Re: Changing buffer mode

[carlmarcos--- via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

Jul 22, 2022, 00:21 by incal@dataswamp.org:

> carlmarcos--- via Users list for the GNU Emacs text editor wrote:
>
>>>>>> With the following function I can change the mode of
>>>>>> a buffer. I would like to change it to use
>>>>>> `completing-read` using a list composed of a selection
>>>>>> of mode names. How can I go about doing that?
>>>>>>
>>>>>
>>>>> Use it?
>>>>>
>>>>>  (completing-read "drop: " '(little boy fat man))
>>>>>
>>>>
>>>> Yes, but then how can I update the buffer with the
>>>> new mode?
>>>>
>>>
>>> The same way you always do it?
>>>
>>
>> I do not know the usual way.
>>
>
> (emacs-lisp-mode) from Lisp and M-x emacs-lisp-mode RET
> interactively ...
>
> Anyway some code for you ... try the examples, last.
>

Although it is good, my intention was to limit the modes to a select few, and for the mode names to be visible to the user through the minibuffer completing-read.  


> ;;; -*- lexical-binding: t -*-
> ;;
> ;; this file:
> ;;   https://dataswamp.org/~incal/emacs-init/set-mode.el
>
> (defun mode-p (fun)
>  (let*((sfx "-mode")
>  (len (length sfx) ))
>  (and (functionp fun)
>  (string= sfx (substring (symbol-name fun) (- len))) )))
>
> (defun set-mode (&optional fun)
>  (interactive
>  (list (completing-read
>  "mode: "
>  obarray
>  (lambda (e) (mode-p e))
>  t
>  nil
>  nil
>  (symbol-name #'normal-mode)
>  )) )
>  (if fun
>  (let ((f (if (stringp fun)
>  (intern fun)
>  fun) ))
>  (when (mode-p f)
>  (apply (list f)) ))
>  (normal-mode) ))
>
> ;; (set-mode #'kill-emacs)        ; safe as not a mode
> ;; (set-mode #'fundamental-mode)  ; function
> ;; (set-mode "emacs-lisp-mode")   ; function name
> ;; (set-mode)                     ; derive mode from extention/hashbang
> ;; M-x set-mode RET conf-mode RET ; interactive explicit
> ;; M-x set-mode RET RET           ; ditto implicit
>
> -- 
> underground experts united
> https://dataswamp.org/~incal
>