:: Either a b -> Maybe b package:rebase

rightToMaybe :: Either a b -> Maybe b
rebase Rebase.Prelude
Maybe get the Right side of an Either. 
rightToMaybe ≡ either (const Nothing) Just
Using Control.Lens: 
rightToMaybe ≡ preview _Right
rightToMaybe x ≡ x^?_Right

>>> rightToMaybe (Left 12)
Nothing

>>> rightToMaybe (Right 12)
Just 12