janet-hashids/hashids.janet

(def DEFAULT_ALPHABET "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890")

(def DEFAULT_SEPS "cfhistuCFHISTU")

(def DEFAULT_SALT "")

(def DEFAULT_MIN_LENGTH 0)

(def MIN_ALPHABET_LENGTH 16)

(def SEP_DIV (/ 7 2))

(def GUARD_DIV 12)


(defn consistent-shuffle [alphabet salt]
  (if (= "" salt) alphabet
    (let [alph-bytes (apply array (string/bytes alphabet))
          salt-bytes (string/bytes salt)]
      (var p 0)

      (loop [i :down [(- (length alph-bytes) 1) 0]]
        (let [v (mod (- (length alph-bytes) i 1) (length salt-bytes))
              n (get salt-bytes v)]
          (set p (+ p n))
          (def j (mod (+ n v p) i))
          (def a (get alph-bytes j))
          (def b (get alph-bytes i))
          (put alph-bytes i a)
          (put alph-bytes j b)
          ))

      (apply string/from-bytes alph-bytes))))


(defn encode [opts num]
  "j0gW")