编码实现js的Set

编码实现js的Set

/**
*
* Set
*
* @author: 阿宁
*
* @date:   2017年5月30日
*
*/
(function(global){

    function Set(){
        this.values = {};
        this.n = 0;
        this.add.apply(this,arguments);
    }

    Set.prototype.add = function(){
        for(var i = 0; i < arguments.length; i++){
            var val = arguments[i];
            var key = Set._v2s(val);
            if(!this.values.hasOwnProperty(key)){
                this.values[key] = val;
                this.n++;
            }
        }
        return this;
    };

    Set.prototype.remove = function(){
        for(var i = 0; i < arguments.length; i++){
            var key = Set._v2s(arguments[i]);
            if(this.values.hasOwnProperty(key)){
                delete this.values[key];
                this.n--;
            }
        }
        return this;
    };

    Set.prototype.contain = function(val){
        return this.values.hasOwnProperty(Set._v2s(val));
    };

    Set.prototype.foreach = function(f,c){
        for(var key in this.values){
            if(this.values.hasOwnProperty(key)){
                f.call(c,this.values[key]);
            }
        }
        return this;
    };

    Set._v2s = function(val){
        switch(val){
            case undefined:return "u";
            case null:return "n";
            case true:return "t";
            case false: return "f";
            default:switch(typeof val){
                case "number":return "#" + val;
                case "string":return """ + val;
                default : return "@" + objectId(val);
            }
        }
        function objectId(val){
            var prop = "|**objectid**|";
            if(!val.hasOwnProperty(prop)){
                val[prop] = Set._v2s.next++;
            }
            return val[prop];
        }
    };

    Set._v2s.next = 100;

    global.Set = Set;

})(this);