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: 103376,58bffef5eda29ec X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-03-18 18:21:20 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!nntp.cs.ubc.ca!cyclone.bc.net!sjc70.webusenet.com!news.webusenet.com!newsfeed2.earthlink.net!newsfeed.earthlink.net!stamper.news.pas.earthlink.net!newsread2.prod.itd.earthlink.net.POSTED!not-for-mail Message-ID: <3E77D44B.7080304@acm.org> From: Jeffrey Carter User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.0.0) Gecko/20020530 X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Clueless :) References: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 19 Mar 2003 02:21:22 GMT NNTP-Posting-Host: 63.184.9.88 X-Complaints-To: abuse@earthlink.net X-Trace: newsread2.prod.itd.earthlink.net 1048040482 63.184.9.88 (Tue, 18 Mar 2003 18:21:22 PST) NNTP-Posting-Date: Tue, 18 Mar 2003 18:21:22 PST Organization: EarthLink Inc. -- http://www.EarthLink.net Xref: archiver1.google.com comp.lang.ada:35491 Date: 2003-03-19T02:21:22+00:00 List-Id: Karel Miklav wrote: > And one more question about the concept supported by keywords bounded, > unbounded, dynamic, fixed-length etc. Like first I must admit I don't > get it; why is there a need for this in Ada, when in tens of other > languages I've seen there is not? And why there are bounded, unbounded > and dynamic versions of Booch components but no polymorphic? Are people > really making collections of 30 (the number is not important but the > last time I made a fixed structure it was on C64 long time ago) elements > like Simon Wright in his Case study? Lots of Ada programs are in safety critical embedded real-time systems, like flying commercial airliners, controlling passenger trains, and the like. It's often unacceptable in such systems to use dynamic allocation ("unbounded" structures) so bounded structures are used, with a maximum size based on worse case analysis. So, yes, there really are people creating fixed maximum size structures even today. Other languages may have more limited application areas, or may be used by less knowledgeable people, and so may only provide unbounded structures. -- Jeff Carter "Don't knock masturbation. It's sex with someone I love." Annie Hall