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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID
	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: eachus@spectre.mitre.org (Robert I. Eachus)
Subject: Re: Software landmines (loops)
Date: 1998/08/31
Message-ID: <EACHUS.98Aug31175445@spectre.mitre.org>#1/1
X-Deja-AN: 386576145
References: <dewar.902415458@merv> <6qfhri$gs7$1@nnrp1.dejanews.com>
 <Pine.BSF.3.96.980807124210.21259B-100000@shell5.ba.best.com>
 <35cb8058.645630787@news.ne.mediaone.net> <dewar.902578088@merv>
 <slrn6sopmg.4fg.jdege@jdege.visi.com> <rfzpddz3s2.fsf@bnp-eng.remcomp.com>
 <902934874.2099.0.nnrp-10.c246a717@news.demon.co.uk> <dewar.903074236@merv>
 <6r1glm$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>
 <35E9C0CD.D225D1F8@earthlink.net>
Organization: The Mitre Corp., Bedford, MA.
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>

In article <35E9C0CD.D225D1F8@earthlink.net> Charles Hixson <charleshixsn@earthlink.net> writes:

 > Now maybe this is what was meant by a "state-machine", as when this kind
 > of construct comes up I do think of goto's, which WOULD make writing the
 > code easier.  I just don't think that they would make understaning it
 > easier.

   Yes, that is a state machine, and there are tools for making them
more understandable.  But if you try to implement one, even that
simple, in a language which doesn't allow gotos or the equivalent, you
have my sympathy.  (In the example, multiple loop exits were used as a
restricted form of goto.  If you do use a goto, you should use the
most restricted form that will do the job.  Good languages have
several available, including a general purpose form.  In Ada the goto
has a few potentially irksome restrictions (you can't use a goto from
one branch of a case statement to another, or out of a subprogram),
but I have never seen a situation where the limits affected a real
program.  (In fact, the most irksome part is probably the necessary
compile-time structures and tests for legality.)

--

					Robert I. Eachus

with Standard_Disclaimer;
use  Standard_Disclaimer;
function Message (Text: in Clever_Ideas) return Better_Ideas is...