Re: [PATCH] terminology tweak: prune -> path limiting

[Matthew DeVore <matvore@google.com>]

On Sat, Dec 8, 2018 at 5:36 PM Junio C Hamano <gitster@pobox.com> wrote:
>
> Matthew DeVore <matvore@google.com> writes:
>
> > In the codebase, "prune" is a highly overloaded term, and it caused me a
> > lot of trouble to figure out what it meant when it was used in the
> > context of path limiting. Stop using the word "prune" when we really
> > mean "path limiting."
>
> path limiting is also used for two purposes.  "pruning", which is to
> cull the side branches that do not contribute the changes made to
> the paths we are interested in, and showing only the changes to the
> paths that match pathspec.
Thank you for the clarification re: side branches.

>
> AFAIK, "prune" is also used to describe unreachable loose objects,
> but that use is fairly isolated and have little risk of being
> confusing too much.  Are there other uses to make you consider it
> "highly overloaded"?

This is what I found:

git prune - cull unreachable loose objects
git fetch --prune - remove remote-tracking refs that no longer exist
at source. Also note "--prune-tags" option
git notes prune - remove notes for non-existing/unreachable objects
git worktree prune - prunes "administrative" files
git prune-packed - removes loose objects that are also in pack files
git filter-branch --prune-empty - removes commits that become empty as
a result of rewriting.

It seems there are three general categories of the use of the term -
 - to remove things from a view (e.g. in path limiting)
 - to remove loose objects for efficiency (git prune, git prune-packed)
 - to remove other things for either efficiency or to reduce cognitive
overhead (git worktree prune, git fetch --prune)

... and each of these categories has 2+ subcategories.

When I tried to figure out what "prune" and "prune_data" ("data" is
quite vague, so these two fields read like "prune_1" and "prune_2")
referred to in "revision.h", I basically did "grep -rn prune" and
looked through the results, but there were too many uses of the term
"prune" to pinpoint its meaning. If I used an IDE I might have been
able to "find usages" of struct revs's prune field, and I probably
*should have* done that, but I didn't have an IDE prepared and I
figured it wasn't important. Then an hour or so later I realized I was
still being confused by this term, and set out to figuring out what it
actually meant.


>
> My gut feeling is that the result is not reducing "overloading" in a
> meaningful way, and this change is not worth the churn, but it
> depends on the answer to the above question.
>
> Thanks.