option-t/esm/maybe/operators/transpose.js

A toolkit of Nullable/Option/Result type implementation in ECMAScript. Their APIs are inspired by Rust's `Option<T>` and `Result<T, E>`.

import { createOk, isOk } from '../../plain_result/core/result.js';
import { isNullOrUndefined } from '../core/maybe.js';
/**
 *  Transposes a `Maybe` of a `Result` into an `Result` of a `Maybe`.
 *
 *  - `null` -> `Ok<null>`.
 *  - `undefined` -> `Ok<undefined>`
 *  - `Ok<T>` -> `Ok<T>`.
 *  - `Err<E>` -> `Err<E>`.
 */
export function transposeMaybeToResult(input) {
    if (isNullOrUndefined(input)) {
        return createOk(input);
    }
    if (isOk(input)) {
        const rv = input;
        return rv;
    }
    const rv = input;
    return rv;
}