vreplace.clj

(defn vreplace
     ([s p r] (replace s p r))
     ([s p r & more]
	(let [pair (take 2 more)
	      next-p (first pair)
	      next-r (second pair)
	      remaining (drop 2 more)]
	  (if next-r
	    (replace (replace s next-p next-r remaining) p r)
	    (replace s p r)))))