Changeset - 21deaee234f7
[Not reviewed]
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MH - 4 years ago 2021-11-12 19:38:16
contact@maxhenger.nl
Add concept of fork statement to language
6 files changed with 147 insertions and 5 deletions:
0 comments (0 inline, 0 general)
src/protocol/ast.rs
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// TODO: @cleanup, rigorous cleanup of dead code and silly object-oriented
 
//  trait impls where I deem them unfit.
 

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

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

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

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

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

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

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

	
 
define_aliased_ast_id!(RootId, Id<Root>, index(Root, protocol_descriptions), alloc(alloc_protocol_description));
 
define_aliased_ast_id!(PragmaId, Id<Pragma>, index(Pragma, pragmas), alloc(alloc_pragma));
 
define_aliased_ast_id!(ImportId, Id<Import>, index(Import, imports), alloc(alloc_import));
 
define_aliased_ast_id!(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!(ForkStatementId, StatementId, index(ForkStatement, Statement::Fork, statements), alloc(alloc_fork_statement));
 
define_new_ast_id!(EndForkStatementId, StatementId, index(EndForkStatement, Statement::EndFork, statements), alloc(alloc_end_fork_statement));
 
define_new_ast_id!(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 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 element_span: InputSpan, // span of this element, not including the child types
 
    pub variant: ParserTypeVariant,
 
}
 

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

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

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

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

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

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

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

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

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

	
 
/// ConcreteType is the representation of a type after the type inference and
 
/// checker is finished. These are fully typed.
 
#[derive(Debug, Clone, Copy, Eq, PartialEq)]
 
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),    // instance of data type
 
    Function(DefinitionId, u32),    // instance of function
 
    Component(DefinitionId, u32),   // instance of a connector
 
}
 

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

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

	
 
#[derive(Debug, Clone, Eq, PartialEq)]
 
pub struct ConcreteType {
 
    pub(crate) parts: Vec<ConcreteTypePart>
 
}
 
@@ -654,1016 +656,1037 @@ impl<'a> Iterator for ConcreteTypeIter<'a> {
 
        // Retrieve the subtree of interest
 
        let start_idx = self.part_idx;
 
        let end_idx = self.concrete.subtree_end_idx(start_idx);
 

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

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

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

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

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

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

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

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

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

	
 
#[derive(Debug, Clone, Copy)]
 
pub enum ComponentVariant {
 
    Primitive,
 
    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),
 
    Fork(ForkStatement),
 
    EndFork(EndForkStatement),
 
    Return(ReturnStatement),
 
    Goto(GotoStatement),
 
    New(NewStatement),
 
    Expression(ExpressionStatement),
 
}
 

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

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

	
 
    pub fn span(&self) -> InputSpan {
 
        match self {
 
            Statement::Block(v) => v.span,
 
            Statement::Local(v) => v.span(),
 
            Statement::Labeled(v) => v.label.span,
 
            Statement::If(v) => v.span,
 
            Statement::While(v) => v.span,
 
            Statement::Break(v) => v.span,
 
            Statement::Continue(v) => v.span,
 
            Statement::Synchronous(v) => v.span,
 
            Statement::Fork(v) => v.span,
 
            Statement::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!(),
 
            Statement::EndBlock(_) | Statement::EndIf(_) | Statement::EndWhile(_) | Statement::EndSynchronous(_) | Statement::EndFork(_) => unreachable!(),
 
        }
 
    }
 
    pub fn link_next(&mut self, next: StatementId) {
 
        match self {
 
            Statement::Block(stmt) => stmt.next = next,
 
            Statement::EndBlock(stmt) => stmt.next = next,
 
            Statement::Local(stmt) => match stmt {
 
                LocalStatement::Channel(stmt) => stmt.next = next,
 
                LocalStatement::Memory(stmt) => stmt.next = next,
 
            },
 
            Statement::EndIf(stmt) => stmt.next = next,
 
            Statement::EndWhile(stmt) => stmt.next = next,
 
            Statement::EndSynchronous(stmt) => stmt.next = next,
 
            Statement::EndFork(stmt) => stmt.next = next,
 
            Statement::New(stmt) => stmt.next = next,
 
            Statement::Expression(stmt) => stmt.next = next,
 
            Statement::Return(_)
 
            | Statement::Break(_)
 
            | Statement::Continue(_)
 
            | Statement::Synchronous(_)
 
            | Statement::Fork(_)
 
            | 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 ForkStatement {
 
    pub this: ForkStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "fork" keyword
 
    pub left_body: BlockStatementId,
 
    pub right_body: Option<BlockStatementId>,
 
    pub end_fork: EndForkStatementId,
 
}
 

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

	
 
#[derive(Debug, Clone)]
 
pub struct 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`"),
 
        }
 
    }
 

	
 
    /// Returns operator span, function name, a binding's "let" span, etc. An
 
    /// indicator for the kind of expression that is being applied.
 
    pub fn operation_span(&self) -> InputSpan {
 
        match self {
 
            Expression::Assignment(expr) => expr.operator_span,
 
            Expression::Binding(expr) => expr.operator_span,
 
            Expression::Conditional(expr) => expr.operator_span,
 
            Expression::Binary(expr) => expr.operator_span,
 
            Expression::Unary(expr) => expr.operator_span,
 
            Expression::Indexing(expr) => expr.operator_span,
 
            Expression::Slicing(expr) => expr.slicing_span,
 
            Expression::Select(expr) => expr.operator_span,
 
            Expression::Literal(expr) => expr.span,
 
            Expression::Cast(expr) => expr.cast_span,
 
            Expression::Call(expr) => expr.func_span,
 
            Expression::Variable(expr) => expr.identifier.span,
 
        }
 
    }
 

	
 
    /// Returns the span covering the entire expression (i.e. including the
 
    /// spans of the arguments as well).
 
    pub fn full_span(&self) -> InputSpan {
 
        match self {
 
            Expression::Assignment(expr) => expr.full_span,
 
            Expression::Binding(expr) => expr.full_span,
 
            Expression::Conditional(expr) => expr.full_span,
 
            Expression::Binary(expr) => expr.full_span,
 
            Expression::Unary(expr) => expr.full_span,
 
            Expression::Indexing(expr) => expr.full_span,
 
            Expression::Slicing(expr) => expr.full_span,
 
            Expression::Select(expr) => expr.full_span,
 
            Expression::Literal(expr) => expr.span,
 
            Expression::Cast(expr) => expr.full_span,
 
            Expression::Call(expr) => expr.full_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 operator_span: InputSpan,
 
    pub full_span: InputSpan,
 
    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 operator_span: InputSpan,
 
    pub full_span: InputSpan,
 
    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 operator_span: InputSpan,
 
    pub full_span: InputSpan,
 
    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 operator_span: InputSpan,
 
    pub full_span: InputSpan,
 
    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 operator_span: InputSpan,
 
    pub full_span: InputSpan,
 
    pub operation: UnaryOperator,
 
    pub expression: ExpressionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    pub unique_id_in_definition: i32,
 
}
 

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

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

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

	
 
#[derive(Debug, Clone)]
 
pub struct CallExpression {
 
    pub this: CallExpressionId,
 
    // Parsing
 
    pub func_span: InputSpan, // of the function name
 
    pub full_span: InputSpan, // includes the arguments and parentheses
 
    pub parser_type: ParserType, // of the function call, not the return type
 
    pub method: Method,
 
    pub arguments: Vec<ExpressionId>,
 
    pub definition: DefinitionId,
 
    // 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,
 
    Print,
 
    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,
 
}
src/protocol/parser/pass_definitions.rs
Show inline comments
 
@@ -43,957 +43,995 @@ impl PassDefinitions {
 
        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();
 

	
 
                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();
 
                        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 {
 
                    types_section.into_vec()
 
                } else {
 
                    types_section.forget();
 
                    Vec::new()
 
                };
 

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

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

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        // Parse function's argument list
 
        let mut parameter_section = self.variables.start_section();
 
        consume_parameter_list(
 
            &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();
 
                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),
 
                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()
 
                    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_FORK {
 
                let id = self.consume_fork_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 

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

	
 
                let fork_stmt = &mut ctx.heap[id];
 
                fork_stmt.end_fork = end_fork;
 
            } 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_fork_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ForkStatementId, ParseError> {
 
        let fork_span = consume_exact_ident(&module.source, iter, KW_STMT_FORK)?;
 
        let left_body = self.consume_block_or_wrapped_statement(module, iter, ctx)?;
 

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

	
 
        Ok(ctx.heap.alloc_fork_statement(|this| ForkStatement{
 
            this,
 
            span: fork_span,
 
            left_body,
 
            right_body,
 
            end_fork: EndForkStatementId::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, "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)?;
 

	
 
        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, 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();
 
            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
 
            (
 
                vec![ParserTypeElement{
 
                    element_span: channel_span,
 
                    variant: ParserTypeVariant::Inferred
 
                }],
 
                channel_span.end
 
            )
 
        };
 

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

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

	
 
        let mut to_port_type = ParserType{ elements: Vec::with_capacity(port_type_len), full_span: port_type_span };
 
        to_port_type.elements.push(ParserTypeElement{
 
            element_span: channel_span,
 
            variant: ParserTypeVariant::Input
 
        });
 
        to_port_type.elements.extend_from_slice(&inner_port_type);
 
        let to = ctx.heap.alloc_variable(|this|Variable{
 
            this,
 
            kind: VariableKind::Local,
 
            identifier: to_identifier,
 
            parser_type: to_port_type,
 
            relative_pos_in_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.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,
 
                    operator_span: assign_span,
 
                    full_span: InputSpan::from_positions(memory_span.begin, initial_expr_end_pos),
 
                    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 operator_span = iter.next_span();
 
            iter.consume();
 

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

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

	
 
            Ok(ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{
 
                this, operator_span, full_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 operator_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)?;
 

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

	
 
            Ok(ctx.heap.alloc_conditional_expression(|this| ConditionalExpression{
 
                this, operator_span, full_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> {
src/protocol/parser/pass_typing.rs
Show inline comments
 
@@ -761,768 +761,781 @@ impl<'a> Iterator for InferenceTypeMarkerIter<'a> {
 
        None
 
    }
 
}
 

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

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

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

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

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

	
 
pub(crate) struct ResolveQueueElement {
 
    // Note that using the `definition_id` and the `monomorph_idx` one may
 
    // query the type table for the full procedure type, thereby retrieving
 
    // the polymorphic arguments to the procedure.
 
    pub(crate) root_id: RootId,
 
    pub(crate) definition_id: DefinitionId,
 
    pub(crate) reserved_monomorph_idx: i32,
 
}
 

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

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

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

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

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

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

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

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

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

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

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

	
 
    // TODO: @cleanup Unsure about this, maybe a pattern will arise after
 
    //  a while.
 
    pub(crate) fn queue_module_definitions(ctx: &mut Ctx, queue: &mut ResolveQueue) {
 
        debug_assert_eq!(ctx.module().phase, ModuleCompilationPhase::ValidatedAndLinked);
 
        let root_id = ctx.module().root_id;
 
        let root = &ctx.heap.protocol_descriptions[root_id];
 
        for definition_id in &root.definitions {
 
            let definition = &ctx.heap[*definition_id];
 

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

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

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

	
 
        // Prepare for visiting the definition
 
        self.reserved_idx = element.reserved_monomorph_idx;
 

	
 
        let proc_base = ctx.types.get_base_definition(&element.definition_id).unwrap();
 
        if proc_base.is_polymorph {
 
            let proc_monos = proc_base.definition.procedure_monomorphs();
 
            let proc_mono = &(*proc_monos)[element.reserved_monomorph_idx as usize];
 

	
 
            for poly_arg in proc_mono.concrete_type.embedded_iter(0) {
 
                self.poly_vars.push(ConcreteType{ parts: Vec::from(poly_arg) });
 
            }
 
        }
 

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

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

	
 
impl Visitor for PassTyping {
 
    // Definitions
 

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

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

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

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

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

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

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

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

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

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

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

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

	
 
    // Statements
 

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

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

	
 
        Ok(())
 
    }
 

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

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

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        Ok(())
 
    }
 

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

	
 
        self.visit_block_stmt(ctx, body_id)
 
    }
 

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

	
 
        self.visit_block_stmt(ctx, left_body_id)?;
 
        if let Some(right_body_id) = right_body_id {
 
            self.visit_block_stmt(ctx, right_body_id)?;
 
        }
 

	
 
        Ok(())
 
    }
 

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

	
 
        self.visit_expr(ctx, expr_id)
 
    }
 

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

	
 
        self.visit_call_expr(ctx, call_expr_id)
 
    }
 

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

	
 
        self.visit_expr(ctx, subexpr_id)
 
    }
 

	
 
    // Expressions
 

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

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

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

	
 
        self.progress_assignment_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_binding_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_conditional_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_binary_expr(ctx, id)
 
    }
 

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

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

	
 
        self.visit_expr(ctx, arg_expr_id)?;
 

	
 
        self.progress_unary_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_indexing_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_slicing_expr(ctx, id)
 
    }
 

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

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

	
 
        self.visit_expr(ctx, subject_expr_id)?;
 

	
 
        self.progress_select_expr(ctx, id)
 
    }
 

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

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

	
 
                self.insert_initial_struct_polymorph_data(ctx, id);
 

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

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

	
 
        self.progress_literal_expr(ctx, id)
 
    }
 

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

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

	
 
        self.visit_expr(ctx, subject_expr_id)?;
 

	
 
        self.progress_cast_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_call_expr(ctx, id)
 
    }
 

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

	
 
        let var_expr = &ctx.heap[id];
 
        debug_assert!(var_expr.declaration.is_some());
 

	
 
        // Not pretty: if a binding expression, then this is the first time we
 
        // encounter the variable, so we still need to insert the variable data.
 
        let declaration = &ctx.heap[var_expr.declaration.unwrap()];
 
        if !self.var_types.contains_key(&declaration.this)  {
 
            debug_assert!(declaration.kind == VariableKind::Binding);
 
            let var_type = self.determine_inference_type_from_parser_type_elements(
 
                &declaration.parser_type.elements, true
 
            );
 
            self.var_types.insert(declaration.this, VarData{
 
                var_type,
 
                used_at: vec![upcast_id],
 
                linked_var: None
 
            });
 
        } else {
 
            let var_data = self.var_types.get_mut(&declaration.this).unwrap();
 
            var_data.used_at.push(upcast_id);
 
        }
 

	
 
        self.progress_variable_expr(ctx, id)
 
    }
 
}
 

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

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

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

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

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

	
 
                poly_type.write_concrete_type(&mut concrete_type);
 
            }
 

	
 
            Ok(concrete_type)
 
        }
 

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

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

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

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

	
 
                    let definition_id = expr.definition;
 
                    let concrete_type = inference_type_to_concrete_type(
 
                        ctx, extra_data.expr_id, &extra_data.poly_vars, first_concrete_part
 
                    )?;
 

	
 
                    match ctx.types.get_procedure_monomorph_index(&definition_id, &concrete_type) {
 
                        Some(reserved_idx) => {
 
                            // Already typechecked, or already put into the resolve queue
 
                            infer_expr.field_or_monomorph_idx = reserved_idx;
 
                        },
 
                        None => {
 
                            // Not typechecked yet, so add an entry in the queue
 
                            let reserved_idx = ctx.types.reserve_procedure_monomorph_index(&definition_id, concrete_type);
 
                            infer_expr.field_or_monomorph_idx = reserved_idx;
 
                            queue.push(ResolveQueueElement{
 
                                root_id: ctx.heap[definition_id].defined_in(),
 
                                definition_id,
 
                                reserved_monomorph_idx: reserved_idx,
 
                            });
 
                        }
 
                    }
 
                },
 
                Expression::Literal(expr) => {
 
                    let definition_id = match &expr.value {
 
                        Literal::Enum(lit) => lit.definition,
 
                        Literal::Union(lit) => lit.definition,
 
                        Literal::Struct(lit) => lit.definition,
 
                        _ => unreachable!(),
 
                    };
 
                    let first_concrete_part = ConcreteTypePart::Instance(definition_id, extra_data.poly_vars.len() as u32);
src/protocol/parser/pass_validation_linking.rs
Show inline comments
 
/*
 
 * pass_validation_linking.rs
 
 *
 
 * The pass that will validate properties of the AST statements (one is not
 
 * allowed to nest synchronous statements, instantiating components occurs in
 
 * the right places, etc.) and expressions (assignments may not occur in
 
 * arbitrary expressions).
 
 *
 
 * Furthermore, this pass will also perform "linking", in the sense of: some AST
 
 * nodes have something to do with one another, so we link them up in this pass
 
 * (e.g. setting the parents of expressions, linking the control flow statements
 
 * like `continue` and `break` up to the respective loop statement, etc.).
 
 *
 
 * There are several "confusing" parts about this pass:
 
 *
 
 * Setting expression parents: this is the simplest one. The pass struct acts
 
 * like a little state machine. When visiting an expression it will set the
 
 * "parent expression" field of the pass to itself, then visit its child. The
 
 * child will look at this "parent expression" field to determine its parent.
 
 *
 
 * Setting the `next` statement: the AST is a tree, but during execution we walk
 
 * a linear path through all statements. So where appropriate a statement may
 
 * set the "previous statement" field of the pass to itself. When visiting the
 
 * subsequent statement it will check this "previous statement", and if set, it
 
 * will link this previous statement up to itself. Not every statement has a
 
 * previous statement. Hence there are two patterns that occur: assigning the
 
 * `next` value, then clearing the "previous statement" field. And assigning the
 
 * `next` value, and then putting the current statement's ID in the "previous
 
 * statement" field. Because it is so common, this file contain two macros that
 
 * perform that operation.
 
 *
 
 * To make storing types for polymorphic procedures simpler and more efficient,
 
 * we assign to each expression in the procedure a unique ID. This is what the
 
 * "next expression index" field achieves. Each expression simply takes the
 
 * current value, and then increments this counter.
 
 */
 

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

	
 
use super::visitor::{
 
    STMT_BUFFER_INIT_CAPACITY,
 
    EXPR_BUFFER_INIT_CAPACITY,
 
    Ctx,
 
    Visitor,
 
    VisitorResult
 
};
 
use crate::protocol::parser::ModuleCompilationPhase;
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

	
 
    fn visit_local_memory_stmt(&mut self, ctx: &mut Ctx, id: MemoryStatementId) -> VisitorResult {
 
        assign_and_replace_next_stmt!(self, ctx, id.upcast().upcast());
 
        Ok(())
 
    }
 

	
 
    fn visit_local_channel_stmt(&mut self, ctx: &mut Ctx, id: ChannelStatementId) -> VisitorResult {
 
        assign_and_replace_next_stmt!(self, ctx, id.upcast().upcast());
 
        Ok(())
 
    }
 

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

	
 
        Ok(())
 
    }
 

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

	
 
        // Visit test expression
 
        debug_assert_eq!(self.expr_parent, ExpressionParent::None);
 
        debug_assert!(self.in_test_expr.is_invalid());
 

	
 
        self.in_test_expr = id.upcast();
 
        self.expr_parent = ExpressionParent::If(id);
 
        self.visit_expr(ctx, test_expr_id)?;
 
        self.in_test_expr = StatementId::new_invalid();
 

	
 
        self.expr_parent = ExpressionParent::None;
 

	
 
        // Visit true and false branch. Executor chooses next statement based on
 
        // test expression, not on if-statement itself.
 
        // test expression, not on if-statement itself. Hence the if statement
 
        // does not have a static subsequent statement.
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 
        self.visit_block_stmt(ctx, true_stmt_id)?;
 
        assign_then_erase_next_stmt!(self, ctx, end_if_id.upcast());
 

	
 
        if let Some(false_id) = false_stmt_id {
 
            self.visit_block_stmt(ctx, false_id)?;
 
            assign_then_erase_next_stmt!(self, ctx, end_if_id.upcast());
 
        }
 

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

	
 
            target_while.end_while
 
        };
 

	
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 
        let stmt = &mut ctx.heap[id];
 
        stmt.target = Some(target_end_while);
 

	
 
        Ok(())
 
    }
 

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

	
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 
        let stmt = &mut ctx.heap[id];
 
        stmt.target = Some(target_while_id);
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_synchronous_stmt(&mut self, ctx: &mut Ctx, id: SynchronousStatementId) -> VisitorResult {
 
        // Check for validity of synchronous statement
 
        let sync_stmt = &ctx.heap[id];
 
        let end_sync_id = sync_stmt.end_sync;
 
        let cur_sync_span = sync_stmt.span;
 
        if !self.in_sync.is_invalid() {
 
            // Nested synchronous statement
 
            let old_sync_span = ctx.heap[self.in_sync].span;
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, cur_sync_span, "Illegal nested synchronous statement"
 
            ).with_info_str_at_span(
 
                &ctx.module().source, old_sync_span, "It is nested in this synchronous statement"
 
            ));
 
        }
 

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

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

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

	
 
        self.in_sync = SynchronousStatementId::new_invalid();
 

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

	
 
    fn visit_goto_stmt(&mut self, ctx: &mut Ctx, id: GotoStatementId) -> VisitorResult {
 
        let target_id = self.find_label(ctx, &ctx.heap[id].label)?;
 
        ctx.heap[id].target = Some(target_id);
 

	
 
        let target = &ctx.heap[target_id];
 
        if self.in_sync != target.in_sync {
 
            // We can only goto the current scope or outer scopes. Because
 
            // nested sync statements are not allowed we must be inside a sync
 
            // statement.
 
            debug_assert!(!self.in_sync.is_invalid());
 
            let goto_stmt = &ctx.heap[id];
 
            let sync_stmt = &ctx.heap[self.in_sync];
 
            return Err(
 
                ParseError::new_error_str_at_span(&ctx.module().source, goto_stmt.span, "goto may not escape the surrounding synchronous block")
 
                .with_info_str_at_span(&ctx.module().source, target.label.span, "this is the target of the goto statement")
 
                .with_info_str_at_span(&ctx.module().source, sync_stmt.span, "which will jump past this statement")
 
            );
 
        }
 

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

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        Ok(())
 
    }
 

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

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

	
 
        Ok(())
 
    }
 

	
 

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

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

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

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

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

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

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

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

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

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

	
 
        let mut seeking_parent = self.expr_parent;
 
        loop {
 
            // Perform upward search to make sure only LogicalAnd is applied to
 
            // the binding expression
 
            let valid = match seeking_parent {
 
                ExpressionParent::If(_) | ExpressionParent::While(_) => {
 
                    // Every parent expression (if any) were LogicalAnd.
 
                    break;
 
                }
 
                ExpressionParent::Expression(parent_id, _) => {
 
                    let parent_expr = &ctx.heap[parent_id];
 
                    match parent_expr {
 
                        Expression::Binary(parent_expr) => {
 
                            // Set new parent to continue the search. Otherwise
 
                            // halt and provide an error using the current
 
                            // parent.
 
                            if parent_expr.operation == BinaryOperator::LogicalAnd {
 
                                seeking_parent = parent_expr.parent;
 
                                true
 
                            } else {
 
                                false
 
                            }
 
                        },
 
                        _ => false,
 
                    }
 
                },
 
                _ => unreachable!(), // nested under if/while, so always expressions as parents
 
            };
 

	
 
            if !valid {
 
                let binding_expr = &ctx.heap[id];
 
                let parent_expr = &ctx.heap[seeking_parent.as_expression()];
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, binding_expr.full_span,
 
                    "only the logical-and operator (&&) may be applied to binding expressions"
 
                ).with_info_str_at_span(
 
                    &ctx.module().source, parent_expr.operation_span(),
 
                    "this was the disallowed operation applied to the result from a binding expression"
 
                ));
 
            }
 
        }
 

	
 
        // Perform all of the index/parent assignment magic
 
        let binding_expr = &mut ctx.heap[id];
 

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

	
 
        let left_expr_id = binary_expr.left;
 
        let right_expr_id = binary_expr.right;
 

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

	
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
 
        self.visit_expr(ctx, left_expr_id)?;
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
 
        self.visit_expr(ctx, right_expr_id)?;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        self.expr_parent = ExpressionParent::Expression(id.upcast(), 0);
 
        self.visit_expr(ctx, expr_id)?;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

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

	
 
        let subject_expr_id = indexing_expr.subject;
 
        let index_expr_id = indexing_expr.index;
 

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

	
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
 
        self.visit_expr(ctx, subject_expr_id)?;
 

	
 
        let old_assignable = self.must_be_assignable.take();
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
 
        self.visit_expr(ctx, index_expr_id)?;
 

	
 
        self.must_be_assignable = old_assignable;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

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

	
 
        if let Some(span) = self.must_be_assignable {
 
            // TODO: @Slicing
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, span, "assignment to slices should be valid in the final language, but is currently not implemented"
 
            ));
 
        }
 

	
 
        let subject_expr_id = slicing_expr.subject;
 
        let from_expr_id = slicing_expr.from_index;
 
        let to_expr_id = slicing_expr.to_index;
 

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

	
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
 
        self.visit_expr(ctx, subject_expr_id)?;
 

	
 
        let old_assignable = self.must_be_assignable.take();
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
 
        self.visit_expr(ctx, from_expr_id)?;
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 2);
 
        self.visit_expr(ctx, to_expr_id)?;
 

	
 
        self.must_be_assignable = old_assignable;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_select_expr(&mut self, ctx: &mut Ctx, id: SelectExpressionId) -> VisitorResult {
 
        let select_expr = &mut ctx.heap[id];
 
        let expr_id = select_expr.subject;
 

	
 
        let old_expr_parent = self.expr_parent;
 
        select_expr.parent = old_expr_parent;
 
        select_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
src/protocol/parser/token_parsing.rs
Show inline comments
 
use crate::collections::ScopedSection;
 
use crate::protocol::ast::*;
 
use crate::protocol::input_source::{
 
    InputSource as InputSource,
 
    InputPosition as InputPosition,
 
    InputSpan,
 
    ParseError,
 
};
 
use super::tokens::*;
 
use super::symbol_table::*;
 
use super::{Module, PassCtx};
 

	
 
// Keywords
 
pub(crate) const KW_LET:       &'static [u8] = b"let";
 
pub(crate) const KW_AS:        &'static [u8] = b"as";
 
pub(crate) const KW_STRUCT:    &'static [u8] = b"struct";
 
pub(crate) const KW_ENUM:      &'static [u8] = b"enum";
 
pub(crate) const KW_UNION:     &'static [u8] = b"union";
 
pub(crate) const KW_FUNCTION:  &'static [u8] = b"func";
 
pub(crate) const KW_PRIMITIVE: &'static [u8] = b"primitive";
 
pub(crate) const KW_COMPOSITE: &'static [u8] = b"composite";
 
pub(crate) const KW_IMPORT:    &'static [u8] = b"import";
 

	
 
// Keywords - literals
 
pub(crate) const KW_LIT_TRUE:  &'static [u8] = b"true";
 
pub(crate) const KW_LIT_FALSE: &'static [u8] = b"false";
 
pub(crate) const KW_LIT_NULL:  &'static [u8] = b"null";
 

	
 
// Keywords - function(like)s
 
pub(crate) const KW_CAST:        &'static [u8] = b"cast";
 
pub(crate) const KW_FUNC_GET:    &'static [u8] = b"get";
 
pub(crate) const KW_FUNC_PUT:    &'static [u8] = b"put";
 
pub(crate) const KW_FUNC_FIRES:  &'static [u8] = b"fires";
 
pub(crate) const KW_FUNC_CREATE: &'static [u8] = b"create";
 
pub(crate) const KW_FUNC_LENGTH: &'static [u8] = b"length";
 
pub(crate) const KW_FUNC_ASSERT: &'static [u8] = b"assert";
 
pub(crate) const KW_FUNC_PRINT:  &'static [u8] = b"print";
 

	
 
// Keywords - statements
 
pub(crate) const KW_STMT_CHANNEL:  &'static [u8] = b"channel";
 
pub(crate) const KW_STMT_IF:       &'static [u8] = b"if";
 
pub(crate) const KW_STMT_ELSE:     &'static [u8] = b"else";
 
pub(crate) const KW_STMT_WHILE:    &'static [u8] = b"while";
 
pub(crate) const KW_STMT_BREAK:    &'static [u8] = b"break";
 
pub(crate) const KW_STMT_CONTINUE: &'static [u8] = b"continue";
 
pub(crate) const KW_STMT_GOTO:     &'static [u8] = b"goto";
 
pub(crate) const KW_STMT_RETURN:   &'static [u8] = b"return";
 
pub(crate) const KW_STMT_SYNC:     &'static [u8] = b"sync";
 
pub(crate) const KW_STMT_FORK:     &'static [u8] = b"fork";
 
pub(crate) const KW_STMT_OR:       &'static [u8] = b"or";
 
pub(crate) const KW_STMT_NEW:      &'static [u8] = b"new";
 

	
 
// Keywords - types
 
// Since types are needed for returning diagnostic information to the user, the
 
// string variants are put here as well.
 
pub(crate) const KW_TYPE_IN_PORT_STR:  &'static str = "in";
 
pub(crate) const KW_TYPE_OUT_PORT_STR: &'static str = "out";
 
pub(crate) const KW_TYPE_MESSAGE_STR:  &'static str = "msg";
 
pub(crate) const KW_TYPE_BOOL_STR:     &'static str = "bool";
 
pub(crate) const KW_TYPE_UINT8_STR:    &'static str = "u8";
 
pub(crate) const KW_TYPE_UINT16_STR:   &'static str = "u16";
 
pub(crate) const KW_TYPE_UINT32_STR:   &'static str = "u32";
 
pub(crate) const KW_TYPE_UINT64_STR:   &'static str = "u64";
 
pub(crate) const KW_TYPE_SINT8_STR:    &'static str = "s8";
 
pub(crate) const KW_TYPE_SINT16_STR:   &'static str = "s16";
 
pub(crate) const KW_TYPE_SINT32_STR:   &'static str = "s32";
 
pub(crate) const KW_TYPE_SINT64_STR:   &'static str = "s64";
 
pub(crate) const KW_TYPE_CHAR_STR:     &'static str = "char";
 
pub(crate) const KW_TYPE_STRING_STR:   &'static str = "string";
 
pub(crate) const KW_TYPE_INFERRED_STR: &'static str = "auto";
 

	
 
pub(crate) const KW_TYPE_IN_PORT:  &'static [u8] = KW_TYPE_IN_PORT_STR.as_bytes();
 
pub(crate) const KW_TYPE_OUT_PORT: &'static [u8] = KW_TYPE_OUT_PORT_STR.as_bytes();
 
pub(crate) const KW_TYPE_MESSAGE:  &'static [u8] = KW_TYPE_MESSAGE_STR.as_bytes();
 
pub(crate) const KW_TYPE_BOOL:     &'static [u8] = KW_TYPE_BOOL_STR.as_bytes();
 
pub(crate) const KW_TYPE_UINT8:    &'static [u8] = KW_TYPE_UINT8_STR.as_bytes();
 
pub(crate) const KW_TYPE_UINT16:   &'static [u8] = KW_TYPE_UINT16_STR.as_bytes();
 
pub(crate) const KW_TYPE_UINT32:   &'static [u8] = KW_TYPE_UINT32_STR.as_bytes();
 
pub(crate) const KW_TYPE_UINT64:   &'static [u8] = KW_TYPE_UINT64_STR.as_bytes();
 
pub(crate) const KW_TYPE_SINT8:    &'static [u8] = KW_TYPE_SINT8_STR.as_bytes();
 
pub(crate) const KW_TYPE_SINT16:   &'static [u8] = KW_TYPE_SINT16_STR.as_bytes();
 
pub(crate) const KW_TYPE_SINT32:   &'static [u8] = KW_TYPE_SINT32_STR.as_bytes();
 
pub(crate) const KW_TYPE_SINT64:   &'static [u8] = KW_TYPE_SINT64_STR.as_bytes();
 
pub(crate) const KW_TYPE_CHAR:     &'static [u8] = KW_TYPE_CHAR_STR.as_bytes();
 
pub(crate) const KW_TYPE_STRING:   &'static [u8] = KW_TYPE_STRING_STR.as_bytes();
 
pub(crate) const KW_TYPE_INFERRED: &'static [u8] = KW_TYPE_INFERRED_STR.as_bytes();
 

	
 
/// A special trait for when consuming comma-separated things such that we can
 
/// push them onto a `Vec` and onto a `ScopedSection`. As we monomorph for
 
/// very specific comma-separated cases I don't expect polymorph bloat.
 
/// Also, I really don't like this solution.
 
pub(crate) trait Extendable {
 
    type Value;
 

	
 
    fn push(&mut self, v: Self::Value);
 
}
 

	
 
impl<T> Extendable for Vec<T> {
 
    type Value = T;
 

	
 
    #[inline]
 
    fn push(&mut self, v: Self::Value) {
 
        (self as &mut Vec<T>).push(v);
 
    }
 
}
 

	
 
impl<T: Sized> Extendable for ScopedSection<T> {
 
    type Value = T;
 

	
 
    #[inline]
 
    fn push(&mut self, v: Self::Value) {
 
        (self as &mut ScopedSection<T>).push(v);
 
    }
 
}
 

	
 
/// Consumes a domain-name identifier: identifiers separated by a dot. For
 
/// simplification of later parsing and span identification the domain-name may
 
/// contain whitespace, but must reside on the same line.
 
pub(crate) fn consume_domain_ident<'a>(
 
    source: &'a InputSource, iter: &mut TokenIter
 
) -> Result<(&'a [u8], InputSpan), ParseError> {
 
    let (_, mut span) = consume_ident(source, iter)?;
 
    while let Some(TokenKind::Dot) = iter.next() {
 
        iter.consume();
 
        let (_, new_span) = consume_ident(source, iter)?;
 
        span.end = new_span.end;
 
    }
 

	
 
    // Not strictly necessary, but probably a reasonable restriction: this
 
    // simplifies parsing of module naming and imports.
 
    if span.begin.line != span.end.line {
 
        return Err(ParseError::new_error_str_at_span(source, span, "module names may not span multiple lines"));
 
    }
 

	
 
    // If module name consists of a single identifier, then it may not match any
 
    // of the reserved keywords
 
    let section = source.section_at_pos(span.begin, span.end);
 
    if is_reserved_keyword(section) {
 
        return Err(ParseError::new_error_str_at_span(source, span, "encountered reserved keyword"));
 
    }
 

	
 
    Ok((source.section_at_pos(span.begin, span.end), span))
 
}
 

	
 
/// Consumes a specific expected token. Be careful to only call this with tokens
 
/// that do not have a variable length.
 
pub(crate) fn consume_token(source: &InputSource, iter: &mut TokenIter, expected: TokenKind) -> Result<InputSpan, ParseError> {
 
    if Some(expected) != iter.next() {
 
        return Err(ParseError::new_error_at_pos(
 
            source, iter.last_valid_pos(),
 
            format!("expected '{}'", expected.token_chars())
 
        ));
 
    }
 
    let span = iter.next_span();
 
    iter.consume();
 
    Ok(span)
 
}
 

	
 
/// Consumes a comma separated list until the closing delimiter is encountered
 
pub(crate) fn consume_comma_separated_until<T, F, E>(
 
    close_delim: TokenKind, source: &InputSource, iter: &mut TokenIter, ctx: &mut PassCtx,
 
    mut consumer_fn: F, target: &mut E, item_name_and_article: &'static str,
 
    close_pos: Option<&mut InputPosition>
 
) -> Result<(), ParseError>
 
    where F: FnMut(&InputSource, &mut TokenIter, &mut PassCtx) -> Result<T, ParseError>,
 
          E: Extendable<Value=T>
 
{
 
    let mut had_comma = true;
 
    let mut next;
 
    loop {
 
        next = iter.next();
 
        if Some(close_delim) == next {
 
            if let Some(close_pos) = close_pos {
 
                // If requested return the position of the closing delimiter
 
                let (_, new_close_pos) = iter.next_positions();
 
                *close_pos = new_close_pos;
 
            }
 
            iter.consume();
 
            break;
 
        } else if !had_comma || next.is_none() {
 
            return Err(ParseError::new_error_at_pos(
 
                source, iter.last_valid_pos(),
 
                format!("expected a '{}', or {}", close_delim.token_chars(), item_name_and_article)
 
            ));
 
        }
 

	
 
        let new_item = consumer_fn(source, iter, ctx)?;
 
        target.push(new_item);
 

	
 
        next = iter.next();
 
        had_comma = next == Some(TokenKind::Comma);
 
        if had_comma {
 
            iter.consume();
 
        }
 
    }
 

	
 
    Ok(())
 
}
 

	
 
/// Consumes a comma-separated list of items if the opening delimiting token is
 
/// encountered. If not, then the iterator will remain at its current position.
 
/// Note that the potential cases may be:
 
/// - No opening delimiter encountered, then we return `false`.
 
/// - Both opening and closing delimiter encountered, but no items.
 
/// - Opening and closing delimiter encountered, and items were processed.
 
/// - Found an opening delimiter, but processing an item failed.
 
pub(crate) fn maybe_consume_comma_separated<T, F, E>(
 
    open_delim: TokenKind, close_delim: TokenKind, source: &InputSource, iter: &mut TokenIter, ctx: &mut PassCtx,
 
    consumer_fn: F, target: &mut E, item_name_and_article: &'static str,
 
    close_pos: Option<&mut InputPosition>
 
) -> Result<bool, ParseError>
 
    where F: FnMut(&InputSource, &mut TokenIter, &mut PassCtx) -> Result<T, ParseError>,
 
          E: Extendable<Value=T>
 
{
 
    if Some(open_delim) != iter.next() {
 
        return Ok(false);
 
    }
 

	
 
    // Opening delimiter encountered, so must parse the comma-separated list.
 
    iter.consume();
 
    consume_comma_separated_until(close_delim, source, iter, ctx, consumer_fn, target, item_name_and_article, close_pos)?;
 

	
 
    Ok(true)
 
}
 

	
 
pub(crate) fn maybe_consume_comma_separated_spilled<F: FnMut(&InputSource, &mut TokenIter, &mut PassCtx) -> Result<(), ParseError>>(
 
    open_delim: TokenKind, close_delim: TokenKind, source: &InputSource,
 
    iter: &mut TokenIter, ctx: &mut PassCtx,
 
    mut consumer_fn: F, item_name_and_article: &'static str
 
) -> Result<bool, ParseError> {
 
    let mut next = iter.next();
 
    if Some(open_delim) != next {
 
        return Ok(false);
 
    }
 

	
 
    iter.consume();
 
    let mut had_comma = true;
 
    loop {
 
        next = iter.next();
 
        if Some(close_delim) == next {
 
            iter.consume();
 
            break;
 
        } else if !had_comma {
 
            return Err(ParseError::new_error_at_pos(
 
                source, iter.last_valid_pos(),
 
                format!("expected a '{}', or {}", close_delim.token_chars(), item_name_and_article)
 
            ));
 
        }
 

	
 
        consumer_fn(source, iter, ctx)?;
 
        next = iter.next();
 
        had_comma = next == Some(TokenKind::Comma);
 
        if had_comma {
 
            iter.consume();
 
        }
 
    }
 

	
 
    Ok(true)
 
}
 

	
 
/// Consumes a comma-separated list and expected the opening and closing
 
/// characters to be present. The returned array may still be empty
 
pub(crate) fn consume_comma_separated<T, F, E>(
 
    open_delim: TokenKind, close_delim: TokenKind, source: &InputSource,
 
    iter: &mut TokenIter, ctx: &mut PassCtx,
 
    consumer_fn: F, target: &mut E, item_name_and_article: &'static str,
 
    list_name_and_article: &'static str, close_pos: Option<&mut InputPosition>
 
) -> Result<(), ParseError>
 
    where F: FnMut(&InputSource, &mut TokenIter, &mut PassCtx) -> Result<T, ParseError>,
 
          E: Extendable<Value=T>
 
{
 
    let first_pos = iter.last_valid_pos();
 
    match maybe_consume_comma_separated(
 
        open_delim, close_delim, source, iter, ctx, consumer_fn, target,
 
        item_name_and_article, close_pos
 
    ) {
 
        Ok(true) => Ok(()),
 
        Ok(false) => {
 
            return Err(ParseError::new_error_at_pos(
 
                source, first_pos,
 
                format!("expected {}", list_name_and_article)
 
            ));
 
        },
 
        Err(err) => Err(err)
 
    }
 
}
 

	
 
/// Consumes an integer literal, may be binary, octal, hexadecimal or decimal,
 
/// and may have separating '_'-characters.
 
/// TODO: @Cleanup, @Performance
 
pub(crate) fn consume_integer_literal(source: &InputSource, iter: &mut TokenIter, buffer: &mut String) -> Result<(u64, InputSpan), ParseError> {
 
    if Some(TokenKind::Integer) != iter.next() {
 
        return Err(ParseError::new_error_str_at_pos(source, iter.last_valid_pos(), "expected an integer literal"));
 
    }
 
    let integer_span = iter.next_span();
 
    iter.consume();
 

	
 
    let integer_text = source.section_at_span(integer_span);
 

	
 
    // Determine radix and offset from prefix
 
    let (radix, input_offset, radix_name) =
 
        if integer_text.starts_with(b"0b") || integer_text.starts_with(b"0B") {
 
            // Binary number
 
            (2, 2, "binary")
 
        } else if integer_text.starts_with(b"0o") || integer_text.starts_with(b"0O") {
 
            // Octal number
 
            (8, 2, "octal")
 
        } else if integer_text.starts_with(b"0x") || integer_text.starts_with(b"0X") {
 
            // Hexadecimal number
 
            (16, 2, "hexadecimal")
 
        } else {
 
            (10, 0, "decimal")
 
        };
 

	
 
    // Take out any of the separating '_' characters
 
    buffer.clear();
 
    for char_idx in input_offset..integer_text.len() {
 
        let char = integer_text[char_idx];
 
        if char == b'_' {
 
            continue;
 
        }
 

	
 
        if !((char >= b'0' && char <= b'9') || (char >= b'A' && char <= b'F') || (char >= b'a' || char <= b'f')) {
 
            return Err(ParseError::new_error_at_span(
 
                source, integer_span,
 
                format!("incorrectly formatted {} number", radix_name)
 
            ));
 
        }
 
        buffer.push(char::from(char));
 
    }
 

	
 
    // Use the cleaned up string to convert to integer
 
    match u64::from_str_radix(&buffer, radix) {
 
        Ok(number) => Ok((number, integer_span)),
 
        Err(_) => Err(ParseError::new_error_at_span(
 
            source, integer_span,
 
            format!("incorrectly formatted {} number", radix_name)
 
        )),
 
    }
 
}
 

	
 
/// Consumes a character literal. We currently support a limited number of
 
/// backslash-escaped characters
 
pub(crate) fn consume_character_literal(
 
    source: &InputSource, iter: &mut TokenIter
 
) -> Result<(char, InputSpan), ParseError> {
 
    if Some(TokenKind::Character) != iter.next() {
 
        return Err(ParseError::new_error_str_at_pos(source, iter.last_valid_pos(), "expected a character literal"));
 
    }
 
    let span = iter.next_span();
 
    iter.consume();
 

	
 
    let char_text = source.section_at_span(span);
 
    if !char_text.is_ascii() {
 
        return Err(ParseError::new_error_str_at_span(
 
            source, span, "expected an ASCII character literal"
 
        ));
 
    }
 

	
 
    match char_text.len() {
 
        0 => return Err(ParseError::new_error_str_at_span(source, span, "too little characters in character literal")),
 
        1 => {
 
            // We already know the text is ascii, so just throw an error if we have the escape
 
            // character.
 
            if char_text[0] == b'\\' {
 
                return Err(ParseError::new_error_str_at_span(source, span, "escape character without subsequent character"));
 
            }
 
            return Ok((char_text[0] as char, span));
 
        },
 
        2 => {
 
            if char_text[0] == b'\\' {
 
                let result = parse_escaped_character(source, span, char_text[1])?;
 
                return Ok((result, span))
 
            }
 
        },
 
        _ => {}
 
    }
 

	
 
    return Err(ParseError::new_error_str_at_span(source, span, "too many characters in character literal"))
 
}
 

	
 
/// Consumes a string literal. We currently support a limited number of
 
/// backslash-escaped characters. Note that the result is stored in the
 
/// buffer.
 
pub(crate) fn consume_string_literal(
 
    source: &InputSource, iter: &mut TokenIter, buffer: &mut String
 
) -> Result<InputSpan, ParseError> {
 
    if Some(TokenKind::String) != iter.next() {
 
        return Err(ParseError::new_error_str_at_pos(source, iter.last_valid_pos(), "expected a string literal"));
 
    }
 

	
 
    buffer.clear();
 
    let span = iter.next_span();
 
    iter.consume();
 

	
 
    let text = source.section_at_span(span);
 
    if !text.is_ascii() {
 
        return Err(ParseError::new_error_str_at_span(source, span, "expected an ASCII string literal"));
 
    }
 

	
 
    debug_assert_eq!(text[0], b'"'); // here as kind of a reminder: the span includes the bounding quotation marks
 
    debug_assert_eq!(text[text.len() - 1], b'"');
 

	
 
    buffer.reserve(text.len() - 2);
 

	
 
    let mut was_escape = false;
 
    for idx in 1..text.len() - 1 {
 
        let cur = text[idx];
 
        let is_escape = cur == b'\\';
 
        if was_escape {
 
            let to_push = parse_escaped_character(source, span, cur)?;
 
            buffer.push(to_push);
 
        } else {
 
            buffer.push(cur as char);
 
        }
 

	
 
        if was_escape && is_escape {
 
            was_escape = false;
 
        } else {
 
            was_escape = is_escape;
 
        }
 
    }
 

	
 
    debug_assert!(!was_escape); // because otherwise we couldn't have ended the string literal
 

	
 
    Ok(span)
 
}
 

	
 
fn parse_escaped_character(source: &InputSource, literal_span: InputSpan, v: u8) -> Result<char, ParseError> {
 
    let result = match v {
 
        b'r' => '\r',
 
        b'n' => '\n',
 
        b't' => '\t',
 
        b'0' => '\0',
 
        b'\\' => '\\',
 
        b'\'' => '\'',
 
        b'"' => '"',
 
        v => {
 
            let msg = if v.is_ascii_graphic() {
 
                format!("unsupported escape character '{}'", v as char)
 
            } else {
 
                format!("unsupported escape character with (unsigned) byte value {}", v)
 
            };
 
            return Err(ParseError::new_error_at_span(source, literal_span, msg))
 
        },
 
    };
 
    Ok(result)
 
}
 

	
 
pub(crate) fn consume_pragma<'a>(source: &'a InputSource, iter: &mut TokenIter) -> Result<(&'a [u8], InputPosition, InputPosition), ParseError> {
 
    if Some(TokenKind::Pragma) != iter.next() {
 
        return Err(ParseError::new_error_str_at_pos(source, iter.last_valid_pos(), "expected a pragma"));
 
    }
 
    let (pragma_start, pragma_end) = iter.next_positions();
 
    iter.consume();
 
    Ok((source.section_at_pos(pragma_start, pragma_end), pragma_start, pragma_end))
 
}
 

	
 
pub(crate) fn has_ident(source: &InputSource, iter: &mut TokenIter, expected: &[u8]) -> bool {
 
    peek_ident(source, iter).map_or(false, |section| section == expected)
 
}
 

	
 
pub(crate) fn peek_ident<'a>(source: &'a InputSource, iter: &mut TokenIter) -> Option<&'a [u8]> {
 
    if Some(TokenKind::Ident) == iter.next() {
 
        let (start, end) = iter.next_positions();
 
        return Some(source.section_at_pos(start, end))
 
    }
 

	
 
    None
 
}
 

	
 
/// Consumes any identifier and returns it together with its span. Does not
 
/// check if the identifier is a reserved keyword.
 
pub(crate) fn consume_any_ident<'a>(
 
    source: &'a InputSource, iter: &mut TokenIter
 
) -> Result<(&'a [u8], InputSpan), ParseError> {
 
    if Some(TokenKind::Ident) != iter.next() {
 
        return Err(ParseError::new_error_str_at_pos(source, iter.last_valid_pos(), "expected an identifier"));
 
    }
 
    let (ident_start, ident_end) = iter.next_positions();
 
    iter.consume();
 
    Ok((source.section_at_pos(ident_start, ident_end), InputSpan::from_positions(ident_start, ident_end)))
 
}
 

	
 
/// Consumes a specific identifier. May or may not be a reserved keyword.
 
pub(crate) fn consume_exact_ident(source: &InputSource, iter: &mut TokenIter, expected: &[u8]) -> Result<InputSpan, ParseError> {
 
    let (ident, pos) = consume_any_ident(source, iter)?;
 
    if ident != expected {
 
        debug_assert!(expected.is_ascii());
 
        return Err(ParseError::new_error_at_pos(
 
            source, iter.last_valid_pos(),
 
            format!("expected the text '{}'", &String::from_utf8_lossy(expected))
 
        ));
 
    }
 
    Ok(pos)
 
}
 

	
 
/// Consumes an identifier that is not a reserved keyword and returns it
 
/// together with its span.
 
pub(crate) fn consume_ident<'a>(
 
    source: &'a InputSource, iter: &mut TokenIter
 
) -> Result<(&'a [u8], InputSpan), ParseError> {
 
    let (ident, span) = consume_any_ident(source, iter)?;
 
    if is_reserved_keyword(ident) {
 
        return Err(ParseError::new_error_str_at_span(source, span, "encountered reserved keyword"));
 
    }
 

	
 
    Ok((ident, span))
 
}
 

	
 
/// Consumes an identifier and immediately intern it into the `StringPool`
 
pub(crate) fn consume_ident_interned(
 
    source: &InputSource, iter: &mut TokenIter, ctx: &mut PassCtx
 
) -> Result<Identifier, ParseError> {
 
    let (value, span) = consume_ident(source, iter)?;
 
    let value = ctx.pool.intern(value);
 
    Ok(Identifier{ span, value })
 
}
 

	
 
fn is_reserved_definition_keyword(text: &[u8]) -> bool {
 
    match text {
 
        KW_STRUCT | KW_ENUM | KW_UNION | KW_FUNCTION | KW_PRIMITIVE | KW_COMPOSITE => true,
 
        _ => false,
 
    }
 
}
 

	
 
fn is_reserved_statement_keyword(text: &[u8]) -> bool {
 
    match text {
 
        KW_IMPORT | KW_AS |
 
        KW_STMT_CHANNEL | KW_STMT_IF | KW_STMT_WHILE |
 
        KW_STMT_BREAK | KW_STMT_CONTINUE | KW_STMT_GOTO | KW_STMT_RETURN |
 
        KW_STMT_SYNC | KW_STMT_NEW => true,
 
        KW_STMT_SYNC | KW_STMT_FORK | KW_STMT_NEW => true,
 
        _ => false,
 
    }
 
}
 

	
 
fn is_reserved_expression_keyword(text: &[u8]) -> bool {
 
    match text {
 
        KW_LET | KW_CAST |
 
        KW_LIT_TRUE | KW_LIT_FALSE | KW_LIT_NULL |
 
        KW_FUNC_GET | KW_FUNC_PUT | KW_FUNC_FIRES | KW_FUNC_CREATE | KW_FUNC_ASSERT | KW_FUNC_LENGTH | KW_FUNC_PRINT => true,
 
        _ => false,
 
    }
 
}
 

	
 
fn is_reserved_type_keyword(text: &[u8]) -> bool {
 
    match text {
 
        KW_TYPE_IN_PORT | KW_TYPE_OUT_PORT | KW_TYPE_MESSAGE | KW_TYPE_BOOL |
 
        KW_TYPE_UINT8 | KW_TYPE_UINT16 | KW_TYPE_UINT32 | KW_TYPE_UINT64 |
 
        KW_TYPE_SINT8 | KW_TYPE_SINT16 | KW_TYPE_SINT32 | KW_TYPE_SINT64 |
 
        KW_TYPE_CHAR | KW_TYPE_STRING |
 
        KW_TYPE_INFERRED => true,
 
        _ => false,
 
    }
 
}
 

	
 
fn is_reserved_keyword(text: &[u8]) -> bool {
 
    return
 
        is_reserved_definition_keyword(text) ||
 
        is_reserved_statement_keyword(text) ||
 
        is_reserved_expression_keyword(text) ||
 
        is_reserved_type_keyword(text);
 
}
 

	
 
pub(crate) fn seek_module(modules: &[Module], root_id: RootId) -> Option<&Module> {
 
    for module in modules {
 
        if module.root_id == root_id {
 
            return Some(module)
 
        }
 
    }
 

	
 
    return None
 
}
 

	
 
/// Constructs a human-readable message indicating why there is a conflict of
 
/// symbols.
 
// Note: passing the `module_idx` is not strictly necessary, but will prevent
 
// programmer mistakes during development: we get a conflict because we're
 
// currently parsing a particular module.
 
pub(crate) fn construct_symbol_conflict_error(
 
    modules: &[Module], module_idx: usize, ctx: &PassCtx, new_symbol: &Symbol, old_symbol: &Symbol
 
) -> ParseError {
 
    let module = &modules[module_idx];
 
    let get_symbol_span_and_msg = |symbol: &Symbol| -> (String, Option<InputSpan>) {
 
        match &symbol.variant {
 
            SymbolVariant::Module(module) => {
 
                let import = &ctx.heap[module.introduced_at];
 
                return (
 
                    format!("the module aliased as '{}' imported here", symbol.name.as_str()),
 
                    Some(import.as_module().span)
 
                );
 
            },
 
            SymbolVariant::Definition(definition) => {
 
                if definition.defined_in_module.is_invalid() {
 
                    // Must be a builtin thing
 
                    return (format!("the builtin '{}'", symbol.name.as_str()), None)
 
                } else {
 
                    if let Some(import_id) = definition.imported_at {
 
                        let import = &ctx.heap[import_id];
 
                        return (
 
                            format!("the type '{}' imported here", symbol.name.as_str()),
 
                            Some(import.as_symbols().span)
 
                        );
 
                    } else {
 
                        // This is a defined symbol. So this must mean that the
 
                        // error was caused by it being defined.
 
                        debug_assert_eq!(definition.defined_in_module, module.root_id);
 

	
 
                        return (
 
                            format!("the type '{}' defined here", symbol.name.as_str()),
 
                            Some(definition.identifier_span)
 
                        )
 
                    }
 
                }
 
            }
 
        }
 
    };
 

	
 
    let (new_symbol_msg, new_symbol_span) = get_symbol_span_and_msg(new_symbol);
 
    let (old_symbol_msg, old_symbol_span) = get_symbol_span_and_msg(old_symbol);
 
    let new_symbol_span = new_symbol_span.unwrap(); // because new symbols cannot be builtin
 

	
 
    match old_symbol_span {
 
        Some(old_symbol_span) => ParseError::new_error_at_span(
 
            &module.source, new_symbol_span, format!("symbol is defined twice: {}", new_symbol_msg)
 
        ).with_info_at_span(
 
            &module.source, old_symbol_span, format!("it conflicts with {}", old_symbol_msg)
 
        ),
 
        None => ParseError::new_error_at_span(
 
            &module.source, new_symbol_span,
 
            format!("symbol is defined twice: {} conflicts with {}", new_symbol_msg, old_symbol_msg)
 
        )
 
    }
 
}
 
\ No newline at end of file
src/protocol/parser/visitor.rs
Show inline comments
 
use crate::protocol::ast::*;
 
use crate::protocol::input_source::ParseError;
 
use crate::protocol::parser::{type_table::*, Module};
 
use crate::protocol::symbol_table::{SymbolTable};
 

	
 
type Unit = ();
 
pub(crate) type VisitorResult = Result<Unit, ParseError>;
 

	
 
/// Globally configured vector capacity for statement buffers in visitor 
 
/// implementations
 
pub(crate) const STMT_BUFFER_INIT_CAPACITY: usize = 256;
 
/// Globally configured vector capacity for expression buffers in visitor
 
/// implementations
 
pub(crate) const EXPR_BUFFER_INIT_CAPACITY: usize = 256;
 

	
 
/// General context structure that is used while traversing the AST.
 
/// TODO: Revise, visitor abstraction is starting to get in the way of programming
 
pub(crate) struct Ctx<'p> {
 
    pub heap: &'p mut Heap,
 
    pub modules: &'p mut [Module],
 
    pub module_idx: usize, // currently considered module
 
    pub symbols: &'p mut SymbolTable,
 
    pub types: &'p mut TypeTable,
 
    pub arch: &'p crate::protocol::TargetArch,
 
}
 

	
 
impl<'p> Ctx<'p> {
 
    /// Returns module `modules[module_idx]`
 
    pub(crate) fn module(&self) -> &Module {
 
        &self.modules[self.module_idx]
 
    }
 

	
 
    pub(crate) fn module_mut(&mut self) -> &mut Module {
 
        &mut self.modules[self.module_idx]
 
    }
 
}
 

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

	
 
                root.definitions[def_index]
 
            };
 

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

	
 
    // Definitions
 
    // --- enum matching
 
    fn visit_definition(&mut self, ctx: &mut Ctx, id: DefinitionId) -> VisitorResult {
 
        match &ctx.heap[id] {
 
            Definition::Enum(def) => {
 
                let def = def.this;
 
                self.visit_enum_definition(ctx, def)
 
            },
 
            Definition::Union(def) => {
 
                let def = def.this;
 
                self.visit_union_definition(ctx, def)
 
            }
 
            Definition::Struct(def) => {
 
                let def = def.this;
 
                self.visit_struct_definition(ctx, def)
 
            },
 
            Definition::Component(def) => {
 
                let def = def.this;
 
                self.visit_component_definition(ctx, def)
 
            },
 
            Definition::Function(def) => {
 
                let def = def.this;
 
                self.visit_function_definition(ctx, def)
 
            }
 
        }
 
    }
 

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

	
 
    // Statements
 
    // --- enum matching
 
    fn visit_stmt(&mut self, ctx: &mut Ctx, id: StatementId) -> VisitorResult {
 
        match &ctx.heap[id] {
 
            Statement::Block(stmt) => {
 
                let this = stmt.this;
 
                self.visit_block_stmt(ctx, this)
 
            },
 
            Statement::EndBlock(_stmt) => Ok(()),
 
            Statement::Local(stmt) => {
 
                let this = stmt.this();
 
                self.visit_local_stmt(ctx, this)
 
            },
 
            Statement::Labeled(stmt) => {
 
                let this = stmt.this;
 
                self.visit_labeled_stmt(ctx, this)
 
            },
 
            Statement::If(stmt) => {
 
                let this = stmt.this;
 
                self.visit_if_stmt(ctx, this)
 
            },
 
            Statement::EndIf(_stmt) => Ok(()),
 
            Statement::While(stmt) => {
 
                let this = stmt.this;
 
                self.visit_while_stmt(ctx, this)
 
            },
 
            Statement::EndWhile(_stmt) => Ok(()),
 
            Statement::Break(stmt) => {
 
                let this = stmt.this;
 
                self.visit_break_stmt(ctx, this)
 
            },
 
            Statement::Continue(stmt) => {
 
                let this = stmt.this;
 
                self.visit_continue_stmt(ctx, this)
 
            },
 
            Statement::Synchronous(stmt) => {
 
                let this = stmt.this;
 
                self.visit_synchronous_stmt(ctx, this)
 
            },
 
            Statement::EndSynchronous(_stmt) => Ok(()),
 
            Statement::Fork(stmt) => {
 
                let this = stmt.this;
 
                self.visit_fork_stmt(ctx, this)
 
            },
 
            Statement::EndFork(_stmt) => Ok(()),
 
            Statement::Return(stmt) => {
 
                let this = stmt.this;
 
                self.visit_return_stmt(ctx, this)
 
            },
 
            Statement::Goto(stmt) => {
 
                let this = stmt.this;
 
                self.visit_goto_stmt(ctx, this)
 
            },
 
            Statement::New(stmt) => {
 
                let this = stmt.this;
 
                self.visit_new_stmt(ctx, this)
 
            },
 
            Statement::Expression(stmt) => {
 
                let this = stmt.this;
 
                self.visit_expr_stmt(ctx, this)
 
            }
 
        }
 
    }
 

	
 
    fn visit_local_stmt(&mut self, ctx: &mut Ctx, id: LocalStatementId) -> VisitorResult {
 
        match &ctx.heap[id] {
 
            LocalStatement::Channel(stmt) => {
 
                let this = stmt.this;
 
                self.visit_local_channel_stmt(ctx, this)
 
            },
 
            LocalStatement::Memory(stmt) => {
 
                let this = stmt.this;
 
                self.visit_local_memory_stmt(ctx, this)
 
            },
 
        }
 
    }
 

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

	
 
    // Expressions
 
    // --- enum matching
 
    fn visit_expr(&mut self, ctx: &mut Ctx, id: ExpressionId) -> VisitorResult {
 
        match &ctx.heap[id] {
 
            Expression::Assignment(expr) => {
 
                let this = expr.this;
 
                self.visit_assignment_expr(ctx, this)
 
            },
 
            Expression::Binding(expr) => {
 
                let this = expr.this;
 
                self.visit_binding_expr(ctx, this)
 
            }
 
            Expression::Conditional(expr) => {
 
                let this = expr.this;
 
                self.visit_conditional_expr(ctx, this)
 
            }
 
            Expression::Binary(expr) => {
 
                let this = expr.this;
 
                self.visit_binary_expr(ctx, this)
 
            }
 
            Expression::Unary(expr) => {
 
                let this = expr.this;
 
                self.visit_unary_expr(ctx, this)
 
            }
 
            Expression::Indexing(expr) => {
 
                let this = expr.this;
 
                self.visit_indexing_expr(ctx, this)
 
            }
 
            Expression::Slicing(expr) => {
 
                let this = expr.this;
 
                self.visit_slicing_expr(ctx, this)
 
            }
 
            Expression::Select(expr) => {
 
                let this = expr.this;
 
                self.visit_select_expr(ctx, this)
 
            }
 
            Expression::Literal(expr) => {
 
                let this = expr.this;
 
                self.visit_literal_expr(ctx, this)
 
            }
 
            Expression::Cast(expr) => {
 
                let this = expr.this;
 
                self.visit_cast_expr(ctx, this)
 
            }
 
            Expression::Call(expr) => {
 
                let this = expr.this;
 
                self.visit_call_expr(ctx, this)
 
            }
 
            Expression::Variable(expr) => {
 
                let this = expr.this;
 
                self.visit_variable_expr(ctx, this)
 
            }
 
        }
 
    }
 

	
 
    fn visit_assignment_expr(&mut self, _ctx: &mut Ctx, _id: AssignmentExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_binding_expr(&mut self, _ctx: &mut Ctx, _id: BindingExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_conditional_expr(&mut self, _ctx: &mut Ctx, _id: ConditionalExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_binary_expr(&mut self, _ctx: &mut Ctx, _id: BinaryExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_unary_expr(&mut self, _ctx: &mut Ctx, _id: UnaryExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_indexing_expr(&mut self, _ctx: &mut Ctx, _id: IndexingExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_slicing_expr(&mut self, _ctx: &mut Ctx, _id: SlicingExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_select_expr(&mut self, _ctx: &mut Ctx, _id: SelectExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_literal_expr(&mut self, _ctx: &mut Ctx, _id: LiteralExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_cast_expr(&mut self, _ctx: &mut Ctx, _id: CastExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_call_expr(&mut self, _ctx: &mut Ctx, _id: CallExpressionId) -> VisitorResult { Ok(()) }
 
    fn visit_variable_expr(&mut self, _ctx: &mut Ctx, _id: VariableExpressionId) -> VisitorResult { Ok(()) }
 
}
 
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