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: 103376,93a8020cc980d113 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Newsgroups: comp.lang.ada Subject: Re: What is wrong with Ada? References: <1176150704.130880.248080@l77g2000hsb.googlegroups.com> <461B52A6.20102@obry.net> <461BA892.3090002@obry.net> <82dgve.spf.ln@hunter.axlog.fr> <1176226291.589741.257600@q75g2000hsh.googlegroups.com> <4eaive.6p9.ln@hunter.axlog.fr> <1rbtw92apxpl1.1ednvo8v6oiq8$.dlg@40tude.net> From: Markus E Leypold Organization: N/A Date: Fri, 13 Apr 2007 02:16:56 +0200 Message-ID: User-Agent: Some cool user agent (SCUG) Cancel-Lock: sha1:y0/IaAwbMS8i+NyW1k3OpYEf8IY= MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii NNTP-Posting-Host: 88.72.204.82 X-Trace: news.arcor-ip.de 1176422972 88.72.204.82 (13 Apr 2007 02:09:32 +0200) X-Complaints-To: abuse@arcor-ip.de Path: g2news1.google.com!news2.google.com!news1.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!newsfeed00.sul.t-online.de!newsfeed01.sul.t-online.de!t-online.de!news.germany.com!news.unit0.net!newsfeed.arcor-ip.de!news.arcor-ip.de!not-for-mail Xref: g2news1.google.com comp.lang.ada:14998 Date: 2007-04-13T02:16:56+02:00 List-Id: "Dmitry A. Kazakov" writes: > Tests should cover all program states. Covering all paths is a rough > approximation of. > But the number of program states is finite, or else the program is wrong > anyway? Don't understand that. Assuming the program terminates fo a give input I the number of states it goes through during execution -- S_1 ... S_n -- is finite. The number of valid input sets is usually less well defined, but assuming (and this is wrong) they are finite, i.e. the sets I \from I_1, I_2 ... I_n are the only valid input then you still have a finite number of program states. Still the number of possible inputs might be rather large (i.e. to a type setter it's all possible books :-), so exhaustive testing is impossible (and your "Tests should cover all program states" is just saying, that you can't test enough). But the set of all inputs is not necessarily finite -- i.e. in the case that the user might enter one data item after the other and get some answer about that item until he enters a end-of-input symbol (stupid example: an interactive prime tester). Since it is nonsense to artificially restrict the length of the user interaction just to get a finite set of input sequences, we will have to live with a infinite number of potential inputs to the program. So the paths covered are also inifinite (program state is still finite since the machine has only finite state). Regards -- Markus