add Problem6 and Problem6 Test Code of 99 Questions in Haskell Wiki

Author: 7vk1

src/Wiki_99_Questions/Problem6.hs

@@ -0,0 +1,8 @@
+-- Problem 6
+-- Find out whether a list is a palindrome.
+-- A palindrome can be read forward or backward; e.g. (x a m a x). 
+
+module Wiki_99_Questions.Problem6 where
+
+isPalindrome :: (Eq a) => [a] -> Bool
+isPalindrome xs = xs == (reverse xs)

studying-haskell.cabal

@@ -20,6 +20,7 @@ library
                      , Wiki_99_Questions.Problem3
                      , Wiki_99_Questions.Problem4
                      , Wiki_99_Questions.Problem5
+                     , Wiki_99_Questions.Problem6
                      , Lib
   build-depends:       base >= 4.7 && < 5
   default-language:    Haskell2010

test/Wiki_99_Questions/Problem6Spec.hs

@@ -0,0 +1,14 @@
+module Wiki_99_Questions.Problem6Spec where
+
+import Test.Hspec
+import Wiki_99_Questions.Problem6
+
+spec :: Spec
+spec = do
+  describe "Test1 for Problem6" $ do
+    it "isPalindrome \"Hello\" -> false" $ do
+      isPalindrome "Hello" `shouldBe` False
+  
+  describe "Test2 for Problem6"  $ do
+    it "isPalindrome \"tweewt\" -> true" $ do
+      isPalindrome "tweewt" `shouldBe` True