On 2/22/20 8:09 PM, Hubert Tong via SG16 wrote:
> On Sat, Feb 22, 2020 at 3:37 PM Jens Maurer via SG16
> <sg16_at_[hidden] <mailto:sg16_at_[hidden]>> wrote:
>
> On 22/02/2020 19.46, Steve Downey via SG16 wrote:
> > Attached are the revised P1949 paper pulling back the changes
> from D1949R2 as presented and the original source. I've also fixed
> up formatting problems. The markdown is the original source and is
> transformed using Michael Parks's wg21 paper system.
> https://github.com/mpark/wg21 and
> https://mpark.github.io/programming/2018/11/16/how-i-format-my-cpp-papers/ .
>
> >
> > Source for p1949 is
> https://github.com/steve-downey/papers/blob/master/p1949.md
> >
> > As this is intended to capture the paper as presented, please
> just review that it is accurate in that regard. However, I'm
> absolutely open to any edits or suggestions for R3. In particular,
> for R3 (or 4) in Varna I'll want to make sure the body of the
> paper reflects and supports the wording, because I hate when they
> don't.
>
> Brief comments on the proposed wording for R3 or so:
>
> - Add periods at the end of the sentences in the new Annex.
> - X.7 needs an empty line
> - Add cross-references from the Annex to the main text where
> the normative statement appears.
> - The underline seems to be forgotten in "start" in lex.name
> <http://lex.name>
> - diff.cpp20.lex "affected subclause" 5.10: also add section label
> - When referring to ISO 10646, it would probably be helpful to
> also give a section number for the rule being relied upon.
>
> - Steve, please add subclause and paragraph numbers (alongside the
> stable name for the subclause) based on an identified IS working draft.
> - The references to ISO 10646 in the first changed paragraph appear to
> be wrong. There is no XID_CONTINUE class in ISO/IEC 10646:2017. The
> reference should be to UAX #44 (please add to the normative
> references). Also, the property name is "XID_Continue".
> - Suggestion:
> An identifier shall<del> conform to the</del><ins>be in</ins> NFC<del>
> normalization</del><ins> as</ins> specified in ISO/IEC 10646.
> <del>If an identifier is encountered that does not, the program is
> ill-formed.</del>
> - I suggest having a note in the paper that the NFC restriction only
> comes into effect for user-defined-integer-literals and
> user-defined-floating-point-literals at phase 7 of translation.
> - Was EWG informed that the proposal can be understood as introducing
> new core language undefined behaviour for existing programs with
> identifiers in NFC form where the concatenation is not in NFC form
> ([cpp.concat])? I note that R1 of the paper was not clear on that
> point and R2 does not identify it as a consideration.
I don't recall discussing this in EWG, but I believe it was discussed at
some point and the conclusion was that an identifier not in NFC form
resulting from such concatenation was ill-formed. Can you elaborate as
to how the UB manifests?
> - Is there an intent to bring the paper to WG 14?

We have a github issue to track doing so:
- https://github.com/sg16-unicode/sg16/issues/56

Tom.

> - In the Annex D entry, the ISO 10646 references should be to UAX #31.
> UAX #31 should be added to the bibliography.
> - In the Annex D entry, do not claim that identifiers can only be
> written a single way. That statement is not true before phase 5 of
> translation.
> - The new Annex should be marked as being informative only.
> - In the new Annex, UAX #31 should be referenced as "UAX #31".
> - The C++ Standard uses "white-space" as an adjective modifying
> "characters".
> - Missing "s" in the introduction to the list of white-space characters.
> - The "minus space" should be "minus the white-space characters".
> - The code font tables should be formatted as real tables with
> headings and no extraneous fields.
>
>
> Jens
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