[Inkscape-devel] Using xpath in Inkscape code?

I would like to be able to select nodes using XPath: https://bugs.launchpad.net/inkscape/+bug/798640

I naively assumed this would be trivial but when I dig in the code it doesn't seem like it is. In particular it is not immediately obvious how to convert between Inkscapes DOM model and libxml2:she model.

The simplest way I can think about now is a workaround involving loading the file with libxml2, and find the nodes in that tree instead.

I can't be the only one wanting to do things like this. I'm obviously missing something, right?