Re: Disable tree-sitter font-locking for smaller ranges

[Theodor Thornhill <theo@thornhill.no>]

On 17 October 2022 07:04:58 CEST, Yuan Fu <casouri@gmail.com> wrote:
>
>
>> On Oct 16, 2022, at 3:32 AM, Theodor Thornhill <theo@thornhill.no> wrote:
>> 
>> 
>> Hi Yuan!
>> 
>> I've been trying to tweak the font-locking for tree-sitter in
>> js/ts-mode, and I'm still struggling with the template strings.  Is
>> there a way to _disable_ font-locking for smaller ranges?
>> 
>> Let's say you have this string:
>> ```
>> `Some string with ${5+5} many template substitutions ${foo().bar().baz()}`;
>> ```
>> 
>> This string will match something like:
>> ```
>> (template_string (template_substitution) :*)
>> ```
>> 
>> If you use this as a query:
>> ```
>> (template_string) @font-lock-string-face
>> ```
>> 
>> Everything inside the string is in string-face.
>> 
>> If you add
>> ```
>> (template_substitution
>> "${" @font-lock-constant-face
>> (_)
>> "}" @font-lock-constant-face)
>> ```
>> 
>> You get font-locking in the ranges inside the squigglies, as expected.
>> However, if there isn't defined any rules for say, "(), . []" etc, the
>> template_string capture will bleed into the substitution, because its
>> range suggests it should.  It would be nice to say something like:
>> 
>> ```
>> (defvar fonts ()
>>  (treesit-font-lock-rules
>>     :language 'tsx
>>     :override t
>>     :feature 'basic
>>     '((template_string (_):* @disabled) @font-lock-string-face 
>>       (template_substitution ["${" "}"] @font-lock-constant-face)))
>> ```
>> 
>> to ensure that whatever is inside the wildcard match will _not_ be
>> considered for the string face, but whatever is still inside the bigger
>> range will.  Is this currently possible?  If not, is
>> it possible to add?  I guess I could make a function that would remove
>> the range, but that seems fiddly and error prone.
>> 
>> I've tried fiddling with the :feature flag in 'treesit-font-lock-rules',
>> but I never found a combination that did what I wanted.
>> 
>> Adding a small image of a stupid snipped just to make the point more visual
>
>The image you attached looks perfectly fine to me. Do you not want to font-lock what’s inside a substitution? I’m not exactly sure what result you want to archive.
>

All the parens, braces, equal, semicolons should be white, as they would in the source file outside of the template string. But the string outside of the ${...} should be string colored. 


>If you don’t want font-lock in substitutions, you can put 
>
>>  '((template_string) @font-lock-string-face 
>>       (template_substitution ["${" "}"] @font-lock-constant-face))
>
>
>After all other queries, and mark these two with :override t. That should do it.
>

Ill try that! 

>Also, when I was browsing tsx’s grammar file, I didn’t find definition of template_substitution at all. That means at least some part of js and tsx’s grammar are not interchangeable.
>
>Yuan

They do some inheritance shenanigans in their files. Most of the grammar is from tree-sitter-Javascript. 

Theo