Remove text surrounded by curly braces.

curly.clj

(defn remove-curlied
  [^String text]
  (let [sb  (StringBuilder.)
        end (int (count text))]
    (loop [state (int 0)
           pos   (int 0)]
      (cond
       (= pos end)   (.toString sb)
       (= (int (.charAt text pos)) (int \{)) (recur (inc state) (inc pos))
       (= (int (.charAt text pos)) (int \})) (recur (dec state) (inc pos))
       (zero? state) (do
                       (.append sb (int (.charAt text pos)))
                       (recur state (inc pos)))
       :else         (recur state (inc pos))))))