'using' - an alternative to the 'with' statement

gistfile1.js

function using (obj) {
  
  var _keys = Object.keys || function(obj) {
    if (obj !== Object(obj)) {
      throw new TypeError('Invalid object');
    }
    var keys = [];
    for (var key in obj) {
      if (Object.prototype.hasOwnProperty.call(obj, key)(obj, key)) {
        keys[keys.length] = key;
      }
    }
    return keys;
  };
  
  return function(cb) {
    var varKeys = _keys(obj);
    for (var i = varKeys.length - 1; i >= 0; i--){
      var value = obj[varKeys[i]];
      if (typeof(value) === 'string') {
        value = '\"' + value + '\"';  
      }
      eval('var '+varKeys[i] + '=' + value);
    };

    eval('(' + cb.toString() + ')')();
  }
}

var scopeObject = {
  aString: 'Guten Tag',
  aNumber: 12,
  aFunction: function(strA) {
    return function(strB) {
      console.log(strA + ' and ' + strB);
    }
  }
}

// Simple benchmark putting 'using' against 'with'

var codez = [
  {
    name: "Using",
    code: function() {

      using(scopeObject)(function() {
        console.log(aNumber);
        console.log(aString);
        aFunction("one")("two");
      });
  
    }
  },
  {
    name: "With",
    code: function() {

      with(scopeObject) {
        console.log(aNumber);
        console.log(aString);
        aFunction("three")("four");
      }

    }
  }
]

for (var i = codez.length - 1; i >= 0; i--){
  var start = new Date();
  codez[i].code();
  console.log(codez[i].name + ": Duration:", new Date() - start);
};