Re: Treesitter injection support

[Pranshu Sharma via "Emacs development discussions." <emacs-devel@gnu.org>]

Yuan Fu <casouri@gmail.com> writes:

>> On Jan 2, 2025, at 6:48 AM, Pranshu Sharma <pranshu@bauherren.ovh> wrote:
>> 
>> 
>> I'm making cperl clone using treesitter, and have done all of
>> highlighting apart from regex and pod.
>> 
>> For regexp, I need different grammer to highlight it, and using the
>> treesit-parser-set-included-ranges doesn't work.  An example:
>> 
>> preq knowledge:
>> 
>> 's/bi?g/small/' replaces instances of 'bg' and 'big' with 'small', and
>> 's/([0-9]+)/$1 + 1/e' incrimental all number (the 'e' at the end tells
>> perl to evaluate the code).
>> 
>> the parse tree of 's/([0-9]+)/$1 + 1/e' is:
>> (substitution_regexp operator: s '
>>     content: (regexp_content not-interpolated not-interpolated) '
>>     (replacement
>>      (scalar $ (varname)))
>>     ' modifiers: (substitution_regexp_modifiers))
>> 
>> (replacement) needs to be conditionally parsed as perl over here because
>> of the 'e' modifier.  Now I cannot use range for this, because say if I
>> had:
>> 
>> 's/(([0-9]+),)+/s#([0-9]+)#$1 + 1#e/e;'
>>                           ^^^^^^          Perl code
>>                ^^^^^^^^^^^^^^^^^^^        Perl code
>> 
>> 
>> The replacement contains another replacment which contains perl code, so
>> it overlaps
>> 
>> So I won't have any way to highlight.  It seems making this work could
>> be possible using nested parsers with their own setting each using own
>> local treesit-range-settings, but this seems really hard with
>> treesit-range-settings being a buffer local variable.
>> 
>
> Ok, so the problem is nested parsers. I don’t think the overlap would
> cause any problem. Right now treesit-range-settings can only give you
> one nested layer. I’ll need to make it support nesting a parser inside
> a local parser of the same language. I’ll work on that once I wrap up
> the thing I’m working on right now :-)

Thanks, this definetly seems like the problem.  Also the
treesit-range-settings seems kind of unstable, example when I purposly
leave closed string before it, and close the string, it doesn't reparse.

-- 
Pranshu Sharma <https://p.bauherren.ovh>