main.dart

import "package:rxdart/rxdart.dart";

void main() async {
  // Emit an incrementing number every 5 seconds
  final parentStream = Stream.periodic(Duration(seconds: 5), (i) => i);

  /// Every second, emit an incrementing number which is multipled by the current parentStream
  final childStream = parentStream.asyncMap((multiplyBy) {
    return Stream.periodic(Duration(seconds: 1), (i) => i * multiplyBy);
  });
  
  // Use `switchMap` to get the latest values from switchMap
  final listener = childStream.switchMap((i) => i).listen((i) {
    print(i);
  });
  await listener.asFuture();
}

/// Using Riverpod
// @riverpod
// Stream<int> parent(Ref ref){
//   return Stream.periodic(Duration(seconds:5),(i)=>i);
// }
// @riverpod
// Stream<int> child(Ref ref, int multiplyBy){
//   return Stream.periodic(Duration(seconds:1),(i)=> i * multiplyBy);
// }
// final parentValue = await ref.watch(parentProvider.future);
// final childValue = ref.watch(childProvider(parentValue).future);