Re: [I18ndir] [art] Fwd: New Version Notification for draft-bray-unichars-04.txt

[Rob Sayre <[e-mail]>]

On Mon, Sep 18, 2023 at 1:17 PM Asmus Freytag <[e-mail]> wrote:

> On 9/18/2023 11:09 AM, Rob Sayre wrote:
>
> On Mon, Sep 18, 2023 at 10:51 AM Rob Sayre <[e-mail]> wrote:
>
>> On Mon, Sep 18, 2023 at 7:05 AM Manger, James <James.H.Manger=
>> [e-mail]> wrote:
>>
>>> For understandable reasons, JSON supports both *(%x0-D7FF /
>>> %xE000-10FFFF) and *(%x0-FFFF) (arbitrary 16-bit data) as models for the
>>> logical strings it can represent.
>>>
>>
>> ECMA-404 is clear: "JSON syntax describes a sequence of Unicode code
>> points." and the discrepancy between this text and RFC8259 is what
>> motivated this document. The document also seems to fairly clearly
>> recommend against using this production if you can help it.
>>
>
> Perhaps this document should reference <
> https://unicode.org/reports/tr17/#Strings> (note authors), which covers
> similar territory.
>
> Thanks for noticing.
>
> The need for transient states that are discoverable (that is, not fully
> encapsulated) is a big reason why many specs are not tighter.
>
> However, there are points in a protocol where strings aren't in a
> transient processing state, and here the full restrictions should apply
> (and be specified).
>
Yes. The problem here is that JSON can transmit stuff resembling these:
"For example, strings in Java, C#, or ECMAScript are Unicode 16-bit
strings, but are not necessarily well-formed UTF-16 sequences." I also
mentioned it because it says "A string data type is simply a sequence of
code units.", which matches ECMA-404 pretty well.

Here, the distinction between "string" and UTF-8/UTF-16/UTF-32 is clearly
drawn. To use James' example:

---

It does not make sense for a spec to define:
  unicode-code-point = %x0-10FFFF
  string = *unicode-code-point

---

It seems to me that TR17 defines "string" this way. Which is not to say
that I recommend sending these things over the internet, just that it can
happen. I think the draft does a decent job discouraging this one, but I
guess it will have to be yet clearer.

thanks,
Rob