Re: Call for volunteers: add tree-sitter support to major modes

[Theodor Thornhill]

Hi!

> Looks good! Here are some comments.
>
> +
> +     ;; FIXME: We need to be able to set the priority for font-locking
> +     ;; somehow.  We cannot just override all of the template string,
> +     ;; as that would mess up interpolated expressions
> +     ;;
> +     ;; (template_string) @font-lock-string-face
> +     (template_substitution ["${" "}"] @font-lock-constant-face)
> +     )))
>
> What exactly do you mean by priority here? Why doesn't :override t
> work?
>

In template strings in JavaScript we have issues with precedence in that
we default to string font locking for everything that does _not_ have
specific rules.  An image speaks a thousand words, so I'll add
screenshots.  What I need is some sort of way to ensure that inside of
template strings font-locking should _not_ happen

> +
> +(defvar js-treesit--defun-query
> +  "[(class_declaration)
> +    (method_definition)
> +    (function_declaration)
> +    (variable_declarator)] @defun")
>
> This should be compiled.
>
> +
> +(defun js--treesit-enable ()
> +  (unless (and (treesit-can-enable-p)
> +               (treesit-language-available-p 'javascript))
> +    (error "Tree sitter isn't available"))
>
> I don't think we should error here, I'd displaying a message instead.
>
> +
> +  ;; Comments
> +  (setq-local comment-start "// ")
> +  (setq-local comment-start-skip "\\(?://+\\|/\\*+\\)\\s *")
> +  (setq-local comment-end "")
>
> I think it's best to not repeat code, could you move this outside the
> (if tree-sitter) form and have it run regardless?
>
> +(defun js--json-treesit-enable ()
> +  (unless (and (treesit-can-enable-p)
> +               (treesit-language-available-p 'json))
> +    (error "Tree sitter isn't available"))
>
> Same as above, IMO message is better.
>

I added some variartion of this.  I think also message is better,
because user-error makes the logic a little harder.  What do you think?


Thanks, see attached patch:

font-lock-on-string.png
Description: PNG image

no-font-lock.png
Description: PNG image

0001-Add-tree-sitter-functionality-to-js-mode.patch
Description: Text Data