Treesitter for syntax highlighting, tokenizing etc...

Lezer is the JS version of Treesitter (C-based).

Codemirror is an editor based on the grammars and tokenizing of Lezer.

Reading through all the tree-sitter docs really helps you understand Lezer better.

https://tree-sitter.github.io/tree-sitter/creating-parsers#command-highlight

Generate a syntax tree from a file ( we don't need to provide a grammar file? Is it bundled?)

$ tree-sitter parse somefile.js <-- takes a long time... Why? With JS?

$ tree-sitter tags grammar.js

You can use these language specific ones https://github.com/tree-sitter/tree-sitter-json/tree/master

^ you can use the rust bindings from this to generate a Rust executable thta parses JSON files

Is only JS included as a grammar by default? Do the others need to be added manually?

Show which are installed $ tree-sitter dump-languages

find the grammar.js from the treesitter language repo
download it to a folder
Run this command in that folder to generate a parser executable for that language/grammar $ tree-sitter generate

$ tree-sitter parse example-file.json (from the same folder??) https://tree-sitter.github.io/tree-sitter/creating-parsers#dependencies

$ tree-sitter highlight json.grammar.json

https://github.com/tree-sitter/tree-sitter/issues/732