I used LLM for the documentaiton, I had this project going on an off for a while (5+ years), first version was in C then when I managed to make first usable compiler, I flattened the history and re-write (mostly replace all) the code into xi - however mostly if/else and loop blocks; therfore, I had it as a self-host compiler (a compiler that written in its own language) - I used AI along the way for refactoring and documentation, but the core idea and most work is done by me.