From: Robert A Duff <bobduff@shell01.TheWorld.com>
Subject: Re: Copying rows in a two dimensional array.
Date: Mon, 08 Feb 2010 16:20:29 -0500
Date: 2010-02-08T16:20:29-05:00 [thread overview]
Message-ID: <wccd40fpgpu.fsf@shell01.TheWorld.com> (raw)
In-Reply-To: 12ezqn0wq0lmm$.s7nr5aueiwa4$.dlg@40tude.net
"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:
> On Mon, 08 Feb 2010 08:15:50 -0500, Robert A Duff wrote:
>
>> Actually, slices are one of the least useful features of Ada.
>> I wouldn't mind (much) if they didn't exist in the first place.
>
> But only if the language provided means to have user-defined ones.
I'm all in favor of allowing users to define their own abstractions,
rather than trying to build-in lots of stuff into the language.
.... Which is
> far from trivial.
It's trivial if you only want slices as R-values.
And anyway, slices as L-values don't really work:
X : String := "abc";
X (2..2) := "xxx";
One might expect X = "axxxc", but of course it raises
an exception instead. You can do that sort of thing in Ada
with unbounded strings -- but then you don't get slice
syntax!
>...You need a lot of related types to describe slices
> themselves and indicator sets (ranges). Plus you have to provide means to
> determine if subarrays overlap in order to implement assignment in a safe
> way. And user-defined assignment itself need to be properly done (syntax,
> referential semantics of function results etc.)
- Bob
next prev parent reply other threads:[~2010-02-08 21:20 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-01 2:11 Copying rows in a two dimensional array Peter C. Chapin
2010-02-01 4:42 ` Jeffrey R. Carter
2010-02-01 6:55 ` Niklas Holsti
2010-02-01 23:36 ` Peter C. Chapin
2010-02-04 4:27 ` Hibou57 (Yannick Duchêne)
2010-02-01 8:37 ` Dmitry A. Kazakov
2010-02-02 0:11 ` Randy Brukardt
2010-02-07 16:13 ` Robert A Duff
2010-02-08 6:30 ` tmoran
2010-02-08 13:15 ` Robert A Duff
2010-02-08 13:45 ` Dmitry A. Kazakov
2010-02-08 21:20 ` Robert A Duff [this message]
2010-02-08 23:26 ` (see below)
2010-02-09 0:36 ` Randy Brukardt
2010-02-09 1:03 ` (see below)
2010-02-09 7:11 ` Pascal Obry
2010-02-09 8:14 ` AdaMagica
2010-02-09 14:33 ` Robert A Duff
2010-02-09 1:05 ` Adam Beneschan
2010-02-09 14:45 ` Robert A Duff
2010-02-09 18:50 ` tmoran
2010-02-09 19:51 ` Pascal Obry
2010-02-09 23:03 ` Robert A Duff
2010-02-08 18:53 ` tmoran
2010-02-08 21:14 ` Robert A Duff
2010-02-08 21:29 ` Pascal Obry
2010-02-09 8:56 ` Jean-Pierre Rosen
2010-02-09 9:14 ` AdaMagica
2010-02-09 11:19 ` Jean-Pierre Rosen
2010-02-09 14:26 ` Robert A Duff
2010-02-09 6:34 ` tmoran
2010-02-09 14:29 ` Robert A Duff
2010-02-09 18:49 ` tmoran
2010-02-09 22:58 ` Robert A Duff
2010-02-01 22:10 ` Jerry
2010-02-02 0:07 ` Randy Brukardt
2010-02-02 8:52 ` Jean-Pierre Rosen
2010-02-02 22:23 ` Jerry
2010-02-03 1:24 ` Adam Beneschan
2010-02-04 4:42 ` Hibou57 (Yannick Duchêne)
2010-02-14 0:42 ` jonathan
2010-02-14 1:54 ` Hibou57 (Yannick Duchêne)
2010-02-14 16:16 ` jonathan
2010-03-22 8:56 ` Ole-Hjalmar Kristensen
2010-02-16 6:51 ` David Thompson
2010-02-04 4:13 ` Hibou57 (Yannick Duchêne)
2010-02-04 9:10 ` Dmitry A. Kazakov
2010-02-04 9:23 ` Hibou57 (Yannick Duchêne)
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