爬虫之自动生成url

Object.extend=function(props){
    //继承父类
    var prototype=Object.create(this.prototype)
    //初始化函数ctor
    var _Class=function(){
        if (this.ctor)
            this.ctor.apply(this, arguments);
    }
    //当前类属性和方法
    for(var k in props){
        prototype[k]= props[k]
    }
    _Class.prototype = prototype;
    //类继承
    _Class.extend=this.extend;
    //类扩展
    _Class.expand = function (prop) {
        for (var name in prop) {
            prototype[name] = prop[name];
        }
    };
    return _Class

}

var AutoStr=Object.extend({
    str:"",
    start:0,
    length:0,
    ctor:function(str){
        var the=this
        this.str=str
        str.replace(/\[(.)-(.)\]/,function(m,p1,p2){
            the.start=p1.charCodeAt(0)
            the.length=p2.charCodeAt(0)-the.start+1
        })
    },
    eq:function(n){
        return this.str.replace(/\[(.)-(.)\]/,String.fromCharCode(this.start+n))
    }
})
var d=new AutoStr("http://www.baidu.com/[a-z].html")
for(var i=0;i< d.length;i++){
    console.log(d.eq(i))
}
//var d=new AutoStr("http://www.baidu.com/[0-9][0-2].html")
//for(var i=0;i< d.length;i++){
//    var v=new AutoStr(d.eq(i))
//    for(var j=0;j< v.length;j++){
//        console.log(v.eq(j))
//    }
//}

　　

http://www.baidu.com/a.html
http://www.baidu.com/b.html
http://www.baidu.com/c.html
http://www.baidu.com/d.html
http://www.baidu.com/e.html
http://www.baidu.com/f.html
http://www.baidu.com/g.html
http://www.baidu.com/h.html
http://www.baidu.com/i.html
http://www.baidu.com/j.html
http://www.baidu.com/k.html
http://www.baidu.com/l.html
http://www.baidu.com/m.html
http://www.baidu.com/n.html
http://www.baidu.com/o.html
http://www.baidu.com/p.html
http://www.baidu.com/q.html
http://www.baidu.com/r.html
http://www.baidu.com/s.html
http://www.baidu.com/t.html
http://www.baidu.com/u.html
http://www.baidu.com/v.html
http://www.baidu.com/w.html
http://www.baidu.com/x.html
http://www.baidu.com/y.html
http://www.baidu.com/z.html