Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> -(defcustom c-ts-mode-indent-style 'gnu
>> +(defcustom c-ts-mode-indent-style "gnu"
>>    "Style used for indentation.
>>  
>>  The selected style could be one of GNU, K&R, LINUX or BSD.  If
>> @@ -100,13 +100,33 @@ c-ts-mode-indent-style
>>  set instead.  This function is expected return a list that
>>  follows the form of `treesit-simple-indent-rules'."
>>    :version "29.1"
>> -  :type '(choice (symbol :tag "Gnu" 'gnu)
>> -                 (symbol :tag "K&R" 'k&r)
>> -                 (symbol :tag "Linux" 'linux)
>> -                 (symbol :tag "BSD" 'bsd)
>> +  :type '(choice (string :tag "Gnu" "gnu")
>> +                 (string :tag "K&R" "k&r")
>> +                 (string :tag "Linux" "linux")
>> +                 (string :tag "BSD" "bsd")
>>                   (function :tag "A function for user customized style" ignore))
>> +  :set #'c-ts-mode--indent-style
>>    :group 'c)
>
> Why change to strings?
> BTW the previous code seems wrong: instead of
>
>     (symbol :tag "FOO" 'foo)
>
> it should be
>
>     (symbol :tag "FOO" foo)
>
> since `'foo` is not a symbol but a list (of two symbols).
>

Thanks, fixed.


>> +(defun c-ts-mode--indent-style (sym val)
>> +  "Custom setter for `c-ts-mode-indent-style'."
>> +  (set-default sym val))
>
> Hmm... why bother use a `:set`ter if it doesn't do anything more than
> the default does?
> Shouldn't it call `treesit--indent-rules-optimize` to (re)set
> `treesit-simple-indent-rules`?
> [ Presumably in all relevant buffers, since the defcustom setting is
>   global.  ]
>

Thanks, done.

>> +(defun c-ts-mode-set-style ()
>> +  (interactive)
>> +  (or (eq major-mode 'c-ts-mode) (eq major-mode 'c++-ts-mode)
>> +      (error "Buffer %s is not a c-ts-mode (c-ts-mode-set-style)"
>> +             (buffer-name)))
>> +  (if-let ((mode (cond ((eq major-mode 'c-ts-mode) 'c)
>> +                       ((eq major-mode 'c++-ts-mode) 'cpp)
>> +                       (t nil)))
>> +           (choice (completing-read "Select style: " '("gnu" "k&r" "linux" "bsd"))))
>
> Here, we probably want to specify `must-match` to `completing-read`
> (which makes it unnecessary to check `if-let`, I think) and we should
> provide a default.
> Also we should probably use the (c-ts-mode--indent-styles mode) alist
> rather than hardcode the set of styles.
>
>> +      (c-ts-mode--indent-style 'c-ts-mode-indent-style choice)
>> +    (kill-local-variable 'treesit-simple-indent-rules)
>> +    (setq-local treesit-simple-indent-rules
>> +                (treesit--indent-rules-optimize
>> +                 (c-ts-mode--set-indent-style mode)))))
>
> Here we presumably want to do the (setq-local
> treesit-simple-indent-rules ...) every time (and set
> `c-ts-mode-indent-style` buffer locally rather than via
> `c-ts-mode--indent-style`, or otherwise provide an additional arg to
> `c-ts-mode--indent-style` to say whether it applies globally or only to
> the current buffer).
>
> BTW, the naming of `c-ts-mode--indent-style` and
> `c-ts-mode--set-indent-style` is confusing.
>
> Also: why `kill-local-variable` just before the `setq-local`?
>
>> -           (pcase c-ts-mode-indent-style
>> -             ('gnu   (alist-get 'gnu (c-ts-mode--indent-styles mode)))
>> -             ('k&r   (alist-get 'k&r (c-ts-mode--indent-styles mode)))
>> -             ('bsd   (alist-get 'bsd (c-ts-mode--indent-styles mode)))
>> -             ('linux (alist-get 'linux (c-ts-mode--indent-styles mode)))))))
>> +           (alist-get c-ts-mode-indent-style
>> +                      (c-ts-mode--indent-styles mode) nil nil #'equal))))
>
> Thanks :-)
>
>
>         Stefan


Does this patch look better?  It also works, now :)

Theo