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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fdb77,953e1a6689d791f6 X-Google-Attributes: gidfdb77,public X-Google-Thread: f79bb,953e1a6689d791f6 X-Google-Attributes: gidf79bb,public X-Google-Thread: fac41,953e1a6689d791f6 X-Google-Attributes: gidfac41,public X-Google-Thread: 103376,953e1a6689d791f6 X-Google-Attributes: gid103376,public From: "Marcos F. F. de Macedo" Subject: Re: Eiffel and Java Date: 1996/11/10 Message-ID: <328592FC.64F26D66@sede.unijui.tche.br>#1/1 X-Deja-AN: 195822850 references: <550sm2$sn1@buggy.news.easynet.net> <55562c$nkd@mulga.cs.mu.OZ.AU> content-type: text/plain; charset=us-ascii organization: NAVOCEANO mime-version: 1.0 newsgroups: comp.lang.eiffel,comp.lang.ada,comp.lang.sather,comp.lang.java.advocacy x-mailer: Mozilla 3.0 (X11; I; Linux 1.2.13 i586) Date: 1996-11-10T00:00:00+00:00 List-Id: Fergus Henderson wrote: > > donh@syd.csa.com.au (Don Harrison) writes: > > >What is the purpose of separating interface and implementation inheritance? > > Suppose I have two existing library classes (perhaps supplied by different > vendors) which have some commonality, but don't inherit from a common > base class. In Sather, one can simply create a new interface and > declare these classes to be instances of this interface, without > modifying the existing code. > > (Is that possible in Java?) This kind of interface/implementation in Sather is diferent of the usual concept. This is subtype/subclass independence. That is a good thing in Sather that I have not yet thinked of the exact consequences. Interfaces in Java have nothing to do with this concepts. Interface in Java is an implementation restriction (not a conceptual one) to avoid multiple-inheritance and work yet work with static typing. Interface is java is just a deferred class with just deferred routines. Nothing more, nothing less. Marcos F. F. de Macedo marcosm@sede.unijui.tche.br UNIJUI - BRAZIL