ComputerProperty

Function.prototype.computed = function() {
  return { computed: true, func: this };
};

var Computize = function(obj) {
  for(var prop in obj) {
    if(typeof obj[prop] == 'object' && obj[prop].computed === true) {
      var func = obj[prop].func;
      delete obj[prop];
      Object.defineProperty(obj, prop, {
        get: func,
        set: func
      });
    }
  }
  return obj;
}

var User = Computize({
  firstName: 'Tony',
  lastName: 'Stark',
  name: function() {
    if(arguments.length > 0) {
      var parts = arguments[0].toString().split(/ /);
      this.firstName = parts[0];
      this.lastName = parts[1] ? parts[1] : this.lastName;
    }
    return this.firstName + ' ' + this.lastName;
  }.computed()
});

console.log(User.name); // Tony Stark
User.name = 'John Doe';
console.log(User.firstName); // John
console.log(User.lastName); // Doe
console.log(User.name); // John Doe