Function unwrapOrElse

Safely get the value out of a Result by returning the wrapped value if it is Ok, or by applying orElseFn to the value in the Err.

This is useful when you need to generate a value (e.g. by using current values in the environment – whether preloaded or by local closure) instead of having a single default value available (as in unwrapOr).

import { ok, err, unwrapOrElse } from 'true-myth/result';

// You can imagine that someOtherValue might be dynamic.
const someOtherValue = 2;
const handleErr = (errValue: string) => errValue.length + someOtherValue;

const anOk = ok<number, string>(42);
console.log(unwrapOrElse(handleErr, anOk));  // 42

const anErr = err<number, string>('oh teh noes');
console.log(unwrapOrElse(handleErr, anErr));  // 13
Copy

Typeparam

T The value wrapped in the Ok.

Typeparam

E The value wrapped in the Err.