Remove AsyncError with Expando.

sdk/lib/async/stream_impl.dart

Index: sdk/lib/async/stream_impl.dart
diff --git a/sdk/lib/async/stream_impl.dart b/sdk/lib/async/stream_impl.dart
index e827adf2e8b6557c45c28b001c4480cdd2370783..8fa1848d14ac0261b2943dfc41c4ba314d457162 100644
--- a/sdk/lib/async/stream_impl.dart
+++ b/sdk/lib/async/stream_impl.dart
@@ -55,6 +55,20 @@ const int _LISTENER_EVENT_ID_SHIFT = 2;
 /// state, shifted by this amount.
 const int _LISTENER_PAUSE_COUNT_SHIFT = 3;
 
+/** Throws the given error in the next cycle. */
+_throwDelayed(var error, [Object stackTrace]) {
+  // We are going to reach the top-level here, but there might be a global
+  // exception handler. This means that we shouldn't print the stack trace.
+  // TODO(floitsch): Find better solution that doesn't print the stack trace
+  // if there is a global exception handler.
+  runAsync(() {
+    if (stackTrace != null) print(stackTrace);
+    var trace = getAttachedStackTrace(error);
+    if (trace != null && trace != stackTrace) print(trace);
+    throw error;
+  });
+}
+
 
 // -------------------------------------------------------------------
 // Common base class for single and multi-subscription streams.
@@ -77,7 +91,7 @@ abstract class _StreamImpl<T> extends Stream<T> {
   // Stream interface.
 
   StreamSubscription<T> listen(void onData(T data),
-                               { void onError(AsyncError error),
+                               { void onError(error),
                                  void onDone(),
                                  bool cancelOnError }) {
     if (_isComplete) {
@@ -123,7 +137,7 @@ abstract class _StreamImpl<T> extends Stream<T> {
    * If a subscription has requested to be unsubscribed on errors,
    * it will be unsubscribed after receiving this event.
    */
-  void _addError(AsyncError error) {
+  void _addError(error) {
     if (_isClosed) throw new StateError("Sending on closed stream");
     if (!_mayFireState) {
       // Not the time to send events.
@@ -374,7 +388,7 @@ abstract class _StreamImpl<T> extends Stream<T> {
   /** Create a subscription object. Called by [subcribe]. */
   _StreamSubscriptionImpl<T> _createSubscription(
       void onData(T data),
-      void onError(AsyncError error),
+      void onError(error),
       void onDone(),
       bool cancelOnError);
 
@@ -493,10 +507,8 @@ abstract class _StreamImpl<T> extends Stream<T> {
     _forEachSubscriber((subscriber) {
       try {
         subscriber._sendData(value);
-      } on AsyncError catch (e) {
-        e.throwDelayed();
       } catch (e, s) {
-        new AsyncError(e, s).throwDelayed();
+        _throwDelayed(e, s);
       }
     });
   }
@@ -504,17 +516,15 @@ abstract class _StreamImpl<T> extends Stream<T> {
   /**
    * Sends an error event directly to each subscriber.
    */
-  void _sendError(AsyncError error) {
+  void _sendError(error) {
     assert(!_isPaused);
     assert(!_isComplete);
     if (!_hasListener) return;
     _forEachSubscriber((subscriber) {
       try {
         subscriber._sendError(error);
-      } on AsyncError catch (e) {
-        e.throwDelayed();
       } catch (e, s) {
-        new AsyncError.withCause(e, s, error).throwDelayed();
+        _throwDelayed(e, s);
       }
     });
   }
@@ -533,10 +543,8 @@ abstract class _StreamImpl<T> extends Stream<T> {
       _cancel(subscriber);
       try {
         subscriber._sendDone();
-      } on AsyncError catch (e) {
-        e.throwDelayed();
       } catch (e, s) {
-        new AsyncError(e, s).throwDelayed();
+        _throwDelayed(e, s);
       }
     });
     assert(!_hasListener);
@@ -592,7 +600,7 @@ class _SingleStreamImpl<T> extends _StreamImpl<T> {
    */
   _StreamSubscriptionImpl<T> _createSubscription(
       void onData(T data),
-      void onError(AsyncError error),
+      void onError(error),
       void onDone(),
       bool cancelOnError) {
     return new _StreamSubscriptionImpl<T>(
@@ -712,7 +720,7 @@ class _MultiStreamImpl<T> extends _StreamImpl<T>
    */
   _StreamListener<T> _createSubscription(
       void onData(T data),
-      void onError(AsyncError error),
+      void onError(error),
       void onDone(),
       bool cancelOnError) {
     return new _StreamSubscriptionImpl<T>(
@@ -841,7 +849,7 @@ class _GeneratedSingleStreamImpl<T> extends _SingleStreamImpl<T> {
     throw new UnsupportedError("Cannot inject events into generated stream");
   }
 
-  void _addError(AsyncError value) {
+  void _addError(value) {
     throw new UnsupportedError("Cannot inject events into generated stream");
   }
 
@@ -876,7 +884,7 @@ class _IterablePendingEvents<T> extends _PendingEvents {
         stream._sendDone();
       }
     } catch (e, s) {
-      stream._sendError(new AsyncError(e, s));
+      stream._sendError(_asyncError(e, s));
       stream._sendDone();
       _isDone = true;
     }
@@ -918,7 +926,7 @@ class _StreamSubscriptionImpl<T> extends _StreamListener<T>
     _onData = handleData;
   }
 
-  void onError(void handleError(AsyncError error)) {
+  void onError(void handleError(error)) {
     if (handleError == null) handleError = _nullErrorHandler;
     _onError = handleError;
   }
@@ -932,7 +940,7 @@ class _StreamSubscriptionImpl<T> extends _StreamListener<T>
     _onData(data);
   }
 
-  void _sendError(AsyncError error) {
+  void _sendError(error) {
     _onError(error);
     if (_cancelOnError) _source._cancel(this);
   }
@@ -961,7 +969,7 @@ class _StreamSubscriptionImpl<T> extends _StreamListener<T>
 
     // Overwrite the onDone and onError handlers.
     onDone(() { result._setValue(futureValue); });
-    onError((AsyncError error) {
+    onError((error) {
       cancel();
       result._setError(error);
     });
@@ -974,7 +982,7 @@ class _StreamSubscriptionImpl<T> extends _StreamListener<T>
 
 // Types of the different handlers on a stream. Types used to type fields.
 typedef void _DataHandler<T>(T value);
-typedef void _ErrorHandler(AsyncError error);
+typedef void _ErrorHandler(error);
 typedef void _DoneHandler();
 
 
@@ -982,8 +990,8 @@ typedef void _DoneHandler();
 void _nullDataHandler(var value) {}
 
 /** Default error handler, reports the error to the global handler. */
-void _nullErrorHandler(AsyncError error) {
-  error.throwDelayed();
+void _nullErrorHandler(error) {
+  _throwDelayed(error);
 }
 
 /** Default done handler, does nothing. */
@@ -1000,7 +1008,7 @@ abstract class _DelayedEvent {
 
 /** A delayed data event. */
 class _DelayedData<T> extends _DelayedEvent{
-  T value;
+  final T value;
   _DelayedData(this.value);
   void perform(_StreamImpl<T> stream) {
     stream._sendData(value);
@@ -1009,7 +1017,7 @@ class _DelayedData<T> extends _DelayedEvent{
 
 /** A delayed error event. */
 class _DelayedError extends _DelayedEvent {
-  AsyncError error;
+  final error;
   _DelayedError(this.error);
   void perform(_StreamImpl stream) {
     stream._sendError(error);
@@ -1113,7 +1121,7 @@ abstract class _InternalLinkList extends _InternalLink {
 /** Abstract type for an internal interface for sending events. */
 abstract class _EventOutputSink<T> {
   _sendData(T data);
-  _sendError(AsyncError error);
+  _sendError(error);
   _sendDone();
 }
 
@@ -1188,7 +1196,7 @@ abstract class _StreamListener<T> extends _InternalLink
   }
 
   _sendData(T data);
-  _sendError(AsyncError error);
+  _sendError(error);
   _sendDone();
 }
 
@@ -1276,7 +1284,7 @@ class _DoneSubscription<T> implements StreamSubscription<T> {
 
   void onData(void handleAction(T value)) {}
 
-  void onError(void handleError(AsyncError error)) {}
+  void onError(void handleError(error)) {}
 
   void onDone(void handleDone()) {
     _handler = handleDone;
@@ -1318,7 +1326,7 @@ class _DoneSubscription<T> implements StreamSubscription<T> {
 
     // Overwrite the onDone and onError handlers.
     onDone(() { result._setValue(futureValue); });
-    onError((AsyncError error) {
+    onError((error) {
       cancel();
       result._setError(error);
     });