bug#75122: Treesit support for show-paren-mode

[Juri Linkov]

>> +(defun treesit-show-paren-data ()
>> +  "A function suitable for `show-paren-data-function' (which see)."
>> +  (let* ((node (treesit-thing-at (point) 'sexp-list))
>> +         (beg (when node (treesit-node-start node)))
>> +         (end (when node (treesit-node-end node))))
>> +    ;; When after the closing node, try the previous position inside the 
>> node
>
> The comment doesn't seem to correspond to the code, or anyway to all the
> cases the code might be handling? I might misunderstand, though.

Sorry for the unclear comment.  I meant that when detecting
the opening node we should use (point).  But for detecting
the closing node we need to check (1- (point)) that is
inside the balanced node at the end of the node.

>> +    (unless (or (eq (point) beg) (eq (point) end) (bobp))
>> +      (setq node (treesit-thing-at (1- (point)) 'sexp-list)
>> +            beg (when node (treesit-node-start node))
>> +            end (when node (treesit-node-end node))))
>
> Without getting into more details, it seems the user options
> show-paren-when-point-inside-paren and show-paren-when-point-in-periphery
> are not handled (don't have any effect).

Thanks for referencing these options.  I didn't dig deeper since
I didn't see these options in the SMIE implementation.  But
these options definitely should be consulted to adjust the location
used in '(treesit-thing-at (1- (point)) ...'

> Not sure what's needed for that, but FWIW SMIE's show-paren integration
> seems to react to the value of the first of these options (even though it's
> never referenced directly in smie.el), while the second one is not
> supported there either.

This is strange since neither is referenced in smie.el.
Ok, need to investigate more.