Checks whether test
accepts any element provided by this stream.
Calls test
on each element of the stream.
If the call returns true
, the returned future is completed with true
and processing stops.
If the stream ends without finding an element that test
accepts,
the returned future is completed with false
.
If this stream contains an error, or if the call to test
throws,
the returned future is completed with that error, and processing stops.
Source
Future<bool> any(bool test(T element)) { _Future<bool> future = new _Future<bool>(); StreamSubscription subscription; subscription = this.listen( (T element) { _runUserCode(() => test(element), (bool isMatch) { if (isMatch) { _cancelAndValue(subscription, future, true); } }, _cancelAndErrorClosure(subscription, future)); }, onError: future._completeError, onDone: () { future._complete(false); }, cancelOnError: true); return future; }