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: 103376,3d3f20d31be1c33a X-Google-Attributes: gid103376,public X-Google-Thread: 1108a1,2c6139ce13be9980 X-Google-Attributes: gid1108a1,public X-Google-Thread: f43e6,2c6139ce13be9980 X-Google-Attributes: gidf43e6,public From: Ted Velkoff Subject: Re: Safety-critical development in Ada and Eiffel Date: 1997/08/16 Message-ID: <33F527C8.32B3@erols.com>#1/1 X-Deja-AN: 264425377 References: <33E9ADE9.4709@flash.net> <33F133D7.71AC@erols.com> <33F25933.7F83@flash.net> <33F27B5C.6A3C@erols.com> <33F44261.7BD3@flash.net> Organization: Erol's Internet Services X-Received-On: 16 Aug 1997 04:05:34 GMT Newsgroups: comp.object,comp.software-eng,comp.lang.ada,comp.lang.eiffel Date: 1997-08-16T00:00:00+00:00 List-Id: Ken Garlington wrote: > > Ted Velkoff wrote: > > > > Ken Garlington responded to an earlier post of mine: > > > > > > This is certainly reasonable. However, once the execution capabilities > > > are removed, it seems fair to ask what Eiffel provides that comments > > > (available in most langauges) don't provide. If there is not a > > > significant > > > difference, then Eiffel would not be any better (in this context) than > > > any other language, so long as the DBC principles were followed. > > > > > > > In my experience, there is a significant difference. I will not presume > > to make a scientific claim; rather I will offer a personal, anecdotal > > example. > >[ Example followed here...] > > I think you're anwering the wrong mail :) I'll try again. > > Please re-read the first paragraph. The discussion is about the value of > Eiffel assertions if they are _always_ turned off, vs. comments. To begin with, by "_always_ turned off", I assume what is meant is "turned off during execution of a delivered system", not "turned off during execution of a delivered system and during its entire development phase". If an Eiffel executable is built with assertion monitoring turned off, it is indeed no different than, say, an Ada executable built using pragma Suppress (Range_Check, for example). This would be appropriate during the final stages of testing a product, for Factory/Site Acceptance Test, and delivery to a customer. For the bulk of development, from design through code, unit and integration testing, one would certainly want to monitor assertions (in Eiffel) or Range_Checks, for instance (in Ada). Clearly these sorts of compile- and run-time checks are far more powerful than mere comments and aid in earlier detection and correction of errors. I say that using Eiffel is superior to using another language with commented assertions because Eiffel makes it so easy and cost-effective to write AND test Boolean-valued assertions during the bulk of the development life-cycle. -- Ted Velkoff