Assignment 20 - Stream with Custom StreamTransformer

assignment20.dart

import 'dart:async';

Stream<dynamic> emit() async* {
  yield 1;
  yield 'hello';
  yield 2;
  yield 'world';
  yield 3;
}

class FilterInt extends StreamTransformerBase<dynamic, int> {
  @override
  Stream<int> bind(Stream<dynamic> stream) {
    return stream.where((event) => event is int).cast<int>();
  }
}

void main() async {
  await for (final value in emit().transform(FilterInt())) {
    print(value);
  }
}