bug#59763: 29.0.60; Filling for c-ts-mode

[Theodor Thornhill via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

On 25 December 2022 02:30:35 CET, Yuan Fu <casouri@gmail.com> wrote:
>
>Theodor Thornhill <theo@thornhill.no> writes:
>
>> On 24 December 2022 09:36:21 CET, Yuan Fu <casouri@gmail.com> wrote:
>>>
>>>Theodor Thornhill <theo@thornhill.no> writes:
>>>
>>>> Yuan Fu <casouri@gmail.com> writes:
>>>>
>>>>>> On Dec 2, 2022, at 6:58 AM, Eli Zaretskii <eliz@gnu.org> wrote:
>>>>>> 
>>>>>>> From: Yuan Fu <casouri@gmail.com>
>>>>>>> Date: Thu, 1 Dec 2022 21:33:06 -0800
>>>>>>> 
>>>>>>> 
>>>>>>> IMO For c-ts-mode to be usable we need to have at least a basic filling
>>>>>>> function. Below is the function I have in my init.el, could someone have
>>>>>>> a look and see if it’s good? Alternatively we could copy out the comment
>>>>>>> and fill it in a temp buffer with c-mode, but I didn’t have the time to try
>>>>>>> it out and see how well it works.
>>>>>> 
>>>>>> Thanks.
>>>>>> 
>>>>>> From quick testing, I see a problem:
>>>>>> 
>>>>>>  . Visit dispnew.c and go to the comment that starts on line 324.  Delete
>>>>>>    the newline between the two lines of the comment, and invoke the
>>>>>>    function.  Observe how the first non-blank character of the comment's
>>>>>>    second line is aligned with the "/*" on the previous line, not with the
>>>>>>    text after "/*" as I'd expect.
>>>>>
>>>>> I see. I’ll need to look at how cc-mode fill comments.
>>>>>
>>>>>> 
>>>>>> Btw, this command should be bound to M-q in ts-c-mode.
>>>>>
>>>>> Will do, once our fill function works well. BTW, Theo, if you have any
>>>>> idea, don’t hesitate to go ahead :-) No obligations, of course.
>>>>>
>>>>> Yuan
>>>>
>>>> Sure!  Added to my list :)  I had a function at some point that used
>>>> c-mode to do this. I'll see if I can polish it a little.
>>>
>>>I did some work in filling, it should work like cc-mode in like 90% of
>>>the cases now, yay!
>>>
>>>Yuan
>>
>> Nice! For all cc-ts-modes?
>
>I only added for c and c++, but support for other modes should be
>identical. And I think we should have something equivalent to cc-mode’s
>init which sets up things that are the same in all C-like languages,
>basically comments and filling.
>
>But I wonder where should we put it, I guess it’s fine to leave it in
>c-ts-mode, since there really isn’t much code. Having other modes to
>require c-ts-mode shouldn’t be a big problem, I think?
>
>Yuan

How about just having treesit-utils.el, or something like that? There are probably many things in the future that will be common among modes, yet won't really warrant inheritance. I think we have such an example in js/typescript too, iirc.