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=-0.4 required=5.0 tests=AC_FROM_MANY_DOTS,BAYES_00 autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,7ee10ec601726fbf X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-10-30 12:45:27 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news.tele.dk!small.news.tele.dk!212.43.194.69!fr.clara.net!heighliner.fr.clara.net!157.161.139.35.MISMATCH!4554679!news.imp.ch!psinet-eu-nl!psiuk-p4!psiuk-p3!uknet!psiuk-n!news.pace.co.uk!nh.pace.co.uk!not-for-mail From: "Marin David Condic" Newsgroups: comp.lang.ada Subject: Re: why not Date: Tue, 30 Oct 2001 14:25:04 -0500 Organization: Posted on a server owned by Pace Micro Technology plc Message-ID: <9rmuqi$es$1@nh.pace.co.uk> References: <3BC5D730.DA950CC7@boeing.com> <9q4pa7$1ad$1@nh.pace.co.uk> <3BC6ACC8.23EF21BC@free.fr> <3BC71F54.1FFE78FA@boeing.com> <1KGx7.26476$ev2.35117@www.newsranger.com> <3BC7AD82.2A0CCCD4@acm.org> <9qhiqr$af0$1@nh.pace.co.uk> <1nDC7.180$6S7.92255364@newssvr11.news.prodigy.com> <9rjsak$bp3$1@nh.pace.co.uk> <9rmhb9$o1b$1@nh.pace.co.uk> <3BDEF0FE.B55FED9E@san.rr.com> NNTP-Posting-Host: dhcp-200-133.miami.pace.co.uk X-Trace: nh.pace.co.uk 1004469906 476 136.170.200.133 (30 Oct 2001 19:25:06 GMT) X-Complaints-To: newsmaster@news.cam.pace.co.uk NNTP-Posting-Date: 30 Oct 2001 19:25:06 GMT X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 Xref: archiver1.google.com comp.lang.ada:15436 Date: 2001-10-30T19:25:06+00:00 List-Id: "Darren New" wrote in message news:3BDEF0FE.B55FED9E@san.rr.com... > Marin David Condic wrote: > > Part of the problem is > > specifying the behavior in sufficient detail to make it verifiable. > > That's what ADTs are supposed to be for. (Not ADT's in the computer > programming sense. ADTs in the "Abstract Data Type" sense, the > mathematical sense.) > > It's not hard. It's just that most programmers think ADTs have (say) > implementations and such. > Perhaps. But not all things in the known universe are ADTs. Some TBD collection of utilities to be added to Ada might be useful, but not mathematically verifiable, or at all simple to write a detailed enough standard for that it can be readily verified by some means. (Think for example what it might mean if part of your collection of tools were to connect up to the OS for some kinds of services? OS Services might vary enough that it would be difficult to demonstrate that you are in compliance with the spirit and/or letter of the law.) I'm not saying it can't be done. Look over Ada.Strings... - it has a reasonably detailed description that can apparently be verified. But getting to that point might not be a simple matter. Its an objection I have heard here from vendors in the past. It might be some disguised version of "That's a lot of work and I don't want to spend time and company resources doing that...", but if it is objected to for any reason, it isn't going to make it into an implementation. Hence, you need some kind of buy-in from the implementors. > > There is > > also a certain amount of inflexibility once it gets into the standard. > > I thought that was the point, yes? Inflexible == you can rely on it not > changing? > Yes, but..... Until you have a collection of code (or at least interfaces) that have maybe built up some experience with usability, you aren't sure if this is quite what the world wants. While extensions might be easily cobbled in by the casual coder (extending the packages, changing the interfaces, etc...) its kind of hard to go back to the standard and say "See that chapter? Let's gut it and start over..." I think until you have a collection of stuff that has a little bit of practical usage behind it, it might be best to avoid enshrining it in a standard where changes are really hard to make. Like I said, I'm not against the idea of it worming its way into an annex in the fullness of time, but I think it would be a good idea to build up some informal semi-standard first just to let it have a little time to evolve. MDC -- Marin David Condic Senior Software Engineer Pace Micro Technology Americas www.pacemicro.com Enabling the digital revolution e-Mail: marin.condic@pacemicro.com Web: http://www.mcondic.com/