Re: LOGO-L> Recursion

[Jim Muller <jmul@cyberramp.net>]

At 11:22 PM 3/18/98 +1000, you wrote:
>Hello,
>I've just joined the list so maybe this has been covered - but I didn't
>see it in the archives.  Can someone explain when we would use tail
>recursion or embedded recursion? Perhaps an example may suffice.
>Thanks in advance,
>Bill Mackay
>

Bill ==>

Here's my favorite example of tailend vs. embedded recursion.

TO AMAZE :N
IF :N > 120 [STOP]
AMAZE :N + 10
FD :N RT 90
END

TO MAZE :N
IF :N > 300 [STOP]
FD :N RT 90
MAZE :N +10
END

Both procedures draw the same figure only AMAZE draws it in reverse. Why?

Here's another one...

TO TEST.RECURSION :N
PR [IS THIS RECURSION?]
IF READWORD = "YES [TES.RECURSION :N + 1]
PRINT :N
END

Answer Yes a few times. Then try No. What happens? Why?

These examples don't really answer your question. However, by playing with
these, you may see other applications...at least I hope so.

Regards...Jim Muller
>+>+>+>+>+>+>+>+>+>+>+>+>+>+>+>
Jim Muller
jmul@cyberramp.net
The Great Logo Adventure at
http://www.cyberramp.net/~jmul
>+>+>+>+>+>+>+>+>+>+>+>+>+>+>+>
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