From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Lower bounds of Strings
Date: Wed, 13 Jan 2021 13:00:17 +0100 [thread overview]
Message-ID: <rtmncd$c2o$1@gioia.aioe.org> (raw)
In-Reply-To: rtl9f3$9bg$1@franka.jacob-sparre.dk
On 2021-01-12 23:56, Randy Brukardt wrote:
> "Shark8" <onewingedshark@gmail.com> wrote in message
> news:50f68100-8909-4fdb-ad26-14bcbc010775n@googlegroups.com...
>> You mention the case where the difference in the indices is 1 as being
>> separate; why?
>
> Because the "natural" implementation of the length of an array works when
> the indices are one apart; you don't need extra code to deal with
> String(1..0) - subtracting the bounds and adding 1 (the usual length
> formula) works fine.
Nothing prevents implementation from using one of the bounds and the
length in the array's dope vector. It is a question of optimization.
Then, maybe I am wrong, but I do not see anything that must prevent
bounds on a null-array from sliding. They could slide to some canonical
range making the "natural" implementation safe.
>> Also, would the sometimes talked about idea of a "null range" have helped
>> the situation out?
>> (I don't think so, since the one is the required implementation, and the
>> other is a syntax- and partially semantic-issue.)
>
> Right, the problem is that the syntax allows too much, and any rule to avoid
> the problem necessarily will take code to make some sort of check.
Syntax can never be the problem, only semantics can.
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2021-01-13 12:00 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-05 11:04 Lower bounds of Strings Stephen Davies
2021-01-05 11:57 ` Dmitry A. Kazakov
2021-01-05 12:32 ` Jeffrey R. Carter
2021-01-05 13:40 ` Dmitry A. Kazakov
2021-01-05 14:31 ` Stephen Davies
2021-01-05 17:24 ` Stephen Davies
2021-01-05 18:28 ` Jeffrey R. Carter
2021-01-05 21:02 ` Stephen Davies
2021-01-07 10:38 ` Stephen Davies
2021-01-07 21:39 ` Randy Brukardt
2021-01-07 22:38 ` Stephen Davies
2021-01-05 12:24 ` Luke A. Guest
2021-01-05 12:49 ` Simon Wright
2021-01-05 12:51 ` Jeffrey R. Carter
2021-01-06 3:08 ` Randy Brukardt
2021-01-06 9:13 ` Dmitry A. Kazakov
2021-01-07 0:17 ` Randy Brukardt
2021-01-07 9:57 ` Dmitry A. Kazakov
2021-01-07 22:03 ` Randy Brukardt
2021-01-08 9:04 ` Dmitry A. Kazakov
2021-01-08 17:23 ` Shark8
2021-01-08 20:19 ` Dmitry A. Kazakov
2021-01-09 2:18 ` Randy Brukardt
2021-01-09 10:53 ` Dmitry A. Kazakov
2021-01-12 8:19 ` Randy Brukardt
2021-01-12 9:37 ` Dmitry A. Kazakov
2021-01-09 2:31 ` Randy Brukardt
2021-01-09 14:52 ` Why UTF-8 (was Re: Lower bounds of Strings) Jeffrey R. Carter
2021-01-09 18:08 ` Dmitry A. Kazakov
2021-01-12 7:58 ` Randy Brukardt
2021-01-11 21:35 ` Lower bounds of Strings Shark8
2021-01-12 8:12 ` Randy Brukardt
2021-01-12 20:51 ` Shark8
2021-01-12 22:56 ` Randy Brukardt
2021-01-13 12:00 ` Dmitry A. Kazakov [this message]
2021-01-13 13:27 ` AdaMagica
2021-01-13 13:53 ` Dmitry A. Kazakov
2021-01-13 14:08 ` Jeffrey R. Carter
2021-01-14 11:38 ` AdaMagica
2021-01-14 12:27 ` Dmitry A. Kazakov
2021-01-14 13:31 ` AdaMagica
2021-01-14 14:02 ` Jeffrey R. Carter
2021-01-14 14:34 ` Dmitry A. Kazakov
2021-01-14 15:28 ` Shark8
2021-01-14 15:41 ` Dmitry A. Kazakov
2021-01-19 21:02 ` G.B.
2021-01-19 22:27 ` Dmitry A. Kazakov
2021-01-20 20:10 ` G.B.
2021-01-20 20:25 ` Dmitry A. Kazakov
2021-01-15 10:24 ` Stephen Davies
2021-01-15 11:41 ` J-P. Rosen
2021-01-15 17:35 ` Stephen Davies
2021-01-15 19:36 ` Egil H H
2021-01-16 12:57 ` Stephen Davies
2021-01-17 14:10 ` Stephen Davies
2021-01-19 5:48 ` Randy Brukardt
2021-01-19 6:13 ` Gautier write-only address
2021-01-15 11:48 ` Jeffrey R. Carter
2021-01-15 13:34 ` Dmitry A. Kazakov
2021-01-15 13:56 ` Stephen Davies
2021-01-15 15:12 ` Jeffrey R. Carter
2021-01-15 17:22 ` Stephen Davies
2021-01-15 21:10 ` Jeffrey R. Carter
2021-01-15 14:00 ` Stephen Davies
2021-01-16 9:30 ` G.B.
2021-01-16 13:13 ` Stephen Davies
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