I'll check this out, thx. I think this project was created just to see what hand coding a lexxer and parser would be like. You know... just for fun. I want to go back afterwards and re-implement it with (f)lex and bison. Probably a good excuse to learn antler as well. I'll check out the tree notation stuff too.
I like lexer/parsers, would you mind sharing the repo?
It's not published yet, but one of us will post is as a Show HN" feature when it is.