Re: [vox-tech] Loop variants should be integers!

2010-04-21 Thread Brian Lavender
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 
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Re: [vox-tech] Loop variants should be integers!

2010-04-21 Thread Brian Lavender
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 
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Re: [vox-tech] Loop variants should be integers!

2010-04-21 Thread Bill Kendrick
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!
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Re: [vox-tech] Loop variants should be integers!

2010-04-21 Thread Chanoch (Ken) Bloom
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.)
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