这里用到一个特殊的类型 Event，它的代码是这样：

class Event {
    constructor() {
        this.flag = false;
        this.value = null;
        this.waiters = [];
    }

    isSet() {
        return this.flag;
    }

    set(value) {
        this.value = value;
        if (!this.flag) {
            this.flag = true;
            while (this.waiters.length > 0) {
                let waiter = this.waiters.shift();
                waiter.resolve(value);
            }
        }
    }

    clear() {
        this.flag = false;
        this.value = null;
    }

    async wait() {
        if (this.flag) {
            return this.value;
        }
        
        let waiter = {};
        let promise = new Promise((resolve, _) => {
            waiter["resolve"] = resolve;
        });
        this.waiters.push(waiter);
        return await promise;
    }
}

【 在 hgoldfish (老鱼) 的大作中提到: 】
: generator 就是 coroutine. 以下是一段使用 coroutine 实现 generator 的代码:
: async generator(result) {
:     for (int i = 0; i < 10; ++i) {
: ...................
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FROM 110.85.22.*