Re: [PATCH v4 05/10] userdiff: add and use for_each_userdiff_driver()

On Fri, Mar 26 2021, Jeff King wrote:

On Thu, Mar 25, 2021 at 02:26:21AM +0100, Ævar Arnfjörð Bjarmason wrote:

quoted

quoted

quoted

    We could add a ifuncname and xifuncname or whatever for it I guess,
    but currently the ICASE behavior in the C code is magic.

Good point. IMHO that is something we should consider fixing
independently. It was a mistake to add builtins that couldn't be
replicated via the config (though I notice it happened quite a while
ago, and nobody seems to have cared, so perhaps it isn't that
important).

I'm conspiring to eventually optimistically replace these ERE patterns
with PCRE if we build with that at some point.

Then you could just prefix your pattern with (?i) here in this and other
things that want icase...

I really like PCRE myself, but is it portable/common enough for us to
start using it for baked-in funcname patterns? I sort of assumed there
were exotic platforms where libpcre wouldn't build (or at least it would
be inconvenient or uncommon to have it). And it would be nice to degrade
those gracefully (or at least better than "I guess you don't get any
builtin funcnames. Tough luck").

I think it's as portable as git, the JIT backend isn't, but PCRE itself
is portably C code, and e.g. everything that python, PHP and any other
number of things that depend on PCRE has had PCRE ported to it.

That plan involves an "git rm -r compat/regex" and a compat/pcre
instead, I have some long-left-over patches for that.