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From: nospam@thanks.com.au (Don Harrison)
Subject: Re: Can't export object of private type
Date: 1999/03/01
Date: 1999-03-01T00:00:00+00:00	[thread overview]
Message-ID: <F7xvzA.Lqn@syd.csa.com.au> (raw)
In-Reply-To: 7be1ou$mjg$2@plug.news.pipex.net

Nick Roberts wrote:

:I think, possibly, you're missing the point, Don!  

Yes, you're right. Sorry about that.

What was missing was the ability to derive a class hierachy of singletons 
and dispatch on the exported objects. This is what I meant by:

>   2) Are polymorphic

Sorry if that wasn't clear enough initially.

:Planet_Id is only an
:identifier of a planet, not the planet itself.  There is only one instance
:of each planet -- kept in terms of variables within (the body of) each
:planet package -- and the corresponding Planet_Id simply gives access to the
:planet.  It's just like having a single object with potentially many access
:values pointing to it; I'm just using integers (type Planet_Id) instead of
:access values.

Got you.

:Again, you must not confuse design with implementation: I'm using packages
:here instead of types, and integers instead of access values.  But these are
:mere implementational details, and nothing to do with the design.  The
:design is: single objects (the planet packages); polymorphic access to them
:(via planet ids and the package Dynamic_Planet).  The 'objects' in our
:design do not have to be objects in implementation (we use packages
:instead); the 'access' values in our design do not have to be access values
:in our implementation (we use integers instead).

Sure. What I'm trying to acheive is a set of implementation techniques for 
OO design that:

  a) Are consistent at least from the perspective of client code. 
     For example, everything that is an object (including singletons) 
     *looks like* an object (and not a module).
  b) Map as directly as possible from the design.
  c) Are idiomatic Ada.

:Hope this clarifies things.

It does.


-- 
Don (Harrison).   donh at syd.csa.com.au






  reply	other threads:[~1999-03-01  0:00 UTC|newest]

Thread overview: 128+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <F7JoCB.JxB@syd.csa.com.au>
1999-02-24  0:00 ` Can't export object of private type Don Harrison
1999-02-24  0:00   ` Tom Moran
1999-02-24  0:00   ` Samuel Mize
1999-02-24  0:00     ` Tucker Taft
1999-02-25  0:00     ` Don Harrison
1999-02-25  0:00       ` fraser
1999-02-26  0:00         ` Don Harrison
     [not found]           ` <7b6nqe$75m$1@remarq.com>
1999-02-26  0:00             ` fraser
1999-02-27  0:00               ` Nick Roberts
1999-02-26  0:00           ` fraser
1999-03-01  0:00             ` Don Harrison
1999-03-01  0:00               ` Matthew Heaney
1999-02-26  0:00           ` Samuel Mize
1999-03-01  0:00             ` Don Harrison
1999-03-01  0:00               ` Matthew Heaney
1999-03-02  0:00               ` fraser
1999-03-03  0:00                 ` Don Harrison
1999-02-28  0:00           ` Matthew Heaney
1999-02-28  0:00         ` Matthew Heaney
1999-02-25  0:00       ` Samuel Mize
1999-02-26  0:00         ` Don Harrison
1999-02-27  0:00           ` Nick Roberts
1999-03-01  0:00             ` Don Harrison
1999-03-02  0:00               ` Matthew Heaney
1999-03-01  0:00             ` Don Harrison
1999-03-01  0:00               ` Matthew Heaney
1999-03-01  0:00                 ` Nick Roberts
1999-03-01  0:00               ` Nick Roberts
1999-03-01  0:00                 ` Don Harrison [this message]
1999-03-02  0:00                   ` Matthew Heaney
1999-03-03  0:00                     ` Don Harrison
1999-03-03  0:00                       ` Samuel Mize
1999-03-04  0:00                         ` Don Harrison
1999-03-07  0:00                     ` Ehud Lamm
1999-03-03  0:00               ` Robert A Duff
1999-03-04  0:00                 ` Don Harrison
1999-03-04  0:00                   ` Robert A Duff
1999-02-28  0:00         ` Matthew Heaney
1999-03-01  0:00           ` Nick Roberts
1999-03-01  0:00             ` Matthew Heaney
1999-03-01  0:00             ` Matthew Heaney
1999-03-02  0:00               ` Nick Roberts
1999-03-01  0:00           ` Samuel Mize
1999-02-25  0:00       ` robert_dewar
1999-02-26  0:00         ` Don Harrison
1999-02-26  0:00           ` robert_dewar
1999-02-26  0:00             ` dennison
1999-02-26  0:00             ` bourguet
1999-02-26  0:00               ` Samuel T. Harris
1999-02-27  0:00                 ` Simon Wright
1999-02-27  0:00                 ` Jean-Pierre Rosen
1999-02-28  0:00               ` dewar
1999-03-01  0:00                 ` bourguet
1999-03-01  0:00             ` Don Harrison
1999-03-01  0:00               ` robert_dewar
1999-03-03  0:00                 ` Don Harrison
1999-03-03  0:00                   ` robert_dewar
1999-03-01  0:00             ` Stephen Leake
1999-02-27  0:00         ` Brian Rogoff
1999-03-01  0:00           ` robert_dewar
1999-02-28  0:00       ` Matthew Heaney
1999-03-01  0:00       ` Tom Moran
1999-03-02  0:00         ` Matthew Heaney
1999-03-02  0:00           ` Tom Moran
1999-03-02  0:00             ` Matthew Heaney
1999-03-02  0:00               ` Tom Moran
1999-03-02  0:00                 ` Matthew Heaney
1999-03-02  0:00                   ` nabbasi
1999-03-02  0:00                     ` Matthew Heaney
1999-03-03  0:00                   ` Don Harrison
1999-03-03  0:00                     ` Single Extension; Polymorphic Arrays Nick Roberts
1999-03-03  0:00                       ` Nick Roberts
1999-03-08  0:00                         ` Matthew Heaney
1999-03-08  0:00                           ` Nick Roberts
1999-03-08  0:00                           ` Tucker Taft
     [not found]                             ` <m3ogm40wav.fsf@mheaney.ni.net>
1999-03-08  0:00                               ` Nick Roberts
1999-03-08  0:00                               ` Tucker Taft
1999-03-08  0:00                                 ` dennison
1999-03-09  0:00                                 ` Nick Roberts
1999-03-03  0:00               ` Can't export object of private type Don Harrison
1999-03-03  0:00                 ` Don Harrison
1999-03-03  0:00                   ` Nick Roberts
1999-03-04  0:00                     ` Don Harrison
1999-03-04  0:00                       ` fraser
1999-03-09  0:00                         ` Don Harrison
1999-03-04  0:00                       ` Nick Roberts
1999-03-04  0:00                         ` robert_dewar
1999-03-05  0:00                           ` Nick Roberts
1999-03-05  0:00                         ` Robert A Duff
1999-03-05  0:00                           ` Abstract Subprograms of Untagged Types Nick Roberts
1999-03-05  0:00                             ` robert_dewar
1999-03-05  0:00                             ` Tucker Taft
1999-03-05  0:00                               ` Nick Roberts
1999-03-06  0:00                               ` robert_dewar
1999-03-04  0:00                       ` Can't export object of private type Nick Roberts
1999-03-08  0:00                         ` Matthew Heaney
1999-03-09  0:00                         ` Don Harrison
1999-03-09  0:00                           ` Matthew Heaney
1999-03-09  0:00                             ` Nick Roberts
1999-03-10  0:00                             ` Don Harrison
1999-03-10  0:00                               ` Matthew Heaney
1999-03-08  0:00                     ` Matthew Heaney
1999-03-08  0:00                       ` Nick Roberts
1999-03-08  0:00                 ` Matthew Heaney
1999-03-10  0:00                   ` Don Harrison
1999-03-10  0:00                     ` Matthew Heaney
1999-03-10  0:00                       ` dennison
1999-03-10  0:00                         ` robert_dewar
1999-03-10  0:00                           ` dennison
1999-03-10  0:00                             ` robert_dewar
1999-03-10  0:00                               ` dennison
1999-03-11  0:00                                 ` robert_dewar
1999-03-11  0:00                                   ` Don Harrison
1999-03-12  0:00                                     ` robert_dewar
1999-03-11  0:00                                 ` bill
1999-03-11  0:00                                   ` Scott Ingram
1999-03-11  0:00                                     ` Larry Kilgallen
1999-03-11  0:00                                   ` dennison
1999-03-12  0:00                                   ` dewar
1999-03-11  0:00                                 ` dennison
1999-03-11  0:00                           ` Don Harrison
1999-03-10  0:00                         ` Robert A Duff
1999-03-10  0:00                           ` dennison
1999-03-11  0:00                             ` dennison
1999-03-10  0:00                           ` robert_dewar
1999-03-03  0:00           ` Don Harrison
1999-02-28  0:00     ` Matthew Heaney
1999-02-28  0:00   ` Matthew Heaney
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