Changeset - ef3eec73f359
[Not reviewed]
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MH - 4 years ago 2021-03-10 15:49:03
contact@maxhenger.nl
WIP on reimplementation of type table supporting polymorphic types
6 files changed:
0 comments (0 inline, 0 general)
notes_max.md
Show inline comments
 
# Noteworthy changes
 

	
 
- `if`, `while`, `synchronous`, `function`, `primitive` and `composite` body statements, if not yet a block, are all converted into a block for simpler parsing/compiling.
 
\ No newline at end of file
 
- `if`, `while`, `synchronous`, `function`, `primitive` and `composite` body statements, if not yet a block, are all converted into a block for simpler parsing/compiling.
 

	
 
# Thinkings: Type System
 

	
 
## Basic Types
 

	
 
Builtin primitive types:
 

	
 
- Boolean: `bool`
 
- Unsigned integers: `u8`, `u16`, `u32`, `u64`
 
- Signed integers: `i8`, `i16`, `i32`, `i64`
 
- Decimal numbers: `f32`, `f64`
 
- Message-based: `in<T>`, `out<T>`, `msg`
 

	
 
Builtin compound types:
 

	
 
- Array: `array<T>`
 

	
 
User-specified types (excluding polymorphism for now):
 

	
 
- Connectors: `primitive`, `composite`
 
- Functions: `func`
 
- Enums: `enum`
 
- Unions: `enum`
 
- Structs: `struct`
 

	
 
## Polymorphic Type Definitions
 

	
 
Various types may be polymorphic. We will exclude builtin polymorphs from the following considerations (i.e. `in`, `out` and `array`, and their associated functions).
 

	
 
Connectors, functions, enums, unions and structs may all be polymorphic. We'll use the C++/rust/Java syntax for specifying polymorphic types:
 

	
 
```pdl
 
primitive fifo<T>(in<T> i, out<T> o) {
 
    // impl
 
}
 

	
 
T pick_one_of_two<T>(T one, T two) {
 
    // impl
 
}
 

	
 
enum Option<T>{ None, Some(T) }
 
enum Result<T, E>{ Ok(T), Err(E) }
 
struct Pair<T> { T first, T second }
 
```
 

	
 
This means that during the initial validation/linker phase all of the types may have polymorphic arguments. These polyargs have just an identifier, we can only determine the concrete type when we encounter it in another body where we either defer the type or where the user has explicitly instantiated the type.
 

	
 
For now we will use the C++-like trait/interfaceless polymorphism: once we know all of the polymorphic arguments we will try to monomorphize the type and check whether or not all calls make sense. This in itself is a recursive operation: inside the polymorph we may use other polymorphic types.
 

	
 
## Polymorphic Type Usage
 

	
 
Within functions and connectors we may employ polymorphic types. The specification of the polymorphic arguments is not required if they can be inferred. Polymorphic arguments may be partially specified by using somekind of throwaway `_` or `auto` type. When we are monomorphizing a type we must be able to fully determine all of the polymorphic arguments, if we can't then we throw a compiler error.
 

	
 
## Conclusions
 

	
 
- 
 
    Type definitions may contain polymorphic arguments. These are simple identifiers. The polymorphic arguments are embedded in definitions, they are erased after type inference on the type's use (e.g. function call or struct instantiation) has finished.
 

	
 
- 
 
    While instantiating polymorphic types (e.g. `T something = call_a_func(3, 5)` or the inferred variant `let something = call_a_func(3, 5)`) we actually need to resolve these types. This implies:
 
    
 
    - Memory declarations will have their type embedded within the memory declaration itself. If we do not know the type yet, or only partially know the type, then we need to mark the type as being inferred.
 
    - Expressions will have their type inferred from the constraints the expression imposes on its arguments, and the types of the arguments themselves. Within an expression tree type information may flow from the root towards the leaves or from the leaves towards the root.
 
    
 
    This implies that type information in the AST must be fully specified. If the type information is not yet fully known then it must be embedded in some kind of datastructure that is used for type inference.
 

	
 
-
 
    A function definition with polyargs seems to behave a bit differently: During the initial definition parsing we may want to make sure that each type in the definition either resolves to a concrete type (optionally with polymorphic arguments) or to one of the polyargs. This would also provide information to the type inference algorithm.
 

	
 
## Conclusions - Parsing
 

	
 
During parsing we want to embed all of the information the programmer has provided to the compiler in the AST. So polyargs go inside type definitions, types that are supposed to be inferred are embedded in the AST, types that depend on polyargs also go into the AST. So we may have:
 

	
 
- Partially concrete types with embedded inferred types (e.g. `let[] list_of_things` is an `Array<auto>` or `Result<auto> thing = Result::Ok(5)` or `let thing = Result::Ok(5)`).
 
- Direct references to polyarg types (e.g. `T list_of_things` or `Result<T> thing = ...` or `T[][] array_of_arrays_yes_sir` and `Tuple2<T, T> = construct_a_thing()`)
 
- Fully inferred types (e.g. `auto thing = 5` or `auto result = call_a_thing()`)
 
- Completely specified types.
 

	
 
## Conclusions - Type Inference
 

	
 
During type inference and typechecking we need to determine all concrete types. So we will arrive at a fully specified type: every polymorphic type will have its polyargs specified. Likewise every inferred type will be fully specified as well.
 

	
 
All of this hints at having to specify two classes of types: `ParserType` and a `Type`. The `ParserType` can be:
 

	
 
- A builtin type (with embedded `ParserType`s where appropriate)
 
- An inferred type
 
- A polyarg type
 
- A symbolic type (with embedded `ParsedType`s where appropriate)
 

	
 
While the final `Type` can be:
 

	
 
- A builtin type (with embedded types where appropriate)
 
- A known user-defined type (with embedded types where appropriate)
 

	
 
Note that we cannot typecheck polymorphic connectors and functions until we monomorphize them.
 
\ No newline at end of file
src/protocol/ast.rs
Show inline comments
 
use std::fmt;
 
use std::fmt::{Debug, Display, Formatter};
 
use std::ops::{Index, IndexMut};
 

	
 
use super::arena::{Arena, Id};
 
// use super::containers::StringAllocator;
 

	
 
// TODO: @cleanup, transform wrapping types into type aliases where possible
 
use crate::protocol::inputsource::*;
 

	
 
/// 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 {
 
    ($name:ident, $parent:ty) => {
 
        pub type $name = $parent;
 
    }
 
}
 

	
 
/// Helper macro that defines a subtype for a particular variant of an AST 
 
/// element ID.
 
macro_rules! define_new_ast_id {
 
    ($name:ident, $parent:ty) => {
 
        #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]
 
        pub struct $name (pub(crate) $parent);
 

	
 
        impl $name {
 
            pub fn upcast(self) -> $parent {
 
                self.0
 
            }
 
        }
 
    };
 
}
 

	
 
define_aliased_ast_id!(RootId, Id<Root>);
 
define_aliased_ast_id!(PragmaId, Id<Pragma>);
 
define_aliased_ast_id!(ImportId, Id<Import>);
 
define_aliased_ast_id!(TypeAnnotationId, Id<TypeAnnotation>);
 
define_aliased_ast_id!(ParserTypeId, Id<ParserType>);
 

	
 
define_aliased_ast_id!(VariableId, Id<Variable>);
 
define_new_ast_id!(ParameterId, VariableId);
 
define_new_ast_id!(LocalId, VariableId);
 

	
 
define_aliased_ast_id!(DefinitionId, Id<Definition>);
 
define_new_ast_id!(StructId, DefinitionId);
 
define_new_ast_id!(EnumId, DefinitionId);
 
define_new_ast_id!(ComponentId, DefinitionId);
 
define_new_ast_id!(FunctionId, DefinitionId);
 

	
 
define_aliased_ast_id!(StatementId, Id<Statement>);
 
define_new_ast_id!(BlockStatementId, StatementId);
 
define_new_ast_id!(LocalStatementId, StatementId);
 
define_new_ast_id!(MemoryStatementId, LocalStatementId);
 
define_new_ast_id!(ChannelStatementId, LocalStatementId);
 
define_new_ast_id!(SkipStatementId, StatementId);
 
define_new_ast_id!(LabeledStatementId, StatementId);
 
define_new_ast_id!(IfStatementId, StatementId);
 
define_new_ast_id!(EndIfStatementId, StatementId);
 
define_new_ast_id!(WhileStatementId, StatementId);
 
define_new_ast_id!(EndWhileStatementId, StatementId);
 
define_new_ast_id!(BreakStatementId, StatementId);
 
define_new_ast_id!(ContinueStatementId, StatementId);
 
define_new_ast_id!(SynchronousStatementId, StatementId);
 
define_new_ast_id!(EndSynchronousStatementId, StatementId);
 
define_new_ast_id!(ReturnStatementId, StatementId);
 
define_new_ast_id!(AssertStatementId, StatementId);
 
define_new_ast_id!(GotoStatementId, StatementId);
 
define_new_ast_id!(NewStatementId, StatementId);
 
define_new_ast_id!(PutStatementId, StatementId);
 
define_new_ast_id!(ExpressionStatementId, StatementId);
 

	
 
define_aliased_ast_id!(ExpressionId, Id<Expression>);
 
define_new_ast_id!(AssignmentExpressionId, ExpressionId);
 
define_new_ast_id!(ConditionalExpressionId, ExpressionId);
 
define_new_ast_id!(BinaryExpressionId, ExpressionId);
 
define_new_ast_id!(UnaryExpressionId, ExpressionId);
 
define_new_ast_id!(IndexingExpressionId, ExpressionId);
 
define_new_ast_id!(SlicingExpressionId, ExpressionId);
 
define_new_ast_id!(SelectExpressionId, ExpressionId);
 
define_new_ast_id!(ArrayExpressionId, ExpressionId);
 
define_new_ast_id!(ConstantExpressionId, ExpressionId);
 
define_new_ast_id!(CallExpressionId, ExpressionId);
 
define_new_ast_id!(VariableExpressionId, ExpressionId);
 

	
 
// TODO: @cleanup - pub qualifiers can be removed once done
 
#[derive(Debug, serde::Serialize, serde::Deserialize)]
 
pub struct Heap {
 
    // Allocators
 
    // #[serde(skip)] string_alloc: StringAllocator,
 
    // 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>,
 
    identifiers: Arena<Identifier>,
 
    pub(crate) type_annotations: Arena<TypeAnnotation>,
 
    pub(crate) parser_types: Arena<ParserType>,
 
    pub(crate) variables: Arena<Variable>,
 
    pub(crate) definitions: Arena<Definition>,
 
    pub(crate) statements: Arena<Statement>,
 
    pub(crate) expressions: Arena<Expression>,
 
}
 

	
 
impl Heap {
 
    pub fn new() -> Heap {
 
        Heap {
 
            // string_alloc: StringAllocator::new(),
 
            protocol_descriptions: Arena::new(),
 
            pragmas: Arena::new(),
 
            imports: Arena::new(),
 
            identifiers: Arena::new(),
 
            type_annotations: Arena::new(),
 
            parser_types: Arena::new(),
 
            variables: Arena::new(),
 
            definitions: Arena::new(),
 
            statements: Arena::new(),
 
            expressions: Arena::new(),
 
        }
 
    }
 
    pub fn alloc_type_annotation(
 
    pub fn alloc_parser_type(
 
        &mut self,
 
        f: impl FnOnce(TypeAnnotationId) -> TypeAnnotation,
 
    ) -> TypeAnnotationId {
 
        self.type_annotations.alloc_with_id(|id| f(id))
 
        f: impl FnOnce(ParserTypeId) -> ParserType,
 
    ) -> ParserTypeId {
 
        self.parser_types.alloc_with_id(|id| f(id))
 
    }
 

	
 
    pub fn alloc_parameter(&mut self, f: impl FnOnce(ParameterId) -> Parameter) -> ParameterId {
 
        ParameterId(
 
            self.variables.alloc_with_id(|id| Variable::Parameter(f(ParameterId(id)))),
 
        )
 
    }
 
    pub fn alloc_local(&mut self, f: impl FnOnce(LocalId) -> Local) -> LocalId {
 
        LocalId(
 
            self.variables.alloc_with_id(|id| Variable::Local(f(LocalId(id)))),
 
        )
 
    }
 
    pub fn alloc_assignment_expression(
 
        &mut self,
 
        f: impl FnOnce(AssignmentExpressionId) -> AssignmentExpression,
 
    ) -> AssignmentExpressionId {
 
        AssignmentExpressionId(
 
            self.expressions.alloc_with_id(|id| {
 
                Expression::Assignment(f(AssignmentExpressionId(id)))
 
            })
 
        )
 
    }
 
    pub fn alloc_conditional_expression(
 
        &mut self,
 
        f: impl FnOnce(ConditionalExpressionId) -> ConditionalExpression,
 
    ) -> ConditionalExpressionId {
 
        ConditionalExpressionId(
 
            self.expressions.alloc_with_id(|id| {
 
                Expression::Conditional(f(ConditionalExpressionId(id)))
 
            })
 
        )
 
    }
 
    pub fn alloc_binary_expression(
 
        &mut self,
 
        f: impl FnOnce(BinaryExpressionId) -> BinaryExpression,
 
    ) -> BinaryExpressionId {
 
        BinaryExpressionId(
 
            self.expressions
 
                .alloc_with_id(|id| Expression::Binary(f(BinaryExpressionId(id)))),
 
        )
 
    }
 
    pub fn alloc_unary_expression(
 
        &mut self,
 
        f: impl FnOnce(UnaryExpressionId) -> UnaryExpression,
 
    ) -> UnaryExpressionId {
 
        UnaryExpressionId(
 
            self.expressions
 
                .alloc_with_id(|id| Expression::Unary(f(UnaryExpressionId(id)))),
 
        )
 
    }
 
    pub fn alloc_slicing_expression(
 
        &mut self,
 
        f: impl FnOnce(SlicingExpressionId) -> SlicingExpression,
 
    ) -> SlicingExpressionId {
 
        SlicingExpressionId(
 
            self.expressions
 
                .alloc_with_id(|id| Expression::Slicing(f(SlicingExpressionId(id)))),
 
        )
 
    }
 
    pub fn alloc_indexing_expression(
 
        &mut self,
 
        f: impl FnOnce(IndexingExpressionId) -> IndexingExpression,
 
    ) -> IndexingExpressionId {
 
        IndexingExpressionId(
 
            self.expressions.alloc_with_id(|id| {
 
                Expression::Indexing(f(IndexingExpressionId(id)))
 
            }),
 
        )
 
    }
 
    pub fn alloc_select_expression(
 
        &mut self,
 
        f: impl FnOnce(SelectExpressionId) -> SelectExpression,
 
    ) -> SelectExpressionId {
 
        SelectExpressionId(
 
            self.expressions
 
                .alloc_with_id(|id| Expression::Select(f(SelectExpressionId(id)))),
 
        )
 
    }
 
    pub fn alloc_array_expression(
 
        &mut self,
 
        f: impl FnOnce(ArrayExpressionId) -> ArrayExpression,
 
    ) -> ArrayExpressionId {
 
        ArrayExpressionId(
 
            self.expressions
 
                .alloc_with_id(|id| Expression::Array(f(ArrayExpressionId(id)))),
 
        )
 
    }
 
    pub fn alloc_constant_expression(
 
        &mut self,
 
        f: impl FnOnce(ConstantExpressionId) -> ConstantExpression,
 
    ) -> ConstantExpressionId {
 
        ConstantExpressionId(
 
            self.expressions.alloc_with_id(|id| {
 
                Expression::Constant(f(ConstantExpressionId(id)))
 
            }),
 
        )
 
    }
 
    pub fn alloc_call_expression(
 
        &mut self,
 
        f: impl FnOnce(CallExpressionId) -> CallExpression,
 
    ) -> CallExpressionId {
 
        CallExpressionId(
 
            self.expressions
 
                .alloc_with_id(|id| Expression::Call(f(CallExpressionId(id)))),
 
        )
 
    }
 
    pub fn alloc_variable_expression(
 
        &mut self,
 
        f: impl FnOnce(VariableExpressionId) -> VariableExpression,
 
    ) -> VariableExpressionId {
 
        VariableExpressionId(
 
            self.expressions.alloc_with_id(|id| {
 
                Expression::Variable(f(VariableExpressionId(id)))
 
            }),
 
        )
 
    }
 
    pub fn alloc_block_statement(
 
        &mut self,
 
        f: impl FnOnce(BlockStatementId) -> BlockStatement,
 
    ) -> BlockStatementId {
 
        BlockStatementId(
 
            self.statements
 
                .alloc_with_id(|id| Statement::Block(f(BlockStatementId(id)))),
 
        )
 
    }
 
    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)))
 
            ))
 
        })))
 
    }
 
    pub fn alloc_skip_statement(
 
        &mut self,
 
        f: impl FnOnce(SkipStatementId) -> SkipStatement,
 
    ) -> SkipStatementId {
 
        SkipStatementId(
 
            self.statements
 
                .alloc_with_id(|id| Statement::Skip(f(SkipStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_if_statement(
 
        &mut self,
 
        f: impl FnOnce(IfStatementId) -> IfStatement,
 
    ) -> IfStatementId {
 
        IfStatementId(
 
            self.statements.alloc_with_id(|id| Statement::If(f(IfStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_end_if_statement(
 
        &mut self,
 
        f: impl FnOnce(EndIfStatementId) -> EndIfStatement,
 
    ) -> EndIfStatementId {
 
        EndIfStatementId(
 
            self.statements
 
                .alloc_with_id(|id| Statement::EndIf(f(EndIfStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_while_statement(
 
        &mut self,
 
        f: impl FnOnce(WhileStatementId) -> WhileStatement,
 
    ) -> WhileStatementId {
 
        WhileStatementId(
 
            self.statements
 
                .alloc_with_id(|id| Statement::While(f(WhileStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_end_while_statement(
 
        &mut self,
 
        f: impl FnOnce(EndWhileStatementId) -> EndWhileStatement,
 
    ) -> EndWhileStatementId {
 
        EndWhileStatementId(
 
            self.statements
 
                .alloc_with_id(|id| Statement::EndWhile(f(EndWhileStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_break_statement(
 
        &mut self,
 
        f: impl FnOnce(BreakStatementId) -> BreakStatement,
 
    ) -> BreakStatementId {
 
        BreakStatementId(
 
            self.statements
 
                .alloc_with_id(|id| Statement::Break(f(BreakStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_continue_statement(
 
        &mut self,
 
        f: impl FnOnce(ContinueStatementId) -> ContinueStatement,
 
    ) -> ContinueStatementId {
 
        ContinueStatementId(
 
            self.statements
 
                .alloc_with_id(|id| Statement::Continue(f(ContinueStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_synchronous_statement(
 
        &mut self,
 
        f: impl FnOnce(SynchronousStatementId) -> SynchronousStatement,
 
    ) -> SynchronousStatementId {
 
        SynchronousStatementId(self.statements.alloc_with_id(|id| {
 
            Statement::Synchronous(f(SynchronousStatementId(id)))
 
        }))
 
    }
 
    pub fn alloc_end_synchronous_statement(
 
        &mut self,
 
        f: impl FnOnce(EndSynchronousStatementId) -> EndSynchronousStatement,
 
    ) -> EndSynchronousStatementId {
 
        EndSynchronousStatementId(self.statements.alloc_with_id(|id| {
 
            Statement::EndSynchronous(f(EndSynchronousStatementId(id)))
 
        }))
 
    }
 
    pub fn alloc_return_statement(
 
        &mut self,
 
        f: impl FnOnce(ReturnStatementId) -> ReturnStatement,
 
    ) -> ReturnStatementId {
 
        ReturnStatementId(
 
            self.statements
 
                .alloc_with_id(|id| Statement::Return(f(ReturnStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_assert_statement(
 
        &mut self,
 
        f: impl FnOnce(AssertStatementId) -> AssertStatement,
 
    ) -> AssertStatementId {
 
        AssertStatementId(
 
            self.statements
 
                .alloc_with_id(|id| Statement::Assert(f(AssertStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_goto_statement(
 
        &mut self,
 
        f: impl FnOnce(GotoStatementId) -> GotoStatement,
 
    ) -> GotoStatementId {
 
        GotoStatementId(
 
            self.statements
 
                .alloc_with_id(|id| Statement::Goto(f(GotoStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_new_statement(
 
        &mut self,
 
        f: impl FnOnce(NewStatementId) -> NewStatement,
 
    ) -> NewStatementId {
 
        NewStatementId(
 
            self.statements.alloc_with_id(|id| Statement::New(f(NewStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_put_statement(
 
        &mut self,
 
        f: impl FnOnce(PutStatementId) -> PutStatement,
 
    ) -> PutStatementId {
 
        PutStatementId(
 
            self.statements.alloc_with_id(|id| Statement::Put(f(PutStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_labeled_statement(
 
        &mut self,
 
        f: impl FnOnce(LabeledStatementId) -> LabeledStatement,
 
    ) -> LabeledStatementId {
 
        LabeledStatementId(
 
            self.statements
 
                .alloc_with_id(|id| Statement::Labeled(f(LabeledStatementId(id)))),
 
        )
 
    }
 
    pub fn alloc_expression_statement(
 
        &mut self,
 
        f: impl FnOnce(ExpressionStatementId) -> ExpressionStatement,
 
    ) -> ExpressionStatementId {
 
        ExpressionStatementId(
 
            self.statements.alloc_with_id(|id| {
 
                Statement::Expression(f(ExpressionStatementId(id)))
 
            }),
 
        )
 
    }
 
    pub fn alloc_struct_definition(&mut self, f: impl FnOnce(StructId) -> StructDefinition) -> StructId {
 
        StructId(self.definitions.alloc_with_id(|id| {
 
            Definition::Struct(f(StructId(id)))
 
        }))
 
    }
 
    pub fn alloc_enum_definition(&mut self, f: impl FnOnce(EnumId) -> EnumDefinition) -> EnumId {
 
        EnumId(self.definitions.alloc_with_id(|id| {
 
            Definition::Enum(f(EnumId(id)))
 
        }))
 
    }
 
    pub fn alloc_component(&mut self, f: impl FnOnce(ComponentId) -> Component) -> ComponentId {
 
        ComponentId(self.definitions.alloc_with_id(|id| {
 
            Definition::Component(f(ComponentId(id)))
 
        }))
 
    }
 
    pub fn alloc_function(&mut self, f: impl FnOnce(FunctionId) -> Function) -> FunctionId {
 
        FunctionId(
 
            self.definitions
 
                .alloc_with_id(|id| Definition::Function(f(FunctionId(id)))),
 
        )
 
    }
 
    pub fn alloc_pragma(&mut self, f: impl FnOnce(PragmaId) -> Pragma) -> PragmaId {
 
        self.pragmas.alloc_with_id(|id| f(id))
 
    }
 
    pub fn alloc_import(&mut self, f: impl FnOnce(ImportId) -> Import) -> ImportId {
 
        self.imports.alloc_with_id(|id| f(id))
 
    }
 
    pub fn alloc_protocol_description(&mut self, f: impl FnOnce(RootId) -> Root) -> RootId {
 
        self.protocol_descriptions.alloc_with_id(|id| f(id))
 
    }
 
}
 

	
 
impl Index<RootId> for Heap {
 
    type Output = Root;
 
    fn index(&self, index: RootId) -> &Self::Output {
 
        &self.protocol_descriptions[index]
 
    }
 
}
 

	
 
impl IndexMut<RootId> for Heap {
 
    fn index_mut(&mut self, index: RootId) -> &mut Self::Output {
 
        &mut self.protocol_descriptions[index]
 
    }
 
}
 

	
 
impl Index<PragmaId> for Heap {
 
    type Output = Pragma;
 
    fn index(&self, index: PragmaId) -> &Self::Output {
 
        &self.pragmas[index]
 
    }
 
}
 

	
 
impl Index<ImportId> for Heap {
 
    type Output = Import;
 
    fn index(&self, index: ImportId) -> &Self::Output {
 
        &self.imports[index]
 
    }
 
}
 

	
 
impl IndexMut<ImportId> for Heap {
 
    fn index_mut(&mut self, index: ImportId) -> &mut Self::Output {
 
        &mut self.imports[index]
 
    }
 
}
 

	
 
impl Index<ParserTypeId> for Heap {
 
    type Output = ParserType;
 
    fn index(&self, index: ParserTypeId) -> &Self::Output {
 
        &self.parser_types[index.index]
 
    }
 
}
 

	
 
impl Index<TypeAnnotationId> for Heap {
 
    type Output = TypeAnnotation;
 
    fn index(&self, index: TypeAnnotationId) -> &Self::Output {
 
        &self.type_annotations[index]
 
    }
 
}
 

	
 
impl Index<VariableId> for Heap {
 
    type Output = Variable;
 
    fn index(&self, index: VariableId) -> &Self::Output {
 
        &self.variables[index]
 
    }
 
}
 

	
 
impl Index<ParameterId> for Heap {
 
    type Output = Parameter;
 
    fn index(&self, index: ParameterId) -> &Self::Output {
 
        &self.variables[index.0].as_parameter()
 
    }
 
}
 

	
 
impl Index<LocalId> for Heap {
 
    type Output = Local;
 
    fn index(&self, index: LocalId) -> &Self::Output {
 
        &self.variables[index.0].as_local()
 
    }
 
}
 

	
 
impl IndexMut<LocalId> for Heap {
 
    fn index_mut(&mut self, index: LocalId) -> &mut Self::Output {
 
        self.variables[index.0].as_local_mut()
 
    }
 
}
 

	
 
impl Index<DefinitionId> for Heap {
 
    type Output = Definition;
 
    fn index(&self, index: DefinitionId) -> &Self::Output {
 
        &self.definitions[index]
 
    }
 
}
 

	
 
impl Index<ComponentId> for Heap {
 
    type Output = Component;
 
    fn index(&self, index: ComponentId) -> &Self::Output {
 
        &self.definitions[index.0].as_component()
 
    }
 
}
 

	
 
impl Index<FunctionId> for Heap {
 
    type Output = Function;
 
    fn index(&self, index: FunctionId) -> &Self::Output {
 
        &self.definitions[index.0].as_function()
 
    }
 
}
 

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

	
 
impl IndexMut<StatementId> for Heap {
 
    fn index_mut(&mut self, index: StatementId) -> &mut Self::Output {
 
        &mut self.statements[index]
 
    }
 
}
 

	
 
impl Index<BlockStatementId> for Heap {
 
    type Output = BlockStatement;
 
    fn index(&self, index: BlockStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_block()
 
    }
 
}
 

	
 
impl IndexMut<BlockStatementId> for Heap {
 
    fn index_mut(&mut self, index: BlockStatementId) -> &mut Self::Output {
 
        (&mut self.statements[index.0]).as_block_mut()
 
    }
 
}
 

	
 
impl Index<LocalStatementId> for Heap {
 
    type Output = LocalStatement;
 
    fn index(&self, index: LocalStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_local()
 
    }
 
}
 

	
 
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()
 
    }
 
}
 

	
 
impl Index<SkipStatementId> for Heap {
 
    type Output = SkipStatement;
 
    fn index(&self, index: SkipStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_skip()
 
    }
 
}
 

	
 
impl Index<LabeledStatementId> for Heap {
 
    type Output = LabeledStatement;
 
    fn index(&self, index: LabeledStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_labeled()
 
    }
 
}
 

	
 
impl IndexMut<LabeledStatementId> for Heap {
 
    fn index_mut(&mut self, index: LabeledStatementId) -> &mut Self::Output {
 
        (&mut self.statements[index.0]).as_labeled_mut()
 
    }
 
}
 

	
 
impl Index<IfStatementId> for Heap {
 
    type Output = IfStatement;
 
    fn index(&self, index: IfStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_if()
 
    }
 
}
 

	
 
impl IndexMut<IfStatementId> for Heap {
 
    fn index_mut(&mut self, index: IfStatementId) -> &mut Self::Output {
 
        self.statements[index.0].as_if_mut()
 
    }
 
}
 

	
 
impl Index<EndIfStatementId> for Heap {
 
    type Output = EndIfStatement;
 
    fn index(&self, index: EndIfStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_end_if()
 
    }
 
}
 

	
 
impl Index<WhileStatementId> for Heap {
 
    type Output = WhileStatement;
 
    fn index(&self, index: WhileStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_while()
 
    }
 
}
 

	
 
impl IndexMut<WhileStatementId> for Heap {
 
    fn index_mut(&mut self, index: WhileStatementId) -> &mut Self::Output {
 
        (&mut self.statements[index.0]).as_while_mut()
 
    }
 
}
 

	
 
impl Index<BreakStatementId> for Heap {
 
    type Output = BreakStatement;
 
    fn index(&self, index: BreakStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_break()
 
    }
 
}
 

	
 
impl IndexMut<BreakStatementId> for Heap {
 
    fn index_mut(&mut self, index: BreakStatementId) -> &mut Self::Output {
 
        (&mut self.statements[index.0]).as_break_mut()
 
    }
 
}
 

	
 
impl Index<ContinueStatementId> for Heap {
 
    type Output = ContinueStatement;
 
    fn index(&self, index: ContinueStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_continue()
 
    }
 
}
 

	
 
impl IndexMut<ContinueStatementId> for Heap {
 
    fn index_mut(&mut self, index: ContinueStatementId) -> &mut Self::Output {
 
        (&mut self.statements[index.0]).as_continue_mut()
 
    }
 
}
 

	
 
impl Index<SynchronousStatementId> for Heap {
 
    type Output = SynchronousStatement;
 
    fn index(&self, index: SynchronousStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_synchronous()
 
    }
 
}
 

	
 
impl IndexMut<SynchronousStatementId> for Heap {
 
    fn index_mut(&mut self, index: SynchronousStatementId) -> &mut Self::Output {
 
        (&mut self.statements[index.0]).as_synchronous_mut()
 
    }
 
}
 

	
 
impl Index<EndSynchronousStatementId> for Heap {
 
    type Output = EndSynchronousStatement;
 
    fn index(&self, index: EndSynchronousStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_end_synchronous()
 
    }
 
}
 

	
 
impl Index<ReturnStatementId> for Heap {
 
    type Output = ReturnStatement;
 
    fn index(&self, index: ReturnStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_return()
 
    }
 
}
 

	
 
impl Index<AssertStatementId> for Heap {
 
    type Output = AssertStatement;
 
    fn index(&self, index: AssertStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_assert()
 
    }
 
}
 

	
 
impl Index<GotoStatementId> for Heap {
 
    type Output = GotoStatement;
 
    fn index(&self, index: GotoStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_goto()
 
    }
 
}
 

	
 
impl IndexMut<GotoStatementId> for Heap {
 
    fn index_mut(&mut self, index: GotoStatementId) -> &mut Self::Output {
 
        (&mut self.statements[index.0]).as_goto_mut()
 
    }
 
}
 

	
 
impl Index<NewStatementId> for Heap {
 
    type Output = NewStatement;
 
    fn index(&self, index: NewStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_new()
 
    }
 
}
 

	
 
impl Index<PutStatementId> for Heap {
 
    type Output = PutStatement;
 
    fn index(&self, index: PutStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_put()
 
    }
 
}
 

	
 
impl Index<ExpressionStatementId> for Heap {
 
    type Output = ExpressionStatement;
 
    fn index(&self, index: ExpressionStatementId) -> &Self::Output {
 
        &self.statements[index.0].as_expression()
 
    }
 
}
 

	
 
impl Index<ExpressionId> for Heap {
 
    type Output = Expression;
 
    fn index(&self, index: ExpressionId) -> &Self::Output {
 
        &self.expressions[index]
 
    }
 
}
 

	
 
impl Index<AssignmentExpressionId> for Heap {
 
    type Output = AssignmentExpression;
 
    fn index(&self, index: AssignmentExpressionId) -> &Self::Output {
 
        &self.expressions[index.0].as_assignment()
 
    }
 
}
 

	
 
impl Index<ConditionalExpressionId> for Heap {
 
    type Output = ConditionalExpression;
 
    fn index(&self, index: ConditionalExpressionId) -> &Self::Output {
 
        &self.expressions[index.0].as_conditional()
 
    }
 
}
 

	
 
impl Index<BinaryExpressionId> for Heap {
 
    type Output = BinaryExpression;
 
    fn index(&self, index: BinaryExpressionId) -> &Self::Output {
 
        &self.expressions[index.0].as_binary()
 
    }
 
}
 

	
 
impl Index<UnaryExpressionId> for Heap {
 
    type Output = UnaryExpression;
 
    fn index(&self, index: UnaryExpressionId) -> &Self::Output {
 
        &self.expressions[index.0].as_unary()
 
    }
 
}
 

	
 
impl Index<IndexingExpressionId> for Heap {
 
    type Output = IndexingExpression;
 
    fn index(&self, index: IndexingExpressionId) -> &Self::Output {
 
        &self.expressions[index.0].as_indexing()
 
    }
 
}
 

	
 
impl Index<SlicingExpressionId> for Heap {
 
    type Output = SlicingExpression;
 
    fn index(&self, index: SlicingExpressionId) -> &Self::Output {
 
        &self.expressions[index.0].as_slicing()
 
    }
 
}
 

	
 
impl Index<SelectExpressionId> for Heap {
 
    type Output = SelectExpression;
 
    fn index(&self, index: SelectExpressionId) -> &Self::Output {
 
        &self.expressions[index.0].as_select()
 
    }
 
}
 

	
 
impl Index<ArrayExpressionId> for Heap {
 
    type Output = ArrayExpression;
 
    fn index(&self, index: ArrayExpressionId) -> &Self::Output {
 
        &self.expressions[index.0].as_array()
 
    }
 
}
 

	
 
impl Index<ConstantExpressionId> for Heap {
 
    type Output = ConstantExpression;
 
    fn index(&self, index: ConstantExpressionId) -> &Self::Output {
 
        &self.expressions[index.0].as_constant()
 
    }
 
}
 

	
 
impl Index<CallExpressionId> for Heap {
 
    type Output = CallExpression;
 
    fn index(&self, index: CallExpressionId) -> &Self::Output {
 
        &self.expressions[index.0].as_call()
 
    }
 
}
 

	
 
impl IndexMut<CallExpressionId> for Heap {
 
    fn index_mut(&mut self, index: CallExpressionId) -> &mut Self::Output {
 
        (&mut self.expressions[index.0]).as_call_mut()
 
    }
 
}
 

	
 
impl Index<VariableExpressionId> for Heap {
 
    type Output = VariableExpression;
 
    fn index(&self, index: VariableExpressionId) -> &Self::Output {
 
        &self.expressions[index.0].as_variable()
 
    }
 
}
 

	
 
impl IndexMut<VariableExpressionId> for Heap {
 
    fn index_mut(&mut self, index: VariableExpressionId) -> &mut Self::Output {
 
        (&mut self.expressions[index.0]).as_variable_mut()
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
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 == id {
 
                return Some(def);
 
            }
 
        }
 
        None
 
    }
 
}
 

	
 
impl SyntaxElement for Root {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

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

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct PragmaVersion {
 
    pub this: PragmaId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub version: u64,
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct PragmaModule {
 
    pub this: PragmaId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub value: Vec<u8>,
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct PragmaOld {
 
    pub this: PragmaId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub value: Vec<u8>,
 
}
 

	
 
impl SyntaxElement for PragmaOld {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

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

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

	
 
impl SyntaxElement for Import {
 
    fn position(&self) -> InputPosition {
 
        match self {
 
            Import::Module(m) => m.position,
 
            Import::Symbols(m) => m.position
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct ImportModule {
 
    pub this: ImportId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub module_name: Vec<u8>,
 
    pub alias: Vec<u8>,
 
    // Phase 2: module resolving
 
    pub module_id: Option<RootId>,
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct AliasedSymbol {
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub name: Vec<u8>,
 
    pub alias: Vec<u8>,
 
    // Phase 2: symbol resolving
 
    pub definition_id: Option<DefinitionId>,
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct ImportSymbols {
 
    pub this: ImportId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub module_name: Vec<u8>,
 
    // Phase 2: module resolving
 
    pub module_id: Option<RootId>,
 
    // Phase 1&2
 
    // if symbols is empty, then we implicitly import all symbols without any
 
    // aliases for them. If it is not empty, then symbols are explicitly
 
    // specified, and optionally given an alias.
 
    pub symbols: Vec<AliasedSymbol>,
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct Identifier {
 
    pub position: InputPosition,
 
    pub value: Vec<u8>
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct NamespacedIdentifier {
 
    pub position: InputPosition,
 
    pub num_namespaces: u8,
 
    pub value: Vec<u8>,
 
}
 

	
 
impl NamespacedIdentifier {
 
    pub(crate) fn iter(&self) -> NamespacedIdentifierIter {
 
        NamespacedIdentifierIter{
 
            value: &self.value,
 
            cur_offset: 0,
 
            num_returned: 0,
 
            num_total: self.num_namespaces
 
        }
 
    }
 
}
 

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

	
 
// TODO: Just keep ref to NamespacedIdentifier
 
pub(crate) struct NamespacedIdentifierIter<'a> {
 
    value: &'a Vec<u8>,
 
    cur_offset: usize,
 
    num_returned: u8,
 
    num_total: u8,
 
}
 

	
 
impl<'a> NamespacedIdentifierIter<'a> {
 
    pub(crate) fn num_returned(&self) -> u8 {
 
        return self.num_returned;
 
    }
 
    pub(crate) fn num_remaining(&self) -> u8 {
 
        return self.num_total - self.num_returned
 
    }
 
}
 

	
 
impl<'a> Iterator for NamespacedIdentifierIter<'a> {
 
    type Item = &'a [u8];
 
    fn next(&mut self) -> Option<Self::Item> {
 
        if self.cur_offset >= self.value.len() {
 
            debug_assert_eq!(self.num_returned, self.num_total);
 
            None
 
        } else {
 
            debug_assert!(self.num_returned < self.num_total);
 
            let start = self.cur_offset;
 
            let mut end = start;
 
            while end < self.value.len() - 1 {
 
                if self.value[end] == b':' && self.value[end + 1] == b':' {
 
                    self.cur_offset = end + 2;
 
                    self.num_returned += 1;
 
                    return Some(&self.value[start..end]);
 
                }
 
                end += 1;
 
            }
 

	
 
            // If NamespacedIdentifier is constructed properly, then we cannot
 
            // end with "::" in the value, so
 
            debug_assert!(end == 0 || (self.value[end - 1] != b':' && self.value[end] != b':'));
 
            debug_assert_eq!(self.num_returned + 1, self.num_total);
 
            self.cur_offset = self.value.len();
 
            self.num_returned += 1;
 
            return Some(&self.value[start..]);
 
        }
 
    }
 
}
 

	
 
impl Display for Identifier {
 
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
 
        // A source identifier is in ASCII range.
 
        write!(f, "{}", String::from_utf8_lossy(&self.value))
 
    }
 
}
 

	
 
/// TODO: @cleanup Maybe handle this differently, preallocate in heap? The
 
///     reason I'm handling it like this now is so we don't allocate types in
 
///     the `Arena` structure if they're the common types defined here.
 
pub enum ParserTypeVariant {
 
    // Basic builtin
 
    Message,
 
    Bool,
 
    Byte,
 
    Short,
 
    Int,
 
    Long,
 
    String,
 
    // Literals (need to get concrete builtin type during typechecking)
 
    IntegerLiteral,
 
    Inferred,
 
    // Complex builtins
 
    Array(ParserTypeId), // array of a type
 
    Input(ParserTypeId), // typed input endpoint of a channel
 
    Output(ParserTypeId), // typed output endpoint of a channel
 
    Symbolic(SymbolicParserType), // symbolic type (definition or polyarg)
 
}
 

	
 
impl ParserTypeVariant {
 
    pub(crate) fn supports_polymorphic_args(&self) -> bool {
 
        use ParserTypeVariant::*;
 
        match ParserTypeVariant {
 
            Message | Bool | Byte | Short | Int | Long | String | IntegerLiteral | Inferred => false,
 
            _ => true
 
        }
 
    }
 
}
 

	
 
/// ParserType is a specification of a type during the parsing phase and initial
 
/// linker/validator phase of the compilation process. These types may be
 
/// (partially) inferred or represent literals (e.g. a integer whose bytesize is
 
/// not yet determined).
 
#[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
 
pub struct ParserType {
 
    pub this: ParserTypeId,
 
    pub pos: InputPosition,
 
    pub variant: ParserTypeVariant,
 
}
 

	
 
/// SymbolicParserType is the specification of a symbolic type. During the
 
/// parsing phase we will only store the identifier of the type. During the
 
/// validation phase we will determine whether it refers to a user-defined type,
 
/// or a polymorphic argument. After the validation phase it may still be the
 
/// case that the resulting `variant` will not pass the typechecker.
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct SymbolicParserType {
 
    // Phase 1: parser
 
    pub identifier: NamespacedIdentifier,
 
    /// The user-specified polymorphic arguments. Zero-length implies that the
 
    /// user did not specify any of them, and they're either not needed or all
 
    /// need to be inferred. Otherwise the number of polymorphic arguments must
 
    /// match those of the corresponding definition
 
    pub poly_args: Vec<ParserTypeId>,
 
    // Phase 2: validation/linking
 
    pub variant: Option<SymbolicParserTypeVariant>
 
}
 

	
 
/// Specifies whether the symbolic type points to an actual user-defined type,
 
/// or whether it points to a polymorphic argument within the definition (e.g.
 
/// a defined variable `T var` within a function `int func<T>()`
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub enum SymbolicParserTypeVariant {
 
    Definition(DefinitionId),
 
    PolyArg((DefinitionId, u32)), // index of polyarg in the definition
 
}
 

	
 
#[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
 
pub enum PrimitiveType {
 
    Input,
 
    Output,
 
    Message,
 
    Boolean,
 
    Byte,
 
    Short,
 
    Int,
 
    Long,
 
    Symbolic(PrimitiveSymbolic)
 
}
 

	
 
// TODO: @cleanup, remove PartialEq implementations
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct PrimitiveSymbolic {
 
    // Phase 1: parser
 
    pub(crate) identifier: NamespacedIdentifier,
 
    // Phase 2: typing
 
    pub(crate) definition: Option<DefinitionId>
 
}
 

	
 
impl PartialEq for PrimitiveSymbolic {
 
    fn eq(&self, other: &Self) -> bool {
 
        self.identifier == other.identifier
 
    }
 
}
 
impl Eq for PrimitiveSymbolic{}
 

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

	
 
#[allow(dead_code)]
 
impl Type {
 
    pub const INPUT: Type = Type { primitive: PrimitiveType::Input, array: false };
 
    pub const OUTPUT: Type = Type { primitive: PrimitiveType::Output, array: false };
 
    pub const MESSAGE: Type = Type { primitive: PrimitiveType::Message, array: false };
 
    pub const BOOLEAN: Type = Type { primitive: PrimitiveType::Boolean, array: false };
 
    pub const BYTE: Type = Type { primitive: PrimitiveType::Byte, array: false };
 
    pub const SHORT: Type = Type { primitive: PrimitiveType::Short, array: false };
 
    pub const INT: Type = Type { primitive: PrimitiveType::Int, array: false };
 
    pub const LONG: Type = Type { primitive: PrimitiveType::Long, array: false };
 

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

	
 
impl Display for Type {
 
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
 
        match &self.primitive {
 
            PrimitiveType::Input => {
 
                write!(f, "in")?;
 
            }
 
            PrimitiveType::Output => {
 
                write!(f, "out")?;
 
            }
 
            PrimitiveType::Message => {
 
                write!(f, "msg")?;
 
            }
 
            PrimitiveType::Boolean => {
 
                write!(f, "boolean")?;
 
            }
 
            PrimitiveType::Byte => {
 
                write!(f, "byte")?;
 
            }
 
            PrimitiveType::Short => {
 
                write!(f, "short")?;
 
            }
 
            PrimitiveType::Int => {
 
                write!(f, "int")?;
 
            }
 
            PrimitiveType::Long => {
 
                write!(f, "long")?;
 
            }
 
            PrimitiveType::Symbolic(data) => {
 
                // Type data is in ASCII range.
 
                if let Some(id) = &data.definition {
 
                    write!(
 
                        f, "Symbolic({}, id: {})", 
 
                        String::from_utf8_lossy(&data.identifier.value),
 
                        id.index
 
                    )?;
 
                } else {
 
                    write!(
 
                        f, "Symbolic({}, id: Unresolved)",
 
                        String::from_utf8_lossy(&data.identifier.value)
 
                    )?;
 
                }
 
            }
 
        }
 
        if self.array {
 
            write!(f, "[]")
 
        } else {
 
            Ok(())
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct TypeAnnotation {
 
    pub this: TypeAnnotationId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub the_type: Type,
 
}
 

	
 
impl SyntaxElement for TypeAnnotation {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
type CharacterData = Vec<u8>;
 
type IntegerData = i64;
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub enum Constant {
 
    Null, // message
 
    True,
 
    False,
 
    Character(CharacterData),
 
    Integer(IntegerData),
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub enum Method {
 
    Get,
 
    Fires,
 
    Create,
 
    Symbolic(MethodSymbolic)
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct MethodSymbolic {
 
    pub(crate) identifier: NamespacedIdentifier,
 
    pub(crate) definition: Option<DefinitionId>
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub enum Field {
 
    Length,
 
    Symbolic(Identifier),
 
}
 
impl Field {
 
    pub fn is_length(&self) -> bool {
 
        match self {
 
            Field::Length => true,
 
            _ => false,
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, Copy, serde::Serialize, serde::Deserialize)]
 
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")
 
        }
 
    }
 
}
 

	
 
pub trait VariableScope {
 
    fn parent_scope(&self, h: &Heap) -> Option<Scope>;
 
    fn get_variable(&self, h: &Heap, id: &Identifier) -> Option<VariableId>;
 
}
 

	
 
impl VariableScope for Scope {
 
    fn parent_scope(&self, h: &Heap) -> Option<Scope> {
 
        match self {
 
            Scope::Definition(def) => h[*def].parent_scope(h),
 
            Scope::Regular(stmt) => h[*stmt].parent_scope(h),
 
            Scope::Synchronous((stmt, _)) => h[*stmt].parent_scope(h),
 
        }
 
    }
 
    fn get_variable(&self, h: &Heap, id: &Identifier) -> Option<VariableId> {
 
        match self {
 
            Scope::Definition(def) => h[*def].get_variable(h, id),
 
            Scope::Regular(stmt) => h[*stmt].get_variable(h, id),
 
            Scope::Synchronous((stmt, _)) => h[*stmt].get_variable(h, id),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub enum Variable {
 
    Parameter(Parameter),
 
    Local(Local),
 
}
 

	
 
impl Variable {
 
    pub fn identifier(&self) -> &Identifier {
 
        match self {
 
            Variable::Parameter(var) => &var.identifier,
 
            Variable::Local(var) => &var.identifier,
 
        }
 
    }
 
    pub fn is_parameter(&self) -> bool {
 
        match self {
 
            Variable::Parameter(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub fn as_parameter(&self) -> &Parameter {
 
        match self {
 
            Variable::Parameter(result) => result,
 
            _ => panic!("Unable to cast `Variable` to `Parameter`"),
 
        }
 
    }
 
    pub fn as_local(&self) -> &Local {
 
        match self {
 
            Variable::Local(result) => result,
 
            _ => panic!("Unable to cast `Variable` to `Local`"),
 
        }
 
    }
 
    pub fn as_local_mut(&mut self) -> &mut Local {
 
        match self {
 
            Variable::Local(result) => result,
 
            _ => panic!("Unable to cast 'Variable' to 'Local'"),
 
        }
 
    }
 
    pub fn the_type<'b>(&self, h: &'b Heap) -> &'b Type {
 
        match self {
 
            Variable::Parameter(param) => &h[param.type_annotation].the_type,
 
            Variable::Local(local) => &h[local.type_annotation].the_type,
 
        }
 
    }
 
}
 

	
 
impl SyntaxElement for Variable {
 
    fn position(&self) -> InputPosition {
 
        match self {
 
            Variable::Parameter(decl) => decl.position(),
 
            Variable::Local(decl) => decl.position(),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct Parameter {
 
    pub this: ParameterId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub type_annotation: TypeAnnotationId,
 
    pub parser_type: ParserTypeId,
 
    pub identifier: Identifier,
 
}
 

	
 
impl SyntaxElement for Parameter {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct Local {
 
    pub this: LocalId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub type_annotation: TypeAnnotationId,
 
    pub parser_type: ParserTypeId,
 
    pub identifier: Identifier,
 
    // Phase 2: linker
 
    pub relative_pos_in_block: u32,
 
}
 
impl SyntaxElement for Local {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub enum Definition {
 
    Struct(StructDefinition),
 
    Enum(EnumDefinition),
 
    Component(Component),
 
    Function(Function),
 
}
 

	
 
impl Definition {
 
    pub fn is_struct(&self) -> bool {
 
        match self {
 
            Definition::Struct(_) => true,
 
            _ => false
 
        }
 
    }
 
    pub fn as_struct(&self) -> &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 fn as_enum(&self) -> &EnumDefinition {
 
        match self {
 
            Definition::Enum(result) => result,
 
            _ => panic!("Unable to cast 'Definition' to 'EnumDefinition'"),
 
        }
 
    }
 
    pub fn is_component(&self) -> bool {
 
        match self {
 
            Definition::Component(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub fn as_component(&self) -> &Component {
 
        match self {
 
            Definition::Component(result) => result,
 
            _ => panic!("Unable to cast `Definition` to `Component`"),
 
        }
 
    }
 
    pub fn as_function(&self) -> &Function {
 
        match self {
 
            Definition::Function(result) => result,
 
            _ => panic!("Unable to cast `Definition` to `Function`"),
 
        }
 
    }
 
    pub fn identifier(&self) -> &Identifier {
 
        match self {
 
            Definition::Struct(def) => &def.identifier,
 
            Definition::Enum(def) => &def.identifier,
 
            Definition::Component(com) => &com.identifier,
 
            Definition::Function(fun) => &fun.identifier,
 
        }
 
    }
 
    pub fn parameters(&self) -> &Vec<ParameterId> {
 
        // TODO: Fix this
 
        static EMPTY_VEC: Vec<ParameterId> = Vec::new();
 
        match self {
 
            Definition::Component(com) => &com.parameters,
 
            Definition::Function(fun) => &fun.parameters,
 
            _ => &EMPTY_VEC,
 
        }
 
    }
 
    pub fn body(&self) -> StatementId {
 
        // TODO: Fix this
 
        match self {
 
            Definition::Component(com) => com.body,
 
            Definition::Function(fun) => fun.body,
 
            _ => panic!("cannot retrieve body (for EnumDefinition or StructDefinition)")
 
        }
 
    }
 
}
 

	
 
impl SyntaxElement for Definition {
 
    fn position(&self) -> InputPosition {
 
        match self {
 
            Definition::Struct(def) => def.position,
 
            Definition::Enum(def) => def.position,
 
            Definition::Component(def) => def.position(),
 
            Definition::Function(def) => def.position(),
 
        }
 
    }
 
}
 

	
 
impl VariableScope for Definition {
 
    fn parent_scope(&self, _h: &Heap) -> Option<Scope> {
 
        None
 
    }
 
    fn get_variable(&self, h: &Heap, id: &Identifier) -> Option<VariableId> {
 
        for &parameter_id in self.parameters().iter() {
 
            let parameter = &h[parameter_id];
 
            if parameter.identifier.value == id.value {
 
                return Some(parameter_id.0);
 
            }
 
        }
 
        None
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct StructFieldDefinition {
 
    pub position: InputPosition,
 
    pub field: Identifier,
 
    pub the_type: TypeAnnotationId,
 
    pub parser_type: ParserTypeId,
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct StructDefinition {
 
    pub this: StructId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    pub fields: Vec<StructFieldDefinition>
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize, PartialEq)]
 
pub enum EnumVariantValue {
 
    None,
 
    Integer(i64),
 
    Type(TypeAnnotationId),
 
    Type(ParserTypeId),
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct EnumVariantDefinition {
 
    pub position: InputPosition,
 
    pub identifier: Identifier,
 
    pub value: EnumVariantValue,
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct EnumDefinition {
 
    pub this: EnumId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    pub variants: Vec<EnumVariantDefinition>,
 
}
 

	
 
#[derive(Debug, Clone, Copy, serde::Serialize, serde::Deserialize)]
 
pub enum ComponentVariant {
 
    Primitive,
 
    Composite,
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct Component {
 
    pub this: ComponentId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub variant: ComponentVariant,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    pub parameters: Vec<ParameterId>,
 
    pub body: StatementId,
 
}
 

	
 
impl SyntaxElement for Component {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct Function {
 
    pub this: FunctionId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub return_type: TypeAnnotationId,
 
    pub return_type: ParserTypeId,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    pub parameters: Vec<ParameterId>,
 
    pub body: StatementId,
 
}
 

	
 
impl SyntaxElement for Function {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub enum Signature {
 
    Component(ComponentSignature),
 
    Function(FunctionSignature),
 
}
 

	
 
impl Signature {
 
    pub fn from_definition(h: &Heap, def: DefinitionId) -> Signature {
 
        // TODO: Fix this
 
        match &h[def] {
 
            Definition::Component(com) => Signature::Component(ComponentSignature {
 
                identifier: com.identifier.clone(), // TODO: @fix
 
                arity: Signature::convert_parameters(h, &com.parameters),
 
            }),
 
            Definition::Function(fun) => Signature::Function(FunctionSignature {
 
                return_type: h[fun.return_type].the_type.clone(),
 
                identifier: fun.identifier.clone(), // TODO: @fix
 
                arity: Signature::convert_parameters(h, &fun.parameters),
 
            }),
 
            _ => panic!("cannot retrieve signature (for StructDefinition or EnumDefinition)")
 
        }
 
    }
 
    fn convert_parameters(h: &Heap, params: &Vec<ParameterId>) -> Vec<Type> {
 
        let mut result = Vec::new();
 
        for &param in params.iter() {
 
            result.push(h[h[param].type_annotation].the_type.clone());
 
        }
 
        result
 
    }
 
    fn identifier(&self) -> &Identifier {
 
        match self {
 
            Signature::Component(com) => &com.identifier,
 
            Signature::Function(fun) => &fun.identifier,
 
        }
 
    }
 
    pub fn is_component(&self) -> bool {
 
        match self {
 
            Signature::Component(_) => true,
 
            Signature::Function(_) => false,
 
        }
 
    }
 
    pub fn is_function(&self) -> bool {
 
        match self {
 
            Signature::Component(_) => false,
 
            Signature::Function(_) => true,
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct ComponentSignature {
 
    pub identifier: Identifier,
 
    pub arity: Vec<Type>,
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct FunctionSignature {
 
    pub return_type: Type,
 
    pub identifier: Identifier,
 
    pub arity: Vec<Type>,
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub enum Statement {
 
    Block(BlockStatement),
 
    Local(LocalStatement),
 
    Skip(SkipStatement),
 
    Labeled(LabeledStatement),
 
    If(IfStatement),
 
    EndIf(EndIfStatement),
 
    While(WhileStatement),
 
    EndWhile(EndWhileStatement),
 
    Break(BreakStatement),
 
    Continue(ContinueStatement),
 
    Synchronous(SynchronousStatement),
 
    EndSynchronous(EndSynchronousStatement),
 
    Return(ReturnStatement),
 
    Assert(AssertStatement),
 
    Goto(GotoStatement),
 
    New(NewStatement),
 
    Put(PutStatement),
 
    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_block_mut(&mut self) -> &mut BlockStatement {
 
        match self {
 
            Statement::Block(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `BlockStatement`"),
 
        }
 
    }
 
    pub fn as_local(&self) -> &LocalStatement {
 
        match self {
 
            Statement::Local(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `LocalStatement`"),
 
        }
 
    }
 
    pub fn as_memory(&self) -> &MemoryStatement {
 
        self.as_local().as_memory()
 
    }
 
    pub fn as_channel(&self) -> &ChannelStatement {
 
        self.as_local().as_channel()
 
    }
 
    pub fn as_skip(&self) -> &SkipStatement {
 
        match self {
 
            Statement::Skip(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `SkipStatement`"),
 
        }
 
    }
 
    pub fn as_labeled(&self) -> &LabeledStatement {
 
        match self {
 
            Statement::Labeled(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `LabeledStatement`"),
 
        }
 
    }
 
    pub fn as_labeled_mut(&mut self) -> &mut LabeledStatement {
 
        match self {
 
            Statement::Labeled(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `LabeledStatement`"),
 
        }
 
    }
 
    pub fn as_if(&self) -> &IfStatement {
 
        match self {
 
            Statement::If(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `IfStatement`"),
 
        }
 
    }
 
    pub fn as_if_mut(&mut self) -> &mut IfStatement {
 
        match self {
 
            Statement::If(result) => result,
 
            _ => panic!("Unable to cast 'Statement' to 'IfStatement'"),
 
        }
 
    }
 
    pub fn as_end_if(&self) -> &EndIfStatement {
 
        match self {
 
            Statement::EndIf(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `EndIfStatement`"),
 
        }
 
    }
 
    pub fn is_while(&self) -> bool {
 
        match self {
 
            Statement::While(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub fn as_while(&self) -> &WhileStatement {
 
        match self {
 
            Statement::While(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `WhileStatement`"),
 
        }
 
    }
 
    pub fn as_while_mut(&mut self) -> &mut WhileStatement {
 
        match self {
 
            Statement::While(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `WhileStatement`"),
 
        }
 
    }
 
    pub fn as_end_while(&self) -> &EndWhileStatement {
 
        match self {
 
            Statement::EndWhile(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `EndWhileStatement`"),
 
        }
 
    }
 
    pub fn as_break(&self) -> &BreakStatement {
 
        match self {
 
            Statement::Break(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `BreakStatement`"),
 
        }
 
    }
 
    pub fn as_break_mut(&mut self) -> &mut BreakStatement {
 
        match self {
 
            Statement::Break(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `BreakStatement`"),
 
        }
 
    }
 
    pub fn as_continue(&self) -> &ContinueStatement {
 
        match self {
 
            Statement::Continue(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `ContinueStatement`"),
 
        }
 
    }
 
    pub fn as_continue_mut(&mut self) -> &mut ContinueStatement {
 
        match self {
 
            Statement::Continue(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `ContinueStatement`"),
 
        }
 
    }
 
    pub fn as_synchronous(&self) -> &SynchronousStatement {
 
        match self {
 
            Statement::Synchronous(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `SynchronousStatement`"),
 
        }
 
    }
 
    pub fn as_synchronous_mut(&mut self) -> &mut SynchronousStatement {
 
        match self {
 
            Statement::Synchronous(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `SynchronousStatement`"),
 
        }
 
    }
 
    pub fn as_end_synchronous(&self) -> &EndSynchronousStatement {
 
        match self {
 
            Statement::EndSynchronous(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `EndSynchronousStatement`"),
 
        }
 
    }
 
    pub fn as_return(&self) -> &ReturnStatement {
 
        match self {
 
            Statement::Return(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `ReturnStatement`"),
 
        }
 
    }
 
    pub fn as_assert(&self) -> &AssertStatement {
 
        match self {
 
            Statement::Assert(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `AssertStatement`"),
 
        }
 
    }
 
    pub fn as_goto(&self) -> &GotoStatement {
 
        match self {
 
            Statement::Goto(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `GotoStatement`"),
 
        }
 
    }
 
    pub fn as_goto_mut(&mut self) -> &mut GotoStatement {
 
        match self {
 
            Statement::Goto(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `GotoStatement`"),
 
        }
 
    }
 
    pub fn as_new(&self) -> &NewStatement {
 
        match self {
 
            Statement::New(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `NewStatement`"),
 
        }
 
    }
 
    pub fn as_put(&self) -> &PutStatement {
 
        match self {
 
            Statement::Put(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `PutStatement`"),
 
        }
 
    }
 
    pub fn as_expression(&self) -> &ExpressionStatement {
 
        match self {
 
            Statement::Expression(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `ExpressionStatement`"),
 
        }
 
    }
 
    pub fn link_next(&mut self, next: StatementId) {
 
        match self {
 
            Statement::Block(_) => todo!(),
 
            Statement::Local(stmt) => match stmt {
 
                LocalStatement::Channel(stmt) => stmt.next = Some(next),
 
                LocalStatement::Memory(stmt) => stmt.next = Some(next),
 
            },
 
            Statement::Skip(stmt) => stmt.next = Some(next),
 
            Statement::EndIf(stmt) => stmt.next = Some(next),
 
            Statement::EndWhile(stmt) => stmt.next = Some(next),
 
            Statement::EndSynchronous(stmt) => stmt.next = Some(next),
 
            Statement::Assert(stmt) => stmt.next = Some(next),
 
            Statement::New(stmt) => stmt.next = Some(next),
 
            Statement::Put(stmt) => stmt.next = Some(next),
 
            Statement::Expression(stmt) => stmt.next = Some(next),
 
            Statement::Return(_)
 
            | Statement::Break(_)
 
            | Statement::Continue(_)
 
            | Statement::Synchronous(_)
 
            | Statement::Goto(_)
 
            | Statement::While(_)
 
            | Statement::Labeled(_)
 
            | Statement::If(_) => unreachable!(),
 
        }
 
    }
 
}
 

	
 
impl SyntaxElement for Statement {
 
    fn position(&self) -> InputPosition {
 
        match self {
 
            Statement::Block(stmt) => stmt.position(),
 
            Statement::Local(stmt) => stmt.position(),
 
            Statement::Skip(stmt) => stmt.position(),
 
            Statement::Labeled(stmt) => stmt.position(),
 
            Statement::If(stmt) => stmt.position(),
 
            Statement::EndIf(stmt) => stmt.position(),
 
            Statement::While(stmt) => stmt.position(),
 
            Statement::EndWhile(stmt) => stmt.position(),
 
            Statement::Break(stmt) => stmt.position(),
 
            Statement::Continue(stmt) => stmt.position(),
 
            Statement::Synchronous(stmt) => stmt.position(),
 
            Statement::EndSynchronous(stmt) => stmt.position(),
 
            Statement::Return(stmt) => stmt.position(),
 
            Statement::Assert(stmt) => stmt.position(),
 
            Statement::Goto(stmt) => stmt.position(),
 
            Statement::New(stmt) => stmt.position(),
 
            Statement::Put(stmt) => stmt.position(),
 
            Statement::Expression(stmt) => stmt.position(),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct BlockStatement {
 
    pub this: BlockStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub statements: Vec<StatementId>,
 
    // Phase 2: linker
 
    pub parent_scope: Option<Scope>,
 
    pub relative_pos_in_parent: u32,
 
    pub locals: Vec<LocalId>,
 
    pub labels: Vec<LabeledStatementId>,
 
}
 

	
 
impl BlockStatement {
 
    pub fn parent_block(&self, h: &Heap) -> Option<BlockStatementId> {
 
        let parent = self.parent_scope.unwrap();
 
        match parent {
 
            Scope::Definition(_) => {
 
                // If the parent scope is a definition, then there is no
 
                // parent block.
 
                None
 
            }
 
            Scope::Synchronous((parent, _)) => {
 
                // It is always the case that when this function is called,
 
                // the parent of a synchronous statement is a block statement:
 
                // nested synchronous statements are flagged illegal,
 
                // and that happens before resolving variables that
 
                // creates the parent_scope references in the first place.
 
                Some(h[parent].parent_scope(h).unwrap().to_block())
 
            }
 
            Scope::Regular(parent) => {
 
                // A variable scope is either a definition, sync, or block.
 
                Some(parent)
 
            }
 
        }
 
    }
 
    pub fn first(&self) -> StatementId {
 
        // It is an invariant (guaranteed by the lexer) that block statements have at least one stmt
 
        *self.statements.first().unwrap()
 
    }
 
}
 

	
 
impl SyntaxElement for BlockStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
impl VariableScope for BlockStatement {
 
    fn parent_scope(&self, _h: &Heap) -> Option<Scope> {
 
        self.parent_scope.clone()
 
    }
 
    fn get_variable(&self, h: &Heap, id: &Identifier) -> Option<VariableId> {
 
        for local_id in self.locals.iter() {
 
            let local = &h[*local_id];
 
            if local.identifier.value == id.value {
 
                return Some(local_id.0);
 
            }
 
        }
 
        None
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
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 next(&self) -> Option<StatementId> {
 
        match self {
 
            LocalStatement::Memory(stmt) => stmt.next,
 
            LocalStatement::Channel(stmt) => stmt.next,
 
        }
 
    }
 
}
 

	
 
impl SyntaxElement for LocalStatement {
 
    fn position(&self) -> InputPosition {
 
        match self {
 
            LocalStatement::Memory(stmt) => stmt.position(),
 
            LocalStatement::Channel(stmt) => stmt.position(),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct MemoryStatement {
 
    pub this: MemoryStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub variable: LocalId,
 
    pub initial: ExpressionId,
 
    // Phase 2: linker
 
    pub next: Option<StatementId>,
 
}
 

	
 
impl SyntaxElement for MemoryStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
/// 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, serde::Serialize, serde::Deserialize)]
 
pub struct ChannelStatement {
 
    pub this: ChannelStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub from: LocalId, // output
 
    pub to: LocalId,   // input
 
    // Phase 2: linker
 
    pub relative_pos_in_block: u32,
 
    pub next: Option<StatementId>,
 
}
 

	
 
impl SyntaxElement for ChannelStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct SkipStatement {
 
    pub this: SkipStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    // Phase 2: linker
 
    pub next: Option<StatementId>,
 
}
 

	
 
impl SyntaxElement for SkipStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

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

	
 
impl SyntaxElement for LabeledStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct IfStatement {
 
    pub this: IfStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub test: ExpressionId,
 
    pub true_body: StatementId,
 
    pub false_body: StatementId,
 
    // Phase 2: linker
 
    pub end_if: Option<EndIfStatementId>,
 
}
 

	
 
impl SyntaxElement for IfStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct EndIfStatement {
 
    pub this: EndIfStatementId,
 
    // Phase 2: linker
 
    pub start_if: IfStatementId,
 
    pub position: InputPosition, // of corresponding if statement
 
    pub next: Option<StatementId>,
 
}
 

	
 
impl SyntaxElement for EndIfStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct WhileStatement {
 
    pub this: WhileStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub test: ExpressionId,
 
    pub body: StatementId,
 
    // Phase 2: linker
 
    pub end_while: Option<EndWhileStatementId>,
 
    pub in_sync: Option<SynchronousStatementId>,
 
}
 

	
 
impl SyntaxElement for WhileStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct EndWhileStatement {
 
    pub this: EndWhileStatementId,
 
    // Phase 2: linker
 
    pub start_while: WhileStatementId,
 
    pub position: InputPosition, // of corresponding while
 
    pub next: Option<StatementId>,
 
}
 

	
 
impl SyntaxElement for EndWhileStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct BreakStatement {
 
    pub this: BreakStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub label: Option<Identifier>,
 
    // Phase 2: linker
 
    pub target: Option<EndWhileStatementId>,
 
}
 

	
 
impl SyntaxElement for BreakStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct ContinueStatement {
 
    pub this: ContinueStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub label: Option<Identifier>,
 
    // Phase 2: linker
 
    pub target: Option<WhileStatementId>,
 
}
 

	
 
impl SyntaxElement for ContinueStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct SynchronousStatement {
 
    pub this: SynchronousStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    // pub parameters: Vec<ParameterId>,
 
    pub body: StatementId,
 
    // Phase 2: linker
 
    pub end_sync: Option<EndSynchronousStatementId>,
 
    pub parent_scope: Option<Scope>,
 
}
 

	
 
impl SyntaxElement for SynchronousStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
impl VariableScope for SynchronousStatement {
 
    fn parent_scope(&self, _h: &Heap) -> Option<Scope> {
 
        self.parent_scope.clone()
 
    }
 
    fn get_variable(&self, _h: &Heap, _id: &Identifier) -> Option<VariableId> {
 
        // TODO: Another case of "where was this used for?"
 
        // for parameter_id in self.parameters.iter() {
 
        //     let parameter = &h[*parameter_id];
 
        //     if parameter.identifier.value == id.value {
 
        //         return Some(parameter_id.0);
 
        //     }
 
        // }
 
        None
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct EndSynchronousStatement {
 
    pub this: EndSynchronousStatementId,
 
    // Phase 2: linker
 
    pub position: InputPosition, // of corresponding sync statement
 
    pub start_sync: SynchronousStatementId,
 
    pub next: Option<StatementId>,
 
}
 

	
 
impl SyntaxElement for EndSynchronousStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct ReturnStatement {
 
    pub this: ReturnStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub expression: ExpressionId,
 
}
 

	
 
impl SyntaxElement for ReturnStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct AssertStatement {
 
    pub this: AssertStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub expression: ExpressionId,
 
    // Phase 2: linker
 
    pub next: Option<StatementId>,
 
}
 

	
 
impl SyntaxElement for AssertStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct GotoStatement {
 
    pub this: GotoStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub label: Identifier,
 
    // Phase 2: linker
 
    pub target: Option<LabeledStatementId>,
 
}
 

	
 
impl SyntaxElement for GotoStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct NewStatement {
 
    pub this: NewStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub expression: CallExpressionId,
 
    // Phase 2: linker
 
    pub next: Option<StatementId>,
 
}
 

	
 
impl SyntaxElement for NewStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct PutStatement {
 
    pub this: PutStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub port: ExpressionId,
 
    pub message: ExpressionId,
 
    // Phase 2: linker
 
    pub next: Option<StatementId>,
 
}
 

	
 
impl SyntaxElement for PutStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct ExpressionStatement {
 
    pub this: ExpressionStatementId,
 
    // Phase 1: parser
 
    pub position: InputPosition,
 
    pub expression: ExpressionId,
 
    // Phase 2: linker
 
    pub next: Option<StatementId>,
 
}
 

	
 
impl SyntaxElement for ExpressionStatement {
 
    fn position(&self) -> InputPosition {
 
        self.position
 
    }
 
}
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub enum Expression {
 
    Assignment(AssignmentExpression),
 
    Conditional(ConditionalExpression),
 
    Binary(BinaryExpression),
 
    Unary(UnaryExpression),
 
    Indexing(IndexingExpression),
 
    Slicing(SlicingExpression),
 
    Select(SelectExpression),
 
    Array(ArrayExpression),
 
    Constant(ConstantExpression),
 
    Call(CallExpression),
 
    Variable(VariableExpression),
 
}
 

	
 
impl Expression {
 
    pub fn as_assignment(&self) -> &AssignmentExpression {
 
        match self {
 
            Expression::Assignment(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `AssignmentExpression`"),
 
        }
 
    }
 
    pub fn as_conditional(&self) -> &ConditionalExpression {
 
        match self {
 
            Expression::Conditional(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `ConditionalExpression`"),
 
        }
 
    }
 
    pub fn as_binary(&self) -> &BinaryExpression {
 
        match self {
 
            Expression::Binary(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `BinaryExpression`"),
 
        }
 
    }
 
    pub fn as_unary(&self) -> &UnaryExpression {
 
        match self {
 
            Expression::Unary(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `UnaryExpression`"),
 
        }
 
    }
 
    pub fn as_indexing(&self) -> &IndexingExpression {
 
        match self {
 
            Expression::Indexing(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `IndexingExpression`"),
 
        }
 
    }
 
    pub fn as_slicing(&self) -> &SlicingExpression {
 
        match self {
 
            Expression::Slicing(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `SlicingExpression`"),
 
        }
 
    }
 
    pub fn as_select(&self) -> &SelectExpression {
 
        match self {
 
            Expression::Select(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `SelectExpression`"),
 
        }
 
    }
 
    pub fn as_array(&self) -> &ArrayExpression {
 
        match self {
 
            Expression::Array(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `ArrayExpression`"),
 
        }
 
    }
 
    pub fn as_constant(&self) -> &ConstantExpression {
 
        match self {
 
            Expression::Constant(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `ConstantExpression`"),
 
        }
 
    }
 
    pub fn as_call(&self) -> &CallExpression {
 
        match self {
 
            Expression::Call(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `CallExpression`"),
 
        }
 
    }
 
    pub fn as_call_mut(&mut self) -> &mut CallExpression {
 
        match self {
 
            Expression::Call(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `CallExpression`"),
 
        }
 
    }
 
    pub fn as_variable(&self) -> &VariableExpression {
 
        match self {
 
            Expression::Variable(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `VariableExpression`"),
 
        }
 
    }
 
    pub fn as_variable_mut(&mut self) -> &mut VariableExpression {
 
        match self {
 
            Expression::Variable(result) => result,
src/protocol/lexer.rs
Show inline comments
 
use crate::protocol::ast::*;
 
use crate::protocol::inputsource::*;
 

	
 
const MAX_LEVEL: usize = 128;
 
const MAX_NAMESPACES: u8 = 8; // only three levels are supported at the moment
 

	
 
fn is_vchar(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c >= 0x21 && c <= 0x7E
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn is_wsp(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c == b' ' || c == b'\t'
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn is_ident_start(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c >= b'A' && c <= b'Z' || c >= b'a' && c <= b'z'
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn is_ident_rest(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c >= b'A' && c <= b'Z' || c >= b'a' && c <= b'z' || c >= b'0' && c <= b'9' || c == b'_'
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn is_constant(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c >= b'0' && c <= b'9' || c == b'\''
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn is_integer_start(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c >= b'0' && c <= b'9'
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn is_integer_rest(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c >= b'0' && c <= b'9'
 
            || c >= b'a' && c <= b'f'
 
            || c >= b'A' && c <= b'F'
 
            || c == b'x'
 
            || c == b'o'
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn lowercase(x: u8) -> u8 {
 
    if x >= b'A' && x <= b'Z' {
 
        x - b'A' + b'a'
 
    } else {
 
        x
 
    }
 
}
 

	
 
pub struct Lexer<'a> {
 
    source: &'a mut InputSource,
 
    level: usize,
 
}
 

	
 
impl Lexer<'_> {
 
    pub fn new(source: &mut InputSource) -> Lexer {
 
        Lexer { source, level: 0 }
 
    }
 
    fn error_at_pos(&self, msg: &str) -> ParseError2 {
 
        ParseError2::new_error(self.source, self.source.pos(), msg)
 
    }
 
    fn consume_line(&mut self) -> Result<Vec<u8>, ParseError2> {
 
        let mut result: Vec<u8> = Vec::new();
 
        let mut next = self.source.next();
 
        while next.is_some() && next != Some(b'\n') && next != Some(b'\r') {
 
            if !(is_vchar(next) || is_wsp(next)) {
 
                return Err(self.error_at_pos("Expected visible character or whitespace"));
 
            }
 
            result.push(next.unwrap());
 
            self.source.consume();
 
            next = self.source.next();
 
        }
 
        if next.is_some() {
 
            self.source.consume();
 
        }
 
        if next == Some(b'\r') && self.source.next() == Some(b'\n') {
 
            self.source.consume();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_whitespace(&mut self, expected: bool) -> Result<(), ParseError2> {
 
        let mut found = false;
 
        let mut next = self.source.next();
 
        while next.is_some() {
 
            if next == Some(b' ')
 
                || next == Some(b'\t')
 
                || next == Some(b'\r')
 
                || next == Some(b'\n')
 
            {
 
                self.source.consume();
 
                next = self.source.next();
 
                found = true;
 
                continue;
 
            }
 
            if next == Some(b'/') {
 
                next = self.source.lookahead(1);
 
                if next == Some(b'/') {
 
                    self.source.consume(); // slash
 
                    self.source.consume(); // slash
 
                    self.consume_line()?;
 
                    next = self.source.next();
 
                    found = true;
 
                    continue;
 
                }
 
                if next == Some(b'*') {
 
                    self.source.consume(); // slash
 
                    self.source.consume(); // star
 
                    next = self.source.next();
 
                    while next.is_some() {
 
                        if next == Some(b'*') {
 
                            next = self.source.lookahead(1);
 
                            if next == Some(b'/') {
 
                                self.source.consume(); // star
 
                                self.source.consume(); // slash
 
                                break;
 
                            }
 
                        }
 
                        self.source.consume();
 
                        next = self.source.next();
 
                    }
 
                    next = self.source.next();
 
                    found = true;
 
                    continue;
 
                }
 
            }
 
            break;
 
        }
 
        if expected && !found {
 
            Err(self.error_at_pos("Expected whitespace"))
 
        } else {
 
            Ok(())
 
        }
 
    }
 
    fn has_keyword(&self, keyword: &[u8]) -> bool {
 
        if !self.source.has(keyword) {
 
            return false;
 
        }
 

	
 
        // Word boundary
 
        if let Some(next) = self.source.lookahead(keyword.len()) {
 
            !(next >= b'A' && next <= b'Z' || next >= b'a' && next <= b'z')
 
        } else {
 
            true
 
        }
 
    }
 
    fn consume_keyword(&mut self, keyword: &[u8]) -> Result<(), ParseError2> {
 
        let len = keyword.len();
 
        for i in 0..len {
 
            let expected = Some(lowercase(keyword[i]));
 
            let next = self.source.next();
 
            if next != expected {
 
                return Err(self.error_at_pos(&format!("Expected keyword '{}'", String::from_utf8_lossy(keyword))));
 
            }
 
            self.source.consume();
 
        }
 
        if let Some(next) = self.source.next() {
 
            if next >= b'A' && next <= b'Z' || next >= b'a' && next <= b'z' || next >= b'0' && next <= b'9' {
 
                return Err(self.error_at_pos(&format!("Expected word boundary after '{}'", String::from_utf8_lossy(keyword))));
 
            }
 
        }
 
        Ok(())
 
    }
 
    fn has_string(&self, string: &[u8]) -> bool {
 
        self.source.has(string)
 
    }
 
    fn consume_string(&mut self, string: &[u8]) -> Result<(), ParseError2> {
 
        let len = string.len();
 
        for i in 0..len {
 
            let expected = Some(string[i]);
 
            let next = self.source.next();
 
            if next != expected {
 
                return Err(self.error_at_pos(&format!("Expected {}", String::from_utf8_lossy(string))));
 
            }
 
            self.source.consume();
 
        }
 
        Ok(())
 
    }
 
    fn consume_ident(&mut self) -> Result<Vec<u8>, ParseError2> {
 
        if !self.has_identifier() {
 
            return Err(self.error_at_pos("Expected identifier"));
 
        }
 
        let mut result = Vec::new();
 
        let mut next = self.source.next();
 
        result.push(next.unwrap());
 
        self.source.consume();
 
        next = self.source.next();
 
        while is_ident_rest(next) {
 
            result.push(next.unwrap());
 
            self.source.consume();
 
            next = self.source.next();
 
        }
 
        Ok(result)
 
    }
 
    fn has_integer(&mut self) -> bool {
 
        is_integer_start(self.source.next())
 
    }
 
    fn consume_integer(&mut self) -> Result<i64, ParseError2> {
 
        let position = self.source.pos();
 
        let mut data = Vec::new();
 
        let mut next = self.source.next();
 
        while is_integer_rest(next) {
 
            data.push(next.unwrap());
 
            self.source.consume();
 
            next = self.source.next();
 
        }
 

	
 
        let data_len = data.len();
 
        debug_assert_ne!(data_len, 0);
 
        if data_len == 1 {
 
            debug_assert!(data[0] >= b'0' && data[0] <= b'9');
 
            return Ok((data[0] - b'0') as i64);
 
        } else {
 
            // TODO: Fix, u64 should be supported as well
 
            let parsed = if data[1] == b'b' {
 
                let data = String::from_utf8_lossy(&data[2..]);
 
                i64::from_str_radix(&data, 2)
 
            } else if data[1] == b'o' {
 
                let data = String::from_utf8_lossy(&data[2..]);
 
                i64::from_str_radix(&data, 8)
 
            } else if data[1] == b'x' {
 
                let data = String::from_utf8_lossy(&data[2..]);
 
                i64::from_str_radix(&data, 16)
 
            } else {
 
                // Assume decimal
 
                let data = String::from_utf8_lossy(&data);
 
                i64::from_str_radix(&data, 10)
 
            };
 

	
 
            if let Err(_err) = parsed {
 
                return Err(ParseError2::new_error(&self.source, position, "Invalid integer constant"));
 
            }
 

	
 
            Ok(parsed.unwrap())
 
        }
 
    }
 

	
 
    // Statement keywords
 
    // TODO: Clean up these functions
 
    fn has_statement_keyword(&self) -> bool {
 
        self.has_keyword(b"channel")
 
            || self.has_keyword(b"skip")
 
            || self.has_keyword(b"if")
 
            || self.has_keyword(b"while")
 
            || self.has_keyword(b"break")
 
            || self.has_keyword(b"continue")
 
            || self.has_keyword(b"synchronous")
 
            || self.has_keyword(b"return")
 
            || self.has_keyword(b"assert")
 
            || self.has_keyword(b"goto")
 
            || self.has_keyword(b"new")
 
            || self.has_keyword(b"put") // TODO: @fix, should be a function, even though it has sideeffects
 
    }
 
    fn has_type_keyword(&self) -> bool {
 
        self.has_keyword(b"in")
 
            || self.has_keyword(b"out")
 
            || self.has_keyword(b"msg")
 
            || self.has_keyword(b"boolean")
 
            || self.has_keyword(b"byte")
 
            || self.has_keyword(b"short")
 
            || self.has_keyword(b"int")
 
            || self.has_keyword(b"long")
 
            || self.has_keyword(b"auto")
 
    }
 
    fn has_builtin_keyword(&self) -> bool {
 
        self.has_keyword(b"get")
 
            || self.has_keyword(b"fires")
 
            || self.has_keyword(b"create")
 
            || self.has_keyword(b"length")
 
    }
 
    fn has_reserved(&self) -> bool {
 
        self.has_statement_keyword()
 
            || self.has_type_keyword()
 
            || self.has_builtin_keyword()
 
            || self.has_keyword(b"let")
 
            || self.has_keyword(b"struct")
 
            || self.has_keyword(b"enum")
 
            || self.has_keyword(b"true")
 
            || self.has_keyword(b"false")
 
            || self.has_keyword(b"null")
 
    }
 

	
 
    // Identifiers
 

	
 
    fn has_identifier(&self) -> bool {
 
        if self.has_statement_keyword() || self.has_type_keyword() || self.has_builtin_keyword() {
 
            return false;
 
        }
 
        let next = self.source.next();
 
        is_ident_start(next)
 
    }
 
    fn consume_identifier(&mut self) -> Result<Identifier, ParseError2> {
 
        if self.has_statement_keyword() || self.has_type_keyword() || self.has_builtin_keyword() {
 
            return Err(self.error_at_pos("Expected identifier"));
 
        }
 
        let position = self.source.pos();
 
        let value = self.consume_ident()?;
 
        Ok(Identifier{ position, value })
 
    }
 
    fn consume_identifier_spilled(&mut self) -> Result<(), ParseError2> {
 
        if self.has_statement_keyword() || self.has_type_keyword() || self.has_builtin_keyword() {
 
            return Err(self.error_at_pos("Expected identifier"));
 
        }
 
        self.consume_ident()?;
 
        Ok(())
 
    }
 
    fn has_namespaced_identifier(&self) -> bool { 
 
        self.has_identifier() 
 
    }
 
    fn consume_namespaced_identifier(&mut self) -> Result<NamespacedIdentifier, ParseError2> {
 
        if self.has_reserved() {
 
            return Err(self.error_at_pos("Encountered reserved keyword"));
 
        }
 

	
 
        let position = self.source.pos();
 
        let mut ns_ident = self.consume_ident()?;
 
        let mut num_namespaces = 1;
 
        while self.has_string(b"::") {
 
            if num_namespaces >= MAX_NAMESPACES {
 
                return Err(self.error_at_pos("Too many namespaces in identifier"));
 
            }
 
            let new_ident = self.consume_ident()?;
 
            ns_ident.extend(b"::");
 
            ns_ident.extend(new_ident);
 
            num_namespaces += 1;
 
        }
 

	
 
        Ok(NamespacedIdentifier{
 
            position,
 
            value: ns_ident,
 
            num_namespaces,
 
        })
 
    }
 

	
 
    // Types and type annotations
 

	
 
    /// Consumes a type definition. When called the input position should be at
 
    /// the type specification. When done the input position will be at the end
 
    /// of the type specifications (hence may be at whitespace).
 
    fn consume_type2(&mut self, h: &mut Heap, allow_inference: bool) -> Result<ParserTypeId, ParseError2> {
 
        // Small helper function to convert in/out polymorphic arguments
 
        let reduce_port_poly_args = |
 
            heap: &mut Heap,
 
            port_pos: &InputPosition,
 
            args: Vec<ParserTypeId>,
 
        | {
 
            match args.len() {
 
                0 => Ok(h.alloc_parser_type(|this| ParserType{
 
                        this,
 
                        pos: port_pos.clone(),
 
                        variant: ParserTypeVariant::Inferred
 
                })),
 
                1 => Ok(args[0]),
 
                _ => Err(())
 
            }
 
        };
 

	
 
        // Consume the type
 
        let pos = self.source.pos();
 
        let parser_type_variant = if self.has_keyword(b"msg") {
 
            self.consume_keyword(b"msg");
 
            ParserTypeVariant::Message
 
        } else if self.has_keyword(b"boolean") {
 
            self.consume_keyword(b"boolean");
 
            ParserTypeVariant::Bool
 
        } else if self.has_keyword(b"byte") {
 
            self.consume_keyword(b"byte");
 
            ParserTypeVariant::Byte
 
        } else if self.has_keyword(b"short") {
 
            self.consume_keyword(b"short");
 
            ParserTypeVariant::Short
 
        } else if self.has_keyword(b"int") {
 
            self.consume_keyword(b"int");
 
            ParserTypeVariant::Int
 
        } else if self.has_keyword(b"long") {
 
            self.consume_keyword(b"long");
 
            ParserTypeVariant::Long
 
        } else if self.has_keyword(b"str") {
 
            self.consume_keyword(b"str");
 
            ParserTypeVariant::String
 
        } else if self.has_keyword(b"auto") {
 
            if !allow_inference {
 
                return Err(ParseError2::new_error(
 
                        &self.source, pos,
 
                        "Type inference is not allowed here"
 
                ));
 
            }
 

	
 
            self.consume_keyword(b"auto");
 
            ParserTypeVariant::Inferred
 
        } else if self.has_keyword(b"in") {
 
            // TODO: @cleanup: not particularly neat to have this special case
 
            //  where we enforce polyargs in the parser-phase
 
            self.consume_keyword(b"in");
 
            let poly_args = self.consume_polymorphic_args(h, allow_inference)?;
 
            let poly_arg = reduce_port_poly_args(h, &pos, poly_args)
 
                .map_err(|| ParseError2::new_error(
 
                    &self.source, pos, "'in' type only accepts up to 1 polymorphic argument"
 
                ))?;
 
            ParserTypeVariant::Input(poly_arg)
 
        } else if self.has_keyword(b"out") {
 
            self.consume_keyword(b"out");
 
            let poly_args = self.consume_polymorphic_args(h, allow_inference)?;
 
            let poly_arg = reduce_port_poly_args(h, &pos, poly_args)
 
                .map_err(|| ParseError2::new_error(
 
                    &self.source, pos, "'out' type only accepts up to 1 polymorphic argument"
 
                ))?;
 
            ParserTypeVariant::Output(poly_arg)
 
        } else {
 
            // Must be a symbolic type
 
            let identifier = self.consume_namespaced_identifier()?;
 
            let poly_args = self.consume_polymorphic_args(h, allow_inference)?;
 
            ParserTypeVariant::Symbolic(SymbolicParserType{identifier, poly_args, variant: None})
 
        };
 

	
 
        // If the type was a basic type (not supporting polymorphic type
 
        // arguments), then we make sure the user did not specify any of them.
 
        let mut backup_pos = self.source.pos();
 
        if !parser_type.supports_polymorphic_args() {
 
            self.consume_whitespace(false)?;
 
            if let Some(b'<') = self.source.next() {
 
                return Err(ParseError2::new_error(
 
                    &self.source, self.source.pos(),
 
                    "This type does not allow polymorphic arguments"
 
                ));
 
            }
 

	
 
            self.source.seek(backup_pos);
 
        }
 

	
 
        let mut parser_type_id = h.alloc_parser_type(|this| ParserType{
 
            this, pos, variant: parser_type_variant
 
        });
 

	
 
        // If we're dealing with arrays, then we need to wrap the currently
 
        // parsed type in array types
 
        self.consume_whitespace(false)?;
 
        while let Some(b'[') = self.source.next() {
 
            let pos = self.source.pos();
 
            self.source.consume();
 
            self.consume_whitespace(false)?;
 
            if let Some(b']') = self.source.next() {
 
                // Type is wrapped in an array
 
                self.source.consume();
 
                parser_type_id = h.alloc_parser_type(|this| ParserType{
 
                    this, pos, variant: ParserTypeVariant::Array(parser_type_id)
 
                });
 
                backup_pos = self.source.pos();
 

	
 
                // In case we're dealing with another array
 
                self.consume_whitespace(false)?;
 
            } else {
 
                return Err(ParseError2::new_error(
 
                    &self.source, pos,
 
                    "Expected a closing ']'"
 
                ));
 
            }
 
        }
 

	
 
        self.source.seek(backup_pos);
 
        Ok(parser_type_id)
 
    }
 

	
 
    /// Consumes polymorphic arguments and its delimiters if specified. The
 
    /// input position may be at whitespace. If polyargs are present then the
 
    /// whitespace and the args are consumed and the input position will be
 
    /// placed after the polyarg list. If polyargs are not present then the
 
    /// input position will remain unmodified and an empty vector will be
 
    /// returned.
 
    ///
 
    /// Polymorphic arguments represent the specification of the parametric
 
    /// types of a polymorphic type: they specify the value of the polymorphic
 
    /// type's polymorphic variables.
 
    fn consume_polymorphic_args(&mut self, h: &mut Heap, allow_inference: bool) -> Result<Vec<ParserTypeId>, ParseError2> {
 
        let backup_pos = self.source.pos();
 
        self.consume_whitespace(false)?;
 
        if let Some(b'<') = self.source.next() {
 
            // Has polymorphic args, at least one type must be specified
 
            self.source.consume();
 
            self.consume_whitespace(false)?;
 
            let mut poly_args = Vec::new();
 

	
 
            loop {
 
                // TODO: @cleanup, remove the no_more_types var
 
                poly_args.push(self.consume_type2(h, allow_inference)?);
 
                self.consume_whitespace(false)?;
 

	
 
                let has_comma = self.source.next() == Some(b',');
 
                if has_comma {
 
                    // We might not actually be getting more types when the
 
                    // comma is at the end of the line, and we get a closing
 
                    // angular bracket on the next line.
 
                    self.source.consume();
 
                    self.consume_whitespace(false)?;
 
                }
 

	
 
                if let Some(b'>') = self.source.next() {
 
                    self.source.consume();
 
                    break;
 
                } else if !has_comma {
 
                    return Err(ParseError2::new_error(
 
                        &self.source, self.source.pos(),
 
                        "Expected the end of the polymorphic argument list"
 
                    ))
 
                }
 
            }
 

	
 
            Ok(poly_args)
 
        } else {
 
            // No polymorphic args
 
            self.source.seek(backup_pos);
 
            Ok(vec!())
 
        }
 
    }
 

	
 
    /// Consumes polymorphic variables. These are identifiers that are used
 
    /// within polymorphic types. The input position may be at whitespace. If
 
    /// polymorphic variables are present then the whitespace, wrapping
 
    /// delimiters and the polymorphic variables are consumed. Otherwise the
 
    /// input position will stay where it is. If no polymorphic variables are
 
    /// present then an empty vector will be returned.
 
    fn consume_polymorphic_vars(&mut self) -> Result<Vec<Identifier>, ParseError2> {
 
        let backup_pos = self.source.pos();
 
        self.consume_whitespace(false)?;
 
        if let Some(b'<') = self.source.next() {
 
            // Found the opening delimiter, we want at least one polyvar
 
            self.source.consume();
 
            self.consume_whitespace(false)?;
 
            let mut poly_vars = Vec::new();
 

	
 
            loop {
 
                poly_vars.push(self.consume_identifier()?);
 
                self.consume_whitespace(false)?;
 

	
 
                let has_comma = self.source.next() == Some(b',');
 
                if has_comma {
 
                    // We may get another variable
 
                    self.source.consume();
 
                    self.consume_whitespace(false)?;
 
                }
 

	
 
                if let Some(b'>') = self.source.next() {
 
                    self.source.consume();
 
                    break;
 
                } else if !has_comma {
 
                    return Err(ParseError2::new_error(
 
                        &self.source, self.source.pos(),
 
                        "Expected the end of the polymorphic variable list"
 
                    ))
 
                }
 
            }
 

	
 
            Ok(poly_vars)
 
        } else {
 
            // No polymorphic args
 
            self.source.seek(backup_pos);
 
            Ok(vec!())
 
        }
 
    }
 

	
 
    fn consume_primitive_type(&mut self) -> Result<PrimitiveType, ParseError2> {
 
        if self.has_keyword(b"in") {
 
            self.consume_keyword(b"in")?;
 
            Ok(PrimitiveType::Input)
 
        } else if self.has_keyword(b"out") {
 
            self.consume_keyword(b"out")?;
 
            Ok(PrimitiveType::Output)
 
        } else if self.has_keyword(b"msg") {
 
            self.consume_keyword(b"msg")?;
 
            Ok(PrimitiveType::Message)
 
        } else if self.has_keyword(b"boolean") {
 
            self.consume_keyword(b"boolean")?;
 
            Ok(PrimitiveType::Boolean)
 
        } else if self.has_keyword(b"byte") {
 
            self.consume_keyword(b"byte")?;
 
            Ok(PrimitiveType::Byte)
 
        } else if self.has_keyword(b"short") {
 
            self.consume_keyword(b"short")?;
 
            Ok(PrimitiveType::Short)
 
        } else if self.has_keyword(b"int") {
 
            self.consume_keyword(b"int")?;
 
            Ok(PrimitiveType::Int)
 
        } else if self.has_keyword(b"long") {
 
            self.consume_keyword(b"long")?;
 
            Ok(PrimitiveType::Long)
 
        } else if self.has_keyword(b"let") {
 
        } else if self.has_keyword(b"auto") {
 
            // TODO: @types
 
            return Err(self.error_at_pos("inferred types using 'let' are reserved, but not yet implemented"));
 
            return Err(self.error_at_pos("inferred types using 'auto' are reserved, but not yet implemented"));
 
        } else {
 
            let identifier = self.consume_namespaced_identifier()?;
 
            Ok(PrimitiveType::Symbolic(PrimitiveSymbolic{
 
                identifier,
 
                definition: None
 
            }))
 
        }
 
    }
 
    fn has_array(&mut self) -> bool {
 
        let backup_pos = self.source.pos();
 
        let mut result = false;
 
        match self.consume_whitespace(false) {
 
            Ok(_) => result = self.has_string(b"["),
 
            Err(_) => {}
 
        }
 
        self.source.seek(backup_pos);
 
        return result;
 
    }
 
    fn consume_type(&mut self) -> Result<Type, ParseError2> {
 
        let primitive = self.consume_primitive_type()?;
 
        let array;
 
        if self.has_array() {
 
            self.consume_string(b"[]")?;
 
            array = true;
 
        } else {
 
            array = false;
 
        }
 
        Ok(Type { primitive, array })
 
    }
 
    fn create_type_annotation_input(&self, h: &mut Heap) -> Result<TypeAnnotationId, ParseError2> {
 
        let position = self.source.pos();
 
        let the_type = Type::INPUT;
 
        let id = h.alloc_type_annotation(|this| TypeAnnotation { this, position, the_type });
 
        Ok(id)
 
    }
 
    fn create_type_annotation_output(&self, h: &mut Heap) -> Result<TypeAnnotationId, ParseError2> {
 
        let position = self.source.pos();
 
        let the_type = Type::OUTPUT;
 
        let id = h.alloc_type_annotation(|this| TypeAnnotation { this, position, the_type });
 
        Ok(id)
 
    }
 
    fn consume_type_annotation(&mut self, h: &mut Heap) -> Result<TypeAnnotationId, ParseError2> {
 
        let position = self.source.pos();
 
        let the_type = self.consume_type()?;
 
        let id = h.alloc_type_annotation(|this| TypeAnnotation { this, position, the_type });
 
        Ok(id)
 
    }
 
    fn consume_type_annotation_spilled(&mut self) -> Result<(), ParseError2> {
 
        self.consume_type()?;
 
        Ok(())
 
    }
 

	
 
    // Parameters
 

	
 
    fn consume_parameter(&mut self, h: &mut Heap) -> Result<ParameterId, ParseError2> {
 
        let position = self.source.pos();
 
        let type_annotation = self.consume_type_annotation(h)?;
 
        let parser_type = self.consume_type2(h, false)?;
 
        self.consume_whitespace(true)?;
 
        let position = self.source.pos();
 
        let identifier = self.consume_identifier()?;
 
        let id =
 
            h.alloc_parameter(|this| Parameter { this, position, type_annotation, identifier });
 
            h.alloc_parameter(|this| Parameter { this, position, parser_type, identifier });
 
        Ok(id)
 
    }
 
    fn consume_parameters(
 
        &mut self,
 
        h: &mut Heap,
 
        params: &mut Vec<ParameterId>,
 
    ) -> Result<(), ParseError2> {
 
        self.consume_string(b"(")?;
 
        self.consume_whitespace(false)?;
 
        if !self.has_string(b")") {
 
            while self.source.next().is_some() {
 
                params.push(self.consume_parameter(h)?);
 
                self.consume_whitespace(false)?;
 
                if self.has_string(b")") {
 
                    break;
 
                }
 
                self.consume_string(b",")?;
 
                self.consume_whitespace(false)?;
 
            }
 
        }
 
        self.consume_string(b")")?;
 

	
 
        Ok(())
 
    }
 

	
 
    // ====================
 
    // Expressions
 
    // ====================
 

	
 
    fn consume_paren_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        self.consume_string(b"(")?;
 
        self.consume_whitespace(false)?;
 
        let result = self.consume_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b")")?;
 
        Ok(result)
 
    }
 
    fn consume_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        if self.level >= MAX_LEVEL {
 
            return Err(self.error_at_pos("Too deeply nested expression"));
 
        }
 
        self.level += 1;
 
        let result = self.consume_assignment_expression(h);
 
        self.level -= 1;
 
        result
 
    }
 
    fn consume_assignment_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        let result = self.consume_conditional_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        if self.has_assignment_operator() {
 
            let position = self.source.pos();
 
            let left = result;
 
            let operation = self.consume_assignment_operator()?;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_expression(h)?;
 
            Ok(h.alloc_assignment_expression(|this| AssignmentExpression {
 
                this,
 
                position,
 
                left,
 
                operation,
 
                right,
 
            })
 
            .upcast())
 
        } else {
 
            Ok(result)
 
        }
 
    }
 
    fn has_assignment_operator(&self) -> bool {
 
        self.has_string(b"=")
 
            || self.has_string(b"*=")
 
            || self.has_string(b"/=")
 
            || self.has_string(b"%=")
 
            || self.has_string(b"+=")
 
            || self.has_string(b"-=")
 
            || self.has_string(b"<<=")
 
            || self.has_string(b">>=")
 
            || self.has_string(b"&=")
 
            || self.has_string(b"^=")
 
            || self.has_string(b"|=")
 
    }
 
    fn consume_assignment_operator(&mut self) -> Result<AssignmentOperator, ParseError2> {
 
        if self.has_string(b"=") {
 
            self.consume_string(b"=")?;
 
            Ok(AssignmentOperator::Set)
 
        } else if self.has_string(b"*=") {
 
            self.consume_string(b"*=")?;
 
            Ok(AssignmentOperator::Multiplied)
 
        } else if self.has_string(b"/=") {
 
            self.consume_string(b"/=")?;
 
            Ok(AssignmentOperator::Divided)
 
        } else if self.has_string(b"%=") {
 
            self.consume_string(b"%=")?;
 
            Ok(AssignmentOperator::Remained)
 
        } else if self.has_string(b"+=") {
 
            self.consume_string(b"+=")?;
 
            Ok(AssignmentOperator::Added)
 
        } else if self.has_string(b"-=") {
 
            self.consume_string(b"-=")?;
 
            Ok(AssignmentOperator::Subtracted)
 
        } else if self.has_string(b"<<=") {
 
            self.consume_string(b"<<=")?;
 
            Ok(AssignmentOperator::ShiftedLeft)
 
        } else if self.has_string(b">>=") {
 
            self.consume_string(b">>=")?;
 
            Ok(AssignmentOperator::ShiftedRight)
 
        } else if self.has_string(b"&=") {
 
            self.consume_string(b"&=")?;
 
            Ok(AssignmentOperator::BitwiseAnded)
 
        } else if self.has_string(b"^=") {
 
            self.consume_string(b"^=")?;
 
            Ok(AssignmentOperator::BitwiseXored)
 
        } else if self.has_string(b"|=") {
 
            self.consume_string(b"|=")?;
 
            Ok(AssignmentOperator::BitwiseOred)
 
        } else {
 
            Err(self.error_at_pos("Expected assignment operator"))
 
        }
 
    }
 
    fn consume_conditional_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        let result = self.consume_concat_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        if self.has_string(b"?") {
 
            let position = self.source.pos();
 
            let test = result;
 
            self.consume_string(b"?")?;
 
            self.consume_whitespace(false)?;
 
            let true_expression = self.consume_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            self.consume_string(b":")?;
 
            self.consume_whitespace(false)?;
 
            let false_expression = self.consume_expression(h)?;
 
            Ok(h.alloc_conditional_expression(|this| ConditionalExpression {
 
                this,
 
                position,
 
                test,
 
                true_expression,
 
                false_expression,
 
            })
 
            .upcast())
 
        } else {
 
            Ok(result)
 
        }
 
    }
 
    fn consume_concat_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        let mut result = self.consume_lor_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"@") {
 
            let position = self.source.pos();
 
            let left = result;
 
            self.consume_string(b"@")?;
 
            let operation = BinaryOperator::Concatenate;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_lor_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_lor_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        let mut result = self.consume_land_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"||") {
 
            let position = self.source.pos();
 
            let left = result;
 
            self.consume_string(b"||")?;
 
            let operation = BinaryOperator::LogicalOr;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_land_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_land_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        let mut result = self.consume_bor_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"&&") {
 
            let position = self.source.pos();
 
            let left = result;
 
            self.consume_string(b"&&")?;
 
            let operation = BinaryOperator::LogicalAnd;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_bor_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_bor_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        let mut result = self.consume_xor_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"|") && !self.has_string(b"||") && !self.has_string(b"|=") {
 
            let position = self.source.pos();
 
            let left = result;
 
            self.consume_string(b"|")?;
 
            let operation = BinaryOperator::BitwiseOr;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_xor_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_xor_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        let mut result = self.consume_band_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"^") && !self.has_string(b"^=") {
 
            let position = self.source.pos();
 
            let left = result;
 
            self.consume_string(b"^")?;
 
            let operation = BinaryOperator::BitwiseXor;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_band_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_band_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        let mut result = self.consume_eq_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"&") && !self.has_string(b"&&") && !self.has_string(b"&=") {
 
            let position = self.source.pos();
 
            let left = result;
 
            self.consume_string(b"&")?;
 
            let operation = BinaryOperator::BitwiseAnd;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_eq_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_eq_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        let mut result = self.consume_rel_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"==") || self.has_string(b"!=") {
 
            let position = self.source.pos();
 
            let left = result;
 
            let operation;
 
            if self.has_string(b"==") {
 
                self.consume_string(b"==")?;
 
                operation = BinaryOperator::Equality;
 
            } else {
 
                self.consume_string(b"!=")?;
 
                operation = BinaryOperator::Inequality;
 
            }
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_rel_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_rel_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        let mut result = self.consume_shift_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"<=")
 
            || self.has_string(b">=")
 
            || self.has_string(b"<") && !self.has_string(b"<<=")
 
            || self.has_string(b">") && !self.has_string(b">>=")
 
        {
 
            let position = self.source.pos();
 
            let left = result;
 
            let operation;
 
            if self.has_string(b"<=") {
 
                self.consume_string(b"<=")?;
 
                operation = BinaryOperator::LessThanEqual;
 
            } else if self.has_string(b">=") {
 
                self.consume_string(b">=")?;
 
                operation = BinaryOperator::GreaterThanEqual;
 
            } else if self.has_string(b"<") {
 
                self.consume_string(b"<")?;
 
                operation = BinaryOperator::LessThan;
 
            } else {
 
                self.consume_string(b">")?;
 
                operation = BinaryOperator::GreaterThan;
 
            }
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_shift_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_shift_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        let mut result = self.consume_add_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"<<") && !self.has_string(b"<<=")
 
            || self.has_string(b">>") && !self.has_string(b">>=")
 
        {
 
            let position = self.source.pos();
 
            let left = result;
 
            let operation;
 
            if self.has_string(b"<<") {
 
                self.consume_string(b"<<")?;
 
                operation = BinaryOperator::ShiftLeft;
 
            } else {
 
                self.consume_string(b">>")?;
 
                operation = BinaryOperator::ShiftRight;
 
            }
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_add_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_add_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        let mut result = self.consume_mul_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"+") && !self.has_string(b"+=")
 
@@ -969,1241 +1195,1300 @@ impl Lexer<'_> {
 
                let expression = result;
 
                self.consume_whitespace(false)?;
 
                result = h
 
                    .alloc_unary_expression(|this| UnaryExpression {
 
                        this,
 
                        position,
 
                        operation,
 
                        expression,
 
                    })
 
                    .upcast();
 
            } else if self.has_string(b"[") {
 
                self.consume_string(b"[")?;
 
                self.consume_whitespace(false)?;
 
                let subject = result;
 
                let index = self.consume_expression(h)?;
 
                self.consume_whitespace(false)?;
 
                if self.has_string(b"..") || self.has_string(b":") {
 
                    position = self.source.pos();
 
                    if self.has_string(b"..") {
 
                        self.consume_string(b"..")?;
 
                    } else {
 
                        self.consume_string(b":")?;
 
                    }
 
                    self.consume_whitespace(false)?;
 
                    let to_index = self.consume_expression(h)?;
 
                    self.consume_whitespace(false)?;
 
                    result = h
 
                        .alloc_slicing_expression(|this| SlicingExpression {
 
                            this,
 
                            position,
 
                            subject,
 
                            from_index: index,
 
                            to_index,
 
                        })
 
                        .upcast();
 
                } else {
 
                    result = h
 
                        .alloc_indexing_expression(|this| IndexingExpression {
 
                            this,
 
                            position,
 
                            subject,
 
                            index,
 
                        })
 
                        .upcast();
 
                }
 
                self.consume_string(b"]")?;
 
                self.consume_whitespace(false)?;
 
            } else {
 
                assert!(self.has_string(b"."));
 
                self.consume_string(b".")?;
 
                self.consume_whitespace(false)?;
 
                let subject = result;
 
                let field;
 
                if self.has_keyword(b"length") {
 
                    self.consume_keyword(b"length")?;
 
                    field = Field::Length;
 
                } else {
 
                    field = Field::Symbolic(self.consume_identifier()?);
 
                }
 
                result = h
 
                    .alloc_select_expression(|this| SelectExpression {
 
                        this,
 
                        position,
 
                        subject,
 
                        field,
 
                    })
 
                    .upcast();
 
            }
 
        }
 
        Ok(result)
 
    }
 
    fn consume_primary_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
        if self.has_string(b"(") {
 
            return self.consume_paren_expression(h);
 
        }
 
        if self.has_string(b"{") {
 
            return Ok(self.consume_array_expression(h)?.upcast());
 
        }
 
        if self.has_constant()
 
            || self.has_keyword(b"null")
 
            || self.has_keyword(b"true")
 
            || self.has_keyword(b"false")
 
        {
 
            return Ok(self.consume_constant_expression(h)?.upcast());
 
        }
 
        if self.has_call_expression() {
 
            return Ok(self.consume_call_expression(h)?.upcast());
 
        }
 
        Ok(self.consume_variable_expression(h)?.upcast())
 
    }
 
    fn consume_array_expression(&mut self, h: &mut Heap) -> Result<ArrayExpressionId, ParseError2> {
 
        let position = self.source.pos();
 
        let mut elements = Vec::new();
 
        self.consume_string(b"{")?;
 
        self.consume_whitespace(false)?;
 
        if !self.has_string(b"}") {
 
            while self.source.next().is_some() {
 
                elements.push(self.consume_expression(h)?);
 
                self.consume_whitespace(false)?;
 
                if self.has_string(b"}") {
 
                    break;
 
                }
 
                self.consume_string(b",")?;
 
                self.consume_whitespace(false)?;
 
            }
 
        }
 
        self.consume_string(b"}")?;
 
        Ok(h.alloc_array_expression(|this| ArrayExpression { this, position, elements }))
 
    }
 
    fn has_constant(&self) -> bool {
 
        is_constant(self.source.next())
 
    }
 
    fn consume_constant_expression(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<ConstantExpressionId, ParseError2> {
 
        let position = self.source.pos();
 
        let value;
 
        if self.has_keyword(b"null") {
 
            self.consume_keyword(b"null")?;
 
            value = Constant::Null;
 
        } else if self.has_keyword(b"true") {
 
            self.consume_keyword(b"true")?;
 
            value = Constant::True;
 
        } else if self.has_keyword(b"false") {
 
            self.consume_keyword(b"false")?;
 
            value = Constant::False;
 
        } else if self.source.next() == Some(b'\'') {
 
            self.source.consume();
 
            let mut data = Vec::new();
 
            let mut next = self.source.next();
 
            while next != Some(b'\'') && (is_vchar(next) || next == Some(b' ')) {
 
                data.push(next.unwrap());
 
                self.source.consume();
 
                next = self.source.next();
 
            }
 
            if next != Some(b'\'') || data.is_empty() {
 
                return Err(self.error_at_pos("Expected character constant"));
 
            }
 
            self.source.consume();
 
            value = Constant::Character(data);
 
        } else {
 
            if !self.has_integer() {
 
                return Err(self.error_at_pos("Expected integer constant"));
 
            }
 

	
 
            value = Constant::Integer(self.consume_integer()?);
 
        }
 
        Ok(h.alloc_constant_expression(|this| ConstantExpression { this, position, value }))
 
    }
 
    fn has_call_expression(&mut self) -> bool {
 
        /* We prevent ambiguity with variables, by looking ahead
 
        the identifier to see if we can find an opening
 
        parenthesis: this signals a call expression. */
 
        if self.has_builtin_keyword() {
 
            return true;
 
        }
 
        let backup_pos = self.source.pos();
 
        let mut result = false;
 
        match self.consume_identifier_spilled() {
 
            Ok(_) => match self.consume_whitespace(false) {
 
                Ok(_) => {
 
                    result = self.has_string(b"(");
 
                }
 
                Err(_) => {}
 
            },
 
            Err(_) => {}
 
        }
 
        self.source.seek(backup_pos);
 
        return result;
 
    }
 
    fn consume_call_expression(&mut self, h: &mut Heap) -> Result<CallExpressionId, ParseError2> {
 
        let position = self.source.pos();
 
        let method;
 
        if self.has_keyword(b"get") {
 
            self.consume_keyword(b"get")?;
 
            method = Method::Get;
 
        } else if self.has_keyword(b"fires") {
 
            self.consume_keyword(b"fires")?;
 
            method = Method::Fires;
 
        } else if self.has_keyword(b"create") {
 
            self.consume_keyword(b"create")?;
 
            method = Method::Create;
 
        } else {
 
            let identifier = self.consume_namespaced_identifier()?;
 
            method = Method::Symbolic(MethodSymbolic{
 
                identifier,
 
                definition: None
 
            })
 
        }
 
        self.consume_whitespace(false)?;
 
        let mut arguments = Vec::new();
 
        self.consume_string(b"(")?;
 
        self.consume_whitespace(false)?;
 
        if !self.has_string(b")") {
 
            while self.source.next().is_some() {
 
                arguments.push(self.consume_expression(h)?);
 
                self.consume_whitespace(false)?;
 
                if self.has_string(b")") {
 
                    break;
 
                }
 
                self.consume_string(b",")?;
 
                self.consume_whitespace(false)?
 
            }
 
        }
 
        self.consume_string(b")")?;
 
        Ok(h.alloc_call_expression(|this| CallExpression {
 
            this,
 
            position,
 
            method,
 
            arguments
 
        }))
 
    }
 
    fn consume_variable_expression(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<VariableExpressionId, ParseError2> {
 
        let position = self.source.pos();
 
        let identifier = self.consume_namespaced_identifier()?;
 
        Ok(h.alloc_variable_expression(|this| VariableExpression {
 
            this,
 
            position,
 
            identifier,
 
            declaration: None,
 
        }))
 
    }
 

	
 
    // ====================
 
    // Statements
 
    // ====================
 

	
 
    /// Consumes any kind of statement from the source and will error if it
 
    /// did not encounter a statement. Will also return an error if the
 
    /// statement is nested too deeply.
 
    ///
 
    /// `wrap_in_block` may be set to true to ensure that the parsed statement
 
    /// will be wrapped in a block statement if it is not already a block
 
    /// statement. This is used to ensure that all `if`, `while` and `sync`
 
    /// statements have a block statement as body.
 
    fn consume_statement(&mut self, h: &mut Heap, wrap_in_block: bool) -> Result<StatementId, ParseError2> {
 
        if self.level >= MAX_LEVEL {
 
            return Err(self.error_at_pos("Too deeply nested statement"));
 
        }
 
        self.level += 1;
 
        let result = self.consume_statement_impl(h, wrap_in_block);
 
        self.level -= 1;
 
        result
 
    }
 
    fn has_label(&mut self) -> bool {
 
        /* To prevent ambiguity with expression statements consisting
 
        only of an identifier, we look ahead and match the colon
 
        that signals a labeled statement. */
 
        let backup_pos = self.source.pos();
 
        let mut result = false;
 
        match self.consume_identifier_spilled() {
 
            Ok(_) => match self.consume_whitespace(false) {
 
                Ok(_) => {
 
                    result = self.has_string(b":");
 
                }
 
                Err(_) => {}
 
            },
 
            Err(_) => {}
 
        }
 
        self.source.seek(backup_pos);
 
        return result;
 
    }
 
    fn consume_statement_impl(&mut self, h: &mut Heap, wrap_in_block: bool) -> Result<StatementId, ParseError2> {
 
        // Parse and allocate statement
 
        let mut must_wrap = true;
 
        let mut stmt_id = if self.has_string(b"{") {
 
            must_wrap = false;
 
            self.consume_block_statement(h)?
 
        } else if self.has_keyword(b"skip") {
 
            must_wrap = false;
 
            self.consume_skip_statement(h)?.upcast()
 
        } else if self.has_keyword(b"if") {
 
            self.consume_if_statement(h)?.upcast()
 
        } else if self.has_keyword(b"while") {
 
            self.consume_while_statement(h)?.upcast()
 
        } else if self.has_keyword(b"break") {
 
            self.consume_break_statement(h)?.upcast()
 
        } else if self.has_keyword(b"continue") {
 
            self.consume_continue_statement(h)?.upcast()
 
        } else if self.has_keyword(b"synchronous") {
 
            self.consume_synchronous_statement(h)?.upcast()
 
        } else if self.has_keyword(b"return") {
 
            self.consume_return_statement(h)?.upcast()
 
        } else if self.has_keyword(b"assert") {
 
            self.consume_assert_statement(h)?.upcast()
 
        } else if self.has_keyword(b"goto") {
 
            self.consume_goto_statement(h)?.upcast()
 
        } else if self.has_keyword(b"new") {
 
            self.consume_new_statement(h)?.upcast()
 
        } else if self.has_keyword(b"put") {
 
            self.consume_put_statement(h)?.upcast()
 
        } else if self.has_label() {
 
            self.consume_labeled_statement(h)?.upcast()
 
        } else {
 
            self.consume_expression_statement(h)?.upcast()
 
        };
 

	
 
        // Wrap if desired and if needed
 
        if must_wrap && wrap_in_block {
 
            let position = h[stmt_id].position();
 
            let block_wrapper = h.alloc_block_statement(|this| BlockStatement{
 
                this,
 
                position,
 
                statements: vec![stmt_id],
 
                parent_scope: None,
 
                relative_pos_in_parent: 0,
 
                locals: Vec::new(),
 
                labels: Vec::new()
 
            });
 

	
 
            stmt_id = block_wrapper.upcast();
 
        }
 

	
 
        Ok(stmt_id)
 
    }
 
    fn has_local_statement(&mut self) -> bool {
 
        /* To avoid ambiguity, we look ahead to find either the
 
        channel keyword that signals a variable declaration, or
 
        a type annotation followed by another identifier.
 
        Example:
 
          my_type[] x = {5}; // memory statement
 
          my_var[5] = x; // assignment expression, expression statement
 
        Note how both the local and the assignment
 
        start with arbitrary identifier followed by [. */
 
        if self.has_keyword(b"channel") {
 
            return true;
 
        }
 
        if self.has_statement_keyword() {
 
            return false;
 
        }
 
        let backup_pos = self.source.pos();
 
        let mut result = false;
 
        if let Ok(_) = self.consume_type_annotation_spilled() {
 
            if let Ok(_) = self.consume_whitespace(false) {
 
                result = self.has_identifier();
 
            }
 
        }
 
        self.source.seek(backup_pos);
 
        return result;
 
    }
 
    fn consume_block_statement(&mut self, h: &mut Heap) -> Result<StatementId, ParseError2> {
 
        let position = self.source.pos();
 
        let mut statements = Vec::new();
 
        self.consume_string(b"{")?;
 
        self.consume_whitespace(false)?;
 
        while self.has_local_statement() {
 
            statements.push(self.consume_local_statement(h)?.upcast());
 
            self.consume_whitespace(false)?;
 
        }
 
        while !self.has_string(b"}") {
 
            statements.push(self.consume_statement(h, false)?);
 
            self.consume_whitespace(false)?;
 
        }
 
        self.consume_string(b"}")?;
 
        if statements.is_empty() {
 
            Ok(h.alloc_skip_statement(|this| SkipStatement { this, position, next: None }).upcast())
 
        } else {
 
            Ok(h.alloc_block_statement(|this| BlockStatement {
 
                this,
 
                position,
 
                statements,
 
                parent_scope: None,
 
                relative_pos_in_parent: 0,
 
                locals: Vec::new(),
 
                labels: Vec::new(),
 
            })
 
            .upcast())
 
        }
 
    }
 
    fn consume_local_statement(&mut self, h: &mut Heap) -> Result<LocalStatementId, ParseError2> {
 
        if self.has_keyword(b"channel") {
 
            Ok(self.consume_channel_statement(h)?.upcast())
 
        } else {
 
            Ok(self.consume_memory_statement(h)?.upcast())
 
        }
 
    }
 
    fn consume_channel_statement(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<ChannelStatementId, ParseError2> {
 
        // Consume channel statement and polymorphic argument if specified
 
        let position = self.source.pos();
 
        self.consume_keyword(b"channel")?;
 

	
 
        let poly_args = self.consume_polymorphic_args(h, true)?;
 
        let poly_arg_id = match poly_args.len() {
 
            0 => h.alloc_parser_type(|this| ParserType{
 
                this, pos: position.clone(), variant: ParserTypeVariant::Inferred,
 
            }),
 
            1 => poly_args[0],
 
            _ => return Err(ParseError2::new_error(
 
                &self.source, self.source.pos(),
 
                "port construction using 'channel' accepts up to 1 polymorphic argument"
 
            ))
 
        };
 
        self.consume_whitespace(true)?;
 
        let from_annotation = self.create_type_annotation_output(h)?;
 
        let from_identifier = self.consume_identifier()?;
 

	
 
        // Consume the output port
 
        let out_parser_type = h.alloc_parser_type(|this| ParserType{
 
            this, pos: position.clone(), variant: ParserTypeVariant::Output(poly_arg_id)
 
        });
 
        let out_identifier = self.consume_identifier()?;
 

	
 
        // Consume the "->" syntax
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b"->")?;
 
        self.consume_whitespace(false)?;
 
        let to_annotation = self.create_type_annotation_input(h)?;
 
        let to_identifier = self.consume_identifier()?;
 

	
 
        // Consume the input port
 
        // TODO: Unsure about this, both ports refer to the same ParserType, is this ok?
 
        let in_parser_type = h.alloc_parser_type(|this| ParserType{
 
            this, pos: position.clone(), variant: ParserTypeVariant::Output(poly_arg_id)
 
        });
 
        let in_identifier = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        let from = h.alloc_local(|this| Local {
 
        let out_port = h.alloc_local(|this| Local {
 
            this,
 
            position,
 
            type_annotation: from_annotation,
 
            identifier: from_identifier,
 
            parser_type: out_parser_type,
 
            identifier: out_identifier,
 
            relative_pos_in_block: 0
 
        });
 
        let to = h.alloc_local(|this| Local {
 
        let in_port = h.alloc_local(|this| Local {
 
            this,
 
            position,
 
            type_annotation: to_annotation,
 
            identifier: to_identifier,
 
            parser_type: in_parser_type,
 
            identifier: in_identifier,
 
            relative_pos_in_block: 0
 
        });
 
        Ok(h.alloc_channel_statement(|this| ChannelStatement {
 
            this,
 
            position,
 
            from,
 
            to,
 
            from: out_port,
 
            to: in_port,
 
            relative_pos_in_block: 0,
 
            next: None,
 
        }))
 
    }
 
    fn consume_memory_statement(&mut self, h: &mut Heap) -> Result<MemoryStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        let type_annotation = self.consume_type_annotation(h)?;
 
        let parser_type = self.consume_type2(h, true)?;
 
        self.consume_whitespace(true)?;
 
        let identifier = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b"=")?;
 
        self.consume_whitespace(false)?;
 
        let initial = self.consume_expression(h)?;
 
        let variable = h.alloc_local(|this| Local {
 
            this,
 
            position,
 
            type_annotation,
 
            parser_type,
 
            identifier,
 
            relative_pos_in_block: 0
 
        });
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_memory_statement(|this| MemoryStatement {
 
            this,
 
            position,
 
            variable,
 
            initial,
 
            next: None,
 
        }))
 
    }
 
    fn consume_labeled_statement(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<LabeledStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        let label = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b":")?;
 
        self.consume_whitespace(false)?;
 
        let body = self.consume_statement(h, false)?;
 
        Ok(h.alloc_labeled_statement(|this| LabeledStatement {
 
            this,
 
            position,
 
            label,
 
            body,
 
            relative_pos_in_block: 0,
 
            in_sync: None,
 
        }))
 
    }
 
    fn consume_skip_statement(&mut self, h: &mut Heap) -> Result<SkipStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"skip")?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_skip_statement(|this| SkipStatement { this, position, next: None }))
 
    }
 
    fn consume_if_statement(&mut self, h: &mut Heap) -> Result<IfStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"if")?;
 
        self.consume_whitespace(false)?;
 
        let test = self.consume_paren_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        let true_body = self.consume_statement(h, true)?;
 
        self.consume_whitespace(false)?;
 
        let false_body = if self.has_keyword(b"else") {
 
            self.consume_keyword(b"else")?;
 
            self.consume_whitespace(false)?;
 
            self.consume_statement(h, true)?
 
        } else {
 
            h.alloc_skip_statement(|this| SkipStatement { this, position, next: None }).upcast()
 
        };
 
        Ok(h.alloc_if_statement(|this| IfStatement { this, position, test, true_body, false_body, end_if: None }))
 
    }
 
    fn consume_while_statement(&mut self, h: &mut Heap) -> Result<WhileStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"while")?;
 
        self.consume_whitespace(false)?;
 
        let test = self.consume_paren_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        let body = self.consume_statement(h, true)?;
 
        Ok(h.alloc_while_statement(|this| WhileStatement {
 
            this,
 
            position,
 
            test,
 
            body,
 
            end_while: None,
 
            in_sync: None,
 
        }))
 
    }
 
    fn consume_break_statement(&mut self, h: &mut Heap) -> Result<BreakStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"break")?;
 
        self.consume_whitespace(false)?;
 
        let label;
 
        if self.has_identifier() {
 
            label = Some(self.consume_identifier()?);
 
            self.consume_whitespace(false)?;
 
        } else {
 
            label = None;
 
        }
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_break_statement(|this| BreakStatement { this, position, label, target: None }))
 
    }
 
    fn consume_continue_statement(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<ContinueStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"continue")?;
 
        self.consume_whitespace(false)?;
 
        let label;
 
        if self.has_identifier() {
 
            label = Some(self.consume_identifier()?);
 
            self.consume_whitespace(false)?;
 
        } else {
 
            label = None;
 
        }
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_continue_statement(|this| ContinueStatement {
 
            this,
 
            position,
 
            label,
 
            target: None,
 
        }))
 
    }
 
    fn consume_synchronous_statement(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<SynchronousStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"synchronous")?;
 
        self.consume_whitespace(false)?;
 
        // TODO: What was the purpose of this? Seems superfluous and confusing?
 
        // let mut parameters = Vec::new();
 
        // if self.has_string(b"(") {
 
        //     self.consume_parameters(h, &mut parameters)?;
 
        //     self.consume_whitespace(false)?;
 
        // } else if !self.has_keyword(b"skip") && !self.has_string(b"{") {
 
        //     return Err(self.error_at_pos("Expected block statement"));
 
        // }
 
        let body = self.consume_statement(h, true)?;
 
        Ok(h.alloc_synchronous_statement(|this| SynchronousStatement {
 
            this,
 
            position,
 
            body,
 
            end_sync: None,
 
            parent_scope: None,
 
        }))
 
    }
 
    fn consume_return_statement(&mut self, h: &mut Heap) -> Result<ReturnStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"return")?;
 
        self.consume_whitespace(false)?;
 
        let expression = if self.has_string(b"(") {
 
            self.consume_paren_expression(h)
 
        } else {
 
            self.consume_expression(h)
 
        }?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_return_statement(|this| ReturnStatement { this, position, expression }))
 
    }
 
    fn consume_assert_statement(&mut self, h: &mut Heap) -> Result<AssertStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"assert")?;
 
        self.consume_whitespace(false)?;
 
        let expression = if self.has_string(b"(") {
 
            self.consume_paren_expression(h)
 
        } else {
 
            self.consume_expression(h)
 
        }?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_assert_statement(|this| AssertStatement {
 
            this,
 
            position,
 
            expression,
 
            next: None,
 
        }))
 
    }
 
    fn consume_goto_statement(&mut self, h: &mut Heap) -> Result<GotoStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"goto")?;
 
        self.consume_whitespace(false)?;
 
        let label = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_goto_statement(|this| GotoStatement { this, position, label, target: None }))
 
    }
 
    fn consume_new_statement(&mut self, h: &mut Heap) -> Result<NewStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"new")?;
 
        self.consume_whitespace(false)?;
 
        let expression = self.consume_call_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_new_statement(|this| NewStatement { this, position, expression, next: None }))
 
    }
 
    fn consume_put_statement(&mut self, h: &mut Heap) -> Result<PutStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"put")?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b"(")?;
 
        let port = self.consume_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b",")?;
 
        self.consume_whitespace(false)?;
 
        let message = self.consume_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b")")?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_put_statement(|this| PutStatement { this, position, port, message, next: None }))
 
    }
 
    fn consume_expression_statement(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<ExpressionStatementId, ParseError2> {
 
        let position = self.source.pos();
 
        let expression = self.consume_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_expression_statement(|this| ExpressionStatement {
 
            this,
 
            position,
 
            expression,
 
            next: None,
 
        }))
 
    }
 

	
 
    // ====================
 
    // Symbol definitions
 
    // ====================
 

	
 
    fn has_symbol_definition(&self) -> bool {
 
        self.has_keyword(b"composite")
 
            || self.has_keyword(b"primitive")
 
            || self.has_type_keyword()
 
            || self.has_identifier()
 
    }
 
    fn consume_symbol_definition(&mut self, h: &mut Heap) -> Result<DefinitionId, ParseError2> {
 
        if self.has_keyword(b"struct") {
 
            Ok(self.consume_struct_definition(h)?.upcast())
 
        } else if self.has_keyword(b"enum") {
 
            Ok(self.consume_enum_definition(h)?.upcast())
 
        } else if self.has_keyword(b"composite") || self.has_keyword(b"primitive") {
 
            Ok(self.consume_component_definition(h)?.upcast())
 
        } else {
 
            Ok(self.consume_function_definition(h)?.upcast())
 
        }
 
    }
 
    fn consume_struct_definition(&mut self, h: &mut Heap) -> Result<StructId, ParseError2> {
 
        // Parse "struct" keyword and its identifier
 
        // Parse "struct" keyword, optional polyvars and its identifier
 
        let struct_pos = self.source.pos();
 
        self.consume_keyword(b"struct")?;
 
        self.consume_whitespace(true)?;
 
        let struct_ident = self.consume_identifier()?;
 
        let poly_vars = self.consume_polymorphic_vars()?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Parse struct fields
 
        self.consume_string(b"{")?;
 
        let mut next = self.source.next();
 
        let mut fields = Vec::new();
 
        while next.is_some() {
 
            let char = next.unwrap();
 
            if char == b'}' {
 
                break;
 
            }
 

	
 
            // Consume field definition
 
            self.consume_whitespace(false)?;
 
            let field_position = self.source.pos();
 
            let field_type = self.consume_type_annotation(h)?;
 
            let field_parser_type = self.consume_type2(h, false)?;
 
            self.consume_whitespace(true)?;
 
            let field_ident = self.consume_identifier()?;
 
            self.consume_whitespace(false)?;
 

	
 
            fields.push(StructFieldDefinition{
 
                position: field_position,
 
                field: field_ident,
 
                the_type: field_type,
 
                parser_type: field_parser_type,
 
            });
 

	
 
            // If we have a comma, then we may or may not have another field
 
            // definition. Otherwise we expect the struct to be fully defined
 
            // and expect a closing brace
 
            next = self.source.next();
 
            if let Some(b',') = next {
 
                self.source.consume();
 
                self.consume_whitespace(false)?;
 
                next = self.source.next();
 
            } else {
 
                break;
 
            }
 
        }
 

	
 
        // End of struct definition, so we expect a closing brace
 
        self.consume_string(b"}")?;
 

	
 
        // Valid struct definition
 
        Ok(h.alloc_struct_definition(|this| StructDefinition{
 
            this,
 
            position: struct_pos,
 
            identifier: struct_ident,
 
            poly_vars,
 
            fields,
 
        }))
 
    }
 
    fn consume_enum_definition(&mut self, h: &mut Heap) -> Result<EnumId, ParseError2> {
 
        // Parse "enum" keyword and its identifier
 
        // Parse "enum" keyword, optional polyvars and its identifier
 
        let enum_pos = self.source.pos();
 
        self.consume_keyword(b"enum")?;
 
        self.consume_whitespace(true)?;
 
        let enum_ident = self.consume_identifier()?;
 
        let poly_vars = self.consume_polymorphic_vars()?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Parse enum variants
 
        self.consume_string(b"{")?;
 
        let mut next = self.source.next();
 
        let mut variants = Vec::new();
 
        while next.is_some() {
 
            let char = next.unwrap();
 
            if char == b'}' {
 
                break;
 
            }
 

	
 
            // Consume variant identifier
 
            self.consume_whitespace(false)?;
 
            let variant_position = self.source.pos();
 
            let variant_ident = self.consume_identifier()?;
 
            self.consume_whitespace(false)?;
 

	
 
            // Consume variant (tag) value: may be nothing, in which case it is
 
            // assigned automatically, may be a constant integer, or an embedded
 
            // type as value, resulting in a tagged union
 
            next = self.source.next();
 
            let variant_value = if let Some(b',') = next {
 
                EnumVariantValue::None
 
            } else if let Some(b'=') = next {
 
                self.source.consume();
 
                self.consume_whitespace(false)?;
 
                if !self.has_integer() {
 
                    return Err(self.error_at_pos("expected integer"));
 
                }
 
                let variant_int = self.consume_integer()?;
 
                self.consume_whitespace(false)?;
 
                EnumVariantValue::Integer(variant_int)
 
            } else if let Some(b'(') = next {
 
                self.source.consume();
 
                self.consume_whitespace(false)?;
 
                let variant_type = self.consume_type_annotation(h)?;
 
                let variant_type = self.consume_type2(h, false)?;
 
                self.consume_whitespace(false)?;
 
                self.consume_string(b")")?;
 
                self.consume_whitespace(false)?;
 
                EnumVariantValue::Type(variant_type)
 
            } else {
 
                return Err(self.error_at_pos("expected ',', '=', or '('"));
 
            };
 

	
 
            variants.push(EnumVariantDefinition{
 
                position: variant_position,
 
                identifier: variant_ident,
 
                value: variant_value
 
            });
 

	
 
            // If we have a comma, then we may or may not have another variant,
 
            // otherwise we expect the enum is fully defined
 
            next = self.source.next();
 
            if let Some(b',') = next {
 
                self.source.consume();
 
                self.consume_whitespace(false)?;
 
                next = self.source.next();
 
            } else {
 
                break;
 
            }
 
        }
 

	
 
        self.consume_string(b"}")?;
 

	
 
        // An enum without variants is somewhat valid, but completely useless
 
        // within the language
 
        if variants.is_empty() {
 
            return Err(ParseError2::new_error(self.source, enum_pos, "enum definition without variants"));
 
        }
 

	
 
        Ok(h.alloc_enum_definition(|this| EnumDefinition{
 
            this,
 
            position: enum_pos,
 
            identifier: enum_ident,
 
            poly_vars,
 
            variants,
 
        }))
 
    }
 
    fn consume_component_definition(&mut self, h: &mut Heap) -> Result<ComponentId, ParseError2> {
 
        // TODO: Cleanup
 
        if self.has_keyword(b"composite") {
 
            Ok(self.consume_composite_definition(h)?)
 
        } else {
 
            Ok(self.consume_primitive_definition(h)?)
 
        }
 
    }
 
    fn consume_composite_definition(&mut self, h: &mut Heap) -> Result<ComponentId, ParseError2> {
 
        // Parse keyword, optional polyvars and the identifier
 
        let position = self.source.pos();
 
        self.consume_keyword(b"composite")?;
 
        self.consume_whitespace(true)?;
 
        let identifier = self.consume_identifier()?;
 
        let poly_vars = self.consume_polymorphic_vars()?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume parameters
 
        let mut parameters = Vec::new();
 
        self.consume_parameters(h, &mut parameters)?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Parse body
 
        let body = self.consume_block_statement(h)?;
 
        Ok(h.alloc_component(|this| Component { 
 
            this, variant: ComponentVariant::Composite, position, identifier, parameters, body 
 
            this,
 
            variant: ComponentVariant::Composite,
 
            position,
 
            identifier,
 
            poly_vars,
 
            parameters,
 
            body
 
        }))
 
    }
 
    fn consume_primitive_definition(&mut self, h: &mut Heap) -> Result<ComponentId, ParseError2> {
 
        // Consume keyword, optional polyvars and identifier
 
        let position = self.source.pos();
 
        self.consume_keyword(b"primitive")?;
 
        self.consume_whitespace(true)?;
 
        let identifier = self.consume_identifier()?;
 
        let poly_vars = self.consume_polymorphic_vars()?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume parameters
 
        let mut parameters = Vec::new();
 
        self.consume_parameters(h, &mut parameters)?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume body
 
        let body = self.consume_block_statement(h)?;
 
        Ok(h.alloc_component(|this| Component { 
 
            this, variant: ComponentVariant::Primitive, position, identifier, parameters, body 
 
            this,
 
            variant: ComponentVariant::Primitive,
 
            position,
 
            identifier,
 
            poly_vars,
 
            parameters,
 
            body
 
        }))
 
    }
 
    fn consume_function_definition(&mut self, h: &mut Heap) -> Result<FunctionId, ParseError2> {
 
        // Consume return type, optional polyvars and identifier
 
        let position = self.source.pos();
 
        let return_type = self.consume_type_annotation(h)?;
 
        self.consume_whitespace(true)?;
 
        let identifier = self.consume_identifier()?;
 
        let poly_vars = self.consume_polymorphic_vars()?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume parameters
 
        let mut parameters = Vec::new();
 
        self.consume_parameters(h, &mut parameters)?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume body
 
        let body = self.consume_block_statement(h)?;
 
        Ok(h.alloc_function(|this| Function {
 
            this,
 
            position,
 
            return_type,
 
            identifier,
 
            poly_vars,
 
            parameters,
 
            body,
 
        }))
 
    }
 
    fn has_pragma(&self) -> bool {
 
        if let Some(c) = self.source.next() {
 
            c == b'#'
 
        } else {
 
            false
 
        }
 
    }
 
    fn consume_pragma(&mut self, h: &mut Heap) -> Result<PragmaId, ParseError2> {
 
        let position = self.source.pos();
 
        let next = self.source.next();
 
        if next != Some(b'#') {
 
            return Err(self.error_at_pos("Expected pragma"));
 
        }
 
        self.source.consume();
 
        if !is_vchar(self.source.next()) {
 
            return Err(self.error_at_pos("Expected pragma"));
 
        }
 
        if self.has_string(b"version") {
 
            self.consume_string(b"version")?;
 
            self.consume_whitespace(true)?;
 
            if !self.has_integer() {
 
                return Err(self.error_at_pos("Expected integer constant"));
 
            }
 
            let version = self.consume_integer()?;
 
            debug_assert!(version >= 0);
 
            return Ok(h.alloc_pragma(|this| Pragma::Version(PragmaVersion{
 
                this, position, version: version as u64
 
            })))
 
        } else if self.has_string(b"module") {
 
            self.consume_string(b"module")?;
 
            self.consume_whitespace(true)?;
 
            if !self.has_identifier() {
 
                return Err(self.error_at_pos("Expected identifier"));
 
            }
 
            let mut value = Vec::new();
 
            let mut ident = self.consume_ident()?;
 
            value.append(&mut ident);
 
            while self.has_string(b".") {
 
                self.consume_string(b".")?;
 
                value.push(b'.');
 
                ident = self.consume_ident()?;
 
                value.append(&mut ident);
 
            }
 
            return Ok(h.alloc_pragma(|this| Pragma::Module(PragmaModule{
 
                this, position, value
 
            })));
 
        } else {
 
            return Err(self.error_at_pos("Unknown pragma"));
 
        }
 
    }
 

	
 
    fn has_import(&self) -> bool {
 
        self.has_keyword(b"import")
 
    }
 
    fn consume_import(&mut self, h: &mut Heap) -> Result<ImportId, ParseError2> {
 
        // Parse the word "import" and the name of the module
 
        let position = self.source.pos();
 
        self.consume_keyword(b"import")?;
 
        self.consume_whitespace(true)?;
 
        let mut value = Vec::new();
 
        let mut ident = self.consume_ident()?;
 
        value.append(&mut ident);
 
        let mut last_ident_start = 0;
 

	
 
        while self.has_string(b".") {
 
            self.consume_string(b".")?;
 
            value.push(b'.');
 
            ident = self.consume_ident()?;
 
            last_ident_start = value.len();
 
            value.append(&mut ident);
 
        }
 

	
 

	
 
        self.consume_whitespace(false)?;
 

	
 
        // Check for the potential aliasing or specific module imports
 
        let import = if self.has_string(b"as") {
 
            self.consume_string(b"as")?;
 
            self.consume_whitespace(true)?;
 
            let alias = self.consume_ident()?;
 

	
 
            h.alloc_import(|this| Import::Module(ImportModule{
 
                this,
 
                position,
 
                module_name: value,
 
                alias,
 
                module_id: None,
 
            }))
 
        } else if self.has_string(b"::") {
 
            self.consume_string(b"::")?;
 
            self.consume_whitespace(false)?;
 

	
 
            if let Some(b'{') = self.source.next() {
 
                // Import specific symbols, optionally with an alias
 
                self.source.consume();
 
                self.consume_whitespace(false)?;
 

	
 
                let mut symbols = Vec::new();
 
                let mut next = self.source.next();
 

	
 
                while next.is_some() {
 
                    let char = next.unwrap();
 
                    if char == b'}' {
 
                        break;
 
                    }
 

	
 
                    let symbol_position = self.source.pos();
 
                    let symbol_name = self.consume_ident()?;
 
                    self.consume_whitespace(false)?;
 
                    if self.has_string(b"as") {
 
                        // Symbol has an alias
 
                        self.consume_string(b"as")?;
 
                        self.consume_whitespace(true)?;
 
                        let symbol_alias = self.consume_ident()?;
 

	
 
                        symbols.push(AliasedSymbol{
 
                            position: symbol_position,
 
                            name: symbol_name,
 
                            alias: symbol_alias,
 
                            definition_id: None,
 
                        });
 
                    } else {
 
                        // Symbol does not have an alias
 
                        symbols.push(AliasedSymbol{
 
                            position: symbol_position,
 
                            name: symbol_name.clone(),
 
                            alias: symbol_name,
 
                            definition_id: None,
 
                        });
 
                    }
 

	
 
                    // A comma indicates that we may have another symbol coming
 
                    // up (not necessary), but if not present then we expect the
 
                    // end of the symbol list
 
                    self.consume_whitespace(false)?;
 

	
 
                    next = self.source.next();
 
                    if let Some(b',') = next {
 
                        self.source.consume();
 
                        self.consume_whitespace(false)?;
 
                        next = self.source.next();
 
                    } else {
 
                        break;
 
                    }
 
                }
 

	
 
                if let Some(b'}') = next {
 
                    // We are fine, push the imported symbols
 
                    self.source.consume();
 
                    if symbols.is_empty() {
 
                        return Err(ParseError2::new_error(self.source, position, "empty symbol import list"));
 
                    }
 

	
 
                    h.alloc_import(|this| Import::Symbols(ImportSymbols{
 
                        this,
 
                        position,
 
                        module_name: value,
 
                        module_id: None,
 
                        symbols,
 
                    }))
 
                } else {
 
                    return Err(self.error_at_pos("Expected '}'"));
 
                }
 
            } else if let Some(b'*') = self.source.next() {
 
                // Import all symbols without alias
 
                self.source.consume();
 
                h.alloc_import(|this| Import::Symbols(ImportSymbols{
 
                    this,
 
                    position,
 
                    module_name: value,
 
                    module_id: None,
 
                    symbols: Vec::new()
 
                }))
 
            } else {
 
                return Err(self.error_at_pos("Expected '*' or '{'"));
 
            }
 
        } else {
 
            // No explicit alias or subimports, so implicit alias
 
            let alias = Vec::from(&value[last_ident_start..]);
 
            h.alloc_import(|this| Import::Module(ImportModule{
 
                this,
 
                position,
 
                module_name: value,
 
                alias,
 
                module_id: None,
 
            }))
 
        };
 

	
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(import)
 
    }
 
    pub fn consume_protocol_description(&mut self, h: &mut Heap) -> Result<RootId, ParseError2> {
 
        let position = self.source.pos();
 
        let mut pragmas = Vec::new();
 
        let mut imports = Vec::new();
 
        let mut definitions = Vec::new();
 
        self.consume_whitespace(false)?;
 
        while self.has_pragma() {
 
            let pragma = self.consume_pragma(h)?;
 
            pragmas.push(pragma);
 
            self.consume_whitespace(false)?;
 
        }
 
        while self.has_import() {
 
            let import = self.consume_import(h)?;
 
            imports.push(import);
 
            self.consume_whitespace(false)?;
 
        }
 
        while self.has_symbol_definition() {
 
            let def = self.consume_symbol_definition(h)?;
 
            definitions.push(def);
 
            self.consume_whitespace(false)?;
 
        }
 
        // end of file
 
        if !self.source.is_eof() {
 
            return Err(self.error_at_pos("Expected end of file"));
 
        }
 
        Ok(h.alloc_protocol_description(|this| Root {
 
            this,
 
            position,
 
            pragmas,
 
            imports,
 
            definitions,
 
        }))
 
    }
 
}
 

	
 
#[cfg(test)]
 
mod tests {
 
    use crate::protocol::ast::*;
 
    use crate::protocol::lexer::*;
 
    use crate::protocol::inputsource::*;
 

	
 
    #[test]
 
    fn test_pragmas() {
 
        let mut h = Heap::new();
 
        let mut input = InputSource::from_string("
 
        #version 0o7777
 
        #module something.dot.separated
 
        ").expect("new InputSource");
 
        let mut lex = Lexer::new(&mut input);
 
        let lexed = lex.consume_protocol_description(&mut h)
 
            .expect("lex input source");
 
        let root = &h[lexed];
 
        assert_eq!(root.pragmas.len(), 2);
 
        let pv = &h[root.pragmas[0]];
 
        let pm = &h[root.pragmas[1]];
 

	
 
        if let Pragma::Version(v) = pv {
 
            assert_eq!(v.version, 0o7777)
 
        } else {
 
            assert!(false, "first pragma not version");
 
        }
 
        if let Pragma::Module(m) = pm {
 
            assert_eq!(m.value, b"something.dot.separated");
 
        } else {
 
            assert!(false, "second pragma not module");
 
        }
 
    }
 

	
 
    #[test]
 
    fn test_import() {
 
        let mut h = Heap::new();
 
        let mut input = InputSource::from_string("
 
        // Module imports, with optional and explicit aliasing
 
        import single_module;
 
        import std.reo;
 
        import something.other as alias;
 
        // Symbol imports
 
        import some_module::*;
 
        import some_module::{Foo as Bar, Qux, Dix as Flu};
 
        import std.reo::{
 
            Foo as Bar, // because thing
 
            Qux as Mox, // more explanations
 
            Dix, /* yesh, import me */
 
        };
 
        ").unwrap();
 
        let mut lex = Lexer::new(&mut input);
 
        let lexed = lex.consume_protocol_description(&mut h).unwrap();
 
        let root = &h[lexed];
 
        assert_eq!(root.imports.len(), 6);
 
        let no_alias_single = h[root.imports[0]].as_module();
 
        let no_alias_multi = h[root.imports[1]].as_module();
 
        let with_alias = h[root.imports[2]].as_module();
 

	
 
        assert_eq!(no_alias_single.module_name, b"single_module");
 
        assert_eq!(no_alias_single.alias, b"single_module");
 
        assert_eq!(no_alias_multi.module_name, b"std.reo");
 
        assert_eq!(no_alias_multi.alias, b"reo");
 
        assert_eq!(with_alias.module_name, b"something.other");
 
        assert_eq!(with_alias.alias, b"alias");
 

	
 
        let all_symbols = h[root.imports[3]].as_symbols();
 
        let single_line_symbols = h[root.imports[4]].as_symbols();
 
        let multi_line_symbols = h[root.imports[5]].as_symbols();
 

	
 
        assert_eq!(all_symbols.module_name, b"some_module");
 
        assert!(all_symbols.symbols.is_empty());
 
        assert_eq!(single_line_symbols.module_name, b"some_module");
 
        assert_eq!(single_line_symbols.symbols.len(), 3);
 
        assert_eq!(single_line_symbols.symbols[0].name, b"Foo");
 
        assert_eq!(single_line_symbols.symbols[0].alias, b"Bar");
 
        assert_eq!(single_line_symbols.symbols[1].name, b"Qux");
 
        assert_eq!(single_line_symbols.symbols[1].alias, b"Qux");
 
        assert_eq!(single_line_symbols.symbols[2].name, b"Dix");
 
        assert_eq!(single_line_symbols.symbols[2].alias, b"Flu");
 
        assert_eq!(multi_line_symbols.module_name, b"std.reo");
 
        assert_eq!(multi_line_symbols.symbols.len(), 3);
 
        assert_eq!(multi_line_symbols.symbols[0].name, b"Foo");
 
        assert_eq!(multi_line_symbols.symbols[0].alias, b"Bar");
 
        assert_eq!(multi_line_symbols.symbols[1].name, b"Qux");
 
        assert_eq!(multi_line_symbols.symbols[1].alias, b"Mox");
 
        assert_eq!(multi_line_symbols.symbols[2].name, b"Dix");
 
        assert_eq!(multi_line_symbols.symbols[2].alias, b"Dix");
 
    }
 

	
 
    #[test]
 
    fn test_struct_definition() {
 
        let mut h = Heap::new();
 
        let mut input = InputSource::from_string("
 
        struct Foo {
 
            byte one,
 
            short two,
 
            Bar three,
 
        }
 
        struct Bar{int[] one, int[] two, Qux[] three}
 
        ").unwrap();
 
        let mut lex = Lexer::new(&mut input);
 
        let lexed = lex.consume_protocol_description(&mut h);
 
        if let Err(err) = &lexed {
 
            println!("{}", err);
 
        }
 
        let lexed = lexed.unwrap();
 
        let root = &h[lexed];
 

	
 
        assert_eq!(root.definitions.len(), 2);
 

	
 
        let symbolic_type = |v: &PrimitiveType| -> Vec<u8> {
 
            if let PrimitiveType::Symbolic(v) = v {
 
                v.identifier.value.clone()
 
            } else {
 
                assert!(false);
 
                unreachable!();
 
            }
 
        };
 

	
 
        let foo_def = h[root.definitions[0]].as_struct();
 
        assert_eq!(foo_def.identifier.value, b"Foo");
 
        assert_eq!(foo_def.fields.len(), 3);
 
        assert_eq!(foo_def.fields[0].field.value, b"one");
 
        assert_eq!(h[foo_def.fields[0].the_type].the_type, Type::BYTE);
 
        assert_eq!(foo_def.fields[1].field.value, b"two");
 
        assert_eq!(h[foo_def.fields[1].the_type].the_type, Type::SHORT);
 
        assert_eq!(foo_def.fields[2].field.value, b"three");
 
        assert_eq!(
 
            symbolic_type(&h[foo_def.fields[2].the_type].the_type.primitive), 
 
            Vec::from("Bar".as_bytes())
 
        );
 

	
 
        let bar_def = h[root.definitions[1]].as_struct();
 
        assert_eq!(bar_def.identifier.value, b"Bar");
 
        assert_eq!(bar_def.fields.len(), 3);
 
        assert_eq!(bar_def.fields[0].field.value, b"one");
 
        assert_eq!(h[bar_def.fields[0].the_type].the_type, Type::INT_ARRAY);
 
        assert_eq!(bar_def.fields[1].field.value, b"two");
 
        assert_eq!(h[bar_def.fields[1].the_type].the_type, Type::INT_ARRAY);
 
        assert_eq!(bar_def.fields[2].field.value, b"three");
 
        assert_eq!(h[bar_def.fields[2].the_type].the_type.array, true);
 
        assert_eq!(
 
            symbolic_type(&h[bar_def.fields[2].the_type].the_type.primitive), 
 
            Vec::from("Qux".as_bytes())
 
        );
 
    }
 

	
 
    #[test]
 
    fn test_enum_definition() {
 
        let mut h = Heap::new();
 
        let mut input = InputSource::from_string("
 
        enum Foo {
 
            A = 0,
src/protocol/parser/mod.rs
Show inline comments
 
mod depth_visitor;
 
mod symbol_table;
 
mod type_table;
 
mod type_table2;
 
mod type_resolver;
 
mod visitor;
 
mod visitor_linker;
 

	
 
use depth_visitor::*;
 
use symbol_table::SymbolTable;
 
use visitor::Visitor2;
 
use visitor_linker::ValidityAndLinkerVisitor;
 
use type_table::TypeTable;
 

	
 
use crate::protocol::ast::*;
 
use crate::protocol::inputsource::*;
 
use crate::protocol::lexer::*;
 

	
 
use std::collections::HashMap;
 
use crate::protocol::ast_printer::ASTWriter;
 

	
 
// TODO: @fixme, pub qualifier
 
pub(crate) struct LexedModule {
 
    pub(crate) source: InputSource,
 
    module_name: Vec<u8>,
 
    version: Option<u64>,
 
    root_id: RootId,
 
}
 

	
 
pub struct Parser {
 
    pub(crate) heap: Heap,
 
    pub(crate) modules: Vec<LexedModule>,
 
    pub(crate) module_lookup: HashMap<Vec<u8>, usize>, // from (optional) module name to `modules` idx
 
}
 

	
 
impl Parser {
 
    pub fn new() -> Self {
 
        Parser{
 
            heap: Heap::new(),
 
            modules: Vec::new(),
 
            module_lookup: HashMap::new()
 
        }
 
    }
 

	
 
    // TODO: @fix, temporary implementation to keep code compilable
 
    pub fn new_with_source(source: InputSource) -> Result<Self, ParseError2> {
 
        let mut parser = Parser::new();
 
        parser.feed(source)?;
 
        Ok(parser)
 
    }
 

	
 
    pub fn feed(&mut self, mut source: InputSource) -> Result<RootId, ParseError2> {
 
        // Lex the input source
 
        let mut lex = Lexer::new(&mut source);
 
        let pd = lex.consume_protocol_description(&mut self.heap)?;
 

	
 
        // Seek the module name and version
 
        let root = &self.heap[pd];
 
        let mut module_name_pos = InputPosition::default();
 
        let mut module_name = Vec::new();
 
        let mut module_version_pos = InputPosition::default();
 
        let mut module_version = None;
 

	
 
        for pragma in &root.pragmas {
 
            match &self.heap[*pragma] {
 
                Pragma::Module(module) => {
 
                    if !module_name.is_empty() {
 
                        return Err(
 
                            ParseError2::new_error(&source, module.position, "Double definition of module name in the same file")
 
                                .with_postfixed_info(&source, module_name_pos, "Previous definition was here")
 
                        )
 
                    }
 

	
 
                    module_name_pos = module.position.clone();
 
                    module_name = module.value.clone();
 
                },
 
                Pragma::Version(version) => {
 
                    if module_version.is_some() {
 
                        return Err(
 
                            ParseError2::new_error(&source, version.position, "Double definition of module version")
 
                                .with_postfixed_info(&source, module_version_pos, "Previous definition was here")
 
                        )
 
                    }
 

	
 
                    module_version_pos = version.position.clone();
 
                    module_version = Some(version.version);
 
                },
 
            }
 
        }
 

	
 
        // Add module to list of modules and prevent naming conflicts
 
        let cur_module_idx = self.modules.len();
 
        if let Some(prev_module_idx) = self.module_lookup.get(&module_name) {
 
            // Find `#module` statement in other module again
 
            let prev_module = &self.modules[*prev_module_idx];
 
            let prev_module_pos = self.heap[prev_module.root_id].pragmas
 
                .iter()
 
                .find_map(|p| {
 
                    match &self.heap[*p] {
 
                        Pragma::Module(module) => Some(module.position.clone()),
 
                        _ => None
 
                    }
 
                })
 
                .unwrap_or(InputPosition::default());
 

	
 
            let module_name_msg = if module_name.is_empty() {
 
                format!("a nameless module")
 
            } else {
 
                format!("module '{}'", String::from_utf8_lossy(&module_name))
 
            };
 

	
 
            return Err(
 
                ParseError2::new_error(&source, module_name_pos, &format!("Double definition of {} across files", module_name_msg))
 
                    .with_postfixed_info(&prev_module.source, prev_module_pos, "Other definition was here")
 
            );
 
        }
 

	
 
        self.modules.push(LexedModule{
 
            source,
 
            module_name: module_name.clone(),
 
            version: module_version,
 
            root_id: pd
 
        });
 
        self.module_lookup.insert(module_name, cur_module_idx);
 
        Ok(pd)
 
    }
 

	
 
    pub fn compile(&mut self) {
 
        // Build module lookup
 
    }
 

	
 
    fn resolve_symbols_and_types(&mut self) -> Result<(SymbolTable, TypeTable), ParseError2> {
 
        // Construct the symbol table to resolve any imports and/or definitions,
 
        // then use the symbol table to actually annotate all of the imports.
 
        // If the type table is constructed correctly then all imports MUST be
 
        // resolvable.
 
        // TODO: Update once namespaced identifiers are implemented
 
        let symbol_table = SymbolTable::new(&self.heap, &self.modules)?;
 

	
 
        // Not pretty, but we need to work around rust's borrowing rules, it is
 
        // totally safe to mutate the contents of an AST element that we are
 
        // not borrowing anywhere else.
 
        // TODO: Maybe directly access heap's members to allow borrowing from
 
        //  mutliple members of Heap? Not pretty though...
 
        let mut module_index = 0;
 
        let mut import_index = 0;
 
        loop {
 
            if module_index >= self.modules.len() {
 
                break;
 
            }
 

	
 
            let module_root_id = self.modules[module_index].root_id;
 
            let import_id = {
 
                let root = &self.heap[module_root_id];
 
                if import_index >= root.imports.len() {
 
                    module_index += 1;
 
                    import_index = 0;
 
                    continue
 
                }
 
                root.imports[import_index]
 
            };
 

	
 
            let import = &mut self.heap[import_id];
 
            match import {
 
                Import::Module(import) => {
 
                    debug_assert!(import.module_id.is_none(), "module import already resolved");
 
                    let target_module_id = symbol_table.resolve_module(&import.module_name)
 
                        .expect("module import is resolved by symbol table");
 
                    import.module_id = Some(target_module_id)
 
                },
 
                Import::Symbols(import) => {
 
                    debug_assert!(import.module_id.is_none(), "module of symbol import already resolved");
 
                    let target_module_id = symbol_table.resolve_module(&import.module_name)
 
                        .expect("symbol import's module is resolved by symbol table");
 
                    import.module_id = Some(target_module_id);
 

	
 
                    for symbol in &mut import.symbols {
 
                        debug_assert!(symbol.definition_id.is_none(), "symbol import already resolved");
 
                        let (_, target_definition_id) = symbol_table.resolve_symbol(module_root_id, &symbol.alias)
 
                            .expect("symbol import is resolved by symbol table")
 
                            .as_definition()
 
                            .expect("symbol import does not resolve to namespace symbol");
 
                        symbol.definition_id = Some(target_definition_id);
 
                    }
 
                }
 
            }
 
        }
 

	
 
        // All imports in the AST are now annotated. We now use the symbol table
 
        // to construct the type table.
 
        let type_table = TypeTable::new(&symbol_table, &self.heap, &self.modules)?;
 

	
 
        Ok((symbol_table, type_table))
 
    }
 

	
 
    // TODO: @fix, temporary impl to keep code compilable
 
    pub fn parse(&mut self) -> Result<RootId, ParseError2> {
 
        assert_eq!(self.modules.len(), 1, "Fix meeeee");
 
        let root_id = self.modules[0].root_id;
 

	
 
        let (mut symbol_table, mut type_table) = self.resolve_symbols_and_types()?;
 

	
 
        // TODO: @cleanup
 
        let mut ctx = visitor::Ctx{
 
            heap: &mut self.heap,
 
            module: &self.modules[0],
 
            symbols: &mut symbol_table,
 
            types: &mut type_table,
 
        };
 
        let mut visit = ValidityAndLinkerVisitor::new();
 
        visit.visit_module(&mut ctx)?;
 

	
 
        if let Err((position, message)) = Self::parse_inner(&mut self.heap, root_id) {
 
            return Err(ParseError2::new_error(&self.modules[0].source, position, &message))
 
        }
 

	
 
        // let mut writer = ASTWriter::new();
 
        // let mut file = std::fs::File::create(std::path::Path::new("ast.txt")).unwrap();
 
        // writer.write_ast(&mut file, &self.heap);
 

	
 
        Ok(root_id)
 
    }
 

	
 
    pub fn parse_inner(h: &mut Heap, pd: RootId) -> VisitorResult {
 
        // TODO: @cleanup, slowly phasing out old compiler
 
        // NestedSynchronousStatements::new().visit_protocol_description(h, pd)?;
 
        // ChannelStatementOccurrences::new().visit_protocol_description(h, pd)?;
 
        // FunctionStatementReturns::new().visit_protocol_description(h, pd)?;
 
        // ComponentStatementReturnNew::new().visit_protocol_description(h, pd)?;
 
        // CheckBuiltinOccurrences::new().visit_protocol_description(h, pd)?;
 
        // BuildSymbolDeclarations::new().visit_protocol_description(h, pd)?;
 
        // LinkCallExpressions::new().visit_protocol_description(h, pd)?;
 
        // BuildScope::new().visit_protocol_description(h, pd)?;
 
        // ResolveVariables::new().visit_protocol_description(h, pd)?;
 
        LinkStatements::new().visit_protocol_description(h, pd)?;
 
        // BuildLabels::new().visit_protocol_description(h, pd)?;
 
        // ResolveLabels::new().visit_protocol_description(h, pd)?;
 
        AssignableExpressions::new().visit_protocol_description(h, pd)?;
 
        IndexableExpressions::new().visit_protocol_description(h, pd)?;
 
        SelectableExpressions::new().visit_protocol_description(h, pd)?;
 

	
 
        Ok(())
 
    }
 
}
 

	
 
#[cfg(test)]
 
mod tests {
 
    use std::fs::File;
 
    use std::io::Read;
 
    use std::path::Path;
 

	
 
    use super::*;
 

	
 
    // #[test]
 
    fn positive_tests() {
 
        for resource in TestFileIter::new("testdata/parser/positive", "pdl") {
 
            let resource = resource.expect("read testdata filepath");
 
            // println!(" * running: {}", &resource);
 
            let path = Path::new(&resource);
 
            let source = InputSource::from_file(&path).unwrap();
 
            // println!("DEBUG -- input:\n{}", String::from_utf8_lossy(&source.input));
 
            let mut parser = Parser::new_with_source(source).expect("parse source");
 
            match parser.parse() {
 
                Ok(_) => {}
 
                Err(err) => {
 
                    println!(" > file: {}", &resource);
 
                    println!("{}", err);
 
                    assert!(false);
 
                }
 
            }
 
        }
 
    }
 

	
 
    // #[test]
 
    fn negative_tests() {
 
        for resource in TestFileIter::new("testdata/parser/negative", "pdl") {
 
            let resource = resource.expect("read testdata filepath");
 
            let path = Path::new(&resource);
 
            let expect = path.with_extension("txt");
 
            let mut source = InputSource::from_file(&path).unwrap();
 
            let mut parser = Parser::new_with_source(source).expect("construct parser");
 
            match parser.parse() {
 
                Ok(pd) => {
 
                    println!("Expected parse error:");
 

	
 
                    let mut cev: Vec<u8> = Vec::new();
 
                    let mut f = File::open(expect).unwrap();
 
                    f.read_to_end(&mut cev).unwrap();
 
                    println!("{}", String::from_utf8_lossy(&cev));
 
                    assert!(false);
 
                }
 
                Err(err) => {
 
                    let expected = format!("{}", err);
 
                    println!("{}", &expected);
 

	
 
                    let mut cev: Vec<u8> = Vec::new();
 
                    let mut f = File::open(expect).unwrap();
 
                    f.read_to_end(&mut cev).unwrap();
 
                    println!("{}", String::from_utf8_lossy(&cev));
 

	
 
                    assert_eq!(expected.as_bytes(), cev);
 
                }
 
            }
 
        }
 
    }
 

	
 
    // #[test]
 
    fn counterexample_tests() {
 
        for resource in TestFileIter::new("testdata/parser/counterexamples", "pdl") {
 
            let resource = resource.expect("read testdata filepath");
 
            let path = Path::new(&resource);
 
            let source = InputSource::from_file(&path).unwrap();
 
            let mut parser = Parser::new_with_source(source).expect("construct parser");
 

	
 
            fn print_header(s: &str) {
 
                println!("{}", "=".repeat(80));
 
                println!(" > File: {}", s);
 
                println!("{}", "=".repeat(80));
 
            }
 

	
 
            match parser.parse() {
 
                Ok(parsed) => {
 
                    print_header(&resource);
 
                    println!("\n  SUCCESS\n\n --- source:\n{}", String::from_utf8_lossy(&parser.modules[0].source.input));
 
                },
 
                Err(err) => {
 
                    print_header(&resource);
 
                    println!(
 
                        "\n  FAILURE\n\n --- error:\n{}\n --- source:\n{}",
 
                        err,
 
                        String::from_utf8_lossy(&parser.modules[0].source.input)
 
                    )
 
                }
 
            }
 
        }
 
    }
 

	
 
    struct TestFileIter {
 
        iter: std::fs::ReadDir,
 
        root: String,
 
        extension: String
 
    }
 

	
 
    impl TestFileIter {
 
        fn new(root_dir: &str, extension: &str) -> Self {
 
            let path = Path::new(root_dir);
 
            assert!(path.is_dir(), "root '{}' is not a directory", root_dir);
 

	
 
            let iter = std::fs::read_dir(path).expect("list dir contents");
 

	
 
            Self {
 
                iter,
 
                root: root_dir.to_string(),
 
                extension: extension.to_string(),
 
            }
 
        }
 
    }
 

	
 
    impl Iterator for TestFileIter {
 
        type Item = Result<String, String>;
 

	
 
        fn next(&mut self) -> Option<Self::Item> {
 
            while let Some(entry) = self.iter.next() {
 
                if let Err(e) = entry {
 
                    return Some(Err(format!("failed to read dir entry, because: {}", e)));
 
                }
 
                let entry = entry.unwrap();
 

	
 
                let path = entry.path();
 
                if !path.is_file() { continue; }
 

	
 
                let extension = path.extension();
 
                if extension.is_none() { continue; }
 
                let extension = extension.unwrap().to_string_lossy();
 
                if extension != self.extension { continue; }
 

	
 
                return Some(Ok(path.to_string_lossy().to_string()));
 
            }
 

	
 
            None
 
        }
 
    }
 
}
src/protocol/parser/symbol_table.rs
Show inline comments
 
// TODO: Maybe allow namespaced-aliased imports. It is currently not possible
 
//  to express the following:
 
//      import Module.Submodule as SubMod
 
//      import SubMod::{Symbol}
 
//  And it is especially not possible to express the following:
 
//      import SubMod::{Symbol}
 
//      import Module.Submodule as SubMod
 
use crate::protocol::ast::*;
 
use crate::protocol::inputsource::*;
 

	
 
use std::collections::{HashMap, hash_map::Entry};
 
use crate::protocol::parser::LexedModule;
 

	
 
#[derive(PartialEq, Eq, Hash)]
 
struct SymbolKey {
 
    module_id: RootId,
 
    symbol_name: Vec<u8>,
 
}
 

	
 
pub(crate) enum Symbol {
 
    Namespace(RootId),
 
    Definition((RootId, DefinitionId)),
 
}
 

	
 
pub(crate) struct SymbolValue {
 
    // Position refers to the origin of the symbol definition (i.e. the module's
 
    // RootId that is in the key being used to lookup this value)
 
    // Position is the place where the symbol is introduced to a module (this
 
    // position always corresponds to the module whose RootId is stored in the
 
    // `SymbolKey` associated with this `SymbolValue`). For a definition this
 
    // is the position where the symbol is defined, for an import this is the
 
    // position of the import statement.
 
    pub(crate) position: InputPosition,
 
    pub(crate) symbol: Symbol,
 
}
 

	
 
impl SymbolValue {
 
    pub(crate) fn is_namespace(&self) -> bool {
 
        match &self.symbol {
 
            Symbol::Namespace(_) => true,
 
            _ => false
 
        }
 
    }
 
    pub(crate) fn as_namespace(&self) -> Option<RootId> {
 
        match &self.symbol {
 
            Symbol::Namespace(root_id) => Some(*root_id),
 
            _ => None,
 
        }
 
    }
 

	
 
    pub(crate) fn as_definition(&self) -> Option<(RootId, DefinitionId)> {
 
        match &self.symbol {
 
            Symbol::Definition((root_id, definition_id)) => Some((*root_id, *definition_id)),
 
            _ => None,
 
        }
 
    }
 
}
 
/// `SymbolTable` is responsible for two parts of the parsing process: firstly
 
/// it ensures that there are no clashing symbol definitions within each file,
 
/// and secondly it will resolve all symbols within a module to their
 
/// appropriate definitions (in case of enums, functions, etc.) and namespaces
 
/// (currently only external modules can act as namespaces). If a symbol clashes
 
/// or if a symbol cannot be resolved this will be an error.
 
///
 
/// Within the compilation process the symbol table is responsible for resolving
 
/// namespaced identifiers (e.g. Module::Enum::EnumVariant) to the appropriate
 
/// definition (i.e. not namespaces; as the language has no way to use
 
/// namespaces except for using them in namespaced identifiers).
 
pub(crate) struct SymbolTable {
 
    // Lookup from module name (not any aliases) to the root id
 
    module_lookup: HashMap<Vec<u8>, RootId>,
 
    // Lookup from within a module, to a particular imported (potentially
 
    // aliased) or defined symbol. Basically speaking: if the source code of a
 
    // module contains correctly imported/defined symbols, then this lookup
 
    // will always return the corresponding definition
 
    symbol_lookup: HashMap<SymbolKey, SymbolValue>,
 
}
 

	
 
impl SymbolTable {
 
    pub(crate) fn new(heap: &Heap, modules: &[LexedModule]) -> Result<Self, ParseError2> {
 
        // Sanity check
 
        if cfg!(debug_assertions) {
 
            for (index, module) in modules.iter().enumerate() {
 
                debug_assert_eq!(
 
                    index, module.root_id.index as usize,
 
                    "module RootId does not correspond to LexedModule index"
 
                )
 
            }
 
        }
 

	
 
        // Preparation: create a lookup from module name to root id. This does
 
        // not take aliasing into account.
 
        let mut module_lookup = HashMap::with_capacity(modules.len());
 
        for module in modules {
 
            // TODO: Maybe put duplicate module name checking here?
 
            // TODO: @string
 
            module_lookup.insert(module.module_name.clone(), module.root_id);
 
        }
 

	
 
        // Preparation: determine total number of imports we will be inserting
 
        // into the lookup table. We could just iterate over the arena, but then
 
        // we don't know the source file the import belongs to.
 
        let mut lookup_reserve_size = 0;
 
        for module in modules {
 
            let module_root = &heap[module.root_id];
 
            for import_id in &module_root.imports {
 
                match &heap[*import_id] {
 
                    Import::Module(_) => lookup_reserve_size += 1,
 
                    Import::Symbols(import) => {
 
                        if import.symbols.is_empty() {
 
                            // Add all symbols from the other module
 
                            match module_lookup.get(&import.module_name) {
 
                                Some(target_module_id) => {
 
                                    lookup_reserve_size += heap[*target_module_id].definitions.len()
 
                                },
 
                                None => {
 
                                    return Err(
 
                                        ParseError2::new_error(&module.source, import.position, "Cannot resolve module")
 
                                    );
 
                                }
 
                            }
 
                        } else {
 
                            lookup_reserve_size += import.symbols.len();
 
                        }
 
                    }
 
                }
 
            }
 

	
 
            lookup_reserve_size += module_root.definitions.len();
 
        }
 

	
 
        let mut table = Self{
 
            module_lookup,
 
            symbol_lookup: HashMap::with_capacity(lookup_reserve_size)
 
        };
 

	
 
        // First pass: we go through all of the modules and add lookups to
 
        // symbols that are defined within that module. Cross-module imports are
 
        // not yet resolved
 
        for module in modules {
 
            let root = &heap[module.root_id];
 
            for definition_id in &root.definitions {
 
                let definition = &heap[*definition_id];
 
                let identifier = definition.identifier();
 
                if let Err(previous_position) = table.add_definition_symbol(
 
                    module.root_id, identifier.position, &identifier.value,
 
                    module.root_id, *definition_id
 
                ) {
 
                    return Err(
 
                        ParseError2::new_error(&module.source, definition.position(), "Symbol is multiply defined")
 
                            .with_postfixed_info(&module.source, previous_position, "Previous definition was here")
 
                    )
 
                }
 
            }
 
        }
 

	
 
        // Second pass: now that we can find symbols in modules, we can resolve
 
        // all imports (if they're correct, that is)
 
        for module in modules {
 
            let root = &heap[module.root_id];
 
            for import_id in &root.imports {
 
                let import = &heap[*import_id];
 
                match import {
 
                    Import::Module(import) => {
 
                        // Find the module using its name
 
                        let target_root_id = table.resolve_module(&import.module_name);
 
                        if target_root_id.is_none() {
 
                            return Err(ParseError2::new_error(&module.source, import.position, "Could not resolve module"));
 
                        }
 
                        let target_root_id = target_root_id.unwrap();
 
                        if target_root_id == module.root_id {
 
                            return Err(ParseError2::new_error(&module.source, import.position, "Illegal import of self"));
 
                        }
 

	
 
                        // Add the target module under its alias
 
                        if let Err(previous_position) = table.add_namespace_symbol(
 
                            module.root_id, import.position,
 
                            &import.alias, target_root_id
 
                        ) {
 
                            return Err(
 
                                ParseError2::new_error(&module.source, import.position, "Symbol is multiply defined")
 
                                    .with_postfixed_info(&module.source, previous_position, "Previous definition was here")
 
                            );
 
                        }
 
                    },
 
                    Import::Symbols(import) => {
 
                        // Find the target module using its name
 
                        let target_root_id = table.resolve_module(&import.module_name);
 
                        if target_root_id.is_none() {
 
                            return Err(ParseError2::new_error(&module.source, import.position, "Could not resolve module of symbol imports"));
 
                        }
 
                        let target_root_id = target_root_id.unwrap();
 
                        if target_root_id == module.root_id {
 
                            return Err(ParseError2::new_error(&module.source, import.position, "Illegal import of self"));
 
                        }
 

	
 
                        // Determine which symbols to import
 
                        if import.symbols.is_empty() {
 
                            // Import of all symbols, not using any aliases
 
                            for definition_id in &heap[target_root_id].definitions {
 
                                let definition = &heap[*definition_id];
 
                                let identifier = definition.identifier();
 
                                if let Err(previous_position) = table.add_definition_symbol(
 
                                    module.root_id, import.position, &identifier.value,
 
                                    target_root_id, *definition_id
 
                                ) {
 
                                    return Err(
 
                                        ParseError2::new_error(
 
                                            &module.source, import.position,
 
                                            &format!("Imported symbol '{}' is already defined", String::from_utf8_lossy(&identifier.value))
 
                                        )
 
                                        .with_postfixed_info(
 
                                            &modules[target_root_id.index as usize].source,
 
                                            definition.position(),
 
                                            "The imported symbol is defined here"
 
                                        )
 
                                        .with_postfixed_info(
 
                                            &module.source, previous_position, "And is previously defined here"
 
                                        )
 
                                    )
 
                                }
 
                            }
 
                        } else {
 
                            // Import of specific symbols, optionally using aliases
 
                            for symbol in &import.symbols {
 
                                // Because we have already added per-module definitions, we can use
 
                                // the table to lookup this particular symbol. Note: within a single
 
                                // module a namespace-import and a symbol-import may not collide.
 
                                // Hence per-module symbols are unique.
 
                                // However: if we import a symbol from another module, we don't want
 
                                // to "import a module's imported symbol". And so if we do find
 
                                // a symbol match, we need to make sure it is a definition from
 
                                // within that module by checking `source_root_id == target_root_id`
 
                                let target_symbol = table.resolve_symbol(target_root_id, &symbol.name);
 
                                let symbol_definition_id = match target_symbol {
 
                                    Some(target_symbol) => {
 
                                        match target_symbol.symbol {
 
                                            Symbol::Definition((symbol_root_id, symbol_definition_id)) => {
 
                                                if symbol_root_id == target_root_id {
 
                                                    Some(symbol_definition_id)
 
                                                } else {
 
                                                    // This is imported within the target module, and not
 
                                                    // defined within the target module
 
                                                    None
 
                                                }
 
                                            },
 
                                            Symbol::Namespace(_) => {
 
                                                // We don't import a module's "module import"
 
                                                None
 
                                            }
 
                                        }
 
                                    },
 
                                    None => None
 
                                };
 

	
 
                                if symbol_definition_id.is_none() {
 
                                    return Err(
 
                                        ParseError2::new_error(&module.source, symbol.position, "Could not resolve symbol")
 
                                    )
 
                                }
 
                                let symbol_definition_id = symbol_definition_id.unwrap();
 

	
 
                                if let Err(previous_position) = table.add_definition_symbol(
 
                                    module.root_id, symbol.position, &symbol.alias,
 
                                    target_root_id, symbol_definition_id
 
                                ) {
 
                                    return Err(
 
                                        ParseError2::new_error(&module.source, symbol.position, "Symbol is multiply defined")
 
                                            .with_postfixed_info(&module.source, previous_position, "Previous definition was here")
 
                                    )
 
                                }
 
                            }
 
                        }
 
                    }
 
                }
 
            }
 
        }
 
        fn find_name(heap: &Heap, root_id: RootId) -> String {
 
            let root = &heap[root_id];
 
            for pragma_id in &root.pragmas {
 
                match &heap[*pragma_id] {
 
                    Pragma::Module(module) => {
 
                        return String::from_utf8_lossy(&module.value).to_string()
 
                    },
 
                    _ => {},
 
                }
 
            }
 

	
 
            return String::from("Unknown")
 
        }
 

	
 
        debug_assert_eq!(
 
            table.symbol_lookup.len(), lookup_reserve_size,
 
            "miscalculated reserved size for symbol lookup table"
 
        );
 
        Ok(table)
 
    }
 

	
 
    /// Resolves a module by its defined name
 
    pub(crate) fn resolve_module(&self, identifier: &Vec<u8>) -> Option<RootId> {
 
        self.module_lookup.get(identifier).map(|v| *v)
 
    }
 

	
 
    /// Resolves a symbol within a particular module, indicated by its RootId,
 
    /// with a single non-namespaced identifier
 
    pub(crate) fn resolve_symbol(&self, within_module_id: RootId, identifier: &Vec<u8>) -> Option<&SymbolValue> {
 
        self.symbol_lookup.get(&SymbolKey{ module_id: within_module_id, symbol_name: identifier.clone() })
 
    }
 

	
 
    /// Resolves a namespaced symbol. It will try to go as far as possible in
 
    /// actually finding a definition or a namespace. So a namespace might be
 
    /// resolved, after it which it finds an actual definition. It may be that
 
    /// the namespaced identifier has more elements that should be checked
 
    /// (i.e. an enum variant, or simply an erroneous instance of too many
 
    /// chained identifiers). This function will return None if nothing could be
 
    /// resolved at all.
 
    pub(crate) fn resolve_namespaced_symbol<'t, 'i>(
 
        &'t self, root_module_id: RootId, identifier: &'i NamespacedIdentifier
 
    ) -> Option<(&SymbolValue, NamespacedIdentifierIter<'i>)> {
 
        let mut iter = identifier.iter();
 
        let mut symbol: Option<&SymbolValue> = None;
 
        let mut within_module_id = root_module_id;
 
        while let Some(partial) = iter.next() {
 
            // Lookup the symbol within the currently iterated upon module
 
            let lookup_key = SymbolKey{ module_id: within_module_id, symbol_name: Vec::from(partial) };
 
            let new_symbol = self.symbol_lookup.get(&lookup_key);
 
            
 
            match new_symbol {
 
                None => {
 
                    // Can't find anything
 
                    break; 
 
                },
 
                Some(new_symbol) => {
 
                    // Found something, but if we already moved to another
 
                    // module then we don't want to keep jumping across modules,
 
                    // we're only interested in symbols defined within that
 
                    // module.
 
                    match &new_symbol.symbol {
 
                        Symbol::Namespace(new_root_id) => {
 
                            if root_module_id != within_module_id {
 
                                // Don't jump from module to module, keep the
 
                                // old symbol (which must be a Namespace) and
 
                                // break
 
                                debug_assert!(symbol.is_some());
 
                                debug_assert!(symbol.unwrap().is_namespace());
 
                                debug_assert!(iter.num_returned() > 1);
 

	
 
                                // For handling this error, we need to revert
 
                                // the iterator by one
 
                                let to_skip = iter.num_returned() - 1;
 
                                iter = identifier.iter();
 
                                for _ in 0..to_skip { iter.next(); }
 
                                break;
 
                            }
 

	
 
                            within_module_id = *new_root_id;
 
                            symbol = Some(new_symbol);
 
                        },
 
                        Symbol::Definition((definition_root_id, _)) => {
 
                            // Found a definition, but if we already jumped
 
                            // modules, then this must be defined within that
 
                            // module.
 
                            if root_module_id != within_module_id && within_module_id != *definition_root_id {
 
                                // This is an imported definition within the module
 
                                // TODO: Maybe factor out? Dunno...
 
                                debug_assert!(symbol.is_some());
 
                                debug_assert!(symbol.unwrap().is_namespace());
 
                                debug_assert!(iter.num_returned() > 1);
 
                                let to_skip = iter.num_returned() - 1;
 
                                iter = identifier.iter();
 
                                for _ in 0..to_skip { iter.next(); }
 
                                break;
 
                            }
 
                            symbol = Some(new_symbol);
 
                            break;
 
                        }
 
                    }
 
                }
 
            }
 
        }
 

	
 
        match symbol {
 
            None => None,
 
            Some(symbol) => Some((symbol, iter))
 
        }
 
    }
 

	
 
    /// Attempts to add a namespace symbol. Returns `Ok` if the symbol was
 
    /// inserted. If the symbol already exists then `Err` will be returned
 
    /// together with the previous definition's source position (in the origin
 
    /// module's source file).
 
    // Note: I would love to return a reference to the value, but Rust is
 
    // preventing me from doing so... That, or I'm not smart enough...
 
    fn add_namespace_symbol(
 
        &mut self, origin_module_id: RootId, origin_position: InputPosition, symbol_name: &Vec<u8>, target_module_id: RootId
 
    ) -> Result<(), InputPosition> {
 
        let key = SymbolKey{
 
            module_id: origin_module_id,
 
            symbol_name: symbol_name.clone()
 
        };
 
        match self.symbol_lookup.entry(key) {
 
            Entry::Occupied(o) => Err(o.get().position),
 
            Entry::Vacant(v) => {
 
                v.insert(SymbolValue{
 
                    position: origin_position,
 
                    symbol: Symbol::Namespace(target_module_id)
 
                });
 
                Ok(())
 
            }
 
        }
 
    }
 

	
 
    /// Attempts to add a definition symbol. Returns `Ok` if the symbol was
 
    /// inserted. If the symbol already exists then `Err` will be returned
 
    /// together with the previous definition's source position (in the origin
 
    /// module's source file).
src/protocol/parser/type_table.rs
Show inline comments
 
// TODO: @fix PrimitiveType for enums/unions
 
use crate::protocol::ast::*;
 
use crate::protocol::parser::symbol_table::{SymbolTable, Symbol};
 
use crate::protocol::inputsource::*;
 
use crate::protocol::parser::*;
 

	
 
use std::collections::HashMap;
 
use crate::common::Formatter;
 

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

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

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

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

	
 
impl DefinedType {
 
    pub(crate) fn type_class(&self) -> TypeClass {
 
        match self {
 
            DefinedType::Enum(_) => TypeClass::Enum,
 
            DefinedType::Union(_) => TypeClass::Union,
 
            DefinedType::Struct(_) => TypeClass::Struct,
 
            DefinedType::Function(_) => TypeClass::Function,
 
            DefinedType::Component(_) => TypeClass::Component
 
        }
 
    }
 
}
 

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

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

	
 
pub struct UnionVariant {
 
    identifier: Identifier,
 
    embedded_type: Option<TypeAnnotationId>,
 
    tag_value: i64,
 
}
 

	
 
/// `UnionType` is the algebraic datatype (or sum type, or discriminated union).
 
/// A value is an element of the union, identified by its tag, and may contain
 
/// a single subtype.
 
pub struct UnionType {
 
    variants: Vec<UnionVariant>,
 
    tag_representation: PrimitiveType
 
}
 

	
 
pub struct StructField {
 
    identifier: Identifier,
 
    field_type: TypeAnnotationId,
 
}
 

	
 
pub struct StructType {
 
    fields: Vec<StructField>,
 
}
 

	
 
pub struct FunctionArgument {
 
    identifier: Identifier,
 
    argument_type: TypeAnnotationId,
 
}
 

	
 
pub struct FunctionType {
 
    return_type: TypeAnnotationId,
 
    arguments: Vec<FunctionArgument>
 
}
 

	
 
pub struct ComponentType {
 
    variant: ComponentVariant,
 
    arguments: Vec<FunctionArgument>
 
}
 

	
 
pub struct TypeTable {
 
    lookup: HashMap<DefinitionId, DefinedType>,
 
}
 

	
 
enum LookupResult {
 
    BuiltIn,
 
    Resolved((RootId, DefinitionId)),
 
    Unresolved((RootId, DefinitionId)),
 
    Error((InputPosition, String)),
 
}
 

	
 
/// `TypeTable` is responsible for walking the entire lexed AST and laying out
 
/// the various user-defined types in terms of bytes and offsets. This process
 
/// may be pseudo-recursive (meaning: it is implemented in a recursive fashion,
 
/// but not in the recursive-function-call kind of way) in case a type depends
 
/// on another type to be resolved.
 
/// TODO: Distinction between resolved types and unresolved types (regarding the
 
///     mixed use of BuiltIns and resolved types) is a bit yucky at the moment,
 
///     will have to come up with something nice in the future.
 
/// TODO: Need to factor out the repeated lookup in some kind of state machine.
 
impl TypeTable {
 
    pub(crate) fn new(
 
        symbols: &SymbolTable, heap: &Heap, modules: &[LexedModule]
 
    ) -> Result<TypeTable, ParseError2> {
 
        if cfg!(debug_assertions) {
 
            for (index, module) in modules.iter().enumerate() {
 
                debug_assert_eq!(index, module.root_id.index as usize)
 
            }
 
        }
 

	
 
        // Estimate total number of definitions we will encounter
 
        let num_definitions = heap.definitions.len();
 
        let mut table = TypeTable{
 
            lookup: HashMap::with_capacity(num_definitions),
 
        };
 

	
 
        // Perform the breadcrumb-based type parsing. For now we do not allow
 
        // cyclic types. 
 
        // TODO: Allow cyclic types. However, we want to have an implementation
 
        //  that is somewhat efficient: if a type is cyclic, then we have to
 
        //  insert a pointer somewhere. However, we don't want to insert them
 
        //  everywhere, for each possible type. Without any further context the
 
        //  decision to place a pointer somewhere is "random", we need to know
 
        //  how the type is used to have an informed opinion on where to place
 
        //  the pointer.
 
        enum Breadcrumb {
 
            Linear((usize, usize)),
 
            Jumping((RootId, DefinitionId))
 
        }
 

	
 
        // Helper to handle the return value from lookup_type_definition. If
 
        // resolved/builtin we return `true`, if an error we complete the error
 
        // and return it. If unresolved then we check for cyclic types and
 
        // return an error if cyclic, otherwise return false (indicating we need
 
        // to continue in the breadcrumb-based resolving loop)
 
        let handle_lookup_result = |
 
            heap: &Heap, all_modules: &[LexedModule], cur_module: &LexedModule,
 
            breadcrumbs: &mut Vec<Breadcrumb>, result: LookupResult
 
        | -> Result<bool, ParseError2> {
 
            return match result {
 
                LookupResult::BuiltIn | LookupResult::Resolved(_) => Ok(true),
 
                LookupResult::Unresolved((new_root_id, new_definition_id)) => {
 
                    // Check for cyclic dependencies
 
                    let mut is_cyclic = false;
 
                    for breadcrumb in breadcrumbs.iter() {
 
                        let (root_id, definition_id) = match breadcrumb {
 
                            Breadcrumb::Linear((root_index, definition_index)) => {
 
                                let root_id = all_modules[*root_index].root_id;
 
                                let definition_id = heap[root_id].definitions[*definition_index];
 
                                (root_id, definition_id)
 
                            },
 
                            Breadcrumb::Jumping(root_id_and_definition_id) => *root_id_and_definition_id
 
                        };
 

	
 
                        if root_id == new_root_id && definition_id == new_definition_id {
 
                            // Oh noes!
 
                            is_cyclic = true;
 
                            break;
 
                        }
 
                    }
 

	
 
                    if is_cyclic {
 
                        let mut error = ParseError2::new_error(
 
                            &all_modules[new_root_id.index as usize].source,
 
                            heap[new_definition_id].position(),
 
                            "Evaluating this definition results in a a cyclic dependency"
 
                        );
 
                        for (index, breadcrumb) in breadcrumbs.iter().enumerate() {
 
                            match breadcrumb {
 
                                Breadcrumb::Linear((root_index, definition_index)) => {
 
                                    debug_assert_eq!(index, 0);
 
                                    error = error.with_postfixed_info(
 
                                        &all_modules[*root_index].source,
 
                                        heap[heap[all_modules[*root_index].root_id].definitions[*definition_index]].position(),
 
                                        "The cycle started with this definition"
 
                                    )
 
                                },
 
                                Breadcrumb::Jumping((root_id, definition_id)) => {
 
                                    debug_assert!(index > 0);
 
                                    error = error.with_postfixed_info(
 
                                        &all_modules[root_id.index as usize].source,
 
                                        heap[*definition_id].position(),
 
                                        "Which depends on this definition"
 
                                    )
 
                                }
 
                            }
 
                        }
 
                        Err(error)
 
                    } else {
 
                        breadcrumbs.push(Breadcrumb::Jumping((new_root_id, new_definition_id)));
 
                        Ok(false)
 
                    }
 
                },
 
                LookupResult::Error((position, message)) => {
 
                    Err(ParseError2::new_error(&cur_module.source, position, &message))
 
                }
 
            }
 
        };
 

	
 
        let mut module_index = 0;
 
        let mut definition_index = 0;
 
        let mut breadcrumbs = Vec::with_capacity(32); // if a user exceeds this, the user sucks at programming
 
        while module_index < modules.len() {
 
            // Go to next module if needed
 
            {
 
                let root = &heap[modules[module_index].root_id];
 
                if definition_index >= root.definitions.len() {
 
                    module_index += 1;
 
                    definition_index = 0;
 
                    continue;
 
                }
 
            }
 

	
 
            // Construct breadcrumbs in case we need to follow some types around
 
            debug_assert!(breadcrumbs.is_empty());
 
            breadcrumbs.push(Breadcrumb::Linear((module_index, definition_index)));
 
            'resolve_loop: while !breadcrumbs.is_empty() {
 
                // Retrieve module, the module's root and the definition
 
                let (module, definition_id) = match breadcrumbs.last().unwrap() {
 
                    Breadcrumb::Linear((module_index, definition_index)) => {
 
                        let module = &modules[*module_index];
 
                        let root = &heap[module.root_id];
 
                        let definition_id = root.definitions[*definition_index];
 
                        (module, definition_id)
 
                    },
 
                    Breadcrumb::Jumping((root_id, definition_id)) => {
 
                        let module = &modules[root_id.index as usize];
 
                        debug_assert_eq!(module.root_id, *root_id);
 
                        (module, *definition_id)
 
                    }
 
                };
 

	
 
                let definition = &heap[definition_id];
 

	
 
                // Because we might have chased around to this particular 
 
                // definition before, we check if we haven't resolved the type
 
                // already.
 
                if table.lookup.contains_key(&definition_id) {
 
                    breadcrumbs.pop();
 
                    continue;
 
                }
 

	
 
                match definition {
 
                    Definition::Enum(definition) => {
 
                        // Check the definition to see if we're dealing with an
 
                        // enum or a union. If we find any union variants then
 
                        // we immediately check if the type is already resolved.
 
                        assert!(definition.poly_vars.is_empty(), "Polyvars for enum not yet implemented");
 
                        let mut has_tag_values = None;
 
                        let mut has_int_values = None;
 
                        for variant in &definition.variants {
 
                            match &variant.value {
 
                                EnumVariantValue::None => {},
 
                                EnumVariantValue::Integer(_) => {
 
                                    if has_int_values.is_none() { has_int_values = Some(variant.position); }
 
                                 },
 
                                EnumVariantValue::Type(variant_type) => { 
 
                                    if has_tag_values.is_none() { has_tag_values = Some(variant.position); }
 

	
 
                                    let variant_type = &heap[*variant_type];
 

	
 
                                    let lookup_result = lookup_type_definition(
 
                                        heap, &table, symbols, module.root_id,
 
                                        &variant_type.the_type.primitive
 
                                    );
 
                                    if !handle_lookup_result(heap, modules, module, &mut breadcrumbs, lookup_result)? {
 
                                        continue 'resolve_loop;
 
                                    }
 
                                },
 
                            }
 
                        }
 

	
 
                        if has_tag_values.is_some() && has_int_values.is_some() {
 
                            // Not entirely illegal, but probably not desired
 
                            let tag_pos = has_tag_values.unwrap();
 
                            let int_pos = has_int_values.unwrap();
 
                            return Err(
 
                                ParseError2::new_error(&module.source, definition.position, "Illegal combination of enum integer variant(s) and enum union variant(s)")
 
                                .with_postfixed_info(&module.source, int_pos, "Explicitly assigning an integer value here")
 
                                .with_postfixed_info(&module.source, tag_pos, "Explicitly declaring a union variant here")
 
                            )
 
                        }
 

	
 
                        // If here, then the definition is a valid discriminated
 
                        // union with all of its types resolved, or a valid
 
                        // enum.
 

	
 
                        // Decide whether to implement as enum or as union
 
                        let is_union = has_tag_values.is_some();
 
                        if is_union {
 
                            // Implement as discriminated union. Because we 
 
                            // checked the availability of types above, we are
 
                            // safe to lookup type definitions
 
                            let mut tag_value = -1;
 
                            let mut variants = Vec::with_capacity(definition.variants.len());
 
                            for variant in &definition.variants {
 
                                tag_value += 1;
 
                                let embedded_type = match &variant.value {
 
                                    EnumVariantValue::None => {
 
                                        None
 
                                    },
 
                                    EnumVariantValue::Type(type_annotation_id) => {
 
                                        // Type should be resolvable, we checked this above
 
                                        let type_annotation = &heap[*type_annotation_id];
 
                                        // TODO: Remove the assert once I'm clear on how to layout "the types" of types
 
                                        if cfg!(debug_assertions) {
 
                                            ensure_type_definition(heap, &table, symbols, module.root_id, &type_annotation.the_type.primitive);
 
                                        }
 

	
 
                                        Some(*type_annotation_id)
 
                                    },
 
                                    EnumVariantValue::Integer(_) => {
 
                                        debug_assert!(false, "Encountered `Integer` variant after asserting enum is a discriminated union");
 
                                        unreachable!();
 
                                    }
 
                                };
 

	
 
                                variants.push(UnionVariant{
 
                                    identifier: variant.identifier.clone(),
 
                                    embedded_type,
 
                                    tag_value,
 
                                })
 
                            }
 

	
 
                            table.add_definition(definition_id, DefinedType::Union(UnionType{
 
                                variants,
 
                                tag_representation: enum_representation(tag_value)
 
                            }));
 
                        } else {
 
                            // Implement as regular enum
 
                            let mut enum_value = -1; // TODO: allow u64 max size
 
                            let mut variants = Vec::with_capacity(definition.variants.len());
 
                            for variant in &definition.variants {
 
                                enum_value += 1;
 
                                match &variant.value {
 
                                    EnumVariantValue::None => {
 
                                        variants.push(EnumVariant{
 
                                            identifier: variant.identifier.clone(),
 
                                            value: enum_value,
 
                                        });
 
                                    },
 
                                    EnumVariantValue::Integer(override_value) => {
 
                                        enum_value = *override_value;
 
                                        variants.push(EnumVariant{
 
                                            identifier: variant.identifier.clone(),
 
                                            value: enum_value,
 
                                        });
 
                                    },
 
                                    EnumVariantValue::Type(_) => {
 
                                        debug_assert!(false, "Encountered `Type` variant after asserting enum is not a discriminated union");
 
                                        unreachable!();
 
                                    }
 
                                }
 
                            }
 

	
 
                            table.add_definition(definition_id, DefinedType::Enum(EnumType{
 
                                variants,
 
                                representation: enum_representation(enum_value),
 
                            }));
 
                        }
 
                    },
 
                    Definition::Struct(definition) => {
 
                        // Before we start allocating fields, make sure we can
 
                        // actually resolve all of the field types
 
                        assert!(definition.poly_vars.is_empty(), "Polyvars for struct not yet implemented");
 
                        for field_definition in &definition.fields {
 
                            let type_definition = &heap[field_definition.the_type];
 
                            let lookup_result = lookup_type_definition(
 
                                heap, &table, symbols, module.root_id,
 
                                &type_definition.the_type.primitive
 
                            );
 
                            if !handle_lookup_result(heap, modules, module, &mut breadcrumbs, lookup_result)? {
 
                                continue 'resolve_loop;
 
                            }
 
                        }
 

	
 
                        // We can resolve everything
 
                        let mut fields = Vec::with_capacity(definition.fields.len());
 
                        for field_definition in &definition.fields {
 
                            let type_annotation = &heap[field_definition.the_type];
 
                            if cfg!(debug_assertions) {
 
                                ensure_type_definition(heap, &table, symbols, module.root_id, &type_annotation.the_type.primitive);
 
                            }
 

	
 
                            fields.push(StructField{
 
                                identifier: field_definition.field.clone(),
 
                                field_type: field_definition.the_type
 
                            });
 
                        }
 

	
 
                        table.add_definition(definition_id, DefinedType::Struct(StructType{
 
                            fields,
 
                        }));
 
                    },
 
                    Definition::Component(definition) => {
 
                        // As always, ensure all parameter types are resolved
 
                        assert!(definition.poly_vars.is_empty(), "Polyvars for component not yet implemented");
 
                        for parameter_id in &definition.parameters {
 
                            let parameter = &heap[*parameter_id];
 
                            let type_definition = &heap[parameter.type_annotation];
 
                            let lookup_result = lookup_type_definition(
 
                                heap, &table, symbols, module.root_id,
 
                                &type_definition.the_type.primitive
 
                            );
 
                            if !handle_lookup_result(heap, modules, module, &mut breadcrumbs, lookup_result)? {
 
                                continue 'resolve_loop;
 
                            }
 
                        }
 

	
 
                        // We can resolve everything
 
                        let mut parameters = Vec::with_capacity(definition.parameters.len());
 
                        for parameter_id in &definition.parameters {
 
                            let parameter = &heap[*parameter_id];
 
                            let type_definition = &heap[parameter.type_annotation];
 
                            if cfg!(debug_assertions) {
 
                                ensure_type_definition(heap, &table, symbols, module.root_id, &type_definition.the_type.primitive);
 
                            }
 

	
 
                            parameters.push(FunctionArgument{
 
                                identifier: parameter.identifier.clone(),
 
                                argument_type: parameter.type_annotation,
 
                            });
 
                        }
 

	
 
                        table.add_definition(definition_id, DefinedType::Component(ComponentType{
 
                            variant: definition.variant,
 
                            arguments: parameters, // Arguments, parameters, tomayto, tomahto
 
                        }));
 
                    },
 
                    Definition::Function(definition) => {
 
                        assert!(definition.poly_vars.is_empty(), "Polyvars for function not yet implemented");
 
                        // Handle checking the return type
 
                        let lookup_result = lookup_type_definition(
 
                            heap, &table, symbols, module.root_id,
 
                            &heap[definition.return_type].the_type.primitive
 
                        );
 
                        if !handle_lookup_result(heap, modules, module, &mut breadcrumbs, lookup_result)? {
 
                            continue 'resolve_loop;
 
                        }
 

	
 
                        for parameter_id in &definition.parameters {
 
                            let parameter = &heap[*parameter_id];
 
                            let type_definition = &heap[parameter.type_annotation];
 
                            let lookup_result = lookup_type_definition(
 
                                heap, &table, symbols, module.root_id,
 
                                &type_definition.the_type.primitive
 
                            );
 
                            if !handle_lookup_result(heap, modules, module, &mut breadcrumbs, lookup_result)? {
 
                                continue 'resolve_loop;
 
                            }
 
                        }
 

	
 
                        // Resolve function's types
 
                        let mut parameters = Vec::with_capacity(definition.parameters.len());
 
                        for parameter_id in &definition.parameters {
 
                            let parameter = &heap[*parameter_id];
 
                            let type_definition = &heap[parameter.type_annotation];
 
                            if cfg!(debug_assertions) {
 
                                ensure_type_definition(heap, &table, symbols, module.root_id, &type_definition.the_type.primitive);
 
                            }
 

	
 
                            parameters.push(FunctionArgument{
 
                                identifier: parameter.identifier.clone(),
 
                                argument_type: parameter.type_annotation
 
                            });
 
                        }
 

	
 
                        table.add_definition(definition_id, DefinedType::Function(FunctionType{
 
                            return_type: definition.return_type.clone(),
 
                            arguments: parameters,
 
                        }));
 
                    },
 
                }
 

	
 
                // If here, then we layed out the current type definition under
 
                // investigation, so:
 
                debug_assert!(!breadcrumbs.is_empty());
 
                breadcrumbs.pop();
 
            }
 

	
 
            // Go to next definition
 
            definition_index += 1;
 
        }
 

	
 
        debug_assert_eq!(
 
            num_definitions, table.lookup.len(),
 
            "expected {} (reserved) definitions in table, got {}",
 
            num_definitions, table.lookup.len()
 
        );
 

	
 
        Ok(table)
 
    }
 

	
 
    pub(crate) fn get_definition(&self, definition_id: &DefinitionId) -> Option<&DefinedType> {
 
        self.lookup.get(definition_id)
 
    }
 

	
 
    fn add_definition(&mut self, definition_id: DefinitionId, definition: DefinedType) {
 
        debug_assert!(!self.lookup.contains_key(&definition_id), "already added definition");
 
        self.lookup.insert(definition_id, definition);
 
    }
 
}
 

	
 
/// Attempts to lookup a type definition using a namespaced identifier. We have
 
/// three success cases: the first is simply that the type is a `BuiltIn` type.
 
/// In the two other cases both we find the definition of the type in the symbol
 
/// table, but in one case it is already `Resolved` in the type table, and in
 
/// the other case it is `Unresolved`. In this last case the type has to be
 
/// resolved before we're able to use it in the `TypeTable` construction
 
/// algorithm.
 
/// In the `Error` case something goes wrong with resolving the type. The error
 
/// message aims to be as helpful as possible to the user.
 
/// The caller should ensure that the `module_root` is where the `identifier`
 
/// lives.
 
fn lookup_type_definition(
 
    heap: &Heap, types: &TypeTable, symbols: &SymbolTable,
 
    module_root: RootId, type_to_resolve: &PrimitiveType
 
) -> LookupResult {
 
    if let PrimitiveType::Symbolic(type_to_resolve) = type_to_resolve {
 
        let identifier = &type_to_resolve.identifier;
 

	
 
        match symbols.resolve_namespaced_symbol(module_root, identifier) {
 
            None => {
 
                // Failed to find anything at all
 
                LookupResult::Error((identifier.position, String::from("Unknown type")))
 
            },
 
            Some((symbol, mut identifier_iter)) => {
 
                match symbol.symbol {
 
                    Symbol::Namespace(_root_id) => {
 
                        // Reference to a namespace, which is not a type. However,
 
                        // the error message depends on whether we have identifiers
 
                        // remaining or not
 
                        if identifier_iter.num_remaining() == 0 {
 
                            LookupResult::Error((
 
                                identifier.position,
 
                                String::from("Expected a type, got a module name")
 
                            ))
 
                        } else {
 
                            let next_identifier = identifier_iter.next().unwrap();
 
                            LookupResult::Error((
 
                                identifier.position,
 
                                format!("Cannot find symbol '{}' in this module", String::from_utf8_lossy(next_identifier))
 
                            ))
 
                        }
 
                    },
 
                    Symbol::Definition((definition_root_id, definition_id)) => {
 
                        // Got a definition, but we may also have more identifier's
 
                        // remaining in the identifier iterator
 
                        let definition = &heap[definition_id];
 
                        if identifier_iter.num_remaining() == 0 {
 
                            // See if the type is resolved, and make sure it is
 
                            // a non-function, non-component type. Ofcourse
 
                            // these are valid types, but we cannot (yet?) use
 
                            // them as function arguments, struct fields or enum
 
                            // variants
 
                            match definition {
 
                                Definition::Component(definition) => {
 
                                    return LookupResult::Error((
 
                                        identifier.position,
 
                                        format!(
 
                                            "Cannot use the component '{}' as an embedded type",
 
                                            String::from_utf8_lossy(&definition.identifier.value)
 
                                        )
 
                                    ));
 
                                },
 
                                Definition::Function(definition) => {
 
                                    return LookupResult::Error((
 
                                        identifier.position,
 
                                        format!(
 
                                            "Cannot use the function '{}' as an embedded type",
 
                                            String::from_utf8_lossy(&definition.identifier.value)
 
                                        )
 
                                    ));
 
                                },
 
                                Definition::Enum(_) | Definition::Struct(_) => {}
 
                            }
 

	
 
                            return if types.lookup.contains_key(&definition_id) {
 
                                LookupResult::Resolved((definition_root_id, definition_id))
 
                            } else {
 
                                LookupResult::Unresolved((definition_root_id, definition_id))
 
                            }
 
                        } else if identifier_iter.num_remaining() == 1 {
 
                            // This is always invalid, but if the type is an
 
                            // enumeration or a union then we want to return a
 
                            // different error message.
 
                            if definition.is_enum() {
 
                                let last_identifier = identifier_iter.next().unwrap();
 
                                return LookupResult::Error((
 
                                    identifier.position,
 
                                    format!(
 
                                        "Expected a type, but got a (possible) enum variant '{}'. Only the enum '{}' itself can be used as a type",
 
                                        String::from_utf8_lossy(last_identifier),
 
                                        String::from_utf8_lossy(&definition.identifier().value)
 
                                    )
 
                                ));
 
                            }
 
                        }
 

	
 
                        // Too much identifiers (>1) for an enumeration, or not an
 
                        // enumeration and we had more identifiers remaining
 
                        LookupResult::Error((
 
                            identifier.position,
 
                            format!(
 
                                "Unknown type '{}', did you mean to use '{}'?",
 
                                String::from_utf8_lossy(&identifier.value),
 
                                String::from_utf8_lossy(&definition.identifier().value)
 
                            )
 
                        ))
 
                    }
 
                }
 
            }
 
        }
 
    } else {
 
        LookupResult::BuiltIn
 
    }
 
}
 

	
 
/// Debugging function to ensure a type is resolved (calling
 
/// `lookup_type_definition` and ensuring its return value is `BuiltIn` or
 
/// `Resolved`
 
#[cfg(debug_assertions)]
 
fn ensure_type_definition(
 
    heap: &Heap, types: &TypeTable, symbols: &SymbolTable,
 
    module_root: RootId, type_to_resolve: &PrimitiveType
 
) {
 
    match lookup_type_definition(heap, types, symbols, module_root, type_to_resolve) {
 
        LookupResult::BuiltIn | LookupResult::Resolved(_) => {},
 
        LookupResult::Unresolved((_, definition_id)) => {
 
            assert!(
 
                false,
 
                "Expected that type definition for {} was resolved by the type table, but it wasn't",
 
                String::from_utf8_lossy(&heap[definition_id].identifier().value)
 
            )
 
        },
 
        LookupResult::Error((_, error)) => {
 
            let message = if let PrimitiveType::Symbolic(symbolic) = type_to_resolve {
 
                format!(
 
                    "Expected that type definition for {} was resolved by the type table, but it returned: {}",
 
                    String::from_utf8_lossy(&symbolic.identifier.value), &error
 
                )
 
            } else {
 
                format!(
 
                    "Expected (non-symbolic!?) type definition to be resolved, but it returned: {}",
 
                    &error
 
                )
 
            };
 
            assert!(false, "{}", message)
 
        }
 
    }
 
}
 

	
 
/// Determines an enumeration's integer representation type, or a union's tag
 
/// type, using the maximum value of the tag. The returned type is always a
 
/// builtin type.
 
/// TODO: Fix for maximum u64 value
 
fn enum_representation(max_tag_value: i64) -> PrimitiveType {
 
    if max_tag_value <= u8::max_value() as i64 {
 
        PrimitiveType::Byte
 
    } else if max_tag_value <= u16::max_value() as i64 {
 
        PrimitiveType::Short
 
    } else if max_tag_value <= u32::max_value() as i64 {
 
        PrimitiveType::Int
 
    } else {
 
        PrimitiveType::Long
 
    }
 
}
 
\ No newline at end of file

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