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=ham
	autolearn_force=no version=3.4.4
X-Google-Thread: 103376,839916f6ca3b6404
X-Google-Attributes: gid103376,domainid0,public,usenet
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news1.google.com!news1.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!newsfeed00.sul.t-online.de!t-online.de!news.k-dsl.de!news.motzarella.org!motzarella.org!news.motzarella.org!not-for-mail
From: Colin Paul Gloster <Colin_Paul_Gloster@ACM.org>
Newsgroups: comp.lang.ada
Subject: Re: not null
Date: Wed, 4 Mar 2009 20:39:19 +0000
Organization: A noiseless patient Spider
Message-ID: <alpine.LNX.2.00.0903042032250.23490@Bluewhite64.example.net>
References: <49ae93bc$0$31872$9b4e6d93@newsspool3.arcor-online.net>
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
X-Trace: news.eternal-september.org
 U2FsdGVkX1+hvX5l8S4igdCSqXiccmAoYyzM2zR5f4spXeFEAsRjJeS4evVTR0LdXVVEGXY5Ab8xNvJiSK4lEmtzsBzP9Ps4gQ7NqGlyhh714opAgVg/9k/QYyELZ2LXJS/lJ1maNg98/hCyYztD5w==
X-Complaints-To: Please send complaints to abuse@motzarella.org with full
 headers
NNTP-Posting-Date: Wed, 4 Mar 2009 20:38:33 +0000 (UTC)
In-Reply-To: <49ae93bc$0$31872$9b4e6d93@newsspool3.arcor-online.net>
X-Auth-Sender: 
 U2FsdGVkX1/qFCCYESlYjQtl+8zeFexP0w7f+Oj2XFWC6PULe855UcifwG39TryNt0acZbauv/4=
Cancel-Lock: sha1:J/9O3wsB7S5h+fl24Y4wEpgn1wY=
X-X-Sender: Colin_Paul@Bluewhite64.example.net
User-Agent: Alpine 2.00 (LNX 1167 2008-08-23)
Xref: g2news1.google.com comp.lang.ada:3949
Date: 2009-03-04T20:39:19+00:00
List-Id: <comp.lang.ada>

On March 4th, 2009, the following webpage was mentioned on news:comp.lang.ada :

|-------------------------------------------------------------------------------------------|
|"[..]                                                                                      |
|http://qconlondon.com/london-2009/presentation/Null+References:+The+Billion+Dollar+Mistake"|
|-------------------------------------------------------------------------------------------|

It seems that Prof. Hoare has made another mistake, as I note that
webpage contained:
"[..] In recent years, a number of program analysers like PREfix and
PREfast in Microsoft [..] give warnings if there is a risk they may be
non-null. [..]"

Warnings might make sense if there is a risk that they could be null,
but why would a possibility of being non-null instead justify the
terms "warnings" and "risk"?

With kind regards,
Colin Paul Gloucester