From: Maciej Sobczak <see.my.homepage@gmail.com>
Subject: Re: Ada Interfaces and the Liskov Substitution Principle
Date: 25 May 2007 00:52:21 -0700
Date: 2007-05-25T00:52:21-07:00 [thread overview]
Message-ID: <1180079541.558215.256570@h2g2000hsg.googlegroups.com> (raw)
In-Reply-To: <f3556m$88d$1@jacob-sparre.dk>
On 25 Maj, 00:58, "Randy Brukardt" <r...@rrsoftware.com> wrote:
> > I was talking about real assignment - and this assumes that two
> > objects already exist and we make one to be equal to the other. There
> > is no way to do it right.
>
> (Using the *correct* terminology as Bob noted)
Yes, thank you both for explaining it - I was using the C++
terminology.
> Given the current Ada rules, what classwide assignment is good for is
> *re*construction:
>
> procedure Do_Something(Y : out Object'Class) is
> begin
> Y := Constructor_Func (<some details of Y>);
> end Do_Something;
>
> that is, the replacement of an object with different one of the same type.
> The Constructor_Func is dispatching on the real type of the LHS object
Interesting. In most of the cases, the factory function creates the
object of whatever type *it* decides (based on its parameters or some
other input values) and initializes the class-wide type accordingly.
The one above means "remake me, please", but it's applicability must
be greatly limited - you neatly write <some details of Y>, but it
should be really <some details of whatever-Y-happens-to-be which we
don't know here>.
That complicates this scheme a bit.
There is a very simple rule of thumb for checking whether any given OO
pattern makes sense - try to stick it to the classical geometry
example.
If it falls off, beware. :-)
--
Maciej Sobczak
http://www.msobczak.com/
next prev parent reply other threads:[~2007-05-25 7:52 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-23 19:47 Ada Interfaces and the Liskov Substitution Principle Stefan Lucks
2007-05-23 20:32 ` Ludovic Brenta
2007-05-23 22:00 ` Randy Brukardt
2007-05-24 0:56 ` Anh Vo
2007-05-24 18:27 ` Pascal Obry
2007-05-24 18:39 ` Dmitry A. Kazakov
2007-05-24 18:51 ` Pascal Obry
2007-05-24 22:44 ` Randy Brukardt
2007-05-24 6:57 ` Stefan Lucks
2007-05-23 20:54 ` Maciej Sobczak
2007-05-23 21:58 ` Randy Brukardt
2007-05-24 7:29 ` Maciej Sobczak
2007-05-24 8:02 ` Dmitry A. Kazakov
2007-05-24 12:58 ` Maciej Sobczak
2007-05-24 13:42 ` Dmitry A. Kazakov
2007-05-24 22:08 ` Robert A Duff
2007-07-01 1:00 ` David Thompson
2007-05-24 22:58 ` Randy Brukardt
2007-05-25 7:52 ` Maciej Sobczak [this message]
2007-05-25 8:21 ` Dmitry A. Kazakov
2007-05-25 20:27 ` Maciej Sobczak
2007-05-26 7:48 ` Dmitry A. Kazakov
2007-05-27 8:30 ` Maciej Sobczak
2007-05-27 10:04 ` Dmitry A. Kazakov
2007-05-29 8:03 ` Maciej Sobczak
2007-05-29 13:18 ` Dmitry A. Kazakov
2007-05-29 13:32 ` Dmitry A. Kazakov
2007-05-29 15:34 ` Maciej Sobczak
2007-05-29 17:07 ` Dmitry A. Kazakov
2007-05-30 7:40 ` Maciej Sobczak
2007-05-30 8:43 ` Dmitry A. Kazakov
2007-05-30 12:54 ` Maciej Sobczak
2007-05-30 13:56 ` Dmitry A. Kazakov
2007-05-30 16:49 ` vgodunko
2007-05-30 20:52 ` Maciej Sobczak
2007-05-31 8:15 ` Dmitry A. Kazakov
2007-05-31 13:46 ` Maciej Sobczak
2007-06-01 7:29 ` Dmitry A. Kazakov
2007-06-01 13:32 ` Maciej Sobczak
2007-06-01 14:53 ` Dmitry A. Kazakov
2007-06-01 20:31 ` Maciej Sobczak
2007-06-02 8:19 ` Dmitry A. Kazakov
2007-06-02 16:49 ` Maciej Sobczak
2007-06-03 7:09 ` Dmitry A. Kazakov
2007-06-03 22:04 ` Maciej Sobczak
2007-06-04 8:08 ` Dmitry A. Kazakov
2007-06-04 17:02 ` Maciej Sobczak
2007-06-05 8:35 ` Dmitry A. Kazakov
2007-06-05 22:12 ` Maciej Sobczak
2007-06-06 8:21 ` Dmitry A. Kazakov
2007-06-06 14:46 ` Maciej Sobczak
2007-06-06 15:11 ` Maciej Sobczak
2007-06-06 15:32 ` Markus E Leypold
2007-05-24 10:42 ` Georg Bauhaus
2007-05-24 13:41 ` Dmitry A. Kazakov
2007-05-25 16:59 ` Markus E Leypold
2007-05-28 9:52 ` Georg Bauhaus
2007-05-28 11:50 ` Dmitry A. Kazakov
2007-05-28 23:32 ` Georg Bauhaus
2007-05-29 12:05 ` Dmitry A. Kazakov
2007-05-29 13:33 ` Georg Bauhaus
2007-05-29 17:29 ` Dmitry A. Kazakov
2007-05-29 20:46 ` Georg Bauhaus
2007-05-30 7:53 ` Dmitry A. Kazakov
2007-05-30 13:18 ` Georg Bauhaus
2007-05-31 10:27 ` Dmitry A. Kazakov
2007-05-31 11:44 ` Georg Bauhaus
2007-06-01 7:37 ` Dmitry A. Kazakov
2007-06-01 10:07 ` Markus E Leypold
2007-06-01 11:41 ` Georg Bauhaus
2007-06-01 13:07 ` Dmitry A. Kazakov
2007-05-28 13:47 ` Markus E Leypold
2007-05-28 23:12 ` Georg Bauhaus
2007-05-28 13:56 ` Markus E Leypold
2007-05-28 23:00 ` Georg Bauhaus
2007-05-24 7:39 ` Dmitry A. Kazakov
2007-05-24 11:12 ` Stefan Lucks
2007-05-24 13:56 ` Dmitry A. Kazakov
2007-05-24 14:41 ` Stefan Lucks
2007-05-24 15:46 ` Dmitry A. Kazakov
2007-05-24 15:00 ` Georg Bauhaus
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