Improve WebSocket interface by making it implement StreamSink.

sdk/lib/io/websocket.dart

 // Copyright (c) 2013, 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.
 
 part of dart.io;
 
 /**
  * Web socket status codes used when closing a web socket connection.
  */
 abstract class WebSocketStatus {
@@ skipping 62 matching lines @@
     return _WebSocketTransformerImpl._isUpgradeRequest(request);
   }
 }
 
 
 /**
  * A client or server web socket connection. The stream exposes the
  * messages received. A text message will be of type [:String:] and a
  * binary message will be of type [:List<int>:].
  */
-abstract class WebSocket implements Stream {
+abstract class WebSocket implements Stream, StreamSink {
   /**
    * Possible states of the connection.
    */
   static const int CONNECTING = 0;
   static const int OPEN = 1;
   static const int CLOSING = 2;
   static const int CLOSED = 3;
 
   /**
    * Create a new web socket connection. The URL supplied in [url]
@@ skipping 30 matching lines @@
    */
   int get closeCode;
 
   /**
    * The close reason set when the web socket connection is closed. If
    * there is no close reason available this property will be [:null:]
    */
   String get closeReason;
 
   /**
    * Closes the web socket connection.

[Søren Gjesse, 2013/04/16 12:41:31]

Please add documentation on the default values. It is possible to not have a
status code and the server will see that. Reason is ignored if there is no
status code. Should we fail in that case?

[Anders Johnsen, 2013/04/16 13:46:22]

Done.

    */
-  void close([int code, String reason]);
+  Future close([int code, String reason]);
 
   /**
    * Sends data on the web socket connection. The data in [data] must
    * be either a [:String:], or a [:List<int>:] holding bytes.
    */
-  void send(data);
+  void add(data);

[Søren Gjesse, 2013/04/16 12:41:31]

We should add addStream with some dartdoc here as well. It should briefly
explain how to get flow control using a StreamController.

How about addError? How will that work?

[Anders Johnsen, 2013/04/16 13:46:22]

addError will more or less just close the connection. No need to extra
information about that (same as on http/socket).

 }
 
 
 class WebSocketException implements Exception {
   const WebSocketException([String this.message = ""]);
   String toString() => "WebSocketException: $message";
   final String message;
 }