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=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,34c2aa33b8bdb1a9
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2002-01-17 06:55:18 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!news-FFM2.ecrc.net!news.iks-jena.de!lutz
From: lutz@iks-jena.de (Lutz Donnerhacke)
Newsgroups: comp.lang.ada
Subject: Re: Sugestion to Multiple Inheritance
Date: Thu, 17 Jan 2002 14:54:51 +0000 (UTC)
Organization: IKS GmbH Jena
Message-ID: <slrna4dpdm.kn.lutz@taranis.iks-jena.de>
References: <slrna3tf3u.kg.lutz@taranis.iks-jena.de>
 <uwuyo4xdv.fsf@gsfc.nasa.gov> <slrna3u9kj.kg.lutz@taranis.iks-jena.de>
 <ug05c4q4o.fsf@gsfc.nasa.gov> <slrna4d2oi.kn.lutz@taranis.iks-jena.de>
 <u3d15nj5n.fsf@gsfc.nasa.gov>
NNTP-Posting-Host: taranis.iks-jena.de
X-Trace: branwen.iks-jena.de 1011279291 11019 217.17.192.37 (17 Jan 2002
 14:54:51 GMT)
X-Complaints-To: usenet@iks-jena.de
NNTP-Posting-Date: Thu, 17 Jan 2002 14:54:51 +0000 (UTC)
User-Agent: slrn/0.9.6.3 (Linux)
Xref: archiver1.google.com comp.lang.ada:19014
Date: 2002-01-17T14:54:51+00:00
List-Id: <comp.lang.ada>

* Stephen Leake wrote:
>lutz@iks-jena.de (Lutz Donnerhacke) writes:
>> >> They do not need to be types at all. They are abstactions => interfaces.
>> >> Example: A describes a sort algorithm. B describes stableness. C describes
>> >> in-place-ness. D describes stable, in-place sort algorithms.
>> >
>> >Well, if they don't have to be types, you can easily do it in Ada. But
>> >all your complaints were that it could not be done with abstract Ada
>> >types.
>> 
>> I'm sorry for providing my solutions in the same posting asking for hints.
>> How can this be done easily?
>
>Just write packages A, B, C, D, with appropriate subprogram
>declarations in the spec, and appropriate comments saying what they
>do. Then in the body of D, call the subprograms in B and C as
>appropriate.
>
>The Ada code will _not_ describe the inheritance structure, except in
>the comments. Perhaps that is why you don't want to do this.

Let's try to code this:

package Sorts is
   function Sort (col : Collection) return Collection is abstract;
   procedure Sort (col : in out Collection) is abstract;
end package Sorts;

with Sorts;
package Stable_Sorts is
   function Sort renames Sorts.Sort;
end package Stable_Sorts;

with Sorts;
package Inplace_Sorts is
   procedure Sort renames Sorts.Sort;
end package Stable_Sorts;

with Stable_Sorts, Inplace_Sorts;
package Stable_Inplace_Sorts is
   procedure Sort renames ?;
end package;