add support for ocaml mli files

[rmmanseau]

the ML and MLI files have separate parsers, but appear to share the same highlights.scm file. this change duplicates the file so that emacs can find the queries when using the ocaml-interface grammar. this is necessary to get proper highlighting in interface files. without it, tree-sitter-hl-mode will silently fail to activate in mli files if the language is set to ocaml-interface.

how an interface file looks with the ocaml parser:

how an interface file looks with the ocaml-interface parser

some additional config is required on the part of the user to ensure that the ocaml-interface parser gets loaded for mli files. I use doom emacs so my configuration looks as follows

(use-package! tuareg
  :init
  (define-derived-mode tuareg-mli-mode tuareg-mode "Tuareg Mli")
  (add-hook! 'tuareg-mli-mode-hook #'tree-sitter!)
  (setq auto-mode-alist (delete '("\\.ml[ip]?\\'" . tuareg-mode) auto-mode-alist))
  (add-to-list 'auto-mode-alist '("\\.ml[p]?\\'" . tuareg-mode))
  (add-to-list 'auto-mode-alist '("\\.mli\\'" . tuareg-mli-mode)))

(after! tree-sitter-langs
  (set-tree-sitter-lang! 'tuareg-mli-mode 'ocaml-interface))

[rmmanseau]

addresses #189 (comment)

[rmmanseau]

configuration snippet provides workaround for #116

[jcs090218]

Highlighting is good. Do you think we need to add the parser as well? 🤔

tree-sitter-load: Cannot find shared library for language: ocaml-interface

[rmmanseau]

not sure what you mean. for me, highlighting worked with just this change & the config snippet i posted. ocaml-interface is provided by the same repo as ocaml, and on my system they are both available. I dont think doom emacs is doing any extra configuration to build ocaml-interface on my setup, but I could be wrong.

im a noob to this repo, just thought it would be helpful to post the changes that gave me correct highlighting in mli files :)

[jcs090218]

I've added ocaml-interface support in #251. Can you see if that works for you?

[rmmanseau]

just got time to try it out, it does work! I had to change my config snippet a tiny bit tho. thanks for doing a proper fix :)

(use-package! tuareg
  :config        <--------------- this needed to be config instead of init
  (define-derived-mode tuareg-mli-mode tuareg-mode "Tuareg Mli")
  (add-hook! 'tuareg-mli-mode-hook #'tree-sitter!)
  (setq auto-mode-alist (delete '("\\.ml[ip]?\\'" . tuareg-mode) auto-mode-alist))
  (add-to-list 'auto-mode-alist '("\\.ml[p]?\\'" . tuareg-mode))
  (add-to-list 'auto-mode-alist '("\\.mli\\'" . tuareg-mli-mode)))

(after! tree-sitter-langs
  (set-tree-sitter-lang! 'tuareg-mli-mode 'ocaml-interface))

[jcs090218]

Closing this now since it's working! :)