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,FREEMAIL_FROM
	autolearn=ham autolearn_force=no version=3.4.4
X-Google-Thread: a07f3367d7,39579ad87542da0e
X-Google-Attributes: gida07f3367d7,public,usenet
X-Google-NewGroupId: yes
X-Google-Language: ENGLISH,UTF8
X-Received: by 10.224.200.202 with SMTP id ex10mr22357848qab.8.1368583778587;
        Tue, 14 May 2013 19:09:38 -0700 (PDT)
Path: 
 y6ni44345qax.0!nntp.google.com!border1.nntp.dca.giganews.com!border4.nntp.dca.giganews.com!border2.nntp.dca.giganews.com!nntp.giganews.com!newsfeed.news.ucla.edu!nrc-news.nrc.ca!News.Dal.Ca!news.litech.org!news.stack.nl!aioe.org!.POSTED!not-for-mail
From: =?utf-8?Q?Yannick_Duch=C3=AAne_=28Hibou57?=
 =?utf-8?Q?=29?=
 <yannick_duchene@yahoo.fr>
Newsgroups: comp.lang.ada
Subject: Re: Seeking for papers about tagged types vs access to subprograms
Date: Sat, 11 May 2013 10:14:19 +0200
Organization: Ada @ Home
Message-ID: <op.wwwuh5m3ule2fv@cardamome>
References: <op.wv8jh1c1ule2fv@cardamome>
 <1vrhb7oc4qbob$.q02vuouyovp5$.dlg@40tude.net> <op.wwn4oak8ule2fv@cardamome>
 <19lrzzbgm77v6.1dzpgqckptaj6.dlg@40tude.net> <kmbohm$elb$1@loke.gir.dk>
 <p0pf97g5w6xg.jhca6ztjwpde$.dlg@40tude.net> <op.wwq9s4l6ule2fv@cardamome>
 <1bfhq7jo34xpi.p8n2vq6yjsea.dlg@40tude.net> <op.wwrefx1pule2fv@cardamome>
 <cps71yzogw24$.7ol98fxcaurj$.dlg@40tude.net> <op.wwriky0dule2fv@cardamome>
 <nd22gfeezrwf$.tlj4yyygrwq3$.dlg@40tude.net> <kmecg6$et4$1@loke.gir.dk>
 <12gn9wvv1gwfk.10ikfju4rzmnj.dlg@40tude.net> <kmh7d4$up3$1@loke.gir.dk>
 <1oy5rmprgawqs.1jz36okze0xju$.dlg@40tude.net> <kmk45u$v45$1@loke.gir.dk>
 <1q2ql1e4rcgko.diszzq1mhaq8$.dlg@40tude.net>
 <518dedd4$0$6581$9b4e6d93@newsspool3.arcor-online.net>
 <hxkln519n179.1kt13z7phxg2f.dlg@40tude.net>
NNTP-Posting-Host: Sz+Cz+YCi2SKRtUDNsu0BQ.user.speranza.aioe.org
Mime-Version: 1.0
X-Complaints-To: abuse@aioe.org
User-Agent: Opera Mail/12.15 (Linux)
X-Notice: Filtered by postfilter v. 0.8.2
Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes
Content-Transfer-Encoding: Quoted-Printable
Date: 2013-05-11T10:14:19+02:00
List-Id: <comp.lang.ada>

Le Sat, 11 May 2013 09:42:14 +0200, Dmitry A. Kazakov  =

<mailbox@dmitry-kazakov.de> a =C3=A9crit:

> "Fail" is a wrong word here. The right wording is ensuring  =

> postconditions.
> That is completely unrelated issue, IMO.
>
> I have a feeling that people confuse typing with this, which is basica=
lly
> program correctness en large. You cannot ensure program correctness  =

> through
> types. And since full correctness proof is unachievable anyway I want =
to
> separate it from types.
>
> Second kind checks (e.g. SPARK) should be optional so that the program=
mer
> would add or remove checks depending on requirements and provability.
>
> Especially because there is also a big difference in the design of typ=
e
> checks and correctness checks. We design types top-down, at least the =
 =

> most
> important ones. Type design is frequently irreversible, few things can=
 be
> changed later without big troubles. It is almost waterfall. On the
> contrary, the correctness checks are bottom-up. You probably never get=
 to
> the top. But you can well figure up essential things at the bottom for=

> which it were possible and desirable to check things statically.

All sounds wise to me, agree.


-- =

=E2=80=9CSyntactic sugar causes cancer of the semi-colons.=E2=80=9D [1]
=E2=80=9CStructured Programming supports the law of the excluded muddle.=
=E2=80=9D [1]
[1]: Epigrams on Programming =E2=80=94 Alan J. =E2=80=94 P. Yale Univers=
ity