I’m with you. It appears to be a fairly bog-standard DFA, but divining that from 4x4 `int`s and a 256 `char` array feels like I’d just be doing all of the heavy lifting, intellectually. However… it does look like it’s trying to detect spaces (that’s the array of 256 `char`, as `char` is self-indexing). I can’t be bothered to remember how `wc` works, but my guess is that the state-machine has transition states for `sp->sp`, `sp->wd`, `wd->wd`, and `wd-sp`. It’d also need error modes. I suppose it doesn’t contain states for escapes?