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=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,1116ece181be1aea X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-09-11 14:05:21 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!wn14feed!worldnet.att.net!204.127.198.203!attbi_feed3!attbi.com!sccrnsc04.POSTED!not-for-mail Message-ID: <3F60E380.4020307@attbi.com> From: "Robert I. Eachus" User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.0.2) Gecko/20021120 Netscape/7.01 X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Is the Writing on the Wall for Ada? References: <3F5F7FDC.30500@attbi.com> <3F6079A9.6080108@attbi.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit NNTP-Posting-Host: 24.34.139.183 X-Complaints-To: abuse@comcast.net X-Trace: sccrnsc04 1063314314 24.34.139.183 (Thu, 11 Sep 2003 21:05:14 GMT) NNTP-Posting-Date: Thu, 11 Sep 2003 21:05:14 GMT Organization: Comcast Online Date: Thu, 11 Sep 2003 21:05:14 GMT Xref: archiver1.google.com comp.lang.ada:42388 Date: 2003-09-11T21:05:14+00:00 List-Id: Stephen Leake wrote: >>But the case I gave is one where multiple inheritance is appropriate. >>It just has to be interface inheritance. In other words I can take an >>interface that assumes polar representation and an interface that >>assumes cartesian representation, and provide a type/class that >>supports both interfaces. > > > I think to make this argument truly convincing, you need to show how > it currently works in C++, and why that is bad. Showing that Ada is ok > the way it is will not convince anyone who is sure it could be better > if it was more like C++. No, someone arguing the other side needs to demonstrate what can be done in language X that can't be done as well or better in Ada (with or without interfaces added). The examples you say are needed have all been thoroughly discussed by the ARG. (And are available on the web see: http://www.ada-auth.org/cgi-bin/cvsweb.cgi/AIs/AI-00251.TXT) We are adding interfaces to Ada because it allows a different style of multiple inheritance than mix-ins, which of course are currently well supported and used in Ada. I have no problem with adding interfaces, since they are a better match to some styles and will be useful for interfacing with other languages that have interfaces. But this self-flagellation by the Ada community is just not appropriate in this case. Other languages support MI through interfaces, fine. The exact same code will work in Ada with interfaces added. Or you can change the idiom and mix interfaces and mix-ins. But type inheritance cannot be from two concrete parents, no matter what the language--one parent has to be abstract. So anyone who condemns Ada for not adding what cannot be done needs to get a life. -- Robert I. Eachus "As far as I'm concerned, war always means failure." -- Jacques Chirac, President of France "As far as France is concerned, you're right." -- Rush Limbaugh