when<TResult extends Object?> method

  1. @optionalTypeArgs
TResult when<TResult extends Object?>(
  1. TResult $default(
    1. CustomShowParams? customShowParams,
    2. CustomShowHeader? customShowHeader,
    3. CustomShowBody? customShowBody
    )
)

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(CustomShowParams? customShowParams,
          CustomShowHeader? customShowHeader, CustomShowBody? customShowBody)
      $default,
) {
  final _that = this;
  switch (_that) {
    case _DdCustomOptions():
      return $default(_that.customShowParams, _that.customShowHeader,
          _that.customShowBody);
  }
}