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,FREEMAIL_FROM autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,1116ece181be1aea X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-10-04 07:18:50 PST Path: archiver1.google.com!news2.google.com!newsfeed.stanford.edu!headwall.stanford.edu!newshub.sdsu.edu!elnk-nf2-pas!newsfeed.earthlink.net!wn14feed!worldnet.att.net!204.127.198.203!attbi_feed3!attbi.com!sccrnsc03.POSTED!not-for-mail Message-ID: <3F7ED6C1.7000608@comcast.net> From: "Robert I. Eachus" User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.0.2) Gecko/20021120 Netscape/7.01 X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Is the Writing on the Wall for Ada? References: <3F7E01EB.8090400@noplace.com> <3F7EC895.8010507@noplace.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit NNTP-Posting-Host: 24.34.139.183 X-Complaints-To: abuse@comcast.net X-Trace: sccrnsc03 1065277129 24.34.139.183 (Sat, 04 Oct 2003 14:18:49 GMT) NNTP-Posting-Date: Sat, 04 Oct 2003 14:18:49 GMT Organization: Comcast Online Date: Sat, 04 Oct 2003 14:18:49 GMT Xref: archiver1.google.com comp.lang.ada:222 Date: 2003-10-04T14:18:49+00:00 List-Id: Marin David Condic wrote: > So a solution does exist - just *START* by getting the ARG & vendors to > issue the proclamation that they are going to start a Quest For The > Conventional Ada Library. I don't even think they'd need to use much of > their time beyond figuring out what sort of structure to use to hand the > project management job off to someone else. They have done that, and Matt for one has responded. But there is a complex issue known as version skew that has an effect here. Version skew is when you have a project that depends on two different standards, call them Foo and Bar. Any new version of Foo will depend on the existing version of Bar, and vice-versa. So if the current versions are Foo3 and Bar4, Foo3 could be designed for Bar3 and Bar4 for Foo2, and there is no way to use the most recent versions of both. The solution of course is when the standards are that closely coupled, to update them and reissue them together. The problem with version skew though is not when two standards are involved. Version skew becomes ugly somewhere between three and five standards. With two standards, there are always two pairings you can use, either the most recent Foo, and the version of Bar it depends on, or the most recent Bar, and the Foo it was designed to use. With three standards, the possibility exists, but is remote, that there is no consistant set of standards you can use. With five, there are twenty potential relations to be satisfied and only five discrete variables. Unless someone has specifically considered the group of standards you are using, or some of the standards are totally independent, version skew will kill you. That is why there will almost certainly be a component library in Ada 0Y. Not because it needs to be there but because having it there eliminates one possibility of version skew. The same for a database interface, and the same for all the annexes that were added to Ada 95. A component library is one thing that many other libraries will depend on, so is a database interface, so is a graphics binding. Bringing as many of these as possible under the Ada standard tent will make it easier to use Ada with domain specific standards, like a test standard, or a guidance system standard, or an aerodynamics standard and so on. -- Robert I. Eachus "Quality is the Buddha. Quality is scientific reality. Quality is the goal of Art. It remains to work these concepts into a practical, down-to-earth context, and for this there is nothing more practical or down-to-earth than what I have been talking about all along...the repair of an old motorcycle." -- from Zen and the Art of Motorcycle Maintenance by Robert Pirsig