Data.Strict.Either

strict-0.5.1: Strict data types and String IO.

Safe Haskell | Safe
Language | Haskell2010

Data.Strict.Either

Description

The strict variant of the standard Haskell `Either` type and the corresponding variants of the functions from Data.Either.

Note that the strict `Either` type is not an applicative functor, and therefore also no monad. The reasons are the same as the ones for the strict `Maybe` type, which are explained in Data.Maybe.Strict.

Synopsis

- data Either a b
  - = Left !a
  - | Right !b
- either :: (a -> c) -> (b -> c) -> Either a b -> c
- isLeft :: Either a b -> Bool
- isRight :: Either a b -> Bool
- fromLeft :: Either a b -> a
- fromRight :: Either a b -> b
- lefts :: [Either a b] -> [a]
- rights :: [Either a b] -> [b]
- partitionEithers :: [Either a b] -> ([a], [b])

# Documentation

data Either a b #

The strict choice type.

Constructors

Left !a |
Right !b |

#### Instances

Instances details

Assoc Either # |
Instance details Defined in Data.Strict.Either Methods assoc :: Either (Either a b) c -> Either a (Either b c) # unassoc :: Either a (Either b c) -> Either (Either a b) c #
Swap Either # |
Instance details Defined in Data.Strict.Either Methods swap :: Either a b -> Either b a #
Bifoldable Either # |
Instance details Defined in Data.Strict.Either Methods bifold :: Monoid m => Either m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> Either a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> Either a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> Either a b -> c #
Bifunctor Either # |
Instance details Defined in Data.Strict.Either Methods bimap :: (a -> b) -> (c -> d) -> Either a c -> Either b d # first :: (a -> b) -> Either a c -> Either b c # second :: (b -> c) -> Either a b -> Either a c #
Bitraversable Either # |
Instance details Defined in Data.Strict.Either Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Either a b -> f (Either c d) #
Eq2 Either # |
Instance details Defined in Data.Strict.Either Methods liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> Either a c -> Either b d -> Bool #
Ord2 Either # |
Instance details Defined in Data.Strict.Either Methods liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> Either a c -> Either b d -> Ordering #
Read2 Either # |
Instance details Defined in Data.Strict.Either Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Either a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Either a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Either a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Either a b] #
Show2 Either # |
Instance details Defined in Data.Strict.Either Methods liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> Either a b -> ShowS # liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [Either a b] -> ShowS #
NFData2 Either # |
Instance details Defined in Data.Strict.Either Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> Either a b -> () #
Hashable2 Either # |
Instance details Defined in Data.Strict.Either Methods liftHashWithSalt2 :: (Int -> a -> Int) -> (Int -> b -> Int) -> Int -> Either a b -> Int #
Generic1 (Either a :: Type -> Type) # |
Instance details Defined in Data.Strict.Either Associated Types
type Rep1 (Either a :: Type -> Type) |
Instance details Defined in Data.Strict.Either type Rep1 (Either a :: Type -> Type) = D1 ('MetaData "Either" "Data.Strict.Either" "strict-0.5.1-1mB1yRAtJfYEfaxRHR0qto" 'False) (C1 ('MetaCons "Left" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 a)) :+: C1 ('MetaCons "Right" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) Par1))
Methods from1 :: Either a a0 -> Rep1 (Either a) a0 # to1 :: Rep1 (Either a) a0 -> Either a a0 #
Eq a => Eq1 (Either a) # |
Instance details Defined in Data.Strict.Either Methods liftEq :: (a0 -> b -> Bool) -> Either a a0 -> Either a b -> Bool #
Ord a => Ord1 (Either a) # |
Instance details Defined in Data.Strict.Either Methods liftCompare :: (a0 -> b -> Ordering) -> Either a a0 -> Either a b -> Ordering #
Read a => Read1 (Either a) # |
Instance details Defined in Data.Strict.Either Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (Either a a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [Either a a0] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (Either a a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [Either a a0] #
Show a => Show1 (Either a) # |
Instance details Defined in Data.Strict.Either Methods liftShowsPrec :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> Int -> Either a a0 -> ShowS # liftShowList :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> [Either a a0] -> ShowS #
NFData a => NFData1 (Either a) # |
Instance details Defined in Data.Strict.Either Methods liftRnf :: (a0 -> ()) -> Either a a0 -> () #
Functor (Either a) # |
Instance details Defined in Data.Strict.Either Methods fmap :: (a0 -> b) -> Either a a0 -> Either a b # (<$) :: a0 -> Either a b -> Either a a0 #
Foldable (Either e) # |
Instance details Defined in Data.Strict.Either Methods fold :: Monoid m => Either e m -> m # foldMap :: Monoid m => (a -> m) -> Either e a -> m # foldMap' :: Monoid m => (a -> m) -> Either e a -> m # foldr :: (a -> b -> b) -> b -> Either e a -> b # foldr' :: (a -> b -> b) -> b -> Either e a -> b # foldl :: (b -> a -> b) -> b -> Either e a -> b # foldl' :: (b -> a -> b) -> b -> Either e a -> b # foldr1 :: (a -> a -> a) -> Either e a -> a # foldl1 :: (a -> a -> a) -> Either e a -> a # toList :: Either e a -> [a] # null :: Either e a -> Bool # length :: Either e a -> Int # elem :: Eq a => a -> Either e a -> Bool # maximum :: Ord a => Either e a -> a # minimum :: Ord a => Either e a -> a # sum :: Num a => Either e a -> a # product :: Num a => Either e a -> a #
Traversable (Either e) # |
Instance details Defined in Data.Strict.Either Methods traverse :: Applicative f => (a -> f b) -> Either e a -> f (Either e b) # sequenceA :: Applicative f => Either e (f a) -> f (Either e a) # mapM :: Monad m => (a -> m b) -> Either e a -> m (Either e b) # sequence :: Monad m => Either e (m a) -> m (Either e a) #
Hashable a => Hashable1 (Either a) # |
Instance details Defined in Data.Strict.Either Methods liftHashWithSalt :: (Int -> a0 -> Int) -> Int -> Either a a0 -> Int #
(Binary a, Binary b) => Binary (Either a b) # |
Instance details Defined in Data.Strict.Either Methods put :: Either a b -> Put # get :: Get (Either a b) # putList :: [Either a b] -> Put #
(NFData a, NFData b) => NFData (Either a b) # |
Instance details Defined in Data.Strict.Either Methods rnf :: Either a b -> () #
Semigroup (Either a b) # |
Instance details Defined in Data.Strict.Either Methods (<>) :: Either a b -> Either a b -> Either a b # sconcat :: NonEmpty (Either a b) -> Either a b # stimes :: Integral b0 => b0 -> Either a b -> Either a b #
(Data a, Data b) => Data (Either a b) # |
Instance details Defined in Data.Strict.Either Methods gfoldl :: (forall d b0. Data d => c (d -> b0) -> d -> c b0) -> (forall g. g -> c g) -> Either a b -> c (Either a b) # gunfold :: (forall b0 r. Data b0 => c (b0 -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Either a b) # toConstr :: Either a b -> Constr # dataTypeOf :: Either a b -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Either a b)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Either a b)) # gmapT :: (forall b0. Data b0 => b0 -> b0) -> Either a b -> Either a b # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Either a b -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Either a b -> r # gmapQ :: (forall d. Data d => d -> u) -> Either a b -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Either a b -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Either a b -> m (Either a b) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Either a b -> m (Either a b) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Either a b -> m (Either a b) #
Generic (Either a b) # |
Instance details Defined in Data.Strict.Either Associated Types
type Rep (Either a b) |
Instance details Defined in Data.Strict.Either type Rep (Either a b) = D1 ('MetaData "Either" "Data.Strict.Either" "strict-0.5.1-1mB1yRAtJfYEfaxRHR0qto" 'False) (C1 ('MetaCons "Left" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 a)) :+: C1 ('MetaCons "Right" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 b)))
Methods from :: Either a b -> Rep (Either a b) x # to :: Rep (Either a b) x -> Either a b #
(Read a, Read b) => Read (Either a b) # |
Instance details Defined in Data.Strict.Either Methods readsPrec :: Int -> ReadS (Either a b) # readList :: ReadS [Either a b] # readPrec :: ReadPrec (Either a b) # readListPrec :: ReadPrec [Either a b] #
(Show a, Show b) => Show (Either a b) # |
Instance details Defined in Data.Strict.Either Methods showsPrec :: Int -> Either a b -> ShowS # show :: Either a b -> String # showList :: [Either a b] -> ShowS #
(Eq a, Eq b) => Eq (Either a b) # |
Instance details Defined in Data.Strict.Either Methods (==) :: Either a b -> Either a b -> Bool # (/=) :: Either a b -> Either a b -> Bool #
(Ord a, Ord b) => Ord (Either a b) # |
Instance details Defined in Data.Strict.Either Methods compare :: Either a b -> Either a b -> Ordering # (<) :: Either a b -> Either a b -> Bool # (<=) :: Either a b -> Either a b -> Bool # (>) :: Either a b -> Either a b -> Bool # (>=) :: Either a b -> Either a b -> Bool # max :: Either a b -> Either a b -> Either a b # min :: Either a b -> Either a b -> Either a b #
(Hashable a, Hashable b) => Hashable (Either a b) # |
Instance details Defined in Data.Strict.Either Methods hashWithSalt :: Int -> Either a b -> Int # hash :: Either a b -> Int #
Strict (Either a b) (Either a b) # |
Instance details Defined in Data.Strict.Classes Methods toStrict :: Either a b -> Either a b # toLazy :: Either a b -> Either a b #
type Rep1 (Either a :: Type -> Type) # |
Instance details Defined in Data.Strict.Either type Rep1 (Either a :: Type -> Type) = D1 ('MetaData "Either" "Data.Strict.Either" "strict-0.5.1-1mB1yRAtJfYEfaxRHR0qto" 'False) (C1 ('MetaCons "Left" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 a)) :+: C1 ('MetaCons "Right" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) Par1))
type Rep (Either a b) # |
Instance details Defined in Data.Strict.Either type Rep (Either a b) = D1 ('MetaData "Either" "Data.Strict.Either" "strict-0.5.1-1mB1yRAtJfYEfaxRHR0qto" 'False) (C1 ('MetaCons "Left" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 a)) :+: C1 ('MetaCons "Right" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 b)))

either :: (a -> c) -> (b -> c) -> Either a b -> c #

Case analysis: if the value is ``Left` a`, apply the first function to `a`; if it is ``Right` b`, apply the second function to `b`.

isLeft :: Either a b -> Bool #

Yields `True` iff the argument is of the form `Left _`.

isRight :: Either a b -> Bool #

Yields `True` iff the argument is of the form `Right _`.

fromLeft :: Either a b -> a #

Extracts the element out of a `Left` and throws an error if the argument is a `Right`.

fromRight :: Either a b -> b #

Extracts the element out of a `Right` and throws an error if the argument is a `Left`.

lefts :: [Either a b] -> [a] #

Analogous to `lefts` in Data.Either.

rights :: [Either a b] -> [b] #

Analogous to `rights` in Data.Either.

partitionEithers :: [Either a b] -> ([a], [b]) #

Analogous to `partitionEithers` in Data.Either.