Аснихронный код с генераторами

async_spawn.js

    function async_spawn(generatorFunc) {
      function continuer(verb, arg) {
        var result;
        try {
              result = generator[verb](arg);
        } catch (err) {
              return Promise.reject(err);
        }
        if (result.done) {
              return result.value;
        } else {
              return Promise.resolve(result.value).then(onFulfilled, onRejected);
        }
      }
      var generator = generatorFunc(Array.prototype.slice.call(arguments, 1));
      var onFulfilled = continuer.bind(continuer, "next");
      var onRejected = continuer.bind(continuer, "throw");
      return onFulfilled();
    }