functionalscript/types/result/module.f.js

FunctionalScript is a purely functional subset of JavaScript

/**
 * A module for representing and handling operations that can succeed or fail.
 *
 * @module
 *
 * @example
 *
 * ```ts
 * import { error, ok, unwrap, type Result } from './module.f.ts'
 *
 * const success: Result<number, string> = ok(42)
 * const failure: Result<number, string> = error('Something went wrong')
 *
 * if (unwrap(success) !== 42) { throw 'error' }
 * const [kind, v] = failure
 * if (kind !== 'error') { throw 'error' }
 * // `v` is inferred as `string` here
 * if (v !== 'Something went wrong') { throw 'error' }
 * ```
 */
/**
 * Creates a successful result.
 *
 * @param value - The value to wrap.
 * @returns A successful result containing the value.
 */
export const ok = (value) => ['ok', value];
/**
 * Creates a failed result.
 *
 * @param e - The error to wrap.
 * @returns A failed result containing the error.
 */
export const error = (e) => ['error', e];
/**
 * Unwraps a result, returning the value if successful or throwing the error if failed.
 *
 * @param param0 - The result to unwrap.
 * @returns The value if the result is successful. Otherwise, throws the error.
 */
export const unwrap = ([kind, v]) => {
    if (kind === 'error') {
        throw v;
    }
    return v;
};