Data commit

Task/Caesar-cipher/Janet/caesar-cipher.janet

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+(def alphabet "abcdefghijklmnopqrstuvwxyz")
+
+(defn rotate
+  "shift bytes given x"
+  [str x]
+  (let [r (% x (length alphabet))
+        b (string/bytes str)
+        abyte (get (string/bytes "a") 0)
+        zbyte (get (string/bytes "z") 0)]
+    (var result @[])
+    (for i 0 (length b)
+      (let [ch (bor (get b i) 0x20)]  # convert uppercase to lowercase
+        (when (and (<= abyte ch) (<= ch zbyte))
+          (array/push result (get alphabet (% (+ (+ (+ (- zbyte abyte) 1) (- ch abyte)) r) (length alphabet)))))))
+    (string/from-bytes ;result)))
+
+(defn code
+  "encodes and decodes str given argument type"
+  [str rot type]
+  (case type
+    :encode (rotate str rot)
+    :decode (rotate str (* rot -1))))
+
+(defn main [& args]
+  (let [cipher (code "The quick brown fox jumps over the lazy dog" 23 :encode)
+        str (code cipher 23 :decode)]
+    (print cipher)
+    (print str)))