when<TResult extends Object?> method

  1. @optionalTypeArgs
TResult when<TResult extends Object?>(
  1. TResult $default(
    1. String? type,
    2. Object? bytes,
    3. int? u64,
    4. String? reuse,
    5. String? metadata,
    6. CustomTransform? transform,
    )
)

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? type, Object? bytes, int? u64, String? reuse,
          String? metadata, CustomTransform? transform)
      $default,
) {
  final _that = this;
  switch (_that) {
    case _CustomTransformArg():
      return $default(_that.type, _that.bytes, _that.u64, _that.reuse,
          _that.metadata, _that.transform);
    case _:
      throw StateError('Unexpected subclass');
  }
}