[Haskell-cafe] Heavy lift-ing

[Jürgen Doser]

El vie, 23-07-2010 a las 16:35 -0700, michael rice escribió:
> Thanks all,
> 
> Wild, at least up to the "optional" part, which I haven't dug into
> yet.
> 
> So the (+) for the Maybe monad and the (+) for the List monad are one
> in the same, the magic springs from the monads.
> 
> Why is it called "lift"-ing?


g :: m a -> m b -> m c
           /\
          /||\
           ||
           ||
f ::   a ->   b ->   c


liftM2 "lifts" the function f and transforms it into the function g =
liftM2 f. 

Does that picture help?

	Jürgen