> How do you solve that in "code CAD"? I mean referring to a geometry that's a result of some previous operations, not one that you manually created.

I've written down some preliminary thoughts here: https://github.com/hannobraun/Fornjot/issues/101#issuecommen...

And let me emphasize, these are just preliminary thoughts. I can see cases where what I wrote there won't work, and I'm sure there are many more problematic cases I haven't thought of yet.

There's still a lot of work to do before any of that even becomes relevant for Fornjot. I'll keep thinking about it in the background, but I don't expect to come up with a meaningful solution before I had a chance to really dive into the topic.

CadQuery has its own approach, which I have yet to study in detail: https://cadquery.readthedocs.io/en/latest/selectors.html