I had fun writing a tree-sitter grammar[1] for jq, mostly based on the gojq parser. I realized it was probably in pretty good shape when a snippet that I thought was valid had a syntax error, which tree-sitter was happy to confirm. jq is a lot of fun to write and think with, and the stdlib is good but quirky. It would really benefit from some more libraries, so it's great to see tools to facilitate writing in it!

[1] https://github.com/flurie/tree-sitter-jq