bug#73404: 30.0.50; [forward/kill/etc]-sexp commands do not behave as expected in tree-sitter modes

[Yuan Fu <casouri@gmail.com>]

> On Jan 8, 2025, at 11:42 PM, Juri Linkov <juri@linkov.net> wrote:
> 
>>>> 1. use keywords like
>>>> 
>>>> (setq-local treesit-thing-settings
>>>>             `((html
>>>>                (:sexp ,(regexp-opt '("element" "text" "attribute" "value")))
>>>>                (:list ,(regexp-opt '("element"")))
>>>>                (:sentence "tag")
>>>>                (:text ,(regexp-opt '("comment" "text"))))))
>>>> 
>>>> 2. use a symbol property like (put 'list 'treesit-thing t)
>>>> 
>>>> You decide ;-)
>>> 
>>> Of course, there are more alternatives:
>>> 
>>> - Use a symbol property like (put 'list 'treesit--this-is-a-function t)
>>> - Refuse functions represented as symbols (callers need to use an
>>> eta-wrapper).
>>> - Distinguish the two cases via a more verbose representation like
>>> `(thing list)` vs `(function list)`.
>>> - Use a string rather than a symbol.
>>> - <I'm sure you can come up with more options>
>> 
>> Thanks.  IMHO it’s best to keep it simple and familiar, so let’s keep
>> using symbols and use a symbol property to solve this edge case.
>> I think this problem is rare enough that we don’t need any fancy
>> solutions for it.
>> 
>> Juri, please feel free to apply your symbol property patch. For the symbol
>> property name, I feel that something like
>> treesit-symbol-predicate/treesit-use-as-symbol-predicate would be more
>> descriptive.
> 
> If we settle on the variant that keeps the current format with symbols,
> wouldn't it better to keep a symbol property name shorter?
> 
> First I proposed 'treesit-predicate', but then realized it's wrong
> since it's opposite to the predicate function.
> 'treesit-thing' was better since it indicates that it's used in
> 'treesit-thing-settings'.
> 
>> Since we don’t have docstrings for symbol properties (right?).
> 
> There are no docstrings for symbol properties indeed.  But I think
> the important property for the name is that it should be unique enough
> to be easily greppable.  But I tried to grep, and 'treesit-thing' finds
> too many matches.
> 
> So probably the most suitable symbol name would be 'treesit-thing-symbol',
> that currently has no occurrences in source code.

Sounds good. Let’s go with it then.

Yuan