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Subject: Re: SG16 meeting summary for February 26th, 2020
From: Hubert Tong (hubert.reinterpretcast_at_[hidden])
Date: 2020-03-03 19:24:14


On Tue, Mar 3, 2020 at 7:33 PM Tom Honermann <tom_at_[hidden]> wrote:

> On 3/2/20 2:53 PM, Hubert Tong wrote:
>
> With respect to Jens's comments as recorded re: P1949 (Identifier syntax):
>
> You are referring to these comments, yes?
>
> - Jens replied that preprocessing-token is distinct and that they get
> converted into identifiers, keywords, etc... at a particular translation
> phase.
> - Jens added that this occurs in translation phase 7 per [lex.phases]p1.7
> and [lex.token]p1. Core language wording should be added here to state that
> an identifier shall be in NFC form.
>
Yes.

>
> Deferring the NFC restriction to phase 7 would not cover the need to match
> macro and macro parameter names to their corresponding references.
>
> That sounds correct to me; at least for the proposal as written. My
> interpretation of the discussion so far has been that there has been no
> intent to address naming of macros and macro parameters. This is why I
> asked during the telecon if the paper should address (preprocessing) tokens
> as well as identifiers. I tend to think that it should since the same
> concerns we have for identifiers seem to apply to preprocessing tokens.
>
The existing text of the standard is not very helpful around this:
preprocessing tokens known as identifiers exist; the conversion from
preprocessing tokens to tokens may decide that the resulting token is a
keyword. It would be a consistent approach to allow deviation from NFC form
except in problematic cases. The preprocessing tokens not in NFC form could
be discarded or stringized during preprocessing.



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