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Re: [SG16] Feedback on P1854: Conversion to literal encoding should not lead to loss of meaning

From: Jens Maurer <Jens.Maurer_at_[hidden]>
Date: Sat, 6 Nov 2021 21:07:57 +0100
On 06/11/2021 16.22, Hubert Tong via SG16 wrote:
> Anyhow, if the intent really is to help only with the visual ambiguity problem, then it would be more consistent to allow /universal-character-name/s that encode to more than one code unit in multicharacter literals (because it's in a multicharacter literal already).

If we use a UCN, we have no source code visual ambiguity
(because a UCN is expressed in basic characters).
Is that a correct understanding of the situation / motivation?
I can't connect your parenthetical remark to that.

> With a focus on the visual ambiguity problem (thanks for reminding), the previous wording to limit /basic-c-char/s to the basic character set is more capable because lots of Unicode display shenanigans will get through the current formulation if the ordinary literal encoding is UCS-2 or UTF-16 (which is possible if CHAR_BIT is large enough).

Do we have sufficient implementation experience / understanding of
existing practice to estimate how much code will break if we
restrict multi-character literals to the basic character set?
(Note that neither @ or $ are in the basic character set.)

(I'm all for restricting multi-character literals as much as possible,
but we should probably avoid stepping on people's toes for non-portable
features that don't really hurt anyone.)


Received on 2021-11-06 15:08:01