Add Stream.empty.

sdk/lib/async/stream_controller.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.
 
 part of dart.async;
 
 // -------------------------------------------------------------------
 // Controller for creating and adding events to a stream.
 // -------------------------------------------------------------------
 
@@ skipping 62 matching lines @@
    * [onResume] call might not be executed.
    */
   factory StreamController({void onListen(),
                             void onPause(),
                             void onResume(),
                             onCancel(),
                             bool sync: false}) {
     if (onListen == null && onPause == null &&
         onResume == null && onCancel == null) {
       return sync
-          ? new _NoCallbackSyncStreamController/*<T>*/()
-          : new _NoCallbackAsyncStreamController/*<T>*/();
+          ? new _NoCallbackSyncStreamController<T>()
+          : new _NoCallbackAsyncStreamController<T>();
     }
     return sync
          ? new _SyncStreamController<T>(onListen, onPause, onResume, onCancel)
          : new _AsyncStreamController<T>(onListen, onPause, onResume, onCancel);
   }
 
   /**
    * A controller where [stream] can be listened to more than once.
    *
    * The [Stream] returned by [stream] is a broadcast stream.
@@ skipping 74 matching lines @@
    */
   bool get isPaused;
 
   /** Whether there is a subscriber on the [Stream]. */
   bool get hasListener;
 
   /**
    * Send or enqueue an error event.
    *
    * If [error] is `null`, it is replaced by a [NullThrownError].
-   *
-   * Also allows an objection stack trace object, on top of what [EventSink]
-   * allows.
    */
   void addError(Object error, [StackTrace stackTrace]);
 
   /**
    * Receives events from [source] and puts them into this controller's stream.
    *
    * Returns a future which completes when the source stream is done.
    *
    * Events must not be added directly to this controller using [add],
    * [addError], [close] or [addStream], until the returned future
@@ skipping 195 matching lines @@
   _Future _doneFuture;
 
   _StreamController();
 
   _NotificationHandler get _onListen;
   _NotificationHandler get _onPause;
   _NotificationHandler get _onResume;
   _NotificationHandler get _onCancel;
 
   // Return a new stream every time. The streams are equal, but not identical.
-  Stream<T> get stream => new _ControllerStream(this);
+  Stream<T> get stream => new _ControllerStream<T>(this);
 
   /**
    * Returns a view of this object that only exposes the [StreamSink] interface.
    */
   StreamSink<T> get sink => new _StreamSinkWrapper<T>(this);
 
   /**
    * Whether a listener has existed and been canceled.
    *
    * After this, adding more events will be ignored.
@@ skipping 343 matching lines @@
                         this._onCancel());
 }
 
 abstract class _NoCallbacks {
   _NotificationHandler get _onListen => null;
   _NotificationHandler get _onPause => null;
   _NotificationHandler get _onResume => null;
   _NotificationHandler get _onCancel => null;
 }
 
-class _NoCallbackAsyncStreamController/*<T>*/ = _StreamController/*<T>*/
-       with _AsyncStreamControllerDispatch/*<T>*/, _NoCallbacks;
+class _NoCallbackAsyncStreamController<T> = _StreamController<T>
+       with _AsyncStreamControllerDispatch<T>, _NoCallbacks;
 
-class _NoCallbackSyncStreamController/*<T>*/ = _StreamController/*<T>*/
-       with _SyncStreamControllerDispatch/*<T>*/, _NoCallbacks;
+class _NoCallbackSyncStreamController<T> = _StreamController<T>
+       with _SyncStreamControllerDispatch<T>, _NoCallbacks;
 
 typedef _NotificationHandler();
 
 Future _runGuarded(_NotificationHandler notificationHandler) {
   if (notificationHandler == null) return null;
   try {
     var result = notificationHandler();
     if (result is Future) return result;
     return null;
   } catch (e, s) {
@@ skipping 126 matching lines @@
   _StreamControllerAddStreamState(_StreamController controller,
                                   this.varData,
                                   Stream source,
                                   bool cancelOnError)
       : super(controller, source, cancelOnError) {
     if (controller.isPaused) {
       addSubscription.pause();
     }
   }
 }