bug#18051: [Emacs-diffs] trunk r117726: Add string collation.

[Eli Zaretskii]

> From: Michael Albinus <michael.albinus@gmx.de>
> Cc: dmantipov@yandex.ru,  eggert@cs.ucla.edu,  18051@debbugs.gnu.org
> Date: Wed, 27 Aug 2014 13:24:48 +0200
> 
> > 2. Should we signal an error if the input strings are not pure-ASCII
> >    or multibyte?  Unibyte strings will at best cause incorrect
> >    results.
> 
> Maybe we shall convert the strings to multibyte, via string_to_multibyte()?

That will not help.

I say code that invokes these functions with unibyte non-ASCII strings
has a bug that should be flagged.

> > 5. The locale names on Windows are different from Posix: Windows uses
> >    3-letter abbreviations of the country and the language,
> >    e.g. "fra_FRA" instead of the Posix "fr_FR".  Do we want the locale
> >    string values used for let-binding the above-mentioned variable to
> >    be portable across systems?  Then we'd need some conversion
> >    database on MS-Windows.
> 
> Here I'm a bit undecided. We could let it to the users to find the
> proper locale name, but this is inconvenient. OTOH it would be much work
> to install a mapping system, and we would need to maintain it. What if
> there would be a new "en_SC" (Scotland) locale? We would need to
> maintain such changes in Emacs forever ...

I think these interfaces will almost always be used with the current
locale.  So with that in mind, I think we can document this issue, and
then safely leave this problem to the code that needs to use
non-default locales.

> > 6. I think we will want case-insensitive version of this function.
> 
> That's also on my todo list. But I'm a little bit undecided whether we
> shall add it to string-collate-* functions, or whether there shall be
> further functions.
> 
> Maybe we could use sort-fold-case for this as indication? Or is this too
> specific?

See my suggestion in the other message.

Thanks.