mapOr<R> method

R mapOr<R>(
  1. R fallback,
  2. R mapper(
    1. T value
    )
)

Maps a successful value, or returns fallback for an Err.

fallback is evaluated before the call. Use mapOrElse when computing it is expensive or needs the error.

final length = const Ok<String, int>('John').mapOr(0, (name) => name.length);

Implementation

R mapOr<R>(R fallback, R Function(T value) mapper) {
  return switch (this) {
    Ok<T, E>(:final value) => mapper(value),
    Err<T, E>() => fallback,
  };
}