- From: Pat Hayes <phayes@ihmc.us>
- Date: Wed, 5 May 2004 09:49:54 -0500
- To: "Craig Schlenoff" <schlenof@cme.nist.gov>
- Cc: public-sws-ig@w3.org
>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 -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ihmc.us http://www.ihmc.us/users/phayes
Received on Wednesday, 5 May 2004 10:50:53 UTC