lazyPig(阿里)

时间

2020-05-27

题目内容

评测题目 2: 实现一个 LazyPig，可以按照以下方式调用:

 LazyPig("Peggy")输出:
Hello，I'm Peggy！

LazyPig("Peggy").sleep(10).eat("dinner")输出
Hello，I'm Peggy！
//等待10秒..
Wake up after 10
Eat dinner~

LazyPig("Peggy").eat("dinner").eat("supper")输出
Hello，I'm Peggy！
Eat dinner~
Eat supper~

//以此类推。

实现

在同步阶段把所有链式调用的方法 push 到异步任务队列中，然后在 setTimeout 宏任务阶段依次执行

class _LazyMan {
  constructor(name) {
    this.taskQueue = []
    this.run()
    this.sayHi(name)
  }
  run() {
    setTimeout(async () => {
      for (let asyncFun of this.taskQueue) {
        await asyncFun()
      }
    }, 0)
  }
  sayHi(name) {
    this.taskQueue.push(async () => console.log(`Hi, this is ${name}`))
    return this
  }
  eat(food) {
    this.taskQueue.push(async () => console.log(`Eat ${food}`))
    return this
  }
  sleep(second) {
    this.taskQueue.push(async () => {
      await this._timeout(second)
      console.log(`Sleep ${second} s`)
    })
    return this
  }
  sleepFirst(second) {
    this.taskQueue.unshift(async () => {
      await this._timeout(second)
      console.log(`Sleep first ${second} s`)
    })
    return this
  }
  _timeout(second) {
    return new Promise((resolve) => {
      setTimeout(resolve, second * 1e3)
    })
  }
}

// 测试
const LazyMan = (name) => {
  return new _LazyMan(name)
}

// LazyMan('Hank');
LazyMan('Peggy').sleep(4).eat('dinner')
// LazyMan('Hank').eat('dinner').eat('supper');
// LazyMan('Hank').sleepFirst(3).eat('supper');