I think that once an object is created, its prototype should be constant.

And we should add features to implement sub-typing built-in types, like Array, since this code exists (found in Zepto):

    zepto.Z = function(dom, selector) {
        dom = dom || []
        dom.__proto__ = $.fn
        dom.selector = selector || ''
        return dom
    }

Using proxies may be one way, but it should be more convinent.

I think that once an object is created, its prototype should be constant.

And we should add features to implement sub-typing built-in types, like Array, since this code exists (found in Zepto):

```js
zepto.Z = function(dom, selector) {
  dom = dom || []
  dom.__proto__ = $.fn
  dom.selector = selector || ''
  return dom
}
```

Using proxies may be one way, but it should be more convinent.