Haskell: Turn the String or list into a palindrome

If string str1 = "abcd", you can turn str1 to palindrome like "abcddcba".

plaindrome = str1 ++ reverse(str1) = "abcd" ++ "dcba" = "abcddcba".

palindrome.hs

getPalindrome :: String -> String
getPalindrome [] = []
getPalindrome (x:xs) = [x] ++ getPalindrome (xs) ++ [x]

*Main> :load palindrome.hs
[1 of 1] Compiling Main             ( palindrome.hs, interpreted )
Ok, modules loaded: Main.
*Main> 
*Main> getPalindrome "abcd"
"abcddcba"
*Main> 
*Main> getPalindrome "a"
"aa"
*Main> getPalindrome "abc"
"abccba"
*Main> 
*Main> getPalindrome "mad"
"maddam"
*Main> 

Since String is internally implemented as list of characters, same logic is used on list of characters also.

*Main> getPalindrome ['a', 'b', 'c']
"abccba"
*Main> 
*Main> getPalindrome ['a', 'b', 'c', 'd']
"abcddcba"
*Main> 
*Main> getPalindrome []
""

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