Yeah, so it's basically a lexer with an extremely simplistic parser.

Compiler parsers aren't a great fit for difftastic. They discard comments, they may not give you output if there are syntax errors, and they're usually tied to a specific language version.

Since this format works well for Comby (Rijnard's talk is excellent: https://www.youtube.com/watch?v=JMZLBB_BFNg ) I'm hopeful it's an adequate solution for Difftastic.

It will also users to add their own custom syntax/config formats.

That said, using tree-sitter might be an option. It's more forgiving than compiler parsers.