From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,38fc011071df5a27 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-05-30 06:04:48 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!nntp.cs.ubc.ca!nntp-relay.ihug.net!ihug.co.nz!falcon.america.net!uunet!dca.uu.net!ash.uu.net!nntp.TheWorld.com!not-for-mail From: Robert A Duff Newsgroups: comp.lang.ada Subject: Re: Ideas for Ada 200X Date: 30 May 2003 09:04:47 -0400 Organization: The World Public Access UNIX, Brookline, MA Message-ID: References: <6a90b886.0305262344.1d558079@posting.google.com> <3ED41344.7090105@spam.com> <3ED46D81.FF62C34F@0.0> <3ED46E07.4340CABC@0.0> <3ED4F3FD.A0EF7079@alfred-hilscher.de> <3ED4ECFC.5060000@cogeco.ca> NNTP-Posting-Host: shell01.theworld.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: pcls4.std.com 1054299887 31495 199.172.62.241 (30 May 2003 13:04:47 GMT) X-Complaints-To: abuse@TheWorld.com NNTP-Posting-Date: Fri, 30 May 2003 13:04:47 +0000 (UTC) User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 Xref: archiver1.google.com comp.lang.ada:38088 Date: 2003-05-30T09:04:47-04:00 List-Id: Lutz Donnerhacke writes: > * Larry Kilgallen wrote: > > In article , Lutz Donnerhacke writes: > >> * Dmitry A. Kazakov wrote: > >>> So, let's make all types "tagged"! I think it could be done little or no > >>> compatibility impact. > >> > >> What about the representation clauses? If you do not use Ada for system > >> programming, don't try to make Ada200x unusable for this purpose. > > > > Let's allow representation clause support for the tags and tagged types ! > > Please show me a representation clause which leave out the tag completely. Tags are not needed for tagged objects. Tags are needed for class-wide objects. If all types were tagged, then a reasonable run-time model would *not* store the tag in every (tagged) object, but only in pointer-to-classwide and the like. Or, one could give the programmer a choice of whether to store the tag with the object -- it's more efficient if you're going to use class-wide types a lot, and less efficient if you're not. - Bob