Even if the details are a bit… inscrutable, I do like that figuring out the structure of this interpreter is quite easy as it's all on one page and easy to see

Even if the details are a bit… inscrutable, I do like that figuring out the structure of this interpreter is quite easy as it's all on one page and easy to see all the “moving parts”. It perhaps looks a bit scary, but it is, IMO, much easier to understand than 1000 lines of Java spread out across 5 different files. In a way, there's less mental overhead.