Object Runtime Fields Evaluator

/**
 * Usage:
 * var o={a:1, b:'!! 1+1', c:'!! alert(\'c\')'};
 * evalObj(o);
 * //o.a===1
 * //o.b===2
 * //o.c() will display an alert
 * 
 * Updated to keep the scope, usage:
 * var o={a:1, b:'!! this.a+1', c:'!! alert(this.b+1)'};
 * evalObj.call(o,o);
 * //o.a===1
 * //o.b===2
 * //o.c() will display an alert with 3
 * 
*/
 
function evalObj(o,rec){
    if (rec === undefined) {
        rec=true;
    }
    for (var name in o){
        var elem=o[name];
        if (elem){
            var telem=typeof elem;
            if (telem==='string' && /^!!/.test(elem)){
                o[name]=new Function('return '+elem.substr(2)).call(this);
            }else if (rec && telem==='object'){
                evalObj.call(this,elem,rec);
            }
        }
    }
    return o;
}