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=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no 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!mx05.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: Is this expected behavior or not Date: Sat, 6 Apr 2013 09:39:12 +0200 Organization: cbb software GmbH Message-ID: <1e5t211h9n19a.ayvvr4wdm89y$.dlg@40tude.net> References: <1gnmajx2fdjju.1bo28xwmzt1nr.dlg@40tude.net> <3gv2jwc95otm.pl2aahsh9ox8.dlg@40tude.net> <1gkxiwepaxvtt$.u3ly33rbwthf.dlg@40tude.net> <1fmcdkj58brky.bjedt0pr39cd$.dlg@40tude.net> <1bj564vat3q1j$.1s4d00rlzx4ux$.dlg@40tude.net> <1cfhriq4xpg9s$.3yl33z705wpn$.dlg@40tude.net> <16wai67izvmu5.13yz864sx1cqd$.dlg@40tude.net> <1xbow8ojtmac9.1sfor8ytiplgx.dlg@40tude.net> Reply-To: mailbox@dmitry-kazakov.de NNTP-Posting-Host: rHWOzyHApalsT5sEUcbvVQ.user.speranza.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: 40tude_Dialog/2.0.15.1 X-Notice: Filtered by postfilter v. 0.8.2 Xref: news.eternal-september.org comp.lang.ada:14891 Date: 2013-04-06T09:39:12+02:00 List-Id: On Fri, 5 Apr 2013 22:23:13 +0200, Stefan.Lucks@uni-weimar.de wrote: > On Fri, 5 Apr 2013, Dmitry A. Kazakov wrote: > >> On Fri, 5 Apr 2013 21:02:43 +0200, Stefan.Lucks@uni-weimar.de wrote: > >> No, I insist that it is up to the programmer to decide whether two types to >> become compatible (relative) or not. Character and Wide_Character are >> evidently relative. > > Integer and Float are "evidently relative". No, as I said it is in the application domain. If your domain were mathematical analysis then, yes, integer and float would be related. When the domain is engineering they are clearly not, because in that domain as well as in most other domains, number is used not as number, but as an object modeling something else. >> I disagree. They wanted to prevent the mess of PL/1 where *arbitrary* >> conversions were applied to semantically unrelated types. Types like >> Character and Wide_Character are semantically related. Conversion from one >> to another is perfectly well defined. > > The same for conversions between Integer and Float. Nope. You cannot convert house number to outdoor temperature. >> And it is all up to the programmer to tell the compiler that S must be >> considered a subtype of T, whatever representation both might have is not >> language's business. > > Arithmetic types and String types are in the same boat here. String types are not models when we consider major use cases for String/Wide_String/Wide_Wide_String. They are entities from one domain meaning same entities [domain: Unicode]. Certainly there are cases when strings can be used to model something else. But it is highly unlikely that they would distinguish String and Wide_String either. Numbers are clearly different, e.g. counting apples and oranges [domain: grocery] -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de