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: 103376,3a1c64628a09855b X-Google-Attributes: gid103376,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII Path: g2news1.google.com!news2.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!nx02.iad01.newshosting.com!newshosting.com!newsfeed.icl.net!newsfeed.fjserv.net!oleane.net!oleane!hunter.axlog.fr!nobody From: Jean-Pierre Rosen Newsgroups: comp.lang.ada Subject: Re: Lack of formal syntax undermines Ada Date: Mon, 14 Apr 2008 09:23:10 +0200 Organization: Adalog Message-ID: <6p0vtf.3ft.ln@hunter.axlog.fr> References: NNTP-Posting-Host: mailhost.axlog.fr Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Trace: s1.news.oleane.net 1208157607 4614 195.25.228.57 (14 Apr 2008 07:20:07 GMT) X-Complaints-To: abuse@oleane.net NNTP-Posting-Date: Mon, 14 Apr 2008 07:20:07 +0000 (UTC) User-Agent: Thunderbird 2.0.0.12 (Windows/20080213) In-Reply-To: Xref: g2news1.google.com comp.lang.ada:20929 Date: 2008-04-14T09:23:10+02:00 List-Id: Adam Beneschan a �crit : > There was an early, pre-1983, version of Ada that had a rule that > functions couldn't have side effects; this version also had "value- > returning procedures" for those cases where you really needed > something that could have side effects with the syntax of a function. > (I think value-returning procedures were allowed to have what are now > referred to as OUT and IN OUT parameters, but I'm not sure.) Since I > don't remember a rule that functions weren't allowed to call > procedures, I don't know how they expected the side-effect rule to be > enforced; maybe the authors figured they could just decree it to be so > and stick implementors with the burden of figuring out how. The actual statement was: "Side effects, e.g. assignments to non-local variables, are not allowed within functions, whether directly, or indirectly through other subprogram calls". Quite a weak statement, as far as implementation is concerned, actually. > This was a long time ago, so of course my memory is hazy. I haven't > looked to see if this draft version of Ada exists somewhere on the > Internet. > I doubt it. At that time, paper was governing the world (I only have a paper copy of the Green reference manual). -- --------------------------------------------------------- J-P. Rosen (rosen@adalog.fr) Visit Adalog's web site at http://www.adalog.fr