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: 103376,9e7db243dfa070d7
X-Google-NewGroupId: yes
X-Google-Attributes: gida07f3367d7,domainid0,public,usenet
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news2.google.com!news3.google.com!feeder.news-service.com!newsfeed.straub-nv.de!noris.net!newsfeed.arcor.de!newsspool4.arcor-online.net!news.arcor.de.POSTED!not-for-mail
From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Do people who use Ada also use ocaml or F#?
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: 
 <b17dc7a8-7f8e-46b7-942c-b08ba83ce8fa@j25g2000yqa.googlegroups.com>
 <gt9eaeq2y4pc$.11t5wghh3e8jh$.dlg@40tude.net>
 <87k4kz3mda.fsf@mid.deneb.enyo.de>
 <amlrr4wam4x6.10s9ynz9e8br$.dlg@40tude.net> <op.vlekzab8ule2fv@garhos>
 <5jjgrklivesk$.z0is5qe7mgbt.dlg@40tude.net>
 <b162afef-505e-492e-80b6-be636de6d236@y23g2000yqd.googlegroups.com>
 <khe570ncicmo.1qbyqnnvl4zrp.dlg@40tude.net>
 <wccpqukc50q.fsf@shell01.TheWorld.com> <82mxpmz7t3.fsf@stephe-leake.org>
 <wcclj56cgsx.fsf@shell01.TheWorld.com>
Date: Sun, 7 Nov 2010 00:03:04 +0100
Message-ID: <t3psuch4qhzm$.ee2rft9bazm6.dlg@40tude.net>
NNTP-Posting-Date: 07 Nov 2010 00:03:03 CET
NNTP-Posting-Host: 1282efc7.newsspool3.arcor-online.net
X-Trace: 
 DXC=<?bDAg`cg[mj5k5aEF7ISmMcF=Q^Z^V3h4Fo<]lROoRa8kF<OcfhCOka]LNHib7JTk[6LHn;2LCVn[<mhadbfdUkgJDmjdkOak`WdeKaLmVnKb
X-Complaints-To: usenet-abuse@arcor.de
Xref: g2news2.google.com comp.lang.ada:16327
Date: 2010-11-07T00:03:03+01:00
List-Id: <comp.lang.ada>

On Sat, 06 Nov 2010 16:56:14 -0400, Robert A Duff wrote:

> Stephen Leake <stephen_leake@stephe-leake.org> writes:
> 
>> To truly test a generic, you need to test with all possible
>> instantiations.
> 
> To "truly" test a procedure, you have to call it with all
> possible parameter values (and all possible globals,
> if it uses those).

Loaded at all possible memory addresses, etc. There is no such thing as a
"true" test. Some things have to be taken for granted/proved.

>> That's much more effort than testing a single concrete procedure.
> 
> Well, I agree that testing a generic is typically harder
> than testing a single procedure.  That's because generics
> are typically more, um, "general".

No, it is because there are more things which can be safely assumed for a
well-designed procedure than for a well-designed generic.

Furthermore, I would bet that practically any generic can be broken per
erroneous instantiation, e.g. by passing function "-" where "+" expected.
We discard these cases as unlike, but we cannot prove that they indeed do
not happen, until we instantiate, with is the essence of being
non-testable. For procedures testing usually covers the inputs necessary to
deduce that it works for all other inputs. Erroneous usages do not exist or
well known/detectable/preventable.

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