:: (x -> y) -> (p -> q) -> Either x p -> Either y q package:rio

Map over both arguments at the same time.
bimap f g ≡ first f . second g

Examples

>>> bimap toUpper (+1) ('j', 3)
('J',4)
>>> bimap toUpper (+1) (Left 'j')
Left 'J'
>>> bimap toUpper (+1) (Right 3)
Right 4