module Exercise where

stops :: String
stops = "pbtdkg"

vowels :: String
vowels = "aeiou"

stopVowelStop :: [(Char, Char, Char)]
stopVowelStop = filter p [(x, y, z) | x <- stops, y <- vowels, z <- stops]
    where p (a, _, _) = a == 'p'

seekritFunc :: String -> Double
seekritFunc x = (/) (fromIntegral (sum (map length (words x)))) (fromIntegral (length (words x)))

myAnd :: [Bool] -> Bool
myAnd = foldr (&&) True

myOr :: [Bool] -> Bool
myOr = foldr (||) False

myAny :: (a -> Bool) -> [a] -> Bool
myAny f = myOr . map f

myElem :: Eq a => a -> [a] -> Bool
myElem x = foldr (\y z -> z || (y == x)) False

myElem' :: Eq a => a -> [a] -> Bool
myElem' needle = any (\x -> x == needle)

myReverse :: [a] -> [a]
myReverse = foldl (flip (:)) []

myMap :: (a -> b) -> [a] -> [b]
myMap f = foldr (\x y -> (f x) : y) []

myFilter :: (a -> Bool) -> [a] -> [a]
myFilter f = foldr (\x xs -> if f x then x : xs else xs) []

squish :: [[a]] -> [a]
squish = foldr (++) []

squishMap :: (a -> [b]) -> [a] -> [b]
squishMap f xs = foldr (++) [] (map f xs)

squishAgain :: [[a]] -> [a]
squishAgain = squishMap id

myMaximumBy :: (a -> a -> Ordering) -> [a] -> a
myMaximumBy f (z:zs) = foldl (\x y -> if (f x y) == GT then x else y) z zs

myMinimumBy :: (a -> a -> Ordering) -> [a] -> a
myMinimumBy f (z:zs) = foldl (\x y -> if (f x y) == LT then x else y) z zs