when<TResult extends Object?> method

@optionalTypeArgs TResult when<TResult extends Object?>(TResult $default(int? version, List<HysteriaUserConfig>? users, List<HysteriaUserConfig>? clients))

A switch-like method, using callbacks.

As opposed to map, this offers destructuring. It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case Subclass2(:final field2):
    return ...;
}

Implementation

@optionalTypeArgs
TResult when<TResult extends Object?>(
  TResult Function(int? version, List<HysteriaUserConfig>? users,
          List<HysteriaUserConfig>? clients)
      $default,
) {
  final _that = this;
  switch (_that) {
    case _HysteriaServerConfig():
      return $default(_that.version, _that.users, _that.clients);
    case _:
      throw StateError('Unexpected subclass');
  }
}