Oh, I should have pointed out my Python lexer-driven parser at https://hg.sr.ht/~dalke/smiview/browse/smiview.py

The lexer: https://hg.sr.ht/~dalke/smiview/browse/smiview.py?rev=tip#L3...

The lexer state transitions: https://hg.sr.ht/~dalke/smiview/browse/smiview.py?rev=tip#L3...