Parse optional and named parameters.

pkg/front_end/lib/src/fasta/parser/parser.dart

 // Copyright (c) 2012, 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 fasta.parser.parser;
 
 import '../scanner.dart' show
     ErrorToken;
 
 import '../scanner/recover.dart' show
@@ skipping 444 matching lines @@
       } else if (identical(value, '{')) {
         token = parseOptionalFormalParameters(token, true);
         break;
       }
       token = parseFormalParameter(token, FormalParameterType.REQUIRED);
     } while (optional(',', token));
     listener.endFormalParameters(parameterCount, begin, token);
     return expect(')', token);
   }
 
-  Token parseFormalParameter(Token token, FormalParameterType type) {
+  Token parseFormalParameter(Token token, FormalParameterType kind) {
     token = parseMetadataStar(token, forParameter: true);
     listener.beginFormalParameter(token);
 
     // Skip over `covariant` token, if the next token is an identifier or
     // modifier.
     // This enables the case where `covariant` is the name of the parameter:
     //    void foo(covariant);
     if (identical(token.stringValue, 'covariant') &&
         (token.next.isIdentifier() || isModifier(token.next))) {
       token = token.next;
@@ skipping 19 matching lines @@
       token = parseTypeVariablesOpt(token);
       token = parseFormalParameters(token);
       listener.endFunctionTypedFormalParameter(token);
     }
     String value = token.stringValue;
     if ((identical('=', value)) || (identical(':', value))) {
       // TODO(ahe): Validate that these are only used for optional parameters.
       Token equal = token;
       token = parseExpression(token.next);
       listener.handleValuedFormalParameter(equal, token);
-      if (type.isRequired) {
+      if (kind.isRequired) {
         reportRecoverableError(
             equal, ErrorKind.RequiredParameterWithDefault);
-      } else if (type.isPositional && identical(':', value)) {
+      } else if (kind.isPositional && identical(':', value)) {
         reportRecoverableError(
             equal, ErrorKind.PositionalParameterWithEquals);
       }
+    } else {
+      listener.handleFormalParameterWithoutValue(token);
     }
-    listener.endFormalParameter(thisKeyword);
+    listener.endFormalParameter(thisKeyword, kind);
     return token;
   }
 
   Token parseOptionalFormalParameters(Token token, bool isNamed) {
     Token begin = token;
     listener.beginOptionalFormalParameters(begin);
     assert((isNamed && optional('{', token)) || optional('[', token));
     int parameterCount = 0;
     do {
       token = token.next;
@@ skipping 2799 matching lines @@
         break;
     }
     if (isRecoverable) {
       listener.handleRecoverableError(token, kind, arguments);
       return null;
     } else {
       return listener.handleUnrecoverableError(token, kind, arguments);
     }
   }
 }