From: AdaMagica <christ-usch.grein@t-online.de>
Subject: Re: Ada package registry?
Date: Sat, 6 Feb 2016 15:08:49 -0800 (PST)
Date: 2016-02-06T15:08:49-08:00 [thread overview]
Message-ID: <d3aa1a29-803e-4a09-93ab-d3973c24eef0@googlegroups.com> (raw)
In-Reply-To: <n93i35$7lp$1@loke.gir.dk>
Am Samstag, 6. Februar 2016 02:25:59 UTC+1 schrieb Randy Brukardt:
> [What I mean by expressing assumptions is that it's unlikely that any real
> Ada code would really run anywhere. I've been having fun with Gautier over
> his "unconditional portability" claim, as one only needs a single
> counter-example to disprove the claim. After a few obvious problems with the
> choices of Janus/Ada were worked out, I pointed out that his types wouldn't
> work on our old U2200 compiler (as that was a 1's completement, 36-bit
> machine). He decided quite reasonably not to worry about that, but that
> means in his case, that means his code is "unconditionally portable" so long
> as your target supports 32-bit integers and is 2's complement. That might be
> 99% of machines, but its not quite unconditional.]
In my Ada courses, I warn participants not to take compiler traits for Ada properties. I also warned them to be aware of implicit presuppositions, e.g. do not assume that integers are implemented as two's complement; if your code somehow depends on this fact, do document it somewhere.
I just try to make them aware of hidden presuppositions.
Whether they will be is a different story. I myself do not know which implicit presuppositions I depended on in my professional life.
I ported MLoC airborne Ada 83 code to Ada 95 on different HW for full scale flight simulation and was astonished how little changes were needed. But I was bitten by the requirement that source and target sizes for Unchecked_Conversion have to be the same. That was a lesson, you can believe me!
next prev parent reply other threads:[~2016-02-06 23:08 UTC|newest]
Thread overview: 132+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-29 1:13 Ada package registry? olivier.henley
2016-01-29 3:43 ` gautier_niouzes
2016-01-29 22:06 ` Randy Brukardt
2016-01-30 17:21 ` Dirk Heinrichs
2016-01-29 14:20 ` David Botton
2016-01-29 22:27 ` Randy Brukardt
2016-01-30 7:35 ` Dmitry A. Kazakov
2016-01-30 22:14 ` Tero Koskinen
2016-01-31 7:51 ` Dmitry A. Kazakov
2016-01-31 15:52 ` Mart van de Wege
2016-01-31 16:21 ` Dmitry A. Kazakov
2016-01-31 19:16 ` olivier.henley
2016-02-01 23:22 ` Randy Brukardt
2016-02-05 19:52 ` Tero Koskinen
2016-02-05 20:42 ` Dmitry A. Kazakov
2016-02-06 1:25 ` Randy Brukardt
2016-02-06 6:09 ` Jeffrey R. Carter
2016-02-08 22:54 ` Randy Brukardt
2016-02-06 23:08 ` AdaMagica [this message]
2016-02-07 7:08 ` gautier_niouzes
2016-02-07 8:50 ` gautier_niouzes
2016-02-08 22:58 ` Randy Brukardt
2016-02-07 10:24 ` gautier_niouzes
2016-01-31 19:10 ` olivier.henley
2016-02-02 0:44 ` Randy Brukardt
2016-02-02 18:45 ` Shark8
2016-02-02 20:14 ` gautier_niouzes
2016-02-02 20:46 ` Shark8
2016-02-02 21:32 ` gautier_niouzes
2016-02-03 4:21 ` Shark8
2016-02-03 9:39 ` Georg Bauhaus
2016-02-02 22:51 ` Randy Brukardt
2016-02-03 4:16 ` Shark8
2016-02-01 8:30 ` Thomas Løcke
2016-02-01 9:32 ` Georg Bauhaus
2016-02-02 8:54 ` Thomas Løcke
2016-02-02 14:51 ` jsquirek
2016-02-02 18:25 ` Dmitry A. Kazakov
2016-02-02 20:05 ` gautier_niouzes
2016-02-02 20:58 ` Björn Lundin
2016-02-02 23:06 ` Randy Brukardt
2016-02-03 7:15 ` Pascal Obry
2016-02-03 22:11 ` Randy Brukardt
2016-02-04 6:51 ` Pascal Obry
2016-02-04 20:52 ` Randy Brukardt
2016-02-05 7:11 ` Pascal Obry
2016-02-06 1:11 ` Randy Brukardt
2016-02-04 9:05 ` Dmitry A. Kazakov
2016-02-04 9:20 ` Mark Carroll
2016-02-04 12:58 ` Nasser M. Abbasi
2016-02-04 21:03 ` Randy Brukardt
2016-02-05 8:31 ` Dmitry A. Kazakov
2016-02-04 16:52 ` Björn Lundin
2016-02-04 16:59 ` Dmitry A. Kazakov
2016-02-04 17:29 ` Björn Lundin
2016-02-04 21:21 ` Randy Brukardt
2016-02-04 22:04 ` Björn Lundin
2016-02-05 8:51 ` Dmitry A. Kazakov
2016-02-05 22:06 ` Björn Lundin
2016-02-06 0:30 ` Randy Brukardt
2016-02-06 23:26 ` Björn Lundin
2016-02-07 0:16 ` Jeffrey R. Carter
2016-02-07 8:02 ` Dmitry A. Kazakov
2016-02-07 8:36 ` gautier_niouzes
2016-02-07 8:52 ` Dmitry A. Kazakov
2016-02-07 10:06 ` gautier_niouzes
2016-02-07 10:23 ` Dmitry A. Kazakov
2016-02-07 20:02 ` Björn Lundin
2016-02-08 8:19 ` Dmitry A. Kazakov
2016-02-07 10:00 ` Georg Bauhaus
2016-02-07 10:18 ` Dmitry A. Kazakov
2016-02-07 19:27 ` Georg Bauhaus
2016-02-07 19:47 ` Georg Bauhaus
2016-02-07 19:54 ` Dmitry A. Kazakov
2016-02-07 22:56 ` Georg Bauhaus
2016-02-08 8:22 ` Dmitry A. Kazakov
2016-02-07 20:11 ` Björn Lundin
2016-02-07 22:11 ` Georg Bauhaus
2016-02-08 8:16 ` Björn Lundin
2016-02-07 19:57 ` Björn Lundin
2016-02-08 8:25 ` Dmitry A. Kazakov
2016-02-08 22:42 ` Randy Brukardt
2016-02-07 20:07 ` Björn Lundin
2016-02-08 8:38 ` Dmitry A. Kazakov
2016-02-08 18:24 ` Björn Lundin
2016-02-08 22:38 ` Randy Brukardt
2016-02-09 20:56 ` Björn Lundin
2016-02-05 12:54 ` G.B.
2016-02-05 13:27 ` Dmitry A. Kazakov
2016-02-05 15:53 ` G.B.
2016-02-05 16:45 ` Dmitry A. Kazakov
2016-02-05 17:58 ` G.B.
2016-02-05 18:47 ` Dmitry A. Kazakov
2016-02-07 9:40 ` Georg Bauhaus
2016-02-07 10:13 ` Dmitry A. Kazakov
2016-02-07 19:21 ` Georg Bauhaus
2016-02-07 19:57 ` Dmitry A. Kazakov
2016-02-07 22:16 ` Georg Bauhaus
2016-02-08 8:20 ` Björn Lundin
2016-02-08 9:03 ` Dmitry A. Kazakov
2016-02-08 10:08 ` G.B.
2016-02-08 13:42 ` Dmitry A. Kazakov
2016-02-06 0:49 ` Randy Brukardt
2016-02-07 8:42 ` Georg Bauhaus
2016-02-04 21:09 ` Randy Brukardt
2016-02-05 8:59 ` Dmitry A. Kazakov
2016-02-06 0:04 ` Randy Brukardt
2016-02-06 8:54 ` Dmitry A. Kazakov
2016-02-08 23:02 ` Randy Brukardt
2016-02-09 8:50 ` Dmitry A. Kazakov
2016-02-11 1:37 ` Randy Brukardt
2016-02-11 8:25 ` Dmitry A. Kazakov
2016-02-11 22:00 ` Randy Brukardt
2016-02-06 18:48 ` olivier.henley
2016-02-09 0:05 ` Randy Brukardt
2016-02-09 3:50 ` Shark8
2016-02-11 1:40 ` Randy Brukardt
2016-02-09 8:04 ` Thomas Løcke
2016-02-09 13:33 ` Alejandro R. Mosteo
2016-02-09 14:58 ` Shark8
2016-02-11 1:46 ` Randy Brukardt
2016-02-11 5:19 ` Shark8
2016-02-09 18:08 ` Jeffrey R. Carter
2016-02-09 21:00 ` Shark8
2016-02-09 21:07 ` Björn Lundin
2016-02-09 21:31 ` Shark8
2016-02-09 23:47 ` Jeffrey R. Carter
2016-02-10 5:10 ` J-P. Rosen
2016-02-11 1:51 ` Randy Brukardt
2016-02-12 16:05 ` Alejandro R. Mosteo
2016-02-13 5:42 ` olivier.henley
2016-02-13 12:20 ` Alejandro R. Mosteo
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