Alex Krycek <krycek@sympatico.ca> wrote:
+---------------
| Is there any way to program a while or do..while loop with MzScheme?
+---------------

Well, you *can*, using macros, but given that the standard Scheme
"do" with no iteration variables:

	(do () (TEST) BODY...)

is exactly the same as:

	(while TEST BODY...)

I usually don't bother with "while" per se. Besides, you almost
always need local iteration variables in a loop, and "do" handles
that for you nicely.

Likewise, "do BODY... while TEST" can be written in standard
Scheme as:

	(let loop ()
	  BODY...
	  (when TEST (loop)))

I usually don't bother with "do-while", either.  Though YMMV...


-Rob

p.s. But if you really *insist* on "while" in MzScheme, try this:

	(define-macro while
	  (lambda (test . body)
	    `(do () (,test) ,@body)))

-----
Rob Warnock, 8L-846		rpw3@sgi.com
Applied Networking		http://reality.sgi.com/rpw3/
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