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=-0.3 required=5.0 tests=BAYES_00,
	REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4
X-Google-Thread: 103376,86c750b8474bf6d5
X-Google-Attributes: gid103376,domainid0,public,usenet
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news1.google.com!news4.google.com!feeder.news-service.com!feeder1.cambrium.nl!feed.tweaknews.nl!news.netcologne.de!newsfeed-hp2.netcologne.de!newsfeed.arcor.de!newsspool3.arcor-online.net!news.arcor.de.POSTED!not-for-mail
From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: About String
Newsgroups: comp.lang.ada
User-Agent: 40tude_Dialog/2.0.15.1
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Reply-To: mailbox@dmitry-kazakov.de
Organization: cbb software GmbH
References: <g2bs6b$h2m$1@registered.motzarella.org> <m2od6d5id7.fsf@mac.com>
 <484ABED3.8040909@obry.net> <UJD2k.71707$%B6.16259@newsfe13.ams2>
 <484b802a$0$23844$4f793bc4@news.tdc.fi>
 <wccod6bu69n.fsf@shell01.TheWorld.com>
 <aca3f318-8a9f-4f87-a315-dded8422f2f0@m36g2000hse.googlegroups.com>
 <wccprqrfwvk.fsf@shell01.TheWorld.com>
 <qqagad66sewe.g85wmpg6y0u6$.dlg@40tude.net>
 <484cfb49$0$6601$9b4e6d93@newsspool2.arcor-online.net>
 <f9xabk2p1obj$.1j3yto2qfpxpc.dlg@40tude.net>
 <484d1759$0$6620$9b4e6d93@newsspool2.arcor-online.net>
Date: Mon, 9 Jun 2008 14:03:37 +0200
Message-ID: <c71ducne10g4$.1uiog7or7vsve.dlg@40tude.net>
NNTP-Posting-Date: 09 Jun 2008 14:03:38 CEST
NNTP-Posting-Host: 1ef55a55.newsspool2.arcor-online.net
X-Trace: 
 DXC=NN1eJ]j[h1[\PS5Xo=M[RVA9EHlD;3YcR4Fo<]lROoRQ8kF<OcfhCO[i>i<cCM^_EU[6LHn;2LCV^7enW;^6ZC`TIXm65S@:3>_A<WBX8O^GOZ
X-Complaints-To: usenet-abuse@arcor.de
Xref: g2news1.google.com comp.lang.ada:632
Date: 2008-06-09T14:03:38+02:00
List-Id: <comp.lang.ada>

On Mon, 09 Jun 2008 13:43:21 +0200, Georg Bauhaus wrote:

> Why closures? I was about to mention nesting, which
> solves this issue in Ada 95 and Ada:

[...]

Only to show what the thing is. [Nested function is a closure too.]

> In a sense, Safe_T works just like constructors that don't raise.

Yes, fail-safe declarations do not raise (per definition).

>> Note, no magic stuff, no exception handlers in declarations, just a simple
>> thing, which Ada should have had from the day one: functional types and
>> literals of.
> 
> With the function's full environment?

Just usual stuff where access type (or a formal generic subprogram) is
presently used instead.

Certainly, no upward closures. So all accessibility checks would apply.
I.e. you would not be able to return a local subprogram.[*]

------------
* Unless [which is a another IMO necessary step] the subprograms is
conditionally pure relatively to the result's type scope.

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