From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Preconditions which anyway would be caught?
Date: Mon, 11 Aug 2014 09:31:07 +0200
Date: 2014-08-11T09:31:07+02:00 [thread overview]
Message-ID: <1b5ytxppxisxu$.nom2sfczulhi$.dlg@40tude.net> (raw)
In-Reply-To: HITFv.512020$Ro3.111072@fx13.iad
On Sun, 10 Aug 2014 18:00:36 -0600, Shark8 wrote:
> On 10-Aug-14 01:24, Dmitry A. Kazakov wrote:
>> Specifying precondition for the sake of having them is meaningless.
>
> Not all preconditions imply a post-condition; sometimes it's simply to
> constrain the values that you're willing to entertain;
All.
> for example if
> you have Natural_Float being a subtype of float (range 0.0 ..
> Float'Last) you could use this in an internal simple simulator with
> Square_Root(X: Natural_Float) return Float being a function therein.
The precondition of Square_Root en-force is True, thus calling Square_Root
(-1.0) is not an error.
Constraints are "dynamic preconditions" in Ada 2012 Newspeak.
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
prev parent reply other threads:[~2014-08-11 7:31 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-09 15:35 Preconditions which anyway would be caught? Victor Porton
2014-08-09 15:40 ` mockturtle
2014-08-09 16:08 ` Jeffrey Carter
2014-08-09 19:21 ` Peter Chapin
2014-08-09 19:24 ` Peter Chapin
2014-08-09 21:04 ` Niklas Holsti
2014-08-09 22:57 ` Peter Chapin
2014-08-10 20:58 ` Niklas Holsti
2014-08-10 7:24 ` Dmitry A. Kazakov
2014-08-11 0:00 ` Shark8
2014-08-11 7:31 ` Dmitry A. Kazakov [this message]
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