zoren

(defn index-of-safe
  "Return index of value (string or char) in s, optionally searching
  forward from from-index. Return nil if value not found.
  Works around https://bugs.openjdk.java.net/browse/JDK-8027640
  so the returned index is always greater equal to from-index.
  This also works around JavaScript's similar behavior."
  [s value from-index]
  (if (< (count s) from-index)
    nil
    (clojure.string/index-of s value from-index)))