19 Oct 2001 06:09:09 +0100, Colin Paul Adams <colin@colina.demon.co.uk> pisze:

But this seems to assume there is a one-to-one mapping of upper-case to lower-case equivalent, and vice-versa. Apparently this is not so.

Indeed, but there exists a default locale-independent case mapping. Language-specific mappings and irregular cases are described as deviations from it.

It seems that whilst the Unicode database's definitions of whether or not a character is upper/lower/title case are normative, the mappings from upper to lower case are only suggestive.

Yes.

what should the primUnicodeToLower/ToUpper operations actually do? Should they be locale sensitive?

I don't think so: they are pure functions, so IMHO they should have a definition independent from the environment. Especially as a proper case mapping requires mapping a character to a few characters sometimes, so a more exact definition would require a different interface: either String -> IO String or IO (String -> String), perhaps taking the locale into account explicitly. -- __("< Marcin Kowalczyk * qrczak@knm.org.pl http://qrczak.ids.net.pl/ \__/ ^^ SYGNATURA ZASTÊPCZA QRCZAK