+(defun turn-right (n)
+ "TURN-RIGHT N => RESULT
+
+ARGUMENTS AND VALUES:
+
+ N: a double, the amount the turtle turns
+ RESULT: undefined
+
+DESCRIPTION:
+
+ The turtle turns right by number degrees. (If number is negative, it turns left.)
+
+ See http://ccl.northwestern.edu/netlogo/docs/dictionary.html#right"
+ (when (not (turtle-p *self*)) (error "Gotta call fd in turtle scope, dude (~A)" *self*))
+ (let
+ ((new-heading (+ (turtle-heading *self*) n)))
+ (setf (turtle-heading *self*)
+ (cond
+ ((< new-heading 0) (+ (mod new-heading -360) 360))
+ ((>= new-heading 360) (mod new-heading 360))
+ (t new-heading)))))
+
+(defun turn-left (n)
+ "TURN-LEFT N => RESULT
+
+ARGUMENTS AND VALUES:
+
+ N: a double, the amount the turtle turns
+ RESULT: undefined
+
+DESCRIPTION:
+
+ The turtle turns left by number degrees. (If number is negative, it turns right.)
+
+ See http://ccl.northwestern.edu/netlogo/docs/dictionary.html#right"
+ (turn-right (- n)))
+