bug#52384: [External] : bug#52384: 26.3; dired buffer navigation tweak

[Juri Linkov]

>> >> > (The Dired+ versions of these commands wrap
>> >> > around, if option `diredp-wrap-around-flag'
>> >> > has its default value of `t'.)
>> >>
>> >> Yet another feature I had already implemented
>> >> since Emacs 21.1 and sent to you for review in 2007.
>> >
>> > Interesting.  Or is that tongue in cheek?
>> >
>> > I just searched all messages I've received from
>> > you, including those in 2007, from mailing lists
>> > and direct mails, and I don't find any such
>> > suggestion or review request.  Could you point
>> > to it - I'm curious.  I expect that if that were
>> > the case I would most likely have added it to
>> > Dired+ long before I did (which was not until
>> > July 12, 2013).
>> 
>> I don't remember exactly, but the closest is in the
>> thread "TAB for non-editing modes" on emacs-devel
>> with the discussion about using TAB in dired
>> to move between directories.  When TAB/S-TAB will go
>> to the next/previous directory, then `<' and `>'
>> will be free to use for going to the first/last file.
>
> This is that thread:
>
> https://lists.gnu.org/archive/html/emacs-devel/2007-09/msg01976.html
>
> I see nothing there that resembles anything like an 
> implementation of wraparound navigation for Dired,
> let alone a request by you to review that.  I don't
> even find any suggestion that such wraparound be
> added to Dired.  I see nothing even vaguely related
> to a suggestion about wraparound navigation.
>
> Checking your and my posts (and others) in that
> thread, I find nothing about any of this.  Could
> you point to the message(s) you're referring to?
> A URL would be good.

Strange, I have a message in the archive from 24 Sep,
but it doesn't exist on the thread that you posted.

> More importantly, `<' and `>' going to the first
> and last file, respectively, has nothing to do with
> wraparound.  So if that's what you suggested or
> implemented, it's something else entirely.

I suggested to use TAB that goes to the next file
and wraps around at boundaries.  Then '>' could be
reused to go to the last file.

>> >> But I don't use it too much because it's not
>> >> so useful with --group-directories-first
>> >> that really should be the default.
>> >
>> > I have that as default for my own use.  But I
>> > often change sort orders, especially for date.
>> 
>> When you change sort orders, directories still
>> remain at the top?  So first are directories
>> sorted by date, then below files sorted by date?
>
> For my own use, I use non-nil `ls-lisp-dirs-first',
> so directories remain listed first.  (But I use
> `emacs -Q` for some testing and some bug filing.)
>
> When `ls-lisp-dirs-first' is non-nil, dirs are
> listed first.  And yes, their order changes when
> sorting is by date vs name, or some other order.
> But as a group, yes, they remain listed first,
> before ordinary files, within any given dir
> listing.
>
> The point is that it can be useful to sometimes
> see some or all dir lines interspersed with
> ordinary-file lines.
>
> Again, a classic example is when subdir listings
> are inserted: Directory lines in those listings
> are separated from those of the main listing and
> from those of other subdir listings.  `>' and
> `<' let you move among consecutive dir lines
> throughout the buffer.
>
> `<' and `>' have their own raisons d'etre.  They
> are not the same as `p' and `n'.  (And yes, it
> makes sense for both >/< and n/p to optionally
> wrap around.)

Maybe then like there is a user option `ls-lisp-dirs-first'
for ls-lisp.el, a similar option should be added to dired as well,
so users won't need to manually add "--group-directories-first"
to `dired-listing-switches'.  Do you agree?