Re: Collation version tracking for macOS

On Mon, Feb 14, 2022 at 10:00 PM Peter Eisentraut
<peter(dot)eisentraut(at)enterprisedb(dot)com> wrote:
> During development, I have been using the attached patch to simulate
> libc collation versions on macOS. It just uses the internal major OS
> version number. I don't know to what the extend the libc locales on
> macOS are maintained or updated at all, so I don't know what practical
> effect this would have. Again, it's mainly for development. If there
> is interest from others, I think we could add this, maybe disabled by
> default, or we just keep it in the mailing list archives for interested
> parties.

Last time I looked into this it seemed like macOS's strcoll() gave
sensible answers in the traditional single-byte encodings, but didn't
understand UTF-8 at all so you get C/strcmp() order. In other words
there was effectively nothing to version. I remember that other old
Unixes used to be like that, and I suspect that they might be using
old pre-UTF-8 FreeBSD code for locales based on a quick peek at [1]
(though FreeBSD itself has since learned to do CLDR-based UTF-8
sorting with a completely new implementation shared with other OSes).
This makes me wonder if Apple is hiding another collation
implementation somewhere up its sleeve -- surely that libc support is
not good enough for the world's shiny globalised macOS/iOS apps?
Maybe UCCompareText() and friends (UnicodeUtilitiesCoreLib) and the
various Obj-C NSString comparison stuff, all of which probably
predates Unixoid macOS (google tells me that UnicodeUtilities.h was
present in macOS 9). It wouldn't be surprising if it shares nothing
with the modern OS's C runtime stuff that came via NeXT. Just
mentioning this as a curiosity, because I was trying to figure out how
that could be left non-working without anyone complaining...

[1] https://github.com/apple-open-source-mirror/Libc/tree/master/locale