From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.66.144.138 with SMTP id sm10mr67196741pab.4.1452056448940; Tue, 05 Jan 2016 21:00:48 -0800 (PST) X-Received: by 10.182.49.197 with SMTP id w5mr425027obn.16.1452056448905; Tue, 05 Jan 2016 21:00:48 -0800 (PST) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!usenet.blueworldhosting.com!feeder01.blueworldhosting.com!border2.nntp.dca1.giganews.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!h5no491733igh.0!news-out.google.com!f6ni44854igq.0!nntp.google.com!o2no296287iga.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Tue, 5 Jan 2016 21:00:48 -0800 (PST) In-Reply-To: <084197af-8e37-4250-a083-b45bd9ab4609@googlegroups.com> Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=2601:18f:900:8350:ba86:87ff:fed6:5907; posting-account=3pYsyQoAAACcI-ym7XtMOI2PDU8gRZS5 NNTP-Posting-Host: 2601:18f:900:8350:ba86:87ff:fed6:5907 References: <7dcd49f3-b04f-4ea3-b431-5c27f73b9afe@googlegroups.com> <87poxixqmy.fsf@theworld.com> <112f5e6c-35c1-483a-b8dd-24f5f76dc6ce@googlegroups.com> <084197af-8e37-4250-a083-b45bd9ab4609@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: Subject: Re: Instantiating package problems From: Andrew Shvets Injection-Date: Wed, 06 Jan 2016 05:00:48 +0000 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Xref: news.eternal-september.org comp.lang.ada:29026 Date: 2016-01-05T21:00:48-08:00 List-Id: On Tuesday, January 5, 2016 at 11:52:00 PM UTC-5, Anh Vo wrote: > On Tuesday, January 5, 2016 at 7:31:00 PM UTC-8, Andrew Shvets wrote: > > On Monday, January 4, 2016 at 3:49:32 PM UTC-5, Anh Vo wrote: > > > On Sunday, January 3, 2016 at 4:07:30 PM UTC-8, Andrew Shvets wrote: > > > > Hi Bob, > > > >=20 > > > > Thanks for writing back. This is the entire example: > > > > http://pastebin.com/GEJT3WzL > > > =20 > > > Just recommend to add a precondition to function Division as shown be= low. 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 Ad= dition where Input1 + Input2 <=3D Integer'Last and Input1 + Input2 >=3D Int= eger'Last.=20 > > >=20 > > > function Division( > > > Input1 : in Integer; > > > Input2 : in Integer) > > > return Integer > > > with pre =3D> Input2 /=3D 0; > > >=20 > > > Anh Vo > >=20 > > I'm not sure that that worked. I added it to my ads file and after com= pilation and then re-running the application, this is what I got: > >=20 > > .... > >=20 > > Division: 4 > >=20 > >=20 > > raised CONSTRAINT_ERROR : calculator.adb:33 divide by zero > >=20 > > Shouldn't the division function been prevented from running the actual = division operation beforehand? >=20 > The preconditions and postconditions are controlled by pragma Assertion_P= olicy. Thus, pragma Assertion_Policy(Check) must be added at the top of the= package specification. Absent of this pragma is equivalent to pragma Asser= tion_Policy (Ignore). That means these conditions are ignored. By the way, = ASSERTION_ERROR exception would be raised instead of CONSTRAINT_ERROR. This is how the body looks like now: http://pastebin.com/Mt0E0HAD I'm still getting a constraint error.