Huh, that's a really interesting approach. I just wrote my first Pratt parser a month ago, and one of the most annoying things was debugging infinite loops in various places (I had both tokenizer bugs where no characters were consumed and parser bugs where a token was emitted but not advanced). It's doubly annoying in Zig, because the default test runner won't print out stdout at all, and won't print stderr unless the program terminates by itself (Ctrl + C doesn't print). I resorted to building the test and running it manually, or jumping into a debugger to figure out recursion issues. It's working now, but if (really when) I run into issues in the future I'll definitely add some helper functions to check emitting invariants.

its also very annoying that one can't have two test names where one is substring of other