What's the general timeline for Value Objects being ready?  I'm
working on a proposal for an object-based CSS object model (as opposed
to the current string-based OM), and it revolves around the leaf
values being immutable objects, so we and authors can create tons of
them without worrying about crazy garbage (because we can cache/reuse
invisibly).

Using value objects would make this explicit, and would allow
convenient operator overloading, so you can do:

var x = CSS.px(5);
var y = CSS.px(10);
var z = x + y;

I'm okay with this being 1 or 2 years down the road.

Alternately, how close can I get to truly immutable objects?  I want
something that can't be expando'd or altered in any way, so our impl
can share objects when possible.

~TJ

What's the general timeline for Value Objects being ready?  I'm
working on a proposal for an object-based CSS object model (as opposed
to the current string-based OM), and it revolves around the leaf
values being immutable objects, so we and authors can create tons of
them without worrying about crazy garbage (because we can cache/reuse
invisibly).

Using value objects would make this explicit, and would allow
convenient operator overloading, so you can do:

```js
var x = CSS.px(5);
var y = CSS.px(10);
var z = x + y;
```

I'm okay with this being 1 or 2 years down the road.

Alternately, how close can I get to truly immutable objects?  I want
something that can't be expando'd or altered in any way, so our impl
can share objects when possible.