Re: Any infrastructure to select one of a few options in Emacs core?

[Marcin Borkowski <mbork@mbork.pl>]

On 2016-05-21, at 01:52, John Mastro <john.b.mastro@gmail.com> wrote:

> John Mastro <john.b.mastro@gmail.com> wrote:
>
>> I played around with a few cosmetic changes to your function and ended
>> up with this:
>
> I realized that, for my use case, it makes more sense to let the caller
> specify the characters rather than automatically using the digits 1-9.
> So I ended up with this instead, which is also a bit shorter and
> simpler.
>
> (defun read-choice (prompt choices)
>   (let ((cursor-in-echo-area t)
>         (prompt (if (get-text-property 0 'face prompt)
>                     prompt
>                   (propertize prompt
>                               'face
>                               'minibuffer-prompt))))
>     (save-window-excursion
>       (pop-to-buffer " *Read choice*" t t)
>       (setq-local cursor-type nil)
>       (erase-buffer)
>       (pcase-dolist (`(,char ,description) choices)
>         (insert (propertize (string char)
>                             'face
>                             'font-lock-variable-name-face)
>                 (format " %s\n" description)))
>       (goto-char (point-min))
>       (fit-window-to-buffer)
>       (or (assoc (read-key prompt) choices)
>           (user-error "Invalid selection")))))

Nice, thanks!  I didn't know about several things you used here - every
day is an opportunity to learn!  (I'll finally have to read about pcase,
too.)  I like especially the `fit-window-to-buffer' function - it seems
it's exactly what I needed, much better than my `delete-other-windows'!

Also, it seems you don't need `setq-local' here, since `cursor-type' is
automatically buffer-local anyway.

> In Emacs's master branch (but not the emacs-25 release branch) there's a
> new function `read-multiple-choice' that's similar in purpose and worth
> a look.

Yes, I've seen that.  Not useful for me, though -- in my use case the
descriptions of the choices are too long (maybe even several lines!).

>         John

Best,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University