maybeWhen<TResult extends Object?> method

  1. @optionalTypeArgs
TResult maybeWhen<TResult extends Object?>(
  1. TResult $default(
    1. Map<int, Policy>? levels,
    2. SystemPolicy? system
    )?, {
  2. required TResult orElse(),
})

A variant of when that fallback to an orElse callback.

It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case _:
    return orElse();
}

Implementation

@optionalTypeArgs
TResult maybeWhen<TResult extends Object?>(
  TResult Function(Map<int, Policy>? levels, SystemPolicy? system)?
      $default, {
  required TResult orElse(),
}) {
  final _that = this;
  switch (_that) {
    case _PolicyConfig() when $default != null:
      return $default(_that.levels, _that.system);
    case _:
      return orElse();
  }
}