/// <summary> /// https://tc39.es/ecma262/#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset /// </summary> private Completion BodyEvaluation( EvaluationContext context, JintExpression lhs, JintStatement stmt, IteratorInstance iteratorRecord, IterationKind iterationKind, LhsKind lhsKind, IteratorKind iteratorKind = IteratorKind.Sync) { var engine = context.Engine; var oldEnv = engine.ExecutionContext.LexicalEnvironment; var v = Undefined.Instance; var destructuring = _destructuring; string lhsName = null; var completionType = CompletionType.Normal; var close = false; try { while (true) { EnvironmentRecord iterationEnv = null; if (!iteratorRecord.TryIteratorStep(out var nextResult)) { close = true; return(new Completion(CompletionType.Normal, v, null, Location)); } if (iteratorKind == IteratorKind.Async) { // nextResult = await nextResult; ExceptionHelper.ThrowNotImplementedException("await"); } var nextValue = nextResult.Get(CommonProperties.Value); close = true; var lhsRef = new ExpressionResult(); if (lhsKind != LhsKind.LexicalBinding) { if (!destructuring) { lhsRef = lhs.Evaluate(context); } } else { iterationEnv = JintEnvironment.NewDeclarativeEnvironment(engine, oldEnv); if (_tdzNames != null) { BindingInstantiation(iterationEnv); } engine.UpdateLexicalEnvironment(iterationEnv); if (!destructuring) { var identifier = (Identifier)((VariableDeclaration)_leftNode).Declarations[0].Id; lhsName ??= identifier.Name; lhsRef = new ExpressionResult(ExpressionCompletionType.Normal, engine.ResolveBinding(lhsName), identifier.Location); } } if (context.DebugMode) { context.Engine.DebugHandler.OnStep(_leftNode); } var status = new Completion(); if (!destructuring) { if (lhsRef.IsAbrupt()) { close = true; status = new Completion(lhsRef); } else if (lhsKind == LhsKind.LexicalBinding) { ((Reference)lhsRef.Value).InitializeReferencedBinding(nextValue); } else { engine.PutValue((Reference)lhsRef.Value, nextValue); } } else { status = BindingPatternAssignmentExpression.ProcessPatterns( context, _assignmentPattern, nextValue, iterationEnv, checkObjectPatternPropertyReference: _lhsKind != LhsKind.VarBinding); if (lhsKind == LhsKind.Assignment) { // DestructuringAssignmentEvaluation of assignmentPattern using nextValue as the argument. } else if (lhsKind == LhsKind.VarBinding) { // BindingInitialization for lhs passing nextValue and undefined as the arguments. } else { // BindingInitialization for lhs passing nextValue and iterationEnv as arguments } } if (status.IsAbrupt()) { engine.UpdateLexicalEnvironment(oldEnv); if (_iterationKind == IterationKind.AsyncIterate) { iteratorRecord.Close(status.Type); return(status); } if (iterationKind == IterationKind.Enumerate) { return(status); } iteratorRecord.Close(status.Type); return(status); } var result = stmt.Execute(context); engine.UpdateLexicalEnvironment(oldEnv); if (!ReferenceEquals(result.Value, null)) { v = result.Value; } if (result.Type == CompletionType.Break && (result.Target == null || result.Target == _statement?.LabelSet?.Name)) { completionType = CompletionType.Normal; return(new Completion(CompletionType.Normal, v, null, Location)); } if (result.Type != CompletionType.Continue || (result.Target != null && result.Target != _statement?.LabelSet?.Name)) { completionType = result.Type; if (result.IsAbrupt()) { close = true; return(result); } } } } catch { completionType = CompletionType.Throw; throw; } finally { if (close) { try { iteratorRecord.Close(completionType); } catch { // if we already have and exception, use it if (completionType != CompletionType.Throw) { throw; } } } engine.UpdateLexicalEnvironment(oldEnv); } }
/// <summary> /// https://tc39.es/ecma262/#sec-runtime-semantics-forin-div-ofbodyevaluation-lhs-stmt-iterator-lhskind-labelset /// </summary> private Completion BodyEvaluation( JintExpression lhs, JintStatement stmt, IIterator iteratorRecord, IterationKind iterationKind, LhsKind lhsKind, IteratorKind iteratorKind = IteratorKind.Sync) { var oldEnv = _engine.ExecutionContext.LexicalEnvironment; var v = Undefined.Instance; var destructuring = _destructuring; string lhsName = null; var completionType = CompletionType.Normal; var close = false; try { while (true) { LexicalEnvironment iterationEnv = null; if (!iteratorRecord.TryIteratorStep(out var nextResult)) { close = true; return(new Completion(CompletionType.Normal, v, null, Location)); } if (iteratorKind == IteratorKind.Async) { // nextResult = await nextResult; } var nextValue = nextResult.Get(CommonProperties.Value); close = true; Reference lhsRef = null; if (lhsKind != LhsKind.LexicalBinding) { if (!destructuring) { lhsRef = (Reference)lhs.Evaluate(); } } else { iterationEnv = LexicalEnvironment.NewDeclarativeEnvironment(_engine, oldEnv); if (_tdzNames != null) { BindingInstantiation(iterationEnv); } _engine.UpdateLexicalEnvironment(iterationEnv); if (!destructuring) { if (lhsName == null) { lhsName = ((Identifier)((VariableDeclaration)_leftNode).Declarations[0].Id).Name; } lhsRef = _engine.ResolveBinding(lhsName); } } if (!destructuring) { // If lhsRef is an abrupt completion, then // Let status be lhsRef. if (lhsKind == LhsKind.LexicalBinding) { lhsRef.InitializeReferencedBinding(nextValue); } else { _engine.PutValue(lhsRef, nextValue); } } else { BindingPatternAssignmentExpression.ProcessPatterns( _engine, _assignmentPattern, nextValue, iterationEnv, checkObjectPatternPropertyReference: _lhsKind != LhsKind.VarBinding); if (lhsKind == LhsKind.Assignment) { // DestructuringAssignmentEvaluation of assignmentPattern using nextValue as the argument. } else if (lhsKind == LhsKind.VarBinding) { // BindingInitialization for lhs passing nextValue and undefined as the arguments. } else { // BindingInitialization for lhs passing nextValue and iterationEnv as arguments } } var result = stmt.Execute(); _engine.UpdateLexicalEnvironment(oldEnv); if (!ReferenceEquals(result.Value, null)) { v = result.Value; } if (result.Type == CompletionType.Break && (result.Identifier == null || result.Identifier == _statement?.LabelSet?.Name)) { return(new Completion(CompletionType.Normal, v, null, Location)); } if (result.Type != CompletionType.Continue || (result.Identifier != null && result.Identifier != _statement?.LabelSet?.Name)) { if (result.Type != CompletionType.Normal) { return(result); } } } } catch { completionType = CompletionType.Throw; throw; } finally { if (close) { iteratorRecord.Close(completionType); } _engine.UpdateLexicalEnvironment(oldEnv); } }
protected override Completion ExecuteInternal() { if (!_initialized) { _initialized = true; Initialize(); } foreach (var declaration in _declarations) { if (_statement.Kind != VariableDeclarationKind.Var && declaration.Left != null) { var lhs = (Reference)declaration.Left.Evaluate(); var value = JsValue.Undefined; if (declaration.Init != null) { value = declaration.Init.GetValue().Clone(); if (declaration.Init._expression.IsFunctionWithName()) { ((FunctionInstance)value).SetFunctionName(lhs.GetReferencedName()); } } lhs.InitializeReferencedBinding(value); _engine._referencePool.Return(lhs); } else if (declaration.Init != null) { if (declaration.LeftPattern != null) { var environment = _statement.Kind != VariableDeclarationKind.Var ? _engine.ExecutionContext.LexicalEnvironment : null; BindingPatternAssignmentExpression.ProcessPatterns( _engine, declaration.LeftPattern, declaration.Init.GetValue(), environment, checkObjectPatternPropertyReference: _statement.Kind != VariableDeclarationKind.Var); } else if (declaration.LeftIdentifierExpression == null || JintAssignmentExpression.SimpleAssignmentExpression.AssignToIdentifier( _engine, declaration.LeftIdentifierExpression, declaration.Init, declaration.EvalOrArguments) is null) { // slow path var lhs = (Reference)declaration.Left.Evaluate(); lhs.AssertValid(_engine); var value = declaration.Init.GetValue().Clone(); if (declaration.Init._expression.IsFunctionWithName()) { ((FunctionInstance)value).SetFunctionName(lhs.GetReferencedName()); } _engine.PutValue(lhs, value); _engine._referencePool.Return(lhs); } } } return(VoidCompletion); }