Re: [I18ndir] draft-bray-unichars-01

[Tim Bray <[e-mail]>]

 Working on a PR to include this input.

On Aug 29, 2023 at 12:10:42 PM, Asmus Freytag <[e-mail]> wrote:

>
> (3)
>
> "reserved for internal use" should be "reserved for internal use by
> application" (as opposed to internal use by the standard).
>

D14 just says “reserved for internal use” and I’m not really comfortable
adding more interpretation.  I’m aware of more interpretation out there on
the net but I think this is OK as it stands?

(4)
> This subset has the advantage of excluding surrogates, which can never add
> any value and have the potential to cause problems.
>
> should be reworded a bit to:
>
> "This subset has the advantage of excluding surrogates, which are not
> assigned to any characters, and thus can never add any value.
> They have the potential to cause problems, for example it is not possible
> to represent them individually in UTF-8."
>

The Unicode Standard says that surrogates can only be used in UTF-16 and
RFC3629 explicitly says they are prohibited. Having said that, it’s easy to
generate UTF-8 that includes them (start by truncating a Java “char” array
incautiously, or just have a bad day while programming in C) and most
(all?) language implementations per Postel’s law will happily give you that
surrogate code point. That’s the problem; although it’s forbidden it can be
done and it does happen.  So I think that instead of “not possible” we
should say something like “… potential to cause problems; while it is
possible to include them in UTF-8 strings, this is forbidden by the
specification of UTF-8”.

Rationale for this suggestion is to be slightly more specific, so the
> reader comes away with the conclusion that the "can never add any value" is
> based on well-founded reasons and not editorial opinion by the writers.
>
> (5)
> The ABNF in section 4.1: the comments are confusing.
>

[more later]

>
>