squishMap maps a function over a list and concatenates the results.
squishMap :: (a -> [b]) -> [a] -> [b]
squishMap f = foldr (\x y -> f x ++ y) []

-- 9
squishMap :: (a -> [b]) -> [a] -> [b]
squishMap f = foldr (\x y -> f x ++ y) []
squishMap f = foldr (\x y -> f x ++ y) []