mini JQuery e data processor

Mini copy of jquery to be light. Class to filter data like mongodb

HTML

<div id="log"></div>

CSS

#log {
    border : solid 1px;
    height : 37px;
}

JavaScript

var d = document;

_query = function(){
   this.elements;
    var self = this;
    this.check = function(value){
     if(!self.elements) return;
      var _value = value?true:false;
      [].map.call(self.elements, function(e){
         e.checked = _value;
     });
    };
    this.map = function(f){
      [].map.call(self.elements, f);
    };
    this.text = function(text){
        if(text == undefined){
            self.map(function(e){ return e.innerText});
        }else{
            self.map(function(e){ e.innerText = text; });
        }
            
    }
};

$ = function(selector, f){
   var items = d.querySelectorAll(selector);
   var _q = new _query();
   _q.elements = items;
   return _q;
}

DataQuery = function(){

}

Array.prototype.Select = function(command){
    var result = new Array(this.length);
    result = this.filter(function(e){        
       var keys = Object.keys(eval("x = " + command));
        var condition = true;
        for(i in keys)
           condition+=e[keys[i]] === command[keys[i]];
        if(condition) return e;
    });
    return result;
}

function log(text){
   $("#log").text(text);
}

log("teste");

var data = [{nome : "Maria"},
            {nome : "Jhon"},
            {nome : "Fred"},
            {nome : "Antonia"}];


result  = data.Select("{'nome' : 'Fred'}");
log(result[2].nome);