承诺驱动的发电机

Question

我正在ES6中测试一个承诺驱动的生成器。基本上，生成器的每个产量都会返回一个承诺，一旦承诺得到解决，它就会恢复生成器。我的实现如下：

function* gen(x) {
    try {
        let result = yield pro(x);
        console.log(`result is ${result}`);

        let result1 = yield pro(result)
        console.log(`result1 is ${result1}`);
    } catch (e) {
        console.log(`error ${e}`);
    }
}

function pro(x) {
    return new Promise((resolve, reject) => {
        let rand = Math.random() * 100;
        let res = rand * x;
        setTimeout(() => { //simulate an async call
            console.log(`rand: ${rand} ---- x:  ${x}`);
            resolve(res);
        }, 1000);
    });
}

function drive(generator) {
    let args = Array.from(arguments).slice(1);
    let it = generator.apply(this, args);
    return Promise.resolve()
        .then(function next(passedIn) {
            let pVal = it.next(passedIn); //pass val to the generator
            if (pVal.done) {
                return pVal.value;
            }

            return Promise.resolve(pVal.value)
                .then(next, (err) => {
                    it.throw(err);
                });

        })
        .catch((err) => console.log(`error ${err}`));
}

drive(gen, 2);

上面的模式是否有任何弱点？感谢。