bug#72210: 31.0.50; Feature request: multi-category support in `icomplete-fido-kill'.

[Eli Zaretskii <eliz@gnu.org>]

> From: Fernando de Morais <fernandodemorais.jf@gmail.com>
> Date: Sat, 20 Jul 2024 11:22:51 -0300
> 
> Dear maintainers,
> 
> `icomplete-fido-kill' works very well, but cannot handle the deletion of
> files or killing buffers when they are behind a multi-category
> ``situation''.  Add this would be useful for those of us that combine
> `icomplete' with, e.g., `consult-buffer'.
> 
> What follows is just the ``hacky'' approach that's currently being used
> in my init:
> 
> #+begin_src emacs-lisp
>   ;; Stolen from Embark <https://git.savannah.gnu.org/cgit/emacs/elpa.git/tree/embark.el?h=externals/embark#n2108>
>   (defun icomplete--refine-multi-category (target)
>     "Refine `multi-category' TARGET to its actual type."
>     (or (let ((mc (get-text-property 0 'multi-category target)))
>   	(cond
>   	 ;; The `cdr' of the `multi-category' property can be a buffer object.
>   	 ((and (eq (car mc) 'buffer) (buffer-live-p (cdr mc)))
>   	  (cons 'buffer (buffer-name (cdr mc))))
>   	 ((stringp (cdr mc)) mc)))
>         (cons 'general target)))
> 
>   (defun icomplete-fido-kill ()
>     "Kill line or current completion, like `ido-mode'.
>   If killing to the end of line make sense, call `kill-line',
>   otherwise kill the currently selected completion candidate.
>   Exactly what killing entails is dependent on the things being
>   completed.  If completing files, it means delete the file.  If
>   completing buffers it means kill the buffer.  Both actions
>   require user confirmation."
>     (interactive)
>     (let ((end (icomplete--field-end)))
>       (if (< (point) end)
>   	(call-interactively 'kill-line)
>         (let* ((all (completion-all-sorted-completions))
>   	     ;; Actual changes (
>   	     (refined-pair (when (eq 'multi-category (icomplete--category))
>   			     (icomplete--refine-multi-category (car all))))
>   	     (cat (or (car-safe refined-pair) (icomplete--category)))
>   	     (thing (or (cdr-safe refined-pair) (car all)))
>   	     ;; )
>   	     (action
>   	      (cl-case cat
>   		(buffer
>   		 (lambda ()
>   		   (when (yes-or-no-p (concat "Kill buffer " thing "? "))
>   		     (kill-buffer thing))))
>   		((project-file file)
>   		 (lambda ()
>   		   (let* ((dir (file-name-directory
>   				(icomplete--field-string)))
>   			  (path (expand-file-name thing dir)))
>   		     (when (yes-or-no-p (concat "Delete file " path "? "))
>   		       (delete-file path) t))))
>   		(t
>   		 (error "Sorry, don't know how to kill things for `%s'"
>   			cat)))))
>   	(when (let (;; Allow `yes-or-no-p' to work and don't let it
>   		    ;; `icomplete-exhibit' anything.
>   		    (enable-recursive-minibuffers t)
>   		    (icomplete-mode nil))
>   		(funcall action))
>   	  (completion--cache-all-sorted-completions
>   	   (icomplete--field-beg)
>   	   (icomplete--field-end)
>   	   (cdr all)))
>   	(message nil)))))
> #+end_src
> 
> Thank you for any consideration on the matter.

João, any comments?