mapNotNull<R> method

Stream<R> mapNotNull<R>(
  1. R? mapper(
    1. T event
    )
)

Maps events to R and filters out null results in a single, efficient pass.

Implementation

Stream<R> mapNotNull<R>(R? Function(T event) mapper) {
  return transform(StreamTransformer<T, R>.fromHandlers(
    handleData: (event, sink) {
      final result = mapper(event);
      if (result != null) {
        sink.add(result); // Implicitly safely casts to R
      }
    },
  ));
}