiftRightEquals    => Some(AO::ShiftedRight),
 
                TK::AndEquals           => Some(AO::BitwiseAnded),
 
                TK::CaretEquals         => Some(AO::BitwiseXored),
 
                TK::OrEquals            => Some(AO::BitwiseOred),
 
                _                       => None
 
            }
 
        }
 

	
 
        let expr = self.consume_conditional_expression(module, iter, ctx)?;
 
        if let Some(operation) = parse_assignment_operator(iter.next()) {
 
            let span = iter.next_span();
 
            iter.consume();
 

	
 
            let left = expr;
 
            let right = self.consume_expression(module, iter, ctx)?;
 

	
 
            Ok(ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{
 
                this, span, left, operation, right,
 
                parent: ExpressionParent::None,
 
                unique_id_in_definition: -1,
 
            }).upcast())
 
        } else {
 
            Ok(expr)
 
        }
 
    }
 

	
 
    fn consume_conditional_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        let result = self.consume_concat_expression(module, iter, ctx)?;
 
        if let Some(TokenKind::Question) = iter.next() {
 
            let span = iter.next_span();
 
            iter.consume();
 

	
 
            let test = result;
 
            let true_expression = self.consume_expression(module, iter, ctx)?;
 
            consume_token(&module.source, iter, TokenKind::Colon)?;
 
            let false_expression = self.consume_expression(module, iter, ctx)?;
 
            Ok(ctx.heap.alloc_conditional_expression(|this| ConditionalExpression{
 
                this, span, test, true_expression, false_expression,
 
                parent: ExpressionParent::None,
 
                unique_id_in_definition: -1,
 
            }).upcast())
 
        } else {
 
            Ok(result)
 
        }
 
    }
 

	
 
    fn consume_concat_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::At) => Some(BinaryOperator::Concatenate),
 
                _ => None
 
            },
 
            Self::consume_logical_or_expression
 
        )
 
    }
 

	
 
    fn consume_logical_or_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::OrOr) => Some(BinaryOperator::LogicalOr),
 
                _ => None
 
            },
 
            Self::consume_logical_and_expression
 
        )
 
    }
 

	
 
    fn consume_logical_and_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::AndAnd) => Some(BinaryOperator::LogicalAnd),
 
                _ => None
 
            },
 
            Self::consume_bitwise_or_expression
 
        )
 
    }
 

	
 
    fn consume_bitwise_or_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::Or) => Some(BinaryOperator::BitwiseOr),
 
                _ => None
 
            },
 
            Self::consume_bitwise_xor_expression
 
        )
 
    }
 

	
 
    fn consume_bitwise_xor_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::Caret) => Some(BinaryOperator::BitwiseXor),
 
                _ => None
 
            },
 
            Self::consume_bitwise_and_expression
 
        )
 
    }
 

	
 
    fn consume_bitwise_and_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::And) => Some(BinaryOperator::BitwiseAnd),
 
                _ => None
 
            },
 
            Self::consume_equality_expression
 
        )
 
    }
 

	
 
    fn consume_equality_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::EqualEqual) => Some(BinaryOperator::Equality),
 
                Some(TokenKind::NotEqual) => Some(BinaryOperator::Inequality),
 
                _ => None
 
            },
 
            Self::consume_relational_expression
 
        )
 
    }
 

	
 
    fn consume_relational_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::OpenAngle) => Some(BinaryOperator::LessThan),
 
                Some(TokenKind::CloseAngle) => Some(BinaryOperator::GreaterThan),
 
                Some(TokenKind::LessEquals) => Some(BinaryOperator::LessThanEqual),
 
                Some(TokenKind::GreaterEquals) => Some(BinaryOperator::GreaterThanEqual),
 
                _ => None
 
            },
 
            Self::consume_shift_expression
 
        )
 
    }
 

	
 
    fn consume_shift_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::ShiftLeft) => Some(BinaryOperator::ShiftLeft),
 
                Some(TokenKind::ShiftRight) => Some(BinaryOperator::ShiftRight),
 
                _ => None
 
            },
 
            Self::consume_add_or_subtract_expression
 
        )
 
    }
 

	
 
    fn consume_add_or_subtract_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::Plus) => Some(BinaryOperator::Add),
 
                Some(TokenKind::Minus) => Some(BinaryOperator::Subtract),
 
                _ => None,
 
            },
 
            Self::consume_multiply_divide_or_modulus_expression
 
        )
 
    }
 

	
 
    fn consume_multiply_divide_or_modulus_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::Star) => Some(BinaryOperator::Multiply),
 
                Some(TokenKind::Slash) => Some(BinaryOperator::Divide),
 
                Some(TokenKind::Percent) => Some(BinaryOperator::Remainder),
 
                _ => None
 
            },
 
            Self::consume_prefix_expression
 
        )
 
    }
 

	
 
    fn consume_prefix_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        fn parse_prefix_token(token: Option<TokenKind>) -> Option<UnaryOperator> {
 
            use TokenKind as TK;
 
            use UnaryOperator as UO;
 
            match token {
 
                Some(TK::Plus) => Some(UO::Positive),
 
                Some(TK::Minus) => Some(UO::Negative),
 
                Some(TK::PlusPlus) => Some(UO::PreIncrement),
 
                Some(TK::MinusMinus) => Some(UO::PreDecrement),
 
                Some(TK::Tilde) => Some(UO::BitwiseNot),
 
                Some(TK::Exclamation) => Some(UO::LogicalNot),
 
                _ => None
 
            }
 
        }
 

	
 
        if let Some(operation) = parse_prefix_token(iter.next()) {
 
            let span = iter.next_span();
 
            iter.consume();
 

	
 
            let expression = self.consume_prefix_expression(module, iter, ctx)?;
 
            Ok(ctx.heap.alloc_unary_expression(|this| UnaryExpression {
 
                this, span, operation, expression,
 
                parent: ExpressionParent::None,
 
                unique_id_in_definition: -1,
 
            }).upcast())
 
        } else {
 
            self.consume_postfix_expression(module, iter, ctx)
 
        }
 
    }
 

	
 
    fn consume_postfix_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        fn has_matching_postfix_token(token: Option<TokenKind>) -> bool {
 
            use TokenKind as TK;
 

	
 
            if token.is_none() { return false; }
 
            match token.unwrap() {
 
                TK::PlusPlus | TK::MinusMinus | TK::OpenSquare | TK::Dot => true,
 
                _ => false
 
            }
 
        }
 

	
 
        let mut result = self.consume_primary_expression(module, iter, ctx)?;
 
        let mut next = iter.next();
 
        while has_matching_postfix_token(next) {
 
            let token = next.unwrap();
 
            let mut span = iter.next_span();
 
            iter.consume();
 

	
 
            if token == TokenKind::PlusPlus {
 
                result = ctx.heap.alloc_unary_expression(|this| UnaryExpression{
 
                    this, span,
 
                    operation: UnaryOperator::PostIncrement,
 
                    expression: result,
 
                    parent: ExpressionParent::None,
 
                    unique_id_in_definition: -1,
 
                }).upcast();
 
            } else if token == TokenKind::MinusMinus {
 
                result = ctx.heap.alloc_unary_expression(|this| UnaryExpression{
 
                    this, span,
 
                    operation: UnaryOperator::PostDecrement,
 
                    expression: result,
 
                    parent: ExpressionParent::None,
 
                    unique_id_in_definition: -1,
 
                }).upcast();
 
            } else if token == TokenKind::OpenSquare {
 
                let subject = result;
 
                let from_index = self.consume_expression(module, iter, ctx)?;
 

	
 
                // Check if we have an indexing or slicing operation
 
                next = iter.next();
 
                if Some(TokenKind::DotDot) == next {
 
                    iter.consume();
 

	
 
                    let to_index = self.consume_expression(module, iter, ctx)?;
 
                    let end_span = consume_token(&module.source, iter, TokenKind::CloseSquare)?;
 
                    span.end = end_span.end;
 

	
 
                    result = ctx.heap.alloc_slicing_expression(|this| SlicingExpression{
 
                        this, span, subject, from_index, to_index,
 
                        parent: ExpressionParent::None,
 
                        unique_id_in_definition: -1,
 
                    }).upcast();
 
                } else if Some(TokenKind::CloseSquare) == next {
 
                    let end_span = consume_token(&module.source, iter, TokenKind::CloseSquare)?;
 
                    span.end = end_span.end;
 

	
 
                    result = ctx.heap.alloc_indexing_expression(|this| IndexingExpression{
 
                        this, span, subject,
 
                        index: from_index,
 
                        parent: ExpressionParent::None,
 
                        unique_id_in_definition: -1,
 
                    }).upcast();
 
                } else {
 
                    return Err(ParseError::new_error_str_at_pos(
 
                        &module.source, iter.last_valid_pos(), "unexpected token: expected ']' or '..'"
 
                    ));
 
                }
 
            } else {
 
                debug_assert_eq!(token, TokenKind::Dot);
 
                let subject = result;
 
                let field_name = consume_ident_interned(&module.source, iter, ctx)?;
 

	
 
                result = ctx.heap.alloc_select_expression(|this| SelectExpression{
 
                    this, span, subject, field_name,
 
                    parent: ExpressionParent::None,
 
                    unique_id_in_definition: -1,
 
                }).upcast();
 
            }
 

	
 
            next = iter.next();
 
        }
 

	
 
        Ok(result)
 
    }
 

	
 
    fn consume_primary_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        let next = iter.next();
 

	
 
        let result = if next == Some(TokenKind::OpenParen) {
 
            // Expression between parentheses
 
            iter.consume();
 
            let result = self.consume_expression(module, iter, ctx)?;
 
            consume_token(&module.source, iter, TokenKind::CloseParen)?;
 

	
 
            result
 
        } else if next == Some(TokenKind::OpenCurly) {
 
            // Array literal
 
            let (start_pos, mut end_pos) = iter.next_positions();
 
            let mut scoped_section = self.expressions.start_section();
 
            consume_comma_separated(
 
                TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
 
                |_source, iter, ctx| self.consume_expression(module, iter, ctx),
 
                &mut scoped_section, "an expression", "a list of expressions", Some(&mut end_pos)
 
            )?;
 

	
 
            ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                this,
 
                span: InputSpan::from_positions(start_pos, end_pos),
 
                value: Literal::Array(scoped_section.into_vec()),
 
                parent: ExpressionParent::None,
 
                unique_id_in_definition: -1,
 
            }).upcast()
 
        } else if next == Some(TokenKind::Integer) {
 
            let (literal, span) = consume_integer_literal(&module.source, iter, &mut self.buffer)?;
 

	
 
            ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                this, span,
 
                value: Literal::Integer(LiteralInteger{ unsigned_value: literal, negated: false }),
 
                parent: ExpressionParent::None,
 
                unique_id_in_definition: -1,
 
            }).upcast()
 
        } else if next == Some(TokenKind::String) {
 
            let span = consume_string_literal(&module.source, iter, &mut self.buffer)?;
 
            let interned = ctx.pool.intern(self.buffer.as_bytes());
 

	
 
            ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                this, span,
 
                value: Literal::String(interned),
 
                parent: ExpressionParent::None,
 
                unique_id_in_definition: -1,
 
            }).upcast()
 
        } else if next == Some(TokenKind::Character) {
 
            let (character, span) = consume_character_literal(&module.source, iter)?;
 

	
 
            ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                this, span,
 
                value: Literal::Character(character),
 
                parent: ExpressionParent::None,
 
                unique_id_in_definition: -1,
 
            }).upcast()
 
        } else if next == Some(TokenKind::Ident) {
 
            // May be a variable, a type instantiation or a function call. If we
 
            // have a single identifier that we cannot find in the type table
 
            // then we're going to assume that we're dealing with a variable.
 
            let ident_span = iter.next_span();
 
            let ident_text = module.source.section_at_span(ident_span);
 
            let symbol = ctx.symbols.get_symbol_by_name(SymbolScope::Module(module.root_id), ident_text);
 

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

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

	
 
                                ctx.heap.alloc_call_expression(|this| CallExpression{
 
                                    this,
 
                                    span: parser_type.elements[0].full_span, // TODO: @Span fix
 
                                    parser_type,
 
                                    method: Method::UserComponent,
 
                                    arguments,
 
                                    definition: target_definition_id,
 
                                    parent: ExpressionParent::None,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            },
 
                            Definition::Function(function_definition) => {
 
                                // Check whether it is a builtin function
 
                                let method = if function_definition.builtin {
 
                                    match function_definition.identifier.value.as_str() {
 
                                        "get" => Method::Get,
 
                                        "put" => Method::Put,
 
                                        "fires" => Method::Fires,
 
                                        "create" => Method::Create,
 
                                        "length" => Method::Length,
 
                                        "assert" => Method::Assert,
 
                                        _ => unreachable!(),
 
                                    }
 
                                } else {
 
                                    Method::UserFunction
 
                                };
 

	
 
                                // Function call: consume the arguments
 
                                let arguments = self.consume_expression_list(module, iter, ctx, None)?;
 

	
 
                                ctx.heap.alloc_call_expression(|this| CallExpression{
 
                                    this,
 
                                    span: parser_type.elements[0].full_span, // TODO: @Span fix
 
                                    parser_type,
 
                                    method,
 
                                    arguments,
 
                                    definition: target_definition_id,
 
                                    parent: ExpressionParent::None,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            }
 
                        }
 
                    },
 
                    _ => {
 
                        // TODO: Casting expressions
 
                        return Err(ParseError::new_error_str_at_span(
 
                            &module.source, parser_type.elements[0].full_span,
 
                            "unexpected type in expression, note that casting expressions are not yet implemented"
 
                        ))
 
                    }
 
                }
 
            } else {
 
                // Check for builtin keywords or builtin functions
 
                if ident_text == KW_LIT_NULL || ident_text == KW_LIT_TRUE || ident_text == KW_LIT_FALSE {
 
                    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 keyword_span = iter.next_span();
 
                    iter.consume();
 

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

	
 
                    ctx.heap.alloc_binding_expression(|this| BindingExpression{
 
                        this,
 
                        span: keyword_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() {
 
                        iter.consume();
 
                        let definition_id = self.cur_definition;
 
                        let poly_vars = ctx.heap[definition_id].poly_vars();
 
                        consume_parser_type(
 
                            &module.source, iter, &ctx.symbols, &ctx.heap,
 
                            poly_vars, SymbolScope::Module(module.root_id), definition_id,
 
                            true, 1
 
                        )?
 
                    } else {
 
                        // Automatic casting with inferred target type
 
                        ParserType{ elements: vec![ParserTypeElement{
 
                            full_span: ident_span, // TODO: @Span fix
 
                            variant: ParserTypeVariant::Inferred,
 
                        }]}
 
                    };
 

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

	
 
                    ctx.heap.alloc_cast_expression(|this| CastExpression{
 
                        this,
 
                        span: ident_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();
 
                    let next = iter.next();
 
                    if Some(TokenKind::ColonColon) == next {
 
                        return Err(ParseError::new_error_str_at_span(&module.source, ident_span, "unknown identifier"));
 
                    } else if Some(TokenKind::OpenParen) == next {
 
                        return Err(ParseError::new_error_str_at_span(
 
                            &module.source, ident_span,
 
                            "unknown identifier, did you mistype a union variant's or a function's name?"
 
                        ));
 
                    } else if Some(TokenKind::OpenCurly) == next {
 
                        return Err(ParseError::new_error_str_at_span(
 
                            &module.source, ident_span,
 
                            "unknown identifier, did you mistype a struct type's name?"
 
                        ))
 
                    }
 

	
 
                    let ident_text = ctx.pool.intern(ident_text);
 
                    let identifier = Identifier { span: ident_span, value: ident_text };
 

	
 
                    ctx.heap.alloc_variable_expression(|this| VariableExpression {
 
                        this,
 
                        identifier,
 
                        declaration: None,
 
                        parent: ExpressionParent::None,
 
                        unique_id_in_definition: -1,
 
                    }).upcast()
 
                }
 
            }
 
        } else {
 
            return Err(ParseError::new_error_str_at_pos(
 
                &module.source, iter.last_valid_pos(), "expected an expression"
 
            ));
 
        };
 

	
 
        Ok(result)
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // Expression Utilities
 
    //--------------------------------------------------------------------------
 

	
 
    #[inline]
 
    fn consume_generic_binary_expression<
 
        M: Fn(Option<TokenKind>) -> Option<BinaryOperator>,
 
        F: Fn(&mut PassDefinitions, &Module, &mut TokenIter, &mut PassCtx) -> Result<ExpressionId, ParseError>
 
    >(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, match_fn: M, higher_precedence_fn: F
 
    ) -> Result<ExpressionId, ParseError> {
 
        let mut result = higher_precedence_fn(self, module, iter, ctx)?;
 
        while let Some(operation) = match_fn(iter.next()) {
 
            let span = iter.next_span();
 
            iter.consume();
 

	
 
            let left = result;
 
            let right = higher_precedence_fn(self, module, iter, ctx)?;
 

	
 
            result = ctx.heap.alloc_binary_expression(|this| BinaryExpression{
 
                this, span, left, operation, right,
 
                parent: ExpressionParent::None,
 
                unique_id_in_definition: -1,
 
            }).upcast();
 
        }
 

	
 
        Ok(result)
 
    }
 

	
 
    #[inline]
 
    fn consume_expression_list(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, end_pos: Option<&mut InputPosition>
 
    ) -> Result<Vec<ExpressionId>, ParseError> {
 
        let mut section = self.expressions.start_section();
 
        consume_comma_separated(
 
            TokenKind::OpenParen, TokenKind::CloseParen, &module.source, iter, ctx,
 
            |_source, iter, ctx| self.consume_expression(module, iter, ctx),
 
            &mut section, "an expression", "a list of expressions", end_pos
 
        )?;
 
        Ok(section.into_vec())
 
    }
 
}
 

	
 
/// Consumes a type. A type always starts with an identifier which may indicate
 
/// a builtin type or a user-defined type. The fact that it may contain
 
/// polymorphic arguments makes it a tree-like structure. Because we cannot rely
 
/// on knowing the exact number of polymorphic arguments we do not check for
 
/// these.
 
///
 
/// Note that the first depth index is used as a hack.
 
// TODO: @Optimize, @Span fix, @Cleanup
 
fn consume_parser_type(
 
    source: &InputSource, iter: &mut TokenIter, symbols: &SymbolTable, heap: &Heap, poly_vars: &[Identifier],
 
    cur_scope: SymbolScope, wrapping_definition: DefinitionId, allow_inference: bool, first_angle_depth: i32,
 
) -> Result<ParserType, ParseError> {
 
    struct Entry{
 
        element: ParserTypeElement,
 
        depth: i32,
 
    }
 

	
 
    // After parsing the array modified "[]", we need to insert an array type
 
    // before the most recently parsed type.
 
    fn insert_array_before(elements: &mut Vec<Entry>, depth: i32, span: InputSpan) {
 
        let index = elements.iter().rposition(|e| e.depth == depth).unwrap();
 
        elements.insert(index, Entry{
 
            element: ParserTypeElement{ full_span: span, variant: ParserTypeVariant::Array },
 
            depth,
 
        });
 
    }
 

	
 
    // Most common case we just have one type, perhaps with some array
 
    // annotations. This is both the hot-path, and simplifies the state machine
 
    // that follows and is responsible for parsing more complicated types.
 
    let element = consume_parser_type_ident(source, iter, symbols, heap, poly_vars, cur_scope, wrapping_definition, allow_inference)?;
 
    if iter.next() != Some(TokenKind::OpenAngle) {
 
        let num_embedded = element.variant.num_embedded();
 
        let mut num_array = 0;
 
        while iter.next() == Some(TokenKind::OpenSquare) {
 
            iter.consume();
 
            consume_token(source, iter, TokenKind::CloseSquare)?;
 
            num_array += 1;
 
        }
 

	
 
        let array_span = element.full_span;
 
        let mut elements = Vec::with_capacity(num_array + num_embedded + 1);
 
        for _ in 0..num_array {
 
            elements.push(ParserTypeElement{ full_span: array_span, variant: ParserTypeVariant::Array });
 
        }
 
        elements.push(element);
 

	
 
        if num_embedded != 0 {
 
            if !allow_inference {
 
                return Err(ParseError::new_error_str_at_span(source, array_span, "type inference is not allowed here"));
 
            }
 

	
 
            for _ in 0..num_embedded {
 
                elements.push(ParserTypeElement { full_span: array_span, variant: ParserTypeVariant::Inferred });
 
            }
 
        }
 

	
 
        for _ in 0..first_angle_depth {
 
            consume_token(source, iter, TokenKind::CloseAngle);
 
        }
 

	
 
        return Ok(ParserType{ elements });
 
    };
 

	
 
    // We have a polymorphic specification. So we start by pushing the item onto
 
    // our stack, then start adding entries together with the angle-brace depth
 
    // at which they're found.
 
    let mut elements = Vec::new();
 
    elements.push(Entry{ element, depth: 0 });
 

	
 
    // Start out with the first '<' consumed.
 
    iter.consume();
 
    enum State { Ident, Open, Close, Comma }
 
    let mut state = State::Open;
 
    let mut angle_depth = first_angle_depth + 1;
 

	
 
    loop {
 
        let next = iter.next();
 

	
 
        match state {
 
            State::Ident => {
 
                // Just parsed an identifier, may expect comma, angled braces,
 
                // or the tokens indicating an array
 
                if Some(TokenKind::OpenAngle) == next {
 
                    angle_depth += 1;
 
                    state = State::Open;
 
                } else if Some(TokenKind::CloseAngle) == next {
 
                    angle_depth -= 1;
 
                    state = State::Close;
 
                } else if Some(TokenKind::ShiftRight) == next {
 
                    angle_depth -= 2;
 
                    state = State::Close;
 
                } else if Some(TokenKind::Comma) == next {
 
                    state = State::Comma;
 
                } else if Some(TokenKind::OpenSquare) == next {
 
                    let (start_pos, _) = iter.next_positions();
 
                    iter.consume(); // consume opening square
 
                    if iter.next() != Some(TokenKind::CloseSquare) {
 
                        return Err(ParseError::new_error_str_at_pos(
 
                            source, iter.last_valid_pos(),
 
                            "unexpected token: expected ']'"
 
                        ));
 
                    }
 
                    let (_, end_pos) = iter.next_positions();
 
                    let array_span = InputSpan::from_positions(start_pos, end_pos);
 
                    insert_array_before(&mut elements, angle_depth, array_span);
 
                } else {
 
                    return Err(ParseError::new_error_str_at_pos(
 
                        source, iter.last_valid_pos(),
 
                        "unexpected token: expected '<', '>', ',' or '['")
 
                    );
 
                }
 

	
 
                iter.consume();
 
            },
 
            State::Open => {
 
                // Just parsed an opening angle bracket, expecting an identifier
 
                let element = consume_parser_type_ident(source, iter, symbols, heap, poly_vars, cur_scope, wrapping_definition, allow_inference)?;
 
                elements.push(Entry{ element, depth: angle_depth });
 
                state = State::Ident;
 
            },
 
            State::Close => {
 
                // Just parsed 1 or 2 closing angle brackets, expecting comma,
 
                // more closing brackets or the tokens indicating an array
 
                if Some(TokenKind::Comma) == next {
 
                    state = State::Comma;
 
                } else if Some(TokenKind::CloseAngle) == next {
 
                    angle_depth -= 1;
 
                    state = State::Close;
 
                } else if Some(TokenKind::ShiftRight) == next {
 
                    angle_depth -= 2;
 
                    state = State::Close;
 
                } else if Some(TokenKind::OpenSquare) == next {
 
                    let (start_pos, _) = iter.next_positions();
 
                    iter.consume();
 
                    if iter.next() != Some(TokenKind::CloseSquare) {
 
                        return Err(ParseError::new_error_str_at_pos(
 
                            source, iter.last_valid_pos(),
 
                            "unexpected token: expected ']'"
 
                        ));
 
                    }
 
                    let (_, end_pos) = iter.next_positions();
 
                    let array_span = InputSpan::from_positions(start_pos, end_pos);
 
                    insert_array_before(&mut elements, angle_depth, array_span);
 
                } else {
 
                    return Err(ParseError::new_error_str_at_pos(
 
                        source, iter.last_valid_pos(),
 
                        "unexpected token: expected ',', '>', or '['")
 
                    );
 
                }
 

	
 
                iter.consume();
 
            },
 
            State::Comma => {
 
                // Just parsed a comma, expecting an identifier or more closing
 
                // braces
 
                if Some(TokenKind::Ident) == next {
 
                    let element = consume_parser_type_ident(source, iter, symbols, heap, poly_vars, cur_scope, wrapping_definition, allow_inference)?;
 
                    elements.push(Entry{ element, depth: angle_depth });
 
                    state = State::Ident;
 
                } else if Some(TokenKind::CloseAngle) == next {
 
                    iter.consume();
 
                    angle_depth -= 1;
 
                    state = State::Close;
 
                } else if Some(TokenKind::ShiftRight) == next {
 
                    iter.consume();
 
                    angle_depth -= 2;
 
                    state = State::Close;
 
                } else {
 
                    return Err(ParseError::new_error_str_at_pos(
 
                        source, iter.last_valid_pos(),
 
                        "unexpected token: expected '>' or a type name"
 
                    ));
 
                }
 
            }
 
        }
 

	
 
        if angle_depth < 0 {
 
            return Err(ParseError::new_error_str_at_pos(source, iter.last_valid_pos(), "unmatched '>'"));
 
        } else if angle_depth == 0 {
 
            break;
 
        }
 
    }
 

	
 
    // If here then we found the correct number of angle braces. But we still
 
    // need to make sure that each encountered type has the correct number of
 
    // embedded types.
 
    let mut idx = 0;
 
    while idx < elements.len() {
 
        let cur_element = &elements[idx];
 
        let expected_subtypes = cur_element.element.variant.num_embedded();
 
        let mut encountered_subtypes = 0;
 
        for peek_idx in idx + 1..elements.len() {
 
            let peek_element = &elements[peek_idx];
 
            if peek_element.depth == cur_element.depth + 1 {
 
                encountered_subtypes += 1;
 
            } else if peek_element.depth <= cur_element.depth {
 
                break;
 
            }
 
        }
 

	
 
        if expected_subtypes != encountered_subtypes {
 
            if encountered_subtypes == 0 {
 
                // Case where we have elided the embedded types, all of them
 
                // should be inferred.
 
                if !allow_inference {
 
                    return Err(ParseError::new_error_str_at_span(
 
                        source, cur_element.element.full_span,
 
                        "type inference is not allowed here"
 
                    ));
 
                }
 

	
 
                // Insert the missing types
 
                let inserted_span = cur_element.element.full_span;
 
                let inserted_depth = cur_element.depth + 1;
 
                elements.reserve(expected_subtypes);
 
                for _ in 0..expected_subtypes {
 
                    elements.insert(idx + 1, Entry{
 
                        element: ParserTypeElement{ full_span: inserted_span, variant: ParserTypeVariant::Inferred },
 
                        depth: inserted_depth,
 
                    });
 
                }
 
            } else {
 
                // Mismatch in number of embedded types, produce a neat error
 
                // message.
 
                let type_name = String::from_utf8_lossy(source.section_at_span(cur_element.element.full_span));
 
                fn polymorphic_name_text(num: usize) -> &'static str {
 
                    if num == 1 { "polymorphic argument" } else { "polymorphic arguments" }
 
                }
 
                fn were_or_was(num: usize) -> &'static str {
 
                    if num == 1 { "was" } else { "were" }
 
                }
 

	
 
                if expected_subtypes == 0 {
 
                    return Err(ParseError::new_error_at_span(
 
                        source, cur_element.element.full_span,
 
                        format!(
 
                            "the type '{}' is not polymorphic, yet {} {} {} provided",
 
                            type_name, encountered_subtypes, polymorphic_name_text(encountered_subtypes),
 
                            were_or_was(encountered_subtypes)
 
                        )
 
                    ));
 
                }
 

	
 
                let maybe_infer_text = if allow_inference {
 
                    " (or none, to perform implicit type inference)"
 
                } else {
 
                    ""
 
                };
 

	
 
                return Err(ParseError::new_error_at_span(
 
                    source, cur_element.element.full_span,
 
                    format!(
 
                        "expected {} {}{} for the type '{}', but {} {} provided",
 
                        expected_subtypes, polymorphic_name_text(expected_subtypes),
 
                        maybe_infer_text, type_name, encountered_subtypes,
 
                        were_or_was(encountered_subtypes)
 
                    )
 
                ));
 
            }
 
        }
 

	
 
        idx += 1;
 
    }
 

	
 
    let mut constructed_elements = Vec::with_capacity(elements.len());
 
    for element in elements.into_iter() {
 
        constructed_elements.push(element.element);
 
    }
 

	
 
    Ok(ParserType{ elements: constructed_elements })
 
}
 

	
 
/// Consumes an identifier for which we assume that it resolves to some kind of
 
/// type. Once we actually arrive at a type we will stop parsing. Hence there
 
/// may be trailing '::' tokens in the iterator.
 
fn consume_parser_type_ident(
 
    source: &InputSource, iter: &mut TokenIter, symbols: &SymbolTable, heap: &Heap, poly_vars: &[Identifier],
 
    mut scope: SymbolScope, wrapping_definition: DefinitionId, allow_inference: bool,
 
) -> Result<ParserTypeElement, ParseError> {
 
    use ParserTypeVariant as PTV;
 
    let (mut type_text, mut type_span) = consume_any_ident(source, iter)?;
 

	
 
    let variant = match type_text {
 
        KW_TYPE_MESSAGE => PTV::Message,
 
        KW_TYPE_BOOL => PTV::Bool,
 
        KW_TYPE_UINT8 => PTV::UInt8,
 
        KW_TYPE_UINT16 => PTV::UInt16,
 
        KW_TYPE_UINT32 => PTV::UInt32,
 
        KW_TYPE_UINT64 => PTV::UInt64,
 
        KW_TYPE_SINT8 => PTV::SInt8,
 
        KW_TYPE_SINT16 => PTV::SInt16,
 
        KW_TYPE_SINT32 => PTV::SInt32,
 
        KW_TYPE_SINT64 => PTV::SInt64,
 
        KW_TYPE_IN_PORT => PTV::Input,
 
        KW_TYPE_OUT_PORT => PTV::Output,
 
        KW_TYPE_CHAR => PTV::Character,
 
        KW_TYPE_STRING => PTV::String,
 
        KW_TYPE_INFERRED => {
 
            if !allow_inference {
 
                return Err(ParseError::new_error_str_at_span(source, type_span, "type inference is not allowed here"));
 
            }
 

	
 
            PTV::Inferred
 
        },
 
        _ => {
 
            // Must be some kind of symbolic type
 
            let mut type_kind = None;
 
            for (poly_idx, poly_var) in poly_vars.iter().enumerate() {
 
                if poly_var.value.as_bytes() == type_text {
 
                    type_kind = Some(PTV::PolymorphicArgument(wrapping_definition, poly_idx as u32));
 
                }
 
            }
 

	
 
            if type_kind.is_none() {
 
                // Check symbol table for definition. To be fair, the language
 
                // only allows a single namespace for now. That said:
 
                let last_symbol = symbols.get_symbol_by_name(scope, type_text);
 
                if last_symbol.is_none() {
 
                    return Err(ParseError::new_error_str_at_span(source, type_span, "unknown type"));
 
                }
 
                let mut last_symbol = last_symbol.unwrap();
 

	
 
                loop {
 
                    match &last_symbol.variant {
 
                        SymbolVariant::Module(symbol_module) => {
 
                            // Expecting more identifiers
 
                            if Some(TokenKind::ColonColon) != iter.next() {
 
                                return Err(ParseError::new_error_str_at_span(source, type_span, "expected a type but got a module"));
 
                            }
 

	
 
                            consume_token(source, iter, TokenKind::ColonColon)?;
 

	
 
                            // Consume next part of type and prepare for next
 
                            // lookup loop
 
                            let (next_text, next_span) = consume_any_ident(source, iter)?;
 
                            let old_text = type_text;
 
                            type_text = next_text;
 
                            type_span.end = next_span.end;
 
                            scope = SymbolScope::Module(symbol_module.root_id);
 

	
 
                            let new_symbol = symbols.get_symbol_by_name_defined_in_scope(scope, type_text);
 
                            if new_symbol.is_none() {
 
                                // If the type is imported in the module then notify the programmer
 
                                // that imports do not leak outside of a module
 
                                let type_name = String::from_utf8_lossy(type_text);
 
                                let module_name = String::from_utf8_lossy(old_text);
 
                                let suffix = if symbols.get_symbol_by_name(scope, type_text).is_some() {
 
                                    format!(
 
                                        ". The module '{}' does import '{}', but these imports are not visible to other modules",
 
                                        &module_name, &type_name
 
                                    )
 
                                } else {
 
                                    String::new()
 
                                };
 

	
 
                                return Err(ParseError::new_error_at_span(
 
                                    source, next_span,
 
                                    format!("unknown type '{}' in module '{}'{}", type_name, module_name, suffix)
 
                                ));
 
                            }
 

	
 
                            last_symbol = new_symbol.unwrap();
 
                        },
 
                        SymbolVariant::Definition(symbol_definition) => {
 
                            let num_poly_vars = heap[symbol_definition.definition_id].poly_vars().len();
 
                            type_kind = Some(PTV::Definition(symbol_definition.definition_id, num_poly_vars as u32));
 
                            break;
 
                        }
 
                    }
 
                }
 
            }
 

	
 
            debug_assert!(type_kind.is_some());
 
            type_kind.unwrap()
 
        },
 
    };
 

	
 
    Ok(ParserTypeElement{ full_span: type_span, variant })
 
}
 

	
 
/// Consumes polymorphic variables and throws them on the floor.
 
fn consume_polymorphic_vars_spilled(source: &InputSource, iter: &mut TokenIter, _ctx: &mut PassCtx) -> Result<(), ParseError> {
 
    maybe_consume_comma_separated_spilled(
 
        TokenKind::OpenAngle, TokenKind::CloseAngle, source, iter, _ctx,
 
        |source, iter, _ctx| {
 
            consume_ident(source, iter)?;
 
            Ok(())
 
        }, "a polymorphic variable"
 
    )?;
 
    Ok(())
 
}
 

	
 
/// Consumes the parameter list to functions/components
 
fn consume_parameter_list(
 
    source: &InputSource, iter: &mut TokenIter, ctx: &mut PassCtx,
 
    target: &mut ScopedSection<VariableId>, scope: SymbolScope, definition_id: DefinitionId
 
) -> Result<(), ParseError> {
 
    consume_comma_separated(
 
        TokenKind::OpenParen, TokenKind::CloseParen, source, iter, ctx,
 
        |source, iter, ctx| {
 
            let poly_vars = ctx.heap[definition_id].poly_vars(); // TODO: @Cleanup, this is really ugly. But rust...
 
            let parser_type = consume_parser_type(
 
                source, iter, &ctx.symbols, &ctx.heap, poly_vars, scope,
 
                definition_id, false, 0
 
            )?;
 
            let identifier = consume_ident_interned(source, iter, ctx)?;
 
            let parameter_id = ctx.heap.alloc_variable(|this| Variable{
 
                this,
 
                kind: VariableKind::Parameter,
 
                parser_type,
 
                identifier,
 
                relative_pos_in_block: 0,
 
                unique_id_in_scope: -1,
 
            });
 
            Ok(parameter_id)
 
        },
 
        target, "a parameter", "a parameter list", None
 
    )
 
}
 
\ No newline at end of file
src/protocol/parser/pass_typing.rs
Show inline comments
 
/// pass_typing
 
///
 
/// Performs type inference and type checking. Type inference is implemented by
 
/// applying constraints on (sub)trees of types. During this process the
 
/// resolver takes the `ParserType` structs (the representation of the types
 
/// written by the programmer), converts them to `InferenceType` structs (the
 
/// temporary data structure used during type inference) and attempts to arrive
 
/// at `ConcreteType` structs (the representation of a fully checked and
 
/// validated type).
 
///
 
/// The resolver will visit every statement and expression relevant to the
 
/// procedure and insert and determine its initial type based on context (e.g. a
 
/// return statement's expression must match the function's return type, an
 
/// if statement's test expression must evaluate to a boolean). When all are
 
/// visited we attempt to make progress in evaluating the types. Whenever a type
 
/// is progressed we queue the related expressions for further type progression.
 
/// Once no more expressions are in the queue the algorithm is finished. At this
 
/// point either all types are inferred (or can be trivially implicitly
 
/// determined), or we have incomplete types. In the latter case we return an
 
/// error.
 
///
 
/// TODO: Needs a thorough rewrite:
 
///  0. polymorph_progress is intentionally broken at the moment. Make it work
 
///     again and use a normal VecSomething.
 
///  1. The foundation for doing all of the work with predetermined indices
 
///     instead of with HashMaps is there, but it is not really used because of
 
///     time constraints. When time is available, rewrite the system such that
 
///     AST IDs are not needed, and only indices into arrays are used.
 
///  2. We're doing a lot of extra work. It seems better to apply the initial
 
///     type based on expression parents, and immediately apply forced
 
///     constraints (arg to a fires() call must be port-like). All of the \
 
///     progress_xxx calls should then only be concerned with "transmitting"
 
///     type inference across their parent/child expressions.
 
///  3. Remove the `msg` type?
 
///  4. Disallow certain types in certain operations (e.g. `Void`).
 

	
 
macro_rules! debug_log_enabled {
 
    () => { false };
 
}
 

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

	
 
use std::collections::{HashMap, HashSet};
 

	
 
use crate::collections::DequeSet;
 
use crate::protocol::ast::*;
 
use crate::protocol::input_source::ParseError;
 
use crate::protocol::parser::ModuleCompilationPhase;
 
use crate::protocol::parser::type_table::*;
 
use crate::protocol::parser::token_parsing::*;
 
use super::visitor::{
 
    STMT_BUFFER_INIT_CAPACITY,
 
    EXPR_BUFFER_INIT_CAPACITY,
 
    Ctx,
 
    Visitor2,
 
    VisitorResult
 
};
 

	
 
const VOID_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::Void ];
 
const MESSAGE_TEMPLATE: [InferenceTypePart; 2] = [ InferenceTypePart::Message, InferenceTypePart::UInt8 ];
 
const BOOL_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::Bool ];
 
const CHARACTER_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::Character ];
 
const STRING_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::String ];
 
const NUMBERLIKE_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::NumberLike ];
 
const INTEGERLIKE_TEMPLATE: [InferenceTypePart; 1] = [ InferenceTypePart::IntegerLike ];
 
const ARRAY_TEMPLATE: [InferenceTypePart; 2] = [ InferenceTypePart::Array, InferenceTypePart::Unknown ];
 
const SLICE_TEMPLATE: [InferenceTypePart; 2] = [ InferenceTypePart::Slice, InferenceTypePart::Unknown ];
 
const ARRAYLIKE_TEMPLATE: [InferenceTypePart; 2] = [ InferenceTypePart::ArrayLike, InferenceTypePart::Unknown ];
 

	
 
/// TODO: @performance Turn into PartialOrd+Ord to simplify checks
 
#[derive(Debug, Clone, Eq, PartialEq)]
 
pub(crate) enum InferenceTypePart {
 
    // When we infer types of AST elements that support polymorphic arguments,
 
    // then we might have the case that multiple embedded types depend on the
 
    // polymorphic type (e.g. func bla(T a, T[] b) -> T[][]). If we can infer
 
    // the type in one place (e.g. argument a), then we may propagate this
 
    // information to other types (e.g. argument b and the return type). For
 
    // this reason we place markers in the `InferenceType` instances such that
 
    // we know which part of the type was originally a polymorphic argument.
 
    Marker(u32),
 
    // Completely unknown type, needs to be inferred
 
    Unknown,
 
    // Partially known type, may be inferred to to be the appropriate related 
 
    // type.
 
    // IndexLike,      // index into array/slice
 
    NumberLike,     // any kind of integer/float
 
    IntegerLike,    // any kind of integer
 
    ArrayLike,      // array or slice. Note that this must have a subtype
 
    PortLike,       // input or output port
 
    // Special types that cannot be instantiated by the user
 
    Void, // For builtin functions that do not return anything
 
    // Concrete types without subtypes
 
    Bool,
 
    UInt8,
 
    UInt16,
 
    UInt32,
 
    UInt64,
 
    SInt8,
 
    SInt16,
 
    SInt32,
 
    SInt64,
 
    Character,
 
    String,
 
    // One subtype
 
    Message,
 
    Array,
 
    Slice,
 
    Input,
 
    Output,
 
    // A user-defined type with any number of subtypes
 
    Instance(DefinitionId, u32)
 
}
 

	
 
impl InferenceTypePart {
 
    fn is_marker(&self) -> bool {
 
        match self {
 
            InferenceTypePart::Marker(_) => true,
 
            _ => false,
 
        }
 
    }
 

	
 
    /// Checks if the type is concrete, markers are interpreted as concrete
 
    /// types.
 
    fn is_concrete(&self) -> bool {
 
        use InferenceTypePart as ITP;
 
        match self {
 
            ITP::Unknown | ITP::NumberLike | ITP::IntegerLike | 
 
            ITP::ArrayLike | ITP::PortLike => false,
 
            _ => true
 
        }
 
    }
 

	
 
    fn is_concrete_number(&self) -> bool {
 
        use InferenceTypePart as ITP;
 
        match self {
 
            ITP::UInt8 | ITP::UInt16 | ITP::UInt32 | ITP::UInt64 |
 
            ITP::SInt8 | ITP::SInt16 | ITP::SInt32 | ITP::SInt64 => true,
 
            _ => false,
 
        }
 
    }
 

	
 
    fn is_concrete_integer(&self) -> bool {
 
        use InferenceTypePart as ITP;
 
        match self {
 
            ITP::UInt8 | ITP::UInt16 | ITP::UInt32 | ITP::UInt64 |
 
            ITP::SInt8 | ITP::SInt16 | ITP::SInt32 | ITP::SInt64 => true,
 
            _ => false,
 
        }
 
    }
 

	
 
    fn is_concrete_msg_array_or_slice(&self) -> bool {
 
        use InferenceTypePart as ITP;
 
        match self {
 
            ITP::Array | ITP::Slice | ITP::Message => true,
 
            _ => false,
 
        }
 
    }
 

	
 
    fn is_concrete_port(&self) -> bool {
 
        use InferenceTypePart as ITP;
 
        match self {
 
            ITP::Input | ITP::Output => true,
 
            _ => false,
 
        }
 
    }
 

	
 
    /// Checks if a part is less specific than the argument. Only checks for 
 
    /// single-part inference (i.e. not the replacement of an `Unknown` variant 
 
    /// with the argument)
 
    fn may_be_inferred_from(&self, arg: &InferenceTypePart) -> bool {
 
        use InferenceTypePart as ITP;
 

	
 
        (*self == ITP::IntegerLike && arg.is_concrete_integer()) ||
 
        (*self == ITP::NumberLike && (arg.is_concrete_number() || *arg == ITP::IntegerLike)) ||
 
        (*self == ITP::ArrayLike && arg.is_concrete_msg_array_or_slice()) ||
 
        (*self == ITP::PortLike && arg.is_concrete_port())
 
    }
 

	
 
    /// Returns the change in "iteration depth" when traversing this particular
 
    /// part. The iteration depth is used to traverse the tree in a linear 
 
    /// fashion. It is basically `number_of_subtypes - 1`
 
    fn depth_change(&self) -> i32 {
 
        use InferenceTypePart as ITP;
 
        match &self {
 
            ITP::Unknown | ITP::NumberLike | ITP::IntegerLike |
 
            ITP::Void | ITP::Bool |
 
            ITP::UInt8 | ITP::UInt16 | ITP::UInt32 | ITP::UInt64 |
 
            ITP::SInt8 | ITP::SInt16 | ITP::SInt32 | ITP::SInt64 |
 
            ITP::Character | ITP::String => {
 
                -1
 
            },
 
            ITP::Marker(_) |
 
            ITP::ArrayLike | ITP::Message | ITP::Array | ITP::Slice |
 
            ITP::PortLike | ITP::Input | ITP::Output => {
 
                // One subtype, so do not modify depth
 
                0
 
            },
 
            ITP::Instance(_, num_args) => {
 
                (*num_args as i32) - 1
 
            }
 
        }
 
    }
 
}
 

	
 
impl From<ConcreteTypePart> for InferenceTypePart {
 
    fn from(v: ConcreteTypePart) -> InferenceTypePart {
 
        use ConcreteTypePart as CTP;
 
        use InferenceTypePart as ITP;
 

	
 
        match v {
 
            CTP::Void => ITP::Void,
 
            CTP::Message => ITP::Message,
 
            CTP::Bool => ITP::Bool,
 
            CTP::UInt8 => ITP::UInt8,
 
            CTP::UInt16 => ITP::UInt16,
 
            CTP::UInt32 => ITP::UInt32,
 
            CTP::UInt64 => ITP::UInt64,
 
            CTP::SInt8 => ITP::SInt8,
 
            CTP::SInt16 => ITP::SInt16,
 
            CTP::SInt32 => ITP::SInt32,
 
            CTP::SInt64 => ITP::SInt64,
 
            CTP::Character => ITP::Character,
 
            CTP::String => ITP::String,
 
            CTP::Array => ITP::Array,
 
            CTP::Slice => ITP::Slice,
 
            CTP::Input => ITP::Input,
 
            CTP::Output => ITP::Output,
 
            CTP::Instance(id, num) => ITP::Instance(id, num),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
struct InferenceType {
 
    has_marker: bool,
 
    is_done: bool,
 
    parts: Vec<InferenceTypePart>,
 
}
 

	
 
impl InferenceType {
 
    /// Generates a new InferenceType. The two boolean flags will be checked in
 
    /// debug mode.
 
    fn new(has_marker: bool, is_done: bool, parts: Vec<InferenceTypePart>) -> Self {
 
        if cfg!(debug_assertions) {
 
            debug_assert!(!parts.is_empty());
 
            let parts_body_marker = parts.iter().any(|v| v.is_marker());
 
            debug_assert_eq!(has_marker, parts_body_marker);
 
            let parts_done = parts.iter().all(|v| v.is_concrete());
 
            debug_assert_eq!(is_done, parts_done, "{:?}", parts);
 
        }
 
        Self{ has_marker, is_done, parts }
 
    }
 

	
 
    /// Replaces a type subtree with the provided subtree. The caller must make
 
    /// sure the the replacement is a well formed type subtree.
 
    fn replace_subtree(&mut self, start_idx: usize, with: &[InferenceTypePart]) {
 
        let end_idx = Self::find_subtree_end_idx(&self.parts, start_idx);
 
        debug_assert_eq!(with.len(), Self::find_subtree_end_idx(with, 0));
 
        self.parts.splice(start_idx..end_idx, with.iter().cloned());
 
        self.recompute_is_done();
 
    }
 

	
 
    // TODO: @performance, might all be done inline in the type inference methods
 
    fn recompute_is_done(&mut self) {
 
        self.is_done = self.parts.iter().all(|v| v.is_concrete());
 
    }
 

	
 
    /// Seeks a body marker starting at the specified position. If a marker is
 
    /// found then its value and the index of the type subtree that follows it
 
    /// is returned.
 
    fn find_marker(&self, mut start_idx: usize) -> Option<(u32, usize)> {
 
        while start_idx < self.parts.len() {
 
            if let InferenceTypePart::Marker(marker) = &self.parts[start_idx] {
 
                return Some((*marker, start_idx + 1))
 
            }
 

	
 
            start_idx += 1;
 
        }
 

	
 
        None
 
    }
 

	
 
    /// Returns an iterator over all body markers and the partial type tree that
 
    /// follows those markers. If it is a problem that `InferenceType` is 
 
    /// borrowed by the iterator, then use `find_body_marker`.
 
    fn marker_iter(&self) -> InferenceTypeMarkerIter {
 
        InferenceTypeMarkerIter::new(&self.parts)
 
    }
 

	
 
    /// Given that the `parts` are a depth-first serialized tree of types, this
 
    /// function finds the subtree anchored at a specific node. The returned 
 
    /// index is exclusive.
 
    fn find_subtree_end_idx(parts: &[InferenceTypePart], start_idx: usize) -> usize {
 
        let mut depth = 1;
 
        let mut idx = start_idx;
 

	
 
        while idx < parts.len() {
 
            depth += parts[idx].depth_change();
 
            if depth == 0 {
 
                return idx + 1;
 
            }
 
            idx += 1;
 
        }
 

	
 
        // If here, then the inference type is malformed
 
        unreachable!();
 
    }
 

	
 
    /// Call that attempts to infer the part at `to_infer.parts[to_infer_idx]` 
 
    /// using the subtree at `template.parts[template_idx]`. Will return 
 
    /// `Some(depth_change_due_to_traversal)` if type inference has been 
 
    /// applied. In this case the indices will also be modified to point to the 
 
    /// next part in both templates. If type inference has not (or: could not) 
 
    /// be applied then `None` will be returned. Note that this might mean that 
 
    /// the types are incompatible.
 
    ///
 
    /// As this is a helper functions, some assumptions: the parts are not 
 
    /// exactly equal, and neither of them contains a marker. Also: only the
 
    /// `to_infer` parts are checked for inference. It might be that this 
 
    /// function returns `None`, but that that `template` is still compatible
 
    /// with `to_infer`, e.g. when `template` has an `Unknown` part.
 
    fn infer_part_for_single_type(
 
        to_infer: &mut InferenceType, to_infer_idx: &mut usize,
 
        template_parts: &[InferenceTypePart], template_idx: &mut usize,
 
    ) -> Option<i32> {
 
        use InferenceTypePart as ITP;
 

	
 
        let to_infer_part = &to_infer.parts[*to_infer_idx];
 
        let template_part = &template_parts[*template_idx];
 

	
 
        // Check for programmer mistakes
 
        debug_assert_ne!(to_infer_part, template_part);
 
        debug_assert!(!to_infer_part.is_marker(), "marker encountered in 'infer part'");
 
        debug_assert!(!template_part.is_marker(), "marker encountered in 'template part'");
 

	
 
        // Inference of a somewhat-specified type
 
        if to_infer_part.may_be_inferred_from(template_part) {
 
            let depth_change = to_infer_part.depth_change();
 
            debug_assert_eq!(depth_change, template_part.depth_change());
 

	
 
            to_infer.parts[*to_infer_idx] = template_part.clone();
 

	
 
            *to_infer_idx += 1;
 
            *template_idx += 1;
 
            return Some(depth_change);
 
        }
 

	
 
        // Inference of a completely unknown type
 
        if *to_infer_part == ITP::Unknown {
 
            // template part is different, so cannot be unknown, hence copy the
 
            // entire subtree. Make sure not to copy markers.
 
            let template_end_idx = Self::find_subtree_end_idx(template_parts, *template_idx);
 
            to_infer.parts[*to_infer_idx] = template_parts[*template_idx].clone(); // first element
 

	
 
            *to_infer_idx += 1;
 
            for template_idx in *template_idx + 1..template_end_idx {
 
                let template_part = &template_parts[template_idx];
 
                if !template_part.is_marker() {
 
                    to_infer.parts.insert(*to_infer_idx, template_part.clone());
 
                    *to_infer_idx += 1;
 
                }
 
            }
 
            *template_idx = template_end_idx;
 

	
 
            // Note: by definition the LHS was Unknown and the RHS traversed a 
 
            // full subtree.
 
            return Some(-1);
 
        }
 

	
 
        None
 
    }
 

	
 
    /// Call that checks if the `to_check` part is compatible with the `infer`
 
    /// part. This is essentially a copy of `infer_part_for_single_type`, but
 
    /// without actually copying the type parts.
 
    fn check_part_for_single_type(
 
        to_check_parts: &[InferenceTypePart], to_check_idx: &mut usize,
 
        template_parts: &[InferenceTypePart], template_idx: &mut usize
 
    ) -> Option<i32> {
 
        use InferenceTypePart as ITP;
 

	
 
        let to_check_part = &to_check_parts[*to_check_idx];
 
        let template_part = &template_parts[*template_idx];
 

	
 
        // Checking programmer errors
 
        debug_assert_ne!(to_check_part, template_part);
 
        debug_assert!(!to_check_part.is_marker(), "marker encountered in 'to_check part'");
 
        debug_assert!(!template_part.is_marker(), "marker encountered in 'template part'");
 

	
 
        if to_check_part.may_be_inferred_from(template_part) {
 
            let depth_change = to_check_part.depth_change();
 
            debug_assert_eq!(depth_change, template_part.depth_change());
 
            *to_check_idx += 1;
 
            *template_idx += 1;
 
            return Some(depth_change);
 
        }
 

	
 
        if *to_check_part == ITP::Unknown {
 
            *to_check_idx += 1;
 
            *template_idx = Self::find_subtree_end_idx(template_parts, *template_idx);
 

	
 
            // By definition LHS and RHS had depth change of -1
 
            return Some(-1);
 
        }
 

	
 
        None
 
    }
 

	
 
    /// Attempts to infer types between two `InferenceType` instances. This 
 
    /// function is unsafe as it accepts pointers to work around Rust's 
 
    /// borrowing rules. The caller must ensure that the pointers are distinct.
 
    unsafe fn infer_subtrees_for_both_types(
 
        type_a: *mut InferenceType, start_idx_a: usize,
 
        type_b: *mut InferenceType, start_idx_b: usize
 
    ) -> DualInferenceResult {
 
        debug_assert!(!std::ptr::eq(type_a, type_b), "encountered pointers to the same inference type");
 
        let type_a = &mut *type_a;
 
        let type_b = &mut *type_b;
 

	
 
        let mut modified_a = false;
 
        let mut modified_b = false;
 
        let mut idx_a = start_idx_a;
 
        let mut idx_b = start_idx_b;
 
        let mut depth = 1;
 

	
 
        while depth > 0 {
 
            // Advance indices if we encounter markers or equal parts
 
            let part_a = &type_a.parts[idx_a];
 
            let part_b = &type_b.parts[idx_b];
 
            
 
            if part_a == part_b {
 
                let depth_change = part_a.depth_change();
 
                depth += depth_change;
 
                debug_assert_eq!(depth_change, part_b.depth_change());
 
                idx_a += 1;
 
                idx_b += 1;
 
                continue;
 
            }
 
            if part_a.is_marker() { idx_a += 1; continue; }
 
            if part_b.is_marker() { idx_b += 1; continue; }
 

	
 
            // Types are not equal and are both not markers
 
            if let Some(depth_change) = Self::infer_part_for_single_type(type_a, &mut idx_a, &type_b.parts, &mut idx_b) {
 
                depth += depth_change;
 
                modified_a = true;
 
                continue;
 
            }
 
            if let Some(depth_change) = Self::infer_part_for_single_type(type_b, &mut idx_b, &type_a.parts, &mut idx_a) {
 
                depth += depth_change;
 
                modified_b = true;
 
                continue;
 
            }
 

	
 
            // Types can not be inferred in any way: types must be incompatible
 
            return DualInferenceResult::Incompatible;
 
        }
 

	
 
        if modified_a { type_a.recompute_is_done(); }
 
        if modified_b { type_b.recompute_is_done(); }
 

	
 
        // If here then we completely inferred the subtrees.
 
        match (modified_a, modified_b) {
 
            (false, false) => DualInferenceResult::Neither,
 
            (false, true) => DualInferenceResult::Second,
 
            (true, false) => DualInferenceResult::First,
 
            (true, true) => DualInferenceResult::Both
 
        }
 
    }
 

	
 
    /// Attempts to infer the first subtree based on the template. Like
 
    /// `infer_subtrees_for_both_types`, but now only applying inference to
 
    /// `to_infer` based on the type information in `template`.
 
    fn infer_subtree_for_single_type(
 
        to_infer: &mut InferenceType, mut to_infer_idx: usize,
 
        template: &[InferenceTypePart], mut template_idx: usize,
 
    ) -> SingleInferenceResult {
 
        let mut modified = false;
 
        let mut depth = 1;
 

	
 
        while depth > 0 {
 
            let to_infer_part = &to_infer.parts[to_infer_idx];
 
            let template_part = &template[template_idx];
 

	
 
            if to_infer_part == template_part {
 
                let depth_change = to_infer_part.depth_change();
 
                depth += depth_change;
 
                debug_assert_eq!(depth_change, template_part.depth_change());
 
                to_infer_idx += 1;
 
                template_idx += 1;
 
                continue;
 
            }
 
            if to_infer_part.is_marker() { to_infer_idx += 1; continue; }
 
            if template_part.is_marker() { template_idx += 1; continue; }
 

	
 
            // Types are not equal and not markers. So check if we can infer 
 
            // anything
 
            if let Some(depth_change) = Self::infer_part_for_single_type(
 
                to_infer, &mut to_infer_idx, template, &mut template_idx
 
            ) {
 
                depth += depth_change;
 
                modified = true;
 
                continue;
 
            }
 

	
 
            // We cannot infer anything, but the template may still be 
 
            // compatible with the type we're inferring
 
            if let Some(depth_change) = Self::check_part_for_single_type(
 
                template, &mut template_idx, &to_infer.parts, &mut to_infer_idx
 
            ) {
 
                depth += depth_change;
 
                continue;
 
            }
 

	
 
            return SingleInferenceResult::Incompatible
 
        }
 

	
 
        if modified {
 
            to_infer.recompute_is_done();
 
            return SingleInferenceResult::Modified;
 
        } else {
 
            return SingleInferenceResult::Unmodified;
 
        }
 
    }
 

	
 
    /// Checks if both types are compatible, doesn't perform any inference
 
    fn check_subtrees(
 
        type_parts_a: &[InferenceTypePart], start_idx_a: usize,
 
        type_parts_b: &[InferenceTypePart], start_idx_b: usize
 
    ) -> bool {
 
        let mut depth = 1;
 
        let mut idx_a = start_idx_a;
 
        let mut idx_b = start_idx_b;
 

	
 
        while depth > 0 {
 
            let part_a = &type_parts_a[idx_a];
 
            let part_b = &type_parts_b[idx_b];
 

	
 
            if part_a == part_b {
 
                let depth_change = part_a.depth_change();
 
                depth += depth_change;
 
                debug_assert_eq!(depth_change, part_b.depth_change());
 
                idx_a += 1;
 
                idx_b += 1;
 
                continue;
 
            }
 
            
 
            if part_a.is_marker() { idx_a += 1; continue; }
 
            if part_b.is_marker() { idx_b += 1; continue; }
 

	
 
            if let Some(depth_change) = Self::check_part_for_single_type(
 
                type_parts_a, &mut idx_a, type_parts_b, &mut idx_b
 
            ) {
 
                depth += depth_change;
 
                continue;
 
            }
 
            if let Some(depth_change) = Self::check_part_for_single_type(
 
                type_parts_b, &mut idx_b, type_parts_a, &mut idx_a
 
            ) {
 
                depth += depth_change;
 
                continue;
 
            }
 

	
 
            return false;
 
        }
 

	
 
        true
 
    }
 

	
 
    /// Performs the conversion of the inference type into a concrete type.
 
    /// By calling this function you must make sure that no unspecified types
 
    /// (e.g. Unknown or IntegerLike) exist in the type.
 
    fn write_concrete_type(&self, concrete_type: &mut ConcreteType) {
 
        use InferenceTypePart as ITP;
 
        use ConcreteTypePart as CTP;
 

	
 
        // Make sure inference type is specified but concrete type is not yet specified
 
        debug_assert!(!self.parts.is_empty());
 
        debug_assert!(concrete_type.parts.is_empty());
 
        concrete_type.parts.reserve(self.parts.len());
 

	
 
        let mut idx = 0;
 
        while idx < self.parts.len() {
 
            let part = &self.parts[idx];
 
            let converted_part = match part {
 
                ITP::Marker(_) => {
 
                    // Markers are removed when writing to the concrete type.
 
                    idx += 1;
 
                    continue;
 
                },
 
                ITP::Unknown | ITP::NumberLike | ITP::IntegerLike | ITP::ArrayLike | ITP::PortLike => {
 
                    // Should not happen if type inferencing works correctly: we
 
                    // should have returned a programmer-readable error or have
 
                    // inferred all types.
 
                    unreachable!("attempted to convert inference type part {:?} into concrete type", part);
 
                },
 
                ITP::Void => CTP::Void,
 
                ITP::Message => CTP::Message,
 
                ITP::Bool => CTP::Bool,
 
                ITP::UInt8 => CTP::UInt8,
 
                ITP::UInt16 => CTP::UInt16,
 
                ITP::UInt32 => CTP::UInt32,
 
                ITP::UInt64 => CTP::UInt64,
 
                ITP::SInt8 => CTP::SInt8,
 
                ITP::SInt16 => CTP::SInt16,
 
                ITP::SInt32 => CTP::SInt32,
 
                ITP::SInt64 => CTP::SInt64,
 
                ITP::Character => CTP::Character,
 
                ITP::String => CTP::String,
 
                ITP::Array => CTP::Array,
 
                ITP::Slice => CTP::Slice,
 
                ITP::Input => CTP::Input,
 
                ITP::Output => CTP::Output,
 
                ITP::Instance(id, num) => CTP::Instance(*id, *num),
 
            };
 

	
 
            concrete_type.parts.push(converted_part);
 
            idx += 1;
 
        }
 
    }
 

	
 
    /// Writes a human-readable version of the type to a string. This is used
 
    /// to display error messages
 
    fn write_display_name(
 
        buffer: &mut String, heap: &Heap, parts: &[InferenceTypePart], mut idx: usize
 
    ) -> usize {
 
        use InferenceTypePart as ITP;
 

	
 
        match &parts[idx] {
 
            ITP::Marker(_marker_idx) => {
 
                if debug_log_enabled!() {
 
                    buffer.push_str(&format!("{{Marker:{}}}", *_marker_idx));
 
                }
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
            },
 
            ITP::Unknown => buffer.push_str("?"),
 
            ITP::NumberLike => buffer.push_str("numberlike"),
 
            ITP::IntegerLike => buffer.push_str("integerlike"),
 
            ITP::ArrayLike => {
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push_str("[?]");
 
            },
 
            ITP::PortLike => {
 
                buffer.push_str("portlike<");
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push('>');
 
            }
 
            ITP::Void => buffer.push_str("void"),
 
            ITP::Bool => buffer.push_str(KW_TYPE_BOOL_STR),
 
            ITP::UInt8 => buffer.push_str(KW_TYPE_UINT8_STR),
 
            ITP::UInt16 => buffer.push_str(KW_TYPE_UINT16_STR),
 
            ITP::UInt32 => buffer.push_str(KW_TYPE_UINT32_STR),
 
            ITP::UInt64 => buffer.push_str(KW_TYPE_UINT64_STR),
 
            ITP::SInt8 => buffer.push_str(KW_TYPE_SINT8_STR),
 
            ITP::SInt16 => buffer.push_str(KW_TYPE_SINT16_STR),
 
            ITP::SInt32 => buffer.push_str(KW_TYPE_SINT32_STR),
 
            ITP::SInt64 => buffer.push_str(KW_TYPE_SINT64_STR),
 
            ITP::Character => buffer.push_str(KW_TYPE_CHAR_STR),
 
            ITP::String => buffer.push_str(KW_TYPE_STRING_STR),
 
            ITP::Message => {
 
                buffer.push_str(KW_TYPE_MESSAGE_STR);
 
                buffer.push('<');
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push('>');
 
            },
 
            ITP::Array => {
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push_str("[]");
 
            },
 
            ITP::Slice => {
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push_str("[..]");
 
            },
 
            ITP::Input => {
 
                buffer.push_str(KW_TYPE_IN_PORT_STR);
 
                buffer.push('<');
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push('>');
 
            },
 
            ITP::Output => {
 
                buffer.push_str(KW_TYPE_OUT_PORT_STR);
 
                buffer.push('<');
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push('>');
 
            },
 
            ITP::Instance(definition_id, num_sub) => {
 
                let definition = &heap[*definition_id];
 
                buffer.push_str(definition.identifier().value.as_str());
 
                if *num_sub > 0 {
 
                    buffer.push('<');
 
                    idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                    for _sub_idx in 1..*num_sub {
 
                        buffer.push_str(", ");
 
                        idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                    }
 
                    buffer.push('>');
 
                }
 
            },
 
        }
 

	
 
        idx
 
    }
 

	
 
    /// Returns the display name of a (part of) the type tree. Will allocate a
 
    /// string.
 
    fn partial_display_name(heap: &Heap, parts: &[InferenceTypePart]) -> String {
 
        let mut buffer = String::with_capacity(parts.len() * 6);
 
        Self::write_display_name(&mut buffer, heap, parts, 0);
 
        buffer
 
    }
 

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

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

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

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

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

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

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

	
 
            self.idx += 1;
 
        }
 

	
 
        None
 
    }
 
}
 

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

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

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

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

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

	
 
pub(crate) struct ResolveQueueElement {
 
    pub(crate) root_id: RootId,
 
    pub(crate) definition_id: DefinitionId,
 
    pub(crate) monomorph_types: Vec<ConcreteType>,
 
    pub(crate) reserved_monomorph_idx: i32,
 
}
 

	
 
impl PartialEq for ResolveQueueElement {
 
    fn eq(&self, other: &Self) -> bool {
 
        return
 
            self.root_id == other.root_id &&
 
            self.definition_id == other.definition_id &&
 
            self.monomorph_types == other.monomorph_types;
 
    }
 
}
 
impl Eq for ResolveQueueElement {}
 

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

	
 
#[derive(Clone)]
 
struct InferenceExpression {
 
    expr_type: InferenceType,       // result type from expression
 
    expr_id: ExpressionId,          // expression that is evaluated
 
    field_or_monomorph_idx: i32,    // index of field, of index of monomorph array in type table
 
    extra_data_idx: i32,     // index of extra data needed for inference
 
}
 

	
 
impl Default for InferenceExpression {
 
    fn default() -> Self {
 
        Self{
 
            expr_type: InferenceType::default(),
 
            expr_id: ExpressionId::new_invalid(),
 
            field_or_monomorph_idx: -1,
 
            extra_data_idx: -1,
 
        }
 
    }
 
}
 

	
 
/// This particular visitor will recurse depth-first into the AST and ensures
 
/// that all expressions have the appropriate types.
 
pub(crate) struct PassTyping {
 
    // Current definition we're typechecking.
 
    reserved_idx: i32,
 
    definition_type: DefinitionType,
 
    poly_vars: Vec<ConcreteType>,
 

	
 
    // Buffers for iteration over substatements and subexpressions
 
    stmt_buffer: Vec<StatementId>,
 
    expr_buffer: Vec<ExpressionId>,
 

	
 
    // Mapping from parser type to inferred type. We attempt to continue to
 
    // specify these types until we're stuck or we've fully determined the type.
 
    var_types: HashMap<VariableId, VarData>,            // types of variables
 
    expr_types: Vec<InferenceExpression>,                     // will be transferred to type table at end
 
    extra_data: Vec<ExtraData>,       // data for polymorph inference
 
    // Keeping track of which expressions need to be reinferred because the
 
    // expressions they're linked to made progression on an associated type
 
    expr_queued: DequeSet<i32>,
 
}
 

	
 
// TODO: @Rename, this is used for a lot of type inferencing. It seems like
 
//  there is a different underlying architecture waiting to surface.
 
struct ExtraData {
 
    expr_id: ExpressionId, // the expression with which this data is associated
 
    definition_id: DefinitionId, // the definition, only used for user feedback
 
    /// Progression of polymorphic variables (if any)
 
    poly_vars: Vec<InferenceType>,
 
    /// Progression of types of call arguments or struct members
 
    embedded: Vec<InferenceType>,
 
    returned: InferenceType,
 
}
 

	
 
impl Default for ExtraData {
 
    fn default() -> Self {
 
        Self{
 
            expr_id: ExpressionId::new_invalid(),
 
            definition_id: DefinitionId::new_invalid(),
 
            poly_vars: Vec::new(),
 
            embedded: Vec::new(),
 
            returned: InferenceType::default(),
 
        }
 
    }
 
}
 

	
 
struct VarData {
 
    /// Type of the variable
 
    var_type: InferenceType,
 
    /// VariableExpressions that use the variable
 
    used_at: Vec<ExpressionId>,
 
    /// For channel statements we link to the other variable such that when one
 
    /// channel's interior type is resolved, we can also resolve the other one.
 
    linked_var: Option<VariableId>,
 
}
 

	
 
impl VarData {
 
    fn new_channel(var_type: InferenceType, other_port: VariableId) -> Self {
 
        Self{ var_type, used_at: Vec::new(), linked_var: Some(other_port) }
 
    }
 
    fn new_local(var_type: InferenceType) -> Self {
 
        Self{ var_type, used_at: Vec::new(), linked_var: None }
 
    }
 
}
 

	
 
impl PassTyping {
 
    pub(crate) fn new() -> Self {
 
        PassTyping {
 
            reserved_idx: -1,
 
            definition_type: DefinitionType::Function(FunctionDefinitionId::new_invalid()),
 
            poly_vars: Vec::new(),
 
            stmt_buffer: Vec::with_capacity(STMT_BUFFER_INIT_CAPACITY),
 
            expr_buffer: Vec::with_capacity(EXPR_BUFFER_INIT_CAPACITY),
 
            var_types: HashMap::new(),
 
            expr_types: Vec::new(),
 
            extra_data: Vec::new(),
 
            expr_queued: DequeSet::new(),
 
        }
 
    }
 

	
 
    // TODO: @cleanup Unsure about this, maybe a pattern will arise after
 
    //  a while.
 
    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 should_add_to_queue = match definition {
 
                Definition::Function(definition) => definition.poly_vars.is_empty(),
 
                Definition::Component(definition) => definition.poly_vars.is_empty(),
 
                Definition::Enum(_) | Definition::Struct(_) | Definition::Union(_) => false,
 
            };
 

	
 
            if should_add_to_queue {
 
                let reserved_idx = ctx.types.reserve_procedure_monomorph_index(definition_id, None);
 
                queue.push(ResolveQueueElement{
 
                    root_id,
 
                    definition_id: *definition_id,
 
                    monomorph_types: Vec::new(),
 
                    reserved_monomorph_idx: reserved_idx,
 
                })
 
            }
 
        }
 
    }
 

	
 
    pub(crate) fn handle_module_definition(
 
        &mut self, ctx: &mut Ctx, queue: &mut ResolveQueue, element: ResolveQueueElement
 
    ) -> VisitorResult {
 
        // Visit the definition
 
        debug_assert_eq!(ctx.module.root_id, element.root_id);
 
        self.reset();
 
        debug_assert!(self.poly_vars.is_empty());
 
        self.reserved_idx = element.reserved_monomorph_idx;
 
        self.poly_vars = element.monomorph_types;
 
        self.visit_definition(ctx, element.definition_id)?;
 

	
 
        // Keep resolving types
 
        self.resolve_types(ctx, queue)?;
 
        Ok(())
 
    }
 

	
 
    fn reset(&mut self) {
 
        self.reserved_idx = -1;
 
        self.definition_type = DefinitionType::Function(FunctionDefinitionId::new_invalid());
 
        self.poly_vars.clear();
 
        self.stmt_buffer.clear();
 
        self.expr_buffer.clear();
 
        self.var_types.clear();
 
        self.expr_types.clear();
 
        self.extra_data.clear();
 
        self.expr_queued.clear();
 
    }
 
}
 

	
 
impl Visitor2 for PassTyping {
 
    // Definitions
 

	
 
    fn visit_component_definition(&mut self, ctx: &mut Ctx, id: ComponentDefinitionId) -> VisitorResult {
 
        self.definition_type = DefinitionType::Component(id);
 

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

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

	
 
        // Reserve data for expression types
 
        debug_assert!(self.expr_types.is_empty());
 
        self.expr_types.resize(comp_def.num_expressions_in_body as usize, Default::default());
 

	
 
        // Visit parameters
 
        for param_id in comp_def.parameters.clone() {
 
            let param = &ctx.heap[param_id];
 
            let var_type = self.determine_inference_type_from_parser_type_elements(&param.parser_type.elements, true);
 
            debug_assert!(var_type.is_done, "expected component arguments to be concrete types");
 
            self.var_types.insert(param_id, VarData::new_local(var_type));
 
        }
 

	
 
        // Visit the body and all of its expressions
 
        let body_stmt_id = ctx.heap[id].body;
 
        self.visit_block_stmt(ctx, body_stmt_id)
 
    }
 

	
 
    fn visit_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();
 
                for concrete_part in &poly_var.parts {
 
                    infer_type_parts.push(InferenceTypePart::from(*concrete_part));
 
                }
 
                let infer_type = InferenceType::new(false, true, infer_type_parts);
 
                debug_log!(" - [{:03}] {:?}", idx, infer_type.display_name(&ctx.heap));
 
            }
 
        }
 
        debug_log!("{}", "-".repeat(50));
 

	
 
        // Reserve data for expression types
 
        debug_assert!(self.expr_types.is_empty());
 
        self.expr_types.resize(func_def.num_expressions_in_body as usize, Default::default());
 

	
 
        // Visit parameters
 
        for param_id in func_def.parameters.clone() {
 
            let param = &ctx.heap[param_id];
 
            let var_type = self.determine_inference_type_from_parser_type_elements(&param.parser_type.elements, true);
 
            debug_assert!(var_type.is_done, "expected function arguments to be concrete types");
 
            self.var_types.insert(param_id, VarData::new_local(var_type));
 
        }
 

	
 
        // Visit all of the expressions within the body
 
        let body_stmt_id = ctx.heap[id].body;
 
        self.visit_block_stmt(ctx, body_stmt_id)
 
    }
 

	
 
    // Statements
 

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

	
 
        for stmt_id in block.statements.clone() {
 
            self.visit_stmt(ctx, stmt_id)?;
 
        }
 

	
 
        Ok(())
 
    }
 

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

	
 
        let local = &ctx.heap[memory_stmt.variable];
 
        let var_type = self.determine_inference_type_from_parser_type_elements(&local.parser_type.elements, true);
 
        self.var_types.insert(memory_stmt.variable, VarData::new_local(var_type));
 

	
 
        Ok(())
 
    }
 

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

	
 
        let from_local = &ctx.heap[channel_stmt.from];
 
        let from_var_type = self.determine_inference_type_from_parser_type_elements(&from_local.parser_type.elements, true);
 
        self.var_types.insert(from_local.this, VarData::new_channel(from_var_type, channel_stmt.to));
 

	
 
        let to_local = &ctx.heap[channel_stmt.to];
 
        let to_var_type = self.determine_inference_type_from_parser_type_elements(&to_local.parser_type.elements, true);
 
        self.var_types.insert(to_local.this, VarData::new_channel(to_var_type, channel_stmt.from));
 

	
 
        Ok(())
 
    }
 

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

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

	
 
        let true_body_id = if_stmt.true_body;
 
        let false_body_id = if_stmt.false_body;
 
        let test_expr_id = if_stmt.test;
 

	
 
        self.visit_expr(ctx, test_expr_id)?;
 
        self.visit_block_stmt(ctx, true_body_id)?;
 
        if let Some(false_body_id) = false_body_id {
 
            self.visit_block_stmt(ctx, false_body_id)?;
 
        }
 

	
 
        Ok(())
 
    }
 

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

	
 
        let body_id = while_stmt.body;
 
        let test_expr_id = while_stmt.test;
 

	
 
        self.visit_expr(ctx, test_expr_id)?;
 
        self.visit_block_stmt(ctx, body_id)?;
 

	
 
        Ok(())
 
    }
 

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

	
 
        self.visit_block_stmt(ctx, body_id)
 
    }
 

	
 
    fn visit_return_stmt(&mut self, ctx: &mut Ctx, id: ReturnStatementId) -> VisitorResult {
 
        let return_stmt = &ctx.heap[id];
 
        debug_assert_eq!(return_stmt.expressions.len(), 1);
 
        let expr_id = return_stmt.expressions[0];
 

	
 
        self.visit_expr(ctx, expr_id)
 
    }
 

	
 
    fn visit_new_stmt(&mut self, ctx: &mut Ctx, id: NewStatementId) -> VisitorResult {
 
        let new_stmt = &ctx.heap[id];
 
        let call_expr_id = new_stmt.expression;
 

	
 
        self.visit_call_expr(ctx, call_expr_id)
 
    }
 

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

	
 
        self.visit_expr(ctx, subexpr_id)
 
    }
 

	
 
    // Expressions
 

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

	
 
        let assign_expr = &ctx.heap[id];
 
        let left_expr_id = assign_expr.left;
 
        let right_expr_id = assign_expr.right;
 

	
 
        self.visit_expr(ctx, left_expr_id)?;
 
        self.visit_expr(ctx, right_expr_id)?;
 

	
 
        self.progress_assignment_expr(ctx, id)
 
    }
 

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

	
 
        let binding_expr = &ctx.heap[id];
 
        let bound_to_id = binding_expr.bound_to;
 
        let bound_from_id = binding_expr.bound_from;
 

	
 
        self.visit_expr(ctx, bound_to_id)?;
 
        self.visit_expr(ctx, bound_from_id)?;
 

	
 
        self.progress_binding_expr(ctx, id)
 
    }
 

	
 
    fn visit_conditional_expr(&mut self, ctx: &mut Ctx, id: ConditionalExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let conditional_expr = &ctx.heap[id];
 
        let test_expr_id = conditional_expr.test;
 
        let true_expr_id = conditional_expr.true_expression;
 
        let false_expr_id = conditional_expr.false_expression;
 

	
 
        self.visit_expr(ctx, test_expr_id)?;
 
        self.visit_expr(ctx, true_expr_id)?;
 
        self.visit_expr(ctx, false_expr_id)?;
 

	
 
        self.progress_conditional_expr(ctx, id)
 
    }
 

	
 
    fn visit_binary_expr(&mut self, ctx: &mut Ctx, id: BinaryExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let binary_expr = &ctx.heap[id];
 
        let lhs_expr_id = binary_expr.left;
 
        let rhs_expr_id = binary_expr.right;
 

	
 
        self.visit_expr(ctx, lhs_expr_id)?;
 
        self.visit_expr(ctx, rhs_expr_id)?;
 

	
 
        self.progress_binary_expr(ctx, id)
 
    }
 

	
 
    fn visit_unary_expr(&mut self, ctx: &mut Ctx, id: UnaryExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let unary_expr = &ctx.heap[id];
 
        let arg_expr_id = unary_expr.expression;
 

	
 
        self.visit_expr(ctx, arg_expr_id)?;
 

	
 
        self.progress_unary_expr(ctx, id)
 
    }
 

	
 
    fn visit_indexing_expr(&mut self, ctx: &mut Ctx, id: IndexingExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let indexing_expr = &ctx.heap[id];
 
        let subject_expr_id = indexing_expr.subject;
 
        let index_expr_id = indexing_expr.index;
 

	
 
        self.visit_expr(ctx, subject_expr_id)?;
 
        self.visit_expr(ctx, index_expr_id)?;
 

	
 
        self.progress_indexing_expr(ctx, id)
 
    }
 

	
 
    fn visit_slicing_expr(&mut self, ctx: &mut Ctx, id: SlicingExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let slicing_expr = &ctx.heap[id];
 
        let subject_expr_id = slicing_expr.subject;
 
        let from_expr_id = slicing_expr.from_index;
 
        let to_expr_id = slicing_expr.to_index;
 

	
 
        self.visit_expr(ctx, subject_expr_id)?;
 
        self.visit_expr(ctx, from_expr_id)?;
 
        self.visit_expr(ctx, to_expr_id)?;
 

	
 
        self.progress_slicing_expr(ctx, id)
 
    }
 

	
 
    fn visit_select_expr(&mut self, ctx: &mut Ctx, id: SelectExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let select_expr = &ctx.heap[id];
 
        let subject_expr_id = select_expr.subject;
 

	
 
        self.visit_expr(ctx, subject_expr_id)?;
 

	
 
        self.progress_select_expr(ctx, id)
 
    }
 

	
 
    fn visit_literal_expr(&mut self, ctx: &mut Ctx, id: LiteralExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let literal_expr = &ctx.heap[id];
 
        match &literal_expr.value {
 
            Literal::Null | Literal::False | Literal::True |
 
            Literal::Integer(_) | Literal::Character(_) | Literal::String(_) => {
 
                // No subexpressions
 
            },
 
            Literal::Struct(literal) => {
 
                // TODO: @performance
 
                let expr_ids: Vec<_> = literal.fields
 
                    .iter()
 
                    .map(|f| f.value)
 
                    .collect();
 

	
 
                self.insert_initial_struct_polymorph_data(ctx, id);
 

	
 
                for expr_id in expr_ids {
 
                    self.visit_expr(ctx, expr_id)?;
 
                }
 
            },
 
            Literal::Enum(_) => {
 
                // Enumerations do not carry any subexpressions, but may still
 
                // have a user-defined polymorphic marker variable. For this 
 
                // reason we may still have to apply inference to this 
 
                // polymorphic variable
 
                self.insert_initial_enum_polymorph_data(ctx, id);
 
            },
 
            Literal::Union(literal) => {
 
                // May carry subexpressions and polymorphic arguments
 
                // TODO: @performance
 
                let expr_ids = literal.values.clone();
 
                self.insert_initial_union_polymorph_data(ctx, id);
 

	
 
                for expr_id in expr_ids {
 
                    self.visit_expr(ctx, expr_id)?;
 
                }
 
            },
 
            Literal::Array(expressions) => {
 
                // TODO: @performance
 
                let expr_ids = expressions.clone();
 
                for expr_id in expr_ids {
 
                    self.visit_expr(ctx, expr_id)?;
 
                }
 
            }
 
        }
 

	
 
        self.progress_literal_expr(ctx, id)
 
    }
 

	
 
    fn visit_cast_expr(&mut self, ctx: &mut Ctx, id: CastExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let cast_expr = &ctx.heap[id];
 
        let subject_expr_id = cast_expr.subject;
 

	
 
        self.visit_expr(ctx, subject_expr_id)?;
 

	
 
        self.progress_cast_expr(ctx, id)
 
    }
 

	
 
    fn visit_call_expr(&mut self, ctx: &mut Ctx, id: CallExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 
        self.insert_initial_call_polymorph_data(ctx, id);
 

	
 
        // By default we set the polymorph idx for calls to 0. If the call ends
 
        // up not being a polymorphic one, then we will select the default
 
        // expression types in the type table
 
        let call_expr = &ctx.heap[id];
 
        self.expr_types[call_expr.unique_id_in_definition as usize].field_or_monomorph_idx = 0;
 

	
 
        // Visit all arguments
 
        for arg_expr_id in call_expr.arguments.clone() { // TODO: @Performance
 
            self.visit_expr(ctx, arg_expr_id)?;
 
        }
 

	
 
        self.progress_call_expr(ctx, id)
 
    }
 

	
 
    fn visit_variable_expr(&mut self, ctx: &mut Ctx, id: VariableExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let var_expr = &ctx.heap[id];
 
        debug_assert!(var_expr.declaration.is_some());
 
        let var_data = self.var_types.get_mut(var_expr.declaration.as_ref().unwrap()).unwrap();
 
        var_data.used_at.push(upcast_id);
 

	
 
        self.progress_variable_expr(ctx, id)
 
    }
 
}
 

	
 
impl PassTyping {
 
    fn temp_get_display_name(&self, ctx: &Ctx, expr_id: ExpressionId) -> String {
 
        let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition();
 
        let expr_type = &self.expr_types[expr_idx as usize].expr_type;
 
        expr_type.display_name(&ctx.heap)
 
    }
 

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

	
 
        // Helper for transferring polymorphic variables to concrete types and
 
        // checking if they're completely specified
 
        fn poly_inference_to_concrete_type(
 
            ctx: &Ctx, expr_id: ExpressionId, inference: &Vec<InferenceType>
 
        ) -> Result<Vec<ConcreteType>, ParseError> {
 
            let mut concrete = Vec::with_capacity(inference.len());
 
            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::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.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)
 
                        )
 
                    ));
 
                }
 

	
 
                let mut concrete_type = ConcreteType::default();
 
                poly_type.write_concrete_type(&mut concrete_type);
 
                concrete.push(concrete_type);
 
            }
 

	
 
            Ok(concrete)
 
        }
 

	
 
        // Inference is now done. But we may still have uninferred types. So we
 
        // check for these.
 
        for (infer_expr_idx, infer_expr) in self.expr_types.iter_mut().enumerate() {
 
            let expr_type = &mut infer_expr.expr_type;
 
            if !expr_type.is_done {
 
                // Auto-infer numberlike/integerlike types to a regular int
 
                if expr_type.parts.len() == 1 && expr_type.parts[0] == InferenceTypePart::IntegerLike {
 
                    expr_type.parts[0] = InferenceTypePart::SInt32;
 
                    self.expr_queued.push_back(infer_expr_idx as i32);
 
                } else {
 
                    let expr = &ctx.heap[infer_expr.expr_id];
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module.source, expr.span(), format!(
 
                            "could not fully infer the type of this expression (got '{}')",
 
                            expr_type.display_name(&ctx.heap)
 
                        )
 
                    ));
 
                }
 
            }
 

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

	
 
            // Extra data is attached, perform typechecking and transfer
 
            // resolved information to the expression
 
            let extra_data = &self.extra_data[infer_expr.extra_data_idx as usize];
 
            if extra_data.poly_vars.is_empty() { continue; }
 

	
 
            // Note that only call and literal expressions need full inference.
 
            // Select expressions also use `extra_data`, but only for temporary
 
            // storage of the struct type whose field it is selecting.
 
            match &ctx.heap[extra_data.expr_id] {
 
                Expression::Call(expr) => {
 
                    if expr.method != Method::UserFunction && expr.method != Method::UserComponent {
 
                        // Builtin function
 
                        continue;
 
                    }
 

	
 
                    let definition_id = expr.definition;
 
                    let poly_types = poly_inference_to_concrete_type(ctx, extra_data.expr_id, &extra_data.poly_vars)?;
 

	
 
                    match ctx.types.get_procedure_monomorph_index(&definition_id, &poly_types) {
 
                        Some(reserved_idx) => {
 
                            // Already typechecked, or already put into the resolve queue
 
                            infer_expr.field_or_monomorph_idx = reserved_idx;
 
                        },
 
                        None => {
 
                            // Not typechecked yet, so add an entry in the queue
 
                            let reserved_idx = ctx.types.reserve_procedure_monomorph_index(&definition_id, Some(poly_types.clone()));
 
                            infer_expr.field_or_monomorph_idx = reserved_idx;
 
                            queue.push(ResolveQueueElement{
 
                                root_id: ctx.heap[definition_id].defined_in(),
 
                                definition_id,
 
                                monomorph_types: poly_types,
 
                                reserved_monomorph_idx: reserved_idx,
 
                            });
 
                        }
 
                    }
 
                },
 
                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 poly_types = poly_inference_to_concrete_type(ctx, extra_data.expr_id, &extra_data.poly_vars)?;
 
                    let mono_index = ctx.types.add_data_monomorph(&definition_id, poly_types);
 
                    infer_expr.field_or_monomorph_idx = mono_index;
 
                },
 
                Expression::Select(_) => {
 
                    debug_assert!(infer_expr.field_or_monomorph_idx >= 0);
 
                },
 
                _ => {
 
                    unreachable!("handling extra data for expression {:?}", &ctx.heap[extra_data.expr_id]);
 
                }
 
            }
 
        }
 

	
 
        // If we did any implicit type forcing, then our queue isn't empty
 
        // anymore
 
        while !self.expr_queued.is_empty() {
 
            let expr_idx = self.expr_queued.pop_back().unwrap();
 
            self.progress_expr(ctx, expr_idx)?;
 
        }
 

	
 
        // Every expression checked, and new monomorphs are queued. Transfer the
 
        // expression information to the type table.
 
        let definition_id = match &self.definition_type {
 
            DefinitionType::Component(id) => id.upcast(),
 
            DefinitionType::Function(id) => id.upcast(),
 
        };
 

	
 
        let target = ctx.types.get_procedure_expression_data_mut(&definition_id, self.reserved_idx);
 
        debug_assert!(target.poly_args == self.poly_vars);
 
        debug_assert!(target.expr_data.is_empty()); // makes sure we never queue something twice
 

	
 
        target.expr_data.reserve(self.expr_types.len());
 
        for infer_expr in self.expr_types.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_idx
 
            });
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    fn progress_expr(&mut self, ctx: &mut Ctx, idx: i32) -> Result<(), ParseError> {
 
        let id = self.expr_types[idx as usize].expr_id; // TODO: @Temp
 
        match &ctx.heap[id] {
 
            Expression::Assignment(expr) => {
 
                let id = expr.this;
 
                self.progress_assignment_expr(ctx, id)
 
            },
 
            Expression::Binding(_expr) => {
 
                unimplemented!("progress binding expression");
 
            Expression::Binding(expr) => {
 
                let id = expr.this;
 
                self.progress_binding_expr(ctx, id)
 
            },
 
            Expression::Conditional(expr) => {
 
                let id = expr.this;
 
                self.progress_conditional_expr(ctx, id)
 
            },
 
            Expression::Binary(expr) => {
 
                let id = expr.this;
 
                self.progress_binary_expr(ctx, id)
 
            },
 
            Expression::Unary(expr) => {
 
                let id = expr.this;
 
                self.progress_unary_expr(ctx, id)
 
            },
 
            Expression::Indexing(expr) => {
 
                let id = expr.this;
 
                self.progress_indexing_expr(ctx, id)
 
            },
 
            Expression::Slicing(expr) => {
 
                let id = expr.this;
 
                self.progress_slicing_expr(ctx, id)
 
            },
 
            Expression::Select(expr) => {
 
                let id = expr.this;
 
                self.progress_select_expr(ctx, id)
 
            },
 
            Expression::Literal(expr) => {
 
                let id = expr.this;
 
                self.progress_literal_expr(ctx, id)
 
            },
 
            Expression::Cast(expr) => {
 
                let id = expr.this;
 
                self.progress_cast_expr(ctx, id)
 
            },
 
            Expression::Call(expr) => {
 
                let id = expr.this;
 
                self.progress_call_expr(ctx, id)
 
            },
 
            Expression::Variable(expr) => {
 
                let id = expr.this;
 
                self.progress_variable_expr(ctx, id)
 
            }
 
        }
 
    }
 

	
 
    fn progress_assignment_expr(&mut self, ctx: &mut Ctx, id: AssignmentExpressionId) -> Result<(), ParseError> {
 
        use AssignmentOperator as AO;
 

	
 
        let upcast_id = id.upcast();
 

	
 
        let expr = &ctx.heap[id];
 
        let arg1_expr_id = expr.left;
 
        let arg2_expr_id = expr.right;
 

	
 
        debug_log!("Assignment expr '{:?}': {}", expr.operation, upcast_id.index);
 
        debug_log!(" * Before:");
 
        debug_log!("   - Arg1 type: {}", self.temp_get_display_name(ctx, arg1_expr_id));
 
        debug_log!("   - Arg2 type: {}", self.temp_get_display_name(ctx, arg2_expr_id));
 
        debug_log!("   - Expr type: {}", self.temp_get_display_name(ctx, upcast_id));
 

	
 
        // Assignment does not return anything (it operates like a statement)
 
        let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &VOID_TEMPLATE)?;
 

	
 
        // Apply forced constraint to LHS value
 
        let progress_forced = match expr.operation {
 
            AO::Set =>
 
                false,
 
            AO::Multiplied | AO::Divided | AO::Added | AO::Subtracted =>
 
                self.apply_forced_constraint(ctx, arg1_expr_id, &NUMBERLIKE_TEMPLATE)?,
 
            AO::Remained | AO::ShiftedLeft | AO::ShiftedRight |
 
            AO::BitwiseAnded | AO::BitwiseXored | AO::BitwiseOred =>
 
                self.apply_forced_constraint(ctx, arg1_expr_id, &INTEGERLIKE_TEMPLATE)?,
 
        };
 

	
 
        let (progress_arg1, progress_arg2) = self.apply_equal2_constraint(
 
            ctx, upcast_id, arg1_expr_id, 0, arg2_expr_id, 0
 
        )?;
 
        debug_assert!(if progress_forced { progress_arg2 } else { true });
 

	
 
        debug_log!(" * After:");
 
        debug_log!("   - Arg1 type [{}]: {}", progress_forced || progress_arg1, self.temp_get_display_name(ctx, arg1_expr_id));
 
        debug_log!("   - Arg2 type [{}]: {}", progress_arg2, self.temp_get_display_name(ctx, arg2_expr_id));
 
        debug_log!("   - Expr type [{}]: {}", progress_expr, self.temp_get_display_name(ctx, upcast_id));
 

	
 

	
 
        if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
 
        if progress_forced || progress_arg1 { self.queue_expr(ctx, arg1_expr_id); }
 
        if progress_arg2 { self.queue_expr(ctx, arg2_expr_id); }
 

	
 
        Ok(())
 
    }
 

	
 
    fn progress_binding_expr(&mut self, ctx: &mut Ctx, id: BindingExpressionId) -> Result<(), ParseError> {
 

	
 
    }
 

	
 
    fn progress_conditional_expr(&mut self, ctx: &mut Ctx, id: ConditionalExpressionId) -> Result<(), ParseError> {
 
        // Note: test expression type is already enforced
 
        let upcast_id = id.upcast();
 
        let expr = &ctx.heap[id];
 
        let arg1_expr_id = expr.true_expression;
 
        let arg2_expr_id = expr.false_expression;
 

	
 
        debug_log!("Conditional expr: {}", upcast_id.index);
 
        debug_log!(" * Before:");
 
        debug_log!("   - Arg1 type: {}", self.temp_get_display_name(ctx, arg1_expr_id));
 
        debug_log!("   - Arg2 type: {}", self.temp_get_display_name(ctx, arg2_expr_id));
 
        debug_log!("   - Expr type: {}", self.temp_get_display_name(ctx, upcast_id));
 

	
 
        let (progress_expr, progress_arg1, progress_arg2) = self.apply_equal3_constraint(
 
            ctx, upcast_id, arg1_expr_id, arg2_expr_id, 0
 
        )?;
 

	
 
        debug_log!(" * After:");
 
        debug_log!("   - Arg1 type [{}]: {}", progress_arg1, self.temp_get_display_name(ctx, arg1_expr_id));
 
        debug_log!("   - Arg2 type [{}]: {}", progress_arg2, self.temp_get_display_name(ctx, arg2_expr_id));
 
        debug_log!("   - Expr type [{}]: {}", progress_expr, self.temp_get_display_name(ctx, upcast_id));
 

	
 
        if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
 
        if progress_arg1 { self.queue_expr(ctx, arg1_expr_id); }
 
        if progress_arg2 { self.queue_expr(ctx, arg2_expr_id); }
 

	
 
        Ok(())
 
    }
 

	
 
    fn progress_binary_expr(&mut self, ctx: &mut Ctx, id: BinaryExpressionId) -> Result<(), ParseError> {
 
        // Note: our expression type might be fixed by our parent, but we still
 
        // need to make sure it matches the type associated with our operation.
 
        use BinaryOperator as BO;
 

	
 
        let upcast_id = id.upcast();
 
        let expr = &ctx.heap[id];
 
        let arg1_id = expr.left;
 
        let arg2_id = expr.right;
 

	
 
        debug_log!("Binary expr '{:?}': {}", expr.operation, upcast_id.index);
 
        debug_log!(" * Before:");
 
        debug_log!("   - Arg1 type: {}", self.temp_get_display_name(ctx, arg1_id));
 
        debug_log!("   - Arg2 type: {}", self.temp_get_display_name(ctx, arg2_id));
 
        debug_log!("   - Expr type: {}", self.temp_get_display_name(ctx, upcast_id));
 

	
 
        let (progress_expr, progress_arg1, progress_arg2) = match expr.operation {
 
            BO::Concatenate => {
 
                // Arguments may be arrays/slices, output is always an array
 
                let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &ARRAY_TEMPLATE)?;
 
                let progress_arg1 = self.apply_forced_constraint(ctx, arg1_id, &ARRAYLIKE_TEMPLATE)?;
 
                let progress_arg2 = self.apply_forced_constraint(ctx, arg2_id, &ARRAYLIKE_TEMPLATE)?;
 

	
 
                // If they're all arraylike, then we want the subtype to match
 
                let (subtype_expr, subtype_arg1, subtype_arg2) =
 
                    self.apply_equal3_constraint(ctx, upcast_id, arg1_id, arg2_id, 1)?;
 

	
 
                (progress_expr || subtype_expr, progress_arg1 || subtype_arg1, progress_arg2 || subtype_arg2)
 
            },
 
            BO::LogicalOr | BO::LogicalAnd => {
 
                // Forced boolean on all
 
                let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
 
                let progress_arg1 = self.apply_forced_constraint(ctx, arg1_id, &BOOL_TEMPLATE)?;
 
                let progress_arg2 = self.apply_forced_constraint(ctx, arg2_id, &BOOL_TEMPLATE)?;
 

	
 
                (progress_expr, progress_arg1, progress_arg2)
 
            },
 
            BO::BitwiseOr | BO::BitwiseXor | BO::BitwiseAnd | BO::Remainder | BO::ShiftLeft | BO::ShiftRight => {
 
                // All equal of integer type
 
                let progress_base = self.apply_forced_constraint(ctx, upcast_id, &INTEGERLIKE_TEMPLATE)?;
 
                let (progress_expr, progress_arg1, progress_arg2) =
 
                    self.apply_equal3_constraint(ctx, upcast_id, arg1_id, arg2_id, 0)?;
 

	
 
                (progress_base || progress_expr, progress_base || progress_arg1, progress_base || progress_arg2)
 
            },
 
            BO::Equality | BO::Inequality => {
 
                // Equal2 on args, forced boolean output
 
                let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
 
                let (progress_arg1, progress_arg2) =
 
                    self.apply_equal2_constraint(ctx, upcast_id, arg1_id, 0, arg2_id, 0)?;
 

	
 
                (progress_expr, progress_arg1, progress_arg2)
 
            },
 
            BO::LessThan | BO::GreaterThan | BO::LessThanEqual | BO::GreaterThanEqual => {
 
                // Equal2 on args with numberlike type, forced boolean output
 
                let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
 
                let progress_arg_base = self.apply_forced_constraint(ctx, arg1_id, &NUMBERLIKE_TEMPLATE)?;
 
                let (progress_arg1, progress_arg2) =
 
                    self.apply_equal2_constraint(ctx, upcast_id, arg1_id, 0, arg2_id, 0)?;
 

	
 
                (progress_expr, progress_arg_base || progress_arg1, progress_arg_base || progress_arg2)
 
            },
 
            BO::Add | BO::Subtract | BO::Multiply | BO::Divide => {
 
                // All equal of number type
 
                let progress_base = self.apply_forced_constraint(ctx, upcast_id, &NUMBERLIKE_TEMPLATE)?;
 
                let (progress_expr, progress_arg1, progress_arg2) =
 
                    self.apply_equal3_constraint(ctx, upcast_id, arg1_id, arg2_id, 0)?;
 

	
 
                (progress_base || progress_expr, progress_base || progress_arg1, progress_base || progress_arg2)
 
            },
 
        };
 

	
 
        debug_log!(" * After:");
 
        debug_log!("   - Arg1 type [{}]: {}", progress_arg1, self.temp_get_display_name(ctx, arg1_id));
 
        debug_log!("   - Arg2 type [{}]: {}", progress_arg2, self.temp_get_display_name(ctx, arg2_id));
 
        debug_log!("   - Expr type [{}]: {}", progress_expr, self.temp_get_display_name(ctx, upcast_id));
 

	
 
        if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
 
        if progress_arg1 { self.queue_expr(ctx, arg1_id); }
 
        if progress_arg2 { self.queue_expr(ctx, arg2_id); }
 

	
 
        Ok(())
 
    }
 

	
 
    fn progress_unary_expr(&mut self, ctx: &mut Ctx, id: UnaryExpressionId) -> Result<(), ParseError> {
 
        use UnaryOperator as UO;
 

	
 
        let upcast_id = id.upcast();
 
        let expr = &ctx.heap[id];
 
        let arg_id = expr.expression;
 

	
 
        debug_log!("Unary expr '{:?}': {}", expr.operation, upcast_id.index);
 
        debug_log!(" * Before:");
 
        debug_log!("   - Arg  type: {}", self.temp_get_display_name(ctx, arg_id));
 
        debug_log!("   - Expr type: {}", self.temp_get_display_name(ctx, upcast_id));
 

	
 
        let (progress_expr, progress_arg) = match expr.operation {
 
            UO::Positive | UO::Negative => {
 
                // Equal types of numeric class
 
                let progress_base = self.apply_forced_constraint(ctx, upcast_id, &NUMBERLIKE_TEMPLATE)?;
 
                let (progress_expr, progress_arg) =
 
                    self.apply_equal2_constraint(ctx, upcast_id, upcast_id, 0, arg_id, 0)?;
 

	
 
                (progress_base || progress_expr, progress_base || progress_arg)
 
            },
 
            UO::BitwiseNot | UO::PreIncrement | UO::PreDecrement | UO::PostIncrement | UO::PostDecrement => {
 
                // Equal types of integer class
 
                let progress_base = self.apply_forced_constraint(ctx, upcast_id, &INTEGERLIKE_TEMPLATE)?;
 
                let (progress_expr, progress_arg) =
 
                    self.apply_equal2_constraint(ctx, upcast_id, upcast_id, 0, arg_id, 0)?;
 

	
 
                (progress_base || progress_expr, progress_base || progress_arg)
 
            },
 
            UO::LogicalNot => {
 
                // Both booleans
 
                let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
 
                let progress_arg = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
 
                (progress_expr, progress_arg)
 
            }
 
        };
 

	
 
        debug_log!(" * After:");
 
        debug_log!("   - Arg  type [{}]: {}", progress_arg, self.temp_get_display_name(ctx, arg_id));
 
        debug_log!("   - Expr type [{}]: {}", progress_expr, self.temp_get_display_name(ctx, upcast_id));
 

	
 
        if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
 
        if progress_arg { self.queue_expr(ctx, arg_id); }
 

	
 
        Ok(())
 
    }
 

	
 
    fn progress_indexing_expr(&mut self, ctx: &mut Ctx, id: IndexingExpressionId) -> Result<(), ParseError> {
 
        let upcast_id = id.upcast();
 
        let expr = &ctx.heap[id];
 
        let subject_id = expr.subject;
 
        let index_id = expr.index;
 

	
 
        debug_log!("Indexing expr: {}", upcast_id.index);
 
        debug_log!(" * Before:");
 
        debug_log!("   - Subject type: {}", self.temp_get_display_name(ctx, subject_id));
 
        debug_log!("   - Index   type: {}", self.temp_get_display_name(ctx, index_id));
 
        debug_log!("   - Expr    type: {}", self.temp_get_display_name(ctx, upcast_id));
 

	
 
        // Make sure subject is arraylike and index is integerlike
 
        let progress_subject_base = self.apply_forced_constraint(ctx, subject_id, &ARRAYLIKE_TEMPLATE)?;
 
        let progress_index = self.apply_forced_constraint(ctx, index_id, &INTEGERLIKE_TEMPLATE)?;
 

	
 
        // Make sure if output is of T then subject is Array<T>
 
        let (progress_expr, progress_subject) =
 
            self.apply_equal2_constraint(ctx, upcast_id, upcast_id, 0, subject_id, 1)?;
 

	
 
        debug_log!(" * After:");
 
        debug_log!("   - Subject type [{}]: {}", progress_subject_base || progress_subject, self.temp_get_display_name(ctx, subject_id));
 
        debug_log!("   - Index   type [{}]: {}", progress_index, self.temp_get_display_name(ctx, index_id));
 
        debug_log!("   - Expr    type [{}]: {}", progress_expr, self.temp_get_display_name(ctx, upcast_id));
 

	
 
        if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
 
        if progress_subject_base || progress_subject { self.queue_expr(ctx, subject_id); }
 
        if progress_index { self.queue_expr(ctx, index_id); }
 

	
 
        Ok(())
 
    }
 

	
 
    fn progress_slicing_expr(&mut self, ctx: &mut Ctx, id: SlicingExpressionId) -> Result<(), ParseError> {
 
        let upcast_id = id.upcast();
 
        let expr = &ctx.heap[id];
 
        let subject_id = expr.subject;
 
        let from_id = expr.from_index;
 
        let to_id = expr.to_index;
 

	
 
        debug_log!("Slicing expr: {}", upcast_id.index);
 
        debug_log!(" * Before:");
 
        debug_log!("   - Subject type: {}", self.temp_get_display_name(ctx, subject_id));
 
        debug_log!("   - FromIdx type: {}", self.temp_get_display_name(ctx, from_id));
 
        debug_log!("   - ToIdx   type: {}", self.temp_get_display_name(ctx, to_id));
 
        debug_log!("   - Expr    type: {}", self.temp_get_display_name(ctx, upcast_id));
 

	
 
        // Make sure subject is arraylike and indices are of equal integerlike
 
        let progress_subject_base = self.apply_forced_constraint(ctx, subject_id, &ARRAYLIKE_TEMPLATE)?;
 
        let progress_idx_base = self.apply_forced_constraint(ctx, from_id, &INTEGERLIKE_TEMPLATE)?;
 
        let (progress_from, progress_to) = self.apply_equal2_constraint(ctx, upcast_id, from_id, 0, to_id, 0)?;
 

	
 
        // Make sure if output is of Slice<T> then subject is Array<T>
 
        let progress_expr_base = self.apply_forced_constraint(ctx, upcast_id, &SLICE_TEMPLATE)?;
 
        let (progress_expr, progress_subject) =
 
            self.apply_equal2_constraint(ctx, upcast_id, upcast_id, 1, subject_id, 1)?;
 

	
 

	
 
        debug_log!(" * After:");
 
        debug_log!("   - Subject type [{}]: {}", progress_subject_base || progress_subject, self.temp_get_display_name(ctx, subject_id));
 
        debug_log!("   - FromIdx type [{}]: {}", progress_idx_base || progress_from, self.temp_get_display_name(ctx, from_id));
 
        debug_log!("   - ToIdx   type [{}]: {}", progress_idx_base || progress_to, self.temp_get_display_name(ctx, to_id));
 
        debug_log!("   - Expr    type [{}]: {}", progress_expr, self.temp_get_display_name(ctx, upcast_id));
 

	
 
        if progress_expr_base || progress_expr { self.queue_expr_parent(ctx, upcast_id); }
 
        if progress_subject_base || progress_subject { self.queue_expr(ctx, subject_id); }
 
        if progress_idx_base || progress_from { self.queue_expr(ctx, from_id); }
 
        if progress_idx_base || progress_to { self.queue_expr(ctx, to_id); }
 

	
 
        Ok(())
 
    }
 

	
 
    fn progress_select_expr(&mut self, ctx: &mut Ctx, id: SelectExpressionId) -> Result<(), ParseError> {
 
        let upcast_id = id.upcast();
 
        
 
        debug_log!("Select expr: {}", upcast_id.index);
 
        debug_log!(" * Before:");
 
        debug_log!("   - Subject type: {}", self.temp_get_display_name(ctx, ctx.heap[id].subject));
 
        debug_log!("   - Expr    type: {}", self.temp_get_display_name(ctx, upcast_id));
 

	
 
        let subject_id = ctx.heap[id].subject;
 
        let subject_expr_idx = ctx.heap[subject_id].get_unique_id_in_definition();
 
        let select_expr = &ctx.heap[id];
 
        let expr_idx = select_expr.unique_id_in_definition;
 

	
 
        let infer_expr = &self.expr_types[expr_idx as usize];
 
        let extra_idx = infer_expr.extra_data_idx;
 

	
 
        fn determine_inference_type_instance<'a>(types: &'a TypeTable, infer_type: &InferenceType) -> Result<Option<&'a DefinedType>, ()> {
 
            for part in &infer_type.parts {
 
                if part.is_marker() || !part.is_concrete() {
 
                    continue;
 
                }
 

	
 
                // Part is concrete, check if it is an instance of something
 
                if let InferenceTypePart::Instance(definition_id, _num_sub) = part {
 
                    // Lookup type definition and ensure the specified field 
 
                    // name exists on the struct
 
                    let definition = types.get_base_definition(definition_id);
 
                    debug_assert!(definition.is_some());
 
                    let definition = definition.unwrap();
 

	
 
                    return Ok(Some(definition))
 
                } else {
 
                    // Expected an instance of something
 
                    return Err(())
 
                }
 
            }
 

	
 
            // Nothing is concrete yet
 
            Ok(None)
 
        }
 

	
 
        if infer_expr.field_or_monomorph_idx < 0 {
 
            // We don't know the field or the definition it is pointing to yet
 
            // Not yet known, check if we can determine it
 
            let subject_type = &self.expr_types[subject_expr_idx as usize].expr_type;
 
            let type_def = determine_inference_type_instance(&ctx.types, subject_type);
 

	
 
            match type_def {
 
                Ok(Some(type_def)) => {
 
                    // Subject type is known, check if it is a
 
                    // struct and the field exists on the struct
 
                    let struct_def = if let DefinedTypeVariant::Struct(struct_def) = &type_def.definition {
 
                        struct_def
 
                    } else {
 
                        return Err(ParseError::new_error_at_span(
 
                            &ctx.module.source, select_expr.field_name.span, format!(
 
                                "Can only apply field access to structs, got a subject of type '{}'",
 
                                subject_type.display_name(&ctx.heap)
 
                            )
 
                        ));
 
                    };
 

	
 
                    let mut struct_def_id = None;
 

	
 
                    for (field_def_idx, field_def) in struct_def.fields.iter().enumerate() {
 
                        if field_def.identifier == select_expr.field_name {
 
                            // Set field definition and index
 
                            let infer_expr = &mut self.expr_types[expr_idx as usize];
 
                            infer_expr.field_or_monomorph_idx = field_def_idx as i32;
 
                            struct_def_id = Some(type_def.ast_definition);
 
                            break;
 
                        }
 
                    }
 

	
 
                    if struct_def_id.is_none() {
 
                        let ast_struct_def = ctx.heap[type_def.ast_definition].as_struct();
 
                        return Err(ParseError::new_error_at_span(
 
                            &ctx.module.source, select_expr.field_name.span, format!(
 
                                "this field does not exist on the struct '{}'",
 
                                ast_struct_def.identifier.value.as_str()
 
                            )
 
                        ))
 
                    }
 

	
 
                    // Encountered definition and field index for the
 
                    // first time
 
                    self.insert_initial_select_polymorph_data(ctx, id, struct_def_id.unwrap());
 
                },
 
                Ok(None) => {
 
                    // Type of subject is not yet known, so we
 
                    // cannot make any progress yet
 
                    return Ok(())
 
                },
 
                Err(()) => {
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module.source, select_expr.field_name.span, format!(
 
                            "Can only apply field access to structs, got a subject of type '{}'",
 
                            subject_type.display_name(&ctx.heap)
 
                        )
 
                    ));
 
                }
 
            }
 
        }
 

	
 
        // If here then field index is known, and the referenced struct type
 
        // information is inserted into `extra_data`. Check to see if we can
 
        // do some mutual inference.
 
        let poly_data = &mut self.extra_data[extra_idx as usize];
 
        let mut poly_progress = HashSet::new();
 

	
 
        // Apply to struct's type
 
        let signature_type: *mut _ = &mut poly_data.embedded[0];
 
        let subject_type: *mut _ = &mut self.expr_types[subject_expr_idx as usize].expr_type;
 

	
 
        let (_, progress_subject) = Self::apply_equal2_signature_constraint(
 
            ctx, upcast_id, Some(subject_id), poly_data, &mut poly_progress,
 
            signature_type, 0, subject_type, 0
 
        )?;
 

	
 
        if progress_subject {
 
            self.expr_queued.push_back(subject_expr_idx);
 
        }
 

	
 
        // Apply to field's type
 
        let signature_type: *mut _ = &mut poly_data.returned;
 
        let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
 

	
 
        let (_, progress_expr) = Self::apply_equal2_signature_constraint(
 
            ctx, upcast_id, None, poly_data, &mut poly_progress,
 
            signature_type, 0, expr_type, 0
 
        )?;
 

	
 
        if progress_expr {
 
            if let Some(parent_id) = ctx.heap[upcast_id].parent_expr_id() {
 
                let parent_idx = ctx.heap[parent_id].get_unique_id_in_definition();
 
                self.expr_queued.push_back(parent_idx);
 
            }
 
        }
 

	
 
        // Reapply progress in polymorphic variables to struct's type
 
        let signature_type: *mut _ = &mut poly_data.embedded[0];
 
        let subject_type: *mut _ = &mut self.expr_types[subject_expr_idx as usize].expr_type;
 

	
 
        let progress_subject = Self::apply_equal2_polyvar_constraint(
 
            poly_data, &poly_progress, signature_type, subject_type
 
        );
 

	
 
        let signature_type: *mut _ = &mut poly_data.returned;
 
        let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
 

	
 
        let progress_expr = Self::apply_equal2_polyvar_constraint(
 
            poly_data, &poly_progress, signature_type, expr_type
 
        );
 

	
 
        if progress_subject { self.queue_expr(ctx, subject_id); }
 
        if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
 

	
 
        debug_log!(" * After:");
 
        debug_log!("   - Subject type [{}]: {}", progress_subject, self.temp_get_display_name(ctx, subject_id));
 
        debug_log!("   - Expr    type [{}]: {}", progress_expr, self.temp_get_display_name(ctx, upcast_id));
 

	
 
        Ok(())
 
    }
 

	
 
    fn progress_literal_expr(&mut self, ctx: &mut Ctx, id: LiteralExpressionId) -> Result<(), ParseError> {
 
        let upcast_id = id.upcast();
 
        let expr = &ctx.heap[id];
 
        let expr_idx = expr.unique_id_in_definition;
 
        let extra_idx = self.expr_types[expr_idx as usize].extra_data_idx;
 

	
 
        debug_log!("Literal expr: {}", upcast_id.index);
 
        debug_log!(" * Before:");
 
        debug_log!("   - Expr type: {}", self.temp_get_display_name(ctx, upcast_id));
 

	
 
        let progress_expr = match &expr.value {
 
            Literal::Null => {
 
                self.apply_forced_constraint(ctx, upcast_id, &MESSAGE_TEMPLATE)?
 
            },
 
            Literal::Integer(_) => {
 
                self.apply_forced_constraint(ctx, upcast_id, &INTEGERLIKE_TEMPLATE)?
 
            },
 
            Literal::True | Literal::False => {
 
                self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?
 
            },
 
            Literal::Character(_) => {
 
                self.apply_forced_constraint(ctx, upcast_id, &CHARACTER_TEMPLATE)?
 
            },
 
            Literal::String(_) => {
 
                self.apply_forced_constraint(ctx, upcast_id, &STRING_TEMPLATE)?
 
            },
 
            Literal::Struct(data) => {
 
                let extra = &mut self.extra_data[extra_idx as usize];
 
                for _poly in &extra.poly_vars {
 
                    debug_log!(" * Poly: {}", _poly.display_name(&ctx.heap));
 
                }
 
                let mut poly_progress = HashSet::new();
 
                debug_assert_eq!(extra.embedded.len(), data.fields.len());
 

	
 
                debug_log!(" * During (inferring types from fields and struct type):");
 

	
 
                // Mutually infer field signature/expression types
 
                for (field_idx, field) in data.fields.iter().enumerate() {
 
                    let field_expr_id = field.value;
 
                    let field_expr_idx = ctx.heap[field_expr_id].get_unique_id_in_definition();
 
                    let signature_type: *mut _ = &mut extra.embedded[field_idx];
 
                    let field_type: *mut _ = &mut self.expr_types[field_expr_idx as usize].expr_type;
 
                    let (_, progress_arg) = Self::apply_equal2_signature_constraint(
 
                        ctx, upcast_id, Some(field_expr_id), extra, &mut poly_progress,
 
                        signature_type, 0, field_type, 0
 
                    )?;
 

	
 
                    debug_log!(
 
                        "   - Field {} type | sig: {}, field: {}", field_idx,
 
                        unsafe{&*signature_type}.display_name(&ctx.heap),
 
                        unsafe{&*field_type}.display_name(&ctx.heap)
 
                    );
 

	
 
                    if progress_arg {
 
                        self.expr_queued.push_back(field_expr_idx);
 
                    }
 
                }
 

	
 
                debug_log!("   - Field poly progress | {:?}", poly_progress);
 

	
 
                // Same for the type of the struct itself
 
                let signature_type: *mut _ = &mut extra.returned;
 
                let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
 
                let (_, progress_expr) = Self::apply_equal2_signature_constraint(
 
                    ctx, upcast_id, None, extra, &mut poly_progress,
 
                    signature_type, 0, expr_type, 0
 
                )?;
 

	
 
                debug_log!(
 
                    "   - Ret type | sig: {}, expr: {}",
 
                    unsafe{&*signature_type}.display_name(&ctx.heap),
 
                    unsafe{&*expr_type}.display_name(&ctx.heap)
 
                );
 
                debug_log!("   - Ret poly progress | {:?}", poly_progress);
 

	
 
                if progress_expr {
 
                    // TODO: @cleanup, cannot call utility self.queue_parent thingo
 
                    if let Some(parent_id) = ctx.heap[upcast_id].parent_expr_id() {
 
                        let parent_idx = ctx.heap[parent_id].get_unique_id_in_definition();
 
                        self.expr_queued.push_back(parent_idx);
 
                    }
 
                }
 

	
 
                // Check which expressions use the polymorphic arguments. If the
 
                // polymorphic variables have been progressed then we try to 
 
                // progress them inside the expression as well.
 
                debug_log!(" * During (reinferring from progressed polyvars):");
 

	
 
                // For all field expressions
 
                for field_idx in 0..extra.embedded.len() {
 
                    // Note: fields in extra.embedded are in the same order as
 
                    // they are specified in the literal. Whereas
 
                    // `data.fields[...].field_idx` points to the field in the
 
                    // struct definition.
 
                    let signature_type: *mut _ = &mut extra.embedded[field_idx];
 
                    let field_expr_id = data.fields[field_idx].value;
 
                    let field_expr_idx = ctx.heap[field_expr_id].get_unique_id_in_definition();
 
                    let field_type: *mut _ = &mut self.expr_types[field_expr_idx as usize].expr_type;
 

	
 
                    let progress_arg = Self::apply_equal2_polyvar_constraint(
 
                        extra, &poly_progress, signature_type, field_type
 
                    );
 

	
 
                    debug_log!(
 
                        "   - Field {} type | sig: {}, field: {}", field_idx,
 
                        unsafe{&*signature_type}.display_name(&ctx.heap),
 
                        unsafe{&*field_type}.display_name(&ctx.heap)
 
                    );
 
                    if progress_arg {
 
                        self.expr_queued.push_back(field_expr_idx);
 
                    }
 
                }
 
                
 
                // For the return type
 
                let signature_type: *mut _ = &mut extra.returned;
 
                let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
 

	
 
                let progress_expr = Self::apply_equal2_polyvar_constraint(
 
                    extra, &poly_progress, signature_type, expr_type
 
                );
 

	
 
                progress_expr
 
            },
 
            Literal::Enum(_) => {
 
                let extra = &mut self.extra_data[extra_idx as usize];
 
                for _poly in &extra.poly_vars {
 
                    debug_log!(" * Poly: {}", _poly.display_name(&ctx.heap));
 
                }
 
                let mut poly_progress = HashSet::new();
 
                
 
                debug_log!(" * During (inferring types from return type)");
 

	
 
                let signature_type: *mut _ = &mut extra.returned;
 
                let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
 
                let (_, progress_expr) = Self::apply_equal2_signature_constraint(
 
                    ctx, upcast_id, None, extra, &mut poly_progress,
 
                    signature_type, 0, expr_type, 0
 
                )?;
 

	
 
                debug_log!(
 
                    "   - Ret type | sig: {}, expr: {}",
 
                    unsafe{&*signature_type}.display_name(&ctx.heap),
 
                    unsafe{&*expr_type}.display_name(&ctx.heap)
 
                );
 

	
 
                if progress_expr {
 
                    // TODO: @cleanup
 
                    if let Some(parent_id) = ctx.heap[upcast_id].parent_expr_id() {
 
                        let parent_idx = ctx.heap[parent_id].get_unique_id_in_definition();
 
                        self.expr_queued.push_back(parent_idx);
 
                    }
 
                }
 

	
 
                debug_log!(" * During (reinferring from progress polyvars):");
 
                let progress_expr = Self::apply_equal2_polyvar_constraint(
 
                    extra, &poly_progress, signature_type, expr_type
 
                );
 

	
 
                progress_expr
 
            },
 
            Literal::Union(data) => {
 
                let extra = &mut self.extra_data[extra_idx as usize];
 
                for _poly in &extra.poly_vars {
 
                    debug_log!(" * Poly: {}", _poly.display_name(&ctx.heap));
 
                }
 
                let mut poly_progress = HashSet::new();
 
                debug_assert_eq!(extra.embedded.len(), data.values.len());
 

	
 
                debug_log!(" * During (inferring types from variant values and union type):");
 

	
 
                // Mutually infer union variant values
 
                for (value_idx, value_expr_id) in data.values.iter().enumerate() {
 
                    let value_expr_id = *value_expr_id;
 
                    let value_expr_idx = ctx.heap[value_expr_id].get_unique_id_in_definition();
 
                    let signature_type: *mut _ = &mut extra.embedded[value_idx];
 
                    let value_type: *mut _ = &mut self.expr_types[value_expr_idx as usize].expr_type;
 
                    let (_, progress_arg) = Self::apply_equal2_signature_constraint(
 
                        ctx, upcast_id, Some(value_expr_id), extra, &mut poly_progress,
 
                        signature_type, 0, value_type, 0 
 
                    )?;
 

	
 
                    debug_log!(
 
                        "   - Value {} type | sig: {}, field: {}", value_idx,
 
                        unsafe{&*signature_type}.display_name(&ctx.heap),
 
                        unsafe{&*value_type}.display_name(&ctx.heap)
 
                    );
 

	
 
                    if progress_arg {
 
                        self.expr_queued.push_back(value_expr_idx);
 
                    }
 
                }
 

	
 
                debug_log!("   - Field poly progress | {:?}", poly_progress);
 

	
 
                // Infer type of union itself
 
                let signature_type: *mut _ = &mut extra.returned;
 
                let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
 
                let (_, progress_expr) = Self::apply_equal2_signature_constraint(
 
                    ctx, upcast_id, None, extra, &mut poly_progress,
 
                    signature_type, 0, expr_type, 0
 
                )?;
 

	
 
                debug_log!(
 
                    "   - Ret type | sig: {}, expr: {}",
 
                    unsafe{&*signature_type}.display_name(&ctx.heap),
 
                    unsafe{&*expr_type}.display_name(&ctx.heap)
 
                );
 
                debug_log!("   - Ret poly progress | {:?}", poly_progress);
 

	
 
                if progress_expr {
 
                    // TODO: @cleanup, borrowing rules
 
                    if let Some(parent_id) = ctx.heap[upcast_id].parent_expr_id() {
 
                        let parent_idx = ctx.heap[parent_id].get_unique_id_in_definition();
 
                        self.expr_queued.push_back(parent_idx);
 
                    }
 
                }
 

	
 
                debug_log!(" * During (reinferring from progress polyvars):");
 
            
 
                // For all embedded values of the union variant
 
                for value_idx in 0..extra.embedded.len() {
 
                    let signature_type: *mut _ = &mut extra.embedded[value_idx];
 
                    let value_expr_id = data.values[value_idx];
 
                    let value_expr_idx = ctx.heap[value_expr_id].get_unique_id_in_definition();
 
                    let value_type: *mut _ = &mut self.expr_types[value_expr_idx as usize].expr_type;
 
                    
 
                    let progress_arg = Self::apply_equal2_polyvar_constraint(
 
                        extra, &poly_progress, signature_type, value_type
 
                    );
 

	
 
                    debug_log!(
 
                        "   - Value {} type | sig: {}, value: {}", value_idx,
 
                        unsafe{&*signature_type}.display_name(&ctx.heap),
 
                        unsafe{&*value_type}.display_name(&ctx.heap)
 
                    );
 
                    if progress_arg {
 
                        self.expr_queued.push_back(value_expr_idx);
 
                    }
 
                }
 

	
 
                // And for the union type itself
 
                let signature_type: *mut _ = &mut extra.returned;
 
                let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
 

	
 
                let progress_expr = Self::apply_equal2_polyvar_constraint(
 
                    extra, &poly_progress, signature_type, expr_type
 
                );
 

	
 
                progress_expr
 
            },
 
            Literal::Array(data) => {
 
                let expr_elements = data.clone(); // TODO: @performance
 
                debug_log!("Array expr ({} elements): {}", expr_elements.len(), upcast_id.index);
 
                debug_log!(" * Before:");
 
                debug_log!("   - Expr type: {}", self.temp_get_display_name(ctx, upcast_id));
 

	
 
                // All elements should have an equal type
 
                let progress = self.apply_equal_n_constraint(ctx, upcast_id, &expr_elements)?;
 
                for (progress_arg, arg_id) in progress.iter().zip(expr_elements.iter()) {
 
                    if *progress_arg {
 
                        self.queue_expr(ctx, *arg_id);
 
                    }
 
                }
 

	
 
                // And the output should be an array of the element types
 
                let mut progress_expr = self.apply_forced_constraint(ctx, upcast_id, &ARRAY_TEMPLATE)?;
 
                if !expr_elements.is_empty() {
 
                    let first_arg_id = expr_elements[0];
 
                    let (inner_expr_progress, arg_progress) = self.apply_equal2_constraint(
 
                        ctx, upcast_id, upcast_id, 1, first_arg_id, 0
 
                    )?;
 

	
 
                    progress_expr = progress_expr || inner_expr_progress;
 

	
 
                    // Note that if the array type progressed the type of the arguments,
 
                    // then we should enqueue this progression function again
 
                    // TODO: @fix Make apply_equal_n accept a start idx as well
 
                    if arg_progress { self.queue_expr(ctx, upcast_id); }
 
                }
 

	
 
                debug_log!(" * After:");
 
                debug_log!("   - Expr type [{}]: {}", progress_expr, self.temp_get_display_name(ctx, upcast_id));
 

	
 
                progress_expr
 
            },
 
        };
 

	
 
        debug_log!(" * After:");
 
        debug_log!("   - Expr type: {}", self.temp_get_display_name(ctx, upcast_id));
 

	
 
        // TODO: FIX!!!!
 
        if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
 

	
 

	
 
        Ok(())
 
    }
 

	
 
    fn progress_cast_expr(&mut self, ctx: &mut Ctx, id: CastExpressionId) -> Result<(), ParseError> {
 
        let upcast_id = id.upcast();
 
        let expr = &ctx.heap[id];
 
        let expr_idx = expr.unique_id_in_definition;
 

	
 
        // The cast expression might have its output type fixed by the
 
        // programmer, so apply that type to the output. Apart from that casting
 
        // acts like a blocker for two-way inference. So we'll just have to wait
 
        // until we know if the cast is valid.
 
        // TODO: Another thing that has to be updated the moment the type
 
        //  inferencer is fully index/job-based
 
        let infer_type = self.determine_inference_type_from_parser_type_elements(&expr.to_type.elements, true);
 
        let expr_progress = self.apply_forced_constraint(ctx, upcast_id, &infer_type.parts)?;
 

	
 
        if expr_progress {
 
            self.queue_expr_parent(ctx, upcast_id);
 
        }
 

	
 
        // Check if the two types are compatible
 
        let subject_idx = ctx.heap[expr.subject].get_unique_id_in_definition();
 
        let expr_type = &self.expr_types[expr_idx as usize].expr_type;
 
        let subject_type = &self.expr_types[subject_idx as usize].expr_type;
 
        if !expr_type.is_done || !subject_type.is_done {
 
            // Not yet done
 
            return Ok(())
 
        }
 

	
 
        // Valid casts: (bool, integer, character) can always be cast to one
 
        // another. A cast from a type to itself is also valid.
 
        fn is_bool_int_or_char(parts: &[InferenceTypePart]) -> bool {
 
            return parts.len() == 1 && (
 
                parts[0] == InferenceTypePart::Bool ||
 
                parts[0] == InferenceTypePart::Character ||
 
                parts[0].is_concrete_integer()
 
            );
 
        }
 

	
 
        let is_valid = if is_bool_int_or_char(&expr_type.parts) && is_bool_int_or_char(&subject_type.parts) {
 
            true
 
        } else if expr_type.parts == subject_type.parts {
 
            true
 
        } else {
 
            false
 
        };
 

	
 
        if !is_valid {
 
            let cast_expr = &ctx.heap[id];
 
            let subject_expr = &ctx.heap[cast_expr.subject];
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module.source, cast_expr.span, "invalid casting operation"
 
            ).with_info_at_span(
 
                &ctx.module.source, subject_expr.span(), format!(
 
                    "cannot cast this type '{}' to the cast type '{}'",
 
                    subject_type.display_name(&ctx.heap),
 
                    expr_type.display_name(&ctx.heap)
 
                )
 
            ));
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    // TODO: @cleanup, see how this can be cleaned up once I implement
 
    //  polymorphic struct/enum/union literals. These likely follow the same
 
    //  pattern as here.
 
    fn progress_call_expr(&mut self, ctx: &mut Ctx, id: CallExpressionId) -> Result<(), ParseError> {
 
        let upcast_id = id.upcast();
 
        let expr = &ctx.heap[id];
 
        let expr_idx = expr.unique_id_in_definition;
 
        let extra_idx = self.expr_types[expr_idx as usize].extra_data_idx;
 

	
 
        debug_log!("Call expr '{}': {}", ctx.heap[expr.definition].identifier().value.as_str(), upcast_id.index);
 
        debug_log!(" * Before:");
 
        debug_log!("   - Expr type: {}", self.temp_get_display_name(ctx, upcast_id));
 
        debug_log!(" * During (inferring types from arguments and return type):");
 

	
 
        let extra = &mut self.extra_data[extra_idx as usize];
 

	
 
        // Check if we can make progress using the arguments and/or return types
 
        // while keeping track of the polyvars we've extended
 
        let mut poly_progress = HashSet::new();
 
        debug_assert_eq!(extra.embedded.len(), expr.arguments.len());
 

	
 
        for (call_arg_idx, arg_id) in expr.arguments.clone().into_iter().enumerate() {
 
            let arg_expr_idx = ctx.heap[arg_id].get_unique_id_in_definition();
 
            let signature_type: *mut _ = &mut extra.embedded[call_arg_idx];
 
            let argument_type: *mut _ = &mut self.expr_types[arg_expr_idx as usize].expr_type;
 
            let (_, progress_arg) = Self::apply_equal2_signature_constraint(
 
                ctx, upcast_id, Some(arg_id), extra, &mut poly_progress,
 
                signature_type, 0, argument_type, 0
 
            )?;
 

	
 
            debug_log!(
 
                "   - Arg {} type | sig: {}, arg: {}", call_arg_idx,
 
                unsafe{&*signature_type}.display_name(&ctx.heap), 
 
                unsafe{&*argument_type}.display_name(&ctx.heap));
 

	
 
            if progress_arg {
 
                // Progressed argument expression
 
                self.expr_queued.push_back(arg_expr_idx);
 
            }
 
        }
 

	
 
        // Do the same for the return type
 
        let signature_type: *mut _ = &mut extra.returned;
 
        let expr_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
 
        let (_, progress_expr) = Self::apply_equal2_signature_constraint(
 
            ctx, upcast_id, None, extra, &mut poly_progress,
 
            signature_type, 0, expr_type, 0
 
        )?;
 

	
 
        debug_log!(
 
            "   - Ret type | sig: {}, expr: {}", 
 
            unsafe{&*signature_type}.display_name(&ctx.heap), 
 
            unsafe{&*expr_type}.display_name(&ctx.heap)
 
        );
 

	
 
        if progress_expr {
 
            // TODO: @cleanup, cannot call utility self.queue_parent thingo
 
            if let Some(parent_id) = ctx.heap[upcast_id].parent_expr_id() {
 
                let parent_idx = ctx.heap[parent_id].get_unique_id_in_definition();
 
                self.expr_queued.push_back(parent_idx);
 
            }
 
        }
 

	
 
        // If we did not have an error in the polymorph inference above, then
 
        // reapplying the polymorph type to each argument type and the return
 
        // type should always succeed.
 
        debug_log!(" * During (reinferring from progressed polyvars):");
 
        for (_poly_idx, _poly_var) in extra.poly_vars.iter().enumerate() {
 
            debug_log!("   - Poly {} | sig: {}", _poly_idx, _poly_var.display_name(&ctx.heap));
 
        }
 
        // TODO: @performance If the algorithm is changed to be more "on demand
 
        //  argument re-evaluation", instead of "all-argument re-evaluation",
 
        //  then this is no longer true
 
        for arg_idx in 0..extra.embedded.len() {
 
            let signature_type: *mut _ = &mut extra.embedded[arg_idx];
 
            let arg_expr_id = expr.arguments[arg_idx];
 
            let arg_expr_idx = ctx.heap[arg_expr_id].get_unique_id_in_definition();
 
            let arg_type: *mut _ = &mut self.expr_types[arg_expr_idx as usize].expr_type;
 
            
 
            let progress_arg = Self::apply_equal2_polyvar_constraint(
 
                extra, &poly_progress,
 
                signature_type, arg_type
 
            );
 
            
 
            debug_log!(
 
                "   - Arg {} type | sig: {}, arg: {}", arg_idx, 
 
                unsafe{&*signature_type}.display_name(&ctx.heap), 
 
                unsafe{&*arg_type}.display_name(&ctx.heap)
 
            );
 
            if progress_arg {
 
                self.expr_queued.push_back(arg_expr_idx);
 
            }
 
        }
 

	
 
        // Once more for the return type
 
        let signature_type: *mut _ = &mut extra.returned;
 
        let ret_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
 

	
 
        let progress_ret = Self::apply_equal2_polyvar_constraint(
 
            extra, &poly_progress, signature_type, ret_type
 
        );
 
        debug_log!(
 
            "   - Ret type | sig: {}, arg: {}", 
 
            unsafe{&*signature_type}.display_name(&ctx.heap), 
 
            unsafe{&*ret_type}.display_name(&ctx.heap)
 
        );
 
        if progress_ret {
 
            self.queue_expr_parent(ctx, upcast_id);
 
        }
 

	
 
        debug_log!(" * After:");
 
        debug_log!("   - Expr type: {}", self.temp_get_display_name(ctx, upcast_id));
 

	
 
        Ok(())
 
    }
 

	
 
    fn progress_variable_expr(&mut self, ctx: &mut Ctx, id: VariableExpressionId) -> Result<(), ParseError> {
 
        let upcast_id = id.upcast();
 
        let var_expr = &ctx.heap[id];
 
        let var_expr_idx = var_expr.unique_id_in_definition;
 
        let var_id = var_expr.declaration.unwrap();
 

	
 
        debug_log!("Variable expr '{}': {}", ctx.heap[var_id].identifier.value.as_str(), upcast_id.index);
 
        debug_log!(" * Before:");
 
        debug_log!("   - Var  type: {}", self.var_types.get(&var_id).unwrap().var_type.display_name(&ctx.heap));
 
        debug_log!("   - Expr type: {}", self.temp_get_display_name(ctx, upcast_id));
 

	
 
        // Retrieve shared variable type and expression type and apply inference
 
        let var_data = self.var_types.get_mut(&var_id).unwrap();
 
        let expr_type = &mut self.expr_types[var_expr_idx as usize].expr_type;
 

	
 
        let infer_res = unsafe{ InferenceType::infer_subtrees_for_both_types(
 
            &mut var_data.var_type as *mut _, 0, expr_type, 0
 
        ) };
 
        if infer_res == DualInferenceResult::Incompatible {
 
            let var_decl = &ctx.heap[var_id];
 
            return Err(ParseError::new_error_at_span(
 
                &ctx.module.source, var_decl.identifier.span, format!(
 
                    "Conflicting types for this variable, previously assigned the type '{}'",
 
                    var_data.var_type.display_name(&ctx.heap)
 
                )
 
            ).with_info_at_span(
 
                &ctx.module.source, var_expr.identifier.span, format!(
 
                    "But inferred to have incompatible type '{}' here",
 
                    expr_type.display_name(&ctx.heap)
 
                )
 
            ))
 
        }
 

	
 
        let progress_var = infer_res.modified_lhs();
 
        let progress_expr = infer_res.modified_rhs();
 

	
 
        if progress_var {
 
            // Let other variable expressions using this type progress as well
 
            for other_expr in var_data.used_at.iter() {
 
                if *other_expr != upcast_id {
 
                    let other_expr_idx = ctx.heap[*other_expr].get_unique_id_in_definition();
 
                    self.expr_queued.push_back(other_expr_idx);
 
                }
 
            }
 

	
 
            // Let a linked port know that our type has updated
 
            if let Some(linked_id) = var_data.linked_var {
 
                // Only perform one-way inference to prevent updating our type,
 
                // this would lead to an inconsistency in the type inference
 
                // algorithm otherwise.
 
                let var_type: *mut _ = &mut var_data.var_type;
 
                let link_data = self.var_types.get_mut(&linked_id).unwrap();
 

	
 
                debug_assert!(
 
                    unsafe{&*var_type}.parts[0] == InferenceTypePart::Input ||
 
                    unsafe{&*var_type}.parts[0] == InferenceTypePart::Output
 
                );
 
                debug_assert!(
 
                    link_data.var_type.parts[0] == InferenceTypePart::Input ||
 
                    link_data.var_type.parts[0] == InferenceTypePart::Output
 
                );
 
                match InferenceType::infer_subtree_for_single_type(&mut link_data.var_type, 1, &unsafe{&*var_type}.parts, 1) {
 
                    SingleInferenceResult::Modified => {
 
                        for other_expr in &link_data.used_at {
 
                            let other_expr_idx = ctx.heap[*other_expr].get_unique_id_in_definition();
 
                            self.expr_queued.push_back(other_expr_idx);
 
                        }
 
                    },
 
                    SingleInferenceResult::Unmodified => {},
 
                    SingleInferenceResult::Incompatible => {
 
                        let var_data = self.var_types.get(&var_id).unwrap();
 
                        let link_data = self.var_types.get(&linked_id).unwrap();
 
                        let var_decl = &ctx.heap[var_id];
 
                        let link_decl = &ctx.heap[linked_id];
 

	
 
                        return Err(ParseError::new_error_at_span(
 
                            &ctx.module.source, var_decl.identifier.span, format!(
 
                                "Conflicting types for this variable, assigned the type '{}'",
 
                                var_data.var_type.display_name(&ctx.heap)
 
                            )
 
                        ).with_info_at_span(
 
                            &ctx.module.source, link_decl.identifier.span, format!(
 
                                "Because it is incompatible with this variable, assigned the type '{}'",
 
                                link_data.var_type.display_name(&ctx.heap)
 
                            )
 
                        ));
 
                    }
 
                }
 
            }
 
        }
 
        if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
 

	
 
        debug_log!(" * After:");
 
        debug_log!("   - Var  type [{}]: {}", progress_var, self.var_types.get(&var_id).unwrap().var_type.display_name(&ctx.heap));
 
        debug_log!("   - Expr type [{}]: {}", progress_expr, self.temp_get_display_name(ctx, upcast_id));
 

	
 

	
 
        Ok(())
 
    }
 

	
 
    fn queue_expr_parent(&mut self, ctx: &Ctx, expr_id: ExpressionId) {
 
        if let ExpressionParent::Expression(parent_expr_id, _) = &ctx.heap[expr_id].parent() {
 
            let expr_idx = ctx.heap[*parent_expr_id].get_unique_id_in_definition();
 
            self.expr_queued.push_back(expr_idx);
 
        }
 
    }
 

	
 
    fn queue_expr(&mut self, ctx: &Ctx, expr_id: ExpressionId) {
 
        let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition();
 
        self.expr_queued.push_back(expr_idx);
 
    }
 

	
 
    /// Applies a forced type constraint: the type associated with the supplied
 
    /// expression will be molded into the provided "template". The template may
 
    /// be fully specified (e.g. a bool) or contain "inference" variables (e.g.
 
    /// an array of T)
 
    fn apply_forced_constraint(
 
        &mut self, ctx: &Ctx, expr_id: ExpressionId, template: &[InferenceTypePart]
 
    ) -> Result<bool, ParseError> {
 
        let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition(); // TODO: @Temp
 
        let expr_type = &mut self.expr_types[expr_idx as usize].expr_type;
 
        match InferenceType::infer_subtree_for_single_type(expr_type, 0, template, 0) {
 
            SingleInferenceResult::Modified => Ok(true),
 
            SingleInferenceResult::Unmodified => Ok(false),
 
            SingleInferenceResult::Incompatible => Err(
 
                self.construct_template_type_error(ctx, expr_id, template)
 
            )
 
        }
 
    }
 

	
 
    fn apply_forced_constraint_types(
 
        to_infer: *mut InferenceType, to_infer_start_idx: usize,
 
        template: &[InferenceTypePart], template_start_idx: usize
 
    ) -> Result<bool, ()> {
 
        match InferenceType::infer_subtree_for_single_type(
 
            unsafe{ &mut *to_infer }, to_infer_start_idx,
 
            template, template_start_idx
 
        ) {
 
            SingleInferenceResult::Modified => Ok(true),
 
            SingleInferenceResult::Unmodified => Ok(false),
 
            SingleInferenceResult::Incompatible => Err(()),
 
        }
 
    }
 

	
 
    /// Applies a type constraint that expects the two provided types to be
 
    /// equal. We attempt to make progress in inferring the types. If the call
 
    /// is successful then the composition of all types are made equal.
 
    /// The "parent" `expr_id` is provided to construct errors.
 
    fn apply_equal2_constraint(
 
        &mut self, ctx: &Ctx, expr_id: ExpressionId,
 
        arg1_id: ExpressionId, arg1_start_idx: usize,
 
        arg2_id: ExpressionId, arg2_start_idx: usize
 
    ) -> Result<(bool, bool), ParseError> {
 
        let arg1_expr_idx = ctx.heap[arg1_id].get_unique_id_in_definition(); // TODO: @Temp
 
        let arg2_expr_idx = ctx.heap[arg2_id].get_unique_id_in_definition();
 
        let arg1_type: *mut _ = &mut self.expr_types[arg1_expr_idx as usize].expr_type;
 
        let arg2_type: *mut _ = &mut self.expr_types[arg2_expr_idx as usize].expr_type;
 

	
 
        let infer_res = unsafe{ InferenceType::infer_subtrees_for_both_types(
 
            arg1_type, arg1_start_idx,
 
            arg2_type, arg2_start_idx
 
        ) };
 
        if infer_res == DualInferenceResult::Incompatible {
 
            return Err(self.construct_arg_type_error(ctx, expr_id, arg1_id, arg2_id));
 
        }
 

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

	
 
    /// Applies an equal2 constraint between a signature type (e.g. a function
 
    /// argument or struct field) and an expression whose type should match that
 
    /// expression. If we make progress on the signature, then we try to see if
 
    /// any of the embedded polymorphic types can be progressed.
 
    ///
 
    /// `outer_expr_id` is the main expression we're progressing (e.g. a 
 
    /// function call), while `expr_id` is the embedded expression we're 
 
    /// matching against the signature. `expression_type` and 
 
    /// `expression_start_idx` belong to `expr_id`.
 
    fn apply_equal2_signature_constraint(
 
        ctx: &Ctx, outer_expr_id: ExpressionId, expr_id: Option<ExpressionId>,
 
        polymorph_data: &mut ExtraData, polymorph_progress: &mut HashSet<u32>,
 
        signature_type: *mut InferenceType, signature_start_idx: usize,
 
        expression_type: *mut InferenceType, expression_start_idx: usize
 
    ) -> Result<(bool, bool), ParseError> {
 
        // Safety: all pointers distinct
 

	
 
        // Infer the signature and expression type
 
        let infer_res = unsafe { 
 
            InferenceType::infer_subtrees_for_both_types(
 
                signature_type, signature_start_idx,
 
                expression_type, expression_start_idx
 
            ) 
 
        };
 

	
 
        if infer_res == DualInferenceResult::Incompatible {
 
            // TODO: Check if I still need to use this
 
            let outer_span = ctx.heap[outer_expr_id].span();
 
            let (span_name, span) = match expr_id {
 
                Some(expr_id) => ("argument's", ctx.heap[expr_id].span()),
 
                None => ("type's", outer_span)
 
            };
 
            let (signature_display_type, expression_display_type) = unsafe { (
 
                (&*signature_type).display_name(&ctx.heap),
 
                (&*expression_type).display_name(&ctx.heap)
 
            ) };
 

	
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module.source, outer_span,
 
                "failed to fully resolve the types of this expression"
 
            ).with_info_at_span(
 
                &ctx.module.source, span, format!(
 
                    "because the {} signature has been resolved to '{}', but the expression has been resolved to '{}'",
 
                    span_name, signature_display_type, expression_display_type
 
                )
 
            ));
 
        }
 

	
 
        // Try to see if we can progress any of the polymorphic variables
 
        let progress_sig = infer_res.modified_lhs();
 
        let progress_expr = infer_res.modified_rhs();
 

	
 
        if progress_sig {
 
            let signature_type = unsafe{&mut *signature_type};
 
            debug_assert!(
 
                signature_type.has_marker,
 
                "made progress on signature type, but it doesn't have a marker"
 
            );
 
            for (poly_idx, poly_section) in signature_type.marker_iter() {
 
                let polymorph_type = &mut polymorph_data.poly_vars[poly_idx as usize];
 
                match Self::apply_forced_constraint_types(
 
                    polymorph_type, 0, poly_section, 0
 
                ) {
 
                    Ok(true) => { polymorph_progress.insert(poly_idx); },
 
                    Ok(false) => {},
 
                    Err(()) => { return Err(Self::construct_poly_arg_error(ctx, polymorph_data, outer_expr_id))}
 
                }
 
            }
 
        }
 
        Ok((progress_sig, progress_expr))
 
    }
 

	
 
    /// Applies equal2 constraints on the signature type for each of the 
 
    /// polymorphic variables. If the signature type is progressed then we 
 
    /// progress the expression type as well.
 
    ///
 
    /// This function assumes that the polymorphic variables have already been
 
    /// progressed as far as possible by calling 
 
    /// `apply_equal2_signature_constraint`. As such, we expect to not encounter
 
    /// any errors.
 
    ///
 
    /// This function returns true if the expression's type has been progressed
 
    fn apply_equal2_polyvar_constraint(
 
        polymorph_data: &ExtraData, _polymorph_progress: &HashSet<u32>,
 
        signature_type: *mut InferenceType, expr_type: *mut InferenceType
 
    ) -> bool {
 
        // Safety: all pointers should be distinct
 
        //         polymorph_data containers may not be modified
 
        let signature_type = unsafe{&mut *signature_type};
 
        let expr_type = unsafe{&mut *expr_type};
 

	
 
        // Iterate through markers in signature type to try and make progress
 
        // on the polymorphic variable        
 
        let mut seek_idx = 0;
 
        let mut modified_sig = false;
 
        
 
        while let Some((poly_idx, start_idx)) = signature_type.find_marker(seek_idx) {
 
            let end_idx = InferenceType::find_subtree_end_idx(&signature_type.parts, start_idx);
 
            // if polymorph_progress.contains(&poly_idx) {
 
                // Need to match subtrees
 
                let polymorph_type = &polymorph_data.poly_vars[poly_idx as usize];
 
                let modified_at_marker = Self::apply_forced_constraint_types(
 
                    signature_type, start_idx, 
 
                    &polymorph_type.parts, 0
 
                ).expect("no failure when applying polyvar constraints");
 

	
 
                modified_sig = modified_sig || modified_at_marker;
 
            // }
 

	
 
            seek_idx = end_idx;
 
        }
 

	
 
        // If we made any progress on the signature's type, then we also need to
 
        // apply it to the expression that is supposed to match the signature.
 
        if modified_sig {
 
            match InferenceType::infer_subtree_for_single_type(
 
                expr_type, 0, &signature_type.parts, 0
 
            ) {
 
                SingleInferenceResult::Modified => true,
 
                SingleInferenceResult::Unmodified => false,
 
                SingleInferenceResult::Incompatible =>
 
                    unreachable!("encountered failure while reapplying modified signature to expression after polyvar inference")
 
            }
 
        } else {
 
            false
 
        }
 
    }
 

	
 
    /// Applies a type constraint that expects all three provided types to be
 
    /// equal. In case we can make progress in inferring the types then we
 
    /// attempt to do so. If the call is successful then the composition of all
 
    /// types is made equal.
 
    fn apply_equal3_constraint(
 
        &mut self, ctx: &Ctx, expr_id: ExpressionId,
 
        arg1_id: ExpressionId, arg2_id: ExpressionId,
 
        start_idx: usize
 
    ) -> Result<(bool, bool, bool), ParseError> {
 
        // Safety: all points are unique
 
        //         containers may not be modified
 
        let expr_expr_idx = ctx.heap[expr_id].get_unique_id_in_definition(); // TODO: @Temp
 
        let arg1_expr_idx = ctx.heap[arg1_id].get_unique_id_in_definition();
 
        let arg2_expr_idx = ctx.heap[arg2_id].get_unique_id_in_definition();
 

	
 
        let expr_type: *mut _ = &mut self.expr_types[expr_expr_idx as usize].expr_type;
 
        let arg1_type: *mut _ = &mut self.expr_types[arg1_expr_idx as usize].expr_type;
 
        let arg2_type: *mut _ = &mut self.expr_types[arg2_expr_idx as usize].expr_type;
 

	
 
        let expr_res = unsafe{
 
            InferenceType::infer_subtrees_for_both_types(expr_type, start_idx, arg1_type, start_idx)
 
        };
 
        if expr_res == DualInferenceResult::Incompatible {
 
            return Err(self.construct_expr_type_error(ctx, expr_id, arg1_id));
 
        }
 

	
 
        let args_res = unsafe{
 
            InferenceType::infer_subtrees_for_both_types(arg1_type, start_idx, arg2_type, start_idx) };
 
        if args_res == DualInferenceResult::Incompatible {
 
            return Err(self.construct_arg_type_error(ctx, expr_id, arg1_id, arg2_id));
 
        }
 

	
 
        // If all types are compatible, but the second call caused the arg1_type
 
        // to be expanded, then we must also assign this to expr_type.
 
        let mut progress_expr = expr_res.modified_lhs();
 
        let mut progress_arg1 = expr_res.modified_rhs();
 
        let progress_arg2 = args_res.modified_rhs();
 

	
 
        if args_res.modified_lhs() { 
 
            unsafe {
 
                let end_idx = InferenceType::find_subtree_end_idx(&(*arg2_type).parts, start_idx);
 
                let subtree = &((*arg2_type).parts[start_idx..end_idx]);
 
                (*expr_type).replace_subtree(start_idx, subtree);
 
            }
 
            progress_expr = true;
 
            progress_arg1 = true;
 
        }
 

	
 
        Ok((progress_expr, progress_arg1, progress_arg2))
 
    }
 

	
 
    // TODO: @optimize Since we only deal with a single type this might be done
 
    //  a lot more efficiently, methinks (disregarding the allocations here)
 
    fn apply_equal_n_constraint(
 
        &mut self, ctx: &Ctx, expr_id: ExpressionId, args: &[ExpressionId],
 
    ) -> Result<Vec<bool>, ParseError> {
 
        // Early exit
 
        match args.len() {
 
            0 => return Ok(vec!()),         // nothing to progress
 
            1 => return Ok(vec![false]),    // only one type, so nothing to infer
 
            _ => {}
 
        }
 

	
 
        let mut progress = Vec::new();
 
        progress.resize(args.len(), false);
 

	
 
        // Do pairwise inference, keep track of the last entry we made progress
 
        // on. Once done we need to update everything to the most-inferred type.
 
        let mut arg_iter = args.iter();
 
        let mut last_arg_id = *arg_iter.next().unwrap();
 
        let mut last_lhs_progressed = 0;
 
        let mut lhs_arg_idx = 0;
 

	
 
        while let Some(next_arg_id) = arg_iter.next() {
 
            let last_expr_idx = ctx.heap[last_arg_id].get_unique_id_in_definition(); // TODO: @Temp
 
            let next_expr_idx = ctx.heap[*next_arg_id].get_unique_id_in_definition();
 
            let last_type: *mut _ = &mut self.expr_types[last_expr_idx as usize].expr_type;
 
            let next_type: *mut _ = &mut self.expr_types[next_expr_idx as usize].expr_type;
 

	
 
            let res = unsafe {
 
                InferenceType::infer_subtrees_for_both_types(last_type, 0, next_type, 0)
 
            };
 

	
 
            if res == DualInferenceResult::Incompatible {
 
                return Err(self.construct_arg_type_error(ctx, expr_id, last_arg_id, *next_arg_id));
 
            }
 

	
 
            if res.modified_lhs() {
 
                // We re-inferred something on the left hand side, so everything
 
                // up until now should be re-inferred.
 
                progress[lhs_arg_idx] = true;
 
                last_lhs_progressed = lhs_arg_idx;
 
            }
 
            progress[lhs_arg_idx + 1] = res.modified_rhs();
 

	
 
            last_arg_id = *next_arg_id;
 
            lhs_arg_idx += 1;
 
        }
 

	
 
        // Re-infer everything. Note that we do not need to re-infer the type
 
        // exactly at `last_lhs_progressed`, but only everything up to it.
 
        let last_arg_expr_idx = ctx.heap[*args.last().unwrap()].get_unique_id_in_definition();
 
        let last_type: *mut _ = &mut self.expr_types[last_arg_expr_idx as usize].expr_type;
 
        for arg_idx in 0..last_lhs_progressed {
 
            let other_arg_expr_idx = ctx.heap[args[arg_idx]].get_unique_id_in_definition();
 
            let arg_type: *mut _ = &mut self.expr_types[other_arg_expr_idx as usize].expr_type;
 
            unsafe{
 
                (*arg_type).replace_subtree(0, &(*last_type).parts);
 
            }
 
            progress[arg_idx] = true;
 
        }
 

	
 
        Ok(progress)
 
    }
 

	
 
    /// Determines the `InferenceType` for the expression based on the
 
    /// expression parent. Note that if the parent is another expression, we do
 
    /// not take special action, instead we let parent expressions fix the type
 
    /// of subexpressions before they have a chance to call this function.
 
    fn insert_initial_expr_inference_type(
 
        &mut self, ctx: &mut Ctx, expr_id: ExpressionId
 
    ) -> Result<(), ParseError> {
 
        use ExpressionParent as EP;
 
        use InferenceTypePart as ITP;
 

	
 
        let expr = &ctx.heap[expr_id];
 
        let inference_type = match expr.parent() {
 
            EP::None =>
 
                // Should have been set by linker
 
                unreachable!(),
 
            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(_) =>
 
                // Must match the return type of the function
 
                if let DefinitionType::Function(func_id) = self.definition_type {
 
                    debug_assert_eq!(ctx.heap[func_id].return_types.len(), 1);
 
                    let returned = &ctx.heap[func_id].return_types[0];
 
                    self.determine_inference_type_from_parser_type_elements(&returned.elements, true)
 
                } else {
 
                    // Cannot happen: definition always set upon body traversal
 
                    // and "return" calls in components are illegal.
 
                    unreachable!();
 
                },
 
            EP::New(_) =>
 
                // Must be a component call, which we assign a "Void" return
 
                // type
 
                InferenceType::new(false, true, vec![ITP::Void]),
 
        };
 

	
 
        let infer_expr = &mut self.expr_types[expr.get_unique_id_in_definition() as usize];
 
        let needs_extra_data = match expr {
 
            Expression::Call(_) => true,
 
            Expression::Literal(expr) => match expr.value {
 
                Literal::Enum(_) | Literal::Union(_) | Literal::Struct(_) => true,
 
                _ => false,
 
            },
 
            Expression::Select(_) => true,
 
            _ => false,
 
        };
 

	
 
        if infer_expr.expr_id.is_invalid() {
 
            // Nothing is set yet
 
            infer_expr.expr_type = inference_type;
 
            infer_expr.expr_id = expr_id;
 
            if needs_extra_data {
 
                let extra_idx = self.extra_data.len() as i32;
 
                self.extra_data.push(ExtraData::default());
 
                infer_expr.extra_data_idx = extra_idx;
 
            }
 
        } else {
 
            // We already have an entry
 
            debug_assert!(false, "does this ever happen?");
 
            if let SingleInferenceResult::Incompatible = InferenceType::infer_subtree_for_single_type(
 
                &mut infer_expr.expr_type, 0, &inference_type.parts, 0
 
            ) {
 
                return Err(self.construct_expr_type_error(ctx, expr_id, expr_id));
 
            }
 

	
 
            debug_assert!((infer_expr.extra_data_idx != -1) == needs_extra_data);
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    fn insert_initial_call_polymorph_data(
 
        &mut self, ctx: &mut Ctx, call_id: CallExpressionId
 
    ) {
 
        // Note: the polymorph variables may be partially specified and may
 
        // contain references to the wrapping definition's (i.e. the proctype
 
        // we are currently visiting) polymorphic arguments.
 
        //
 
        // The arguments of the call may refer to polymorphic variables in the
 
        // definition of the function we're calling, not of the wrapping
 
        // definition. We insert markers in these inferred types to be able to
 
        // map them back and forth to the polymorphic arguments of the function
 
        // we are calling.
 
        let call = &ctx.heap[call_id];
 
        let extra_data_idx = self.expr_types[call.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
 
        debug_assert!(extra_data_idx != -1, "insert initial call polymorph data, no preallocated ExtraData");
 

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

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

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

	
 
        let return_type = match returned {
 
            None => {
 
                // Component, so returns a "Void"
 
                InferenceType::new(false, true, vec![InferenceTypePart::Void])
 
            },
 
            Some(returned) => {
 
                debug_assert_eq!(returned.len(), 1); // TODO: @ReturnTypes
 
                let returned = &returned[0];
 
                self.determine_inference_type_from_parser_type_elements(&returned.elements, false)
 
            }
 
        };
 

	
 
        self.extra_data[extra_data_idx as usize] = ExtraData{
 
            expr_id: call_id.upcast(),
 
            definition_id: call.definition,
 
            poly_vars: poly_args,
 
            embedded: parameter_types,
 
            returned: return_type
 
        };
 
    }
 

	
 
    fn insert_initial_struct_polymorph_data(
 
        &mut self, ctx: &mut Ctx, lit_id: LiteralExpressionId,
 
    ) {
 
        use InferenceTypePart as ITP;
 
        let literal = &ctx.heap[lit_id];
 
        let extra_data_idx = self.expr_types[literal.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
 
        debug_assert!(extra_data_idx != -1, "initial struct polymorph data, but no preallocated ExtraData");
 
        let literal = ctx.heap[lit_id].value.as_struct();
 

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

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

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

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

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

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

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

	
 
        self.extra_data[extra_data_idx as usize] = ExtraData{
 
            expr_id: lit_id.upcast(),
 
            definition_id: literal.definition,
 
            poly_vars: poly_args,
 
            embedded: embedded_types,
 
            returned: return_type,
 
        };
 
    }
 

	
 
    /// 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
 
    ) {
 
        use InferenceTypePart as ITP;
 
        let literal = &ctx.heap[lit_id];
 
        let extra_data_idx = self.expr_types[literal.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
 
        debug_assert!(extra_data_idx != -1, "initial enum polymorph data, but no preallocated ExtraData");
 
        let literal = ctx.heap[lit_id].value.as_enum();
 

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

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

	
 
        // Handle enum type itself
 
        let parts_reserved = 1 + poly_args.len() + total_num_poly_parts;
 
        let mut parts = Vec::with_capacity(parts_reserved);
 
        parts.push(ITP::Instance(literal.definition, poly_args.len() as u32));
 
        let mut enum_type_done = true;
 
        for (poly_var_idx, poly_var) in poly_args.iter().enumerate() {
 
            if !poly_var.is_done { enum_type_done = false; }
 

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

	
 
        debug_assert_eq!(parts.len(), parts_reserved);
 
        let enum_type = InferenceType::new(!poly_args.is_empty(), enum_type_done, parts);
src/protocol/parser/pass_validation_linking.rs
Show inline comments
 
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::{
 
    STMT_BUFFER_INIT_CAPACITY,
 
    EXPR_BUFFER_INIT_CAPACITY,
 
    Ctx, 
 
    Visitor2, 
 
    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(),
 
        }
 
    }
 
}
 

	
 
/// 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.
 
///
 
///
 
/// Because of this scheme expressions will not be visited in the breadth-first
 
/// pass.
 
pub(crate) struct PassValidationLinking {
 
    // `in_sync` is `Some(id)` if the visitor is visiting the children of a
 
    // synchronous statement. A single value is sufficient as nested
 
    // synchronous statements are not allowed
 
    in_sync: Option<SynchronousStatementId>,
 
    // `in_while` contains the last encountered `While` statement. This is used
 
    // to resolve unlabeled `Continue`/`Break` statements.
 
    in_while: Option<WhileStatementId>,
 
    // 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_test_expr: StatementId, // wrapping if/while stmt id
 
    in_binding_expr: BindingExpressionId, // to resolve variable expressions
 
    in_binding_expr_lhs: bool,
 
    // Traversal state: current scope (which can be used to find the parent
 
    // scope) and the definition variant we are considering.
 
    cur_scope: Scope,
 
    def_type: DefinitionType,
 
    // Parent expression (the previous stmt/expression we visited that could be
 
    // used as an expression parent)
 
    expr_parent: ExpressionParent,
 
    // Set by parent to indicate that child expression must be assignable. The
 
    // child will throw an error if it is not assignable. The stored span is
 
    // used for the error's position
 
    must_be_assignable: Option<InputSpan>,
 
    // Keeping track of relative positions and unique IDs.
 
    relative_pos_in_block: u32, // of statements: to determine when variables are visible
 
    next_expr_index: i32, // to arrive at a unique ID for all expressions within a definition
 
    // 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>,
 
}
 

	
 
impl PassValidationLinking {
 
    pub(crate) fn new() -> Self {
 
        Self{
 
            in_sync: None,
 
            in_while: None,
 
            in_sync: SynchronousStatementId::new_invalid(),
 
            in_while: WhileStatementId::new_invalid(),
 
            in_test_expr: StatementId::new_invalid(),
 
            in_binding_expr: BindingExpressionId::new_invalid(),
 
            in_binding_expr_lhs: false,
 
            cur_scope: Scope::Definition(DefinitionId::new_invalid()),
 
            expr_parent: ExpressionParent::None,
 
            def_type: DefinitionType::Function(FunctionDefinitionId::new_invalid()),
 
            must_be_assignable: None,
 
            relative_pos_in_block: 0,
 
            next_expr_index: 0,
 
            variable_buffer: ScopedBuffer::new_reserved(128),
 
            definition_buffer: ScopedBuffer::new_reserved(128),
 
            statement_buffer: ScopedBuffer::new_reserved(STMT_BUFFER_INIT_CAPACITY),
 
            expression_buffer: ScopedBuffer::new_reserved(EXPR_BUFFER_INIT_CAPACITY),
 
        }
 
    }
 

	
 
    fn reset_state(&mut self) {
 
        self.in_sync = None;
 
        self.in_while = None;
 
        self.in_sync = SynchronousStatementId::new_invalid();
 
        self.in_while = WhileStatementId::new_invalid();
 
        self.in_test_expr = StatementId::new_invalid();
 
        self.in_binding_expr = BindingExpressionId::new_invalid();
 
        self.in_binding_expr_lhs = false;
 
        self.cur_scope = Scope::Definition(DefinitionId::new_invalid());
 
        self.expr_parent = ExpressionParent::None;
 
        self.def_type = DefinitionType::Function(FunctionDefinitionId::new_invalid());
 
        self.expr_parent = ExpressionParent::None;
 
        self.must_be_assignable = None;
 
        self.relative_pos_in_block = 0;
 
        self.next_expr_index = 0
 
    }
 
}
 

	
 
impl Visitor2 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_idx in 0..section.len() {
 
            let definition_id = section[definition_idx];
 
            self.visit_definition(ctx, definition_id)?;
 
        }
 
        section.forget();
 

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

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

	
 
        self.def_type = match &ctx.heap[id].variant {
 
            ComponentVariant::Primitive => DefinitionType::Primitive(id),
 
            ComponentVariant::Composite => DefinitionType::Composite(id),
 
        };
 
        self.cur_scope = Scope::Definition(id.upcast());
 
        self.expr_parent = ExpressionParent::None;
 

	
 
        // Visit parameters and assign a unique scope ID
 
        let definition = &ctx.heap[id];
 
        let body_id = definition.body;
 
        let section = self.variable_buffer.start_section_initialized(&definition.parameters);
 
        for variable_idx in 0..section.len() {
 
            let variable_id = section[variable_idx];
 
            let variable = &mut ctx.heap[variable_id];
 
            variable.unique_id_in_scope = variable_idx as i32;
 
        }
 
        section.forget();
 

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

	
 
        // Assign total number of expressions and assign an in-block unique ID
 
        // to each of the locals in the procedure.
 
        ctx.heap[id].num_expressions_in_body = self.next_expr_index;
 
        self.visit_definition_and_assign_local_ids(ctx, id.upcast());
 

	
 
        Ok(())
 
    }
 

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

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

	
 
        // Visit parameters and assign a unique scope ID
 
        let definition = &ctx.heap[id];
 
        let body_id = definition.body;
 
        let section = self.variable_buffer.start_section_initialized(&definition.parameters);
 
        for variable_idx in 0..section.len() {
 
            let variable_id = section[variable_idx];
 
            let variable = &mut ctx.heap[variable_id];
 
            variable.unique_id_in_scope = variable_idx as i32;
 
        }
 
        section.forget();
 

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

	
 
        // Assign total number of expressions and assign an in-block unique ID
 
        // to each of the locals in the procedure.
 
        ctx.heap[id].num_expressions_in_body = self.next_expr_index;
 
        self.visit_definition_and_assign_local_ids(ctx, id.upcast());
 

	
 
        Ok(())
 
    }
 

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

	
 
    fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
 
        self.visit_block_stmt_with_hint(ctx, id, None)
 
    }
 

	
 
    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 {
 
        let body_id = ctx.heap[id].body;
 
        self.visit_stmt(ctx, body_id)?;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_if_stmt(&mut self, ctx: &mut Ctx, id: IfStatementId) -> VisitorResult {
 
        // Traverse expression and bodies
 
        let (test_id, true_id, false_id) = {
 
            let stmt = &ctx.heap[id];
 
            (stmt.test, stmt.true_body, stmt.false_body)
 
        };
 
        let if_stmt = &ctx.heap[id];
 
        let test_expr_id = if_stmt.test;
 
        let true_stmt_id = if_stmt.true_body;
 
        let false_stmt_id = if_stmt.false_body;
 

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

	
 
        self.expr_parent = ExpressionParent::None;
 

	
 
        self.visit_block_stmt(ctx, true_id)?;
 
        if let Some(false_id) = false_id {
 
        self.visit_block_stmt(ctx, true_stmt_id)?;
 
        if let Some(false_id) = false_stmt_id {
 
            self.visit_block_stmt(ctx, false_id)?;
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_while_stmt(&mut self, ctx: &mut Ctx, id: WhileStatementId) -> VisitorResult {
 
        let (test_id, body_id) = {
 
            let stmt = &ctx.heap[id];
 
            (stmt.test, stmt.body)
 
        };
 
        let old_while = self.in_while.replace(id);
 
        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_id)?;
 
        self.expr_parent = ExpressionParent::None;
 
        self.in_test_expr = StatementId::new_invalid();
 

	
 
        self.expr_parent = ExpressionParent::None;
 
        self.visit_block_stmt(ctx, body_id)?;
 
        self.in_while = old_while;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_break_stmt(&mut self, ctx: &mut Ctx, id: BreakStatementId) -> VisitorResult {
 
        // Resolve break target
 
        let target_end_while = {
 
            let stmt = &ctx.heap[id];
 
            let target_while_id = self.resolve_break_or_continue_target(ctx, stmt.span, &stmt.label)?;
 
            let target_while = &ctx.heap[target_while_id];
 
            debug_assert!(!target_while.end_while.is_invalid());
 

	
 
            target_while.end_while
 
        };
 

	
 
        let stmt = &mut ctx.heap[id];
 
        stmt.target = Some(target_end_while);
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_continue_stmt(&mut self, ctx: &mut Ctx, id: ContinueStatementId) -> VisitorResult {
 
        // Resolve continue target
 
        let target_while_id = {
 
            let stmt = &ctx.heap[id];
 
            self.resolve_break_or_continue_target(ctx, stmt.span, &stmt.label)?
 
        };
 

	
 
        let stmt = &mut ctx.heap[id];
 
        stmt.target = Some(target_while_id);
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_synchronous_stmt(&mut self, ctx: &mut Ctx, id: SynchronousStatementId) -> VisitorResult {
 
        // Check for validity of synchronous statement
 
        let cur_sync_span = ctx.heap[id].span;
 
        if self.in_sync.is_some() {
 
        if !self.in_sync.is_invalid() {
 
            // Nested synchronous statement
 
            let old_sync_span = ctx.heap[self.in_sync.unwrap()].span;
 
            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() {
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module.source, cur_sync_span,
 
                "synchronous statements may only be used in primitive components"
 
            ));
 
        }
 

	
 
        let sync_body = ctx.heap[id].body;
 
        let old = self.in_sync.replace(id);
 
        debug_assert!(self.in_sync.is_invalid());
 
        self.in_sync = id;
 
        self.visit_block_stmt_with_hint(ctx, sync_body, Some(id))?;
 
        self.in_sync = old;
 

	
 
        self.in_sync = SynchronousStatementId::new_invalid();
 

	
 
        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() {
 
            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
 
        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 {
 
        let target_id = self.find_label(ctx, &ctx.heap[id].label)?;
 
        ctx.heap[id].target = Some(target_id);
 

	
 
        let target = &ctx.heap[target_id];
 
        if self.in_sync != target.in_sync {
 
            // We can only goto the current scope or outer scopes. Because
 
            // nested sync statements are not allowed so if the value does
 
            // not match, then we must be inside a sync scope
 
            debug_assert!(self.in_sync.is_some());
 
            // nested sync statements are not allowed we must be inside a sync
 
            // statement.
 
            debug_assert!(!self.in_sync.is_invalid());
 
            let goto_stmt = &ctx.heap[id];
 
            let sync_stmt = &ctx.heap[self.in_sync.unwrap()];
 
            let sync_stmt = &ctx.heap[self.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.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")
 
            );
 
        }
 

	
 
        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() {
 
            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;
 

	
 
        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;
 

	
 
        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];
 

	
 
        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.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();
 
        let binding_expr = &mut ctx.heap[id];
 

	
 
        // 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() {
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module.source, binding_expr.span,
 
                "binding expressions can only be used inside the testing expression of 'if' and 'while' statements"
 
            ));
 
        }
 

	
 
        if !self.in_binding_expr.is_invalid() {
 
            let binding_expr = &ctx.heap[id];
 
            let previous_expr = &ctx.heap[self.in_binding_expr];
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module.source, binding_expr.span,
 
                "nested binding expressions are not allowed"
 
            ).with_info_str_at_span(
 
                &ctx.module.source, previous_expr.span,
 
                "the outer binding expression is found here"
 
            ));
 
        }
 

	
 
        let old_expr_parent = self.expr_parent;
 
        binding_expr.parent = old_expr_parent;
 
        binding_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 
        self.in_binding_expr = id;
 

	
 
        // Perform preliminary check on children: binding expressions only make
 
        // sense if the left hand side is just a variable expression, or if it
 
        // is a literal of some sort. The typechecker will take care of the rest
 
        let bound_to_id = binding_expr.bound_to;
 
        let bound_from_id = binding_expr.bound_from;
 

	
 
        match &ctx.heap[bound_to_id] {
 
            // Variables may not be binding variables, and literals may
 
            // actually not contain binding variables. But in that case we just
 
            // perform an equality check.
 
            Expression::Variable(_) => {}
 
            Expression::Literal(_) => {},
 
            _ => {
 
                let binding_expr = &ctx.heap[id];
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module.source, binding_expr.span,
 
                    "the left hand side of a binding expression may only be a variable or a literal expression"
 
                ));
 
            },
 
        }
 

	
 
        // Visit the children themselves
 
        self.in_binding_expr_lhs = true;
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
 
        self.visit_expr(ctx, bound_to_id);
 
        self.in_binding_expr_lhs = false;
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
 
        self.visit_expr(ctx, bound_from_id);
 

	
 
        self.expr_parent = old_expr_parent;
 
        self.in_binding_expr = BindingExpressionId::new_invalid();
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_conditional_expr(&mut self, ctx: &mut Ctx, id: ConditionalExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        let conditional_expr = &mut ctx.heap[id];
 

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

	
 
        let test_expr_id = conditional_expr.test;
 
        let true_expr_id = conditional_expr.true_expression;
 
        let false_expr_id = conditional_expr.false_expression;
 

	
 
        let old_expr_parent = self.expr_parent;
 
        conditional_expr.parent = old_expr_parent;
 
        conditional_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
 
        self.visit_expr(ctx, test_expr_id)?;
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
 
        self.visit_expr(ctx, true_expr_id)?;
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 2);
 
        self.visit_expr(ctx, false_expr_id)?;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_binary_expr(&mut self, ctx: &mut Ctx, id: BinaryExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        let binary_expr = &mut ctx.heap[id];
 

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

	
 
        let left_expr_id = binary_expr.left;
 
        let right_expr_id = binary_expr.right;
 

	
 
        let old_expr_parent = self.expr_parent;
 
        binary_expr.parent = old_expr_parent;
 
        binary_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
 
        self.visit_expr(ctx, left_expr_id)?;
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
 
        self.visit_expr(ctx, right_expr_id)?;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

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

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

	
 
        let old_expr_parent = self.expr_parent;
 
        unary_expr.parent = old_expr_parent;
 
        unary_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        self.expr_parent = ExpressionParent::Expression(id.upcast(), 0);
 
        self.visit_expr(ctx, expr_id)?;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_indexing_expr(&mut self, ctx: &mut Ctx, id: IndexingExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        let indexing_expr = &mut ctx.heap[id];
 

	
 
        let subject_expr_id = indexing_expr.subject;
 
        let index_expr_id = indexing_expr.index;
 

	
 
        let old_expr_parent = self.expr_parent;
 
        indexing_expr.parent = old_expr_parent;
 
        indexing_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
 
        self.visit_expr(ctx, subject_expr_id)?;
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
 
        self.visit_expr(ctx, index_expr_id)?;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_slicing_expr(&mut self, ctx: &mut Ctx, id: SlicingExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        let slicing_expr = &mut ctx.heap[id];
 

	
 
        let subject_expr_id = slicing_expr.subject;
 
        let from_expr_id = slicing_expr.from_index;
 
        let to_expr_id = slicing_expr.to_index;
 

	
 
        let old_expr_parent = self.expr_parent;
 
        slicing_expr.parent = old_expr_parent;
 
        slicing_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
 
        self.visit_expr(ctx, subject_expr_id)?;
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
 
        self.visit_expr(ctx, from_expr_id)?;
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 2);
 
        self.visit_expr(ctx, to_expr_id)?;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_select_expr(&mut self, ctx: &mut Ctx, id: SelectExpressionId) -> VisitorResult {
 
        let select_expr = &mut ctx.heap[id];
 
        let expr_id = select_expr.subject;
 

	
 
        let old_expr_parent = self.expr_parent;
 
        select_expr.parent = old_expr_parent;
 
        select_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        self.expr_parent = ExpressionParent::Expression(id.upcast(), 0);
 
        self.visit_expr(ctx, expr_id)?;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_literal_expr(&mut self, ctx: &mut Ctx, id: LiteralExpressionId) -> VisitorResult {
 
        let literal_expr = &mut ctx.heap[id];
 
        let old_expr_parent = self.expr_parent;
 
        literal_expr.parent = old_expr_parent;
 
        literal_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

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

	
 
        match &mut literal_expr.value {
 
            Literal::Null | Literal::True | Literal::False |
 
            Literal::Character(_) | Literal::String(_) | Literal::Integer(_) => {
 
                // Just the parent has to be set, done above
 
            },
 
            Literal::Struct(literal) => {
 
                let upcast_id = id.upcast();
 
                // Retrieve type definition
 
                let type_definition = ctx.types.get_base_definition(&literal.definition).unwrap();
 
                let struct_definition = type_definition.definition.as_struct();
 

	
 
                // Make sure all fields are specified, none are specified twice
 
                // and all fields exist on the struct definition
 
                let mut specified = Vec::new(); // TODO: @performance
 
                specified.resize(struct_definition.fields.len(), false);
 

	
 
                for field in &mut literal.fields {
 
                    // Find field in the struct definition
 
                    let field_idx = struct_definition.fields.iter().position(|v| v.identifier == field.identifier);
 
                    if field_idx.is_none() {
 
                        let field_span = field.identifier.span;
 
                        let literal = ctx.heap[id].value.as_struct();
 
                        let ast_definition = &ctx.heap[literal.definition];
 
                        return Err(ParseError::new_error_at_span(
 
                            &ctx.module.source, field_span, format!(
 
                                "This field does not exist on the struct '{}'",
 
                                ast_definition.identifier().value.as_str()
 
                            )
 
                        ));
 
                    }
 
                    field.field_idx = field_idx.unwrap();
 

	
 
                    // Check if specified more than once
 
                    if specified[field.field_idx] {
 
                        return Err(ParseError::new_error_str_at_span(
 
                            &ctx.module.source, field.identifier.span,
 
                            "This field is specified more than once"
 
                        ));
 
                    }
 

	
 
                    specified[field.field_idx] = true;
 
                }
 

	
 
                if !specified.iter().all(|v| *v) {
 
                    // Some fields were not specified
 
                    let mut not_specified = String::new();
 
                    let mut num_not_specified = 0;
 
                    for (def_field_idx, is_specified) in specified.iter().enumerate() {
 
                        if !is_specified {
 
                            if !not_specified.is_empty() { not_specified.push_str(", ") }
 
                            let field_ident = &struct_definition.fields[def_field_idx].identifier;
 
                            not_specified.push_str(field_ident.value.as_str());
 
                            num_not_specified += 1;
 
                        }
 
                    }
 

	
 
                    debug_assert!(num_not_specified > 0);
 
                    let msg = if num_not_specified == 1 {
 
                        format!("not all fields are specified, '{}' is missing", not_specified)
 
                    } else {
 
                        format!("not all fields are specified, [{}] are missing", not_specified)
 
                    };
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module.source, literal.parser_type.elements[0].full_span, msg
 
                    ));
 
                }
 

	
 
                // Need to traverse fields expressions in struct and evaluate
 
                // the poly args
 
                let mut expr_section = self.expression_buffer.start_section();
 
                for field in &literal.fields {
 
                    expr_section.push(field.value);
 
                }
 

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

	
 
                expr_section.forget();
 
            },
 
            Literal::Enum(literal) => {
 
                // Make sure the variant exists
 
                let type_definition = ctx.types.get_base_definition(&literal.definition).unwrap();
 
                let enum_definition = type_definition.definition.as_enum();
 

	
 
                let variant_idx = enum_definition.variants.iter().position(|v| {
 
                    v.identifier == literal.variant
 
                });
 

	
 
                if variant_idx.is_none() {
 
                    let literal = ctx.heap[id].value.as_enum();
 
                    let ast_definition = ctx.heap[literal.definition].as_enum();
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module.source, literal.parser_type.elements[0].full_span, format!(
 
                            "the variant '{}' does not exist on the enum '{}'",
 
                            literal.variant.value.as_str(), ast_definition.identifier.value.as_str()
 
                        )
 
                    ));
 
                }
 

	
 
                literal.variant_idx = variant_idx.unwrap();
 
            },
 
            Literal::Union(literal) => {
 
                // Make sure the variant exists
 
                let type_definition = ctx.types.get_base_definition(&literal.definition).unwrap();
 
                let union_definition = type_definition.definition.as_union();
 

	
 
                let variant_idx = union_definition.variants.iter().position(|v| {
 
                    v.identifier == literal.variant
 
                });
 
                if variant_idx.is_none() {
 
                    let literal = ctx.heap[id].value.as_union();
 
                    let ast_definition = ctx.heap[literal.definition].as_union();
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module.source, literal.parser_type.elements[0].full_span, format!(
 
                            "the variant '{}' does not exist on the union '{}'",
 
                            literal.variant.value.as_str(), ast_definition.identifier.value.as_str()
 
                        )
 
                    ));
 
                }
 

	
 
                literal.variant_idx = variant_idx.unwrap();
 

	
 
                // Make sure the number of specified values matches the expected
 
                // number of embedded values in the union variant.
 
                let union_variant = &union_definition.variants[literal.variant_idx];
 
                if union_variant.embedded.len() != literal.values.len() {
 
                    let literal = ctx.heap[id].value.as_union();
 
                    let ast_definition = ctx.heap[literal.definition].as_union();
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module.source, literal.parser_type.elements[0].full_span, format!(
 
                            "The variant '{}' of union '{}' expects {} embedded values, but {} were specified",
 
                            literal.variant.value.as_str(), ast_definition.identifier.value.as_str(),
 
                            union_variant.embedded.len(), literal.values.len()
 
                        ),
 
                    ))
 
                }
 

	
 
                // Traverse embedded values of union (if any) and evaluate the
 
                // polymorphic arguments
 
                let upcast_id = id.upcast();
 
                let mut expr_section = self.expression_buffer.start_section();
 
                for value in &literal.values {
 
                    expr_section.push(*value);
 
                }
 

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

	
 
                expr_section.forget();
 
            },
 
            Literal::Array(literal) => {
 
                // 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 = &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 call expression"
 
            ))
 
        }
 

	
 
        // Check whether the method is allowed to be called within the code's
 
        // context (in sync, definition type, etc.)
 
        let mut expected_wrapping_new_stmt = false;
 
        match &mut call_expr.method {
 
            Method::Get => {
 
                if !self.def_type.is_primitive() {
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module.source, call_expr.span,
 
                        "a call to 'get' may only occur in primitive component definitions"
 
                    ));
 
                }
 
                if self.in_sync.is_none() {
 
                if !self.in_sync.is_invalid() {
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module.source, call_expr.span,
 
                        "a call to 'get' may only occur inside synchronous blocks"
 
                    ));
 
                }
 
            },
 
            Method::Put => {
 
                if !self.def_type.is_primitive() {
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module.source, call_expr.span,
 
                        "a call to 'put' may only occur in primitive component definitions"
 
                    ));
 
                }
 
                if self.in_sync.is_none() {
 
                if !self.in_sync.is_invalid() {
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module.source, call_expr.span,
 
                        "a call to 'put' may only occur inside synchronous blocks"
 
                    ));
 
                }
 
            },
 
            Method::Fires => {
 
                if !self.def_type.is_primitive() {
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module.source, call_expr.span,
 
                        "a call to 'fires' may only occur in primitive component definitions"
 
                    ));
 
                }
 
                if self.in_sync.is_none() {
 
                if !self.in_sync.is_invalid() {
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module.source, call_expr.span,
 
                        "a call to 'fires' may only occur inside synchronous blocks"
 
                    ));
 
                }
 
            },
 
            Method::Create => {},
 
            Method::Length => {},
 
            Method::Assert => {
 
                if self.def_type.is_function() {
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module.source, call_expr.span,
 
                        "assert statement may only occur in components"
 
                    ));
 
                }
 
                if self.in_sync.is_none() {
 
                if !self.in_sync.is_invalid() {
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module.source, call_expr.span,
 
                        "assert statements may only occur inside synchronous blocks"
 
                    ));
 
                }
 
            },
 
            Method::UserFunction => {},
 
            Method::UserComponent => {
 
                expected_wrapping_new_stmt = true;
 
            },
 
        }
 

	
 
        if expected_wrapping_new_stmt {
 
            if !self.expr_parent.is_new() {
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module.source, call_expr.span,
 
                    "cannot call a component, it can only be instantiated by using 'new'"
 
                ));
 
            }
 
        } else {
 
            if self.expr_parent.is_new() {
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module.source, call_expr.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 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()),
 
        };
 

	
 
        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" };
 
            return Err(ParseError::new_error_at_span(
 
                &ctx.module.source, call_expr.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];
 
        let variable_id = self.find_variable(ctx, self.relative_pos_in_block, &var_expr.identifier)?;
 
        let variable_id = match self.find_variable(ctx, self.relative_pos_in_block, &var_expr.identifier) {
 
            Ok(variable_id) => {
 
                // Regular variable
 
                variable_id
 
            },
 
            Err(()) => {
 
                // Couldn't find variable, but if we're in a binding expression,
 
                // then this may be the thing we're binding to.
 
                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 and arrays can have
 
                                // subexpressions, so we're always fine
 
                                if cfg!(debug_assertions) {
 
                                    match lit_expr.value {
 
                                        Literal::Struct(_) | Literal::Union(_) | Literal::Array(_) => {},
 
                                        _ => unreachable!(),
 
                                    }
 
                                }
 

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

	
 
                if !is_valid_binding {
 
                    let binding_expr = &ctx.heap[self.in_binding_expr];
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module.source, var_expr.identifier.span,
 
                        "illegal location for binding variable: binding variables may only be nested under a binding expression, or a struct, union or array literal"
 
                    ).with_info_at_span(
 
                        &ctx.module.source, binding_expr.span, format!(
 
                            "'{}' was interpreted as a binding variable because the variable is not declared and it is nested under this binding expression",
 
                            var_expr.identifier.value.as_str()
 
                        )
 
                    ));
 
                }
 

	
 
                // By now we know that this is a valid binding expression. Given
 
                // that a binding expression must be nested under an if/while
 
                // statement, we now add the variable to the (implicit) block
 
                // statement following the if/while statement.
 
                let bound_identifier = var_expr.identifier.clone();
 
                let bound_variable_id = ctx.heap.alloc_variable(|this| Variable{
 
                    this,
 
                    kind: VariableKind::Binding,
 
                    parser_type: ParserType{ elements: vec![
 
                        ParserTypeElement{ full_span: bound_identifier.span, variant: ParserTypeVariant::Inferred }
 
                    ]},
 
                    identifier: bound_identifier,
 
                    relative_pos_in_block: 0,
 
                    unique_id_in_scope: -1,
 
                });
 

	
 
                let body_stmt_id = match &ctx.heap[self.in_test_expr] {
 
                    Statement::If(stmt) => stmt.true_body,
 
                    Statement::While(stmt) => stmt.body,
 
                    _ => unreachable!(),
 
                };
 
                let body_scope = Scope::Regular(body_stmt_id);
 
                self.checked_at_single_scope_add_local(ctx, body_scope, 0, bound_variable_id)?;
 

	
 
                bound_variable_id
 
            }
 
        };
 

	
 
        let var_expr = &mut ctx.heap[id];
 
        var_expr.declaration = Some(variable_id);
 
        var_expr.parent = self.expr_parent;
 
        var_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        Ok(())
 
    }
 
}
 

	
 
impl PassValidationLinking {
 
    //--------------------------------------------------------------------------
 
    // Special traversal
 
    //--------------------------------------------------------------------------
 

	
 
    fn visit_block_stmt_with_hint(&mut self, ctx: &mut Ctx, id: BlockStatementId, hint: Option<SynchronousStatementId>) -> VisitorResult {
 
        // Set parent scope and relative position in the parent scope. Remember
 
        // these values to set them back to the old values when we're done with
 
        // the traversal of the block's statements.
 
        let scope_next_unique_id = get_scope_next_unique_id(ctx, &self.cur_scope);
 

	
 
        let body = &mut ctx.heap[id];
 
        body.parent_scope = self.cur_scope.clone();
 
        body.relative_pos_in_parent = self.relative_pos_in_block;
 
        body.first_unique_id_in_scope = scope_next_unique_id;
 
        body.next_unique_id_in_scope = scope_next_unique_id;
 

	
 
        let old_scope = self.cur_scope.clone();
 
        self.cur_scope = match hint {
 
        let new_scope = match hint {
 
            Some(sync_id) => Scope::Synchronous((sync_id, id)),
 
            None => Scope::Regular(id),
 
        };
 

	
 
        match old_scope {
 
            Scope::Definition(_def_id) => {
 
                // Don't do anything. Block is implicitly a child of a
 
                // definition scope.
 
                if cfg!(debug_assertions) {
 
                    match &ctx.heap[_def_id] {
 
                        Definition::Function(proc_def) => debug_assert_eq!(proc_def.body, id),
 
                        Definition::Component(proc_def) => debug_assert_eq!(proc_def.body, id),
 
                        _ => unreachable!(),
 
                    }
 
                }
 
            },
 
            Scope::Regular(block_id) | Scope::Synchronous((_, block_id)) => {
 
                let parent_block = &mut ctx.heap[block_id];
 
                parent_block.scope_node.nested.push(new_scope);
 
            }
 
        }
 

	
 
        self.cur_scope = new_scope;
 

	
 
        let body = &mut ctx.heap[id];
 
        body.scope_node.parent = old_scope;
 
        body.relative_pos_in_parent = self.relative_pos_in_block;
 

	
 
        let old_relative_pos = self.relative_pos_in_block;
 

	
 
        // Copy statement IDs into buffer
 
        let statement_section = self.statement_buffer.start_section_initialized(&body.statements);
 

	
 
        // Perform the breadth-first pass. Its main purpose is to find labeled
 
        // statements such that we can find the `goto`-targets immediately when
 
        // performing the depth pass
 
        for stmt_idx in 0..statement_section.len() {
 
            self.relative_pos_in_block = stmt_idx as u32;
 
            self.visit_statement_for_locals_labels_and_in_sync(ctx, self.relative_pos_in_block, statement_section[stmt_idx])?;
 
        }
 

	
 
        // Perform the depth-first traversal
 
        for stmt_idx in 0..statement_section.len() {
 
            self.relative_pos_in_block = stmt_idx as u32;
 
            self.visit_stmt(ctx, statement_section[stmt_idx])?;
 
        }
 

	
 
        self.cur_scope = old_scope;
 
        self.relative_pos_in_block = old_relative_pos;
 
        statement_section.forget();
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_statement_for_locals_labels_and_in_sync(&mut self, ctx: &mut Ctx, relative_pos: u32, id: StatementId) -> VisitorResult {
 
        let statement = &mut ctx.heap[id];
 
        match statement {
 
            Statement::Local(stmt) => {
 
                match stmt {
 
                    LocalStatement::Memory(local) => {
 
                        let variable_id = local.variable;
 
                        self.checked_local_add(ctx, relative_pos, variable_id)?;
 
                        self.checked_add_local(ctx, relative_pos, variable_id)?;
 
                    },
 
                    LocalStatement::Channel(local) => {
 
                        let from_id = local.from;
 
                        let to_id = local.to;
 
                        self.checked_local_add(ctx, relative_pos, from_id)?;
 
                        self.checked_local_add(ctx, relative_pos, to_id)?;
 
                        self.checked_add_local(ctx, relative_pos, from_id)?;
 
                        self.checked_add_local(ctx, relative_pos, to_id)?;
 
                    }
 
                }
 
            }
 
            Statement::Labeled(stmt) => {
 
                let stmt_id = stmt.this;
 
                let body_id = stmt.body;
 
                self.checked_label_add(ctx, relative_pos, self.in_sync, stmt_id)?;
 
                self.checked_add_label(ctx, relative_pos, self.in_sync, stmt_id)?;
 
                self.visit_statement_for_locals_labels_and_in_sync(ctx, relative_pos, body_id)?;
 
            },
 
            Statement::While(stmt) => {
 
                stmt.in_sync = self.in_sync;
 
            },
 
            _ => {},
 
        }
 

	
 
        return Ok(())
 
    }
 

	
 
    fn visit_definition_and_assign_local_ids(&mut self, ctx: &mut Ctx, definition_id: DefinitionId) {
 
        let mut var_counter = 0;
 

	
 
        // Set IDs on parameters
 
        let (param_section, body_id) = match &ctx.heap[definition_id] {
 
            Definition::Function(func_def) => (
 
                self.variable_buffer.start_section_initialized(&func_def.parameters),
 
                func_def.body
 
            ),
 
            Definition::Component(comp_def) => (
 
                self.variable_buffer.start_section_initialized(&comp_def.parameters),
 
                comp_def.body
 
            ),
 
            _ => unreachable!(),
 
        } ;
 

	
 
        for idx in 0..param_section.len() {
 
            let var_id = param_section[idx];
 
            let var = &mut ctx.heap[var_id];
 
            var.unique_id_in_scope = var_counter;
 
            var_counter += 1;
 
        }
 

	
 
        param_section.forget();
 

	
 
        // Recurse into body
 
        self.visit_block_and_assign_local_ids(ctx, body_id, var_counter);
 
    }
 

	
 
    fn visit_block_and_assign_local_ids(&mut self, ctx: &mut Ctx, block_id: BlockStatementId, mut var_counter: i32) {
 
        let block_stmt = &mut ctx.heap[block_id];
 
        block_stmt.first_unique_id_in_scope = var_counter;
 

	
 
        let var_section = self.variable_buffer.start_section_initialized(&block_stmt.locals);
 
        let mut scope_section = self.statement_buffer.start_section();
 
        for child_scope in &block_stmt.scope_node.nested {
 
            debug_assert!(child_scope.is_block(), "found a child scope that is not a block statement");
 
            scope_section.push(child_scope.to_block().upcast());
 
        }
 

	
 
        let mut var_idx = 0;
 
        let mut scope_idx = 0;
 
        while var_idx < var_section.len() || scope_idx < scope_section.len() {
 
            let relative_var_pos = if var_idx < var_section.len() {
 
                ctx.heap[var_section[var_idx]].relative_pos_in_block
 
            } else {
 
                u32::MAX
 
            };
 

	
 
            let relative_scope_pos = if scope_idx < scope_section.len() {
 
                ctx.heap[scope_section[scope_idx]].as_block().relative_pos_in_parent
 
            } else {
 
                u32::MAX
 
            };
 

	
 
            debug_assert!(!(relative_var_pos == u32::MAX && relative_scope_pos == u32::MAX));
 

	
 
            // In certain cases the relative variable position is the same as
 
            // the scope position (insertion of binding variables). In that case
 
            // the variable should be treated first
 
            if relative_var_pos <= relative_scope_pos {
 
                let var = &mut ctx.heap[var_section[var_idx]];
 
                var.unique_id_in_scope = var_counter;
 
                var_counter += 1;
 
                var_idx += 1;
 
            } else {
 
                // Boy oh boy
 
                let block_id = ctx.heap[scope_section[scope_idx]].as_block().this;
 
                self.visit_block_and_assign_local_ids(ctx, block_id, var_counter);
 
                scope_idx += 1;
 
            }
 
        }
 

	
 
        var_section.forget();
 
        scope_section.forget();
 

	
 
        // Done assigning all IDs, assign the last ID to the block statement scope
 
        let block_stmt = &mut ctx.heap[block_id];
 
        block_stmt.next_unique_id_in_scope = var_counter;
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // 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_local_add(&mut self, ctx: &mut Ctx, relative_pos: u32, id: VariableId) -> Result<(), ParseError> {
 
    fn checked_add_local(&mut self, ctx: &mut Ctx, relative_pos: u32, id: VariableId) -> Result<(), ParseError> {
 
        debug_assert!(self.cur_scope.is_block());
 
        let local = &ctx.heap[id];
 
        let mut scope = &self.cur_scope;
 

	
 
        // Make sure we do not conflict with any global symbols
 
        let cur_scope = SymbolScope::Definition(self.def_type.definition_id());
 
        {
 
            let ident = &ctx.heap[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"
 
        loop {
 
            // We immediately go to the parent scope. We check the current scope
 
            // in the call at the end. Likewise for checking the symbol table.
 
            let block = &ctx.heap[scope.to_block()];
 

	
 
            scope = &block.scope_node.parent;
 
            if let Scope::Definition(definition_id) = scope {
 
                // At outer scope, check parameters of function/component
 
                for parameter_id in ctx.heap[*definition_id].parameters() {
 
                    let parameter = &ctx.heap[*parameter_id];
 
                    if local.identifier == parameter.identifier {
 
                        return Err(
 
                            ParseError::new_error_str_at_span(
 
                                &ctx.module.source, local.identifier.span, "Local variable name conflicts with parameter"
 
                            ).with_info_str_at_span(
 
                    &ctx.module.source, symbol.variant.span_of_introduction(&ctx.heap), "the conflicting symbol is introduced here"
 
                ));
 
                                &ctx.module.source, parameter.identifier.span, "Parameter definition is found here"
 
                            )
 
                        );
 
                    }
 
                }
 

	
 
        let local = &mut ctx.heap[id];
 
        local.relative_pos_in_block = relative_pos;
 
                // No collisions
 
                break;
 
            }
 

	
 
        // Make sure we do not shadow any variables in any of the scopes. Note
 
        // that variables in parent scopes may be declared later
 
        let local = &ctx.heap[id];
 
        let mut scope = &self.cur_scope;
 
        let mut local_relative_pos = self.relative_pos_in_block;
 
            // If here then the parent scope is a block scope
 
            let local_relative_pos = ctx.heap[scope.to_block()].relative_pos_in_parent;
 

	
 
        loop {
 
            debug_assert!(scope.is_block(), "scope is not a block");
 
            let block = &ctx.heap[scope.to_block()];
 
            for other_local_id in &block.locals {
 
                let other_local = &ctx.heap[*other_local_id];
 
                // Position check in case another variable with the same name
 
                // is defined in a higher-level scope, but later than the scope
 
                // in which the current variable resides.
 
                if local.this != *other_local_id &&
 
                    local_relative_pos >= other_local.relative_pos_in_block &&
 
                    local.identifier == other_local.identifier {
 
                    // Collision within this scope
 
                    return Err(
 
                        ParseError::new_error_str_at_span(
 
                            &ctx.module.source, local.identifier.span, "Local variable name conflicts with another variable"
 
                        ).with_info_str_at_span(
 
                            &ctx.module.source, other_local.identifier.span, "Previous variable is found here"
 
                        )
 
                    );
 
                }
 
            }
 
        }
 

	
 
            // Current scope is fine, move to parent scope if any
 
            scope = &block.parent_scope;
 
            if let Scope::Definition(definition_id) = scope {
 
                // At outer scope, check parameters of function/component
 
                for parameter_id in ctx.heap[*definition_id].parameters() {
 
                    let parameter = &ctx.heap[*parameter_id];
 
                    if local.identifier == parameter.identifier {
 
        // No collisions in any of the parent scope, attempt to add to scope
 
        self.checked_at_single_scope_add_local(ctx, self.cur_scope, relative_pos, id)
 
    }
 

	
 
    /// Adds a local variable to the specified scope. Will check the specified
 
    /// scope for variable conflicts and the symbol table for global conflicts.
 
    /// Will NOT check parent scopes of the specified scope.
 
    fn checked_at_single_scope_add_local(
 
        &mut self, ctx: &mut Ctx, scope: Scope, relative_pos: u32, id: VariableId
 
    ) -> Result<(), ParseError> {
 
        // Check the symbol table for conflicts
 
        {
 
            let cur_scope = SymbolScope::Definition(self.def_type.definition_id());
 
            let ident = &ctx.heap[id].identifier;
 
            if let Some(symbol) = ctx.symbols.get_symbol_by_name(cur_scope, &ident.value.as_bytes()) {
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module.source, ident.span,
 
                    "local variable declaration conflicts with symbol"
 
                ).with_info_str_at_span(
 
                    &ctx.module.source, symbol.variant.span_of_introduction(&ctx.heap), "the conflicting symbol is introduced here"
 
                ));
 
            }
 
        }
 

	
 
        // Check the specified scope for conflicts
 
        let local = &ctx.heap[id];
 

	
 
        debug_assert!(scope.is_block());
 
        let block = &ctx.heap[scope.to_block()];
 
        for other_local_id in &block.locals {
 
            let other_local = &ctx.heap[*other_local_id];
 
            if local.this != other_local.this &&
 
                relative_pos >= other_local.relative_pos_in_block &&
 
                local.identifier == other_local.identifier {
 
                // Collision
 
                return Err(
 
                    ParseError::new_error_str_at_span(
 
                                &ctx.module.source, local.identifier.span, "Local variable name conflicts with parameter"
 
                        &ctx.module.source, local.identifier.span, "Local variable name conflicts with another variable"
 
                    ).with_info_str_at_span(
 
                                &ctx.module.source, parameter.identifier.span, "Parameter definition is found here"
 
                        &ctx.module.source, other_local.identifier.span, "Previous variable is found here"
 
                    )
 
                );
 
            }
 
        }
 

	
 
                break;
 
            }
 

	
 
            // If here, then we are dealing with a block-like parent block
 
            local_relative_pos = ctx.heap[scope.to_block()].relative_pos_in_parent;
 
        }
 

	
 
        // No collisions at all
 
        let block = &mut ctx.heap[self.cur_scope.to_block()];
 
        // No collisions
 
        let block = &mut ctx.heap[scope.to_block()];
 
        block.locals.push(id);
 
        let unique_id_in_scope = block.next_unique_id_in_scope;
 
        block.next_unique_id_in_scope += 1;
 

	
 
        let variable = &mut ctx.heap[id];
 
        variable.unique_id_in_scope = unique_id_in_scope;
 
        let local = &mut ctx.heap[id];
 
        local.relative_pos_in_block = 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: u32, identifier: &Identifier) -> Result<VariableId, ParseError> {
 
    fn find_variable(&self, ctx: &Ctx, mut relative_pos: u32, identifier: &Identifier) -> Result<VariableId, ()> {
 
        debug_assert!(self.cur_scope.is_block());
 

	
 
        // TODO: May still refer to an alias of a global symbol using a single
 
        //  identifier in the namespace.
 
        // No need to use iterator over namespaces if here
 
        let mut scope = &self.cur_scope;
 
        
 
        loop {
 
            debug_assert!(scope.is_block());
 
            let block = &ctx.heap[scope.to_block()];
 
            
 
            for local_id in &block.locals {
 
                let local = &ctx.heap[*local_id];
 
                
 
                if local.relative_pos_in_block < relative_pos && identifier == &local.identifier {
 
                    return Ok(*local_id);
 
                }
 
            }
 

	
 
            scope = &block.parent_scope;
 
            scope = &block.scope_node.parent;
 
            if !scope.is_block() {
 
                // Definition scope, need to check arguments to definition
 
                match scope {
 
                    Scope::Definition(definition_id) => {
 
                        let definition = &ctx.heap[*definition_id];
 
                        for parameter_id in definition.parameters() {
 
                            let parameter = &ctx.heap[*parameter_id];
 
                            if identifier == &parameter.identifier {
 
                                return Ok(*parameter_id);
 
                            }
 
                        }
 
                    },
 
                    _ => unreachable!(),
 
                }
 

	
 
                // Variable could not be found
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module.source, identifier.span, "unresolved variable"
 
                ));
 
                return Err(())
 
            } else {
 
                relative_pos = block.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_label_add(&mut self, ctx: &mut Ctx, relative_pos: u32, in_sync: Option<SynchronousStatementId>, id: LabeledStatementId) -> Result<(), ParseError> {
 
    fn checked_add_label(&mut self, ctx: &mut Ctx, relative_pos: u32, in_sync: SynchronousStatementId, id: LabeledStatementId) -> Result<(), ParseError> {
 
        debug_assert!(self.cur_scope.is_block());
 

	
 
        // Make sure label is not defined within the current scope or any of the
 
        // parent scope.
 
        let label = &mut ctx.heap[id];
 
        label.relative_pos_in_block = relative_pos;
 
        label.in_sync = in_sync;
 

	
 
        let label = &ctx.heap[id];
 
        let mut scope = &self.cur_scope;
 

	
 
        loop {
 
            debug_assert!(scope.is_block(), "scope is not a block");
 
            let block = &ctx.heap[scope.to_block()];
 
            for other_label_id in &block.labels {
 
                let other_label = &ctx.heap[*other_label_id];
 
                if other_label.label == label.label {
 
                    // Collision
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module.source, label.label.span, "label name is used more than once"
 
                    ).with_info_str_at_span(
 
                        &ctx.module.source, other_label.label.span, "the other label is found here"
 
                    ));
 
                }
 
            }
 

	
 
            scope = &block.parent_scope;
 
            scope = &block.scope_node.parent;
 
            if !scope.is_block() {
 
                break;
 
            }
 
        }
 

	
 
        // No collisions
 
        let block = &mut ctx.heap[self.cur_scope.to_block()];
 
        block.labels.push(id);
 

	
 
        Ok(())
 
    }
 

	
 
    /// Finds a particular labeled statement by its identifier. Once found it
 
    /// will make sure that the target label does not skip over any variable
 
    /// declarations within the scope in which the label was found.
 
    fn find_label(&self, ctx: &Ctx, identifier: &Identifier) -> Result<LabeledStatementId, ParseError> {
 
        debug_assert!(self.cur_scope.is_block());
 

	
 
        let mut scope = &self.cur_scope;
 
        loop {
 
            debug_assert!(scope.is_block(), "scope is not a block");
 
            let relative_scope_pos = ctx.heap[scope.to_block()].relative_pos_in_parent;
 

	
 
            let block = &ctx.heap[scope.to_block()];
 
            for label_id in &block.labels {
 
                let label = &ctx.heap[*label_id];
 
                if label.label == *identifier {
 
                    for local_id in &block.locals {
 
                        // TODO: Better to do this in control flow analysis, it
 
                        //  is legal to skip over a variable declaration if it
 
                        //  is not actually being used. I might be missing
 
                        //  something here when laying out the bytecode...
 
                        let local = &ctx.heap[*local_id];
 
                        if local.relative_pos_in_block > relative_scope_pos && local.relative_pos_in_block < label.relative_pos_in_block {
 
                            return Err(
 
                                ParseError::new_error_str_at_span(&ctx.module.source, identifier.span, "this target label skips over a variable declaration")
 
                                .with_info_str_at_span(&ctx.module.source, label.label.span, "because it jumps to this label")
 
                                .with_info_str_at_span(&ctx.module.source, local.identifier.span, "which skips over this variable")
 
                            );
 
                        }
 
                    }
 
                    return Ok(*label_id);
 
                }
 
            }
 

	
 
            scope = &block.parent_scope;
 
            scope = &block.scope_node.parent;
 
            if !scope.is_block() {
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module.source, identifier.span, "could not find this label"
 
                ));
 
            }
 

	
 
        }
 
    }
 

	
 
    /// This function will check if the provided while statement ID has a block
 
    /// statement that is one of our current parents.
 
    fn has_parent_while_scope(&self, ctx: &Ctx, id: WhileStatementId) -> bool {
 
        let mut scope = &self.cur_scope;
 
        let while_stmt = &ctx.heap[id];
 
        loop {
 
            debug_assert!(scope.is_block());
 
            let block = scope.to_block();
 
            if while_stmt.body == block {
 
                return true;
 
            }
 

	
 
            let block = &ctx.heap[block];
 
            scope = &block.parent_scope;
 
            scope = &block.scope_node.parent;
 
            if !scope.is_block() {
 
                return false;
 
            }
 
        }
 
    }
 

	
 
    /// This function should be called while dealing with break/continue
 
    /// statements. It will try to find the targeted while statement, using the
 
    /// target label if provided. If a valid target is found then the loop's
 
    /// ID will be returned, otherwise a parsing error is constructed.
 
    /// The provided input position should be the position of the break/continue
 
    /// statement.
 
    fn resolve_break_or_continue_target(&self, ctx: &Ctx, span: InputSpan, label: &Option<Identifier>) -> Result<WhileStatementId, ParseError> {
 
        let target = match label {
 
            Some(label) => {
 
                let target_id = self.find_label(ctx, label)?;
 

	
 
                // Make sure break target is a while statement
 
                let target = &ctx.heap[target_id];
 
                if let Statement::While(target_stmt) = &ctx.heap[target.body] {
 
                    // Even though we have a target while statement, the break might not be
 
                    // present underneath this particular labeled while statement
 
                    if !self.has_parent_while_scope(ctx, target_stmt.this) {
 
                        return Err(ParseError::new_error_str_at_span(
 
                            &ctx.module.source, label.span, "break statement is not nested under the target label's while statement"
 
                        ).with_info_str_at_span(
 
                            &ctx.module.source, target.label.span, "the targeted label is found here"
 
                        ));
 
                    }
 

	
 
                    target_stmt.this
 
                } else {
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module.source, label.span, "incorrect break target label, it must target a while loop"
 
                    ).with_info_str_at_span(
 
                        &ctx.module.source, target.label.span, "The targeted label is found here"
 
                    ));
 
                }
 
            },
 
            None => {
 
                // Use the enclosing while statement, the break must be
 
                // nested within that while statement
 
                if self.in_while.is_none() {
 
                if self.in_while.is_invalid() {
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module.source, span, "Break statement is not nested under a while loop"
 
                    ));
 
                }
 

	
 
                self.in_while.unwrap()
 
                self.in_while
 
            }
 
        };
 

	
 
        // We have a valid target for the break statement. But we need to
 
        // make sure we will not break out of a synchronous block
 
        {
 
            let target_while = &ctx.heap[target];
 
            if target_while.in_sync != self.in_sync {
 
                // Break is nested under while statement, so can only escape a
 
                // sync block if the sync is nested inside the while statement.
 
                debug_assert!(self.in_sync.is_some());
 
                let sync_stmt = &ctx.heap[self.in_sync.unwrap()];
 
                debug_assert!(!self.in_sync.is_invalid());
 
                let sync_stmt = &ctx.heap[self.in_sync];
 
                return Err(
 
                    ParseError::new_error_str_at_span(&ctx.module.source, span, "break may not escape the surrounding synchronous block")
 
                        .with_info_str_at_span(&ctx.module.source, target_while.span, "the break escapes out of this loop")
 
                        .with_info_str_at_span(&ctx.module.source, sync_stmt.span, "And would therefore escape this synchronous block")
 
                );
 
            }
 
        }
 

	
 
        Ok(target)
 
    }
 
}
 
\ No newline at end of file
 

	
 
fn get_scope_next_unique_id(ctx: &Ctx, scope: &Scope) -> i32 {
 
    match scope {
 
        Scope::Definition(definition_id) => {
 
            let definition = &ctx.heap[*definition_id];
 
            match definition {
 
                Definition::Component(definition) => definition.parameters.len() as i32,
 
                Definition::Function(definition) => definition.parameters.len() as i32,
 
                _ => unreachable!("Scope::Definition points to non-procedure type")
 
            }
 
        },
 
        Scope::Synchronous((_, block_id)) | Scope::Regular(block_id) => {
 
            let block = &ctx.heap[*block_id];
 
            block.next_unique_id_in_scope
 
        }
 
    }
 
}
 
\ No newline at end of file
src/protocol/tests/eval_casting.rs
Show inline comments
 
use super::*;
 

	
 
#[test]
 
fn test_valid_unsigned_casting() {
 
    Tester::new_single_source_expect_ok("cast u8", "
 
        func foo() -> bool {
 
            u64 large_width = 255;
 
            u8 small_width = 255;
 

	
 
            // Explicit casting
 
            auto large_exp_to_08 = cast<u8> (large_width);
 
            auto large_exp_to_16 = cast<u16>(large_width);
 
            auto large_exp_to_32 = cast<u32>(large_width);
 
            auto large_exp_to_64 = cast<u64>(large_width);
 

	
 
            auto small_exp_to_08 = cast<u8> (small_width);
 
            auto small_exp_to_16 = cast<u16>(small_width);
 
            auto small_exp_to_32 = cast<u32>(small_width);
 
            auto small_exp_to_64 = cast<u64>(small_width);
 

	
 
            // Implicit casting
 
            u8  large_imp_to_08 = cast(large_width);
 
            u16 large_imp_to_16 = cast(large_width);
 
            u32 large_imp_to_32 = cast(large_width);
 
            u64 large_imp_to_64 = cast(large_width);
 

	
 
            u8  small_imp_to_08 = cast(small_width);
 
            u16 small_imp_to_16 = cast(small_width);
 
            u32 small_imp_to_32 = cast(small_width);
 
            u64 small_imp_to_64 = cast(small_width);
 

	
 
            return
 
                large_exp_to_08 == 255 && large_exp_to_16 == 255 && large_exp_to_32 == 255 && large_exp_to_64 == 255 &&
 
                small_exp_to_08 == 255 && small_exp_to_16 == 255 && small_exp_to_32 == 255 && small_exp_to_64 == 255 &&
 
                large_imp_to_08 == 255 && large_imp_to_16 == 255 && large_imp_to_32 == 255 && large_imp_to_64 == 255 &&
 
                small_imp_to_08 == 255 && small_imp_to_16 == 255 && small_imp_to_32 == 255 && small_imp_to_64 == 255;
 
        }
 
    ").for_function("foo", |f| { f
 
        .call_ok(Some(Value::Bool(true)));
 
    });
 
}
 

	
 
#[test]
 
fn test_invalid_casting() {
 
    fn generate_source(input_type: &str, input_value: &str, output_type: &str) -> String {
 
        return format!("
 
        func foo() -> u32 {{
 
            {} value = {};
 
            {} result = cast(value);
 
            return 0;
 
        }}
 
        ", input_type, input_value, output_type);
 
    }
 

	
 
    fn perform_test(input_type: &str, input_value: &str, output_type: &str) {
 
        Tester::new_single_source_expect_ok(
 
            format!("invalid cast {} to {}", input_type, output_type),
 
            generate_source(input_type, input_value, output_type)
 
        ).for_function("foo", |f| {
 
            f.call_err(&format!("'{}' which doesn't fit in a type '{}'", input_value, output_type));
 
        });
 
    }
 

	
 
    // Not exhaustive, good enough
 
    let tests = [
 
        // Unsigned large to small width
 
        ("u16", "256", "u8"),
 
        ("u32", "256", "u8"),
 
        ("u64", "256", "u8"),
 
        ("u32", "65536", "u16"),
 
        ("u64", "65536", "u16"),
 
        // Signed to unsigned
 
        ("s8", "-1", "u8"),
 
        ("s32", "-1", "u16"),
 
        ("s32", "65536", "u16"),
 
        // Signed to signed of smaller width
 
        ("s16", "-129", "s8"),
 
        ("s16", "128", "s8")
 
        ("s16", "128", "s8"),
 
        // Unsigned to signed
 
        ("u8", "128", "s8"),
 
        ("u16", "32768", "s16")
 
    ];
 

	
 
    for (input_type, input_value, output_type) in &tests {
 
        perform_test(input_type, input_value, output_type);
 
    }
 
}
 
\ No newline at end of file
src/protocol/tests/mod.rs
Show inline comments
 
/**
 
 * protocol/tests.rs
 
 *
 
 * Contains tests for various parts of the lexer/parser and the evaluator of the
 
 * code. These are intended to be temporary tests such that we're sure that we
 
 * don't break existing functionality.
 
 *
 
 * In the future these should be replaced by proper testing protocols.
 
 */
 

	
 
mod utils;
 
mod lexer;
 
mod parser_validation;
 
mod parser_inference;
 
mod parser_monomorphs;
 
mod parser_imports;
 
mod parser_binding;
 
mod eval_operators;
 
mod eval_calls;
 
mod eval_casting;
 
mod eval_silly;
 

	
 
pub(crate) use utils::{Tester}; // the testing harness
 
pub(crate) use crate::protocol::eval::value::*; // to test functions
 
\ No newline at end of file
src/protocol/tests/parser_binding.rs
Show inline comments
 
new file 100644
 
use super::*;
 

	
 
#[test]
 
fn test_correct_binding() {
 
    Tester::new_single_source_expect_ok("binding bare", )
 
}
 
\ No newline at end of file
src/protocol/tests/utils.rs
Show inline comments
 
use crate::collections::StringPool;
 
use crate::protocol::{
 
    Module,
 
    ast::*,
 
    input_source::*,
 
    parser::{
 
        Parser,
 
        type_table::{TypeTable, DefinedTypeVariant},
 
        symbol_table::SymbolTable,
 
        token_parsing::*,
 
    },
 
    eval::*,
 
};
 

	
 
// Carries information about the test into utility structures for builder-like
 
// assertions
 
#[derive(Clone, Copy)]
 
struct TestCtx<'a> {
 
    test_name: &'a str,
 
    heap: &'a Heap,
 
    modules: &'a Vec<Module>,
 
    types: &'a TypeTable,
 
    symbols: &'a SymbolTable,
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Interface for parsing and compiling
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct Tester {
 
    test_name: String,
 
    sources: Vec<String>
 
}
 

	
 
impl Tester {
 
    /// Constructs a new tester, allows adding multiple sources before compiling
 
    pub(crate) fn new<S: ToString>(test_name: S) -> Self {
 
        Self{
 
            test_name: test_name.to_string(),
 
            sources: Vec::new()
 
        }
 
    }
 

	
 
    /// Utility for quick tests that use a single source file and expect the
 
    /// compilation to succeed.
 
    pub(crate) fn new_single_source_expect_ok<T: ToString, S: ToString>(test_name: T, source: S) -> AstOkTester {
 
        Self::new(test_name)
 
            .with_source(source)
 
            .compile()
 
            .expect_ok()
 
    }
 

	
 
    /// Utility for quick tests that use a single source file and expect the
 
    /// compilation to fail.
 
    pub(crate) fn new_single_source_expect_err<T: ToString, S: ToString>(test_name: T, source: S) -> AstErrTester {
 
        Self::new(test_name)
 
            .with_source(source)
 
            .compile()
 
            .expect_err()
 
    }
 

	
 
    pub(crate) fn with_source<S: ToString>(mut self, source: S) -> Self {
 
        self.sources.push(source.to_string());
 
        self
 
    }
 

	
 
    pub(crate) fn compile(self) -> AstTesterResult {
 
        let mut parser = Parser::new();
 
        for source in self.sources.into_iter() {
 
            let source = source.into_bytes();
 
            let input_source = InputSource::new(String::from(""), source);
 

	
 
            if let Err(err) = parser.feed(input_source) {
 
                return AstTesterResult::Err(AstErrTester::new(self.test_name, err))
 
            }
 
        }
 

	
 
        if let Err(err) = parser.parse() {
 
            return AstTesterResult::Err(AstErrTester::new(self.test_name, err))
 
        }
 

	
 
        AstTesterResult::Ok(AstOkTester::new(self.test_name, parser))
 
    }
 
}
 

	
 
pub(crate) enum AstTesterResult {
 
    Ok(AstOkTester),
 
    Err(AstErrTester)
 
}
 

	
 
impl AstTesterResult {
 
    pub(crate) fn expect_ok(self) -> AstOkTester {
 
        match self {
 
            AstTesterResult::Ok(v) => v,
 
            AstTesterResult::Err(err) => {
 
                let wrapped = ErrorTester{ test_name: &err.test_name, error: &err.error };
 
                println!("DEBUG: Full error:\n{}", &err.error);
 
                assert!(
 
                    false,
 
                    "[{}] Expected compilation to succeed, but it failed with {}",
 
                    err.test_name, wrapped.assert_postfix()
 
                );
 
                unreachable!();
 
            }
 
        }
 
    }
 

	
 
    pub(crate) fn expect_err(self) -> AstErrTester {
 
        match self {
 
            AstTesterResult::Ok(ok) => {
 
                assert!(false, "[{}] Expected compilation to fail, but it succeeded", ok.test_name);
 
                unreachable!();
 
            },
 
            AstTesterResult::Err(err) => err,
 
        }
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Interface for successful compilation
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct AstOkTester {
 
    test_name: String,
 
    modules: Vec<Module>,
 
    heap: Heap,
 
    symbols: SymbolTable,
 
    types: TypeTable,
 
    pool: StringPool, // This is stored because if we drop it on the floor, we lose all our `StringRef<'static>`s
 
}
 

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

	
 
    pub(crate) fn for_struct<F: Fn(StructTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Struct(definition) = definition {
 
                if definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found struct with the same name
 
                let tester = StructTester::new(self.ctx(), 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 tester = UnionTester::new(self.ctx(), definition);
 
                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 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>,
 
    def: &'a StructDefinition,
 
}
 

	
 
impl<'a> StructTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a StructDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn assert_num_fields(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.def.fields.len(),
 
            "[{}] Expected {} struct fields, but found {} for {}",
 
            self.ctx.test_name, num, self.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.def.this.upcast());
 
        assert!(
 
            is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
 
            self.ctx.test_name, num, num_encountered, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    /// Asserts that a monomorph exist, separate polymorphic variable types by
 
    /// a semicolon.
 
    pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
 
        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
 
        assert!(
 
            has_monomorph, "[{}] Expected to find monomorph {}, but got {} for {}",
 
            self.ctx.test_name, serialized_monomorph, &serialized, 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.def.fields {
 
            if field.field.value.as_str() == name {
 
                let tester = StructFieldTester::new(self.ctx, field);
 
                f(tester);
 
                return self;
 
            }
 
        }
 

	
 
        assert!(
 
            false, "[{}] Could not find struct field '{}' for {}",
 
            self.ctx.test_name, name, self.assert_postfix()
 
        );
 
        unreachable!();
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("Struct{ name: ");
 
        v.push_str(self.def.identifier.value.as_str());
 
        v.push_str(", fields: [");
 
        for (field_idx, field) in self.def.fields.iter().enumerate() {
 
            if field_idx != 0 { v.push_str(", "); }
 
            v.push_str(field.field.value.as_str());
 
        }
 
        v.push_str("] }");
 
        v
 
    }
 
}
 

	
 
pub(crate) struct StructFieldTester<'a> {
 
    ctx: TestCtx<'a>,
 
    def: &'a StructFieldDefinition,
 
}
 

	
 
impl<'a> StructFieldTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a StructFieldDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn assert_parser_type(self, expected: &str) -> Self {
 
        let mut serialized_type = String::new();
 
        serialize_parser_type(&mut serialized_type, &self.ctx.heap, &self.def.parser_type);
 
        assert_eq!(
 
            expected, &serialized_type,
 
            "[{}] Expected type '{}', but got '{}' for {}",
 
            self.ctx.test_name, expected, &serialized_type, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut serialized_type = String::new();
 
        serialize_parser_type(&mut serialized_type, &self.ctx.heap, &self.def.parser_type);
 
        format!("StructField{{ name: {}, parser_type: {} }}", self.def.field.value.as_str(), serialized_type)
 
    }
 
}
 

	
 
pub(crate) struct EnumTester<'a> {
 
    ctx: TestCtx<'a>,
 
    def: &'a EnumDefinition,
 
}
 

	
 
impl<'a> EnumTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a EnumDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn assert_num_variants(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.def.variants.len(),
 
            "[{}] Expected {} enum variants, but found {} for {}",
 
            self.ctx.test_name, num, self.def.variants.len(), self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
 
        let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.def.this.upcast());
 
        assert!(
 
            is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
 
            self.ctx.test_name, num, num_encountered, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
 
        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
 
        assert!(
 
            has_monomorph, "[{}] Expected to find monomorph {}, but got {} for {}",
 
            self.ctx.test_name, serialized_monomorph, serialized, 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>,
 
    def: &'a UnionDefinition,
 
}
 

	
 
impl<'a> UnionTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a UnionDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn assert_num_variants(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.def.variants.len(),
 
            "[{}] Expected {} union variants, but found {} for {}",
 
            self.ctx.test_name, num, self.def.variants.len(), self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
 
        let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.def.this.upcast());
 
        assert!(
 
            is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
 
            self.ctx.test_name, num, num_encountered, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
 
        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
 
        assert!(
 
            has_monomorph, "[{}] Expected to find monomorph {}, but got {} for {}",
 
            self.ctx.test_name, serialized_monomorph, serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("Union{ 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 FunctionTester<'a> {
 
    ctx: TestCtx<'a>,
 
    def: &'a FunctionDefinition,
 
}
 

	
 
impl<'a> FunctionTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a FunctionDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn for_variable<F: Fn(VariableTester)>(self, name: &str, f: F) -> Self {
 
        // Find the memory statement in order to find the local
 
        let mem_stmt_id = seek_stmt(
 
            self.ctx.heap, self.def.body.upcast(),
 
            &|stmt| {
 
                if let Statement::Local(local) = stmt {
 
                    if let LocalStatement::Memory(memory) = local {
 
                        let local = &self.ctx.heap[memory.variable];
 
                        if local.identifier.value.as_str() == name {
 
                            return true;
 
                        }
 
                    }
 
                }
 

	
 
                false
 
            }
 
        );
 

	
 
        assert!(
 
            mem_stmt_id.is_some(), "[{}] Failed to find variable '{}' in {}",
 
            self.ctx.test_name, name, self.assert_postfix()
 
        );
 

	
 
        let mem_stmt_id = mem_stmt_id.unwrap();
 
        let local_id = self.ctx.heap[mem_stmt_id].as_memory().variable;
 
        let local = &self.ctx.heap[local_id];
 

	
 
        // Find the assignment expression that follows it
 
        let assignment_id = seek_expr_in_stmt(
 
            self.ctx.heap, self.def.body.upcast(),
 
            &|expr| {
 
                if let Expression::Assignment(assign_expr) = expr {
 
                    if let Expression::Variable(variable_expr) = &self.ctx.heap[assign_expr.left] {
 
                        if variable_expr.identifier.span.begin.offset == local.identifier.span.begin.offset {
 
                            return true;
 
                        }
 
                    }
 
                }
 

	
 
                false
 
            }
 
        );
 

	
 
        assert!(
 
            assignment_id.is_some(), "[{}] Failed to find assignment to variable '{}' in {}",
 
            self.ctx.test_name, name, self.assert_postfix()
 
        );
 

	
 
        let assignment = &self.ctx.heap[assignment_id.unwrap()];
 

	
 
        // Construct tester and pass to tester function
 
        let tester = VariableTester::new(
 
            self.ctx, self.def.this.upcast(), local, 
 
            assignment.as_assignment()
 
        );
 
        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.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::*;
 
        use crate::runtime::*;
 

	
 
        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 error:\n{}", 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 {
 
        use crate::protocol::*;
 
        use crate::runtime::*;
 

	
 
        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: Got evaluation error:\n{}", 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::*;
 
        use crate::runtime::*;
 

	
 
        let mut prompt = Prompt::new(&self.ctx.types, &self.ctx.heap, self.def.this.upcast(), 0, ValueGroup::new_stack(Vec::new()));
 
        let mut call_context = EvalContext::None;
 
        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,
 
    assignment: &'a AssignmentExpression,
 
}
 

	
 
impl<'a> VariableTester<'a> {
 
    fn new(
 
        ctx: TestCtx<'a>, definition_id: DefinitionId, variable: &'a Variable, assignment: &'a AssignmentExpression
 
    ) -> Self {
 
        Self{ ctx, definition_id, variable, assignment }
 
    }
 

	
 
    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 = self.ctx.types.get_procedure_expression_data(&self.definition_id, 0);
 
        let lhs = self.ctx.heap[self.assignment.left].as_variable();
 
        let concrete_type = &mono_data.expr_data[lhs.unique_id_in_definition as usize].expr_type;
 

	
 
        // Serialize and check
 
        let mut serialized = String::new();
 
        serialize_concrete_type(&mut serialized, self.ctx.heap, self.definition_id, concrete_type);
 

	
 
        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 = self.ctx.types.get_procedure_expression_data(&self.definition_id, 0);
 
        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 mut serialized = String::new();
 
        serialize_concrete_type(&mut serialized, self.ctx.heap, self.definition_id, concrete_type);
 

	
 
        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
 
        )
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// 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
 
    }
 

	
 
    // TODO: @tokenizer This should really be removed, as compilation should be
 
    //  deterministic, but we're currently using rather inefficient hashsets for
 
    //  the type inference, so remove once compiler architecture has changed.
 
    pub(crate) fn assert_any_msg_has(self, msg: &str) -> Self {
 
        let mut is_present = false;
 
        for statement in &self.error.statements {
 
            if statement.message.contains(msg) {
 
                is_present = true;
 
                break;
 
            }
 
        }
 

	
 
        assert!(
 
            is_present, "[{}] Expected an error statement to contain '{}' for {}",
 
            self.test_name, 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) {
 
    use DefinedTypeVariant::*;
 

	
 
    let type_def = ctx.types.get_base_definition(&definition_id).unwrap();
 
    let num_on_type = match &type_def.definition {
 
        Struct(v) => v.monomorphs.len(),
 
        Enum(v) => v.monomorphs.len(),
 
        Union(v) => v.monomorphs.len(),
 
        Function(v) => v.monomorphs.len(),
 
        Component(v) => v.monomorphs.len(),
 
    };
 

	
 
    (num_on_type == num, num_on_type)
 
}
 

	
 
fn has_monomorph(ctx: TestCtx, definition_id: DefinitionId, serialized_monomorph: &str) -> (bool, String) {
 
    use DefinedTypeVariant::*;
 

	
 
    let type_def = ctx.types.get_base_definition(&definition_id).unwrap();
 

	
 
    // Note: full_buffer is just for error reporting
 
    let mut full_buffer = String::new();
 
    let mut has_match = false;
 

	
 
    let serialize_monomorph = |monomorph: &Vec<ConcreteType>| -> String {
 
        let mut buffer = String::new();
 
        for (element_idx, element) in monomorph.iter().enumerate() {
 
            if element_idx != 0 {
 
                buffer.push(';');
 
            }
 
            serialize_concrete_type(&mut buffer, ctx.heap, definition_id, element);
 
        }
 

	
 
        buffer
 
    };
 

	
 
    full_buffer.push('[');
 
    let mut append_to_full_buffer = |buffer: String| {
 
        if full_buffer.len() != 1 {
 
            full_buffer.push_str(", ");
 
        }
 
        full_buffer.push('"');
 
        full_buffer.push_str(&buffer);
 
        full_buffer.push('"');
 
    };
 

	
 
    match &type_def.definition {
 
        Enum(_) | Union(_) | Struct(_) => {
 
            let monomorphs = type_def.definition.data_monomorphs();
 
            for monomorph in monomorphs.iter() {
 
                let buffer = serialize_monomorph(&monomorph.poly_args);
 
                if buffer == serialized_monomorph {
 
                    has_match = true;
 
                }
 
                append_to_full_buffer(buffer);
 
            }
 
        },
 
        Function(_) | Component(_) => {
 
            let monomorphs = type_def.definition.procedure_monomorphs();
 
            for monomorph in monomorphs.iter() {
 
                let buffer = serialize_monomorph(&monomorph.poly_args);
 
                if buffer == serialized_monomorph {
 
                    has_match = true;
 
                }
 
                append_to_full_buffer(buffer);
 
            }
 
        }
 
    }
 

	
 
    full_buffer.push(']');
 

	
 
    (has_match, full_buffer)
 
}
 

	
 
fn serialize_parser_type(buffer: &mut String, heap: &Heap, parser_type: &ParserType) {
 
    use ParserTypeVariant as PTV;
 

	
 
    fn write_bytes(buffer: &mut String, bytes: &[u8]) {
 
        let utf8 = String::from_utf8_lossy(bytes);
 
        buffer.push_str(&utf8);
 
    }
 

	
 
    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::PolymorphicArgument(definition_id, poly_idx) => {
 
                let definition = &heap[*definition_id];
 
                let poly_arg = &definition.poly_vars()[*poly_idx as usize];
 
                buffer.push_str(poly_arg.value.as_str());
 
            },
 
            PTV::Definition(definition_id, num_embedded) => {
 
                let definition = &heap[*definition_id];
 
                buffer.push_str(definition.identifier().value.as_str());
 

	
 
                let num_embedded = *num_embedded;
 
                if num_embedded != 0 {
 
                    buffer.push('<');
 
                    for embedded_idx in 0..num_embedded {
 
                        if embedded_idx != 0 {
 
                            buffer.push(',');
 
                        }
 
                        idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                    }
 
                    buffer.push('>');
 
                }
 
            }
 
        }
 

	
 
        idx
 
    }
 

	
 
    serialize_variant(buffer, heap, parser_type, 0);
 
}
 

	
 
fn serialize_concrete_type(buffer: &mut String, heap: &Heap, def: DefinitionId, concrete: &ConcreteType) {
 
    // Retrieve polymorphic variables
 
    let poly_vars = heap[def].poly_vars();
 

	
 
    fn write_bytes(buffer: &mut String, bytes: &[u8]) {
 
        let utf8 = String::from_utf8_lossy(bytes);
 
        buffer.push_str(&utf8);
 
    }
 

	
 
    fn serialize_recursive(
 
        buffer: &mut String, heap: &Heap, poly_vars: &Vec<Identifier>, concrete: &ConcreteType, mut idx: usize
 
    ) -> usize {
 
        use ConcreteTypePart as CTP;
 

	
 
        let part = &concrete.parts[idx];
 
        match part {
 
            CTP::Void => buffer.push_str("void"),
 
            CTP::Message => write_bytes(buffer, KW_TYPE_MESSAGE),
 
            CTP::Bool => write_bytes(buffer, KW_TYPE_BOOL),
 
            CTP::UInt8 => write_bytes(buffer, KW_TYPE_UINT8),
 
            CTP::UInt16 => write_bytes(buffer, KW_TYPE_UINT16),
 
            CTP::UInt32 => write_bytes(buffer, KW_TYPE_UINT32),
 
            CTP::UInt64 => write_bytes(buffer, KW_TYPE_UINT64),
 
            CTP::SInt8 => write_bytes(buffer, KW_TYPE_SINT8),
 
            CTP::SInt16 => write_bytes(buffer, KW_TYPE_SINT16),
 
            CTP::SInt32 => write_bytes(buffer, KW_TYPE_SINT32),
 
            CTP::SInt64 => write_bytes(buffer, KW_TYPE_SINT64),
 
            CTP::Character => write_bytes(buffer, KW_TYPE_CHAR),
 
            CTP::String => write_bytes(buffer, KW_TYPE_STRING),
 
            CTP::Array => {
 
                idx = serialize_recursive(buffer, heap, poly_vars, concrete, idx + 1);
 
                buffer.push_str("[]");
 
            },
 
            CTP::Slice => {
 
                idx = serialize_recursive(buffer, heap, poly_vars, concrete, idx + 1);
 
                buffer.push_str("[..]");
 
            },
 
            CTP::Input => {
 
                write_bytes(buffer, KW_TYPE_IN_PORT);
 
                buffer.push('<');
 
                idx = serialize_recursive(buffer, heap, poly_vars, concrete, idx + 1);
 
                buffer.push('>');
 
            },
 
            CTP::Output => {
 
                write_bytes(buffer, KW_TYPE_OUT_PORT);
 
                buffer.push('<');
 
                idx = serialize_recursive(buffer, heap, poly_vars, concrete, idx + 1);
 
                buffer.push('>');
 
            },
 
            CTP::Instance(definition_id, num_sub) => {
 
                let definition_name = heap[*definition_id].identifier();
 
                buffer.push_str(definition_name.value.as_str());
 
                if *num_sub != 0 {
 
                    buffer.push('<');
 
                    for sub_idx in 0..*num_sub {
 
                        if sub_idx != 0 { buffer.push(','); }
 
                        idx = serialize_recursive(buffer, heap, poly_vars, concrete, idx + 1);
 
                    }
 
                    buffer.push('>');
 
                }
 
            }
 
        }
 

	
 
        idx
 
    }
 

	
 
    serialize_recursive(buffer, heap, poly_vars, concrete, 0);
 
}
 

	
 
fn seek_def_in_modules<'a>(heap: &Heap, modules: &'a [Module], def_id: DefinitionId) -> Option<&'a Module> {
 
    for module in modules {
 
        let root = &heap.protocol_descriptions[module.root_id];
 
        for definition in &root.definitions {
 
            if *definition == def_id {
 
                return Some(module)
 
            }
 
        }
 
    }
 

	
 
    None
 
}
 

	
 
fn seek_stmt<F: Fn(&Statement) -> bool>(heap: &Heap, start: StatementId, f: &F) -> Option<StatementId> {
 
    let stmt = &heap[start];
 
    if f(stmt) { return Some(start); }
 

	
 
    // This statement wasn't it, try to recurse
 
    let matched = match stmt {
 
        Statement::Block(block) => {
 
            for sub_id in &block.statements {
 
                if let Some(id) = seek_stmt(heap, *sub_id, f) {
 
                    return Some(id);
 
                }
 
            }
 

	
 
            None
 
        },
 
        Statement::Labeled(stmt) => seek_stmt(heap, stmt.body, f),
 
        Statement::If(stmt) => {
 
            if let Some(id) = seek_stmt(heap, stmt.true_body.upcast(), f) {
 
                return Some(id);
 
            } else if let Some(false_body) = stmt.false_body {
 
                if let Some(id) = seek_stmt(heap, false_body.upcast(), f) {
 
                    return Some(id);
 
                }
 
            }
 
            None
 
        },
 
        Statement::While(stmt) => seek_stmt(heap, stmt.body.upcast(), f),
 
        Statement::Synchronous(stmt) => seek_stmt(heap, stmt.body.upcast(), f),
 
        _ => None
 
    };
 

	
 
    matched
 
}
 

	
 
fn seek_expr_in_expr<F: Fn(&Expression) -> bool>(heap: &Heap, start: ExpressionId, f: &F) -> Option<ExpressionId> {
 
    let expr = &heap[start];
 
    if f(expr) { return Some(start); }
 

	
 
    match expr {
 
        Expression::Assignment(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.left, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.right, f))
 
        },
 
        Expression::Binding(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.left.upcast(), f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.right, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.bound_to, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.bound_from, f))
 
        }
 
        Expression::Conditional(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.test, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.true_expression, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.false_expression, f))
 
        },
 
        Expression::Binary(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.left, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.right, f))
 
        },
 
        Expression::Unary(expr) => {
 
            seek_expr_in_expr(heap, expr.expression, f)
 
        },
 
        Expression::Indexing(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.subject, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.index, f))
 
        },
 
        Expression::Slicing(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.subject, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.from_index, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.to_index, f))
 
        },
 
        Expression::Select(expr) => {
 
            seek_expr_in_expr(heap, expr.subject, f)
 
        },
 
        Expression::Literal(expr) => {
 
            if let Literal::Struct(lit) = &expr.value {
 
                for field in &lit.fields {
 
                    if let Some(id) = seek_expr_in_expr(heap, field.value, f) {
 
                        return Some(id)
 
                    }
 
                }
 
            } else if let Literal::Array(elements) = &expr.value {
 
                for element in elements {
 
                    if let Some(id) = seek_expr_in_expr(heap, *element, f) {
 
                        return Some(id)
 
                    }
 
                }
 
            }
 
            None
 
        },
 
        Expression::Cast(expr) => {
 
            seek_expr_in_expr(heap, expr.subject, f)
 
        }
 
        Expression::Call(expr) => {
 
            for arg in &expr.arguments {
 
                if let Some(id) = seek_expr_in_expr(heap, *arg, f) {
 
                    return Some(id)
 
                }
 
            }
 
            None
 
        },
 
        Expression::Variable(_expr) => {
 
            None
 
        }
 
    }
 
}
 

	
 
fn seek_expr_in_stmt<F: Fn(&Expression) -> bool>(heap: &Heap, start: StatementId, f: &F) -> Option<ExpressionId> {
 
    let stmt = &heap[start];
 

	
 
    match stmt {
 
        Statement::Block(stmt) => {
 
            for stmt_id in &stmt.statements {
 
                if let Some(id) = seek_expr_in_stmt(heap, *stmt_id, f) {
 
                    return Some(id)
 
                }
 
            }
 
            None
 
        },
 
        Statement::Labeled(stmt) => {
 
            seek_expr_in_stmt(heap, stmt.body, f)
 
        },
 
        Statement::If(stmt) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, stmt.test, f))
 
            .or_else(|| seek_expr_in_stmt(heap, stmt.true_body.upcast(), f))
 
            .or_else(|| if let Some(false_body) = stmt.false_body {
 
                seek_expr_in_stmt(heap, false_body.upcast(), f)
 
            } else {
 
                None
 
            })
 
        },
 
        Statement::While(stmt) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, stmt.test, f))
 
            .or_else(|| seek_expr_in_stmt(heap, stmt.body.upcast(), f))
 
        },
 
        Statement::Synchronous(stmt) => {
 
            seek_expr_in_stmt(heap, stmt.body.upcast(), f)
 
        },
 
        Statement::Return(stmt) => {
 
            for expr_id in &stmt.expressions {
 
                if let Some(id) = seek_expr_in_expr(heap, *expr_id, f) {
 
                    return Some(id);
 
                }
 
            }
 
            None
 
        },
 
        Statement::New(stmt) => {
 
            seek_expr_in_expr(heap, stmt.expression.upcast(), f)
 
        },
 
        Statement::Expression(stmt) => {
 
            seek_expr_in_expr(heap, stmt.expression, f)
 
        },
 
        _ => None
 
    }
 
}
 
\ No newline at end of file
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