hasNext property Null safety
Whether the stream has any more events.
Returns a future that completes with true
if the stream has any
more events, whether data or error.
If the stream closes without producing any more events, the returned
future completes with false
.
Can be used before using next to avoid getting an error in the
future returned by next
in the case where there are no more events.
Another alternative is to use take(1)
which returns either zero or
one events.
Implementation
Future<bool> get hasNext {
_checkNotClosed();
var hasNextRequest = _HasNextRequest<T>();
_addRequest(hasNextRequest);
return hasNextRequest.future;
}