From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Generic Package
Date: Mon, 30 Apr 2007 14:16:29 +0200
Date: 2007-04-30T14:16:07+02:00 [thread overview]
Message-ID: <maztz79bn7ey.1bxuei6uqjiwu.dlg@40tude.net> (raw)
In-Reply-To: 1177929029.6111.34.camel@localhost
On Mon, 30 Apr 2007 12:30:29 +0200, Georg Bauhaus wrote:
> On Sun, 2007-04-29 at 10:19 +0200, Dmitry A. Kazakov wrote:
>
> My subprogram can hardly be arranged to be called with an element
> more than once by For_Each, or not at all (instantiation not
> being recursive in Ada):
> "your subprogram is called with each element once" is part of the
> contract of For_Each.
The point is that you cannot state this contract formally. It is equivalent
to the well-ordering principle, I guess.
> So it is not a question of trusting the iterator but rather
> a mere consequence of trust in the iterator being defined
> as required by the specification of iterator.
But you could not present any formal specification of.
Consider the program that counts elements of a set:
C : Protected_Integer;
procedure Count is
begin
C.Inc;
end Count;
begin
C.Set (0);
foreach S do Count;
How could you prove that C.Get = S'Length?
>>> Is there iteration in the following SETL expression?
>>>
>>> Result := { x : x in {1, 3, 24, 17, 11} | P(x) };
>>
>> Iteration in what? In the language construct? In Result? Consider a
>> possibility that Result were computed at compile time. Would it still be
>> iteration?
>
> That's the point, there is iteration in this set former, but it
> happens behind the scene: on an AS-IF basis, it does not even matter
> when (or even if) iteration is happening;
Right, that is _the_ point. What is the reason to call this "iteration,"
rather than an operation constructing a new set?
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2007-04-30 12:16 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-25 22:15 Generic Package andrew.carroll
2007-04-26 0:07 ` Jeffrey R. Carter
2007-04-26 7:46 ` Markus E Leypold
2007-04-26 6:02 ` Martin Krischik
2007-04-26 7:57 ` Dmitry A. Kazakov
2007-04-26 15:31 ` andrew.carroll
2007-04-26 16:07 ` Georg Bauhaus
2007-04-26 19:40 ` andrew.carroll
2007-04-26 20:01 ` Georg Bauhaus
2007-04-26 18:54 ` Dmitry A. Kazakov
2007-04-26 21:52 ` Simon Wright
2007-04-27 9:00 ` Dmitry A. Kazakov
2007-04-27 11:11 ` Georg Bauhaus
2007-04-27 12:06 ` Dmitry A. Kazakov
2007-04-27 12:52 ` Markus E Leypold
2007-04-27 14:10 ` Georg Bauhaus
2007-04-27 14:16 ` Dmitry A. Kazakov
2007-04-27 21:44 ` Georg Bauhaus
2007-04-28 7:38 ` Dmitry A. Kazakov
2007-04-28 17:50 ` Simon Wright
2007-04-28 21:04 ` Ray Blaak
2007-04-29 16:33 ` Markus E Leypold
2007-04-27 19:44 ` Simon Wright
2007-04-27 20:34 ` Dmitry A. Kazakov
2007-04-27 21:16 ` Simon Wright
2007-04-28 7:36 ` Dmitry A. Kazakov
2007-04-27 11:43 ` Markus E Leypold
2007-04-28 17:35 ` Dmitry A. Kazakov
2007-04-28 23:06 ` Georg Bauhaus
2007-04-29 8:19 ` Dmitry A. Kazakov
2007-04-29 15:10 ` (see below)
2007-04-29 17:48 ` Dmitry A. Kazakov
2007-04-29 22:36 ` (see below)
2007-04-30 6:58 ` Dmitry A. Kazakov
2007-04-30 9:59 ` Markus E Leypold
2007-04-30 10:01 ` Markus E Leypold
2007-04-30 10:36 ` Georg Bauhaus
2007-04-30 10:40 ` Georg Bauhaus
2007-04-30 12:14 ` Dmitry A. Kazakov
2007-04-30 14:57 ` (see below)
2007-04-30 10:30 ` Georg Bauhaus
2007-04-30 12:16 ` Dmitry A. Kazakov [this message]
2007-04-30 14:48 ` Georg Bauhaus
2007-04-30 16:29 ` Dmitry A. Kazakov
2007-04-30 17:24 ` Georg Bauhaus
2007-04-30 18:54 ` Dmitry A. Kazakov
2007-04-30 19:29 ` Simon Wright
2007-04-30 20:04 ` Dmitry A. Kazakov
2007-05-01 0:11 ` Markus E Leypold
2007-05-01 9:02 ` Georg Bauhaus
2007-05-01 10:19 ` Dmitry A. Kazakov
2007-05-01 13:42 ` Georg Bauhaus
2007-05-01 17:16 ` Dmitry A. Kazakov
2007-05-01 19:14 ` Randy Brukardt
2007-05-01 20:14 ` Dmitry A. Kazakov
2007-05-02 7:52 ` Markus E Leypold
2007-05-02 8:06 ` Markus E Leypold
2007-05-03 0:37 ` Randy Brukardt
2007-05-03 8:36 ` Markus E Leypold
2007-05-03 23:16 ` Randy Brukardt
2007-05-04 0:15 ` Markus E Leypold
2007-05-01 21:41 ` Georg Bauhaus
2007-05-02 6:57 ` Ray Blaak
2007-05-02 8:22 ` Markus E Leypold
2007-05-02 8:07 ` Markus E Leypold
2007-05-02 10:29 ` Dmitry A. Kazakov
2007-05-02 11:48 ` Georg Bauhaus
2007-05-02 11:50 ` Georg Bauhaus
2007-05-02 13:12 ` Dmitry A. Kazakov
2007-05-02 14:21 ` Markus E Leypold
2007-05-03 18:27 ` Georg Bauhaus
2007-05-03 19:07 ` Dmitry A. Kazakov
2007-05-03 19:49 ` Markus E Leypold
2007-04-29 16:26 ` Markus E Leypold
2007-04-26 21:50 ` Simon Wright
2007-04-27 4:45 ` Jeffrey R. Carter
2007-04-27 7:45 ` Martin Krischik
2007-04-27 22:54 ` Georg Bauhaus
2007-04-30 20:13 ` Matthew Heaney
2007-04-26 20:48 ` andrew.carroll
-- strict thread matches above, loose matches on Subject: below --
2003-12-02 23:15 Mr. J.
2003-12-03 9:31 ` Dmitry A. Kazakov
2003-12-02 23:13 generic package Ratson Janiv
2003-12-03 17:39 ` Stephen Leake
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