From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
	ip-172-31-74-118.ec2.internal
X-Spam-Level: 
X-Spam-Status: No, score=-0.9 required=3.0 tests=BAYES_00,XPRIO autolearn=no
	autolearn_force=no version=3.4.6
Path: eternal-september.org!reader02.eternal-september.org!gandalf.srv.welterde.de!news.jacob-sparre.dk!franka.jacob-sparre.dk!pnx.dk!.POSTED.rrsoftware.com!not-for-mail
From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Adacore joins with Ferrous Systems to support Rust
Date: Thu, 3 Feb 2022 21:20:08 -0600
Organization: JSA Research & Innovation
Message-ID: <sti619$p1k$1@franka.jacob-sparre.dk>
References: <87o83pzlvm.fsf@nightsong.com> <stdvgv$76k$1@gioia.aioe.org> <87bkzpyqx3.fsf@nightsong.com> <stfbf5$bvi$1@gioia.aioe.org> <8735l0zo6j.fsf@nightsong.com> <stfg0v$1luk$1@gioia.aioe.org> <lyleys1932.fsf@pushface.org> <stgj3j$12g8$1@gioia.aioe.org>
Injection-Date: Fri, 4 Feb 2022 03:20:09 -0000 (UTC)
Injection-Info: franka.jacob-sparre.dk; posting-host="rrsoftware.com:24.196.82.226";
	logging-data="25652"; mail-complaints-to="news@jacob-sparre.dk"
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 6.00.2900.5931
X-RFC2646: Format=Flowed; Response
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.7246
Xref: reader02.eternal-september.org comp.lang.ada:63469
List-Id: <comp.lang.ada>

"Luke A. Guest" <laguest@archeia.com> wrote in message 
news:stgj3j$12g8$1@gioia.aioe.org...
> On 03/02/2022 11:30, Simon Wright wrote:
>> "Luke A. Guest" <laguest@archeia.com> writes:
>>
>>> At uni, we didn't even touch on tagged types, but used controlled
>>> types
>>
>> Of course controlled types are implemented as tagged types. ISTR Dmitry
>
> We had a book with a reading guide. We weren't shown the specs showing the 
> type of controlled/limited_controlled. So, when you don't have that 
> information and only know that you can derive from it and then implement 2 
> or 3 subprograms, you don't need to know about OOP in Ada.
>
> Just like we didn't touch generic packages until much later in the year, 
> generic subprograms, yeah, because u_d was required early on.
>
>> objecting to this, I think he was right (philosophically; I've no idea
>> about the practicality of alternate approaches).
>
> How else would you do controlled types?

Ada 9x originally had a bunch of magic attributes (similar to streaming). It 
was very complex and got dumped in the dustbin during "scope reduction". 
Later on, some of us were bemoaning that a critical feature (finalization) 
had gotten lost in Ada 9x, and Tucker came up with the idea to build it on 
top of tagged types as a massive simplification (at the loss of a bit of 
power). People often complain that Ada finalization is complex, and it is, 
except all of the alternatives are a lot more complex. :-)

                   Randy.