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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Generic-Package Elaboration Question / Possible GNAT Bug.
Date: Tue, 22 Nov 2011 09:21:41 +0100
Date: 2011-11-22T09:21:41+01:00	[thread overview]
Message-ID: <2hbtv0mgdhek$.yv6k7nmd8l5j$.dlg@40tude.net> (raw)
In-Reply-To: wccmxbpp8ku.fsf@shell01.TheWorld.com

On Mon, 21 Nov 2011 14:41:05 -0500, Robert A Duff wrote:

> "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:
> 
>> Conversion of errors into exceptions is an extremely bad idea. The same
>> fault is represented by dynamic pre-/pos-conditions, assertions,
>> accessibility checks, tag errors.
> 
> But it's not feasible to catch all errors statically.

It is same as to say that it is infeasible to determine program legality
statically. Legality is static per definition.

> If you made a
> rule that all preconditions (for example) must be statically checked,
> that would simply mean lots of preconditions are inexpressible.

If a "precondition" is not static then it is just a part of the *code*
determining the control flow. In earlier times such things were called
prologue and epilogue. There are many issues with them:

1. Stuffing declarative regions with executable code;
2. Defeating principles of structured programming: non-local control flow;
3. Ignoring separation of implementation and interface.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de



  reply	other threads:[~2011-11-22  8:21 UTC|newest]

Thread overview: 86+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-19 21:14 Generic-Package Elaboration Question / Possible GNAT Bug Shark8
2011-11-19 22:12 ` Robert A Duff
2011-11-19 23:36   ` Shark8
2011-11-20  9:55     ` Dmitry A. Kazakov
2011-11-21  7:25       ` AdaMagica
2011-11-21  8:43         ` Dmitry A. Kazakov
2011-11-21 10:25           ` AdaMagica
2011-11-21 13:08           ` Robert A Duff
2011-11-21 13:50             ` Dmitry A. Kazakov
2011-11-21 19:41               ` Robert A Duff
2011-11-22  8:21                 ` Dmitry A. Kazakov [this message]
2011-11-21 20:40               ` J-P. Rosen
2011-11-22  8:29                 ` Dmitry A. Kazakov
2011-11-22 10:25                   ` Georg Bauhaus
2011-11-22 14:32                     ` Dmitry A. Kazakov
2011-11-22 15:02                       ` Georg Bauhaus
2011-11-22 16:23                         ` Dmitry A. Kazakov
2011-11-22 17:46                           ` Georg Bauhaus
2011-11-22 19:15                             ` Dmitry A. Kazakov
2011-11-22 21:03                               ` Randy Brukardt
2011-11-22 21:26                                 ` Dmitry A. Kazakov
2011-11-23  0:07                                   ` Georg Bauhaus
2011-11-23  8:44                                     ` Dmitry A. Kazakov
2011-11-23  9:32                                       ` Simon Wright
2011-11-23  9:56                                         ` Dmitry A. Kazakov
2011-11-23 11:03                                           ` Georg Bauhaus
2011-11-23 11:13                                             ` Dmitry A. Kazakov
2011-11-23 11:25                                               ` Georg Bauhaus
2011-11-23 13:14                                                 ` Dmitry A. Kazakov
2011-11-23 13:59                                                   ` Georg Bauhaus
2011-11-23 14:43                                                     ` Dmitry A. Kazakov
2011-11-23 16:10                                                       ` Georg Bauhaus
2011-11-23 19:51                                                         ` Dmitry A. Kazakov
2011-11-24  0:59                                                           ` Georg Bauhaus
2011-11-24  9:14                                                             ` Dmitry A. Kazakov
2011-11-23 15:12                                           ` Simon Wright
2011-11-23 19:53                                             ` Dmitry A. Kazakov
2011-11-24  8:07                                               ` Simon Wright
2011-11-24  9:27                                                 ` Dmitry A. Kazakov
2011-11-24 10:49                                                   ` Georg Bauhaus
2011-11-24 13:14                                                     ` Dmitry A. Kazakov
2011-11-24 14:31                                                       ` Georg Bauhaus
2011-11-24 16:32                                                         ` Dmitry A. Kazakov
2011-11-24 11:15                                                 ` Brian Drummond
2011-11-24 18:12                                                   ` Simon Wright
2011-11-24 23:52                                                     ` Brian Drummond
2011-11-23 10:35                                         ` Brian Drummond
2011-11-23  9:54                                       ` Georg Bauhaus
2011-11-23 10:30                                         ` Dmitry A. Kazakov
2011-11-23  4:08                                 ` Yannick Duchêne (Hibou57)
2011-11-23  4:11                                 ` Yannick Duchêne (Hibou57)
2011-11-22 23:52                               ` Georg Bauhaus
2011-11-23  9:04                                 ` Dmitry A. Kazakov
2011-11-23 11:15                                   ` Georg Bauhaus
2011-11-23 13:30                                     ` Dmitry A. Kazakov
2011-11-23 14:42                                       ` Georg Bauhaus
2011-11-23 19:48                                         ` Dmitry A. Kazakov
2011-11-24  1:36                                           ` Georg Bauhaus
2011-11-24 10:52                                             ` Dmitry A. Kazakov
2011-11-24 11:30                                               ` Georg Bauhaus
2011-11-24 12:52                                                 ` Dmitry A. Kazakov
2011-11-24 14:45                                                   ` Georg Bauhaus
2011-11-25  9:54                                                     ` Dmitry A. Kazakov
2011-11-24  7:46                                           ` stefan-lucks
2011-11-24  3:07                           ` Shark8
2011-11-24  6:07                             ` Yannick Duchêne (Hibou57)
2011-11-24 10:10                             ` Dmitry A. Kazakov
2011-11-24 11:15                               ` Georg Bauhaus
2011-11-24 22:48                               ` Shark8
2011-11-25  9:25                                 ` Yannick Duchêne (Hibou57)
2011-11-26 21:59                                   ` Shark8
2011-11-25  9:47                                 ` Dmitry A. Kazakov
2011-11-25 10:15                                   ` Georg Bauhaus
2011-11-25 10:51                                     ` Yannick Duchêne (Hibou57)
2011-11-25 15:45                                   ` Georg Bauhaus
2011-11-25 16:05                                     ` Yannick Duchêne (Hibou57)
2011-11-25 16:19                                     ` Yannick Duchêne (Hibou57)
2011-11-23  3:49                         ` Yannick Duchêne (Hibou57)
2011-11-23  8:50                           ` Georg Bauhaus
2011-11-23  9:45                             ` Yannick Duchêne (Hibou57)
2011-11-23 10:55                               ` Georg Bauhaus
2011-11-23  3:20             ` Yannick Duchêne (Hibou57)
2011-11-23 15:05               ` Robert A Duff
2011-11-21 17:00 ` Adam Beneschan
2011-11-23  3:13 ` Yannick Duchêne (Hibou57)
2011-11-24  3:47   ` Shark8
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