From: Robert A Duff <bobduff@shell01.TheWorld.com>
Subject: Re: Local vs global variables in ADA
Date: Tue, 5 Nov 2002 22:37:51 GMT
Date: 2002-11-05T22:37:51+00:00 [thread overview]
Message-ID: <wcc4ravfxs0.fsf@shell01.TheWorld.com> (raw)
In-Reply-To: u3cqg9b8l.fsf@gsfc.nasa.gov
Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov> writes:
> Never use a "while" loop. Mostly because "exit when" is much clearer,
> partly because I've used other languages that had slightly different
> definitions of "while", and I can't keep them straight.
Like what? I mean, which languages have different definitions of
"while" loops, and what are the differences. I thought "while" loops
were one of the few cases where there is pretty much agreement on the
semantics across languages.
I like while loops, and use them in favor of loop/exit whenever the exit
condition happens at the top.
I seem to recall some issue in SPARK, where they discouraged while
loops. Something about wanting to put a loop-invariant before the exit
condition? Maybe one of the SPARK folks can comment on that. I'm happy
to write assertions that help program-proving tools, if they also help
me, the human reader (or at least neutral to the human reader), but I'm
a bit uncomfortable using a style that helps tools, but hinders humans.
- Bob
next prev parent reply other threads:[~2002-11-05 22:37 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-11-03 18:17 Local vs global variables in ADA Roger
2002-11-03 19:03 ` Per Sandbergs
2002-11-03 19:31 ` Eric Jacoboni
2002-11-04 1:47 ` Jeffrey Carter
2002-11-04 13:27 ` Wes Groleau
2002-11-04 20:48 ` Jeffrey Carter
2002-11-05 8:43 ` Fraser Wilson
2002-11-05 13:53 ` Charles H. Sampson
2002-11-06 4:59 ` R. Tim Coslet
2002-11-05 17:28 ` Stephen Leake
2002-11-05 17:38 ` Jean-Pierre Rosen
2002-11-05 19:57 ` Jeffrey Carter
2002-11-06 9:11 ` Jean-Pierre Rosen
2002-11-05 20:26 ` Vinzent Hoefler
2002-11-05 23:14 ` Wes Groleau
2002-11-06 9:16 ` Jean-Pierre Rosen
2002-11-06 13:49 ` Wes Groleau
2002-11-05 22:37 ` Robert A Duff [this message]
2002-11-05 23:46 ` Larry Hazel
2002-11-06 2:19 ` Dennis Lee Bieber
2002-11-06 13:45 ` Dan Nagle
2002-11-07 0:30 ` Dennis Lee Bieber
2002-11-06 2:15 ` Dennis Lee Bieber
2002-11-06 7:04 ` Martin Dowie
2002-11-06 14:40 ` john mann
2002-11-07 0:25 ` Dennis Lee Bieber
2002-11-07 14:58 ` Robert A Duff
2002-11-07 15:38 ` Jean-Pierre Rosen
2002-11-08 1:43 ` Jeffrey Carter
2002-11-06 7:18 ` Dale Stanbrough
2002-11-06 15:40 ` Rod Chapman
2002-11-06 17:34 ` Stephen Leake
2002-11-10 1:36 ` loop statements, was " David Thompson
2002-11-05 19:54 ` Jeffrey Carter
2002-11-04 13:47 ` Martin Dowie
-- strict thread matches above, loose matches on Subject: below --
2002-11-05 6:42 Grein, Christoph
2002-11-05 15:59 ` Martin Dowie
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