From: Winkler, Arnold F
Sent: Thursday, August 08, 2002 6:42 AM
To: 'Thomas Plum'; John Benito; Ann Bennett; Frank Farance; John Hill;
Rex Jaeschke; Nobuyoshi Mori; Don Schricker; Keld Jørn Simonsen; Willem
Wakker; Tom Plum (WG21)
Cc: 'Asmus Freytag'; 'Ken Whistler'
Subject: RE: Agenda for Character set ad-hoc - 26th August

Tom,

The definition of characters for safe use in identifiers is in Annex A of ISO TR 10176.  This table is provided by Ken Whistler, based on the relevant Unicode table.  

TR 10176 is using the repertoire of approved ISO 10646 characters and might thus be a bit more restrictive than the Unicode table at any time, but WG20 makes sure that the 10176 Annex A table is always synchronized with a major release of the Unicode standard.

Yes, you are right, it would be much easier to just point to the Unicode definition.  This request could be one of the results of the characterset ad-hoc at the SC22 plenary and a resolution from SC22 directing WG20 to document that pointer in its next revision of TR 10176.

TR 10176, edition #4 is currently in the DTR ballot process (SC22 N3419), the proposed table is at http://wwwold.dkuug.dk/jtc1/sc22/wg20/docs/TR10176-4-table.txt

Tom, I hope that helps you to assess your options and take appropriate action at the SC22 plenary.

Arnold

> -----Original Message-----
> From: Thomas Plum [mailto:tplum@plumhall.com]
> Sent: Wednesday, August 07, 2002 10:23 PM
> To: John Benito; Ann Bennett; Frank Farance; John Hill; Rex Jaeschke;
> Nobuyoshi Mori; Don Schricker; Keld Jørn Simonsen; Willem Wakker;
> Winkler, Arnold F; Tom Plum (WG21)
> Subject: Re: Agenda for Character set ad-hoc - 26th August
> 
> 
> I think C++ was the first language to define extended identifiers
> ... anyway, one of the first.  We know that the table embedded
> in the C++ standard is an old table.  For my part, I was waiting
> until WG20 and Unicode Consortium worked out some process for
> harmonizing the process of defining extended-id characters.  But
> we've seen Java, ECMAscript, and C# pointing to Unicode specs,
> meanwhile C and Cobol use WG20 tables, so I've kept quiet
> and proposed no changes to the old C++ tables.
> 
> SC22 should take some note of the definition (in XML?) of
> characters that should _never_ be used in an identifier.  One
> fairly-reasonable approach to identifiers is to allow anything
> that isn't on the black-list.
> 
> The Java spec refers the language spec to the system API spec:
> IsIdentifierStart and IsIdentifierPart (roughly ... from memory).
> SC22 specs should encourage use of system API facilities; let
> only one group of people have to track this evolution, not
> every compiler group.
> 
> If WG20 believes that Unicode got it wrong on two, or three, or
> N, specific identifier characters, then publish an N-paragraph
> TR that clarifies what the problems are, but otherwise point to
> the relevant Unicode spec.  Having an independently-
> maintained table is a nuisance.
> 
> 
> 
> At 02:27 PM 7/22/2002 -0700, John Benito wrote:
>  >Hi All,
>  >
>  >This is just a reminder that I would like
>  >to have the documents for the agenda by
>  >the 9th of August, as specified in my mail
>  >of 25-Jun.  I have sent the preliminary
>  >agenda to the SC22 secretariat for circulation,
>  >with the forewarning that it will be updated
>  >before the ad-hoc.
>  >
>  >Thanks,
>  >
>  >jb -
> 
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