September 2017 Update

Task/Palindrome-detection/Haskell/palindrome-detection-2.hs

@@ -1,3 +1,19 @@
-is_palindrome_r x | length x <= 1 = True
-                  | head x == last x = is_palindrome_r . tail. init $ x
-                  | otherwise = False
+import Data.Char (toLower)
+
+isPalindrome :: String -> Bool
+isPalindrome = (==) <*> reverse
+
+-- Alternatively, comparing just the first half with the reversed latter half
+isPal :: String -> Bool
+isPal s =
+  let (q, r) = quotRem (length s) 2
+  in take q s == reverse (drop (q + r) s)
+
+sample :: String
+sample = "In girum imus nocte et consumimur igni"
+
+prepared :: String -> String
+prepared = filter (' ' /=) . fmap toLower
+
+main :: IO ()
+main = print $ [isPalindrome, isPal] <*> [prepared sample]

Task/Palindrome-detection/Haskell/palindrome-detection-3.hs

@@ -0,0 +1,3 @@
+is_palindrome_r x | length x <= 1 = True
+                  | head x == last x = is_palindrome_r . tail. init $ x
+                  | otherwise = False