Data.Either.Validation

either-5.0.2: Combinators for working with sums

Copyright | (c) 2014 Chris Allen Edward Kmett
License | BSD-style
Maintainer | ekmett@gmail.com
Stability | provisional
Portability | portable
Safe Haskell | Safe-Inferred
Language | Haskell2010

Data.Either.Validation

Description

Monoidal `Validation` sibling to `Either`.

Synopsis

- data Validation e a
  - = Failure e
  - | Success a
- _Success :: forall c a b p f. (Choice p, Applicative f) => p a (f b) -> p (Validation c a) (f (Validation c b))
- _Failure :: forall a c b p f. (Choice p, Applicative f) => p a (f b) -> p (Validation a c) (f (Validation b c))
- eitherToValidation :: Either e a -> Validation e a
- validationToEither :: Validation e a -> Either e a
- _Validation :: forall e a g b p f. (Profunctor p, Functor f) => p (Either e a) (f (Either g b)) -> p (Validation e a) (f (Validation g b))
- vap :: Semigroup m => Either m (a -> b) -> Either m a -> Either m b
- ealt :: Validation e a -> Validation e a -> Validation e a
- vapm :: Monoid m => Either m (a -> b) -> Either m a -> Either m b
- apm :: Monoid m => Validation m (a -> b) -> Validation m a -> Validation m b

# Documentation

data Validation e a #

`Validation` is `Either` with a Left that is a `Monoid`

Constructors

Failure e |
Success a |

#### Instances

Instances details

Bifoldable Validation # |
Instance details Defined in Data.Either.Validation 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 #
Bifunctor Validation # |
Instance details Defined in Data.Either.Validation 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 # |
Instance details Defined in Data.Either.Validation Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Validation a b -> f (Validation c d) #
(Semigroup e, Monoid e) => Alternative (Validation e) # |
Instance details Defined in Data.Either.Validation 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] #
Semigroup e => Applicative (Validation e) # |
Instance details Defined in Data.Either.Validation Methods pure :: a -> Validation e a # (<*>) :: Validation e (a -> b) -> Validation e a -> Validation e b # liftA2 :: (a -> b -> c) -> Validation e a -> Validation e b -> Validation e c # (*>) :: Validation e a -> Validation e b -> Validation e b # (<*) :: Validation e a -> Validation e b -> Validation e a #
Functor (Validation e) # |
Instance details Defined in Data.Either.Validation Methods fmap :: (a -> b) -> Validation e a -> Validation e b # (<$) :: a -> Validation e b -> Validation e a #
Foldable (Validation e) # |
Instance details Defined in Data.Either.Validation Methods fold :: Monoid m => Validation e m -> m # foldMap :: Monoid m => (a -> m) -> Validation e a -> 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) # |
Instance details Defined in Data.Either.Validation 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 => Alt (Validation e) # | For two errors, this instance reports both of them.
Instance details Defined in Data.Either.Validation 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] #
Semigroup e => Apply (Validation e) # |
Instance details Defined in Data.Either.Validation Methods (<.>) :: 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 # liftF2 :: (a -> b -> c) -> Validation e a -> Validation e b -> Validation e c #
Monoid e => Monoid (Validation e a) # |
Instance details Defined in Data.Either.Validation 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) # |
Instance details Defined in Data.Either.Validation Methods (<>) :: Validation e a -> Validation e a -> Validation e a # sconcat :: NonEmpty (Validation e a) -> Validation e a # stimes :: Integral b => b -> Validation e a -> Validation e a #
(Show e, Show a) => Show (Validation e a) # |
Instance details Defined in Data.Either.Validation Methods showsPrec :: Int -> Validation e a -> ShowS # show :: Validation e a -> String # showList :: [Validation e a] -> ShowS #
(Eq e, Eq a) => Eq (Validation e a) # |
Instance details Defined in Data.Either.Validation Methods (==) :: Validation e a -> Validation e a -> Bool # (/=) :: Validation e a -> Validation e a -> Bool #
(Ord e, Ord a) => Ord (Validation e a) # |
Instance details Defined in Data.Either.Validation 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 #

_Success :: forall c a b p f. (Choice p, Applicative f) => p a (f b) -> p (Validation c a) (f (Validation c b)) #

_Failure :: forall a c b p f. (Choice p, Applicative f) => p a (f b) -> p (Validation a c) (f (Validation b c)) #

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

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

_Validation :: forall e a g b p f. (Profunctor p, Functor f) => p (Either e a) (f (Either g b)) -> p (Validation e a) (f (Validation g b)) #

`Validation` is isomorphic to `Either`

vap :: Semigroup m => Either m (a -> b) -> Either m a -> Either m b #

ealt :: Validation e a -> Validation e a -> Validation e a #

vapm :: Monoid m => Either m (a -> b) -> Either m a -> Either m b #

apm :: Monoid m => Validation m (a -> b) -> Validation m a -> Validation m b #