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: 103376,1592759aa83d0d45 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-05-29 10:45:02 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!hammer.uoregon.edu!skates!not-for-mail From: Stephen Leake Newsgroups: comp.lang.ada Subject: Re: MI in Ada 200X Date: 29 May 2003 13:38:28 -0400 Organization: NASA Goddard Space Flight Center (skates.gsfc.nasa.gov) Message-ID: References: <0Pxza.699607$OV.652508@rwcrnsc54> <4a4de33a.0305280557.5d5aba37@posting.google.com> NNTP-Posting-Host: anarres.gsfc.nasa.gov Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: skates.gsfc.nasa.gov 1054230870 21953 128.183.235.92 (29 May 2003 17:54:30 GMT) X-Complaints-To: usenet@news.gsfc.nasa.gov NNTP-Posting-Date: 29 May 2003 17:54:30 GMT User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 Xref: archiver1.google.com comp.lang.ada:38008 Date: 2003-05-29T17:54:30+00:00 List-Id: Hyman Rosen writes: > Here's a particular example which is ever annoying in Java. A > common design pattern in Java is to have an interface, and then > make a companion class which implements the interface and provides > do-nothing implementations for all the methods. If you want a class > which implements both interfaces and does nothing for most of the > methods, you can't inherit from both companion classes. Instead, > you must reimplement at least one set of the dunsel methods. Interestingly, the Ada interface type proposal AI solves this particular problem, by allowing interface types to have explicitly null procedures: type T is interface; procedure Foo (Item : in T) is null; :). -- -- Stephe