Implement cascaded calls.

lib/compiler/implementation/scanner/listener.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.
 
 final bool VERBOSE = false;
 
 class Listener {
   void beginArguments(Token token) {
   }
 
   void endArguments(int count, Token beginToken, Token endToken) {
   }
 
   void beginBlock(Token token) {
   }
 
   void endBlock(int count, Token beginToken, Token endToken) {
   }
 
+  void beginCascade(Token token) {
+  }
+
+  void endCascade() {
+  }
+
   void beginClassBody(Token token) {
   }
 
   void endClassBody(int memberCount, Token beginToken, Token endToken) {
   }
 
   void beginClassDeclaration(Token token) {
   }
 
   void endClassDeclaration(int interfacesCount, Token beginToken,
@@ skipping 973 matching lines @@
     pushNode(new LiteralBool(token, (t, e) => handleOnError(t, e)));
   }
 
   void handleLiteralNull(Token token) {
     pushNode(new LiteralNull(token));
   }
 
   void handleBinaryExpression(Token token) {
     Node argument = popNode();
     Node receiver = popNode();
-    if (token.stringValue === '.') {
+    String tokenString = token.stringValue;
+    if (tokenString === '.' || tokenString === '..') {
       if (argument is !Send) internalError(node: argument);
       if (argument.asSend().receiver !== null) internalError(node: argument);
       if (argument is SendSet) internalError(node: argument);
       pushNode(argument.asSend().copyWithReceiver(receiver));
     } else {
       NodeList arguments = new NodeList.singleton(argument);
       pushNode(new Send(receiver, new Operator(token), arguments));
     }
   }
 
+  void beginCascade(Token token) {
+    pushNode(new CascadeReceiver(popNode(), token));
+  }
+
+  void endCascade() {
+    pushNode(new Cascade(popNode()));
+  }
+
   void handleAssignmentExpression(Token token) {
     Node arg = popNode();
     Node node = popNode();
     Send send = node.asSend();
     if (send === null) internalError(node: node);
     if (!(send.isPropertyAccess || send.isIndex)) internalError(node: send);
     if (send.asSendSet() !== null) internalError(node: send);
     NodeList arguments;
     if (send.isIndex) {
       Link<Node> link = new Link<Node>(arg);
@@ skipping 433 matching lines @@
 
 Node parse(DiagnosticListener diagnosticListener,
            CompilationUnitElement element,
            doParse(Parser parser)) {
   NodeListener listener = new NodeListener(diagnosticListener, element);
   doParse(new Parser(listener));
   Node node = listener.popNode();
   assert(listener.nodes.isEmpty());
   return node;
 }