Re: Q: Is there a built-in way to read multiple file names?

[Ihor Radchenko <yantar92@posteo.net>]

Eli Zaretskii <eliz@gnu.org> writes:

>> May you please explain in more details how you envision such multi-file
>> selection interface?
>
> Basically, present a Dired-like list of files and let the users mark
> the files they want to select.  Many GUI programs show file-selection
> dialogs, which allow selection of more than one file, and that is what
> I had in mind.

Will something like

------------- dired-completion-mode -----------------
[candidates]
-rw-r--r--  1 yantar92 yantar92   936 Jun 25 10:22 CONTRIBUTE.org
-rw-r--r--  1 yantar92 yantar92 35151 Jun 25 10:22 COPYING
------------------- minibuffer ------------------------
Choose files: CO

work?

Basically, instead of the completion buffer, there is dired-derived
buffer narrowed according to the minibuffer input.

Then, users can mark files by switching to "dired-completion-mode" and
using the usual dired mark commands, including bulk marks.

------------- dired-completion-mode -----------------
[selected files]
-rw-r--r--  1 yantar92 yantar92 35151 Jun 25 10:22 COPYING <MARKED>
[candidates]
-rw-r--r--  1 yantar92 yantar92   936 Jun 25 10:22 CONTRIBUTE.org
------------------- minibuffer ------------------------
Choose files: CO

Later, users can go back to minibuffer and change the input, narrowing
to a potentially different set of files:

------------- dired-completion-mode -----------------
[selected files]
-rw-r--r--  1 yantar92 yantar92 35151 Jun 25 10:22 COPYING <MARKED>
[candidates]
drwxr-xr-x  8 yantar92 yantar92  4096 Jul 13 16:04 .git
-rw-r--r--  1 yantar92 yantar92  1044 Jun 25 10:22 .gitignore
-rw-r--r--  1 yantar92 yantar92    95 Jun 25 10:22 .gitmodules
------------------- minibuffer ------------------------
Choose files: git

They can then mark the new files as needed

------------- dired-completion-mode -----------------
[selected files]
-rw-r--r--  1 yantar92 yantar92 35151 Jun 25 10:22 COPYING <MARKED>
drwxr-xr-x  8 yantar92 yantar92  4096 Jul 13 16:04 .git <MARKED>
-rw-r--r--  1 yantar92 yantar92    95 Jun 25 10:22 .gitmodules <MARKED>
[candidates]
-rw-r--r--  1 yantar92 yantar92  1044 Jun 25 10:22 .gitignore
------------------- minibuffer ------------------------
Choose files: git

... or unmark, by using the unmark commands in the same buffer on
"selected files".

>> > The display parts might be suitable for selection, but the entire
>> > completion machinery behind this makes absolutely no sense for the
>> > purpose of selection based on attributes that are not names or
>> > collection of strings.
>> 
>> Is it? AFAIK, packages like consult allow searching by metadata. Isn't
>> custom COLLECTION function not suitable?
>
> Of course, one can make the COLLECTION function do whatever one wants,
> including coffee, love, and whatnot.  But how in the world could the
> result be called "completion" if it doesn't complete anything??

This sounds a bit strange, but I think that this line of the discussion
is deviating from my central question of multi-file selection.
How exactly the minibuffer input is matched against the files (be it
just a file name/path or also attributes/contents/major mode/what not)
is not my concern. Let's focus on selecting multiple files via
completion.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>