From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 15 Mar 2023 19:24:18 GMT
Subject: Re: [PATCH v2 1/8] for-each-ref: add --stdin option
Message-ID: <xmqqpm99om1p.fsf@gitster.g>
In-Reply-To: <ZBIFEXuE5Um9Z4zM@coredump.intra.peff.net>

Jeff King <peff@peff.net> writes:

> ... we may
> want some kind of "literal" mode, that takes in a list of refs rather
> than a list of patterns, and does a sorted-merge with the list of
> available refs (or uses a hash table, I guess, but for-each-ref also
> tries to avoid even being linear in the total number of refs, so you'd
> still want to find the lowest/highest to bound the iteration).

Exactly.

I actually was wondering if "literal" mode can just take a list of
<things>, and when a <thing> is not a refname, use it as if it
were. I.e. %(refname) would parrot it, while %(refname:short) would
not shorten and still parrot it, if the <thing> is 73876f4861c, but
something like %(subject) would still work.

For that, I suspect ref-filter.c::filter_refs() would need to learn
a different kind fo finter->kind that iterates over the literal
"refs" that was fed from the standard input, instead of calling
for_each_fullref_in() for the given hierarchy, but the new iterator
should be able to reuse the ref_filter_hander() for the heavy
lifting.