
30 Jul
2010
30 Jul
'10
6:17 a.m.
I don't understand why to call "impure" to the types instances of a class. Monad is simply a class with their methods. Even the "pure" list is a monad. The only difference between Monad and other classes is do notation, and only affects notation. The "impure" side is a type, not a class: IO.