stylelint-bundle-worker.js
function memoize(type, pattern, options, fn) {
  var key = utils.createKey(type + '=' + pattern, options);

  if (options && options.cache === false) {
    return fn(pattern, options);
  }

  if (cache.has(type, key)) {
    return cache.get(type, key);
  }

  var val = fn(pattern, options);
  cache.set(type, key, val);
  return val;
}
function memoize(type, pattern, options, fn) {
  var key = utils.createKey(type + '=' + pattern, options);

  if (options && options.cache === false) {
    return fn(pattern, options);
  }

  if (cache.has(type, key)) {
    return cache.get(type, key);
  }

  var val = fn(pattern, options);
  cache.set(type, key, val);
  return val;
}
Memoize a generated regex or function. A unique key is generated
from the `type` (usually method name), the `pattern`, and
user-defined options.