bimap -package:bimap package:relude

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

Maps a function over both elements of a bifunctor.

>>> bimapBoth length ([True], [False, True])
(1,2)

>>> map (bimapBoth not) [Left True, Right False]
[Left False,Right True]

Fmaps functions for nested bifunctor. Short for fmap (bimap f g).

>>> bimapF not length $ Just (False, ['a', 'b'])
Just (True,2)

A default definition of bimap in terms of the Bitraversable operations.

bimapDefault f g ≡
runIdentity . bitraverse (Identity . f) (Identity . g)