v0.22.0

New Features:

• Watch

  Registers a watch function that has access to its own handle.

  This can be used to 1) stop a watch function directly from within the watch function and 2)
  prevent code from running on the first call of the watch function.

  final watch = Watch((state) {
    final value = a();
    
    state.afterInit();
  
    // The following is only run after the first call
    print('A = $value');
    
    if (value > 10) {
      state.stop();
    }
  });