Changeset - 5dea649b3ffd
[Not reviewed]
src/collections/mod.rs
Show inline comments
 
mod string_pool;
 
mod scoped_buffer;
 
mod sets;
 

	
 

	
 
pub(crate) use string_pool::{StringPool, StringRef};
 
pub(crate) use scoped_buffer::{ScopedBuffer, ScopedSection};
 
pub(crate) use sets::{DequeSet, VecSet};
 
\ No newline at end of file
 
pub(crate) use sets::DequeSet;
 
\ No newline at end of file
src/collections/sets.rs
Show inline comments
 
#![allow(dead_code)] // For now, come back to this when compiler has matured -- MH 27/05/21
 

	
 
use std::collections::VecDeque;
 

	
 
/// Simple double ended queue that ensures that all elements are unique. Queue
 
/// elements are not ordered (we expect the queue to be rather small).
 
pub struct DequeSet<T: Eq> {
 
    inner: VecDeque<T>,
 
}
 

	
 
impl<T: Eq> DequeSet<T> {
 
    pub fn new() -> Self {
 
        Self{ inner: VecDeque::new() }
 
    }
 

	
 
    #[inline]
 
    pub fn pop_front(&mut self) -> Option<T> {
 
        self.inner.pop_front()
 
    }
 

	
 
    #[inline]
 
    pub fn pop_back(&mut self) -> Option<T> {
 
        self.inner.pop_back()
 
    }
 

	
 
    #[inline]
 
    pub fn push_back(&mut self, to_push: T) {
 
        for element in self.inner.iter() {
 
            if *element == to_push {
 
                return;
 
            }
 
        }
 

	
 
        self.inner.push_back(to_push);
 
    }
 

	
 
    #[inline]
 
    pub fn push_front(&mut self, to_push: T) {
 
        for element in self.inner.iter() {
 
            if *element == to_push {
 
                return;
 
            }
 
        }
 

	
 
        self.inner.push_front(to_push);
 
    }
 

	
 
    #[inline]
 
    pub fn clear(&mut self) {
 
        self.inner.clear();
 
    }
 

	
 
    #[inline]
 
    pub fn is_empty(&self) -> bool {
 
        self.inner.is_empty()
 
    }
 
}
 

	
 
/// Simple vector set that ensures that all elements are unique. Elements are
 
/// not ordered (we expect the vector to be small).
 
pub struct VecSet<T: Eq> {
 
    inner: Vec<T>,
 
}
 

	
 
impl<T: Eq> VecSet<T> {
 
    pub fn new() -> Self {
 
        Self{ inner: Vec::new() }
 
    }
 

	
 
    #[inline]
 
    pub fn pop(&mut self) -> Option<T> {
 
        self.inner.pop()
 
    }
 

	
 
    #[inline]
 
    pub fn push(&mut self, to_push: T) {
 
        for element in self.inner.iter() {
 
            if *element == to_push {
 
                return;
 
            }
 
        }
 

	
 
        self.inner.push(to_push);
 
    }
 

	
 
    #[inline]
 
    pub fn clear(&mut self) {
 
        self.inner.clear();
 
    }
 

	
 
    #[inline]
 
    pub fn is_empty(&self) -> bool {
 
        self.inner.is_empty()
 
    }
 
}
 
\ No newline at end of file
src/protocol/arena.rs
Show inline comments
 
use crate::common::*;
 
use core::hash::Hash;
 
use core::marker::PhantomData;
 

	
 
pub struct Id<T> {
 
    // Not actually a signed index into the heap. But the index is set to -1 if
 
    // we don't know an ID yet. This is checked during debug mode.
 
    pub(crate) index: i32,
 
    _phantom: PhantomData<T>,
 
}
 

	
 
impl<T> Id<T> {
 
    pub(crate) fn new_invalid() -> Self     { Self{ index: -1, _phantom: Default::default() } }
 
    pub(crate) fn new(index: i32) -> Self   { Self{ index, _phantom: Default::default() } }
 
    pub(crate) fn is_invalid(&self) -> bool { self.index < 0 }
 
}
 

	
 
#[derive(Debug)]
 
pub(crate) struct Arena<T> {
 
    store: Vec<T>,
 
}
 
//////////////////////////////////
 

	
 
impl<T> Debug for Id<T> {
 
    fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
 
        f.debug_struct("Id").field("index", &self.index).finish()
 
    }
 
}
 
impl<T> Clone for Id<T> {
 
    fn clone(&self) -> Self {
 
        *self
 
    }
 
}
 
impl<T> Copy for Id<T> {}
 
impl<T> PartialEq for Id<T> {
 
    fn eq(&self, other: &Self) -> bool {
 
        self.index.eq(&other.index)
 
    }
 
}
 
impl<T> Eq for Id<T> {}
 
impl<T> Hash for Id<T> {
 
    fn hash<H: std::hash::Hasher>(&self, h: &mut H) {
 
        self.index.hash(h);
 
    }
 
}
 

	
 
impl<T> Arena<T> {
 
    pub fn new() -> Self {
 
        Self { store: vec![] }
 
    }
 

	
 
    pub fn alloc_with_id(&mut self, f: impl FnOnce(Id<T>) -> T) -> Id<T> {
 
        // Lets keep this a runtime assert.
 
        assert!(self.store.len() < i32::max_value() as usize, "Arena out of capacity");
 
        let id = Id::new(self.store.len() as i32);
 
        self.store.push(f(id));
 
        id
 
    }
 

	
 
    // Compiler-internal direct retrieval
 
    pub(crate) fn get(&self, idx: usize) -> &T {
 
        return &self.store[idx]
 
    }
 
    pub(crate) fn get_id(&self, idx: usize) -> Id<T> {
 
        debug_assert!(idx < self.store.len());
 
        return Id::new(idx as i32);
 
    }
 

	
 
    pub fn iter(&self) -> impl Iterator<Item = &T> {
 
        self.store.iter()
 
    }
 

	
 
    pub fn len(&self) -> usize {
 
        self.store.len()
 
    }
 
}
 
impl<T> core::ops::Index<Id<T>> for Arena<T> {
 
    type Output = T;
 
    fn index(&self, id: Id<T>) -> &Self::Output {
 
        debug_assert!(!id.is_invalid(), "attempted to index into Arena with an invalid id (index < 0)");
 
        self.store.index(id.index as usize)
 
    }
 
}
 
impl<T> core::ops::IndexMut<Id<T>> for Arena<T> {
 
    fn index_mut(&mut self, id: Id<T>) -> &mut Self::Output {
 
        debug_assert!(!id.is_invalid(), "attempted to index_mut into Arena with an invalid id (index < 0)");
 
        self.store.index_mut(id.index as usize)
 
    }
 
}
 
\ No newline at end of file
src/protocol/ast.rs
Show inline comments
 
// TODO: @cleanup, rigorous cleanup of dead code and silly object-oriented
 
//  trait impls where I deem them unfit.
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
#[derive(Debug, Clone)]
 
pub struct ParserTypeElement {
 
    // TODO: @Fix span
 
    pub full_span: InputSpan, // full span of type, including any polymorphic arguments
 
    pub variant: ParserTypeVariant,
 
}
 

	
 
/// ParserType is a specification of a type during the parsing phase and initial
 
/// linker/validator phase of the compilation process. These types may be
 
/// (partially) inferred or represent literals (e.g. a integer whose bytesize is
 
/// not yet determined).
 
#[derive(Debug, Clone)]
 
pub struct ParserType {
 
    pub elements: Vec<ParserTypeElement>
 
}
 

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

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

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

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

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

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

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

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

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

	
 
/// ConcreteType is the representation of a type after resolving symbolic types
 
/// and performing type inference
 
#[derive(Debug, Clone, Copy, Eq, PartialEq)]
 
pub enum ConcreteTypePart {
 
    // Special types (cannot be explicitly constructed by the programmer)
 
    Void,
 
    // Builtin types without nested types
 
    Message,
 
    Bool,
 
    UInt8, UInt16, UInt32, UInt64,
 
    SInt8, SInt16, SInt32, SInt64,
 
    Character, String,
 
    // Builtin types with one nested type
 
    Array,
 
    Slice,
 
    Input,
 
    Output,
 
    // User defined type with any number of nested types
 
    Instance(DefinitionId, u32),
 
}
 

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
#[derive(Debug, Clone)]
 
pub struct Variable {
 
    pub this: VariableId,
 
    // Parsing
 
    pub kind: VariableKind,
 
    pub parser_type: ParserType,
 
    pub identifier: Identifier,
 
    // Validator/linker
 
    pub relative_pos_in_block: u32,
 
    pub unique_id_in_scope: i32, // Temporary fix until proper bytecode/asm is generated
 
}
 

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

	
 
impl Definition {
 
    pub fn is_struct(&self) -> bool {
 
        match self {
 
            Definition::Struct(_) => true,
 
            _ => false
 
        }
 
    }
 
    pub(crate) fn as_struct(&self) -> &StructDefinition {
 
        match self {
 
            Definition::Struct(result) => result,
 
            _ => panic!("Unable to cast 'Definition' to 'StructDefinition'"),
 
        }
 
    }
 
    pub(crate) fn as_struct_mut(&mut self) -> &mut StructDefinition {
 
        match self {
 
            Definition::Struct(result) => result,
 
            _ => panic!("Unable to cast 'Definition' to 'StructDefinition'"),
 
        }
 
    }
 
    pub fn is_enum(&self) -> bool {
 
        match self {
 
            Definition::Enum(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub(crate) fn as_enum(&self) -> &EnumDefinition {
 
        match self {
 
            Definition::Enum(result) => result,
 
            _ => panic!("Unable to cast 'Definition' to 'EnumDefinition'"),
 
        }
 
    }
 
    pub(crate) fn as_enum_mut(&mut self) -> &mut EnumDefinition {
 
        match self {
 
            Definition::Enum(result) => result,
 
            _ => panic!("Unable to cast 'Definition' to 'EnumDefinition'"),
 
        }
 
    }
 
    pub fn is_union(&self) -> bool {
 
        match self {
 
            Definition::Union(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub(crate) fn as_union(&self) -> &UnionDefinition {
 
        match self {
 
            Definition::Union(result) => result, 
 
            _ => panic!("Unable to cast 'Definition' to 'UnionDefinition'"),
 
        }
 
    }
 
    pub(crate) fn as_union_mut(&mut self) -> &mut UnionDefinition {
 
        match self {
 
            Definition::Union(result) => result,
 
            _ => panic!("Unable to cast 'Definition' to 'UnionDefinition'"),
 
        }
 
    }
 
    pub fn is_component(&self) -> bool {
 
        match self {
 
            Definition::Component(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub(crate) fn as_component(&self) -> &ComponentDefinition {
 
        match self {
 
            Definition::Component(result) => result,
 
            _ => panic!("Unable to cast `Definition` to `Component`"),
 
        }
 
    }
 
    pub(crate) fn as_component_mut(&mut self) -> &mut ComponentDefinition {
 
        match self {
 
            Definition::Component(result) => result,
 
            _ => panic!("Unable to cast `Definition` to `Component`"),
 
        }
 
    }
 
    pub fn is_function(&self) -> bool {
 
        match self {
 
            Definition::Function(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub(crate) fn as_function(&self) -> &FunctionDefinition {
 
        match self {
 
            Definition::Function(result) => result,
 
            _ => panic!("Unable to cast `Definition` to `Function`"),
 
        }
 
    }
 
    pub(crate) fn as_function_mut(&mut self) -> &mut FunctionDefinition {
 
        match self {
 
            Definition::Function(result) => result,
 
            _ => panic!("Unable to cast `Definition` to `Function`"),
 
        }
 
    }
 
    pub fn parameters(&self) -> &Vec<VariableId> {
 
        match self {
 
            Definition::Component(def) => &def.parameters,
 
            Definition::Function(def) => &def.parameters,
 
            _ => panic!("Called parameters() on {:?}", self)
 
        }
 
    }
 
    pub fn defined_in(&self) -> RootId {
 
        match self {
 
            Definition::Struct(def) => def.defined_in,
 
            Definition::Enum(def) => def.defined_in,
 
            Definition::Union(def) => def.defined_in,
 
            Definition::Component(def) => def.defined_in,
 
            Definition::Function(def) => def.defined_in,
 
        }
 
    }
 
    pub fn identifier(&self) -> &Identifier {
 
        match self {
 
            Definition::Struct(def) => &def.identifier,
 
            Definition::Enum(def) => &def.identifier,
 
            Definition::Union(def) => &def.identifier,
 
            Definition::Component(def) => &def.identifier,
 
            Definition::Function(def) => &def.identifier,
 
        }
 
    }
 
    pub fn poly_vars(&self) -> &Vec<Identifier> {
 
        match self {
 
            Definition::Struct(def) => &def.poly_vars,
 
            Definition::Enum(def) => &def.poly_vars,
 
            Definition::Union(def) => &def.poly_vars,
 
            Definition::Component(def) => &def.poly_vars,
 
            Definition::Function(def) => &def.poly_vars,
 
        }
 
    }
 
}
 

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

	
 
#[derive(Debug, Clone)]
 
pub struct StructDefinition {
 
    pub this: StructDefinitionId,
 
    pub defined_in: RootId,
 
    // Phase 1: symbol scanning
 
    // Symbol scanning
 
    pub span: InputSpan,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    // Phase 2: parsing
 
    // Parsing
 
    pub fields: Vec<StructFieldDefinition>
 
}
 

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

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

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

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

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

	
 
#[derive(Debug, Clone)]
 
pub enum UnionVariantValue {
 
    None,
 
    Embedded(Vec<ParserType>),
 
}
 

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

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

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

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

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

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

	
 
// Note that we will have function definitions for builtin functions as well. In
 
// that case the span, the identifier span and the body are all invalid.
 
#[derive(Debug, Clone)]
 
pub struct FunctionDefinition {
 
    pub this: FunctionDefinitionId,
 
    pub defined_in: RootId,
 
    // Symbol scanning
 
    pub builtin: bool,
 
    pub span: InputSpan,
 
    pub identifier: Identifier,
 
    pub poly_vars: Vec<Identifier>,
 
    // Parser
 
    pub return_types: Vec<ParserType>,
 
    pub parameters: Vec<VariableId>,
 
    pub body: BlockStatementId,
 
    // Validation/linking
 
    pub num_expressions_in_body: i32,
 
}
 

	
 
impl FunctionDefinition {
 
    pub(crate) fn new_empty(
 
        this: FunctionDefinitionId, defined_in: RootId, span: InputSpan,
 
        identifier: Identifier, poly_vars: Vec<Identifier>
 
    ) -> Self {
 
        Self {
 
            this, defined_in,
 
            builtin: false,
 
            span, identifier, poly_vars,
 
            return_types: Vec::new(),
 
            parameters: Vec::new(),
 
            body: BlockStatementId::new_invalid(),
 
            num_expressions_in_body: -1,
 
        }
 
    }
 
}
 

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

	
 
impl Statement {
 
    pub fn is_block(&self) -> bool {
 
        match self {
 
            Statement::Block(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub fn as_block(&self) -> &BlockStatement {
 
        match self {
 
            Statement::Block(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `BlockStatement`"),
 
        }
 
    }
 
    pub fn as_block_mut(&mut self) -> &mut BlockStatement {
 
        match self {
 
            Statement::Block(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `BlockStatement`"),
 
        }
 
    }
 
    pub fn as_local(&self) -> &LocalStatement {
 
        match self {
 
            Statement::Local(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `LocalStatement`"),
 
        }
 
    }
 
    pub fn as_memory(&self) -> &MemoryStatement {
 
        self.as_local().as_memory()
 
    }
 
    pub fn as_channel(&self) -> &ChannelStatement {
 
        self.as_local().as_channel()
 
    }
 
    pub fn as_labeled(&self) -> &LabeledStatement {
 
        match self {
 
            Statement::Labeled(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `LabeledStatement`"),
 
        }
 
    }
 
    pub fn as_labeled_mut(&mut self) -> &mut LabeledStatement {
 
        match self {
 
            Statement::Labeled(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `LabeledStatement`"),
 
        }
 
    }
 
    pub fn as_if(&self) -> &IfStatement {
 
        match self {
 
            Statement::If(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `IfStatement`"),
 
        }
 
    }
 
    pub fn as_if_mut(&mut self) -> &mut IfStatement {
 
        match self {
 
            Statement::If(result) => result,
 
            _ => panic!("Unable to cast 'Statement' to 'IfStatement'"),
 
        }
 
    }
 
    pub fn as_end_if(&self) -> &EndIfStatement {
 
        match self {
 
            Statement::EndIf(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `EndIfStatement`"),
 
        }
 
    }
 
    pub fn is_while(&self) -> bool {
 
        match self {
 
            Statement::While(_) => true,
 
            _ => false,
 
        }
 
    }
 
    pub fn as_while(&self) -> &WhileStatement {
 
        match self {
 
            Statement::While(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `WhileStatement`"),
 
        }
 
    }
 
    pub fn as_while_mut(&mut self) -> &mut WhileStatement {
 
        match self {
 
            Statement::While(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `WhileStatement`"),
 
        }
 
    }
 
    pub fn as_end_while(&self) -> &EndWhileStatement {
 
        match self {
 
            Statement::EndWhile(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `EndWhileStatement`"),
 
        }
 
    }
 
    pub fn as_break(&self) -> &BreakStatement {
 
        match self {
 
            Statement::Break(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `BreakStatement`"),
 
        }
 
    }
 
    pub fn as_break_mut(&mut self) -> &mut BreakStatement {
 
        match self {
 
            Statement::Break(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `BreakStatement`"),
 
        }
 
    }
 
    pub fn as_continue(&self) -> &ContinueStatement {
 
        match self {
 
            Statement::Continue(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `ContinueStatement`"),
 
        }
 
    }
 
    pub fn as_continue_mut(&mut self) -> &mut ContinueStatement {
 
        match self {
 
            Statement::Continue(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `ContinueStatement`"),
 
        }
 
    }
 
    pub fn as_synchronous(&self) -> &SynchronousStatement {
 
        match self {
 
            Statement::Synchronous(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `SynchronousStatement`"),
 
        }
 
    }
 
    pub fn as_synchronous_mut(&mut self) -> &mut SynchronousStatement {
 
        match self {
 
            Statement::Synchronous(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `SynchronousStatement`"),
 
        }
 
    }
 
    pub fn as_end_synchronous(&self) -> &EndSynchronousStatement {
 
        match self {
 
            Statement::EndSynchronous(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `EndSynchronousStatement`"),
 
        }
 
    }
 
    pub fn as_return(&self) -> &ReturnStatement {
 
        match self {
 
            Statement::Return(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `ReturnStatement`"),
 
        }
 
    }
 
    pub fn as_goto(&self) -> &GotoStatement {
 
        match self {
 
            Statement::Goto(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `GotoStatement`"),
 
        }
 
    }
 
    pub fn as_goto_mut(&mut self) -> &mut GotoStatement {
 
        match self {
 
            Statement::Goto(result) => result,
 
            _ => panic!("Unable to cast `Statement` to `GotoStatement`"),
 
        }
 
    }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
impl Expression {
 
    pub fn as_assignment(&self) -> &AssignmentExpression {
 
        match self {
 
            Expression::Assignment(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `AssignmentExpression`"),
 
        }
 
    }
 
    pub fn as_conditional(&self) -> &ConditionalExpression {
 
        match self {
 
            Expression::Conditional(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `ConditionalExpression`"),
 
        }
 
    }
 
    pub fn as_binary(&self) -> &BinaryExpression {
 
        match self {
 
            Expression::Binary(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `BinaryExpression`"),
 
        }
 
    }
 
    pub fn as_unary(&self) -> &UnaryExpression {
 
        match self {
 
            Expression::Unary(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `UnaryExpression`"),
 
        }
 
    }
 
    pub fn as_indexing(&self) -> &IndexingExpression {
 
        match self {
 
            Expression::Indexing(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `IndexingExpression`"),
 
        }
 
    }
 
    pub fn as_slicing(&self) -> &SlicingExpression {
 
        match self {
 
            Expression::Slicing(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `SlicingExpression`"),
 
        }
 
    }
 
    pub fn as_select(&self) -> &SelectExpression {
 
        match self {
 
            Expression::Select(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `SelectExpression`"),
 
        }
 
    }
 
    pub fn as_call(&self) -> &CallExpression {
 
        match self {
 
            Expression::Call(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `CallExpression`"),
 
        }
 
    }
 
    pub fn as_call_mut(&mut self) -> &mut CallExpression {
 
        match self {
 
            Expression::Call(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `CallExpression`"),
 
        }
 
    }
 
    pub fn as_variable(&self) -> &VariableExpression {
 
        match self {
 
            Expression::Variable(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `VariableExpression`"),
 
        }
 
    }
 
    pub fn as_variable_mut(&mut self) -> &mut VariableExpression {
 
        match self {
 
            Expression::Variable(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `VariableExpression`"),
 
        }
 
    }
 

	
 
    pub fn span(&self) -> InputSpan {
 
        match self {
 
            Expression::Assignment(expr) => expr.span,
 
            Expression::Binding(expr) => expr.span,
 
            Expression::Conditional(expr) => expr.span,
 
            Expression::Binary(expr) => expr.span,
 
            Expression::Unary(expr) => expr.span,
 
            Expression::Indexing(expr) => expr.span,
 
            Expression::Slicing(expr) => expr.span,
 
            Expression::Select(expr) => expr.span,
 
            Expression::Literal(expr) => expr.span,
 
            Expression::Cast(expr) => expr.span,
 
            Expression::Call(expr) => expr.span,
 
            Expression::Variable(expr) => expr.identifier.span,
 
        }
 
    }
 
    // TODO: @cleanup
 
    pub fn parent(&self) -> &ExpressionParent {
 
        match self {
 
            Expression::Assignment(expr) => &expr.parent,
 
            Expression::Binding(expr) => &expr.parent,
 
            Expression::Conditional(expr) => &expr.parent,
 
            Expression::Binary(expr) => &expr.parent,
 
            Expression::Unary(expr) => &expr.parent,
 
            Expression::Indexing(expr) => &expr.parent,
 
            Expression::Slicing(expr) => &expr.parent,
 
            Expression::Select(expr) => &expr.parent,
 
            Expression::Literal(expr) => &expr.parent,
 
            Expression::Cast(expr) => &expr.parent,
 
            Expression::Call(expr) => &expr.parent,
 
            Expression::Variable(expr) => &expr.parent,
 
        }
 
    }
 
    // TODO: @cleanup
 
    pub fn parent_expr_id(&self) -> Option<ExpressionId> {
 
        if let ExpressionParent::Expression(id, _) = self.parent() {
 
            Some(*id)
 
        } else {
 
            None
 
        }
 
    }
 
    // TODO: @cleanup
 
    pub fn set_parent(&mut self, parent: ExpressionParent) {
 
        match self {
 
            Expression::Assignment(expr) => expr.parent = parent,
 
            Expression::Binding(expr) => expr.parent = parent,
 
            Expression::Conditional(expr) => expr.parent = parent,
 
            Expression::Binary(expr) => expr.parent = parent,
 
            Expression::Unary(expr) => expr.parent = parent,
 
            Expression::Indexing(expr) => expr.parent = parent,
 
            Expression::Slicing(expr) => expr.parent = parent,
 
            Expression::Select(expr) => expr.parent = parent,
 
            Expression::Literal(expr) => expr.parent = parent,
 
            Expression::Cast(expr) => expr.parent = parent,
 
            Expression::Call(expr) => expr.parent = parent,
 
            Expression::Variable(expr) => expr.parent = parent,
 
        }
 
    }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
const INDENT: usize = 2;
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
                self.kv(indent2).with_s_key("Field").with_identifier_val(&expr.field_name);
 
                self.kv(indent2).with_s_key("Parent")
 
                    .with_custom_val(|v| write_expression_parent(v, &expr.parent));
 
            },
 
            Expression::Literal(expr) => {
 
                self.kv(indent).with_id(PREFIX_LITERAL_EXPR_ID, expr.this.0.index)
 
                    .with_s_key("LiteralExpr");
 

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

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

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

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

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

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

	
 
                        self.kv(indent3).with_s_key("Elements");
 
                        for expr_id in data {
 
                            self.write_expr(heap, *expr_id, indent4);
 
                        }
 
                    }
 
                }
 

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

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

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

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

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

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

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

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

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

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

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

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

	
 
    fn write_element(target: &mut String, heap: &Heap, t: &ParserType, mut element_idx: usize) -> usize {
 
        let element = &t.elements[element_idx];
 
        match &element.variant {
 
            PTV::Void => target.push_str("void"),
 
            PTV::InputOrOutput => {
 
                target.push_str("portlike<");
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push('>');
 
            },
 
            PTV::ArrayLike => {
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push_str("[???]");
 
            },
 
            PTV::IntegerLike => target.push_str("integerlike"),
 
            PTV::Message => { target.push_str(KW_TYPE_MESSAGE_STR); },
 
            PTV::Bool => { target.push_str(KW_TYPE_BOOL_STR); },
 
            PTV::UInt8 => { target.push_str(KW_TYPE_UINT8_STR); },
 
            PTV::UInt16 => { target.push_str(KW_TYPE_UINT16_STR); },
 
            PTV::UInt32 => { target.push_str(KW_TYPE_UINT32_STR); },
 
            PTV::UInt64 => { target.push_str(KW_TYPE_UINT64_STR); },
 
            PTV::SInt8 => { target.push_str(KW_TYPE_SINT8_STR); },
 
            PTV::SInt16 => { target.push_str(KW_TYPE_SINT16_STR); },
 
            PTV::SInt32 => { target.push_str(KW_TYPE_SINT32_STR); },
 
            PTV::SInt64 => { target.push_str(KW_TYPE_SINT64_STR); },
 
            PTV::Character => { target.push_str(KW_TYPE_CHAR_STR); },
 
            PTV::String => { target.push_str(KW_TYPE_STRING_STR); },
 
            PTV::IntegerLiteral => { target.push_str("int_literal"); },
 
            PTV::Inferred => { target.push_str(KW_TYPE_INFERRED_STR); },
 
            PTV::Array => {
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push_str("[]");
 
            },
 
            PTV::Input => {
 
                target.push_str(KW_TYPE_IN_PORT_STR);
 
                target.push('<');
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push('>');
 
            },
 
            PTV::Output => {
 
                target.push_str(KW_TYPE_OUT_PORT_STR);
 
                target.push('<');
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push('>');
 
            },
 
            PTV::PolymorphicArgument(definition_id, arg_idx) => {
 
                let definition = &heap[*definition_id];
 
                let poly_var = &definition.poly_vars()[*arg_idx as usize].value;
 
                target.push_str(poly_var.as_str());
 
            },
 
            PTV::Definition(definition_id, num_embedded) => {
 
                let definition = &heap[*definition_id];
 
                let definition_ident = definition.identifier().value.as_str();
 
                target.push_str(definition_ident);
 

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

	
 
        element_idx
 
    }
 

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

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

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

	
 
        match &t.parts[idx] {
 
            CTP::Void => target.push_str("void"),
 
            CTP::Message => target.push_str("msg"),
 
            CTP::Bool => target.push_str("bool"),
 
            CTP::UInt8 => target.push_str(KW_TYPE_UINT8_STR),
 
            CTP::UInt16 => target.push_str(KW_TYPE_UINT16_STR),
 
            CTP::UInt32 => target.push_str(KW_TYPE_UINT32_STR),
 
            CTP::UInt64 => target.push_str(KW_TYPE_UINT64_STR),
 
            CTP::SInt8 => target.push_str(KW_TYPE_SINT8_STR),
 
            CTP::SInt16 => target.push_str(KW_TYPE_SINT16_STR),
 
            CTP::SInt32 => target.push_str(KW_TYPE_SINT32_STR),
 
            CTP::SInt64 => target.push_str(KW_TYPE_SINT64_STR),
 
            CTP::Character => target.push_str(KW_TYPE_CHAR_STR),
 
            CTP::String => target.push_str(KW_TYPE_STRING_STR),
 
            CTP::Array => {
 
                idx = write_concrete_part(target, heap, def_id, t, idx + 1);
 
                target.push_str("[]");
 
            },
 
            CTP::Slice => {
 
                idx = write_concrete_part(target, heap, def_id, t, idx + 1);
 
                target.push_str("[..]");
 
            }
 
            CTP::Input => {
 
                target.push_str("in<");
 
                idx = write_concrete_part(target, heap, def_id, t, idx + 1);
 
                target.push('>');
 
            },
 
            CTP::Output => {
 
                target.push_str("out<");
 
                idx = write_concrete_part(target, heap, def_id, t, idx + 1);
 
                target.push('>')
 
            },
 
            CTP::Instance(definition_id, num_embedded) => {
 
                let identifier = heap[*definition_id].identifier();
 
                target.push_str(identifier.value.as_str());
 
                target.push('<');
 
                for idx_embedded in 0..*num_embedded {
 
                    if idx_embedded != 0 {
 
                        target.push_str(", ");
 
                    }
 
                    idx = write_concrete_part(target, heap, def_id, t, idx + 1);
 
                }
 
                target.push('>');
 
            }
 
        }
 

	
 
        idx + 1
 
    }
 

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

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

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

	
 
use std::collections::VecDeque;
 

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

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

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

	
 
#[derive(Debug, Clone)]
 
pub(crate) struct Frame {
 
    pub(crate) definition: DefinitionId,
 
    pub(crate) monomorph_idx: i32,
 
    pub(crate) position: StatementId,
 
    pub(crate) expr_stack: VecDeque<ExprInstruction>, // hack for expression evaluation, evaluated by popping from back
 
    pub(crate) expr_values: VecDeque<Value>, // hack for expression results, evaluated by popping from front/back
 
    pub(crate) max_stack_size: u32,
 
}
 

	
 
impl Frame {
 
    /// Creates a new execution frame. Does not modify the stack in any way.
 
    pub fn new(heap: &Heap, definition_id: DefinitionId, monomorph_idx: i32) -> Self {
 
        let definition = &heap[definition_id];
 
        let first_statement = match definition {
 
            Definition::Component(definition) => definition.body,
 
            Definition::Function(definition) => definition.body,
 
            _ => unreachable!("initializing frame with {:?} instead of a function/component", definition),
 
        };
 

	
 
        // Another not-so-pretty thing that has to be replaced somewhere in the
 
        // future...
 
        fn determine_max_stack_size(heap: &Heap, block_id: BlockStatementId, max_size: &mut u32) {
 
            let block_stmt = &heap[block_id];
 
            debug_assert!(block_stmt.next_unique_id_in_scope >= 0);
 

	
 
            // Check current block
 
            let cur_size = block_stmt.next_unique_id_in_scope as u32;
 
            if cur_size > *max_size { *max_size = cur_size; }
 

	
 
            // And child blocks
 
            for child_scope in &block_stmt.scope_node.nested {
 
                determine_max_stack_size(heap, child_scope.to_block(), max_size);
 
            }
 
        }
 

	
 
        let mut max_stack_size = 0;
 
        determine_max_stack_size(heap, first_statement, &mut max_stack_size);
 

	
 
        Frame{
 
            definition: definition_id,
 
            monomorph_idx,
 
            position: first_statement.upcast(),
 
            expr_stack: VecDeque::with_capacity(128),
 
            expr_values: VecDeque::with_capacity(128),
 
            max_stack_size,
 
        }
 
    }
 

	
 
    /// Prepares a single expression for execution. This involves walking the
 
    /// expression tree and putting them in the `expr_stack` such that
 
    /// continuously popping from its back will evaluate the expression. The
 
    /// results of each expression will be stored by pushing onto `expr_values`.
 
    pub fn prepare_single_expression(&mut self, heap: &Heap, expr_id: ExpressionId) {
 
        debug_assert!(self.expr_stack.is_empty());
 
        self.expr_values.clear(); // May not be empty if last expression result(s) were discarded
 

	
 
        self.serialize_expression(heap, expr_id);
 
    }
 

	
 
    /// Prepares multiple expressions for execution (i.e. evaluating all
 
    /// function arguments or all elements of an array/union literal). Per
 
    /// expression this works the same as `prepare_single_expression`. However
 
    /// after each expression is evaluated we insert a `PushValToFront`
 
    /// instruction
 
    pub fn prepare_multiple_expressions(&mut self, heap: &Heap, expr_ids: &[ExpressionId]) {
 
        debug_assert!(self.expr_stack.is_empty());
 
        self.expr_values.clear();
 

	
 
        for expr_id in expr_ids {
 
            self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
            self.serialize_expression(heap, *expr_id);
 
        }
 
    }
 

	
 
    /// Performs depth-first serialization of expression tree. Let's not care
 
    /// about performance for a temporary runtime implementation
 
    fn serialize_expression(&mut self, heap: &Heap, id: ExpressionId) {
 
        self.expr_stack.push_back(ExprInstruction::EvalExpr(id));
 

	
 
        match &heap[id] {
 
            Expression::Assignment(expr) => {
 
                self.serialize_expression(heap, expr.left);
 
                self.serialize_expression(heap, expr.right);
 
            },
 
            Expression::Binding(expr) => {
 
                self.serialize_expression(heap, expr.bound_to);
 
                self.serialize_expression(heap, expr.bound_from);
 
            },
 
            Expression::Conditional(expr) => {
 
                self.serialize_expression(heap, expr.test);
 
            },
 
            Expression::Binary(expr) => {
 
                self.serialize_expression(heap, expr.left);
 
                self.serialize_expression(heap, expr.right);
 
            },
 
            Expression::Unary(expr) => {
 
                self.serialize_expression(heap, expr.expression);
 
            },
 
            Expression::Indexing(expr) => {
 
                self.serialize_expression(heap, expr.index);
 
                self.serialize_expression(heap, expr.subject);
 
            },
 
            Expression::Slicing(expr) => {
 
                self.serialize_expression(heap, expr.from_index);
 
                self.serialize_expression(heap, expr.to_index);
 
                self.serialize_expression(heap, expr.subject);
 
            },
 
            Expression::Select(expr) => {
 
                self.serialize_expression(heap, expr.subject);
 
            },
 
            Expression::Literal(expr) => {
 
                // Here we only care about literals that have subexpressions
 
                match &expr.value {
 
                    Literal::Null | Literal::True | Literal::False |
 
                    Literal::Character(_) | Literal::String(_) |
 
                    Literal::Integer(_) | Literal::Enum(_) => {
 
                        // No subexpressions
 
                    },
 
                    Literal::Struct(literal) => {
 
                        // Note: fields expressions are evaluated in programmer-
 
                        // specified order. But struct construction expects them
 
                        // in type-defined order. I might want to come back to
 
                        // this.
 
                        let mut _num_pushed = 0;
 
                        for want_field_idx in 0..literal.fields.len() {
 
                            for field in &literal.fields {
 
                                if field.field_idx == want_field_idx {
 
                                    _num_pushed += 1;
 
                                    self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                                    self.serialize_expression(heap, field.value);
 
                                }
 
                            }
 
                        }
 
                        debug_assert_eq!(_num_pushed, literal.fields.len())
 
                    },
 
                    Literal::Union(literal) => {
 
                        for value_expr_id in &literal.values {
 
                            self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                            self.serialize_expression(heap, *value_expr_id);
 
                        }
 
                    },
 
                    Literal::Array(value_expr_ids) => {
 
                        for value_expr_id in value_expr_ids {
 
                            self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                            self.serialize_expression(heap, *value_expr_id);
 
                        }
 
                    }
 
                }
 
            },
 
            Expression::Cast(expr) => {
 
                self.serialize_expression(heap, expr.subject);
 
            }
 
            Expression::Call(expr) => {
 
                for arg_expr_id in &expr.arguments {
 
                    self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                    self.serialize_expression(heap, *arg_expr_id);
 
                }
 
            },
 
            Expression::Variable(expr) => {
 
            Expression::Variable(_expr) => {
 
                // No subexpressions
 
            }
 
        }
 
    }
 
}
 

	
 
type EvalResult = Result<EvalContinuation, EvalError>;
 

	
 
pub enum EvalContinuation {
 
    Stepping,
 
    Inconsistent,
 
    Terminal,
 
    SyncBlockStart,
 
    SyncBlockEnd,
 
    NewComponent(DefinitionId, i32, ValueGroup),
 
    BlockFires(Value),
 
    BlockGet(Value),
 
    Put(Value, Value),
 
}
 

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

	
 
impl Prompt {
 
    pub fn new(_types: &TypeTable, heap: &Heap, def: DefinitionId, monomorph_idx: i32, args: ValueGroup) -> Self {
 
        let mut prompt = Self{
 
            frames: Vec::new(),
 
            store: Store::new(),
 
        };
 

	
 
        // Maybe do typechecking in the future?
 
        debug_assert!((monomorph_idx as usize) < _types.get_base_definition(&def).unwrap().definition.procedure_monomorphs().len());
 
        let new_frame = Frame::new(heap, def, monomorph_idx);
 
        let max_stack_size = new_frame.max_stack_size;
 
        prompt.frames.push(new_frame);
 
        args.into_store(&mut prompt.store);
 
        prompt.store.reserve_stack(max_stack_size);
 

	
 
        prompt
 
    }
 

	
 
    pub(crate) fn step(&mut self, types: &TypeTable, heap: &Heap, modules: &[Module], ctx: &mut EvalContext) -> EvalResult {
 
        // Helper function to transfer multiple values from the expression value
 
        // array into a heap region (e.g. constructing arrays or structs).
 
        fn transfer_expression_values_front_into_heap(cur_frame: &mut Frame, store: &mut Store, num_values: usize) -> HeapPos {
 
            let heap_pos = store.alloc_heap();
 

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

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

	
 
            heap_pos
 
        }
 

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

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

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

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

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

	
 
        // Execute all pending expressions
 
        while !cur_frame.expr_stack.is_empty() {
 
            let next = cur_frame.expr_stack.pop_back().unwrap();
 
            debug_log!("Expr stack: {:?}", next);
 
            match next {
 
                ExprInstruction::PushValToFront => {
 
                    cur_frame.expr_values.rotate_right(1);
 
                },
 
                ExprInstruction::EvalExpr(expr_id) => {
 
                    let expr = &heap[expr_id];
 
                    match expr {
 
                        Expression::Assignment(expr) => {
 
                            let to = cur_frame.expr_values.pop_back().unwrap().as_ref();
 
                            let rhs = cur_frame.expr_values.pop_back().unwrap();
 

	
 
                            // Note: although not pretty, the assignment operator takes ownership
 
                            // of the right-hand side value when possible. So we do not drop the
 
                            // rhs's optionally owned heap data.
 
                            let rhs = self.store.read_take_ownership(rhs);
 
                            apply_assignment_operator(&mut self.store, to, expr.operation, rhs);
 
                        },
 
                        Expression::Binding(_expr) => {
 
                            let bind_to = cur_frame.expr_values.pop_back().unwrap();
 
                            let bind_from = cur_frame.expr_values.pop_back().unwrap();
 
                            let bind_to_heap_pos = bind_to.get_heap_pos();
 
                            let bind_from_heap_pos = bind_from.get_heap_pos();
 

	
 
                            let result = apply_binding_operator(&mut self.store, bind_to, bind_from);
 
                            self.store.drop_value(bind_to_heap_pos);
 
                            self.store.drop_value(bind_from_heap_pos);
 
                            cur_frame.expr_values.push_back(Value::Bool(result));
 
                        },
 
                        Expression::Conditional(expr) => {
 
                            // Evaluate testing expression, then extend the
 
                            // expression stack with the appropriate expression
 
                            let test_result = cur_frame.expr_values.pop_back().unwrap().as_bool();
 
                            if test_result {
 
                                cur_frame.serialize_expression(heap, expr.true_expression);
 
                            } else {
 
                                cur_frame.serialize_expression(heap, expr.false_expression);
 
                            }
 
                        },
 
                        Expression::Binary(expr) => {
 
                            let lhs = cur_frame.expr_values.pop_back().unwrap();
 
                            let rhs = cur_frame.expr_values.pop_back().unwrap();
 
                            let result = apply_binary_operator(&mut self.store, &lhs, expr.operation, &rhs);
 
                            cur_frame.expr_values.push_back(result);
 
                            self.store.drop_value(lhs.get_heap_pos());
 
                            self.store.drop_value(rhs.get_heap_pos());
 
                        },
 
                        Expression::Unary(expr) => {
 
                            let val = cur_frame.expr_values.pop_back().unwrap();
 
                            let result = apply_unary_operator(&mut self.store, expr.operation, &val);
 
                            cur_frame.expr_values.push_back(result);
 
                            self.store.drop_value(val.get_heap_pos());
 
                        },
 
                        Expression::Indexing(expr) => {
 
                        Expression::Indexing(_expr) => {
 
                            // Evaluate index. Never heap allocated so we do
 
                            // not have to drop it.
 
                            let index = cur_frame.expr_values.pop_back().unwrap();
 
                            let index = self.store.maybe_read_ref(&index);
 

	
 
                            debug_assert!(index.is_integer());
 
                            let index = if index.is_signed_integer() {
 
                                index.as_signed_integer() as i64
 
                            } else {
 
                                index.as_unsigned_integer() as i64
 
                            };
 

	
 
                            let subject = cur_frame.expr_values.pop_back().unwrap();
 

	
 
                            let (deallocate_heap_pos, value_to_push, subject_heap_pos) = match subject {
 
                            let (deallocate_heap_pos, value_to_push) = match subject {
 
                                Value::Ref(value_ref) => {
 
                                    // Our expression stack value is a reference to something that
 
                                    // exists in the normal stack/heap. We don't want to deallocate
 
                                    // this thing. Rather we want to return a reference to it.
 
                                    let subject = self.store.read_ref(value_ref);
 
                                    let subject_heap_pos = match subject {
 
                                        Value::String(v) => *v,
 
                                        Value::Array(v) => *v,
 
                                        Value::Message(v) => *v,
 
                                        _ => unreachable!(),
 
                                    };
 

	
 
                                    if array_inclusive_index_is_invalid(&self.store, subject_heap_pos, index) {
 
                                        return Err(construct_array_error(self, modules, heap, expr_id, subject_heap_pos, index));
 
                                    }
 

	
 
                                    (None, Value::Ref(ValueId::Heap(subject_heap_pos, index as u32)), subject_heap_pos)
 
                                    (None, Value::Ref(ValueId::Heap(subject_heap_pos, index as u32)))
 
                                },
 
                                _ => {
 
                                    // Our value lives on the expression stack, hence we need to
 
                                    // clone whatever we're referring to. Then drop the subject.
 
                                    let subject_heap_pos = match &subject {
 
                                        Value::String(v) => *v,
 
                                        Value::Array(v) => *v,
 
                                        Value::Message(v) => *v,
 
                                        _ => unreachable!(),
 
                                    };
 

	
 
                                    if array_inclusive_index_is_invalid(&self.store, subject_heap_pos, index) {
 
                                        return Err(construct_array_error(self, modules, heap, expr_id, subject_heap_pos, index));
 
                                    }
 

	
 
                                    let subject_indexed = Value::Ref(ValueId::Heap(subject_heap_pos, index as u32));
 
                                    (Some(subject_heap_pos), self.store.clone_value(subject_indexed), subject_heap_pos)
 
                                    (Some(subject_heap_pos), self.store.clone_value(subject_indexed))
 
                                },
 
                            };
 

	
 
                            cur_frame.expr_values.push_back(value_to_push);
 
                            self.store.drop_value(deallocate_heap_pos);
 
                        },
 
                        Expression::Slicing(expr) => {
 
                            // Evaluate indices
 
                            let from_index = cur_frame.expr_values.pop_back().unwrap();
 
                            let from_index = self.store.maybe_read_ref(&from_index);
 
                            let to_index = cur_frame.expr_values.pop_back().unwrap();
 
                            let to_index = self.store.maybe_read_ref(&to_index);
 

	
 
                            debug_assert!(from_index.is_integer() && to_index.is_integer());
 
                            let from_index = if from_index.is_signed_integer() {
 
                                from_index.as_signed_integer()
 
                            } else {
 
                                from_index.as_unsigned_integer() as i64
 
                            };
 
                            let to_index = if to_index.is_signed_integer() {
 
                                to_index.as_signed_integer()
 
                            } else {
 
                                to_index.as_unsigned_integer() as i64
 
                            };
 

	
 
                            // Dereference subject if needed
 
                            let subject = cur_frame.expr_values.pop_back().unwrap();
 
                            let deref_subject = self.store.maybe_read_ref(&subject);
 

	
 
                            // Slicing needs to produce a copy anyway (with the
 
                            // current evaluator implementation)
 
                            enum ValueKind{ Array, String, Message }
 
                            let (value_kind, array_heap_pos) = match deref_subject {
 
                                Value::Array(v) => (ValueKind::Array, *v),
 
                                Value::String(v) => (ValueKind::String, *v),
 
                                Value::Message(v) => (ValueKind::Message, *v),
 
                                _ => unreachable!()
 
                            };
 

	
 
                            if array_inclusive_index_is_invalid(&self.store, array_heap_pos, from_index) {
 
                                return Err(construct_array_error(self, modules, heap, expr.from_index, array_heap_pos, from_index));
 
                            }
 
                            if array_exclusive_index_is_invalid(&self.store, array_heap_pos, to_index) {
 
                                return Err(construct_array_error(self, modules, heap, expr.to_index, array_heap_pos, to_index));
 
                            }
 

	
 
                            // Again: would love to push directly, but rust...
 
                            let new_heap_pos = self.store.alloc_heap();
 
                            debug_assert!(self.store.heap_regions[new_heap_pos as usize].values.is_empty());
 
                            if to_index > from_index {
 
                                let from_index = from_index as usize;
 
                                let to_index = to_index as usize;
 
                                let mut values = Vec::with_capacity(to_index - from_index);
 
                                for idx in from_index..to_index {
 
                                    let value = self.store.heap_regions[array_heap_pos as usize].values[idx].clone();
 
                                    values.push(self.store.clone_value(value));
 
                                }
 

	
 
                                self.store.heap_regions[new_heap_pos as usize].values = values;
 

	
 
                            } // else: empty range
 

	
 
                            cur_frame.expr_values.push_back(match value_kind {
 
                                ValueKind::Array => Value::Array(new_heap_pos),
 
                                ValueKind::String => Value::String(new_heap_pos),
 
                                ValueKind::Message => Value::Message(new_heap_pos),
 
                            });
 

	
 
                            // Dropping the original subject, because we don't
 
                            // want to drop something on the stack
 
                            self.store.drop_value(subject.get_heap_pos());
 
                        },
 
                        Expression::Select(expr) => {
 
                            let subject= cur_frame.expr_values.pop_back().unwrap();
 
                            let mono_data = types.get_procedure_expression_data(&cur_frame.definition, cur_frame.monomorph_idx);
 
                            let field_idx = mono_data.expr_data[expr.unique_id_in_definition as usize].field_or_monomorph_idx as u32;
 

	
 
                            // Note: same as above: clone if value lives on expr stack, simply
 
                            // refer to it if it already lives on the stack/heap.
 
                            let (deallocate_heap_pos, value_to_push) = match subject {
 
                                Value::Ref(value_ref) => {
 
                                    let subject = self.store.read_ref(value_ref);
 
                                    let subject_heap_pos = subject.as_struct();
 

	
 
                                    (None, Value::Ref(ValueId::Heap(subject_heap_pos, field_idx)))
 
                                },
 
                                _ => {
 
                                    let subject_heap_pos = subject.as_struct();
 
                                    let subject_indexed = Value::Ref(ValueId::Heap(subject_heap_pos, field_idx));
 
                                    (Some(subject_heap_pos), self.store.clone_value(subject_indexed))
 
                                },
 
                            };
 

	
 
                            cur_frame.expr_values.push_back(value_to_push);
 
                            self.store.drop_value(deallocate_heap_pos);
 
                        },
 
                        Expression::Literal(expr) => {
 
                            let value = match &expr.value {
 
                                Literal::Null => Value::Null,
 
                                Literal::True => Value::Bool(true),
 
                                Literal::False => Value::Bool(false),
 
                                Literal::Character(lit_value) => Value::Char(*lit_value),
 
                                Literal::String(lit_value) => {
 
                                    let heap_pos = self.store.alloc_heap();
 
                                    let values = &mut self.store.heap_regions[heap_pos as usize].values;
 
                                    let value = lit_value.as_str();
 
                                    debug_assert!(values.is_empty());
 
                                    values.reserve(value.len());
 
                                    for character in value.as_bytes() {
 
                                        debug_assert!(character.is_ascii());
 
                                        values.push(Value::Char(*character as char));
 
                                    }
 
                                    Value::String(heap_pos)
 
                                }
 
                                Literal::Integer(lit_value) => {
 
                                    use ConcreteTypePart as CTP;
 
                                    let def_types = types.get_procedure_expression_data(&cur_frame.definition, cur_frame.monomorph_idx);
 
                                    let concrete_type = &def_types.expr_data[expr.unique_id_in_definition as usize].expr_type;
 

	
 
                                    debug_assert_eq!(concrete_type.parts.len(), 1);
 
                                    match concrete_type.parts[0] {
 
                                        CTP::UInt8  => Value::UInt8(lit_value.unsigned_value as u8),
 
                                        CTP::UInt16 => Value::UInt16(lit_value.unsigned_value as u16),
 
                                        CTP::UInt32 => Value::UInt32(lit_value.unsigned_value as u32),
 
                                        CTP::UInt64 => Value::UInt64(lit_value.unsigned_value as u64),
 
                                        CTP::SInt8  => Value::SInt8(lit_value.unsigned_value as i8),
 
                                        CTP::SInt16 => Value::SInt16(lit_value.unsigned_value as i16),
 
                                        CTP::SInt32 => Value::SInt32(lit_value.unsigned_value as i32),
 
                                        CTP::SInt64 => Value::SInt64(lit_value.unsigned_value as i64),
 
                                        _ => unreachable!("got concrete type {:?} for integer literal at expr {:?}", concrete_type, expr_id),
 
                                    }
 
                                }
 
                                Literal::Struct(lit_value) => {
 
                                    let heap_pos = transfer_expression_values_front_into_heap(
 
                                        cur_frame, &mut self.store, lit_value.fields.len()
 
                                    );
 
                                    Value::Struct(heap_pos)
 
                                }
 
                                Literal::Enum(lit_value) => {
 
                                    Value::Enum(lit_value.variant_idx as i64)
 
                                }
 
                                Literal::Union(lit_value) => {
 
                                    let heap_pos = transfer_expression_values_front_into_heap(
 
                                        cur_frame, &mut self.store, lit_value.values.len()
 
                                    );
 
                                    Value::Union(lit_value.variant_idx as i64, heap_pos)
 
                                }
 
                                Literal::Array(lit_value) => {
 
                                    let heap_pos = transfer_expression_values_front_into_heap(
 
                                        cur_frame, &mut self.store, lit_value.len()
 
                                    );
 
                                    Value::Array(heap_pos)
 
                                }
 
                            };
 

	
 
                            cur_frame.expr_values.push_back(value);
 
                        },
 
                        Expression::Cast(expr) => {
 
                            let mono_data = types.get_procedure_expression_data(&cur_frame.definition, cur_frame.monomorph_idx);
 
                            let output_type = &mono_data.expr_data[expr.unique_id_in_definition as usize].expr_type;
 

	
 
                            // Typechecking reduced this to two cases: either we
 
                            // have casting noop (same types), or we're casting
 
                            // between integer/bool/char types.
 
                            let subject = cur_frame.expr_values.pop_back().unwrap();
 
                            match apply_casting(&mut self.store, output_type, &subject) {
 
                                Ok(value) => cur_frame.expr_values.push_back(value),
 
                                Err(msg) => {
 
                                    return Err(EvalError::new_error_at_expr(self, modules, heap, expr.this.upcast(), msg));
 
                                }
 
                            }
 

	
 
                            self.store.drop_value(subject.get_heap_pos());
 
                        }
 
                        Expression::Call(expr) => {
 
                            // If we're dealing with a builtin we don't do any
 
                            // fancy shenanigans at all, just push the result.
 
                            match expr.method {
 
                                Method::Get => {
 
                                    let value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let value = self.store.maybe_read_ref(&value).clone();
 

	
 
                                    match ctx.get(value.clone(), &mut self.store) {
 
                                        Some(result) => {
 
                                            cur_frame.expr_values.push_back(result)
 
                                        },
 
                                        None => {
 
                                            cur_frame.expr_values.push_front(value.clone());
 
                                            cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
 
                                            return Ok(EvalContinuation::BlockGet(value));
 
                                        }
 
                                    }
 
                                },
 
                                Method::Put => {
 
                                    let port_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let deref_port_value = self.store.maybe_read_ref(&port_value).clone();
 
                                    let msg_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let deref_msg_value = self.store.maybe_read_ref(&msg_value).clone();
 

	
 
                                    if ctx.did_put(deref_port_value.clone()) {
 
                                        // We're fine, deallocate in case the expression value stack
 
                                        // held an owned value
 
                                        self.store.drop_value(msg_value.get_heap_pos());
 
                                    } else {
 
                                        cur_frame.expr_values.push_front(msg_value);
 
                                        cur_frame.expr_values.push_front(port_value);
 
                                        cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
 
                                        return Ok(EvalContinuation::Put(deref_port_value, deref_msg_value));
 
                                    }
 
                                },
 
                                Method::Fires => {
 
                                    let port_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let port_value_deref = self.store.maybe_read_ref(&port_value).clone();
 
                                    match ctx.fires(port_value_deref.clone()) {
 
                                        None => {
 
                                            cur_frame.expr_values.push_front(port_value);
 
                                            cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
 
                                            return Ok(EvalContinuation::BlockFires(port_value_deref));
 
                                        },
 
                                        Some(value) => {
 
                                            cur_frame.expr_values.push_back(value);
 
                                        }
 
                                    }
 
                                },
 
                                Method::Create => {
 
                                    let length_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let length_value = self.store.maybe_read_ref(&length_value);
 
                                    let length = if length_value.is_signed_integer() {
 
                                        let length_value = length_value.as_signed_integer();
 
                                        if length_value < 0 {
 
                                            return Err(EvalError::new_error_at_expr(
 
                                                self, modules, heap, expr_id,
 
                                                format!("got length '{}', can only create a message with a non-negative length", length_value)
 
                                            ));
 
                                        }
 

	
 
                                        length_value as u64
 
                                    } else {
 
                                        debug_assert!(length_value.is_unsigned_integer());
 
                                        length_value.as_unsigned_integer()
 
                                    };
 

	
 
                                    let heap_pos = self.store.alloc_heap();
 
                                    let values = &mut self.store.heap_regions[heap_pos as usize].values;
 
                                    debug_assert!(values.is_empty());
 
                                    values.resize(length as usize, Value::UInt8(0));
 
                                    cur_frame.expr_values.push_back(Value::Message(heap_pos));
 
                                },
 
                                Method::Length => {
 
                                    let value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let value_heap_pos = value.get_heap_pos();
 
                                    let value = self.store.maybe_read_ref(&value);
 

	
 
                                    let heap_pos = match value {
 
                                        Value::Array(pos) => *pos,
 
                                        Value::String(pos) => *pos,
 
                                        _ => unreachable!("length(...) on {:?}", value),
 
                                    };
 

	
 
                                    let len = self.store.heap_regions[heap_pos as usize].values.len();
 

	
 
                                    // TODO: @PtrInt
 
                                    cur_frame.expr_values.push_back(Value::UInt32(len as u32));
 
                                    self.store.drop_value(value_heap_pos);
 
                                },
 
                                Method::Assert => {
 
                                    let value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let value = self.store.maybe_read_ref(&value).clone();
 
                                    if !value.as_bool() {
 
                                        return Ok(EvalContinuation::Inconsistent)
 
                                    }
 
                                },
 
                                Method::UserComponent => {
 
                                    // This is actually handled by the evaluation
 
                                    // of the statement.
 
                                    debug_assert_eq!(heap[expr.definition].parameters().len(), cur_frame.expr_values.len());
 
                                    debug_assert_eq!(heap[cur_frame.position].as_new().expression, expr.this)
 
                                },
 
                                Method::UserFunction => {
 
                                    // Push a new frame. Note that all expressions have
 
                                    // been pushed to the front, so they're in the order
 
                                    // of the definition.
 
                                    let num_args = expr.arguments.len();
 

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

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

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

	
 
                                    // Push the new frame and reserve its stack size
 
                                    let new_frame = Frame::new(heap, expr.definition, call_data.field_or_monomorph_idx);
 
                                    let new_stack_size = new_frame.max_stack_size;
 
                                    self.frames.push(new_frame);
 
                                    self.store.cur_stack_boundary = new_stack_boundary;
 
                                    self.store.reserve_stack(new_stack_size);
 

	
 
                                    // To simplify the logic a little bit we will now
 
                                    // return and ask our caller to call us again
 
                                    return Ok(EvalContinuation::Stepping);
 
                                },
 
                            }
 
                        },
 
                        Expression::Variable(expr) => {
 
                            let variable = &heap[expr.declaration.unwrap()];
 
                            let ref_value = if expr.used_as_binding_target {
 
                                Value::Binding(variable.unique_id_in_scope as StackPos)
 
                            } else {
 
                                Value::Ref(ValueId::Stack(variable.unique_id_in_scope as StackPos))
 
                            };
 
                            cur_frame.expr_values.push_back(ref_value);
 
                        }
 
                    }
 
                }
 
            }
 
        }
 

	
 
        debug_log!("Frame [{:?}] at {:?}", cur_frame.definition, cur_frame.position);
 
        if debug_enabled!() {
 
            debug_log!("Expression value stack (size = {}):", cur_frame.expr_values.len());
 
            for (stack_idx, stack_val) in cur_frame.expr_values.iter().enumerate() {
 
                debug_log!("  [{:03}] {:?}", stack_idx, stack_val);
 
            for (_stack_idx, _stack_val) in cur_frame.expr_values.iter().enumerate() {
 
                debug_log!("  [{:03}] {:?}", _stack_idx, _stack_val);
 
            }
 

	
 
            debug_log!("Stack (size = {}):", self.store.stack.len());
 
            for (stack_idx, stack_val) in self.store.stack.iter().enumerate() {
 
                debug_log!("  [{:03}] {:?}", stack_idx, stack_val);
 
            for (_stack_idx, _stack_val) in self.store.stack.iter().enumerate() {
 
                debug_log!("  [{:03}] {:?}", _stack_idx, _stack_val);
 
            }
 

	
 
            debug_log!("Heap:");
 
            for (heap_idx, heap_region) in self.store.heap_regions.iter().enumerate() {
 
                let is_free = self.store.free_regions.iter().any(|idx| *idx as usize == heap_idx);
 
                debug_log!("  [{:03}] in_use: {}, len: {}, vals: {:?}", heap_idx, !is_free, heap_region.values.len(), &heap_region.values);
 
            for (_heap_idx, _heap_region) in self.store.heap_regions.iter().enumerate() {
 
                let _is_free = self.store.free_regions.iter().any(|idx| *idx as usize == _heap_idx);
 
                debug_log!("  [{:03}] in_use: {}, len: {}, vals: {:?}", _heap_idx, !_is_free, heap_region.values.len(), &_heap_region.values);
 
            }
 
        }
 
        // No (more) expressions to evaluate. So evaluate statement (that may
 
        // depend on the result on the last evaluated expression(s))
 
        let stmt = &heap[cur_frame.position];
 
        let return_value = match stmt {
 
            Statement::Block(stmt) => {
 
                cur_frame.position = stmt.statements[0];
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndBlock(stmt) => {
 
                let block = &heap[stmt.start_block];
 
                self.store.clear_stack(block.first_unique_id_in_scope as usize);
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Local(stmt) => {
 
                match stmt {
 
                    LocalStatement::Memory(stmt) => {
 
                        let variable = &heap[stmt.variable];
 
                        self.store.write(ValueId::Stack(variable.unique_id_in_scope as u32), Value::Unassigned);
 

	
 
                        cur_frame.position = stmt.next;
 
                    },
 
                    LocalStatement::Channel(stmt) => {
 
                        let [from_value, to_value] = ctx.new_channel();
 
                        self.store.write(ValueId::Stack(heap[stmt.from].unique_id_in_scope as u32), from_value);
 
                        self.store.write(ValueId::Stack(heap[stmt.to].unique_id_in_scope as u32), to_value);
 

	
 
                        cur_frame.position = stmt.next;
 
                    }
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Labeled(stmt) => {
 
                cur_frame.position = stmt.body;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::If(stmt) => {
 
                debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for if statement");
 
                let test_value = cur_frame.expr_values.pop_back().unwrap();
 
                let test_value = self.store.maybe_read_ref(&test_value).as_bool();
 
                if test_value {
 
                    cur_frame.position = stmt.true_body.upcast();
 
                } else if let Some(false_body) = stmt.false_body {
 
                    cur_frame.position = false_body.upcast();
 
                } else {
 
                    // Not true, and no false body
 
                    cur_frame.position = stmt.end_if.upcast();
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndIf(stmt) => {
 
                cur_frame.position = stmt.next;
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::While(stmt) => {
 
                debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for while statement");
 
                let test_value = cur_frame.expr_values.pop_back().unwrap();
 
                let test_value = self.store.maybe_read_ref(&test_value).as_bool();
 
                if test_value {
 
                    cur_frame.position = stmt.body.upcast();
 
                } else {
 
                    cur_frame.position = stmt.end_while.upcast();
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndWhile(stmt) => {
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Break(stmt) => {
 
                cur_frame.position = stmt.target.unwrap().upcast();
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Continue(stmt) => {
 
                cur_frame.position = stmt.target.unwrap().upcast();
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Synchronous(stmt) => {
 
                cur_frame.position = stmt.body.upcast();
 

	
 
                Ok(EvalContinuation::SyncBlockStart)
 
            },
 
            Statement::EndSynchronous(stmt) => {
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::SyncBlockEnd)
 
            },
 
            Statement::Return(stmt) => {
 
            Statement::Return(_stmt) => {
 
                debug_assert!(heap[cur_frame.definition].is_function());
 
                debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for return statement");
 

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

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

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

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

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

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

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

	
 
                let mono_data = types.get_procedure_expression_data(&cur_frame.definition, cur_frame.monomorph_idx);
 
                let expr_data = &mono_data.expr_data[call_expr.unique_id_in_definition as usize];
 

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

	
 
                // Construct argument group, thereby copying heap regions
 
                let argument_group = ValueGroup::from_store(&self.store, &args);
 

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

	
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::NewComponent(call_expr.definition, expr_data.field_or_monomorph_idx, argument_group))
 
            },
 
            Statement::Expression(stmt) => {
 
                // The expression has just been completely evaluated. Some
 
                // values might have remained on the expression value stack.
 
                // cur_frame.expr_values.clear(); PROPER CLEARING
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
        };
 

	
 
        assert!(
 
            cur_frame.expr_values.is_empty(),
 
            "This is a debugging assertion that will fail if you perform expressions without \
 
            assigning to anything. This should be completely valid, and this assertion should be \
 
            replaced by something that clears the expression values if needed, but I'll keep this \
 
            in for now for debugging purposes."
 
        );
 

	
 
        // If the next statement requires evaluating expressions then we push
 
        // these onto the expression stack. This way we will evaluate this
 
        // stack in the next loop, then evaluate the statement using the result
 
        // from the expression evaluation.
 
        if !cur_frame.position.is_invalid() {
 
            let stmt = &heap[cur_frame.position];
 

	
 
            match stmt {
 
                Statement::If(stmt) => cur_frame.prepare_single_expression(heap, stmt.test),
 
                Statement::While(stmt) => cur_frame.prepare_single_expression(heap, stmt.test),
 
                Statement::Return(stmt) => {
 
                    debug_assert_eq!(stmt.expressions.len(), 1); // TODO: @ReturnValues
 
                    cur_frame.prepare_single_expression(heap, stmt.expressions[0]);
 
                },
 
                Statement::New(stmt) => {
 
                    // Note that we will end up not evaluating the call itself.
 
                    // Rather we will evaluate its expressions and then
 
                    // instantiate the component upon reaching the "new" stmt.
 
                    let call_expr = &heap[stmt.expression];
 
                    cur_frame.prepare_multiple_expressions(heap, &call_expr.arguments);
 
                },
 
                Statement::Expression(stmt) => {
 
                    cur_frame.prepare_single_expression(heap, stmt.expression);
 
                }
 
                _ => {},
 
            }
 
        }
 

	
 
        return_value
 
    }
 
}
 
\ No newline at end of file
src/protocol/eval/value.rs
Show inline comments
 
@@ -33,845 +33,846 @@ pub enum Value {
 
    // Builtin types
 
    Input(PortId),
 
    Output(PortId),
 
    Message(HeapPos),
 
    Null,
 
    Bool(bool),
 
    Char(char),
 
    String(HeapPos),
 
    UInt8(u8),
 
    UInt16(u16),
 
    UInt32(u32),
 
    UInt64(u64),
 
    SInt8(i8),
 
    SInt16(i16),
 
    SInt32(i32),
 
    SInt64(i64),
 
    Array(HeapPos),
 
    // Instances of user-defined types
 
    Enum(i64),
 
    Union(i64, HeapPos),
 
    Struct(HeapPos),
 
}
 

	
 
macro_rules! impl_union_unpack_as_value {
 
    ($func_name:ident, $variant_name:path, $return_type:ty) => {
 
        impl Value {
 
            pub(crate) fn $func_name(&self) -> $return_type {
 
                match self {
 
                    $variant_name(v) => *v,
 
                    _ => panic!(concat!("called ", stringify!($func_name()), " on {:?}"), self),
 
                }
 
            }
 
        }
 
    }
 
}
 

	
 
impl_union_unpack_as_value!(as_stack_boundary, Value::PrevStackBoundary, isize);
 
impl_union_unpack_as_value!(as_ref,     Value::Ref,     ValueId);
 
impl_union_unpack_as_value!(as_input,   Value::Input,   PortId);
 
impl_union_unpack_as_value!(as_output,  Value::Output,  PortId);
 
impl_union_unpack_as_value!(as_message, Value::Message, HeapPos);
 
impl_union_unpack_as_value!(as_bool,    Value::Bool,    bool);
 
impl_union_unpack_as_value!(as_char,    Value::Char,    char);
 
impl_union_unpack_as_value!(as_string,  Value::String,  HeapPos);
 
impl_union_unpack_as_value!(as_uint8,   Value::UInt8,   u8);
 
impl_union_unpack_as_value!(as_uint16,  Value::UInt16,  u16);
 
impl_union_unpack_as_value!(as_uint32,  Value::UInt32,  u32);
 
impl_union_unpack_as_value!(as_uint64,  Value::UInt64,  u64);
 
impl_union_unpack_as_value!(as_sint8,   Value::SInt8,   i8);
 
impl_union_unpack_as_value!(as_sint16,  Value::SInt16,  i16);
 
impl_union_unpack_as_value!(as_sint32,  Value::SInt32,  i32);
 
impl_union_unpack_as_value!(as_sint64,  Value::SInt64,  i64);
 
impl_union_unpack_as_value!(as_array,   Value::Array,   HeapPos);
 
impl_union_unpack_as_value!(as_enum,    Value::Enum,    i64);
 
impl_union_unpack_as_value!(as_struct,  Value::Struct,  HeapPos);
 

	
 
impl Value {
 
    pub(crate) fn as_union(&self) -> (i64, HeapPos) {
 
        match self {
 
            Value::Union(tag, v) => (*tag, *v),
 
            _ => panic!("called as_union on {:?}", self),
 
        }
 
    }
 

	
 
    pub(crate) fn is_integer(&self) -> bool {
 
        match self {
 
            Value::UInt8(_) | Value::UInt16(_) | Value::UInt32(_) | Value::UInt64(_) |
 
            Value::SInt8(_) | Value::SInt16(_) | Value::SInt32(_) | Value::SInt64(_) => true,
 
            _ => false
 
        }
 
    }
 

	
 
    pub(crate) fn is_unsigned_integer(&self) -> bool {
 
        match self {
 
            Value::UInt8(_) | Value::UInt16(_) | Value::UInt32(_) | Value::UInt64(_) => true,
 
            _ => false
 
        }
 
    }
 

	
 
    pub(crate) fn is_signed_integer(&self) -> bool {
 
        match self {
 
            Value::SInt8(_) | Value::SInt16(_) | Value::SInt32(_) | Value::SInt64(_) => true,
 
            _ => false
 
        }
 
    }
 

	
 
    pub(crate) fn as_unsigned_integer(&self) -> u64 {
 
        match self {
 
            Value::UInt8(v)  => *v as u64,
 
            Value::UInt16(v) => *v as u64,
 
            Value::UInt32(v) => *v as u64,
 
            Value::UInt64(v) => *v as u64,
 
            _ => unreachable!("called as_unsigned_integer on {:?}", self),
 
        }
 
    }
 

	
 
    pub(crate) fn as_signed_integer(&self) -> i64 {
 
        match self {
 
            Value::SInt8(v)  => *v as i64,
 
            Value::SInt16(v) => *v as i64,
 
            Value::SInt32(v) => *v as i64,
 
            Value::SInt64(v) => *v as i64,
 
            _ => unreachable!("called as_signed_integer on {:?}", self)
 
        }
 
    }
 

	
 
    /// Returns the heap position associated with the value. If the value
 
    /// doesn't store anything in the heap then we return `None`.
 
    pub(crate) fn get_heap_pos(&self) -> Option<HeapPos> {
 
        match self {
 
            Value::Message(v) => Some(*v),
 
            Value::Array(v) => Some(*v),
 
            Value::Union(_, v) => Some(*v),
 
            Value::Struct(v) => Some(*v),
 
            _ => None
 
        }
 
    }
 
}
 

	
 
/// When providing arguments to a new component, or when transferring values
 
/// from one component's store to a newly instantiated component, one has to
 
/// transfer stack and heap values. This `ValueGroup` represents such a
 
/// temporary group of values with potential heap allocations.
 
///
 
/// Constructing such a ValueGroup manually requires some extra care to make
 
/// sure all elements of `values` point to valid elements of `regions`.
 
///
 
/// Again: this is a temporary thing, hopefully removed once we move to a
 
/// bytecode interpreter.
 
pub struct ValueGroup {
 
    pub(crate) values: Vec<Value>,
 
    pub(crate) regions: Vec<Vec<Value>>
 
}
 

	
 
impl ValueGroup {
 
    pub(crate) fn new_stack(values: Vec<Value>) -> Self {
 
        debug_assert!(values.iter().all(|v| v.get_heap_pos().is_none()));
 
        Self{
 
            values,
 
            regions: Vec::new(),
 
        }
 
    }
 
    pub(crate) fn from_store(store: &Store, values: &[Value]) -> Self {
 
        let mut group = ValueGroup{
 
            values: Vec::with_capacity(values.len()),
 
            regions: Vec::with_capacity(values.len()), // estimation
 
        };
 

	
 
        for value in values {
 
            let transferred = group.retrieve_value(value, store);
 
            group.values.push(transferred);
 
        }
 

	
 
        group
 
    }
 

	
 
    /// Transfers a provided value from a store into a local value with its
 
    /// heap allocations (if any) stored in the ValueGroup. Calling this
 
    /// function will not store the returned value in the `values` member.
 
    fn retrieve_value(&mut self, value: &Value, from_store: &Store) -> Value {
 
        let value = from_store.maybe_read_ref(value);
 
        if let Some(heap_pos) = value.get_heap_pos() {
 
            // Value points to a heap allocation, so transfer the heap values
 
            // internally.
 
            let from_region = &from_store.heap_regions[heap_pos as usize].values;
 
            let mut new_region = Vec::with_capacity(from_region.len());
 
            for value in from_region {
 
                let transferred = self.retrieve_value(value, from_store);
 
                new_region.push(transferred);
 
            }
 

	
 
            // Region is constructed, store internally and return the new value.
 
            let new_region_idx = self.regions.len() as HeapPos;
 
            self.regions.push(new_region);
 

	
 
            return match value {
 
                Value::Message(_)    => Value::Message(new_region_idx),
 
                Value::String(_)     => Value::String(new_region_idx),
 
                Value::Array(_)      => Value::Array(new_region_idx),
 
                Value::Union(tag, _) => Value::Union(*tag, new_region_idx),
 
                Value::Struct(_)     => Value::Struct(new_region_idx),
 
                _ => unreachable!(),
 
            };
 
        } else {
 
            return value.clone();
 
        }
 
    }
 

	
 
    /// Transfers the heap values and the stack values into the store. Stack
 
    /// values are pushed onto the Store's stack in the order in which they
 
    /// appear in the value group.
 
    pub(crate) fn into_store(self, store: &mut Store) {
 
        for value in &self.values {
 
            let transferred = self.provide_value(value, store);
 
            store.stack.push(transferred);
 
        }
 
    }
 

	
 
    fn provide_value(&self, value: &Value, to_store: &mut Store) -> Value {
 
        if let Some(from_heap_pos) = value.get_heap_pos() {
 
            let from_heap_pos = from_heap_pos as usize;
 
            let to_heap_pos = to_store.alloc_heap();
 
            let to_heap_pos_usize = to_heap_pos as usize;
 
            to_store.heap_regions[to_heap_pos_usize].values.reserve(self.regions[from_heap_pos].len());
 

	
 
            for value in &self.regions[from_heap_pos as usize] {
 
                let transferred = self.provide_value(value, to_store);
 
                to_store.heap_regions[to_heap_pos_usize].values.push(transferred);
 
            }
 

	
 
            return match value {
 
                Value::Message(_)    => Value::Message(to_heap_pos),
 
                Value::String(_)     => Value::String(to_heap_pos),
 
                Value::Array(_)      => Value::Array(to_heap_pos),
 
                Value::Union(tag, _) => Value::Union(*tag, to_heap_pos),
 
                Value::Struct(_)     => Value::Struct(to_heap_pos),
 
                _ => unreachable!(),
 
            };
 
        } else {
 
            return value.clone();
 
        }
 
    }
 
}
 

	
 
impl Default for ValueGroup {
 
    /// Returns an empty ValueGroup
 
    fn default() -> Self {
 
        Self { values: Vec::new(), regions: Vec::new() }
 
    }
 
}
 

	
 
pub(crate) fn apply_assignment_operator(store: &mut Store, lhs: ValueId, op: AssignmentOperator, rhs: Value) {
 
    use AssignmentOperator as AO;
 

	
 
    macro_rules! apply_int_op {
 
        ($lhs:ident, $assignment_tokens:tt, $operator:ident, $rhs:ident) => {
 
            match $lhs {
 
                Value::UInt8(v)  => { *v $assignment_tokens $rhs.as_uint8();  },
 
                Value::UInt16(v) => { *v $assignment_tokens $rhs.as_uint16(); },
 
                Value::UInt32(v) => { *v $assignment_tokens $rhs.as_uint32(); },
 
                Value::UInt64(v) => { *v $assignment_tokens $rhs.as_uint64(); },
 
                Value::SInt8(v)  => { *v $assignment_tokens $rhs.as_sint8();  },
 
                Value::SInt16(v) => { *v $assignment_tokens $rhs.as_sint16(); },
 
                Value::SInt32(v) => { *v $assignment_tokens $rhs.as_sint32(); },
 
                Value::SInt64(v) => { *v $assignment_tokens $rhs.as_sint64(); },
 
                _ => unreachable!("apply_assignment_operator {:?} on lhs {:?} and rhs {:?}", $operator, $lhs, $rhs),
 
            }
 
        }
 
    }
 

	
 
    // let rhs = store.maybe_read_ref(&rhs).clone(); // we don't own this thing, so don't drop it
 
    let lhs = store.read_mut_ref(lhs);
 

	
 
    let mut to_dealloc = None;
 
    match op {
 
        AO::Set => {
 
            match lhs {
 
                Value::Unassigned => { *lhs = rhs; },
 
                Value::Input(v)  => { *v = rhs.as_input(); },
 
                Value::Output(v) => { *v = rhs.as_output(); },
 
                Value::Message(v)  => { to_dealloc = Some(*v); *v = rhs.as_message(); },
 
                Value::Bool(v)    => { *v = rhs.as_bool(); },
 
                Value::Char(v) => { *v = rhs.as_char(); },
 
                Value::String(v) => { *v = rhs.as_string().clone(); },
 
                Value::UInt8(v) => { *v = rhs.as_uint8(); },
 
                Value::UInt16(v) => { *v = rhs.as_uint16(); },
 
                Value::UInt32(v) => { *v = rhs.as_uint32(); },
 
                Value::UInt64(v) => { *v = rhs.as_uint64(); },
 
                Value::SInt8(v) => { *v = rhs.as_sint8(); },
 
                Value::SInt16(v) => { *v = rhs.as_sint16(); },
 
                Value::SInt32(v) => { *v = rhs.as_sint32(); },
 
                Value::SInt64(v) => { *v = rhs.as_sint64(); },
 
                Value::Array(v) => { to_dealloc = Some(*v); *v = rhs.as_array(); },
 
                Value::Enum(v) => { *v = rhs.as_enum(); },
 
                Value::Union(lhs_tag, lhs_heap_pos) => {
 
                    to_dealloc = Some(*lhs_heap_pos);
 
                    let (rhs_tag, rhs_heap_pos) = rhs.as_union();
 
                    *lhs_tag = rhs_tag;
 
                    *lhs_heap_pos = rhs_heap_pos;
 
                }
 
                Value::Struct(v) => { to_dealloc = Some(*v); *v = rhs.as_struct(); },
 
                _ => unreachable!("apply_assignment_operator {:?} on lhs {:?} and rhs {:?}", op, lhs, rhs),
 
            }
 
        },
 
        AO::Multiplied =>   { apply_int_op!(lhs, *=,  op, rhs) },
 
        AO::Divided =>      { apply_int_op!(lhs, /=,  op, rhs) },
 
        AO::Remained =>     { apply_int_op!(lhs, %=,  op, rhs) },
 
        AO::Added =>        { apply_int_op!(lhs, +=,  op, rhs) },
 
        AO::Subtracted =>   { apply_int_op!(lhs, -=,  op, rhs) },
 
        AO::ShiftedLeft =>  { apply_int_op!(lhs, <<=, op, rhs) },
 
        AO::ShiftedRight => { apply_int_op!(lhs, >>=, op, rhs) },
 
        AO::BitwiseAnded => { apply_int_op!(lhs, &=,  op, rhs) },
 
        AO::BitwiseXored => { apply_int_op!(lhs, ^=,  op, rhs) },
 
        AO::BitwiseOred =>  { apply_int_op!(lhs, |=,  op, rhs) },
 
    }
 

	
 
    if let Some(heap_pos) = to_dealloc {
 
        store.drop_heap_pos(heap_pos);
 
    }
 
}
 

	
 
pub(crate) fn apply_binary_operator(store: &mut Store, lhs: &Value, op: BinaryOperator, rhs: &Value) -> Value {
 
    use BinaryOperator as BO;
 

	
 
    macro_rules! apply_int_op_and_return_self {
 
        ($lhs:ident, $operator_tokens:tt, $operator:ident, $rhs:ident) => {
 
            return match $lhs {
 
                Value::UInt8(v)  => { Value::UInt8( *v $operator_tokens $rhs.as_uint8() ) },
 
                Value::UInt16(v) => { Value::UInt16(*v $operator_tokens $rhs.as_uint16()) },
 
                Value::UInt32(v) => { Value::UInt32(*v $operator_tokens $rhs.as_uint32()) },
 
                Value::UInt64(v) => { Value::UInt64(*v $operator_tokens $rhs.as_uint64()) },
 
                Value::SInt8(v)  => { Value::SInt8( *v $operator_tokens $rhs.as_sint8() ) },
 
                Value::SInt16(v) => { Value::SInt16(*v $operator_tokens $rhs.as_sint16()) },
 
                Value::SInt32(v) => { Value::SInt32(*v $operator_tokens $rhs.as_sint32()) },
 
                Value::SInt64(v) => { Value::SInt64(*v $operator_tokens $rhs.as_sint64()) },
 
                _ => unreachable!("apply_binary_operator {:?} on lhs {:?} and rhs {:?}", $operator, $lhs, $rhs)
 
            };
 
        }
 
    }
 

	
 
    macro_rules! apply_int_op_and_return_bool {
 
        ($lhs:ident, $operator_tokens:tt, $operator:ident, $rhs:ident) => {
 
            return match $lhs {
 
                Value::UInt8(v)  => { Value::Bool(*v $operator_tokens $rhs.as_uint8() ) },
 
                Value::UInt16(v) => { Value::Bool(*v $operator_tokens $rhs.as_uint16()) },
 
                Value::UInt32(v) => { Value::Bool(*v $operator_tokens $rhs.as_uint32()) },
 
                Value::UInt64(v) => { Value::Bool(*v $operator_tokens $rhs.as_uint64()) },
 
                Value::SInt8(v)  => { Value::Bool(*v $operator_tokens $rhs.as_sint8() ) },
 
                Value::SInt16(v) => { Value::Bool(*v $operator_tokens $rhs.as_sint16()) },
 
                Value::SInt32(v) => { Value::Bool(*v $operator_tokens $rhs.as_sint32()) },
 
                Value::SInt64(v) => { Value::Bool(*v $operator_tokens $rhs.as_sint64()) },
 
                _ => unreachable!("apply_binary_operator {:?} on lhs {:?} and rhs {:?}", $operator, $lhs, $rhs)
 
            };
 
        }
 
    }
 

	
 
    // We need to handle concatenate in a special way because it needs the store
 
    // mutably.
 
    if op == BO::Concatenate {
 
        let target_heap_pos = store.alloc_heap();
 
        let lhs_heap_pos;
 
        let rhs_heap_pos;
 

	
 
        let lhs = store.maybe_read_ref(lhs);
 
        let rhs = store.maybe_read_ref(rhs);
 

	
 
        enum ValueKind { Message, String, Array }
 
        let value_kind;
 

	
 
        match lhs {
 
            Value::Message(lhs_pos) => {
 
                lhs_heap_pos = *lhs_pos;
 
                rhs_heap_pos = rhs.as_message();
 
                value_kind = ValueKind::Message;
 
            },
 
            Value::String(lhs_pos) => {
 
                lhs_heap_pos = *lhs_pos;
 
                rhs_heap_pos = rhs.as_string();
 
                value_kind = ValueKind::String;
 
            },
 
            Value::Array(lhs_pos) => {
 
                lhs_heap_pos = *lhs_pos;
 
                rhs_heap_pos = rhs.as_array();
 
                value_kind = ValueKind::Array;
 
            },
 
            _ => unreachable!("apply_binary_operator {:?} on lhs {:?} and rhs {:?}", op, lhs, rhs)
 
        }
 

	
 
        let lhs_heap_pos = lhs_heap_pos as usize;
 
        let rhs_heap_pos = rhs_heap_pos as usize;
 

	
 
        // TODO: I hate this, but fine...
 
        let mut concatenated = Vec::new();
 
        let lhs_len = store.heap_regions[lhs_heap_pos].values.len();
 
        let rhs_len = store.heap_regions[rhs_heap_pos].values.len();
 
        concatenated.reserve(lhs_len + rhs_len);
 
        for idx in 0..lhs_len {
 
            concatenated.push(store.clone_value(store.heap_regions[lhs_heap_pos].values[idx].clone()));
 
        }
 
        for idx in 0..rhs_len {
 
            concatenated.push(store.clone_value(store.heap_regions[rhs_heap_pos].values[idx].clone()));
 
        }
 

	
 
        store.heap_regions[target_heap_pos as usize].values = concatenated;
 

	
 
        return match value_kind{
 
            ValueKind::Message => Value::Message(target_heap_pos),
 
            ValueKind::String => Value::String(target_heap_pos),
 
            ValueKind::Array => Value::Array(target_heap_pos),
 
        };
 
    }
 

	
 
    // If any of the values are references, retrieve the thing they're referring
 
    // to.
 
    let lhs = store.maybe_read_ref(lhs);
 
    let rhs = store.maybe_read_ref(rhs);
 

	
 
    match op {
 
        BO::Concatenate => unreachable!(),
 
        BO::LogicalOr => {
 
            return Value::Bool(lhs.as_bool() || rhs.as_bool());
 
        },
 
        BO::LogicalAnd => {
 
            return Value::Bool(lhs.as_bool() && rhs.as_bool());
 
        },
 
        BO::BitwiseOr        => { apply_int_op_and_return_self!(lhs, |,  op, rhs); },
 
        BO::BitwiseXor       => { apply_int_op_and_return_self!(lhs, ^,  op, rhs); },
 
        BO::BitwiseAnd       => { apply_int_op_and_return_self!(lhs, &,  op, rhs); },
 
        BO::Equality         => { Value::Bool(apply_equality_operator(store, lhs, rhs)) },
 
        BO::Inequality       => { Value::Bool(apply_inequality_operator(store, lhs, rhs)) },
 
        BO::LessThan         => { apply_int_op_and_return_bool!(lhs, <,  op, rhs); },
 
        BO::GreaterThan      => { apply_int_op_and_return_bool!(lhs, >,  op, rhs); },
 
        BO::LessThanEqual    => { apply_int_op_and_return_bool!(lhs, <=, op, rhs); },
 
        BO::GreaterThanEqual => { apply_int_op_and_return_bool!(lhs, >=, op, rhs); },
 
        BO::ShiftLeft        => { apply_int_op_and_return_self!(lhs, <<, op, rhs); },
 
        BO::ShiftRight       => { apply_int_op_and_return_self!(lhs, >>, op, rhs); },
 
        BO::Add              => { apply_int_op_and_return_self!(lhs, +,  op, rhs); },
 
        BO::Subtract         => { apply_int_op_and_return_self!(lhs, -,  op, rhs); },
 
        BO::Multiply         => { apply_int_op_and_return_self!(lhs, *,  op, rhs); },
 
        BO::Divide           => { apply_int_op_and_return_self!(lhs, /,  op, rhs); },
 
        BO::Remainder        => { apply_int_op_and_return_self!(lhs, %,  op, rhs); }
 
    }
 
}
 

	
 
pub(crate) fn apply_unary_operator(store: &mut Store, op: UnaryOperator, value: &Value) -> Value {
 
    use UnaryOperator as UO;
 

	
 
    macro_rules! apply_int_expr_and_return {
 
        ($value:ident, $apply:tt, $op:ident) => {
 
            return match $value {
 
                Value::UInt8(v)  => Value::UInt8($apply *v),
 
                Value::UInt16(v) => Value::UInt16($apply *v),
 
                Value::UInt32(v) => Value::UInt32($apply *v),
 
                Value::UInt64(v) => Value::UInt64($apply *v),
 
                Value::SInt8(v)  => Value::SInt8($apply *v),
 
                Value::SInt16(v) => Value::SInt16($apply *v),
 
                Value::SInt32(v) => Value::SInt32($apply *v),
 
                Value::SInt64(v) => Value::SInt64($apply *v),
 
                _ => unreachable!("apply_unary_operator {:?} on value {:?}", $op, $value),
 
            };
 
        }
 
    }
 

	
 
    // If the value is a reference, retrieve the thing it is referring to
 
    let value = store.maybe_read_ref(value);
 

	
 
    match op {
 
        UO::Positive => {
 
            debug_assert!(value.is_integer());
 
            return value.clone();
 
        },
 
        UO::Negative => {
 
            // TODO: Error on negating unsigned integers
 
            return match value {
 
                Value::SInt8(v) => Value::SInt8(-*v),
 
                Value::SInt16(v) => Value::SInt16(-*v),
 
                Value::SInt32(v) => Value::SInt32(-*v),
 
                Value::SInt64(v) => Value::SInt64(-*v),
 
                _ => unreachable!("apply_unary_operator {:?} on value {:?}", op, value),
 
            }
 
        },
 
        UO::BitwiseNot => { apply_int_expr_and_return!(value, !, op)},
 
        UO::LogicalNot => { return Value::Bool(!value.as_bool()); },
 
    }
 
}
 

	
 
pub(crate) fn apply_casting(store: &mut Store, output_type: &ConcreteType, subject: &Value) -> Result<Value, String> {
 
    // To simplify the casting logic: if the output type is not a simple
 
    // integer/boolean/character, then the type checker made sure that the two
 
    // types must be equal, hence we can do a simple clone.
 
    use ConcreteTypePart as CTP;
 
    let part = &output_type.parts[0];
 
    match part {
 
        CTP::Bool | CTP::Character |
 
        CTP::UInt8 | CTP::UInt16 | CTP::UInt32 | CTP::UInt64 |
 
        CTP::SInt8 | CTP::SInt16 | CTP::SInt32 | CTP::SInt64 => {
 
            // Do the checking of these below
 
            debug_assert_eq!(output_type.parts.len(), 1);
 
        },
 
        _ => {
 
            return Ok(store.clone_value(subject.clone()));
 
        },
 
    }
 

	
 
    // Note: character is not included, needs per-type checking
 
    macro_rules! unchecked_cast {
 
        ($input: expr, $output_part: expr) => {
 
            return Ok(match $output_part {
 
                CTP::UInt8 => Value::UInt8($input as u8),
 
                CTP::UInt16 => Value::UInt16($input as u16),
 
                CTP::UInt32 => Value::UInt32($input as u32),
 
                CTP::UInt64 => Value::UInt64($input as u64),
 
                CTP::SInt8 => Value::SInt8($input as i8),
 
                CTP::SInt16 => Value::SInt16($input as i16),
 
                CTP::SInt32 => Value::SInt32($input as i32),
 
                CTP::SInt64 => Value::SInt64($input as i64),
 
                _ => unreachable!()
 
            })
 
        }
 
    }
 

	
 
    macro_rules! from_unsigned_cast {
 
        ($input:expr, $input_type:ty, $output_part:expr) => {
 
            {
 
                let target_type_name = match $output_part {
 
                    CTP::Bool => return Ok(Value::Bool($input != 0)),
 
                    CTP::Character => if $input <= u8::MAX as $input_type {
 
                        return Ok(Value::Char(($input as u8) as char))
 
                    } else {
 
                        KW_TYPE_CHAR_STR
 
                    },
 
                    CTP::UInt8 => if $input <= u8::MAX as $input_type {
 
                        return Ok(Value::UInt8($input as u8))
 
                    } else {
 
                        KW_TYPE_UINT8_STR
 
                    },
 
                    CTP::UInt16 => if $input <= u16::MAX as $input_type {
 
                        return Ok(Value::UInt16($input as u16))
 
                    } else {
 
                        KW_TYPE_UINT16_STR
 
                    },
 
                    CTP::UInt32 => if $input <= u32::MAX as $input_type {
 
                        return Ok(Value::UInt32($input as u32))
 
                    } else {
 
                        KW_TYPE_UINT32_STR
 
                    },
 
                    CTP::UInt64 => return Ok(Value::UInt64($input as u64)), // any unsigned int to u64 is fine
 
                    CTP::SInt8 => if $input <= i8::MAX as $input_type {
 
                        return Ok(Value::SInt8($input as i8))
 
                    } else {
 
                        KW_TYPE_SINT8_STR
 
                    },
 
                    CTP::SInt16 => if $input <= i16::MAX as $input_type {
 
                        return Ok(Value::SInt16($input as i16))
 
                    } else {
 
                        KW_TYPE_SINT16_STR
 
                    },
 
                    CTP::SInt32 => if $input <= i32::MAX as $input_type {
 
                        return Ok(Value::SInt32($input as i32))
 
                    } else {
 
                        KW_TYPE_SINT32_STR
 
                    },
 
                    CTP::SInt64 => if $input <= i64::MAX as $input_type {
 
                        return Ok(Value::SInt64($input as i64))
 
                    } else {
 
                        KW_TYPE_SINT64_STR
 
                    },
 
                    _ => unreachable!(),
 
                };
 

	
 
                return Err(format!("value is '{}' which doesn't fit in a type '{}'", $input, target_type_name));
 
            }
 
        }
 
    }
 

	
 
    macro_rules! from_signed_cast {
 
        // Programmer note: for signed checking we cannot do
 
        //  output_type::MAX as input_type,
 
        //
 
        // because if the output type's width is larger than the input type,
 
        // then the cast results in a negative number. So we mask with the
 
        // maximum possible value the input type can become. As in:
 
        //  (output_type::MAX as input_type) & input_type::MAX
 
        //
 
        // This way:
 
        // 1. output width is larger than input width: fine in all cases, we
 
        //  simply compare against the max input value, which is always true.
 
        // 2. output width is equal to input width: by masking we "remove the
 
        //  signed bit from the unsigned number" and again compare against the
 
        //  maximum input value.
 
        // 3. output width is smaller than the input width: masking does nothing
 
        //  because the signed bit is never set, and we simply compare against
 
        //  the maximum possible output value.
 
        //
 
        // A similar kind of mechanism for the minimum value, but here we do
 
        // a binary OR. We do a:
 
        //  (output_type::MIN as input_type) & input_type::MIN
 
        //
 
        // This way:
 
        // 1. output width is larger than input width: initial cast truncates to
 
        //  0, then we OR with the actual minimum value, so we attain the
 
        //  minimum value of the input type.
 
        // 2. output width is equal to input width: we OR the minimum value with
 
        //  itself.
 
        // 3. output width is smaller than input width: the cast produces the
 
        //  min value of the output type, the subsequent OR does nothing, as it
 
        //  essentially just sets the signed bit (which must already be set,
 
        //  since we're dealing with a signed minimum value)
 
        //
 
        // After all of this expanding, we simply hope the compiler does a best
 
        // effort constant expression evaluation, and presto!
 
        ($input:expr, $input_type:ty, $output_type:expr) => {
 
            {
 
                let target_type_name = match $output_type {
 
                    CTP::Bool => return Ok(Value::Bool($input != 0)),
 
                    CTP::Character => if $input >= 0 && $input <= (u8::max as $input_type & <$input_type>::MAX) {
 
                        return Ok(Value::Char(($input as u8) as char))
 
                    } else {
 
                        KW_TYPE_CHAR_STR
 
                    },
 
                    CTP::UInt8 => if $input >= 0 && $input <= ((u8::MAX as $input_type) & <$input_type>::MAX) {
 
                        return Ok(Value::UInt8($input as u8));
 
                    } else {
 
                        KW_TYPE_UINT8_STR
 
                    },
 
                    CTP::UInt16 => if $input >= 0 && $input <= ((u16::MAX as $input_type) & <$input_type>::MAX) {
 
                        return Ok(Value::UInt16($input as u16));
 
                    } else {
 
                        KW_TYPE_UINT16_STR
 
                    },
 
                    CTP::UInt32 => if $input >= 0 && $input <= ((u32::MAX as $input_type) & <$input_type>::MAX) {
 
                        return Ok(Value::UInt32($input as u32));
 
                    } else {
 
                        KW_TYPE_UINT32_STR
 
                    },
 
                    CTP::UInt64 => if $input >= 0 && $input <= ((u64::MAX as $input_type) & <$input_type>::MAX) {
 
                        return Ok(Value::UInt64($input as u64));
 
                    } else {
 
                        KW_TYPE_UINT64_STR
 
                    },
 
                    CTP::SInt8 => if $input >= ((i8::MIN as $input_type) | <$input_type>::MIN) && $input <= ((i8::MAX as $input_type) & <$input_type>::MAX) {
 
                        return Ok(Value::SInt8($input as i8));
 
                    } else {
 
                        KW_TYPE_SINT8_STR
 
                    },
 
                    CTP::SInt16 => if $input >= ((i16::MIN as $input_type | <$input_type>::MIN)) && $input <= ((i16::MAX as $input_type) & <$input_type>::MAX) {
 
                        return Ok(Value::SInt16($input as i16));
 
                    } else {
 
                        KW_TYPE_SINT16_STR
 
                    },
 
                    CTP::SInt32 => if $input >= ((i32::MIN as $input_type | <$input_type>::MIN)) && $input <= ((i32::MAX as $input_type) & <$input_type>::MAX) {
 
                        return Ok(Value::SInt32($input as i32));
 
                    } else {
 
                        KW_TYPE_SINT32_STR
 
                    },
 
                    CTP::SInt64 => return Ok(Value::SInt64($input as i64)),
 
                    _ => unreachable!(),
 
                };
 

	
 
                return Err(format!("value is '{}' which doesn't fit in a type '{}'", $input, target_type_name));
 
            }
 
        }
 
    }
 

	
 
    // If here, then the types might still be equal, but at least we're dealing
 
    // with a simple integer/boolean/character input and output type.
 
    let subject = store.maybe_read_ref(subject);
 
    match subject {
 
        Value::Bool(val) => {
 
            match part {
 
                CTP::Bool => return Ok(Value::Bool(*val)),
 
                CTP::Character => return Ok(Value::Char(1 as char)),
 
                _ => unchecked_cast!(*val, part),
 
            }
 
        },
 
        Value::Char(val) => {
 
            match part {
 
                CTP::Bool => return Ok(Value::Bool(*val != 0 as char)),
 
                CTP::Character => return Ok(Value::Char(*val)),
 
                _ => unchecked_cast!(*val, part),
 
            }
 
        },
 
        Value::UInt8(val) => from_unsigned_cast!(*val, u8, part),
 
        Value::UInt16(val) => from_unsigned_cast!(*val, u16, part),
 
        Value::UInt32(val) => from_unsigned_cast!(*val, u32, part),
 
        Value::UInt64(val) => from_unsigned_cast!(*val, u64, part),
 
        Value::SInt8(val) => from_signed_cast!(*val, i8, part),
 
        Value::SInt16(val) => from_signed_cast!(*val, i16, part),
 
        Value::SInt32(val) => from_signed_cast!(*val, i32, part),
 
        Value::SInt64(val) => from_signed_cast!(*val, i64, part),
 
        _ => unreachable!("mismatch between 'cast' type checking and 'cast' evaluation"),
 
    }
 
}
 

	
 
/// Recursively checks for equality.
 
pub(crate) fn apply_equality_operator(store: &Store, lhs: &Value, rhs: &Value) -> bool {
 
    let lhs = store.maybe_read_ref(lhs);
 
    let rhs = store.maybe_read_ref(rhs);
 

	
 
    fn eval_equality_heap(store: &Store, lhs_pos: HeapPos, rhs_pos: HeapPos) -> bool {
 
        let lhs_vals = &store.heap_regions[lhs_pos as usize].values;
 
        let rhs_vals = &store.heap_regions[rhs_pos as usize].values;
 
        let lhs_len = lhs_vals.len();
 
        if lhs_len != rhs_vals.len() {
 
            return false;
 
        }
 

	
 
        for idx in 0..lhs_len {
 
            let lhs_val = &lhs_vals[idx];
 
            let rhs_val = &rhs_vals[idx];
 
            if !apply_equality_operator(store, lhs_val, rhs_val) {
 
                return false;
 
            }
 
        }
 

	
 
        return true;
 
    }
 

	
 
    match lhs {
 
        Value::Input(v) => *v == rhs.as_input(),
 
        Value::Output(v) => *v == rhs.as_output(),
 
        Value::Message(lhs_pos) => eval_equality_heap(store, *lhs_pos, rhs.as_message()),
 
        Value::Null => todo!("remove null"),
 
        Value::Bool(v) => *v == rhs.as_bool(),
 
        Value::Char(v) => *v == rhs.as_char(),
 
        Value::String(lhs_pos) => eval_equality_heap(store, *lhs_pos, rhs.as_string()),
 
        Value::UInt8(v) => *v == rhs.as_uint8(),
 
        Value::UInt16(v) => *v == rhs.as_uint16(),
 
        Value::UInt32(v) => *v == rhs.as_uint32(),
 
        Value::UInt64(v) => *v == rhs.as_uint64(),
 
        Value::SInt8(v) => *v == rhs.as_sint8(),
 
        Value::SInt16(v) => *v == rhs.as_sint16(),
 
        Value::SInt32(v) => *v == rhs.as_sint32(),
 
        Value::SInt64(v) => *v == rhs.as_sint64(),
 
        Value::Array(lhs_pos) => eval_equality_heap(store, *lhs_pos, rhs.as_array()),
 
        Value::Enum(v) => *v == rhs.as_enum(),
 
        Value::Union(lhs_tag, lhs_pos) => {
 
            let (rhs_tag, rhs_pos) = rhs.as_union();
 
            if *lhs_tag != rhs_tag {
 
                return false;
 
            }
 
            eval_equality_heap(store, *lhs_pos, rhs_pos)
 
        },
 
        Value::Struct(lhs_pos) => eval_equality_heap(store, *lhs_pos, rhs.as_struct()),
 
        _ => unreachable!("apply_equality_operator to lhs {:?}", lhs),
 
    }
 
}
 

	
 
/// Recursively checks for inequality
 
pub(crate) fn apply_inequality_operator(store: &Store, lhs: &Value, rhs: &Value) -> bool {
 
    let lhs = store.maybe_read_ref(lhs);
 
    let rhs = store.maybe_read_ref(rhs);
 

	
 
    fn eval_inequality_heap(store: &Store, lhs_pos: HeapPos, rhs_pos: HeapPos) -> bool {
 
        let lhs_vals = &store.heap_regions[lhs_pos as usize].values;
 
        let rhs_vals = &store.heap_regions[rhs_pos as usize].values;
 
        let lhs_len = lhs_vals.len();
 
        if lhs_len != rhs_vals.len() {
 
            return true;
 
        }
 

	
 
        for idx in 0..lhs_len {
 
            let lhs_val = &lhs_vals[idx];
 
            let rhs_val = &rhs_vals[idx];
 
            if apply_inequality_operator(store, lhs_val, rhs_val) {
 
                return true;
 
            }
 
        }
 

	
 
        return false;
 
    }
 

	
 
    match lhs {
 
        Value::Input(v) => *v != rhs.as_input(),
 
        Value::Output(v) => *v != rhs.as_output(),
 
        Value::Message(lhs_pos) => eval_inequality_heap(store, *lhs_pos, rhs.as_message()),
 
        Value::Null => todo!("remove null"),
 
        Value::Bool(v) => *v != rhs.as_bool(),
 
        Value::Char(v) => *v != rhs.as_char(),
 
        Value::String(lhs_pos) => eval_inequality_heap(store, *lhs_pos, rhs.as_string()),
 
        Value::UInt8(v) => *v != rhs.as_uint8(),
 
        Value::UInt16(v) => *v != rhs.as_uint16(),
 
        Value::UInt32(v) => *v != rhs.as_uint32(),
 
        Value::UInt64(v) => *v != rhs.as_uint64(),
 
        Value::SInt8(v) => *v != rhs.as_sint8(),
 
        Value::SInt16(v) => *v != rhs.as_sint16(),
 
        Value::SInt32(v) => *v != rhs.as_sint32(),
 
        Value::SInt64(v) => *v != rhs.as_sint64(),
 
        Value::Array(lhs_pos) => eval_inequality_heap(store, *lhs_pos, rhs.as_array()),
 
        Value::Enum(v) => *v != rhs.as_enum(),
 
        Value::Union(lhs_tag, lhs_pos) => {
 
            let (rhs_tag, rhs_pos) = rhs.as_union();
 
            if *lhs_tag != rhs_tag {
 
                return true;
 
            }
 
            eval_inequality_heap(store, *lhs_pos, rhs_pos)
 
        },
 
        Value::String(lhs_pos) => eval_inequality_heap(store, *lhs_pos, rhs.as_struct()),
 
        Value::Struct(lhs_pos) => eval_inequality_heap(store, *lhs_pos, rhs.as_struct()),
 
        _ => unreachable!("apply_inequality_operator to lhs {:?}", lhs)
 
    }
 
}
 

	
 
/// Recursively applies binding operator. Essentially an equality operator with
 
/// special handling if the LHS contains a binding reference to a stack
 
/// stack variable.
 
// Note: that there is a lot of `Value.clone()` going on here. As always: this
 
// is potentially cloning the references to heap values, not actually cloning
 
// those heap regions into a new heap region.
 
pub(crate) fn apply_binding_operator(store: &mut Store, lhs: Value, rhs: Value) -> bool {
 
    let lhs = store.maybe_read_ref(&lhs).clone();
 
    let rhs = store.maybe_read_ref(&rhs).clone();
 

	
 
    fn eval_binding_heap(store: &mut Store, lhs_pos: HeapPos, rhs_pos: HeapPos) -> bool {
 
        let lhs_len = store.heap_regions[lhs_pos as usize].values.len();
 
        let rhs_len = store.heap_regions[rhs_pos as usize].values.len();
 
        if lhs_len != rhs_len {
 
            return false;
 
        }
 

	
 
        for idx in 0..lhs_len {
 
            // More rust shenanigans... I'm going to calm myself by saying that
 
            // this is just a temporary evaluator implementation.
 
            let lhs_val = store.heap_regions[lhs_pos as usize].values[idx].clone();
 
            let rhs_val = store.heap_regions[rhs_pos as usize].values[idx].clone();
 
            if !apply_binding_operator(store, lhs_val, rhs_val) {
 
                return false;
 
            }
 
        }
 

	
 
        return true;
 
    }
 

	
 
    match lhs {
 
        Value::Binding(var_pos) => {
 
            let to_write = store.clone_value(rhs.clone());
 
            store.write(ValueId::Stack(var_pos), to_write);
 
            return true;
 
        },
 
        Value::Input(v) => v == rhs.as_input(),
 
        Value::Output(v) => v == rhs.as_output(),
 
        Value::Message(lhs_pos) => eval_binding_heap(store, lhs_pos, rhs.as_message()),
 
        Value::Null => todo!("remove null"),
 
        Value::Bool(v) => v == rhs.as_bool(),
 
        Value::Char(v) => v == rhs.as_char(),
 
        Value::String(lhs_pos) => eval_binding_heap(store, lhs_pos, rhs.as_string()),
 
        Value::UInt8(v) => v == rhs.as_uint8(),
 
        Value::UInt16(v) => v == rhs.as_uint16(),
 
        Value::UInt32(v) => v == rhs.as_uint32(),
 
        Value::UInt64(v) => v == rhs.as_uint64(),
 
        Value::SInt8(v) => v == rhs.as_sint8(),
 
        Value::SInt16(v) => v == rhs.as_sint16(),
 
        Value::SInt32(v) => v == rhs.as_sint32(),
 
        Value::SInt64(v) => v == rhs.as_sint64(),
 
        Value::Array(lhs_pos) => eval_binding_heap(store, lhs_pos, rhs.as_array()),
 
        Value::Enum(v) => v == rhs.as_enum(),
 
        Value::Union(lhs_tag, lhs_pos) => {
 
            let (rhs_tag, rhs_pos) = rhs.as_union();
 
            if lhs_tag != rhs_tag {
 
                return false;
 
            }
 
            eval_binding_heap(store, lhs_pos, rhs_pos)
 
        },
 
        Value::Struct(lhs_pos) => eval_binding_heap(store, lhs_pos, rhs.as_struct()),
 
        _ => unreachable!("apply_binding_operator to lhs {:?}", lhs),
 
    }
 
}
 
\ No newline at end of file
src/protocol/eval_old.rs
Show inline comments
 
deleted file
src/protocol/input_source.rs
Show inline comments
 
use std::fmt;
 
use std::sync::{RwLock, RwLockReadGuard};
 
use std::fmt::Write;
 

	
 
#[derive(Debug, Clone, Copy)]
 
pub struct InputPosition {
 
    pub line: u32,
 
    pub offset: u32,
 
}
 

	
 
impl InputPosition {
 
    pub(crate) fn with_offset(&self, offset: u32) -> Self {
 
        InputPosition { line: self.line, offset: self.offset + offset }
 
    }
 
}
 

	
 
#[derive(Debug, Clone, Copy)]
 
pub struct InputSpan {
 
    pub begin: InputPosition,
 
    pub end: InputPosition,
 
}
 

	
 
impl InputSpan {
 
    // This will only be used for builtin functions
 
    #[inline]
 
    pub fn new() -> InputSpan {
 
        InputSpan{ begin: InputPosition{ line: 0, offset: 0 }, end: InputPosition{ line: 0, offset: 0 }}
 
    }
 

	
 
    #[inline]
 
    pub fn from_positions(begin: InputPosition, end: InputPosition) -> Self {
 
        Self { begin, end }
 
    }
 
}
 

	
 
/// Wrapper around source file with optional filename. Ensures that the file is
 
/// only scanned once.
 
pub struct InputSource {
 
    pub(crate) filename: String,
 
    pub(crate) input: Vec<u8>,
 
    // Iteration
 
    line: u32,
 
    offset: usize,
 
    // State tracking
 
    pub(crate) had_error: Option<ParseError>,
 
    // The offset_lookup is built on-demand upon attempting to report an error.
 
    // Only one procedure will actually create the lookup, afterwards only read
 
    // locks will be held.
 
    offset_lookup: RwLock<Vec<u32>>,
 
}
 

	
 
impl InputSource {
 
    pub fn new(filename: String, input: Vec<u8>) -> Self {
 
        Self{
 
            filename,
 
            input,
 
            line: 1,
 
            offset: 0,
 
            had_error: None,
 
            offset_lookup: RwLock::new(Vec::new()),
 
        }
 
    }
 

	
 
    #[cfg(test)]
 
    pub fn new_test(input: &str) -> Self {
 
        let bytes = Vec::from(input.as_bytes());
 
        return Self::new(String::from("test"), bytes)
 
    }
 

	
 
    #[inline]
 
    pub fn pos(&self) -> InputPosition {
 
        InputPosition { line: self.line, offset: self.offset as u32 }
 
    }
 

	
 
    pub fn next(&self) -> Option<u8> {
 
        if self.offset < self.input.len() {
 
            Some(self.input[self.offset])
 
        } else {
 
            None
 
        }
 
    }
 

	
 
    pub fn lookahead(&self, offset: usize) -> Option<u8> {
 
        let offset_pos = self.offset + offset;
 
        if offset_pos < self.input.len() {
 
            Some(self.input[offset_pos])
 
        } else {
 
            None
 
        }
 
    }
 

	
 
    #[inline]
 
    pub fn section_at_pos(&self, start: InputPosition, end: InputPosition) -> &[u8] {
 
        &self.input[start.offset as usize..end.offset as usize]
 
    }
 

	
 
    #[inline]
 
    pub fn section_at_span(&self, span: InputSpan) -> &[u8] {
 
        &self.input[span.begin.offset as usize..span.end.offset as usize]
 
    }
 

	
 
    // Consumes the next character. Will check well-formedness of newlines: \r
 
    // must be followed by a \n, because this is used for error reporting. Will
 
    // not check for ascii-ness of the file, better left to a tokenizer.
 
    pub fn consume(&mut self) {
 
        match self.next() {
 
            Some(b'\r') => {
 
                if Some(b'\n') == self.lookahead(1) {
 
                    // Well formed file
 
                    self.offset += 1;
 
                } else {
 
                    // Not a well-formed file, pretend like we can continue
 
                    self.offset += 1;
 
                    self.set_error("Encountered carriage-feed without a following newline");
 
                }
 
            },
 
            Some(b'\n') => {
 
                self.line += 1;
 
                self.offset += 1;
 
            },
 
            Some(_) => {
 
                self.offset += 1;
 
            }
 
            None => {}
 
        }
 

	
 
        // Maybe we actually want to check this in release mode. Then again:
 
        // a 4 gigabyte source file... Really?
 
        debug_assert!(self.offset < u32::max_value() as usize);
 
    }
 

	
 
    fn set_error(&mut self, msg: &str) {
 
        if self.had_error.is_none() {
 
            self.had_error = Some(ParseError::new_error_str_at_pos(self, self.pos(), msg));
 
        }
 
    }
 

	
 
    fn get_lookup(&self) -> RwLockReadGuard<Vec<u32>> {
 
        // Once constructed the lookup always contains one element. We use this
 
        // to see if it is constructed already.
 
        {
 
            let lookup = self.offset_lookup.read().unwrap();
 
            if !lookup.is_empty() {
 
                return lookup;
 
            }
 
        }
 

	
 
        // Lookup was not constructed yet
 
        let mut lookup = self.offset_lookup.write().unwrap();
 
        if !lookup.is_empty() {
 
            // Somebody created it before we had the chance
 
            drop(lookup);
 
            let lookup = self.offset_lookup.read().unwrap();
 
            return lookup;
 
        }
 

	
 
        // Build the line number (!) to offset lookup, so offset by 1. We 
 
        // assume the entire source file is scanned (most common case) for
 
        // preallocation.
 
        lookup.reserve(self.line as usize + 2);
 
        lookup.push(0); // line 0: never used
 
        lookup.push(0); // first line: first character
 

	
 
        for char_idx in 0..self.input.len() {
 
            if self.input[char_idx] == b'\n' {
 
                lookup.push(char_idx as u32 + 1);
 
            }
 
        }
 

	
 
        lookup.push(self.input.len() as u32 + 1); // for lookup_line_end, intentionally adding one character
 
        debug_assert_eq!(self.line as usize + 2, lookup.len(), "remove me: i am a testing assert and sometimes invalid");
 

	
 
        // Return created lookup
 
        drop(lookup);
 
        let lookup = self.offset_lookup.read().unwrap();
 
        return lookup;
 
    }
 

	
 
    /// Retrieves offset at which line starts (right after newline)
 
    fn lookup_line_start_offset(&self, line_number: u32) -> u32 {
 
        let lookup = self.get_lookup();
 
        lookup[line_number as usize]
 
    }
 

	
 
    /// Retrieves offset at which line ends (at the newline character or the
 
    /// preceding carriage feed for \r\n-encoded newlines)
 
    fn lookup_line_end_offset(&self, line_number: u32) -> u32 {
 
        let lookup = self.get_lookup();
 
        let offset = lookup[(line_number + 1) as usize] - 1;
 
        let offset_usize = offset as usize;
 

	
 
        // Compensate for newlines and a potential carriage feed. Note that the
 
        // end position is exclusive. So we only need to compensate for a
 
        // "\r\n"
 
        if offset_usize > 0 && offset_usize < self.input.len() && self.input[offset_usize] == b'\n' && self.input[offset_usize - 1] == b'\r' {
 
            offset - 1
 
        } else {
 
            offset
 
        }
 
    }
 
}
 

	
 
#[derive(Debug)]
 
pub enum StatementKind {
 
    Info,
 
    Error
 
}
 

	
 
#[derive(Debug)]
 
pub enum ContextKind {
 
    SingleLine,
 
    MultiLine,
 
}
 

	
 
#[derive(Debug)]
 
pub struct ErrorStatement {
 
    pub(crate) statement_kind: StatementKind,
 
    pub(crate) context_kind: ContextKind,
 
    pub(crate) start_line: u32,
 
    pub(crate) start_column: u32,
 
    pub(crate) end_line: u32,
 
    pub(crate) end_column: u32,
 
    pub(crate) filename: String,
 
    pub(crate) context: String,
 
    pub(crate) message: String,
 
}
 

	
 
impl ErrorStatement {
 
    fn from_source_at_pos(statement_kind: StatementKind, source: &InputSource, position: InputPosition, message: String) -> Self {
 
        // Seek line start and end
 
        let line_start = source.lookup_line_start_offset(position.line);
 
        let line_end = source.lookup_line_end_offset(position.line);
 
        let context = Self::create_context(source, line_start as usize, line_end as usize);
 
        debug_assert!(position.offset >= line_start);
 
        let column = position.offset - line_start + 1;
 

	
 
        Self{
 
            statement_kind,
 
            context_kind: ContextKind::SingleLine,
 
            start_line: position.line,
 
            start_column: column,
 
            end_line: position.line,
 
            end_column: column + 1,
 
            filename: source.filename.clone(),
 
            context,
 
            message,
 
        }
 
    }
 

	
 
    pub(crate) fn from_source_at_span(statement_kind: StatementKind, source: &InputSource, span: InputSpan, message: String) -> Self {
 
        debug_assert!(span.end.line >= span.begin.line);
 
        debug_assert!(span.end.offset >= span.begin.offset);
 

	
 
        let first_line_start = source.lookup_line_start_offset(span.begin.line);
 
        let last_line_start = source.lookup_line_start_offset(span.end.line);
 
        let last_line_end = source.lookup_line_end_offset(span.end.line);
 
        let context = Self::create_context(source, first_line_start as usize, last_line_end as usize);
 
        debug_assert!(span.begin.offset >= first_line_start);
 
        let start_column = span.begin.offset - first_line_start + 1;
 
        let end_column = span.end.offset - last_line_start + 1;
 

	
 
        let context_kind = if span.begin.line == span.end.line {
 
            ContextKind::SingleLine
 
        } else {
 
            ContextKind::MultiLine
 
        };
 

	
 
        Self{
 
            statement_kind,
 
            context_kind,
 
            start_line: span.begin.line,
 
            start_column,
 
            end_line: span.end.line,
 
            end_column,
 
            filename: source.filename.clone(),
 
            context,
 
            message,
 
        }
 
    }
 

	
 
    /// Produces context from source
 
    fn create_context(source: &InputSource, start: usize, end: usize) -> String {
 
        let context_raw = &source.input[start..end];
 
        String::from_utf8_lossy(context_raw).to_string()
 
    }
 
}
 

	
 
impl fmt::Display for ErrorStatement {
 
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 
        // Write kind of statement and message
 
        match self.statement_kind {
 
            StatementKind::Info => f.write_str(" INFO: ")?,
 
            StatementKind::Error => f.write_str("ERROR: ")?,
 
        }
 
        f.write_str(&self.message)?;
 
        f.write_char('\n')?;
 

	
 
        // Write originating file/line/column
 
        f.write_str(" +- ")?;
 
        if !self.filename.is_empty() {
 
            write!(f, "in {} ", self.filename)?;
 
        }
 

	
 
        match self.context_kind {
 
            ContextKind::SingleLine => writeln!(f, " at {}:{}", self.start_line, self.start_column),
 
            ContextKind::MultiLine => writeln!(
 
                f, " from {}:{} to {}:{}",
 
                self.start_line, self.start_column, self.end_line, self.end_column
 
            )
 
        }?;
 

	
 
        // Helper function for writing context: converting tabs into 4 spaces
 
        // (oh, the controversy!) and creating an annotated line
 
        fn transform_context(source: &str, target: &mut String) {
 
            for char in source.chars() {
 
                if char == '\t' {
 
                    target.push_str("    ");
 
                } else {
 
                    target.push(char);
 
                }
 
            }
 
        }
 

	
 
        fn extend_annotation(first_col: u32, last_col: u32, source: &str, target: &mut String, extend_char: char) {
 
            debug_assert!(first_col > 0 && last_col > first_col);
 

	
 
            // If the first index exceeds the size of the context then we should
 
            // have a message placed at the newline character
 
            let first_idx = first_col as usize - 1;
 
            let last_idx = last_col as usize - 1;
 
            if first_idx >= source.len() {
 
                // If any of these fail then the logic behind reporting errors
 
                // is incorrect.
 
                debug_assert_eq!(first_idx, source.len());
 
                debug_assert_eq!(first_idx + 1, last_idx);
 
                target.push(extend_char);
 
            } else {
 
                for (char_idx, char) in source.chars().enumerate().skip(first_idx) {
 
                    if char_idx == last_idx as usize {
 
                        break;
 
                    }
 

	
 
                    if char == '\t' {
 
                        for _ in 0..4 { target.push(extend_char); }
 
                    } else {
 
                        target.push(extend_char);
 
                    }
 
                }
 
            }
 
        }
 

	
 
        // Write source context
 
        writeln!(f, " | ")?;
 

	
 
        let mut context = String::with_capacity(128);
 
        let mut annotation = String::with_capacity(128);
 

	
 
        match self.context_kind {
 
            ContextKind::SingleLine => {
 
                // Write single line of context with indicator for the offending
 
                // span underneath.
 
                context.push_str(" |  ");
 
                transform_context(&self.context, &mut context);
 
                context.push('\n');
 
                f.write_str(&context)?;
 

	
 
                annotation.push_str(" | ");
 
                extend_annotation(1, self.start_column + 1, &self.context, &mut annotation, ' ');
 
                extend_annotation(self.start_column, self.end_column, &self.context, &mut annotation, '~');
 
                annotation.push('\n');
 

	
 
                f.write_str(&annotation)?;
 
            },
 
            ContextKind::MultiLine => {
 
                // Annotate all offending lines
 
                // - first line
 
                let mut lines = self.context.lines();
 
                let first_line = lines.next().unwrap();
 
                transform_context(first_line, &mut context);
 
                writeln!(f, " |- {}", &context)?;
 

	
 
                // - remaining lines
 
                let mut last_line = first_line;
 
                while let Some(cur_line) = lines.next() {
 
                    context.clear();
 
                    transform_context(cur_line, &mut context);
 
                    writeln!(f, " |  {}", &context)?;
 
                    last_line = cur_line;
 
                }
 

	
 
                // - underline beneath last line
 
                annotation.push_str(" \\__");
 
                extend_annotation(1, self.end_column, &last_line, &mut annotation, '_');
 
                annotation.push_str("/\n");
 
                f.write_str(&annotation)?;
 
            }
 
        }
 

	
 
        Ok(())
 
    }
 
}
 

	
 
#[derive(Debug)]
 
pub struct ParseError {
 
    pub(crate) statements: Vec<ErrorStatement>
 
}
 

	
 
impl fmt::Display for ParseError {
 
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 
        if self.statements.is_empty() {
 
            return Ok(())
 
        }
 

	
 
        self.statements[0].fmt(f)?;
 
        for statement in self.statements.iter().skip(1) {
 
            writeln!(f)?;
 
            statement.fmt(f)?;
 
        }
 

	
 
        Ok(())
 
    }
 
}
 

	
 
impl ParseError {
 
    pub fn new_error_at_pos(source: &InputSource, position: InputPosition, message: String) -> Self {
 
        Self{ statements: vec!(ErrorStatement::from_source_at_pos(
 
            StatementKind::Error, source, position, message
 
        )) }
 
    }
 

	
 
    pub fn new_error_str_at_pos(source: &InputSource, position: InputPosition, message: &str) -> Self {
 
        Self{ statements: vec!(ErrorStatement::from_source_at_pos(
 
            StatementKind::Error, source, position, message.to_string()
 
        )) }
 
    }
 

	
 
    pub fn new_error_at_span(source: &InputSource, span: InputSpan, message: String) -> Self {
 
        Self{ statements: vec!(ErrorStatement::from_source_at_span(
 
            StatementKind::Error, source, span, message
 
        )) }
 
    }
 

	
 
    pub fn new_error_str_at_span(source: &InputSource, span: InputSpan, message: &str) -> Self {
 
        Self{ statements: vec!(ErrorStatement::from_source_at_span(
 
            StatementKind::Error, source, span, message.to_string()
 
        )) }
 
    }
 

	
 
    pub fn with_at_pos(mut self, error_type: StatementKind, source: &InputSource, position: InputPosition, message: String) -> Self {
 
        self.statements.push(ErrorStatement::from_source_at_pos(error_type, source, position, message));
 
        self
 
    }
 

	
 
    pub fn with_at_span(mut self, error_type: StatementKind, source: &InputSource, span: InputSpan, message: String) -> Self {
 
        self.statements.push(ErrorStatement::from_source_at_span(error_type, source, span, message.to_string()));
 
        self
 
    }
 

	
 
    pub fn with_info_at_pos(self, source: &InputSource, position: InputPosition, msg: String) -> Self {
 
        self.with_at_pos(StatementKind::Info, source, position, msg)
 
    }
 

	
 
    pub fn with_info_str_at_pos(self, source: &InputSource, position: InputPosition, msg: &str) -> Self {
 
        self.with_at_pos(StatementKind::Info, source, position, msg.to_string())
 
    }
 

	
 
    pub fn with_info_at_span(self, source: &InputSource, span: InputSpan, msg: String) -> Self {
 
        self.with_at_span(StatementKind::Info, source, span, msg)
 
    }
 

	
 
    pub fn with_info_str_at_span(self, source: &InputSource, span: InputSpan, msg: &str) -> Self {
 
        self.with_at_span(StatementKind::Info, source, span, msg.to_string())
 
    }
 
}
src/protocol/mod.rs
Show inline comments
 
mod arena;
 
mod eval;
 
pub(crate) mod input_source;
 
mod parser;
 
#[cfg(test)] mod tests;
 

	
 
pub(crate) mod ast;
 
pub(crate) mod ast_printer;
 

	
 
use std::sync::Mutex;
 

	
 
use crate::collections::{StringPool, StringRef};
 
use crate::common::*;
 
use crate::protocol::ast::*;
 
use crate::protocol::eval::*;
 
use crate::protocol::input_source::*;
 
use crate::protocol::parser::*;
 
use crate::protocol::type_table::*;
 

	
 
/// A protocol description module
 
pub struct Module {
 
    pub(crate) source: InputSource,
 
    pub(crate) root_id: RootId,
 
    pub(crate) name: Option<StringRef<'static>>,
 
}
 
/// Description of a protocol object, used to configure new connectors.
 
#[repr(C)]
 
pub struct ProtocolDescription {
 
    modules: Vec<Module>,
 
    heap: Heap,
 
    types: TypeTable,
 
    pool: Mutex<StringPool>,
 
}
 
#[derive(Debug, Clone)]
 
pub(crate) struct ComponentState {
 
    prompt: Prompt,
 
}
 
pub(crate) enum EvalContext<'a> {
 
    Nonsync(&'a mut NonsyncProtoContext<'a>),
 
    Sync(&'a mut SyncProtoContext<'a>),
 
    None,
 
}
 
//////////////////////////////////////////////
 

	
 
impl std::fmt::Debug for ProtocolDescription {
 
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
 
        write!(f, "(An opaque protocol description)")
 
    }
 
}
 
impl ProtocolDescription {
 
    // TODO: Allow for multi-file compilation
 
    pub fn parse(buffer: &[u8]) -> Result<Self, String> {
 
        // TODO: @fixme, keep code compilable, but needs support for multiple
 
        //  input files.
 
        let source = InputSource::new(String::new(), Vec::from(buffer));
 
        let mut parser = Parser::new();
 
        parser.feed(source).expect("failed to feed source");
 
        
 
        if let Err(err) = parser.parse() {
 
            println!("ERROR:\n{}", err);
 
            return Err(format!("{}", err))
 
        }
 

	
 
        debug_assert_eq!(parser.modules.len(), 1, "only supporting one module here for now");
 
        let modules: Vec<Module> = parser.modules.into_iter()
 
            .map(|module| Module{
 
                source: module.source,
 
                root_id: module.root_id,
 
                name: module.name.map(|(_, name)| name)
 
            })
 
            .collect();
 

	
 
        return Ok(ProtocolDescription {
 
            modules,
 
            heap: parser.heap,
 
            types: parser.type_table,
 
            pool: Mutex::new(parser.string_pool),
 
        });
 
    }
 
    pub(crate) fn component_polarities(
 
        &self,
 
        module_name: &[u8],
 
        identifier: &[u8],
 
    ) -> Result<Vec<Polarity>, AddComponentError> {
 
        use AddComponentError::*;
 

	
 
        let module_root = self.lookup_module_root(module_name);
 
        if module_root.is_none() {
 
            return Err(AddComponentError::NoSuchModule);
 
        }
 
        let module_root = module_root.unwrap();
 

	
 
        let root = &self.heap[module_root];
 
        let def = root.get_definition_ident(&self.heap, identifier);
 
        if def.is_none() {
 
            return Err(NoSuchComponent);
 
        }
 

	
 
        let def = &self.heap[def.unwrap()];
 
        if !def.is_component() {
 
            return Err(NoSuchComponent);
 
        }
 

	
 
        for &param in def.parameters().iter() {
 
            let param = &self.heap[param];
 
            let first_element = &param.parser_type.elements[0];
 

	
 
            match first_element.variant {
 
                ParserTypeVariant::Input | ParserTypeVariant::Output => continue,
 
                _ => {
 
                    return Err(NonPortTypeParameters);
 
                }
 
            }
 
        }
 

	
 
        let mut result = Vec::new();
 
        for &param in def.parameters().iter() {
 
            let param = &self.heap[param];
 
            let first_element = &param.parser_type.elements[0];
 

	
 
            if first_element.variant == ParserTypeVariant::Input {
 
                result.push(Polarity::Getter)
 
            } else if first_element.variant == ParserTypeVariant::Output {
 
                result.push(Polarity::Putter)
 
            } else {
 
                unreachable!()
 
            }
 
        }
 
        Ok(result)
 
    }
 
    // expects port polarities to be correct
 
    pub(crate) fn new_component(&self, module_name: &[u8], identifier: &[u8], ports: &[PortId]) -> ComponentState {
 
        let mut args = Vec::new();
 
        for (&x, y) in ports.iter().zip(self.component_polarities(module_name, identifier).unwrap()) {
 
            match y {
 
                Polarity::Getter => args.push(Value::Input(x)),
 
                Polarity::Putter => args.push(Value::Output(x)),
 
            }
 
        }
 

	
 
        let module_root = self.lookup_module_root(module_name).unwrap();
 
        let root = &self.heap[module_root];
 
        let def = root.get_definition_ident(&self.heap, identifier).unwrap();
 
        ComponentState { prompt: Prompt::new(&self.types, &self.heap, def, 0, ValueGroup::new_stack(args)) }
 
    }
 

	
 
    fn lookup_module_root(&self, module_name: &[u8]) -> Option<RootId> {
 
        for module in self.modules.iter() {
 
            match &module.name {
 
                Some(name) => if name.as_bytes() == module_name {
 
                    return Some(module.root_id);
 
                },
 
                None => if module_name.is_empty() {
 
                    return Some(module.root_id);
 
                }
 
            }
 
        }
 

	
 
        return None;
 
    }
 
}
 
impl ComponentState {
 
    pub(crate) fn nonsync_run<'a: 'b, 'b>(
 
        &'a mut self,
 
        context: &'b mut NonsyncProtoContext<'b>,
 
        pd: &'a ProtocolDescription,
 
    ) -> NonsyncBlocker {
 
        let mut context = EvalContext::Nonsync(context);
 
        loop {
 
            let result = self.prompt.step(&pd.types, &pd.heap, &pd.modules, &mut context);
 
            match result {
 
                Err(err) => {
 
                    println!("Evaluation error:\n{}", err);
 
                    panic!("proper error handling when component fails");
 
                },
 
                Ok(cont) => match cont {
 
                    EvalContinuation::Stepping => continue,
 
                    EvalContinuation::Inconsistent => return NonsyncBlocker::Inconsistent,
 
                    EvalContinuation::Terminal => return NonsyncBlocker::ComponentExit,
 
                    EvalContinuation::SyncBlockStart => return NonsyncBlocker::SyncBlockStart,
 
                    // Not possible to end sync block if never entered one
 
                    EvalContinuation::SyncBlockEnd => unreachable!(),
 
                    EvalContinuation::NewComponent(definition_id, monomorph_idx, args) => {
 
                        // Look up definition (TODO for now, assume it is a definition)
 
                        let mut moved_ports = HashSet::new();
 
                        for arg in args.values.iter() {
 
                            match arg {
 
                                Value::Output(port) => {
 
                                    moved_ports.insert(*port);
 
                                }
 
                                Value::Input(port) => {
 
                                    moved_ports.insert(*port);
 
                                }
 
                                _ => {}
 
                            }
 
                        }
 
                        for region in args.regions.iter() {
 
                            for arg in region {
 
                                match arg {
 
                                    Value::Output(port) => { moved_ports.insert(*port); },
 
                                    Value::Input(port) => { moved_ports.insert(*port); },
 
                                    _ => {},
 
                                }
 
                            }
 
                        }
 
                        let init_state = ComponentState { prompt: Prompt::new(&pd.types, &pd.heap, definition_id, monomorph_idx, args) };
 
                        context.new_component(moved_ports, init_state);
 
                        // Continue stepping
 
                        continue;
 
                    }
 
                    // Outside synchronous blocks, no fires/get/put happens
 
                    EvalContinuation::BlockFires(_) => unreachable!(),
 
                    EvalContinuation::BlockGet(_) => unreachable!(),
 
                    EvalContinuation::Put(_, _) => unreachable!(),
 
                },
 
            }
 
        }
 
    }
 

	
 
    pub(crate) fn sync_run<'a: 'b, 'b>(
 
        &'a mut self,
 
        context: &'b mut SyncProtoContext<'b>,
 
        pd: &'a ProtocolDescription,
 
    ) -> SyncBlocker {
 
        let mut context = EvalContext::Sync(context);
 
        loop {
 
            let result = self.prompt.step(&pd.types, &pd.heap, &pd.modules, &mut context);
 
            match result {
 
                Err(err) => {
 
                    println!("Evaluation error:\n{}", err);
 
                    panic!("proper error handling when component fails");
 
                },
 
                Ok(cont) => match cont {
 
                    EvalContinuation::Stepping => continue,
 
                    EvalContinuation::Inconsistent => return SyncBlocker::Inconsistent,
 
                    // First need to exit synchronous block before definition may end
 
                    EvalContinuation::Terminal => unreachable!(),
 
                    // No nested synchronous blocks
 
                    EvalContinuation::SyncBlockStart => unreachable!(),
 
                    EvalContinuation::SyncBlockEnd => return SyncBlocker::SyncBlockEnd,
 
                    // Not possible to create component in sync block
 
                    EvalContinuation::NewComponent(_, _, _) => unreachable!(),
 
                    EvalContinuation::BlockFires(port) => match port {
 
                        Value::Output(port) => {
 
                            return SyncBlocker::CouldntCheckFiring(port);
 
                        }
 
                        Value::Input(port) => {
 
                            return SyncBlocker::CouldntCheckFiring(port);
 
                        }
 
                        _ => unreachable!(),
 
                    },
 
                    EvalContinuation::BlockGet(port) => match port {
 
                        Value::Output(port) => {
 
                            return SyncBlocker::CouldntReadMsg(port);
 
                        }
 
                        Value::Input(port) => {
 
                            return SyncBlocker::CouldntReadMsg(port);
 
                        }
 
                        _ => unreachable!(),
 
                    },
 
                    EvalContinuation::Put(port, message) => {
 
                        let value;
 
                        match port {
 
                            Value::Output(port_value) => {
 
                                value = port_value;
 
                            }
 
                            Value::Input(port_value) => {
 
                                value = port_value;
 
                            }
 
                            _ => unreachable!(),
 
                        }
 
                        let payload;
 
                        match message {
 
                            Value::Null => {
 
                                return SyncBlocker::Inconsistent;
 
                            },
 
                            Value::Message(heap_pos) => {
 
                                // Create a copy of the payload
 
                                let values = &self.prompt.store.heap_regions[heap_pos as usize].values;
 
                                let mut bytes = Vec::with_capacity(values.len());
 
                                for value in values {
 
                                    bytes.push(value.as_uint8());
 
                                }
 
                                payload = Payload(Arc::new(bytes));
 
                            }
 
                            _ => unreachable!(),
 
                        }
 
                        return SyncBlocker::PutMsg(value, payload);
 
                    }
 
                },
 
            }
 
        }
 
    }
 
}
 
impl EvalContext<'_> {
 
    // fn random(&mut self) -> LongValue {
 
    //     match self {
 
    //         // EvalContext::None => unreachable!(),
 
    //         EvalContext::Nonsync(_context) => todo!(),
 
    //         EvalContext::Sync(_) => unreachable!(),
 
    //     }
 
    // }
 
    fn new_component(&mut self, moved_ports: HashSet<PortId>, init_state: ComponentState) -> () {
 
        match self {
 
            EvalContext::None => unreachable!(),
 
            EvalContext::Nonsync(context) => {
 
                context.new_component(moved_ports, init_state)
 
            }
 
            EvalContext::Sync(_) => unreachable!(),
 
        }
 
    }
 
    fn new_channel(&mut self) -> [Value; 2] {
 
        match self {
 
            EvalContext::None => unreachable!(),
 
            EvalContext::Nonsync(context) => {
 
                let [from, to] = context.new_port_pair();
 
                let from = Value::Output(from);
 
                let to = Value::Input(to);
 
                return [from, to];
 
            }
 
            EvalContext::Sync(_) => unreachable!(),
 
        }
 
    }
 
    fn fires(&mut self, port: Value) -> Option<Value> {
 
        match self {
 
            EvalContext::None => unreachable!(),
 
            EvalContext::Nonsync(_) => unreachable!(),
 
            EvalContext::Sync(context) => match port {
 
                Value::Output(port) => context.is_firing(port).map(Value::Bool),
 
                Value::Input(port) => context.is_firing(port).map(Value::Bool),
 
                _ => unreachable!(),
 
            },
 
        }
 
    }
 
    fn get(&mut self, port: Value, store: &mut Store) -> Option<Value> {
 
        match self {
 
            EvalContext::None => unreachable!(),
 
            EvalContext::Nonsync(_) => unreachable!(),
 
            EvalContext::Sync(context) => match port {
 
                Value::Output(port) => {
 
                    debug_assert!(false, "Getting from an output port? Am I mad?");
 
                    unreachable!();
 
                }
 
                Value::Input(port) => {
 
                    let payload = context.read_msg(port);
 
                    if payload.is_none() { return None; }
 

	
 
                    let heap_pos = store.alloc_heap();
 
                    let heap_pos_usize = heap_pos as usize;
 
                    let payload = payload.unwrap();
 
                    store.heap_regions[heap_pos_usize].values.reserve(payload.0.len());
 
                    for value in payload.0.iter() {
 
                        store.heap_regions[heap_pos_usize].values.push(Value::UInt8(*value));
 
                    }
 

	
 
                    return Some(Value::Message(heap_pos));
 
                }
 
                _ => unreachable!(),
 
            },
 
        }
 
    }
 
    fn did_put(&mut self, port: Value) -> bool {
 
        match self {
 
            EvalContext::None => unreachable!("did_put in None context"),
 
            EvalContext::Nonsync(_) => unreachable!("did_put in nonsync context"),
 
            EvalContext::Sync(context) => match port {
 
                Value::Output(port) => {
 
                    context.did_put_or_get(port)
 
                },
 
                Value::Input(_) => unreachable!("did_put on input port"),
 
                _ => unreachable!("did_put on non-port value")
 
                _ => unreachable!("did_put on non-output port value")
 
            }
 
        }
 
    }
 
}
src/protocol/parser/mod.rs
Show inline comments
 
mod depth_visitor;
 
pub(crate) mod symbol_table;
 
pub(crate) mod type_table;
 
pub(crate) mod tokens;
 
pub(crate) mod token_parsing;
 
pub(crate) mod pass_tokenizer;
 
pub(crate) mod pass_symbols;
 
pub(crate) mod pass_imports;
 
pub(crate) mod pass_definitions;
 
pub(crate) mod pass_validation_linking;
 
pub(crate) mod pass_typing;
 
mod visitor;
 

	
 
use depth_visitor::*;
 
use tokens::*;
 
use crate::collections::*;
 
use visitor::Visitor2;
 
use pass_tokenizer::PassTokenizer;
 
use pass_symbols::PassSymbols;
 
use pass_imports::PassImport;
 
use pass_definitions::PassDefinitions;
 
use pass_validation_linking::PassValidationLinking;
 
use pass_typing::{PassTyping, ResolveQueue};
 
use symbol_table::*;
 
use type_table::TypeTable;
 

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

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

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

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

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

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

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

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

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

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

	
 
        parser
 
    }
 

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

	
 
        // Continue compilation with the remaining phases now that the types
 
        // are all in the type table
 
        for module_idx in 0..self.modules.len() {
 
            // TODO: Remove the entire Visitor abstraction. It really doesn't
 
            //  make sense considering the amount of special handling we do
 
            //  in each pass.
 
            let mut ctx = visitor::Ctx{
 
                heap: &mut self.heap,
 
                module: &mut self.modules[module_idx],
 
                symbols: &mut self.symbol_table,
 
                types: &mut self.type_table,
 
            };
 
            self.pass_validation.visit_module(&mut ctx)?;
 
        }
 

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

	
 
        // Perform remaining steps
 
        // TODO: Phase out at some point
 
        for module in &self.modules {
 
            let root_id = module.root_id;
 
            if let Err((position, message)) = Self::parse_inner(&mut self.heap, root_id) {
 
                return Err(ParseError::new_error_str_at_pos(&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);
 
        if let Some(filename) = &self.write_ast_to {
 
            let mut writer = ASTWriter::new();
 
            let mut file = std::fs::File::create(std::path::Path::new(filename)).unwrap();
 
            writer.write_ast(&mut file, &self.heap);
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    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(())
 
    }
 
}
 

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

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

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

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

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

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

	
 
    p.symbol_table.insert_symbol(SymbolScope::Global, Symbol{
 
        name: func_ident_ref,
 
        variant: SymbolVariant::Definition(SymbolDefinition{
 
            defined_in_module: RootId::new_invalid(),
 
            defined_in_scope: SymbolScope::Global,
 
            definition_span: InputSpan::new(),
 
            identifier_span: InputSpan::new(),
 
            imported_at: None,
 
            class: DefinitionClass::Function,
 
            definition_id: func_id.upcast(),
 
        })
 
    }).unwrap();
 
}
 
\ No newline at end of file
src/protocol/parser/pass_typing.rs
Show inline comments
 
@@ -274,3158 +274,3159 @@ impl InferenceType {
 
        self.is_done = self.parts.iter().all(|v| v.is_concrete());
 
    }
 

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

	
 
            start_idx += 1;
 
        }
 

	
 
        None
 
    }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
        None
 
    }
 

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

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

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

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

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

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

	
 
        None
 
    }
 

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

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

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

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

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

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

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

	
 
    /// Attempts to infer the first subtree based on the template. Like
 
    /// `infer_subtrees_for_both_types`, but now only applying inference to
 
    /// `to_infer` based on the type information in `template`.
 
    ///
 
    /// The `forced_template` flag controls whether `to_infer` is considered
 
    /// valid if it is more specific then the template. When `forced_template`
 
    /// is false, then as long as the `to_infer` and `template` types are
 
    /// compatible the inference will succeed. If `forced_template` is true,
 
    /// then `to_infer` MUST be less specific than `template` (e.g.
 
    /// `IntegerLike` is less specific than `UInt32`)
 
    fn infer_subtree_for_single_type(
 
        to_infer: &mut InferenceType, mut to_infer_idx: usize,
 
        template: &[InferenceTypePart], mut template_idx: usize,
 
        forced_template: bool,
 
    ) -> SingleInferenceResult {
 
        let mut modified = false;
 
        let mut depth = 1;
 

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

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

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

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

	
 
            return SingleInferenceResult::Incompatible
 
        }
 

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

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

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

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

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

	
 
            return false;
 
        }
 

	
 
        true
 
    }
 

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

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

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

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

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

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

	
 
        idx
 
    }
 

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

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

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

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

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

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

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

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

	
 
            self.idx += 1;
 
        }
 

	
 
        None
 
    }
 
}
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
            let should_add_to_queue = match definition {
 
                Definition::Function(definition) => definition.poly_vars.is_empty(),
 
                Definition::Component(definition) => definition.poly_vars.is_empty(),
 
                Definition::Enum(_) | Definition::Struct(_) | Definition::Union(_) => false,
 
            };
 

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

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

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

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

	
 
impl Visitor2 for PassTyping {
 
    // Definitions
 

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

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

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

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

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

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

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

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

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

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

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

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

	
 
    // Statements
 

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

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

	
 
        Ok(())
 
    }
 

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

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

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        Ok(())
 
    }
 

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

	
 
        self.visit_block_stmt(ctx, body_id)
 
    }
 

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

	
 
        self.visit_expr(ctx, expr_id)
 
    }
 

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

	
 
        self.visit_call_expr(ctx, call_expr_id)
 
    }
 

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

	
 
        self.visit_expr(ctx, subexpr_id)
 
    }
 

	
 
    // Expressions
 

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

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

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

	
 
        self.progress_assignment_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_binding_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_conditional_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_binary_expr(ctx, id)
 
    }
 

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

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

	
 
        self.visit_expr(ctx, arg_expr_id)?;
 

	
 
        self.progress_unary_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_indexing_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_slicing_expr(ctx, id)
 
    }
 

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

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

	
 
        self.visit_expr(ctx, subject_expr_id)?;
 

	
 
        self.progress_select_expr(ctx, id)
 
    }
 

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

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

	
 
                self.insert_initial_struct_polymorph_data(ctx, id);
 

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

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

	
 
        self.progress_literal_expr(ctx, id)
 
    }
 

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

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

	
 
        self.visit_expr(ctx, subject_expr_id)?;
 

	
 
        self.progress_cast_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_call_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_variable_expr(ctx, id)
 
    }
 
}
 

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

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

	
 
        // Helper for transferring polymorphic variables to concrete types and
 
        // checking if they're completely specified
 
        fn poly_inference_to_concrete_type(
 
            ctx: &Ctx, expr_id: ExpressionId, inference: &Vec<InferenceType>
 
        ) -> Result<Vec<ConcreteType>, ParseError> {
 
            let mut concrete = Vec::with_capacity(inference.len());
 
            for (poly_idx, poly_type) in inference.iter().enumerate() {
 
                if !poly_type.is_done {
 
                    let expr = &ctx.heap[expr_id];
 
                    let definition = match expr {
 
                        Expression::Call(expr) => expr.definition,
 
                        Expression::Literal(expr) => match &expr.value {
 
                            Literal::Enum(lit) => lit.definition,
 
                            Literal::Union(lit) => lit.definition,
 
                            Literal::Struct(lit) => lit.definition,
 
                            _ => unreachable!()
 
                        },
 
                        _ => unreachable!(),
 
                    };
 
                    let poly_vars = ctx.heap[definition].poly_vars();
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module.source, expr.span(), format!(
 
                            "could not fully infer the type of polymorphic variable '{}' of this expression (got '{}')",
 
                            poly_vars[poly_idx].value.as_str(), poly_type.display_name(&ctx.heap)
 
                        )
 
                    ));
 
                }
 

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

	
 
            Ok(concrete)
 
        }
 

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

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

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

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

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

	
 
                    match ctx.types.get_procedure_monomorph_index(&definition_id, &poly_types) {
 
                        Some(reserved_idx) => {
 
                            // Already typechecked, or already put into the resolve queue
 
                            infer_expr.field_or_monomorph_idx = reserved_idx;
 
                        },
 
                        None => {
 
                            // Not typechecked yet, so add an entry in the queue
 
                            let reserved_idx = ctx.types.reserve_procedure_monomorph_index(&definition_id, Some(poly_types.clone()));
 
                            infer_expr.field_or_monomorph_idx = reserved_idx;
 
                            queue.push(ResolveQueueElement{
 
                                root_id: ctx.heap[definition_id].defined_in(),
 
                                definition_id,
 
                                monomorph_types: poly_types,
 
                                reserved_monomorph_idx: reserved_idx,
 
                            });
 
                        }
 
                    }
 
                },
 
                Expression::Literal(expr) => {
 
                    let definition_id = match &expr.value {
 
                        Literal::Enum(lit) => lit.definition,
 
                        Literal::Union(lit) => lit.definition,
 
                        Literal::Struct(lit) => lit.definition,
 
                        _ => unreachable!(),
 
                    };
 

	
 
                    let poly_types = poly_inference_to_concrete_type(ctx, extra_data.expr_id, &extra_data.poly_vars)?;
 
                    let mono_index = ctx.types.add_data_monomorph(&definition_id, poly_types);
 
                    infer_expr.field_or_monomorph_idx = mono_index;
 
                },
 
                Expression::Select(_) => {
 
                    debug_assert!(infer_expr.field_or_monomorph_idx >= 0);
 
                },
 
                _ => {
 
                    unreachable!("handling extra data for expression {:?}", &ctx.heap[extra_data.expr_id]);
 
                }
 
            }
 
        }
 

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

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

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

	
 
        target.expr_data.reserve(self.expr_types.len());
 
        for infer_expr in self.expr_types.iter() {
 
            let mut concrete = ConcreteType::default();
 
            infer_expr.expr_type.write_concrete_type(&mut concrete);
 
            target.expr_data.push(MonomorphExpression{
 
                expr_type: concrete,
 
                field_or_monomorph_idx: infer_expr.field_or_monomorph_idx
 
            });
 
        }
 

	
 
        Ok(())
 
    }
 

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

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

	
 
        let upcast_id = id.upcast();
 

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

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

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

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

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

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

	
 

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

	
 
        Ok(())
 
    }
 

	
 
    fn progress_binding_expr(&mut self, ctx: &mut Ctx, id: BindingExpressionId) -> Result<(), ParseError> {
 
        let upcast_id = id.upcast();
 
        let binding_expr = &ctx.heap[id];
 
        let bound_from_id = binding_expr.bound_from;
 
        let bound_to_id = binding_expr.bound_to;
 

	
 
        // Output is always a boolean. The two arguments should be of equal
 
        // type.
 
        let progress_expr = self.apply_forced_constraint(ctx, upcast_id, &BOOL_TEMPLATE)?;
 
        let (progress_from, progress_to) = self.apply_equal2_constraint(ctx, upcast_id, bound_from_id, 0, bound_to_id, 0)?;
 

	
 
        if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
 
        if progress_from { self.queue_expr(ctx, bound_from_id); }
 
        if progress_to { self.queue_expr(ctx, bound_to_id); }
 

	
 
        Ok(())
 
    }
 

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

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

	
 
        // I keep confusing myself: this applies equality of types between the
 
        // condition branches' types, and the result from the conditional
 
        // expression, because the result from the conditional is one of the
 
        // branches.
 
        let (progress_expr, progress_arg1, progress_arg2) = self.apply_equal3_constraint(
 
            ctx, upcast_id, arg1_expr_id, arg2_expr_id, 0
 
        )?;
 

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

	
 

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

	
 
            // Nothing is concrete yet
 
            Ok(None)
 
        }
 

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

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

	
 
                    let mut struct_def_id = None;
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
                    progress_expr = progress_expr || inner_expr_progress;
 

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

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

	
 
                progress_expr
 
            },
 
        };
 

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

	
 
        // Check if the two types are compatible
 
        debug_log!(" * After:");
 
        debug_log!("   - Expr type [{}]: {}", expr_progress, self.temp_get_display_name(ctx, upcast_id));
 
        debug_log!("   - Expr type [{}]: {}", expr_progress, self.debug_get_display_name(ctx, upcast_id));
 
        debug_log!("   - Note that the subject type can never be inferred");
 
        debug_log!(" * Decision:");
 

	
 
        let subject_idx = ctx.heap[expr.subject].get_unique_id_in_definition();
 
        let expr_type = &self.expr_types[expr_idx as usize].expr_type;
 
        let subject_type = &self.expr_types[subject_idx as usize].expr_type;
 
        if !expr_type.is_done || !subject_type.is_done {
 
            // Not yet done
 
            debug_log!("   - Casting is valid: unknown as the types are not yet complete");
 
            return Ok(())
 
        }
 

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

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

	
 
        debug_log!("   - Casting is valid: {}", is_valid);
 

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

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

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

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

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

	
 

	
 
        Ok(())
 
    }
 

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

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

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

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

	
 
    /// Applies a forced constraint: the supplied expression's type MUST be
 
    /// inferred from the template, the other way around is considered invalid.
 
    fn apply_forced_constraint(
 
        &mut self, ctx: &Ctx, expr_id: ExpressionId, template: &[InferenceTypePart]
 
    ) -> Result<bool, ParseError> {
 
        let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition();
 
        let expr_type = &mut self.expr_types[expr_idx as usize].expr_type;
 
        match InferenceType::infer_subtree_for_single_type(expr_type, 0, template, 0, true) {
 
            SingleInferenceResult::Modified => Ok(true),
 
            SingleInferenceResult::Unmodified => Ok(false),
 
            SingleInferenceResult::Incompatible => Err(
 
                self.construct_template_type_error(ctx, expr_id, template)
 
            )
 
        }
 
    }
 

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

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

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

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

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

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

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

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

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

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

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

	
 
                modified_sig = modified_sig || modified_at_marker;
 
            // }
 

	
 
            seek_idx = end_idx;
 
        }
 

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

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

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

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

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

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

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

	
 
        Ok((progress_expr, progress_arg1, progress_arg2))
 
    }
 

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

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

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

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

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

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

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

	
 
            last_arg_id = *next_arg_id;
 
            lhs_arg_idx += 1;
 
        }
 

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

	
 
        Ok(progress)
 
    }
 

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

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

	
 
                if is_conditional && *idx_in_parent == 0 {
 
                    InferenceType::new(false, true, vec![ITP::Bool])
 
                } else {
 
                    InferenceType::new(false, false, vec![ITP::Unknown])
 
                }
 
            },
 
            EP::If(_) | EP::While(_) =>
 
                // Must be a boolean
 
                InferenceType::new(false, true, vec![ITP::Bool]),
 
            EP::Return(_) =>
 
                // Must match the return type of the function
 
                if let DefinitionType::Function(func_id) = self.definition_type {
 
                    debug_assert_eq!(ctx.heap[func_id].return_types.len(), 1);
 
                    let returned = &ctx.heap[func_id].return_types[0];
 
                    self.determine_inference_type_from_parser_type_elements(&returned.elements, true)
 
                } else {
 
                    // Cannot happen: definition always set upon body traversal
 
                    // and "return" calls in components are illegal.
 
                    unreachable!();
 
                },
 
            EP::New(_) =>
 
                // Must be a component call, which we assign a "Void" return
 
                // type
 
                InferenceType::new(false, true, vec![ITP::Void]),
 
        };
 

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
    /// Inserts the extra polymorphic data struct for enum expressions. These
 
    /// can never be determined from the enum itself, but may be inferred from
 
    /// the use of the enum.
 
    fn insert_initial_enum_polymorph_data(
 
        &mut self, ctx: &Ctx, lit_id: LiteralExpressionId
 
    ) {
 
        use InferenceTypePart as ITP;
 
        let literal = &ctx.heap[lit_id];
 
        let extra_data_idx = self.expr_types[literal.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
 
        debug_assert!(extra_data_idx != -1, "initial enum polymorph data, but no preallocated ExtraData");
 
        let literal = ctx.heap[lit_id].value.as_enum();
 

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

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

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

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

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

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

	
 
    /// Inserts the extra polymorphic data struct for unions. The polymorphic
 
    /// arguments may be partially determined from embedded values in the union.
 
    fn insert_initial_union_polymorph_data(
 
        &mut self, ctx: &Ctx, lit_id: LiteralExpressionId
 
    ) {
 
        use InferenceTypePart as ITP;
 
        let literal = &ctx.heap[lit_id];
 
        let extra_data_idx = self.expr_types[literal.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
 
        debug_assert!(extra_data_idx != -1, "initial union polymorph data, but no preallocated ExtraData");
 
        let literal = ctx.heap[lit_id].value.as_union();
 

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

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

	
 
        // Handle any of the embedded values in the variant, if specified
 
        let definition_id = literal.definition;
 
        let type_definition = ctx.types.get_base_definition(&definition_id).unwrap();
 
        let union_definition = type_definition.definition.as_union();
 
        debug_assert_eq!(poly_args.len(), type_definition.poly_vars.len());
 

	
 
        let variant_definition = &union_definition.variants[literal.variant_idx];
 
        debug_assert_eq!(variant_definition.embedded.len(), literal.values.len());
 

	
 
        let mut embedded = Vec::with_capacity(variant_definition.embedded.len());
 
        for embedded_parser_type in &variant_definition.embedded {
 
            let inference_type = self.determine_inference_type_from_parser_type_elements(&embedded_parser_type.elements, false);
 
            embedded.push(inference_type);
 
        }
 

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

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

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

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

	
 
    /// Inserts the extra polymorphic data struct. Assumes that the select
 
    /// expression's referenced (definition_id, field_idx) has been resolved.
 
    fn insert_initial_select_polymorph_data(
 
        &mut self, ctx: &Ctx, select_id: SelectExpressionId, struct_def_id: DefinitionId
 
    ) {
 
        use InferenceTypePart as ITP;
 

	
 
        // Retrieve relevant data
 
        let expr = &ctx.heap[select_id];
 
        let expr_type = &self.expr_types[expr.unique_id_in_definition as usize];
 
        let field_idx = expr_type.field_or_monomorph_idx as usize;
 
        let extra_data_idx = expr_type.extra_data_idx; // TODO: @Temp
 
        debug_assert!(extra_data_idx != -1, "initial select polymorph data, but no preallocated ExtraData");
 

	
 
        let definition = ctx.heap[struct_def_id].as_struct();
 

	
 
        // Generate initial polyvar types and struct type
 
        // TODO: @Performance: we can immediately set the polyvars of the subject's struct type
 
        let num_poly_vars = definition.poly_vars.len();
 
        let mut poly_vars = Vec::with_capacity(num_poly_vars);
 
        let struct_parts_reserved = 1 + 2 * num_poly_vars;
 
        let mut struct_parts = Vec::with_capacity(struct_parts_reserved);
 
        struct_parts.push(ITP::Instance(struct_def_id, num_poly_vars as u32));
 

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

	
 
        // Generate initial field type
 
        let field_type = self.determine_inference_type_from_parser_type_elements(&definition.fields[field_idx].parser_type.elements, false);
 
        self.extra_data[extra_data_idx as usize] = ExtraData{
 
            expr_id: select_id.upcast(),
 
            definition_id: struct_def_id,
 
            poly_vars,
 
            embedded: vec![InferenceType::new(num_poly_vars != 0, num_poly_vars == 0, struct_parts)],
 
            returned: field_type
 
        };
 
    }
 

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

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

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

	
src/protocol/parser/symbol_table.rs
Show inline comments
 
/// symbol_table.rs
 
///
 
/// The datastructure used to lookup symbols within particular scopes. Scopes
 
/// may be module-level or definition level, although imports and definitions
 
/// within definitions are currently not allowed.
 
///
 
/// TODO: Once the compiler has matured, find out ways to optimize to prevent
 
///     the repeated HashMap lookup.
 

	
 
use std::collections::HashMap;
 
use std::collections::hash_map::Entry;
 

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

	
 
const RESERVED_SYMBOLS: usize = 32;
 

	
 
#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
 
pub enum SymbolScope {
 
    Global,
 
    Module(RootId),
 
    Definition(DefinitionId),
 
}
 

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

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

	
 
impl DefinitionClass {
 
    fn as_symbol_class(&self) -> SymbolClass {
 
        match self {
 
            DefinitionClass::Struct => SymbolClass::Struct,
 
            DefinitionClass::Enum => SymbolClass::Enum,
 
            DefinitionClass::Union => SymbolClass::Union,
 
            DefinitionClass::Function => SymbolClass::Function,
 
            DefinitionClass::Component => SymbolClass::Component,
 
        }
 
    }
 
}
 

	
 
struct ScopedSymbols {
 
    scope: SymbolScope,
 
    parent_scope: Option<SymbolScope>,
 
    child_scopes: Vec<SymbolScope>,
 
    symbols: Vec<Symbol>,
 
}
 

	
 
impl ScopedSymbols {
 
    fn get_symbol<'a>(&'a self, name: &StringRef) -> Option<&'a Symbol> {
 
        for symbol in self.symbols.iter() {
 
            if symbol.name == *name {
 
                return Some(symbol);
 
            }
 
        }
 

	
 
        None
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct SymbolModule {
 
    pub root_id: RootId,
 
    pub introduced_at: ImportId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct SymbolDefinition {
 
    // Definition location (not necessarily the place where the symbol
 
    // is introduced, as it may be imported). Builtin symbols will have invalid
 
    // spans and module IDs
 
    pub defined_in_module: RootId,
 
    pub defined_in_scope: SymbolScope,
 
    pub definition_span: InputSpan, // full span of definition
 
    pub identifier_span: InputSpan, // span of just the identifier
 
    // Location where the symbol is introduced in its scope
 
    pub imported_at: Option<ImportId>,
 
    // Definition in the heap, with a utility enum to determine its
 
    // class if the ID is not needed.
 
    pub class: DefinitionClass,
 
    pub definition_id: DefinitionId,
 
}
 

	
 
impl SymbolDefinition {
 
    /// Clones the entire data structure, but replaces the `imported_at` field
 
    /// with the supplied `ImportId`.
 
    pub(crate) fn into_imported(mut self, imported_at: ImportId) -> Self {
 
        self.imported_at = Some(imported_at);
 
        self
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub enum SymbolVariant {
 
    Module(SymbolModule),
 
    Definition(SymbolDefinition),
 
}
 

	
 
impl SymbolVariant {
 
    /// Returns the span at which the item was introduced. For an imported
 
    /// item (all modules, and imported types) this returns the span of the
 
    /// import. For a defined type this returns the span of the identifier
 
    pub(crate) fn span_of_introduction(&self, heap: &Heap) -> InputSpan {
 
        match self {
 
            SymbolVariant::Module(v) => heap[v.introduced_at].span(),
 
            SymbolVariant::Definition(v) => if let Some(import_id) = v.imported_at {
 
                heap[import_id].span()
 
            } else {
 
                v.identifier_span
 
            },
 
        }
 
    }
 

	
 
    pub(crate) fn as_definition(&self) -> &SymbolDefinition {
 
        match self {
 
            SymbolVariant::Module(_) => unreachable!("called 'as_definition' on {:?}", self),
 
            SymbolVariant::Definition(v) => v,
 
        }
 
    }
 
}
 

	
 
/// TODO: @Cleanup - remove clone everywhere
 
#[derive(Debug, Clone)]
 
pub struct Symbol {
 
    pub name: StringRef<'static>,
 
    pub variant: SymbolVariant,
 
}
 

	
 
impl Symbol {
 
    pub(crate) fn class(&self) -> SymbolClass {
 
        match &self.variant {
 
            SymbolVariant::Module(_) => SymbolClass::Module,
 
            SymbolVariant::Definition(data) => data.class.as_symbol_class(),
 
        }
 
    }
 
}
 

	
 
pub struct SymbolTable {
 
    module_lookup: HashMap<StringRef<'static>, RootId>,
 
    scope_lookup: HashMap<SymbolScope, ScopedSymbols>,
 
}
 

	
 
impl SymbolTable {
 
    pub(crate) fn new() -> Self {
 
        Self{
 
            module_lookup: HashMap::new(),
 
            scope_lookup: HashMap::new(),
 
        }
 
    }
 
    /// Inserts a new module by its name. Upon module naming conflict the
 
    /// previously associated `RootId` will be returned.
 
    pub(crate) fn insert_module(&mut self, module_name: StringRef<'static>, root_id: RootId) -> Result<(), RootId> {
 
        match self.module_lookup.entry(module_name) {
 
            Entry::Occupied(v) => {
 
                Err(*v.get())
 
            },
 
            Entry::Vacant(v) => {
 
                v.insert(root_id);
 
                Ok(())
 
            }
 
        }
 
    }
 

	
 
    /// Retrieves module `RootId` by name
 
    pub(crate) fn get_module_by_name(&mut self, name: &[u8]) -> Option<RootId> {
 
        let string_ref = StringRef::new(name);
 
        self.module_lookup.get(&string_ref).map(|v| *v)
 
    }
 

	
 
    /// Inserts a new symbol scope. The parent must have been added to the
 
    /// symbol table before.
 
    pub(crate) fn insert_scope(&mut self, parent_scope: Option<SymbolScope>, new_scope: SymbolScope) {
 
        debug_assert!(
 
            parent_scope.is_none() || self.scope_lookup.contains_key(parent_scope.as_ref().unwrap()),
 
            "inserting scope {:?} but parent {:?} does not exist", new_scope, parent_scope
 
        );
 
        debug_assert!(!self.scope_lookup.contains_key(&new_scope), "inserting scope {:?}, but it already exists", new_scope);
 

	
 
        if let Some(parent_scope) = parent_scope {
 
            let parent = self.scope_lookup.get_mut(&parent_scope).unwrap();
 
            parent.child_scopes.push(new_scope);
 
        }
 

	
 
        let scope = ScopedSymbols {
 
            scope: new_scope,
 
            parent_scope,
 
            child_scopes: Vec::with_capacity(RESERVED_SYMBOLS),
 
            symbols: Vec::with_capacity(RESERVED_SYMBOLS)
 
        };
 
        self.scope_lookup.insert(new_scope, scope);
 
    }
 

	
 
    /// Inserts a symbol into a particular scope. The symbol's name may not
 
    /// exist in the scope or any of its parents. If it does collide then the
 
    /// symbol will be returned, together with the symbol that has the same
 
    /// name.
 
    // Note: we do not return a reference because Rust doesn't like it.
 
    pub(crate) fn insert_symbol(&mut self, in_scope: SymbolScope, symbol: Symbol) -> Result<(), (Symbol, Symbol)> {
 
        debug_assert!(self.scope_lookup.contains_key(&in_scope), "inserting symbol {}, but scope {:?} does not exist", symbol.name.as_str(), in_scope);
 
        let mut seek_scope = in_scope;
 
        loop {
 
            let scoped_symbols = self.scope_lookup.get(&seek_scope).unwrap();
 
            for existing_symbol in scoped_symbols.symbols.iter() {
 
                if symbol.name == existing_symbol.name {
 
                    return Err((symbol, existing_symbol.clone()))
 
                }
 
            }
 

	
 
            match scoped_symbols.parent_scope {
 
                Some(parent_scope) => { seek_scope = parent_scope; },
 
                None => { break; }
 
            }
 
        }
 

	
 
        // If here, then there is no collision
 
        let scoped_symbols = self.scope_lookup.get_mut(&in_scope).unwrap();
 
        scoped_symbols.symbols.push(symbol);
 
        Ok(())
 
    }
 

	
 
    /// Retrieves a symbol by name by searching in a particular scope and that scope's parents. The
 
    /// returned symbol may both be imported as defined within any of the searched scopes.
 
    pub(crate) fn get_symbol_by_name(
 
        &self, mut in_scope: SymbolScope, name: &[u8]
 
    ) -> Option<&Symbol> {
 
        let string_ref = StringRef::new(name);
 
        loop {
 
            let scope = self.scope_lookup.get(&in_scope);
 
            if scope.is_none() {
 
                return None;
 
            }
 
            let scope = scope.unwrap();
 

	
 
            if let Some(symbol) = scope.get_symbol(&string_ref) {
 
                return Some(symbol);
 
            } else {
 
                // Could not find symbol in current scope, seek in the parent scope if it exists
 
                match &scope.parent_scope {
 
                    Some(parent_scope) => { in_scope = *parent_scope; },
 
                    None => return None,
 
                }
 
            }
 
        }
 
    }
 

	
 
    /// Retrieves a symbol by name by searching in a particular scope and that scope's parents. The
 
    /// returned symbol must be defined within any of the searched scopes and may not be imported.
 
    /// In case such an imported symbol exists then this function still returns `None`.
 
    pub(crate) fn get_symbol_by_name_defined_in_scope(
 
        &self, in_scope: SymbolScope, name: &[u8]
 
    ) -> Option<&Symbol> {
 
        match self.get_symbol_by_name(in_scope, name) {
 
            Some(symbol) => {
 
                match &symbol.variant {
 
                    SymbolVariant::Module(_) => {
 
                        None // in-scope modules are always imported
 
                    },
 
                    SymbolVariant::Definition(variant) => {
 
                        if variant.imported_at.is_some() || variant.defined_in_scope == SymbolScope::Global {
 
                            // Symbol is imported or lives in the global scope.
 
                            // Things in the global scope are defined by the
 
                            // compiler.
 
                            None
 
                        } else {
 
                            Some(symbol)
 
                        }
 
                    }
 
                }
 
            },
 
            None => None,
 
        }
 
    }
 

	
 
    /// Retrieves all symbols that are defined within a particular scope. Imported symbols are
 
    /// ignored. Returns `true` if the scope was found (which may contain 0 defined symbols) and
 
    /// `false` if the scope was not found.
 
    pub(crate) fn get_all_symbols_defined_in_scope(&self, in_scope: SymbolScope, target: &mut Vec<Symbol>) -> bool {
 
        match self.scope_lookup.get(&in_scope) {
 
            Some(scope) => {
 
                for symbol in &scope.symbols {
 
                    if let SymbolVariant::Definition(definition) = &symbol.variant {
 
                        if definition.imported_at.is_some() {
 
                            continue;
 
                        }
 

	
 
                        // Defined in scope, so push onto target
 
                        target.push(symbol.clone());
 
                    }
 
                }
 

	
 
                true
 
            },
 
            None => false,
 
        }
 
    }
 
}
 
\ No newline at end of file
src/protocol/parser/type_table.rs
Show inline comments
 
use std::fmt::{Formatter, Result as FmtResult};
 
use std::collections::{HashMap, VecDeque};
 
use std::collections::HashMap;
 

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

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

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

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

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

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

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

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

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

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

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

	
 
    pub(crate) fn data_monomorphs(&self) -> &Vec<DataMonomorph> {
 
        use DefinedTypeVariant::*;
 

	
 
        match self {
 
            Enum(v) => &v.monomorphs,
 
            Union(v) => &v.monomorphs,
 
            Struct(v) => &v.monomorphs,
 
            _ => unreachable!("cannot get data monomorphs from {}", self.type_class()),
 
        }
 
    }
 

	
 
    pub(crate) fn data_monomorphs_mut(&mut self) -> &mut Vec<DataMonomorph> {
 
        use DefinedTypeVariant::*;
 

	
 
        match self {
 
            Enum(v) => &mut v.monomorphs,
 
            Union(v) => &mut v.monomorphs,
 
            Struct(v) => &mut v.monomorphs,
 
            _ => unreachable!("cannot get data monomorphs from {}", self.type_class()),
 
        }
 
    }
 

	
 
    pub(crate) fn procedure_monomorphs(&self) -> &Vec<ProcedureMonomorph> {
 
        use DefinedTypeVariant::*;
 

	
 
        match self {
 
            Function(v) => &v.monomorphs,
 
            Component(v) => &v.monomorphs,
 
            _ => unreachable!("cannot get procedure monomorphs from {}", self.type_class()),
 
        }
 
    }
 

	
 
    pub(crate) fn procedure_monomorphs_mut(&mut self) -> &mut Vec<ProcedureMonomorph> {
 
        use DefinedTypeVariant::*;
 

	
 
        match self {
 
            Function(v) => &mut v.monomorphs,
 
            Component(v) => &mut v.monomorphs,
 
            _ => unreachable!("cannot get procedure monomorphs from {}", self.type_class()),
 
        }
 
    }
 
}
 

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

	
 
/// Data associated with a monomorphized datatype
 
pub struct DataMonomorph {
 
    pub poly_args: Vec<ConcreteType>,
 
}
 

	
 
/// Data associated with a monomorphized procedure type. Has the wrong name,
 
/// because it will also be used to store expression data for a non-polymorphic
 
/// procedure. (in that case, there will only ever be one)
 
pub struct ProcedureMonomorph {
 
    // Expression data for one particular monomorph
 
    pub poly_args: Vec<ConcreteType>,
 
    pub expr_data: Vec<MonomorphExpression>,
 
}
 

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

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

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

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

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

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

	
 
pub struct FunctionType {
 
    pub return_types: Vec<ParserType>,
 
    pub arguments: Vec<FunctionArgument>,
 
    pub monomorphs: Vec<ProcedureMonomorph>,
 
}
 

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

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

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

	
 
//------------------------------------------------------------------------------
 
// Type table
 
//------------------------------------------------------------------------------
 

	
 
// TODO: @cleanup Do I really need this, doesn't make the code that much cleaner
 
struct TypeIterator {
 
    breadcrumbs: Vec<(RootId, DefinitionId)>
 
}
 

	
 
impl TypeIterator {
 
    fn new() -> Self {
 
        Self{ breadcrumbs: Vec::with_capacity(32) }
 
    }
 

	
 
    fn reset(&mut self, root_id: RootId, definition_id: DefinitionId) {
 
        self.breadcrumbs.clear();
 
        self.breadcrumbs.push((root_id, definition_id))
 
    }
 

	
 
    fn push(&mut self, root_id: RootId, definition_id: DefinitionId) {
 
        self.breadcrumbs.push((root_id, definition_id));
 
    }
 

	
 
    fn contains(&self, root_id: RootId, definition_id: DefinitionId) -> bool {
 
        for (stored_root_id, stored_definition_id) in self.breadcrumbs.iter() {
 
            if *stored_root_id == root_id && *stored_definition_id == definition_id { return true; }
 
        }
 

	
 
        return false
 
    }
 

	
 
    fn top(&self) -> Option<(RootId, DefinitionId)> {
 
        self.breadcrumbs.last().map(|(r, d)| (*r, *d))
 
    }
 

	
 
    fn pop(&mut self) {
 
        debug_assert!(!self.breadcrumbs.is_empty());
 
        self.breadcrumbs.pop();
 
    }
 
}
 

	
 
/// Result from attempting to resolve a `ParserType` using the symbol table and
 
/// the type table.
 
enum ResolveResult {
 
    Builtin,
 
    PolymoprhicArgument,
 
    /// ParserType points to a user-defined type that is already resolved in the
 
    /// type table.
 
    Resolved(RootId, DefinitionId),
 
    /// ParserType points to a user-defined type that is not yet resolved into
 
    /// the type table.
 
    Unresolved(RootId, DefinitionId)
 
}
 

	
 
pub struct TypeTable {
 
    /// Lookup from AST DefinitionId to a defined type. Considering possible
 
    /// polymorphs is done inside the `DefinedType` struct.
 
    lookup: HashMap<DefinitionId, DefinedType>,
 
    /// Iterator over `(module, definition)` tuples used as workspace to make sure
 
    /// that each base definition of all a type's subtypes are resolved.
 
    iter: TypeIterator,
 
    /// Iterator over `parser type`s during the process where `parser types` are
 
    /// resolved into a `(module, definition)` tuple.
 
    parser_type_iter: VecDeque<ParserTypeId>,
 
}
 

	
 
impl TypeTable {
 
    /// Construct a new type table without any resolved types.
 
    pub(crate) fn new() -> Self {
 
        Self{ 
 
            lookup: HashMap::new(), 
 
            iter: TypeIterator::new(),
 
            parser_type_iter: VecDeque::with_capacity(64), 
 
        }
 
    }
 

	
 
    pub(crate) fn build_base_types(&mut self, modules: &mut [Module], ctx: &mut PassCtx) -> Result<(), ParseError> {
 
        // Make sure we're allowed to cast root_id to index into ctx.modules
 
        debug_assert!(modules.iter().all(|m| m.phase >= ModuleCompilationPhase::DefinitionsParsed));
 
        debug_assert!(self.lookup.is_empty());
 
        debug_assert!(self.iter.top().is_none());
 
        debug_assert!(self.parser_type_iter.is_empty());
 

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

	
 
        // Use context to guess hashmap size
 
        let reserve_size = ctx.heap.definitions.len();
 
        self.lookup.reserve(reserve_size);
 

	
 
        for definition_idx in 0..ctx.heap.definitions.len() {
 
            let definition_id = ctx.heap.definitions.get_id(definition_idx);
 
            self.resolve_base_definition(modules, ctx, definition_id)?;
 
        }
 

	
 
        debug_assert_eq!(self.lookup.len(), reserve_size, "mismatch in reserved size of type table"); // NOTE: Temp fix for builtin functions
 
        for module in modules {
 
            module.phase = ModuleCompilationPhase::TypesAddedToTable;
 
        }
 

	
 
        Ok(())
 
    }
 

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

	
 
    /// Returns the index into the monomorph type array if the procedure type
 
    /// already has a (reserved) monomorph.
 
    pub(crate) fn get_procedure_monomorph_index(&self, definition_id: &DefinitionId, types: &Vec<ConcreteType>) -> Option<i32> {
 
        let def = self.lookup.get(definition_id).unwrap();
 
        if def.is_polymorph {
 
            let monos = def.definition.procedure_monomorphs();
 
            return monos.iter()
 
                .position(|v| v.poly_args == *types)
 
                .map(|v| v as i32);
 
        } else {
 
            // We don't actually care about the types
 
            let monos = def.definition.procedure_monomorphs();
 
            if monos.is_empty() {
 
                return None
 
            } else {
 
                return Some(0)
 
            }
 
        }
 
    }
 

	
 
    /// Returns a mutable reference to a procedure's monomorph expression data.
 
    /// Used by typechecker to fill in previously reserved type information
 
    pub(crate) fn get_procedure_expression_data_mut(&mut self, definition_id: &DefinitionId, monomorph_idx: i32) -> &mut ProcedureMonomorph {
 
        debug_assert!(monomorph_idx >= 0);
 
        let def = self.lookup.get_mut(definition_id).unwrap();
 
        let monomorphs = def.definition.procedure_monomorphs_mut();
 
        return &mut monomorphs[monomorph_idx as usize];
 
    }
 

	
 
    pub(crate) fn get_procedure_expression_data(&self, definition_id: &DefinitionId, monomorph_idx: i32) -> &ProcedureMonomorph {
 
        debug_assert!(monomorph_idx >= 0);
 
        let def = self.lookup.get(definition_id).unwrap();
 
        let monomorphs = def.definition.procedure_monomorphs();
 
        return &monomorphs[monomorph_idx as usize];
 
    }
 

	
 
    /// Reserves space for a monomorph of a polymorphic procedure. The index
 
    /// will point into a (reserved) slot of the array of expression types. The
 
    /// monomorph may NOT exist yet (because the reservation implies that we're
 
    /// going to be performing typechecking on it, and we don't want to
 
    /// check the same monomorph twice)
 
    pub(crate) fn reserve_procedure_monomorph_index(&mut self, definition_id: &DefinitionId, types: Option<Vec<ConcreteType>>) -> i32 {
 
        let def = self.lookup.get_mut(definition_id).unwrap();
 
        if let Some(types) = types {
 
            // Expecting a polymorphic procedure
 
            let monos = def.definition.procedure_monomorphs_mut();
 
            debug_assert!(def.is_polymorph);
 
            debug_assert!(def.poly_vars.len() == types.len());
 
            debug_assert!(monos.iter().find(|v| v.poly_args == types).is_none());
 

	
 
            let mono_idx = monos.len();
 
            monos.push(ProcedureMonomorph{ poly_args: types, expr_data: Vec::new() });
 

	
 
            return mono_idx as i32;
 
        } else {
 
            // Expecting a non-polymorphic procedure
 
            let monos = def.definition.procedure_monomorphs_mut();
 
            debug_assert!(!def.is_polymorph);
 
            debug_assert!(def.poly_vars.is_empty());
 
            debug_assert!(monos.is_empty());
 

	
 
            monos.push(ProcedureMonomorph{ poly_args: Vec::new(), expr_data: Vec::new() });
 

	
 
            return 0;
 
        }
 
    }
 

	
 
    /// Adds a datatype polymorph to the type table. Will not add the
 
    /// monomorph if it is already present, or if the type's polymorphic
 
    /// variables are all unused.
 
    pub(crate) fn add_data_monomorph(&mut self, definition_id: &DefinitionId, types: Vec<ConcreteType>) -> i32 {
 
        let def = self.lookup.get_mut(definition_id).unwrap();
 
        if !def.is_polymorph {
 
            // Not a polymorph, or polyvars are not used in type definition
 
            return 0;
 
        }
 

	
 
        let monos = def.definition.data_monomorphs_mut();
 
        if let Some(index) = monos.iter().position(|v| v.poly_args == types) {
 
            // We already know about this monomorph
 
            return index as i32;
 
        }
 

	
 
        let index = monos.len();
 
        monos.push(DataMonomorph{ poly_args: types });
 
        return index as i32;
 
    }
 

	
 
    /// This function will resolve just the basic definition of the type, it
 
    /// will not handle any of the monomorphized instances of the type.
 
    fn resolve_base_definition<'a>(&'a mut self, modules: &[Module], ctx: &mut PassCtx, definition_id: DefinitionId) -> Result<(), ParseError> {
 
        // Check if we have already resolved the base definition
 
        if self.lookup.contains_key(&definition_id) { return Ok(()); }
 

	
 
        let root_id = ctx.heap[definition_id].defined_in();
 
        self.iter.reset(root_id, definition_id);
 

	
 
        while let Some((root_id, definition_id)) = self.iter.top() {
 
            // We have a type to resolve
 
            let definition = &ctx.heap[definition_id];
 

	
 
            let can_pop_breadcrumb = match definition {
 
                // Bit ugly, since we already have the definition, but we need
 
                // to work around rust borrowing rules...
 
                Definition::Enum(_) => self.resolve_base_enum_definition(modules, ctx, root_id, definition_id),
 
                Definition::Union(_) => self.resolve_base_union_definition(modules, ctx, root_id, definition_id),
 
                Definition::Struct(_) => self.resolve_base_struct_definition(modules, ctx, root_id, definition_id),
 
                Definition::Component(_) => self.resolve_base_component_definition(modules, ctx, root_id, definition_id),
 
                Definition::Function(_) => self.resolve_base_function_definition(modules, ctx, root_id, definition_id),
 
            }?;
 

	
 
            // Otherwise: `ingest_resolve_result` has pushed a new breadcrumb
 
            // that we must follow before we can resolve the current type
 
            if can_pop_breadcrumb {
 
                self.iter.pop();
 
            }
 
        }
 

	
 
        // We must have resolved the type
 
        debug_assert!(self.lookup.contains_key(&definition_id), "base type not resolved");
 
        Ok(())
 
    }
 

	
 
    /// Resolve the basic enum definition to an entry in the type table. It will
 
    /// not instantiate any monomorphized instances of polymorphic enum
 
    /// definitions. If a subtype has to be resolved first then this function
 
    /// will return `false` after calling `ingest_resolve_result`.
 
    fn resolve_base_enum_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, root_id: RootId, definition_id: DefinitionId) -> Result<bool, ParseError> {
 
        debug_assert!(ctx.heap[definition_id].is_enum());
 
        debug_assert!(!self.lookup.contains_key(&definition_id), "base enum already resolved");
 
        
 
        let definition = ctx.heap[definition_id].as_enum();
 

	
 
        let mut enum_value = -1;
 
        let mut min_enum_value = 0;
 
        let mut max_enum_value = 0;
 
        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,
 
                    });
 
                }
 
            }
 
            if enum_value < min_enum_value { min_enum_value = enum_value; }
 
            else if enum_value > max_enum_value { max_enum_value = enum_value; }
 
        }
 

	
 
        // Ensure enum names and polymorphic args do not conflict
 
        self.check_identifier_collision(
 
            modules, root_id, &variants, |variant| &variant.identifier, "enum variant"
 
        )?;
 

	
 
        // Because we're parsing an enum, the programmer cannot put the
 
        // polymorphic variables inside the variants. But the polymorphic
 
        // variables might still be present as "marker types"
 
        self.check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
 
        let poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
 

	
 
        self.lookup.insert(definition_id, DefinedType {
 
            ast_root: root_id,
 
            ast_definition: definition_id,
 
            definition: DefinedTypeVariant::Enum(EnumType{
 
                variants,
 
                representation: Self::enum_tag_type(min_enum_value, max_enum_value),
 
                monomorphs: Vec::new(),
 
            }),
 
            poly_vars,
 
            is_polymorph: false,
 
        });
 

	
 
        Ok(true)
 
    }
 

	
 
    /// Resolves the basic union definiton to an entry in the type table. It
 
    /// will not instantiate any monomorphized instances of polymorphic union
 
    /// definitions. If a subtype has to be resolved first then this function
 
    /// will return `false` after calling `ingest_resolve_result`.
 
    fn resolve_base_union_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, root_id: RootId, definition_id: DefinitionId) -> Result<bool, ParseError> {
 
        debug_assert!(ctx.heap[definition_id].is_union());
 
        debug_assert!(!self.lookup.contains_key(&definition_id), "base union already resolved");
 

	
 
        let definition = ctx.heap[definition_id].as_union();
 

	
 
        // Make sure all embedded types are resolved
 
        for variant in &definition.variants {
 
            match &variant.value {
 
                UnionVariantValue::None => {},
 
                UnionVariantValue::Embedded(embedded) => {
 
                    for parser_type in embedded {
 
                        let resolve_result = self.resolve_base_parser_type(modules, ctx, root_id, parser_type, false)?;
 
                        if !self.ingest_resolve_result(modules, ctx, resolve_result)? {
 
                            return Ok(false)
 
                        }
 
                    }
 
                }
 
            }
 
        }
 

	
 
        // If here then all embedded types are resolved
 

	
 
        // Determine the union variants
 
        let mut tag_value = -1;
 
        let mut variants = Vec::with_capacity(definition.variants.len());
 
        for variant in &definition.variants {
 
            tag_value += 1;
 
            let embedded = match &variant.value {
 
                UnionVariantValue::None => { Vec::new() },
 
                UnionVariantValue::Embedded(embedded) => {
 
                    // Type should be resolvable, we checked this above
 
                    embedded.clone()
 
                },
 
            };
 

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

	
 
        // Ensure union names and polymorphic args do not conflict
 
        self.check_identifier_collision(
 
            modules, root_id, &variants, |variant| &variant.identifier, "union variant"
 
        )?;
 
        self.check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
 

	
 
        // Construct polymorphic variables and mark the ones that are in use
 
        let mut poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
 
        for variant in &variants {
 
            for parser_type in &variant.embedded {
 
                Self::mark_used_polymorphic_variables(&mut poly_vars, parser_type);
 
            }
 
        }
 
        let is_polymorph = poly_vars.iter().any(|arg| arg.is_in_use);
 

	
 
        // Insert base definition in type table
 
        self.lookup.insert(definition_id, DefinedType {
 
            ast_root: root_id,
 
            ast_definition: definition_id,
 
            definition: DefinedTypeVariant::Union(UnionType{
 
                variants,
 
                tag_representation: Self::enum_tag_type(-1, tag_value),
 
                monomorphs: Vec::new(),
 
            }),
 
            poly_vars,
 
            is_polymorph,
 
        });
 

	
 
        Ok(true)
 
    }
 

	
 
    /// Resolves the basic struct definition to an entry in the type table. It
 
    /// will not instantiate any monomorphized instances of polymorphic struct
 
    /// definitions.
 
    fn resolve_base_struct_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, root_id: RootId, definition_id: DefinitionId) -> Result<bool, ParseError> {
 
        debug_assert!(ctx.heap[definition_id].is_struct());
 
        debug_assert!(!self.lookup.contains_key(&definition_id), "base struct already resolved");
 

	
 
        let definition = ctx.heap[definition_id].as_struct();
 

	
 
        // Make sure all fields point to resolvable types
 
        for field_definition in &definition.fields {
 
            let resolve_result = self.resolve_base_parser_type(modules, ctx, root_id, &field_definition.parser_type, false)?;
 
            if !self.ingest_resolve_result(modules, ctx, resolve_result)? {
 
                return Ok(false)
 
            }
 
        }
 

	
 
        // All fields types are resolved, construct base type
 
        let mut fields = Vec::with_capacity(definition.fields.len());
 
        for field_definition in &definition.fields {
 
            fields.push(StructField{
 
                identifier: field_definition.field.clone(),
 
                parser_type: field_definition.parser_type.clone(),
 
            })
 
        }
 

	
 
        // And make sure no conflicts exist in field names and/or polymorphic args
 
        self.check_identifier_collision(
 
            modules, root_id, &fields, |field| &field.identifier, "struct field"
 
        )?;
 
        self.check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
 

	
 
        // Construct representation of polymorphic arguments
 
        let mut poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
 
        for field in &fields {
 
            Self::mark_used_polymorphic_variables(&mut poly_vars, &field.parser_type);
 
        }
 

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

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

	
 
        Ok(true)
 
    }
 

	
 
    /// Resolves the basic function definition to an entry in the type table. It
 
    /// will not instantiate any monomorphized instances of polymorphic function
 
    /// definitions.
 
    fn resolve_base_function_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, root_id: RootId, definition_id: DefinitionId) -> Result<bool, ParseError> {
 
        debug_assert!(ctx.heap[definition_id].is_function());
 
        debug_assert!(!self.lookup.contains_key(&definition_id), "base function already resolved");
 

	
 
        let definition = ctx.heap[definition_id].as_function();
 

	
 
        // Check the return type
 
        debug_assert_eq!(definition.return_types.len(), 1, "not one return type"); // TODO: @ReturnValues
 
        let resolve_result = self.resolve_base_parser_type(modules, ctx, root_id, &definition.return_types[0], definition.builtin)?;
 
        if !self.ingest_resolve_result(modules, ctx, resolve_result)? {
 
            return Ok(false)
 
        }
 

	
 
        // Check the argument types
 
        for param_id in &definition.parameters {
 
            let param = &ctx.heap[*param_id];
 
            let resolve_result = self.resolve_base_parser_type(modules, ctx, root_id, &param.parser_type, definition.builtin)?;
 
            if !self.ingest_resolve_result(modules, ctx, resolve_result)? {
 
                return Ok(false)
 
            }
 
        }
 

	
 
        // Construct arguments to function
 
        let mut arguments = Vec::with_capacity(definition.parameters.len());
 
        for param_id in &definition.parameters {
 
            let param = &ctx.heap[*param_id];
 
            arguments.push(FunctionArgument{
 
                identifier: param.identifier.clone(),
 
                parser_type: param.parser_type.clone(),
 
            })
 
        }
 

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

	
 
        // Construct polymorphic arguments
 
        let mut poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
 
        Self::mark_used_polymorphic_variables(&mut poly_vars, &definition.return_types[0]);
 
        for argument in &arguments {
 
            Self::mark_used_polymorphic_variables(&mut poly_vars, &argument.parser_type);
 
        }
 
        let is_polymorph = poly_vars.iter().any(|arg| arg.is_in_use);
 

	
 
        // Construct entry in type table
 
        self.lookup.insert(definition_id, DefinedType{
 
            ast_root: root_id,
 
            ast_definition: definition_id,
 
            definition: DefinedTypeVariant::Function(FunctionType{
 
                return_types: definition.return_types.clone(),
 
                arguments,
 
                monomorphs: Vec::new(),
 
            }),
 
            poly_vars,
 
            is_polymorph,
 
        });
 

	
 
        Ok(true)
 
    }
 

	
 
    /// Resolves the basic component definition to an entry in the type table.
 
    /// It will not instantiate any monomorphized instancees of polymorphic
 
    /// component definitions.
 
    fn resolve_base_component_definition(&mut self, modules: &[Module], ctx: &mut PassCtx, root_id: RootId, definition_id: DefinitionId) -> Result<bool, ParseError> {
 
        debug_assert!(ctx.heap[definition_id].is_component());
 
        debug_assert!(!self.lookup.contains_key(&definition_id), "base component already resolved");
 

	
 
        let definition = ctx.heap[definition_id].as_component();
 
        let component_variant = definition.variant;
 

	
 
        // Check argument types
 
        for param_id in &definition.parameters {
 
            let param = &ctx.heap[*param_id];
 
            let resolve_result = self.resolve_base_parser_type(modules, ctx, root_id, &param.parser_type, false)?;
 
            if !self.ingest_resolve_result(modules, ctx, resolve_result)? {
 
                return Ok(false)
 
            }
 
        }
 

	
 
        // Construct argument types
 
        let mut arguments = Vec::with_capacity(definition.parameters.len());
 
        for param_id in &definition.parameters {
 
            let param = &ctx.heap[*param_id];
 
            arguments.push(FunctionArgument{
 
                identifier: param.identifier.clone(),
 
                parser_type: param.parser_type.clone()
 
            })
 
        }
 

	
 
        // Check conflict of argument and polyarg identifiers
 
        self.check_identifier_collision(
 
            modules, root_id, &arguments, |arg| &arg.identifier, "component argument"
 
        )?;
 
        self.check_poly_args_collision(modules, ctx, root_id, &definition.poly_vars)?;
 

	
 
        // Construct polymorphic arguments
 
        let mut poly_vars = Self::create_polymorphic_variables(&definition.poly_vars);
 
        for argument in &arguments {
 
            Self::mark_used_polymorphic_variables(&mut poly_vars, &argument.parser_type);
 
        }
 

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

	
 
        // Construct entry in type table
 
        self.lookup.insert(definition_id, DefinedType{
 
            ast_root: root_id,
 
            ast_definition: definition_id,
 
            definition: DefinedTypeVariant::Component(ComponentType{
 
                variant: component_variant,
 
                arguments,
 
                monomorphs: Vec::new(),
 
            }),
 
            poly_vars,
 
            is_polymorph,
 
        });
 

	
 
        Ok(true)
 
    }
 

	
 
    /// Takes a ResolveResult and returns `true` if the caller can happily
 
    /// continue resolving its current type, or `false` if the caller must break
 
    /// resolving the current type and exit to the outer resolving loop. In the
 
    /// latter case the `result` value was `ResolveResult::Unresolved`, implying
 
    /// that the type must be resolved first.
 
    fn ingest_resolve_result(&mut self, modules: &[Module], ctx: &PassCtx, result: ResolveResult) -> Result<bool, ParseError> {
 
        match result {
 
            ResolveResult::Builtin | ResolveResult::PolymoprhicArgument => Ok(true),
 
            ResolveResult::Resolved(_, _) => Ok(true),
 
            ResolveResult::Unresolved(root_id, definition_id) => {
 
                if self.iter.contains(root_id, definition_id) {
 
                    // Cyclic dependency encountered
 
                    // TODO: Allow this
 
                    let module_source = &modules[root_id.index as usize].source;
 
                    let mut error = ParseError::new_error_str_at_span(
 
                        module_source, ctx.heap[definition_id].identifier().span,
 
                        "Evaluating this type definition results in a cyclic type"
 
                    );
 

	
 
                    for (breadcrumb_idx, (root_id, definition_id)) in self.iter.breadcrumbs.iter().enumerate() {
 
                        let msg = if breadcrumb_idx == 0 {
 
                            "The cycle started with this definition"
 
                        } else {
 
                            "Which depends on this definition"
 
                        };
 

	
 
                        let module_source = &modules[root_id.index as usize].source;
 
                        error = error.with_info_str_at_span(module_source, ctx.heap[*definition_id].identifier().span, msg);
 
                    }
 

	
 
                    Err(error)
 
                } else {
 
                    // Type is not yet resolved, so push IDs on iterator and
 
                    // continue the resolving loop
 
                    self.iter.push(root_id, definition_id);
 
                    Ok(false)
 
                }
 
            }
 
        }
 
    }
 

	
 
    /// Each type may consist of embedded types. If this type does not have a
 
    /// fixed implementation (e.g. an input port may have an embedded type
 
    /// indicating the type of messages, but it always exists in the runtime as
 
    /// a port identifier, so it has a fixed implementation) then this function
 
    /// will traverse the embedded types to ensure all of them are resolved.
 
    ///
 
    /// Hence if one checks a particular parser type for being resolved, one may
 
    /// get back a result value indicating an embedded type (with a different
 
    /// DefinitionId) is unresolved.
 
    fn resolve_base_parser_type(
 
        &mut self, modules: &[Module], ctx: &PassCtx, root_id: RootId,
 
        parser_type: &ParserType, is_builtin: bool
 
    ) -> Result<ResolveResult, ParseError> {
 
        // Note that as we iterate over the elements of a
 
        use ParserTypeVariant as PTV;
 

	
 
        // Result for the very first time we resolve a type (i.e the outer type
 
        // that we're actually looking up)
 
        let mut resolve_result = None;
 
        let mut set_resolve_result = |v: ResolveResult| {
 
            if resolve_result.is_none() { resolve_result = Some(v); }
 
        };
 

	
 
        for element in parser_type.elements.iter() {
 
            match element.variant {
 
                PTV::Void | PTV::InputOrOutput | PTV::ArrayLike | PTV::IntegerLike => {
 
                    if is_builtin {
 
                        set_resolve_result(ResolveResult::Builtin);
 
                    } else {
 
                        unreachable!("compiler-only ParserTypeVariant within type definition");
 
                    }
 
                },
 
                PTV::Message | PTV::Bool |
 
                PTV::UInt8 | PTV::UInt16 | PTV::UInt32 | PTV::UInt64 |
 
                PTV::SInt8 | PTV::SInt16 | PTV::SInt32 | PTV::SInt64 |
 
                PTV::Character | PTV::String |
 
                PTV::Array | PTV::Input | PTV::Output => {
 
                    // Nothing to do: these are builtin types or types with a
 
                    // fixed implementation
 
                    set_resolve_result(ResolveResult::Builtin);
 
                },
 
                PTV::IntegerLiteral | PTV::Inferred => {
 
                    // As we're parsing the type definitions where these kinds
 
                    // of types are impossible/disallowed to express:
 
                    unreachable!("illegal ParserTypeVariant within type definition");
 
                },
 
                PTV::PolymorphicArgument(_, _) => {
 
                    set_resolve_result(ResolveResult::PolymoprhicArgument);
 
                },
 
                PTV::Definition(embedded_id, _) => {
 
                    let definition = &ctx.heap[embedded_id];
 
                    if !(definition.is_struct() || definition.is_enum() || definition.is_union()) {
 
                        let module_source = &modules[root_id.index as usize].source;
 
                        return Err(ParseError::new_error_str_at_span(
 
                            module_source, element.full_span, "expected a datatype (struct, enum or union)"
 
                        ))
 
                    }
 

	
 
                    if self.lookup.contains_key(&embedded_id) {
 
                        set_resolve_result(ResolveResult::Resolved(definition.defined_in(), embedded_id))
 
                    } else {
 
                        return Ok(ResolveResult::Unresolved(definition.defined_in(), embedded_id))
 
                    }
 
                }
 
            }
 
        }
 

	
 
        // If here then all types in the embedded type's tree were resolved.
 
        debug_assert!(resolve_result.is_some(), "faulty logic in ParserType resolver");
 
        return Ok(resolve_result.unwrap())
 
    }
 

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

	
 
        Ok(())
 
    }
 

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

	
 
            // Check if identifier conflicts with a symbol defined or imported
 
            // in the current module
 
            if let Some(symbol) = ctx.symbols.get_symbol_by_name(SymbolScope::Module(root_id), poly_arg.value.as_bytes()) {
 
                // We have a conflict
 
                let module_source = &modules[root_id.index as usize].source;
 
                let introduction_span = symbol.variant.span_of_introduction(ctx.heap);
 
                return Err(ParseError::new_error_str_at_span(
 
                    module_source, poly_arg.span,
 
                    "This polymorphic argument conflicts with another symbol"
 
                ).with_info_str_at_span(
 
                    module_source, introduction_span,
 
                    "It conflicts due to this symbol"
 
                ));
 
            }
 
        }
 

	
 
        // All arguments are fine
 
        Ok(())
 
    }
 

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

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

	
 
        result
 
    }
 

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

	
 
    fn enum_tag_type(min_tag_value: i64, max_tag_value: i64) -> PrimitiveType {
 
        // TODO: @consistency tag values should be handled correctly
 
        debug_assert!(min_tag_value <= max_tag_value);
 
        let abs_max_value = min_tag_value.abs().max(max_tag_value.abs());
 
        if abs_max_value <= u8::max_value() as i64 {
 
            PrimitiveType::Byte
 
        } else if abs_max_value <= u16::max_value() as i64 {
 
            PrimitiveType::Short
 
        } else if abs_max_value <= u32::max_value() as i64 {
 
            PrimitiveType::Int
 
        } else {
 
            PrimitiveType::Long
 
        }
 
    }
 
}
 
\ No newline at end of file
src/protocol/tests/utils.rs
Show inline comments
 
use crate::collections::StringPool;
 
use crate::protocol::{
 
    Module,
 
    ast::*,
 
    input_source::*,
 
    parser::{
 
        Parser,
 
        type_table::{TypeTable, DefinedTypeVariant},
 
        symbol_table::SymbolTable,
 
        token_parsing::*,
 
    },
 
    eval::*,
 
};
 

	
 
// Carries information about the test into utility structures for builder-like
 
// assertions
 
#[derive(Clone, Copy)]
 
struct TestCtx<'a> {
 
    test_name: &'a str,
 
    heap: &'a Heap,
 
    modules: &'a Vec<Module>,
 
    types: &'a TypeTable,
 
    symbols: &'a SymbolTable,
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Interface for parsing and compiling
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct Tester {
 
    test_name: String,
 
    sources: Vec<String>
 
}
 

	
 
impl Tester {
 
    /// Constructs a new tester, allows adding multiple sources before compiling
 
    pub(crate) fn new<S: ToString>(test_name: S) -> Self {
 
        Self{
 
            test_name: test_name.to_string(),
 
            sources: Vec::new()
 
        }
 
    }
 

	
 
    /// Utility for quick tests that use a single source file and expect the
 
    /// compilation to succeed.
 
    pub(crate) fn new_single_source_expect_ok<T: ToString, S: ToString>(test_name: T, source: S) -> AstOkTester {
 
        Self::new(test_name)
 
            .with_source(source)
 
            .compile()
 
            .expect_ok()
 
    }
 

	
 
    /// Utility for quick tests that use a single source file and expect the
 
    /// compilation to fail.
 
    pub(crate) fn new_single_source_expect_err<T: ToString, S: ToString>(test_name: T, source: S) -> AstErrTester {
 
        Self::new(test_name)
 
            .with_source(source)
 
            .compile()
 
            .expect_err()
 
    }
 

	
 
    pub(crate) fn with_source<S: ToString>(mut self, source: S) -> Self {
 
        self.sources.push(source.to_string());
 
        self
 
    }
 

	
 
    pub(crate) fn compile(self) -> AstTesterResult {
 
        let mut parser = Parser::new();
 
        for source in self.sources.into_iter() {
 
            let source = source.into_bytes();
 
            let input_source = InputSource::new(String::from(""), source);
 

	
 
            if let Err(err) = parser.feed(input_source) {
 
                return AstTesterResult::Err(AstErrTester::new(self.test_name, err))
 
            }
 
        }
 

	
 
        if let Err(err) = parser.parse() {
 
            return AstTesterResult::Err(AstErrTester::new(self.test_name, err))
 
        }
 

	
 
        AstTesterResult::Ok(AstOkTester::new(self.test_name, parser))
 
    }
 
}
 

	
 
pub(crate) enum AstTesterResult {
 
    Ok(AstOkTester),
 
    Err(AstErrTester)
 
}
 

	
 
impl AstTesterResult {
 
    pub(crate) fn expect_ok(self) -> AstOkTester {
 
        match self {
 
            AstTesterResult::Ok(v) => v,
 
            AstTesterResult::Err(err) => {
 
                let wrapped = ErrorTester{ test_name: &err.test_name, error: &err.error };
 
                println!("DEBUG: Full error:\n{}", &err.error);
 
                assert!(
 
                    false,
 
                    "[{}] Expected compilation to succeed, but it failed with {}",
 
                    err.test_name, wrapped.assert_postfix()
 
                );
 
                unreachable!();
 
            }
 
        }
 
    }
 

	
 
    pub(crate) fn expect_err(self) -> AstErrTester {
 
        match self {
 
            AstTesterResult::Ok(ok) => {
 
                assert!(false, "[{}] Expected compilation to fail, but it succeeded", ok.test_name);
 
                unreachable!();
 
            },
 
            AstTesterResult::Err(err) => err,
 
        }
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Interface for successful compilation
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct AstOkTester {
 
    test_name: String,
 
    modules: Vec<Module>,
 
    heap: Heap,
 
    symbols: SymbolTable,
 
    types: TypeTable,
 
    pool: StringPool, // This is stored because if we drop it on the floor, we lose all our `StringRef<'static>`s
 
}
 

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

	
 
    pub(crate) fn for_struct<F: Fn(StructTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Struct(definition) = definition {
 
                if definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found struct with the same name
 
                let tester = StructTester::new(self.ctx(), definition);
 
                f(tester);
 
                found = true;
 
                break
 
            }
 
        }
 

	
 
        assert!(
 
            found, "[{}] Failed to find definition for struct '{}'",
 
            self.test_name, name
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn for_enum<F: Fn(EnumTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Enum(definition) = definition {
 
                if definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found enum with the same name
 
                let tester = EnumTester::new(self.ctx(), definition);
 
                f(tester);
 
                found = true;
 
                break;
 
            }
 
        }
 

	
 
        assert!(
 
            found, "[{}] Failed to find definition for enum '{}'",
 
            self.test_name, name
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn for_union<F: Fn(UnionTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Union(definition) = definition {
 
                if definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found union with the same name
 
                let tester = UnionTester::new(self.ctx(), definition);
 
                f(tester);
 
                found = true;
 
                break;
 
            }
 
        }
 

	
 
        assert!(
 
            found, "[{}] Failed to find definition for union '{}'",
 
            self.test_name, name
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn for_function<F: FnOnce(FunctionTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Function(definition) = definition {
 
                if definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found function
 
                let tester = FunctionTester::new(self.ctx(), definition);
 
                f(tester);
 
                found = true;
 
                break;
 
            }
 
        }
 

	
 
        if found { return self }
 

	
 
        assert!(
 
            false, "[{}] failed to find definition for function '{}'",
 
            self.test_name, name
 
        );
 
        unreachable!();
 
    }
 

	
 
    fn ctx(&self) -> TestCtx {
 
        TestCtx{
 
            test_name: &self.test_name,
 
            modules: &self.modules,
 
            heap: &self.heap,
 
            types: &self.types,
 
            symbols: &self.symbols,
 
        }
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Utilities for successful compilation
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct StructTester<'a> {
 
    ctx: TestCtx<'a>,
 
    def: &'a StructDefinition,
 
}
 

	
 
impl<'a> StructTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a StructDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn assert_num_fields(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.def.fields.len(),
 
            "[{}] Expected {} struct fields, but found {} for {}",
 
            self.ctx.test_name, num, self.def.fields.len(), self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
 
        let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.def.this.upcast());
 
        assert!(
 
            is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
 
            self.ctx.test_name, num, num_encountered, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    /// Asserts that a monomorph exist, separate polymorphic variable types by
 
    /// a semicolon.
 
    pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
 
        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
 
        assert!(
 
            has_monomorph, "[{}] Expected to find monomorph {}, but got {} for {}",
 
            self.ctx.test_name, serialized_monomorph, &serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn for_field<F: Fn(StructFieldTester)>(self, name: &str, f: F) -> Self {
 
        // Find field with specified name
 
        for field in &self.def.fields {
 
            if field.field.value.as_str() == name {
 
                let tester = StructFieldTester::new(self.ctx, field);
 
                f(tester);
 
                return self;
 
            }
 
        }
 

	
 
        assert!(
 
            false, "[{}] Could not find struct field '{}' for {}",
 
            self.ctx.test_name, name, self.assert_postfix()
 
        );
 
        unreachable!();
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("Struct{ name: ");
 
        v.push_str(self.def.identifier.value.as_str());
 
        v.push_str(", fields: [");
 
        for (field_idx, field) in self.def.fields.iter().enumerate() {
 
            if field_idx != 0 { v.push_str(", "); }
 
            v.push_str(field.field.value.as_str());
 
        }
 
        v.push_str("] }");
 
        v
 
    }
 
}
 

	
 
pub(crate) struct StructFieldTester<'a> {
 
    ctx: TestCtx<'a>,
 
    def: &'a StructFieldDefinition,
 
}
 

	
 
impl<'a> StructFieldTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a StructFieldDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn assert_parser_type(self, expected: &str) -> Self {
 
        let mut serialized_type = String::new();
 
        serialize_parser_type(&mut serialized_type, &self.ctx.heap, &self.def.parser_type);
 
        assert_eq!(
 
            expected, &serialized_type,
 
            "[{}] Expected type '{}', but got '{}' for {}",
 
            self.ctx.test_name, expected, &serialized_type, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut serialized_type = String::new();
 
        serialize_parser_type(&mut serialized_type, &self.ctx.heap, &self.def.parser_type);
 
        format!("StructField{{ name: {}, parser_type: {} }}", self.def.field.value.as_str(), serialized_type)
 
    }
 
}
 

	
 
pub(crate) struct EnumTester<'a> {
 
    ctx: TestCtx<'a>,
 
    def: &'a EnumDefinition,
 
}
 

	
 
impl<'a> EnumTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a EnumDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn assert_num_variants(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.def.variants.len(),
 
            "[{}] Expected {} enum variants, but found {} for {}",
 
            self.ctx.test_name, num, self.def.variants.len(), self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
 
        let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.def.this.upcast());
 
        assert!(
 
            is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
 
            self.ctx.test_name, num, num_encountered, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
 
        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
 
        assert!(
 
            has_monomorph, "[{}] Expected to find monomorph {}, but got {} for {}",
 
            self.ctx.test_name, serialized_monomorph, serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("Enum{ name: ");
 
        v.push_str(self.def.identifier.value.as_str());
 
        v.push_str(", variants: [");
 
        for (variant_idx, variant) in self.def.variants.iter().enumerate() {
 
            if variant_idx != 0 { v.push_str(", "); }
 
            v.push_str(variant.identifier.value.as_str());
 
        }
 
        v.push_str("] }");
 
        v
 
    }
 
}
 

	
 
pub(crate) struct UnionTester<'a> {
 
    ctx: TestCtx<'a>,
 
    def: &'a UnionDefinition,
 
}
 

	
 
impl<'a> UnionTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a UnionDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn assert_num_variants(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.def.variants.len(),
 
            "[{}] Expected {} union variants, but found {} for {}",
 
            self.ctx.test_name, num, self.def.variants.len(), self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
 
        let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.def.this.upcast());
 
        assert!(
 
            is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
 
            self.ctx.test_name, num, num_encountered, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
 
        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
 
        assert!(
 
            has_monomorph, "[{}] Expected to find monomorph {}, but got {} for {}",
 
            self.ctx.test_name, serialized_monomorph, serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("Union{ name: ");
 
        v.push_str(self.def.identifier.value.as_str());
 
        v.push_str(", variants: [");
 
        for (variant_idx, variant) in self.def.variants.iter().enumerate() {
 
            if variant_idx != 0 { v.push_str(", "); }
 
            v.push_str(variant.identifier.value.as_str());
 
        }
 
        v.push_str("] }");
 
        v
 
    }
 
}
 

	
 
pub(crate) struct FunctionTester<'a> {
 
    ctx: TestCtx<'a>,
 
    def: &'a FunctionDefinition,
 
}
 

	
 
impl<'a> FunctionTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a FunctionDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn for_variable<F: Fn(VariableTester)>(self, name: &str, f: F) -> Self {
 
        // Seek through the blocks in order to find the variable
 
        let wrapping_block_id = seek_stmt(
 
            self.ctx.heap, self.def.body.upcast(),
 
            &|stmt| {
 
                if let Statement::Block(block) = stmt {
 
                    for local_id in &block.locals {
 
                        let var = &self.ctx.heap[*local_id];
 
                        if var.identifier.value.as_str() == name {
 
                            return true;
 
                        }
 
                    }
 
                }
 

	
 
                false
 
            }
 
        );
 

	
 
        let mut found_local_id = None;
 
        if let Some(block_id) = wrapping_block_id {
 
            let block_stmt = self.ctx.heap[block_id].as_block();
 
            for local_id in &block_stmt.locals {
 
                let var = &self.ctx.heap[*local_id];
 
                if var.identifier.value.as_str() == name {
 
                    found_local_id = Some(*local_id);
 
                }
 
            }
 
        }
 

	
 
        assert!(
 
            found_local_id.is_some(), "[{}] Failed to find variable '{}' in {}",
 
            self.ctx.test_name, name, self.assert_postfix()
 
        );
 

	
 
        let local = &self.ctx.heap[found_local_id.unwrap()];
 

	
 
        // Find an instance of the variable expression so we can determine its
 
        // type.
 
        let var_expr = seek_expr_in_stmt(
 
            self.ctx.heap, self.def.body.upcast(),
 
            &|expr| {
 
                if let Expression::Variable(variable_expr) = expr {
 
                    if variable_expr.identifier.value.as_str() == name {
 
                        return true;
 
                    }
 
                }
 

	
 
                false
 
            }
 
        );
 

	
 
        assert!(
 
            var_expr.is_some(), "[{}] Failed to find variable expression of '{}' in {}",
 
            self.ctx.test_name, name, self.assert_postfix()
 
        );
 

	
 
        let var_expr = &self.ctx.heap[var_expr.unwrap()];
 

	
 
        // Construct tester and pass to tester function
 
        let tester = VariableTester::new(
 
            self.ctx, self.def.this.upcast(), local,
 
            var_expr.as_variable()
 
        );
 

	
 
        f(tester);
 

	
 
        self
 
    }
 

	
 
    /// Finds a specific expression within a function. There are two matchers:
 
    /// one outer matcher (to find a rough indication of the expression) and an
 
    /// inner matcher to find the exact expression. 
 
    ///
 
    /// The reason being that, for example, a function's body might be littered
 
    /// with addition symbols, so we first match on "some_var + some_other_var",
 
    /// and then match exactly on "+".
 
    pub(crate) fn for_expression_by_source<F: Fn(ExpressionTester)>(self, outer_match: &str, inner_match: &str, f: F) -> Self {
 
        // Seek the expression in the source code
 
        assert!(outer_match.contains(inner_match), "improper testing code");
 

	
 
        let module = seek_def_in_modules(
 
            &self.ctx.heap, &self.ctx.modules, self.def.this.upcast()
 
        ).unwrap();
 

	
 
        // Find the first occurrence of the expression after the definition of
 
        // the function, we'll check that it is included in the body later.
 
        let mut outer_match_idx = self.def.span.begin.offset as usize;
 
        while outer_match_idx < module.source.input.len() {
 
            if module.source.input[outer_match_idx..].starts_with(outer_match.as_bytes()) {
 
                break;
 
            }
 
            outer_match_idx += 1
 
        }
 

	
 
        assert!(
 
            outer_match_idx < module.source.input.len(),
 
            "[{}] Failed to find '{}' within the source that contains {}",
 
            self.ctx.test_name, outer_match, self.assert_postfix()
 
        );
 
        let inner_match_idx = outer_match_idx + outer_match.find(inner_match).unwrap();
 

	
 
        // Use the inner match index to find the expression
 
        let expr_id = seek_expr_in_stmt(
 
            &self.ctx.heap, self.def.body.upcast(),
 
            &|expr| expr.span().begin.offset as usize == inner_match_idx
 
        );
 
        assert!(
 
            expr_id.is_some(),
 
            "[{}] Failed to find '{}' within the source that contains {} \
 
            (note: expression was found, but not within the specified function",
 
            self.ctx.test_name, outer_match, self.assert_postfix()
 
        );
 
        let expr_id = expr_id.unwrap();
 

	
 
        // We have the expression, call the testing function
 
        let tester = ExpressionTester::new(
 
            self.ctx, self.def.this.upcast(), &self.ctx.heap[expr_id]
 
        );
 
        f(tester);
 

	
 
        self
 
    }
 

	
 
    pub(crate) fn call_ok(self, expected_result: Option<Value>) -> Self {
 
        use crate::protocol::*;
 
        use crate::runtime::*;
 

	
 
        let (prompt, result) = self.eval_until_end();
 
        match result {
 
            Ok(_) => {
 
                assert!(
 
                    prompt.store.stack.len() > 0, // note: stack never shrinks
 
                    "[{}] No value on stack after calling function for {}",
 
                    self.ctx.test_name, self.assert_postfix()
 
                );
 
            },
 
            Err(err) => {
 
                println!("DEBUG: Formatted evaluation error:\n{}", err);
 
                assert!(
 
                    false,
 
                    "[{}] Expected call to succeed, but got {:?} for {}",
 
                    self.ctx.test_name, err, self.assert_postfix()
 
                )
 
            }
 
        }
 

	
 
        if let Some(expected_result) = expected_result {
 
            debug_assert!(expected_result.get_heap_pos().is_none(), "comparing against heap thingamajigs is not yet implemented");
 
            assert!(
 
                value::apply_equality_operator(&prompt.store, &prompt.store.stack[0], &expected_result),
 
                "[{}] Result from call was {:?}, but expected {:?} for {}",
 
                self.ctx.test_name, &prompt.store.stack[0], &expected_result, self.assert_postfix()
 
            )
 
        }
 

	
 
        self
 
    }
 

	
 
    // Keeping this simple for now, will likely change
 
    pub(crate) fn call_err(self, expected_result: &str) -> Self {
 
        let (_, result) = self.eval_until_end();
 
        match result {
 
            Ok(_) => {
 
                assert!(
 
                    false,
 
                    "[{}] Expected an error, but evaluation finished successfully for {}",
 
                    self.ctx.test_name, self.assert_postfix()
 
                );
 
            },
 
            Err(err) => {
 
                println!("DEBUG: Formatted evaluation error:\n{}", err);
 
                debug_assert_eq!(err.statements.len(), 1);
 
                assert!(
 
                    err.statements[0].message.contains(&expected_result),
 
                    "[{}] Expected error message to contain '{}', but it was '{}' for {}",
 
                    self.ctx.test_name, expected_result, err.statements[0].message, self.assert_postfix()
 
                );
 
            }
 
        }
 

	
 
        self
 
    }
 

	
 
    fn eval_until_end(&self) -> (Prompt, Result<EvalContinuation, EvalError>) {
 
        use crate::protocol::*;
 

	
 
        let mut prompt = Prompt::new(&self.ctx.types, &self.ctx.heap, self.def.this.upcast(), 0, ValueGroup::new_stack(Vec::new()));
 
        let mut call_context = EvalContext::None;
 
        loop {
 
            let result = prompt.step(&self.ctx.types, &self.ctx.heap, &self.ctx.modules, &mut call_context);
 
            match result {
 
                Ok(EvalContinuation::Stepping) => {},
 
                _ => return (prompt, result),
 
            }
 
        }
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        format!("Function{{ name: {} }}", self.def.identifier.value.as_str())
 
    }
 
}
 

	
 
pub(crate) struct VariableTester<'a> {
 
    ctx: TestCtx<'a>,
 
    definition_id: DefinitionId,
 
    variable: &'a Variable,
 
    var_expr: &'a VariableExpression,
 
}
 

	
 
impl<'a> VariableTester<'a> {
 
    fn new(
 
        ctx: TestCtx<'a>, definition_id: DefinitionId, variable: &'a Variable, var_expr: &'a VariableExpression
 
    ) -> Self {
 
        Self{ ctx, definition_id, variable, var_expr }
 
    }
 

	
 
    pub(crate) fn assert_parser_type(self, expected: &str) -> Self {
 
        let mut serialized = String::new();
 
        serialize_parser_type(&mut serialized, self.ctx.heap, &self.variable.parser_type);
 

	
 
        assert_eq!(
 
            expected, &serialized,
 
            "[{}] Expected parser type '{}', but got '{}' for {}",
 
            self.ctx.test_name, expected, &serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_concrete_type(self, expected: &str) -> Self {
 
        // Lookup concrete type in type table
 
        let mono_data = self.ctx.types.get_procedure_expression_data(&self.definition_id, 0);
 
        let concrete_type = &mono_data.expr_data[self.var_expr.unique_id_in_definition as usize].expr_type;
 

	
 
        // Serialize and check
 
        let mut serialized = String::new();
 
        serialize_concrete_type(&mut serialized, self.ctx.heap, self.definition_id, concrete_type);
 

	
 
        assert_eq!(
 
            expected, &serialized,
 
            "[{}] Expected concrete type '{}', but got '{}' for {}",
 
            self.ctx.test_name, expected, &serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        format!("Variable{{ name: {} }}", self.variable.identifier.value.as_str())
 
    }
 
}
 

	
 
pub(crate) struct ExpressionTester<'a> {
 
    ctx: TestCtx<'a>,
 
    definition_id: DefinitionId, // of the enclosing function/component
 
    expr: &'a Expression
 
}
 

	
 
impl<'a> ExpressionTester<'a> {
 
    fn new(
 
        ctx: TestCtx<'a>, definition_id: DefinitionId, expr: &'a Expression
 
    ) -> Self {
 
        Self{ ctx, definition_id, expr }
 
    }
 

	
 
    pub(crate) fn assert_concrete_type(self, expected: &str) -> Self {
 
        // Lookup concrete type
 
        let mono_data = self.ctx.types.get_procedure_expression_data(&self.definition_id, 0);
 
        let expr_index = self.expr.get_unique_id_in_definition();
 
        let concrete_type = &mono_data.expr_data[expr_index as usize].expr_type;
 

	
 
        // Serialize and check type
 
        let mut serialized = String::new();
 
        serialize_concrete_type(&mut serialized, self.ctx.heap, self.definition_id, concrete_type);
 

	
 
        assert_eq!(
 
            expected, &serialized,
 
            "[{}] Expected concrete type '{}', but got '{}' for {}",
 
            self.ctx.test_name, expected, &serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        format!(
 
            "Expression{{ debug: {:?} }}",
 
            self.expr
 
        )
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Interface for failed compilation
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct AstErrTester {
 
    test_name: String,
 
    error: ParseError,
 
}
 

	
 
impl AstErrTester {
 
    fn new(test_name: String, error: ParseError) -> Self {
 
        Self{ test_name, error }
 
    }
 

	
 
    pub(crate) fn error<F: Fn(ErrorTester)>(&self, f: F) {
 
        // Maybe multiple errors will be supported in the future
 
        let tester = ErrorTester{ test_name: &self.test_name, error: &self.error };
 
        f(tester)
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Utilities for failed compilation
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct ErrorTester<'a> {
 
    test_name: &'a str,
 
    error: &'a ParseError,
 
}
 

	
 
impl<'a> ErrorTester<'a> {
 
    pub(crate) fn assert_num(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.error.statements.len(),
 
            "[{}] expected error to consist of '{}' parts, but encountered '{}' for {}",
 
            self.test_name, num, self.error.statements.len(), self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    pub(crate) fn assert_ctx_has(self, idx: usize, msg: &str) -> Self {
 
        assert!(
 
            self.error.statements[idx].context.contains(msg),
 
            "[{}] expected error statement {}'s context to contain '{}' for {}",
 
            self.test_name, idx, msg, self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    pub(crate) fn assert_msg_has(self, idx: usize, msg: &str) -> Self {
 
        assert!(
 
            self.error.statements[idx].message.contains(msg),
 
            "[{}] expected error statement {}'s message to contain '{}' for {}",
 
            self.test_name, idx, msg, self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    // TODO: @tokenizer This should really be removed, as compilation should be
 
    //  deterministic, but we're currently using rather inefficient hashsets for
 
    //  the type inference, so remove once compiler architecture has changed.
 
    pub(crate) fn assert_any_msg_has(self, msg: &str) -> Self {
 
        let mut is_present = false;
 
        for statement in &self.error.statements {
 
            if statement.message.contains(msg) {
 
                is_present = true;
 
                break;
 
            }
 
        }
 

	
 
        assert!(
 
            is_present, "[{}] Expected an error statement to contain '{}' for {}",
 
            self.test_name, msg, self.assert_postfix()
 
        );
 
        
 
        self
 
    }
 

	
 
    /// Seeks the index of the pattern in the context message, then checks if
 
    /// the input position corresponds to that index.
 
    pub (crate) fn assert_occurs_at(self, idx: usize, pattern: &str) -> Self {
 
        let pos = self.error.statements[idx].context.find(pattern);
 
        assert!(
 
            pos.is_some(),
 
            "[{}] incorrect occurs_at: '{}' could not be found in the context for {}",
 
            self.test_name, pattern, self.assert_postfix()
 
        );
 
        let pos = pos.unwrap();
 
        let col = self.error.statements[idx].start_column as usize;
 
        assert_eq!(
 
            pos + 1, col,
 
            "[{}] Expected error to occur at column {}, but found it at {} for {}",
 
            self.test_name, pos + 1, col, self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("error: [");
 
        for (idx, stmt) in self.error.statements.iter().enumerate() {
 
            if idx != 0 {
 
                v.push_str(", ");
 
            }
 

	
 
            v.push_str(&format!("{{ context: {}, message: {} }}", &stmt.context, stmt.message));
 
        }
 
        v.push(']');
 
        v
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Generic utilities
 
//------------------------------------------------------------------------------
 

	
 
fn has_equal_num_monomorphs(ctx: TestCtx, num: usize, definition_id: DefinitionId) -> (bool, usize) {
 
    use DefinedTypeVariant::*;
 

	
 
    let type_def = ctx.types.get_base_definition(&definition_id).unwrap();
 
    let num_on_type = match &type_def.definition {
 
        Struct(v) => v.monomorphs.len(),
 
        Enum(v) => v.monomorphs.len(),
 
        Union(v) => v.monomorphs.len(),
 
        Function(v) => v.monomorphs.len(),
 
        Component(v) => v.monomorphs.len(),
 
    };
 

	
 
    (num_on_type == num, num_on_type)
 
}
 

	
 
fn has_monomorph(ctx: TestCtx, definition_id: DefinitionId, serialized_monomorph: &str) -> (bool, String) {
 
    use DefinedTypeVariant::*;
 

	
 
    let type_def = ctx.types.get_base_definition(&definition_id).unwrap();
 

	
 
    // Note: full_buffer is just for error reporting
 
    let mut full_buffer = String::new();
 
    let mut has_match = false;
 

	
 
    let serialize_monomorph = |monomorph: &Vec<ConcreteType>| -> String {
 
        let mut buffer = String::new();
 
        for (element_idx, element) in monomorph.iter().enumerate() {
 
            if element_idx != 0 {
 
                buffer.push(';');
 
            }
 
            serialize_concrete_type(&mut buffer, ctx.heap, definition_id, element);
 
        }
 

	
 
        buffer
 
    };
 

	
 
    full_buffer.push('[');
 
    let mut append_to_full_buffer = |buffer: String| {
 
        if full_buffer.len() != 1 {
 
            full_buffer.push_str(", ");
 
        }
 
        full_buffer.push('"');
 
        full_buffer.push_str(&buffer);
 
        full_buffer.push('"');
 
    };
 

	
 
    match &type_def.definition {
 
        Enum(_) | Union(_) | Struct(_) => {
 
            let monomorphs = type_def.definition.data_monomorphs();
 
            for monomorph in monomorphs.iter() {
 
                let buffer = serialize_monomorph(&monomorph.poly_args);
 
                if buffer == serialized_monomorph {
 
                    has_match = true;
 
                }
 
                append_to_full_buffer(buffer);
 
            }
 
        },
 
        Function(_) | Component(_) => {
 
            let monomorphs = type_def.definition.procedure_monomorphs();
 
            for monomorph in monomorphs.iter() {
 
                let buffer = serialize_monomorph(&monomorph.poly_args);
 
                if buffer == serialized_monomorph {
 
                    has_match = true;
 
                }
 
                append_to_full_buffer(buffer);
 
            }
 
        }
 
    }
 

	
 
    full_buffer.push(']');
 

	
 
    (has_match, full_buffer)
 
}
 

	
 
fn serialize_parser_type(buffer: &mut String, heap: &Heap, parser_type: &ParserType) {
 
    use ParserTypeVariant as PTV;
 

	
 
    fn write_bytes(buffer: &mut String, bytes: &[u8]) {
 
        let utf8 = String::from_utf8_lossy(bytes);
 
        buffer.push_str(&utf8);
 
    }
 

	
 
    fn serialize_variant(buffer: &mut String, heap: &Heap, parser_type: &ParserType, mut idx: usize) -> usize {
 
        match &parser_type.elements[idx].variant {
 
            PTV::Void => buffer.push_str("void"),
 
            PTV::InputOrOutput => {
 
                buffer.push_str("portlike<");
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push('>');
 
            },
 
            PTV::ArrayLike => {
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push_str("[???]");
 
            },
 
            PTV::IntegerLike => buffer.push_str("integerlike"),
 
            PTV::Message => buffer.push_str(KW_TYPE_MESSAGE_STR),
 
            PTV::Bool => buffer.push_str(KW_TYPE_BOOL_STR),
 
            PTV::UInt8 => buffer.push_str(KW_TYPE_UINT8_STR),
 
            PTV::UInt16 => buffer.push_str(KW_TYPE_UINT16_STR),
 
            PTV::UInt32 => buffer.push_str(KW_TYPE_UINT32_STR),
 
            PTV::UInt64 => buffer.push_str(KW_TYPE_UINT64_STR),
 
            PTV::SInt8 => buffer.push_str(KW_TYPE_SINT8_STR),
 
            PTV::SInt16 => buffer.push_str(KW_TYPE_SINT16_STR),
 
            PTV::SInt32 => buffer.push_str(KW_TYPE_SINT32_STR),
 
            PTV::SInt64 => buffer.push_str(KW_TYPE_SINT64_STR),
 
            PTV::Character => buffer.push_str(KW_TYPE_CHAR_STR),
 
            PTV::String => buffer.push_str(KW_TYPE_STRING_STR),
 
            PTV::IntegerLiteral => buffer.push_str("int_literal"),
 
            PTV::Inferred => buffer.push_str(KW_TYPE_INFERRED_STR),
 
            PTV::Array => {
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push_str("[]");
 
            },
 
            PTV::Input => {
 
                buffer.push_str(KW_TYPE_IN_PORT_STR);
 
                buffer.push('<');
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push('>');
 
            },
 
            PTV::Output => {
 
                buffer.push_str(KW_TYPE_OUT_PORT_STR);
 
                buffer.push('<');
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push('>');
 
            },
 
            PTV::PolymorphicArgument(definition_id, poly_idx) => {
 
                let definition = &heap[*definition_id];
 
                let poly_arg = &definition.poly_vars()[*poly_idx as usize];
 
                buffer.push_str(poly_arg.value.as_str());
 
            },
 
            PTV::Definition(definition_id, num_embedded) => {
 
                let definition = &heap[*definition_id];
 
                buffer.push_str(definition.identifier().value.as_str());
 

	
 
                let num_embedded = *num_embedded;
 
                if num_embedded != 0 {
 
                    buffer.push('<');
 
                    for embedded_idx in 0..num_embedded {
 
                        if embedded_idx != 0 {
 
                            buffer.push(',');
 
                        }
 
                        idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                    }
 
                    buffer.push('>');
 
                }
 
            }
 
        }
 

	
 
        idx
 
    }
 

	
 
    serialize_variant(buffer, heap, parser_type, 0);
 
}
 

	
 
fn serialize_concrete_type(buffer: &mut String, heap: &Heap, def: DefinitionId, concrete: &ConcreteType) {
 
    // Retrieve polymorphic variables
 
    let poly_vars = heap[def].poly_vars();
 

	
 
    fn write_bytes(buffer: &mut String, bytes: &[u8]) {
 
        let utf8 = String::from_utf8_lossy(bytes);
 
        buffer.push_str(&utf8);
 
    }
 

	
 
    fn serialize_recursive(
 
        buffer: &mut String, heap: &Heap, poly_vars: &Vec<Identifier>, concrete: &ConcreteType, mut idx: usize
 
    ) -> usize {
 
        use ConcreteTypePart as CTP;
 

	
 
        let part = &concrete.parts[idx];
 
        match part {
 
            CTP::Void => buffer.push_str("void"),
 
            CTP::Message => write_bytes(buffer, KW_TYPE_MESSAGE),
 
            CTP::Bool => write_bytes(buffer, KW_TYPE_BOOL),
 
            CTP::UInt8 => write_bytes(buffer, KW_TYPE_UINT8),
 
            CTP::UInt16 => write_bytes(buffer, KW_TYPE_UINT16),
 
            CTP::UInt32 => write_bytes(buffer, KW_TYPE_UINT32),
 
            CTP::UInt64 => write_bytes(buffer, KW_TYPE_UINT64),
 
            CTP::SInt8 => write_bytes(buffer, KW_TYPE_SINT8),
 
            CTP::SInt16 => write_bytes(buffer, KW_TYPE_SINT16),
 
            CTP::SInt32 => write_bytes(buffer, KW_TYPE_SINT32),
 
            CTP::SInt64 => write_bytes(buffer, KW_TYPE_SINT64),
 
            CTP::Character => write_bytes(buffer, KW_TYPE_CHAR),
 
            CTP::String => write_bytes(buffer, KW_TYPE_STRING),
 
            CTP::Array => {
 
                idx = serialize_recursive(buffer, heap, poly_vars, concrete, idx + 1);
 
                buffer.push_str("[]");
 
            },
 
            CTP::Slice => {
 
                idx = serialize_recursive(buffer, heap, poly_vars, concrete, idx + 1);
 
                buffer.push_str("[..]");
 
            },
 
            CTP::Input => {
 
                write_bytes(buffer, KW_TYPE_IN_PORT);
 
                buffer.push('<');
 
                idx = serialize_recursive(buffer, heap, poly_vars, concrete, idx + 1);
 
                buffer.push('>');
 
            },
 
            CTP::Output => {
 
                write_bytes(buffer, KW_TYPE_OUT_PORT);
 
                buffer.push('<');
 
                idx = serialize_recursive(buffer, heap, poly_vars, concrete, idx + 1);
 
                buffer.push('>');
 
            },
 
            CTP::Instance(definition_id, num_sub) => {
 
                let definition_name = heap[*definition_id].identifier();
 
                buffer.push_str(definition_name.value.as_str());
 
                if *num_sub != 0 {
 
                    buffer.push('<');
 
                    for sub_idx in 0..*num_sub {
 
                        if sub_idx != 0 { buffer.push(','); }
 
                        idx = serialize_recursive(buffer, heap, poly_vars, concrete, idx + 1);
 
                    }
 
                    buffer.push('>');
 
                }
 
            }
 
        }
 

	
 
        idx
 
    }
 

	
 
    serialize_recursive(buffer, heap, poly_vars, concrete, 0);
 
}
 

	
 
fn seek_def_in_modules<'a>(heap: &Heap, modules: &'a [Module], def_id: DefinitionId) -> Option<&'a Module> {
 
    for module in modules {
 
        let root = &heap.protocol_descriptions[module.root_id];
 
        for definition in &root.definitions {
 
            if *definition == def_id {
 
                return Some(module)
 
            }
 
        }
 
    }
 

	
 
    None
 
}
 

	
 
fn seek_stmt<F: Fn(&Statement) -> bool>(heap: &Heap, start: StatementId, f: &F) -> Option<StatementId> {
 
    let stmt = &heap[start];
 
    if f(stmt) { return Some(start); }
 

	
 
    // This statement wasn't it, try to recurse
 
    let matched = match stmt {
 
        Statement::Block(block) => {
 
            for sub_id in &block.statements {
 
                if let Some(id) = seek_stmt(heap, *sub_id, f) {
 
                    return Some(id);
 
                }
 
            }
 

	
 
            None
 
        },
 
        Statement::Labeled(stmt) => seek_stmt(heap, stmt.body, f),
 
        Statement::If(stmt) => {
 
            if let Some(id) = seek_stmt(heap, stmt.true_body.upcast(), f) {
 
                return Some(id);
 
            } else if let Some(false_body) = stmt.false_body {
 
                if let Some(id) = seek_stmt(heap, false_body.upcast(), f) {
 
                    return Some(id);
 
                }
 
            }
 
            None
 
        },
 
        Statement::While(stmt) => seek_stmt(heap, stmt.body.upcast(), f),
 
        Statement::Synchronous(stmt) => seek_stmt(heap, stmt.body.upcast(), f),
 
        _ => None
 
    };
 

	
 
    matched
 
}
 

	
 
fn seek_expr_in_expr<F: Fn(&Expression) -> bool>(heap: &Heap, start: ExpressionId, f: &F) -> Option<ExpressionId> {
 
    let expr = &heap[start];
 
    if f(expr) { return Some(start); }
 

	
 
    match expr {
 
        Expression::Assignment(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.left, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.right, f))
 
        },
 
        Expression::Binding(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.bound_to, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.bound_from, f))
 
        }
 
        Expression::Conditional(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.test, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.true_expression, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.false_expression, f))
 
        },
 
        Expression::Binary(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.left, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.right, f))
 
        },
 
        Expression::Unary(expr) => {
 
            seek_expr_in_expr(heap, expr.expression, f)
 
        },
 
        Expression::Indexing(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.subject, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.index, f))
 
        },
 
        Expression::Slicing(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.subject, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.from_index, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.to_index, f))
 
        },
 
        Expression::Select(expr) => {
 
            seek_expr_in_expr(heap, expr.subject, f)
 
        },
 
        Expression::Literal(expr) => {
 
            if let Literal::Struct(lit) = &expr.value {
 
                for field in &lit.fields {
 
                    if let Some(id) = seek_expr_in_expr(heap, field.value, f) {
 
                        return Some(id)
 
                    }
 
                }
 
            } else if let Literal::Array(elements) = &expr.value {
 
                for element in elements {
 
                    if let Some(id) = seek_expr_in_expr(heap, *element, f) {
 
                        return Some(id)
 
                    }
 
                }
 
            }
 
            None
 
        },
 
        Expression::Cast(expr) => {
 
            seek_expr_in_expr(heap, expr.subject, f)
 
        }
 
        Expression::Call(expr) => {
 
            for arg in &expr.arguments {
 
                if let Some(id) = seek_expr_in_expr(heap, *arg, f) {
 
                    return Some(id)
 
                }
 
            }
 
            None
 
        },
 
        Expression::Variable(_expr) => {
 
            None
 
        }
 
    }
 
}
 

	
 
fn seek_expr_in_stmt<F: Fn(&Expression) -> bool>(heap: &Heap, start: StatementId, f: &F) -> Option<ExpressionId> {
 
    let stmt = &heap[start];
 

	
 
    match stmt {
 
        Statement::Block(stmt) => {
 
            for stmt_id in &stmt.statements {
 
                if let Some(id) = seek_expr_in_stmt(heap, *stmt_id, f) {
 
                    return Some(id)
 
                }
 
            }
 
            None
 
        },
 
        Statement::Labeled(stmt) => {
 
            seek_expr_in_stmt(heap, stmt.body, f)
 
        },
 
        Statement::If(stmt) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, stmt.test, f))
 
            .or_else(|| seek_expr_in_stmt(heap, stmt.true_body.upcast(), f))
 
            .or_else(|| if let Some(false_body) = stmt.false_body {
 
                seek_expr_in_stmt(heap, false_body.upcast(), f)
 
            } else {
 
                None
 
            })
 
        },
 
        Statement::While(stmt) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, stmt.test, f))
 
            .or_else(|| seek_expr_in_stmt(heap, stmt.body.upcast(), f))
 
        },
 
        Statement::Synchronous(stmt) => {
 
            seek_expr_in_stmt(heap, stmt.body.upcast(), f)
 
        },
 
        Statement::Return(stmt) => {
 
            for expr_id in &stmt.expressions {
 
                if let Some(id) = seek_expr_in_expr(heap, *expr_id, f) {
 
                    return Some(id);
 
                }
 
            }
 
            None
 
        },
 
        Statement::New(stmt) => {
 
            seek_expr_in_expr(heap, stmt.expression.upcast(), f)
 
        },
 
        Statement::Expression(stmt) => {
 
            seek_expr_in_expr(heap, stmt.expression, f)
 
        },
 
        _ => None
 
    }
 
}
 
\ No newline at end of file
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