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,cd5005cccfba0311
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news2.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!wns14feed!worldnet.att.net!attbi_s21.POSTED!53ab2750!not-for-mail
From: "Jeffrey R. Carter" <jrcarter@acm.org>
User-Agent: Thunderbird 1.5.0.9 (Windows/20061207)
MIME-Version: 1.0
Newsgroups: comp.lang.ada
Subject: Re: Topological Sort Help
References: <1170618852.885855.258390@j27g2000cwj.googlegroups.com>
   <87sldllhpt.fsf@ludovic-brenta.org>
   <1170707421.136089.281290@l53g2000cwa.googlegroups.com>
   <87y7ncjq4y.fsf@ludovic-brenta.org>
   <1170728294.194370.133540@k78g2000cwa.googlegroups.com>
   <1170752808.678318.252960@l53g2000cwa.googlegroups.com>
   <1170897552.495666.223180@v33g2000cwv.googlegroups.com>
   <N6Kyh.382953$1i1.102160@attbi_s72>
 <1170960817.632329.117990@v45g2000cwv.googlegroups.com>
In-Reply-To: <1170960817.632329.117990@v45g2000cwv.googlegroups.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Message-ID: <obTyh.263629$aJ.19483@attbi_s21>
NNTP-Posting-Host: 12.201.97.213
X-Complaints-To: abuse@mchsi.com
X-Trace: attbi_s21 1170997076 12.201.97.213 (Fri, 09 Feb 2007 04:57:56 GMT)
NNTP-Posting-Date: Fri, 09 Feb 2007 04:57:56 GMT
Organization: AT&T ASP.att.net
Date: Fri, 09 Feb 2007 04:57:56 GMT
Xref: g2news2.google.com comp.lang.ada:9167
Date: 2007-02-09T04:57:56+00:00
List-Id: <comp.lang.ada>

isaac2004 wrote:
> an exit when makes no sense in this situation because there is no
> finite stopping condition, if you look at the algorithm provided, i
> see it harder top implement an exit when loop
> 
> WHILE IsEmpty(G) /= False DO

This kind of construct generally indicates the coder doesn't understand 
the concept of Booleans.

There's always an "exit when" equivalent to a while loop. Your loop is 
equivalent to

while Isempty (G) loop

which is equivalent to

loop
    exit when not Isempty (G);

Note that I'm not dealing with your algorithm here; I'm merely 
suggesting that if you're having trouble with the condition for 
continuing the loop, you might find it easier to think in terms of the 
condition for exiting the loop.

-- 
Jeff Carter
"What I wouldn't give for a large sock with horse manure in it."
Annie Hall
42