CSY/reowolf Changeset - 811e0bec1c0f · Centrum Wiskunde & Informatica (CWI)

Changeset - 811e0bec1c0f

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MH - 3 years ago 2022-02-03 15:38:40
contact@maxhenger.nl

Initial setup of tree rewriting

5 files changed with 100 insertions and 3 deletions:

src/protocol/ast.rs

src/protocol/eval/executor.rs

src/protocol/parser/mod.rs

src/protocol/parser/pass_rewriting.rs

src/protocol/parser/pass_validation_linking.rs

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src/protocol/ast.rs

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@@ @@ -982,893 +982,898 @@ pub struct UnionDefinition { @@
     pub identifier: Identifier,
     pub poly_vars: Vec<Identifier>,
     // Phase 2: parsing
     pub variants: Vec<UnionVariantDefinition>,
+}
 impl UnionDefinition {
     pub(crate) fn new_empty(
         this: UnionDefinitionId, defined_in: RootId, span: InputSpan,
         identifier: Identifier, poly_vars: Vec<Identifier>
     ) -> Self {
         Self{ this, defined_in, span, identifier, poly_vars, variants: Vec::new() }
+    }
+}
 #[derive(Debug, Clone, Copy)]
 pub enum ComponentVariant {
     Primitive,
     Composite,
+}
 #[derive(Debug, Clone)]
 pub struct ComponentDefinition {
     pub this: ComponentDefinitionId,
     pub defined_in: RootId,
     // Symbol scanning
     pub span: InputSpan,
     pub variant: ComponentVariant,
     pub identifier: Identifier,
     pub poly_vars: Vec<Identifier>,
     // Parsing
     pub parameters: Vec<VariableId>,
     pub body: BlockStatementId,
     // Validation/linking
     pub num_expressions_in_body: i32,
+}
 impl ComponentDefinition {
     // Used for preallocation during symbol scanning
     pub(crate) fn new_empty(
         this: ComponentDefinitionId, defined_in: RootId, span: InputSpan,
         variant: ComponentVariant, identifier: Identifier, poly_vars: Vec<Identifier>
     ) -> Self {
         Self{
             this, defined_in, span, variant, identifier, poly_vars,
             parameters: Vec::new(),
             body: BlockStatementId::new_invalid(),
             num_expressions_in_body: -1,
+        }
+    }
+}
 // Note that we will have function definitions for builtin functions as well. In
 // that case the span, the identifier span and the body are all invalid.
 #[derive(Debug, Clone)]
 pub struct FunctionDefinition {
     pub this: FunctionDefinitionId,
     pub defined_in: RootId,
     // Symbol scanning
     pub builtin: bool,
     pub span: InputSpan,
     pub identifier: Identifier,
     pub poly_vars: Vec<Identifier>,
     // Parser
     pub return_types: Vec<ParserType>,
     pub parameters: Vec<VariableId>,
     pub body: BlockStatementId,
     // Validation/linking
     pub num_expressions_in_body: i32,
+}
 impl FunctionDefinition {
     pub(crate) fn new_empty(
         this: FunctionDefinitionId, defined_in: RootId, span: InputSpan,
         identifier: Identifier, poly_vars: Vec<Identifier>
     ) -> Self {
         Self {
             this, defined_in,
             builtin: false,
             span, identifier, poly_vars,
             return_types: Vec::new(),
             parameters: Vec::new(),
             body: BlockStatementId::new_invalid(),
             num_expressions_in_body: -1,
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub enum Statement {
     Block(BlockStatement),
     EndBlock(EndBlockStatement),
     Local(LocalStatement),
     Labeled(LabeledStatement),
     If(IfStatement),
     EndIf(EndIfStatement),
     While(WhileStatement),
     EndWhile(EndWhileStatement),
     Break(BreakStatement),
     Continue(ContinueStatement),
     Synchronous(SynchronousStatement),
     EndSynchronous(EndSynchronousStatement),
     Fork(ForkStatement),
     EndFork(EndForkStatement),
     Select(SelectStatement),
     EndSelect(EndSelectStatement),
     Return(ReturnStatement),
     Goto(GotoStatement),
     New(NewStatement),
     Expression(ExpressionStatement),
+}
 impl Statement {
     pub fn as_block(&self) -> &BlockStatement {
         match self {
             Statement::Block(result) => result,
             _ => panic!("Unable to cast `Statement` to `BlockStatement`"),
+        }
+    }
     pub fn as_local(&self) -> &LocalStatement {
         match self {
             Statement::Local(result) => result,
             _ => panic!("Unable to cast `Statement` to `LocalStatement`"),
+        }
+    }
     pub fn as_memory(&self) -> &MemoryStatement {
         self.as_local().as_memory()
+    }
     pub fn as_channel(&self) -> &ChannelStatement {
         self.as_local().as_channel()
+    }
     pub fn as_new(&self) -> &NewStatement {
         match self {
             Statement::New(result) => result,
             _ => panic!("Unable to cast `Statement` to `NewStatement`"),
+        }
+    }
     pub fn span(&self) -> InputSpan {
         match self {
             Statement::Block(v) => v.span,
             Statement::Local(v) => v.span(),
             Statement::Labeled(v) => v.label.span,
             Statement::If(v) => v.span,
             Statement::While(v) => v.span,
             Statement::Break(v) => v.span,
             Statement::Continue(v) => v.span,
             Statement::Synchronous(v) => v.span,
             Statement::Fork(v) => v.span,
             Statement::Select(v) => v.span,
             Statement::Return(v) => v.span,
             Statement::Goto(v) => v.span,
             Statement::New(v) => v.span,
             Statement::Expression(v) => v.span,
             Statement::EndBlock(_)
             | Statement::EndIf(_)
             | Statement::EndWhile(_)
             | Statement::EndSynchronous(_)
             | Statement::EndFork(_)
             | Statement::EndSelect(_) => unreachable!(),
+        }
+    }
     pub fn link_next(&mut self, next: StatementId) {
         match self {
             Statement::Block(stmt) => stmt.next = next,
             Statement::EndBlock(stmt) => stmt.next = next,
             Statement::Local(stmt) => match stmt {
                 LocalStatement::Channel(stmt) => stmt.next = next,
                 LocalStatement::Memory(stmt) => stmt.next = next,
             },
             Statement::EndIf(stmt) => stmt.next = next,
             Statement::EndWhile(stmt) => stmt.next = next,
             Statement::EndSynchronous(stmt) => stmt.next = next,
             Statement::EndFork(stmt) => stmt.next = next,
             Statement::EndSelect(stmt) => stmt.next = next,
             Statement::New(stmt) => stmt.next = next,
             Statement::Expression(stmt) => stmt.next = next,
             Statement::Return(_)
             | Statement::Break(_)
             | Statement::Continue(_)
             | Statement::Synchronous(_)
             | Statement::Fork(_)
             | Statement::Select(_)
             | Statement::Goto(_)
             | Statement::While(_)
             | Statement::Labeled(_)
             | Statement::If(_) => unreachable!(),
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub struct BlockStatement {
     pub this: BlockStatementId,
     // Phase 1: parser
     pub is_implicit: bool,
     pub span: InputSpan, // of the complete block
     pub statements: Vec<StatementId>,
     pub end_block: EndBlockStatementId,
     // Phase 2: linker
     pub scope_node: ScopeNode,
     pub first_unique_id_in_scope: i32, // Temporary fix until proper bytecode/asm is generated
     pub next_unique_id_in_scope: i32, // Temporary fix until proper bytecode/asm is generated
     pub locals: Vec<VariableId>,
     pub labels: Vec<LabeledStatementId>,
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct EndBlockStatement {
     pub this: EndBlockStatementId,
     // Parser
     pub start_block: BlockStatementId,
     // Validation/Linking
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub enum LocalStatement {
     Memory(MemoryStatement),
     Channel(ChannelStatement),
+}
 impl LocalStatement {
     pub fn this(&self) -> LocalStatementId {
         match self {
             LocalStatement::Memory(stmt) => stmt.this.upcast(),
             LocalStatement::Channel(stmt) => stmt.this.upcast(),
+        }
+    }
     pub fn as_memory(&self) -> &MemoryStatement {
         match self {
             LocalStatement::Memory(result) => result,
             _ => panic!("Unable to cast `LocalStatement` to `MemoryStatement`"),
+        }
+    }
     pub fn as_channel(&self) -> &ChannelStatement {
         match self {
             LocalStatement::Channel(result) => result,
             _ => panic!("Unable to cast `LocalStatement` to `ChannelStatement`"),
+        }
+    }
     pub fn span(&self) -> InputSpan {
         match self {
             LocalStatement::Channel(v) => v.span,
             LocalStatement::Memory(v) => v.span,
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub struct MemoryStatement {
     pub this: MemoryStatementId,
     // Phase 1: parser
     pub span: InputSpan,
     pub variable: VariableId,
     pub initial_expr: AssignmentExpressionId,
     // Phase 2: linker
     pub next: StatementId,
+}
 /// ChannelStatement is the declaration of an input and output port associated
 /// with the same channel. Note that the polarity of the ports are from the
 /// point of view of the component. So an output port is something that a
 /// component uses to send data over (i.e. it is the "input end" of the
 /// channel), and vice versa.
 #[derive(Debug, Clone)]
 pub struct ChannelStatement {
     pub this: ChannelStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "channel" keyword
     pub from: VariableId, // output
     pub to: VariableId,   // input
     // Phase 2: linker
     pub relative_pos_in_block: i32,
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct LabeledStatement {
     pub this: LabeledStatementId,
     // Phase 1: parser
     pub label: Identifier,
     pub body: StatementId,
     // Phase 2: linker
     pub relative_pos_in_block: i32,
     pub in_sync: SynchronousStatementId, // may be invalid
+}
 #[derive(Debug, Clone)]
 pub struct IfStatement {
     pub this: IfStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "if" keyword
     pub test: ExpressionId,
     pub true_body: BlockStatementId,
     pub false_body: Option<BlockStatementId>,
     pub end_if: EndIfStatementId,
+}
 #[derive(Debug, Clone)]
 pub struct EndIfStatement {
     pub this: EndIfStatementId,
     pub start_if: IfStatementId,
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct WhileStatement {
     pub this: WhileStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "while" keyword
     pub test: ExpressionId,
     pub body: BlockStatementId,
     pub end_while: EndWhileStatementId,
     pub in_sync: SynchronousStatementId, // may be invalid
+}
 #[derive(Debug, Clone)]
 pub struct EndWhileStatement {
     pub this: EndWhileStatementId,
     pub start_while: WhileStatementId,
     // Phase 2: linker
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct BreakStatement {
     pub this: BreakStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "break" keyword
     pub label: Option<Identifier>,
     // Phase 2: linker
     pub target: EndWhileStatementId, // invalid if not yet set
+}
 #[derive(Debug, Clone)]
 pub struct ContinueStatement {
     pub this: ContinueStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "continue" keyword
     pub label: Option<Identifier>,
     // Phase 2: linker
     pub target: WhileStatementId, // invalid if not yet set
+}
 #[derive(Debug, Clone)]
 pub struct SynchronousStatement {
     pub this: SynchronousStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "sync" keyword
     pub body: BlockStatementId,
     pub end_sync: EndSynchronousStatementId,
+}
 #[derive(Debug, Clone)]
 pub struct EndSynchronousStatement {
     pub this: EndSynchronousStatementId,
     pub start_sync: SynchronousStatementId,
     // Phase 2: linker
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct ForkStatement {
     pub this: ForkStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "fork" keyword
     pub left_body: BlockStatementId,
     pub right_body: Option<BlockStatementId>,
     pub end_fork: EndForkStatementId,
+}
 #[derive(Debug, Clone)]
 pub struct EndForkStatement {
     pub this: EndForkStatementId,
     pub start_fork: ForkStatementId,
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct SelectStatement {
     pub this: SelectStatementId,
     pub span: InputSpan, // of the "select" keyword
     pub cases: Vec<SelectCase>,
     pub end_select: EndSelectStatementId,
+}
 #[derive(Debug, Clone)]
 pub struct SelectCase {
     // The guard statement of a `select` is either a MemoryStatement or an
     // ExpressionStatement. Nothing else is allowed by the initial parsing
     pub guard: StatementId,
     pub block: BlockStatementId,
     // Phase 2: Validation and Linking
     pub involved_ports: Vec<(CallExpressionId, ExpressionId)>, // call to `get` and its port argument
+}
 #[derive(Debug, Clone)]
 pub struct EndSelectStatement {
     pub this: EndSelectStatementId,
     pub start_select: SelectStatementId,
     pub next: StatementId,
+}
 #[derive(Debug, Clone)]
 pub struct ReturnStatement {
     pub this: ReturnStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "return" keyword
     pub expressions: Vec<ExpressionId>,
+}
 #[derive(Debug, Clone)]
 pub struct GotoStatement {
     pub this: GotoStatementId,
     // Phase 1: parser
     pub span: InputSpan, // of the "goto" keyword
     pub label: Identifier,
     // Phase 2: linker
     pub target: LabeledStatementId, // invalid if not yet set
+}
 #[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
     Memory(MemoryStatementId),
     If(IfStatementId),
     While(WhileStatementId),
     Return(ReturnStatementId),
     New(NewStatementId),
     ExpressionStmt(ExpressionStatementId),
     Expression(ExpressionId, u32) // index within expression (e.g LHS or RHS of expression)
+}
 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 enum SelectKind {
     StructField(Identifier),
     TupleMember(u64), // u64 is overkill, but space is taken up by `StructField` variant anyway
+}
 #[derive(Debug, Clone)]
 pub struct SelectExpression {
     pub this: SelectExpressionId,
     // Parsing
     pub operator_span: InputSpan, // of the '.'
     pub full_span: InputSpan, // includes subject and field
     pub subject: ExpressionId,
     pub kind: SelectKind,
     // Validator/Linker
     pub parent: ExpressionParent,
     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
+    // Builtin, accessible by programmer
     Get,
     Put,
     Fires,
     Create,
     Length,
     Assert,
     Print,
     // Builtin, not accessible by programmer
     SelectStart, // SelectStart(total_num_cases, total_num_ports)
     SelectRegisterCasePort, // SelectRegisterCasePort(case_index, port_index, port_id)
     SelectWait, // SelectWait() -> u32
     // User-defined
     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/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
+            }
+        }
+    }
+}
 pub 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 = match expr.kind {
                                         SelectKind::StructField(_) => subject.as_struct(),
                                         SelectKind::TupleMember(_) => subject.as_tuple(),
                                     };
                                     (None, Value::Ref(ValueId::Heap(subject_heap_pos, field_idx)))
                                 },
                                 _ => {
                                     let subject_heap_pos = match expr.kind {
                                         SelectKind::StructField(_) => subject.as_struct(),
                                         SelectKind::TupleMember(_) => subject.as_tuple(),
                                     };
                                     let subject_indexed = Value::Ref(ValueId::Heap(subject_heap_pos, field_idx));
                                     (Some(subject_heap_pos), self.store.clone_value(subject_indexed))
                                 },
                             };
                             cur_frame.expr_values.push_back(value_to_push);
                             self.store.drop_value(deallocate_heap_pos);
                         },
                         Expression::Literal(expr) => {
                             let value = match &expr.value {
                                 Literal::Null => Value::Null,
                                 Literal::True => Value::Bool(true),
                                 Literal::False => Value::Bool(false),
                                 Literal::Character(lit_value) => Value::Char(*lit_value),
                                 Literal::String(lit_value) => {
                                     let heap_pos = self.store.alloc_heap();
                                     let values = &mut self.store.heap_regions[heap_pos as usize].values;
                                     let value = lit_value.as_str();
                                     debug_assert!(values.is_empty());
                                     values.reserve(value.len());
                                     for character in value.as_bytes() {
                                         debug_assert!(character.is_ascii());
                                         values.push(Value::Char(*character as char));
+                                    }
                                     Value::String(heap_pos)
+                                }
                                 Literal::Integer(lit_value) => {
                                     use ConcreteTypePart as CTP;
                                     let 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::SelectStart => {
                                     todo!("select start");
                                 },
                                 Method::SelectRegisterCasePort => {
                                     todo!("select register");
                                 },
                                 Method::SelectWait => {
                                     todo!("select wait");
                                 },
                                 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) => {
                         if cfg!(debug_assertions) {
                             let variable = &heap[stmt.variable];
                             debug_assert!(match self.store.read_ref(ValueId::Stack(variable.unique_id_in_scope as u32)) {
                                 Value::Unassigned => false,
                                 _ => true,
                             });
+                        }
                         cur_frame.position = stmt.next;
                         Ok(EvalContinuation::Stepping)
                     },
                     LocalStatement::Channel(stmt) => {
                         // Need to create a new channel by requesting it from
                         // the runtime.
                         match ctx.created_channel() {
                             None => {
                                 // No channel is pending. So request one
                                     Ok(EvalContinuation::NewChannel)
                             },
                             Some((put_port, get_port)) => {
                                 self.store.write(ValueId::Stack(heap[stmt.from].unique_id_in_scope as u32), put_port);
                                 self.store.write(ValueId::Stack(heap[stmt.to].unique_id_in_scope as u32), get_port);
                                 cur_frame.position = stmt.next;
                                 Ok(EvalContinuation::Stepping)
+                            }
+                        }
+                    }
+                }
             },
             Statement::Labeled(stmt) => {
                 cur_frame.position = stmt.body;
                 Ok(EvalContinuation::Stepping)
             },
             Statement::If(stmt) => {
                 debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for if statement");
                 let test_value = cur_frame.expr_values.pop_back().unwrap();
                 let test_value = self.store.maybe_read_ref(&test_value).as_bool();
                 if test_value {
                     cur_frame.position = stmt.true_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.upcast();
                 Ok(EvalContinuation::Stepping)
             },
             Statement::Continue(stmt) => {
                 cur_frame.position = stmt.target.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::Select(_stmt) => {
                 todo!("implement select evaluation")
             },
             Statement::EndSelect(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
                 self.store.clear_stack(0);
                 self.store.stack.truncate(self.store.cur_stack_boundary + 1);
                 let prev_stack_idx = self.store.stack.pop().unwrap().as_stack_boundary();
                 // TODO: Temporary hack for testing, remove at some point
                 if self.frames.is_empty() {
                     debug_assert!(prev_stack_idx == -1);
                     debug_assert!(self.store.stack.len() == 0);
                     self.store.stack.push(return_value);
                     return Ok(EvalContinuation::ComponentTerminated);
+                }
                 debug_assert!(prev_stack_idx >= 0);
                 // Return to original state of stack frame
                 self.store.cur_stack_boundary = prev_stack_idx as usize;
                 let cur_frame = self.frames.last_mut().unwrap();
                 cur_frame.expr_values.push_back(return_value);
                 // We just returned to the previous frame, which might be in
                 // the middle of evaluating expressions for a particular
                 // statement. So we don't want to enter the code below.
                 return Ok(EvalContinuation::Stepping);
             },
             Statement::Goto(stmt) => {
                 cur_frame.position = stmt.target.upcast();
                 Ok(EvalContinuation::Stepping)
             },
             Statement::New(stmt) => {
                 let call_expr = &heap[stmt.expression];
                 debug_assert!(heap[call_expr.definition].is_component());
                 debug_assert_eq!(
                     cur_frame.expr_values.len(), heap[call_expr.definition].parameters().len(),
                     "mismatch in expr stack size and number of arguments for new statement"
                 );
                 let mono_data = types.get_procedure_monomorph(cur_frame.monomorph_idx);
                 let expr_data = &mono_data.expr_data[call_expr.unique_id_in_definition as usize];
                 // Note that due to expression value evaluation they exist in
                 // reverse order on the stack.
                 // TODO: Revise this code, keep it as is to be compatible with current runtime
                 let mut args = Vec::new();
                 while let Some(value) = cur_frame.expr_values.pop_front() {
                     args.push(value);
+                }
                 // Construct argument group, thereby copying heap regions
                 let argument_group = ValueGroup::from_store(&self.store, &args);
                 // println!("Creating {} with\n{:#?}", heap[call_expr.definition].identifier().value.as_str(), argument_group);
                 // Clear any heap regions
                 for arg in &args {
                     self.store.drop_value(arg.get_heap_pos());
+                }
                 cur_frame.position = stmt.next;
                 Ok(EvalContinuation::NewComponent(call_expr.definition, expr_data.field_or_monomorph_idx, argument_group))
             },
             Statement::Expression(stmt) => {
                 // The expression has just been completely evaluated. Some
                 // values might have remained on the expression value stack.
                 // cur_frame.expr_values.clear(); PROPER CLEARING
                 cur_frame.position = stmt.next;
                 Ok(EvalContinuation::Stepping)
             },
         };
         assert!(
             cur_frame.expr_values.is_empty(),
             "This is a debugging assertion that will fail if you perform expressions without \
             assigning to anything. This should be completely valid, and this assertion should be \
             replaced by something that clears the expression values if needed, but I'll keep this \
             in for now for debugging purposes."
         );
         // If the next statement requires evaluating expressions then we push
         // these onto the expression stack. This way we will evaluate this
         // stack in the next loop, then evaluate the statement using the result
         // from the expression evaluation.
         if !cur_frame.position.is_invalid() {
             let stmt = &heap[cur_frame.position];
             match stmt {
                 Statement::Local(stmt) => {
                     if let LocalStatement::Memory(stmt) = stmt {
                         // Setup as unassigned, when we execute the memory
                         // statement (after evaluating expression), it should no
                         // longer be `Unassigned`.
                         let variable = &heap[stmt.variable];
                         self.store.write(ValueId::Stack(variable.unique_id_in_scope as u32), Value::Unassigned);
                         cur_frame.prepare_single_expression(heap, stmt.initial_expr.upcast());
+                    }
                 },
                 Statement::If(stmt) => cur_frame.prepare_single_expression(heap, stmt.test),
                 Statement::While(stmt) => cur_frame.prepare_single_expression(heap, stmt.test),
                 Statement::Return(stmt) => {
                     debug_assert_eq!(stmt.expressions.len(), 1); // TODO: @ReturnValues
                     cur_frame.prepare_single_expression(heap, stmt.expressions[0]);
                 },
                 Statement::New(stmt) => {
                     // Note that we will end up not evaluating the call itself.
                     // Rather we will evaluate its expressions and then
                     // instantiate the component upon reaching the "new" stmt.
                     let call_expr = &heap[stmt.expression];
                     cur_frame.prepare_multiple_expressions(heap, &call_expr.arguments);
                 },
                 Statement::Expression(stmt) => {
                     cur_frame.prepare_single_expression(heap, stmt.expression);
+                }
                 _ => {},
+            }
+        }
         return_value
+    }
     /// Constructs an error at the current expression that lives at the top of
     /// the expression stack. Falls back to constructing an error at the current
     /// statement if there is no expression.
     pub(crate) fn new_error_at_expr(&self, modules: &[Module], heap: &Heap, error_message: String) -> EvalError {
         let last_frame = self.frames.last().unwrap();
         for instruction in last_frame.expr_stack.iter().rev() {
             if let ExprInstruction::EvalExpr(expression_id) = instruction {
                 return EvalError::new_error_at_expr(
                     self, modules, heap, *expression_id, error_message
                 );
+            }
+        }
         // If here then expression stack was empty (cannot have just rotate
         // instructions)
         panic!("attempted to construct evaluation error without any expressions to evaluate in frame");
+    }
+}
@@ \ No newline at end of file @@

src/protocol/parser/mod.rs

➞

Show inline comments

 pub(crate) mod symbol_table;
 pub(crate) mod type_table;
 pub(crate) mod tokens;
 pub(crate) mod token_parsing;
 pub(crate) mod pass_tokenizer;
 pub(crate) mod pass_symbols;
 pub(crate) mod pass_imports;
 pub(crate) mod pass_definitions;
 pub(crate) mod pass_definitions_types;
 pub(crate) mod pass_validation_linking;
 pub(crate) mod pass_rewriting;
 pub(crate) mod pass_typing;
 mod visitor;
 use tokens::*;
 use crate::collections::*;
 use visitor::Visitor;
 use pass_tokenizer::PassTokenizer;
 use pass_symbols::PassSymbols;
 use pass_imports::PassImport;
 use pass_definitions::PassDefinitions;
 use pass_validation_linking::PassValidationLinking;
 use pass_typing::{PassTyping, ResolveQueue};
 use symbol_table::*;
 use type_table::TypeTable;
 use crate::protocol::ast::*;
 use crate::protocol::input_source::*;
 use crate::protocol::ast_printer::ASTWriter;
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub enum ModuleCompilationPhase {
     Tokenized,              // source is tokenized
     SymbolsScanned,         // all definitions are linked to their type class
     ImportsResolved,        // all imports are added to the symbol table
     DefinitionsParsed,      // produced the AST for the entire module
     TypesAddedToTable,      // added all definitions to the type table
     ValidatedAndLinked,     // AST is traversed and has linked the required AST nodes
     Rewritten,              // Special AST nodes are rewritten into regular AST nodes
     // When we continue with the compiler:
     // Typed,                  // Type inference and checking has been performed
+}
 pub struct Module {
     // Buffers
     pub source: InputSource,
     pub tokens: TokenBuffer,
     // Identifiers
     pub root_id: RootId,
     pub name: Option<(PragmaId, StringRef<'static>)>,
     pub version: Option<(PragmaId, i64)>,
     pub phase: ModuleCompilationPhase,
+}
 // TODO: This is kind of wrong. Because when we're producing bytecode we would
 //       like the bytecode itself to not have the notion of the size of a pointer
 //       type. But until I figure out what we do want I'll just set everything
 //       to a 64-bit architecture.
 pub struct TargetArch {
     pub array_size_alignment: (usize, usize),
     pub slice_size_alignment: (usize, usize),
     pub string_size_alignment: (usize, usize),
     pub port_size_alignment: (usize, usize),
     pub pointer_size_alignment: (usize, usize),
+}
 pub struct PassCtx<'a> {
     heap: &'a mut Heap,
     symbols: &'a mut SymbolTable,
     pool: &'a mut StringPool,
     arch: &'a TargetArch,
+}
 pub struct Parser {
     // Storage of all information created/gathered during compilation.
     pub(crate) heap: Heap,
     pub(crate) string_pool: StringPool, // Do not deallocate, holds all strings
     pub(crate) modules: Vec<Module>,
     pub(crate) symbol_table: SymbolTable,
     pub(crate) type_table: TypeTable,
     // Compiler passes, used as little state machine that keep their memory
     // around.
     pass_tokenizer: PassTokenizer,
     pass_symbols: PassSymbols,
     pass_import: PassImport,
     pass_definitions: PassDefinitions,
     pass_validation: PassValidationLinking,
     pass_typing: PassTyping,
     // Compiler options
     pub write_ast_to: Option<String>,
     pub(crate) arch: TargetArch,
+}
 impl Parser {
     pub fn new() -> Self {
         let mut parser = Parser{
             heap: Heap::new(),
             string_pool: StringPool::new(),
             modules: Vec::new(),
             symbol_table: SymbolTable::new(),
             type_table: TypeTable::new(),
             pass_tokenizer: PassTokenizer::new(),
             pass_symbols: PassSymbols::new(),
             pass_import: PassImport::new(),
             pass_definitions: PassDefinitions::new(),
             pass_validation: PassValidationLinking::new(),
             pass_typing: PassTyping::new(),
             write_ast_to: None,
             arch: TargetArch {
                 array_size_alignment: (3*8, 8), // pointer, length, capacity
                 slice_size_alignment: (2*8, 8), // pointer, length
                 string_size_alignment: (3*8, 8), // pointer, length, capacity
                 port_size_alignment: (3*4, 4), // two u32s: connector + port ID
                 pointer_size_alignment: (8, 8),
+            }
         };
         parser.symbol_table.insert_scope(None, SymbolScope::Global);
         fn quick_type(variants: &[ParserTypeVariant]) -> ParserType {
             let mut t = ParserType{ elements: Vec::with_capacity(variants.len()), full_span: InputSpan::new() };
             for variant in variants {
                 t.elements.push(ParserTypeElement{ element_span: InputSpan::new(), variant: variant.clone() });
+            }
+            t
+        }
         use ParserTypeVariant as PTV;
         insert_builtin_function(&mut parser, "get", &["T"], |id| (
             vec![
                 ("input", quick_type(&[PTV::Input, PTV::PolymorphicArgument(id.upcast(), 0)]))
             ],
             quick_type(&[PTV::PolymorphicArgument(id.upcast(), 0)])
         ));
         insert_builtin_function(&mut parser, "put", &["T"], |id| (
             vec![
                 ("output", quick_type(&[PTV::Output, PTV::PolymorphicArgument(id.upcast(), 0)])),
                 ("value", quick_type(&[PTV::PolymorphicArgument(id.upcast(), 0)])),
             ],
             quick_type(&[PTV::Void])
         ));
         insert_builtin_function(&mut parser, "fires", &["T"], |id| (
             vec![
                 ("port", quick_type(&[PTV::InputOrOutput, PTV::PolymorphicArgument(id.upcast(), 0)]))
             ],
             quick_type(&[PTV::Bool])
         ));
         insert_builtin_function(&mut parser, "create", &["T"], |id| (
             vec![
                 ("length", quick_type(&[PTV::IntegerLike]))
             ],
             quick_type(&[PTV::ArrayLike, PTV::PolymorphicArgument(id.upcast(), 0)])
         ));
         insert_builtin_function(&mut parser, "length", &["T"], |id| (
             vec![
                 ("array", quick_type(&[PTV::ArrayLike, PTV::PolymorphicArgument(id.upcast(), 0)]))
             ],
             quick_type(&[PTV::UInt32]) // TODO: @PtrInt
         ));
         insert_builtin_function(&mut parser, "assert", &[], |_id| (
             vec![
                 ("condition", quick_type(&[PTV::Bool])),
             ],
             quick_type(&[PTV::Void])
         ));
         insert_builtin_function(&mut parser, "print", &[], |_id| (
             vec![
                 ("message", quick_type(&[PTV::String])),
             ],
             quick_type(&[PTV::Void])
         ));
         parser
+    }
     pub fn feed(&mut self, mut source: InputSource) -> Result<(), ParseError> {
         let mut token_buffer = TokenBuffer::new();
         self.pass_tokenizer.tokenize(&mut source, &mut token_buffer)?;
         let module = Module{
             source,
             tokens: token_buffer,
             root_id: RootId::new_invalid(),
             name: None,
             version: None,
             phase: ModuleCompilationPhase::Tokenized,
         };
         self.modules.push(module);
         Ok(())
+    }
     pub fn parse(&mut self) -> Result<(), ParseError> {
         let mut pass_ctx = PassCtx{
             heap: &mut self.heap,
             symbols: &mut self.symbol_table,
             pool: &mut self.string_pool,
             arch: &self.arch,
         };
         // Advance all modules to the phase where all symbols are scanned
         for module_idx in 0..self.modules.len() {
             self.pass_symbols.parse(&mut self.modules, module_idx, &mut pass_ctx)?;
+        }
         // With all symbols scanned, perform further compilation until we can
         // add all base types to the type table.
         for module_idx in 0..self.modules.len() {
             self.pass_import.parse(&mut self.modules, module_idx, &mut pass_ctx)?;
             self.pass_definitions.parse(&mut self.modules, module_idx, &mut pass_ctx)?;
+        }
         // Add every known type to the type table
         self.type_table.build_base_types(&mut self.modules, &mut pass_ctx)?;
         // Continue compilation with the remaining phases now that the types
         // are all in the type table
         for module_idx in 0..self.modules.len() {
             let mut ctx = visitor::Ctx{
                 heap: &mut self.heap,
                 modules: &mut self.modules,
                 module_idx,
                 symbols: &mut self.symbol_table,
                 types: &mut self.type_table,
                 arch: &self.arch,
             };
             self.pass_validation.visit_module(&mut ctx)?;
+        }
         // Perform typechecking on all modules
         let mut queue = ResolveQueue::new();
         for module_idx in 0..self.modules.len() {
             let mut ctx = visitor::Ctx{
                 heap: &mut self.heap,
                 modules: &mut self.modules,
                 module_idx,
                 symbols: &mut self.symbol_table,
                 types: &mut self.type_table,
                 arch: &self.arch,
             };
             PassTyping::queue_module_definitions(&mut ctx, &mut queue);
         };
         while !queue.is_empty() {
             let top = queue.pop().unwrap();
             let mut ctx = visitor::Ctx{
                 heap: &mut self.heap,
                 modules: &mut self.modules,
                 module_idx: top.root_id.index as usize,
                 symbols: &mut self.symbol_table,
                 types: &mut self.type_table,
                 arch: &self.arch,
             };
             self.pass_typing.handle_module_definition(&mut ctx, &mut queue, top)?;
+        }
         // Write out desired information
         if let Some(filename) = &self.write_ast_to {
             let mut writer = ASTWriter::new();
             let mut file = std::fs::File::create(std::path::Path::new(filename)).unwrap();
             writer.write_ast(&mut file, &self.heap);
+        }
         Ok(())
+    }
+}
 // Note: args and return type need to be a function because we need to know the function ID.
 fn insert_builtin_function<T: Fn(FunctionDefinitionId) -> (Vec<(&'static str, ParserType)>, ParserType)> (
     p: &mut Parser, func_name: &str, polymorphic: &[&str], arg_and_return_fn: T) {
     let mut poly_vars = Vec::with_capacity(polymorphic.len());
     for poly_var in polymorphic {
         poly_vars.push(Identifier{ span: InputSpan::new(), value: p.string_pool.intern(poly_var.as_bytes()) });
+    }
     let func_ident_ref = p.string_pool.intern(func_name.as_bytes());
     let func_id = p.heap.alloc_function_definition(|this| FunctionDefinition{
         this,
         defined_in: RootId::new_invalid(),
         builtin: true,
         span: InputSpan::new(),
         identifier: Identifier{ span: InputSpan::new(), value: func_ident_ref.clone() },
         poly_vars,
         return_types: Vec::new(),
         parameters: Vec::new(),
         body: BlockStatementId::new_invalid(),
         num_expressions_in_body: -1,
     });
     let (args, ret) = arg_and_return_fn(func_id);
     let mut parameters = Vec::with_capacity(args.len());
     for (arg_name, arg_type) in args {
         let identifier = Identifier{ span: InputSpan::new(), value: p.string_pool.intern(arg_name.as_bytes()) };
         let param_id = p.heap.alloc_variable(|this| Variable{
             this,
             kind: VariableKind::Parameter,
             parser_type: arg_type.clone(),
             identifier,
             relative_pos_in_block: 0,
             unique_id_in_scope: 0
         });
         parameters.push(param_id);
+    }
     let func = &mut p.heap[func_id];
     func.parameters = parameters;
     func.return_types.push(ret);
     p.symbol_table.insert_symbol(SymbolScope::Global, Symbol{
         name: func_ident_ref,
         variant: SymbolVariant::Definition(SymbolDefinition{
             defined_in_module: RootId::new_invalid(),
             defined_in_scope: SymbolScope::Global,
             definition_span: InputSpan::new(),
             identifier_span: InputSpan::new(),
             imported_at: None,
             class: DefinitionClass::Function,
             definition_id: func_id.upcast(),
         })
     }).unwrap();
+}
@@ \ No newline at end of file @@

src/protocol/parser/pass_rewriting.rs

➞

Show inline comments

@@ new file 100644 @@
 use crate::collections::*;
 use crate::protocol::*;
 use super::visitor::*;
 pub(crate) struct PassRewriting {
     statement_buffer: ScopedBuffer<StatementId>,
+}
 impl PassRewriting {
     pub(crate) fn new() -> Self {
         Self{
             statement_buffer: ScopedBuffer::with_capacity(16),
+        }
+    }
+}
 impl Visitor for PassRewriting {
     // --- Visiting procedures
     fn visit_component_definition(&mut self, ctx: &mut Ctx, id: ComponentDefinitionId) -> VisitorResult {
         let def = &ctx.heap[id];
         let body_id = def.body;
         return self.visit_block_stmt(ctx, body_id);
+    }
     fn visit_function_definition(&mut self, ctx: &mut Ctx, id: FunctionDefinitionId) -> VisitorResult {
         let def = &ctx.heap[id];
         let body_id = def.body;
         return self.visit_block_stmt(ctx, body_id);
+    }
     // --- Visiting statements (that are not the select statement)
     fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
         let block_stmt = &ctx.heap[id];
         let stmt_section = self.statement_buffer.start_section_initialized(&block_stmt.statements);
         for stmt_idx in 0..stmt_section.len() {
             self.visit_stmt(ctx, stmt_section[stmt_idx])?;
+        }
         stmt_section.forget();
         return Ok(())
+    }
     fn visit_labeled_stmt(&mut self, ctx: &mut Ctx, id: LabeledStatementId) -> VisitorResult {
         let labeled_stmt = &ctx.heap[id];
         let body_id = labeled_stmt.body;
         return self.visit_stmt(ctx, body_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;
         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)?;
+        }
         return 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;
         return self.visit_block_stmt(ctx, body_id);
+    }
     // --- Visiting the select statement
     fn visit_select_stmt(&mut self, ctx: &mut Ctx, id: SelectStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         return Ok(())
+    }
+}
@@ \ No newline at end of file @@

src/protocol/parser/pass_validation_linking.rs

➞

Show inline comments

 /*
  * pass_validation_linking.rs
+ *
  * The pass that will validate properties of the AST statements (one is not
  * allowed to nest synchronous statements, instantiating components occurs in
  * the right places, etc.) and expressions (assignments may not occur in
  * arbitrary expressions).
+ *
  * Furthermore, this pass will also perform "linking", in the sense of: some AST
  * nodes have something to do with one another, so we link them up in this pass
  * (e.g. setting the parents of expressions, linking the control flow statements
  * like `continue` and `break` up to the respective loop statement, etc.).
+ *
  * There are several "confusing" parts about this pass:
+ *
  * Setting expression parents: this is the simplest one. The pass struct acts
  * like a little state machine. When visiting an expression it will set the
  * "parent expression" field of the pass to itself, then visit its child. The
  * child will look at this "parent expression" field to determine its parent.
+ *
  * Setting the `next` statement: the AST is a tree, but during execution we walk
  * a linear path through all statements. So where appropriate a statement may
  * set the "previous statement" field of the pass to itself. When visiting the
  * subsequent statement it will check this "previous statement", and if set, it
  * will link this previous statement up to itself. Not every statement has a
  * previous statement. Hence there are two patterns that occur: assigning the
  * `next` value, then clearing the "previous statement" field. And assigning the
  * `next` value, and then putting the current statement's ID in the "previous
  * statement" field. Because it is so common, this file contain two macros that
  * perform that operation.
+ *
  * To make storing types for polymorphic procedures simpler and more efficient,
  * we assign to each expression in the procedure a unique ID. This is what the
  * "next expression index" field achieves. Each expression simply takes the
  * current value, and then increments this counter.
  */
 use crate::collections::{ScopedBuffer};
 use crate::protocol::ast::*;
 use crate::protocol::input_source::*;
 use crate::protocol::parser::symbol_table::*;
 use crate::protocol::parser::type_table::*;
 use super::visitor::{
     BUFFER_INIT_CAPACITY,
     Ctx,
     Visitor,
     VisitorResult
 };
 use crate::protocol::parser::ModuleCompilationPhase;
 #[derive(PartialEq, Eq)]
 enum DefinitionType {
     Primitive(ComponentDefinitionId),
     Composite(ComponentDefinitionId),
     Function(FunctionDefinitionId)
+}
 impl DefinitionType {
     fn is_primitive(&self) -> bool { if let Self::Primitive(_) = self { true } else { false } }
     fn is_composite(&self) -> bool { if let Self::Composite(_) = self { true } else { false } }
     fn is_function(&self) -> bool { if let Self::Function(_) = self { true } else { false } }
     fn definition_id(&self) -> DefinitionId {
         match self {
             DefinitionType::Primitive(v) => v.upcast(),
             DefinitionType::Composite(v) => v.upcast(),
             DefinitionType::Function(v) => v.upcast(),
+        }
+    }
+}
 struct ControlFlowStatement {
     in_sync: SynchronousStatementId,
     in_while: WhileStatementId,
     in_scope: Scope,
     statement: StatementId, // of 'break', 'continue' or 'goto'
+}
 /// This particular visitor will go through the entire AST in a recursive manner
 /// and check if all statements and expressions are legal (e.g. no "return"
 /// statements in component definitions), and will link certain AST nodes to
 /// their appropriate targets (e.g. goto statements, or function calls).
 ///
 /// This visitor will not perform control-flow analysis (e.g. making sure that
 /// each function actually returns) and will also not perform type checking. So
 /// the linking of function calls and component instantiations will be checked
 /// and linked to the appropriate definitions, but the return types and/or
 /// arguments will not be checked for validity.
 ///
 /// The main idea is, because we're visiting nodes in a tree, to do as much as
 /// we can while we have the memory in cache.
 pub(crate) struct PassValidationLinking {
     // Traversal state, all valid IDs if inside a certain AST element. Otherwise
     // `id.is_invalid()` returns true.
     in_sync: SynchronousStatementId,
     in_while: WhileStatementId, // to resolve labeled continue/break
     in_select_guard: SelectStatementId, // for detection/rejection of builtin calls
     in_select_arm: u32,
     in_test_expr: StatementId, // wrapping if/while stmt id
     in_binding_expr: BindingExpressionId, // to resolve variable expressions
     in_binding_expr_lhs: bool,
     // Traversal state, current scope (which can be used to find the parent
     // scope) and the definition variant we are considering.
     cur_scope: Scope,
     def_type: DefinitionType,
     // "Trailing" traversal state, set be child/prev stmt/expr used by next one
     prev_stmt: StatementId,
     expr_parent: ExpressionParent,
     // Set by parent to indicate that child expression must be assignable. The
     // child will throw an error if it is not assignable. The stored span is
     // used for the error's position
     must_be_assignable: Option<InputSpan>,
     // Keeping track of relative positions and unique IDs.
     relative_pos_in_block: i32, // of statements: to determine when variables are visible
     next_expr_index: i32, // to arrive at a unique ID for all expressions within a definition
     // Control flow statements that require label resolving
     control_flow_stmts: Vec<ControlFlowStatement>,
     // Various temporary buffers for traversal. Essentially working around
     // Rust's borrowing rules since it cannot understand we're modifying AST
     // members but not the AST container.
     variable_buffer: ScopedBuffer<VariableId>,
     definition_buffer: ScopedBuffer<DefinitionId>,
     statement_buffer: ScopedBuffer<StatementId>,
     expression_buffer: ScopedBuffer<ExpressionId>,
+}
 impl PassValidationLinking {
     pub(crate) fn new() -> Self {
         Self{
             in_sync: SynchronousStatementId::new_invalid(),
             in_while: WhileStatementId::new_invalid(),
             in_select_guard: SelectStatementId::new_invalid(),
             in_select_arm: 0,
             in_test_expr: StatementId::new_invalid(),
             in_binding_expr: BindingExpressionId::new_invalid(),
             in_binding_expr_lhs: false,
             cur_scope: Scope::new_invalid(),
             prev_stmt: StatementId::new_invalid(),
             expr_parent: ExpressionParent::None,
             def_type: DefinitionType::Function(FunctionDefinitionId::new_invalid()),
             must_be_assignable: None,
             relative_pos_in_block: 0,
             next_expr_index: 0,
             control_flow_stmts: Vec::with_capacity(32),
             variable_buffer: ScopedBuffer::with_capacity(128),
             definition_buffer: ScopedBuffer::with_capacity(128),
             statement_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAPACITY),
             expression_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAPACITY),
+        }
+    }
     fn reset_state(&mut self) {
         self.in_sync = SynchronousStatementId::new_invalid();
         self.in_while = WhileStatementId::new_invalid();
         self.in_select_guard = SelectStatementId::new_invalid();
         self.in_test_expr = StatementId::new_invalid();
         self.in_binding_expr = BindingExpressionId::new_invalid();
         self.in_binding_expr_lhs = false;
         self.cur_scope = Scope::new_invalid();
         self.def_type = DefinitionType::Function(FunctionDefinitionId::new_invalid());
         self.prev_stmt = StatementId::new_invalid();
         self.expr_parent = ExpressionParent::None;
         self.must_be_assignable = None;
         self.relative_pos_in_block = 0;
         self.next_expr_index = 0;
         self.control_flow_stmts.clear();
+    }
+}
 macro_rules! assign_then_erase_next_stmt {
     ($self:ident, $ctx:ident, $stmt_id:expr) => {
         if !$self.prev_stmt.is_invalid() {
             $ctx.heap[$self.prev_stmt].link_next($stmt_id);
             $self.prev_stmt = StatementId::new_invalid();
+        }
+    }
+}
 macro_rules! assign_and_replace_next_stmt {
     ($self:ident, $ctx:ident, $stmt_id:expr) => {
         if !$self.prev_stmt.is_invalid() {
             $ctx.heap[$self.prev_stmt].link_next($stmt_id);
+        }
         $self.prev_stmt = $stmt_id;
+    }
+}
 impl Visitor for PassValidationLinking {
     fn visit_module(&mut self, ctx: &mut Ctx) -> VisitorResult {
         debug_assert_eq!(ctx.module().phase, ModuleCompilationPhase::TypesAddedToTable);
         let root = &ctx.heap[ctx.module().root_id];
         let section = self.definition_buffer.start_section_initialized(&root.definitions);
         for definition_id in section.iter_copied() {
             self.visit_definition(ctx, definition_id)?;
+        }
         section.forget();
         ctx.module_mut().phase = ModuleCompilationPhase::ValidatedAndLinked;
         Ok(())
+    }
     //--------------------------------------------------------------------------
     // Definition visitors
     //--------------------------------------------------------------------------
     fn visit_component_definition(&mut self, ctx: &mut Ctx, id: ComponentDefinitionId) -> VisitorResult {
         self.reset_state();
         self.def_type = match &ctx.heap[id].variant {
             ComponentVariant::Primitive => DefinitionType::Primitive(id),
             ComponentVariant::Composite => DefinitionType::Composite(id),
         };
         self.cur_scope = Scope::Definition(id.upcast());
         self.expr_parent = ExpressionParent::None;
         // Visit parameters and assign a unique scope ID
         let definition = &ctx.heap[id];
         let body_id = definition.body;
         let section = self.variable_buffer.start_section_initialized(&definition.parameters);
         for variable_idx in 0..section.len() {
             let variable_id = section[variable_idx];
             let variable = &mut ctx.heap[variable_id];
             variable.unique_id_in_scope = variable_idx as i32;
+        }
         section.forget();
         // Visit statements in component body
         self.visit_block_stmt(ctx, body_id)?;
         // Assign total number of expressions and assign an in-block unique ID
         // to each of the locals in the procedure.
         ctx.heap[id].num_expressions_in_body = self.next_expr_index;
         self.visit_definition_and_assign_local_ids(ctx, id.upcast());
         self.resolve_pending_control_flow_targets(ctx)?;
         Ok(())
+    }
     fn visit_function_definition(&mut self, ctx: &mut Ctx, id: FunctionDefinitionId) -> VisitorResult {
         self.reset_state();
         // Set internal statement indices
         self.def_type = DefinitionType::Function(id);
         self.cur_scope = Scope::Definition(id.upcast());
         self.expr_parent = ExpressionParent::None;
         // Visit parameters and assign a unique scope ID
         let definition = &ctx.heap[id];
         let body_id = definition.body;
         let section = self.variable_buffer.start_section_initialized(&definition.parameters);
         for variable_idx in 0..section.len() {
             let variable_id = section[variable_idx];
             let variable = &mut ctx.heap[variable_id];
             variable.unique_id_in_scope = variable_idx as i32;
+        }
         section.forget();
         // Visit statements in function body
         self.visit_block_stmt(ctx, body_id)?;
         // Assign total number of expressions and assign an in-block unique ID
         // to each of the locals in the procedure.
         ctx.heap[id].num_expressions_in_body = self.next_expr_index;
         self.visit_definition_and_assign_local_ids(ctx, id.upcast());
         self.resolve_pending_control_flow_targets(ctx)?;
         Ok(())
+    }
     //--------------------------------------------------------------------------
     // Statement visitors
     //--------------------------------------------------------------------------
     fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
         let old_scope = self.push_statement_scope(ctx, Scope::Regular(id));
         // Set end of block
         let block_stmt = &ctx.heap[id];
         let end_block_id = block_stmt.end_block;
         // Copy statement IDs into buffer
         // Traverse statements in block
         let statement_section = self.statement_buffer.start_section_initialized(&block_stmt.statements);
         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 i32;
             self.visit_stmt(ctx, statement_section[stmt_idx])?;
+        }
         statement_section.forget();
         assign_and_replace_next_stmt!(self, ctx, end_block_id.upcast());
         self.pop_statement_scope(old_scope);
         Ok(())
+    }
     fn visit_local_memory_stmt(&mut self, ctx: &mut Ctx, id: MemoryStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         let expr_id = stmt.initial_expr;
         let variable_id = stmt.variable;
         self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_block, variable_id)?;
         assign_and_replace_next_stmt!(self, ctx, id.upcast().upcast());
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         self.expr_parent = ExpressionParent::Memory(id);
         self.visit_assignment_expr(ctx, expr_id)?;
         self.expr_parent = ExpressionParent::None;
         Ok(())
+    }
     fn visit_local_channel_stmt(&mut self, ctx: &mut Ctx, id: ChannelStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         let from_id = stmt.from;
         let to_id = stmt.to;
         self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_block, from_id)?;
         self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_block, to_id)?;
         assign_and_replace_next_stmt!(self, ctx, id.upcast().upcast());
         Ok(())
+    }
     fn visit_labeled_stmt(&mut self, ctx: &mut Ctx, id: LabeledStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         let body_id = stmt.body;
         self.checked_add_label(ctx, self.relative_pos_in_block, self.in_sync, id)?;
         self.visit_stmt(ctx, body_id)?;
         Ok(())
+    }
     fn visit_if_stmt(&mut self, ctx: &mut Ctx, id: IfStatementId) -> VisitorResult {
         let if_stmt = &ctx.heap[id];
         let end_if_id = if_stmt.end_if;
         let test_expr_id = if_stmt.test;
         let true_stmt_id = if_stmt.true_body;
         let false_stmt_id = if_stmt.false_body;
         // Visit test expression
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         debug_assert!(self.in_test_expr.is_invalid());
         self.in_test_expr = id.upcast();
         self.expr_parent = ExpressionParent::If(id);
         self.visit_expr(ctx, test_expr_id)?;
         self.in_test_expr = StatementId::new_invalid();
         self.expr_parent = ExpressionParent::None;
         // Visit true and false branch. Executor chooses next statement based on
         // test expression, not on if-statement itself. Hence the if statement
         // does not have a static subsequent statement.
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         self.visit_block_stmt(ctx, true_stmt_id)?;
         assign_then_erase_next_stmt!(self, ctx, end_if_id.upcast());
         if let Some(false_id) = false_stmt_id {
             self.visit_block_stmt(ctx, false_id)?;
             assign_then_erase_next_stmt!(self, ctx, end_if_id.upcast());
+        }
         self.prev_stmt = end_if_id.upcast();
         Ok(())
+    }
     fn visit_while_stmt(&mut self, ctx: &mut Ctx, id: WhileStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         let end_while_id = stmt.end_while;
         let test_expr_id = stmt.test;
         let body_stmt_id = stmt.body;
         let old_while = self.in_while;
         self.in_while = id;
         // Visit test expression
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         debug_assert!(self.in_test_expr.is_invalid());
         self.in_test_expr = id.upcast();
         self.expr_parent = ExpressionParent::While(id);
         self.visit_expr(ctx, test_expr_id)?;
         self.in_test_expr = StatementId::new_invalid();
         // Link up to body statement
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         self.expr_parent = ExpressionParent::None;
         self.visit_block_stmt(ctx, body_stmt_id)?;
         self.in_while = old_while;
         // Link final entry in while's block statement back to the while. The
         // executor will go to the end-while statement if the test expression
         // is false, so put that in as the new previous stmt
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         self.prev_stmt = end_while_id.upcast();
         Ok(())
+    }
     fn visit_break_stmt(&mut self, ctx: &mut Ctx, id: BreakStatementId) -> VisitorResult {
         self.control_flow_stmts.push(ControlFlowStatement{
             in_sync: self.in_sync,
             in_while: self.in_while,
             in_scope: self.cur_scope,
             statement: id.upcast()
         });
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         Ok(())
+    }
     fn visit_continue_stmt(&mut self, ctx: &mut Ctx, id: ContinueStatementId) -> VisitorResult {
         self.control_flow_stmts.push(ControlFlowStatement{
             in_sync: self.in_sync,
             in_while: self.in_while,
             in_scope: self.cur_scope,
             statement: id.upcast()
         });
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         Ok(())
+    }
     fn visit_synchronous_stmt(&mut self, ctx: &mut Ctx, id: SynchronousStatementId) -> VisitorResult {
         // Check for validity of synchronous statement
         let sync_stmt = &ctx.heap[id];
         let end_sync_id = sync_stmt.end_sync;
         let cur_sync_span = sync_stmt.span;
         if !self.in_sync.is_invalid() {
             // Nested synchronous statement
             let old_sync_span = ctx.heap[self.in_sync].span;
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, cur_sync_span, "Illegal nested synchronous statement"
             ).with_info_str_at_span(
                 &ctx.module().source, old_sync_span, "It is nested in this synchronous statement"
             ));
+        }
         if !self.def_type.is_primitive() {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, cur_sync_span,
                 "synchronous statements may only be used in primitive components"
             ));
+        }
         // Synchronous statement implicitly moves to its block
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         // Visit block statement. Note that we explicitly push the scope here
         // (and the `visit_block_stmt` will also push, but without effect) to
         // ensure the scope contains the sync ID.
         let sync_body = ctx.heap[id].body;
         debug_assert!(self.in_sync.is_invalid());
         self.in_sync = id;
         let old_scope = self.push_statement_scope(ctx, Scope::Synchronous(id, sync_body));
         self.visit_block_stmt(ctx, sync_body)?;
         self.pop_statement_scope(old_scope);
         assign_and_replace_next_stmt!(self, ctx, end_sync_id.upcast());
         self.in_sync = SynchronousStatementId::new_invalid();
         Ok(())
+    }
     fn visit_fork_stmt(&mut self, ctx: &mut Ctx, id: ForkStatementId) -> VisitorResult {
         let fork_stmt = &ctx.heap[id];
         let end_fork_id = fork_stmt.end_fork;
         let left_body_id = fork_stmt.left_body;
         let right_body_id = fork_stmt.right_body;
         // Fork statements may only occur inside sync blocks
         if self.in_sync.is_invalid() {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, fork_stmt.span,
                 "Forking may only occur inside sync blocks"
             ));
+        }
         // Visit the respective bodies. Like the if statement, a fork statement
         // does not have a single static subsequent statement. It forks and then
         // each fork has a different next statement.
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         self.visit_block_stmt(ctx, left_body_id)?;
         assign_then_erase_next_stmt!(self, ctx, end_fork_id.upcast());
         if let Some(right_body_id) = right_body_id {
             self.visit_block_stmt(ctx, right_body_id)?;
             assign_then_erase_next_stmt!(self, ctx, end_fork_id.upcast());
+        }
         self.prev_stmt = end_fork_id.upcast();
         Ok(())
+    }
     fn visit_select_stmt(&mut self, ctx: &mut Ctx, id: SelectStatementId) -> VisitorResult {
         let select_stmt = &ctx.heap[id];
         let end_select_id = select_stmt.end_select;
         // Select statements may only occur inside sync blocks
         if self.in_sync.is_invalid() {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, select_stmt.span,
                 "select statements may only occur inside sync blocks"
             ));
+        }
         if !self.def_type.is_primitive() {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, select_stmt.span,
                 "select statements may only be used in primitive components"
             ));
+        }
         // Visit the various arms in the select block
         let mut case_stmt_ids = self.statement_buffer.start_section();
         let num_cases = select_stmt.cases.len();
         for case in &select_stmt.cases {
             // Note: we add both to the buffer, retrieve them later in indexed
             // fashion
             case_stmt_ids.push(case.guard);
             case_stmt_ids.push(case.block.upcast());
+        }
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         for idx in 0..num_cases {
             let base_idx = 2 * idx;
             let guard_id     = case_stmt_ids[base_idx    ];
             let arm_block_id = case_stmt_ids[base_idx + 1];
             debug_assert_eq!(ctx.heap[arm_block_id].as_block().this.upcast(), arm_block_id); // backwards way of saying arm_block_id is a BlockStatementId
             let arm_block_id = BlockStatementId(arm_block_id);
             // The guard statement ends up belonging to the block statement
             // following the arm. The reason we parse it separately is to
             // extract all of the "get" calls.
             let old_scope = self.push_statement_scope(ctx, Scope::Regular(arm_block_id));
             // Visit the guard of this arm
             debug_assert!(self.in_select_guard.is_invalid());
             self.in_select_guard = id;
             self.in_select_arm = idx as u32;
             self.visit_stmt(ctx, guard_id)?;
             self.in_select_guard = SelectStatementId::new_invalid();
             // Visit the code associated with the guard
             self.visit_block_stmt(ctx, arm_block_id)?;
             self.pop_statement_scope(old_scope);
             // Link up last statement in block to EndSelect
             assign_then_erase_next_stmt!(self, ctx, end_select_id.upcast());
+        }
         self.in_select_guard = SelectStatementId::new_invalid();
         self.prev_stmt = end_select_id.upcast();
         Ok(())
+    }
     fn visit_return_stmt(&mut self, ctx: &mut Ctx, id: ReturnStatementId) -> VisitorResult {
         // Check if "return" occurs within a function
         let stmt = &ctx.heap[id];
         if !self.def_type.is_function() {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, stmt.span,
                 "return statements may only appear in function bodies"
             ));
+        }
         // If here then we are within a function
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         debug_assert_eq!(ctx.heap[id].expressions.len(), 1);
         self.expr_parent = ExpressionParent::Return(id);
         self.visit_expr(ctx, ctx.heap[id].expressions[0])?;
         self.expr_parent = ExpressionParent::None;
         Ok(())
+    }
     fn visit_goto_stmt(&mut self, ctx: &mut Ctx, id: GotoStatementId) -> VisitorResult {
         self.control_flow_stmts.push(ControlFlowStatement{
             in_sync: self.in_sync,
             in_while: self.in_while,
             in_scope: self.cur_scope,
             statement: id.upcast(),
         });
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         Ok(())
+    }
     fn visit_new_stmt(&mut self, ctx: &mut Ctx, id: NewStatementId) -> VisitorResult {
         // Make sure the new statement occurs inside a composite component
         if !self.def_type.is_composite() {
             let new_stmt = &ctx.heap[id];
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, new_stmt.span,
                 "instantiating components may only be done in composite components"
             ));
+        }
         // Recurse into call expression (which will check the expression parent
         // to ensure that the "new" statment instantiates a component)
         let call_expr_id = ctx.heap[id].expression;
         assign_and_replace_next_stmt!(self, ctx, id.upcast());
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         self.expr_parent = ExpressionParent::New(id);
         self.visit_call_expr(ctx, call_expr_id)?;
         self.expr_parent = ExpressionParent::None;
         Ok(())
+    }
     fn visit_expr_stmt(&mut self, ctx: &mut Ctx, id: ExpressionStatementId) -> VisitorResult {
         let expr_id = ctx.heap[id].expression;
         assign_and_replace_next_stmt!(self, ctx, id.upcast());
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         self.expr_parent = ExpressionParent::ExpressionStmt(id);
         self.visit_expr(ctx, expr_id)?;
         self.expr_parent = ExpressionParent::None;
         Ok(())
+    }
     //--------------------------------------------------------------------------
     // Expression visitors
     //--------------------------------------------------------------------------
     fn visit_assignment_expr(&mut self, ctx: &mut Ctx, id: AssignmentExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         let assignment_expr = &mut ctx.heap[id];
         // Although we call assignment an expression to simplify the compiler's
         // code (mainly typechecking), we disallow nested use in expressions
         match self.expr_parent {
             // Look at us: lying through our teeth while providing error messages.
             ExpressionParent::Memory(_) => {},
             ExpressionParent::ExpressionStmt(_) => {},
             _ => {
                 let assignment_span = assignment_expr.full_span;
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, assignment_span,
                     "assignments are statements, and cannot be used in expressions"
                 ))
             },
+        }
         let left_expr_id = assignment_expr.left;
         let right_expr_id = assignment_expr.right;
         let old_expr_parent = self.expr_parent;
         assignment_expr.parent = old_expr_parent;
         assignment_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.must_be_assignable = Some(assignment_expr.operator_span);
         self.visit_expr(ctx, left_expr_id)?;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.must_be_assignable = None;
         self.visit_expr(ctx, right_expr_id)?;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_binding_expr(&mut self, ctx: &mut Ctx, id: BindingExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         // Check for valid context of binding expression
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a binding expression"
             ));
+        }
         if self.in_test_expr.is_invalid() {
             let binding_expr = &ctx.heap[id];
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, binding_expr.full_span,
                 "binding expressions can only be used inside the testing expression of 'if' and 'while' statements"
             ));
+        }
         if !self.in_binding_expr.is_invalid() {
             let binding_expr = &ctx.heap[id];
             let previous_expr = &ctx.heap[self.in_binding_expr];
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, binding_expr.full_span,
                 "nested binding expressions are not allowed"
             ).with_info_str_at_span(
                 &ctx.module().source, previous_expr.operator_span,
                 "the outer binding expression is found here"
             ));
+        }
         let mut seeking_parent = self.expr_parent;
         loop {
             // Perform upward search to make sure only LogicalAnd is applied to
             // the binding expression
             let valid = match seeking_parent {
                 ExpressionParent::If(_) | ExpressionParent::While(_) => {
                     // Every parent expression (if any) were LogicalAnd.
                     break;
+                }
                 ExpressionParent::Expression(parent_id, _) => {
                     let parent_expr = &ctx.heap[parent_id];
                     match parent_expr {
                         Expression::Binary(parent_expr) => {
                             // Set new parent to continue the search. Otherwise
                             // halt and provide an error using the current
                             // parent.
                             if parent_expr.operation == BinaryOperator::LogicalAnd {
                                 seeking_parent = parent_expr.parent;
                                 true
                             } else {
                                 false
+                            }
                         },
                         _ => false,
+                    }
                 },
                 _ => unreachable!(), // nested under if/while, so always expressions as parents
             };
             if !valid {
                 let binding_expr = &ctx.heap[id];
                 let parent_expr = &ctx.heap[seeking_parent.as_expression()];
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, binding_expr.full_span,
                     "only the logical-and operator (&&) may be applied to binding expressions"
                 ).with_info_str_at_span(
                     &ctx.module().source, parent_expr.operation_span(),
                     "this was the disallowed operation applied to the result from a binding expression"
                 ));
+            }
+        }
         // Perform all of the index/parent assignment magic
         let binding_expr = &mut ctx.heap[id];
         let old_expr_parent = self.expr_parent;
         binding_expr.parent = old_expr_parent;
         binding_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.in_binding_expr = id;
         // Perform preliminary check on children: binding expressions only make
         // sense if the left hand side is just a variable expression, or if it
         // is a literal of some sort. The typechecker will take care of the rest
         let bound_to_id = binding_expr.bound_to;
         let bound_from_id = binding_expr.bound_from;
         match &ctx.heap[bound_to_id] {
             // Variables may not be binding variables, and literals may
             // actually not contain binding variables. But in that case we just
             // perform an equality check.
             Expression::Variable(_) => {}
             Expression::Literal(_) => {},
             _ => {
                 let binding_expr = &ctx.heap[id];
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, binding_expr.operator_span,
                     "the left hand side of a binding expression may only be a variable or a literal expression"
                 ));
             },
+        }
         // Visit the children themselves
         self.in_binding_expr_lhs = true;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.visit_expr(ctx, bound_to_id)?;
         self.in_binding_expr_lhs = false;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.visit_expr(ctx, bound_from_id)?;
         self.expr_parent = old_expr_parent;
         self.in_binding_expr = BindingExpressionId::new_invalid();
         Ok(())
+    }
     fn visit_conditional_expr(&mut self, ctx: &mut Ctx, id: ConditionalExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         let conditional_expr = &mut ctx.heap[id];
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a conditional expression"
             ))
+        }
         let test_expr_id = conditional_expr.test;
         let true_expr_id = conditional_expr.true_expression;
         let false_expr_id = conditional_expr.false_expression;
         let old_expr_parent = self.expr_parent;
         conditional_expr.parent = old_expr_parent;
         conditional_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.visit_expr(ctx, test_expr_id)?;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.visit_expr(ctx, true_expr_id)?;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 2);
         self.visit_expr(ctx, false_expr_id)?;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_binary_expr(&mut self, ctx: &mut Ctx, id: BinaryExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         let binary_expr = &mut ctx.heap[id];
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a binary expression"
             ))
+        }
         let left_expr_id = binary_expr.left;
         let right_expr_id = binary_expr.right;
         let old_expr_parent = self.expr_parent;
         binary_expr.parent = old_expr_parent;
         binary_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.visit_expr(ctx, left_expr_id)?;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.visit_expr(ctx, right_expr_id)?;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_unary_expr(&mut self, ctx: &mut Ctx, id: UnaryExpressionId) -> VisitorResult {
         let unary_expr = &mut ctx.heap[id];
         let expr_id = unary_expr.expression;
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a unary expression"
             ))
+        }
         let old_expr_parent = self.expr_parent;
         unary_expr.parent = old_expr_parent;
         unary_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(id.upcast(), 0);
         self.visit_expr(ctx, expr_id)?;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_indexing_expr(&mut self, ctx: &mut Ctx, id: IndexingExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         let indexing_expr = &mut ctx.heap[id];
         let subject_expr_id = indexing_expr.subject;
         let index_expr_id = indexing_expr.index;
         let old_expr_parent = self.expr_parent;
         indexing_expr.parent = old_expr_parent;
         indexing_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.visit_expr(ctx, subject_expr_id)?;
         let old_assignable = self.must_be_assignable.take();
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.visit_expr(ctx, index_expr_id)?;
         self.must_be_assignable = old_assignable;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_slicing_expr(&mut self, ctx: &mut Ctx, id: SlicingExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         let slicing_expr = &mut ctx.heap[id];
         if let Some(span) = self.must_be_assignable {
             // TODO: @Slicing
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "assignment to slices should be valid in the final language, but is currently not implemented"
             ));
+        }
         let subject_expr_id = slicing_expr.subject;
         let from_expr_id = slicing_expr.from_index;
         let to_expr_id = slicing_expr.to_index;
         let old_expr_parent = self.expr_parent;
         slicing_expr.parent = old_expr_parent;
         slicing_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.visit_expr(ctx, subject_expr_id)?;
         let old_assignable = self.must_be_assignable.take();
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.visit_expr(ctx, from_expr_id)?;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 2);
         self.visit_expr(ctx, to_expr_id)?;
         self.must_be_assignable = old_assignable;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_select_expr(&mut self, ctx: &mut Ctx, id: SelectExpressionId) -> VisitorResult {
         let select_expr = &mut ctx.heap[id];
         let expr_id = select_expr.subject;
         let old_expr_parent = self.expr_parent;
         select_expr.parent = old_expr_parent;
         select_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         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::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 = &ctx.heap[id];
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a call expression"
             ))
+        }
         // Check whether the method is allowed to be called within the code's
         // context (in sync, definition type, etc.)
         let mut expecting_wrapping_new_stmt = false;
         let mut expecting_primitive_def = false;
         let mut expecting_wrapping_sync_stmt = false;
         let mut expecting_no_select_stmt = false;
         match call_expr.method {
             Method::Get => {
                 expecting_primitive_def = true;
                 expecting_wrapping_sync_stmt = true;
                 if !self.in_select_guard.is_invalid() {
                     // In a select guard. Take the argument (i.e. the port we're
                     // retrieving from) and add it to the list of involved ports
                     // of the guard
                     if call_expr.arguments.len() == 1 {
                         // We're checking the number of arguments later, for now
                         // assume it is correct.
                         let argument = call_expr.arguments[0];
                         let select_stmt = &mut ctx.heap[self.in_select_guard];
                         let select_case = &mut select_stmt.cases[self.in_select_arm as usize];
                         select_case.involved_ports.push((id, argument));
+                    }
+                }
             },
             Method::Put => {
                 expecting_primitive_def = true;
                 expecting_wrapping_sync_stmt = true;
                 expecting_no_select_stmt = true;
             },
             Method::Fires => {
                 expecting_primitive_def = true;
                 expecting_wrapping_sync_stmt = true;
             },
             Method::Create => {},
             Method::Length => {},
             Method::Assert => {
                 expecting_wrapping_sync_stmt = true;
                 expecting_no_select_stmt = true;
                 if self.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"
                     ));
+                }
             },
             Method::Print => {},
             Method::SelectStart
             | Method::SelectRegisterCasePort
             | Method::SelectWait => unreachable!(), // not usable by programmer directly
             Method::UserFunction => {},
             Method::UserComponent => {
                 expecting_wrapping_new_stmt = true;
             },
+        }
         let call_expr = &mut ctx.heap[id];
         fn get_span_and_name<'a>(ctx: &'a Ctx, id: CallExpressionId) -> (InputSpan, String) {
             let call = &ctx.heap[id];
             let span = call.func_span;
             let name = String::from_utf8_lossy(ctx.module().source.section_at_span(span)).to_string();
             return (span, name);
+        }
         if expecting_primitive_def {
             if !self.def_type.is_primitive() {
                 let (call_span, func_name) = get_span_and_name(ctx, id);
                 return Err(ParseError::new_error_at_span(
                     &ctx.module().source, call_span,
                     format!("a call to '{}' may only occur in primitive component definitions", func_name)
                 ));
+            }
+        }
         if expecting_wrapping_sync_stmt {
             if self.in_sync.is_invalid() {
                 let (call_span, func_name) = get_span_and_name(ctx, id);
                 return Err(ParseError::new_error_at_span(
                     &ctx.module().source, call_span,
                     format!("a call to '{}' may only occur inside synchronous blocks", func_name)
                 ))
+            }
+        }
         if expecting_no_select_stmt {
             if !self.in_select_guard.is_invalid() {
                 let (call_span, func_name) = get_span_and_name(ctx, id);
                 return Err(ParseError::new_error_at_span(
                     &ctx.module().source, call_span,
                     format!("a call to '{}' may not occur in a select statement's guard", func_name)
                 ));
+            }
+        }
         if expecting_wrapping_new_stmt {
             if !self.expr_parent.is_new() {
                 let call_span = call_expr.func_span;
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, call_span,
                     "cannot call a component, it can only be instantiated by using 'new'"
                 ));
+            }
         } else {
             if self.expr_parent.is_new() {
                 let call_span = call_expr.func_span;
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, call_span,
                     "only components can be instantiated, this is a function"
                 ));
+            }
+        }
         // Check the number of arguments
         let call_definition = ctx.types.get_base_definition(&call_expr.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];
         // Check if declaration was already resolved (this occurs for the
         // variable expr that is on the LHS of the assignment expr that is
         // associated with a variable declaration)
         let mut variable_id = var_expr.declaration;
         let mut is_binding_target = false;
         // Otherwise try to find it
         if variable_id.is_none() {
             variable_id = self.find_variable(ctx, self.relative_pos_in_block, &var_expr.identifier);
+        }
         // Otherwise try to see if is a variable introduced by a binding expr
         let variable_id = if let Some(variable_id) = variable_id {
             variable_id
         } else {
             if self.in_binding_expr.is_invalid() || !self.in_binding_expr_lhs {
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, var_expr.identifier.span, "unresolved variable"
                 ));
+            }
             // This is a binding variable, but it may only appear in very
             // specific locations.
             let is_valid_binding = match self.expr_parent {
                 ExpressionParent::Expression(expr_id, idx) => {
                     match &ctx.heap[expr_id] {
                         Expression::Binding(_binding_expr) => {
                             // Nested binding is disallowed, and because of
                             // the check above we know we're directly at the
                             // LHS of the binding expression
                             debug_assert_eq!(_binding_expr.this, self.in_binding_expr);
                             debug_assert_eq!(idx, 0);
                             true
+                        }
                         Expression::Literal(lit_expr) => {
                             // Only struct, unions, tuples and arrays can
                             // have subexpressions, so we're always fine
                             if cfg!(debug_assertions) {
                                 match lit_expr.value {
                                     Literal::Struct(_) | Literal::Union(_) | Literal::Array(_) | Literal::Tuple(_) => {},
                                     _ => unreachable!(),
+                                }
+                            }
                             true
                         },
                         _ => false,
+                    }
                 },
                 _ => {
                     false
+                }
             };
             if !is_valid_binding {
                 let binding_expr = &ctx.heap[self.in_binding_expr];
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, var_expr.identifier.span,
                     "illegal location for binding variable: binding variables may only be nested under a binding expression, or a struct, union or array literal"
                 ).with_info_at_span(
                     &ctx.module().source, binding_expr.operator_span, format!(
                         "'{}' was interpreted as a binding variable because the variable is not declared and it is nested under this binding expression",
                         var_expr.identifier.value.as_str()
+                    )
                 ));
+            }
             // By now we know that this is a valid binding expression. Given
             // that a binding expression must be nested under an if/while
             // statement, we now add the variable to the (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, -1, bound_variable_id)?; // add at -1 such that first statement can access
             is_binding_target = true;
             bound_variable_id
         };
         let var_expr = &mut ctx.heap[id];
         var_expr.declaration = Some(variable_id);
         var_expr.used_as_binding_target = is_binding_target;
         var_expr.parent = self.expr_parent;
         var_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         Ok(())
+    }
+}
 impl PassValidationLinking {
     //--------------------------------------------------------------------------
     // Special traversal
     //--------------------------------------------------------------------------
     /// Pushes a new scope associated with a particular statement. If that
     /// statement already has an associated scope (i.e. scope associated with
     /// sync statement or select statement's arm) then we won't do anything.
     /// In all cases the caller must call `pop_statement_scope` with the scope
     /// and relative scope position returned by this function.
     fn push_statement_scope(&mut self, ctx: &mut Ctx, new_scope: Scope) -> (Scope, i32) {
         let old_scope = self.cur_scope.clone();
         debug_assert!(new_scope.is_block()); // never call for Definition scope
         let is_new_block = if old_scope.is_block() {
             old_scope.to_block() != new_scope.to_block()
         } else {
             true
         };
         if !is_new_block {
             // No need to push, but still return old scope, we pretend like we
             // replaced it.
             debug_assert!(!ctx.heap[new_scope.to_block()].scope_node.parent.is_invalid());
             return (old_scope, self.relative_pos_in_block);
+        }
         // This is a new block, so link it up
         if old_scope.is_block() {
             let parent_block = &mut ctx.heap[old_scope.to_block()];
             parent_block.scope_node.nested.push(new_scope);
+        }
         self.cur_scope = new_scope;
         let cur_block = &mut ctx.heap[new_scope.to_block()];
         cur_block.scope_node.parent = old_scope;
         cur_block.scope_node.relative_pos_in_parent = self.relative_pos_in_block;
         let old_relative_pos = self.relative_pos_in_block;
         self.relative_pos_in_block = -1;
         return (old_scope, old_relative_pos)
+    }
     fn pop_statement_scope(&mut self, scope_to_restore: (Scope, i32)) {
         self.cur_scope = scope_to_restore.0;
         self.relative_pos_in_block = scope_to_restore.1;
+    }
     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 var_id in param_section.iter_copied() {
             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 {
                 i32::MAX
             };
             let relative_scope_pos = if scope_idx < scope_section.len() {
                 ctx.heap[scope_section[scope_idx]].as_block().scope_node.relative_pos_in_parent
             } else {
                 i32::MAX
             };
             debug_assert!(!(relative_var_pos == i32::MAX && relative_scope_pos == i32::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;
+    }
     fn resolve_pending_control_flow_targets(&mut self, ctx: &mut Ctx) -> Result<(), ParseError> {
         for entry in &self.control_flow_stmts {
             let stmt = &ctx.heap[entry.statement];
             match stmt {
                 Statement::Break(stmt) => {
                     let stmt_id = stmt.this;
                     let target_while_id = Self::resolve_break_or_continue_target(ctx, entry, stmt.span, &stmt.label)?;
                     let target_while_stmt = &ctx.heap[target_while_id];
                     let target_end_while_id = target_while_stmt.end_while;
                     debug_assert!(!target_end_while_id.is_invalid());
                     let break_stmt = &mut ctx.heap[stmt_id];
                     break_stmt.target = target_end_while_id;
                 },
                 Statement::Continue(stmt) => {
                     let stmt_id = stmt.this;
                     let target_while_id = Self::resolve_break_or_continue_target(ctx, entry, stmt.span, &stmt.label)?;
                     let continue_stmt = &mut ctx.heap[stmt_id];
                     continue_stmt.target = target_while_id;
                 },
                 Statement::Goto(stmt) => {
                     let stmt_id = stmt.this;
                     let target_id = Self::find_label(entry.in_scope, ctx, &stmt.label)?;
                     let target_stmt = &ctx.heap[target_id];
                     if entry.in_sync != target_stmt.in_sync {
                         // Nested sync not allowed. And goto can only go to
                         // outer scopes, so we must be escaping from a sync.
                         debug_assert!(target_stmt.in_sync.is_invalid());    // target not in sync
                         debug_assert!(!entry.in_sync.is_invalid()); // but the goto is in sync
                         let goto_stmt = &ctx.heap[stmt_id];
                         let sync_stmt = &ctx.heap[entry.in_sync];
                         return Err(
                             ParseError::new_error_str_at_span(&ctx.module().source, goto_stmt.span, "goto may not escape the surrounding synchronous block")
                             .with_info_str_at_span(&ctx.module().source, target_stmt.label.span, "this is the target of the goto statement")
                             .with_info_str_at_span(&ctx.module().source, sync_stmt.span, "which will jump past this statement")
                         );
+                    }
                     let goto_stmt = &mut ctx.heap[stmt_id];
                     goto_stmt.target = target_id;
                 },
                 _ => unreachable!("cannot resolve control flow target for {:?}", stmt),
+            }
+        }
         return Ok(())
+    }
     //--------------------------------------------------------------------------
     // Utilities
     //--------------------------------------------------------------------------
     /// Adds a local variable to the current scope. It will also annotate the
     /// `Local` in the AST with its relative position in the block.
     fn checked_add_local(&mut self, ctx: &mut Ctx, target_scope: Scope, target_relative_pos: i32, id: VariableId) -> Result<(), ParseError> {
         debug_assert!(target_scope.is_block());
         let local = &ctx.heap[id];
         // We immediately go to the parent scope. We check the target scope
         // in the call at the end. That is also where we check for collisions
         // with symbols.
         let block = &ctx.heap[target_scope.to_block()];
         let mut scope = block.scope_node.parent;
         let mut cur_relative_pos = block.scope_node.relative_pos_in_parent;
         loop {
             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 block = &ctx.heap[scope.to_block()];
             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 &&
                     cur_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"
+                        )
                     );
+                }
+            }
             scope = block.scope_node.parent;
             cur_relative_pos = block.scope_node.relative_pos_in_parent;
+        }
         // No collisions in any of the parent scope, attempt to add to scope
         self.checked_at_single_scope_add_local(ctx, target_scope, target_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: i32, 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: i32, identifier: &Identifier) -> Option<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 Some(*local_id);
+                }
+            }
             scope = &block.scope_node.parent;
             if !scope.is_block() {
                 // Definition scope, need to check arguments to definition
                 match scope {
                     Scope::Definition(definition_id) => {
                         let definition = &ctx.heap[*definition_id];
                         for parameter_id in definition.parameters() {
                             let parameter = &ctx.heap[*parameter_id];
                             if identifier == &parameter.identifier {
                                 return Some(*parameter_id);
+                            }
+                        }
                     },
                     _ => unreachable!(),
+                }
                 // Variable could not be found
                 return None
             } else {
                 relative_pos = block.scope_node.relative_pos_in_parent;
+            }
+        }
+    }
     /// Adds a particular label to the current scope. Will return an error if
     /// there is another label with the same name visible in the current scope.
     fn checked_add_label(&mut self, ctx: &mut Ctx, relative_pos: i32, in_sync: SynchronousStatementId, id: LabeledStatementId) -> Result<(), ParseError> {
         debug_assert!(self.cur_scope.is_block());
         // Make sure label is not defined within the current scope or any of the
         // parent scope.
         let label = &mut ctx.heap[id];
         label.relative_pos_in_block = relative_pos;
         label.in_sync = in_sync;
         let label = &ctx.heap[id];
         let mut scope = &self.cur_scope;
         loop {
             debug_assert!(scope.is_block(), "scope is not a block");
             let block = &ctx.heap[scope.to_block()];
             for other_label_id in &block.labels {
                 let other_label = &ctx.heap[*other_label_id];
                 if other_label.label == label.label {
                     // Collision
                     return Err(ParseError::new_error_str_at_span(
                         &ctx.module().source, label.label.span, "label name is used more than once"
                     ).with_info_str_at_span(
                         &ctx.module().source, other_label.label.span, "the other label is found here"
                     ));
+                }
+            }
             scope = &block.scope_node.parent;
             if !scope.is_block() {
                 break;
+            }
+        }
         // No collisions
         let block = &mut ctx.heap[self.cur_scope.to_block()];
         block.labels.push(id);
         Ok(())
+    }
     /// Finds a particular labeled statement by its identifier. Once found it
     /// will make sure that the target label does not skip over any variable
     /// declarations within the scope in which the label was found.
     fn find_label(mut scope: Scope, ctx: &Ctx, identifier: &Identifier) -> Result<LabeledStatementId, ParseError> {
         debug_assert!(scope.is_block());
         loop {
             debug_assert!(scope.is_block(), "scope is not a block");
             let relative_scope_pos = ctx.heap[scope.to_block()].scope_node.relative_pos_in_parent;
             let block = &ctx.heap[scope.to_block()];
             for label_id in &block.labels {
                 let label = &ctx.heap[*label_id];
                 if label.label == *identifier {
                     for local_id in &block.locals {
                         // TODO: Better to do this in control flow analysis, it
                         //  is legal to skip over a variable declaration if it
                         //  is not actually being used. I might be missing
                         //  something here when laying out the bytecode...
                         let local = &ctx.heap[*local_id];
                         if local.relative_pos_in_block > relative_scope_pos && local.relative_pos_in_block < label.relative_pos_in_block {
                             return Err(
                                 ParseError::new_error_str_at_span(&ctx.module().source, identifier.span, "this target label skips over a variable declaration")
                                 .with_info_str_at_span(&ctx.module().source, label.label.span, "because it jumps to this label")
                                 .with_info_str_at_span(&ctx.module().source, local.identifier.span, "which skips over this variable")
                             );
+                        }
+                    }
                     return Ok(*label_id);
+                }
+            }
             scope = block.scope_node.parent;
             if !scope.is_block() {
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, identifier.span, "could not find this label"
                 ));
+            }
+        }
+    }
     /// This function will check if the provided while statement ID has a block
     /// statement that is one of our current parents.
     fn has_parent_while_scope(mut scope: Scope, ctx: &Ctx, id: WhileStatementId) -> bool {
         let while_stmt = &ctx.heap[id];
         loop {
             debug_assert!(scope.is_block());
             let block = scope.to_block();
             if while_stmt.body == block {
                 return true;
+            }
             let block = &ctx.heap[block];
             scope = block.scope_node.parent;
             if !scope.is_block() {
                 return false;
+            }
+        }
+    }
     /// This function should be called while dealing with break/continue
     /// statements. It will try to find the targeted while statement, using the
     /// target label if provided. If a valid target is found then the loop's
     /// ID will be returned, otherwise a parsing error is constructed.
     /// The provided input position should be the position of the break/continue
     /// statement.
     fn resolve_break_or_continue_target(ctx: &Ctx, control_flow: &ControlFlowStatement, span: InputSpan, label: &Option<Identifier>) -> Result<WhileStatementId, ParseError> {
         let target = match label {
             Some(label) => {
                 let target_id = Self::find_label(control_flow.in_scope, ctx, label)?;
                 // Make sure break target is a while statement
                 let target = &ctx.heap[target_id];
                 if let Statement::While(target_stmt) = &ctx.heap[target.body] {
                     // Even though we have a target while statement, the break might not be
                     // present underneath this particular labeled while statement
                     if !Self::has_parent_while_scope(control_flow.in_scope, ctx, target_stmt.this) {
                         return Err(ParseError::new_error_str_at_span(
                             &ctx.module().source, label.span, "break statement is not nested under the target label's while statement"
                         ).with_info_str_at_span(
                             &ctx.module().source, target.label.span, "the targeted label is found here"
                         ));
+                    }
                     target_stmt.this
                 } else {
                     return Err(ParseError::new_error_str_at_span(
                         &ctx.module().source, label.span, "incorrect break target label, it must target a while loop"
                     ).with_info_str_at_span(
                         &ctx.module().source, target.label.span, "The targeted label is found here"
                     ));
+                }
             },
             None => {
                 // Use the enclosing while statement, the break must be
                 // nested within that while statement
                 if control_flow.in_while.is_invalid() {
                     return Err(ParseError::new_error_str_at_span(
                         &ctx.module().source, span, "Break statement is not nested under a while loop"
                     ));
+                }
                 control_flow.in_while
+            }
         };
         // We have a valid target for the break statement. But we need to
         // make sure we will not break out of a synchronous block
+        {
             let target_while = &ctx.heap[target];
             if target_while.in_sync != control_flow.in_sync {
                 // Break is nested under while statement, so can only escape a
                 // sync block if the sync is nested inside the while statement.
                 debug_assert!(!control_flow.in_sync.is_invalid());
                 let sync_stmt = &ctx.heap[control_flow.in_sync];
                 return Err(
                     ParseError::new_error_str_at_span(&ctx.module().source, span, "break may not escape the surrounding synchronous block")
                         .with_info_str_at_span(&ctx.module().source, target_while.span, "the break escapes out of this loop")
                         .with_info_str_at_span(&ctx.module().source, sync_stmt.span, "And would therefore escape this synchronous block")
                 );
+            }
+        }
         Ok(target)
+    }
+}
@@ \ No newline at end of file @@

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