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: 103376,4b06f8f15f01a568
X-Google-Attributes: gid103376,public
X-Google-Thread: f43e6,9a0ff0bffdf63657
X-Google-Attributes: gidf43e6,public
From: ell@access.digex.net (Ell)
Subject: Re: Software landmines (loops)
Date: 1998/08/31
Message-ID: <35ead1be.659708@news.erols.com>#1/1
X-Deja-AN: 386477710
Content-Transfer-Encoding: 7bit
References: <dewar.903074236@merv> <6r1glm$bvh$1@nnrp1.dejanews.com>
 <dewar.903281994@merv> <6r9f8h$jtm$1@nnrp1.dejanews.com>
 <6renh8$ga7$1@nnrp1.dejanews.com> <6rf59b$2ud$1@nnrp1.dejanews.com>
 <l5HC1.6840$wN.1856764@news.giganews.com> <6rfra4$rul$1@nnrp1.dejanews.com>
 <35DBDD24.D003404D@calfp.co.uk> <m3ogt3qgca.fsf@mheaney.ni.net>
 <6sbuod$fra$1@hirame.wwa.com> <35f51e53.48044143@news.erols.com>
 <6sdiav$e0g$1@hirame.wwa.com> <m3af4mq7f4.fsf@mheaney.ni.net>
Content-Type: text/plain; charset=us-ascii
X-Complaints-To: abuse@rcn.com
X-Trace: winter.news.erols.com 904582086 4001 207.172.118.160 (31 Aug 1998
 16:48:06 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: 1998-08-31T00:00:00+00:00
List-Id: <comp.lang.ada>

>"Robert Martin" <rmartin@oma.com> writes:

Matthew Heaney wrote:
>> >>>For example, there's a pernicious myth that exiting (or returning) from
>> >>>the middle of a loop is bad, and that the only proper way to write a
>> >>>loop is to state the termination condition explicitly, as a predicate
>> >>>appearing at the top of the loop.

RCM wrote:
>> >>Yes.  That pernicious myth is called "structured programming".

Elliott wrote:
>> >Please cite even just a single structured programming text, or founder
>> >where what you say here was asserted.
 
> "Structured Programming", Dijkstra, Dahl, Hoare, Academic Press, 1972. p.
> 16-23 "7. On Understanding Programs".

> Actually this section says that there are two different kinds of
> loops. one that is tested at the top; and another which is tested at
> the bottom.  But in all cases, the elements of structure programming
> have a single entry and a single exit.  A loop that exits in the
> middle, violates this maxim.

Please show me a Dijkstra, Dahle, Hoare quote that says "the elements
of structure[d] programming have a single entry and single exit."

Elliott
-- 
   :=***=:  Objective  *  Pre-code Modelling  *  Holistic  :=***=:
                 Hallmarks of the best SW Engineering
         "The domain object model is the foundation of OOD."
 Check out SW Modeller vs SW Craftite Central : 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.