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=-0.3 required=5.0 tests=BAYES_00,
	REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4
Path: 
 eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!.POSTED!not-for-mail
From: "G.B." <bauhaus@notmyhomepage.invalid>
Newsgroups: comp.lang.ada
Subject: Re: A function that cannot be called?
Date: Fri, 19 Oct 2018 16:00:06 +0200
Organization: A noiseless patient Spider
Message-ID: <pqco17$2vr$1@dont-email.me>
References: <pq9tf7$9bf$1@dont-email.me>
 <7ab688d0-b6b8-459c-b5b7-39b6c35daad2@googlegroups.com>
 <pqanbb$hl5$1@dont-email.me> <pqau10$us1$1@franka.jacob-sparre.dk>
Reply-To: nonlegitur@notmyhomepage.de
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Fri, 19 Oct 2018 14:00:07 -0000 (UTC)
Injection-Info: reader02.eternal-september.org;
 posting-host="189888e645ecebbf26e597f043adf425";
	logging-data="3067"; mail-complaints-to="abuse@eternal-september.org";
	posting-account="U2FsdGVkX1/w0LyDNUyoll2g06l0nKQ9ktjljQIBx30="
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:52.0)
 Gecko/20100101 Thunderbird/52.9.1
Cancel-Lock: sha1:WGb0PtJeBhzC21qOko8MP+yabkU=
In-Reply-To: <pqau10$us1$1@franka.jacob-sparre.dk>
Content-Language: de-DE
X-Mozilla-News-Host: news://news.arcor.de
Xref: reader02.eternal-september.org comp.lang.ada:54653
Date: 2018-10-19T16:00:06+02:00
List-Id: <comp.lang.ada>

On 18.10.18 23:30, Randy Brukardt wrote:

> If you don't want any objects at all (which would be weird, as
> types have no real use until some object is created of it or a descendant),
> then don't create any.

Not having any objects at all needs to be a feature of the
Ada language's type system, at least for this kind of competition.
(Hence hiding the full type in a private nest with no body.)

The members of the functionist faction will turn their eyes
towards the cieling in dispair:
it is these weird functions involving uninhabited types that have
turned out to be essential for the interplay between logicians
and computer scientists discovering practical solutions. For
example, what about a type system that guarantees termination?