when<TResult extends Object?> method

  1. @optionalTypeArgs
TResult when<TResult extends Object?>(
  1. TResult $default(
    1. String id,
    2. bool selected,
    3. PPShippingType? type,
    4. PPUnitAmount? unitAmount,
    )
)

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(String id, bool selected, PPShippingType? type,
          PPUnitAmount? unitAmount)
      $default,
) {
  final _that = this;
  switch (_that) {
    case _PPOptions():
      return $default(_that.id, _that.selected, _that.type, _that.unitAmount);
    case _:
      throw StateError('Unexpected subclass');
  }
}