Re: Tree-sitter integration on feature/tree-sitter

[Yoav Marco]

Yuan Fu <casouri@gmail.com> writes:
>> That reminds me -- Yuan, have you seen my PR to tree-sitter-langs, Hacky
>> support for treesit in Emacs core [2]?
>>
>> It uses tree-sitter-langs' groundwork for fetching grammars and
>> packaging highlighting queries, but uses treesit instead of the
>> tree-sitter dynamic module.
>>
>> Enabling highlighting is just M-x treesit-langs-hl-mode in major-modes
>> that tree-sitter-langs supports.
>>
>> [2]: https://github.com/emacs-tree-sitter/tree-sitter-langs/pull/99
>
> Ah yes, I’ve seen it. I think the part that automatically downloads and builds
> language definitions is very useful. It cannot be in Emacs core because we
> cannot distribute language definitions, but it could be a very useful ELPA or
> MELPA package.

Yeah, I agree. tree-sitter-langs makes it very easy to use
elisp-tree-sitter and now also the newer treesit.

> The part that automatically generate highlighting is also useful,
> but I’m not sure how would we use it.

A little neatpick -- it doesn't really 'generate', just converts
tree-sitter-langs' hand-crafted highlights.scm query files to be usable
by treesit too.

> We probably don’t want to add a tree-sitterify-mode that just enables
> tree-sitter highlight in a mode—I prefer that we change each major
> mode to use tree-sitter features.

I agree, though since grammars aren't packaged with Emacs, major-modes
that *are* packaged with Emacs would need to only use treesit when the
grammars are avaliable. Or do we expect grammars to be a dependency when
users are installing Emacs?

> Also I think it makes more sense if you just fork it rather than making a PR.

Yeah, I don't really expect it to be merged.

My reason for the PR is for it to be more of a talking point about
collaboration between treesit and tree-sitter-langs. I used
elisp-tree-sitter before trying the feature/tree-sitter branch, and I
really like the richness of its highlighting (which comes from the
highlights.scm files).

  Yoav