Safe Haskell	Safe-Inferred
Language	Haskell2010

Data.Bitraversable.Compat

Synopsis

Documentation

firstA :: Bitraversable t => Applicative f => (a -> f c) -> t a b -> f (t c b) Source #

Traverses only over the first argument.

firstA f ≡ bitraverse f pure

secondA :: Bitraversable t => Applicative f => (b -> f c) -> t a b -> f (t a c) Source #

Traverses only over the second argument.

secondA f ≡ bitraverse pure f

Expand

Basic usage:

>>> secondA (find odd) (Left [])
Just (Left [])

>>> secondA (find odd) (Left [1, 2, 3])
Just (Left [1,2,3])

>>> secondA (find odd) (Right [4, 5])
Just (Right 5)

>>> secondA (find odd) ([1, 2, 3], [4, 5])
Just ([1,2,3],5)

>>> secondA (find odd) ([1,2,3], [4])
Nothing

Since: 4.21.0.0