nested selectors with rework-parent or css-whitespace

It would be awesome if we could nest selectors in a macro with [css-whitespace](https://github.com/visionmedia/css-whitespace)

``` javascript
@macro btn-state
&:hover
position: $1
```

or possibly with [rework-parent](https://github.com/fgnass/rework-parent)

``` javascript
@macro btn-state {}

&:hover {
position: $1
}
```

I'm not sure if this is doable but it would be a really nice addition. It's almost the only reason why I don't use rework in production and still prefer stylus or sass haha.

Thoughts on this?