From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Instantiating package problems
Date: Mon, 4 Jan 2016 22:10:54 +0100
Date: 2016-01-04T22:10:54+01:00 [thread overview]
Message-ID: <n6en12$5jn$2@gioia.aioe.org> (raw)
In-Reply-To: f2fabc7b-a6a4-49db-85ac-d0fedf6cf95e@googlegroups.com
On 2016-01-04 21:49, Anh Vo wrote:
> On Sunday, January 3, 2016 at 4:07:30 PM UTC-8, Andrew Shvets wrote:
>> Hi Bob,
>>
>> Thanks for writing back. This is the entire example:
>> http://pastebin.com/GEJT3WzL
>
> Just recommend to add a precondition to function Division as shown below.
> By the way, this feature is part of latest Ada (Ada 2012). In addition,
> you should think about adding precondition to other operations such as
> Addition where Input1 + Input2 <= Integer'Last and Input1 + Input2 >=
Integer'Last.
>
> function Division(
> Input1 : in Integer;
> Input2 : in Integer)
> return Integer
> with pre => Input2 /= 0;
The correct precondition of integer division is
Input1/Input2 in Integer'Range
Note that it precludes zero divide, provided Ada 2012 can understand it,
according to 3.5.4 (8) it must, but I am not a language lawer.
For a 2's complement machine the offending case is
Input1 = Integer'First
Input2 = -1
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2016-01-04 21:10 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-03 18:40 Instantiating package problems Andrew Shvets
2016-01-03 20:27 ` Georg Bauhaus
2016-01-03 21:21 ` Andrew Shvets
2016-01-03 21:04 ` Jeffrey R. Carter
2016-01-03 21:27 ` Andrew Shvets
2016-01-03 22:39 ` Jeffrey R. Carter
2016-01-03 22:08 ` Bob Duff
2016-01-04 0:07 ` Andrew Shvets
2016-01-04 0:30 ` Andrew Shvets
2016-01-04 13:43 ` G.B.
2016-01-04 14:23 ` Brian Drummond
2016-01-04 20:49 ` Anh Vo
2016-01-04 21:10 ` Dmitry A. Kazakov [this message]
2016-01-04 22:39 ` Anh Vo
2016-01-05 1:42 ` Anh Vo
2016-01-05 7:35 ` Dmitry A. Kazakov
2016-01-06 2:46 ` Andrew Shvets
2016-01-06 8:53 ` Dmitry A. Kazakov
2016-01-06 3:30 ` Andrew Shvets
2016-01-06 4:51 ` Anh Vo
2016-01-06 4:54 ` Anh Vo
2016-01-06 5:00 ` Andrew Shvets
2016-01-06 5:07 ` Anh Vo
2016-01-07 4:41 ` Andrew Shvets
2016-01-07 5:41 ` Anh Vo
2016-01-09 20:14 ` Andrew Shvets
2016-01-10 19:43 ` Andrew Shvets
2016-01-10 21:38 ` Jeffrey R. Carter
2016-01-10 21:50 ` Georg Bauhaus
2016-01-10 21:58 ` Andrew Shvets
2016-01-06 13:07 ` G.B.
2016-01-07 4:42 ` Andrew Shvets
2016-01-06 14:25 ` Bob Duff
2016-01-06 23:48 ` Anh Vo
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