drools 一个开放源码的规则引擎

				;; Load our Userfunctions
				(load-package control.HardwareFunctions)
				
				;; Create a simulator
				(defglobal ?*hw* = (init-simulator 33))
				
				(defglobal ?*set-point* = 70)
				
				;; Tell Jess about the Java Bean classes
				(defclass Thermometer control.Thermometer)
				(defclass Vent control.Vent)
				(defclass HeatPump control.HeatPump)
				
				;; Create the Vent and Thermometer Beans
				(bind ?n (n-floors))
				(while (> ?n 0) do
				       (definstance Thermometer (new control.Thermometer ?*hw* ?n))
				       (definstance Vent (new control.Vent ?*hw* ?n))
				       (bind ?n (- ?n 1)))
				
				;; Create the HeatPump Beans
				(bind ?n (n-heatpumps))
				(while (> ?n 0) do
				       (definstance HeatPump (new control.HeatPump ?*hw* ?n))
				       (bind ?n (- ?n 1)))
				
				;; Deffunctions
				(deffunction too-cold (?t)
				  (return (< ?t (- ?*set-point* 2))))
				
				(deffunction too-hot (?t)
				  (return (> ?t (+ ?*set-point* 2))))
				
				;; Heat pump rules
				(defrule floor-too-cold-pump-off
				  (HeatPump (state "off") (number ?p))
				  (Thermometer (floor ?f&:(eq ?p (which-pump ?f)))
				               (reading ?t&:(too-cold ?t)))
				  =>
				  (set-hp-state ?p heating))
				
				(defrule floors-hot-enough
				  (HeatPump (state "heating") (number ?p))
				  (not (Thermometer (floor ?f&:(eq ?p (which-pump ?f)))
				                    (reading ?t&:(< ?t ?*set-point*))))
				  =>
				  (set-hp-state ?p off))
				
				(defrule floor-too-hot-pump-off
				  (HeatPump (state "off") (number ?p))
				  (Thermometer (floor ?f&:(eq ?p (which-pump ?f)))
				               (reading ?t&:(too-hot ?t)))
				  =>
				  (set-hp-state ?p cooling))
				
				(defrule floors-cool-enough
				  (HeatPump (state "cooling") (number ?p))
				  (not (Thermometer (floor ?f&:(eq ?p (which-pump ?f)))
				                    (reading ?t&:(> ?t ?*set-point*))))
				  =>
				  (set-hp-state ?p off))
				
				(defrule floor-too-cold-vent-closed
				  (HeatPump (state "heating") (number ?p))
				  (Vent (state "closed") (floor ?f&:(eq ?p (which-pump ?f))))
				  (Thermometer (floor ?f)
				               (reading ?t&:(< ?t ?*set-point*)))
				  =>
				  (set-vent-state ?f open))
				
				(defrule floor-too-cold-vent-open
				  (HeatPump (state "cooling") (number ?p))
				  (Vent (state "open") (floor ?f&:(eq ?p (which-pump ?f))))
				  (Thermometer (floor ?f)
				               (reading ?t&:(< ?t ?*set-point*)))
				  =>
				  (set-vent-state ?f closed))
				
				(defrule floor-too-hot-vent-closed
				  (HeatPump (state "cooling") (number ?p))
				  (Vent (state "closed") (floor ?f&:(eq ?p (which-pump ?f))))
				  (Thermometer (floor ?f)
				               (reading ?t&:(> ?t ?*set-point*)))
				  =>
				  (set-vent-state ?f open))
				
				(defrule floor-too-hot-vent-open
				  (HeatPump (state "heating") (number ?p))
				  (Vent (state "open") (floor ?f&:(eq ?p (which-pump ?f))))
				  (Thermometer (floor ?f)
				               (reading ?t&:(> ?t ?*set-point*)))
				  =>
				  (set-vent-state ?f closed))
				
				(watch rules)
				(run-until-halt)