From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Example Ada calling Gnu Scientific Library (GSL)
Date: Fri, 31 Mar 2017 20:50:00 +0200
Date: 2017-03-31T20:50:00+02:00 [thread overview]
Message-ID: <obm8co$1hnd$1@gioia.aioe.org> (raw)
In-Reply-To: obm740$4il$1@dont-email.me
On 2017-03-31 20:31, G.B. wrote:
> On 30.03.17 16:22, Dmitry A. Kazakov wrote:
>> Preconditions may help, do we have formal generic pre-/post-conditions?
>
> As a hint to a user of generic package, it seems
> possible to announce aspects of FP Types required:
>
> generic
> type Fractional is digits <>;
> package R is
> type T is new Fractional
> with
> Dynamic_Predicate => (Fractional'Digits >= 8
> and T in -4.0 .. +4.0);
> function Algo (X : T) return T;
> end R;
This is of course different from specifying it in the formal part. The
only reason for generics ever exist is static substitution and static
checks. With dynamic checks in place a class-based model is as efficient
as generic expansion.
BTW, there are two kinds of constraints:
1. That certain values are included
2. That certain values are excluded
with uncounted variations of, e.g. that the range includes zero and is
symmetric around zero etc.
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2017-03-31 18:50 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-29 1:29 Example Ada calling Gnu Scientific Library (GSL) Leo Brewin
2017-03-29 7:01 ` gautier_niouzes
2017-03-29 7:23 ` Dmitry A. Kazakov
2017-03-30 12:39 ` gautier_niouzes
2017-03-30 14:22 ` Dmitry A. Kazakov
2017-03-30 20:44 ` Randy Brukardt
2017-03-31 18:31 ` G.B.
2017-03-31 18:50 ` Dmitry A. Kazakov [this message]
2017-03-29 7:19 ` hreba
2017-03-29 20:07 ` Randy Brukardt
2017-04-04 21:25 ` hreba
2017-04-05 16:29 ` Simon Wright
2017-04-05 20:21 ` hreba
2017-04-06 7:30 ` Simon Wright
2017-04-07 18:45 ` hreba
2017-04-08 8:28 ` Simon Wright
2017-04-09 10:57 ` hreba
2017-04-09 15:17 ` Simon Wright
2017-04-10 8:53 ` hreba
2017-04-10 9:47 ` Dmitry A. Kazakov
2017-04-10 15:39 ` hreba
2017-04-10 17:16 ` Dmitry A. Kazakov
2017-04-10 17:43 ` Simon Wright
2017-04-10 15:44 ` Simon Wright
2017-04-11 17:31 ` hreba
2017-04-11 18:45 ` Simon Wright
2017-04-11 19:46 ` Dmitry A. Kazakov
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