Clojure Soundex

soundex.clj

;;Example of Clojure Soundex Code for my blog 
;;http://javazquez.com/juan/2012/08/28/clojure-soundex/

(def val-map {"FBVP" 1,"CGJKQSXZ" 2,"DT" 3,"L" 4,"MN" 5,"R" 6, "AEIOU" "!" }))

(defn map-builder [alphas num]
  (zipmap alphas (repeat num)))	
	
(def conversion-map 
  (reduce merge (map #(map-builder (key %) (val % )) val-map) ))			

;;The non value '!' is critical for the dup removal since letters are counted twice if seperated by a vowel			
(defn soundex-helper [word]	
  (-> 
    (apply str (map conversion-map (.toUpperCase word ) ));map datatype will act as filter
    (clojure.string/replace #"(?i)([\d])\1+" "$1" );replace dups
    (subs 1 );remove first
    (clojure.string/replace "!" "" );pull out non value
    (str "000");pad with trailing 0s 
    (subs 0 3)))	

(defn soundex [word]
	(str (first word) (soundex-helper word)));

;; tests
(=(soundex  "Ashcroft") "A261")
(=(soundex  "Ashcraft") "A261")
(=(soundex  "Tymczak") "T522")
(=(soundex  "Pfister") "P236")
(=(soundex  "Lukaskiewicz") "L222")
(=(soundex  "Rubin") "R150")
(=(soundex  "Rupert") "R163")
(=(soundex  "Robert") "R163")
(=(soundex  "Vazquez") "V220")