From: AdaMagica <christ-usch.grein@t-online.de>
Subject: Re: discriminant questions
Date: Tue, 20 Sep 2011 22:03:27 -0700 (PDT)
Date: 2011-09-20T22:03:27-07:00 [thread overview]
Message-ID: <5892818f-17c9-4349-add3-af40bd92c3d1@1g2000yqm.googlegroups.com> (raw)
In-Reply-To: 862244d4-c7ca-4590-ac97-e2988ac27872@f8g2000yqf.googlegroups.com
On 21 Sep., 01:28, ytomino <aghi...@gmail.com> wrote:
> (To avoid confusion, I do not use names of "Get" and "Set".)
>
> function Element (C : Container) return Element_Type;
> function Set_Element (C : Container; New_Item : Element_Type);
>
> These functions may copy Element_Type.
> It's futile cost if Element_Type'Size is large.
>
> function Element (C : Container) return access constant Element_Type;
>
> It's dangerous. the reason is written in AdaCore Gem #107.
>
> procedure Query_Element (C : Container; Process : access procedure
> (Item : in Element_Type));
> procedure Update_Element (C : Container; Process : access procedure
> (Item : in out Element_Type));
>
> These procedures are better than above functions.
> No copy, no dangerous.
> But, we must make nested subprogram, so source code may be verbosity.
>
> function Constant__Reference (C : Container) return
> Constant_Reference_Type;
> function Reference (C : Container) return Reference_Type;
>
> These functions give same effects as Query_Element and Update_Element.
> And These are simple to use.
>
> In fact, Element, Set_Element, Query_Element and Update_Element are
> able to be implemented with Reference.
> The reverse is impossible.
Nice synthesis.
> Therefore I think Constant__Reference and Reference are more better
> functions ... aside from primitive or not.
> I also understand your feeling because the mechanism of accessor is
> complex a little to call primitive.
> But accessor is a nice idea, not kludge.
And in Ada 2012, you write
type Accessor (Data: access T) is limited private
with Implicit_Dereference => Data;
Get (P).Data.all := 42; -- is then equivalent to
Get (P) := 42;
next prev parent reply other threads:[~2011-09-21 5:03 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-17 16:30 discriminant questions ytomino
2011-09-17 17:19 ` Dmitry A. Kazakov
2011-09-17 17:46 ` ytomino
2011-09-17 19:41 ` Dmitry A. Kazakov
2011-09-17 22:55 ` ytomino
2011-09-18 8:50 ` Dmitry A. Kazakov
2011-09-18 10:54 ` ytomino
2011-09-18 11:35 ` Dmitry A. Kazakov
2011-09-18 12:41 ` ytomino
2011-09-18 13:17 ` Dmitry A. Kazakov
2011-09-18 16:22 ` ytomino
2011-09-18 16:32 ` ytomino
2011-09-18 18:15 ` Dmitry A. Kazakov
2011-09-18 23:44 ` ytomino
2011-09-19 7:27 ` Dmitry A. Kazakov
2011-09-18 14:43 ` Dmitry A. Kazakov
2011-09-18 16:46 ` Robert A Duff
2011-09-18 18:01 ` Dmitry A. Kazakov
2011-09-18 19:20 ` Maciej Sobczak
2011-09-19 7:39 ` Dmitry A. Kazakov
2011-09-19 20:00 ` Maciej Sobczak
2011-09-20 7:33 ` Dmitry A. Kazakov
2011-09-20 15:45 ` Maciej Sobczak
2011-09-20 16:48 ` Dmitry A. Kazakov
2011-09-20 20:19 ` Maciej Sobczak
2011-09-21 7:48 ` Dmitry A. Kazakov
2011-09-21 20:51 ` Maciej Sobczak
2011-09-22 8:07 ` Dmitry A. Kazakov
2011-09-22 20:57 ` Maciej Sobczak
2011-09-23 7:59 ` Dmitry A. Kazakov
2011-09-23 10:57 ` Georg Bauhaus
2011-09-23 22:30 ` Randy Brukardt
2011-09-23 22:50 ` Randy Brukardt
2011-09-24 6:46 ` Dmitry A. Kazakov
2011-09-26 22:48 ` Randy Brukardt
2011-09-27 8:10 ` Dmitry A. Kazakov
2011-09-27 10:18 ` Georg Bauhaus
2011-09-27 12:14 ` Dmitry A. Kazakov
2011-09-27 15:11 ` Georg Bauhaus
2011-09-27 15:38 ` Dmitry A. Kazakov
2011-09-27 18:06 ` Georg Bauhaus
2011-09-27 19:06 ` Dmitry A. Kazakov
2011-09-29 0:01 ` Georg Bauhaus
2011-09-29 8:26 ` Dmitry A. Kazakov
2011-09-30 1:24 ` Randy Brukardt
2011-09-30 8:10 ` Dmitry A. Kazakov
2011-09-30 10:07 ` Georg Bauhaus
2011-09-30 12:38 ` Dmitry A. Kazakov
2011-09-30 17:40 ` Georg Bauhaus
2011-09-30 18:55 ` Dmitry A. Kazakov
2011-09-23 9:23 ` Stephen Leake
2011-09-23 9:48 ` Dmitry A. Kazakov
2011-09-23 22:42 ` Randy Brukardt
2011-09-24 6:56 ` Dmitry A. Kazakov
2011-09-26 22:43 ` Randy Brukardt
2011-09-24 10:47 ` Stephen Leake
2011-09-24 12:54 ` Simon Wright
2011-09-24 14:46 ` Dmitry A. Kazakov
2011-09-24 16:21 ` Simon Wright
2011-09-24 16:43 ` Dmitry A. Kazakov
2011-09-22 2:52 ` Randy Brukardt
2011-09-22 8:11 ` Dmitry A. Kazakov
2011-09-20 0:01 ` Randy Brukardt
2011-09-20 7:38 ` Dmitry A. Kazakov
2011-09-20 11:11 ` AdaMagica
2011-09-20 12:09 ` Dmitry A. Kazakov
2011-09-20 12:31 ` AdaMagica
2011-09-20 12:57 ` Dmitry A. Kazakov
2011-09-20 23:28 ` ytomino
2011-09-21 5:03 ` AdaMagica [this message]
2011-09-21 8:08 ` Dmitry A. Kazakov
2011-09-21 10:03 ` Georg Bauhaus
2011-09-21 10:29 ` Dmitry A. Kazakov
2011-09-22 3:21 ` Randy Brukardt
2011-09-22 3:05 ` Randy Brukardt
2011-09-19 23:35 ` Randy Brukardt
2011-09-20 21:39 ` ytomino
2011-09-22 3:32 ` Randy Brukardt
2011-09-18 16:32 ` ytomino
2011-09-19 14:46 ` ytomino
2011-09-19 15:14 ` Dmitry A. Kazakov
2011-09-19 17:49 ` ytomino
2011-09-20 7:29 ` Georg Bauhaus
2011-09-20 19:50 ` ytomino
2011-09-20 8:08 ` Dmitry A. Kazakov
2011-09-20 18:47 ` ytomino
2011-09-21 8:16 ` Dmitry A. Kazakov
2011-09-21 9:55 ` ytomino
2011-09-22 3:26 ` Randy Brukardt
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