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=-1.9 required=5.0 tests=BAYES_00
	autolearn=unavailable autolearn_force=no version=3.4.4
Path: 
 eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail
From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Ada Successor Language
Date: Tue, 26 Jun 2018 16:17:00 +0200
Organization: Aioe.org NNTP Server
Message-ID: <pgthsr$o89$1@gioia.aioe.org>
References: <5e86db65-84b9-4b5b-9aea-427a658b5ae7@googlegroups.com>
 <878t7u1cfm.fsf@nightsong.com>
 <c22391d4-94b6-4ed3-96c0-1e9a84c4a99c@googlegroups.com>
 <b1141508-e692-46f6-b536-4a72081dfb45@googlegroups.com>
 <foqeocF7l4fU1@mid.individual.net> <pg949k$jmv$1@dont-email.me>
 <foqjvhF8kskU1@mid.individual.net>
 <776f3645-ed0c-4118-9b4d-21660e3bba4b@googlegroups.com>
 <pg9bd9$eo9$1@gioia.aioe.org> <87602fbu2g.fsf@nightsong.com>
 <pgad3n$1sop$1@gioia.aioe.org> <87po0mziqt.fsf@nightsong.com>
 <pgbm5e$c1l$1@gioia.aioe.org> <87fu1izfgs.fsf@nightsong.com>
 <pgd1hq$ca2$1@gioia.aioe.org> <878t75nwad.fsf@adaheads.home>
 <pgqas8$mjm$1@dont-email.me> <pgqnt3$6rv$1@gioia.aioe.org>
 <fpcb15Fk3saU1@mid.individual.net> <pgqtq4$hon$1@gioia.aioe.org>
 <pgqv45$k7b$1@gioia.aioe.org> <pgr15g$nhb$1@gioia.aioe.org>
 <c43110cb-9dd3-4b3c-a0f2-533d27108ab3@googlegroups.com>
 <pgsqso$1ecd$2@gioia.aioe.org>
 <15b6f89f-997b-45ac-86b4-2e614bb624c2@googlegroups.com>
NNTP-Posting-Host: MyFhHs417jM9AgzRpXn7yg.user.gioia.aioe.org
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
X-Complaints-To: abuse@aioe.org
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101
 Thunderbird/52.8.0
X-Notice: Filtered by postfilter v. 0.8.3
Content-Language: en-US
Xref: reader02.eternal-september.org comp.lang.ada:53329
Date: 2018-06-26T16:17:00+02:00
List-Id: <comp.lang.ada>

On 2018-06-26 15:59, Dan'l Miller wrote:
> On Tuesday, June 26, 2018 at 2:44:26 AM UTC-5, Dmitry A. Kazakov wrote:
>> On 2018-06-25 18:21, Dan'l Miller wrote:
>>> On Monday, June 25, 2018 at 10:19:15 AM UTC-5, Dmitry A. Kazakov wrote:
>>>> On 2018-06-25 16:44, J-P. Rosen wrote:
>>>>> Le 25/06/2018 à 16:21, Dmitry A. Kazakov a écrit :
>>>>
>>>>>> Ada could allow T'Class for untagged T. T'Class would be an indefinite
>>>>>> type with values consisting of the actual type's tag and its value. When
>>>>>> T is by-value type, you pass T'Class to a subprogram as tag + value.
>>>>>> When T is by-reference type, you pass tag + reference.
>>>>>>
>>>>>> Upon dispatch, you strip the tag from the value or reference before
>>>>>> passing value/reference down.
>>>>>
>>>>> It was a requirement of Ada95 that OOP be strictly contained, and that
>>>>> the same typing system as Ada83 be kept for those who don't want OOP.
>>>>
>>>> Don't want OO, don't declare T'Class objects. Where is a problem?
>>>
>>> The problem is that you just proposed 'Class for non-OO semantics.  Your proposal violates the Principal of Least Surprise.
>>
>> Remember, Ada is a strongly typed language, T'Class is not T, there is
>> no way it could break or change anything in T.
> 
> Quit putting non sequitur words in my mouth.  I never said that it would break anything in T.  I said that it would break T'Class in •some• situations of the untagged extended records,

Such situations are strictly non-existent for neither T'Class nor record 
extensions are presently allowed for non-tagged types.

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