What methods can be used to implement a data stream in Dart?

In Dart, there are several approaches to implementing data streams (streams):

1. Stream and StreamController — the primary way to work with streams. StreamController allows creating a stream to which events can be added, and Stream is the stream itself that you can subscribe to.

final controller = StreamController<int>();

controller.stream.listen((data) {
  print('Received: $data');
});

controller.add(1);
controller.add(2);
controller.close();

2. Asynchronous generators (async)* — allow creating a data stream using a function that returns a Stream and uses the yield keyword to emit values.

Stream<int> countStream(int to) async* {
  for (int i = 1; i <= to; i++) {
    yield i;
    await Future.delayed(Duration(seconds: 1));
  }
}

countStream(3).listen(print);

3. Using ready-made streams from libraries — for example, Stream.periodic for periodic events.

Thus, the main methods are using StreamController for creating and managing streams and asynchronous generators for conveniently creating streams with data generation logic.