gistfile1.hs

import Test.QuickCheck

myFirst :: [x] -> x
myFirst (x:xs) = x

prop_myFirst xs = not (null xs) ==> myFirst xs == head xs

myLast :: [x] -> x
myLast [x] = x
myLast (x:xs) = myLast xs

prop_myLast xs = not (null xs) ==> myLast xs == last xs

myButLast :: [x] -> x
myButLast [x,_] = x
myButLast (x:xs) = myButLast xs

prop_myButLast xs = not (null xs) && not (null (tail xs)) ==> myButLast xs == last (init xs)

elementAt :: [x] -> Int -> x
elementAt (x:xs) 1 = x
elementAt (x:xs) n = elementAt xs (n-1)

prop_elementAt xs = not (null xs) ==> and (zipWith (==) (map (elementAt xs) [1..]) xs) == True  -- roconnor

myLength :: [x] -> Int
myLength [] = 0
myLength (x:xs) = 1 + myLength xs

prop_myLength xs = myLength xs == length xs

myReverse :: [x] -> [x]
myReverse [] = []
myReverse (x:xs) = myReverse xs ++ [x]

prop_myReverse xs = myReverse xs == reverse xs where types = (xs :: [Int])

isPalindrome :: Eq a => [a] -> Bool
isPalindrome [] = True
isPalindrome [x] = True
isPalindrome (x:xs) = (x == (last xs)) && isPalindrome (init xs)

prop_isPalindrome xs = isPalindrome xs == (xs == reverse xs) where types = (xs :: [Char])