+(defun turtles-here (&optional breed)
+ "TURTLES-HERE => TURTLES
+
+ARGUMENTS AND VALUES:
+
+ TURTLES: an agentset
+
+DESCRIPTION:
+
+ Returns the agentset consisting of all the turtles sharing the patch
+ with the agent in by *self*
+
+ See http://ccl.northwestern.edu/netlogo/docs/dictionary.html#turtles-here"
+ (when (not (turtle-p *self*)) (error "Gotta call turtles-here with a turtle"))
+ (let
+ ((patch-turtles (patch-turtles (patch-at (turtle-xcor *self*) (turtle-ycor *self*)))))
+ (list->agentset
+ (if breed (remove breed patch-turtles :key #'turtle-breed :test-not #'eql) patch-turtles)
+ (or breed :turtles))))
+