module Glob where

-- Implement each of the following functions:

f1 :: a -> b -> a
f1 = undefined

f2 :: a -> (a -> b) -> b
f2 = undefined

f3 :: a -> a -> (a -> b) -> b
f3 = undefined

f4 :: a -> b
f4 = undefined


-- The types of some other functions we'll use.
--
-- sum :: [Int] -> Int
-- map :: (a -> b) -> [a] -> [b]
-- filter :: (a -> Bool) -> [a] -> [a]


-- | A mystery function. We only know its type.
--    * What can it potentially do?
--    * What can it definitely not do?
glob :: [a] -> [a]
glob = undefined


-- Which of the following theorems are true?
--
--      sum . glob <=> glob . sum
--    map f . glob <=> glob . map f
-- filter f . glob <=> glob . filter f