description

# every method Null safety

Future<bool> every (

1. bool test(
   1. T element
   )

)

Checks whether `test` accepts all elements provided by this stream.

Calls `test` on each element of this stream. If the call returns `false`, the returned future is completed with `false` and processing stops.

If this stream ends without finding an element that `test` rejects, the returned future is completed with `true`.

If this stream emits an error, or if the call to `test` throws, the returned future is completed with that error, and processing stops.

## Implementation

    Future<bool> every(bool test(T element)) {
      _Future<bool> future = new _Future<bool>();
      StreamSubscription<T> subscription =
          this.listen(null, onError: future._completeError, onDone: () {
        future._complete(true);
      }, cancelOnError: true);
      subscription.onData((T element) {
        _runUserCode(() => test(element), (bool isMatch) {
          if (!isMatch) {
            _cancelAndValue(subscription, future, false);
          }
        }, _cancelAndErrorClosure(subscription, future));
      });
      return future;
    }