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Unicode 16 Alpha Review has started

From: Robin Leroy <eggrobin_at_[hidden]>
Date: Fri, 9 Feb 2024 16:49:09 +0100
Dear ISO/IEC JTC 1/SC 22/WG 21/SG 16,

As I mentioned during the 2024-02-07 meeting, the alpha review period has
begun for Unicode Version 16.0, slated for release later this year.
See the blog post
https://blog.unicode.org/2024/02/unicode-160-alpha-review-opens-for.html
and the PRI background document
https://www.unicode.org/review/pri497/pri497-background.html.

As mentioned in the PRI background document, alpha review is for early
review and comment on the repertoire proposed for eventual publication in
Unicode 16.0.
In particular, this is your last chance to propose corrections to character
names, which show up in C++ via named-universal-character
<http://eel.is/c++draft/lex.charset#nt:named-universal-character>.

Some aspects of the répertoire have direct implications on properties and
algorithms; this is especially the case when it comes to Normalization
Forms.
In particular, in Unicode 16.0, some characters are encoded with
decompositions that interact with each other in novel ways. It is important
to note that *there is no change to the normalization algorithm*: a
straightforward implementation of normalization as described in the Unicode
Standard for decades will handle these new characters fine. However, for
some optimized implementations of normalization, these characters may
constitute new edge cases. See
https://www.unicode.org/review/pri497/pri497-background.html, under
*Normalization:
Important Novel Behavior*.

Implementers of normalization (which includes implementers of C++23 by
[lex.name]
paragraph 1 <https://eel.is/c++draft/lex.name#1>) should check that their
implementation works with the draft 16.0α data files, and that it passes
the conformance tests in the associated NormalizationTest.txt.
Of course, while they should get a head start on ironing out potential
issues, implementers should not actually release a 16.0α normalizer, nor
even a 16.0β normalizer later this year; only after final publication in
September should products or implementations be released based on 16.0 data
files.

Best regards,

Robin Leroy

Received on 2024-02-09 15:49:29