Function orElse

orElse<R extends Result.Base, R2 extends Result.Base>(
result: R,
alternative: R2,
): R2 | NarrowToOk<R>

Returns the Result if it is Ok, otherwise returns the alternative.

Type Parameters

R extends Result.Base
The input Result.Base type.
R2 extends Result.Base

Parameters

result: R
The Result to check.
alternative: R2
The alternative Result to return if the first is Err.

Returns R2 | NarrowToOk<R>

The first Result if Ok, otherwise the alternative.

Example

const primary = Result.ok('primary');
const fallback = Result.ok('fallback');
const failure = Result.err('failure');

assert.deepStrictEqual(Result.orElse(primary, fallback), primary);
assert.deepStrictEqual(Result.orElse(failure, fallback), fallback);

const orElseFallback = Result.orElse(Result.ok('default'));

assert.deepStrictEqual(
  orElseFallback(Result.err('missing')),
  Result.ok('default'),
);
assert.deepStrictEqual(orElseFallback(Result.ok('value')), Result.ok('value'));

orElse<S, E, S2, E2>(
alternative: Result<S2, E2>,
): (result: Result<S, E>) => Result<S2, E2> | Result<S, E>

Returns the Result if it is Ok, otherwise returns the alternative.

Type Parameters

Parameters

alternative: Result<S2, E2>
The alternative Result to return if the first is Err.

Returns (result: Result<S, E>) => Result<S2, E2> | Result<S, E>

The first Result if Ok, otherwise the alternative.

Example

const primary = Result.ok('primary');
const fallback = Result.ok('fallback');
const failure = Result.err('failure');

assert.deepStrictEqual(Result.orElse(primary, fallback), primary);
assert.deepStrictEqual(Result.orElse(failure, fallback), fallback);

const orElseFallback = Result.orElse(Result.ok('default'));

assert.deepStrictEqual(
  orElseFallback(Result.err('missing')),
  Result.ok('default'),
);
assert.deepStrictEqual(orElseFallback(Result.ok('value')), Result.ok('value'));

Function orElse

Type Parameters

Parameters

Returns R2 | NarrowToOk<R>

Example

Type Parameters

Parameters

Returns (result: Result<S, E>) => Result<S2, E2> | Result<S, E>

Example

Settings