From: FGD <presbeis@look.ca>
Subject: Re: A case where Ada defaults to unsafe?
Date: Mon, 07 Jan 2002 13:40:18 -0500
Date: 2002-01-07T13:40:18-05:00 [thread overview]
Message-ID: <3C39EB92.6040200@look.ca> (raw)
In-Reply-To: 3C39E520.6030508@mail.com
Hyman Rosen wrote:
> Pat Rogers wrote:
>
>> Well of course "and" is allowed to ignore one of the operands; if the
>> first one
>> evaluated is false, there is no need to evaluate the second. We are
>> just not
>> guaranteed which is evaluated first.
>
> You are quite wrong. So much for the claim that experienced Ada
> programmers simply learn the difference between "and" and "and then"!
> See, for example, 3.8 in the Ada83 Rationale.
>
That's not quite right either, the end result of "cond_1 and cond_2"
must be *as if* both cond_1 and cond_2 were evaluated. The Boolean
operator and is just like any function, but it is expanded inline and
may be optimized by the compiler. So the compiler could omit the
evaluation of a condition if it is known not to have side effects. This
happens frequently when the conditions are comparisons of numeric types
for example.
-- Frank
next prev parent reply other threads:[~2002-01-07 18:40 UTC|newest]
Thread overview: 127+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-01-03 20:29 A case where Ada defaults to unsafe? Hyman Rosen
2002-01-03 20:38 ` Darren New
2002-01-03 21:36 ` Hyman Rosen
2002-01-04 14:29 ` Wes Groleau
2002-01-03 21:27 ` James Rogers
2002-01-03 21:32 ` Frank J. Lhota
2002-01-03 21:51 ` Hyman Rosen
2002-01-03 22:22 ` Ted Dennison
2002-01-03 23:07 ` Hyman Rosen
2002-01-03 23:38 ` Nick Williams
2002-01-04 0:15 ` Florian Weimer
2002-01-04 7:40 ` Preben Randhol
2002-01-04 14:39 ` Wes Groleau
2002-01-04 15:16 ` Ted Dennison
2002-01-04 3:35 ` Eric Merritt
2002-01-04 14:39 ` Robert A Duff
2002-01-04 14:27 ` Robert A Duff
2002-01-04 15:39 ` Larry Kilgallen
2002-01-04 15:57 ` Ted Dennison
2002-01-04 16:05 ` Ted Dennison
2002-01-10 21:22 ` Robert A Duff
2002-01-11 9:14 ` Dmitry A. Kazakov
2002-01-04 16:19 ` Brian Rogoff
2002-01-04 16:31 ` Ted Dennison
2002-01-08 20:55 ` Mark Lundquist
2002-01-16 0:14 ` Matthew Heaney
2002-01-16 20:19 ` Robert A Duff
2002-01-10 21:29 ` Robert A Duff
2002-01-11 9:25 ` Dmitry A. Kazakov
2002-01-19 0:35 ` Brian Rogoff
2002-01-19 14:15 ` Robert A Duff
2002-01-19 23:10 ` Brian Rogoff
2002-01-04 16:29 ` Robert Dewar
2002-01-04 17:32 ` Hyman Rosen
2002-01-04 18:50 ` Matthew Heaney
2002-01-04 18:56 ` Darren New
2002-01-04 19:10 ` Hyman Rosen
2002-01-04 20:08 ` Matthew Heaney
2002-01-04 20:14 ` Ted Dennison
2002-01-04 20:20 ` Hyman Rosen
2002-01-04 21:16 ` Larry Kilgallen
2002-01-04 21:33 ` Ted Dennison
2002-01-07 15:39 ` Hyman Rosen
2002-01-07 16:06 ` Ted Dennison
2002-01-07 16:50 ` Larry Kilgallen
2002-01-07 17:18 ` Hyman Rosen
2002-01-07 17:26 ` Pat Rogers
2002-01-07 18:12 ` Hyman Rosen
2002-01-07 18:40 ` FGD [this message]
2002-01-07 20:04 ` Pat Rogers
2002-01-05 0:08 ` Nick Roberts
2002-01-05 10:57 ` Simon Wright
2002-01-08 23:27 ` Nick Roberts
2002-01-09 9:58 ` Stuart Palin
2002-01-09 11:11 ` Nick Roberts
2002-01-10 20:32 ` Robert A Duff
2002-01-11 9:45 ` Stuart Palin
2002-01-11 13:32 ` Robert A Duff
2002-01-11 20:26 ` Literate Programming [was: A case where ...] Nick Roberts
2002-01-12 16:37 ` Georg Bauhaus
2002-01-13 14:46 ` Nick Roberts
2002-01-14 14:17 ` Eric Merritt
2002-01-14 23:20 ` Nick Roberts
2002-01-15 18:54 ` Eric Merritt
2002-01-14 14:34 ` Stephen Leake
2002-01-14 13:14 ` A case where Ada defaults to unsafe? Stuart Palin
2002-01-14 14:38 ` Preben Randhol
2002-01-16 6:00 ` Simon Wright
2002-01-17 3:04 ` David Starner
2002-01-17 15:08 ` Georg Bauhaus
2002-01-17 20:25 ` Simon Wright
2002-01-17 9:56 ` Stuart Palin
[not found] ` <3 <3C469FE6.B2C67ED6@baesystems.com>
2002-01-17 20:32 ` Simon Wright
2002-01-14 14:35 ` Preben Randhol
2002-01-14 16:36 ` Robert A Duff
2002-01-12 12:27 ` Simon Wright
2002-01-05 0:32 ` Robert Dewar
2002-01-14 16:09 ` Matthieu Moy
2002-01-20 8:59 ` Hyman Rosen
2002-01-20 19:13 ` Jim Rogers
2002-01-20 21:19 ` Ray Blaak
2002-01-03 22:07 ` Ted Dennison
2002-01-04 17:12 ` Preben Randhol
2002-01-04 17:21 ` Jean-Marc Bourguet
2002-01-04 18:54 ` Ted Dennison
2002-01-04 3:17 ` Larry Kilgallen
2002-01-04 8:27 ` Thierry Lelegard
2002-01-04 8:39 ` tmoran
2002-01-04 9:03 ` Thierry Lelegard
2002-01-04 14:43 ` Wes Groleau
2002-01-04 15:45 ` Ted Dennison
2002-01-04 16:37 ` Wes Groleau
2002-01-04 16:56 ` Ted Dennison
2002-01-04 11:51 ` Larry Kilgallen
2002-01-04 12:41 ` M. A. Alves
2002-01-04 15:42 ` Ted Dennison
2002-01-04 17:16 ` Hyman Rosen
2002-01-04 19:12 ` Ted Dennison
2002-01-04 23:36 ` Matthew Woodcraft
2002-01-05 15:00 ` Steve Doiel
2002-01-10 20:49 ` Robert A Duff
-- strict thread matches above, loose matches on Subject: below --
2002-01-03 23:18 Gautier Write-only-address
2002-01-03 23:26 Gautier Write-only-address
2002-01-03 23:54 ` Larry Hazel
2002-01-04 14:33 ` Robert A Duff
2002-01-05 12:47 Gautier Write-only-address
2002-01-07 16:24 ` Ted Dennison
2002-01-07 18:17 ` FGD
2002-01-07 18:21 ` Hyman Rosen
2002-01-07 20:26 ` Matthew Woodcraft
2002-01-07 21:16 ` Hyman Rosen
2002-01-13 8:23 ` Hyman Rosen
2002-01-13 9:06 ` Preben Randhol
2002-01-13 10:41 ` Larry Kilgallen
2002-01-14 5:47 ` Hyman Rosen
2002-01-14 12:41 ` Georg Bauhaus
2002-01-13 18:21 ` Michal Nowak
2002-01-14 1:29 ` Ted Dennison
2002-01-14 14:36 ` Ted Dennison
2002-01-14 22:43 ` Michal Nowak
2002-01-10 20:47 ` Robert A Duff
2002-01-10 23:37 ` Preben Randhol
2002-01-11 1:31 ` Robert A Duff
2002-01-11 20:32 ` Nick Roberts
2002-01-11 16:47 ` Hyman Rosen
2002-01-07 16:45 Gautier Write-only-address
2002-01-07 19:33 ` Ted Dennison
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