Changeset - 6eafa2cfcfd0
[Not reviewed]
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MH - 4 years ago 2021-05-28 14:46:37
contact@maxhenger.nl
Fix ParserType spans, fix some bugs
3 files changed:
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!(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));
 

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

	
 
impl Heap {
 
    pub fn new() -> Heap {
 
        Heap {
 
            // string_alloc: StringAllocator::new(),
 
            protocol_descriptions: Arena::new(),
 
            pragmas: Arena::new(),
 
            imports: Arena::new(),
 
            variables: Arena::new(),
 
            definitions: Arena::new(),
 
            statements: Arena::new(),
 
            expressions: Arena::new(),
 
        }
 
    }
 
    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 {
 
    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
 
    Definition(DefinitionId, u32), // u32 = number of subsequent types in the type tree.
 
}
 

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

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

	
 
/// ParserTypeElement is an element of the type tree. An element may be
 
/// implicit, meaning that the user didn't specify the type, but it was set by
 
/// the compiler.
 
#[derive(Debug, Clone)]
 
pub struct ParserTypeElement {
 
    // TODO: @Fix span
 
    pub full_span: InputSpan, // full span of type, including any polymorphic arguments
 
    pub element_span: InputSpan, // span of this element, not including the child types
 
    pub variant: ParserTypeVariant,
 
}
 

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

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

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

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

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

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

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

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

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

	
 
/// ConcreteType is the representation of a type after resolving symbolic types
 
/// and performing type inference
 
/// ConcreteType is the representation of a type after the type inference and
 
/// checker is finished. These are fully typed.
 
#[derive(Debug, Clone, Copy, Eq, PartialEq)]
 
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() }
 
    }
 
}
 

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

	
 
#[derive(Debug, Clone)]
 
pub struct Variable {
 
    pub this: VariableId,
 
    // Parsing
 
    pub kind: VariableKind,
 
    pub parser_type: ParserType,
 
    pub identifier: Identifier,
 
    // Validator/linker
 
    pub relative_pos_in_block: 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,
 
    // Symbol scanning
 
    pub span: InputSpan,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    // Parsing
 
    pub fields: Vec<StructFieldDefinition>
 
}
 

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

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

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

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

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

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

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

	
 
    pub fn span(&self) -> InputSpan {
 
        match self {
 
            Statement::Block(v) => v.span,
 
            Statement::Local(v) => v.span(),
 
            Statement::Labeled(v) => v.label.span,
 
            Statement::If(v) => v.span,
 
            Statement::While(v) => v.span,
 
            Statement::Break(v) => v.span,
 
            Statement::Continue(v) => v.span,
 
            Statement::Synchronous(v) => v.span,
 
            Statement::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(stmt) => stmt.next = next,
 
            Statement::EndBlock(stmt) => stmt.next = next,
 
            Statement::Local(stmt) => match stmt {
 
                LocalStatement::Channel(stmt) => stmt.next = next,
 
                LocalStatement::Memory(stmt) => stmt.next = next,
 
            },
 
            Statement::EndIf(stmt) => stmt.next = next,
 
            Statement::EndWhile(stmt) => stmt.next = next,
 
            Statement::EndSynchronous(stmt) => stmt.next = next,
 
            Statement::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 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>,
 
    pub next: StatementId,
 
}
 

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

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

	
 
impl LocalStatement {
 
    pub fn this(&self) -> LocalStatementId {
 
        match self {
 
            LocalStatement::Memory(stmt) => stmt.this.upcast(),
 
            LocalStatement::Channel(stmt) => stmt.this.upcast(),
 
        }
 
    }
 
    pub fn as_memory(&self) -> &MemoryStatement {
 
        match self {
 
            LocalStatement::Memory(result) => result,
 
            _ => panic!("Unable to cast `LocalStatement` to `MemoryStatement`"),
 
        }
 
    }
 
    pub fn as_channel(&self) -> &ChannelStatement {
 
        match self {
 
            LocalStatement::Channel(result) => result,
 
            _ => panic!("Unable to cast `LocalStatement` to `ChannelStatement`"),
 
        }
 
    }
 
    pub fn span(&self) -> InputSpan {
 
        match self {
 
            LocalStatement::Channel(v) => v.span,
 
            LocalStatement::Memory(v) => v.span,
 
        }
 
    }
 
}
 

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

	
 
#[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,
 
        }
 
    }
 

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

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

	
 
impl Expression {
 
    pub fn as_variable(&self) -> &VariableExpression {
 
        match self {
 
            Expression::Variable(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `VariableExpression`"),
 
        }
 
    }
 

	
 
    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
 
        }
 
    }
 

	
 
    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,
 
    Concatenated,
 
    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, // 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,
 
}
 

	
 
#[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_enum(&self) -> &LiteralEnum {
 
        if let Literal::Enum(literal) = self {
 
            literal
 
        } else {
 
            unreachable!("Attempted to obtain {:?} as Literal::Enum", self)
 
        }
 
    }
 

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

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

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

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

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

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

	
 
#[derive(Debug, Clone)]
 
pub struct VariableExpression {
 
    pub this: VariableExpressionId,
 
    // Parsing
 
    pub identifier: Identifier,
 
    // Validator/Linker
 
    pub declaration: Option<VariableId>,
 
    pub used_as_binding_target: bool,
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 
\ No newline at end of file
src/protocol/parser/mod.rs
Show inline comments
 
pub(crate) mod symbol_table;
 
pub(crate) mod type_table;
 
pub(crate) mod tokens;
 
pub(crate) mod token_parsing;
 
pub(crate) mod pass_tokenizer;
 
pub(crate) mod pass_symbols;
 
pub(crate) mod pass_imports;
 
pub(crate) mod pass_definitions;
 
pub(crate) mod pass_validation_linking;
 
pub(crate) mod pass_typing;
 
mod visitor;
 

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

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

	
 
use crate::protocol::ast_printer::ASTWriter;
 

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

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

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

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

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

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

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

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

	
 
        parser
 
    }
 

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 
}
 

	
 
// Note: args and return type need to be a function because we need to know the function ID.
 
fn insert_builtin_function<T: Fn(FunctionDefinitionId) -> (Vec<(&'static str, ParserType)>, ParserType)> (
 
    p: &mut Parser, func_name: &str, polymorphic: &[&str], arg_and_return_fn: T) {
 

	
 
    let mut poly_vars = Vec::with_capacity(polymorphic.len());
 
    for poly_var in polymorphic {
 
        poly_vars.push(Identifier{ span: InputSpan::new(), value: p.string_pool.intern(poly_var.as_bytes()) });
 
    }
 

	
 
    let func_ident_ref = p.string_pool.intern(func_name.as_bytes());
 
    let func_id = p.heap.alloc_function_definition(|this| FunctionDefinition{
 
        this,
 
        defined_in: RootId::new_invalid(),
 
        builtin: true,
 
        span: InputSpan::new(),
 
        identifier: Identifier{ span: InputSpan::new(), value: func_ident_ref.clone() },
 
        poly_vars,
 
        return_types: Vec::new(),
 
        parameters: Vec::new(),
 
        body: BlockStatementId::new_invalid(),
 
        num_expressions_in_body: -1,
 
    });
 

	
 
    let (args, ret) = arg_and_return_fn(func_id);
 

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

	
 
    let func = &mut p.heap[func_id];
 
    func.parameters = parameters;
 
    func.return_types.push(ret);
 

	
 
    p.symbol_table.insert_symbol(SymbolScope::Global, Symbol{
 
        name: func_ident_ref,
 
        variant: SymbolVariant::Definition(SymbolDefinition{
 
            defined_in_module: RootId::new_invalid(),
 
            defined_in_scope: SymbolScope::Global,
 
            definition_span: InputSpan::new(),
 
            identifier_span: InputSpan::new(),
 
            imported_at: None,
 
            class: DefinitionClass::Function,
 
            definition_id: func_id.upcast(),
 
        })
 
    }).unwrap();
 
}
 
\ 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 poly_vars = ctx.heap[definition_id].poly_vars();
 

	
 
                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...
 
                        let poly_vars = ctx.heap[definition_id].poly_vars();
 
                        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...
 
                let poly_vars = ctx.heap[definition_id].poly_vars();
 
                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();
 

	
 
            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
 
                span: InputSpan::from_positions(wrap_begin_pos, wrap_end_pos),
 
                statements,
 
                end_block: EndBlockStatementId::new_invalid(),
 
                scope_node: ScopeNode::new_invalid(),
 
                first_unique_id_in_scope: -1,
 
                next_unique_id_in_scope: -1,
 
                relative_pos_in_parent: 0,
 
                locals: Vec::new(),
 
                labels: Vec::new(),
 
                next: StatementId::new_invalid(),
 
            });
 

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

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

	
 
            Ok(id)
 
        }
 
    }
 

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

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

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

	
 
        Ok(id)
 
    }
 

	
 
    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: 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(),
 
        }))
 
    }
 

	
 
    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
 
            &mut scoped_section, "an expression", None
 
        )?;
 
        let expressions = scoped_section.into_vec();
 

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

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

	
 
    fn consume_goto_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<GotoStatementId, ParseError> {
 
        let goto_span = consume_exact_ident(&module.source, iter, KW_STMT_GOTO)?;
 
        let label = consume_ident_interned(&module.source, iter, ctx)?;
 
        consume_token(&module.source, iter, TokenKind::SemiColon)?;
 
        Ok(ctx.heap.alloc_goto_statement(|this| GotoStatement{
 
            this,
 
            span: goto_span,
 
            label,
 
            target: 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 inner_port_type = if Some(TokenKind::OpenAngle) == iter.next() {
 
        let (inner_port_type, end_pos) = if Some(TokenKind::OpenAngle) == iter.next() {
 
            // Retrieve the type of the channel, we're cheating a bit here by
 
            // consuming the first '<' and setting the initial angle depth to 1
 
            // such that our final '>' will be consumed as well.
 
            iter.consume();
 
            let definition_id = self.cur_definition;
 
            let poly_vars = ctx.heap[definition_id].poly_vars();
 
            consume_parser_type(
 
            let parser_type = consume_parser_type(
 
                &module.source, iter, &ctx.symbols, &ctx.heap,
 
                poly_vars, SymbolScope::Module(module.root_id), definition_id,
 
                true, 1
 
            )?
 
            )?;
 

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

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

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

	
 
        let mut to_port_type = ParserType{ elements: Vec::with_capacity(port_type_len) };
 
        to_port_type.elements.push(ParserTypeElement{ full_span: channel_span, variant: ParserTypeVariant::Input });
 
        to_port_type.elements.extend_from_slice(&inner_port_type.elements);
 
        let mut to_port_type = ParserType{ elements: Vec::with_capacity(port_type_len), full_span: port_type_span };
 
        to_port_type.elements.push(ParserTypeElement{
 
            element_span: channel_span,
 
            variant: ParserTypeVariant::Input
 
        });
 
        to_port_type.elements.extend_from_slice(&inner_port_type);
 
        let to = ctx.heap.alloc_variable(|this|Variable{
 
            this,
 
            kind: VariableKind::Local,
 
            identifier: to_identifier,
 
            parser_type: to_port_type,
 
            relative_pos_in_block: 0,
 
            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: 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 memory_span = InputSpan::from_positions(parser_type.full_span.begin, identifier.span.end);
 
                let assign_span = consume_token(&module.source, iter, TokenKind::Equal)?;
 

	
 
                let initial_expr_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,
 
                    used_as_binding_target: false,
 
                    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::AtEquals            => Some(AO::Concatenated),
 
                TK::StarEquals          => Some(AO::Multiplied),
 
                TK::SlashEquals         => Some(AO::Divided),
 
                TK::PercentEquals       => Some(AO::Remained),
 
                TK::PlusEquals          => Some(AO::Added),
 
                TK::MinusEquals         => Some(AO::Subtracted),
 
                TK::ShiftLeftEquals     => Some(AO::ShiftedLeft),
 
                TK::ShiftRightEquals    => Some(AO::ShiftedRight),
 
                TK::AndEquals           => Some(AO::BitwiseAnded),
 
                TK::CaretEquals         => Some(AO::BitwiseXored),
 
                TK::OrEquals            => Some(AO::BitwiseOred),
 
                _                       => None
 
            }
 
        }
 

	
 
        let expr = self.consume_conditional_expression(module, iter, ctx)?;
 
        if let Some(operation) = parse_assignment_operator(iter.next()) {
 
            let 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::Tilde) => Some(UO::BitwiseNot),
 
                Some(TK::Exclamation) => Some(UO::LogicalNot),
 
                _ => None
 
            }
 
        }
 

	
 
        let next = iter.next();
 
        if let Some(operation) = parse_prefix_token(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 if next == Some(TokenKind::PlusPlus) {
 
            return Err(ParseError::new_error_str_at_span(
 
                &module.source, iter.next_span(), "prefix increment is not supported in the language"
 
            ));
 
        } else if next == Some(TokenKind::MinusMinus) {
 
            return Err(ParseError::new_error_str_at_span(
 
                &module.source, iter.next_span(), "prefix decrement is not supported in this language"
 
            ));
 
        } else {
 
            self.consume_postfix_expression(module, iter, ctx)
 
        }
 
    }
 

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

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

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

	
 
            if token == TokenKind::PlusPlus {
 
                return Err(ParseError::new_error_str_at_span(
 
                    &module.source, span, "postfix increment is not supported in this language"
 
                ));
 
            } else if token == TokenKind::MinusMinus {
 
                return Err(ParseError::new_error_str_at_span(
 
                    &module.source, span, "prefix increment is not supported in this language"
 
                ));
 
            } else if token == TokenKind::OpenSquare {
 
                let subject = result;
 
                let from_index = self.consume_expression(module, iter, ctx)?;
 

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

	
 
                    let to_index = self.consume_expression(module, iter, ctx)?;
 
                    let end_span = consume_token(&module.source, iter, TokenKind::CloseSquare)?;
 
                    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
 
                                    span: parser_type.full_span,
 
                                    parser_type,
 
                                    method: Method::UserComponent,
 
                                    arguments,
 
                                    definition: target_definition_id,
 
                                    parent: ExpressionParent::None,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            },
 
                            Definition::Function(function_definition) => {
 
                                // 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
 
                                    span: parser_type.full_span,
 
                                    parser_type,
 
                                    method,
 
                                    arguments,
 
                                    definition: target_definition_id,
 
                                    parent: ExpressionParent::None,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            }
 
                        }
 
                    },
 
                    _ => {
 
                        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"
 
                            &module.source, parser_type.full_span, "unexpected type in expression"
 
                        ))
 
                    }
 
                }
 
            } else {
 
                // Check for builtin keywords or builtin functions
 
                if ident_text == KW_LIT_NULL || ident_text == KW_LIT_TRUE || ident_text == KW_LIT_FALSE {
 
                    iter.consume();
 

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

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

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

	
 
                    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,
 
                        }]}
 
                        ParserType{
 
                            elements: vec![ParserTypeElement{
 
                                element_span: ident_span,
 
                                variant: ParserTypeVariant::Inferred,
 
                            }],
 
                            full_span: ident_span
 
                        }
 
                    };
 

	
 
                    consume_token(&module.source, iter, TokenKind::OpenParen)?;
 
                    let subject = self.consume_expression(module, iter, ctx)?;
 
                    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?"
 
                            "unknown identifier, did you mistype a union variant's, component's, or function's name?"
 
                        ));
 
                    } else if Some(TokenKind::OpenCurly) == next {
 
                        return Err(ParseError::new_error_str_at_span(
 
                            &module.source, ident_span,
 
                            "unknown identifier, did you mistype a struct type's name?"
 
                        ))
 
                    }
 

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

	
 
                    ctx.heap.alloc_variable_expression(|this| VariableExpression {
 
                        this,
 
                        identifier,
 
                        declaration: None,
 
                        used_as_binding_target: false,
 
                        parent: ExpressionParent::None,
 
                        unique_id_in_definition: -1,
 
                    }).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
 
// TODO: @Optimize, @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();
 
        let num_embedded = elements[index].element.variant.num_embedded();
 
        elements.insert(index, Entry{
 
            element: ParserTypeElement{ full_span: span, variant: ParserTypeVariant::Array },
 
            element: ParserTypeElement{ element_span: span, variant: ParserTypeVariant::Array },
 
            depth,
 
        });
 

	
 
        // Now the original element, and all of its children, should have their
 
        // depth incremented by 1
 
        elements[index + 1].depth += 1;
 
        if num_embedded != 0 {
 
            for idx in index + 2..elements.len() {
 
                let element = &mut elements[idx];
 
                if element.depth >= depth + 1 {
 
                    element.depth += 1;
 
                } else {
 
                    break;
 
                }
 
            }
 
        }
 
    }
 

	
 
    // 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)?;
 
    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;
 
        let first_pos = element.element_span.begin;
 
        let mut last_pos = element.element_span.end;
 
        let mut elements = Vec::with_capacity(num_embedded + 2); // type itself + embedded + 1 (maybe) array type
 

	
 
        // Consume any potential array elements
 
        while iter.next() == Some(TokenKind::OpenSquare) {
 
            let mut array_span = iter.next_span();
 
            iter.consume();
 

	
 
            let end_span = iter.next_span();
 
            array_span.end = end_span.end;
 
            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 });
 
            last_pos = end_span.end;
 
            elements.push(ParserTypeElement{ element_span: array_span, variant: ParserTypeVariant::Array });
 
        }
 

	
 
        // Push the element itself
 
        let element_span = element.element_span;
 
        elements.push(element);
 

	
 
        // Check if polymorphic arguments are expected
 
        if num_embedded != 0 {
 
            if !allow_inference {
 
                return Err(ParseError::new_error_str_at_span(source, array_span, "type inference is not allowed here"));
 
                return Err(ParseError::new_error_str_at_span(source, element_span, "type inference is not allowed here"));
 
            }
 

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

	
 
        // When we have applied the initial-open-angle hack (e.g. consuming an
 
        // explicit type on a channel), then we consume the closing angles as
 
        // well.
 
        for _ in 0..first_angle_depth {
 
            let (_, angle_end_pos) = iter.next_positions();
 
            last_pos = angle_end_pos;
 
            consume_token(source, iter, TokenKind::CloseAngle)?;
 
        }
 

	
 
        return Ok(ParserType{ elements });
 
        return Ok(ParserType{
 
            elements,
 
            full_span: InputSpan::from_positions(first_pos, last_pos)
 
        });
 
    };
 

	
 
    // 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();
 
    let first_pos = element.element_span.begin;
 
    let mut last_pos = element.element_span.end;
 
    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 {
 
                    let (_, end_angle_pos) = iter.next_positions();
 
                    last_pos = end_angle_pos;
 
                    angle_depth -= 1;
 
                    state = State::Close;
 
                } else if Some(TokenKind::ShiftRight) == next {
 
                    let (_, end_angle_pos) = iter.next_positions();
 
                    last_pos = end_angle_pos;
 
                    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 {
 
                    let (_, end_angle_pos) = iter.next_positions();
 
                    last_pos = end_angle_pos;
 
                    angle_depth -= 1;
 
                    state = State::Close;
 
                } else if Some(TokenKind::ShiftRight) == next {
 
                    let (_, end_angle_pos) = iter.next_positions();
 
                    last_pos = end_angle_pos;
 
                    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 {
 
                    let (_, end_angle_pos) = iter.next_positions();
 
                    last_pos = end_angle_pos;
 
                    iter.consume();
 
                    angle_depth -= 1;
 
                    state = State::Close;
 
                } else if Some(TokenKind::ShiftRight) == next {
 
                    let (_, end_angle_pos) = iter.next_positions();
 
                    last_pos = end_angle_pos;
 
                    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() {
 
    for idx in 0..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,
 
                        source, cur_element.element.element_span,
 
                        "type inference is not allowed here"
 
                    ));
 
                }
 

	
 
                // Insert the missing types
 
                let inserted_span = cur_element.element.full_span;
 
                // Insert the missing types (in reverse order, but they're all
 
                // of the "inferred" type anyway).
 
                let inserted_span = cur_element.element.element_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 },
 
                        element: ParserTypeElement{ element_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));
 
                let type_name = String::from_utf8_lossy(source.section_at_span(cur_element.element.element_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,
 
                        source, cur_element.element.element_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,
 
                    source, cur_element.element.element_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 })
 
    Ok(ParserType{
 
        elements: constructed_elements,
 
        full_span: InputSpan::from_positions(first_pos, last_pos)
 
    })
 
}
 

	
 
/// 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.
 
/// may be trailing '::' tokens in the iterator, or the subsequent specification
 
/// of polymorphic arguments.
 
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 })
 
    Ok(ParserTypeElement{ element_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 poly_vars = ctx.heap[definition_id].poly_vars(); // Rust being rust, multiple lookups
 
            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

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