Soundex algorithm in Clojure

soundex.clj

(defn soundex [data]
	(let [ contains-char? (fn [the-string the-char]
							(some #(= the-char %) the-string))
		find-first-map-val (fn [m v]
							(last (first (filter #(contains-char? (first %) v) m))))
		compress (fn [xs]
			(reduce #(if (= (last %1) %2) %1 (concat %1 (list %2))) '() xs))
		fill (fn [x l w]
			(if (> l (.length (str x))) (recur (str x w) l w) (.substring (str x) 0 l)))
		code-gen { "BFPV" "1"
						"CGJKQSXZ" "2"
						"DT" "3"
						"L" "4"
						"MN" "5"
						"R" "6" }
		data (clojure.string/upper-case (first (clojure.string/split data #"\s")))
		result (map (fn [x]
				(find-first-map-val code-gen x)) (rest data)) ]
		(fill (reduce str (compress (keep identity (cons (first data) result))))
			4 "0")))