public static bool TryBindInNewScope(SyntaxTreeNode node, BindingContext bindingContext, TypeDescription expectedType, out Expression boundExpression, out Exception bindingError) { bindingContext = bindingContext.CreateNestedContext(); var result = TryBind(node, bindingContext, expectedType, out boundExpression, out bindingError); bindingContext.CompleteNullPropagation(ref boundExpression); return(result); }
public static bool TryBind(SyntaxTreeNode node, BindingContext bindingContext, TypeDescription expectedType, out Expression boundExpression, out Exception bindingError) { if (node == null) { throw new ArgumentNullException("node"); } if (bindingContext == null) { throw new ArgumentNullException("bindingContext"); } if (expectedType == null) { throw new ArgumentNullException("expectedType"); } boundExpression = null; bindingError = null; // try get type of lambda from node var lambdaTypeName = node.GetTypeName(throwOnError: false); var lambdaType = default(Type); if (lambdaTypeName != null) { if (bindingContext.TryResolveType(lambdaTypeName, out lambdaType) == false) { bindingError = new ExpressionParserException(string.Format(Properties.Resources.EXCEPTION_BIND_UNABLETORESOLVETYPE, lambdaTypeName), node); return(false); } else { expectedType = TypeDescription.GetTypeDescription(lambdaType); } } if (expectedType.HasGenericParameters || !expectedType.IsDelegate) { bindingError = new ExpressionParserException(string.Format(Properties.Resources.EXCEPTION_BIND_VALIDDELEGATETYPEISEXPECTED, expectedType.ToString())); return(false); } var expressionType = node.GetExpressionType(throwOnError: true); var bodyNode = node.GetExpression(throwOnError: true); var argumentsTree = node.GetArguments(throwOnError: false); var lambdaInvokeMethod = expectedType.GetMembers(Constants.DELEGATE_INVOKE_NAME).FirstOrDefault(m => m.IsMethod && !m.IsStatic); if (lambdaInvokeMethod == null) { bindingError = new MissingMethodException(string.Format(Resources.EXCEPTION_BIND_MISSINGMETHOD, expectedType.ToString(), Constants.DELEGATE_INVOKE_NAME)); return(false); } if (lambdaInvokeMethod.GetParametersCount() != argumentsTree.Count) { bindingError = new ExpressionParserException(string.Format(Properties.Resources.EXCEPTION_BIND_INVALIDLAMBDAARGUMENTS, expectedType)); return(false); } var argumentNames = new string[argumentsTree.Count]; for (var i = 0; i < argumentNames.Length; i++) { var argumentNameTree = default(SyntaxTreeNode); var argumentNameTreeType = default(string); if (argumentsTree.TryGetValue(i, out argumentNameTree) == false || argumentNameTree == null || (argumentNameTreeType = argumentNameTree.GetExpressionType(throwOnError: true)) == null || (argumentNameTreeType == Constants.EXPRESSION_TYPE_PROPERTY_OR_FIELD || argumentNameTreeType == Constants.EXPRESSION_TYPE_MEMBER_RESOLVE || argumentNameTreeType == Constants.EXPRESSION_TYPE_PARAMETER) == false) { bindingError = new ExpressionParserException(string.Format(Properties.Resources.EXCEPTION_BIND_MISSINGATTRONNODE, Constants.EXPRESSION_ATTRIBUTE, expressionType), node); return(false); } argumentNames[i] = argumentNameTree.GetMemberName(throwOnError: true); } var lambdaParameters = new ParameterExpression[argumentsTree.Count]; for (var i = 0; i < argumentsTree.Count; i++) { lambdaParameters[i] = Expression.Parameter(lambdaInvokeMethod.GetParameter(i).ParameterType, argumentNames[i]); } var currentParameters = bindingContext.Parameters; var newParameters = new List <ParameterExpression>(lambdaParameters.Length + currentParameters.Count); // add all lambda's parameters newParameters.AddRange(lambdaParameters); // add closure parameters foreach (var parameterExpr in currentParameters) { if (Array.IndexOf(argumentNames, parameterExpr.Name) < 0) { newParameters.Add(parameterExpr); } } var nestedBindingContext = bindingContext.CreateNestedContext(newParameters.AsReadOnly(), lambdaInvokeMethod.ResultType); var body = default(Expression); if (AnyBinder.TryBindInNewScope(bodyNode, nestedBindingContext, TypeDescription.GetTypeDescription(lambdaInvokeMethod.ResultType), out body, out bindingError) == false) { return(false); } Debug.Assert(body != null, "body != null"); boundExpression = Expression.Lambda(expectedType, body, lambdaParameters); return(true); }