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=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!newsfeed.kamp.net!newsfeed.kamp.net!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Niklas Holsti Newsgroups: comp.lang.ada Subject: Re: Ada.Strings.Fixed.Count raises Storage_Error Date: Wed, 29 Jun 2016 20:43:47 +0300 Organization: Tidorum Ltd Message-ID: References: <57346ac8$0$4570$426a74cc@news.free.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Trace: individual.net /6Sl84J1w/v6qQeIuKeFhgFpVkdoHDH1xhLdwDQE5H9u6z8UYF Cancel-Lock: sha1:OOvr3DmtSri3MjdQ2/pwn0D6YVA= User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 In-Reply-To: Xref: news.eternal-september.org comp.lang.ada:30969 Date: 2016-06-29T20:43:47+03:00 List-Id: On 16-06-29 12:13 , J-P. Rosen wrote: > Le 29/06/2016 à 10:15, Niklas Holsti a écrit : >>> This is a category >>> of problem that the ARG decided long ago should be considered >>> pathologies. The original case was a program that checked whether a >>> task returned by a function was Terminated. >> >> I don't see any connection between these problems. Can you give a >> reference for the "original case", an AI number perhaps? > It was an example of a "pathology", because this one was the first case > of a pathology in the language. It was discovered long before there were > AIs (1983 or 1984), and named after the poor guy who tripped on it > first: Rosen's Pathology. Thanks for this information, Jean-Paul. According to your post in http://computer-programming-forum.com/44-ada/cdf3e22c34c4de36.htm, this "pathology" was present in Ada 83, but was cured in Ada 95: "It was related to a function returning a local task object, which is no more allowed." This suggests to me that the definition of Ada 83 was either ambiguous in this case, or required too much effort from the implementation for this feature compared to the benefits of the feature, and consequently the language was changed to eliminate the feature. Thus, Rosen's pathology was not tolerated, which seems to be what Robert Eachus is suggesting, but eliminated. The analogous elimination in this case (String with 'Last = Integer'Last) would be to change the language to define the index subtype of String to run from 1 to Integer'Last - 1. The alternative, to correct the library routine to work even in this case, seems better to me. -- Niklas Holsti Tidorum Ltd niklas holsti tidorum fi . @ .