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From: Maciej Sobczak <see.my.homepage@gmail.com>
Subject: Re: discriminant questions
Date: Mon, 19 Sep 2011 13:00:15 -0700 (PDT)
Date: 2011-09-19T13:00:15-07:00	[thread overview]
Message-ID: <b210b96b-806d-4add-8ac0-fa2ce568f855@u20g2000yqj.googlegroups.com> (raw)
In-Reply-To: osxb9aktb5va$.gl2adls3llnz$.dlg@40tude.net

On Sep 19, 9:39 am, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
wrote:

> > Problem: enumerate elements from two parallel containers (aka
> > zipping).
>
> What is wrong with using relative positions? Actually, mathematically,
> there is no other way, and the word enumeration technically means a mapping
> of the elements of a set onto a set numbers.

Mathematically you can pretend that the physicality of some operations
can be ignored.
But try your idea with linked lists.

> > Which might mean that the concept of pointers is not completely
> > missing the point (pun intended).
>
> It does. Consider a container located in a machine registers, where are the
> pointers?

I'm not interested in impractical examples.

Note also that it is a problem of the compiler, not mine - the same
issue as with access to single variable, which might be possibly
stored in a register. I don't need to know how this is done at the
level of registers, I'm interested in high-level results.

> The pointer itself is based on an enumeration in mathematical
> sense of this word, where memory elements are mapped onto numbers.

Interesting, but off-topic. What we are interested in is not memory
elements, but the ability of some entity (the iterator) to represent -
and be dereferenced! - a value within the container.

> The problem of pointers/iterators etc is that they require more than needed
> (persistent element identity), which is a burden for both the container
> designer and the user of.

Could you elaborate and why this is a problem?

> But Ada tried not fall into this.

But now we see that the idea is useful. Like in container zipping.

--
Maciej Sobczak * http://www.msobczak.com * http://www.inspirel.com



  reply	other threads:[~2011-09-19 20:00 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 [this message]
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
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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