Function walk

packages/dev/docs/src/utils.js:13–28

(obj, fn, k = null)

 */

export function walk(obj, fn, k = null) {
  let recurse = obj => {
    if (Array.isArray(obj)) {
      return obj.map((item, i) => walk(item, fn, k));
    } else if (obj && typeof obj === 'object') {
      let res = {};
      for (let key in obj) {
        res[key] = walk(obj[key], fn, key);
      }
      return res;
    } else {
      return obj;
    }
  };
  return fn(obj, k, recurse);
}

export function getUsedLinks(obj, links, usedLinks = {}) {
  walk(obj, (t, k, recurse) => {