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: 103376,34257fd17abeba14 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news4.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!wns14feed!worldnet.att.net!attbi_s71.POSTED!53ab2750!not-for-mail From: "Jeffrey R. Carter" Organization: jrcarter at acm dot org User-Agent: Thunderbird 1.5.0.5 (Windows/20060719) MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: [SPARK] Code safety and information hiding References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Message-ID: NNTP-Posting-Host: 12.201.97.176 X-Complaints-To: abuse@mchsi.com X-Trace: attbi_s71 1155838103 12.201.97.176 (Thu, 17 Aug 2006 18:08:23 GMT) NNTP-Posting-Date: Thu, 17 Aug 2006 18:08:23 GMT Date: Thu, 17 Aug 2006 18:08:23 GMT Xref: g2news2.google.com comp.lang.ada:6245 Date: 2006-08-17T18:08:23+00:00 List-Id: Maciej Sobczak wrote: > > Interesting, but it looks that there is another solution to this: > refinement. The specification only says that there is some State and the > body clarifies what are the components of the State. This decouples the > minor design decisions (like the choice of names in the implementation) > from the clients, which then only need to know what affects the state - > now treated in abstract terms - and what doesn't. Right. That's what I was showing you, in its simplest version. > Agreed. Moreover, SPARK calls "global" even those variables, which are > actually local in the scope that encloses the definition of the given > subprogram. Intuitively, "globalness" of some name should not be a > property of the place where the name is used. Those are what I called state variables. -- Jeff Carter "I'm particularly glad that these lovely children were here today to hear that speech. Not only was it authentic frontier gibberish, it expressed a courage little seen in this day and age." Blazing Saddles 88