option-t/esm/nullable/operators/xor.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 { isNull } from '../core/nullable.js';
/**
 *  Return one of this pattern:
 *
 *  1. a=others, b=null => _a_
 *  2. a=null, b=others => _b_
 *  3. Others => `null`
 */
export function xorForNullable(a, b) {
    const aIsNull = isNull(a);
    const bIsNull = isNull(b);
    if (!aIsNull && bIsNull) {
        return a;
    }
    else if (aIsNull && !bIsNull) {
        return b;
    }
    else {
        return null;
    }
}