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 autolearn=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!news.eternal-september.org!feeder.eternal-september.org!nntp-feed.chiark.greenend.org.uk!ewrotcd!reality.xs3.de!news.jacob-sparre.dk!franka.jacob-sparre.dk!pnx.dk!.POSTED!not-for-mail From: "Randy Brukardt" Newsgroups: comp.lang.ada Subject: Re: Ada 2012 Constraints (WRT an Ada IR) Date: Fri, 16 Dec 2016 13:46:38 -0600 Organization: JSA Research & Innovation Message-ID: References: NNTP-Posting-Host: rrsoftware.com X-Trace: franka.jacob-sparre.dk 1481917599 19875 24.196.82.226 (16 Dec 2016 19:46:39 GMT) X-Complaints-To: news@jacob-sparre.dk NNTP-Posting-Date: Fri, 16 Dec 2016 19:46:39 +0000 (UTC) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 X-RFC2646: Format=Flowed; Response Xref: news.eternal-september.org comp.lang.ada:32885 Date: 2016-12-16T13:46:38-06:00 List-Id: "Dmitry A. Kazakov" wrote in message news:o309ac$1f4q$2@gioia.aioe.org... > On 15/12/2016 23:24, Randy Brukardt wrote: >> "Dmitry A. Kazakov" wrote in message >> news:o2tlcd$1aro$2@gioia.aioe.org... >>> On 14/12/2016 23:40, Randy Brukardt wrote: >>>> [Yet again had to break the thread because the thread has gotten too >>>> long >>>> to >>>> reply to - RLB] >>>> >>>> "Dmitry A. Kazakov" wrote in message >>>> news:o2s8l1$1fef$1@gioia.aioe.org... >>>>> On 2016-12-14 20:23, Shark8 wrote: >>>> ... >>>>>> You are observably wrong. >>>>>> If you supply a negative number, the body of X never executes. >>>>> >>>>> Of course it does. Semantically any effect of a call to X is due to >>>>> X's >>>>> body. There is nothing else there. >>>> >>>> This is clearly false. The definition of the execution of a subprogram >>>> call >>>> (RM 6.4(10/2)) specifically says that the parameter associations are >>>> evaluated before the subprogram body is executed. 6.4.1 says that >>>> evaluation >>>> of the parameter associations include the conversion to the formal >>>> subtype - >>>> that conversion does the check that raises Constraint_Error. >>> >>> And semantically all this is a part of the body. >> >> I just quoted the rules in the RM that say specifically that it is not >> part >> of the body. > > What the problem? There is time to fix the RM wording. Call it "user > specified body" as opposed to the "body in effect". What possible good would it do? If such a change subtly changed the effect of Ada programs, that would be very bad, and if it didn't, it would just be churn for no reason. (The rule of thumb being that a change that doesn't change the behavior of any user or implementer is an unnecessary change.) The semantics of Ada are what the RM defines them to be, not what you or I or anyone else wishes they were. That's the whole point of having the semantics of the language defined by a Standard. Randy.