Re: on helm substantial differences

[Eli Zaretskii <eliz@gnu.org>]

> From: Juri Linkov <juri@linkov.net>
> Cc: Jean Louis <bugs@gnu.support>,  Gregory Heytings <ghe@sdf.org>,
>   spacibba@aol.com,  andreyk.mad@gmail.com,  emacs-devel@gnu.org,
>   rudalics@gmx.at,  monnier@iro.umontreal.ca,  Eli Zaretskii <eliz@gnu.org>
> Date: Sun, 15 Nov 2020 22:07:47 +0200
> 
> It would be nice if in addition to already existing 'annotation-function'
> 'completing-read' also supported 'format-function' or 'display-function',
> i.e. a function that would return a completion candidate to display
> in the *Completions* buffer.  This will allow completions to use
> the same format that is typical to a package's default format, e.g.
> typing TAB in the 'C-x d' minibuffer could display completions in the
> the *Completions* buffer in Dired format:
> 
>   Click on a completion to select it.
>   In this buffer, type RET to select the completion near point.
>   Possible completions are:
>   -rw-rw-r-- 1   185,205 2020-11-14 21:52 minibuffer.el
>   -rw-rw-r-- 1     8,386 2020-11-14 21:52 minibuf-eldef.el
>   …
> 
> 'M-x package-install RET a TAB' could display completions in 'package' format:
> 
>   Click on a completion to select it.
>   In this buffer, type RET to select the completion near point.
>   Possible completions are:
>   ada-mode       7.1.4     available   gnu   major-mode for editing Ada sources
>   ada-ref-man    2020.1    available   gnu   Ada Reference Manual 2012
>   …
> 
> 'C-x b' - completions with the format of 'list-buffers', etc.

This will have to be an opt-in feature.  It presents completion
candidates in such a radically different form that people will be
confused; I would be.  We cannot change the default behavior so
radically, and on top of that make the display different in each mode.

Thanks.