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=0.2 required=5.0 tests=BAYES_00,INVALID_MSGID,
	REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: fac41,9a0ff0bffdf63657
X-Google-Attributes: gidfac41,public
X-Google-Thread: 1108a1,9a0ff0bffdf63657
X-Google-Attributes: gid1108a1,public
X-Google-Thread: f43e6,9a0ff0bffdf63657
X-Google-Attributes: gidf43e6,public
X-Google-Thread: 103376,4b06f8f15f01a568
X-Google-Attributes: gid103376,public
From: ell@access.digex.net (Ell)
Subject: Re: Software landmines (loops)
Date: 1998/10/06
Message-ID: <361bcc75.29858784@news.erols.com>#1/1
X-Deja-AN: 398195530
Content-Transfer-Encoding: 7bit
References: <35DBDD24.D003404D@calfp.co.uk> <m3ogt3qgca.fsf@mheaney.ni.net>
 <6sbuod$fra$1@hirame.wwa.com> <35f51e53.48044143@news.erols.com>
 <6sdiav$e0g$1@hirame.wwa.com> <u90k5f1j1.fsf@gsfc.nasa.gov>
 <6sfcft$70p$1@hirame.wwa.com>
 <1dg8p3r.vfredh1aou58iN@n207167116191.inetworld.net>
 <6v2nr9$t8l$1@hirame.wwa.com> <6v39i0$fte$1@winter.news.erols.com>
 <6v4d5l$blb$1@hirame.wwa.com> <6v5en9$d46$1@winter.news.erols.com>
 <slrn71j84h.jq0.NOSPAMmbkennelNOSPAM@lyapunov.ucsd.edu>
Content-Type: text/plain; charset=us-ascii
X-Complaints-To: abuse@rcn.com
X-Trace: winter.news.erols.com 907660702 19558 207.172.52.49 (6 Oct 1998
 07:58:22 GMT)
Organization: Universe
Mime-Version: 1.0
Reply-To: ell@access.digex.net
Newsgroups: comp.lang.eiffel,comp.object,comp.software-eng,comp.lang.ada
Date: 1998-10-06T00:00:00+00:00
List-Id: <comp.lang.ada>

NOSPAMmbkennelNOSPAM@yahoo.com (Matt Kennel) wrote:

>On Sat, 3 Oct 1998 11:02:08 -0400, John I. Moore, Jr. wrote:
>:2.  Mills construct of do-while-do has a single entry and single exit,
>:    as do all of the other structured programming constructs.  Using
>:    an Ada-like syntax, consider the following:
>:
>:    loop
>:       get x;
>:       exit when x satisfies some condition;
>:       process x;
>:    end loop;
>:
>:    I contend that this logic is natural, that the loop has only a
>:    single entry and exit, and that it doesn't violate any of the
>:    structured programming guidelines.  Of course, one can rewrite
>:    it by using a standard while-loop, just as one can rewrite any
>:    repeat-until loop using a while-loop, but in order to do so you
>:    must repeat some part of the logic outside of the loop.
>
>Why is that loop morally superior to one like
>
>    loop
>       get x;
>       exit when x satisfies some condition;
>       partially process x;
>       exit if the preliminary processing shows something wrong
>       continue to process x;
>    end loop;
>
>Which does not have a single exit? 

This one:

>:   loop
>:       get x;
>:       exit when x satisfies some condition;
>:       process x;
>:    end loop;

based on discussion I think should really be:

    loop
       get x;
       exit when x satisfies some condition;
       process x;
    reloop;

Elliott
--
                :=***=:   VOTE  NO  TO  MODERATION!   :=***=: 
CRAFTISM SHOULD NOT USE USENET RESOURCES TO AVOID CRITICISM!
              MODERATORS SHOULD NOT HAVE LIFETIME TERMS!
        :=***=:  Objective  *  Pre-code Modelling  *  Holistic  :=***=:
                      Hallmarks of the best SW Engineering
  Study Phony Crafite OO vs. Genuine OO: http://www.access.digex.net/~ell
    Copyright 1998 Elliott. exclusive of others' writing. may be copied
      without permission only in the comp.* usenet and bitnet groups.