From: Simon Wright <simon@pushface.org>
Subject: Re: Ada Annoyances
Date: Sat, 24 Jun 2017 20:55:03 +0100
Date: 2017-06-24T20:55:03+01:00 [thread overview]
Message-ID: <ly4lv540vc.fsf@pushface.org> (raw)
In-Reply-To: 4921bd4e-3827-a7ac-7f2d-d60edbc514a3@tidorum.invalid
Niklas Holsti <niklas.holsti@tidorum.invalid> writes:
> For some time, I have had in mind a possible Ada extension to solve
> point (b): an attribute/aspect that would let the programmer set a
> static upper bound on the size of any object in T'Class. If we call
> this aspect Maximum_Size (or perhaps Maximum_Size'Class), the
> programmer could use it like this:
>
> type Root is tagged record ... end record
> with Maximum_Size => 128;
>
> type Child is new Root with record ... end record;
> -- The compiler checks that Child'Size is at most 128 bits, and
> -- rejects the program otherwise.
>
> It would now be legal to create statically sized data structures using
> Root'Class, without dynamic memory allocation, by allocating 128 bits
> for each value of type Root'Class:
GNAT is happy with
type Parent is tagged null record
with Dynamic_Predicate => Size (Parent) < 128;
function Size (P : Parent'Class) return Integer is (P'Size);
type Large is array (1 .. 10) of Integer;
type Child is new Parent with record
L : Large;
end record;
Declaring an object of type Child raises Assert_Failure.
Of course you'd much rather have a static compile-time check!
next prev parent reply other threads:[~2017-06-24 19:55 UTC|newest]
Thread overview: 116+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-21 1:12 Ada Annoyances pythoner6
2017-06-21 10:13 ` Lucretia
2017-06-23 15:27 ` raph.amiard
2017-06-23 17:49 ` Randy Brukardt
2017-06-23 19:21 ` Niklas Holsti
2017-06-24 4:02 ` Shark8
2017-06-24 19:55 ` Simon Wright [this message]
2017-06-24 20:56 ` Niklas Holsti
2017-06-25 23:43 ` Randy Brukardt
2017-06-26 20:20 ` Niklas Holsti
2017-06-26 21:47 ` Randy Brukardt
2017-06-26 22:23 ` Dmitry A. Kazakov
2017-06-29 19:00 ` Niklas Holsti
2017-06-29 21:29 ` Robert A Duff
2017-06-30 0:50 ` Randy Brukardt
2017-07-03 20:39 ` Robert A Duff
2017-07-04 19:52 ` Niklas Holsti
2017-07-04 19:32 ` Niklas Holsti
2017-06-30 0:47 ` Randy Brukardt
2017-06-30 18:45 ` Niklas Holsti
2017-06-30 20:06 ` Robert A Duff
2017-06-29 21:12 ` Robert A Duff
2017-07-04 19:30 ` Niklas Holsti
2017-07-05 20:03 ` Robert A Duff
2017-06-23 19:22 ` Niklas Holsti
2017-06-30 15:02 ` Norman Worth
2017-06-30 23:49 ` pythoner6
2017-07-03 0:04 ` Randy Brukardt
2017-07-03 17:47 ` Jere
2017-07-03 19:43 ` Dmitry A. Kazakov
2017-07-04 2:18 ` Randy Brukardt
2017-12-17 13:47 ` Prefixed notation for non tagged types Jere
2017-12-17 15:06 ` Simon Wright
2017-12-17 15:33 ` Dmitry A. Kazakov
2017-12-18 22:31 ` Randy Brukardt
2017-12-19 0:40 ` Jere
2017-12-19 23:04 ` Randy Brukardt
2017-12-20 12:33 ` Robert Eachus
2017-06-21 11:58 ` Ada Annoyances joakimds
2017-06-21 12:29 ` Pascal Obry
2017-06-21 14:52 ` pythoner6
2017-06-21 16:11 ` J-P. Rosen
2017-06-21 16:12 ` Dmitry A. Kazakov
2017-06-21 22:45 ` pythoner6
2017-06-22 7:29 ` Dmitry A. Kazakov
2017-06-22 10:29 ` pythoner6
2017-06-22 11:04 ` Egil H H
2017-06-22 13:30 ` Dmitry A. Kazakov
2017-06-22 19:22 ` Niklas Holsti
2017-06-22 21:52 ` Dmitry A. Kazakov
2017-06-23 9:33 ` AdaMagica
2017-06-23 10:25 ` Simon Wright
2017-06-23 1:00 ` pythoner6
2017-06-23 15:23 ` raph.amiard
2017-06-23 16:10 ` Dmitry A. Kazakov
2017-06-23 17:41 ` Randy Brukardt
2017-06-23 18:56 ` Maciej Sobczak
2017-06-23 22:18 ` pythoner6
2017-06-24 8:05 ` Dmitry A. Kazakov
2017-06-24 8:35 ` Maciej Sobczak
2017-06-24 9:07 ` Dmitry A. Kazakov
2017-06-24 20:50 ` Maciej Sobczak
2017-06-24 21:06 ` Dmitry A. Kazakov
2017-06-25 11:33 ` Maciej Sobczak
2017-06-25 14:32 ` Dmitry A. Kazakov
2017-06-25 20:50 ` Maciej Sobczak
2017-06-26 7:58 ` Dmitry A. Kazakov
2017-06-26 13:24 ` Maciej Sobczak
2017-06-26 16:38 ` Dmitry A. Kazakov
2017-06-26 20:42 ` Maciej Sobczak
2017-06-24 8:34 ` Maciej Sobczak
2017-06-24 13:06 ` pythoner6
2017-06-24 15:40 ` Dmitry A. Kazakov
2017-06-26 0:06 ` Randy Brukardt
2017-06-26 20:35 ` Maciej Sobczak
2017-06-26 21:40 ` Randy Brukardt
2017-06-27 7:23 ` Maciej Sobczak
2017-06-27 20:38 ` Randy Brukardt
2017-06-28 8:21 ` Dmitry A. Kazakov
2017-06-28 20:50 ` Randy Brukardt
2017-06-28 23:18 ` Nasser M. Abbasi
2017-06-29 7:27 ` Dmitry A. Kazakov
2017-06-29 16:24 ` Jeffrey R. Carter
2017-06-29 16:51 ` Nasser M. Abbasi
2017-07-04 23:40 ` Luke A. Guest
2017-07-05 5:29 ` J-P. Rosen
2017-07-05 13:49 ` Dennis Lee Bieber
2017-07-05 17:49 ` Jeffrey R. Carter
2017-06-29 21:46 ` darkestkhan
2017-06-29 7:15 ` Dmitry A. Kazakov
2017-06-30 0:42 ` Randy Brukardt
2017-06-30 7:36 ` Dmitry A. Kazakov
2017-06-28 13:07 ` Maciej Sobczak
2017-06-27 7:26 ` Dmitry A. Kazakov
2017-06-27 20:41 ` Randy Brukardt
2017-06-28 7:57 ` Dmitry A. Kazakov
2017-06-27 15:19 ` AdaMagica
2017-06-27 16:32 ` Dmitry A. Kazakov
2017-06-28 13:15 ` Maciej Sobczak
2017-06-28 14:05 ` AdaMagica
2017-06-29 21:17 ` Robert A Duff
2017-06-30 7:44 ` Dmitry A. Kazakov
2017-06-30 7:49 ` J-P. Rosen
2017-06-30 8:28 ` Dmitry A. Kazakov
2017-06-30 10:14 ` J-P. Rosen
2017-06-30 10:30 ` Dmitry A. Kazakov
2017-06-28 20:53 ` Randy Brukardt
2017-12-17 16:24 ` Mehdi Saada
2017-12-17 17:27 ` Dmitry A. Kazakov
2017-12-18 23:09 ` Randy Brukardt
2017-12-19 9:25 ` Dmitry A. Kazakov
2017-06-21 20:40 ` G.B.
2017-06-21 22:25 ` pythoner6
2017-06-26 11:01 ` Vincent
2017-06-26 11:15 ` Alejandro R. Mosteo
2017-06-26 16:35 ` Pascal Obry
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