JavaScript: like JSON.stringify but handles functions, good for creating arbitrary .js objects?

stringify.js

var stringify = function(obj, prop) {
  var placeholder = '____PLACEHOLDER____';
  var fns = [];
  var json = JSON.stringify(obj, function(key, value) {
    if (typeof value === 'function') {
      fns.push(value);
      return placeholder;
    }
    return value;
  }, 2);
  json = json.replace(new RegExp('"' + placeholder + '"', 'g'), function(_) {
    return fns.shift();
  });
  return 'this["' + prop + '"] = ' + json + ';';
};

usage.js

var foo = {
  a: function() { return 'a'; },
  b: function() { return 'b'; },
  'bar.baz': {
    'omg ponies!!': function() { return 'c'; }
  }
};

console.log(stringify(foo, 'foo'));

// this["foo"] = {
//   "a": function () { return 'a'; },
//   "b": function () { return 'b'; },
//   "bar.baz": {
//     "omg ponies!!": function () { return 'c'; }
//   }
// };

Then how do you turn it back into a JS object again?