BYOG — bring your own grammar

Tree-sitter has grammars for verilog, json, yaml, dart, html and almost any other format. Register one, and a rule can target the exact part of that format it needs to judge: a domain team writes its review questions as rules over the files only it understands.

Writing the queries is not hard with a coding agent. jint capture prints what a grammar captures, with no classifier call, so the agent can check its work as it goes.

The grammar directory

A grammar is one directory under $JINT_GRAMMAR_DIR, default ~/.jint/grammars. The directory name is the grammar id. It holds three files:

<id>.wasm is the compiled grammar. Build it with tree-sitter generate && tree-sitter build --wasm. Its export must be tree_sitter_<id>. Leave it out for an embedded id, such as python, and the embedded parser is reused.
extensions.json is a bare JSON array of dot-prefixed extensions, such as [".v", ".sv"].
queries.scm holds the patterns that assign captures and the #set! directives. For an embedded id, it replaces the embedded queries, unless its first line is ; extends, which adds to them.

Captures

A pattern gives a syntax node a capture. Use a shared capture (function, method, class, type, binding, comment, import) and the targets and every shipped rule work on your language unchanged. Anything else is your own capture, which needs one directive. See captures.

(module_declaration) @type
(always_construct) @function
(net_declaration) @binding
(comment) @comment

Check what it captures:

jint capture design.v

Every problem, such as a node type the grammar does not have, fails at setup and says what to fix.