設計 LazyMan 類

實現以下功能:

LazyMan('Tony');
// Hi I am Tony

LazyMan('Tony').sleep(10).eat('lunch');
// Hi I am Tony
// 等待了10秒...
// I am eating lunch

LazyMan('Tony').eat('lunch').sleep(10).eat('dinner');
// Hi I am Tony
// I am eating lunch
// 等待了10秒...
// I am eating diner

LazyMan('Tony').eat('lunch').eat('dinner').sleepFirst(5).sleep(10).eat('junk food');
// Hi I am Tony
// 等待了5秒...
// I am eating lunch
// I am eating dinner
// 等待了10秒...
// I am eating junk food

class Lazy {
    cbs = []
    constructor(name) {
        console.log(`Hi I am${name}`)
        this.runner()
    }
    runner () {
        // 微任務處理隊列cbs
        Promise.resolve().then(async res => {
            while (this.cbs.length) {
                await this.cbs.shift()()
            }
        })
        return this
    }
    timePromise (time) {
        return new Promise((resolve, reject) => {
            setTimeout(() => {
                console.log(`等待了${time}s`)
                resolve()
            }, time * 1000)
        })
    }
    eat (name) {
        this.cbs.push(() => {
            console.log(`I am eating ${name}`)
            return Promise.resolve()
        })
        return this
    }
    sleepFirst (time) {
        this.cbs.unshift(() => this.timePromise.call(this, time))
        return this
    }
    sleep (time) {
        this.cbs.push(() => this.timePromise.call(this, time))
        return this
    }
}
new Lazy('Tony').eat('lunch').eat('dinner').sleep(10).eat('orange').sleepFirst(5)

非promise的鏈式調用

class Lazy {
    cbs = []
    constructor(name) {
        console.log(`Hi I am${name}`)
        this.runner()
    }
    runner () {
        Promise.resolve().then(() => this.next())
    }
    next () {
        this.cbs.length && this.cbs.shift()()
    }
    timePromise (time) {
        return  setTimeout(() => {
                console.log.call(console, `等待了${time}s`)
                this.next()
        }, time * 1000)
    }
    eat (name) {
        this.cbs.push(() => {
            console.log(`I am eating ${name}`)
            this.next()
        })
        return this
    }
    sleepFirst (time) {
        this.cbs.unshift(() => this.timePromise.call(this, time))
        return this
    }
    sleep (time) {
        this.cbs.push(() => this.timePromise.call(this, time))
        return this
    }
}
new Lazy('Tony').eat('lunch').eat('dinner').sleep(10).eat('orange').sleepFirst(5)