LazyMan--流程控制

问题描述

实现一个LazyMan，可以按照以下方式调用:
LazyMan(“Hank”)输出:
Hi! This is Hank!
LazyMan(“Hank”).sleep(10).eat(“dinner”)输出
Hi! This is Hank!
//等待10秒..
Wake up after 10
Eat dinner~
LazyMan(“Hank”).eat(“dinner”).eat(“supper”)输出
Hi This is Hank!
Eat dinner~
Eat supper~
LazyMan(“Hank”).sleepFirst(5).eat(“supper”)输出
//等待5秒
Wake up after 5
Hi This is Hank!
Eat supper

function _LazyMan(name) {
    this.task = []
    this.greet = function (name) {
        this.task.push(() => {
            console.log(`Hi This is ${name}!`)
            this.next()
        })
    }
    this.greet(name)
    setTimeout(() => {
        this.next()
    }, 0);
    this.sleep = function (time) {
        this.task.push(() => {
            setTimeout(() => {
                console.log(`Wake up after ${time}`)
                this.next()
            }, time)
        })
        return this
    }
    this.eat = function (food) {
        this.task.push(() => {
            console.log(`Eat ${food}`)
            this.next()
        })
        return this
    }
    this.sleepFirst = function (time) {
        this.task.unshift(() => {
            setTimeout(() => {
                console.log(`Wake up after ${time}`)
                this.next()
            }, time);
        })
        return this
    }

    this.next = function () {
        if (this.task[0]) {
            let fn = this.task.shift()
            fn()
        }
    }
}

function LazyMan(name) {
    return new _LazyMan(name)
}
LazyMan('Hank').sleep(10).eat('dinner').sleepFirst(100)