From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID
	autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,56dbd715fa74735a
X-Google-Attributes: gid103376,public
From: John Volan <johnv@ac3i.dseg.ti.com>
Subject: Re: Mutually dependent private types
Date: 1998/05/29
Message-ID: <356F1F11.3B9A68E3@ac3i.dseg.ti.com>#1/1
X-Deja-AN: 357755044
Content-Transfer-Encoding: 7bit
References: <6k25ra$6j7$1@nnrp1.dejanews.com>
 <matthew_heaney-ya023680002105982333070001@news.ni.net>
 <3565B105.9BFB4788@ac3i.dseg.ti.com>
 <matthew_heaney-ya023680002205981805440001@news.ni.net>
 <356B226F.EF05E927@ac3i.dseg.ti.com> <m3d8d08yk6.fsf@mheaney.ni.net>
 <356C8A02.44354B09@ac3i.dseg.ti.com> <m3g1hvs1u3.fsf@mheaney.ni.net>
 <356E09A1.B493FE89@ac3i.dseg.ti.com>
 <Pine.BSF.3.96.980529083534.1132A-100000@shell5.ba.best.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Organization: Raytheon Systems Company, Advanced C3I Systems
Newsgroups: comp.lang.ada
Date: 1998-05-29T00:00:00+00:00
List-Id: <comp.lang.ada>


Brian Rogoff wrote:
> 
> Lets explore the idea a little more though. If there were some better
> (read: more direct) support for multiple inheritance in Ada, the
> inheritance collision argument is weakened, and the workaround can become
> the blessed solution. Since an extension is being proposed anyways,
> perhaps the single inheritance restriction should be rethought.

I'd still object to using inheritance to simulate forward type
declarations, on the grounds that it proliferates "spurious" extra
parent types, and forces programmers to do unnecessary downcasting type
conversions.  A true forward type declaration doesn't introduce a
different type, it's just a different view of the same type, in the same
sense that a private type declaration and its full type declaration are
just two views of the same type.

-- 
Signature volanSignature = 
  new Signature
  ( /*name:      */ "John G. Volan",
    /*employer:  */ "Raytheon Advanced C3I Systems, San Jose",
    /*workEmail: */ "johnv@ac3i.dseg.ti.com",
    /*homeEmail: */ "johnvolan@sprintmail.com",
    /*selfPlug:  */ "Sun Certified Java Programmer",
    /*twoCents:  */ "Java would be even cooler with Ada95's " +
                    "generics, enumerated types, function types, " +
                    "named parameter passing, etc...",
    /*disclaimer:*/ "These views not packaged in COM.ti.dseg.ac3i, " +
                    "so loading them throws DontQuoteMeError. :-)" );