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,FREEMAIL_FROM autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.107.5.137 with SMTP id 131mr15416018iof.117.1511467053533; Thu, 23 Nov 2017 11:57:33 -0800 (PST) X-Received: by 10.157.32.78 with SMTP id n72mr1093219ota.12.1511467053445; Thu, 23 Nov 2017 11:57:33 -0800 (PST) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!news.kjsl.com!usenet.stanford.edu!d140no4730168itd.0!news-out.google.com!193ni8616iti.0!nntp.google.com!i6no4727920itb.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Thu, 23 Nov 2017 11:57:33 -0800 (PST) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=81.50.36.200; posting-account=94GLqQoAAABRDKJ5vWVBzCDWAEq47F5V NNTP-Posting-Host: 81.50.36.200 References: <6a5368c5-f015-4dcb-9291-e77b40fa1bf1@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: Subject: Re: some trivial questions? From: Blady Injection-Date: Thu, 23 Nov 2017 19:57:33 +0000 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Xref: feeder.eternal-september.org comp.lang.ada:49120 Date: 2017-11-23T11:57:33-08:00 List-Id: Le mercredi 22 novembre 2017 01:56:29 UTC+1, Randy Brukardt a =C3=A9crit=C2= =A0: <...> > Similar issues have occurred for every version of Ada since. (Attempts to= =20 > fix the problem of tagged derived types in generic units among others hav= e=20 > died because of compatibility concerns. Similarly, my attempt to allow=20 > untagged type declarations in the private part of protected types seems t= o=20 > have died for that reason, even though it's not possible for there to be = an=20 > incompatibility [I think]. I think there is a currently open AI that=20 > probably will be eventually dropped because of compatibility concerns,=20 > rather than making it into Ada 2020. And so it goes...) <...> > Randy. Hello, Avoiding compatibility issues is mostly a concern for customers of existing= commercial Ada compilers. Here is the Ada standard implementation of some commercial Ada compilers: AdaCore: Ada 2012 PTC ObjectAda (Atego): Ada 2005 PTC ApexAda (Rational): Ada 2005 DDC International: Ada 95 Green Hills Software: Ada 95 Irvine Compiler Corporation: Ada 95 (Ada 2005 is in limited beta testing) OC-Systems: Ada 95 RR Software: Ada 95 (selected Ada 2007 features) XGC: Ada 95 SCORE Ada DDC-I: Ada 95 XD Ada DXC Technology: Ada 95 (Please correct if I'm wrong) (see full list with WEB link on http://www.adalog.fr/fr/outils_payants.html= ) I'm quite surprise not to find some still with Ada 83, maybe old DEC or IBM= ones. In 2017, why aren't they all at Ada 2012 standard? One clue may be that customers which are mainly conservative (Spatial, Aero= nautics, Defense... domains) are not so demanding. Remember "The demand mak= es the offer". Then the evolution process is made of small compatible changes to be attrac= tive to customers and then compiler providers. But in majority they don't upgrade! Thus who cares about being compatible for new standard? So go on attractive changes, more fashionable some people says disruptive c= hanges, with possibly compatibility issues that may fixed after. The point is that some duration is mandatory to analyse true effects of com= patibility issues and after make them residuals. Thus when commercial compiler providers and their customers are well aware = of residuals issues they can decide to upgrade (or not) for stable attracti= ve features. Surely idealistic point of view ;-) Actually, it is a question of trade off, maybe the present cursor position = is too conservative. Regards Pascal.