September Morn Update

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

@@ -1,20 +1,17 @@
 import Data.Char (ord, chr, isUpper, isAlpha)
+import Data.Bool (bool)
 
 caesar, uncaesar :: Int -> String -> String
-caesar = (<$>) . tr
+caesar = fmap . tr
 
 uncaesar = caesar . negate
 
 tr :: Int -> Char -> Char
 tr offset c
-  | isAlpha c = chr $ intAlpha + mod ((ord c - intAlpha) + offset) 26
+  | isAlpha c =
+    let i = ord $ bool 'a' 'A' (isUpper c)
+    in chr $ i + mod ((ord c - i) + offset) 26
   | otherwise = c
-  where
-    intAlpha =
-      ord
-        (if isUpper c
-           then 'A'
-           else 'a')
 
 main :: IO ()
 main = mapM_ print [encoded, decoded]