Re: German sharp S uppercase mapping

[Kent Karlsson via Unicode]

Skickat från min iPhone 26 nov. 2024 kl. 22:19 skrev Asmus Freytag via Unicode <unicode@corp.unicode.org>:  On 11/26/2024 8:59 AM, Peter Constable via Unicode wrote: The case pair stability requirement applies to default data. Conforming applications can still tailor case mapping behaviour use language-specific overrides. However, the default case pairs as defined in the SpecialCasing.txt and UnicodeData.txt files must remain stable so as not to break existing implementations of file systems or other identifier systems that depend on the default case pairs. Peter The case pair stability is indeed important, if not essential for identifiers. However, in the past, we may have been a bit cavalier on how an identifier-safe casing (default) intersects with text processing in general. I think there's a case to be maded for someone writing a short proposal to clarify whatever language we are using and to make clear, among other things, that **text processing** should be using the appropriate locale-based casing (from CLDR). We should probably go further and explicitly reposition the "default" casing as "identifier-safe" because that is what motivates the stability requirements. There's one more wrinkle. Because the sharp S is not natively used outside German, Did you mean “outside Germany”? It is not used for German in Switzerland. But, IIUC, used for Colognian/Kölsch with the uppercase/lowercase mapping. Or, at least, so I was told several years ago. it would be reasonable to have a multicultural case mapping that treats this, and all cases where local usages do not conflict, according to the evolving rules of of the local culture(s) that use the character, so that there's an optional level between identtifier stable and fully local case mappings. To borrow a bit of terminology from some other implementation we need these levels: InvariantCulture (stable default/identifier-safe) CommonCulture (current culture, common defaul texcept for conflicting use) LocalCulture (current culture... one per locale ID) (Throw in regional if you have to, somewhere). The ideal case would be one where out of the box text processing operations can default to something that performs according to the current (evolving) needs for as many cultures as possible (except where they have contradictory treatment of the same character). And where the fully invariant case is positioned to make clear where it's applicable (identifier) and where its use is therefore mandatory. A./ -----Original Message----- From: Unicode <unicode-boun...@corp.unicode.org> On Behalf Of Daniel Buncic via Unicode Sent: November 26, 2024 2:44 AM To: unicode@corp.unicode.org Subject: Re: German sharp S uppercase mapping <snip> As to the case pair stability guarantee, ... if case folding changes in that language, then Unicode has to adjust. It would be poor service to the public to stick to a case mapping that is no longer valid just because Unicode came into existence at a time when it was still valid. ... <snip>