Package: emacs;
Reported by: Juri Linkov <juri <at> linkov.net>
Date: Tue, 25 Mar 2025 18:30:02 UTC
Severity: normal
Fixed in version 31.0.50
Done: Juri Linkov <juri <at> linkov.net>
Bug is archived. No further changes may be made.
Message #40 received at 77255 <at> debbugs.gnu.org (full text, mbox):
From: Vincenzo Pupillo <v.pupillo <at> gmail.com> To: Yuan Fu <casouri <at> gmail.com>, Juri Linkov <juri <at> linkov.net> Cc: 77255 <at> debbugs.gnu.org Subject: Re: bug#77255: Treesit font-lock override for embed ranges Date: Tue, 01 Apr 2025 21:17:55 +0200
Wow!!! Great work!
In data lunedì 31 marzo 2025 18:57:18 Ora legale dell’Europa centrale, Juri
Linkov ha scritto:
> >>> Looks reasonable to me. But if it’s a minor mode, we might need to
> >>> have a way to negate the change made to treesit-font-lock-settings?
> >>> OTOH if we use :override, we might run into an override arm race when
> >>> enabling multiple minor modes, etc.
> >>
> >> We could declare that the last minor mode wins. But indeed still need
> >> a way to restore the original treesit-font-lock-settings after disabling
> >> the minor mode.
>
> I'm convinced now that minor modes should be avoided since it's not
> straightforward to revert the original settings when they are disabled.
>
> Everything works nicely in the attached example of the liquid major mode
> where liquid is the primary parser. Currently it copies settings
> from mhtml-ts-mode. But later I'll try to inherit from mhtml-ts-mode.
>
> >> BTW, I found another problem. Please confirm if the range rules allow
> >> only one query per embed language, or I'm doing something wrong?
> >
> > That’s curious, even if you included multiple patterns in the query, it’s
> > still one query; and the range functions support multiple captured ranges
> > when setting up ranges. So something is wrong here. (See
> > treesit-query-range) I can look into this, but give me a few days.
>
> Multiple captured ranges are not needed anymore for the attached example.
>
> >> This revealed another problem. Actually, Liquid is a preprocessor.
> >> Since it can be embedded everywhere in every html node, not depending on
> >> the structure in the html parser, it would be more correct first to use
> >> the liquid parser, and then allow html+js+css parsers to handle
> >> remaining parts. But both liquid and html parsers should apply
> >> on the whole file. The only difference is that liquid has a higher
> >> precedence to decide what overlapping parts belong to the liquid parser.
> >> Or maybe it makes sense to have two primary parsers? They both could
> >> add own highlighting. And in regard to navigation, one of primary
> >> parsers could have a precedence.
> >
> > IMO preprocessor definitely should be the primary parser and let HTML
> > embed
> > in it. In the case of Liquid, it happens to uses a syntax that’s
> > compatible
> > to HTML; that’s fine, but it’s worth it or even necessary to add support
> > for multiple primary parsers because of it. As for precedence, it can be
> > customized by treesit-language-at-point-function.
>
> Thanks for the suggestion to use the preprocessor as the primary parser.
> So multiple primary parsers are not required anymore since other parsers
> are embedded to the primary parser ('define-treesit-generic-mode' sets
> the primary parser). And everything works for any embedded level:
>
> liquid -> html -> js -> jsdoc
> liquid -> html -> css
> liquid -> yaml
>
> #+begin_src emacs-lisp
> (define-treesit-generic-mode liquid-generic-ts-mode
> "Tree-sitter generic mode for Liquid templates."
>
> :lang 'liquid
> :source "https://github.com/hankthetank27/tree-sitter-liquid"
> :mode-remap '(html-mode mhtml-mode html-ts-mode mhtml-ts-mode)
> :name "Liquid"
>
> ;; TODO: :parent mhtml-ts-mode
>
> (treesit-parser-create 'html)
> (treesit-parser-create 'css)
> (treesit-parser-create 'javascript)
>
> (setq-local treesit-range-settings
> (treesit-range-rules
>
> :embed 'html
> :host 'liquid
>
> '(((template_content) @cap))
>
> :embed 'javascript
> :host 'liquid
>
> '(((js_content) @cap))
>
> :embed 'css
> :host 'liquid
>
> '(((style_content) @cap))
>
> :embed 'javascript
> :host 'html
>
> '((script_element
> (start_tag (tag_name))
> (raw_text) @cap))
>
> :embed 'css
> :host 'html
>
> '((style_element
> (start_tag (tag_name))
> (raw_text) @cap))))
>
> (when (treesit-ready-p 'yaml t)
> (treesit-parser-create 'yaml)
> (setq-local treesit-range-settings
> (append treesit-range-settings
> (treesit-range-rules
>
> :embed 'yaml
> :host 'liquid
>
> '(((front_matter) @cap))))))
>
> (setq-local treesit-font-lock-settings
> (append treesit-font-lock-settings
> html-ts-mode--font-lock-settings
> js--treesit-font-lock-settings
> (treesit-replace-font-lock-feature-settings
> (treesit-font-lock-rules
>
> :language 'css
> :override t
> :feature 'variable
>
> '((plain_value) @mhtml-ts-mode--colorize-css-value
> (color_value) @mhtml-ts-mode--colorize-css-value))
> css--treesit-settings)))
>
> (setq-local treesit-font-lock-feature-list
> (treesit-merge-font-lock-feature-list
> treesit-font-lock-feature-list
> (treesit-merge-font-lock-feature-list
> html-ts-mode--treesit-font-lock-feature-list
> (treesit-merge-font-lock-feature-list
> js--treesit-font-lock-feature-list
> css--treesit-font-lock-feature-list))))
>
> (when (treesit-ready-p 'jsdoc t)
> (treesit-parser-create 'jsdoc)
> (setq-local treesit-range-settings
> (append treesit-range-settings
> (treesit-range-rules
>
> :embed 'jsdoc
> :host 'javascript
> :local t
>
> `(((comment) @cap
> (:match ,js--treesit-jsdoc-beginning-regexp
> @cap)))))))
>
> (setq treesit-thing-settings
> (append
> `((liquid (sexp (not ,(rx bos (or "program") eos)))
> (list ,(rx bos (or "range"
> "if_statement"
> "for_loop_statement"
> "case_statement"
> "unless_statement"
> "capture_statement"
> "form_statement"
> "tablerow_statement"
> "paginate_statement")
> eos))))
> mhtml-ts-mode--treesit-thing-settings))
>
> (setq-local treesit-aggregated-outline-predicate
> `((liquid . ,(rx bos (or "if_statement"
> "for_loop_statement")
> eos))
> (html . ,#'html-ts-mode--outline-predicate)
> (javascript . ,js-ts-mode--outline-predicate)
> (css . ,css-ts-mode--outline-predicate))))
> #+end_src
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