Update charted to 0.4.8 and roll

packages/async/lib/src/stream_completer.dart

Index: packages/async/lib/src/stream_completer.dart
diff --git a/packages/async/lib/src/stream_completer.dart b/packages/async/lib/src/stream_completer.dart
index c343e6e7bd2330ccda59e9c793f96b0de3fbed50..4311de5216a7fd0faa10d49e2d0789ba557a1600 100644
--- a/packages/async/lib/src/stream_completer.dart
+++ b/packages/async/lib/src/stream_completer.dart
@@ -2,8 +2,6 @@
 // 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 async.stream_completer;
-
 import "dart:async";
 
 /// A single-subscription [stream] where the contents are provided later.
@@ -26,7 +24,7 @@ import "dart:async";
 /// the listen is performed directly on the source stream.
 class StreamCompleter<T> {
   /// The stream doing the actual work, is returned by [stream].
-  final _CompleterStream _stream = new _CompleterStream<T>();
+  final _stream = new _CompleterStream<T>();
 
   /// Convert a `Future<Stream>` to a `Stream`.
   ///
@@ -36,12 +34,9 @@ class StreamCompleter<T> {
   ///
   /// If the future completes with an error, the returned stream will
   /// instead contain just that error.
-  static Stream fromFuture(Future<Stream> streamFuture) {
-    var completer = new StreamCompleter();
-    streamFuture.then(completer.setSourceStream,
-                      onError: (e, s) {
-                        completer.setSourceStream(streamFuture.asStream());
-                      });
+  static Stream<T> fromFuture<T>(Future<Stream<T>> streamFuture) {
+    var completer = new StreamCompleter<T>();
+    streamFuture.then(completer.setSourceStream, onError: completer.setError);
     return completer.stream;
   }
 
@@ -76,8 +71,8 @@ class StreamCompleter<T> {
   /// it is immediately listened to, and its events are forwarded to the
   /// existing subscription.
   ///
-  /// Either [setSourceStream] or [setEmpty] may be called at most once.
-  /// Trying to call either of them again will fail.
+  /// Any one of [setSourceStream], [setEmpty], and [setError] may be called at
+  /// most once. Trying to call any of them again will fail.
   void setSourceStream(Stream<T> sourceStream) {
     if (_stream._isSourceStreamSet) {
       throw new StateError("Source stream already set");
@@ -87,14 +82,24 @@ class StreamCompleter<T> {
 
   /// Equivalent to setting an empty stream using [setSourceStream].
   ///
-  /// Either [setSourceStream] or [setEmpty] may be called at most once.
-  /// Trying to call either of them again will fail.
+  /// Any one of [setSourceStream], [setEmpty], and [setError] may be called at
+  /// most once. Trying to call any of them again will fail.
   void setEmpty() {
     if (_stream._isSourceStreamSet) {
       throw new StateError("Source stream already set");
     }
     _stream._setEmpty();
   }
+
+  /// Completes this to a stream that emits [error] and then closes.
+  ///
+  /// This is useful when the process of creating the data for the stream fails.
+  ///
+  /// Any one of [setSourceStream], [setEmpty], and [setError] may be called at
+  /// most once. Trying to call any of them again will fail.
+  void setError(error, [StackTrace stackTrace]) {
+    setSourceStream(new Stream.fromFuture(new Future.error(error, stackTrace)));
+  }
 }
 
 /// Stream completed by [StreamCompleter].
@@ -103,32 +108,30 @@ class _CompleterStream<T> extends Stream<T> {
   ///
   /// Created if the user listens on this stream before the source stream
   /// is set, or if using [_setEmpty] so there is no source stream.
-  StreamController _controller;
+  StreamController<T> _controller;
 
   /// Source stream for the events provided by this stream.
   ///
   /// Set when the completer sets the source stream using [_setSourceStream]
   /// or [_setEmpty].
-  Stream _sourceStream;
+  Stream<T> _sourceStream;
 
   StreamSubscription<T> listen(onData(T data),
-                               {Function onError,
-                                void onDone(),
-                                bool cancelOnError}) {
+      {Function onError, void onDone(), bool cancelOnError}) {
     if (_controller == null) {
       if (_sourceStream != null && !_sourceStream.isBroadcast) {
         // If the source stream is itself single subscription,
         // just listen to it directly instead of creating a controller.
-        return _sourceStream.listen(onData, onError: onError, onDone: onDone,
-                                    cancelOnError: cancelOnError);
+        return _sourceStream.listen(onData,
+            onError: onError, onDone: onDone, cancelOnError: cancelOnError);
       }
       _createController();
       if (_sourceStream != null) {
         _linkStreamToController();
       }
     }
-    return _controller.stream.listen(onData, onError: onError, onDone: onDone,
-                                     cancelOnError: cancelOnError);
+    return _controller.stream.listen(onData,
+        onError: onError, onDone: onDone, cancelOnError: cancelOnError);
   }
 
   /// Whether a source stream has been set.
@@ -155,8 +158,9 @@ class _CompleterStream<T> extends Stream<T> {
   void _linkStreamToController() {
     assert(_controller != null);
     assert(_sourceStream != null);
-    _controller.addStream(_sourceStream, cancelOnError: false)
-               .whenComplete(_controller.close);
+    _controller
+        .addStream(_sourceStream, cancelOnError: false)
+        .whenComplete(_controller.close);
   }
 
   /// Sets an empty source stream.
@@ -168,7 +172,7 @@ class _CompleterStream<T> extends Stream<T> {
     if (_controller == null) {
       _createController();
     }
-    _sourceStream = _controller.stream;  // Mark stream as set.
+    _sourceStream = _controller.stream; // Mark stream as set.
     _controller.close();
   }