module M where

import qualified Data.List as List

last_cur :: [a] -> a
last_cur xs = last xs

last_unsnoc :: [a] -> Maybe a
last_unsnoc xs = fmap snd (List.unsnoc xs)

init_cur :: [a] -> [a]
init_cur xs = init xs

init_unsnoc :: [a] -> Maybe [a]
init_unsnoc xs = fmap fst (List.unsnoc xs)