Descendant selectors don't appear to work for callbacks #1

I've been playing with this code for a good chunk of the afternoon. I very much like the style of this interface to parsing, especially the URLParser and its incremental callback approach.

The one snag I seem to have hit is that, while I can use selectors like "foo > bar" to find elements in the DOM I get back from the full parse, it does not appear that I can use a selector like that with performSelector:forElementsMatching:. Sibling selectors like "foo + bar" do seem to work, as far as I can tell.

Is that intended behavior?