Re: [PATCH] git-diff.txt: prefer not using <commit>..<commit>

[Elijah Newren <newren@gmail.com>]

On Mon, Mar 18, 2019 at 12:07 PM Ævar Arnfjörð Bjarmason
<avarab@gmail.com> wrote:
> On Mon, Mar 18 2019, Elijah Newren wrote:
>
> > On Sun, Mar 17, 2019 at 6:41 AM Ævar Arnfjörð Bjarmason
> > <avarab@gmail.com> wrote:
> >> On Sun, Mar 17 2019, Denton Liu wrote:
> >>

> Some of this thread's confusing, and on re-reading I see my reply hasn't
> helped much.
>
> To clarify. There's at least these things to consider:
>
> 1. What should the semantics of .. or ... be?
> 2. What semantics (regardless of syntax) should we recommend for common cases?
> 3. Depending on #1 and #2, can we make our docs less confusing?

That's a good framework; thanks for clarifying.  Junio has weighed in
already, but there were two other things I thought I'd still comment
on.  First, I think this list could use another item, related to #3:

4. Given backward compatibility and existing use-case constraints, is
there at least a way to warn users of possible confusion besides just
the docs?

I suggested one answer elsewhere in this thread (cf.
CABPp-BEy9nN=aV8Y+ueYqv299umHoF2E=8D7heJARM4Qa7P5JQ@mail.gmail.com);
not sure what others think of it yet.

> Anecdotally I've seen ".." in all forms be *way* more common among
> users, even though if you sat them down and explained to them what it
> does v.s. "..." they'd usually say they wanted the latter.
>
> I did some brief scraping of .bash_history on one of our big shared
> servers just now that has a lot of users (100-200) using git for daily
> development. I've got many pages of things like "@{u}..",
> "<tag1>..<tag2>", "<rev>.. -- <path>" etc. against just a couple of uses
> of "...". The "<rev1> <rev2>" form gets a bit of use, but maybe 1/2 of
> "..".

Wow, that is extremely surprising to me.  I have no mechanism to
access any such data (nor any mechanism for pushing new git versions
out to users other than sending out an email about new upstream
releases and asking them to update).  So, I did the next best thing
and sent out a poll to developers (all of whom use git daily); there's
a self-selection bias in the responses that probably tilts away from
novice users, but it's all I had:

Which do you use the most?
1.`git diff A B`    `11`
2. `git diff A..B`    `2`
3. `git diff A...B`
4. I never use any of these    `5`

The responses were 11 for #1 (with a number expressing in follow-ups
that it was the only form of these three they ever used, though some
still used other forms sometimes), 2 for #2 (one of whom responded to
requests for more details and found out he was using it wrong and that
he could save a character by using form #1 in cases where A was the
merge base, which he was happy about), 0 for #3, and 5 for #4.

That was still a lot more voting for the '..' form than I expected,
but still far less than what you have seen.  I wonder if there's a
regional difference?