mapErr<F> method
Maps an error value and leaves successful values unchanged.
final readable = const Err<int, String>('bad')
.mapErr((error) => 'error: $error');
final unchanged = const Ok<int, String>(42)
.mapErr((error) => 'error: $error');
Implementation
@override
Result<T, F> mapErr<F>(F Function(E error) mapper) {
return Ok<T, F>(value);
}