From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: function Is_Open (File : File_Type) return Boolean; :Text_io
Date: Tue, 27 Oct 2015 21:04:19 +0100
Date: 2015-10-27T21:04:19+01:00 [thread overview]
Message-ID: <1dzlgoh4u2j7t$.1un3dfy0oeigd$.dlg@40tude.net> (raw)
In-Reply-To: n0o9fb$3pq$2@dont-email.me
On Tue, 27 Oct 2015 17:43:36 +0100, G.B. wrote:
> On 27.10.15 16:26, Dmitry A. Kazakov wrote:
>> How do you know if some callers would not appreciate Status_Error as
>> a possible outcome?
>
> Actually, this situation is what contracts are made for,
> I think:
> as a caller, you say what you want the procedure to do,
> or else you don't sign this contract. I.e., a redesign
> via ECR is in order before you sign.
Sure, except that you don't subscribe the contract you cannot fulfill.
The point can be summarized this way. If an exception is a part of the
contract then Status_Error is much better than Constraint_Error and is
already there. If the contract is not to raise, then, firstly, there is no
way to enforce it, and, secondly, if there were a way, proving no
Status_Error would be no harder than no Constraint_Error. Ergo, no use.
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2015-10-27 20:04 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-26 10:00 function Is_Open (File : File_Type) return Boolean; :Text_io comicfanzine
2015-10-26 11:27 ` Simon Wright
2015-10-26 13:25 ` comicfanzine
2015-10-26 18:01 ` Simon Wright
2015-10-26 19:03 ` AdaMagica
2015-10-27 11:30 ` Simon Wright
2015-10-26 18:02 ` Jeffrey R. Carter
2015-10-26 13:28 ` comicfanzine
2015-10-26 15:07 ` Jacob Sparre Andersen
2015-10-26 16:37 ` AdaMagica
2015-10-26 20:46 ` J-P. Rosen
2015-10-27 8:42 ` comicfanzine
2015-10-27 11:34 ` Simon Wright
2015-10-28 13:32 ` comicfanzine
2015-10-27 8:51 ` comicfanzine
2015-10-27 17:15 ` Jeffrey R. Carter
2015-10-26 22:48 ` Bob Duff
2015-10-27 8:30 ` Dmitry A. Kazakov
2015-10-27 13:30 ` Bob Duff
2015-10-27 14:00 ` G.B.
2015-10-27 15:26 ` Dmitry A. Kazakov
2015-10-27 16:43 ` G.B.
2015-10-27 20:04 ` Dmitry A. Kazakov [this message]
2015-10-28 11:06 ` Georg Bauhaus
2015-10-28 17:58 ` Randy Brukardt
2015-10-28 18:20 ` Dmitry A. Kazakov
2015-10-28 20:36 ` Bob Duff
2015-10-28 21:02 ` Dmitry A. Kazakov
2015-10-29 11:25 ` AdaMagica
2015-10-29 13:37 ` Dmitry A. Kazakov
2015-10-29 17:57 ` AdaMagica
2015-10-29 18:12 ` AdaMagica
2015-10-29 18:26 ` Dmitry A. Kazakov
2015-10-30 8:27 ` Jacob Sparre Andersen
2015-10-30 9:11 ` J-P. Rosen
2015-10-29 11:47 ` G.B.
2015-10-29 13:01 ` J-P. Rosen
2015-10-29 14:00 ` Dmitry A. Kazakov
2015-10-30 1:06 ` Georg Bauhaus
2015-10-30 8:39 ` Dmitry A. Kazakov
2015-10-30 14:32 ` G.B.
2015-10-30 16:20 ` Dmitry A. Kazakov
2015-10-30 19:07 ` G.B.
2015-10-31 9:31 ` Dmitry A. Kazakov
2015-10-31 11:17 ` Georg Bauhaus
2015-10-30 14:40 ` G.B.
2015-10-30 16:26 ` Dmitry A. Kazakov
2015-10-28 20:07 ` Bob Duff
2015-10-28 20:59 ` Dmitry A. Kazakov
2015-10-27 14:02 ` G.B.
2015-10-27 15:10 ` Dmitry A. Kazakov
2015-10-27 16:41 ` G.B.
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