Re: Repeat-While vs. Repeat-Until

Craig Schlenoff wrote:

> Thanks Pat. That make sense. Is there any chance of having this restriction
> added into the OWL-S documentation to minimize ambiguity?

Yes.  Thanks (belatedly) for bringing this to light.  The internal 
comments in Process.owl and the tech. overview have been updated per 
Pat's clarification, in the soon-to-be-announced 1.1 release.

(The tech overview changes aren't online yet.)

Regards,
David

> 
> Craig
> 
> -----Original Message-----
> From: Pat Hayes [mailto:phayes@ihmc.us]
> Sent: Wednesday, May 05, 2004 10:50 AM
> To: Craig Schlenoff
> Cc: public-sws-ig@w3.org
> Subject: Re: Repeat-While vs. Repeat-Until
> 
> 
> 
>>Is there any difference in these two constructs as to when the condition is
>>evaluated? In particular, I am looking for a construct that will evaluate
>>the condition FIRST before the action is even executed one time. It is
>>unclear from the documentation when the condition is evaluated for each of
>>these constructs.
>>
>>I understand the difference between the two constructs with respect to
>>functionality (repeat-while performs an action while a condition is true,
>>repeat-until performs an action until a condition becomes true). I just
>>don't understand when the condition is evaluated.
> 
> 
> Many years ago, when I used to teach programming, the standard way to
> characterize these constructions differed in exactly this way.
> Repeat-while tests for the condition, exits if it is false and does
> the operation if the condition is true, then loops. Repeat-until does
> the operation, tests for the condition, exits if it is true, and
> otherwise loops. So while while may never act, until always acts at
> least once. I'd recommend this, it is very handy.
> 
> Pat Hayes
> 
> 
>>Thanks,
>>
>>Craig
>>
>>---------------------------------
>>Craig Schlenoff
>>Mechanical Engineer
>>Knowledge Systems Group
>>Intelligent Systems Division
>>Manufacturing Engineering Laboratory
>>National Institute of Standards and Technology (NIST)
>>100 Bureau Drive, Stop 8230
>>Gaithersburg, MD 20899-8230
>>Phone: 301-975-3456
>>Fax: 301-990-9688
>>Email: craig.schlenoff@nist.gov
> 
> 
> 
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Received on Tuesday, 14 September 2004 06:07:05 UTC