Data commit

Task/Palindrome-detection/Haskell/palindrome-detection-1.hs

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+is_palindrome x = x == reverse x

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

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+import Data.Bifunctor (second)
+import Data.Char (toLower)
+
+------------------- PALINDROME DETECTION -----------------
+
+isPalindrome :: Eq a => [a] -> Bool
+isPalindrome = (==) <*> reverse
+
+-- Or, comparing just the leftward characters with
+-- with a reflection of just the rightward characters.
+
+isPal :: String -> Bool
+isPal s =
+  let (q, r) = quotRem (length s) 2
+   in uncurry (==) $
+        second (reverse . drop r) $ splitAt q s
+
+--------------------------- TEST -------------------------
+main :: IO ()
+main =
+  mapM_ putStrLn $
+    (showResult <$> [isPalindrome, isPal])
+      <*> fmap
+        prepared
+        [ "",
+          "a",
+          "ab",
+          "aba",
+          "abba",
+          "In girum imus nocte et consumimur igni"
+        ]
+
+prepared :: String -> String
+prepared cs = [toLower c | c <- cs, ' ' /= c]
+
+showResult f s = (show s) <> " -> " <> show (f s)

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

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+is_palindrome_r x | length x <= 1 = True
+                  | head x == last x = is_palindrome_r . tail. init $ x
+                  | otherwise = False