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,FREEMAIL_FROM autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,1e3f2eac5c026e3 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-12-16 19:20:04 PST Path: archiver1.google.com!news2.google.com!newsfeed2.dallas1.level3.net!news.level3.com!zeus.visi.com!news-out.visi.com!green.octanews.net!news.octanews.net!cox.net!news-xfer.cox.net!in.100proofnews.com!in.100proofnews.com!pd7cy1no!shaw.ca!news3.optonline.net!newsfeed-east.nntpserver.com!nntpserver.com!border1.nntp.ash.giganews.com!firehose2!nntp4!intern1.nntp.aus1.giganews.com!nntp.giganews.com!nntp.comcast.com!news.comcast.com.POSTED!not-for-mail NNTP-Posting-Date: Tue, 16 Dec 2003 21:20:00 -0600 Date: Tue, 16 Dec 2003 22:19:59 -0500 From: "Robert I. Eachus" User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: SIGada Conference References: <468D78E4EE5C6A4093A4C00F29DF513D04B82B08@VS2.hdi.tvcabo> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Message-ID: NNTP-Posting-Host: 24.34.214.193 X-Trace: sv3-5yVKjYyl+i1J5UijSY5+InnWa4xmh6Fgwhn82XUrKJaByEtLk37WopMoeutua31pVq0Argizre5S/ql!puxkE9REUCcURKoELOjYKAJNd/2fKznfqVqHYvY+TLrPJ+iOmmLUjAZxMDVaag== X-Complaints-To: abuse@comcast.net X-DMCA-Complaints-To: dmca@comcast.net X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.1 Xref: archiver1.google.com comp.lang.ada:3495 Date: 2003-12-16T22:19:59-05:00 List-Id: Stephen Leake wrote: > Since the ARG people are _very_ smart, and _very_ motivated to > conserve implementors time, I suspect you are wrong :). Personally, I > think Java-style interfaces will let me do things I simply cannot do > now. Thanks for the compliment. But I think everyone should be aware that we don't care whether or not a feature is "necessary." What we really agonize about is how to make programming in Ada easier and make it more likely that Ada programs will satisfy all the "ilities." The interfaces proposal allows a style of multiple inheritance that is currently not well supported in Ada. Wonderful. But the reason that it is a slam dunk that it will be in there, even if it does result in adding a new reserved word, is that it makes in much easier in many cases for a programmer to document what he is really trying to do. It is possible to make fancy use of generics and dispatching so that you can have one specification matched by different bodies. But the fact that different members of a class are handled in very different ways is hidden in the structure of the program. Interfaces allow a programmer to say he is doing just that, and doing it intentionally. For example you can have an indexed list type that calls different sort routines, hash table, radix sort, b-tree, etc. depending on the type of the index. With interfaces the "documentation" of this occurs where the interface is implemented for a specific type of index, rather than where the index types are declared. (And you don't need to manufacture a tagged parent type to make it work.) -- Robert I. Eachus "The war on terror is a different kind of war, waged capture by capture, cell by cell, and victory by victory. Our security is assured by our perseverance and by our sure belief in the success of liberty." -- George W. Bush