data-structure-algebra/doubly-linked-list

import assert from 'assert';

import Node from './Node.js';
import _last from './_last.js';

/**
 * Returns the last node of a list.
 *
 * @param {Node} first First node of the list.
 * @return {Node} Last node of the list.
 */
export default function last(first) {
    assert(first === null || first instanceof Node);
    return first === null ? null : _last(first);
}