Add Stream.fromIterable

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 617a616b25037a38a629cf357a5b3800f4e8ea0d..d27dfef5d5f070877f181628970fc2cabf02d1f9 100644
--- a/sdk/lib/async/stream_impl.dart
+++ b/sdk/lib/async/stream_impl.dart
@@ -625,6 +625,51 @@ class _MultiStreamImpl<T> extends _StreamImpl<T>
   }
 }
 
+
+/** Abstract superclass for streams that generate their own events. */
+abstract class _GeneratedSingleStreamImpl<T> extends _SingleStreamImpl<T> {
+
+  void _onSubscriptionStateChange() {
+    if (_hasSubscribers && !_isClosed) {
+      new Timer(0, (_) {
+        _handlePendingEvents();
+      });
+    }
+  }
+
+  void _generateNextEvent();
+
+  void _handlePendingEvents() {
+    while (!_isPaused) {
+      super._handlePendingEvents();
+      if (!_isPaused && !_isClosed) {
+        _generateNextEvent();
+      }
+    }
+  }
+}
+
+
+/** Stream that gets its events from an [Iterable]. */
+class _IterableSingleStreamImpl<T> extends _GeneratedSingleStreamImpl<T> {
+  Iterator<T> _iterator;
+
+  _IterableSingleStreamImpl(Iterable<T> data) : _iterator = data.iterator;
+
+  void _generateNextEvent() {
+    try {
+      if (_iterator.moveNext()) {
+        _add(_iterator.current);
+        return;
+      }
+    } catch (e, s) {
+      _signalError(new AsyncError(e, s));
+    }
+    _close();
+  }
+}
+
+
 /**
  * The subscription class that the [StreamController] uses.
  *