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,a1ce307c10055549
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2002-12-21 07:48:37 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!cyclone.bc.net!sjc70.webusenet.com!news.webusenet.com!newsfeed2.earthlink.net!newsfeed.earthlink.net!stamper.news.pas.earthlink.net!stamper.news.atl.earthlink.net!harp.news.atl.earthlink.net!not-for-mail
From: "Marin David Condic" <mcondic.auntie.spam@acm.org>
Newsgroups: comp.lang.ada
Subject: Re: calenday (was Re: IBM Acquires Rational Ada
Date: Sat, 21 Dec 2002 10:48:18 -0500
Organization: MindSpring Enterprises
Message-ID: <au22gl$hc5$1@slb0.atl.mindspring.net>
References: <atqd1n$pin$1@slb9.atl.mindspring.net>
 <5JfM9.395655$P31.145145@rwcrnsc53> <atsh0u$jlt$1@slb2.atl.mindspring.net>
 <v04c0ul05vht40@corp.supernews.com> <atv5fj$ldi$1@slb5.atl.mindspring.net>
 <FxwVAF3i62TM@eisner.encompasserve.org>
NNTP-Posting-Host: d1.56.ba.29
X-Server-Date: 21 Dec 2002 15:48:37 GMT
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 5.00.2314.1300
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300
Xref: archiver1.google.com comp.lang.ada:32156
Date: 2002-12-21T15:48:37+00:00
List-Id: <comp.lang.ada>

Fine. Same deal with messages or other structures. Place them after the tag
(exactly represented) and load/store with an offset from the start of the
record. I suppose it might be a bit easier if the tag appears after
everything - but that just creates problems if you want to extend the
record. I can always do overlays or offsets or addresses or something
similar to get past the tag so long as I know exactly where it is and how
big it is.

Would you think the case you cited would be something that would need tagged
records or would it more appropriately be represented by a plain-vanilla
record? Where would you want to put the tag if not at offset 0?

MDC
--
======================================================================
Marin David Condic
I work for: http://www.belcan.com/
My project is: http://www.jast.mil/

Send Replies To: m c o n d i c @ a c m . o r g

    "I'd trade it all for just a little more"
        --  Charles Montgomery Burns, [4F10]
======================================================================

Larry Kilgallen <Kilgallen@SpamCop.net> wrote in message
news:FxwVAF3i62TM@eisner.encompasserve.org...
>
> It depends on whether there are external constraints on the record.
> VMS kernel data structures, for instance, use the first 64 bits for
> a doubly-linked list, the next 16 bits for length and the 16 bits
> after that for a "type" (the closest thing to a constraint or tag).
>
> Interoperation with other languages is crucial in this domain, unlike
> all-Ada environments.