Re: case-insensitive string comparison

[Eli Zaretskii]

> From: Sam Steingold <sds@gnu.org>
> Date: Tue, 26 Jul 2022 10:16:08 -0400
> 
> > Could be something macOS-specific.  Maybe your system doesn't define
> > the __STDC_ISO_10646__ feature?  In that case, string-collate-equalp
> > (see the doc string) behaves like string-equal, and that one doesn't
> > have a case-insensitive variant.
> 
> How do I find out?
> --8<---------------cut here---------------start------------->8---
> echo  > .zzz.c;
> gcc -E -dM .zzz.c | grep __STDC_ISO_10646__
> --8<---------------cut here---------------end--------------->8---
> does not print anything, but maybe I need to `#include' something?

No, that exactly means you are getting the string-equal fallback
instead.  Here on GNU/Linux I get

  $ gcc -E -dM foo.c | fgrep 10646
  #define __STDC_ISO_10646__ 201706L

> >> I want to be able to use `string-equal-ignore-case' as a :test argument
> >> to things like `cl-find'.
> >
> > Then write a thin wrapper around compare-strings, and be done.
> 
> I think the need is sufficiently generic, e.g., BBDB provides such a
> wrapper, as, I am sure, do many other packages.
> Many core files can be simplified by using `string-equal-ignore-case'
> (just like with the `string-prefix-p').

I'm not convinced, but I won't mount the barricades if Lars and/or
others think we need this.