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From: "Randy Brukardt" <randy@rrsoftware.com>
Subject: Re: private types
Date: Fri, 17 Mar 2006 19:17:32 -0600
Date: 2006-03-17T19:17:32-06:00	[thread overview]
Message-ID: <e_mdncFXrsg5wobZnZ2dnUVZ_t2dnZ2d@megapath.net> (raw)
In-Reply-To: sa4hd5x1wgd.fsf@snoopy.microcomaustralia.com.au

"Brian May" <bam@snoopy.apana.org.au> wrote in message
news:sa4hd5x1wgd.fsf@snoopy.microcomaustralia.com.au...
...
> For testing the code, as found_it is undefined in the second test, it
> is possible it might just fluke the tests you give it and pass
> everyone.
>
> The first code is predictable though, and as long as you give it the
> same inputs, it will always produce the same outputs, making it easier
> (IMHO) to test.

It's not just testing. Ada 95 is very clear that an Ada compiler cannot
assume an object is in range unless it can prove it is initialized. Explicit
initialization makes this proof trivial (and leaving it out may make it
impossible to prove.) Thus, given
    A : Positive := 10;
    B : Positive;
the compiler can assume that A is in range, potentially being able to
eliminate checks and speeding up the code. But it cannot assume that B is in
range (unless it can prove that it is initialized further on).

So I recommend initalizing everything (or assigning it immediately after the
begin) that could be significant to performance.

                                     Randy.





  parent reply	other threads:[~2006-03-18  1:17 UTC|newest]

Thread overview: 93+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-03-13 19:58 private types ada_student
2006-03-13 20:27 ` Mark Lorenzen
2006-03-13 21:05   ` Pascal Obry
2006-03-13 21:07   ` ada_student
2006-03-13 21:45     ` Simon Wright
2006-03-14  4:51 ` Jeffrey R. Carter
2006-03-14  7:44   ` Brian May
2006-03-14  8:25     ` Ludovic Brenta
2006-03-14  8:47     ` Alex R. Mosteo
2006-03-17  4:33     ` Justin Gombos
2006-03-17  5:17       ` Brian May
2006-03-17 22:50         ` Justin Gombos
2006-03-18  1:17         ` Randy Brukardt [this message]
2006-03-18  2:17           ` Justin Gombos
2006-03-21  0:08             ` Randy Brukardt
2006-03-18  8:39           ` Uninitialized variables (was: Re: private types) Dirk Craeynest
2006-03-18 14:06             ` Gautier
2006-03-18 14:36               ` Uninitialized variables Jeffrey Creem
2006-03-21  0:22             ` Uninitialized variables (was: Re: private types) Randy Brukardt
2006-03-21  0:38             ` Randy Brukardt
2006-03-18 12:06           ` private types Martin Dowie
2006-03-18 12:47           ` Robert A Duff
2006-03-17  7:40       ` Maciej Sobczak
2006-03-17 16:41         ` Frank J. Lhota
2006-03-17 23:36         ` Justin Gombos
2006-03-18  1:32           ` Randy Brukardt
2006-03-18  3:21             ` Handling invalid objects Justin Gombos
2006-03-18  7:35               ` Jeffrey R. Carter
2006-03-18 16:10                 ` Justin Gombos
2006-03-19 11:00                   ` Simon Wright
2006-03-20 23:57                   ` Randy Brukardt
2006-03-22  2:06                     ` Justin Gombos
2006-03-22  5:23                       ` tmoran
2006-03-22  8:48                         ` Dmitry A. Kazakov
2006-03-22  9:24                           ` Maciej Sobczak
2006-03-22 11:05                             ` Dmitry A. Kazakov
2006-03-22 16:42                               ` Maciej Sobczak
2006-03-22 18:06                                 ` Stefan Lucks
2006-03-23 13:20                                 ` Dmitry A. Kazakov
2006-03-18  8:57               ` Jacob Sparre Andersen
2006-03-19 19:07                 ` Dr. Adrian Wrigley
2006-03-20 15:25                   ` Robert A Duff
2006-03-19 22:06               ` Brian May
2006-03-20 21:17                 ` Jeffrey R. Carter
2006-03-20 23:44               ` Randy Brukardt
2006-03-22  1:27                 ` Justin Gombos
2006-03-18  9:20           ` private types Dmitry A. Kazakov
2006-03-17 13:18       ` Robert A Duff
2006-03-17 23:44         ` Justin Gombos
2006-03-18  9:24           ` Dmitry A. Kazakov
2006-03-18 12:56           ` Robert A Duff
2006-03-18 15:06             ` Justin Gombos
2006-03-19  9:35               ` Martin Krischik
2006-03-19 14:52                 ` Peter C. Chapin
2006-03-19 15:08                   ` Björn Persson
2006-03-19 16:34                     ` Martin Krischik
2006-03-20  9:57                       ` Maciej Sobczak
2006-03-20 10:58                         ` Peter C. Chapin
2006-03-20 11:19                           ` Peter C. Chapin
2006-03-20 13:06                           ` Maciej Sobczak
2006-03-20 15:19                         ` Robert A Duff
2006-03-20 16:47                           ` James Dennett
2006-03-20 19:12                         ` Martin Krischik
2006-03-21  7:27                           ` Maciej Sobczak
2006-03-20 19:32                         ` Martin Krischik
2006-03-21  7:41                           ` Maciej Sobczak
2006-03-20 20:29                       ` Simon Wright
2006-03-19 17:43                     ` Larry Kilgallen
2006-03-19 22:11                     ` Peter C. Chapin
2006-03-19 18:15                 ` Robert A Duff
2006-03-19 19:20                   ` Martin Krischik
2006-03-19 20:43                     ` Dr. Adrian Wrigley
2006-03-20 15:01                       ` Robert A Duff
2006-03-27  4:07                       ` Dave Thompson
2006-03-20  9:40                     ` Maciej Sobczak
2006-03-20 15:09                       ` Robert A Duff
2006-03-21  8:07                         ` Maciej Sobczak
2006-03-26 18:53                           ` Robert A Duff
2006-03-19 19:27                 ` Jeffrey R. Carter
2006-03-25 21:40               ` Robert A Duff
2006-03-26  0:10                 ` Justin Gombos
2006-03-26  1:00                   ` Robert A Duff
2006-03-26  6:37                     ` Jeffrey R. Carter
2006-03-26 15:43                       ` Justin Gombos
2006-03-26 16:32                         ` Robert A Duff
2006-03-26 16:51                       ` Robert A Duff
2006-03-26 19:41                         ` Jeffrey R. Carter
2006-03-26  3:15                 ` Frank J. Lhota
2006-03-26 18:28                   ` Robert A Duff
2006-03-26 19:43                     ` Jeffrey R. Carter
2006-03-26 19:59                     ` Simon Wright
     [not found] <bctruong.1.00117123@draper.com>
1999-07-28  0:00 ` Stanley R. Allen
1999-07-28  0:00   ` Thomas Hood
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