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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: A bad counterintuitive behaviour of Ada about OO
Date: Fri, 8 Aug 2014 10:26:23 +0200
Date: 2014-08-08T10:26:23+02:00	[thread overview]
Message-ID: <1oj0b4rwma99b$.1iqu11p0ea556$.dlg@40tude.net> (raw)
In-Reply-To: mD%Ev.229884$AN6.142135@fx01.iad

On Fri, 08 Aug 2014 02:12:00 -0600, Shark8 wrote:

> Restriction is so pervasive [we all used it in math, esp. for proofs], 
> and useful that I find it amazing that Ada's Subtype facility *isn't* a 
> common thing in programming languages -- and there are [lots of] 
> programmers who seem not to grasp the utility thereof. :(

It is a common thing still. E.g. const int is such a type, int constrained
by disallowing mutators.

OO favored extension because it keept substitutability for immutable
operations. Extension breaks mutators and out-arguments/results, which
aren't supported anyway in most OOPL.

The idea that subtyping can be directly reflect substitutability is the
root problem and the idea that the set of values could somehow define the
type so generalization or specialization might mean something. Ada's
subtypes suffer this as well. Both are wrong.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de


  reply	other threads:[~2014-08-08  8:26 UTC|newest]

Thread overview: 73+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-05 20:09 A bad counterintuitive behaviour of Ada about OO Victor Porton
2014-08-05 20:58 ` Simon Wright
2014-08-05 21:06   ` Victor Porton
2014-08-05 21:51     ` Niklas Holsti
2014-08-05 22:13       ` Victor Porton
2014-08-05 22:35   ` Victor Porton
2014-08-05 23:25     ` Adam Beneschan
2014-08-05 20:59 ` Dmitry A. Kazakov
2014-08-05 21:07   ` Victor Porton
2014-08-05 22:39     ` Shark8
2014-08-05 21:11   ` Victor Porton
2014-08-06  7:26     ` Dmitry A. Kazakov
2014-08-07  7:41       ` Maciej Sobczak
2014-08-07  8:50         ` Dmitry A. Kazakov
2014-08-08  7:54           ` Maciej Sobczak
2014-08-08  8:14             ` Dmitry A. Kazakov
2014-08-08 13:06               ` Maciej Sobczak
2014-08-08 13:22                 ` Dmitry A. Kazakov
2014-08-08 22:32                   ` Randy Brukardt
2014-08-09 16:11                   ` Maciej Sobczak
2014-08-09 16:48                     ` Dmitry A. Kazakov
2014-08-10 20:55                       ` Maciej Sobczak
2014-08-11  7:41                         ` Dmitry A. Kazakov
2014-08-11  7:58                           ` Maciej Sobczak
2014-08-11  8:23                             ` Dmitry A. Kazakov
2014-08-12  7:50                               ` Maciej Sobczak
2014-08-11 11:35                             ` G.B.
2014-08-08 22:26                 ` Randy Brukardt
2014-08-08  8:34             ` Shark8
2014-08-08 12:59               ` Maciej Sobczak
2014-08-08 22:37                 ` Randy Brukardt
2014-08-08 22:53                   ` Jeffrey Carter
2014-08-07  8:58         ` J-P. Rosen
2014-08-07  9:40           ` Dmitry A. Kazakov
2014-08-07 11:17             ` J-P. Rosen
2014-08-07 12:28               ` Dmitry A. Kazakov
2014-08-07 13:34                 ` J-P. Rosen
2014-08-07 16:10                   ` Dmitry A. Kazakov
2014-08-07 18:14                     ` Robert A Duff
2014-08-07 19:41                       ` Dmitry A. Kazakov
2014-08-07 20:53                         ` Robert A Duff
2014-08-08  7:43                           ` Dmitry A. Kazakov
2014-08-08  8:18                             ` Shark8
2014-08-08  7:45                     ` J-P. Rosen
2014-08-08  8:04                       ` Dmitry A. Kazakov
2014-08-08  8:55                         ` J-P. Rosen
2014-08-08  9:13                           ` Dmitry A. Kazakov
2014-08-08 10:01                             ` J-P. Rosen
2014-08-08 10:53                               ` Dmitry A. Kazakov
2014-08-08 10:56                                 ` Victor Porton
2014-08-08 12:00                                 ` J-P. Rosen
2014-08-08 13:11                                   ` Dmitry A. Kazakov
2014-08-08 13:53                                     ` J-P. Rosen
2014-08-08 20:23                                       ` Dmitry A. Kazakov
2014-08-07 20:29                   ` Shark8
2014-08-08  7:49                     ` J-P. Rosen
2014-08-08  8:12                       ` Shark8
2014-08-08  8:26                         ` Dmitry A. Kazakov [this message]
2014-08-08 11:10                           ` Shark8
2014-08-08 11:20                             ` Dmitry A. Kazakov
2014-08-08 19:34                               ` Shark8
2014-08-08 20:23                                 ` Dmitry A. Kazakov
2014-08-07 15:03           ` Jeffrey Carter
2014-08-08  7:48           ` Maciej Sobczak
2014-08-08  8:51             ` J-P. Rosen
2014-08-08 13:25               ` Maciej Sobczak
2014-08-08 13:34                 ` J-P. Rosen
2014-08-08 13:52                   ` Dmitry A. Kazakov
2014-08-08 14:21                     ` J-P. Rosen
2014-08-08 20:23                       ` Dmitry A. Kazakov
2014-08-08 22:08                     ` Randy Brukardt
2014-08-08 22:18                 ` Randy Brukardt
2014-08-06  4:50 ` Per Sandberg
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