Inverts DNA sequences in the form of strings

sequence-inverter.clj

(ns sequence-inverter.core
  (:gen-class))

(defn invert-char
  [char]
  (let [char-map {"A" "C"
                  "C" "A"
                  "G" "T"
                  "T" "G"}]
    (get char-map char)))

(defn valid-sequence?
  [sequence]
  (every? #(contains? #{"A" "C" "G" "T"} %) sequence))

(defn invert-sequence
  [sequence]
  (let [string-sec (vec (map str (.toUpperCase sequence)))]
    (if (valid-sequence? string-sec)
      (->> string-sec
           (map #(invert-char %))
           clojure.string/join)
      (str "Invalid Sequence"))))