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 10.180.109.166 with SMTP id ht6mr1643949wib.0.1368583585987;
        Tue, 14 May 2013 19:06:25 -0700 (PDT)
Path: 
 hg5ni110155wib.1!nntp.google.com!feeder1.cambriumusenet.nl!feed.tweaknews.nl!193.141.40.65.MISMATCH!npeer.de.kpn-eurorings.net!npeer-ng0.de.kpn-eurorings.net!border2.nntp.ams2.giganews.com!border4.nntp.ams.giganews.com!border2.nntp.ams.giganews.com!border2.nntp.dca.giganews.com!nntp.giganews.com!newsfeed.news.ucla.edu!nrc-news.nrc.ca!News.Dal.Ca!citadel.nobulus.com!goblin1!goblin2!goblin.stu.neva.ru!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: Fri, 10 May 2013 06:29:12 +0200
Organization: Ada @ Home
Message-ID: <op.wwupeyo3ule2fv@cardamome>
References: <op.wv8jh1c1ule2fv@cardamome> <op.wwbvqzkeule2fv@cardamome>
 <op.wwnp2zkrule2fv@cardamome> <u3jaslg5kca7.1gk5ds3d4sx2y$.dlg@40tude.net>
 <op.wwnsmtteule2fv@cardamome> <17ceq51ydy3s0.s94miqqzbg5w.dlg@40tude.net>
 <op.wwny5jerule2fv@cardamome> <1vrhb7oc4qbob$.q02vuouyovp5$.dlg@40tude.net>
 <op.wwn4oak8ule2fv@cardamome> <19lrzzbgm77v6.1dzpgqckptaj6.dlg@40tude.net>
NNTP-Posting-Host: uGUognJZXpdb++Da0QvCqg.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: 2013-05-10T06:29:12+02:00
List-Id: <comp.lang.ada>

Le Mon, 06 May 2013 20:55:34 +0200, Dmitry A. Kazakov  =

<mailbox@dmitry-kazakov.de> a =C3=A9crit:
>
> Instead of banishing exceptions one should put contracts on them.
>

In the meanwhile, that's hard to have exception contract without breakin=
g  =

separation of implementation and specification; or else, the specificati=
on  =

would have to express requirements on the implementation, which is not a=
  =

so bad idea on its own, but which is something foreign to Ada, except as=
  =

comments.

However, there is an big=E2=80=91picture contract on exceptions which wo=
uld be  =

simple an useful without breaking privacy of implementation: a sub=E2=80=
=91program  =

may or may not raise synchronous exceptions. This contract would be enou=
gh  =

I believe, especially with the help of the (non=E2=80=91standard) pragma=
  =

`No_Exception_Propagation`.

Asynchronous exceptions, such as hardware error, memory chip error, OS  =

error, and so on, would be left uncovered. Anyway, I see nothing else if=
  =

not a rather immediate program termination when it occurs (may be just  =

logging a short static message, and then terminate).

-- =

=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