从Node JS中的生成器获取返回值

Question

我似乎无法弄清楚如何获得发电机的返回值 - 任何人都知道我做错了什么？

function getGeneratorReturn() {
    var generator = runGenerator();
    var generatorReturn = null;

    var done = false;
    while(!done) {
        var currentNext = generator.next();
        console.log('Current next:', currentNext);
        generatorReturn = currentNext.value;
        done = currentNext.done;
    }

    return generatorReturn;
}

function* runGenerator() {
    var a = yield 1;
    var b = yield 2;
    var c = a + b;

    return c;
}

var generatorReturn = getGeneratorReturn();
console.log(generatorReturn); // Should output 3, is outputting NaN

注意:您需要运行带有--harmony选项的节点0.11.12才能运行此代码.

Answer 1

如果currentNext.done是true,curentNext.value有返回值.

您可以将循环编写为:

var next;
while (!(next = generator.next()).done) {
    var yieldedValue = next.value;
}
var returnValue = next.value;