Idiomatic way to sum a list of Maybe Int in haskell

Question

Is there a more idiomatic way to implement the following? I feel like I\'m missing a way to get rid of the lambda, but couldn\'t figure out a way to convert it to point-free. Ma

Answer 1

You can lift the (+) in the Maybe Monad with:

input> fold (liftM2 (+)) (Just 0) [Just 1, Just 2]
Just 3
input> fold (liftM2 (+)) (Just 0) [Just 1, Just 2, Nothing]
Nothing