async.js style using YUI promises

gistfile1.js

function async(args, fn) {
  return Y.batch.apply(Y, Y.Array.map(args, function (arg) {
    return new Y.Promise(function (resolve, reject) {
      fn(arg, function (err, result) {
        if (err) {
          reject(err);
        } else {
          resolve(result);
        }
      });
    });
  });
}

async(['foo.php', 'bar.php'], Y.io).then(fn);