Ast changes to support the covariant keyword

pkg/analyzer/lib/src/dart/ast/ast.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.dart.ast.ast;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/syntactic_entity.dart';
@@ skipping 3428 matching lines @@
   }
 
   @override
   Token get beginToken => _parameter.beginToken;
 
   @override
   Iterable<SyntacticEntity> get childEntities =>
       new ChildEntities()..add(_parameter)..add(separator)..add(_defaultValue);
 
   @override
+  Token get covariantKeyword => null;
+
+  @override
   Expression get defaultValue => _defaultValue;
 
   @override
   void set defaultValue(Expression expression) {
     _defaultValue = _becomeParentOf(expression as AstNodeImpl);
   }
 
   @override
   Token get endToken {
     if (_defaultValue != null) {
@@ skipping 4636 matching lines @@
    * parameter does not have a documentation comment associated with it.
    */
   Comment _comment;
 
   /**
    * The annotations associated with this parameter.
    */
   NodeList<Annotation> _metadata;
 
   /**
+   * The 'covariant' keyword, or `null` if the keyword was not used.
+   */
+  Token covariantKeyword;
+
+  /**
    * The name of the parameter being declared.
    */
   SimpleIdentifier _identifier;
 
   /**
    * Initialize a newly created formal parameter. Either or both of the
    * [comment] and [metadata] can be `null` if the parameter does not have the
    * corresponding attribute.
    */
   NormalFormalParameterImpl(CommentImpl comment, List<Annotation> metadata,
@@ skipping 47 matching lines @@
 
   ChildEntities get _childEntities {
     ChildEntities result = new ChildEntities();
     if (_commentIsBeforeAnnotations()) {
       result
         ..add(_comment)
         ..addAll(_metadata);
     } else {
       result.addAll(sortedCommentAndAnnotations);
     }
+    if (covariantKeyword != null) {
+      result.add(covariantKeyword);

[scheglov, 2017/01/18 04:29:59]

Do we need to update beginToken?

[Brian Wilkerson, 2017/01/18 17:19:29]

Yes. Good catch. I'll have an update out shortly.

+    }
     return result;
   }
 
   @override
   void visitChildren(AstVisitor visitor) {
     //
     // Note that subclasses are responsible for visiting the identifier because
     // they often need to visit other nodes before visiting the identifier.
     //
     if (_commentIsBeforeAnnotations()) {
@@ skipping 3255 matching lines @@
 
   @override
   dynamic/*=E*/ accept/*<E>*/(AstVisitor/*<E>*/ visitor) =>
       visitor.visitYieldStatement(this);
 
   @override
   void visitChildren(AstVisitor visitor) {
     _expression?.accept(visitor);
   }
 }