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=-0.9 required=5.0 tests=BAYES_00,FORGED_GMAIL_RCVD, FREEMAIL_FROM autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: 103376,29d8139471e3f53e X-Google-NewGroupId: yes X-Google-Attributes: gida07f3367d7,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!postnews.google.com!t3g2000vbb.googlegroups.com!not-for-mail From: Maciej Sobczak Newsgroups: comp.lang.ada Subject: Re: Preventing type extensions Date: Sun, 12 Sep 2010 14:23:19 -0700 (PDT) Organization: http://groups.google.com Message-ID: <66a3704c-54f9-4f04-8860-aa12f516134b@t3g2000vbb.googlegroups.com> References: <87iq2bfenl.fsf@mid.deneb.enyo.de> <874odv9npv.fsf@ludovic-brenta.org> <87y6b7cedd.fsf@mid.deneb.enyo.de> NNTP-Posting-Host: 85.2.43.5 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 X-Trace: posting.google.com 1284326599 31966 127.0.0.1 (12 Sep 2010 21:23:19 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Sun, 12 Sep 2010 21:23:19 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: t3g2000vbb.googlegroups.com; posting-host=85.2.43.5; posting-account=bMuEOQoAAACUUr_ghL3RBIi5neBZ5w_S User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2.7) Gecko/20100713 Firefox/3.6.7,gzip(gfe) Xref: g2news1.google.com comp.lang.ada:14029 Date: 2010-09-12T14:23:19-07:00 List-Id: On 12 Wrz, 14:53, Florian Weimer wrote: > > Why do you want to make the type publicly tagged if not to allow type > > extension? > > I want to use some features which come with tagged types, like the OO > call notation Which shows that combining the "OO notation" with tagged types was a bad idea at the language design level. > or the fact that the type implements an interface. If it implements an abstract interface, then why extending it further is a problem? From the user point of view (that is, from the point of view of the subprogram that accepts Some_Interface'Class and operates on it), it does not matter how deep is the hierarchy. -- Maciej Sobczak * http://www.inspirel.com YAMI4 - Messaging Solution for Distributed Systems http://www.inspirel.com/yami4