From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-25) on ip-172-31-91-241.ec2.internal X-Spam-Level: X-Spam-Status: No, score=0.0 required=3.0 tests=none autolearn=unavailable autolearn_force=no version=4.0.1 Path: nntp.eternal-september.org!eternal-september.org!feeder.eternal-september.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: In precision typing we trust Date: Mon, 25 Aug 2025 22:09:14 +0200 Organization: A noiseless patient Spider Message-ID: <108ift9$3kh0r$1@dont-email.me> References: <107uv9g$3019a$1@dont-email.me> <107v1ji$303of$1@dont-email.me> <336fbb5f-a279-ea8e-67fd-f62bb00d6a89@irrt.De> <107vfb9$34cpj$1@dont-email.me> <10855lq$gj8l$1@dont-email.me> <1088h1a$19635$1@dont-email.me> <1089p1i$1ig1d$1@dont-email.me> <108aq2p$1qo9o$1@dont-email.me> <108dh2l$2f5h3$1@dont-email.me> <108ej11$2mbr8$1@dont-email.me> <108g1fv$32gqg$3@dont-email.me> <108h6b7$3a75k$3@dont-email.me> <87plcjn5ru.fsf@nightsong.com> <108hek3$3c6u1$1@dont-email.me> <87ldn7mil5.fsf@nightsong.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Mon, 25 Aug 2025 20:09:14 +0000 (UTC) Injection-Info: dont-email.me; posting-host="83346f1a4a3a4ac997eb0857b159dfbd"; logging-data="3818523"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18SwU10DOsOHSoDQUbf4UhS5k4XGtEUH8g=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:nMAyjMdZk1KNRynIuGiEWlPL5ZU= Content-Language: en-US In-Reply-To: <87ldn7mil5.fsf@nightsong.com> Xref: feeder.eternal-september.org comp.lang.ada:66919 List-Id: On 2025-08-25 19:12, Paul Rubin wrote: > "Dmitry A. Kazakov" writes: >> Why do I need to instantiate a class? Provided that it is obviously >> impossible since the class is an open set of types. > > You aren't using the term "class" the way Python or the rest of the OOP > world does. Call the thing (a set of types closed under derivation) the way you want. If class means type, fine. The question remains why should I need to instantiate it beyond declaring an object of? E.g. FORTRAN-IV REAL*8 X works fine without classes, metaclasses etc. > You also aren't in charge of which usage is "correct". The > term is used in many different ways. Can you provide a citation where I said anything about correct wording? I merely asked you what were a practical purpose of having metaclasses in programming without buzz words. > You can read more about metaclasses here: > > https://en.wikipedia.org/wiki/Metaclass From the text: "In object-oriented programming, a metaclass is a class whose instances are classes themselves" How is that, except for sloppiness "class is ... a class", different from a set of sets of types? -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de