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-Thread: 103376,f2690a5e963b61b6 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news4.google.com!newshub.sdsu.edu!elnk-nf2-pas!newsfeed.earthlink.net!stamper.news.pas.earthlink.net!stamper.news.atl.earthlink.net!newsread3.news.atl.earthlink.net.POSTED!14bb18d8!not-for-mail Sender: mheaney@MHEANEYX200 Newsgroups: comp.lang.ada Subject: Re: GCC 4.0 Ada.Containers Cursor danger. References: <1120474891.635131.216700@g44g2000cwa.googlegroups.com> <42cb8d21$0$22761$9b4e6d93@newsread2.arcor-online.net> <42cd064c$0$10817$9b4e6d93@newsread4.arcor-online.net> <42cda8c4$0$22780$9b4e6d93@newsread2.arcor-online.net> <1u3hh2597i4ne$.1ryetugksbmus.dlg@40tude.net> <1120834341.499757.133770@g43g2000cwa.googlegroups.com> <1121093867.964444.232420@g14g2000cwa.googlegroups.com> <42d2bc2d$0$20148$9b4e6d93@newsread2.arcor-online.net> <1121134291.379399.79460@z14g2000cwz.googlegroups.com> <42d46b51$0$18005$9b4e6d93@newsread4.arcor-online.net> <42d6ef47$0$7644$9b4e6d93@newsread2.arcor-online.net> <1eg30i81gqy2a$.ljhncmxt8d7w.dlg@40tude.net> From: Matthew Heaney Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 15 Jul 2005 12:10:39 GMT NNTP-Posting-Host: 24.149.57.125 X-Complaints-To: abuse@earthlink.net X-Trace: newsread3.news.atl.earthlink.net 1121429439 24.149.57.125 (Fri, 15 Jul 2005 05:10:39 PDT) NNTP-Posting-Date: Fri, 15 Jul 2005 05:10:39 PDT Organization: EarthLink Inc. -- http://www.EarthLink.net Xref: g2news1.google.com comp.lang.ada:3633 Date: 2005-07-15T12:10:39+00:00 List-Id: "Dmitry A. Kazakov" writes: > Think about differences between: > > - An unordered set of unordered elements Does not exist in the Ada 2005 standard container library. > - An unordered set of ordered elements Does not exist in the Ada 2005 standard container library. > - An ordered set of unordered elements The Ada 2005 standard container library calls that a "hashed set." > - An ordered set of ordered elements (and these orders are different) The Ada 2005 standard container library calls that an "ordered set." > Hmm, what about ring buffers? Does not exist in the Ada 2005 standard container library. > And for proofs it is essential that the premises were correct. Programming > is not much different... Yes, that's called a "reference manual." > > I find Cursors useful when I want to put an index set into > > operations inside a computer. When I'm can use any container, how > > could I implement index sets without Cursors? > > You are mixing implementation and interface. Of course a container must "mix implementation and interface," since it has to provide access to its elements. The essential container design problem is doing that without exposing representation details. Cursors are that mechanism. There's nothing bad about this; it's simply the nature of a container abstraction. The container should get out of the way as much as possible, since it's the elements we care about. > [and again, sets could be searchable and not] The sets in the Ada 2005 standard container library are searchable.