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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fac41,2c6139ce13be9980 X-Google-Attributes: gidfac41,public X-Google-Thread: 1108a1,2c6139ce13be9980 X-Google-Attributes: gid1108a1,public X-Google-Thread: f43e6,2c6139ce13be9980 X-Google-Attributes: gidf43e6,public X-Google-Thread: 103376,3d3f20d31be1c33a X-Google-Attributes: gid103376,public From: paul.johnson@gecm.com (Paul Johnson) Subject: Re: Safety-critical development in Ada and Eiffel Date: 1997/07/18 Message-ID: <5qnbkm$ft$4@miranda.gmrc.gecm.com>#1/1 X-Deja-AN: 257532781 References: <33CBBF4B.7BAF@pseserv3.fw.hac.com> <33CC64CE.44A3@flash.net> <5qklt1$4el$2@miranda.gmrc.gecm.com> <5qkun1$35r@gcsin3.geccs.gecm.com> Organization: GEC-Marconi Research Centre Newsgroups: comp.object,comp.software-eng,comp.lang.ada,comp.lang.eiffel Date: 1997-07-18T00:00:00+00:00 List-Id: In article <5qkun1$35r@gcsin3.geccs.gecm.com>, stuart.palin@gecm.com says... (in reply to my argument that Eiffel assertions are propogated up through the structure) >I am not at all convinced by this Paul, in our experiences with SPARK, >where formal specifications are hoisted up through the program structure >revealing dependencies of lower level routines it is all too easy to end >up with an unmanageable number of annotations (assertions). In most Eiffel code this is not a problem because the classes implement abstractions, and the assertions relate to those abstractions. However I can certainly believe that in numerical computation with subranges (which in practice means anything except bignums), you get all sorts of messy problems of the sort that Stuart describes. I therefore conceed the point. Most programmers can simply ignore arithmetic overflow issues. Safety critical people can't. Paul. -- Paul Johnson | GEC-Marconi Ltd is not responsible for my opinions. | +44 1245 242244 +-----------+-----------------------------------------+ Work: | You are lost in a twisty maze of little Home: | standards, all different.