collect<T> function

Stream<T> collect <T>(Iterable<Future<T>> futures)

Returns a stream of completion events for the input futures.

Successfully completed futures yield data events, while futures completed with errors yield error events.

The iterator obtained from futures is only advanced once the previous future completes and yields an event. Thus, lazily creating the futures is supported, for example:

collect(files.map((file) => file.readAsString()));

If you need to modify futures, or a backing collection thereof, before the returned stream is done, pass a copy instead to avoid a ConcurrentModificationError:

collect(files.toList().map((file) => file.readAsString()));

Implementation 

Stream<T> collect<T>(Iterable<Future<T>> futures) =>
    new Stream.fromIterable(futures).asyncMap((f) => f);