Parse generic function declarations with/without type.

pkg/analyzer/lib/src/generated/parser.dart

 // Copyright (c) 2014, 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 analyzer.src.generated.parser;
 
 import 'dart:collection';
 import "dart:math" as math;
 
 import 'package:analyzer/src/generated/ast.dart';
@@ skipping 4201 matching lines @@
     }
     // Consume all operator tokens.
     Token token = startToken.next;
     while (token.isOperator) {
       token = token.next;
     }
     // Formal parameter list is expect now.
     return _tokenMatches(token, TokenType.OPEN_PAREN);
   }
 
+  bool _isPeekGenericTypeParametersAndOpenParen() {
+    if (!parseGenericMethods) {
+      return false;
+    }
+    Token token = _skipTypeArgumentList(_peek());
+    return token != null && _tokenMatches(token, TokenType.OPEN_PAREN);
+  }
+
   /**
    * Return `true` if the current token appears to be the beginning of a switch
    * member.
    */
   bool _isSwitchMember() {
     Token token = _currentToken;
     while (_tokenMatches(token, TokenType.IDENTIFIER) &&
         _tokenMatches(token.next, TokenType.COLON)) {
       token = token.next.next;
     }
@@ skipping 977 matching lines @@
         variables.add(
             new VariableDeclaration(_createSyntheticIdentifier(), null, null));
         return new TopLevelVariableDeclaration(
             commentAndMetadata.comment,
             commentAndMetadata.metadata,
             new VariableDeclarationList(null, null, keyword, null, variables),
             _expectSemicolon());
       }
       _reportErrorForToken(ParserErrorCode.EXPECTED_EXECUTABLE, _currentToken);
       return null;
+    } else if (_isPeekGenericTypeParametersAndOpenParen()) {
+      return _parseFunctionDeclaration(
+          commentAndMetadata, modifiers.externalKeyword, null);
     } else if (_tokenMatches(_peek(), TokenType.OPEN_PAREN)) {
       TypeName returnType = _parseOptionalTypeNameComment();
       _validateModifiersForTopLevelFunction(modifiers);
       return _parseFunctionDeclaration(
           commentAndMetadata, modifiers.externalKeyword, returnType);
     } else if (_peek()
         .matchesAny([TokenType.EQ, TokenType.COMMA, TokenType.SEMICOLON])) {
       if (modifiers.constKeyword == null &&
           modifiers.finalKeyword == null &&
           modifiers.varKeyword == null) {
@@ skipping 39 matching lines @@
           new VariableDeclaration(_createSyntheticIdentifier(), null, null));
       return new TopLevelVariableDeclaration(
           commentAndMetadata.comment,
           commentAndMetadata.metadata,
           new VariableDeclarationList(null, null, null, returnType, variables),
           semicolon);
     }
     if (_peek().matchesAny([
       TokenType.OPEN_PAREN,
       TokenType.FUNCTION,
-      TokenType.OPEN_CURLY_BRACKET
+      TokenType.OPEN_CURLY_BRACKET,
+      TokenType.LT
     ])) {
       _validateModifiersForTopLevelFunction(modifiers);
       return _parseFunctionDeclaration(
           commentAndMetadata, modifiers.externalKeyword, returnType);
     }
     return new TopLevelVariableDeclaration(
         commentAndMetadata.comment,
         commentAndMetadata.metadata,
         _parseVariableDeclarationListAfterType(
             null, _validateModifiersForTopLevelVariable(modifiers), returnType),
@@ skipping 6030 matching lines @@
   }
 
   /**
    * Copy resolution data from the [fromNode] to the [toNode].
    */
   static void copyResolutionData(AstNode fromNode, AstNode toNode) {
     ResolutionCopier copier = new ResolutionCopier();
     copier._isEqualNodes(fromNode, toNode);
   }
 }