module Util where

uniq :: Eq a => [a] -> [a]
uniq (x:y:xs) | x == y    = uniq (x:xs)
              | otherwise = x : uniq (y:xs)
uniq xs = xs

uniqOn :: Eq b => (a -> b) -> [a] -> [a]
uniqOn f (x:y:xs) | f x == f y = uniqOn f (x:xs)
                  | otherwise  = x : uniqOn f (y:xs)
uniqOn _ xs = xs