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" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: In precision typing we trust
Date: Thu, 28 Aug 2025 11:43:15 +0200
Organization: A noiseless patient Spider
Message-ID: <108p8bi$16qn1$6@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$1@dont-email.me> <mgmhbtF8u6bU1@mid.individual.net>
 <10855lq$gj8l$1@dont-email.me> <1088h1a$19635$1@dont-email.me>
 <1089p1i$1ig1d$1@dont-email.me> <108aq2p$1qo9o$1@dont-email.me>
 <108b1r3$1sj3c$1@dont-email.me> <108dh4t$2f5h3$2@dont-email.me>
 <108dkik$2g20p$1@dont-email.me> <108g1cg$32gqg$2@dont-email.me>
 <108h6b0$3a75k$2@dont-email.me> <108iiq5$3lihe$3@dont-email.me>
 <108mhhk$j2jt$1@dont-email.me> <108mis1$j4cj$1@dont-email.me>
 <108o33p$vok4$5@dont-email.me> <108o6rp$10njb$1@dont-email.me>
 <108o7cm$10qct$1@dont-email.me> <108o845$10pj9$3@dont-email.me>
 <108p65h$17vk1$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Thu, 28 Aug 2025 09:43:15 +0000 (UTC)
Injection-Info: dont-email.me; posting-host="6f970729dc22bef6d204ec8c3c6ab955";
	logging-data="1272545"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/bjK/YQXy7wp/9C8AzjrL/XQoI1eOHvSY="
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:bxsG89Jz0BsORd5ToMey5d84YMo=
In-Reply-To: <108p65h$17vk1$1@dont-email.me>
Content-Language: en-US
Xref: feeder.eternal-september.org comp.lang.ada:66971
List-Id: <comp.lang.ada>

On 2025-08-28 11:05, Kevin Chadwick wrote:

>> But can you do type checking dynamically, at run-time?
>>
> 
> 'Valid

Except that this is not checking of the type, which is not possible on 
fundamental grounds.

It is checking a value of an object for constraints. That a value might 
violate the constraints is itself a result of type violation when the 
value was coerced to the type by an operation not defined on the type, 
e.g. per Unchecked_Conversion or memory mapping.

But the point you make is correct it is same as Python's "type 
checking," namely lets take something apparently untyped and see if that 
thing could pass for the given type.

In Python everything is untyped even when type annotations are used.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de