Re: [vox-tech] Loop variants should be integers!
On Wed, Apr 21, 2010 at 06:05:17PM -0700, Bill Kendrick wrote: > On Wed, Apr 21, 2010 at 05:48:49PM -0700, Brian Lavender wrote: > > I recently met a guy at SacJUG who lived next door to Bertrand Meyer! He > > said he might be able to convince him to come and speak here in the > > Sacramento Area. Would that be cool or what?!!! > > FYI, Wikipedia tells me: > > "Since October 2001, he has been Professor of Software Engineering at > ETH Zurich, the Swiss Federal Institute of Technology, where he > pursues research on building trusted components (reusable software > elements) with a guaranteed level of quality." We'll make sure to tell the airline to stick a stopover in Sacramento on his way back from Switzerland to Santa Barbara. -- Brian Lavender http://www.brie.com/brian/ "For every complex problem there is an answer that is clear, simple, and wrong." - H. L. Mencken ___ vox-tech mailing list vox-tech@lists.lugod.org http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] Loop variants should be integers!
On Wed, Apr 21, 2010 at 08:02:16PM -0500, Chanoch (Ken) Bloom wrote: > On Wed, 2010-04-21 at 17:48 -0700, Brian Lavender wrote: > > So, I am switching my loop variants ("i" in this case) to integers. Here > > is convincing evidence. ;-) > > > > http://archive.eiffel.com/doc/faq/variant.html > > > > I recently met a guy at SacJUG who lived next door to Bertrand Meyer! He > > said he might be able to convince him to come and speak here in the > > Sacramento Area. Would that be cool or what?!!! > > > > Of course, if I had used Eiffel for this program, I could have put an > > invariant condition on i, such that it is never less than zero greater > > than the number of elements in the array. > > > > brian > > This requires that they be integers as opposed to floating point > numbers. It doesn't require that they be signed ints (as opposed to > unsigned). I guess you are correct. I was just thinking that 4 billion is not less than 0. I just discovered nana. It appears you to do much the same stuff that is in Eiffel in C. I can put an invariant condition around the loop and all should be good Now that I disovered what was wrong with my code of curse, it shouldn't be much of a problem now. http://savannah.gnu.org/projects/nana Well, I need to check it out. I am a little tired now. Probably should get some rest before I annoy everyone on the list with half field antics. brian -- Brian Lavender http://www.brie.com/brian/ "For every complex problem there is an answer that is clear, simple, and wrong." - H. L. Mencken ___ vox-tech mailing list vox-tech@lists.lugod.org http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] Loop variants should be integers!
On Wed, Apr 21, 2010 at 05:48:49PM -0700, Brian Lavender wrote: > I recently met a guy at SacJUG who lived next door to Bertrand Meyer! He > said he might be able to convince him to come and speak here in the > Sacramento Area. Would that be cool or what?!!! FYI, Wikipedia tells me: "Since October 2001, he has been Professor of Software Engineering at ETH Zurich, the Swiss Federal Institute of Technology, where he pursues research on building trusted components (reusable software elements) with a guaranteed level of quality." -bill! ___ vox-tech mailing list vox-tech@lists.lugod.org http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] Loop variants should be integers!
On Wed, 2010-04-21 at 17:48 -0700, Brian Lavender wrote: > So, I am switching my loop variants ("i" in this case) to integers. Here > is convincing evidence. ;-) > > http://archive.eiffel.com/doc/faq/variant.html > > I recently met a guy at SacJUG who lived next door to Bertrand Meyer! He > said he might be able to convince him to come and speak here in the > Sacramento Area. Would that be cool or what?!!! > > Of course, if I had used Eiffel for this program, I could have put an > invariant condition on i, such that it is never less than zero greater > than the number of elements in the array. > > brian This requires that they be integers as opposed to floating point numbers. It doesn't require that they be signed ints (as opposed to unsigned). --Ken (Who's TA'ing a class on this right now.) ___ vox-tech mailing list vox-tech@lists.lugod.org http://lists.lugod.org/mailman/listinfo/vox-tech