mapOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>({
  1. TResult? regular(
    1. OwnedGiftRegular value
    )?,
  2. TResult? unique(
    1. OwnedGiftUnique value
    )?,
})

A variant of map that fallback to returning null.

It is equivalent to doing:

switch (sealedClass) {
  case final Subclass value:
    return ...;
  case _:
    return null;
}

Implementation

@optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>({
  TResult? Function(OwnedGiftRegular value)? regular,
  TResult? Function(OwnedGiftUnique value)? unique,
}) {
  final _that = this;
  switch (_that) {
    case OwnedGiftRegular() when regular != null:
      return regular(_that);
    case OwnedGiftUnique() when unique != null:
      return unique(_that);
    case _:
      return null;
  }
}