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: 103376,2510538eb4348710 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-09-04 02:21:38 PST Path: archiver1.google.com!newsfeed.google.com!newsfeed.stanford.edu!newsfeeds.belnet.be!news.belnet.be!uni-erlangen.de!news-nue1.dfn.de!newsfeed.r-kom.de!newsfeed.stueberl.de!newsfeed.vmunix.org!newsfeed2.easynews.net!easynews.net!news.cid.net!news.enyo.de!news1.enyo.de!not-for-mail From: Florian Weimer Newsgroups: comp.lang.ada Subject: Re: A generic list package Date: Tue, 04 Sep 2001 11:40:29 +0200 Organization: Enyo's not your organization Message-ID: <87vgizl2eq.fsf@deneb.enyo.de> References: <87ae0dp7gn.fsf@deneb.enyo.de> <3B93BB3F.11AB1B0B@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Xref: archiver1.google.com comp.lang.ada:12675 Date: 2001-09-04T11:40:29+02:00 List-Id: Jeffrey Carter writes: >> > I find it curious that you expect the client to provide the "next" >> > field/operation, rather than declaring a Node_Type containing the >> > user's type and a Next field. Can you elaborate on this? > > I would say that this approach does not qualify as an ADT. The client > must understand the internal representation to be used in the list and > declare a set of types and operations appropriately. That does not seem > "abstract". All the data types you can express in Ada cannot qualify as abstract data types. ;-) Ada can only provide implementations of abstract data types, and in the implementation process, some abstraction is always lost. However, I agree that the Next_Of/Set_Next interface as at a very low abstraction level, and it does not represent an implementation of the usual 'list' ADT (but of another ADT).