Copyright	(c) 2014 Chris Allen, Edward Kmett
License	BSD-style
Maintainer	ekmett@gmail.com
Stability	provisional
Portability	portable
Safe Haskell	Safe
Language	Haskell98

Data.Either.Validation

Description

Monoidal Validation sibling to Either.

Synopsis

Documentation

data Validation e a Source

Validation is Either with a Left that is a Monoid

Constructors

Failure e
Success a

Instances

Bifunctor Validation Source
Methods bimap :: (a -> b) -> (c -> d) -> Validation a c -> Validation b d first :: (a -> b) -> Validation a c -> Validation b c second :: (b -> c) -> Validation a b -> Validation a c
Bitraversable Validation Source
Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Validation a b -> f (Validation c d) bisequenceA :: Applicative f => Validation (f a) (f b) -> f (Validation a b) bimapM :: Monad m => (a -> m c) -> (b -> m d) -> Validation a b -> m (Validation c d) bisequence :: Monad m => Validation (m a) (m b) -> m (Validation a b)
Bifoldable Validation Source
Methods bifold :: Monoid m => Validation m m -> m bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> Validation a b -> m bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> Validation a b -> c bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> Validation a b -> c
Functor (Validation e) Source
Methods fmap :: (a -> b) -> Validation e a -> Validation e b (<$) :: a -> Validation e b -> Validation e a
Semigroup e => Applicative (Validation e) Source
Methods pure :: a -> Validation e a (<>) :: Validation e (a -> b) -> Validation e a -> Validation e b (>) :: Validation e a -> Validation e b -> Validation e b (<*) :: Validation e a -> Validation e b -> Validation e a
Foldable (Validation e) Source
Methods fold :: Monoid m => Validation e m -> m foldMap :: Monoid m => (a -> m) -> Validation e a -> m foldr :: (a -> b -> b) -> b -> Validation e a -> b foldr' :: (a -> b -> b) -> b -> Validation e a -> b foldl :: (b -> a -> b) -> b -> Validation e a -> b foldl' :: (b -> a -> b) -> b -> Validation e a -> b foldr1 :: (a -> a -> a) -> Validation e a -> a foldl1 :: (a -> a -> a) -> Validation e a -> a toList :: Validation e a -> [a] null :: Validation e a -> Bool length :: Validation e a -> Int elem :: Eq a => a -> Validation e a -> Bool maximum :: Ord a => Validation e a -> a minimum :: Ord a => Validation e a -> a sum :: Num a => Validation e a -> a product :: Num a => Validation e a -> a
Traversable (Validation e) Source
Methods traverse :: Applicative f => (a -> f b) -> Validation e a -> f (Validation e b) sequenceA :: Applicative f => Validation e (f a) -> f (Validation e a) mapM :: Monad m => (a -> m b) -> Validation e a -> m (Validation e b) sequence :: Monad m => Validation e (m a) -> m (Validation e a)
(Semigroup e, Monoid e) => Alternative (Validation e) Source
Methods empty :: Validation e a (<\|>) :: Validation e a -> Validation e a -> Validation e a some :: Validation e a -> Validation e [a] many :: Validation e a -> Validation e [a]
Alt (Validation e) Source
Methods (<!>) :: Validation e a -> Validation e a -> Validation e a some :: Applicative (Validation e) => Validation e a -> Validation e [a] many :: Applicative (Validation e) => Validation e a -> Validation e [a]
(Eq e, Eq a) => Eq (Validation e a) Source
Methods (==) :: Validation e a -> Validation e a -> Bool (/=) :: Validation e a -> Validation e a -> Bool
(Ord e, Ord a) => Ord (Validation e a) Source
Methods compare :: Validation e a -> Validation e a -> Ordering (<) :: Validation e a -> Validation e a -> Bool (<=) :: Validation e a -> Validation e a -> Bool (>) :: Validation e a -> Validation e a -> Bool (>=) :: Validation e a -> Validation e a -> Bool max :: Validation e a -> Validation e a -> Validation e a min :: Validation e a -> Validation e a -> Validation e a
(Show e, Show a) => Show (Validation e a) Source
Methods showsPrec :: Int -> Validation e a -> ShowS show :: Validation e a -> String showList :: [Validation e a] -> ShowS
Monoid e => Monoid (Validation e a) Source
Methods mempty :: Validation e a mappend :: Validation e a -> Validation e a -> Validation e a mconcat :: [Validation e a] -> Validation e a
Semigroup e => Semigroup (Validation e a) Source
Methods (<>) :: Validation e a -> Validation e a -> Validation e a sconcat :: NonEmpty (Validation e a) -> Validation e a times1p :: Natural -> Validation e a -> Validation e a

_Success :: Prism (Validation c a) (Validation c b) a b Source

_Failure :: Prism (Validation a c) (Validation b c) a b Source

eitherToValidation :: Either e a -> Validation e a Source

validationToEither :: Validation e a -> Either e a Source

_Validation :: Iso (Validation e a) (Validation g b) (Either e a) (Either g b) Source

Validation is isomorphic to Either