问题描述：

实现目前一些主流框架的循环渲染

// ali-for  
var items = [  
    {name:'item1'},  
    {name:'item2'}  
];  
var str = '<div ali-for="item in items">{{item.name}}<div>';  
  
var ParseDom = function(str){  
    // your code here  
}  
// 对应生成的dom  
// <div>item1</div>  
// <div>item2</div>  

程序如下：

var ParseDom = function(str){
    // your code here
    var reg1 = /\sali-for=\"[a-zA-Z\s]+\"/gi, //获得 ali-for="item in items"
        reg2 = /\{{2}[a-zA-Z\.]+\}{2}/gi, //获得{{item.name}}
        reg3 = /\.[a-zA-Z]+/gi, //获得.name
        len = items.length

    var temp = str.replace(reg1,''), //tmp = '<div>{{item.name}}</div>'
        fill = str.match(reg2)[0], //fill = "{{item.name}}"
        key = str.match(reg2)[0].match(reg3)[0].slice(1), //key = "name"
        clone_temp = '',
        str = ''

    for(var i=0;i<len;i++){
        clone_temp = temp
        st r+= clone_temp.replace(fill,items[i][key])
    }
    console.log(str)
}