Changeset - 77bdf7d1ef92
[Not reviewed]
src/protocol/ast.rs
Show inline comments
 
@@ -1350,467 +1350,468 @@ pub struct GotoStatement {
 
    pub span: InputSpan, // of the "goto" keyword
 
    pub label: Identifier,
 
    // Phase 2: linker
 
    pub target: Option<LabeledStatementId>,
 
}
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
#[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,
 
    pub unique_id_in_definition: i32,
 
}
 
\ No newline at end of file
src/protocol/ast_printer.rs
Show inline comments
 
@@ -325,661 +325,669 @@ impl ASTWriter {
 
                for poly_var_id in &def.poly_vars {
 
                    self.kv(indent3).with_s_key("PolyVar").with_identifier_val(&poly_var_id);
 
                }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
                self.kv(indent2).with_s_key("EndWhile").with_disp_val(&stmt.end_while.0.index);
 
                self.kv(indent2).with_s_key("InSync")
 
                    .with_disp_val(&stmt.in_sync.0.index);
 
                self.kv(indent2).with_s_key("Condition");
 
                self.write_expr(heap, stmt.test, indent3);
 
                self.kv(indent2).with_s_key("Body");
 
                self.write_stmt(heap, stmt.body.upcast(), indent3);
 
            },
 
            Statement::EndWhile(stmt) => {
 
                self.kv(indent).with_id(PREFIX_ENDWHILE_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("EndWhile");
 
                self.kv(indent2).with_s_key("StartWhile").with_disp_val(&stmt.start_while.0.index);
 
                self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
 
            },
 
            Statement::Break(stmt) => {
 
                self.kv(indent).with_id(PREFIX_BREAK_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Break");
 
                self.kv(indent2).with_s_key("Label")
 
                    .with_opt_identifier_val(stmt.label.as_ref());
 
                self.kv(indent2).with_s_key("Target")
 
                    .with_opt_disp_val(stmt.target.as_ref().map(|v| &v.0.index));
 
            },
 
            Statement::Continue(stmt) => {
 
                self.kv(indent).with_id(PREFIX_CONTINUE_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Continue");
 
                self.kv(indent2).with_s_key("Label")
 
                    .with_opt_identifier_val(stmt.label.as_ref());
 
                self.kv(indent2).with_s_key("Target")
 
                    .with_opt_disp_val(stmt.target.as_ref().map(|v| &v.0.index));
 
            },
 
            Statement::Synchronous(stmt) => {
 
                self.kv(indent).with_id(PREFIX_SYNC_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Synchronous");
 
                self.kv(indent2).with_s_key("EndSync").with_disp_val(&stmt.end_sync.0.index);
 
                self.kv(indent2).with_s_key("Body");
 
                self.write_stmt(heap, stmt.body.upcast(), indent3);
 
            },
 
            Statement::EndSynchronous(stmt) => {
 
                self.kv(indent).with_id(PREFIX_ENDSYNC_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("EndSynchronous");
 
                self.kv(indent2).with_s_key("StartSync").with_disp_val(&stmt.start_sync.0.index);
 
                self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
 
            },
 
            Statement::Fork(stmt) => {
 
                self.kv(indent).with_id(PREFIX_FORK_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Fork");
 
                self.kv(indent2).with_s_key("EndFork").with_disp_val(&stmt.end_fork.0.index);
 
                self.kv(indent2).with_s_key("LeftBody");
 
                self.write_stmt(heap, stmt.left_body.upcast(), indent3);
 

	
 
                if let Some(right_body_id) = stmt.right_body {
 
                    self.kv(indent2).with_s_key("RightBody");
 
                    self.write_stmt(heap, right_body_id.upcast(), indent3);
 
                }
 
            },
 
            Statement::EndFork(stmt) => {
 
                self.kv(indent).with_id(PREFIX_END_FORK_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("EndFork");
 
                self.kv(indent2).with_s_key("StartFork").with_disp_val(&stmt.start_fork.0.index);
 
                self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
 
            }
 
            Statement::Return(stmt) => {
 
                self.kv(indent).with_id(PREFIX_RETURN_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Return");
 
                self.kv(indent2).with_s_key("Expressions");
 
                for expr_id in &stmt.expressions {
 
                    self.write_expr(heap, *expr_id, indent3);
 
                }
 
            },
 
            Statement::Goto(stmt) => {
 
                self.kv(indent).with_id(PREFIX_GOTO_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("Goto");
 
                self.kv(indent2).with_s_key("Label").with_identifier_val(&stmt.label);
 
                self.kv(indent2).with_s_key("Target")
 
                    .with_opt_disp_val(stmt.target.as_ref().map(|v| &v.0.index));
 
            },
 
            Statement::New(stmt) => {
 
                self.kv(indent).with_id(PREFIX_NEW_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("New");
 
                self.kv(indent2).with_s_key("Expression");
 
                self.write_expr(heap, stmt.expression.upcast(), indent3);
 
                self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
 
            },
 
            Statement::Expression(stmt) => {
 
                self.kv(indent).with_id(PREFIX_EXPR_STMT_ID, stmt.this.0.index)
 
                    .with_s_key("ExpressionStatement");
 
                self.write_expr(heap, stmt.expression, indent2);
 
                self.kv(indent2).with_s_key("Next").with_disp_val(&stmt.next.index);
 
            }
 
        }
 
    }
 

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

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

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

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

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

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

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

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

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

	
 
                        self.kv(indent3).with_s_key("Elements");
 
                        for expr_id in data {
 
                            self.write_expr(heap, *expr_id, indent4);
 
                        }
 
                    },
 
                    Literal::Tuple(data) => {
 
                        val.with_s_val("Tuple");
 
                        let indent4 = indent3 + 1;
 
                        self.kv(indent3).with_s_key("Elements");
 
                        for expr_id in data {
 
                            self.write_expr(heap, *expr_id, indent4);
 
                        }
 
                    }
 
                }
 

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

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

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

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

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

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

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

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

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

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

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

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

	
 
    fn write_element(target: &mut String, heap: &Heap, t: &ParserType, mut element_idx: usize) -> usize {
 
        let element = &t.elements[element_idx];
 
        match &element.variant {
 
            PTV::Void => target.push_str("void"),
 
            PTV::InputOrOutput => {
 
                target.push_str("portlike<");
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push('>');
 
            },
 
            PTV::ArrayLike => {
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push_str("[???]");
 
            },
 
            PTV::IntegerLike => target.push_str("integerlike"),
 
            PTV::Message => { target.push_str(KW_TYPE_MESSAGE_STR); },
 
            PTV::Bool => { target.push_str(KW_TYPE_BOOL_STR); },
 
            PTV::UInt8 => { target.push_str(KW_TYPE_UINT8_STR); },
 
            PTV::UInt16 => { target.push_str(KW_TYPE_UINT16_STR); },
 
            PTV::UInt32 => { target.push_str(KW_TYPE_UINT32_STR); },
 
            PTV::UInt64 => { target.push_str(KW_TYPE_UINT64_STR); },
 
            PTV::SInt8 => { target.push_str(KW_TYPE_SINT8_STR); },
 
            PTV::SInt16 => { target.push_str(KW_TYPE_SINT16_STR); },
 
            PTV::SInt32 => { target.push_str(KW_TYPE_SINT32_STR); },
 
            PTV::SInt64 => { target.push_str(KW_TYPE_SINT64_STR); },
 
            PTV::Character => { target.push_str(KW_TYPE_CHAR_STR); },
 
            PTV::String => { target.push_str(KW_TYPE_STRING_STR); },
 
            PTV::IntegerLiteral => { target.push_str("int_literal"); },
 
            PTV::Inferred => { target.push_str(KW_TYPE_INFERRED_STR); },
 
            PTV::Array => {
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push_str("[]");
 
            },
 
            PTV::Input => {
 
                target.push_str(KW_TYPE_IN_PORT_STR);
 
                target.push('<');
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push('>');
 
            },
 
            PTV::Output => {
 
                target.push_str(KW_TYPE_OUT_PORT_STR);
 
                target.push('<');
 
                element_idx = write_element(target, heap, t, element_idx + 1);
 
                target.push('>');
 
            },
 
            PTV::Tuple(num_embedded) => {
 
                target.push('(');
 
                let num_embedded = *num_embedded;
 
                for embedded_idx in 0..num_embedded {
 
                    if embedded_idx != 0 {
 
                        target.push(',');
 
                    }
 
                    element_idx = write_element(target, heap, t, element_idx + 1);
 
                }
 
                target.push(')');
 
            }
 
            PTV::PolymorphicArgument(definition_id, arg_idx) => {
 
                let definition = &heap[*definition_id];
 
                let poly_var = &definition.poly_vars()[*arg_idx as usize].value;
 
                target.push_str(poly_var.as_str());
 
            },
 
            PTV::Definition(definition_id, num_embedded) => {
 
                let definition = &heap[*definition_id];
 
                let definition_ident = definition.identifier().value.as_str();
 
                target.push_str(definition_ident);
 

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

	
 
        element_idx
 
    }
 

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

	
 
fn write_concrete_type(target: &mut String, heap: &Heap, def_id: DefinitionId, t: &ConcreteType) {
 
    use ConcreteTypePart as CTP;
 

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

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

	
 
        idx + 1
 
    }
 

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

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

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

	
 
use std::collections::VecDeque;
 

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

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

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

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

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

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

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

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

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

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

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

	
 
        self.serialize_expression(heap, expr_id);
 
    }
 

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

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

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

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

	
 
type EvalResult = Result<EvalContinuation, EvalError>;
 

	
 
#[derive(Debug)]
 
pub enum EvalContinuation {
 
    // Returned in both sync and non-sync modes
 
    Stepping,
 
    // Returned only in sync mode
 
    BranchInconsistent,
 
    SyncBlockEnd,
 
    NewFork,
 
    BlockFires(PortId),
 
    BlockGet(PortId),
 
    Put(PortId, ValueGroup),
 
    // Returned only in non-sync mode
 
    ComponentTerminated,
 
    SyncBlockStart,
 
    NewComponent(DefinitionId, i32, ValueGroup),
 
    NewChannel,
 
}
 

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

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

	
 
        // Maybe do typechecking in the future?
 
        let new_frame = Frame::new(heap, def, monomorph_idx);
 
        let max_stack_size = new_frame.max_stack_size;
 
        prompt.frames.push(new_frame);
 
        args.into_store(&mut prompt.store);
 
        prompt.store.reserve_stack(max_stack_size);
 

	
 
        prompt
 
    }
 

	
 
    /// Big 'ol function right here. Didn't want to break it up unnecessarily.
 
    /// It consists of, in sequence: executing any expressions that should be
 
    /// executed before the next statement can be evaluated, then a section that
 
    /// performs debug printing, and finally a section that takes the next
 
    /// statement and executes it. If the statement requires any expressions to
 
    /// be evaluated, then they will be added such that the next time `step` is
 
    /// called, all of these expressions are indeed evaluated.
 
    pub(crate) fn step(&mut self, types: &TypeTable, heap: &Heap, modules: &[Module], ctx: &mut impl RunContext) -> EvalResult {
 
        // Helper function to transfer multiple values from the expression value
 
        // array into a heap region (e.g. constructing arrays or structs).
 
        fn transfer_expression_values_front_into_heap(cur_frame: &mut Frame, store: &mut Store, num_values: usize) -> HeapPos {
 
            let heap_pos = store.alloc_heap();
 

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

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

	
 
            heap_pos
 
        }
 

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

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

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

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

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

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

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

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

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

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

	
 
                            let (deallocate_heap_pos, value_to_push) = 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 = types.get_procedure_monomorph(cur_frame.monomorph_idx);
 
                            let field_idx = mono_data.expr_data[expr.unique_id_in_definition as usize].field_or_monomorph_idx as u32;
 

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

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

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

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

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

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

	
 
                                    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 = match port_value_deref {
 
                                        Value::Input(port_id) => port_id,
 
                                        Value::Output(port_id) => port_id,
 
                                        _ => unreachable!("executor calling 'fires' on value {:?}", port_value_deref),
 
                                    };
 

	
 
                                    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::UserComponent => {
 
                                    // This is actually handled by the evaluation
 
                                    // of the statement.
 
                                    debug_assert_eq!(heap[expr.definition].parameters().len(), cur_frame.expr_values.len());
 
                                    debug_assert_eq!(heap[cur_frame.position].as_new().expression, expr.this)
 
                                },
 
                                Method::UserFunction => {
 
                                    // Push a new frame. Note that all expressions have
 
                                    // been pushed to the front, so they're in the order
 
                                    // of the definition.
 
                                    let num_args = expr.arguments.len();
 

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

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

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

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

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

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

	
 
            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];
 
                self.store.clear_stack(block.first_unique_id_in_scope as usize);
 
                cur_frame.position = stmt.next;
 

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

	
 
                        cur_frame.position = stmt.next;
 
                        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_body.upcast();
 
                } else if let Some(false_body) = stmt.false_body {
 
                    cur_frame.position = false_body.upcast();
 
                } else {
 
                    // Not true, and no false body
 
                    cur_frame.position = stmt.end_if.upcast();
 
                }
 

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

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

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

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

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

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

	
 
                Ok(EvalContinuation::SyncBlockEnd)
 
            },
 
            Statement::Fork(stmt) => {
 
                if stmt.right_body.is_none() {
 
                    // No reason to fork
 
                    cur_frame.position = stmt.left_body.upcast();
 
                } 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.upcast();
 
                        } else {
 
                            cur_frame.position = stmt.right_body.unwrap().upcast();
 
                        }
 
                    } 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::Return(_stmt) => {
 
                debug_assert!(heap[cur_frame.definition].is_function());
 
                debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for return statement");
 

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

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

	
 
                // Clean up our section of the stack
src/protocol/eval/value.rs
Show inline comments
 
use std::collections::VecDeque;
 

	
 
use super::store::*;
 
use crate::protocol::ast::{
 
    AssignmentOperator,
 
    BinaryOperator,
 
    UnaryOperator,
 
    ConcreteType,
 
    ConcreteTypePart,
 
};
 
use crate::protocol::parser::token_parsing::*;
 

	
 
pub type StackPos = u32;
 
pub type HeapPos = u32;
 

	
 
#[derive(Debug, Copy, Clone)]
 
pub enum ValueId {
 
    Stack(StackPos), // place on stack
 
    Heap(HeapPos, u32), // allocated region + values within that region
 
}
 

	
 
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 
pub struct PortId{
 
    pub(crate) id: u32
 
}
 

	
 
impl PortId {
 
    pub fn new(id: u32) -> Self {
 
        return Self{ id };
 
    }
 
}
 

	
 
/// Represents a value stored on the stack or on the heap. Some values contain
 
/// a `HeapPos`, implying that they're stored in the store's `Heap`. Clearing
 
/// a `Value` with a `HeapPos` from a stack must also clear the associated
 
/// region from the `Heap`.
 
#[derive(Debug, Clone)]
 
pub enum Value {
 
    // Special types, never encountered during evaluation if the compiler works correctly
 
    Unassigned,                 // Marker when variables are first declared, immediately followed by assignment
 
    PrevStackBoundary(isize),   // Marker for stack frame beginning, so we can pop stack values
 
    Ref(ValueId),               // Reference to a value, used by expressions producing references
 
    Binding(StackPos),          // Reference to a binding variable (reserved on the stack)
 
    // Builtin types
 
    Input(PortId),
 
    Output(PortId),
 
    Message(HeapPos),
 
    Null,
 
    Bool(bool),
 
    Char(char),
 
    String(HeapPos),
 
    UInt8(u8),
 
    UInt16(u16),
 
    UInt32(u32),
 
    UInt64(u64),
 
    SInt8(i8),
 
    SInt16(i16),
 
    SInt32(i32),
 
    SInt64(i64),
 
    Array(HeapPos),
 
    Tuple(HeapPos),
 
    // Instances of user-defined types
 
    Enum(i64),
 
    Union(i64, HeapPos),
 
    Struct(HeapPos),
 
}
 

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

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

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

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

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

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

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

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

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

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

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

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

	
 
        group
 
    }
 

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

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

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

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

	
 
    /// Transfers the heap values into the store, but will put the stack values
 
    /// into the provided `VecDeque`. This is mainly used to merge `ValueGroup`
 
    /// instances retrieved by the code by `get` calls into the expression
 
    /// stack.
 
    pub(crate) fn into_stack(self, stack: &mut VecDeque<Value>, store: &mut Store) {
 
        for value in &self.values {
 
            let transferred = self.provide_value(value, store);
 
            stack.push_back(transferred);
 
        }
 
    }
 

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

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

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

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

	
 
enum ValueKind { Message, String, Array }
 

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

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

	
 
    let lhs = store.read_mut_ref(lhs);
 

	
 
    let mut to_dealloc = None;
 
    match op {
 
        AO::Set => {
 
            match lhs {
 
                Value::Unassigned => { *lhs = rhs; },
 
                Value::Input(v)  => { *v = rhs.as_input(); },
 
                Value::Output(v) => { *v = rhs.as_output(); },
 
                Value::Message(v)  => { to_dealloc = Some(*v); *v = rhs.as_message(); },
 
                Value::Bool(v)    => { *v = rhs.as_bool(); },
 
                Value::Char(v) => { *v = rhs.as_char(); },
 
                Value::String(v) => { *v = rhs.as_string().clone(); },
 
                Value::UInt8(v) => { *v = rhs.as_uint8(); },
 
                Value::UInt16(v) => { *v = rhs.as_uint16(); },
 
                Value::UInt32(v) => { *v = rhs.as_uint32(); },
 
                Value::UInt64(v) => { *v = rhs.as_uint64(); },
 
                Value::SInt8(v) => { *v = rhs.as_sint8(); },
 
                Value::SInt16(v) => { *v = rhs.as_sint16(); },
 
                Value::SInt32(v) => { *v = rhs.as_sint32(); },
 
                Value::SInt64(v) => { *v = rhs.as_sint64(); },
 
                Value::Array(v) => { to_dealloc = Some(*v); *v = rhs.as_array(); },
 
                Value::Tuple(v) => { to_dealloc = Some(*v); *v = rhs.as_tuple(); },
 
                Value::Enum(v) => { *v = rhs.as_enum(); },
 
                Value::Union(lhs_tag, lhs_heap_pos) => {
 
                    to_dealloc = Some(*lhs_heap_pos);
 
                    let (rhs_tag, rhs_heap_pos) = rhs.as_union();
 
                    *lhs_tag = rhs_tag;
 
                    *lhs_heap_pos = rhs_heap_pos;
 
                }
 
                Value::Struct(v) => { to_dealloc = Some(*v); *v = rhs.as_struct(); },
 
                _ => unreachable!("apply_assignment_operator {:?} on lhs {:?} and rhs {:?}", op, lhs, rhs),
 
            }
 
        },
 
        AO::Concatenated => {
 
            let lhs_heap_pos = lhs.get_heap_pos().unwrap() as usize;
 
            let rhs_heap_pos = rhs.get_heap_pos().unwrap() as usize;
 

	
 
            // To prevent borrowing crap, swap out heap region with a temp empty array
 
            let mut total = Vec::new();
 
            std::mem::swap(&mut total, &mut store.heap_regions[lhs_heap_pos].values);
 

	
 
            // Push everything onto the swapped vector
 
            let rhs_len = store.heap_regions[rhs_heap_pos].values.len();
 
            total.reserve(rhs_len);
 
            for value_idx in 0..rhs_len {
 
                total.push(store.clone_value(store.heap_regions[rhs_heap_pos].values[value_idx].clone()));
 
            }
 

	
 
            // Swap back in place
 
            std::mem::swap(&mut total, &mut store.heap_regions[lhs_heap_pos].values);
 

	
 
            // We took ownership of the RHS, but we copied it into the LHS, so
 
            // different form assignment we need to drop the RHS heap pos.
 
            to_dealloc = Some(rhs_heap_pos as u32);
 
        },
 
        AO::Multiplied =>   { apply_int_op!(lhs, *=,  op, rhs) },
 
        AO::Divided =>      { apply_int_op!(lhs, /=,  op, rhs) },
 
        AO::Remained =>     { apply_int_op!(lhs, %=,  op, rhs) },
 
        AO::Added =>        { apply_int_op!(lhs, +=,  op, rhs) },
 
        AO::Subtracted =>   { apply_int_op!(lhs, -=,  op, rhs) },
 
        AO::ShiftedLeft =>  { apply_int_op!(lhs, <<=, op, rhs) },
 
        AO::ShiftedRight => { apply_int_op!(lhs, >>=, op, rhs) },
 
        AO::BitwiseAnded => { apply_int_op!(lhs, &=,  op, rhs) },
 
        AO::BitwiseXored => { apply_int_op!(lhs, ^=,  op, rhs) },
 
        AO::BitwiseOred =>  { apply_int_op!(lhs, |=,  op, rhs) },
 
    }
 

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

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

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

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

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

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

	
 
        let value_kind;
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
        return true;
 
    }
 

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

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

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

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

	
 
        return false;
 
    }
 

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

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

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

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

	
 
        return true;
 
    }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
        lookup.push(self.input.len() as u32 + 1); // for lookup_line_end, intentionally adding one character
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 
}
 

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

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

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

	
 
        Ok(())
 
    }
 
}
 

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

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

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

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

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

	
 
    pub fn with_info_at_span(self, source: &InputSource, span: InputSpan, msg: String) -> Self {
src/protocol/parser/pass_definitions.rs
Show inline comments
 
@@ -21,844 +21,857 @@ pub(crate) struct PassDefinitions {
 
    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::new_reserved(128),
 
            enum_variants: ScopedBuffer::new_reserved(128),
 
            union_variants: ScopedBuffer::new_reserved(128),
 
            variables: ScopedBuffer::new_reserved(128),
 
            expressions: ScopedBuffer::new_reserved(128),
 
            statements: ScopedBuffer::new_reserved(128),
 
            parser_types: ScopedBuffer::new_reserved(128),
 
        }
 
    }
 

	
 
    pub(crate) fn parse(&mut self, modules: &mut [Module], module_idx: usize, ctx: &mut PassCtx) -> Result<(), ParseError> {
 
        let module = &modules[module_idx];
 
        let module_range = &module.tokens.ranges[0];
 
        debug_assert_eq!(module.phase, ModuleCompilationPhase::ImportsResolved);
 
        debug_assert_eq!(module_range.range_kind, TokenRangeKind::Module);
 

	
 
        // Although we only need to parse the definitions, we want to go through
 
        // code ranges as well such that we can throw errors if we get
 
        // unexpected tokens at the module level of the source.
 
        let mut range_idx = module_range.first_child_idx;
 
        loop {
 
            let range_idx_usize = range_idx as usize;
 
            let cur_range = &module.tokens.ranges[range_idx_usize];
 

	
 
            match cur_range.range_kind {
 
                TokenRangeKind::Module => unreachable!(), // should not be reachable
 
                TokenRangeKind::Pragma | TokenRangeKind::Import => {
 
                    // Already fully parsed, fall through and go to next range
 
                },
 
                TokenRangeKind::Definition | TokenRangeKind::Code => {
 
                    // Visit range even if it is a "code" range to provide
 
                    // proper error messages.
 
                    self.visit_range(modules, module_idx, ctx, range_idx_usize)?;
 
                },
 
            }
 

	
 
            if cur_range.next_sibling_idx == NO_SIBLING {
 
                break;
 
            } else {
 
                range_idx = cur_range.next_sibling_idx;
 
            }
 
        }
 

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

	
 
        Ok(())
 
    }
 

	
 
    fn visit_range(
 
        &mut self, modules: &[Module], module_idx: usize, ctx: &mut PassCtx, range_idx: usize
 
    ) -> Result<(), ParseError> {
 
        let module = &modules[module_idx];
 
        let cur_range = &module.tokens.ranges[range_idx];
 
        debug_assert!(cur_range.range_kind == TokenRangeKind::Definition || cur_range.range_kind == TokenRangeKind::Code);
 

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

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

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

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

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

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

	
 
                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, 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, 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;
 

	
 
        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
 
        )?;
 
        let parameters = parameter_section.into_vec();
 

	
 
        // Consume return types
 
        consume_token(&module.source, iter, TokenKind::ArrowRight)?;
 
        let mut return_types = self.parser_types.start_section();
 
        let mut open_curly_pos = iter.last_valid_pos(); // bogus value
 
        consume_comma_separated_until(
 
            TokenKind::OpenCurly, &module.source, iter, ctx,
 
            |source, iter, ctx| {
 
                let poly_vars = ctx.heap[definition_id].poly_vars();
 
                self.type_parser.consume_parser_type(
 
                    iter, &ctx.heap, source, &ctx.symbols, poly_vars, definition_id,
 
                    module_scope, false, None
 
                )
 
            },
 
            &mut return_types, "a return type", Some(&mut open_curly_pos)
 
        )?;
 
        let return_types = return_types.into_vec();
 

	
 
        match return_types.len() {
 
            0 => return Err(ParseError::new_error_str_at_pos(&module.source, open_curly_pos, "expected a return type")),
 
            1 => {},
 
            _ => return Err(ParseError::new_error_str_at_pos(&module.source, open_curly_pos, "multiple return types are not (yet) allowed")),
 
        }
 

	
 
        // Consume block
 
        let body = self.consume_block_statement_without_leading_curly(module, iter, ctx, open_curly_pos)?;
 

	
 
        // Assign everything in the preallocated AST node
 
        let function = ctx.heap[definition_id].as_function_mut();
 
        function.return_types = return_types;
 
        function.parameters = parameters;
 
        function.body = body;
 

	
 
        Ok(())
 
    }
 

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

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

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

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

	
 
        // Consume block
 
        let body = self.consume_block_statement(module, iter, ctx)?;
 

	
 
        // Assign everything in the AST node
 
        let component = ctx.heap[definition_id].as_component_mut();
 
        component.parameters = parameters;
 
        component.body = body;
 

	
 
        Ok(())
 
    }
 

	
 
    /// Consumes a block statement. If the resulting statement is not a block
 
    /// (e.g. for a shorthand "if (expr) single_statement") then it will be
 
    /// wrapped in one
 
    fn consume_block_or_wrapped_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<BlockStatementId, ParseError> {
 
        if Some(TokenKind::OpenCurly) == iter.next() {
 
            // This is a block statement
 
            self.consume_block_statement(module, iter, ctx)
 
        } else {
 
            // Not a block statement, so wrap it in one
 
            let mut statements = self.statements.start_section();
 
            let wrap_begin_pos = iter.last_valid_pos();
 
            self.consume_statement(module, iter, ctx, &mut statements)?;
 
            let wrap_end_pos = iter.last_valid_pos();
 

	
 
            let statements = statements.into_vec();
 

	
 
            let id = ctx.heap.alloc_block_statement(|this| BlockStatement{
 
                this,
 
                is_implicit: true,
 
                span: InputSpan::from_positions(wrap_begin_pos, wrap_end_pos),
 
                statements,
 
                end_block: EndBlockStatementId::new_invalid(),
 
                scope_node: ScopeNode::new_invalid(),
 
                first_unique_id_in_scope: -1,
 
                next_unique_id_in_scope: -1,
 
                relative_pos_in_parent: 0,
 
                locals: Vec::new(),
 
                labels: Vec::new(),
 
                next: StatementId::new_invalid(),
 
            });
 

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

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

	
 
            Ok(id)
 
        }
 
    }
 

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

	
 
        if next == TokenKind::OpenCurly {
 
            let id = self.consume_block_statement(module, iter, ctx)?;
 
            section.push(id.upcast());
 
        } else if next == TokenKind::Ident {
 
            let ident = peek_ident(&module.source, iter).unwrap();
 
            if ident == KW_STMT_IF {
 
                // Consume if statement and place end-if statement directly
 
                // after it.
 
                let id = self.consume_if_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 

	
 
                let end_if = ctx.heap.alloc_end_if_statement(|this| EndIfStatement{
 
                    this, start_if: id, next: StatementId::new_invalid()
 
                let end_if = ctx.heap.alloc_end_if_statement(|this| EndIfStatement {
 
                    this,
 
                    start_if: id,
 
                    next: StatementId::new_invalid()
 
                });
 
                section.push(end_if.upcast());
 

	
 
                let if_stmt = &mut ctx.heap[id];
 
                if_stmt.end_if = end_if;
 
            } else if ident == KW_STMT_WHILE {
 
                let id = self.consume_while_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 

	
 
                let end_while = ctx.heap.alloc_end_while_statement(|this| EndWhileStatement{
 
                    this, start_while: id, next: StatementId::new_invalid()
 
                let end_while = ctx.heap.alloc_end_while_statement(|this| EndWhileStatement {
 
                    this,
 
                    start_while: id,
 
                    next: StatementId::new_invalid()
 
                });
 
                section.push(end_while.upcast());
 

	
 
                let while_stmt = &mut ctx.heap[id];
 
                while_stmt.end_while = end_while;
 
            } else if ident == KW_STMT_BREAK {
 
                let id = self.consume_break_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 
            } else if ident == KW_STMT_CONTINUE {
 
                let id = self.consume_continue_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 
            } else if ident == KW_STMT_SYNC {
 
                let id = self.consume_synchronous_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 

	
 
                let end_sync = ctx.heap.alloc_end_synchronous_statement(|this| EndSynchronousStatement {
 
                    this,
 
                    start_sync: id,
 
                    next: StatementId::new_invalid()
 
                });
 
                section.push(end_sync.upcast());
 

	
 
                let sync_stmt = &mut ctx.heap[id];
 
                sync_stmt.end_sync = end_sync;
 
            } else if ident == KW_STMT_FORK {
 
                let id = self.consume_fork_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 

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

	
 
                let fork_stmt = &mut ctx.heap[id];
 
                fork_stmt.end_fork = end_fork;
 
            } else if ident == KW_STMT_RETURN {
 
                let id = self.consume_return_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 
            } else if ident == KW_STMT_GOTO {
 
                let id = self.consume_goto_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 
            } else if ident == KW_STMT_NEW {
 
                let id = self.consume_new_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 
            } else if ident == KW_STMT_CHANNEL {
 
                let id = self.consume_channel_statement(module, iter, ctx)?;
 
                section.push(id.upcast().upcast());
 
            } else if iter.peek() == Some(TokenKind::Colon) {
 
                self.consume_labeled_statement(module, iter, ctx, section)?;
 
            } else {
 
                // Two fallback possibilities: the first one is a memory
 
                // declaration, the other one is to parse it as a normal
 
                // expression. This is a bit ugly.
 
                if let Some((memory_stmt_id, assignment_stmt_id)) = self.maybe_consume_memory_statement(module, iter, ctx)? {
 
                    section.push(memory_stmt_id.upcast().upcast());
 
                    section.push(assignment_stmt_id.upcast());
 
                } else {
 
                    let id = self.consume_expression_statement(module, iter, ctx)?;
 
                    section.push(id.upcast());
 
                }
 
            }
 
        } else if next == TokenKind::OpenParen {
 
            // Same as above: memory statement or normal expression
 
            if let Some((memory_stmt_id, assignment_stmt_id)) = self.maybe_consume_memory_statement(module, iter, ctx)? {
 
                section.push(memory_stmt_id.upcast().upcast());
 
                section.push(assignment_stmt_id.upcast());
 
            } else {
 
                let id = self.consume_expression_statement(module, iter, ctx)?;
 
                section.push(id.upcast());
 
            }
 
        } else {
 
            let id = self.consume_expression_statement(module, iter, ctx)?;
 
            section.push(id.upcast());
 
        }
 

	
 
        return Ok(());
 
    }
 

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

	
 
    fn consume_block_statement_without_leading_curly(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, open_curly_pos: InputPosition
 
    ) -> Result<BlockStatementId, ParseError> {
 
        let mut stmt_section = self.statements.start_section();
 
        let mut next = iter.next();
 
        while next != Some(TokenKind::CloseCurly) {
 
            if next.is_none() {
 
                return Err(ParseError::new_error_str_at_pos(
 
                    &module.source, iter.last_valid_pos(), "expected a statement or '}'"
 
                ));
 
            }
 
            self.consume_statement(module, iter, ctx, &mut stmt_section)?;
 
            next = iter.next();
 
        }
 

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

	
 
        let id = ctx.heap.alloc_block_statement(|this| BlockStatement{
 
            this,
 
            is_implicit: false,
 
            span: block_span,
 
            statements,
 
            end_block: EndBlockStatementId::new_invalid(),
 
            scope_node: ScopeNode::new_invalid(),
 
            first_unique_id_in_scope: -1,
 
            next_unique_id_in_scope: -1,
 
            relative_pos_in_parent: 0,
 
            locals: Vec::new(),
 
            labels: Vec::new(),
 
            next: StatementId::new_invalid(),
 
        });
 

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

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

	
 
        Ok(id)
 
    }
 

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

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

	
 
        Ok(ctx.heap.alloc_if_statement(|this| IfStatement{
 
            this,
 
            span: if_span,
 
            test,
 
            true_body,
 
            false_body,
 
            end_if: EndIfStatementId::new_invalid(),
 
        }))
 
    }
 

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

	
 
        Ok(ctx.heap.alloc_while_statement(|this| WhileStatement{
 
            this,
 
            span: while_span,
 
            test,
 
            body,
 
            end_while: EndWhileStatementId::new_invalid(),
 
            in_sync: SynchronousStatementId::new_invalid(),
 
        }))
 
    }
 

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

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

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

	
 
        Ok(ctx.heap.alloc_synchronous_statement(|this| SynchronousStatement{
 
            this,
 
            span: synchronous_span,
 
            body,
 
            end_sync: EndSynchronousStatementId::new_invalid(),
 
        }))
 
    }
 

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

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

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

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

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

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

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

	
 
    fn consume_goto_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<GotoStatementId, ParseError> {
 
        let goto_span = consume_exact_ident(&module.source, iter, KW_STMT_GOTO)?;
 
        let label = consume_ident_interned(&module.source, iter, ctx)?;
 
        consume_token(&module.source, iter, TokenKind::SemiColon)?;
 
        Ok(ctx.heap.alloc_goto_statement(|this| GotoStatement{
 
            this,
 
            span: goto_span,
 
            label,
 
            target: None
 
        }))
 
    }
 

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

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

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

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

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

	
 
    fn consume_channel_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ChannelStatementId, ParseError> {
 
        // Consume channel specification
 
        let channel_span = consume_exact_ident(&module.source, iter, KW_STMT_CHANNEL)?;
 
        let (inner_port_type, end_pos) = if Some(TokenKind::OpenAngle) == iter.next() {
 
            // Retrieve the type of the channel, we're cheating a bit here by
 
            // consuming the first '<' and setting the initial angle depth to 1
 
            // such that our final '>' will be consumed as well.
 
            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, 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_block: 0,
 
            unique_id_in_scope: -1,
 
        });
 

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

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

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

	
 
        // Not pretty: consume_statement may produce more than one statement.
 
        // The values in the section need to be in the correct order if some
 
        // kind of outer block is consumed, so we take another section, push
 
        // the expressions in that one, and then allocate the labeled statement.
 
        let mut inner_section = self.statements.start_section();
 
        self.consume_statement(module, iter, ctx, &mut inner_section)?;
 
        debug_assert!(inner_section.len() >= 1);
 

	
 
        let stmt_id = ctx.heap.alloc_labeled_statement(|this| LabeledStatement {
 
            this,
 
            label,
 
            body: inner_section[0],
 
            relative_pos_in_block: 0,
 
            in_sync: SynchronousStatementId::new_invalid(),
 
        });
 

	
 
        if inner_section.len() == 1 {
 
            // Produce the labeled statement pointing to the first statement.
 
            // This is by far the most common case.
 
            inner_section.forget();
 
            section.push(stmt_id.upcast());
 
        } else {
 
            // Produce the labeled statement using the first statement, and push
 
            // the remaining ones at the end.
 
            let inner_statements = inner_section.into_vec();
 
            section.push(stmt_id.upcast());
 
            for idx in 1..inner_statements.len() {
 
                section.push(inner_statements[idx])
 
            }
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    fn maybe_consume_memory_statement(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<Option<(MemoryStatementId, ExpressionStatementId)>, ParseError> {
 
        // This is a bit ugly. It would be nicer if we could somehow
 
        // consume the expression with a type hint if we do get a valid
 
        // type, but we don't get an identifier following it
 
        let iter_state = iter.save();
 
        let definition_id = self.cur_definition;
 
        let poly_vars = ctx.heap[definition_id].poly_vars();
 
@@ -949,796 +962,850 @@ impl PassDefinitions {
 
    }
 

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

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

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

	
 
            if token.is_none() {
 
                return None
 
            }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
    fn consume_relational_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::OpenAngle) => Some(BinaryOperator::LessThan),
 
                Some(TokenKind::CloseAngle) => Some(BinaryOperator::GreaterThan),
 
                Some(TokenKind::LessEquals) => Some(BinaryOperator::LessThanEqual),
 
                Some(TokenKind::GreaterEquals) => Some(BinaryOperator::GreaterThanEqual),
 
                _ => None
 
            },
 
            Self::consume_shift_expression
 
        )
 
    }
 

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

	
 
    fn consume_add_or_subtract_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::Plus) => Some(BinaryOperator::Add),
 
                Some(TokenKind::Minus) => Some(BinaryOperator::Subtract),
 
                _ => None,
 
            },
 
            Self::consume_multiply_divide_or_modulus_expression
 
        )
 
    }
 

	
 
    fn consume_multiply_divide_or_modulus_expression(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
 
    ) -> Result<ExpressionId, ParseError> {
 
        self.consume_generic_binary_expression(
 
            module, iter, ctx,
 
            |token| match token {
 
                Some(TokenKind::Star) => Some(BinaryOperator::Multiply),
 
                Some(TokenKind::Slash) => Some(BinaryOperator::Divide),
 
                Some(TokenKind::Percent) => Some(BinaryOperator::Remainder),
 
                _ => None
 
            },
 
            Self::consume_prefix_expression
 
        )
 
    }
 

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

	
 
        let next = iter.next();
 
        if let Some(operation) = parse_prefix_token(next) {
 
            let 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,
 
                unique_id_in_definition: -1,
 
            }).upcast())
 
        } else if next == Some(TokenKind::PlusPlus) {
 
            return Err(ParseError::new_error_str_at_span(
 
                &module.source, iter.next_span(), "prefix increment is not supported in the language"
 
            ));
 
        } else if next == Some(TokenKind::MinusMinus) {
 
            return Err(ParseError::new_error_str_at_span(
 
                &module.source, iter.next_span(), "prefix decrement is not supported in this language"
 
            ));
 
        } else {
 
            self.consume_postfix_expression(module, iter, ctx)
 
        }
 
    }
 

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

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

	
 
        let mut result = self.consume_primary_expression(module, iter, ctx)?;
 
        let mut next = iter.next();
 
        while has_matching_postfix_token(next) {
 
            let token = next.unwrap();
 
            let mut 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,
 
                        unique_id_in_definition: -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,
 
                        unique_id_in_definition: -1,
 
                    }).upcast();
 
                } else {
 
                    return Err(ParseError::new_error_str_at_pos(
 
                        &module.source, iter.last_valid_pos(), "unexpected token: expected ']' or '..'"
 
                    ));
 
                }
 
            } else {
 
                debug_assert_eq!(token, TokenKind::Dot);
 
                let subject = result;
 
                let field_name = consume_ident_interned(&module.source, iter, ctx)?;
 

	
 
                let full_span = InputSpan::from_positions(
 
                    ctx.heap[subject].full_span().begin, field_name.span.end
 
                );
 
                result = ctx.heap.alloc_select_expression(|this| SelectExpression{
 
                    this, operator_span, full_span, subject, field_name,
 
                    parent: ExpressionParent::None,
 
                    unique_id_in_definition: -1,
 
                }).upcast();
 
            }
 

	
 
            next = iter.next();
 
        }
 

	
 
        Ok(result)
 
    }
 

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

	
 
        let result = if next == Some(TokenKind::OpenParen) {
 
            // Expression between parentheses
 
            // 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 = self.consume_expression(module, iter, ctx)?;
 
            consume_token(&module.source, iter, TokenKind::CloseParen)?;
 
            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,
 
                    unique_id_in_definition: -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,
 
                        unique_id_in_definition: -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,
 
                unique_id_in_definition: -1,
 
            }).upcast()
 
        } else if next == Some(TokenKind::Integer) {
 
            let (literal, span) = consume_integer_literal(&module.source, iter, &mut self.buffer)?;
 

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

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

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

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

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

	
 
                let symbol_scope = SymbolScope::Definition(self.cur_definition);
 
                let poly_vars = ctx.heap[self.cur_definition].poly_vars();
 
                let parser_type = self.type_parser.consume_parser_type(
 
                    iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars, self.cur_definition,
 
                    symbol_scope, true, 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,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            },
 
                            Definition::Enum(_) => {
 
                                // Enum literal: consume the variant
 
                                consume_token(&module.source, iter, TokenKind::ColonColon)?;
 
                                let variant = consume_ident_interned(&module.source, iter, ctx)?;
 

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

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

	
 
                                ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
                                    this,
 
                                    span: InputSpan::from_positions(ident_span.begin, end_pos),
 
                                    value: Literal::Union(LiteralUnion{
 
                                        parser_type, variant, values,
 
                                        definition: target_definition_id,
 
                                        variant_idx: 0,
 
                                    }),
 
                                    parent: ExpressionParent::None,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            },
 
                            Definition::Component(_) => {
 
                                // Component instantiation
 
                                let 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: Method::UserComponent,
 
                                    arguments,
 
                                    definition: target_definition_id,
 
                                    parent: ExpressionParent::None,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            },
 
                            Definition::Function(function_definition) => {
 
                                // Check whether it is a builtin function
 
                                let method = if function_definition.builtin {
 
                                    match function_definition.identifier.value.as_bytes() {
 
                                        KW_FUNC_GET => Method::Get,
 
                                        KW_FUNC_PUT => Method::Put,
 
                                        KW_FUNC_FIRES => Method::Fires,
 
                                        KW_FUNC_CREATE => Method::Create,
 
                                        KW_FUNC_LENGTH => Method::Length,
 
                                        KW_FUNC_ASSERT => Method::Assert,
 
                                        KW_FUNC_PRINT => Method::Print,
 
                                        _ => unreachable!(),
 
                                    }
 
                                } else {
 
                                    Method::UserFunction
 
                                };
 

	
 
                                // 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,
 
                                    definition: target_definition_id,
 
                                    parent: ExpressionParent::None,
 
                                    unique_id_in_definition: -1,
 
                                }).upcast()
 
                            }
 
                        }
 
                    },
 
                    _ => {
 
                        return Err(ParseError::new_error_str_at_span(
 
                            &module.source, parser_type.full_span, "unexpected type in expression"
 
                        ))
 
                    }
 
                }
 
            } else {
 
                // Check for builtin keywords or builtin functions
 
                if ident_text == KW_LIT_NULL || ident_text == KW_LIT_TRUE || ident_text == KW_LIT_FALSE {
 
                    iter.consume();
 

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

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

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

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

	
 
        Ok(result)
 
    }
 

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

	
 
    #[inline]
 
    fn consume_generic_binary_expression<
 
        M: Fn(Option<TokenKind>) -> Option<BinaryOperator>,
 
        F: Fn(&mut PassDefinitions, &Module, &mut TokenIter, &mut PassCtx) -> Result<ExpressionId, ParseError>
 
    >(
 
        &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, match_fn: M, higher_precedence_fn: F
 
    ) -> Result<ExpressionId, ParseError> {
 
        let mut result = higher_precedence_fn(self, module, iter, ctx)?;
 
        while let Some(operation) = match_fn(iter.next()) {
 
            let 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,
 
                unique_id_in_definition: -1,
 
            }).upcast();
 
        }
 

	
 
        Ok(result)
 
    }
 

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

	
 
/// Consumes 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
 
) -> 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, 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_block: 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_definitions_types.rs
Show inline comments
 
use crate::protocol::parser::*;
 
use crate::protocol::parser::token_parsing::*;
 

	
 
#[derive(Debug)]
 
struct Entry {
 
    element: ParserTypeElement,
 
    depth: i32,
 
}
 

	
 
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 
enum DepthKind {
 
    Tuple, // because we had a `(` token
 
    PolyArgs, // because we had a `<` token
 
}
 

	
 
#[derive(Debug)]
 
struct DepthElement {
 
    kind: DepthKind,
 
    entry_index: u32, // in `entries` array of parser
 
    pos: InputPosition,
 
}
 

	
 
/// Current parsing state, for documentation's sake: types may be named, or may
 
/// be tuples. Named types may have polymorphic arguments (if the type
 
/// declaration allows) and a type may be turned into an array of that type by
 
/// postfixing a "[]".
 
#[derive(Debug)]
 
enum ParseState {
 
    TypeMaybePolyArgs,  // just parsed a type, might have poly arguments
 
    TypeNeverPolyArgs,  // just parsed a type that cannot have poly arguments
 
    PolyArgStart,       // just opened a polymorphic argument list
 
    TupleStart,         // just opened a tuple list
 
    ParsedComma,        // just had a comma
 
}
 

	
 
/// Parsers tokens into `ParserType` instances (yes, the name of the struct is
 
/// silly). Essentially a little state machine with its own temporary storage.
 
#[derive(Debug)]
 
pub(crate) struct ParserTypeParser {
 
    entries: Vec<Entry>,
 
    depths: Vec<DepthElement>,
 
    parse_state: ParseState,
 
    first_pos: InputPosition,
 
    last_pos: InputPosition,
 
}
 

	
 
impl ParserTypeParser {
 
    pub(crate) fn new() -> Self {
 
        return Self{
 
            entries: Vec::with_capacity(16),
 
            depths: Vec::with_capacity(16),
 
            parse_state: ParseState::TypeMaybePolyArgs,
 
            first_pos: InputPosition{ line: 0, offset: 0 },
 
            last_pos: InputPosition{ line: 0, offset: 0 }
 
        }
 
    }
 

	
 
    pub(crate) fn consume_parser_type(
 
        &mut self, iter: &mut TokenIter, heap: &Heap, source: &InputSource,
 
        symbols: &SymbolTable, poly_vars: &[Identifier],
 
        wrapping_definition: DefinitionId, cur_scope: SymbolScope,
 
        allow_inference: bool, inside_angular_bracket: Option<InputPosition>,
 
    ) -> Result<ParserType, ParseError> {
 
        // Prepare
 
        self.entries.clear();
 
        self.depths.clear();
 

	
 
        // Setup processing
 
        if let Some(bracket_pos) = inside_angular_bracket {
 
            self.push_depth(DepthKind::PolyArgs, u32::MAX, bracket_pos);
 
        }
 

	
 
        let initial_state = match iter.next() {
 
            Some(TokenKind::Ident) => {
 
                let element = Self::consume_parser_type_element(
 
                    iter, source, heap, symbols, wrapping_definition, poly_vars, cur_scope, allow_inference
 
                )?;
 
                self.first_pos = element.element_span.begin;
 
                self.last_pos = element.element_span.end;
 

	
 
                self.entries.push(Entry{
 
                    element,
 
                    depth: self.cur_depth(),
 
                });
 

	
 
                // Due to the nature of the subsequent type parsing algorithm,
 
                // we check the opening polymorphic argument list paren here.
 
                if let Some(TokenKind::OpenAngle) = iter.next() {
 
                    self.consume_open_angle(iter);
 
                    ParseState::PolyArgStart
 
                } else {
 
                    ParseState::TypeMaybePolyArgs
 
                }
 
            },
 
            Some(TokenKind::OpenParen) => {
 
                let tuple_start_pos = iter.next_start_position();
 
                self.first_pos = tuple_start_pos; // last pos will be set later, this is a tuple
 

	
 
                let tuple_entry_index = self.entries.len() as u32;
 
                let tuple_depth = self.cur_depth();
 
                self.push_depth(DepthKind::Tuple, tuple_entry_index, tuple_start_pos);
 
                self.entries.push(Entry{
 
                    element: ParserTypeElement{
 
                        element_span: InputSpan::from_positions(tuple_start_pos, tuple_start_pos),
 
                        variant: ParserTypeVariant::Tuple(0),
 
                    },
 
                    depth: tuple_depth,
 
                });
 
                iter.consume();
 

	
 
                ParseState::TupleStart
 
            },
 
            _ => return Err(ParseError::new_error_str_at_pos(source, iter.last_valid_pos(), "expected a type")),
 
        };
 

	
 
        self.parse_state = initial_state;
 

	
 
        // Depth stack and entries are initialized, continue until depth stack
 
        // is empty, or until an unexpected set of tokens is encountered
 
        while !self.depths.is_empty() {
 
            let next = iter.next();
 

	
 
            match self.parse_state {
 
                ParseState::TypeMaybePolyArgs => {
 
                    // Allowed tokens: , < > >> ) [
 
                    match next {
 
                        Some(TokenKind::Comma) => self.consume_comma(iter),
 
                        Some(TokenKind::OpenAngle) => self.consume_open_angle(iter),
 
                        Some(TokenKind::CloseAngle) => self.consume_close_angle(source, iter)?,
 
                        Some(TokenKind::ShiftRight) => self.consume_double_close_angle(source, iter)?,
 
                        Some(TokenKind::CloseParen) => self.consume_close_paren(source, iter)?,
 
                        Some(TokenKind::OpenSquare) => self.consume_square_parens(source, iter)?,
 
                        _ => return Err(ParseError::new_error_str_at_pos(
 
                            source, iter.last_valid_pos(),
 
                            "unexpected token: expected ',', '<', '>', '<<', ')' or '['"
 
                        )),
 
                    }
 
                },
 
                ParseState::TypeNeverPolyArgs => {
 
                    // Allowed tokens: , > >> ) [
 
                    match next {
 
                        Some(TokenKind::Comma) => self.consume_comma(iter),
 
                        Some(TokenKind::CloseAngle) => self.consume_close_angle(source, iter)?,
 
                        Some(TokenKind::ShiftRight) => self.consume_double_close_angle(source, iter)?,
 
                        Some(TokenKind::CloseParen) => self.consume_close_paren(source, iter)?,
 
                        Some(TokenKind::OpenSquare) => self.consume_square_parens(source, iter)?,
 
                        _ => return Err(ParseError::new_error_str_at_pos(
 
                            source, iter.last_valid_pos(),
 
                            "unexpected token: expected ',', '>', '>>', ')' or '['"
 
                        )),
 
                    }
 
                },
 
                ParseState::PolyArgStart => {
 
                    // Allowed tokens: ident (
 
                    match next {
 
                        Some(TokenKind::Ident) => self.consume_type_idents(
 
                            source, heap, symbols, wrapping_definition, poly_vars, cur_scope, allow_inference, iter
 
                        )?,
 
                        Some(TokenKind::OpenParen) => self.consume_open_paren(iter),
 
                        _ => return Err(ParseError::new_error_str_at_pos(
 
                            source, iter.last_valid_pos(),
 
                            "unexpected token: expected typename or '('"
 
                        )),
 
                    }
 
                },
 
                ParseState::TupleStart => {
 
                    // Allowed tokens: ident )
 
                    // Allowed tokens: ident ( )
 
                    // We'll strip the nested tuple later in this function
 
                    match next {
 
                        Some(TokenKind::Ident) => self.consume_type_idents(
 
                            source, heap, symbols, wrapping_definition, poly_vars, cur_scope, allow_inference, iter
 
                        )?,
 
                        Some(TokenKind::OpenParen) => self.consume_open_paren(iter),
 
                        Some(TokenKind::CloseParen) => self.consume_close_paren(source, iter)?,
 
                        _ => return Err(ParseError::new_error_str_at_pos(
 
                            source, iter.last_valid_pos(),
 
                            "unexpected token: expected typename or ')'"
 
                        )),
 
                    }
 
                },
 
                ParseState::ParsedComma => {
 
                    // Allowed tokens: ident ( > >> )
 
                    match next {
 
                        Some(TokenKind::Ident) => self.consume_type_idents(
 
                            source, heap, symbols, wrapping_definition, poly_vars, cur_scope, allow_inference, iter
 
                        )?,
 
                        Some(TokenKind::OpenParen) => self.consume_open_paren(iter),
 
                        Some(TokenKind::CloseAngle) => self.consume_close_angle(source, iter)?,
 
                        Some(TokenKind::ShiftRight) => self.consume_double_close_angle(source, iter)?,
 
                        Some(TokenKind::CloseParen) => self.consume_close_paren(source, iter)?,
 
                        _ => return Err(ParseError::new_error_str_at_pos(
 
                            source, iter.last_valid_pos(),
 
                            "unexpected token: expected typename, '(', '>', '>>' or ')'"
 
                        ))
 
                    }
 
                }
 
            }
 
        }
 

	
 
        // If here then we have found the correct number of closing braces.
 
        // However we might still have any number of array postfixed
 
        if inside_angular_bracket.is_none() {
 
            while Some(TokenKind::OpenSquare) == iter.next() {
 
                self.consume_square_parens(source, iter)?;
 
            }
 
        }
 

	
 
        // Type should be completed. But we still need to check the polymorphic
 
        // arguments and strip tuples with just one embedded type.
 
        let num_entries = self.entries.len();
 

	
 
        for el_index in 0..num_entries {
 
            let cur_element = &self.entries[el_index];
 

	
 
            // Peek ahead to see how many embedded types we have
 
            let mut encountered_embedded = 0;
 
            for peek_index in el_index + 1..num_entries {
 
                let peek_element = &self.entries[peek_index];
 
                if peek_element.depth == cur_element.depth + 1 {
 
                    encountered_embedded += 1;
 
                } else if peek_element.depth <= cur_element.depth {
 
                    break;
 
                }
 
            }
 

	
 
            // If we're dealing with a tuple then we don't need to determine if
 
            // the number of embedded types is correct, we simply need to set it
 
            // to whatever what was encountered.
 
            if let ParserTypeVariant::Tuple(_) = cur_element.element.variant {
 
                self.entries[el_index].element.variant = ParserTypeVariant::Tuple(encountered_embedded);
 
            } else {
 
                let expected_embedded = cur_element.element.variant.num_embedded() as u32;
 
                if expected_embedded != encountered_embedded {
 
                    if encountered_embedded == 0 {
 
                        // Every polymorphic argument should be inferred
 
                        if !allow_inference {
 
                            return Err(ParseError::new_error_str_at_span(
 
                                source, cur_element.element.element_span,
 
                                "type inference is not allowed here"
 
                            ));
 
                        }
 

	
 
                        // Insert missing types
 
                        let inserted_span = cur_element.element.element_span;
 
                        let inserted_depth = cur_element.depth + 1;
 
                        self.entries.reserve(expected_embedded as usize);
 
                        for _ in 0..expected_embedded {
 
                            self.entries.insert(el_index + 1, Entry {
 
                                element: ParserTypeElement {
 
                                    element_span: inserted_span,
 
                                    variant: ParserTypeVariant::Inferred,
 
                                },
 
                                depth: inserted_depth,
 
                            });
 
                        }
 
                    } else {
 
                        // Mismatch in number of embedded types
 
                        return Err(Self::construct_poly_arg_mismatch_error(
 
                            source, cur_element.element.element_span, allow_inference,
 
                            expected_embedded, encountered_embedded
 
                        ));
 
                    }
 
                }
 
            }
 
        }
 

	
 
        // Convert the results from parsing into the `ParserType`
 
        let mut elements = Vec::with_capacity(self.entries.len());
 
        debug_assert!(!self.entries.is_empty());
 

	
 
        for entry in self.entries.drain(..) {
 
            if ParserTypeVariant::Tuple(1) == entry.element.variant {
 
                // We strip these ones
 
            } else {
 
                elements.push(entry.element);
 
            }
 
        }
 

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

	
 
    // --- Parsing Utilities
 

	
 
    #[inline]
 
    fn consume_type_idents(
 
        &mut self, source: &InputSource, heap: &Heap, symbols: &SymbolTable,
 
        wrapping_definition: DefinitionId, poly_vars: &[Identifier],
 
        cur_scope: SymbolScope, allow_inference: bool, iter: &mut TokenIter
 
    ) -> Result<(), ParseError> {
 
        let element = Self::consume_parser_type_element(
 
            iter, source, heap, symbols, wrapping_definition, poly_vars, cur_scope, allow_inference
 
        )?;
 
        let depth = self.cur_depth();
 
        self.last_pos = element.element_span.end;
 
        self.entries.push(Entry{ element, depth });
 
        self.parse_state = ParseState::TypeMaybePolyArgs;
 

	
 
        return Ok(());
 
    }
 

	
 
    #[inline]
 
    fn consume_open_angle(&mut self, iter: &mut TokenIter) {
 
        // Note: open angular bracket is only consumed when we just parsed an
 
        //  ident-based type. So the last element of the `entries` array is the
 
        //  one that this angular bracket starts the polymorphic arguments for.
 
        let angle_start_pos = iter.next_start_position();
 
        let entry_index = (self.entries.len() - 1) as u32;
 
        self.push_depth(DepthKind::PolyArgs, entry_index, angle_start_pos);
 
        self.parse_state = ParseState::PolyArgStart;
 

	
 
        iter.consume();
 
    }
 

	
 
    #[inline]
 
    fn consume_close_angle(&mut self, source: &InputSource, iter: &mut TokenIter) -> Result<(), ParseError> {
 
        let (angle_start_pos, angle_end_pos) = iter.next_positions();
 
        self.last_pos = angle_end_pos;
 
        self.pop_depth(source, DepthKind::PolyArgs, angle_start_pos)?;
 
        self.parse_state = ParseState::TypeNeverPolyArgs;
 

	
 
        iter.consume();
 
        return Ok(())
 
    }
 

	
 
    #[inline]
 
    fn consume_double_close_angle(&mut self, source: &InputSource, iter: &mut TokenIter) -> Result<(), ParseError> {
 
        let (angle_start_pos, angle_end_pos) = iter.next_positions();
 
        self.last_pos = angle_end_pos;
 

	
 
        self.pop_depth(source, DepthKind::PolyArgs, angle_start_pos)?; // first '>' in '>>'.
 
        self.pop_depth(source, DepthKind::PolyArgs, angle_start_pos.with_offset(1))?; // second '>' in '>>'
 
        self.parse_state = ParseState::TypeNeverPolyArgs;
 

	
 
        iter.consume(); // consume once, '>>' is one token
 
        return Ok(())
 
    }
 

	
 
    #[inline]
 
    fn consume_open_paren(&mut self, iter: &mut TokenIter) {
 
        let paren_start_pos = iter.next_start_position();
 
        let cur_depth = self.cur_depth();
 
        let entry_index = self.entries.len() as u32;
 
        self.entries.push(Entry{
 
            element: ParserTypeElement {
 
                element_span: InputSpan::from_positions(paren_start_pos, paren_start_pos),
 
                variant: ParserTypeVariant::Tuple(0),
 
            },
 
            depth: cur_depth,
 
        });
 

	
 
        self.push_depth(DepthKind::Tuple, entry_index, paren_start_pos);
 
        self.parse_state = ParseState::TupleStart;
 

	
 
        iter.consume();
 
    }
 

	
 
    #[inline]
 
    fn consume_close_paren(&mut self, source: &InputSource, iter: &mut TokenIter) -> Result<(), ParseError> {
 
        let (paren_start_pos, paren_end_pos) = iter.next_positions();
 
        self.last_pos = paren_end_pos;
 
        let tuple_type_index = self.pop_depth(source, DepthKind::Tuple, paren_start_pos)?;
 
        self.entries[tuple_type_index as usize].element.element_span.end = paren_end_pos.with_offset(1);
 
        self.parse_state = ParseState::TypeNeverPolyArgs;
 

	
 
        iter.consume();
 
        return Ok(())
 
    }
 

	
 
    #[inline]
 
    fn consume_comma(&mut self, iter: &mut TokenIter) {
 
        iter.consume();
 
        self.parse_state = ParseState::ParsedComma;
 
    }
 

	
 
    #[inline]
 
    fn consume_square_parens(&mut self, source: &InputSource, iter: &mut TokenIter) -> Result<(), ParseError> {
 
        // Consume the opening square paren that forms the postfixed array type
 
        let array_start_pos = iter.next_start_position();
 
        iter.consume();
 
        if iter.next() != Some(TokenKind::CloseSquare) {
 
            return Err(ParseError::new_error_str_at_pos(
 
                source, iter.last_valid_pos(),
 
                "unexpected token: expected ']'"
 
            ));
 
        }
 

	
 
        let (_, array_end_pos) = iter.next_positions();
 
        let array_span = InputSpan::from_positions(array_start_pos, array_end_pos);
 
        self.last_pos = array_end_pos;
 
        iter.consume();
 

	
 
        // In the language we put the array specification after a type, in the
 
        // type tree we need to make the array type the parent, so:
 
        let insert_depth = self.cur_depth();
 
        let insert_at = self.entries.iter().rposition(|e| e.depth == insert_depth).unwrap();
 
        let num_embedded = self.entries[insert_at].element.variant.num_embedded();
 

	
 
        self.entries.insert(insert_at, Entry{
 
            element: ParserTypeElement{
 
                element_span: array_span,
 
                variant: ParserTypeVariant::Array,
 
            },
 
            depth: insert_depth
 
        });
 

	
 
        // Need to increment the depth of the child types
 
        self.entries[insert_at + 1].depth += 1; // element we applied the array type to
 
        if num_embedded != 0 {
 
            for index in insert_at + 2..self.entries.len() {
 
                let element = &mut self.entries[index];
 
                if element.depth >= insert_depth + 1 {
 
                    element.depth += 1;
 
                } else {
 
                    break;
 
                }
 
            }
 
        }
 

	
 
        return Ok(())
 
    }
 

	
 
    /// Consumes a namespaced identifier that should resolve to some kind of
 
    /// type. There may be commas or polymorphic arguments remaining after this
 
    /// function has finished.
 
    fn consume_parser_type_element(
 
        iter: &mut TokenIter, source: &InputSource, heap: &Heap, symbols: &SymbolTable,
 
        wrapping_definition: DefinitionId, poly_vars: &[Identifier],
 
        mut scope: SymbolScope, allow_inference: bool,
 
    ) -> Result<ParserTypeElement, ParseError> {
 
        use ParserTypeVariant as PTV;
 
        let (mut type_text, mut type_span) = consume_any_ident(source, iter)?;
 

	
 
        let variant = match type_text {
 
            KW_TYPE_MESSAGE => PTV::Message,
 
            KW_TYPE_BOOL => PTV::Bool,
 
            KW_TYPE_UINT8 => PTV::UInt8,
 
            KW_TYPE_UINT16 => PTV::UInt16,
 
            KW_TYPE_UINT32 => PTV::UInt32,
 
            KW_TYPE_UINT64 => PTV::UInt64,
 
            KW_TYPE_SINT8 => PTV::SInt8,
 
            KW_TYPE_SINT16 => PTV::SInt16,
 
            KW_TYPE_SINT32 => PTV::SInt32,
 
            KW_TYPE_SINT64 => PTV::SInt64,
 
            KW_TYPE_IN_PORT => PTV::Input,
 
            KW_TYPE_OUT_PORT => PTV::Output,
 
            KW_TYPE_CHAR => PTV::Character,
 
            KW_TYPE_STRING => PTV::String,
 
            KW_TYPE_INFERRED => {
 
                if !allow_inference {
 
                    return Err(ParseError::new_error_str_at_span(
 
                        source, type_span, "type inference is not allowed here"
 
                    ));
 
                }
 

	
 
                PTV::Inferred
 
            },
 
            _ => {
 
                // Must be some kind of symbolic type
 
                let mut type_kind = None;
 
                for (poly_idx, poly_var) in poly_vars.iter().enumerate() {
 
                    if poly_var.value.as_bytes() == type_text {
 
                        type_kind = Some(PTV::PolymorphicArgument(wrapping_definition, poly_idx as u32));
 
                    }
 
                }
 

	
 
                if type_kind.is_none() {
 
                    // Check symbol table for definition. To be fair, the language
 
                    // only allows a single namespace for now. That said:
 
                    let last_symbol = symbols.get_symbol_by_name(scope, type_text);
 
                    if last_symbol.is_none() {
 
                        return Err(ParseError::new_error_str_at_span(
 
                            source, type_span, "unknown type"
 
                        ));
 
                    }
 
                    let mut last_symbol = last_symbol.unwrap();
 

	
 
                    // Resolving scopes until we reach the intended type
 
                    loop {
 
                        match &last_symbol.variant {
 
                            SymbolVariant::Module(symbol_module) => {
 
                                // Expecting more identifiers
 
                                if Some(TokenKind::ColonColon) != iter.next() {
 
                                    return Err(ParseError::new_error_str_at_span(
 
                                        source, type_span, "expected a type but got a module"
 
                                    ));
 
                                }
 

	
 
                                consume_token(source, iter, TokenKind::ColonColon)?;
 

	
 
                                // Consume next part of type and prepare for next
 
                                // lookup loop
 
                                let (next_text, next_span) = consume_any_ident(source, iter)?;
 
                                let old_text = type_text;
 
                                type_text = next_text;
 
                                type_span.end = next_span.end;
 
                                scope = SymbolScope::Module(symbol_module.root_id);
 

	
 
                                let new_symbol = symbols.get_symbol_by_name_defined_in_scope(scope, type_text);
 
                                if new_symbol.is_none() {
 
                                    // If the type is imported in the module then notify the programmer
 
                                    // that imports do not leak outside of a module
 
                                    let type_name = String::from_utf8_lossy(type_text);
 
                                    let module_name = String::from_utf8_lossy(old_text);
 
                                    let suffix = if symbols.get_symbol_by_name(scope, type_text).is_some() {
 
                                        format!(
 
                                            ". The module '{}' does import '{}', but these imports are not visible to other modules",
 
                                            &module_name, &type_name
 
                                        )
 
                                    } else {
 
                                        String::new()
 
                                    };
 

	
 
                                    let message = format!("unknown type '{}' in module '{}'{}", type_name, module_name, suffix);
 
                                    return Err(ParseError::new_error_at_span(source, next_span, message));
 
                                }
 

	
 
                                last_symbol = new_symbol.unwrap();
 
                            },
 
                            SymbolVariant::Definition(symbol_definition) => {
 
                                let num_poly_vars = heap[symbol_definition.definition_id].poly_vars().len();
 
                                type_kind = Some(PTV::Definition(symbol_definition.definition_id, num_poly_vars as u32));
 
                                break;
 
                            }
 
                        }
 
                    }
 
                }
 

	
 
                debug_assert!(type_kind.is_some());
 
                type_kind.unwrap()
 
            },
 
        };
 

	
 
        Ok(ParserTypeElement{ element_span: type_span, variant })
 
    }
 

	
 
    // --- Parsing Depth Management
 

	
 
    #[inline]
 
    fn push_depth(&mut self, kind: DepthKind, entry_index: u32, pos: InputPosition) {
 
        self.depths.push(DepthElement{ kind, entry_index, pos });
 
    }
 

	
 
    #[inline]
 
    fn pop_depth(&mut self, source: &InputSource, kind: DepthKind, pos: InputPosition) -> Result<u32, ParseError> {
 
        if self.depths.is_empty() {
 
            // More closing parens than opening ones
 
            let message = match kind {
 
                DepthKind::Tuple => "unmatched ')'",
 
                DepthKind::PolyArgs => "unmatched '>'",
 
            };
 
            return Err(ParseError::new_error_str_at_pos(source, pos, message))
 
        }
 

	
 
        let last = self.depths.last().unwrap();
src/protocol/parser/pass_typing.rs
Show inline comments
 
@@ -960,997 +960,1008 @@ impl PassTyping {
 
                let concrete_type = ConcreteType{ parts: vec![first_concrete_part] };
 
                let reserved_idx = ctx.types.reserve_procedure_monomorph_index(definition_id, concrete_type);
 
                queue.push(ResolveQueueElement{
 
                    root_id,
 
                    definition_id: *definition_id,
 
                    reserved_monomorph_idx: reserved_idx,
 
                })
 
            }
 
        }
 
    }
 

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

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

	
 
        let proc_base = ctx.types.get_base_definition(&element.definition_id).unwrap();
 
        if proc_base.is_polymorph {
 
            let monomorph = ctx.types.get_monomorph(element.reserved_monomorph_idx);
 
            for poly_arg in monomorph.concrete_type.embedded_iter(0) {
 
                self.poly_vars.push(ConcreteType{ parts: Vec::from(poly_arg) });
 
            }
 
        }
 

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

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

	
 
impl Visitor for PassTyping {
 
    // Definitions
 

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

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

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

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

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

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

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

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

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

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

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

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

	
 
    // Statements
 

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

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

	
 
        Ok(())
 
    }
 

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

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

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        Ok(())
 
    }
 

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

	
 
        self.visit_block_stmt(ctx, body_id)
 
    }
 

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

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

	
 
        Ok(())
 
    }
 

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

	
 
        self.visit_expr(ctx, expr_id)
 
    }
 

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

	
 
        self.visit_call_expr(ctx, call_expr_id)
 
    }
 

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

	
 
        self.visit_expr(ctx, subexpr_id)
 
    }
 

	
 
    // Expressions
 

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

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

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

	
 
        self.progress_assignment_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_binding_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_conditional_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_binary_expr(ctx, id)
 
    }
 

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

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

	
 
        self.visit_expr(ctx, arg_expr_id)?;
 

	
 
        self.progress_unary_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_indexing_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_slicing_expr(ctx, id)
 
    }
 

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

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

	
 
        self.visit_expr(ctx, subject_expr_id)?;
 

	
 
        self.progress_select_expr(ctx, id)
 
    }
 

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

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

	
 
                self.insert_initial_struct_polymorph_data(ctx, id);
 

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

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

	
 
        self.progress_literal_expr(ctx, id)
 
    }
 

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

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

	
 
        self.visit_expr(ctx, subject_expr_id)?;
 

	
 
        self.progress_cast_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_call_expr(ctx, id)
 
    }
 

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

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

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

	
 
        self.progress_variable_expr(ctx, id)
 
    }
 
}
 

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

	
 
    fn resolve_types(&mut self, ctx: &mut Ctx, queue: &mut ResolveQueue) -> Result<(), ParseError> {
 
        // Keep inferring until we can no longer make any progress
 
        while !self.expr_queued.is_empty() {
 
            let next_expr_idx = self.expr_queued.pop_front().unwrap();
 
            self.progress_expr(ctx, next_expr_idx)?;
 
            // Make as much progress as possible without forced integer
 
            // inference.
 
            while !self.expr_queued.is_empty() {
 
                let next_expr_idx = self.expr_queued.pop_front().unwrap();
 
                self.progress_expr(ctx, next_expr_idx)?;
 
            }
 

	
 
            // Nothing is queued anymore. However we might have integer literals
 
            // whose type cannot be inferred. For convenience's sake we'll
 
            // infer these to be s32.
 
            for (infer_expr_idx, infer_expr) in self.expr_types.iter_mut().enumerate() {
 
                let expr_type = &mut infer_expr.expr_type;
 
                if !expr_type.is_done && expr_type.parts.len() == 1 && expr_type.parts[0] == InferenceTypePart::IntegerLike {
 
                    // Force integer type to s32
 
                    println!("DEBUG: Autoinferring (idx {}) {}", infer_expr.expr_id.index, String::from_utf8_lossy(ctx.module().source.section_at_span(ctx.heap[infer_expr.expr_id].full_span())));
 
                    expr_type.parts[0] = InferenceTypePart::SInt32;
 
                    expr_type.is_done = true;
 

	
 
                    // Requeue expression (and its parent, if it exists)
 
                    self.expr_queued.push_back(infer_expr_idx as i32);
 

	
 
                    if let Some(parent_expr) = ctx.heap[infer_expr.expr_id].parent_expr_id() {
 
                        let parent_idx = ctx.heap[parent_expr].get_unique_id_in_definition();
 
                        self.expr_queued.push_back(parent_idx);
 
                    }
 
                }
 
            }
 
        }
 

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

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

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

	
 
                poly_type.write_concrete_type(&mut concrete_type);
 
            }
 

	
 
            Ok(concrete_type)
 
        }
 

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

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

	
 
            // Extra data is attached, perform typechecking and transfer
 
            // resolved information to the expression
 
            let extra_data = &self.extra_data[infer_expr.extra_data_idx as usize];
 

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

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

	
 
                    match ctx.types.get_procedure_monomorph_index(&definition_id, &concrete_type.parts) {
 
                        Some(reserved_idx) => {
 
                            // Already typechecked, or already put into the resolve queue
 
                            infer_expr.field_or_monomorph_idx = reserved_idx;
 
                        },
 
                        None => {
 
                            // Not typechecked yet, so add an entry in the queue
 
                            let reserved_idx = ctx.types.reserve_procedure_monomorph_index(&definition_id, concrete_type);
 
                            infer_expr.field_or_monomorph_idx = reserved_idx;
 
                            queue.push(ResolveQueueElement{
 
                            queue.push(ResolveQueueElement {
 
                                root_id: ctx.heap[definition_id].defined_in(),
 
                                definition_id,
 
                                reserved_monomorph_idx: reserved_idx,
 
                            });
 
                        }
 
                    }
 
                },
 
                Expression::Literal(expr) => {
 
                    let definition_id = match &expr.value {
 
                        Literal::Enum(lit) => lit.definition,
 
                        Literal::Union(lit) => lit.definition,
 
                        Literal::Struct(lit) => lit.definition,
 
                        _ => unreachable!(),
 
                    };
 
                    let first_concrete_part = ConcreteTypePart::Instance(definition_id, extra_data.poly_vars.len() as u32);
 
                    let concrete_type = inference_type_to_concrete_type(
 
                        ctx, extra_data.expr_id, &extra_data.poly_vars, first_concrete_part
 
                    )?;
 
                    let mono_index = ctx.types.add_data_monomorph(ctx.modules, ctx.heap, ctx.arch, definition_id, concrete_type)?;
 
                    infer_expr.field_or_monomorph_idx = mono_index;
 
                },
 
                Expression::Select(_) => {
 
                    debug_assert!(infer_expr.field_or_monomorph_idx >= 0);
 
                },
 
                _ => {
 
                    unreachable!("handling extra data for expression {:?}", &ctx.heap[extra_data.expr_id]);
 
                }
 
            }
 
        }
 

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

	
 
        // Every expression checked, and new monomorphs are queued. Transfer the
 
        // expression information to the type table.
 
        let procedure_arguments = match &self.definition_type {
 
            DefinitionType::Component(id) => {
 
                let definition = &ctx.heap[*id];
 
                &definition.parameters
 
            },
 
            DefinitionType::Function(id) => {
 
                let definition = &ctx.heap[*id];
 
                &definition.parameters
 
            },
 
        };
 

	
 
        let target = ctx.types.get_procedure_monomorph_mut(self.reserved_idx);
 
        debug_assert!(target.arg_types.is_empty()); // makes sure we never queue a procedure's type inferencing twice
 
        debug_assert!(target.expr_data.is_empty());
 

	
 
        // - Write the arguments to the procedure
 
        target.arg_types.reserve(procedure_arguments.len());
 
        for argument_id in procedure_arguments {
 
            let mut concrete = ConcreteType::default();
 
            let argument_type = self.var_types.get(argument_id).unwrap();
 
            argument_type.var_type.write_concrete_type(&mut concrete);
 
            target.arg_types.push(concrete);
 
        }
 

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

	
 
        Ok(())
 
    }
 

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

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

	
 
        let upcast_id = id.upcast();
 

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

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

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

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

	
 
        let (progress_arg1, progress_arg2) = self.apply_equal2_constraint(
 
            ctx, upcast_id, arg1_expr_id, 0, arg2_expr_id, 0
 
        )?;
 

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

	
 

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

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

	
 
        let (progress_expr, progress_arg1, progress_arg2) = match expr.operation {
 
            BO::Concatenate => {
 
                // Two cases: if one of the arguments or the output type is a
 
                // string, then all must be strings. Otherwise the arguments
 
                // must be arraylike and the output will be a array.
 
                let (expr_is_str, expr_is_not_str) = self.type_is_certainly_or_certainly_not_string(ctx, upcast_id);
 
                let (arg1_is_str, arg1_is_not_str) = self.type_is_certainly_or_certainly_not_string(ctx, arg1_id);
 
                let (arg2_is_str, arg2_is_not_str) = self.type_is_certainly_or_certainly_not_string(ctx, arg2_id);
 

	
 
                let someone_is_str = expr_is_str || arg1_is_str || arg2_is_str;
 
                let someone_is_not_str = expr_is_not_str || arg1_is_not_str || arg2_is_not_str;
 

	
 
                // Note: this statement is an expression returning the progression bools
 
                if someone_is_str {
 
                    // One of the arguments is a string, then all must be strings
 
                    self.apply_equal3_constraint(ctx, upcast_id, arg1_id, arg2_id, 0)?
 
                } else {
 
                    let progress_expr = if someone_is_not_str {
 
                        // Output must be a normal array
 
                        self.apply_template_constraint(ctx, upcast_id, &ARRAY_TEMPLATE)?
 
                    } else {
 
                        // Output may still be anything
 
                        self.apply_template_constraint(ctx, upcast_id, &ARRAYLIKE_TEMPLATE)?
 
                    };
 

	
 
                    let progress_arg1 = self.apply_template_constraint(ctx, arg1_id, &ARRAYLIKE_TEMPLATE)?;
 
                    let progress_arg2 = self.apply_template_constraint(ctx, arg2_id, &ARRAYLIKE_TEMPLATE)?;
 

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

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

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

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

	
 
        Ok(())
 
@@ -2080,1363 +2091,1406 @@ impl PassTyping {
 
                        if field_def.identifier == select_expr.field_name {
 
                            // Set field definition and index
 
                            let infer_expr = &mut self.expr_types[expr_idx as usize];
 
                            infer_expr.field_or_monomorph_idx = field_def_idx as i32;
 
                            struct_def_id = Some(type_def.ast_definition);
 
                            break;
 
                        }
 
                    }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
                    progress_expr = progress_expr || inner_expr_progress;
 

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

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

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

	
 
                // Initial tuple constraint
 
                let num_members = expr_elements.len();
 
                let mut initial_type = Vec::with_capacity(num_members + 1); // TODO: @performance
 
                initial_type.push(InferenceTypePart::Tuple(num_members as u32));
 
                for _ in 0..num_members {
 
                    initial_type.push(InferenceTypePart::Unknown);
 
                }
 
                let mut progress_expr = self.apply_template_constraint(ctx, upcast_id, &initial_type)?;
 

	
 
                // The elements of the tuple can have any type, but they must
 
                // end up as arguments to the output tuple type.
 
                debug_log!(" * During (checking expressions constituting tuple):");
 
                for (member_expr_index, member_expr_id) in expr_elements.iter().enumerate() {
 
                    // For the current expression index, (re)compute the
 
                    // position in the tuple type where the types should match.
 
                    let mut start_index = 1; // first element is Tuple type, second is the first child
 
                    for _ in 0..member_expr_index {
 
                        let tuple_expr_index = ctx.heap[id].unique_id_in_definition;
 
                        let tuple_type = &self.expr_types[tuple_expr_index as usize].expr_type;
 
                        start_index = InferenceType::find_subtree_end_idx(&tuple_type.parts, start_index);
 
                        debug_assert_ne!(start_index, tuple_type.parts.len()); // would imply less tuple type children than member expressions
 
                    }
 

	
 
                    // Apply the constraint
 
                    let (member_progress_expr, member_progress) = self.apply_equal2_constraint(
 
                        ctx, upcast_id, upcast_id, start_index, *member_expr_id, 0
 
                    )?;
 
                    debug_log!("   - Member {} type | {}", member_expr_index, self.debug_get_display_name(ctx, *member_expr_id));
 
                    progress_expr = progress_expr || member_progress_expr;
 

	
 
                    if member_progress {
 
                        self.queue_expr(ctx, *member_expr_id);
 
                    }
 
                }
 

	
 
                progress_expr
 
            }
 
        };
 

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

	
 
            debug_log!(
 
                "   - Arg {} type | sig: {}, arg: {}", call_arg_idx,
 
                unsafe{&*signature_type}.display_name(&ctx.heap), 
 
                unsafe{&*argument_type}.display_name(&ctx.heap));
 

	
 
            if progress_arg {
 
                // Progressed argument expression
 
                self.expr_queued.push_back(arg_expr_idx);
 
            }
 
        }
 

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

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

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

	
 
        // If we did not have an error in the polymorph inference above, then
 
        // reapplying the polymorph type to each argument type and the return
 
        // type should always succeed.
 
        debug_log!(" * During (reinferring from progressed polyvars):");
 
        for (_poly_idx, _poly_var) in extra.poly_vars.iter().enumerate() {
 
            debug_log!("   - Poly {} | sig: {}", _poly_idx, _poly_var.display_name(&ctx.heap));
 
        }
 
        // TODO: @performance If the algorithm is changed to be more "on demand
 
        //  argument re-evaluation", instead of "all-argument re-evaluation",
 
        //  then this is no longer true
 
        for arg_idx in 0..extra.embedded.len() {
 
            let signature_type: *mut _ = &mut extra.embedded[arg_idx];
 
            let arg_expr_id = expr.arguments[arg_idx];
 
            let arg_expr_idx = ctx.heap[arg_expr_id].get_unique_id_in_definition();
 
            let arg_type: *mut _ = &mut self.expr_types[arg_expr_idx as usize].expr_type;
 
            
 
            let progress_arg = Self::apply_equal2_polyvar_constraint(
 
                extra, &poly_progress,
 
                signature_type, arg_type
 
            );
 
            
 
            debug_log!(
 
                "   - Arg {} type | sig: {}, arg: {}", arg_idx, 
 
                unsafe{&*signature_type}.display_name(&ctx.heap), 
 
                unsafe{&*arg_type}.display_name(&ctx.heap)
 
            );
 
            if progress_arg {
 
                self.expr_queued.push_back(arg_expr_idx);
 
            }
 
        }
 

	
 
        // Once more for the return type
 
        let signature_type: *mut _ = &mut extra.returned;
 
        let ret_type: *mut _ = &mut self.expr_types[expr_idx as usize].expr_type;
 

	
 
        let progress_ret = Self::apply_equal2_polyvar_constraint(
 
            extra, &poly_progress, signature_type, ret_type
 
        );
 
        debug_log!(
 
            "   - Ret type | sig: {}, arg: {}", 
 
            unsafe{&*signature_type}.display_name(&ctx.heap), 
 
            unsafe{&*ret_type}.display_name(&ctx.heap)
 
        );
 
        if progress_ret {
 
            self.queue_expr_parent(ctx, upcast_id);
 
        }
 

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

	
 
        Ok(())
 
    }
 

	
 
    fn progress_variable_expr(&mut self, ctx: &mut Ctx, id: VariableExpressionId) -> Result<(), ParseError> {
 
        let upcast_id = id.upcast();
 
        let var_expr = &ctx.heap[id];
 
        let var_expr_idx = var_expr.unique_id_in_definition;
 
        let var_id = var_expr.declaration.unwrap();
 

	
 
        debug_log!("Variable expr '{}': {}", ctx.heap[var_id].identifier.value.as_str(), upcast_id.index);
 
        debug_log!(" * Before:");
 
        debug_log!("   - Var  type: {}", self.var_types.get(&var_id).unwrap().var_type.display_name(&ctx.heap));
 
        debug_log!("   - Expr type: {}", self.debug_get_display_name(ctx, upcast_id));
 

	
 
        // Retrieve shared variable type and expression type and apply inference
 
        let var_data = self.var_types.get_mut(&var_id).unwrap();
 
        let expr_type = &mut self.expr_types[var_expr_idx as usize].expr_type;
 

	
 
        let infer_res = unsafe{ InferenceType::infer_subtrees_for_both_types(
 
            &mut var_data.var_type as *mut _, 0, expr_type, 0
 
        ) };
 
        if infer_res == DualInferenceResult::Incompatible {
 
            let var_decl = &ctx.heap[var_id];
 
            return Err(ParseError::new_error_at_span(
 
                &ctx.module().source, var_decl.identifier.span, format!(
 
                    "Conflicting types for this variable, previously assigned the type '{}'",
 
                    var_data.var_type.display_name(&ctx.heap)
 
                )
 
            ).with_info_at_span(
 
                &ctx.module().source, var_expr.identifier.span, format!(
 
                    "But inferred to have incompatible type '{}' here",
 
                    expr_type.display_name(&ctx.heap)
 
                )
 
            ))
 
        }
 

	
 
        let progress_var = infer_res.modified_lhs();
 
        let progress_expr = infer_res.modified_rhs();
 

	
 
        if progress_var {
 
            // Let other variable expressions using this type progress as well
 
            for other_expr in var_data.used_at.iter() {
 
                if *other_expr != upcast_id {
 
                    let other_expr_idx = ctx.heap[*other_expr].get_unique_id_in_definition();
 
                    self.expr_queued.push_back(other_expr_idx);
 
                }
 
            }
 

	
 
            // Let a linked port know that our type has updated
 
            if let Some(linked_id) = var_data.linked_var {
 
                // Only perform one-way inference to prevent updating our type,
 
                // this would lead to an inconsistency in the type inference
 
                // algorithm otherwise.
 
                let var_type: *mut _ = &mut var_data.var_type;
 
                let link_data = self.var_types.get_mut(&linked_id).unwrap();
 

	
 
                debug_assert!(
 
                    unsafe{&*var_type}.parts[0] == InferenceTypePart::Input ||
 
                    unsafe{&*var_type}.parts[0] == InferenceTypePart::Output
 
                );
 
                debug_assert!(
 
                    link_data.var_type.parts[0] == InferenceTypePart::Input ||
 
                    link_data.var_type.parts[0] == InferenceTypePart::Output
 
                );
 
                match InferenceType::infer_subtree_for_single_type(&mut link_data.var_type, 1, &unsafe{&*var_type}.parts, 1, false) {
 
                    SingleInferenceResult::Modified => {
 
                        for other_expr in &link_data.used_at {
 
                            let other_expr_idx = ctx.heap[*other_expr].get_unique_id_in_definition();
 
                            self.expr_queued.push_back(other_expr_idx);
 
                        }
 
                    },
 
                    SingleInferenceResult::Unmodified => {},
 
                    SingleInferenceResult::Incompatible => {
 
                        let var_data = self.var_types.get(&var_id).unwrap();
 
                        let link_data = self.var_types.get(&linked_id).unwrap();
 
                        let var_decl = &ctx.heap[var_id];
 
                        let link_decl = &ctx.heap[linked_id];
 

	
 
                        return Err(ParseError::new_error_at_span(
 
                            &ctx.module().source, var_decl.identifier.span, format!(
 
                                "Conflicting types for this variable, assigned the type '{}'",
 
                                var_data.var_type.display_name(&ctx.heap)
 
                            )
 
                        ).with_info_at_span(
 
                            &ctx.module().source, link_decl.identifier.span, format!(
 
                                "Because it is incompatible with this variable, assigned the type '{}'",
 
                                link_data.var_type.display_name(&ctx.heap)
 
                            )
 
                        ));
 
                    }
 
                }
 
            }
 
        }
 
        if progress_expr { self.queue_expr_parent(ctx, upcast_id); }
 

	
 
        debug_log!(" * After:");
 
        debug_log!("   - Var  type [{}]: {}", progress_var, self.var_types.get(&var_id).unwrap().var_type.display_name(&ctx.heap));
 
        debug_log!("   - Expr type [{}]: {}", progress_expr, self.debug_get_display_name(ctx, upcast_id));
 

	
 

	
 
        Ok(())
 
    }
 

	
 
    fn queue_expr_parent(&mut self, ctx: &Ctx, expr_id: ExpressionId) {
 
        if let ExpressionParent::Expression(parent_expr_id, _) = &ctx.heap[expr_id].parent() {
 
            let expr_idx = ctx.heap[*parent_expr_id].get_unique_id_in_definition();
 
            self.expr_queued.push_back(expr_idx);
 
        }
 
    }
 

	
 
    fn queue_expr(&mut self, ctx: &Ctx, expr_id: ExpressionId) {
 
        let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition();
 
        self.expr_queued.push_back(expr_idx);
 
    }
 

	
 

	
 
    // first returned is certainly string, second is certainly not
 
    fn type_is_certainly_or_certainly_not_string(&self, ctx: &Ctx, expr_id: ExpressionId) -> (bool, bool) {
 
        let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition();
 
        let expr_type = &self.expr_types[expr_idx as usize].expr_type;
 
        if expr_type.is_done {
 
            if expr_type.parts[0] == InferenceTypePart::String {
 
                return (true, false);
 
            } else {
 
                return (false, true);
 
            }
 
        }
 

	
 
        (false, false)
 
    }
 

	
 
    /// Applies a template type constraint: the type associated with the
 
    /// supplied expression will be molded into the provided `template`. But
 
    /// will be considered valid if the template could've been molded into the
 
    /// expression type as well. Hence the template may be fully specified (e.g.
 
    /// a bool) or contain "inference" variables (e.g. an array of T)
 
    fn apply_template_constraint(
 
        &mut self, ctx: &Ctx, expr_id: ExpressionId, template: &[InferenceTypePart]
 
    ) -> Result<bool, ParseError> {
 
        let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition(); // TODO: @Temp
 
        let expr_type = &mut self.expr_types[expr_idx as usize].expr_type;
 
        match InferenceType::infer_subtree_for_single_type(expr_type, 0, template, 0, false) {
 
            SingleInferenceResult::Modified => Ok(true),
 
            SingleInferenceResult::Unmodified => Ok(false),
 
            SingleInferenceResult::Incompatible => Err(
 
                self.construct_template_type_error(ctx, expr_id, template)
 
            )
 
        }
 
    }
 

	
 
    fn apply_template_constraint_to_types(
 
        to_infer: *mut InferenceType, to_infer_start_idx: usize,
 
        template: &[InferenceTypePart], template_start_idx: usize
 
    ) -> Result<bool, ()> {
 
        match InferenceType::infer_subtree_for_single_type(
 
            unsafe{ &mut *to_infer }, to_infer_start_idx,
 
            template, template_start_idx, false
 
        ) {
 
            SingleInferenceResult::Modified => Ok(true),
 
            SingleInferenceResult::Unmodified => Ok(false),
 
            SingleInferenceResult::Incompatible => Err(()),
 
        }
 
    }
 

	
 
    /// Applies a forced constraint: the supplied expression's type MUST be
 
    /// inferred from the template, the other way around is considered invalid.
 
    fn apply_forced_constraint(
 
        &mut self, ctx: &Ctx, expr_id: ExpressionId, template: &[InferenceTypePart]
 
    ) -> Result<bool, ParseError> {
 
        let expr_idx = ctx.heap[expr_id].get_unique_id_in_definition();
 
        let expr_type = &mut self.expr_types[expr_idx as usize].expr_type;
 
        match InferenceType::infer_subtree_for_single_type(expr_type, 0, template, 0, true) {
 
            SingleInferenceResult::Modified => Ok(true),
 
            SingleInferenceResult::Unmodified => Ok(false),
 
            SingleInferenceResult::Incompatible => Err(
 
                self.construct_template_type_error(ctx, expr_id, template)
 
            )
 
        }
 
    }
 

	
 
    /// Applies a type constraint that expects the two provided types to be
 
    /// equal. We attempt to make progress in inferring the types. If the call
 
    /// is successful then the composition of all types are made equal.
 
    /// The "parent" `expr_id` is provided to construct errors.
 
    fn apply_equal2_constraint(
 
        &mut self, ctx: &Ctx, expr_id: ExpressionId,
 
        arg1_id: ExpressionId, arg1_start_idx: usize,
 
        arg2_id: ExpressionId, arg2_start_idx: usize
 
    ) -> Result<(bool, bool), ParseError> {
 
        let arg1_expr_idx = ctx.heap[arg1_id].get_unique_id_in_definition(); // TODO: @Temp
 
        let arg2_expr_idx = ctx.heap[arg2_id].get_unique_id_in_definition();
 
        let arg1_type: *mut _ = &mut self.expr_types[arg1_expr_idx as usize].expr_type;
 
        let arg2_type: *mut _ = &mut self.expr_types[arg2_expr_idx as usize].expr_type;
 

	
 
        let infer_res = unsafe{ InferenceType::infer_subtrees_for_both_types(
 
            arg1_type, arg1_start_idx,
 
            arg2_type, arg2_start_idx
 
        ) };
 
        if infer_res == DualInferenceResult::Incompatible {
 
            return Err(self.construct_arg_type_error(ctx, expr_id, arg1_id, arg2_id));
 
        }
 

	
 
        Ok((infer_res.modified_lhs(), infer_res.modified_rhs()))
 
    }
 

	
 
    /// Applies an equal2 constraint between a signature type (e.g. a function
 
    /// argument or struct field) and an expression whose type should match that
 
    /// expression. If we make progress on the signature, then we try to see if
 
    /// any of the embedded polymorphic types can be progressed.
 
    ///
 
    /// `outer_expr_id` is the main expression we're progressing (e.g. a 
 
    /// function call), while `expr_id` is the embedded expression we're 
 
    /// matching against the signature. `expression_type` and 
 
    /// `expression_start_idx` belong to `expr_id`.
 
    fn apply_equal2_signature_constraint(
 
        ctx: &Ctx, outer_expr_id: ExpressionId, expr_id: Option<ExpressionId>,
 
        polymorph_data: &mut ExtraData, polymorph_progress: &mut HashSet<u32>,
 
        signature_type: *mut InferenceType, signature_start_idx: usize,
 
        expression_type: *mut InferenceType, expression_start_idx: usize
 
    ) -> Result<(bool, bool), ParseError> {
 
        // Safety: all pointers distinct
 

	
 
        // Infer the signature and expression type
 
        let infer_res = unsafe { 
 
            InferenceType::infer_subtrees_for_both_types(
 
                signature_type, signature_start_idx,
 
                expression_type, expression_start_idx
 
            ) 
 
        };
 

	
 
        if infer_res == DualInferenceResult::Incompatible {
 
            // TODO: Check if I still need to use this
 
            let outer_span = ctx.heap[outer_expr_id].full_span();
 
            let (span_name, span) = match expr_id {
 
                Some(expr_id) => ("argument's", ctx.heap[expr_id].full_span()),
 
                None => ("type's", outer_span)
 
            };
 
            let (signature_display_type, expression_display_type) = unsafe { (
 
                (&*signature_type).display_name(&ctx.heap),
 
                (&*expression_type).display_name(&ctx.heap)
 
            ) };
 

	
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, outer_span,
 
                "failed to fully resolve the types of this expression"
 
            ).with_info_at_span(
 
                &ctx.module().source, span, format!(
 
                    "because the {} signature has been resolved to '{}', but the expression has been resolved to '{}'",
 
                    span_name, signature_display_type, expression_display_type
 
                )
 
            ));
 
        }
 

	
 
        // Try to see if we can progress any of the polymorphic variables
 
        let progress_sig = infer_res.modified_lhs();
 
        let progress_expr = infer_res.modified_rhs();
 

	
 
        if progress_sig {
 
            let signature_type = unsafe{&mut *signature_type};
 
            debug_assert!(
 
                signature_type.has_marker,
 
                "made progress on signature type, but it doesn't have a marker"
 
            );
 
            for (poly_idx, poly_section) in signature_type.marker_iter() {
 
                let polymorph_type = &mut polymorph_data.poly_vars[poly_idx as usize];
 
                match Self::apply_template_constraint_to_types(
 
                    polymorph_type, 0, poly_section, 0
 
                ) {
 
                    Ok(true) => { polymorph_progress.insert(poly_idx); },
 
                    Ok(false) => {},
 
                    Err(()) => { return Err(Self::construct_poly_arg_error(ctx, polymorph_data, outer_expr_id))}
 
                }
 
            }
 
        }
 
        Ok((progress_sig, progress_expr))
 
    }
 

	
 
    /// Applies equal2 constraints on the signature type for each of the 
 
    /// polymorphic variables. If the signature type is progressed then we 
 
    /// progress the expression type as well.
 
    ///
 
    /// This function assumes that the polymorphic variables have already been
 
    /// progressed as far as possible by calling 
 
    /// `apply_equal2_signature_constraint`. As such, we expect to not encounter
 
    /// any errors.
 
    ///
 
    /// This function returns true if the expression's type has been progressed
 
    fn apply_equal2_polyvar_constraint(
 
        polymorph_data: &ExtraData, _polymorph_progress: &HashSet<u32>,
 
        signature_type: *mut InferenceType, expr_type: *mut InferenceType
 
    ) -> bool {
 
        // Safety: all pointers should be distinct
 
        //         polymorph_data containers may not be modified
 
        let signature_type = unsafe{&mut *signature_type};
 
        let expr_type = unsafe{&mut *expr_type};
 

	
 
        // Iterate through markers in signature type to try and make progress
 
        // on the polymorphic variable        
 
        let mut seek_idx = 0;
 
        let mut modified_sig = false;
 
        
 
        while let Some((poly_idx, start_idx)) = signature_type.find_marker(seek_idx) {
 
            let end_idx = InferenceType::find_subtree_end_idx(&signature_type.parts, start_idx);
 
            // if polymorph_progress.contains(&poly_idx) {
 
                // Need to match subtrees
 
                let polymorph_type = &polymorph_data.poly_vars[poly_idx as usize];
 
                let modified_at_marker = Self::apply_template_constraint_to_types(
 
                    signature_type, start_idx, 
 
                    &polymorph_type.parts, 0
 
                ).expect("no failure when applying polyvar constraints");
 

	
 
                modified_sig = modified_sig || modified_at_marker;
 
            // }
 

	
 
            seek_idx = end_idx;
 
        }
 

	
 
        // If we made any progress on the signature's type, then we also need to
 
        // apply it to the expression that is supposed to match the signature.
 
        if modified_sig {
 
            match InferenceType::infer_subtree_for_single_type(
 
                expr_type, 0, &signature_type.parts, 0, true
 
            ) {
 
                SingleInferenceResult::Modified => true,
 
                SingleInferenceResult::Unmodified => false,
 
                SingleInferenceResult::Incompatible =>
 
                    unreachable!("encountered failure while reapplying modified signature to expression after polyvar inference")
 
            }
 
        } else {
 
            false
 
        }
 
    }
 

	
 
    /// Applies a type constraint that expects all three provided types to be
 
    /// equal. In case we can make progress in inferring the types then we
 
    /// attempt to do so. If the call is successful then the composition of all
 
    /// types is made equal.
 
    fn apply_equal3_constraint(
 
        &mut self, ctx: &Ctx, expr_id: ExpressionId,
 
        arg1_id: ExpressionId, arg2_id: ExpressionId,
 
        start_idx: usize
 
    ) -> Result<(bool, bool, bool), ParseError> {
 
        // Safety: all points are unique
 
        //         containers may not be modified
 
        let expr_expr_idx = ctx.heap[expr_id].get_unique_id_in_definition(); // TODO: @Temp
 
        let arg1_expr_idx = ctx.heap[arg1_id].get_unique_id_in_definition();
 
        let arg2_expr_idx = ctx.heap[arg2_id].get_unique_id_in_definition();
 

	
 
        let expr_type: *mut _ = &mut self.expr_types[expr_expr_idx as usize].expr_type;
 
        let arg1_type: *mut _ = &mut self.expr_types[arg1_expr_idx as usize].expr_type;
 
        let arg2_type: *mut _ = &mut self.expr_types[arg2_expr_idx as usize].expr_type;
 

	
 
        let expr_res = unsafe{
 
            InferenceType::infer_subtrees_for_both_types(expr_type, start_idx, arg1_type, start_idx)
 
        };
 
        if expr_res == DualInferenceResult::Incompatible {
 
            return Err(self.construct_expr_type_error(ctx, expr_id, arg1_id));
 
        }
 

	
 
        let args_res = unsafe{
 
            InferenceType::infer_subtrees_for_both_types(arg1_type, start_idx, arg2_type, start_idx) };
 
        if args_res == DualInferenceResult::Incompatible {
 
            return Err(self.construct_arg_type_error(ctx, expr_id, arg1_id, arg2_id));
 
        }
 

	
 
        // If all types are compatible, but the second call caused the arg1_type
 
        // to be expanded, then we must also assign this to expr_type.
 
        let mut progress_expr = expr_res.modified_lhs();
 
        let mut progress_arg1 = expr_res.modified_rhs();
 
        let progress_arg2 = args_res.modified_rhs();
 

	
 
        if args_res.modified_lhs() { 
 
            unsafe {
 
                let end_idx = InferenceType::find_subtree_end_idx(&(*arg2_type).parts, start_idx);
 
                let subtree = &((*arg2_type).parts[start_idx..end_idx]);
 
                (*expr_type).replace_subtree(start_idx, subtree);
 
            }
 
            progress_expr = true;
 
            progress_arg1 = true;
 
        }
 

	
 
        Ok((progress_expr, progress_arg1, progress_arg2))
 
    }
 

	
 
    // TODO: @optimize Since we only deal with a single type this might be done
 
    //  a lot more efficiently, methinks (disregarding the allocations here)
 
    fn apply_equal_n_constraint(
 
        &mut self, ctx: &Ctx, expr_id: ExpressionId, args: &[ExpressionId],
 
    ) -> Result<Vec<bool>, ParseError> {
 
        // Early exit
 
        match args.len() {
 
            0 => return Ok(vec!()),         // nothing to progress
 
            1 => return Ok(vec![false]),    // only one type, so nothing to infer
 
            _ => {}
 
        }
 

	
 
        let mut progress = Vec::new();
 
        let mut progress = Vec::new(); // TODO: @Performance
 
        progress.resize(args.len(), false);
 

	
 
        // Do pairwise inference, keep track of the last entry we made progress
 
        // on. Once done we need to update everything to the most-inferred type.
 
        let mut arg_iter = args.iter();
 
        let mut last_arg_id = *arg_iter.next().unwrap();
 
        let mut last_lhs_progressed = 0;
 
        let mut lhs_arg_idx = 0;
 

	
 
        while let Some(next_arg_id) = arg_iter.next() {
 
            let last_expr_idx = ctx.heap[last_arg_id].get_unique_id_in_definition(); // TODO: @Temp
 
            let next_expr_idx = ctx.heap[*next_arg_id].get_unique_id_in_definition();
 
            let last_type: *mut _ = &mut self.expr_types[last_expr_idx as usize].expr_type;
 
            let next_type: *mut _ = &mut self.expr_types[next_expr_idx as usize].expr_type;
 

	
 
            let res = unsafe {
 
                InferenceType::infer_subtrees_for_both_types(last_type, 0, next_type, 0)
 
            };
 

	
 
            if res == DualInferenceResult::Incompatible {
 
                return Err(self.construct_arg_type_error(ctx, expr_id, last_arg_id, *next_arg_id));
 
            }
 

	
 
            if res.modified_lhs() {
 
                // We re-inferred something on the left hand side, so everything
 
                // up until now should be re-inferred.
 
                progress[lhs_arg_idx] = true;
 
                last_lhs_progressed = lhs_arg_idx;
 
            }
 
            progress[lhs_arg_idx + 1] = res.modified_rhs();
 

	
 
            last_arg_id = *next_arg_id;
 
            lhs_arg_idx += 1;
 
        }
 

	
 
        // Re-infer everything. Note that we do not need to re-infer the type
 
        // exactly at `last_lhs_progressed`, but only everything up to it.
 
        let last_arg_expr_idx = ctx.heap[*args.last().unwrap()].get_unique_id_in_definition();
 
        let last_type: *mut _ = &mut self.expr_types[last_arg_expr_idx as usize].expr_type;
 
        for arg_idx in 0..last_lhs_progressed {
 
            let other_arg_expr_idx = ctx.heap[args[arg_idx]].get_unique_id_in_definition();
 
            let arg_type: *mut _ = &mut self.expr_types[other_arg_expr_idx as usize].expr_type;
 
            unsafe{
 
                (*arg_type).replace_subtree(0, &(*last_type).parts);
 
            }
 
            progress[arg_idx] = true;
 
        }
 

	
 
        Ok(progress)
 
    }
 

	
 
    /// Determines the `InferenceType` for the expression based on the
 
    /// expression parent. Note that if the parent is another expression, we do
 
    /// not take special action, instead we let parent expressions fix the type
 
    /// of subexpressions before they have a chance to call this function.
 
    fn insert_initial_expr_inference_type(
 
        &mut self, ctx: &mut Ctx, expr_id: ExpressionId
 
    ) -> Result<(), ParseError> {
 
        use ExpressionParent as EP;
 
        use InferenceTypePart as ITP;
 

	
 
        let expr = &ctx.heap[expr_id];
 
        let inference_type = match expr.parent() {
 
            EP::None =>
 
                // Should have been set by linker
 
                unreachable!(),
 
            EP::ExpressionStmt(_) =>
 
                // Determined during type inference
 
                InferenceType::new(false, false, vec![ITP::Unknown]),
 
            EP::Expression(parent_id, idx_in_parent) => {
 
                // If we are the test expression of a conditional expression,
 
                // then we must resolve to a boolean
 
                let is_conditional = if let Expression::Conditional(_) = &ctx.heap[*parent_id] {
 
                    true
 
                } else {
 
                    false
 
                };
 

	
 
                if is_conditional && *idx_in_parent == 0 {
 
                    InferenceType::new(false, true, vec![ITP::Bool])
 
                } else {
 
                    InferenceType::new(false, false, vec![ITP::Unknown])
 
                }
 
            },
 
            EP::If(_) | EP::While(_) =>
 
                // Must be a boolean
 
                InferenceType::new(false, true, vec![ITP::Bool]),
 
            EP::Return(_) =>
 
                // Must match the return type of the function
 
                if let DefinitionType::Function(func_id) = self.definition_type {
 
                    debug_assert_eq!(ctx.heap[func_id].return_types.len(), 1);
 
                    let returned = &ctx.heap[func_id].return_types[0];
 
                    self.determine_inference_type_from_parser_type_elements(&returned.elements, true)
 
                } else {
 
                    // Cannot happen: definition always set upon body traversal
 
                    // and "return" calls in components are illegal.
 
                    unreachable!();
 
                },
 
            EP::New(_) =>
 
                // Must be a component call, which we assign a "Void" return
 
                // type
 
                InferenceType::new(false, true, vec![ITP::Void]),
 
        };
 

	
 
        let infer_expr = &mut self.expr_types[expr.get_unique_id_in_definition() as usize];
 
        let needs_extra_data = match expr {
 
            Expression::Call(_) => true,
 
            Expression::Literal(expr) => match expr.value {
 
                Literal::Enum(_) | Literal::Union(_) | Literal::Struct(_) => true,
 
                _ => false,
 
            },
 
            Expression::Select(_) => true,
 
            _ => false,
 
        };
 

	
 
        if infer_expr.expr_id.is_invalid() {
 
            // Nothing is set yet
 
            infer_expr.expr_type = inference_type;
 
            infer_expr.expr_id = expr_id;
 
            if needs_extra_data {
 
                let extra_idx = self.extra_data.len() as i32;
 
                self.extra_data.push(ExtraData::default());
 
                infer_expr.extra_data_idx = extra_idx;
 
            }
 
        } else {
 
            // We already have an entry
 
            debug_assert!(false, "does this ever happen?");
 
            if let SingleInferenceResult::Incompatible = InferenceType::infer_subtree_for_single_type(
 
                &mut infer_expr.expr_type, 0, &inference_type.parts, 0, false
 
            ) {
 
                return Err(self.construct_expr_type_error(ctx, expr_id, expr_id));
 
            }
 

	
 
            debug_assert!((infer_expr.extra_data_idx != -1) == needs_extra_data);
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    fn insert_initial_call_polymorph_data(
 
        &mut self, ctx: &mut Ctx, call_id: CallExpressionId
 
    ) {
 
        // Note: the polymorph variables may be partially specified and may
 
        // contain references to the wrapping definition's (i.e. the proctype
 
        // we are currently visiting) polymorphic arguments.
 
        //
 
        // The arguments of the call may refer to polymorphic variables in the
 
        // definition of the function we're calling, not of the wrapping
 
        // definition. We insert markers in these inferred types to be able to
 
        // map them back and forth to the polymorphic arguments of the function
 
        // we are calling.
 
        let call = &ctx.heap[call_id];
 
        let extra_data_idx = self.expr_types[call.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
 
        debug_assert!(extra_data_idx != -1, "insert initial call polymorph data, no preallocated ExtraData");
 

	
 
        // Handle the polymorphic arguments (if there are any)
 
        let num_poly_args = call.parser_type.elements[0].variant.num_embedded();
 
        let mut poly_args = Vec::with_capacity(num_poly_args);
 
        for embedded_elements in call.parser_type.iter_embedded(0) {
 
            poly_args.push(self.determine_inference_type_from_parser_type_elements(embedded_elements, true));
 
        }
 

	
 
        // Handle the arguments and return types
 
        let definition = &ctx.heap[call.definition];
 
        let (parameters, returned) = match definition {
 
            Definition::Component(definition) => {
 
                debug_assert_eq!(poly_args.len(), definition.poly_vars.len());
 
                (&definition.parameters, None)
 
            },
 
            Definition::Function(definition) => {
 
                debug_assert_eq!(poly_args.len(), definition.poly_vars.len());
 
                (&definition.parameters, Some(&definition.return_types))
 
            },
 
            Definition::Struct(_) | Definition::Enum(_) | Definition::Union(_) => {
 
                unreachable!("insert_initial_call_polymorph data for non-procedure type");
 
            },
 
        };
 

	
 
        let mut parameter_types = Vec::with_capacity(parameters.len());
 
        for parameter_id in parameters.clone().into_iter() { // TODO: @Performance @Now
 
            let param = &ctx.heap[parameter_id];
 
            parameter_types.push(self.determine_inference_type_from_parser_type_elements(&param.parser_type.elements, false));
 
        }
 

	
 
        let return_type = match returned {
 
            None => {
 
                // Component, so returns a "Void"
 
                InferenceType::new(false, true, vec![InferenceTypePart::Void])
 
            },
 
            Some(returned) => {
 
                debug_assert_eq!(returned.len(), 1); // TODO: @ReturnTypes
 
                let returned = &returned[0];
 
                self.determine_inference_type_from_parser_type_elements(&returned.elements, false)
 
            }
 
        };
 

	
 
        self.extra_data[extra_data_idx as usize] = ExtraData{
 
            expr_id: call_id.upcast(),
 
            definition_id: call.definition,
 
            poly_vars: poly_args,
 
            embedded: parameter_types,
 
            returned: return_type
 
        };
 
    }
 

	
 
    fn insert_initial_struct_polymorph_data(
 
        &mut self, ctx: &mut Ctx, lit_id: LiteralExpressionId,
 
    ) {
 
        use InferenceTypePart as ITP;
 
        let literal = &ctx.heap[lit_id];
 
        let extra_data_idx = self.expr_types[literal.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
 
        debug_assert!(extra_data_idx != -1, "initial struct polymorph data, but no preallocated ExtraData");
 
        let literal = ctx.heap[lit_id].value.as_struct();
 

	
 
        // Handle polymorphic arguments
 
        let num_embedded = literal.parser_type.elements[0].variant.num_embedded();
 
        let mut total_num_poly_parts = 0;
 
        let mut poly_args = Vec::with_capacity(num_embedded);
 

	
 
        for embedded_elements in literal.parser_type.iter_embedded(0) {
 
            let poly_type = self.determine_inference_type_from_parser_type_elements(embedded_elements, true);
 
            total_num_poly_parts += poly_type.parts.len();
 
            poly_args.push(poly_type);
 
        }
 

	
 
        // Handle parser types on struct definition
 
        let defined_type = ctx.types.get_base_definition(&literal.definition).unwrap();
 
        let struct_type = defined_type.definition.as_struct();
 
        debug_assert_eq!(poly_args.len(), defined_type.poly_vars.len());
 

	
 
        // Note: programmer is capable of specifying fields in a struct literal
 
        // in a different order than on the definition. We take the literal-
 
        // specified order to be leading.
 
        let mut embedded_types = Vec::with_capacity(struct_type.fields.len());
 
        for lit_field in literal.fields.iter() {
 
            let def_field = &struct_type.fields[lit_field.field_idx];
 
            let inference_type = self.determine_inference_type_from_parser_type_elements(&def_field.parser_type.elements, false);
 
            embedded_types.push(inference_type);
 
        }
 

	
 
        // Return type is the struct type itself, with the appropriate 
 
        // polymorphic variables. So:
 
        // - 1 part for definition
 
        // - N_poly_arg marker parts for each polymorphic argument
 
        // - all the parts for the currently known polymorphic arguments 
 
        let parts_reserved = 1 + poly_args.len() + total_num_poly_parts;
 
        let mut parts = Vec::with_capacity(parts_reserved);
 
        parts.push(ITP::Instance(literal.definition, poly_args.len() as u32));
 
        let mut return_type_done = true;
 
        for (poly_var_idx, poly_var) in poly_args.iter().enumerate() {
 
            if !poly_var.is_done { return_type_done = false; }
 

	
 
            parts.push(ITP::Marker(poly_var_idx as u32));
 
            parts.extend(poly_var.parts.iter().cloned());
 
        }
 

	
 
        debug_assert_eq!(parts.len(), parts_reserved);
 
        let return_type = InferenceType::new(!poly_args.is_empty(), return_type_done, parts);
 

	
 
        self.extra_data[extra_data_idx as usize] = ExtraData{
 
            expr_id: lit_id.upcast(),
 
            definition_id: literal.definition,
 
            poly_vars: poly_args,
 
            embedded: embedded_types,
 
            returned: return_type,
 
        };
 
    }
 

	
 
    /// Inserts the extra polymorphic data struct for enum expressions. These
 
    /// can never be determined from the enum itself, but may be inferred from
 
    /// the use of the enum.
 
    fn insert_initial_enum_polymorph_data(
 
        &mut self, ctx: &Ctx, lit_id: LiteralExpressionId
 
    ) {
 
        use InferenceTypePart as ITP;
 
        let literal = &ctx.heap[lit_id];
 
        let extra_data_idx = self.expr_types[literal.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
 
        debug_assert!(extra_data_idx != -1, "initial enum polymorph data, but no preallocated ExtraData");
 
        let literal = ctx.heap[lit_id].value.as_enum();
 

	
 
        // Handle polymorphic arguments to the enum
 
        let num_poly_args = literal.parser_type.elements[0].variant.num_embedded();
 
        let mut total_num_poly_parts = 0;
 
        let mut poly_args = Vec::with_capacity(num_poly_args);
 

	
 
        for embedded_elements in literal.parser_type.iter_embedded(0) {
 
            let poly_type = self.determine_inference_type_from_parser_type_elements(embedded_elements, true);
 
            total_num_poly_parts += poly_type.parts.len();
 
            poly_args.push(poly_type);
 
        }
 

	
 
        // Handle enum type itself
 
        let parts_reserved = 1 + poly_args.len() + total_num_poly_parts;
 
        let mut parts = Vec::with_capacity(parts_reserved);
 
        parts.push(ITP::Instance(literal.definition, poly_args.len() as u32));
 
        let mut enum_type_done = true;
 
        for (poly_var_idx, poly_var) in poly_args.iter().enumerate() {
 
            if !poly_var.is_done { enum_type_done = false; }
 

	
 
            parts.push(ITP::Marker(poly_var_idx as u32));
 
            parts.extend(poly_var.parts.iter().cloned());
 
        }
 

	
 
        debug_assert_eq!(parts.len(), parts_reserved);
 
        let enum_type = InferenceType::new(!poly_args.is_empty(), enum_type_done, parts);
 

	
 
        self.extra_data[extra_data_idx as usize] = ExtraData{
 
            expr_id: lit_id.upcast(),
 
            definition_id: literal.definition,
 
            poly_vars: poly_args,
 
            embedded: Vec::new(),
 
            returned: enum_type,
 
        };
 
    }
 

	
 
    /// Inserts the extra polymorphic data struct for unions. The polymorphic
 
    /// arguments may be partially determined from embedded values in the union.
 
    fn insert_initial_union_polymorph_data(
 
        &mut self, ctx: &Ctx, lit_id: LiteralExpressionId
 
    ) {
 
        use InferenceTypePart as ITP;
 
        let literal = &ctx.heap[lit_id];
 
        let extra_data_idx = self.expr_types[literal.unique_id_in_definition as usize].extra_data_idx; // TODO: @Temp
 
        debug_assert!(extra_data_idx != -1, "initial union polymorph data, but no preallocated ExtraData");
 
        let literal = ctx.heap[lit_id].value.as_union();
 

	
 
        // Construct the polymorphic variables
 
        let num_poly_args = literal.parser_type.elements[0].variant.num_embedded();
 
        let mut total_num_poly_parts = 0;
 
        let mut poly_args = Vec::with_capacity(num_poly_args);
 

	
 
        for embedded_elements in literal.parser_type.iter_embedded(0) {
 
            let poly_type = self.determine_inference_type_from_parser_type_elements(embedded_elements, true);
 
            total_num_poly_parts += poly_type.parts.len();
 
            poly_args.push(poly_type);
 
        }
 

	
 
        // Handle any of the embedded values in the variant, if specified
 
        let definition_id = literal.definition;
 
        let type_definition = ctx.types.get_base_definition(&definition_id).unwrap();
 
        let union_definition = type_definition.definition.as_union();
 
        debug_assert_eq!(poly_args.len(), type_definition.poly_vars.len());
 

	
 
        let variant_definition = &union_definition.variants[literal.variant_idx];
 
        debug_assert_eq!(variant_definition.embedded.len(), literal.values.len());
 

	
 
        let mut embedded = Vec::with_capacity(variant_definition.embedded.len());
 
        for embedded_parser_type in &variant_definition.embedded {
 
            let inference_type = self.determine_inference_type_from_parser_type_elements(&embedded_parser_type.elements, false);
 
            embedded.push(inference_type);
 
        }
 

	
 
        // Handle the type of the union itself
 
        let parts_reserved = 1 + poly_args.len() + total_num_poly_parts;
 
        let mut parts = Vec::with_capacity(parts_reserved);
 
        parts.push(ITP::Instance(definition_id, poly_args.len() as u32));
 
        let mut union_type_done = true;
 
        for (poly_var_idx, poly_var) in poly_args.iter().enumerate() {
 
            if !poly_var.is_done { union_type_done = false; }
 

	
 
            parts.push(ITP::Marker(poly_var_idx as u32));
 
            parts.extend(poly_var.parts.iter().cloned());
 
        }
 

	
 
        debug_assert_eq!(parts_reserved, parts.len());
 
        let union_type = InferenceType::new(!poly_args.is_empty(), union_type_done, parts);
 

	
 
        self.extra_data[extra_data_idx as usize] = ExtraData{
 
            expr_id: lit_id.upcast(),
 
            definition_id: literal.definition,
 
            poly_vars: poly_args,
 
            embedded,
 
            returned: union_type
 
        };
 
    }
 

	
 
    /// Inserts the extra polymorphic data struct. Assumes that the select
 
    /// expression's referenced (definition_id, field_idx) has been resolved.
 
    fn insert_initial_select_polymorph_data(
 
        &mut self, ctx: &Ctx, select_id: SelectExpressionId, struct_def_id: DefinitionId
 
    ) {
 
        use InferenceTypePart as ITP;
 

	
 
        // Retrieve relevant data
src/protocol/parser/pass_validation_linking.rs
Show inline comments
 
@@ -621,992 +621,992 @@ impl Visitor for PassValidationLinking {
 
            if !valid {
 
                let binding_expr = &ctx.heap[id];
 
                let parent_expr = &ctx.heap[seeking_parent.as_expression()];
 
                return Err(ParseError::new_error_str_at_span(
 
                    &ctx.module().source, binding_expr.full_span,
 
                    "only the logical-and operator (&&) may be applied to binding expressions"
 
                ).with_info_str_at_span(
 
                    &ctx.module().source, parent_expr.operation_span(),
 
                    "this was the disallowed operation applied to the result from a binding expression"
 
                ));
 
            }
 
        }
 

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

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

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

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

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

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

	
 
        Ok(())
 
    }
 

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

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

	
 
        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;
 
        literal_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        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::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;
 
        cast_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        // 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 = &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 call expression"
 
            ))
 
        }
 

	
 
        // Check whether the method is allowed to be called within the code's
 
        // context (in sync, definition type, etc.)
 
        let mut expected_wrapping_new_stmt = false;
 
        match &mut call_expr.method {
 
            Method::Get => {
 
                if !self.def_type.is_primitive() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "a call to 'get' may only occur in primitive component definitions"
 
                    ));
 
                }
 
                if self.in_sync.is_invalid() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "a call to 'get' may only occur inside synchronous blocks"
 
                    ));
 
                }
 
            },
 
            Method::Put => {
 
                if !self.def_type.is_primitive() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "a call to 'put' may only occur in primitive component definitions"
 
                    ));
 
                }
 
                if self.in_sync.is_invalid() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "a call to 'put' may only occur inside synchronous blocks"
 
                    ));
 
                }
 
            },
 
            Method::Fires => {
 
                if !self.def_type.is_primitive() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "a call to 'fires' may only occur in primitive component definitions"
 
                    ));
 
                }
 
                if self.in_sync.is_invalid() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "a call to 'fires' may only occur inside synchronous blocks"
 
                    ));
 
                }
 
            },
 
            Method::Create => {},
 
            Method::Length => {},
 
            Method::Assert => {
 
                if self.def_type.is_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"
 
                    ));
 
                }
 
                if self.in_sync.is_invalid() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "assert statements may only occur inside synchronous blocks"
 
                    ));
 
                }
 
            },
 
            Method::Print => {},
 
            Method::UserFunction => {},
 
            Method::UserComponent => {
 
                expected_wrapping_new_stmt = true;
 
            },
 
        }
 

	
 
        if expected_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.definition).unwrap();
 
        let num_expected_args = match &call_definition.definition {
 
            DefinedTypeVariant::Function(definition) => definition.arguments.len(),
 
            DefinedTypeVariant::Component(definition) => definition.arguments.len(),
 
            v => unreachable!("encountered {} type in call expression", v.type_class()),
 
        };
 

	
 
        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;
 
        call_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        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];
 

	
 
        let (variable_id, is_binding_target) = match self.find_variable(ctx, self.relative_pos_in_block, &var_expr.identifier) {
 
            Ok(variable_id) => {
 
                // Regular variable
 
                (variable_id, false)
 
            },
 
            Err(()) => {
 
                // Couldn't find variable, but if we're in a binding expression,
 
                // then this may be the thing we're binding to.
 
                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 and arrays can have
 
                                // subexpressions, so we're always fine
 
                                if cfg!(debug_assertions) {
 
                                    match lit_expr.value {
 
                                        Literal::Struct(_) | Literal::Union(_) | Literal::Array(_) => {},
 
                                        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 (implicit) block
 
                // statement following the if/while 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_block: 0,
 
                    unique_id_in_scope: -1,
 
                });
 

	
 
                let body_stmt_id = match &ctx.heap[self.in_test_expr] {
 
                    Statement::If(stmt) => stmt.true_body,
 
                    Statement::While(stmt) => stmt.body,
 
                    _ => unreachable!(),
 
                };
 
                let body_scope = Scope::Regular(body_stmt_id);
 
                self.checked_at_single_scope_add_local(ctx, body_scope, 0, bound_variable_id)?;
 

	
 
                (bound_variable_id, true)
 
            }
 
        };
 

	
 
        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;
 
        var_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        Ok(())
 
    }
 
}
 

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

	
 
    fn visit_block_stmt_with_hint(&mut self, ctx: &mut Ctx, id: BlockStatementId, hint: Option<SynchronousStatementId>) -> VisitorResult {
 
        // Set parent scope and relative position in the parent scope. Remember
 
        // these values to set them back to the old values when we're done with
 
        // the traversal of the block's statements.
 
        let old_scope = self.cur_scope.clone();
 
        let new_scope = match hint {
 
            Some(sync_id) => Scope::Synchronous((sync_id, id)),
 
            None => Scope::Regular(id),
 
        };
 

	
 
        match old_scope {
 
            Scope::Definition(_def_id) => {
 
                // Don't do anything. Block is implicitly a child of a
 
                // definition scope.
 
                if cfg!(debug_assertions) {
 
                    match &ctx.heap[_def_id] {
 
                        Definition::Function(proc_def) => debug_assert_eq!(proc_def.body, id),
 
                        Definition::Component(proc_def) => debug_assert_eq!(proc_def.body, id),
 
                        _ => unreachable!(),
 
                    }
 
                }
 
            },
 
            Scope::Regular(block_id) | Scope::Synchronous((_, block_id)) => {
 
                let parent_block = &mut ctx.heap[block_id];
 
                parent_block.scope_node.nested.push(new_scope);
 
            }
 
        }
 

	
 
        self.cur_scope = new_scope;
 

	
 
        let body = &mut ctx.heap[id];
 
        body.scope_node.parent = old_scope;
 
        body.relative_pos_in_parent = self.relative_pos_in_block;
 
        let end_block_id = body.end_block;
 

	
 
        let old_relative_pos = self.relative_pos_in_block;
 

	
 
        // Copy statement IDs into buffer
 
        let statement_section = self.statement_buffer.start_section_initialized(&body.statements);
 

	
 
        // Perform the breadth-first pass. Its main purpose is to find labeled
 
        // statements such that we can find the `goto`-targets immediately when
 
        // performing the depth pass
 
        for stmt_idx in 0..statement_section.len() {
 
            self.relative_pos_in_block = stmt_idx as u32;
 
            self.visit_statement_for_locals_labels_and_in_sync(ctx, self.relative_pos_in_block, statement_section[stmt_idx])?;
 
        }
 

	
 
        // Perform the depth-first traversal
 
        assign_and_replace_next_stmt!(self, ctx, id.upcast());
 
        for stmt_idx in 0..statement_section.len() {
 
            self.relative_pos_in_block = stmt_idx as u32;
 
            self.visit_stmt(ctx, statement_section[stmt_idx])?;
 
        }
 
        assign_and_replace_next_stmt!(self, ctx, end_block_id.upcast());
 

	
 
        self.cur_scope = old_scope;
 
        self.relative_pos_in_block = old_relative_pos;
 
        statement_section.forget();
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_statement_for_locals_labels_and_in_sync(&mut self, ctx: &mut Ctx, relative_pos: u32, id: StatementId) -> VisitorResult {
 
        let statement = &mut ctx.heap[id];
 
        match statement {
 
            Statement::Local(stmt) => {
 
                match stmt {
 
                    LocalStatement::Memory(local) => {
 
                        let variable_id = local.variable;
 
                        self.checked_add_local(ctx, relative_pos, variable_id)?;
 
                    },
 
                    LocalStatement::Channel(local) => {
 
                        let from_id = local.from;
 
                        let to_id = local.to;
 
                        self.checked_add_local(ctx, relative_pos, from_id)?;
 
                        self.checked_add_local(ctx, relative_pos, to_id)?;
 
                    }
 
                }
 
            }
 
            Statement::Labeled(stmt) => {
 
                let stmt_id = stmt.this;
 
                let body_id = stmt.body;
 
                self.checked_add_label(ctx, relative_pos, self.in_sync, stmt_id)?;
 
                self.visit_statement_for_locals_labels_and_in_sync(ctx, relative_pos, body_id)?;
 
            },
 
            Statement::While(stmt) => {
 
                stmt.in_sync = self.in_sync;
 
            },
 
            _ => {},
 
        }
 

	
 
        return Ok(())
 
    }
 

	
 
    fn visit_definition_and_assign_local_ids(&mut self, ctx: &mut Ctx, definition_id: DefinitionId) {
 
        let mut var_counter = 0;
 

	
 
        // Set IDs on parameters
 
        let (param_section, body_id) = match &ctx.heap[definition_id] {
 
            Definition::Function(func_def) => (
 
                self.variable_buffer.start_section_initialized(&func_def.parameters),
 
                func_def.body
 
            ),
 
            Definition::Component(comp_def) => (
 
                self.variable_buffer.start_section_initialized(&comp_def.parameters),
 
                comp_def.body
 
            ),
 
            _ => unreachable!(),
 
        } ;
 

	
 
        for idx in 0..param_section.len() {
 
            let var_id = param_section[idx];
 
            let var = &mut ctx.heap[var_id];
 
            var.unique_id_in_scope = var_counter;
 
            var_counter += 1;
 
        }
 

	
 
        param_section.forget();
 

	
 
        // Recurse into body
 
        self.visit_block_and_assign_local_ids(ctx, body_id, var_counter);
 
    }
 

	
 
    fn visit_block_and_assign_local_ids(&mut self, ctx: &mut Ctx, block_id: BlockStatementId, mut var_counter: i32) {
 
        let block_stmt = &mut ctx.heap[block_id];
 
        block_stmt.first_unique_id_in_scope = var_counter;
 

	
 
        let var_section = self.variable_buffer.start_section_initialized(&block_stmt.locals);
 
        let mut scope_section = self.statement_buffer.start_section();
 
        for child_scope in &block_stmt.scope_node.nested {
 
            debug_assert!(child_scope.is_block(), "found a child scope that is not a block statement");
 
            scope_section.push(child_scope.to_block().upcast());
 
        }
 

	
 
        let mut var_idx = 0;
 
        let mut scope_idx = 0;
 
        while var_idx < var_section.len() || scope_idx < scope_section.len() {
 
            let relative_var_pos = if var_idx < var_section.len() {
 
                ctx.heap[var_section[var_idx]].relative_pos_in_block
 
            } else {
 
                u32::MAX
 
            };
 

	
 
            let relative_scope_pos = if scope_idx < scope_section.len() {
 
                ctx.heap[scope_section[scope_idx]].as_block().relative_pos_in_parent
 
            } else {
 
                u32::MAX
 
            };
 

	
 
            debug_assert!(!(relative_var_pos == u32::MAX && relative_scope_pos == u32::MAX));
 

	
 
            // In certain cases the relative variable position is the same as
 
            // the scope position (insertion of binding variables). In that case
 
            // the variable should be treated first
 
            if relative_var_pos <= relative_scope_pos {
 
                let var = &mut ctx.heap[var_section[var_idx]];
 
                var.unique_id_in_scope = var_counter;
 
                var_counter += 1;
 
                var_idx += 1;
 
            } else {
 
                // Boy oh boy
 
                let block_id = ctx.heap[scope_section[scope_idx]].as_block().this;
 
                self.visit_block_and_assign_local_ids(ctx, block_id, var_counter);
 
                scope_idx += 1;
 
            }
 
        }
 

	
 
        var_section.forget();
 
        scope_section.forget();
 

	
 
        // Done assigning all IDs, assign the last ID to the block statement scope
 
        let block_stmt = &mut ctx.heap[block_id];
 
        block_stmt.next_unique_id_in_scope = var_counter;
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // 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, relative_pos: u32, id: VariableId) -> Result<(), ParseError> {
 
        debug_assert!(self.cur_scope.is_block());
 
        let local = &ctx.heap[id];
 
        let mut scope = &self.cur_scope;
 

	
 
        loop {
 
            // We immediately go to the parent scope. We check the current scope
 
            // in the call at the end. Likewise for checking the symbol table.
 
            let block = &ctx.heap[scope.to_block()];
 

	
 
            scope = &block.scope_node.parent;
 
            if let Scope::Definition(definition_id) = scope {
 
                // At outer scope, check parameters of function/component
 
                for parameter_id in ctx.heap[*definition_id].parameters() {
 
                    let parameter = &ctx.heap[*parameter_id];
 
                    if local.identifier == parameter.identifier {
 
                        return Err(
 
                            ParseError::new_error_str_at_span(
 
                                &ctx.module().source, local.identifier.span, "Local variable name conflicts with parameter"
 
                            ).with_info_str_at_span(
 
                                &ctx.module().source, parameter.identifier.span, "Parameter definition is found here"
 
                            )
 
                        );
 
                    }
 
                }
 

	
 
                // No collisions
 
                break;
 
            }
 

	
 
            // If here then the parent scope is a block scope
 
            let local_relative_pos = ctx.heap[scope.to_block()].relative_pos_in_parent;
 

	
 
            for other_local_id in &block.locals {
 
                let other_local = &ctx.heap[*other_local_id];
 
                // Position check in case another variable with the same name
 
                // is defined in a higher-level scope, but later than the scope
 
                // in which the current variable resides.
 
                if local.this != *other_local_id &&
 
                    local_relative_pos >= other_local.relative_pos_in_block &&
 
                    local.identifier == other_local.identifier {
 
                    // Collision within this scope
 
                    return Err(
 
                        ParseError::new_error_str_at_span(
 
                            &ctx.module().source, local.identifier.span, "Local variable name conflicts with another variable"
 
                        ).with_info_str_at_span(
 
                            &ctx.module().source, other_local.identifier.span, "Previous variable is found here"
 
                        )
 
                    );
 
                }
 
            }
 
        }
 

	
 
        // No collisions in any of the parent scope, attempt to add to scope
 
        self.checked_at_single_scope_add_local(ctx, self.cur_scope, relative_pos, 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: Scope, relative_pos: u32, id: VariableId
 
    ) -> Result<(), ParseError> {
 
        // Check the symbol table for conflicts
 
        {
 
            let cur_scope = SymbolScope::Definition(self.def_type.definition_id());
 
            let ident = &ctx.heap[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 local = &ctx.heap[id];
 

	
 
        debug_assert!(scope.is_block());
 
        let block = &ctx.heap[scope.to_block()];
 
        for other_local_id in &block.locals {
 
            let other_local = &ctx.heap[*other_local_id];
 
            if local.this != other_local.this &&
 
                relative_pos >= other_local.relative_pos_in_block &&
 
                local.identifier == other_local.identifier {
 
                // Collision
 
                return Err(
 
                    ParseError::new_error_str_at_span(
 
                        &ctx.module().source, local.identifier.span, "Local variable name conflicts with another variable"
 
                    ).with_info_str_at_span(
 
                        &ctx.module().source, other_local.identifier.span, "Previous variable is found here"
 
                    )
 
                );
 
            }
 
        }
 

	
 
        // No collisions
 
        let block = &mut ctx.heap[scope.to_block()];
 
        block.locals.push(id);
 

	
 
        let local = &mut ctx.heap[id];
 
        local.relative_pos_in_block = relative_pos;
 

	
 
        Ok(())
 
    }
 

	
 
    /// Finds a variable in the visitor's scope that must appear before the
 
    /// specified relative position within that block.
 
    fn find_variable(&self, ctx: &Ctx, mut relative_pos: u32, identifier: &Identifier) -> Result<VariableId, ()> {
 
        debug_assert!(self.cur_scope.is_block());
 

	
 
        // No need to use iterator over namespaces if here
 
        let mut scope = &self.cur_scope;
 
        
 
        loop {
 
            debug_assert!(scope.is_block());
 
            let block = &ctx.heap[scope.to_block()];
 
            
 
            for local_id in &block.locals {
 
                let local = &ctx.heap[*local_id];
 
                
 
                if local.relative_pos_in_block <= relative_pos && identifier == &local.identifier {
 
                    return Ok(*local_id);
 
                }
 
            }
src/protocol/parser/token_parsing.rs
Show inline comments
 
use crate::collections::ScopedSection;
 
use crate::protocol::ast::*;
 
use crate::protocol::input_source::{
 
    InputSource as InputSource,
 
    InputPosition as InputPosition,
 
    InputSpan,
 
    ParseError,
 
};
 
use super::tokens::*;
 
use super::symbol_table::*;
 
use super::{Module, PassCtx};
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
 
    Ok(())
 
}
 

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

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

	
 
    Ok(true)
 
}
 

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

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

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

	
 
    Ok(true)
 
}
 

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

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

	
 
    let integer_text = source.section_at_span(integer_span);
 

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

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

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

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

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

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

	
 
    debug_assert!(char_text.len() >= 2); // always includes the bounding "'"
 
    match char_text.len() {
 
        0 => return Err(ParseError::new_error_str_at_span(source, span, "too little characters in character literal")),
 
        1 => {
 
        2 => return Err(ParseError::new_error_str_at_span(source, span, "too little characters in character literal")),
 
        3 => {
 
            // We already know the text is ascii, so just throw an error if we have the escape
 
            // character.
 
            if char_text[0] == b'\\' {
 
            if char_text[1] == b'\\' {
 
                return Err(ParseError::new_error_str_at_span(source, span, "escape character without subsequent character"));
 
            }
 
            return Ok((char_text[0] as char, span));
 
            return Ok((char_text[1] as char, span));
 
        },
 
        2 => {
 
            if char_text[0] == b'\\' {
 
                let result = parse_escaped_character(source, span, char_text[1])?;
 
        4 => {
 
            if char_text[1] == b'\\' {
 
                let result = parse_escaped_character(source, span, char_text[2])?;
 
                return Ok((result, span))
 
            }
 
        },
 
        _ => {}
 
    }
 

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

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

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

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

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

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

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

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

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

	
 
    Ok(span)
 
}
 

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

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

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

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

	
 
    None
 
}
 

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

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

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

	
 
    Ok((ident, span))
 
}
 

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

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

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

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

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

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

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

	
 
    return None
 
}
 

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

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

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

	
 
    match old_symbol_span {
 
        Some(old_symbol_span) => ParseError::new_error_at_span(
 
            &module.source, new_symbol_span, format!("symbol is defined twice: {}", new_symbol_msg)
 
        ).with_info_at_span(
 
            &module.source, old_symbol_span, format!("it conflicts with {}", old_symbol_msg)
 
        ),
 
        None => ParseError::new_error_at_span(
 
            &module.source, new_symbol_span,
 
            format!("symbol is defined twice: {} conflicts with {}", new_symbol_msg, old_symbol_msg)
 
        )
 
    }
 
}
 
\ No newline at end of file
src/protocol/parser/type_table.rs
Show inline comments
 
/**
 
 * type_table.rs
 
 *
 
 * The type table is a lookup from AST definition (which contains just what the
 
 * programmer typed) to a type with additional information computed (e.g. the
 
 * byte size and offsets of struct members). The type table should be considered
 
 * the authoritative source of information on types by the compiler (not the
 
 * AST itself!).
 
 *
 
 * The type table operates in two modes: one is where we just look up the type,
 
 * check its fields for correctness and mark whether it is polymorphic or not.
 
 * The second one is where we compute byte sizes, alignment and offsets.
 
 *
 
 * The basic algorithm for type resolving and computing byte sizes is to
 
 * recursively try to lay out each member type of a particular type. This is
 
 * done in a stack-like fashion, where each embedded type pushes a breadcrumb
 
 * unto the stack. We may discover a cycle in embedded types (we call this a
 
 * "type loop"). After which the type table attempts to break the type loop by
 
 * making specific types heap-allocated. Upon doing so we know their size
 
 * because their stack-size is now based on pointers. Hence breaking the type
 
 * loop required for computing the byte size of types.
 
 *
 
 * The reason for these type shenanigans is because PDL is a value-based
 
 * language, but we would still like to be able to express recursively defined
 
 * types like trees or linked lists. Hence we need to insert pointers somewhere
 
 * to break these cycles.
 
 *
 
 * We will insert these pointers into the variants of unions. However note that
 
 * we can only compute the stack size of a union until we've looked at *all*
 
 * variants. Hence we perform an initial pass where we detect type loops, a
 
 * second pass where we compute the stack sizes of everything, and a third pass
 
 * where we actually compute the size of the heap allocations for unions.
 
 *
 
 * As a final bit of global documentation: non-polymorphic types will always
 
 * have one "monomorph" entry. This contains the non-polymorphic type's memory
 
 * layout.
 
 */
 

	
 
use std::fmt::{Formatter, Result as FmtResult};
 
use std::collections::HashMap;
 

	
 
use crate::protocol::ast::*;
 
use crate::protocol::parser::symbol_table::SymbolScope;
 
use crate::protocol::input_source::ParseError;
 
use crate::protocol::parser::*;
 

	
 
//------------------------------------------------------------------------------
 
// Defined Types
 
//------------------------------------------------------------------------------
 

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

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

	
 
    pub(crate) fn is_data_type(&self) -> bool {
 
        match self {
 
            TypeClass::Enum | TypeClass::Union | TypeClass::Struct => true,
 
            TypeClass::Function | TypeClass::Component => false,
 
        }
 
    }
 
}
 

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

	
 
/// Struct wrapping around a potentially polymorphic type. If the type does not
 
/// have any polymorphic arguments then it will not have any monomorphs and
 
/// `is_polymorph` will be set to `false`. A type with polymorphic arguments
 
/// only has `is_polymorph` set to `true` if the polymorphic arguments actually
 
/// appear in the types associated types (function return argument, struct
 
/// field, enum variant, etc.). Otherwise the polymorphic argument is just a
 
/// marker and does not influence the bytesize of the type.
 
pub struct DefinedType {
 
    pub(crate) ast_root: RootId,
 
    pub(crate) ast_definition: DefinitionId,
 
    pub(crate) definition: DefinedTypeVariant,
 
    pub(crate) poly_vars: Vec<PolymorphicVariable>,
 
    pub(crate) is_polymorph: bool,
 
}
 

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

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

	
 
    pub(crate) fn as_struct(&self) -> &StructType {
 
        match self {
 
            DefinedTypeVariant::Struct(v) => v,
 
            _ => unreachable!("Cannot convert {} to struct variant", self.type_class())
 
        }
 
    }
 

	
 
    pub(crate) fn as_struct_mut(&mut self) -> &mut StructType {
 
        match self {
 
            DefinedTypeVariant::Struct(v) => v,
 
            _ => unreachable!("Cannot convert {} to struct variant", self.type_class())
 
        }
 
    }
 

	
 
    pub(crate) fn as_enum(&self) -> &EnumType {
 
        match self {
 
            DefinedTypeVariant::Enum(v) => v,
 
            _ => unreachable!("Cannot convert {} to enum variant", self.type_class())
 
        }
 
    }
 

	
 
    pub(crate) fn as_enum_mut(&mut self) -> &mut EnumType {
 
        match self {
 
            DefinedTypeVariant::Enum(v) => v,
 
            _ => unreachable!("Cannot convert {} to enum variant", self.type_class())
 
        }
 
    }
 

	
 
    pub(crate) fn as_union(&self) -> &UnionType {
 
        match self {
 
            DefinedTypeVariant::Union(v) => v,
 
            _ => unreachable!("Cannot convert {} to union variant", self.type_class())
 
        }
 
    }
 

	
 
    pub(crate) fn as_union_mut(&mut self) -> &mut UnionType {
 
        match self {
 
            DefinedTypeVariant::Union(v) => v,
 
            _ => unreachable!("Cannot convert {} to union variant", self.type_class())
 
        }
 
    }
 
}
 

	
 
pub struct PolymorphicVariable {
 
    identifier: Identifier,
 
    is_in_use: bool, // a polymorphic argument may be defined, but not used by the type definition
 
}
 

	
 
/// `EnumType` is the classical C/C++ enum type. It has various variants with
 
/// an assigned integer value. The integer values may be user-defined,
 
/// compiler-defined, or a mix of the two. If a user assigns the same enum
 
/// value multiple times, we assume the user is an expert and we consider both
 
/// variants to be equal to one another.
 
pub struct EnumType {
 
    pub variants: Vec<EnumVariant>,
 
    pub minimum_tag_value: i64,
 
    pub maximum_tag_value: i64,
 
    pub tag_type: ConcreteType,
 
    pub size: usize,
 
    pub alignment: usize,
 
}
 

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

	
 
/// `UnionType` is the algebraic datatype (or sum type, or discriminated union).
 
/// A value is an element of the union, identified by its tag, and may contain
 
/// a single subtype.
 
/// For potentially infinite types (i.e. a tree, or a linked list) only unions
 
/// can break the infinite cycle. So when we lay out these unions in memory we
 
/// will reserve enough space on the stack for all union variants that do not
 
/// cause "type loops" (i.e. a union `A` with a variant containing a struct
 
/// `B`). And we will reserve enough space on the heap (and store a pointer in
 
/// the union) for all variants which do cause type loops (i.e. a union `A`
 
/// with a variant to a struct `B` that contains the union `A` again).
 
pub struct UnionType {
 
    pub variants: Vec<UnionVariant>,
 
    pub tag_type: ConcreteType,
 
    pub tag_size: usize,
 
}
 

	
 
pub struct UnionVariant {
 
    pub identifier: Identifier,
 
    pub embedded: Vec<ParserType>, // zero-length does not have embedded values
 
    pub tag_value: i64,
 
}
 

	
 
/// `StructType` is a generic C-like struct type (or record type, or product
 
/// type) type.
 
pub struct StructType {
 
    pub fields: Vec<StructField>,
 
}
 

	
 
pub struct StructField {
 
    pub identifier: Identifier,
 
    pub parser_type: ParserType,
 
}
 

	
 
/// `FunctionType` is what you expect it to be: a particular function's
 
/// signature.
 
pub struct FunctionType {
 
    pub return_types: Vec<ParserType>,
 
    pub arguments: Vec<FunctionArgument>,
 
}
 

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

	
 
pub struct FunctionArgument {
 
    identifier: Identifier,
 
    parser_type: ParserType,
 
}
 

	
 
/// Represents the data associated with a single expression after type inference
 
/// for a monomorph (or just the normal expression types, if dealing with a
 
/// non-polymorphic function/component).
 
pub struct MonomorphExpression {
 
    // The output type of the expression. Note that for a function it is not the
 
    // function's signature but its return type
 
    pub(crate) expr_type: ConcreteType,
 
    // Has multiple meanings: the field index for select expressions, the
 
    // monomorph index for polymorphic function calls or literals. Negative
 
    // values are never used, but used to catch programming errors.
 
    pub(crate) field_or_monomorph_idx: i32,
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Type monomorph storage
 
//------------------------------------------------------------------------------
 

	
 
/// Generic monomorph has a specific concrete type, a size and an alignment.
 
/// Extra data is in the `MonomorphVariant` per kind of type.
 
pub(crate) struct TypeMonomorph {
 
    pub concrete_type: ConcreteType,
 
    pub size: usize,
 
    pub alignment: usize,
 
    pub variant: MonomorphVariant,
 
}
 

	
 
pub(crate) enum MonomorphVariant {
 
    Enum, // no extra data
 
    Struct(StructMonomorph),
 
    Union(UnionMonomorph),
 
    Procedure(ProcedureMonomorph), // functions, components
 
    Tuple(TupleMonomorph),
 
}
 

	
 
impl MonomorphVariant {
 
    fn as_struct(&self) -> &StructMonomorph {
 
        match self {
 
            MonomorphVariant::Struct(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn as_struct_mut(&mut self) -> &mut StructMonomorph {
 
        match self {
 
            MonomorphVariant::Struct(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    pub(crate) fn as_union(&self) -> &UnionMonomorph {
 
        match self {
 
            MonomorphVariant::Union(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn as_union_mut(&mut self) -> &mut UnionMonomorph {
 
        match self {
 
            MonomorphVariant::Union(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn as_tuple(&self) -> &TupleMonomorph {
 
        match self {
 
            MonomorphVariant::Tuple(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn as_tuple_mut(&mut self) -> &mut TupleMonomorph {
 
        match self {
 
            MonomorphVariant::Tuple(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn as_procedure(&self) -> &ProcedureMonomorph {
 
        match self {
 
            MonomorphVariant::Procedure(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn as_procedure_mut(&mut self) -> &mut ProcedureMonomorph {
 
        match self {
 
            MonomorphVariant::Procedure(v) => v,
 
            _ => unreachable!(),
 
        }
 
    }
 
}
 

	
 
/// Struct monomorph
 
pub struct StructMonomorph {
 
    pub fields: Vec<StructMonomorphField>,
 
}
 

	
 
pub struct StructMonomorphField {
 
    pub concrete_type: ConcreteType,
 
    pub size: usize,
 
    pub alignment: usize,
 
    pub offset: usize,
 
}
 

	
 
/// Union monomorph
 
pub struct UnionMonomorph {
 
    pub variants: Vec<UnionMonomorphVariant>,
 
    pub tag_size: usize, // copied from `UnionType` upon monomorph construction.
 
    // note that the stack size is in the `TypeMonomorph` struct. This size and
 
    // alignment will include the size of the union tag.
 
    //
 
    // heap_size contains the allocated size of the union in the case it
 
    // is used to break a type loop. If it is 0, then it doesn't require
 
    // allocation and lives entirely on the stack.
 
    pub heap_size: usize,
 
    pub heap_alignment: usize,
 
}
 

	
 
pub struct UnionMonomorphVariant {
 
    pub lives_on_heap: bool,
 
    pub embedded: Vec<UnionMonomorphEmbedded>,
 
}
 

	
 
pub struct UnionMonomorphEmbedded {
 
    pub concrete_type: ConcreteType,
 
    // Note that the meaning of the offset (and alignment) depend on whether or
 
    // not the variant lives on the stack/heap. If it lives on the stack then
 
    // they refer to the offset from the start of the union value (so the first
 
    // embedded type lives at a non-zero offset, because the union tag sits in
 
    // the front). If it lives on the heap then it refers to the offset from the
 
    // allocated memory region (so the first embedded type lives at a 0 offset).
 
    pub size: usize,
 
    pub alignment: usize,
 
    pub offset: usize,
 
}
 

	
 
/// Procedure (functions and components of all possible types) monomorph. Also
 
/// stores the expression type data from the typechecking/inferencing pass.
 
pub struct ProcedureMonomorph {
 
    // Expression data for one particular monomorph
 
    pub arg_types: Vec<ConcreteType>,
 
    pub expr_data: Vec<MonomorphExpression>,
 
}
 

	
 
/// Tuple monomorph. Again a kind of exception because one cannot define a named
 
/// tuple type containing explicit polymorphic variables. But again: we need to
 
/// store size/offset/alignment information, so we do it here.
 
pub struct TupleMonomorph {
 
    pub members: Vec<TupleMonomorphMember>
 
}
 

	
 
pub struct TupleMonomorphMember {
 
    pub concrete_type: ConcreteType,
 
    pub size: usize,
 
    pub alignment: usize,
 
    pub offset: usize,
 
}
 

	
 
/// Key used to perform lookups in the monomorph table. It computes a hash of
 
/// the type while not taking the unused polymorphic variables of the base type
 
/// into account (e.g. `struct Foo<A,B>{ A field }`, here `B` is an unused
 
/// polymorphic variable).
 
struct MonomorphKey {
 
    parts: Vec<ConcreteTypePart>,
 
    in_use: Vec<bool>, // TODO: @Performance, limit num args and use two `u64` as bitflags or something
 
}
 

	
 
use std::hash::*;
 

	
 
impl Hash for MonomorphKey {
 
    fn hash<H: Hasher>(&self, state: &mut H) {
 
        // if `in_use` is empty, then we may assume the type is not polymorphic
 
        // (or all types are in use)
 
        if self.in_use.is_empty() {
 
            self.parts.hash(state);
 
        } else {
 
            // type is polymorphic
 
            self.parts[0].hash(state);
 

	
 
            // note: hash is computed in a unique way, because practically
 
            // speaking `in_use` is fixed per base type. So we cannot have the
 
            // same base type (hence: a type with the same DefinitionId) with
 
            // different different polymorphic variables in use.
 
            let mut in_use_index = 0;
 
            for section in ConcreteTypeIter::new(self.parts.as_slice(), 0) {
 
                if self.in_use[in_use_index] {
 
                    section.hash(state);
 
                }
 
                in_use_index += 1;
 
            }
 
        }
 
    }
 
}
 

	
 
impl PartialEq for MonomorphKey {
 
    fn eq(&self, other: &Self) -> bool {
 
        if self.in_use.is_empty() {
 
            let temp_result = self.parts == other.parts;
 
            return temp_result;
 
        } else {
 
            // Outer type does not match
 
            if self.parts[0] != other.parts[0] {
 
                return false;
 
            }
 

	
 
            debug_assert_eq!(self.parts[0].num_embedded() as usize, self.in_use.len());
 
            let mut iter_self = ConcreteTypeIter::new(self.parts.as_slice(), 0);
 
            let mut iter_other = ConcreteTypeIter::new(other.parts.as_slice(), 0);
 
            let mut index = 0;
 
            while let Some(section_self) = iter_self.next() {
 
                let section_other = iter_other.next().unwrap();
 
                let in_use = self.in_use[index];
 
                index += 1;
 

	
 
                if !in_use {
 
                    continue;
 
                }
 

	
 
                if section_self != section_other {
 
                    return false;
 
                }
 
            }
 

	
 
            return true;
 
        }
 
    }
 
}
 

	
 
impl Eq for MonomorphKey {}
 

	
 
use std::cell::UnsafeCell;
 

	
 
/// Lookup table for monomorphs. Wrapped in a special struct because we don't
 
/// want to allocate for each lookup (what we really want is a HashMap that
 
/// exposes it CompareFn and HashFn, but whatevs).
 
pub(crate) struct MonomorphTable {
 
    lookup: HashMap<MonomorphKey, i32>, // indexes into `monomorphs`
 
    pub(crate) monomorphs: Vec<TypeMonomorph>,
 
    // We use an UnsafeCell because this is only used internally per call to
 
    // `get_monomorph_index` calls. This is safe because `&TypeMonomorph`s
 
    // retrieved for this class remain valid when the key is mutated and the
 
    // type table is not multithreaded.
 
    //
 
    // I added this because we don't want to allocate for each lookup, hence we
 
    // need a reusable `key` internal to this class. This in turn makes
 
    // `get_monomorph_index` a mutable call. Now the code that calls this
 
    // function (even though we're not mutating the table!) needs a lot of extra
 
    // boilerplate. I opted for the `UnsafeCell` instead of the boilerplate.
 
    key: UnsafeCell<MonomorphKey>,
 
}
 

	
 
impl MonomorphTable {
 
    fn new() -> Self {
 
        return Self {
 
            lookup: HashMap::with_capacity(256),
 
            monomorphs: Vec::with_capacity(256),
 
            key: UnsafeCell::new(MonomorphKey{
 
                parts: Vec::with_capacity(32),
 
                in_use: Vec::with_capacity(32),
 
            }),
 
        }
 
    }
 

	
 
    fn insert_with_zero_size_and_alignment(&mut self, concrete_type: ConcreteType, in_use: &[PolymorphicVariable], variant: MonomorphVariant) -> i32 {
 
        let key = MonomorphKey{
 
            parts: Vec::from(concrete_type.parts.as_slice()),
 
            in_use: in_use.iter().map(|v| v.is_in_use).collect(),
 
        };
 
        let index = self.monomorphs.len();
 
        let _result = self.lookup.insert(key, index as i32);
 
        debug_assert!(_result.is_none()); // did not exist yet
 
        self.monomorphs.push(TypeMonomorph{
 
            concrete_type,
 
            size: 0,
 
            alignment: 0,
 
            variant,
 
        });
 

	
 
        return index as i32;
 
    }
 

	
 
    fn get_monomorph_index(&self, parts: &[ConcreteTypePart], in_use: &[PolymorphicVariable]) -> Option<i32> {
 
        let key = unsafe {
 
            // Clear-and-extend to, at some point, prevent future allocations
 
            let key = &mut *self.key.get();
 
            key.parts.clear();
 
            key.parts.extend_from_slice(parts);
 
            key.in_use.clear();
 
            key.in_use.extend(in_use.iter().map(|v| v.is_in_use));
 

	
 
            &*key
 
        };
 

	
 
        match self.lookup.get(key) {
 
            Some(index) => return Some(*index),
 
            None => return None,
 
        }
 
    }
 

	
 
    #[inline]
 
    fn get(&self, index: i32) -> &TypeMonomorph {
 
        debug_assert!(index >= 0);
 
        return &self.monomorphs[index as usize];
 
    }
 

	
 
    #[inline]
 
    fn get_mut(&mut self, index: i32) -> &mut TypeMonomorph {
 
        debug_assert!(index >= 0);
 
        return &mut self.monomorphs[index as usize];
 
    }
 

	
 
    fn get_monomorph_size_alignment(&self, index: i32) -> Option<(usize, usize)> {
 
        let monomorph = self.get(index);
 
        if monomorph.size == 0 && monomorph.alignment == 0 {
 
            // If both are zero, then we wish to mean: we haven't actually
 
            // computed the size and alignment yet. So:
 
            return None;
 
        } else {
 
            return Some((monomorph.size, monomorph.alignment));
 
        }
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Type table
 
//------------------------------------------------------------------------------
 

	
 
// Programmer note: keep this struct free of dynamically allocated memory
 
#[derive(Clone)]
 
struct TypeLoopBreadcrumb {
 
    monomorph_idx: i32,
 
    next_member: u32,
 
    next_embedded: u32, // for unions, the index into the variant's embedded types
 
}
 

	
 
#[derive(Clone)]
 
struct MemoryBreadcrumb {
 
    monomorph_idx: i32,
 
    next_member: u32,
 
    next_embedded: u32,
 
    first_size_alignment_idx: u32,
 
}
 

	
 
#[derive(Debug, PartialEq, Eq)]
 
enum TypeLoopResult {
 
    TypeExists,
 
    PushBreadcrumb(DefinitionId, ConcreteType),
 
    TypeLoop(usize), // index into vec of breadcrumbs at which the type matched
 
}
 

	
 
enum MemoryLayoutResult {
 
    TypeExists(usize, usize), // (size, alignment)
 
    PushBreadcrumb(MemoryBreadcrumb),
 
}
 

	
 
// TODO: @Optimize, initial memory-unoptimized implementation
 
struct TypeLoopEntry {
 
    monomorph_idx: i32,
 
    is_union: bool,
 
}
 

	
 
struct TypeLoop {
 
    members: Vec<TypeLoopEntry>
 
}
 

	
 
pub struct TypeTable {
 
    /// Lookup from AST DefinitionId to a defined type. Also lookups for
 
    /// concrete type to monomorphs
 
    pub(crate) type_lookup: HashMap<DefinitionId, DefinedType>,
 
    pub(crate) mono_lookup: MonomorphTable,
 
    /// Breadcrumbs left behind while trying to find type loops. Also used to
 
    /// determine sizes of types when all type loops are detected.
 
    type_loop_breadcrumbs: Vec<TypeLoopBreadcrumb>,
 
    type_loops: Vec<TypeLoop>,
 
    /// Stores all encountered types during type loop detection. Used afterwards
 
    /// to iterate over all types in order to compute size/alignment.
 
    encountered_types: Vec<TypeLoopEntry>,
 
    /// Breadcrumbs and temporary storage during memory layout computation.
 
    memory_layout_breadcrumbs: Vec<MemoryBreadcrumb>,
 
    size_alignment_stack: Vec<(usize, usize)>,
 
}
 

	
 
impl TypeTable {
 
    /// Construct a new type table without any resolved types.
 
    pub(crate) fn new() -> Self {
 
        Self{ 
 
            type_lookup: HashMap::with_capacity(128),
 
            mono_lookup: MonomorphTable::new(),
 
            type_loop_breadcrumbs: Vec::with_capacity(32),
 
            type_loops: Vec::with_capacity(8),
 
            encountered_types: Vec::with_capacity(32),
 
            memory_layout_breadcrumbs: Vec::with_capacity(32),
 
            size_alignment_stack: Vec::with_capacity(64),
 
        }
 
    }
 

	
 
    /// Iterates over all defined types (polymorphic and non-polymorphic) and
 
    /// add their types in two passes. In the first pass we will just add the
 
    /// base types (we will not consider monomorphs, and we will not compute
 
    /// byte sizes). In the second pass we will compute byte sizes of
 
    /// non-polymorphic types, and potentially the monomorphs that are embedded
 
    /// in those types.
 
    pub(crate) fn build_base_types(&mut self, modules: &mut [Module], ctx: &mut PassCtx) -> Result<(), ParseError> {
 
        // Make sure we're allowed to cast root_id to index into ctx.modules
 
        debug_assert!(modules.iter().all(|m| m.phase >= ModuleCompilationPhase::DefinitionsParsed));
 
        debug_assert!(self.type_lookup.is_empty());
 

	
 
        if cfg!(debug_assertions) {
 
            for (index, module) in modules.iter().enumerate() {
 
                debug_assert_eq!(index, module.root_id.index as usize);
 
            }
 
        }
 

	
 
        // Use context to guess hashmap size of the base types
 
        let reserve_size = ctx.heap.definitions.len();
 
        self.type_lookup.reserve(reserve_size);
 

	
 
        // Resolve all base types
 
        for definition_idx in 0..ctx.heap.definitions.len() {
 
            let definition_id = ctx.heap.definitions.get_id(definition_idx);
 
            let definition = &ctx.heap[definition_id];
 

	
 
            match definition {
 
                Definition::Enum(_) => self.build_base_enum_definition(modules, ctx, definition_id)?,
 
                Definition::Union(_) => self.build_base_union_definition(modules, ctx, definition_id)?,
 
                Definition::Struct(_) => self.build_base_struct_definition(modules, ctx, definition_id)?,
 
                Definition::Function(_) => self.build_base_function_definition(modules, ctx, definition_id)?,
 
                Definition::Component(_) => self.build_base_component_definition(modules, ctx, definition_id)?,
 
            }
 
        }
 

	
 
        debug_assert_eq!(self.type_lookup.len(), reserve_size, "mismatch in reserved size of type table"); // NOTE: Temp fix for builtin functions
 
        for module in modules.iter_mut() {
 
            module.phase = ModuleCompilationPhase::TypesAddedToTable;
 
        }
 

	
 
        // Go through all types again, lay out all types that are not
 
        // polymorphic. This might cause us to lay out types that are monomorphs
 
        // of polymorphic types.
 
        for definition_idx in 0..ctx.heap.definitions.len() {
 
            let definition_id = ctx.heap.definitions.get_id(definition_idx);
 
            let poly_type = self.type_lookup.get(&definition_id).unwrap();
 

	
 
            if !poly_type.definition.type_class().is_data_type() || !poly_type.poly_vars.is_empty() {
 
                continue;
 
            }
 

	
 
            // If here then the type is a data type without polymorphic
 
            // variables, but we might have instantiated it already, so:
 
            let concrete_parts = [ConcreteTypePart::Instance(definition_id, 0)];
 
            let mono_index = self.mono_lookup.get_monomorph_index(&concrete_parts, &[]);
 
            if mono_index.is_none() {
 
                self.detect_and_resolve_type_loops_for(
 
                    modules, ctx.heap,
src/protocol/tests/eval_binding.rs
Show inline comments
 
use super::*;
 

	
 
#[test]
 
fn test_binding_from_struct() {
 
    Tester::new_single_source_expect_ok("top level", "
 
        struct Foo{ u32 field }
 
        func foo() -> u32 {
 
            if (let Foo{ field: thing } = Foo{ field: 1337 }) { return thing; }
 
            return 0;
 
        }
 
    ").for_function("foo", |f| {
 
        f.call_ok(Some(Value::UInt32(1337)));
 
    });
 

	
 
    Tester::new_single_source_expect_ok("nested", "
 
        struct Nested<T>{ T inner }
 
        struct Foo{ u32 field }
 
        func make<T>(T val) -> Nested<T> {
 
            return Nested{ inner: val };
 
        }
 
        func foo() -> u32 {
 
            if (let Nested{ inner: Nested { inner: to_get } } = make(make(Foo{ field: 42 }))) {
 
                return to_get.field;
 
            }
 
            return 0;
 
        }
 
    ").for_function("foo", |f| {
 
        f.call_ok(Some(Value::UInt32(42)));
 
    });
 
}
 

	
 
#[test]
 
fn test_binding_from_array() {
 
    Tester::new_single_source_expect_ok("top level", "
 
        func foo() -> bool {
 
            // Mismatches in length
 
            bool failure1 = false;
 
            u32[] vals = { 1, 2, 3 };
 
            if (let {1, a} = vals) { failure1 = true; }
 

	
 
            bool failure2 = false;
 
            if (let {} = vals) { failure2 = true; }
 

	
 
            bool failure3 = false;
 
            if (let {1, 2, 3, 4} = vals) { failure3 = true; }
 

	
 
            // Mismatches in known values
 
            bool failure4 = false;
 
            if (let {1, 3, a} = vals) { failure4 = true; }
 

	
 
            // Matching with known variables
 
            auto constant_one = 1;
 
            auto constant_two = 2;
 
            auto constant_three = 3;
 
            bool success1 = false;
 
            if (
 
                let {binding_one, constant_two, constant_three} = vals &&
 
                let {constant_one, binding_two, constant_three} = vals &&
 
                let {constant_one, constant_two, binding_three} = vals
 
            ) {
 
                success1 = binding_one == 1 && binding_two == 2 && binding_three == 3;
 
            }
 

	
 
            // Matching with literals
 
            bool success2 = false;
 
            if (let {binding_one, 2, 3} = vals && let {1, binding_two, 3} = vals && let {1, 2, binding_three} = vals) {
 
                success2 = binding_one == 1 && binding_two == 2 && binding_three == 3;
 
            }
 

	
 
            // Matching all
 
            bool success3 = false;
 
            if (let {binding_one, binding_two, binding_three} = vals && let {1, 2, 3} = vals) {
 
                success3 = true;
 
            }
 

	
 
            return
 
                !failure1 && !failure2 && !failure3 && !failure4 &&
 
                success1 && success2 && success3;
 
        }
 
    ").for_function("foo", |f| { f
 
        .call_ok(Some(Value::Bool(true)));
 
    });
 
}
 

	
 
#[test]
 
fn test_binding_from_union() {
 
    Tester::new_single_source_expect_ok("option type", "
 
        union Option<T> { Some(T), None }
 

	
 
        func is_some<T>(Option<T> opt) -> bool {
 
            if (let Option::Some(throwaway) = opt) return true;
 
            else                                   return false;
 
        }
 
        func is_none<T>(Option<T> opt) -> bool {
 
            if (let Option::Some(throwaway) = opt) return false;
 
            else                                   return true;
 
        }
 

	
 
        func foo() -> u32 {
 
            // Hey look, we're so modern, we have algebraic discriminated sum datauniontypes
 
            auto something = Option::Some(5);
 
            auto nonething = Option<u32>::None;
 

	
 
            bool success1 = false;
 
            if (let Option::Some(value) = something && let Option::None = nonething) {
 
                success1 = value == 5;
 
            }
 

	
 
            bool success2 = false;
 
            if (is_some(something) && is_none(nonething)) {
 
                success2 = true;
 
            }
 

	
 
            bool success3 = true;
 
            if (let Option::None = something) success3 = false;
 
            if (let Option::Some(value) = nonething) success3 = false;
 

	
 
            bool success4 = true;
 
            if (is_none(something) || is_some(nonething)) success4 = false;
 

	
 
            if (success1 && success2 && success3 && success4) {
 
                if (let Option::Some(value) = something) return value;
 
            }
 

	
 
            return 0;
 
        }
 
    ").for_function("foo", |f| { f
 
        .call_ok(Some(Value::UInt32(5)));
 
    });
 
}
 

	
 
#[test]
 
fn test_binding_from_tuple() {
 
    Tester::new_single_source_expect_ok("tuple binding", "
 
        func foo() -> u32 {
 
            u64 value = 2000;
 
            auto tuple = (\"hello\", value, 21);
 

	
 
            bool success1 = false;
 
            if (let (\"hello\", value, 21) = tuple && let (a, b, c) = tuple) {
 
                success1 = a == \"hello\" && b == value && c == 21;
 
            }
 

	
 
            bool success2 = true;
 
            if (let (\"nope\", a, b) = tuple) success2 = false;
 
            if (let (\"hello\", 2001, 21) = tuple) success2 = false;
 
            if (let (a, 2001, b) = tuple) success2 = false;
 
            if (let (a, b, 22) = tuple) success2 = false;
 

	
 
            bool success3 = false;
 
            if (let (\"hello\", v2a, v3a) = tuple && let (v1a, 2000, v3b) = tuple && let (v1b, v2b, 21) = tuple) {
 
                success3 = v1a == v1b && v2a == v2b && v3a == v3b;
 
            }
 

	
 
            if (success1 && success2 && success3 && let (\"hello\", a, b) = tuple) {
 
                return cast(a) + b;
 
            }
 

	
 
            return 0;
 
        }
 
    ").for_function("foo", |f| { f
 
        .call_ok(Some(Value::UInt32(2021)));
 
    });
 
}
 

	
 
#[test]
 
fn test_binding_fizz_buzz() {
 
    Tester::new_single_source_expect_ok("am I employable?", "
 
        union Fizzable { Number(u32), FizzBuzz, Fizz, Buzz }
 

	
 
        func construct_fizz_buzz_very_slow(u32 num) -> Fizzable[] {
 
            u32 counter = 1;
 
            auto result = {};
 
            while (counter <= num) {
 
                auto value = Fizzable::Number(counter);
 
                if (counter % 5 == 0) {
 
                    if (counter % 3 == 0) {
 
                        value = Fizzable::FizzBuzz;
 
                    } else {
 
                        value = Fizzable::Buzz;
 
                    }
 
                } else if (counter % 3 == 0) {
 
                    value = Fizzable::Fizz;
 
                }
 

	
 
                result = result @ { value }; // woohoo, no array builtins!
 
                counter += 1;
 
            }
 

	
 
            return result;
 
        }
 

	
 
        func construct_fizz_buzz_slightly_less_slow(u32 num) -> Fizzable[] {
 
            u32 counter = 1;
 
            auto result = {};
 
            while (counter <= num) {
 
                auto value = Fizzable::Number(counter);
 
                if (counter % 5 == 0) {
 
                    if (counter % 3 == 0) {
 
                        value = Fizzable::FizzBuzz;
 
                    } else {
 
                        value = Fizzable::Buzz;
 
                    }
 
                } else if (counter % 3 == 0) {
 
                    value = Fizzable::Fizz;
 
                }
 

	
 
                result @= { value }; // woohoo, no array builtins!
 
                counter += 1;
 
            }
 

	
 
            return result;
 
        }
 

	
 
        func test_fizz_buzz(Fizzable[] fizzoid) -> bool {
 
            u32 idx = 0;
 
            bool valid = true;
 
            while (idx < length(fizzoid)) {
 
                auto number = idx + 1;
 
                auto is_div3 = number % 3 == 0;
 
                auto is_div5 = number % 5 == 0;
 

	
 
                if (let Fizzable::Number(got) = fizzoid[idx]) {
 
                    valid = valid && got == number && !is_div3 && !is_div5;
 
                } else if (let Fizzable::FizzBuzz = fizzoid[idx]) {
 
                    valid = valid && is_div3 && is_div5;
 
                } else if (let Fizzable::Fizz = fizzoid[idx]) {
 
                    valid = valid && is_div3 && !is_div5;
 
                } else if (let Fizzable::Buzz = fizzoid[idx]) {
 
                    valid = valid && !is_div3 && is_div5;
 
                } else {
 
                    // Impossibruuu!
 
                    valid = false;
 
                }
 

	
 
                idx += 1;
 
            }
 

	
 
            return valid;
 
        }
 

	
 
        func fizz_buzz() -> bool {
 
            // auto fizz_more_slow = construct_fizz_buzz_very_slow(100);
 
            // return test_fizz_buzz(fizz_more_slow);
 
            // auto fizz_less_slow = construct_fizz_buzz_slightly_less_slow(10000000);
 
            // return test_fizz_buzz(fizz_less_slow);
 

	
 
            auto fizz_more_slow2 = construct_fizz_buzz_very_slow(100);
 
            auto fizz_less_slow2 = construct_fizz_buzz_slightly_less_slow(100);
 
            return test_fizz_buzz(fizz_more_slow2) && test_fizz_buzz(fizz_less_slow2);
 
        }
 
    ").for_function("fizz_buzz", |f| { f
 
        .call_ok(Some(Value::Bool(true)));
 
    });
 
}
 
\ No newline at end of file
src/protocol/tests/eval_operators.rs
Show inline comments
 
use super::*;
 

	
 
#[test]
 
fn test_assignment_operators() {
 
    fn construct_source(value_type: &str, value_initial: &str, value_op: &str) -> String {
 
        return format!(
 
            "func foo() -> {} {{
 
                {} value = {};
 
                value {};
 
                return value;
 
            }}",
 
            value_type, value_type, value_initial, value_op
 
        );
 
    }
 

	
 
    fn perform_test(name: &str, source: String, expected_value: Value) {
 
        Tester::new_single_source_expect_ok(name, source)
 
            .for_function("foo", move |f| {
 
                f.call_ok(Some(expected_value));
 
            });
 
    }
 

	
 
    perform_test(
 
        "set",
 
        construct_source("u32", "1", "= 5"),
 
        Value::UInt32(5)
 
    );
 

	
 
    perform_test(
 
        "multiplied",
 
        construct_source("u32", "2", "*= 4"),
 
        Value::UInt32(8)
 
    );
 

	
 
    perform_test(
 
        "divided",
 
        construct_source("u32", "8", "/= 4"),
 
        Value::UInt32(2)
 
    );
 

	
 
    perform_test(
 
        "remained",
 
        construct_source("u32", "8", "%= 3"),
 
        Value::UInt32(2)
 
    );
 

	
 
    perform_test(
 
        "added",
 
        construct_source("u32", "2", "+= 4"),
 
        Value::UInt32(6)
 
    );
 

	
 
    perform_test(
 
        "subtracted",
 
        construct_source("u32", "6", "-= 4"),
 
        Value::UInt32(2)
 
    );
 

	
 
    perform_test(
 
        "shifted left",
 
        construct_source("u32", "2", "<<= 2"),
 
        Value::UInt32(8)
 
    );
 

	
 
    perform_test(
 
        "shifted right",
 
        construct_source("u32", "8", ">>= 2"),
 
        Value::UInt32(2)
 
    );
 

	
 
    perform_test(
 
        "bitwise and",
 
        construct_source("u32", "15", "&= 35"),
 
        Value::UInt32(3)
 
    );
 

	
 
    perform_test(
 
        "bitwise xor",
 
        construct_source("u32", "3", "^= 7"),
 
        Value::UInt32(4)
 
    );
 

	
 
    perform_test(
 
        "bitwise or",
 
        construct_source("u32", "12", "|= 3"),
 
        Value::UInt32(15)
 
    );
 
}
 

	
 
#[test]
 
fn test_binary_integer_operators() {
 
    fn construct_source(value_type: &str, code: &str) -> String {
 
        format!("
 
        func foo() -> {} {{
 
            {}
 
        }}
 
        ", value_type, code)
 
    }
 

	
 
    fn perform_test(test_name: &str, value_type: &str, code: &str, expected_value: Value) {
 
        Tester::new_single_source_expect_ok(test_name, construct_source(value_type, code))
 
            .for_function("foo", move |f| {
 
                f.call_ok(Some(expected_value));
 
            });
 
    }
 

	
 
    perform_test(
 
        "bitwise_or", "u16",
 
        "auto a = 3; return a | 4;", Value::UInt16(7)
 
    );
 
    perform_test(
 
        "bitwise_xor", "u16",
 
        "auto a = 3; return a ^ 7;", Value::UInt16(4)
 
    );
 
    perform_test(
 
        "bitwise and", "u16",
 
        "auto a = 0b110011; return a & 0b011110;", Value::UInt16(0b010010)
 
    );
 
    perform_test(
 
        "shift left", "u16",
 
        "auto a = 0x0F; return a << 4;", Value::UInt16(0xF0)
 
    );
 
    perform_test(
 
        "shift right", "u64",
 
        "auto a = 0xF0; return a >> 4;", Value::UInt64(0x0F)
 
    );
 
    perform_test(
 
        "add", "u32",
 
        "auto a = 5; return a + 5;", Value::UInt32(10)
 
    );
 
    perform_test(
 
        "subtract", "u32",
 
        "auto a = 3; return a - 3;", Value::UInt32(0)
 
    );
 
    perform_test(
 
        "multiply", "u8",
 
        "auto a = 2 * 2; return a * 2 * 2;", Value::UInt8(16)
 
    );
 
    perform_test(
 
        "divide", "u8",
 
        "auto a = 32 / 2; return a / 2 / 2;", Value::UInt8(4)
 
    );
 
    perform_test(
 
        "remainder", "u16",
 
        "auto a = 29; return a % 3;", Value::UInt16(2)
 
    );
 
}
 

	
 
#[test]
 
fn test_tuple_operators() {
 
    Tester::new_single_source_expect_ok("tuple equality", "
 
    func test_func() -> bool {
 
        auto a1 = (8, 16, 32);
 
        (u8, u16, u32) a2 = (8, 16, 32);
 
        auto b1 = ();
 
        () b2 = ();
 

	
 
        return a1 == a2 && a2 == (8, 16, 32) && b1 == b2 && b2 == ();
 
    }
 
    ").for_function("test_func", |f| { f
 
        .call_ok(Some(Value::Bool(true)));
 
    });
 

	
 
    Tester::new_single_source_expect_ok("tuple inequality", "
 
    func test_func() -> bool {
 
        auto a = (8, 16, 32);
 
        (u8, u16, u32) a_same = (8, 16, 32);
 
        auto a_diff = (0b111, 0b1111, 0b11111);
 
        auto b = ();
 
        return
 
            !(a != a_same) &&
 
            a != a_diff &&
 
            a != (8, 16, 320) &&
 
            !(b != ());
 
    }
 
    ").for_function("test_func", |f| { f
 
        .call_ok(Some(Value::Bool(true)));
 
    });
 
}
 

	
 
#[test]
 
fn test_string_operators() {
 
    Tester::new_single_source_expect_ok("string concatenation", "
 
func create_concatenated(string left, string right) -> string {
 
    return left @ \", but also \" @ right;
 
}
 
func perform_concatenate(string left, string right) -> string {
 
    left @= \", but also \";
 
    left @= right;
 
    return left;
 
}
 
func foo() -> bool {
 
    auto left = \"Darth Vader\";
 
    auto right = \"Anakin Skywalker\";
 
    auto res1 = create_concatenated(left, right);
 
    auto res2 = perform_concatenate(left, right);
 
    auto expected = \"Darth Vader, but also Anakin Skywalker\";
 

	
 
    return
 
        res1 == expected &&
 
        res2 == \"Darth Vader, but also Anakin Skywalker\" &&
 
        res1 != \"This kind of thing\" && res2 != \"Another likewise kind of thing\";
 
}
 
    ").for_function("foo", |f| { f
 
        .call_ok(Some(Value::Bool(true)));
 
    });
 
}
 
\ No newline at end of file
src/protocol/tests/parser_literals.rs
Show inline comments
 
use super::*;
 

	
 
#[test]
 
fn test_binary_literals() {
 
    Tester::new_single_source_expect_ok("valid", "
 
        func test() -> u32 {
 
            u8  v1 = 0b0100_0010;
 
            u16 v2 = 0b10101010;
 
            u32 v3 = 0b10000001_01111110;
 
            u64 v4 = 0b1001_0110_1001_0110;
 

	
 
            return 0b10110;
 
        }
 
    ");
 

	
 
    Tester::new_single_source_expect_err("invalid character", "
 
        func test() -> u32 {
 
            return 0b10011001_10012001;
 
        }
 
    ").error(|e| { e.assert_msg_has(0, "incorrectly formatted binary number"); });
 

	
 
    Tester::new_single_source_expect_err("no characters", "
 
        func test() -> u32 { return 0b; }
 
    ").error(|e| { e.assert_msg_has(0, "incorrectly formatted binary number"); });
 

	
 
    Tester::new_single_source_expect_err("only separators", "
 
        func test() -> u32 { return 0b____; }
 
    ").error(|e| { e.assert_msg_has(0, "incorrectly formatted binary number"); });
 
}
 

	
 
#[test]
 
fn test_string_literals() {
 
    Tester::new_single_source_expect_ok("valid", "
 
        func test() -> string {
 
            auto v1 = \"Hello, world!\";
 
            auto v2 = \"\\t\\r\\n\\\\\"; // why hello there, confusing thing
 
            auto v3 = \"\";
 
            return \"No way, dude!\";
 
        }
 
    ").for_function("test", |f| { f
 
        .for_variable("v1", |v| { v.assert_concrete_type("string"); })
 
        .for_variable("v2", |v| { v.assert_concrete_type("string"); })
 
        .for_variable("v3", |v| { v.assert_concrete_type("string"); });
 
    });
 

	
 
    Tester::new_single_source_expect_err("unterminated simple", "
 
        func test() -> string { return \"'; }
 
    ").error(|e| { e
 
        .assert_num(1)
 
        .assert_occurs_at(0, "\"")
 
        .assert_msg_has(0, "unterminated");
 
    });
 

	
 
    Tester::new_single_source_expect_err("unterminated with preceding escaped", "
 
        func test() -> string { return \"\\\"; }
 
    ").error(|e| { e
 
        .assert_num(1)
 
        .assert_occurs_at(0, "\"\\")
 
        .assert_msg_has(0, "unterminated");
 
    });
 

	
 
    Tester::new_single_source_expect_err("invalid escaped character", "
 
        func test() -> string { return \"\\y\"; }
 
    ").error(|e| { e.assert_msg_has(0, "unsupported escape character 'y'"); });
 

	
 
    // Note sure if this should always be in here...
 
    Tester::new_single_source_expect_err("non-ASCII string", "
 
        func test() -> string { return \"💧\"; }
 
    ").error(|e| { e.assert_msg_has(0, "non-ASCII character in string literal"); });
 
}
 

	
 
#[test]
 
fn test_tuple_literals() {
 
    Tester::new_single_source_expect_ok("zero tuples", "
 
        func test() -> () {
 
            // Looks like lisp :)
 
            auto t1 = ();
 
            () t2 = ();
 
            auto t3 = (());
 
            () t4 = (());
 
            auto t5 = ((((()))));
 
            ((())) t6 = ((((()))));
 

	
 
            return ();
 
        }
 
    ").for_function("test", |f| { f
 
        .for_variable("t1", |v| { v.assert_concrete_type("()"); })
 
        .for_variable("t2", |v| { v.assert_concrete_type("()"); })
 
        .for_variable("t3", |v| { v.assert_concrete_type("()"); })
 
        .for_variable("t4", |v| { v.assert_concrete_type("()"); })
 
        .for_variable("t5", |v| { v.assert_concrete_type("()"); })
 
        .for_variable("t6", |v| { v.assert_concrete_type("()"); });
 
    });
 

	
 
    // All one-tuples (T) are transformed into T to prevent ambiguity
 
    Tester::new_single_source_expect_ok("one tuples", "
 
        func test() -> (u32) {
 
            auto a = (0);
 
            (s32) b = (1);
 
            ((((s32)))) c = ((2));
 
        }
 
    ").for_function("test", |f| { f
 
        .for_variable("a", |v| { v.assert_concrete_type("s32"); })
 
        .for_variable("b", |v| { v.assert_concrete_type("s32"); })
 
        .for_variable("c", |v| { v.assert_concrete_type("s32"); });
 
    });
 

	
 
    Tester::new_single_source_expect_ok("actual tuples", "
 
        func test() -> (u32, u32) {
 
            (u8,u16,u32) a = (0, 1, 2);
 
            auto b = a;
 
            auto c = (3, 4, 5);
 
            ((auto, auto)) d = (a, c);
 
            auto e = (\"hello\", 'c', 5 + 2);
 
            return ((0), (1));
 
        }
 
    ").for_function("test", |f| { f
 
        .for_variable("a", |v| { v.assert_concrete_type("(u8,u16,u32)"); })
 
        .for_variable("b", |v| { v.assert_concrete_type("(u8,u16,u32)"); })
 
        .for_variable("c", |v| { v.assert_concrete_type("(s32,s32,s32)"); })
 
        .for_variable("d", |v| { v.assert_concrete_type("((u8,u16,u32),(s32,s32,s32))"); })
 
        .for_variable("e", |v| { v.assert_concrete_type("(string,char,s32)"); });
 
    });
 
}
 
\ No newline at end of file
src/protocol/tests/utils.rs
Show inline comments
 
@@ -24,1243 +24,1242 @@ struct TestCtx<'a> {
 
pub(crate) struct Tester {
 
    test_name: String,
 
    sources: Vec<String>
 
}
 

	
 
impl Tester {
 
    /// Constructs a new tester, allows adding multiple sources before compiling
 
    pub(crate) fn new<S: ToString>(test_name: S) -> Self {
 
        Self{
 
            test_name: test_name.to_string(),
 
            sources: Vec::new()
 
        }
 
    }
 

	
 
    /// Utility for quick tests that use a single source file and expect the
 
    /// compilation to succeed.
 
    pub(crate) fn new_single_source_expect_ok<T: ToString, S: ToString>(test_name: T, source: S) -> AstOkTester {
 
        Self::new(test_name)
 
            .with_source(source)
 
            .compile()
 
            .expect_ok()
 
    }
 

	
 
    /// Utility for quick tests that use a single source file and expect the
 
    /// compilation to fail.
 
    pub(crate) fn new_single_source_expect_err<T: ToString, S: ToString>(test_name: T, source: S) -> AstErrTester {
 
        Self::new(test_name)
 
            .with_source(source)
 
            .compile()
 
            .expect_err()
 
    }
 

	
 
    pub(crate) fn with_source<S: ToString>(mut self, source: S) -> Self {
 
        self.sources.push(source.to_string());
 
        self
 
    }
 

	
 
    pub(crate) fn compile(self) -> AstTesterResult {
 
        let mut parser = Parser::new();
 
        for source in self.sources.into_iter() {
 
            let source = source.into_bytes();
 
            let input_source = InputSource::new(String::from(""), source);
 

	
 
            if let Err(err) = parser.feed(input_source) {
 
                return AstTesterResult::Err(AstErrTester::new(self.test_name, err))
 
            }
 
        }
 

	
 
        if let Err(err) = parser.parse() {
 
            return AstTesterResult::Err(AstErrTester::new(self.test_name, err))
 
        }
 

	
 
        AstTesterResult::Ok(AstOkTester::new(self.test_name, parser))
 
    }
 
}
 

	
 
pub(crate) enum AstTesterResult {
 
    Ok(AstOkTester),
 
    Err(AstErrTester)
 
}
 

	
 
impl AstTesterResult {
 
    pub(crate) fn expect_ok(self) -> AstOkTester {
 
        match self {
 
            AstTesterResult::Ok(v) => v,
 
            AstTesterResult::Err(err) => {
 
                let wrapped = ErrorTester{ test_name: &err.test_name, error: &err.error };
 
                println!("DEBUG: Full error:\n{}", &err.error);
 
                assert!(
 
                    false,
 
                    "[{}] Expected compilation to succeed, but it failed with {}",
 
                    err.test_name, wrapped.assert_postfix()
 
                );
 
                unreachable!();
 
            }
 
        }
 
    }
 

	
 
    pub(crate) fn expect_err(self) -> AstErrTester {
 
        match self {
 
            AstTesterResult::Ok(ok) => {
 
                assert!(false, "[{}] Expected compilation to fail, but it succeeded", ok.test_name);
 
                unreachable!();
 
            },
 
            AstTesterResult::Err(err) => err,
 
        }
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Interface for successful compilation
 
//------------------------------------------------------------------------------
 

	
 
#[allow(dead_code)]
 
pub(crate) struct AstOkTester {
 
    test_name: String,
 
    modules: Vec<Module>,
 
    heap: Heap,
 
    symbols: SymbolTable,
 
    types: TypeTable,
 
    pool: StringPool, // This is stored because if we drop it on the floor, we lose all our `StringRef<'static>`s
 
}
 

	
 
impl AstOkTester {
 
    fn new(test_name: String, parser: Parser) -> Self {
 
        Self {
 
            test_name,
 
            modules: parser.modules.into_iter().map(|module| Module{
 
                source: module.source,
 
                root_id: module.root_id,
 
                name: module.name.map(|(_, name)| name)
 
            }).collect(),
 
            heap: parser.heap,
 
            symbols: parser.symbol_table,
 
            types: parser.type_table,
 
            pool: parser.string_pool,
 
        }
 
    }
 

	
 
    pub(crate) fn for_struct<F: Fn(StructTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Struct(ast_definition) = definition {
 
                if ast_definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found struct with the same name
 
                let definition_id = ast_definition.this.upcast();
 
                let type_entry = self.types.get_base_definition(&definition_id).unwrap();
 
                let type_definition = type_entry.definition.as_struct();
 

	
 
                let tester = StructTester::new(self.ctx(), ast_definition, type_definition);
 
                f(tester);
 
                found = true;
 
                break
 
            }
 
        }
 

	
 
        assert!(
 
            found, "[{}] Failed to find definition for struct '{}'",
 
            self.test_name, name
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn for_enum<F: Fn(EnumTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Enum(definition) = definition {
 
                if definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found enum with the same name
 
                let tester = EnumTester::new(self.ctx(), definition);
 
                f(tester);
 
                found = true;
 
                break;
 
            }
 
        }
 

	
 
        assert!(
 
            found, "[{}] Failed to find definition for enum '{}'",
 
            self.test_name, name
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn for_union<F: Fn(UnionTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Union(definition) = definition {
 
                if definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found union with the same name
 
                let definition_id = definition.this.upcast();
 
                let base_type = self.types.get_base_definition(&definition_id).unwrap();
 
                let tester = UnionTester::new(self.ctx(), definition, &base_type.definition.as_union());
 
                f(tester);
 
                found = true;
 
                break;
 
            }
 
        }
 

	
 
        assert!(
 
            found, "[{}] Failed to find definition for union '{}'",
 
            self.test_name, name
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn for_function<F: FnOnce(FunctionTester)>(self, name: &str, f: F) -> Self {
 
        let mut found = false;
 
        for definition in self.heap.definitions.iter() {
 
            if let Definition::Function(definition) = definition {
 
                if definition.identifier.value.as_str() != name {
 
                    continue;
 
                }
 

	
 
                // Found function
 
                let tester = FunctionTester::new(self.ctx(), definition);
 
                f(tester);
 
                found = true;
 
                break;
 
            }
 
        }
 

	
 
        if found { return self }
 

	
 
        assert!(
 
            false, "[{}] failed to find definition for function '{}'",
 
            self.test_name, name
 
        );
 
        unreachable!();
 
    }
 

	
 
    fn ctx(&self) -> TestCtx {
 
        TestCtx{
 
            test_name: &self.test_name,
 
            modules: &self.modules,
 
            heap: &self.heap,
 
            types: &self.types,
 
            symbols: &self.symbols,
 
        }
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Utilities for successful compilation
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct StructTester<'a> {
 
    ctx: TestCtx<'a>,
 
    ast_def: &'a StructDefinition,
 
    type_def: &'a StructType,
 
}
 

	
 
impl<'a> StructTester<'a> {
 
    fn new(ctx: TestCtx<'a>, ast_def: &'a StructDefinition, type_def: &'a StructType) -> Self {
 
        Self{ ctx, ast_def, type_def }
 
    }
 

	
 
    pub(crate) fn assert_num_fields(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.ast_def.fields.len(),
 
            "[{}] Expected {} struct fields, but found {} for {}",
 
            self.ctx.test_name, num, self.ast_def.fields.len(), self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
 
        let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.ast_def.this.upcast());
 
        assert!(
 
            is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
 
            self.ctx.test_name, num, num_encountered, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
 
        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.ast_def.this.upcast(), serialized_monomorph);
 
        assert!(
 
            has_monomorph.is_some(), "[{}] Expected to find monomorph {}, but got {} for {}",
 
            self.ctx.test_name, serialized_monomorph, &serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_size_alignment(mut self, monomorph: &str, size: usize, alignment: usize) -> Self {
 
        self = self.assert_has_monomorph(monomorph);
 
        let (mono_idx, _) = has_monomorph(self.ctx, self.ast_def.this.upcast(), monomorph);
 
        let mono_idx = mono_idx.unwrap();
 
        let mono = self.ctx.types.get_monomorph(mono_idx);
 

	
 
        assert!(
 
            mono.size == size && mono.alignment == alignment,
 
            "[{}] Expected (size,alignment) of ({}, {}), but got ({}, {}) for {}",
 
            self.ctx.test_name, size, alignment, mono.size, mono.alignment, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn for_field<F: Fn(StructFieldTester)>(self, name: &str, f: F) -> Self {
 
        // Find field with specified name
 
        for field in &self.ast_def.fields {
 
            if field.field.value.as_str() == name {
 
                let tester = StructFieldTester::new(self.ctx, field);
 
                f(tester);
 
                return self;
 
            }
 
        }
 

	
 
        assert!(
 
            false, "[{}] Could not find struct field '{}' for {}",
 
            self.ctx.test_name, name, self.assert_postfix()
 
        );
 
        unreachable!();
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("Struct{ name: ");
 
        v.push_str(self.ast_def.identifier.value.as_str());
 
        v.push_str(", fields: [");
 
        for (field_idx, field) in self.ast_def.fields.iter().enumerate() {
 
            if field_idx != 0 { v.push_str(", "); }
 
            v.push_str(field.field.value.as_str());
 
        }
 
        v.push_str("] }");
 
        v
 
    }
 
}
 

	
 
pub(crate) struct StructFieldTester<'a> {
 
    ctx: TestCtx<'a>,
 
    def: &'a StructFieldDefinition,
 
}
 

	
 
impl<'a> StructFieldTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a StructFieldDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn assert_parser_type(self, expected: &str) -> Self {
 
        let mut serialized_type = String::new();
 
        serialize_parser_type(&mut serialized_type, &self.ctx.heap, &self.def.parser_type);
 
        assert_eq!(
 
            expected, &serialized_type,
 
            "[{}] Expected type '{}', but got '{}' for {}",
 
            self.ctx.test_name, expected, &serialized_type, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut serialized_type = String::new();
 
        serialize_parser_type(&mut serialized_type, &self.ctx.heap, &self.def.parser_type);
 
        format!("StructField{{ name: {}, parser_type: {} }}", self.def.field.value.as_str(), serialized_type)
 
    }
 
}
 

	
 
pub(crate) struct EnumTester<'a> {
 
    ctx: TestCtx<'a>,
 
    def: &'a EnumDefinition,
 
}
 

	
 
impl<'a> EnumTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a EnumDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn assert_num_variants(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.def.variants.len(),
 
            "[{}] Expected {} enum variants, but found {} for {}",
 
            self.ctx.test_name, num, self.def.variants.len(), self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
 
        let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.def.this.upcast());
 
        assert!(
 
            is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
 
            self.ctx.test_name, num, num_encountered, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
 
        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
 
        assert!(
 
            has_monomorph.is_some(), "[{}] Expected to find monomorph {}, but got {} for {}",
 
            self.ctx.test_name, serialized_monomorph, serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_size_alignment(mut self, serialized_monomorph: &str, size: usize, alignment: usize) -> Self {
 
        self = self.assert_has_monomorph(serialized_monomorph);
 
        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
 
        let (has_monomorph, _) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
 
        let mono_index = has_monomorph.unwrap();
 
        let mono = self.ctx.types.get_monomorph(mono_index);
 

	
 
        assert!(
 
            mono.size == size && mono.alignment == alignment,
 
            "[{}] Expected (size,alignment) of ({}, {}), but got ({}, {}) for {}",
 
            self.ctx.test_name, size, alignment, mono.size, mono.alignment, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("Enum{ name: ");
 
        v.push_str(self.def.identifier.value.as_str());
 
        v.push_str(", variants: [");
 
        for (variant_idx, variant) in self.def.variants.iter().enumerate() {
 
            if variant_idx != 0 { v.push_str(", "); }
 
            v.push_str(variant.identifier.value.as_str());
 
        }
 
        v.push_str("] }");
 
        v
 
    }
 
}
 

	
 
pub(crate) struct UnionTester<'a> {
 
    ctx: TestCtx<'a>,
 
    ast_def: &'a UnionDefinition,
 
    type_def: &'a UnionType,
 
}
 

	
 
impl<'a> UnionTester<'a> {
 
    fn new(ctx: TestCtx<'a>, ast_def: &'a UnionDefinition, type_def: &'a UnionType) -> Self {
 
        Self{ ctx, ast_def, type_def }
 
    }
 

	
 
    pub(crate) fn assert_num_variants(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.ast_def.variants.len(),
 
            "[{}] Expected {} union variants, but found {} for {}",
 
            self.ctx.test_name, num, self.ast_def.variants.len(), self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_num_monomorphs(self, num: usize) -> Self {
 
        let (is_equal, num_encountered) = has_equal_num_monomorphs(self.ctx, num, self.ast_def.this.upcast());
 
        assert!(
 
            is_equal, "[{}] Expected {} monomorphs, but got {} for {}",
 
            self.ctx.test_name, num, num_encountered, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_has_monomorph(self, serialized_monomorph: &str) -> Self {
 
        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.ast_def.this.upcast(), serialized_monomorph);
 
        assert!(
 
            has_monomorph.is_some(), "[{}] Expected to find monomorph {}, but got {} for {}",
 
            self.ctx.test_name, serialized_monomorph, serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_size_alignment(
 
        mut self, serialized_monomorph: &str,
 
        stack_size: usize, stack_alignment: usize, heap_size: usize, heap_alignment: usize
 
    ) -> Self {
 
        self = self.assert_has_monomorph(serialized_monomorph);
 
        let (mono_idx, _) = has_monomorph(self.ctx, self.ast_def.this.upcast(), serialized_monomorph);
 
        let mono_idx = mono_idx.unwrap();
 
        let mono_base = self.ctx.types.get_monomorph(mono_idx);
 
        let mono_union = mono_base.variant.as_union();
 

	
 
        assert!(
 
            stack_size == mono_base.size && stack_alignment == mono_base.alignment &&
 
                heap_size == mono_union.heap_size && heap_alignment == mono_union.heap_alignment,
 
            "[{}] Expected (stack | heap) (size, alignment) of ({}, {} | {}, {}), but got ({}, {} | {}, {}) for {}",
 
            self.ctx.test_name,
 
            stack_size, stack_alignment, heap_size, heap_alignment,
 
            mono_base.size, mono_base.alignment, mono_union.heap_size, mono_union.heap_alignment,
 
            self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("Union{ name: ");
 
        v.push_str(self.ast_def.identifier.value.as_str());
 
        v.push_str(", variants: [");
 
        for (variant_idx, variant) in self.ast_def.variants.iter().enumerate() {
 
            if variant_idx != 0 { v.push_str(", "); }
 
            v.push_str(variant.identifier.value.as_str());
 
        }
 
        v.push_str("] }");
 
        v
 
    }
 
}
 

	
 
pub(crate) struct FunctionTester<'a> {
 
    ctx: TestCtx<'a>,
 
    def: &'a FunctionDefinition,
 
}
 

	
 
impl<'a> FunctionTester<'a> {
 
    fn new(ctx: TestCtx<'a>, def: &'a FunctionDefinition) -> Self {
 
        Self{ ctx, def }
 
    }
 

	
 
    pub(crate) fn for_variable<F: Fn(VariableTester)>(self, name: &str, f: F) -> Self {
 
        // Seek through the blocks in order to find the variable
 
        let wrapping_block_id = seek_stmt(
 
            self.ctx.heap, self.def.body.upcast(),
 
            &|stmt| {
 
                if let Statement::Block(block) = stmt {
 
                    for local_id in &block.locals {
 
                        let var = &self.ctx.heap[*local_id];
 
                        if var.identifier.value.as_str() == name {
 
                            return true;
 
                        }
 
                    }
 
                }
 

	
 
                false
 
            }
 
        );
 

	
 
        let mut found_local_id = None;
 
        if let Some(block_id) = wrapping_block_id {
 
            let block_stmt = self.ctx.heap[block_id].as_block();
 
            for local_id in &block_stmt.locals {
 
                let var = &self.ctx.heap[*local_id];
 
                if var.identifier.value.as_str() == name {
 
                    found_local_id = Some(*local_id);
 
                }
 
            }
 
        }
 

	
 
        assert!(
 
            found_local_id.is_some(), "[{}] Failed to find variable '{}' in {}",
 
            self.ctx.test_name, name, self.assert_postfix()
 
        );
 

	
 
        let local = &self.ctx.heap[found_local_id.unwrap()];
 

	
 
        // Find an instance of the variable expression so we can determine its
 
        // type.
 
        let var_expr = seek_expr_in_stmt(
 
            self.ctx.heap, self.def.body.upcast(),
 
            &|expr| {
 
                if let Expression::Variable(variable_expr) = expr {
 
                    if variable_expr.identifier.value.as_str() == name {
 
                        return true;
 
                    }
 
                }
 

	
 
                false
 
            }
 
        );
 

	
 
        assert!(
 
            var_expr.is_some(), "[{}] Failed to find variable expression of '{}' in {}",
 
            self.ctx.test_name, name, self.assert_postfix()
 
        );
 

	
 
        let var_expr = &self.ctx.heap[var_expr.unwrap()];
 

	
 
        // Construct tester and pass to tester function
 
        let tester = VariableTester::new(
 
            self.ctx, self.def.this.upcast(), local,
 
            var_expr.as_variable()
 
        );
 

	
 
        f(tester);
 

	
 
        self
 
    }
 

	
 
    /// Finds a specific expression within a function. There are two matchers:
 
    /// one outer matcher (to find a rough indication of the expression) and an
 
    /// inner matcher to find the exact expression. 
 
    ///
 
    /// The reason being that, for example, a function's body might be littered
 
    /// with addition symbols, so we first match on "some_var + some_other_var",
 
    /// and then match exactly on "+".
 
    pub(crate) fn for_expression_by_source<F: Fn(ExpressionTester)>(self, outer_match: &str, inner_match: &str, f: F) -> Self {
 
        // Seek the expression in the source code
 
        assert!(outer_match.contains(inner_match), "improper testing code");
 

	
 
        let module = seek_def_in_modules(
 
            &self.ctx.heap, &self.ctx.modules, self.def.this.upcast()
 
        ).unwrap();
 

	
 
        // Find the first occurrence of the expression after the definition of
 
        // the function, we'll check that it is included in the body later.
 
        let mut outer_match_idx = self.def.span.begin.offset as usize;
 
        while outer_match_idx < module.source.input.len() {
 
            if module.source.input[outer_match_idx..].starts_with(outer_match.as_bytes()) {
 
                break;
 
            }
 
            outer_match_idx += 1
 
        }
 

	
 
        assert!(
 
            outer_match_idx < module.source.input.len(),
 
            "[{}] Failed to find '{}' within the source that contains {}",
 
            self.ctx.test_name, outer_match, self.assert_postfix()
 
        );
 
        let inner_match_idx = outer_match_idx + outer_match.find(inner_match).unwrap();
 

	
 
        // Use the inner match index to find the expression
 
        let expr_id = seek_expr_in_stmt(
 
            &self.ctx.heap, self.def.body.upcast(),
 
            &|expr| expr.operation_span().begin.offset as usize == inner_match_idx
 
        );
 
        assert!(
 
            expr_id.is_some(),
 
            "[{}] Failed to find '{}' within the source that contains {} \
 
            (note: expression was found, but not within the specified function",
 
            self.ctx.test_name, outer_match, self.assert_postfix()
 
        );
 
        let expr_id = expr_id.unwrap();
 

	
 
        // We have the expression, call the testing function
 
        let tester = ExpressionTester::new(
 
            self.ctx, self.def.this.upcast(), &self.ctx.heap[expr_id]
 
        );
 
        f(tester);
 

	
 
        self
 
    }
 

	
 
    pub(crate) fn call_ok(self, expected_result: Option<Value>) -> Self {
 
        use crate::protocol::*;
 

	
 
        let (prompt, result) = self.eval_until_end();
 
        match result {
 
            Ok(_) => {
 
                assert!(
 
                    prompt.store.stack.len() > 0, // note: stack never shrinks
 
                    "[{}] No value on stack after calling function for {}",
 
                    self.ctx.test_name, self.assert_postfix()
 
                );
 
            },
 
            Err(err) => {
 
                println!("DEBUG: Formatted evaluation error:\n{}", err);
 
                assert!(
 
                    false,
 
                    "[{}] Expected call to succeed, but got {:?} for {}",
 
                    self.ctx.test_name, err, self.assert_postfix()
 
                )
 
            }
 
        }
 

	
 
        if let Some(expected_result) = expected_result {
 
            debug_assert!(expected_result.get_heap_pos().is_none(), "comparing against heap thingamajigs is not yet implemented");
 
            assert!(
 
                value::apply_equality_operator(&prompt.store, &prompt.store.stack[0], &expected_result),
 
                "[{}] Result from call was {:?}, but expected {:?} for {}",
 
                self.ctx.test_name, &prompt.store.stack[0], &expected_result, self.assert_postfix()
 
            )
 
        }
 

	
 
        self
 
    }
 

	
 
    // Keeping this simple for now, will likely change
 
    pub(crate) fn call_err(self, expected_result: &str) -> Self {
 
        let (_, result) = self.eval_until_end();
 
        match result {
 
            Ok(_) => {
 
                assert!(
 
                    false,
 
                    "[{}] Expected an error, but evaluation finished successfully for {}",
 
                    self.ctx.test_name, self.assert_postfix()
 
                );
 
            },
 
            Err(err) => {
 
                println!("DEBUG: Formatted evaluation error:\n{}", err);
 
                debug_assert_eq!(err.statements.len(), 1);
 
                assert!(
 
                    err.statements[0].message.contains(&expected_result),
 
                    "[{}] Expected error message to contain '{}', but it was '{}' for {}",
 
                    self.ctx.test_name, expected_result, err.statements[0].message, self.assert_postfix()
 
                );
 
            }
 
        }
 

	
 
        self
 
    }
 

	
 
    fn eval_until_end(&self) -> (Prompt, Result<EvalContinuation, EvalError>) {
 
        use crate::protocol::*;
 

	
 
        // Assuming the function is not polymorphic
 
        let definition_id = self.def.this.upcast();
 
        let func_type = [ConcreteTypePart::Function(definition_id, 0)];
 
        let mono_index = self.ctx.types.get_procedure_monomorph_index(&definition_id, &func_type).unwrap();
 

	
 
        let mut prompt = Prompt::new(&self.ctx.types, &self.ctx.heap, self.def.this.upcast(), mono_index, ValueGroup::new_stack(Vec::new()));
 
        let mut call_context = FakeRunContext{};
 
        loop {
 
            let result = prompt.step(&self.ctx.types, &self.ctx.heap, &self.ctx.modules, &mut call_context);
 
            match result {
 
                Ok(EvalContinuation::Stepping) => {},
 
                _ => return (prompt, result),
 
            }
 
        }
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        format!("Function{{ name: {} }}", self.def.identifier.value.as_str())
 
    }
 
}
 

	
 
pub(crate) struct VariableTester<'a> {
 
    ctx: TestCtx<'a>,
 
    definition_id: DefinitionId,
 
    variable: &'a Variable,
 
    var_expr: &'a VariableExpression,
 
}
 

	
 
impl<'a> VariableTester<'a> {
 
    fn new(
 
        ctx: TestCtx<'a>, definition_id: DefinitionId, variable: &'a Variable, var_expr: &'a VariableExpression
 
    ) -> Self {
 
        Self{ ctx, definition_id, variable, var_expr }
 
    }
 

	
 
    pub(crate) fn assert_parser_type(self, expected: &str) -> Self {
 
        let mut serialized = String::new();
 
        serialize_parser_type(&mut serialized, self.ctx.heap, &self.variable.parser_type);
 

	
 
        assert_eq!(
 
            expected, &serialized,
 
            "[{}] Expected parser type '{}', but got '{}' for {}",
 
            self.ctx.test_name, expected, &serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    pub(crate) fn assert_concrete_type(self, expected: &str) -> Self {
 
        // Lookup concrete type in type table
 
        let mono_data = get_procedure_monomorph(&self.ctx.heap, &self.ctx.types, self.definition_id);
 
        let concrete_type = &mono_data.expr_data[self.var_expr.unique_id_in_definition as usize].expr_type;
 

	
 
        // Serialize and check
 
        let mut serialized = concrete_type.display_name(self.ctx.heap);
 
        let serialized = concrete_type.display_name(self.ctx.heap);
 

	
 
        assert_eq!(
 
            expected, &serialized,
 
            "[{}] Expected concrete type '{}', but got '{}' for {}",
 
            self.ctx.test_name, expected, &serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        format!("Variable{{ name: {} }}", self.variable.identifier.value.as_str())
 
    }
 
}
 

	
 
pub(crate) struct ExpressionTester<'a> {
 
    ctx: TestCtx<'a>,
 
    definition_id: DefinitionId, // of the enclosing function/component
 
    expr: &'a Expression
 
}
 

	
 
impl<'a> ExpressionTester<'a> {
 
    fn new(
 
        ctx: TestCtx<'a>, definition_id: DefinitionId, expr: &'a Expression
 
    ) -> Self {
 
        Self{ ctx, definition_id, expr }
 
    }
 

	
 
    pub(crate) fn assert_concrete_type(self, expected: &str) -> Self {
 
        // Lookup concrete type
 
        let mono_data = get_procedure_monomorph(&self.ctx.heap, &self.ctx.types, self.definition_id);
 
        let expr_index = self.expr.get_unique_id_in_definition();
 
        let concrete_type = &mono_data.expr_data[expr_index as usize].expr_type;
 

	
 
        // Serialize and check type
 
        let mut serialized = concrete_type.display_name(self.ctx.heap);
 
        let serialized = concrete_type.display_name(self.ctx.heap);
 

	
 
        assert_eq!(
 
            expected, &serialized,
 
            "[{}] Expected concrete type '{}', but got '{}' for {}",
 
            self.ctx.test_name, expected, &serialized, self.assert_postfix()
 
        );
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        format!(
 
            "Expression{{ debug: {:?} }}",
 
            self.expr
 
        )
 
    }
 
}
 

	
 
fn get_procedure_monomorph<'a>(heap: &Heap, types: &'a TypeTable, definition_id: DefinitionId) -> &'a ProcedureMonomorph {
 
    let ast_definition = &heap[definition_id];
 
    let func_type = if ast_definition.is_function() {
 
        [ConcreteTypePart::Function(definition_id, 0)]
 
    } else if ast_definition.is_component() {
 
        [ConcreteTypePart::Component(definition_id, 0)]
 
    } else {
 
        assert!(false);
 
        unreachable!()
 
    };
 

	
 
    let mono_index = types.get_procedure_monomorph_index(&definition_id, &func_type).unwrap();
 
    let mono_data = types.get_procedure_monomorph(mono_index);
 

	
 
    mono_data
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Interface for failed compilation
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct AstErrTester {
 
    test_name: String,
 
    error: ParseError,
 
}
 

	
 
impl AstErrTester {
 
    fn new(test_name: String, error: ParseError) -> Self {
 
        Self{ test_name, error }
 
    }
 

	
 
    pub(crate) fn error<F: Fn(ErrorTester)>(&self, f: F) {
 
        // Maybe multiple errors will be supported in the future
 
        let tester = ErrorTester{ test_name: &self.test_name, error: &self.error };
 
        f(tester)
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Utilities for failed compilation
 
//------------------------------------------------------------------------------
 

	
 
pub(crate) struct ErrorTester<'a> {
 
    test_name: &'a str,
 
    error: &'a ParseError,
 
}
 

	
 
impl<'a> ErrorTester<'a> {
 
    pub(crate) fn assert_num(self, num: usize) -> Self {
 
        assert_eq!(
 
            num, self.error.statements.len(),
 
            "[{}] expected error to consist of '{}' parts, but encountered '{}' for {}",
 
            self.test_name, num, self.error.statements.len(), self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    pub(crate) fn assert_ctx_has(self, idx: usize, msg: &str) -> Self {
 
        assert!(
 
            self.error.statements[idx].context.contains(msg),
 
            "[{}] expected error statement {}'s context to contain '{}' for {}",
 
            self.test_name, idx, msg, self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    pub(crate) fn assert_msg_has(self, idx: usize, msg: &str) -> Self {
 
        assert!(
 
            self.error.statements[idx].message.contains(msg),
 
            "[{}] expected error statement {}'s message to contain '{}' for {}",
 
            self.test_name, idx, msg, self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    /// Seeks the index of the pattern in the context message, then checks if
 
    /// the input position corresponds to that index.
 
    pub (crate) fn assert_occurs_at(self, idx: usize, pattern: &str) -> Self {
 
        let pos = self.error.statements[idx].context.find(pattern);
 
        assert!(
 
            pos.is_some(),
 
            "[{}] incorrect occurs_at: '{}' could not be found in the context for {}",
 
            self.test_name, pattern, self.assert_postfix()
 
        );
 
        let pos = pos.unwrap();
 
        let col = self.error.statements[idx].start_column as usize;
 
        assert_eq!(
 
            pos + 1, col,
 
            "[{}] Expected error to occur at column {}, but found it at {} for {}",
 
            self.test_name, pos + 1, col, self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("error: [");
 
        for (idx, stmt) in self.error.statements.iter().enumerate() {
 
            if idx != 0 {
 
                v.push_str(", ");
 
            }
 

	
 
            v.push_str(&format!("{{ context: {}, message: {} }}", &stmt.context, stmt.message));
 
        }
 
        v.push(']');
 
        v
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Generic utilities
 
//------------------------------------------------------------------------------
 

	
 
fn has_equal_num_monomorphs(ctx: TestCtx, num: usize, definition_id: DefinitionId) -> (bool, usize) {
 
    // Again: inefficient, but its testing code
 
    let type_def = ctx.types.get_base_definition(&definition_id).unwrap();
 
    let mut num_on_type = 0;
 

	
 
    for mono in &ctx.types.mono_lookup.monomorphs {
 
        match &mono.concrete_type.parts[0] {
 
            ConcreteTypePart::Instance(def_id, _) |
 
            ConcreteTypePart::Function(def_id, _) |
 
            ConcreteTypePart::Component(def_id, _) => {
 
                if *def_id == definition_id {
 
                    num_on_type += 1;
 
                }
 
            },
 
            _ => {},
 
        };
 
    }
 

	
 
    (num_on_type == num, num_on_type)
 
}
 

	
 
fn has_monomorph(ctx: TestCtx, definition_id: DefinitionId, serialized_monomorph: &str) -> (Option<i32>, String) {
 
    // Note: full_buffer is just for error reporting
 
    let mut full_buffer = String::new();
 
    let mut has_match = None;
 

	
 
    full_buffer.push('[');
 
    let mut append_to_full_buffer = |concrete_type: &ConcreteType, mono_idx: usize| {
 
        if full_buffer.len() != 1 {
 
            full_buffer.push_str(", ");
 
        }
 
        full_buffer.push('"');
 

	
 
        let first_idx = full_buffer.len();
 
        full_buffer.push_str(concrete_type.display_name(ctx.heap).as_str());
 
        if &full_buffer[first_idx..] == serialized_monomorph {
 
            has_match = Some(mono_idx as i32);
 
        }
 

	
 
        full_buffer.push('"');
 
    };
 

	
 
    // Bit wasteful, but this is (temporary?) testing code:
 
    for (mono_idx, mono) in ctx.types.mono_lookup.monomorphs.iter().enumerate() {
 
        let got_definition_id = match &mono.concrete_type.parts[0] {
 
            ConcreteTypePart::Instance(v, _) |
 
            ConcreteTypePart::Function(v, _) |
 
            ConcreteTypePart::Component(v, _) => *v,
 
            _ => DefinitionId::new_invalid(),
 
        };
 
        if got_definition_id == definition_id {
 
            append_to_full_buffer(&mono.concrete_type, mono_idx);
 
        }
 
    }
 

	
 
    full_buffer.push(']');
 

	
 
    (has_match, full_buffer)
 
}
 

	
 
fn serialize_parser_type(buffer: &mut String, heap: &Heap, parser_type: &ParserType) {
 
    use ParserTypeVariant as PTV;
 

	
 
    fn serialize_variant(buffer: &mut String, heap: &Heap, parser_type: &ParserType, mut idx: usize) -> usize {
 
        match &parser_type.elements[idx].variant {
 
            PTV::Void => buffer.push_str("void"),
 
            PTV::InputOrOutput => {
 
                buffer.push_str("portlike<");
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push('>');
 
            },
 
            PTV::ArrayLike => {
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push_str("[???]");
 
            },
 
            PTV::IntegerLike => buffer.push_str("integerlike"),
 
            PTV::Message => buffer.push_str(KW_TYPE_MESSAGE_STR),
 
            PTV::Bool => buffer.push_str(KW_TYPE_BOOL_STR),
 
            PTV::UInt8 => buffer.push_str(KW_TYPE_UINT8_STR),
 
            PTV::UInt16 => buffer.push_str(KW_TYPE_UINT16_STR),
 
            PTV::UInt32 => buffer.push_str(KW_TYPE_UINT32_STR),
 
            PTV::UInt64 => buffer.push_str(KW_TYPE_UINT64_STR),
 
            PTV::SInt8 => buffer.push_str(KW_TYPE_SINT8_STR),
 
            PTV::SInt16 => buffer.push_str(KW_TYPE_SINT16_STR),
 
            PTV::SInt32 => buffer.push_str(KW_TYPE_SINT32_STR),
 
            PTV::SInt64 => buffer.push_str(KW_TYPE_SINT64_STR),
 
            PTV::Character => buffer.push_str(KW_TYPE_CHAR_STR),
 
            PTV::String => buffer.push_str(KW_TYPE_STRING_STR),
 
            PTV::IntegerLiteral => buffer.push_str("int_literal"),
 
            PTV::Inferred => buffer.push_str(KW_TYPE_INFERRED_STR),
 
            PTV::Array => {
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push_str("[]");
 
            },
 
            PTV::Input => {
 
                buffer.push_str(KW_TYPE_IN_PORT_STR);
 
                buffer.push('<');
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push('>');
 
            },
 
            PTV::Output => {
 
                buffer.push_str(KW_TYPE_OUT_PORT_STR);
 
                buffer.push('<');
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push('>');
 
            },
 
            PTV::Tuple(num_embedded) => {
 
                buffer.push('(');
 
                for embedded_idx in 0..*num_embedded {
 
                    if embedded_idx != 0 {
 
                        buffer.push(',');
 
                    }
 
                    idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                }
 
                buffer.push(')');
 
            },
 
            PTV::PolymorphicArgument(definition_id, poly_idx) => {
 
                let definition = &heap[*definition_id];
 
                let poly_arg = &definition.poly_vars()[*poly_idx as usize];
 
                buffer.push_str(poly_arg.value.as_str());
 
            },
 
            PTV::Definition(definition_id, num_embedded) => {
 
                let definition = &heap[*definition_id];
 
                buffer.push_str(definition.identifier().value.as_str());
 

	
 
                let num_embedded = *num_embedded;
 
                if num_embedded != 0 {
 
                    buffer.push('<');
 
                    for embedded_idx in 0..num_embedded {
 
                        if embedded_idx != 0 {
 
                            buffer.push(',');
 
                        }
 
                        idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                    }
 
                    buffer.push('>');
 
                }
 
            }
 
        }
 

	
 
        idx
 
    }
 

	
 
    serialize_variant(buffer, heap, parser_type, 0);
 
}
 

	
 
fn seek_def_in_modules<'a>(heap: &Heap, modules: &'a [Module], def_id: DefinitionId) -> Option<&'a Module> {
 
    for module in modules {
 
        let root = &heap.protocol_descriptions[module.root_id];
 
        for definition in &root.definitions {
 
            if *definition == def_id {
 
                return Some(module)
 
            }
 
        }
 
    }
 

	
 
    None
 
}
 

	
 
fn seek_stmt<F: Fn(&Statement) -> bool>(heap: &Heap, start: StatementId, f: &F) -> Option<StatementId> {
 
    let stmt = &heap[start];
 
    if f(stmt) { return Some(start); }
 

	
 
    // This statement wasn't it, try to recurse
 
    let matched = match stmt {
 
        Statement::Block(block) => {
 
            for sub_id in &block.statements {
 
                if let Some(id) = seek_stmt(heap, *sub_id, f) {
 
                    return Some(id);
 
                }
 
            }
 

	
 
            None
 
        },
 
        Statement::Labeled(stmt) => seek_stmt(heap, stmt.body, f),
 
        Statement::If(stmt) => {
 
            if let Some(id) = seek_stmt(heap, stmt.true_body.upcast(), f) {
 
                return Some(id);
 
            } else if let Some(false_body) = stmt.false_body {
 
                if let Some(id) = seek_stmt(heap, false_body.upcast(), f) {
 
                    return Some(id);
 
                }
 
            }
 
            None
 
        },
 
        Statement::While(stmt) => seek_stmt(heap, stmt.body.upcast(), f),
 
        Statement::Synchronous(stmt) => seek_stmt(heap, stmt.body.upcast(), f),
 
        _ => None
 
    };
 

	
 
    matched
 
}
 

	
 
fn seek_expr_in_expr<F: Fn(&Expression) -> bool>(heap: &Heap, start: ExpressionId, f: &F) -> Option<ExpressionId> {
 
    let expr = &heap[start];
 
    if f(expr) { return Some(start); }
 

	
 
    match expr {
 
        Expression::Assignment(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.left, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.right, f))
 
        },
 
        Expression::Binding(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.bound_to, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.bound_from, f))
 
        }
 
        Expression::Conditional(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.test, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.true_expression, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.false_expression, f))
 
        },
 
        Expression::Binary(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.left, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.right, f))
 
        },
 
        Expression::Unary(expr) => {
 
            seek_expr_in_expr(heap, expr.expression, f)
 
        },
 
        Expression::Indexing(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.subject, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.index, f))
 
        },
 
        Expression::Slicing(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.subject, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.from_index, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.to_index, f))
 
        },
 
        Expression::Select(expr) => {
 
            seek_expr_in_expr(heap, expr.subject, f)
 
        },
 
        Expression::Literal(expr) => {
 
            if let Literal::Struct(lit) = &expr.value {
 
                for field in &lit.fields {
 
                    if let Some(id) = seek_expr_in_expr(heap, field.value, f) {
 
                        return Some(id)
 
                    }
 
                }
 
            } else if let Literal::Array(elements) = &expr.value {
 
                for element in elements {
 
                    if let Some(id) = seek_expr_in_expr(heap, *element, f) {
 
                        return Some(id)
 
                    }
 
                }
 
            }
 
            None
 
        },
 
        Expression::Cast(expr) => {
 
            seek_expr_in_expr(heap, expr.subject, f)
 
        }
 
        Expression::Call(expr) => {
 
            for arg in &expr.arguments {
 
                if let Some(id) = seek_expr_in_expr(heap, *arg, f) {
 
                    return Some(id)
 
                }
 
            }
 
            None
 
        },
 
        Expression::Variable(_expr) => {
 
            None
 
        }
 
    }
 
}
 

	
 
fn seek_expr_in_stmt<F: Fn(&Expression) -> bool>(heap: &Heap, start: StatementId, f: &F) -> Option<ExpressionId> {
 
    let stmt = &heap[start];
 

	
 
    match stmt {
 
        Statement::Block(stmt) => {
 
            for stmt_id in &stmt.statements {
 
                if let Some(id) = seek_expr_in_stmt(heap, *stmt_id, f) {
 
                    return Some(id)
 
                }
 
            }
 
            None
 
        },
 
        Statement::Labeled(stmt) => {
 
            seek_expr_in_stmt(heap, stmt.body, f)
 
        },
 
        Statement::If(stmt) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, stmt.test, f))
 
            .or_else(|| seek_expr_in_stmt(heap, stmt.true_body.upcast(), f))
 
            .or_else(|| if let Some(false_body) = stmt.false_body {
 
                seek_expr_in_stmt(heap, false_body.upcast(), f)
 
            } else {
 
                None
 
            })
 
        },
 
        Statement::While(stmt) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, stmt.test, f))
 
            .or_else(|| seek_expr_in_stmt(heap, stmt.body.upcast(), f))
 
        },
 
        Statement::Synchronous(stmt) => {
 
            seek_expr_in_stmt(heap, stmt.body.upcast(), f)
 
        },
 
        Statement::Return(stmt) => {
 
            for expr_id in &stmt.expressions {
 
                if let Some(id) = seek_expr_in_expr(heap, *expr_id, f) {
 
                    return Some(id);
 
                }
 
            }
 
            None
 
        },
 
        Statement::New(stmt) => {
 
            seek_expr_in_expr(heap, stmt.expression.upcast(), f)
 
        },
 
        Statement::Expression(stmt) => {
 
            seek_expr_in_expr(heap, stmt.expression, f)
 
        },
 
        _ => None
 
    }
 
}
 

	
 
struct FakeRunContext{}
 
impl RunContext for FakeRunContext {
 
    fn performed_put(&mut self, _port: PortId) -> bool {
 
        unreachable!("'put' called in compiler testing code")
 
    }
 

	
 
    fn performed_get(&mut self, _port: PortId) -> Option<ValueGroup> {
 
        unreachable!("'get' called in compiler testing code")
 
    }
 

	
 
    fn fires(&mut self, _port: PortId) -> Option<Value> {
 
        unreachable!("'fires' called in compiler testing code")
 
    }
 

	
 
    fn performed_fork(&mut self) -> Option<bool> {
 
        unreachable!("'fork' called in compiler testing code")
 
    }
 

	
 
    fn created_channel(&mut self) -> Option<(Value, Value)> {
 
        unreachable!("channel created in compiler testing code")
 
    }
 
}
 
\ No newline at end of file
0 comments (0 inline, 0 general)