Changeset - 95e019faaf52
[Not reviewed]
0 8 1
mh - 3 years ago 2022-03-29 18:18:12
contact@maxhenger.nl
Getting builtin component instantiation to compile
9 files changed with 42 insertions and 14 deletions:
0 comments (0 inline, 0 general)
src/protocol/ast.rs
Show inline comments
 
@@ -1457,528 +1457,531 @@ pub struct NewStatement {
 
    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
 
    Memory(MemoryStatementId),
 
    If(IfStatementId),
 
    While(WhileStatementId),
 
    Return(ReturnStatementId),
 
    New(NewStatementId),
 
    ExpressionStmt(ExpressionStatementId),
 
    Expression(ExpressionId, u32) // index within expression (e.g LHS or RHS of expression, or index in array literal, etc.)
 
}
 

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

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

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

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

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

	
 
    /// Returns the span covering the entire expression (i.e. including the
 
    /// spans of the arguments as well).
 
    pub fn full_span(&self) -> InputSpan {
 
        match self {
 
            Expression::Assignment(expr) => expr.full_span,
 
            Expression::Binding(expr) => expr.full_span,
 
            Expression::Conditional(expr) => expr.full_span,
 
            Expression::Binary(expr) => expr.full_span,
 
            Expression::Unary(expr) => expr.full_span,
 
            Expression::Indexing(expr) => expr.full_span,
 
            Expression::Slicing(expr) => expr.full_span,
 
            Expression::Select(expr) => expr.full_span,
 
            Expression::Literal(expr) => expr.span,
 
            Expression::Cast(expr) => expr.full_span,
 
            Expression::Call(expr) => expr.full_span,
 
            Expression::Variable(expr) => expr.identifier.span,
 
        }
 
    }
 

	
 
    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,
 
        }
 
    }
 

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

	
 
    pub fn parent_expr_id(&self) -> Option<ExpressionId> {
 
        if let ExpressionParent::Expression(id, _) = self.parent() {
 
            Some(*id)
 
        } else {
 
            None
 
        }
 
    }
 

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

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

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

	
 
#[derive(Debug, Clone)]
 
pub struct AssignmentExpression {
 
    pub this: AssignmentExpressionId,
 
    // Parsing
 
    pub operator_span: InputSpan,
 
    pub full_span: InputSpan,
 
    pub left: ExpressionId,
 
    pub operation: AssignmentOperator,
 
    pub right: ExpressionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    // Typing
 
    pub type_index: i32,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct BindingExpression {
 
    pub this: BindingExpressionId,
 
    // Parsing
 
    pub operator_span: InputSpan,
 
    pub full_span: InputSpan,
 
    pub bound_to: ExpressionId,
 
    pub bound_from: ExpressionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    // Typing
 
    pub type_index: i32,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ConditionalExpression {
 
    pub this: ConditionalExpressionId,
 
    // Parsing
 
    pub operator_span: InputSpan,
 
    pub full_span: InputSpan,
 
    pub test: ExpressionId,
 
    pub true_expression: ExpressionId,
 
    pub false_expression: ExpressionId,
 
    // Validator/Linking
 
    pub parent: ExpressionParent,
 
    // Typing
 
    pub type_index: i32,
 
}
 

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

	
 
#[derive(Debug, Clone)]
 
pub struct BinaryExpression {
 
    pub this: BinaryExpressionId,
 
    // Parsing
 
    pub operator_span: InputSpan,
 
    pub full_span: InputSpan,
 
    pub left: ExpressionId,
 
    pub operation: BinaryOperator,
 
    pub right: ExpressionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    // Typing
 
    pub type_index: i32,
 
}
 

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

	
 
#[derive(Debug, Clone)]
 
pub struct UnaryExpression {
 
    pub this: UnaryExpressionId,
 
    // Parsing
 
    pub operator_span: InputSpan,
 
    pub full_span: InputSpan,
 
    pub operation: UnaryOperator,
 
    pub expression: ExpressionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    // Typing
 
    pub type_index: i32,
 
}
 

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

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

	
 
#[derive(Debug, Clone)]
 
pub enum SelectKind {
 
    StructField(Identifier),
 
    TupleMember(u64), // u64 is overkill, but space is taken up by `StructField` variant anyway
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct SelectExpression {
 
    pub this: SelectExpressionId,
 
    // Parsing
 
    pub operator_span: InputSpan, // of the '.'
 
    pub full_span: InputSpan, // includes subject and field
 
    pub subject: ExpressionId,
 
    pub kind: SelectKind,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    // Typing
 
    pub type_index: i32,
 
}
 

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

	
 
#[derive(Debug, Clone)]
 
pub struct CallExpression {
 
    pub this: CallExpressionId,
 
    // Parsing
 
    pub func_span: InputSpan, // of the function name
 
    pub full_span: InputSpan, // includes the arguments and parentheses
 
    pub parser_type: ParserType, // of the function call, not the return type
 
    pub method: Method,
 
    pub arguments: Vec<ExpressionId>,
 
    pub procedure: ProcedureDefinitionId,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    // Typing
 
    pub type_index: i32,
 
}
 

	
 
#[derive(Debug, Clone, PartialEq, Eq)]
 
pub enum Method {
 
    // Builtin, accessible by programmer
 
    // Builtin function, accessible by programmer
 
    Get,
 
    Put,
 
    Fires,
 
    Create,
 
    Length,
 
    Assert,
 
    Print,
 
    // Builtin, not accessible by programmer
 
    // Builtin function, not accessible by programmer
 
    SelectStart, // SelectStart(total_num_cases, total_num_ports)
 
    SelectRegisterCasePort, // SelectRegisterCasePort(case_index, port_index, port_id)
 
    SelectWait, // SelectWait() -> u32
 
    // Builtin component,
 
    ComponentRandomU32,
 
    // User-defined
 
    UserFunction,
 
    UserComponent,
 
}
 

	
 
impl Method {
 
    pub(crate) fn is_public_builtin(&self) -> bool {
 
        use Method::*;
 
        match self {
 
            Get | Put | Fires | Create | Length | Assert | Print => true,
 
            ComponentRandomU32 => true,
 
            _ => false,
 
        }
 
    }
 

	
 
    pub(crate) fn is_user_defined(&self) -> bool {
 
        use Method::*;
 
        match self {
 
            UserFunction | UserComponent => true,
 
            _ => false,
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct LiteralExpression {
 
    pub this: LiteralExpressionId,
 
    // Parsing
 
    pub span: InputSpan,
 
    pub value: Literal,
 
    // Validator/Linker
 
    pub parent: ExpressionParent,
 
    // Typing
 
    pub type_index: 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>),
 
    Tuple(Vec<ExpressionId>),
 
}
 

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

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

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

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

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

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

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

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

	
 
#[derive(Debug, Clone)]
 
pub struct VariableExpression {
 
    pub this: VariableExpressionId,
 
    // Parsing
 
    pub identifier: Identifier,
 
    // Validator/Linker
 
    pub declaration: Option<VariableId>,
 
    pub used_as_binding_target: bool,
 
    pub parent: ExpressionParent,
 
    // Typing
 
    pub type_index: i32,
 
}
 
\ No newline at end of file
src/protocol/eval/executor.rs
Show inline comments
 
@@ -374,773 +374,777 @@ impl Prompt {
 
                            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)))
 
                                },
 
                                _ => {
 
                                    // 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))
 
                                },
 
                            };
 

	
 
                            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 = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                            let field_idx = mono_data.expr_info[expr.type_index as usize].variant.as_select() 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 = match expr.kind {
 
                                        SelectKind::StructField(_) => subject.as_struct(),
 
                                        SelectKind::TupleMember(_) => subject.as_tuple(),
 
                                    };
 

	
 
                                    (None, Value::Ref(ValueId::Heap(subject_heap_pos, field_idx)))
 
                                },
 
                                _ => {
 
                                    let subject_heap_pos = match expr.kind {
 
                                        SelectKind::StructField(_) => subject.as_struct(),
 
                                        SelectKind::TupleMember(_) => subject.as_tuple(),
 
                                    };
 
                                    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 mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                                    let type_id = mono_data.expr_info[expr.type_index as usize].type_id;
 
                                    let concrete_type = &types.get_monomorph(type_id).concrete_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)
 
                                }
 
                                Literal::Tuple(lit_value) => {
 
                                    let heap_pos = transfer_expression_values_front_into_heap(
 
                                        cur_frame, &mut self.store, lit_value.len()
 
                                    );
 
                                    Value::Tuple(heap_pos)
 
                                }
 
                            };
 

	
 
                            cur_frame.expr_values.push_back(value);
 
                        },
 
                        Expression::Cast(expr) => {
 
                            let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                            let type_id = mono_data.expr_info[expr.type_index as usize].type_id;
 
                            let concrete_type = &types.get_monomorph(type_id).concrete_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, concrete_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();
 

	
 
                                    let port_id = if let Value::Input(port_id) = value {
 
                                        port_id
 
                                    } else {
 
                                        unreachable!("executor calling 'get' on value {:?}", value)
 
                                    };
 

	
 
                                    match ctx.performed_get(port_id) {
 
                                        Some(result) => {
 
                                            // We have the result. Merge the `ValueGroup` with the
 
                                            // stack/heap storage.
 
                                            debug_assert_eq!(result.values.len(), 1);
 
                                            result.into_stack(&mut cur_frame.expr_values, &mut self.store);
 
                                        },
 
                                        None => {
 
                                            // Don't have the result yet, prepare the expression to
 
                                            // get run again after we've received a message.
 
                                            cur_frame.expr_values.push_front(value.clone());
 
                                            cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
 
                                            return Ok(EvalContinuation::BlockGet(port_id));
 
                                        }
 
                                    }
 
                                },
 
                                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 port_id = if let Value::Output(port_id) = deref_port_value {
 
                                        port_id
 
                                    } else {
 
                                        unreachable!("executor calling 'put' on value {:?}", deref_port_value)
 
                                    };
 

	
 
                                    let msg_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let deref_msg_value = self.store.maybe_read_ref(&msg_value).clone();
 

	
 
                                    if ctx.performed_put(port_id) {
 
                                        // We're fine, deallocate in case the expression value stack
 
                                        // held an owned value
 
                                        self.store.drop_value(msg_value.get_heap_pos());
 
                                    } else {
 
                                        // Prepare to execute again
 
                                        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));
 
                                        let value_group = ValueGroup::from_store(&self.store, &[deref_msg_value]);
 
                                        return Ok(EvalContinuation::Put(port_id, value_group));
 
                                    }
 
                                },
 
                                Method::Fires => {
 
                                    let port_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let port_value_deref = self.store.maybe_read_ref(&port_value).clone();
 
                                    let port_id = port_value_deref.as_port_id();
 

	
 
                                    match ctx.fires(port_id) {
 
                                        None => {
 
                                            cur_frame.expr_values.push_front(port_value);
 
                                            cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
 
                                            return Ok(EvalContinuation::BlockFires(port_id));
 
                                        },
 
                                        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::BranchInconsistent)
 
                                    }
 
                                },
 
                                Method::Print => {
 
                                    // Convert the runtime-variant of a string
 
                                    // into an actual string.
 
                                    let value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let value_heap_pos = value.as_string();
 
                                    let elements = &self.store.heap_regions[value_heap_pos as usize].values;
 

	
 
                                    let mut message = String::with_capacity(elements.len());
 
                                    for element in elements {
 
                                        message.push(element.as_char());
 
                                    }
 

	
 
                                    // Drop the heap-allocated value from the
 
                                    // store
 
                                    self.store.drop_heap_pos(value_heap_pos);
 
                                    println!("{}", message);
 
                                },
 
                                Method::SelectStart => {
 
                                    let num_cases = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_uint32();
 
                                    let num_ports = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_uint32();
 

	
 
                                    return Ok(EvalContinuation::SelectStart(num_cases, num_ports));
 
                                },
 
                                Method::SelectRegisterCasePort => {
 
                                    let case_index = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_uint32();
 
                                    let port_index = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_uint32();
 
                                    let port_value = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_port_id();
 

	
 
                                    return Ok(EvalContinuation::SelectRegisterPort(case_index, port_index, port_value));
 
                                },
 
                                Method::SelectWait => {
 
                                    match ctx.performed_select_wait() {
 
                                        Some(select_index) => {
 
                                            cur_frame.expr_values.push_back(Value::UInt32(select_index));
 
                                        },
 
                                        None => {
 
                                            cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr.this.upcast()));
 
                                            return Ok(EvalContinuation::SelectWait)
 
                                        },
 
                                    }
 
                                },
 
                                Method::ComponentRandomU32 => {
 
                                    debug_assert_eq!(heap[expr.procedure].parameters.len(), cur_frame.expr_values.len());
 
                                    debug_assert_eq!(heap[cur_frame.position].as_new().expression, expr.this);
 
                                },
 
                                Method::UserComponent => {
 
                                    // This is actually handled by the evaluation
 
                                    // of the statement.
 
                                    debug_assert_eq!(heap[expr.procedure].parameters.len(), cur_frame.expr_values.len());
 
                                    debug_assert_eq!(heap[cur_frame.position].as_new().expression, expr.this)
 
                                    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 = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                                    let (type_id, monomorph_index) = mono_data.expr_info[expr.type_index as usize].variant.as_procedure();
 

	
 
                                    // Push the new frame and reserve its stack size
 
                                    let new_frame = Frame::new(heap, expr.procedure, type_id, monomorph_index);
 
                                    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);
 
            }
 

	
 
            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);
 
            }
 

	
 
            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);
 
            }
 
        }
 
        // 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) => {
 
                debug_assert!(stmt.statements.is_empty() || stmt.next == stmt.statements[0]);
 
                cur_frame.position = stmt.next;
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndBlock(stmt) => {
 
                let block = &heap[stmt.start_block];
 
                let scope = &heap[block.scope];
 
                self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 
                cur_frame.position = stmt.next;
 

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

	
 
                        cur_frame.position = stmt.next;
 
                        Ok(EvalContinuation::Stepping)
 
                    },
 
                    LocalStatement::Channel(stmt) => {
 
                        // Need to create a new channel by requesting it from
 
                        // the runtime.
 
                        match ctx.created_channel() {
 
                            None => {
 
                                // No channel is pending. So request one
 
                                    Ok(EvalContinuation::NewChannel)
 
                            },
 
                            Some((put_port, get_port)) => {
 
                                self.store.write(ValueId::Stack(heap[stmt.from].unique_id_in_scope as u32), put_port);
 
                                self.store.write(ValueId::Stack(heap[stmt.to].unique_id_in_scope as u32), get_port);
 
                                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_case.body;
 
                } else if let Some(false_body) = stmt.false_case {
 
                    cur_frame.position = false_body.body;
 
                } 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;
 
                let if_stmt = &heap[stmt.start_if];
 
                debug_assert_eq!(
 
                    heap[if_stmt.true_case.scope].first_unique_id_in_scope,
 
                    heap[if_stmt.false_case.unwrap_or(if_stmt.true_case).scope].first_unique_id_in_scope,
 
                );
 
                let scope = &heap[if_stmt.true_case.scope];
 
                self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 
                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;
 
                } else {
 
                    cur_frame.position = stmt.end_while.upcast();
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndWhile(stmt) => {
 
                cur_frame.position = stmt.next;
 
                let start_while = &heap[stmt.start_while];
 
                let scope = &heap[start_while.scope];
 
                self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Break(stmt) => {
 
                cur_frame.position = stmt.target.upcast();
 

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

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

	
 
                Ok(EvalContinuation::SyncBlockStart)
 
            },
 
            Statement::EndSynchronous(stmt) => {
 
                cur_frame.position = stmt.next;
 
                let start_synchronous = &heap[stmt.start_sync];
 
                let scope = &heap[start_synchronous.scope];
 
                self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 

	
 
                Ok(EvalContinuation::SyncBlockEnd)
 
            },
 
            Statement::Fork(stmt) => {
 
                if stmt.right_body.is_none() {
 
                    // No reason to fork
 
                    cur_frame.position = stmt.left_body;
 
                } else {
 
                    // Need to fork
 
                    if let Some(go_left) = ctx.performed_fork() {
 
                        // Runtime has created a fork
 
                        if go_left {
 
                            cur_frame.position = stmt.left_body;
 
                        } else {
 
                            cur_frame.position = stmt.right_body.unwrap();
 
                        }
 
                    } else {
 
                        // Request the runtime to create a fork of the current
 
                        // branch
 
                        return Ok(EvalContinuation::NewFork);
 
                    }
 
                }
 

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

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Select(stmt) => {
 
                // This is a trampoline for the statements that were placed by
 
                // the AST transformation pass
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndSelect(stmt) => {
 
                cur_frame.position = stmt.next;
 
                let start_select = &heap[stmt.start_select];
 
                if let Some(select_case) = start_select.cases.first() {
 
                    let scope = &heap[select_case.scope];
 
                    self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Return(_stmt) => {
 
                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::ComponentTerminated);
 
                }
 

	
 
                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.upcast();
 

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

	
 
                let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                let type_id = mono_data.expr_info[call_expr.type_index as usize].variant.as_procedure().0;
 

	
 
                // 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.procedure, type_id, 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::Local(stmt) => {
 
                    if let LocalStatement::Memory(stmt) = stmt {
 
                        // Setup as unassigned, when we execute the memory
 
                        // statement (after evaluating expression), it should no
 
                        // longer be `Unassigned`.
 
                        let variable = &heap[stmt.variable];
 
                        self.store.write(ValueId::Stack(variable.unique_id_in_scope as u32), Value::Unassigned);
 
                        cur_frame.prepare_single_expression(heap, stmt.initial_expr.upcast());
 
                    }
 
                },
 
                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
 
    }
 

	
 
    /// Constructs an error at the current expression that lives at the top of
 
    /// the expression stack. Falls back to constructing an error at the current
 
    /// statement if there is no expression.
 
    pub(crate) fn new_error_at_expr(&self, modules: &[Module], heap: &Heap, error_message: String) -> EvalError {
 
        let last_frame = self.frames.last().unwrap();
 
        for instruction in last_frame.expr_stack.iter().rev() {
 
            if let ExprInstruction::EvalExpr(expression_id) = instruction {
 
                return EvalError::new_error_at_expr(
 
                    self, modules, heap, *expression_id, error_message
 
                );
 
            }
 
        }
 

	
 
        // If here then expression stack was empty (cannot have just rotate
 
        // instructions)
 
        panic!("attempted to construct evaluation error without any expressions to evaluate in frame");
 
    }
src/protocol/parser/mod.rs
Show inline comments
 
#[macro_use] mod 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_definitions_types;
 
pub(crate) mod pass_validation_linking;
 
pub(crate) mod pass_rewriting;
 
pub(crate) mod pass_typing;
 
pub(crate) mod pass_stack_size;
 

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

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

	
 
use crate::protocol::ast_writer::ASTWriter;
 
use crate::protocol::parser::type_table::PolymorphicVariable;
 
use crate::protocol::token_writer::TokenWriter;
 

	
 
const REOWOLF_PATH_ENV: &'static str = "REOWOLF_ROOT"; // first lookup reowolf path
 
const REOWOLF_PATH_DIR: &'static str = "std"; // then try folder in current working directory
 

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

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

	
 
pub struct TargetArch {
 
    pub void_type_id: TypeId,
 
    pub message_type_id: TypeId,
 
    pub bool_type_id: TypeId,
 
    pub uint8_type_id: TypeId,
 
    pub uint16_type_id: TypeId,
 
    pub uint32_type_id: TypeId,
 
    pub uint64_type_id: TypeId,
 
    pub sint8_type_id: TypeId,
 
    pub sint16_type_id: TypeId,
 
    pub sint32_type_id: TypeId,
 
    pub sint64_type_id: TypeId,
 
    pub char_type_id: TypeId,
 
    pub string_type_id: TypeId,
 
    pub array_type_id: TypeId,
 
    pub slice_type_id: TypeId,
 
    pub input_type_id: TypeId,
 
    pub output_type_id: TypeId,
 
    pub pointer_type_id: TypeId,
 
}
 

	
 
impl TargetArch {
 
    fn new() -> Self {
 
        return Self{
 
            void_type_id: TypeId::new_invalid(),
 
            bool_type_id: TypeId::new_invalid(),
 
            message_type_id: TypeId::new_invalid(),
 
            uint8_type_id: TypeId::new_invalid(),
 
            uint16_type_id: TypeId::new_invalid(),
 
            uint32_type_id: TypeId::new_invalid(),
 
            uint64_type_id: TypeId::new_invalid(),
 
            sint8_type_id: TypeId::new_invalid(),
 
            sint16_type_id: TypeId::new_invalid(),
 
            sint32_type_id: TypeId::new_invalid(),
 
            sint64_type_id: TypeId::new_invalid(),
 
            char_type_id: TypeId::new_invalid(),
 
            string_type_id: TypeId::new_invalid(),
 
            array_type_id: TypeId::new_invalid(),
 
            slice_type_id: TypeId::new_invalid(),
 
            input_type_id: TypeId::new_invalid(),
 
            output_type_id: TypeId::new_invalid(),
 
            pointer_type_id: TypeId::new_invalid(),
 
        }
 
    }
 
}
 

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

	
 
pub struct Parser {
 
    // Storage of all information created/gathered during compilation.
 
    pub(crate) heap: Heap,
 
    pub(crate) string_pool: StringPool, // Do not deallocate, holds all strings
 
    pub(crate) modules: Vec<Module>,
 
    pub(crate) symbol_table: SymbolTable,
 
    pub(crate) type_table: TypeTable,
 
    pub(crate) global_module_index: usize, // contains globals, implicitly imported everywhere
 
    // 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,
 
    pass_rewriting: PassRewriting,
 
    pass_stack_size: PassStackSize,
 
    // Compiler options
 
    pub write_tokens_to: Option<String>,
 
    pub write_ast_to: Option<String>,
 
    pub(crate) arch: TargetArch,
 
}
 

	
 
impl Parser {
 
    pub fn new() -> Result<Self, String> {
 
        let mut parser = Parser{
 
            heap: Heap::new(),
 
            string_pool: StringPool::new(),
 
            modules: Vec::new(),
 
            symbol_table: SymbolTable::new(),
 
            type_table: TypeTable::new(),
 
            global_module_index: 0,
 
            pass_tokenizer: PassTokenizer::new(),
 
            pass_symbols: PassSymbols::new(),
 
            pass_import: PassImport::new(),
 
            pass_definitions: PassDefinitions::new(),
 
            pass_validation: PassValidationLinking::new(),
 
            pass_typing: PassTyping::new(),
 
            pass_rewriting: PassRewriting::new(),
 
            pass_stack_size: PassStackSize::new(),
 
            write_tokens_to: None,
 
            write_ast_to: None,
 
            arch: TargetArch::new(),
 
        };
 

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

	
 
        // Insert builtin types
 
        // TODO: At some point use correct values for size/alignment
 
        parser.arch.void_type_id    = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Void], false, 0, 1);
 
        parser.arch.message_type_id = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Message], false, 24, 8);
 
        parser.arch.bool_type_id    = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Bool], false, 1, 1);
 
        parser.arch.uint8_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::UInt8], false, 1, 1);
 
        parser.arch.uint16_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::UInt16], false, 2, 2);
 
        parser.arch.uint32_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::UInt32], false, 4, 4);
 
        parser.arch.uint64_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::UInt64], false, 8, 8);
 
        parser.arch.sint8_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::SInt8], false, 1, 1);
 
        parser.arch.sint16_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::SInt16], false, 2, 2);
 
        parser.arch.sint32_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::SInt32], false, 4, 4);
 
        parser.arch.sint64_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::SInt64], false, 8, 8);
 
        parser.arch.char_type_id    = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Character], false, 4, 4);
 
        parser.arch.string_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::String], false, 24, 8);
 
        parser.arch.array_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Array, ConcreteTypePart::Void], true, 24, 8);
 
        parser.arch.slice_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Slice, ConcreteTypePart::Void], true, 16, 4);
 
        parser.arch.input_type_id   = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Input, ConcreteTypePart::Void], true, 8, 8);
 
        parser.arch.output_type_id  = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Output, ConcreteTypePart::Void], true, 8, 8);
 
        parser.arch.pointer_type_id = insert_builtin_type(&mut parser.type_table, vec![ConcreteTypePart::Pointer, ConcreteTypePart::Void], true, 8, 8);
 

	
 
        // Parse standard library
 
        parser.feed_standard_library()?;
 

	
 
        return Ok(parser)
 
    }
 

	
 
    /// Feeds a new InputSource to the parser, which will tokenize it and store
 
    /// it internally for later parsing (when all modules are present). Returns
 
    /// the index of the new module.
 
    pub fn feed(&mut self, mut source: InputSource) -> Result<usize, ParseError> {
 
        return self.feed_internal(source, false);
 
    }
 

	
 
    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,
 
            arch: &self.arch,
 
        };
 

	
 
        // 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)?;
 
        }
 

	
 
        if let Some(filename) = &self.write_tokens_to {
 
            let mut writer = TokenWriter::new();
 
            let mut file = std::fs::File::create(std::path::Path::new(filename)).unwrap();
 
            writer.write(&mut file, &self.modules);
 
        }
 

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

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

	
 
        // Perform typechecking on all modules
 
        let mut queue = ResolveQueue::new();
 
        for module_idx in 0..self.modules.len() {
 
            let mut ctx = visitor::Ctx{
 
                heap: &mut self.heap,
 
                modules: &mut self.modules,
 
                module_idx,
 
                symbols: &mut self.symbol_table,
 
                types: &mut self.type_table,
 
                arch: &self.arch,
 
            };
 
            self.pass_typing.queue_module_definitions(&mut ctx, &mut queue);
 
        };
 
        while !queue.is_empty() {
 
            let top = queue.pop_front().unwrap();
 
            let mut ctx = visitor::Ctx{
 
                heap: &mut self.heap,
 
                modules: &mut self.modules,
 
                module_idx: top.root_id.index as usize,
 
                symbols: &mut self.symbol_table,
 
                types: &mut self.type_table,
 
                arch: &self.arch,
 
            };
 
            self.pass_typing.handle_module_definition(&mut ctx, &mut queue, top)?;
 
        }
 

	
 
        // Rewrite nodes in tree, then prepare for execution of code
 
        for module_idx in 0..self.modules.len() {
 
            self.modules[module_idx].phase = ModuleCompilationPhase::Typed;
 
            let mut ctx = visitor::Ctx{
 
                heap: &mut self.heap,
 
                modules: &mut self.modules,
 
                module_idx,
 
                symbols: &mut self.symbol_table,
 
                types: &mut self.type_table,
 
                arch: &self.arch,
 
            };
 
            self.pass_rewriting.visit_module(&mut ctx)?;
 
            self.pass_stack_size.visit_module(&mut ctx)?;
 
        }
 

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

	
 
        Ok(())
 
    }
 

	
 
    /// Tries to find the standard library and add the files for parsing.
 
    fn feed_standard_library(&mut self) -> Result<(), String> {
 
        use std::env;
 
        use std::path::{Path, PathBuf};
 
        use std::fs;
 

	
 
        const FILES: [&'static str; 1] = [
 
        const FILES: [&'static str; 2] = [
 
            "std.global.pdl",
 
            "std.random.pdl",
 
        ];
 

	
 
        // Determine base directory
 
        let (base_path, from_env) = if let Ok(path) = env::var(REOWOLF_PATH_ENV) {
 
            // Path variable is set
 
            (path, true)
 
        } else {
 
            let mut path = String::with_capacity(REOWOLF_PATH_DIR.len() + 2);
 
            path.push_str("./");
 
            path.push_str(REOWOLF_PATH_DIR);
 
            (path, false)
 
        };
 

	
 
        // Make sure directory exists
 
        let path = Path::new(&base_path);
 
        if !path.exists() {
 
            return Err(format!("std lib root directory '{}' does not exist", base_path));
 
        }
 

	
 
        // Try to load all standard library files. We might need a more unified
 
        // way to do this in the future (i.e. a "std" package, containing all
 
        // of the modules)
 
        let mut file_path = PathBuf::new();
 
        let mut first_file = true;
 

	
 
        for file in FILES {
 
            file_path.clear();
 
            file_path.push(path);
 
            file_path.push(file);
 

	
 
            let source = fs::read(file_path.as_path());
 
            if let Err(err) = source {
 
                return Err(format!(
 
                    "failed to read std lib file '{}' in root directory '{}', because: {}",
 
                    file, base_path, err
 
                ));
 
            }
 

	
 
            let source = source.unwrap();
 
            let input_source = InputSource::new(file.to_string(), source);
 

	
 
            let module_index = self.feed_internal(input_source, true);
 
            if let Err(err) = module_index {
 
                // A bit of a hack, but shouldn't really happen anyway: the
 
                // compiler should ship with a decent standard library (at some
 
                // point)
 
                return Err(format!("{}", err));
 
            }
 
            let module_index = module_index.unwrap();
 

	
 
            if first_file {
 
                self.global_module_index = module_index;
 
                first_file = false;
 
            }
 
        }
 

	
 
        return Ok(())
 
    }
 

	
 
    fn feed_internal(&mut self, mut source: InputSource, is_compiler_file: bool) -> Result<usize, ParseError> {
 
        let mut token_buffer = TokenBuffer::new();
 
        self.pass_tokenizer.tokenize(&mut source, &mut token_buffer)?;
 

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

	
 
        return Ok(module_index);
 
    }
 
}
 

	
 
fn insert_builtin_type(type_table: &mut TypeTable, parts: Vec<ConcreteTypePart>, has_poly_var: bool, size: usize, alignment: usize) -> TypeId {
 
    const POLY_VARS: [PolymorphicVariable; 1] = [PolymorphicVariable{
 
        identifier: Identifier::new_empty(InputSpan::new()),
 
        is_in_use: false,
 
    }];
 

	
 
    let concrete_type = ConcreteType{ parts };
 
    let poly_var = if has_poly_var {
 
        POLY_VARS.as_slice()
 
    } else {
 
        &[]
 
    };
 

	
 
    return type_table.add_builtin_data_type(concrete_type, poly_var, size, alignment);
 
}
 
\ No newline at end of file
src/protocol/parser/pass_definitions.rs
Show inline comments
 
use crate::protocol::ast::*;
 
use super::symbol_table::*;
 
use super::{Module, ModuleCompilationPhase, PassCtx};
 
use super::tokens::*;
 
use super::token_parsing::*;
 
use super::pass_definitions_types::*;
 

	
 
use crate::protocol::input_source::{InputSource, InputPosition, InputSpan, ParseError};
 
use crate::collections::*;
 

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

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

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

	
 
        // We iterate through the entire document. If we find a marker that has
 
        // been handled then we skip over it. It is important that we properly
 
        // parse all other tokens in the document to ensure that we throw the
 
        // correct kind of errors.
 
        let num_tokens = module.tokens.tokens.len() as u32;
 
        let num_markers = module.tokens.markers.len();
 

	
 
        let mut marker_index = 0;
 
        let mut first_token_index = 0;
 
        while first_token_index < num_tokens {
 
            // Seek ahead to the next marker that was already handled.
 
            let mut last_token_index = num_tokens;
 
            let mut new_first_token_index = num_tokens;
 
            while marker_index < num_markers {
 
                let marker = &module.tokens.markers[marker_index];
 
                marker_index += 1;
 
                if marker.handled {
 
                    last_token_index = marker.first_token;
 
                    new_first_token_index = marker.last_token;
 
                    break;
 
                }
 
            }
 

	
 
            self.visit_token_range(modules, module_idx, ctx, first_token_index, last_token_index)?;
 
            first_token_index = new_first_token_index;
 
        }
 

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

	
 
        Ok(())
 
    }
 

	
 
    fn visit_token_range(
 
        &mut self, modules: &[Module], module_idx: usize, ctx: &mut PassCtx,
 
        token_range_begin: u32, token_range_end: u32,
 
    ) -> Result<(), ParseError> {
 
        let module = &modules[module_idx];
 

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

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

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

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

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

	
 
        let mut fields_section = self.struct_fields.start_section();
 
        consume_comma_separated(
 
            TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
 
            |source, iter, ctx| {
 
                let poly_vars = ctx.heap[definition_id].poly_vars();
 

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

	
 
                let mut types_section = self.parser_types.start_section();
 

	
 
                let has_embedded = maybe_consume_comma_separated(
 
                    TokenKind::OpenParen, TokenKind::CloseParen, source, iter, ctx,
 
                    |source, iter, ctx| {
 
                        let poly_vars = ctx.heap[definition_id].poly_vars();
 
                        self.type_parser.consume_parser_type(
 
                            iter, &ctx.heap, source, &ctx.symbols, poly_vars, definition_id,
 
                            module_scope, false, false, None
 
                        )
 
                    },
 
                    &mut types_section, "an embedded type", Some(&mut close_pos)
 
                )?;
 
                let value = if has_embedded {
 
                    types_section.into_vec()
 
                } else {
 
                    types_section.forget();
 
                    Vec::new()
 
                };
 

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

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

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        // Parse function's argument list
 
        let mut parameter_section = self.variables.start_section();
 
        consume_parameter_list(
 
            &mut self.type_parser, &module.source, iter, ctx, &mut parameter_section,
 
            module_scope, definition_id, allow_compiler_types
 
        )?;
 
        let parameters = parameter_section.into_vec();
 

	
 
        // Consume return types
 
        consume_token(&module.source, iter, TokenKind::ArrowRight)?;
 
        let poly_vars = ctx.heap[definition_id].poly_vars();
 
        let parser_type = self.type_parser.consume_parser_type(
 
            iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars, definition_id,
 
            module_scope, false, allow_compiler_types, None
 
        )?;
 

	
 
        // Consume body
 
        let (body_id, source) = self.consume_procedure_body(module, iter, ctx, definition_id, ProcedureKind::Function)?;
 
        let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Definition(definition_id)));
 

	
 
        // Assign everything in the preallocated AST node
 
        let function = ctx.heap[definition_id].as_procedure_mut();
 
        function.source = source;
 
        function.return_type = Some(parser_type);
 
        function.parameters = parameters;
 
        function.scope = scope_id;
 
        function.body = body_id;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_component_definition(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<(), ParseError> {
 
        // Consume component variant and name
 
        let (_variant_text, _) = consume_any_ident(&module.source, iter)?;
 
        debug_assert!(_variant_text == KW_PRIMITIVE || _variant_text == KW_COMPOSITE);
 
        let (ident_text, _) = consume_ident(&module.source, iter)?;
 

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

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

	
 
        // Parse component's argument list
 
        let mut parameter_section = self.variables.start_section();
 
        consume_parameter_list(
 
            &mut self.type_parser, &module.source, iter, ctx, &mut parameter_section,
 
            module_scope, definition_id, allow_compiler_types
 
        )?;
 
        let parameters = parameter_section.into_vec();
 

	
 
        // Consume body
 
        let procedure_kind = ctx.heap[definition_id].as_procedure().kind;
 
        let (body_id, source) = self.consume_procedure_body(module, iter, ctx, definition_id, procedure_kind)?;
 
        let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Definition(definition_id)));
 

	
 
        // Assign everything in the AST node
 
        let component = ctx.heap[definition_id].as_procedure_mut();
 
        debug_assert!(component.return_type.is_none());
 
        component.source = source;
 
        component.parameters = parameters;
 
        component.scope = scope_id;
 
        component.body = body_id;
 

	
 
        Ok(())
 
    }
 

	
 
    /// Consumes a procedure's body: either a user-defined procedure, which we
 
    /// parse as normal, or a builtin function, where we'll make sure we expect
 
    /// the particular builtin.
 
    ///
 
    /// We expect that the procedure's name is already stored in the
 
    /// preallocated AST node.
 
    fn consume_procedure_body(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, definition_id: DefinitionId, kind: ProcedureKind
 
    ) -> Result<(BlockStatementId, ProcedureSource), ParseError> {
 
        if iter.next() == Some(TokenKind::OpenCurly) && iter.peek() == Some(TokenKind::Pragma) {
 
            // Consume the placeholder "{ #builtin }" tokens
 
            iter.consume(); // opening curly brace
 
            let (pragma, pragma_span) = consume_pragma(&module.source, iter)?;
 
            if pragma != b"#builtin" {
 
                return Err(ParseError::new_error_str_at_span(
 
                    &module.source, pragma_span,
 
                    "expected a '#builtin' pragma, or a function body"
 
                ));
 
            }
 

	
 
            if iter.next() != Some(TokenKind::CloseCurly) {
 
                // Just to keep the compiler writers in line ;)
 
                panic!("compiler error: when using the #builtin pragma, wrap it in curly braces");
 
            }
 
            iter.consume();
 

	
 
            // Retrieve module and procedure name
 
            assert!(module.name.is_some(), "compiler error: builtin procedure body in unnamed module");
 
            let (_, module_name) = module.name.as_ref().unwrap();
 
            let module_name = module_name.as_str();
 

	
 
            let definition = ctx.heap[definition_id].as_procedure();
 
            let procedure_name = definition.identifier.value.as_str();
 

	
 
            let source = match (module_name, procedure_name) {
 
                ("std.global", "get") => ProcedureSource::FuncGet,
 
                ("std.global", "put") => ProcedureSource::FuncPut,
 
                ("std.global", "fires") => ProcedureSource::FuncFires,
 
                ("std.global", "create") => ProcedureSource::FuncCreate,
 
                ("std.global", "length") => ProcedureSource::FuncLength,
 
                ("std.global", "assert") => ProcedureSource::FuncAssert,
 
                ("std.global", "print") => ProcedureSource::FuncPrint,
 
                ("std.random", "random_u32") => ProcedureSource::CompRandomU32,
 
                _ => panic!(
 
                    "compiler error: unknown builtin procedure '{}' in module '{}'",
 
                    procedure_name, module_name
 
                ),
 
            };
 

	
 
            return Ok((BlockStatementId::new_invalid(), source));
 
        } else {
 
            let body_id = self.consume_block_statement(module, iter, ctx)?;
 
            let source = match kind {
 
                ProcedureKind::Function =>
 
                    ProcedureSource::FuncUserDefined,
 
                ProcedureKind::Primitive | ProcedureKind::Composite =>
 
                    ProcedureSource::CompUserDefined,
 
            };
 

	
 
            return Ok((body_id, source))
 
        }
 
    }
 

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

	
 
        if next == TokenKind::OpenCurly {
 
            let id = self.consume_block_statement(module, iter, ctx)?;
 
            return Ok(id.upcast());
 
        } else if next == TokenKind::Ident {
 
            let ident = peek_ident(&module.source, iter).unwrap();
 
            if ident == KW_STMT_IF {
 
                // Consume if statement and place end-if statement directly
 
                // after it.
 
                let id = self.consume_if_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_WHILE {
 
                let id = self.consume_while_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_BREAK {
 
                let id = self.consume_break_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_CONTINUE {
 
                let id = self.consume_continue_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_SYNC {
 
                let id = self.consume_synchronous_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_FORK {
 
                let id = self.consume_fork_statement(module, iter, ctx)?;
 

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

	
 
                let fork_stmt = &mut ctx.heap[id];
 
                fork_stmt.end_fork = end_fork;
 

	
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_SELECT {
 
                let id = self.consume_select_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_RETURN {
 
                let id = self.consume_return_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_GOTO {
 
                let id = self.consume_goto_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_NEW {
 
                let id = self.consume_new_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else if ident == KW_STMT_CHANNEL {
 
                let id = self.consume_channel_statement(module, iter, ctx)?;
 
                return Ok(id.upcast().upcast());
 
            } else if iter.peek() == Some(TokenKind::Colon) {
 
                let id = self.consume_labeled_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            } else {
 
                // Two fallback possibilities: the first one is a memory
 
                // declaration, the other one is to parse it as a normal
 
                // expression. This is a bit ugly.
 
                if let Some(memory_stmt_id) = self.maybe_consume_memory_statement_without_semicolon(module, iter, ctx)? {
 
                    consume_token(&module.source, iter, TokenKind::SemiColon)?;
 
                    return Ok(memory_stmt_id.upcast().upcast());
 
                } else {
 
                    let id = self.consume_expression_statement(module, iter, ctx)?;
 
                    return Ok(id.upcast());
 
                }
 
            }
 
        } else if next == TokenKind::OpenParen {
 
            // Same as above: memory statement or normal expression
 
            if let Some(memory_stmt_id) = self.maybe_consume_memory_statement_without_semicolon(module, iter, ctx)? {
 
                consume_token(&module.source, iter, TokenKind::SemiColon)?;
 
                return Ok(memory_stmt_id.upcast().upcast());
 
            } else {
 
                let id = self.consume_expression_statement(module, iter, ctx)?;
 
                return Ok(id.upcast());
 
            }
 
        } else {
 
            let id = self.consume_expression_statement(module, iter, ctx)?;
 
            return Ok(id.upcast());
 
        }
 
    }
 

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

	
 
        let mut stmt_section = self.statements.start_section();
 
        let mut next = iter.next();
 
        while next != Some(TokenKind::CloseCurly) {
 
            if next.is_none() {
 
                return Err(ParseError::new_error_str_at_pos(
 
                    &module.source, iter.last_valid_pos(), "expected a statement or '}'"
 
                ));
 
            }
 
            let stmt_id = self.consume_statement(module, iter, ctx)?;
 
            stmt_section.push(stmt_id);
 
            next = iter.next();
 
        }
 

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

	
 
        let block_id = ctx.heap.alloc_block_statement(|this| BlockStatement{
 
            this,
 
            span: block_span,
 
            statements,
 
            end_block: EndBlockStatementId::new_invalid(),
 
            scope: ScopeId::new_invalid(),
 
            next: StatementId::new_invalid(),
 
        });
 
        let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Block(block_id)));
 

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

	
 
        let block_stmt = &mut ctx.heap[block_id];
 
        block_stmt.end_block = end_block_id;
 
        block_stmt.scope = scope_id;
 

	
 
        Ok(block_id)
 
    }
 

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

	
 
        // Consume bodies of if-statement
 
        let true_body = IfStatementCase{
 
            body: self.consume_statement(module, iter, ctx)?,
 
            scope: ScopeId::new_invalid(),
 
        };
 

	
 
        let false_body = if has_ident(&module.source, iter, KW_STMT_ELSE) {
 
            iter.consume();
 
            let false_body = IfStatementCase{
 
                body: self.consume_statement(module, iter, ctx)?,
 
                scope: ScopeId::new_invalid(),
 
            };
 

	
 
            Some(false_body)
 
        } else {
 
            None
 
        };
 

	
 
        // Construct AST elements
 
        let if_stmt_id = ctx.heap.alloc_if_statement(|this| IfStatement{
 
            this,
 
            span: if_span,
 
            test,
 
            true_case: true_body,
 
            false_case: false_body,
 
            end_if: EndIfStatementId::new_invalid(),
 
        });
 
        let end_if_stmt_id = ctx.heap.alloc_end_if_statement(|this| EndIfStatement{
 
            this,
 
            start_if: if_stmt_id,
 
            next: StatementId::new_invalid(),
 
        });
 
        let true_scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::If(if_stmt_id, true)));
 
        let false_scope_id = if false_body.is_some() {
 
            Some(ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::If(if_stmt_id, false))))
 
        } else {
 
            None
 
        };
 

	
 
        let if_stmt = &mut ctx.heap[if_stmt_id];
 
        if_stmt.end_if = end_if_stmt_id;
 
        if_stmt.true_case.scope = true_scope_id;
 
        if let Some(false_case) = &mut if_stmt.false_case {
 
            false_case.scope = false_scope_id.unwrap();
 
        }
 

	
 
        return Ok(if_stmt_id);
 
    }
 

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

	
 
        let while_stmt_id = ctx.heap.alloc_while_statement(|this| WhileStatement{
 
            this,
 
            span: while_span,
 
            test,
 
            scope: ScopeId::new_invalid(),
 
            body,
 
            end_while: EndWhileStatementId::new_invalid(),
 
            in_sync: SynchronousStatementId::new_invalid(),
 
        });
 
        let end_while_stmt_id = ctx.heap.alloc_end_while_statement(|this| EndWhileStatement{
 
            this,
 
            start_while: while_stmt_id,
 
            next: StatementId::new_invalid(),
 
        });
 
        let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::While(while_stmt_id)));
 

	
 
        let while_stmt = &mut ctx.heap[while_stmt_id];
 
        while_stmt.scope = scope_id;
 
        while_stmt.end_while = end_while_stmt_id;
 

	
 
        Ok(while_stmt_id)
 
    }
 

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

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

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

	
 
        let sync_stmt_id = ctx.heap.alloc_synchronous_statement(|this| SynchronousStatement{
 
            this,
 
            span: synchronous_span,
 
            scope: ScopeId::new_invalid(),
 
            body,
 
            end_sync: EndSynchronousStatementId::new_invalid(),
 
        });
 
        let end_sync_stmt_id = ctx.heap.alloc_end_synchronous_statement(|this| EndSynchronousStatement{
 
            this,
 
            start_sync: sync_stmt_id,
 
            next: StatementId::new_invalid(),
 
        });
 
        let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Synchronous(sync_stmt_id)));
 

	
 
        let sync_stmt = &mut ctx.heap[sync_stmt_id];
 
        sync_stmt.scope = scope_id;
 
        sync_stmt.end_sync = end_sync_stmt_id;
 

	
 
        return Ok(sync_stmt_id);
 
    }
 

	
 
    fn consume_fork_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ForkStatementId, ParseError> {
 
        let fork_span = consume_exact_ident(&module.source, iter, KW_STMT_FORK)?;
 
        let left_body = self.consume_statement(module, iter, ctx)?;
 

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

	
 
        Ok(ctx.heap.alloc_fork_statement(|this| ForkStatement{
 
            this,
 
            span: fork_span,
 
            left_body,
 
            right_body,
 
            end_fork: EndForkStatementId::new_invalid(),
 
        }))
 
    }
 

	
 
    fn consume_select_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<SelectStatementId, ParseError> {
 
        let select_span = consume_exact_ident(&module.source, iter, KW_STMT_SELECT)?;
 
        consume_token(&module.source, iter, TokenKind::OpenCurly)?;
 

	
 
        let mut cases = Vec::new();
 
        let mut next = iter.next();
 

	
 
        while Some(TokenKind::CloseCurly) != next {
 
            let guard = match self.maybe_consume_memory_statement_without_semicolon(module, iter, ctx)? {
 
                Some(guard_mem_stmt) => guard_mem_stmt.upcast().upcast(),
 
                None => {
 
                    let start_pos = iter.last_valid_pos();
 
                    let expr = self.consume_expression(module, iter, ctx)?;
 
                    let end_pos = iter.last_valid_pos();
 

	
 
                    let guard_expr_stmt = ctx.heap.alloc_expression_statement(|this| ExpressionStatement{
 
                        this,
 
                        span: InputSpan::from_positions(start_pos, end_pos),
 
                        expression: expr,
 
                        next: StatementId::new_invalid(),
 
                    });
 

	
 
                    guard_expr_stmt.upcast()
 
                },
 
            };
 
            consume_token(&module.source, iter, TokenKind::ArrowRight)?;
 
            let block = self.consume_statement(module, iter, ctx)?;
 
            cases.push(SelectCase{
 
                guard,
 
                body: block,
 
                scope: ScopeId::new_invalid(),
 
                involved_ports: Vec::with_capacity(1)
 
            });
 

	
 
            next = iter.next();
 
        }
 

	
 
        consume_token(&module.source, iter, TokenKind::CloseCurly)?;
 

	
 
        let num_cases = cases.len();
 
        let select_stmt_id = ctx.heap.alloc_select_statement(|this| SelectStatement{
 
            this,
 
            span: select_span,
 
            cases,
 
            end_select: EndSelectStatementId::new_invalid(),
 
            relative_pos_in_parent: -1,
 
            next: StatementId::new_invalid(),
 
        });
 

	
 
        let end_select_stmt_id = ctx.heap.alloc_end_select_statement(|this| EndSelectStatement{
 
            this,
 
            start_select: select_stmt_id,
 
            next: StatementId::new_invalid(),
 
        });
 

	
 
        let select_stmt = &mut ctx.heap[select_stmt_id];
 
        select_stmt.end_select = end_select_stmt_id;
 

	
 
        for case_index in 0..num_cases {
 
            let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::SelectCase(select_stmt_id, case_index as u32)));
 
            let select_stmt = &mut ctx.heap[select_stmt_id];
 
            let select_case = &mut select_stmt.cases[case_index];
 
            select_case.scope = scope_id;
 
        }
 

	
 
        return Ok(select_stmt_id)
 
    }
 

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

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

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

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

	
 
    fn consume_goto_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<GotoStatementId, ParseError> {
 
        let goto_span = consume_exact_ident(&module.source, iter, KW_STMT_GOTO)?;
 
        let label = consume_ident_interned(&module.source, iter, ctx)?;
 
        consume_token(&module.source, iter, TokenKind::SemiColon)?;
 
        Ok(ctx.heap.alloc_goto_statement(|this| GotoStatement{
 
            this,
 
            span: goto_span,
 
            label,
 
            target: LabeledStatementId::new_invalid(),
 
        }))
 
    }
 

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

	
 
        let start_pos = iter.last_valid_pos();
 
        let expression_id = self.consume_primary_expression(module, iter, ctx)?;
 
        let expression = &ctx.heap[expression_id];
 
        let mut valid = false;
 

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

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

	
 
        debug_assert!(!call_id.is_invalid());
 
        Ok(ctx.heap.alloc_new_statement(|this| NewStatement{
 
            this,
 
            span: new_span,
 
            expression: call_id,
 
            next: StatementId::new_invalid(),
 
        }))
 
    }
 

	
 
    fn consume_channel_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ChannelStatementId, ParseError> {
 
        // Consume channel specification
 
        let channel_span = consume_exact_ident(&module.source, iter, KW_STMT_CHANNEL)?;
 
        let (inner_port_type, end_pos) = if Some(TokenKind::OpenAngle) == iter.next() {
 
            // Retrieve the type of the channel, we're cheating a bit here by
 
            // consuming the first '<' and setting the initial angle depth to 1
 
            // such that our final '>' will be consumed as well.
 
            let angle_start_pos = iter.next_start_position();
 
            iter.consume();
 
            let definition_id = self.cur_definition;
 
            let poly_vars = ctx.heap[definition_id].poly_vars();
 
            let parser_type = self.type_parser.consume_parser_type(
 
                iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars,
 
                definition_id, SymbolScope::Module(module.root_id),
 
                true, false, Some(angle_start_pos)
 
            )?;
 

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

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

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

	
 
        let mut to_port_type = ParserType{ elements: Vec::with_capacity(port_type_len), full_span: port_type_span };
 
        to_port_type.elements.push(ParserTypeElement{
 
            element_span: channel_span,
 
            variant: ParserTypeVariant::Input
 
        });
 
        to_port_type.elements.extend_from_slice(&inner_port_type);
 
        let to = ctx.heap.alloc_variable(|this|Variable{
 
            this,
 
            kind: VariableKind::Local,
 
            identifier: to_identifier,
 
            parser_type: to_port_type,
 
            relative_pos_in_parent: 0,
 
            unique_id_in_scope: -1,
 
        });
 

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

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

	
 
        let inner_stmt_id = self.consume_statement(module, iter, ctx)?;
 
        let stmt_id = ctx.heap.alloc_labeled_statement(|this| LabeledStatement {
 
            this,
 
            label,
 
            body: inner_stmt_id,
 
            relative_pos_in_parent: 0,
 
            in_sync: SynchronousStatementId::new_invalid(),
 
        });
 

	
 
        return Ok(stmt_id);
 
    }
 

	
 
    /// Attempts to consume a memory statement (a statement along the lines of
 
    /// `type var_name = initial_expr`). Will return `Ok(None)` if it didn't
 
    /// seem like there was a memory statement, `Ok(Some(...))` if there was
 
    /// one, and `Err(...)` if its reasonable to assume that there was a memory
 
    /// statement, but we failed to parse it.
 
    fn maybe_consume_memory_statement_without_semicolon(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<Option<MemoryStatementId>, ParseError> {
 
        // This is a bit ugly. It would be nicer if we could somehow
 
        // consume the expression with a type hint if we do get a valid
 
        // type, but we don't get an identifier following it
 
        let iter_state = iter.save();
 
        let definition_id = self.cur_definition;
 
        let poly_vars = ctx.heap[definition_id].poly_vars();
 

	
 
        let parser_type = self.type_parser.consume_parser_type(
 
            iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars,
 
            definition_id, SymbolScope::Definition(definition_id),
 
            true, false, None
 
        );
 

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

	
 
                let initial_expr_id = self.consume_expression(module, iter, ctx)?;
 
                let initial_expr_end_pos = iter.last_valid_pos();
 

	
 
                // Create the AST variable
 
                let local_id = ctx.heap.alloc_variable(|this| Variable{
 
                    this,
 
                    kind: VariableKind::Local,
 
                    identifier: identifier.clone(),
 
                    parser_type,
 
                    relative_pos_in_parent: 0,
 
                    unique_id_in_scope: -1,
 
                });
 

	
 
                // Create the initial assignment expression
 
                // Note: we set the initial variable declaration here
 
                let variable_expr_id = ctx.heap.alloc_variable_expression(|this| VariableExpression{
 
                    this,
 
                    identifier,
 
                    declaration: Some(local_id),
 
                    used_as_binding_target: false,
 
                    parent: ExpressionParent::None,
 
                    type_index: -1,
 
                });
 
                let assignment_expr_id = ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{
 
                    this,
 
                    operator_span: assign_span,
 
                    full_span: InputSpan::from_positions(memory_span.begin, initial_expr_end_pos),
 
                    left: variable_expr_id.upcast(),
 
                    operation: AssignmentOperator::Set,
 
                    right: initial_expr_id,
 
                    parent: ExpressionParent::None,
 
                    type_index: -1,
 
                });
 

	
 
                // Put both together in the memory statement
 
                let memory_stmt_id = ctx.heap.alloc_memory_statement(|this| MemoryStatement{
 
                    this,
 
                    span: memory_span,
 
                    variable: local_id,
 
                    initial_expr: assignment_expr_id,
 
                    next: StatementId::new_invalid()
 
                });
 

	
 
                return Ok(Some(memory_stmt_id));
 
            }
 
        }
 

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

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

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

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

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

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

	
 
            if token.is_none() {
 
                return None
 
            }
 

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

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

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

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

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

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

	
 
            let test = result;
 
            let true_expression = self.consume_expression(module, iter, ctx)?;
 
            consume_token(&module.source, iter, TokenKind::Colon)?;
 
            let false_expression = self.consume_expression(module, iter, ctx)?;
 

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

	
 
            Ok(ctx.heap.alloc_conditional_expression(|this| ConditionalExpression{
 
                this, operator_span, full_span, test, true_expression, false_expression,
 
                parent: ExpressionParent::None,
 
                type_index: -1,
 
            }).upcast())
 
        } else {
 
            Ok(result)
 
        }
 
    }
 

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

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

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

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

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

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

	
 
    fn consume_equality_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
@@ -1277,618 +1276,619 @@ impl PassDefinitions {
 
                Some(TokenKind::Slash) => Some(BinaryOperator::Divide),
 
                Some(TokenKind::Percent) => Some(BinaryOperator::Remainder),
 
                _ => None
 
            },
 
            Self::consume_prefix_expression
 
        )
 
    }
 

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

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

	
 
            let expression = self.consume_prefix_expression(module, iter, ctx)?;
 
            let full_span = InputSpan::from_positions(
 
                operator_span.begin, ctx.heap[expression].full_span().end,
 
            );
 
            Ok(ctx.heap.alloc_unary_expression(|this| UnaryExpression {
 
                this, operator_span, full_span, operation, expression,
 
                parent: ExpressionParent::None,
 
                type_index: -1,
 
            }).upcast())
 
        } else if next == Some(TokenKind::PlusPlus) {
 
            return Err(ParseError::new_error_str_at_span(
 
                &module.source, iter.next_span(), "prefix increment is not supported in the language"
 
            ));
 
        } else if next == Some(TokenKind::MinusMinus) {
 
            return Err(ParseError::new_error_str_at_span(
 
                &module.source, iter.next_span(), "prefix decrement is not supported in this language"
 
            ));
 
        } else {
 
            self.consume_postfix_expression(module, iter, ctx)
 
        }
 
    }
 

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

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

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

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

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

	
 
                    let to_index = self.consume_expression(module, iter, ctx)?;
 
                    let end_span = consume_token(&module.source, iter, TokenKind::CloseSquare)?;
 
                    operator_span.end = end_span.end;
 
                    let full_span = InputSpan::from_positions(
 
                        ctx.heap[subject].full_span().begin, operator_span.end
 
                    );
 

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

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

	
 
                    result = ctx.heap.alloc_indexing_expression(|this| IndexingExpression{
 
                        this, operator_span, full_span, subject,
 
                        index: from_index,
 
                        parent: ExpressionParent::None,
 
                        type_index: -1,
 
                    }).upcast();
 
                } else {
 
                    return Err(ParseError::new_error_str_at_pos(
 
                        &module.source, iter.last_valid_pos(), "unexpected token: expected ']' or '..'"
 
                    ));
 
                }
 
            } else {
 
                // Can be a select expression for struct fields, or a select
 
                // for a tuple element.
 
                debug_assert_eq!(token, TokenKind::Dot);
 
                let subject = result;
 

	
 
                let next = iter.next();
 
                let (select_kind, full_span) = if Some(TokenKind::Integer) == next {
 
                    // Tuple member
 
                    let (index, index_span) = consume_integer_literal(&module.source, iter, &mut self.buffer)?;
 
                    let full_span = InputSpan::from_positions(
 
                        ctx.heap[subject].full_span().begin, index_span.end
 
                    );
 

	
 
                    (SelectKind::TupleMember(index), full_span)
 
                } else if Some(TokenKind::Ident) == next {
 
                    // Struct field
 
                    let field_name = consume_ident_interned(&module.source, iter, ctx)?;
 

	
 
                    let full_span = InputSpan::from_positions(
 
                        ctx.heap[subject].full_span().begin, field_name.span.end
 
                    );
 

	
 
                    (SelectKind::StructField(field_name), full_span)
 
                } else {
 
                    return Err(ParseError::new_error_str_at_pos(
 
                        &module.source, iter.last_valid_pos(), "unexpected token: expected integer or identifier"
 
                    ));
 
                };
 

	
 
                result = ctx.heap.alloc_select_expression(|this| SelectExpression{
 
                    this, operator_span, full_span, subject,
 
                    kind: select_kind,
 
                    parent: ExpressionParent::None,
 
                    type_index: -1,
 
                }).upcast();
 
            }
 

	
 
            next = iter.next();
 
        }
 

	
 
        Ok(result)
 
    }
 

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

	
 
        let result = if next == Some(TokenKind::OpenParen) {
 
            // Something parenthesized. This can mean several things: we have
 
            // a parenthesized expression or we have a tuple literal. They are
 
            // ambiguous when the tuple has one member. But like the tuple type
 
            // parsing we interpret all one-tuples as parenthesized expressions.
 
            //
 
            // Practically (to prevent unnecessary `consume_expression` calls)
 
            // we distinguish the zero-tuple, the parenthesized expression, and
 
            // the N-tuple (for N > 1).
 
            let open_paren_pos = iter.next_start_position();
 
            iter.consume();
 
            let result = if Some(TokenKind::CloseParen) == iter.next() {
 
                // Zero-tuple
 
                let (_, close_paren_pos) = iter.next_positions();
 
                iter.consume();
 

	
 
                let literal_id = ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                    this,
 
                    span: InputSpan::from_positions(open_paren_pos, close_paren_pos),
 
                    value: Literal::Tuple(Vec::new()),
 
                    parent: ExpressionParent::None,
 
                    type_index: -1,
 
                });
 

	
 
                literal_id.upcast()
 
            } else {
 
                // Start by consuming one expression, then check for a comma
 
                let expr_id = self.consume_expression(module, iter, ctx)?;
 
                if Some(TokenKind::Comma) == iter.next() && Some(TokenKind::CloseParen) != iter.peek() {
 
                    // Must be an N-tuple
 
                    iter.consume(); // the comma
 
                    let mut scoped_section = self.expressions.start_section();
 
                    scoped_section.push(expr_id);
 

	
 
                    let mut close_paren_pos = open_paren_pos;
 
                    consume_comma_separated_until(
 
                        TokenKind::CloseParen, &module.source, iter, ctx,
 
                        |_source, iter, ctx| self.consume_expression(module, iter, ctx),
 
                        &mut scoped_section, "an expression", Some(&mut close_paren_pos)
 
                    )?;
 
                    debug_assert!(scoped_section.len() > 1); // peeked token wasn't CloseParen, must be expression
 

	
 
                    let literal_id = ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                        this,
 
                        span: InputSpan::from_positions(open_paren_pos, close_paren_pos),
 
                        value: Literal::Tuple(scoped_section.into_vec()),
 
                        parent: ExpressionParent::None,
 
                        type_index: -1,
 
                    });
 

	
 
                    literal_id.upcast()
 
                } else {
 
                    // Assume we're dealing with a normal expression
 
                    consume_token(&module.source, iter, TokenKind::CloseParen)?;
 

	
 
                    expr_id
 
                }
 
            };
 

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

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

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

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

	
 
            ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                this, span,
 
                value: Literal::Character(character),
 
                parent: ExpressionParent::None,
 
                type_index: -1,
 
            }).upcast()
 
        } else if next == Some(TokenKind::Ident) {
 
            // May be a variable, a type instantiation or a function call. If we
 
            // have a single identifier that we cannot find in the type table
 
            // then we're going to assume that we're dealing with a variable.
 

	
 
            let ident_span = iter.next_span();
 
            let ident_text = module.source.section_at_span(ident_span);
 
            let symbol = ctx.symbols.get_symbol_by_name(SymbolScope::Module(module.root_id), ident_text);
 

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

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

	
 
                                ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                                    this,
 
                                    span: InputSpan::from_positions(ident_span.begin, last_token),
 
                                    value: Literal::Struct(LiteralStruct{
 
                                        parser_type,
 
                                        fields: struct_fields,
 
                                        definition: target_definition_id,
 
                                    }),
 
                                    parent: ExpressionParent::None,
 
                                    type_index: -1,
 
                                }).upcast()
 
                            },
 
                            Definition::Enum(_) => {
 
                                // Enum literal: consume the variant
 
                                consume_token(&module.source, iter, TokenKind::ColonColon)?;
 
                                let variant = consume_ident_interned(&module.source, iter, ctx)?;
 

	
 
                                ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                                    this,
 
                                    span: InputSpan::from_positions(ident_span.begin, variant.span.end),
 
                                    value: Literal::Enum(LiteralEnum{
 
                                        parser_type,
 
                                        variant,
 
                                        definition: target_definition_id,
 
                                        variant_idx: 0
 
                                    }),
 
                                    parent: ExpressionParent::None,
 
                                    type_index: -1,
 
                                }).upcast()
 
                            },
 
                            Definition::Union(_) => {
 
                                // Union literal: consume the variant
 
                                consume_token(&module.source, iter, TokenKind::ColonColon)?;
 
                                let variant = consume_ident_interned(&module.source, iter, ctx)?;
 

	
 
                                // Consume any possible embedded values
 
                                let mut end_pos = variant.span.end;
 
                                let values = if Some(TokenKind::OpenParen) == iter.next() {
 
                                    self.consume_expression_list(module, iter, ctx, Some(&mut end_pos))?
 
                                } else {
 
                                    Vec::new()
 
                                };
 

	
 
                                ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                                    this,
 
                                    span: InputSpan::from_positions(ident_span.begin, end_pos),
 
                                    value: Literal::Union(LiteralUnion{
 
                                        parser_type, variant, values,
 
                                        definition: target_definition_id,
 
                                        variant_idx: 0,
 
                                    }),
 
                                    parent: ExpressionParent::None,
 
                                    type_index: -1,
 
                                }).upcast()
 
                            },
 
                            Definition::Procedure(proc_def) => {
 
                                // Check whether it is a builtin function
 
                                // TODO: Once we start generating bytecode this is unnecessary
 
                                let procedure_id = proc_def.this;
 
                                let method = match proc_def.source {
 
                                    ProcedureSource::FuncUserDefined => Method::UserFunction,
 
                                    ProcedureSource::CompUserDefined => Method::UserComponent,
 
                                    ProcedureSource::FuncGet => Method::Get,
 
                                    ProcedureSource::FuncPut => Method::Put,
 
                                    ProcedureSource::FuncFires => Method::Fires,
 
                                    ProcedureSource::FuncCreate => Method::Create,
 
                                    ProcedureSource::FuncLength => Method::Length,
 
                                    ProcedureSource::FuncAssert => Method::Assert,
 
                                    ProcedureSource::FuncPrint => Method::Print,
 
                                    _ => todo!("other proc sources")
 
                                    ProcedureSource::CompRandomU32 => Method::ComponentRandomU32,
 
                                    _ => todo!("other procedure sources"),
 
                                };
 

	
 
                                // Function call: consume the arguments
 
                                let func_span = parser_type.full_span;
 
                                let mut full_span = func_span;
 
                                let arguments = self.consume_expression_list(
 
                                    module, iter, ctx, Some(&mut full_span.end)
 
                                )?;
 

	
 
                                ctx.heap.alloc_call_expression(|this| CallExpression{
 
                                    this, func_span, full_span, parser_type, method, arguments,
 
                                    procedure: procedure_id,
 
                                    parent: ExpressionParent::None,
 
                                    type_index: -1,
 
                                }).upcast()
 
                            }
 
                        }
 
                    },
 
                    _ => {
 
                        return Err(ParseError::new_error_str_at_span(
 
                            &module.source, parser_type.full_span, "unexpected type in expression"
 
                        ))
 
                    }
 
                }
 
            } else {
 
                // Check for builtin keywords or builtin functions
 
                if ident_text == KW_LIT_NULL || ident_text == KW_LIT_TRUE || ident_text == KW_LIT_FALSE {
 
                    iter.consume();
 

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

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

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

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

	
 
                    ctx.heap.alloc_binding_expression(|this| BindingExpression{
 
                        this, operator_span, full_span, bound_to, bound_from,
 
                        parent: ExpressionParent::None,
 
                        type_index: -1,
 
                    }).upcast()
 
                } else if ident_text == KW_CAST {
 
                    // Casting expression
 
                    iter.consume();
 
                    let to_type = if Some(TokenKind::OpenAngle) == iter.next() {
 
                        let angle_start_pos = iter.next_start_position();
 
                        iter.consume();
 
                        let definition_id = self.cur_definition;
 
                        let poly_vars = ctx.heap[definition_id].poly_vars();
 
                        self.type_parser.consume_parser_type(
 
                            iter, &ctx.heap, &module.source, &ctx.symbols,
 
                            poly_vars, definition_id, SymbolScope::Module(module.root_id),
 
                            true, false, Some(angle_start_pos)
 
                        )?
 
                    } else {
 
                        // Automatic casting with inferred target type
 
                        ParserType{
 
                            elements: vec![ParserTypeElement{
 
                                element_span: ident_span,
 
                                variant: ParserTypeVariant::Inferred,
 
                            }],
 
                            full_span: ident_span
 
                        }
 
                    };
 

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

	
 
                    ctx.heap.alloc_cast_expression(|this| CastExpression{
 
                        this,
 
                        cast_span: to_type.full_span,
 
                        full_span, to_type, subject,
 
                        parent: ExpressionParent::None,
 
                        type_index: -1,
 
                    }).upcast()
 
                } else {
 
                    // Not a builtin literal, but also not a known type. So we
 
                    // assume it is a variable expression. Although if we do,
 
                    // then if a programmer mistyped a struct/function name the
 
                    // error messages will be rather cryptic. For polymorphic
 
                    // arguments we can't really do anything at all (because it
 
                    // uses the '<' token). In the other cases we try to provide
 
                    // a better error message.
 
                    iter.consume();
 
                    let next = iter.next();
 
                    if Some(TokenKind::ColonColon) == next {
 
                        return Err(ParseError::new_error_str_at_span(&module.source, ident_span, "unknown identifier"));
 
                    } else if Some(TokenKind::OpenParen) == next {
 
                        return Err(ParseError::new_error_str_at_span(
 
                            &module.source, ident_span,
 
                            "unknown identifier, did you mistype a union variant's, component's, or function's name?"
 
                        ));
 
                    } else if Some(TokenKind::OpenCurly) == next {
 
                        return Err(ParseError::new_error_str_at_span(
 
                            &module.source, ident_span,
 
                            "unknown identifier, did you mistype a struct type's name?"
 
                        ))
 
                    }
 

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

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

	
 
        Ok(result)
 
    }
 

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

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

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

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

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

	
 
        Ok(result)
 
    }
 

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

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

	
 
/// Consumes the parameter list to functions/components
 
fn consume_parameter_list(
 
    parser: &mut ParserTypeParser, source: &InputSource, iter: &mut TokenIter,
 
    ctx: &mut PassCtx, target: &mut ScopedSection<VariableId>,
 
    scope: SymbolScope, definition_id: DefinitionId, allow_compiler_types: bool
 
) -> Result<(), ParseError> {
 
    consume_comma_separated(
 
        TokenKind::OpenParen, TokenKind::CloseParen, source, iter, ctx,
 
        |source, iter, ctx| {
 
            let poly_vars = ctx.heap[definition_id].poly_vars(); // Rust being rust, multiple lookups
 
            let parser_type = parser.consume_parser_type(
 
                iter, &ctx.heap, source, &ctx.symbols, poly_vars, definition_id,
 
                scope, false, allow_compiler_types, None
 
            )?;
 
            let identifier = consume_ident_interned(source, iter, ctx)?;
 
            let parameter_id = ctx.heap.alloc_variable(|this| Variable{
 
                this,
 
                kind: VariableKind::Parameter,
 
                parser_type,
 
                identifier,
 
                relative_pos_in_parent: 0,
 
                unique_id_in_scope: -1,
 
            });
 
            Ok(parameter_id)
 
        },
 
        target, "a parameter", "a parameter list", None
 
    )
 
}
 
\ No newline at end of file
src/protocol/parser/pass_validation_linking.rs
Show inline comments
 
@@ -779,768 +779,771 @@ impl Visitor for PassValidationLinking {
 
        let binary_expr = &mut ctx.heap[id];
 

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

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

	
 
        let old_expr_parent = self.expr_parent;
 
        binary_expr.parent = old_expr_parent;
 

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

	
 
        Ok(())
 
    }
 

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

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

	
 
        let old_expr_parent = self.expr_parent;
 
        unary_expr.parent = old_expr_parent;
 

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

	
 
        Ok(())
 
    }
 

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

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

	
 
        let old_expr_parent = self.expr_parent;
 
        indexing_expr.parent = old_expr_parent;
 

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        let old_expr_parent = self.expr_parent;
 
        slicing_expr.parent = old_expr_parent;
 

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

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

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

	
 
        Ok(())
 
    }
 

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

	
 
        let old_expr_parent = self.expr_parent;
 
        select_expr.parent = old_expr_parent;
 

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

	
 
        Ok(())
 
    }
 

	
 
    fn visit_literal_expr(&mut self, ctx: &mut Ctx, id: LiteralExpressionId) -> VisitorResult {
 
        let literal_expr = &mut ctx.heap[id];
 
        let old_expr_parent = self.expr_parent;
 
        literal_expr.parent = old_expr_parent;
 

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

	
 
        match &mut literal_expr.value {
 
            Literal::Null | Literal::True | Literal::False |
 
            Literal::Character(_) | Literal::String(_) | Literal::Integer(_) => {
 
                // Just the parent has to be set, done above
 
            },
 
            Literal::Struct(literal) => {
 
                let upcast_id = id.upcast();
 
                // Retrieve type definition
 
                let type_definition = ctx.types.get_base_definition(&literal.definition).unwrap();
 
                let struct_definition = type_definition.definition.as_struct();
 

	
 
                // Make sure all fields are specified, none are specified twice
 
                // and all fields exist on the struct definition
 
                let mut specified = Vec::new(); // TODO: @performance
 
                specified.resize(struct_definition.fields.len(), false);
 

	
 
                for field in &mut literal.fields {
 
                    // Find field in the struct definition
 
                    let field_idx = struct_definition.fields.iter().position(|v| v.identifier == field.identifier);
 
                    if field_idx.is_none() {
 
                        let field_span = field.identifier.span;
 
                        let literal = ctx.heap[id].value.as_struct();
 
                        let ast_definition = &ctx.heap[literal.definition];
 
                        return Err(ParseError::new_error_at_span(
 
                            &ctx.module().source, field_span, format!(
 
                                "This field does not exist on the struct '{}'",
 
                                ast_definition.identifier().value.as_str()
 
                            )
 
                        ));
 
                    }
 
                    field.field_idx = field_idx.unwrap();
 

	
 
                    // Check if specified more than once
 
                    if specified[field.field_idx] {
 
                        let field_span = field.identifier.span;
 
                        return Err(ParseError::new_error_str_at_span(
 
                            &ctx.module().source, field_span,
 
                            "This field is specified more than once"
 
                        ));
 
                    }
 

	
 
                    specified[field.field_idx] = true;
 
                }
 

	
 
                if !specified.iter().all(|v| *v) {
 
                    // Some fields were not specified
 
                    let mut not_specified = String::new();
 
                    let mut num_not_specified = 0;
 
                    for (def_field_idx, is_specified) in specified.iter().enumerate() {
 
                        if !is_specified {
 
                            if !not_specified.is_empty() { not_specified.push_str(", ") }
 
                            let field_ident = &struct_definition.fields[def_field_idx].identifier;
 
                            not_specified.push_str(field_ident.value.as_str());
 
                            num_not_specified += 1;
 
                        }
 
                    }
 

	
 
                    debug_assert!(num_not_specified > 0);
 
                    let msg = if num_not_specified == 1 {
 
                        format!("not all fields are specified, '{}' is missing", not_specified)
 
                    } else {
 
                        format!("not all fields are specified, [{}] are missing", not_specified)
 
                    };
 

	
 
                    let literal_span = literal.parser_type.full_span;
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module().source, literal_span, msg
 
                    ));
 
                }
 

	
 
                // Need to traverse fields expressions in struct and evaluate
 
                // the poly args
 
                let mut expr_section = self.expression_buffer.start_section();
 
                for field in &literal.fields {
 
                    expr_section.push(field.value);
 
                }
 

	
 
                for expr_idx in 0..expr_section.len() {
 
                    let expr_id = expr_section[expr_idx];
 
                    self.expr_parent = ExpressionParent::Expression(upcast_id, expr_idx as u32);
 
                    self.visit_expr(ctx, expr_id)?;
 
                }
 

	
 
                expr_section.forget();
 
            },
 
            Literal::Enum(literal) => {
 
                // Make sure the variant exists
 
                let type_definition = ctx.types.get_base_definition(&literal.definition).unwrap();
 
                let enum_definition = type_definition.definition.as_enum();
 

	
 
                let variant_idx = enum_definition.variants.iter().position(|v| {
 
                    v.identifier == literal.variant
 
                });
 

	
 
                if variant_idx.is_none() {
 
                    let literal = ctx.heap[id].value.as_enum();
 
                    let ast_definition = ctx.heap[literal.definition].as_enum();
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module().source, literal.parser_type.full_span, format!(
 
                            "the variant '{}' does not exist on the enum '{}'",
 
                            literal.variant.value.as_str(), ast_definition.identifier.value.as_str()
 
                        )
 
                    ));
 
                }
 

	
 
                literal.variant_idx = variant_idx.unwrap();
 
            },
 
            Literal::Union(literal) => {
 
                // Make sure the variant exists
 
                let type_definition = ctx.types.get_base_definition(&literal.definition).unwrap();
 
                let union_definition = type_definition.definition.as_union();
 

	
 
                let variant_idx = union_definition.variants.iter().position(|v| {
 
                    v.identifier == literal.variant
 
                });
 
                if variant_idx.is_none() {
 
                    let literal = ctx.heap[id].value.as_union();
 
                    let ast_definition = ctx.heap[literal.definition].as_union();
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module().source, literal.parser_type.full_span, format!(
 
                            "the variant '{}' does not exist on the union '{}'",
 
                            literal.variant.value.as_str(), ast_definition.identifier.value.as_str()
 
                        )
 
                    ));
 
                }
 

	
 
                literal.variant_idx = variant_idx.unwrap();
 

	
 
                // Make sure the number of specified values matches the expected
 
                // number of embedded values in the union variant.
 
                let union_variant = &union_definition.variants[literal.variant_idx];
 
                if union_variant.embedded.len() != literal.values.len() {
 
                    let literal = ctx.heap[id].value.as_union();
 
                    let ast_definition = ctx.heap[literal.definition].as_union();
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module().source, literal.parser_type.full_span, format!(
 
                            "The variant '{}' of union '{}' expects {} embedded values, but {} were specified",
 
                            literal.variant.value.as_str(), ast_definition.identifier.value.as_str(),
 
                            union_variant.embedded.len(), literal.values.len()
 
                        ),
 
                    ))
 
                }
 

	
 
                // Traverse embedded values of union (if any) and evaluate the
 
                // polymorphic arguments
 
                let upcast_id = id.upcast();
 
                let mut expr_section = self.expression_buffer.start_section();
 
                for value in &literal.values {
 
                    expr_section.push(*value);
 
                }
 

	
 
                for expr_idx in 0..expr_section.len() {
 
                    let expr_id = expr_section[expr_idx];
 
                    self.expr_parent = ExpressionParent::Expression(upcast_id, expr_idx as u32);
 
                    self.visit_expr(ctx, expr_id)?;
 
                }
 

	
 
                expr_section.forget();
 
            },
 
            Literal::Array(literal) | Literal::Tuple(literal) => {
 
                // Visit all expressions in the array
 
                let upcast_id = id.upcast();
 
                let expr_section = self.expression_buffer.start_section_initialized(literal);
 
                for expr_idx in 0..expr_section.len() {
 
                    let expr_id = expr_section[expr_idx];
 
                    self.expr_parent = ExpressionParent::Expression(upcast_id, expr_idx as u32);
 
                    self.visit_expr(ctx, expr_id)?;
 
                }
 

	
 
                expr_section.forget();
 
            }
 
        }
 

	
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_cast_expr(&mut self, ctx: &mut Ctx, id: CastExpressionId) -> VisitorResult {
 
        let cast_expr = &mut ctx.heap[id];
 

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

	
 
        let upcast_id = id.upcast();
 
        let old_expr_parent = self.expr_parent;
 
        cast_expr.parent = old_expr_parent;
 

	
 
        // Recurse into the thing that we're casting
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
 
        let subject_id = cast_expr.subject;
 
        self.visit_expr(ctx, subject_id)?;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_call_expr(&mut self, ctx: &mut Ctx, id: CallExpressionId) -> VisitorResult {
 
        let call_expr = &ctx.heap[id];
 

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

	
 
        // Check whether the method is allowed to be called within the code's
 
        // context (in sync, definition type, etc.)
 
        let mut expecting_wrapping_new_stmt = false;
 
        let mut expecting_primitive_def = false;
 
        let mut expecting_wrapping_sync_stmt = false;
 
        let mut expecting_no_select_stmt = false;
 

	
 
        match call_expr.method {
 
            Method::Get => {
 
                expecting_primitive_def = true;
 
                expecting_wrapping_sync_stmt = true;
 
                if !self.in_select_guard.is_invalid() {
 
                    // In a select guard. Take the argument (i.e. the port we're
 
                    // retrieving from) and add it to the list of involved ports
 
                    // of the guard
 
                    if call_expr.arguments.len() == 1 {
 
                        // We're checking the number of arguments later, for now
 
                        // assume it is correct.
 
                        let argument = call_expr.arguments[0];
 
                        let select_stmt = &mut ctx.heap[self.in_select_guard];
 
                        let select_case = &mut select_stmt.cases[self.in_select_arm as usize];
 
                        select_case.involved_ports.push((id, argument));
 
                    }
 
                }
 
            },
 
            Method::Put => {
 
                expecting_primitive_def = true;
 
                expecting_wrapping_sync_stmt = true;
 
                expecting_no_select_stmt = true;
 
            },
 
            Method::Fires => {
 
                expecting_primitive_def = true;
 
                expecting_wrapping_sync_stmt = true;
 
            },
 
            Method::Create => {},
 
            Method::Length => {},
 
            Method::Assert => {
 
                expecting_wrapping_sync_stmt = true;
 
                expecting_no_select_stmt = true;
 
                if self.proc_kind == ProcedureKind::Function {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "assert statement may only occur in components"
 
                    ));
 
                }
 
            },
 
            Method::Print => {},
 
            Method::SelectStart
 
            | Method::SelectRegisterCasePort
 
            | Method::SelectWait => unreachable!(), // not usable by programmer directly
 
            Method::ComponentRandomU32 => {
 
                expecting_wrapping_new_stmt = true;
 
            },
 
            Method::UserFunction => {}
 
            Method::UserComponent => {
 
                expecting_wrapping_new_stmt = true;
 
            },
 
        }
 

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

	
 
        fn get_span_and_name<'a>(ctx: &'a Ctx, id: CallExpressionId) -> (InputSpan, String) {
 
            let call = &ctx.heap[id];
 
            let span = call.func_span;
 
            let name = String::from_utf8_lossy(ctx.module().source.section_at_span(span)).to_string();
 
            return (span, name);
 
        }
 
        if expecting_primitive_def {
 
            if self.proc_kind != ProcedureKind::Primitive {
 
                let (call_span, func_name) = get_span_and_name(ctx, id);
 
                return Err(ParseError::new_error_at_span(
 
                    &ctx.module().source, call_span,
 
                    format!("a call to '{}' may only occur in primitive component definitions", func_name)
 
                ));
 
            }
 
        }
 

	
 
        if expecting_wrapping_sync_stmt {
 
            if self.in_sync.is_invalid() {
 
                let (call_span, func_name) = get_span_and_name(ctx, id);
 
                return Err(ParseError::new_error_at_span(
 
                    &ctx.module().source, call_span,
 
                    format!("a call to '{}' may only occur inside synchronous blocks", func_name)
 
                ))
 
            }
 
        }
 

	
 
        if expecting_no_select_stmt {
 
            if !self.in_select_guard.is_invalid() {
 
                let (call_span, func_name) = get_span_and_name(ctx, id);
 
                return Err(ParseError::new_error_at_span(
 
                    &ctx.module().source, call_span,
 
                    format!("a call to '{}' may not occur in a select statement's guard", func_name)
 
                ));
 
            }
 
        }
 

	
 
        if expecting_wrapping_new_stmt {
 
            if !self.expr_parent.is_new() {
 
                let call_span = call_expr.func_span;
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, call_span,
 
                    "cannot call a component, it can only be instantiated by using 'new'"
 
                ));
 
            }
 
        } else {
 
            if self.expr_parent.is_new() {
 
                let call_span = call_expr.func_span;
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, call_span,
 
                    "only components can be instantiated, this is a function"
 
                ));
 
            }
 
        }
 

	
 
        // Check the number of arguments
 
        let call_definition = ctx.types.get_base_definition(&call_expr.procedure.upcast()).unwrap();
 
        let num_expected_args = match &call_definition.definition {
 
            DefinedTypeVariant::Procedure(definition) => definition.arguments.len(),
 
            _ => unreachable!(),
 
        };
 

	
 
        let num_provided_args = call_expr.arguments.len();
 
        if num_provided_args != num_expected_args {
 
            let argument_text = if num_expected_args == 1 { "argument" } else { "arguments" };
 
            let call_span = call_expr.full_span;
 
            return Err(ParseError::new_error_at_span(
 
                &ctx.module().source, call_span, format!(
 
                    "expected {} {}, but {} were provided",
 
                    num_expected_args, argument_text, num_provided_args
 
                )
 
            ));
 
        }
 

	
 
        // Recurse into all of the arguments and set the expression's parent
 
        let upcast_id = id.upcast();
 

	
 
        let section = self.expression_buffer.start_section_initialized(&call_expr.arguments);
 
        let old_expr_parent = self.expr_parent;
 
        call_expr.parent = old_expr_parent;
 

	
 
        for arg_expr_idx in 0..section.len() {
 
            let arg_expr_id = section[arg_expr_idx];
 
            self.expr_parent = ExpressionParent::Expression(upcast_id, arg_expr_idx as u32);
 
            self.visit_expr(ctx, arg_expr_id)?;
 
        }
 

	
 
        section.forget();
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_variable_expr(&mut self, ctx: &mut Ctx, id: VariableExpressionId) -> VisitorResult {
 
        let var_expr = &ctx.heap[id];
 

	
 
        // Check if declaration was already resolved (this occurs for the
 
        // variable expr that is on the LHS of the assignment expr that is
 
        // associated with a variable declaration)
 
        let mut variable_id = var_expr.declaration;
 
        let mut is_binding_target = false;
 

	
 
        // Otherwise try to find it
 
        if variable_id.is_none() {
 
            variable_id = self.find_variable(ctx, self.relative_pos_in_parent, &var_expr.identifier);
 
        }
 

	
 
        // Otherwise try to see if is a variable introduced by a binding expr
 
        let variable_id = if let Some(variable_id) = variable_id {
 
            variable_id
 
        } else {
 
            if self.in_binding_expr.is_invalid() || !self.in_binding_expr_lhs {
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, var_expr.identifier.span, "unresolved variable"
 
                ));
 
            }
 

	
 
            // This is a binding variable, but it may only appear in very
 
            // specific locations.
 
            let is_valid_binding = match self.expr_parent {
 
                ExpressionParent::Expression(expr_id, idx) => {
 
                    match &ctx.heap[expr_id] {
 
                        Expression::Binding(_binding_expr) => {
 
                            // Nested binding is disallowed, and because of
 
                            // the check above we know we're directly at the
 
                            // LHS of the binding expression
 
                            debug_assert_eq!(_binding_expr.this, self.in_binding_expr);
 
                            debug_assert_eq!(idx, 0);
 
                            true
 
                        }
 
                        Expression::Literal(_lit_expr) => {
 
                            // Only struct, unions, tuples and arrays can
 
                            // have subexpressions, so we're always fine
 
                            dbg_code!({
 
                                match _lit_expr.value {
 
                                    Literal::Struct(_) | Literal::Union(_) | Literal::Array(_) | Literal::Tuple(_) => {},
 
                                    _ => unreachable!(),
 
                                }
 
                            });
 

	
 
                            true
 
                        },
 
                        _ => false,
 
                    }
 
                },
 
                _ => {
 
                    false
 
                }
 
            };
 

	
 
            if !is_valid_binding {
 
                let binding_expr = &ctx.heap[self.in_binding_expr];
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, var_expr.identifier.span,
 
                    "illegal location for binding variable: binding variables may only be nested under a binding expression, or a struct, union or array literal"
 
                ).with_info_at_span(
 
                    &ctx.module().source, binding_expr.operator_span, format!(
 
                        "'{}' was interpreted as a binding variable because the variable is not declared and it is nested under this binding expression",
 
                        var_expr.identifier.value.as_str()
 
                    )
 
                ));
 
            }
 

	
 
            // By now we know that this is a valid binding expression. Given
 
            // that a binding expression must be nested under an if/while
 
            // statement, we now add the variable to the scope associated with
 
            // that statement.
 
            let bound_identifier = var_expr.identifier.clone();
 
            let bound_variable_id = ctx.heap.alloc_variable(|this| Variable {
 
                this,
 
                kind: VariableKind::Binding,
 
                parser_type: ParserType {
 
                    elements: vec![ParserTypeElement {
 
                        element_span: bound_identifier.span,
 
                        variant: ParserTypeVariant::Inferred
 
                    }],
 
                    full_span: bound_identifier.span
 
                },
 
                identifier: bound_identifier,
 
                relative_pos_in_parent: 0,
 
                unique_id_in_scope: -1,
 
            });
 

	
 
            let scope_id = match &ctx.heap[self.in_test_expr] {
 
                Statement::If(stmt) => stmt.true_case.scope,
 
                Statement::While(stmt) => stmt.scope,
 
                _ => unreachable!(),
 
            };
 

	
 
            self.checked_at_single_scope_add_local(ctx, scope_id, -1, bound_variable_id)?; // add at -1 such that first statement can find the variable if needed
 

	
 
            is_binding_target = true;
 
            bound_variable_id
 
        };
 

	
 
        let var_expr = &mut ctx.heap[id];
 
        var_expr.declaration = Some(variable_id);
 
        var_expr.used_as_binding_target = is_binding_target;
 
        var_expr.parent = self.expr_parent;
 

	
 
        Ok(())
 
    }
 
}
 

	
 
impl PassValidationLinking {
 
    //--------------------------------------------------------------------------
 
    // Special traversal
 
    //--------------------------------------------------------------------------
 

	
 
    /// Pushes a new scope associated with a particular statement. If that
 
    /// statement already has an associated scope (i.e. scope associated with
 
    /// sync statement or select statement's arm) then we won't do anything.
 
    /// In all cases the caller must call `pop_statement_scope` with the scope
 
    /// and relative scope position returned by this function.
 
    fn push_scope(&mut self, ctx: &mut Ctx, is_top_level_scope: bool, pushed_scope_id: ScopeId) -> (ScopeId, i32) {
 
        // Set the properties of the pushed scope (it is already created during
 
        // AST construction, but most values are not yet set to their correct
 
        // values)
 
        let old_scope_id = self.cur_scope;
 

	
 
        let scope = &mut ctx.heap[pushed_scope_id];
 
        if !is_top_level_scope {
 
            scope.parent = Some(old_scope_id);
 
        }
 

	
 
        scope.relative_pos_in_parent = self.relative_pos_in_parent;
 
        let old_relative_pos = self.relative_pos_in_parent;
 
        self.relative_pos_in_parent = 0;
 

	
 
        // Link up scopes
 
        if !is_top_level_scope {
 
            let old_scope = &mut ctx.heap[old_scope_id];
 
            old_scope.nested.push(pushed_scope_id);
 
        }
 

	
 
        // Set as current traversal scope, then return old scope
 
        self.cur_scope = pushed_scope_id;
 
        return (old_scope_id, old_relative_pos)
 
    }
 

	
 
    fn pop_scope(&mut self, scope_to_restore: (ScopeId, i32)) {
 
        self.cur_scope = scope_to_restore.0;
 
        self.relative_pos_in_parent = scope_to_restore.1;
 
    }
 

	
 
    fn resolve_pending_control_flow_targets(&mut self, ctx: &mut Ctx) -> Result<(), ParseError> {
 
        for entry in &self.control_flow_stmts {
 
            let stmt = &ctx.heap[entry.statement];
 

	
 
            match stmt {
 
                Statement::Break(stmt) => {
 
                    let stmt_id = stmt.this;
 
                    let target_while_id = Self::resolve_break_or_continue_target(ctx, entry, stmt.span, &stmt.label)?;
 
                    let target_while_stmt = &ctx.heap[target_while_id];
 
                    let target_end_while_id = target_while_stmt.end_while;
 
                    debug_assert!(!target_end_while_id.is_invalid());
 

	
 
                    let break_stmt = &mut ctx.heap[stmt_id];
 
                    break_stmt.target = target_end_while_id;
 
                },
 
                Statement::Continue(stmt) => {
 
                    let stmt_id = stmt.this;
 
                    let target_while_id = Self::resolve_break_or_continue_target(ctx, entry, stmt.span, &stmt.label)?;
 

	
 
                    let continue_stmt = &mut ctx.heap[stmt_id];
 
                    continue_stmt.target = target_while_id;
 
                },
 
                Statement::Goto(stmt) => {
 
                    let stmt_id = stmt.this;
 
                    let target_id = Self::find_label(entry.in_scope, ctx, &stmt.label)?;
 
                    let target_stmt = &ctx.heap[target_id];
 
                    if entry.in_sync != target_stmt.in_sync {
 
                        // Nested sync not allowed. And goto can only go to
 
                        // outer scopes, so we must be escaping from a sync.
 
                        debug_assert!(target_stmt.in_sync.is_invalid());    // target not in sync
 
                        debug_assert!(!entry.in_sync.is_invalid()); // but the goto is in sync
 
                        let goto_stmt = &ctx.heap[stmt_id];
 
                        let sync_stmt = &ctx.heap[entry.in_sync];
 
                        return Err(
 
                            ParseError::new_error_str_at_span(&ctx.module().source, goto_stmt.span, "goto may not escape the surrounding synchronous block")
 
                            .with_info_str_at_span(&ctx.module().source, target_stmt.label.span, "this is the target of the goto statement")
 
                            .with_info_str_at_span(&ctx.module().source, sync_stmt.span, "which will jump past this statement")
 
                        );
 
                    }
 

	
 
                    let goto_stmt = &mut ctx.heap[stmt_id];
 
                    goto_stmt.target = target_id;
 
                },
 
                _ => unreachable!("cannot resolve control flow target for {:?}", stmt),
 
            }
 
        }
 

	
 
        return Ok(())
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // Utilities
 
    //--------------------------------------------------------------------------
 

	
 
    /// Adds a local variable to the current scope. It will also annotate the
 
    /// `Local` in the AST with its relative position in the block.
 
    fn checked_add_local(&mut self, ctx: &mut Ctx, target_scope_id: ScopeId, target_relative_pos: i32, new_variable_id: VariableId) -> Result<(), ParseError> {
 
        let new_variable = &ctx.heap[new_variable_id];
 

	
 
        // We immediately go to the parent scope. We check the target scope
 
        // in the call at the end. That is also where we check for collisions
 
        // with symbols.
 
        let mut scope = &ctx.heap[target_scope_id];
 
        let mut cur_relative_pos = scope.relative_pos_in_parent;
 
        while let Some(scope_parent_id) = scope.parent {
 
            scope = &ctx.heap[scope_parent_id];
 

	
 
            // Check for collisions
 
            for variable_id in scope.variables.iter().copied() {
 
                let existing_variable = &ctx.heap[variable_id];
 
                if existing_variable.identifier == new_variable.identifier &&
 
                    existing_variable.this != new_variable_id &&
 
                    cur_relative_pos >= existing_variable.relative_pos_in_parent {
 
                    return Err(
 
                        ParseError::new_error_str_at_span(
 
                            &ctx.module().source, new_variable.identifier.span, "Local variable name conflicts with another variable"
 
                        ).with_info_str_at_span(
 
                            &ctx.module().source, existing_variable.identifier.span, "Previous variable is found here"
 
                        )
 
                    );
 
                }
 
            }
 

	
 
            cur_relative_pos = scope.relative_pos_in_parent;
 
        }
 

	
 
        // No collisions in any of the parent scope, attempt to add to scope
 
        self.checked_at_single_scope_add_local(ctx, target_scope_id, target_relative_pos, new_variable_id)
 
    }
 

	
 
    /// Adds a local variable to the specified scope. Will check the specified
 
    /// scope for variable conflicts and the symbol table for global conflicts.
 
    /// Will NOT check parent scopes of the specified scope.
 
    fn checked_at_single_scope_add_local(
 
        &mut self, ctx: &mut Ctx, scope_id: ScopeId, relative_pos: i32, new_variable_id: VariableId
 
    ) -> Result<(), ParseError> {
 
        // Check the symbol table for conflicts
 
        {
 
            let cur_scope = SymbolScope::Definition(self.proc_id.upcast());
 
            let ident = &ctx.heap[new_variable_id].identifier;
 
            if let Some(symbol) = ctx.symbols.get_symbol_by_name(cur_scope, &ident.value.as_bytes()) {
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, ident.span,
 
                    "local variable declaration conflicts with symbol"
 
                ).with_info_str_at_span(
 
                    &ctx.module().source, symbol.variant.span_of_introduction(&ctx.heap), "the conflicting symbol is introduced here"
 
                ));
 
            }
 
        }
 

	
 
        // Check the specified scope for conflicts
 
        let new_variable = &ctx.heap[new_variable_id];
 
        let scope = &ctx.heap[scope_id];
 

	
 
        for variable_id in scope.variables.iter().copied() {
 
            let old_variable = &ctx.heap[variable_id];
 
            if new_variable.this != old_variable.this &&
 
                // relative_pos >= other_local.relative_pos_in_block &&
 
                new_variable.identifier == old_variable.identifier {
 
                // Collision
 
                return Err(
 
                    ParseError::new_error_str_at_span(
 
                        &ctx.module().source, new_variable.identifier.span, "Local variable name conflicts with another variable"
 
                    ).with_info_str_at_span(
 
                        &ctx.module().source, old_variable.identifier.span, "Previous variable is found here"
 
                    )
 
                );
 
            }
 
        }
 

	
 
        // No collisions
 
        let scope = &mut ctx.heap[scope_id];
src/protocol/parser/type_table.rs
Show inline comments
 
@@ -1664,579 +1664,580 @@ impl TypeTable {
 
    /// concrete type.
 
    fn construct_concrete_type(member_type: &ParserType, container_type: &ConcreteType) -> ConcreteType {
 
        use ParserTypeVariant as PTV;
 
        use ConcreteTypePart as CTP;
 

	
 
        // TODO: Combine with code in pass_typing.rs
 
        fn parser_to_concrete_part(part: &ParserTypeVariant) -> Option<ConcreteTypePart> {
 
            match part {
 
                PTV::Void      => Some(CTP::Void),
 
                PTV::Message   => Some(CTP::Message),
 
                PTV::Bool      => Some(CTP::Bool),
 
                PTV::UInt8     => Some(CTP::UInt8),
 
                PTV::UInt16    => Some(CTP::UInt16),
 
                PTV::UInt32    => Some(CTP::UInt32),
 
                PTV::UInt64    => Some(CTP::UInt64),
 
                PTV::SInt8     => Some(CTP::SInt8),
 
                PTV::SInt16    => Some(CTP::SInt16),
 
                PTV::SInt32    => Some(CTP::SInt32),
 
                PTV::SInt64    => Some(CTP::SInt64),
 
                PTV::Character => Some(CTP::Character),
 
                PTV::String    => Some(CTP::String),
 
                PTV::Array     => Some(CTP::Array),
 
                PTV::Input     => Some(CTP::Input),
 
                PTV::Output    => Some(CTP::Output),
 
                PTV::Tuple(num) => Some(CTP::Tuple(*num)),
 
                PTV::Definition(definition_id, num) => Some(CTP::Instance(*definition_id, *num)),
 
                _              => None
 
            }
 
        }
 

	
 
        let mut parts = Vec::with_capacity(member_type.elements.len()); // usually a correct estimation, might not be
 
        for member_part in &member_type.elements {
 
            // Check if we have a regular builtin type
 
            if let Some(part) = parser_to_concrete_part(&member_part.variant) {
 
                parts.push(part);
 
                continue;
 
            }
 

	
 
            // Not builtin, but if all code is working correctly, we only care
 
            // about the polymorphic argument at this point.
 
            if let PTV::PolymorphicArgument(_container_definition_id, poly_arg_idx) = member_part.variant {
 
                debug_assert_eq!(_container_definition_id, get_concrete_type_definition(&container_type.parts).unwrap());
 

	
 
                let mut container_iter = container_type.embedded_iter(0);
 
                for _ in 0..poly_arg_idx {
 
                    container_iter.next();
 
                }
 

	
 
                let poly_section = container_iter.next().unwrap();
 
                parts.extend(poly_section);
 

	
 
                continue;
 
            }
 

	
 
            unreachable!("unexpected type part {:?} from {:?}", member_part, member_type);
 
        }
 

	
 
        return ConcreteType{ parts };
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // Determining memory layout for types
 
    //--------------------------------------------------------------------------
 

	
 
    /// Should be called after type loops are detected (and resolved
 
    /// successfully). As a result of this call we expect the
 
    /// `encountered_types` array to be filled. We'll calculate size/alignment/
 
    /// offset values for those types in this routine.
 
    fn lay_out_memory_for_encountered_types(&mut self, arch: &TargetArch) {
 
        // Programmers note: this works like a little stack machine. We have
 
        // memory layout breadcrumbs which, like the type loop breadcrumbs, keep
 
        // track of the currently considered member type. This breadcrumb also
 
        // stores an index into the `size_alignment_stack`, which will be used
 
        // to store intermediate size/alignment pairs until all members are
 
        // resolved. Note that this `size_alignment_stack` is NOT an
 
        // optimization, we're working around borrowing rules here.
 

	
 
        // Just finished type loop detection, so we're left with the encountered
 
        // types only. If we don't have any (a builtin type's monomorph was
 
        // added to the type table) then this function shouldn't be called at
 
        // all.
 
        debug_assert!(self.type_loops.is_empty());
 
        debug_assert!(!self.encountered_types.is_empty());
 
        debug_assert!(self.memory_layout_breadcrumbs.is_empty());
 
        debug_assert!(self.size_alignment_stack.is_empty());
 

	
 
        let (ptr_size, ptr_align) = self.mono_types[arch.pointer_type_id.0 as usize].get_size_alignment().unwrap();
 

	
 
        // Push the first entry (the type we originally started with when we
 
        // were detecting type loops)
 
        let first_entry = &self.encountered_types[0];
 
        self.memory_layout_breadcrumbs.push(MemoryBreadcrumb{
 
            type_id: first_entry.type_id,
 
            next_member: 0,
 
            next_embedded: 0,
 
            first_size_alignment_idx: 0,
 
        });
 

	
 
        // Enter the main resolving loop
 
        'breadcrumb_loop: while !self.memory_layout_breadcrumbs.is_empty() {
 
            let cur_breadcrumb_idx = self.memory_layout_breadcrumbs.len() - 1;
 
            let mut breadcrumb = self.memory_layout_breadcrumbs[cur_breadcrumb_idx].clone();
 

	
 
            let mono_type = &self.mono_types[breadcrumb.type_id.0 as usize];
 
            match &mono_type.variant {
 
                MonoTypeVariant::Builtin | MonoTypeVariant::Enum => {
 
                    // Size should already be computed
 
                    dbg_code!({
 
                        let mono_type = &self.mono_types[breadcrumb.type_id.0 as usize];
 
                        debug_assert!(mono_type.size != 0 && mono_type.alignment != 0);
 
                    });
 
                },
 
                MonoTypeVariant::Union(mono_type) => {
 
                    // Retrieve size/alignment of each embedded type. We do not
 
                    // compute the offsets or total type sizes yet.
 
                    let num_variants = mono_type.variants.len() as u32;
 
                    while breadcrumb.next_member < num_variants {
 
                        let mono_variant = &mono_type.variants[breadcrumb.next_member as usize];
 

	
 
                        if mono_variant.lives_on_heap {
 
                            // To prevent type loops we made this a heap-
 
                            // allocated variant. This implies we cannot
 
                            // compute sizes of members at this point.
 
                        } else {
 
                            let num_embedded = mono_variant.embedded.len() as u32;
 
                            while breadcrumb.next_embedded < num_embedded {
 
                                let mono_embedded = &mono_variant.embedded[breadcrumb.next_embedded as usize];
 
                                let layout_result = Self::get_memory_layout_or_breadcrumb(
 
                                    &self.definition_lookup, &self.mono_type_lookup, &self.mono_types,
 
                                    &mut self.mono_search_key, arch, &mono_embedded.concrete_type.parts,
 
                                    self.size_alignment_stack.len()
 
                                );
 
                                match layout_result {
 
                                    MemoryLayoutResult::TypeExists(size, alignment) => {
 
                                        self.size_alignment_stack.push((size, alignment));
 
                                    },
 
                                    MemoryLayoutResult::PushBreadcrumb(new_breadcrumb) => {
 
                                        self.memory_layout_breadcrumbs[cur_breadcrumb_idx] = breadcrumb;
 
                                        self.memory_layout_breadcrumbs.push(new_breadcrumb);
 
                                        continue 'breadcrumb_loop;
 
                                    }
 
                                }
 

	
 
                                breadcrumb.next_embedded += 1;
 
                            }
 
                        }
 

	
 
                        breadcrumb.next_member += 1;
 
                        breadcrumb.next_embedded = 0;
 
                    }
 

	
 
                    // If here then we can at least compute the stack size of
 
                    // the type, we'll have to come back at the very end to
 
                    // fill in the heap size/alignment/offset of each heap-
 
                    // allocated variant.
 
                    let mut max_size = mono_type.tag_size;
 
                    let mut max_alignment = mono_type.tag_size;
 

	
 
                    let mono_type = &mut self.mono_types[breadcrumb.type_id.0 as usize];
 
                    let union_type = mono_type.variant.as_union_mut();
 
                    let mut size_alignment_idx = breadcrumb.first_size_alignment_idx as usize;
 

	
 
                    for variant in &mut union_type.variants {
 
                        // We're doing stack computations, so always start with
 
                        // the tag size/alignment.
 
                        let mut variant_offset = union_type.tag_size;
 
                        let mut variant_alignment = union_type.tag_size;
 

	
 
                        if variant.lives_on_heap {
 
                            // Variant lives on heap, so just a pointer
 
                            align_offset_to(&mut variant_offset, ptr_align);
 

	
 
                            variant_offset += ptr_size;
 
                            variant_alignment = variant_alignment.max(ptr_align);
 
                        } else {
 
                            // Variant lives on stack, so walk all embedded
 
                            // types.
 
                            for embedded in &mut variant.embedded {
 
                                let (size, alignment) = self.size_alignment_stack[size_alignment_idx];
 
                                embedded.size = size;
 
                                embedded.alignment = alignment;
 
                                size_alignment_idx += 1;
 

	
 
                                align_offset_to(&mut variant_offset, alignment);
 
                                embedded.offset = variant_offset;
 

	
 
                                variant_offset += size;
 
                                variant_alignment = variant_alignment.max(alignment);
 
                            }
 
                        };
 

	
 
                        max_size = max_size.max(variant_offset);
 
                        max_alignment = max_alignment.max(variant_alignment);
 
                    }
 

	
 
                    mono_type.size = max_size;
 
                    mono_type.alignment = max_alignment;
 
                    self.size_alignment_stack.truncate(breadcrumb.first_size_alignment_idx as usize);
 
                },
 
                MonoTypeVariant::Struct(mono_type) => {
 
                    // Retrieve size and alignment of each struct member. We'll
 
                    // compute the offsets once all of those are known
 
                    let num_fields = mono_type.fields.len() as u32;
 
                    while breadcrumb.next_member < num_fields {
 
                        let mono_field = &mono_type.fields[breadcrumb.next_member as usize];
 

	
 
                        let layout_result = Self::get_memory_layout_or_breadcrumb(
 
                            &self.definition_lookup, &self.mono_type_lookup, &self.mono_types,
 
                            &mut self.mono_search_key, arch, &mono_field.concrete_type.parts,
 
                            self.size_alignment_stack.len()
 
                        );
 
                        match layout_result {
 
                            MemoryLayoutResult::TypeExists(size, alignment) => {
 
                                self.size_alignment_stack.push((size, alignment))
 
                            },
 
                            MemoryLayoutResult::PushBreadcrumb(new_breadcrumb) => {
 
                                self.memory_layout_breadcrumbs[cur_breadcrumb_idx] = breadcrumb;
 
                                self.memory_layout_breadcrumbs.push(new_breadcrumb);
 
                                continue 'breadcrumb_loop;
 
                            },
 
                        }
 

	
 
                        breadcrumb.next_member += 1;
 
                    }
 

	
 
                    // Compute offsets and size of total type
 
                    let mut cur_offset = 0;
 
                    let mut max_alignment = 1;
 

	
 
                    let mono_type = &mut self.mono_types[breadcrumb.type_id.0 as usize];
 
                    let struct_type = mono_type.variant.as_struct_mut();
 
                    let mut size_alignment_idx = breadcrumb.first_size_alignment_idx as usize;
 

	
 
                    for field in &mut struct_type.fields {
 
                        let (size, alignment) = self.size_alignment_stack[size_alignment_idx];
 
                        field.size = size;
 
                        field.alignment = alignment;
 
                        size_alignment_idx += 1;
 

	
 
                        align_offset_to(&mut cur_offset, alignment);
 
                        field.offset = cur_offset;
 

	
 
                        cur_offset += size;
 
                        max_alignment = max_alignment.max(alignment);
 
                    }
 

	
 
                    mono_type.size = cur_offset;
 
                    mono_type.alignment = max_alignment;
 
                    self.size_alignment_stack.truncate(breadcrumb.first_size_alignment_idx as usize);
 
                },
 
                MonoTypeVariant::Procedure(_) => {
 
                    unreachable!();
 
                },
 
                MonoTypeVariant::Tuple(mono_type) => {
 
                    let num_members = mono_type.members.len() as u32;
 
                    while breadcrumb.next_member < num_members {
 
                        let mono_member = &mono_type.members[breadcrumb.next_member as usize];
 
                        let layout_result = Self::get_memory_layout_or_breadcrumb(
 
                            &self.definition_lookup, &self.mono_type_lookup, &self.mono_types,
 
                            &mut self.mono_search_key, arch, &mono_member.concrete_type.parts,
 
                            self.size_alignment_stack.len()
 
                        );
 
                        match layout_result {
 
                            MemoryLayoutResult::TypeExists(size, alignment) => {
 
                                self.size_alignment_stack.push((size, alignment));
 
                            },
 
                            MemoryLayoutResult::PushBreadcrumb(new_breadcrumb) => {
 
                                self.memory_layout_breadcrumbs[cur_breadcrumb_idx] = breadcrumb;
 
                                self.memory_layout_breadcrumbs.push(new_breadcrumb);
 
                                continue 'breadcrumb_loop;
 
                            },
 
                        }
 

	
 
                        breadcrumb.next_member += 1;
 
                    }
 

	
 
                    // If here then we can compute the memory layout of the tuple.
 
                    let mut cur_offset = 0;
 
                    let mut max_alignment = 1;
 

	
 
                    let mono_type = &mut self.mono_types[breadcrumb.type_id.0 as usize];
 
                    let mono_tuple = mono_type.variant.as_tuple_mut();
 
                    let mut size_alignment_index = breadcrumb.first_size_alignment_idx as usize;
 
                    for member_index in 0..num_members {
 
                        let (member_size, member_alignment) = self.size_alignment_stack[size_alignment_index];
 
                        align_offset_to(&mut cur_offset, member_alignment);
 
                        size_alignment_index += 1;
 

	
 
                        let member = &mut mono_tuple.members[member_index as usize];
 
                        member.size = member_size;
 
                        member.alignment = member_alignment;
 
                        member.offset = cur_offset;
 

	
 
                        cur_offset += member_size;
 
                        max_alignment = max_alignment.max(member_alignment);
 
                    }
 

	
 
                    mono_type.size = cur_offset;
 
                    mono_type.alignment = max_alignment;
 
                    self.size_alignment_stack.truncate(breadcrumb.first_size_alignment_idx as usize);
 
                },
 
            }
 

	
 
            // If here, then we completely layed out the current type. So move
 
            // to the next breadcrumb
 
            self.memory_layout_breadcrumbs.pop();
 
        }
 

	
 
        debug_assert!(self.size_alignment_stack.is_empty());
 

	
 
        // If here then all types have been layed out. What remains is to
 
        // compute the sizes/alignment/offsets of the heap variants of the
 
        // unions we have encountered.
 
        for entry in &self.encountered_types {
 
            if !entry.is_union {
 
                continue;
 
            }
 

	
 
            // First pass, use buffer to store size/alignment to prevent
 
            // borrowing issues.
 
            let mono_type = self.mono_types[entry.type_id.0 as usize].variant.as_union();
 
            for variant in &mono_type.variants {
 
                if !variant.lives_on_heap {
 
                    continue;
 
                }
 

	
 
                debug_assert!(!variant.embedded.is_empty());
 

	
 
                for embedded in &variant.embedded {
 
                    let layout_result = Self::get_memory_layout_or_breadcrumb(
 
                        &self.definition_lookup, &self.mono_type_lookup, &self.mono_types,
 
                        &mut self.mono_search_key, arch, &embedded.concrete_type.parts,
 
                        self.size_alignment_stack.len()
 
                    );
 
                    match layout_result {
 
                        MemoryLayoutResult::TypeExists(size, alignment) => {
 
                            self.size_alignment_stack.push((size, alignment));
 
                        },
 
                        _ => unreachable!(), // type was not truly infinite, so type must have been found
 
                    }
 
                }
 
            }
 

	
 
            // Second pass, apply the size/alignment values in our buffer
 
            let mono_type = self.mono_types[entry.type_id.0 as usize].variant.as_union_mut();
 

	
 
            let mut max_size = 0;
 
            let mut max_alignment = 1;
 
            let mut size_alignment_idx = 0;
 

	
 
            for variant in &mut mono_type.variants {
 
                if !variant.lives_on_heap {
 
                    continue;
 
                }
 

	
 
                let mut variant_offset = 0;
 
                let mut variant_alignment = 1;
 

	
 
                for embedded in &mut variant.embedded {
 
                    let (size, alignment) = self.size_alignment_stack[size_alignment_idx];
 
                    embedded.size = size;
 
                    embedded.alignment = alignment;
 
                    size_alignment_idx += 1;
 

	
 
                    align_offset_to(&mut variant_offset, alignment);
 
                    embedded.alignment = variant_offset;
 

	
 
                    variant_offset += size;
 
                    variant_alignment = variant_alignment.max(alignment);
 
                }
 

	
 
                max_size = max_size.max(variant_offset);
 
                max_alignment = max_alignment.max(variant_alignment);
 
            }
 

	
 
            if max_size != 0 {
 
                // At least one entry lives on the heap
 
                mono_type.heap_size = max_size;
 
                mono_type.heap_alignment = max_alignment;
 
            }
 
        }
 

	
 
        // And now, we're actually, properly, done
 
        self.encountered_types.clear();
 
        self.size_alignment_stack.clear();
 
    }
 

	
 
    /// Attempts to compute size/alignment for the provided type. Note that this
 
    /// is called *after* type loops have been succesfully resolved. Hence we
 
    /// may assume that all monomorph entries exist, but we may not assume that
 
    /// those entries already have their size/alignment computed.
 
    // Passed parameters are messy. But need to strike balance between borrowing
 
    // and allocations in hot loops. So it is what it is.
 
    fn get_memory_layout_or_breadcrumb(
 
        definition_map: &DefinitionMap, mono_type_map: &MonoTypeMap, mono_types: &MonoTypeArray,
 
        search_key: &mut MonoSearchKey, arch: &TargetArch, parts: &[ConcreteTypePart],
 
        size_alignment_stack_len: usize,
 
    ) -> MemoryLayoutResult {
 
        use ConcreteTypePart as CTP;
 

	
 
        debug_assert!(!parts.is_empty());
 
        let type_id = match parts[0] {
 
            CTP::Void      => arch.void_type_id,
 
            CTP::Message   => arch.message_type_id,
 
            CTP::Bool      => arch.bool_type_id,
 
            CTP::UInt8     => arch.uint8_type_id,
 
            CTP::UInt16    => arch.uint16_type_id,
 
            CTP::UInt32    => arch.uint32_type_id,
 
            CTP::UInt64    => arch.uint64_type_id,
 
            CTP::SInt8     => arch.sint8_type_id,
 
            CTP::SInt16    => arch.sint16_type_id,
 
            CTP::SInt32    => arch.sint32_type_id,
 
            CTP::SInt64    => arch.sint64_type_id,
 
            CTP::Character => arch.char_type_id,
 
            CTP::String    => arch.string_type_id,
 
            CTP::Array     => arch.array_type_id,
 
            CTP::Slice     => arch.slice_type_id,
 
            CTP::Input     => arch.input_type_id,
 
            CTP::Output    => arch.output_type_id,
 
            CTP::Pointer   => arch.pointer_type_id,
 
            CTP::Tuple(_) => {
 
                Self::set_search_key_to_tuple(search_key, definition_map, parts);
 
                let type_id = mono_type_map.get(&search_key).copied().unwrap();
 

	
 
                type_id
 
            },
 
            CTP::Instance(definition_id, _) => {
 
                // Retrieve entry and the specific monomorph index by applying
 
                // the full concrete type.
 
                let definition_type = definition_map.get(&definition_id).unwrap();
 
                search_key.set(parts, &definition_type.poly_vars);
 
                let type_id = mono_type_map.get(&search_key).copied().unwrap();
 

	
 
                type_id
 
            },
 
            CTP::Function(_, _) | CTP::Component(_, _) => {
 
                todo!("storage for 'function pointers'");
 
            }
 
        };
 

	
 
        let mono_type = &mono_types[type_id.0 as usize];
 
        if let Some((size, alignment)) = mono_type.get_size_alignment() {
 
            return MemoryLayoutResult::TypeExists(size, alignment);
 
        } else {
 
            return MemoryLayoutResult::PushBreadcrumb(MemoryBreadcrumb{
 
                type_id,
 
                next_member: 0,
 
                next_embedded: 0,
 
                first_size_alignment_idx: size_alignment_stack_len as u32,
 
            });
 
        }
 
    }
 

	
 
    /// Returns tag concrete type (always a builtin integer type), the size of
 
    /// that type in bytes (and implicitly, its alignment)
 
    fn variant_tag_type_from_values(min_val: i64, max_val: i64) -> (ConcreteType, usize) {
 
        debug_assert!(min_val <= max_val);
 

	
 
        let (part, size) = if min_val >= 0 {
 
            // Can be an unsigned integer
 
            if max_val <= (u8::MAX as i64) {
 
                (ConcreteTypePart::UInt8, 1)
 
            } else if max_val <= (u16::MAX as i64) {
 
                (ConcreteTypePart::UInt16, 2)
 
            } else if max_val <= (u32::MAX as i64) {
 
                (ConcreteTypePart::UInt32, 4)
 
            } else {
 
                (ConcreteTypePart::UInt64, 8)
 
            }
 
        } else {
 
            // Must be a signed integer
 
            if min_val >= (i8::MIN as i64) && max_val <= (i8::MAX as i64) {
 
                (ConcreteTypePart::SInt8, 1)
 
            } else if min_val >= (i16::MIN as i64) && max_val <= (i16::MAX as i64) {
 
                (ConcreteTypePart::SInt16, 2)
 
            } else if min_val >= (i32::MIN as i64) && max_val <= (i32::MAX as i64) {
 
                (ConcreteTypePart::SInt32, 4)
 
            } else {
 
                (ConcreteTypePart::SInt64, 8)
 
            }
 
        };
 

	
 
        return (ConcreteType{ parts: vec![part] }, size);
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // 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;
 
            }
 
        }
 
    }
 

	
 
    /// Sets the search key to a specific type.
 
    fn set_search_key_to_type(search_key: &mut MonoSearchKey, definition_map: &DefinitionMap, type_parts: &[ConcreteTypePart]) {
 
        use ConcreteTypePart as CTP;
 

	
 
        match type_parts[0] {
 
            // Builtin types without any embedded types
 
            CTP::Void | CTP::Message | CTP::Bool |
 
            CTP::UInt8 | CTP::UInt16 | CTP::UInt32 | CTP::UInt64 |
 
            CTP::SInt8 | CTP::SInt16 | CTP::SInt32 | CTP::SInt64 |
 
            CTP::Character | CTP::String => {
 
                debug_assert_eq!(type_parts.len(), 1);
 
                search_key.set_top_type(type_parts[0]);
 
            },
 
            // Builtin types with a single nested type
 
            CTP::Array | CTP::Slice | CTP::Input | CTP::Output | CTP::Pointer => {
 
                debug_assert_eq!(type_parts[0].num_embedded(), 1);
 
                search_key.set(type_parts, &POLY_VARS_IN_USE[..1])
 
            },
 
            // User-defined types
 
            CTP::Tuple(_) => {
 
                Self::set_search_key_to_tuple(search_key, definition_map, type_parts);
 
            },
 
            CTP::Instance(definition_id, _) => {
 
                let definition_type = definition_map.get(&definition_id).unwrap();
 
                search_key.set(type_parts, &definition_type.poly_vars);
 
            },
 
            CTP::Function(_, _) | CTP::Component(_, _) => {
 
                todo!("implement function pointers")
 
            },
 
        }
 
    }
 

	
 
    fn set_search_key_to_tuple(search_key: &mut MonoSearchKey, definition_map: &DefinitionMap, type_parts: &[ConcreteTypePart]) {
 
        dbg_code!({
 
            let is_tuple = if let ConcreteTypePart::Tuple(_) = type_parts[0] { true } else { false };
 
            assert!(is_tuple);
 
        });
 
        search_key.set_top_type(type_parts[0]);
 
        for subtree in ConcreteTypeIter::new(type_parts, 0) {
 
            if let Some(definition_id) = get_concrete_type_definition(subtree) {
 
                // A definition, so retrieve poly var usage info
 
                let definition_type = definition_map.get(&definition_id).unwrap();
 
                search_key.push_subtree(subtree, &definition_type.poly_vars);
 
            } else {
 
                // Not a definition, so all type information is important
 
                search_key.push_subtype(subtree, true);
 
            }
 
        }
 
    }
 
}
 

	
 
#[inline]
 
fn align_offset_to(offset: &mut usize, alignment: usize) {
 
    debug_assert!(alignment > 0);
 
    let alignment_min_1 = alignment - 1;
 
    *offset += alignment_min_1;
 
    *offset &= !(alignment_min_1);
 
}
 

	
 
#[inline]
 
fn get_concrete_type_definition(concrete_parts: &[ConcreteTypePart]) -> Option<DefinitionId> {
 
    match concrete_parts[0] {
 
        ConcreteTypePart::Instance(definition_id, _) => {
 
            return Some(definition_id)
 
        },
 
        ConcreteTypePart::Function(definition_id, _) |
 
        ConcreteTypePart::Component(definition_id, _) => {
 
            return Some(definition_id.upcast());
 
        },
 
        _ => {
 
            return None;
 
        },
 
    }
 
}
 
\ No newline at end of file
src/runtime2/tests/mod.rs
Show inline comments
 
use crate::protocol::*;
 
use crate::protocol::eval::*;
 
use crate::runtime2::runtime::*;
 
use crate::runtime2::component::{CompCtx, CompPDL};
 

	
 
fn create_component(rt: &Runtime, module_name: &str, routine_name: &str, args: ValueGroup) {
 
    let prompt = rt.inner.protocol.new_component(
 
        module_name.as_bytes(), routine_name.as_bytes(), args
 
    ).expect("create prompt");
 
    let reserved = rt.inner.start_create_pdl_component();
 
    let ctx = CompCtx::new(&reserved);
 
    let (key, _) = rt.inner.finish_create_pdl_component(reserved, CompPDL::new(prompt, 0), ctx, false);
 
    rt.inner.enqueue_work(key);
 
}
 

	
 
fn no_args() -> ValueGroup { ValueGroup::new_stack(Vec::new()) }
 

	
 
#[test]
 
fn test_component_creation() {
 
    let pd = ProtocolDescription::parse(b"
 
    primitive nothing_at_all() {
 
        s32 a = 5;
 
        auto b = 5 + a;
 
    }
 
    ").expect("compilation");
 
    let rt = Runtime::new(1, true, pd);
 

	
 
    for _i in 0..20 {
 
        create_component(&rt, "", "nothing_at_all", no_args());
 
    }
 
}
 

	
 
#[test]
 
fn test_component_communication() {
 
    let pd = ProtocolDescription::parse(b"
 
    primitive sender(out<u32> o, u32 outside_loops, u32 inside_loops) {
 
        u32 outside_index = 0;
 
        while (outside_index < outside_loops) {
 
            u32 inside_index = 0;
 
            sync while (inside_index < inside_loops) {
 
                put(o, inside_index);
 
                inside_index += 1;
 
            }
 
            outside_index += 1;
 
        }
 
    }
 

	
 
    primitive receiver(in<u32> i, u32 outside_loops, u32 inside_loops) {
 
        u32 outside_index = 0;
 
        while (outside_index < outside_loops) {
 
            u32 inside_index = 0;
 
            sync while (inside_index < inside_loops) {
 
                auto val = get(i);
 
                while (val != inside_index) {} // infinite loop if incorrect value is received
 
                inside_index += 1;
 
            }
 
            outside_index += 1;
 
        }
 
    }
 

	
 
    composite constructor() {
 
        channel o_orom -> i_orom;
 
        channel o_mrom -> i_mrom;
 
        channel o_ormm -> i_ormm;
 
        channel o_mrmm -> i_mrmm;
 

	
 
        // one round, one message per round
 
        new sender(o_orom, 1, 1);
 
        new receiver(i_orom, 1, 1);
 

	
 
        // multiple rounds, one message per round
 
        new sender(o_mrom, 5, 1);
 
        new receiver(i_mrom, 5, 1);
 

	
 
        // one round, multiple messages per round
 
        new sender(o_ormm, 1, 5);
 
        new receiver(i_ormm, 1, 5);
 

	
 
        // multiple rounds, multiple messages per round
 
        new sender(o_mrmm, 5, 5);
 
        new receiver(i_mrmm, 5, 5);
 
    }").expect("compilation");
 
    let rt = Runtime::new(3, true, pd);
 
    create_component(&rt, "", "constructor", no_args());
 
}
 

	
 
#[test]
 
fn test_intermediate_messenger() {
 
    let pd = ProtocolDescription::parse(b"
 
    primitive receiver<T>(in<T> rx, u32 num) {
 
        auto index = 0;
 
        while (index < num) {
 
            sync { auto v = get(rx); }
 
            index += 1;
 
        }
 
    }
 

	
 
    primitive middleman<T>(in<T> rx, out<T> tx, u32 num) {
 
        auto index = 0;
 
        while (index < num) {
 
            sync { put(tx, get(rx)); }
 
            index += 1;
 
        }
 
    }
 

	
 
    primitive sender<T>(out<T> tx, u32 num) {
 
        auto index = 0;
 
        while (index < num) {
 
            sync put(tx, 1337);
 
            index += 1;
 
        }
 
    }
 

	
 
    composite constructor_template<T>() {
 
        auto num = 0;
 
        channel<T> tx_a -> rx_a;
 
        channel tx_b -> rx_b;
 
        new sender(tx_a, 3);
 
        new middleman(rx_a, tx_b, 3);
 
        new receiver(rx_b, 3);
 
    }
 

	
 
    composite constructor() {
 
        new constructor_template<u16>();
 
        new constructor_template<u32>();
 
        new constructor_template<u64>();
 
        new constructor_template<s16>();
 
        new constructor_template<s32>();
 
        new constructor_template<s64>();
 
    }
 
    ").expect("compilation");
 
    let rt = Runtime::new(3, true, pd);
 
    create_component(&rt, "", "constructor", no_args());
 
}
 

	
 
#[test]
 
fn test_simple_select() {
 
    let pd = ProtocolDescription::parse(b"
 
    func infinite_assert<T>(T val, T expected) -> () {
 
        while (val != expected) { print(\"nope!\"); }
 
        return ();
 
    }
 

	
 
    primitive receiver(in<u32> in_a, in<u32> in_b, u32 num_sends) {
 
        auto num_from_a = 0;
 
        auto num_from_b = 0;
 
        while (num_from_a + num_from_b < 2 * num_sends) {
 
            sync select {
 
                auto v = get(in_a) -> {
 
                    print(\"got something from A\");
 
                    auto _ = infinite_assert(v, num_from_a);
 
                    num_from_a += 1;
 
                }
 
                auto v = get(in_b) -> {
 
                    print(\"got something from B\");
 
                    auto _ = infinite_assert(v, num_from_b);
 
                    num_from_b += 1;
 
                }
 
            }
 
        }
 
    }
 

	
 
    primitive sender(out<u32> tx, u32 num_sends) {
 
        auto index = 0;
 
        while (index < num_sends) {
 
            sync {
 
                put(tx, index);
 
                index += 1;
 
            }
 
        }
 
    }
 

	
 
    composite constructor() {
 
        auto num_sends = 15;
 
        channel tx_a -> rx_a;
 
        channel tx_b -> rx_b;
 
        new sender(tx_a, num_sends);
 
        new receiver(rx_a, rx_b, num_sends);
 
        new sender(tx_b, num_sends);
 
    }
 
    ").expect("compilation");
 
    let rt = Runtime::new(3, false, pd);
 
    create_component(&rt, "", "constructor", no_args());
 
}
 

	
 
#[test]
 
fn test_unguarded_select() {
 
    let pd = ProtocolDescription::parse(b"
 
    primitive constructor_outside_select() {
 
        u32 index = 0;
 
        while (index < 5) {
 
            sync select { auto v = () -> print(\"hello\"); }
 
            index += 1;
 
        }
 
    }
 

	
 
    primitive constructor_inside_select() {
 
        u32 index = 0;
 
        while (index < 5) {
 
            sync select { auto v = () -> index += 1; }
 
        }
 
    }
 
    ").expect("compilation");
 
    let rt = Runtime::new(3, false, pd);
 
    create_component(&rt, "", "constructor_outside_select", no_args());
 
    create_component(&rt, "", "constructor_inside_select", no_args());
 
}
 

	
 
#[test]
 
fn test_empty_select() {
 
    let pd = ProtocolDescription::parse(b"
 
    primitive constructor() {
 
        u32 index = 0;
 
        while (index < 5) {
 
            sync select {}
 
            index += 1;
 
        }
 
    }
 
    ").expect("compilation");
 
    let rt = Runtime::new(3, false, pd);
 
    create_component(&rt, "", "constructor", no_args());
 
}
 

	
 
#[test]
 
fn test_random_u32_temporary_thingo() {
 
    let pd = ProtocolDescription::parse(b"
 
    primitive random_taker(in<u32> generator) {
 
        sync {
 
            auto a = get(generator);
 
        }
 
    }
 

	
 
    composite constructor() {
 
        channel tx -> rx;
 
        new random_u32(tx, 1, 100);
 
        new random_taker(rx);
 
    }
 
    ").expect("compilation");
 
}
 
\ No newline at end of file
std/std.global.pdl
Show inline comments
 
#module std.global
 

	
 
// Note: parsing of token ranges and pragma needs to change. For now we insert
 
// spaces to work with the current system. Needs to be a system where the
 
// pragmas, "func" keywords (and similar keywords) indicate initial points to
 
// start parsing.
 

	
 
func get<T>(in<T> input) -> T { #builtin }
 
func put<T>(out<T> output, T value) -> #type_void { #builtin }
 
func fires<T>(#type_portlike<T> port) -> bool { #builtin }
 
func create<T>(#type_integerlike len) -> T[] { #builtin }
 
func length<T>(#type_arraylike<T> array) -> u32 { #builtin }
 
func assert(bool condition) -> #type_void { #builtin }
 
func print(string message) -> #type_void { #builtin }
 
\ No newline at end of file
std/std.random.pdl
Show inline comments
 
new file 100644
 
#module std.random
 

	
 
primitive random_u32(out<u32> generator, u32 min, u32 max) { #builtin }
0 comments (0 inline, 0 general)