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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,1e67a7db835cf5a8 X-Google-Attributes: gid103376,public From: Tucker Taft Subject: Re: Binary files vs Portablity vs Ada Date: 1999/11/08 Message-ID: <3827555C.D8E87932@averstar.com>#1/1 X-Deja-AN: 546099769 Content-Transfer-Encoding: 7bit Sender: news@inmet.camb.inmet.com (USENET news) X-Nntp-Posting-Host: houdini.burl.averstar.com References: <7vt67r$qv0$1@coward.ks.cc.utah.edu> <7vurt3$ojd$1@nnrp1.deja.com> <7vuto0$pv0$1@nnrp1.deja.com> <7vvrin$gp9$1@nnrp1.deja.com> <8074m8$bk8$1@nnrp1.deja.com> X-Accept-Language: en Content-Type: text/plain; charset=us-ascii Organization: AverStar (formerly Intermetrics) Burlington, MA USA Mime-Version: 1.0 Newsgroups: comp.lang.ada Date: 1999-11-08T00:00:00+00:00 List-Id: Ted Dennison wrote: > > In article <7vvrin$gp9$1@nnrp1.deja.com>, > Robert Dewar wrote: > > In article <7vuto0$pv0$1@nnrp1.deja.com>, > > Ted Dennison wrote: > > > There's no reason to > > > expect that your vendor would do something goofy with the data > > > (like compress it or something), but there's nothing stopping > > > them either. > > There is specific implementation advice on this subject: > > Perhaps. But advice is just that; advice. No guarantees. If you are > trying to do something universally portable, you can't count on > implementation advice. > > > Now an implementation could conceivably refuse to follow this > > implementation advice, but then it must document this fact: > > That's only an issue if you have two particular implementations you want > it to work between. But no one asked about portability between two > particular compilers. The issue is portability in general. > ... It is always a bit frustrating to follow discussions like this where people keep arguing about how this or that is not "guaranteed" by the Ada RM, when other languages have far fewer guarantees to begin with, and no strictly-obeyed standard and validation suite available. Portability is not an absolute. It is defined relative to the platforms and compilers of interest. The Ada RM tries to avoid overspecification, partly because it is trying to handle any sort of target environment, with storage elements varying from 8 bits each to 60 bits each. If you limit yourself to things which are "guaranteed" portable by the RM, you will probably be disappointed. If instead you concentrate on localizing your target-specific assumptions, rather than spreading them around, you use some common sense, and try your code on whatever compilers you have ready access to, you will probably be happier... > T.E.D. -- -Tucker Taft stt@averstar.com http://www.averstar.com/~stt/ Technical Director, Distributed IT Solutions (www.averstar.com/tools) AverStar (formerly Intermetrics, Inc.) Burlington, MA USA