From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: New aggregates with Ada 2022.
Date: Tue, 28 Jun 2022 09:52:11 +0200 [thread overview]
Message-ID: <t9ebvc$1amt$1@gioia.aioe.org> (raw)
In-Reply-To: t9d7u5$ogle$1@dont-email.me
On 2022-06-27 23:37, Randy Brukardt wrote:
> The distributed overhead that they cause is
> immense (for instance, you can't have a discontigious array represesentation
> with slices, unless you are willing to pay a substantial cost for *every*
> array parameter). They're the anti-abstraction feature.
There is nothing wrong with having non-contiguous slices of
non-contiguous arrays! Contiguity of index does not automatically imply
contiguity of element allocation, unless specifically required by the
[sub]type constraint.
1D array abstraction is a mapping index -> element where
1. Index has an order. Index has operations 'Succ and 'Pred;
2. The mapping is convex. If there are elements for two indices, then
there are elements for all indices between them.
Contiguity is a representation constraint.
One should be able to have an array equivalent of unbounded string with
unbounded slices both allocated non-contiguously. The slices you could
shrink or expand:
Text (45..80) := ""; -- Cut a piece off
At the same time one should have a contiguous subtype of the same
unbounded string for interfacing purposes, dealt by copy-out copy-in.
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2022-06-28 7:52 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-19 7:59 New aggregates with Ada 2022 Blady
2022-06-19 14:15 ` Simon Wright
2022-06-20 19:36 ` Blady
2022-06-20 22:01 ` Simon Wright
2022-06-20 21:47 ` Randy Brukardt
2022-06-20 22:18 ` Dmitry A. Kazakov
2022-06-21 23:28 ` Randy Brukardt
2022-06-22 9:04 ` Dmitry A. Kazakov
2022-06-23 1:06 ` Randy Brukardt
2022-06-23 9:32 ` Dmitry A. Kazakov
2022-06-23 10:53 ` G.B.
2022-06-24 1:21 ` Randy Brukardt
2022-06-24 1:24 ` Randy Brukardt
2022-06-24 6:50 ` Dmitry A. Kazakov
2022-06-25 3:13 ` Randy Brukardt
2022-06-25 8:50 ` Dmitry A. Kazakov
2022-06-27 21:37 ` Randy Brukardt
2022-06-28 5:36 ` Niklas Holsti
2022-06-29 4:01 ` Randy Brukardt
2022-06-29 8:30 ` Jeffrey R.Carter
2022-06-29 9:04 ` Dmitry A. Kazakov
2022-06-30 5:03 ` Randy Brukardt
2022-06-30 8:44 ` Dmitry A. Kazakov
2022-06-29 11:06 ` Niklas Holsti
2022-06-29 12:53 ` Jeffrey R.Carter
2022-06-30 5:07 ` Randy Brukardt
2022-06-30 5:14 ` Randy Brukardt
2022-06-30 8:31 ` Marius Amado-Alves
2022-07-01 5:20 ` Randy Brukardt
2022-06-30 10:30 ` Jeffrey R.Carter
2022-06-30 15:48 ` Marius Amado-Alves
2022-06-30 16:39 ` Jeffrey R.Carter
2022-07-01 0:07 ` Marius Amado-Alves
2022-06-28 7:52 ` Dmitry A. Kazakov [this message]
2022-06-29 4:07 ` Randy Brukardt
2022-06-29 7:24 ` Dmitry A. Kazakov
2022-06-30 5:00 ` Randy Brukardt
2022-06-21 23:39 ` Randy Brukardt
2022-06-22 8:26 ` Dmitry A. Kazakov
2022-06-23 1:10 ` Randy Brukardt
2022-06-23 9:32 ` Dmitry A. Kazakov
2022-06-20 22:10 ` Jesper Quorning
2022-06-20 22:59 ` Jesper Quorning
2022-06-21 23:20 ` Randy Brukardt
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