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,c35edbbda4c7f58f 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!newsread1.news.pas.earthlink.net.POSTED!a6202946!not-for-mail From: Jeffrey Carter Organization: jrcarter commercial-at acm [period | full stop] org User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.4) Gecko/20030624 X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Conditional compilation in Ada? References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Message-ID: Date: Thu, 18 Nov 2004 17:44:15 GMT NNTP-Posting-Host: 63.184.104.77 X-Complaints-To: abuse@earthlink.net X-Trace: newsread1.news.pas.earthlink.net 1100799855 63.184.104.77 (Thu, 18 Nov 2004 09:44:15 PST) NNTP-Posting-Date: Thu, 18 Nov 2004 09:44:15 PST Xref: g2news1.google.com comp.lang.ada:6276 Date: 2004-11-18T17:44:15+00:00 List-Id: Steve wrote: > Using variant records means explicitly checking for the variant type and > taking different action based on the variant. Creating a new variation of > the record means modifying the original record (modifying proven code is > never a good thing when it is easily avoided) and chasing each part of the > code that takes different action based on the variants. Since the compiler points out any place where you've forgotten, this is hardly a problem; indeed, I would claim that it's an advantage over OOP, where forgetting to redefine an operation is ignored by the compiler, and you get the wrong action instead. In a well designed system, all the code dealing with the variant record and its variants will be together, so there's no "chasing each part of the code". Another advantage of using a variant record is that what happens is explicit in the code, not hidden is some package that is not mentioned in a context clause. > Using objects means deriving a new object and overloading specific > operations for that object. The base object isn't touched. And operations that are mistakenly not overridden become run-time errors. > Also: If the object is declared statically, the dispatching may happen > statically. This is true, but it seems that the nature of OP's problem would prevent this. -- Jeff Carter "I fart in your general direction." Monty Python & the Holy Grail 05