orElse

function Result.orElse(
    result: Result<T, E>,
    transform: (error: E) => Result<U, F>
): Result<T | U, F>

Uses a fallback result computed by transform if the current result is an Err. If the result is Ok, returns it unchanged. If the result is an Err, calls transform with the error value to produce an alternative result.

Example

data-first

Result.orElse(ok(5), (e) => ok(0));
// Ok<number>(5)

Result.orElse(err("fail"), (e) => ok(0));
// Ok<number>(0)

Result.orElse(err("fail"), (e) => err(`Handled: ${e}`));
// Err<string>("Handled: fail")

data-last

pipe(
    err("fail"),
    Result.orElse((e) => ok(0)),
);
// Ok<number>(0)