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=-0.9 required=5.0 tests=BAYES_00,FORGED_GMAIL_RCVD,
	FREEMAIL_FROM autolearn=no autolearn_force=no version=3.4.4
Path: 
 buffer2.nntp.dca1.giganews.com!border2.nntp.dca1.giganews.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!usenet.blueworldhosting.com!feeder01.blueworldhosting.com!feeder.erje.net!1.eu.feeder.erje.net!eternal-september.org!feeder.eternal-september.org!mx02.eternal-september.org!.POSTED!not-for-mail
From: =?UTF-8?B?QmrDtnJuIEx1bmRpbg==?= <b.f.lundin@gmail.com>
Newsgroups: comp.lang.ada
Subject: Re: Ada design bug or GNAT bug?
Date: Sat, 04 Jul 2015 14:00:57 +0200
Organization: A noiseless patient Spider
Message-ID: <mn8hok$fdf$1@dont-email.me>
References: <yo94phsbcvht$.1bktwe2qoqntt$.dlg@40tude.net>
	<mm58b5$9k0$1@loke.gir.dk>
 <4lrj5zz2u2z.u8x9cf7xzic6.dlg@40tude.net>	<mm9h84$5n8$1@loke.gir.dk>
	<d4629c07-4005-4bd3-8fa6-85d088fb83c9@googlegroups.com>
	<58f64fa9-7d0b-44dd-870c-77d9afcb82c4@googlegroups.com>
	<mn4jj1$n50$3@loke.gir.dk>
	<4228c0ea-837d-42a0-b2a8-a98d8d30f820@googlegroups.com>
 <lyy4iwxt4m.fsf@pushface.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
Injection-Date: Sat, 4 Jul 2015 11:58:12 +0000 (UTC)
Injection-Info: mx02.eternal-september.org;
 posting-host="d2d02d9cc3d0011cde6cddd52020399a";
 logging-data="15791"; mail-complaints-to="abuse@eternal-september.org";
 posting-account="U2FsdGVkX184NFFbMqklQedQPn4oj8dU"
User-Agent: Mozilla/5.0 (X11; Linux x86_64;
 rv:31.0) Gecko/20100101 Icedove/31.4.0
In-Reply-To: <lyy4iwxt4m.fsf@pushface.org>
Cancel-Lock: sha1:jXF8q/dzg91cWw9eRBp4sFNfYtQ=
Xref: number.nntp.giganews.com comp.lang.ada:193916
Date: 2015-07-04T14:00:57+02:00
List-Id: <comp.lang.ada>

On 2015-07-04 09:46, Simon Wright wrote:
> Shark8 <onewingedshark@gmail.com> writes:
> 
>> Also, I seem to recall your dislike of INTERFACEs -- in hindsight,
>> what would you have done differently if you needed the mechanism of
>> "Type T has functions X, Y, and X" applied to a group of types?
>> Generics, or some variations thereof?
> 
> Generic signature packages?
> 

I had this problem when implementing another companies proprietary
communications protocol, that we needed to communicate with.
The physical devices were picking-robots.
All messages had a common headers and then message specific fields.
And they had to have certain functions. To_String, Save_to_Database,
Send, etc.

Since I had complete control over the implementation, I
ended up using inheritance from an abstract type.

Some functions of the abstract type were implemented,
and others - to specialized for the inherited type -
was declared abstract.


--
Björn