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=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: grassroots thoughts on access types Date: Sat, 10 Feb 2018 09:28:28 +0100 Organization: Aioe.org NNTP Server Message-ID: References: <5d9134c9-a7d4-468e-8685-ebbb393eabea@googlegroups.com> NNTP-Posting-Host: 9s2HXjYgtb87Rt4JbNw44Q.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 Content-Language: en-US X-Notice: Filtered by postfilter v. 0.8.3 Xref: reader02.eternal-september.org comp.lang.ada:50358 Date: 2018-02-10T09:28:28+01:00 List-Id: On 2018-02-10 01:43, Mehdi Saada wrote: > For iteration, do you prefer the lighter alternative of GNAT's Iterable aspect ? Iteration is a construct/operation of an interface (ordered set). All you need is ordered set interface implemented by the corresponding type. (Aspects are no less hacks than anonymous access type is) > type List is private with > Iterable => (First => First_Cursor, > Next => Advance, > Has_Element => Cursor_Has_Element, > [Element => Get_Element]); > > Though I haven't used it yet (but will as soon as I have to write an ADT), if I read well, "Cursor" can be anything, There should be no cursors, at least none when dealing with sets. Cursors (= pointers) should be used only for low-level linked data structures, when ordered set interface implementation is too expensive. For example in the case of linked list or graph. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de