From: Kenneth Whistler (kenw@sybase.com)
Date: Mon May 05 2008 - 15:07:44 CDT
Richard Wordingham said:
> ...
> > * Strong normalization stability
> ...
The following is actually referring to Case Pair Stability,
not Strong Normalization Stability:
>
> The condition, "More formally, for given versions V and U of Unicode, and
> any two characters X and Y that are both assigned according to both V and
> U::" could usefully be clarified by replacing 'two characters X and Y' by
> 'two distinct characters X and Y'.
I'm not seeing the useful clarification here. The conditions are
trivially true for any uncased character if you want to test the
edge condition and assume X = Y, since an uncased character casemaps
to itself.
> Readers may not assume that all parts of
> a Unicode declaration are true, so the freedom to make a character lowercase
> and add an uppercase partner might not be believed.
What part of "A character that is not part of a case pair could become
part of one if the new case pair is formed at the time of the
addition of a new character to Unicode" is unclear or not to be
believed?
Here are a couple recent additions of a capital version of a case pair
for a character that had been already encoded as of Unicode 4.0 or
earlier:
023D ; 4.1 # LATIN CAPITAL LETTER L WITH BAR
03CF ; 5.1 # GREEK CAPITAL KAI SYMBOL
So you already have an existence proof that such things happen.
Now existence of such a change in the past is not proof that it
*will* happen again in the future, of course. But no character
encoding committee is going to say ahead of time exactly what *will*
be encoded, because nobody knows that until proposals have been submitted,
discussed, and ballotted.
--Ken
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