Initial data commit

Task/Caesar-cipher/Haskell/caesar-cipher-2.hs

@@ -0,0 +1,24 @@
+import Data.Bool (bool)
+import Data.Char (chr, isAlpha, isUpper, ord)
+
+---------------------- CAESAR CIPHER ---------------------
+
+caesar, uncaesar :: Int -> String -> String
+caesar = fmap . tr
+uncaesar = caesar . negate
+
+tr :: Int -> Char -> Char
+tr offset c
+  | isAlpha c =
+      chr
+        . ((+) <*> (flip mod 26 . (-) (offset + ord c)))
+        $ bool 97 65 (isUpper c)
+  | otherwise = c
+
+--------------------------- TEST -------------------------
+main :: IO ()
+main = do
+  let k = -114
+      cipher = caesar k
+      plain = "Curio, Cesare venne, e vide e vinse ? "
+  mapM_ putStrLn $ [cipher, uncaesar k . cipher] <*> [plain]