levenshtein.clj

(defn levenshtein [vec1 vec2]
  (cond (empty? vec1) (count vec2)
	(empty? vec2) (count vec1)
	:else
	(let [distance (make-array Integer (count vec1) (count vec2))]
	  (doseq [i (range (count vec1))]
	    (aset distance i 0 i))
	  (doseq [j (range (count vec2))]
	    (aset distance 0 j j))
	  (doseq [i (range 1 (count vec1))]
	    (doseq [j (range 1 (count vec2))]
	      (aset distance i j
		    (min (inc (aget distance (dec i) j))
			 (inc (aget distance i (dec j)))
			 (+ (aget distance (dec i) (dec j))
			    (if (= (vec1 (dec i))
				   (vec2 (dec j)))
			      0 1))))))
	  (aget distance (dec (count vec1)) (dec (count vec2))))))