option-t/esm/maybe/operators/and.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 { isNotNullOrUndefined, isNullOrUndefined } from '../core/maybe.js';
/**
 *  Return _b_ if _a_ is not `null` and `undefined`.
 *  Otherwise, return _a_.
 */
export function andForMaybe(a, b) {
    if (isNullOrUndefined(a)) {
        return a;
    }
    if (isNotNullOrUndefined(a)) {
        return b;
    }
    throw new EvalError('here should be unreachable');
}