yes function

YesController yes(IOSink sink, [ String message = 'y', bool flushMayBeSync = true ])

Writes the given message, followed by a newline, to the given sink repeatedly.

If no message is provided, y will be used.

flushMayBeSync must be true if the sink's IOSink.flush implementation can return a synchronous future. If it is set incorrectly, the event loop will be blocked until the sink closes. When it's safe to do so, setting flushMayBeSync to false can offer a significant performance boost.

Returns a YesController that can be used to monitor and terminate the operation.

Implementation

YesController yes(
  IOSink sink, [
  String message = 'y',
  bool flushMayBeSync = // ignore: avoid_positional_boolean_parameters
      true,
]) {
  final messageData = sink.encoding.encode('$message\n');
  var stopWriting = false;

  Future<void> start() async {
    sink.done.then((_) => stopWriting = true);
    // ignore: literal_only_boolean_expressions
    while (!stopWriting) {
      try {
        sink.add(messageData);
        await sink.flush();
        // If the flush operation could be synchronous, let the event loop
        // continue, and resume in the next task.
        if (flushMayBeSync) await Future<void>.delayed(Duration.zero);
      } on IOException {
        // Stop writing data when the sink stops accepting it.
        break;
      }
    }
  }

  void stop() => stopWriting = true;

  return YesController(start(), stop);
}