es6实现
 1 class _LazyMan {
 2   constructor(name) {
 3     this.tasks = [];
 4     this.sleep = this.sleep.bind(this);
 5     this.eat = this.eat.bind(this);
 6     this.tasks.push(((name) => {
 7       return () => {
 8         console.log(‘Hi! This is ‘ + name + ‘!‘);
 9           this.next();
10       }
11    })(name));
12      setTimeout(() => {
13        this.next();
14      }, 0);
15   }
16 
17   next() {
18     const fn = this.tasks.shift();
19     fn && fn();
20   }
21   eat(name) {
22     const fn = (() => {
23       return () => {
24         console.log(‘Eat ‘+ name +‘~‘);
25         this.next();
26       }
27     })(name);
28     this.tasks.push(fn);
29     return this;
30   }
31   sleep(time) {
32     const fn = (() => {
33       return () => {
34         setTimeout(() => {
35           console.log(‘Wake up after ‘+ time +‘s!‘);
36           this.next();
37         }, time * 1000);
38       }
39     })(time);
40     this.tasks.push(fn);
41     return this;
42   }
43   sleepFirst(time) {
44     const fn = () => {
45       setTimeout(() => {
46         console.log(‘Wake up after ‘+time+‘s!‘);
47         this.next();
48       },time*1000);
49     }
50     this.tasks.unshift(fn);
51     return this;
52   }
53 }
54 
55 const LazyMan = (name) => {return new _LazyMan(name)}

es5实现
 1 function _LazyMan(name){
 2     this.tasks=[];
 3     var self=this;
 4     var fn=(function(n){
 5         var name=n;
 6         return function(){
 7             console.log(‘Hi! This is ‘+name+‘!‘);
 8             self.next();
 9         }
10     })(name);
11     this.tasks.push(fn);
12     setTimeout(function(){
13         self.next();
14     },0);
15 }
16 
17 _LazyMan.prototype.next=function(){
18     var fn=this.tasks.shift();
19     fn&&fn();
20 }
21 _LazyMan.prototype.eat=function(name){
22     var self=this;
23     var fn=(function(name){
24         return function(){
25             console.log(‘Eat ‘+name+‘~‘);
26             self.next();
27         }
28     })(name);
29     this.tasks.push(fn);
30     return this;
31 }
32 _LazyMan.prototype.sleep=function(time){
33     var self=this;
34     var fn=(function(time){
35         return function(){
36             setTimeout(function(){
37                 console.log(‘Wake up after ‘+time+‘s!‘);
38                 self.next();
39             },time*1000);
40         }
41     })(time);
42     this.tasks.push(fn);
43     return this;
44 }
45 _LazyMan.prototype.sleepFirst=function(time){
46     var self=this;
47     var fn=(function(time){
48         return function(){
49             setTimeout(function(){
50                 console.log(‘Wake up after ‘+time+‘s!‘);
51                 self.next();
52             },time*1000);
53         }
54     })(time);
55     this.tasks.unshift(fn);
56     return this;
57 }
58 //封装
59 function LazyMan(name){
60     return new _LazyMan(name);
61 }