Distinguish SimpleIdentifier uses and declarations at parse time.

pkg/analyzer/lib/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.
 
 /**
  * Defines the AST model. The AST (Abstract Syntax Tree) model describes the
  * syntactic (as opposed to semantic) structure of Dart code. The semantic
  * structure of the code is modeled by the
  * [element model](../element/element.dart).
  *
@@ skipping 6686 matching lines @@
  *    initialCharacter ::= '_' | '$' | letter
  *
  *    internalCharacter ::= '_' | '$' | letter | digit
  *
  * Clients may not extend, implement or mix-in this class.
  */
 abstract class SimpleIdentifier extends Identifier {
   /**
    * Initialize a newly created identifier.
    */
-  factory SimpleIdentifier(Token token) = SimpleIdentifierImpl;
+  factory SimpleIdentifier(Token token, {bool isDeclaration: false}) {
+    if (isDeclaration) {
+      return new DeclaredSimpleIdentifier(token);
+    }
+    return new SimpleIdentifierImpl(token);
+  }
 
   /**
    * Return the auxiliary elements associated with this identifier, or `null` if
    * this identifier is not in both a getter and setter context. The auxiliary
    * elements hold the static and propagated elements associated with the getter
    * context.
    */
   // TODO(brianwilkerson) Replace this API.
   AuxiliaryElements get auxiliaryElements;
 
@@ skipping 1375 matching lines @@
   /**
    * Return the 'yield' keyword.
    */
   Token get yieldKeyword;
 
   /**
    * Return the 'yield' keyword to the given [token].
    */
   void set yieldKeyword(Token token);
 }