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,f039470e8f537101 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-07-29 18:22:38 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!arclight.uoregon.edu!enews.sgi.com!news.xtra.co.nz!53ab2750!not-for-mail Newsgroups: comp.lang.ada Subject: Re: Non-philosophical definition of Eiffel? From: Berend de Boer Message-ID: User-Agent: Gnus/5.090014 (Oort Gnus v0.14) Emacs/21.2 (i386-msvc-nt5.0.2195) References: <1058968422.225561@master.nyc.kbcfp.com> <3F200AD0.94F79098@adaworks.com> <7u9Ua.13412$634.10307@nwrdny03.gnilink.net> <3F215120.1040706@attbi.com> <1059151910.357790@master.nyc.kbcfp.com> <1059416297.548253@master.nyc.kbcfp.com> <1059510832.459614@master.nyc.kbcfp.com> Cancel-Lock: sha1:QzUmaC9mjSjkeFc4+bPH1bD22so= MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 30 Jul 2003 13:20:51 +1200 NNTP-Posting-Host: 219.88.64.124 X-Complaints-To: newsadmin@xtra.co.nz X-Trace: news.xtra.co.nz 1059528158 219.88.64.124 (Wed, 30 Jul 2003 13:22:38 NZST) NNTP-Posting-Date: Wed, 30 Jul 2003 13:22:38 NZST Organization: Xtra Xref: archiver1.google.com comp.lang.ada:40977 Date: 2003-07-30T13:20:51+12:00 List-Id: >>>>> "Hyman" == Hyman Rosen writes: Hyman> Berend de Boer wrote: >> 1. No one needs to use the facility if you don't want it. Hyman> Unfortunately, I believe this facility is heavily Hyman> intertwined with generics and container classes in Hyman> Eiffel. I think they adopted the notion that if D is a Hyman> subclass of B, then container-of-D should be a subclass of Hyman> container-of-B. Yes and no: 1. The situation only occurs if you have a routine that actually has the generic type as argument. 2. There are no "container classes in Eiffel". It's not part of the language. There are several popular ones though. 3. And let me tell you that a container-of-D is a subclass of container-of-B is very useful in practice. Other languages might say they don't this "type-hole", but if you look at the code they're riddled with typecasts to workaround it. So essentially, it's a nonsen argument if you look at actual code. I prefer a language that has a known hole above a language where I must use type casts all over the place, any day every day. -- Regards, Berend. (-: