Safe Haskell	None
Language	Haskell2010

Data.These

Contents

Functions to get rid of These
Partition

Description

The These type and associated operations. Now enhanced with Control.Lens magic!

Synopsis

data These a b
- = This a
- | That b
- | These a b
these :: (a -> c) -> (b -> c) -> (a -> b -> c) -> These a b -> c
fromThese :: a -> b -> These a b -> (a, b)
mergeThese :: (a -> a -> a) -> These a a -> a
mergeTheseWith :: (a -> c) -> (b -> c) -> (c -> c -> c) -> These a b -> c
partitionThese :: [These a b] -> ([a], [b], [(a, b)])
partitionHereThere :: [These a b] -> ([a], [b])

Documentation

data These a b Source #

The These type represents values with two non-exclusive possibilities.

This can be useful to represent combinations of two values, where the combination is defined if either input is. Algebraically, the type These A B represents (A + B + AB), which doesn't factor easily into sums and products--a type like Either A (B, Maybe A) is unclear and awkward to use.

These has straightforward instances of Functor, Monad, &c., and behaves like a hybrid error/writer monad, as would be expected.

For zipping and unzipping of structures with These values, see Data.Align.

Constructors

This a
That b
These a b

Instances

Arbitrary2 These Source #	Since: 0.7.4
Instance details Defined in Data.These Methods liftArbitrary2 :: Gen a -> Gen b -> Gen (These a b) # liftShrink2 :: (a -> [a]) -> (b -> [b]) -> These a b -> [These a b] #
ToJSON2 These Source #	Since: 0.7.2
Instance details Defined in Data.These Methods liftToJSON2 :: (a -> Value) -> ([a] -> Value) -> (b -> Value) -> ([b] -> Value) -> These a b -> Value # liftToJSONList2 :: (a -> Value) -> ([a] -> Value) -> (b -> Value) -> ([b] -> Value) -> [These a b] -> Value # liftToEncoding2 :: (a -> Encoding) -> ([a] -> Encoding) -> (b -> Encoding) -> ([b] -> Encoding) -> These a b -> Encoding # liftToEncodingList2 :: (a -> Encoding) -> ([a] -> Encoding) -> (b -> Encoding) -> ([b] -> Encoding) -> [These a b] -> Encoding #
FromJSON2 These Source #	Since: 0.7.2
Instance details Defined in Data.These Methods liftParseJSON2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (These a b) # liftParseJSONList2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [These a b] #
Bifunctor These Source #
Instance details Defined in Data.These Methods bimap :: (a -> b) -> (c -> d) -> These a c -> These b d # first :: (a -> b) -> These a c -> These b c # second :: (b -> c) -> These a b -> These a c #
Swap These Source #	Since: 0.8
Instance details Defined in Data.These Methods swap :: These a b -> These b a #
Assoc These Source #	Since: 0.8
Instance details Defined in Data.These Methods assoc :: These (These a b) c -> These a (These b c) # unassoc :: These a (These b c) -> These (These a b) c #
Bitraversable These Source #
Instance details Defined in Data.These Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> These a b -> f (These c d) #
Bifoldable These Source #
Instance details Defined in Data.These Methods bifold :: Monoid m => These m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> These a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> These a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> These a b -> c #
Bitraversable1 These Source #
Instance details Defined in Data.These Methods bitraverse1 :: Apply f => (a -> f b) -> (c -> f d) -> These a c -> f (These b d) # bisequence1 :: Apply f => These (f a) (f b) -> f (These a b) #
Swapped These Source #	Since: 0.7.6
Instance details Defined in Data.These Methods swapped :: Iso (These a b) (These c d) (These b a) (These d c) #
Bifoldable1 These Source #
Instance details Defined in Data.These Methods bifold1 :: Semigroup m => These m m -> m # bifoldMap1 :: Semigroup m => (a -> m) -> (b -> m) -> These a b -> m #
Bicrosswalk These Source #
Instance details Defined in Data.Align Methods bicrosswalk :: Align f => (a -> f c) -> (b -> f d) -> These a b -> f (These c d) Source # bisequenceL :: Align f => These (f a) (f b) -> f (These a b) Source #
Semigroup c => MonadChronicle c (These c) Source #
Instance details Defined in Control.Monad.Chronicle.Class Methods dictate :: c -> These c () Source # disclose :: Default a => c -> These c a Source # confess :: c -> These c a Source # memento :: These c a -> These c (Either c a) Source # absolve :: a -> These c a -> These c a Source # condemn :: These c a -> These c a Source # retcon :: (c -> c) -> These c a -> These c a Source # chronicle :: These c a -> These c a Source #
Semigroup a => Monad (These a) Source #
Instance details Defined in Data.These Methods (>>=) :: These a a0 -> (a0 -> These a b) -> These a b # (>>) :: These a a0 -> These a b -> These a b # return :: a0 -> These a a0 # fail :: String -> These a a0 #
Functor (These a) Source #
Instance details Defined in Data.These Methods fmap :: (a0 -> b) -> These a a0 -> These a b # (<$) :: a0 -> These a b -> These a a0 #
Semigroup a => Applicative (These a) Source #
Instance details Defined in Data.These Methods pure :: a0 -> These a a0 # (<>) :: These a (a0 -> b) -> These a a0 -> These a b # liftA2 :: (a0 -> b -> c) -> These a a0 -> These a b -> These a c # (>) :: These a a0 -> These a b -> These a b # (<*) :: These a a0 -> These a b -> These a a0 #
Foldable (These a) Source #
Instance details Defined in Data.These Methods fold :: Monoid m => These a m -> m # foldMap :: Monoid m => (a0 -> m) -> These a a0 -> m # foldr :: (a0 -> b -> b) -> b -> These a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> These a a0 -> b # foldl :: (b -> a0 -> b) -> b -> These a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> These a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # toList :: These a a0 -> [a0] # null :: These a a0 -> Bool # length :: These a a0 -> Int # elem :: Eq a0 => a0 -> These a a0 -> Bool # maximum :: Ord a0 => These a a0 -> a0 # minimum :: Ord a0 => These a a0 -> a0 # sum :: Num a0 => These a a0 -> a0 # product :: Num a0 => These a a0 -> a0 #
Traversable (These a) Source #
Instance details Defined in Data.These Methods traverse :: Applicative f => (a0 -> f b) -> These a a0 -> f (These a b) # sequenceA :: Applicative f => These a (f a0) -> f (These a a0) # mapM :: Monad m => (a0 -> m b) -> These a a0 -> m (These a b) # sequence :: Monad m => These a (m a0) -> m (These a a0) #
Arbitrary a => Arbitrary1 (These a) Source #	Since: 0.7.4
Instance details Defined in Data.These Methods liftArbitrary :: Gen a0 -> Gen (These a a0) # liftShrink :: (a0 -> [a0]) -> These a a0 -> [These a a0] #
ToJSON a => ToJSON1 (These a) Source #	Since: 0.7.2
Instance details Defined in Data.These Methods liftToJSON :: (a0 -> Value) -> ([a0] -> Value) -> These a a0 -> Value # liftToJSONList :: (a0 -> Value) -> ([a0] -> Value) -> [These a a0] -> Value # liftToEncoding :: (a0 -> Encoding) -> ([a0] -> Encoding) -> These a a0 -> Encoding # liftToEncodingList :: (a0 -> Encoding) -> ([a0] -> Encoding) -> [These a a0] -> Encoding #
FromJSON a => FromJSON1 (These a) Source #	Since: 0.7.2
Instance details Defined in Data.These Methods liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (These a a0) # liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [These a a0] #
Semigroup a => Apply (These a) Source #
Instance details Defined in Data.These Methods (<.>) :: These a (a0 -> b) -> These a a0 -> These a b # (.>) :: These a a0 -> These a b -> These a b # (<.) :: These a a0 -> These a b -> These a a0 # liftF2 :: (a0 -> b -> c) -> These a a0 -> These a b -> These a c #
Semigroup a => Bind (These a) Source #
Instance details Defined in Data.These Methods (>>-) :: These a a0 -> (a0 -> These a b) -> These a b # join :: These a (These a a0) -> These a a0 #
Crosswalk (These a) Source #
Instance details Defined in Data.Align Methods crosswalk :: Align f => (a0 -> f b) -> These a a0 -> f (These a b) Source # sequenceL :: Align f => These a (f a0) -> f (These a a0) Source #
(Eq a, Eq b) => Eq (These a b) Source #
Instance details Defined in Data.These Methods (==) :: These a b -> These a b -> Bool # (/=) :: These a b -> These a b -> Bool #
(Data a, Data b) => Data (These a b) Source #
Instance details Defined in Data.These Methods gfoldl :: (forall d b0. Data d => c (d -> b0) -> d -> c b0) -> (forall g. g -> c g) -> These a b -> c (These a b) # gunfold :: (forall b0 r. Data b0 => c (b0 -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (These a b) # toConstr :: These a b -> Constr # dataTypeOf :: These a b -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (These a b)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (These a b)) # gmapT :: (forall b0. Data b0 => b0 -> b0) -> These a b -> These a b # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> These a b -> r # gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> These a b -> r # gmapQ :: (forall d. Data d => d -> u) -> These a b -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> These a b -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> These a b -> m (These a b) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> These a b -> m (These a b) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> These a b -> m (These a b) #
(Ord a, Ord b) => Ord (These a b) Source #
Instance details Defined in Data.These Methods compare :: These a b -> These a b -> Ordering # (<) :: These a b -> These a b -> Bool # (<=) :: These a b -> These a b -> Bool # (>) :: These a b -> These a b -> Bool # (>=) :: These a b -> These a b -> Bool # max :: These a b -> These a b -> These a b # min :: These a b -> These a b -> These a b #
(Read a, Read b) => Read (These a b) Source #
Instance details Defined in Data.These Methods readsPrec :: Int -> ReadS (These a b) # readList :: ReadS [These a b] # readPrec :: ReadPrec (These a b) # readListPrec :: ReadPrec [These a b] #
(Show a, Show b) => Show (These a b) Source #
Instance details Defined in Data.These Methods showsPrec :: Int -> These a b -> ShowS # show :: These a b -> String # showList :: [These a b] -> ShowS #
Generic (These a b) Source #
Instance details Defined in Data.These Associated Types type Rep (These a b) :: Type -> Type # Methods from :: These a b -> Rep (These a b) x # to :: Rep (These a b) x -> These a b #
(Semigroup a, Semigroup b) => Semigroup (These a b) Source #
Instance details Defined in Data.These Methods (<>) :: These a b -> These a b -> These a b # sconcat :: NonEmpty (These a b) -> These a b # stimes :: Integral b0 => b0 -> These a b -> These a b #
(Function a, Function b) => Function (These a b) Source #	Since: 0.7.1
Instance details Defined in Data.These Methods function :: (These a b -> b0) -> These a b :-> b0 #
(Arbitrary a, Arbitrary b) => Arbitrary (These a b) Source #	Since: 0.7.1
Instance details Defined in Data.These Methods arbitrary :: Gen (These a b) # shrink :: These a b -> [These a b] #
(CoArbitrary a, CoArbitrary b) => CoArbitrary (These a b) Source #	Since: 0.7.1
Instance details Defined in Data.These Methods coarbitrary :: These a b -> Gen b0 -> Gen b0 #
(Hashable a, Hashable b) => Hashable (These a b) Source #
Instance details Defined in Data.These Methods hashWithSalt :: Int -> These a b -> Int # hash :: These a b -> Int #
(ToJSON a, ToJSON b) => ToJSON (These a b) Source #	Since: 0.7.1
Instance details Defined in Data.These Methods toJSON :: These a b -> Value # toEncoding :: These a b -> Encoding # toJSONList :: [These a b] -> Value # toEncodingList :: [These a b] -> Encoding #
(FromJSON a, FromJSON b) => FromJSON (These a b) Source #	Since: 0.7.1
Instance details Defined in Data.These Methods parseJSON :: Value -> Parser (These a b) # parseJSONList :: Value -> Parser [These a b] #
(Binary a, Binary b) => Binary (These a b) Source #	Since: 0.7.1
Instance details Defined in Data.These Methods put :: These a b -> Put # get :: Get (These a b) # putList :: [These a b] -> Put #
(NFData a, NFData b) => NFData (These a b) Source #	Since: 0.7.1
Instance details Defined in Data.These Methods rnf :: These a b -> () #
type Rep (These a b) Source #
Instance details Defined in Data.These type Rep (These a b) = D1 (MetaData "These" "Data.These" "these-0.8-9wgUxemvjEQWnU42wPp6o" False) (C1 (MetaCons "This" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 a)) :+: (C1 (MetaCons "That" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 b)) :+: C1 (MetaCons "These" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 a) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 b))))

Functions to get rid of `These`

these :: (a -> c) -> (b -> c) -> (a -> b -> c) -> These a b -> c Source #

Case analysis for the These type.

fromThese :: a -> b -> These a b -> (a, b) Source #

Takes two default values and produces a tuple.

mergeThese :: (a -> a -> a) -> These a a -> a Source #

Coalesce with the provided operation.

mergeTheseWith :: (a -> c) -> (b -> c) -> (c -> c -> c) -> These a b -> c Source #

bimap and coalesce results with the provided operation.

Partition

partitionThese :: [These a b] -> ([a], [b], [(a, b)]) Source #

Select each constructor and partition them into separate lists.

partitionHereThere :: [These a b] -> ([a], [b]) Source #

Select here and there elements and partition them into separate lists.

Since: 0.8

Documentation

Functions to get rid of These

Partition

Functions to get rid of `These`