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: 103376,50137bb64a119cfc X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-02-21 12:23:35 PST Path: archiver1.google.com!news1.google.com!sn-xit-02!sn-xit-04!sn-xit-06!sn-post-01!supernews.com!corp.supernews.com!not-for-mail From: "Randy Brukardt" Newsgroups: comp.lang.ada Subject: Re: "access constant" discriminant Date: Fri, 21 Feb 2003 14:21:04 -0600 Organization: Posted via Supernews, http://www.supernews.com Message-ID: References: <_TO1a.14664$9y2.6601@nwrddc01.gnilink.net> <3CS1a.55972$2H6.1357@sccrnsc04> <3E4E9248.3E71D984@adaworks.com> <1ec946d1.0302201642.66eb93e5@posting.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Newsreader: Microsoft Outlook Express 4.72.3612.1700 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3719.2500 X-Complaints-To: abuse@supernews.com Xref: archiver1.google.com comp.lang.ada:34378 Date: 2003-02-21T14:21:04-06:00 List-Id: Lutz Donnerhacke wrote in message ... >* Matthew Heaney wrote: >> Access discriminants are very powerful. No serious Ada95 program can >> be written without them. > >If there is a serious program without access discriminants, let's call it a >Spark program, or trivial, ok? Claw doesn't use access discriminants. That's in large part because they cause limited 'poisoning', as they're restricted to limited types. We prefered to use Adjust to make assignment work properly. Indeed, I'm not aware of any real Ada program, serious or otherwise, that actually uses access discriminants. I know that they were buggy in Janus/Ada until very recently, and we never received any bug reports on them. So, as a practical matter, these are a very marginal feature of Ada with very limited uses. In any case, Matt's statement would probably have been better if it said: Access discriminants are very powerful. They are very much underutilized, probably because hardly anybody understands them. Sweeping statements about programming style are not likely to be helpful. I tend to feel about finalization like Matt apparently does about access discriminants, but the only time I would say something like "No serious Ada program can be written without them." is when I'm looking for fight. Even though I believe that is true, I'm well aware that there are many, many Ada projects which have an irrational fear of finalization, and to characterize them as not being "serious" is not likely to make any friends. Randy.