手写一个简易版的promise

下面是手写简易版promise的代码

class promise2{

  //成功时
  
  succeed = null
  
  //失败时
  
  fail =null
  
  //状态  pending是newpromise时
  
  state = 'pending'
  


  resolve(resuit){
  
    
  //设置延时器是为了让代码先都执行完
    
   setTimeout(() => {
   
   //状态  fuifilled是完成时
     
   this.state = 'fuifilled'
     
   this.succeed = resuit 
    })
  }


  reject(reason){
  
   setTimeout(() => {
    
   //状态   rejected是错误时
      
   this.state = 'rejected'
      
   this.fail = reason
      
   })
  }
  
  //fn就是promise内部执行的函数
  
  constructor(fn){
  
   fn(this.succeed.bind(this),this.fail.bind(this))
    
  }
  
  //then的使用
  
  then(succeed,fail){
  
   this.succeed = succeed
    
   this.fail = fail
   
  }
  
}