2019-07-24 实现一个lazyman函数

[dorseysen]

//  需具备的功能细节如下：
/**   
    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

    以此类推。
*/

[dorseysen]

//  这里的核心其实就是实现一个简单的任务消费队列

class _LazyMan {

    constructor (personName) {

        this.personName = personName;
        this.task = [];
        this.init();
    }
    init () {

        let _self = this;

        let fn = function () {
            console.log('Hi! This is ' + _self.personName + '!');
            _self.next();
        }
        _self.task.push(fn);

        setTimeout(() => _self.next(), 0);
    }
    //  队列指针往右位移一位并删除队列指针前面的已完成任务。
    next () {
        let fn = this.task.shift();
        fn && fn();
    }
    eat (meal) {

        let _self = this;
        let fn = function () {
            console.log('Eat ' + meal + '~');
            _self.next();
        }
        this.task.push(fn);
        return this;
    }
    sleep (time) {

        let _self = this;
        let fn = function () {
            // console.log('sleep ing...');
            setTimeout(() => {
                console.log('sleep completed, Wake up after ' + time + ' second');
                _self.next();
            }, time * 1000);
        }
        this.task.push(fn);
        return this;
    }
    sleepFirst (time) {

        let _self = this;
        let fn = function () {
            // console.log('sleepFirst ing...');
            setTimeout(() => {
                console.log('sleepFirst completed, Wake up after ' + time + ' second');
                _self.next();
            }, time * 1000);
        }
        this.task.unshift(fn);
        return this;
    }
}

function LazyMan (personName) {

    return new _LazyMan(personName);
}
// LazyMan('Hank').sleep(10);
// LazyMan("Hank").sleep(5).eat("dinner");
LazyMan("dorsey").eat("breakfirst").sleep(2).eat("lunch").sleep(2).eat("dinner").sleepFirst(2);