mapOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>({
  1. TResult? file(
    1. XXFile value
    )?,
  2. TResult? network(
    1. XXImage 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(XXFile value)? file,
  TResult? Function(XXImage value)? network,
}) {
  final _that = this;
  switch (_that) {
    case XXFile() when file != null:
      return file(_that);
    case XXImage() when network != null:
      return network(_that);
    case _:
      return null;
  }
}