harmenjanssen

(def vowels "aeiou")

(defn is-vowel [ch] (not (nil? (some #{ch} vowels))))

(defn abs [n] (max n (- n)))

(defn distance
  "Returns the distance from the number x to the closest number in xs"
  [xs x]
  (apply min (map (fn [y] (abs (- y x))) xs)))