mostly optimized version of https://github.com/jaley/curly/blob/92a21267f9772cd5eb93a2306612978b15b0c031/src/curly/core.clj

remove-curlied-optimized2.clj

;; mutate a StringBuilder in place. Listen for the sound of a clojure bunny dying somewhere..
;;
(defn remove-curlied-optimized2
  "Remove {something} from a string or {something else}"
  [^String text]
  (let [ tb (StringBuilder. text)]
    (loop [lo (.lastIndexOf tb "{" )
           lc (.indexOf tb "}" lo)]
      (assert (<= lo lc)) ; sanity check.
      (if (= -1 lo)
        (.toString tb)
        (do
          (.delete tb lo (inc lc))
          (let [nlo (.lastIndexOf tb "{")]
            (recur nlo (.indexOf tb "}" nlo))))))))