I've been wondering when someone would finally use the actual code structure to do RAG. It seems like such an obvious, if somewhat harder (at least if you need to support many languages), approach.
The vector/keyword based RAG results I've seen so far for large code bases (my experience is Cody) has been quite bad. For a smaller projects (using Cursor) it seems to work quite well though.
Aider has been doing that for a long time now, it was the first project to do this afaik.
The most funny thing is how synchronicity worked its magic:
Roo Code experimental code indexing using vector DB dropped 3 days ago. Theire using Tree-sitter (the same as Aider) to parse sources into ASTs and do vector embedding on that product, instead of plaintext.