Improve parsing of async and generator methods.

pkg/compiler/lib/src/parser/element_listener.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart2js.parser.element_listener;
 
 import '../common.dart';
 import '../diagnostics/messages.dart' show MessageTemplate;
 import '../elements/elements.dart'
     show Element, LibraryElement, MetadataAnnotation;
@@ skipping 723 matching lines @@
 
       case ErrorKind.BuiltInIdentifierAsType:
         errorCode = MessageKind.GENERIC;
         arguments = {"text": "Can't use '${token.lexeme}' as a type."};
         break;
 
       case ErrorKind.BuiltInIdentifierInDeclaration:
         errorCode = MessageKind.GENERIC;
         arguments = {"text": "Can't use '${token.lexeme}' as a name here."};
         break;
+
+      case ErrorKind.AbstractNotSync:
+        errorCode = MessageKind.GENERIC;
+        arguments = {
+          "text": "Abstract methods can't use 'async', 'async*', or 'sync*'."
+        };
+        return; // Ignored. This error is already implemented elsewhere.
+
+      case ErrorKind.SetterNotSync:
+        errorCode = MessageKind.GENERIC;
+        arguments = {
+          "text": "Setters can't use 'async', 'async*', or 'sync*'."
+        };
+        return; // Ignored. This error is already implemented elsewhere.
+
+      case ErrorKind.FactoryNotSync:
+        errorCode = MessageKind.GENERIC;
+        arguments = {
+          "text": "Factories can't use 'async', 'async*', or 'sync*'."
+        };
+        return; // Ignored. This error is already implemented elsewhere.
+
+      case ErrorKind.AwaitForNotAsync:
+        errorCode = MessageKind.GENERIC;
+        arguments = {
+          "text": "Asynchronous for-loop can only be used "
+              "in 'async' or 'async*' methods."
+        };
+        return; // Ignored. This error is already implemented elsewhere.
+
+      case ErrorKind.AsyncAsIdentifier:
+        errorCode = MessageKind.GENERIC;
+        arguments = {
+          "text": "'async' can't be used as an identifier in "
+              "'async', 'async*', or 'sync*' methods."
+        };
+        break;
+
+      case ErrorKind.YieldNotGenerator:
+        errorCode = MessageKind.GENERIC;
+        arguments = {
+          "text": "'yield' can only be used in 'sync*' or 'async*' methods."
+        };
+        return; // Ignored. This error is already implemented elsewhere.
+
+      case ErrorKind.YieldAsIdentifier:
+        errorCode = MessageKind.GENERIC;
+        arguments = {
+          "text": "'yield' can't be used as an identifier in "
+              "'async', 'async*', or 'sync*' methods."
+        };
+        return; // Ignored. This error is already implemented elsewhere.
+
+      case ErrorKind.GeneratorReturnsValue:
+        errorCode = MessageKind.GENERIC;
+        arguments = {"text": "'sync*' and 'async*' can't return a value."};
+        return; // Ignored. This error is already implemented elsewhere.
+
+      case ErrorKind.AwaitNotAsync:
+        errorCode = MessageKind.GENERIC;
+        arguments = {
+          "text": "'await' can only be used in 'async' or 'async*' methods."
+        };
+        return; // Ignored. This error is already implemented elsewhere.
+
+      case ErrorKind.AwaitAsIdentifier:
+        errorCode = MessageKind.GENERIC;
+        arguments = {
+          "text": "'await' can't be used as an identifier in "
+              "'async', 'async*', or 'sync*' methods."
+        };
+        return; // Ignored. This error is already implemented elsewhere.
     }
     SourceSpan span = reporter.spanFromToken(token);
     reportError(span, errorCode, arguments);
   }
 
   /// Finds the preceding token via the begin token of the last AST node pushed
   /// on the [nodes] stack.
   Token findPrecedingToken(Token token) {
     Token result;
     Link<Node> nodes = this.nodes;
@@ skipping 215 matching lines @@
       memberErrors = memberErrors.tail.prepend(true);
     }
     reporter.reportErrorMessage(spannable, errorCode, arguments);
   }
 
   void reportErrorFromToken(Token token, MessageKind errorCode,
       [Map arguments = const {}]) {
     reportError(reporter.spanFromToken(token), errorCode, arguments);
   }
 }