bug#60623: 30.0.50; Add forward-sentence with tree sitter support

[Theodor Thornhill]

Juri Linkov <juri@linkov.net> writes:

>>>> >A good practice is to name such a function
>>>> >e.g. forward-sentence-default-function.
>>>>
>>>> Is this practice used anywhere else? Iirc
>>>> forward-sexp-function doesn't follow that
>>>> practice.
>>>
>>>On the other hand, if the value must always
>>>be a function, then having "-default-" in
>>>the name makes sense.
>>
>> So is this to be considered an improvement to forward-sexp too, then?
>
> Sorry, I can't find where a lambda is set to forward-sexp-function.
> I only see this:
>
>   (defvar forward-sexp-function nil
>
> But if it will be set to a function later, it would be nice
> to define a default function as well.

I meant the way we did with 'transpose-sexps', where there now is a
'transpose-sexps-function' variable containing the factored-out earlier
implementation.  And by if "this is an improvement" I meant declaring a
specific defun as the default value for the defvar in question.  Maybe I
should add the same change which is now developing here there too.

What do you think?

Theo