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
        }
      },
    ),
  );
}