Documentation

>>> pointfree "I'm not a valid Haskell expression!"
[]
>>> pointfree "sum xs = foldr (+) 0 xs"
["sum = id (fix (const (foldr (+) 0)))","sum = fix (const (foldr (+) 0))","sum = foldr (+) 0"]

>>> pointfree' "I'm not a valid Haskell expression!"
Nothing
>>> pointfree' "sum xs = foldr (+) 0 xs"
Just "sum = foldr (+) 0"