actually do the letter matching for the scrabble program.

match-letters.clj

(defn match-letters? [letters line]
  (loop [letter-freq (frequencies (clojure.string/lower-case letters))
         line-freq (frequencies (clojure.string/lower-case line))]
    (if (empty? line-freq)
      (if (not-any? neg? (vals letter-freq)) true false)
        (if (contains? letter-freq (key (first line-freq)))
          (recur (update-in letter-freq [(key (first line-freq))] - (line-freq (key (first line-freq)))) (dissoc line-freq (key (first line-freq))))
        false))))