toNFKC(toCaseFold(toNFKC(cp))) != cp and toNFKC failures

Patrik Fältström patrik at
Fri May 27 15:34:54 CEST 2011

On 27 maj 2011, at 05.43, Simon Josefsson wrote:

> Am I correct in using toNFKC(cp) = UNDEFINED for this situation, and
> specify that toCaseFold(UNDEFINED) = UNDEFINED and toNFKC(UNDEFINED) =
> UNDEFINED and then also that UNDEFINED is never equal to any code point?

I would say "yes".

At least my view is that toNFKC(cp) != cp for values of cp that is undefined, as you see on the webpage you showed.

Only if toNFKC(cp) is defined, AND the result is cp, the value will be TRUE.


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