these-1.2.1: An either-or-both data type.
Safe HaskellSafe
LanguageHaskell2010

Data.These

Description

The These type and associated operations.

Synopsis

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

Instances details
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 #

Swap These Source #

Since: 0.8

Instance details

Defined in Data.These

Methods

swap :: These a b -> These b a #

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 #

Bifoldable1 These Source #

Since: 1.2

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 #

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 #

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) #

Eq2 These Source #

Since: 1.1.1

Instance details

Defined in Data.These

Methods

liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> These a c -> These b d -> Bool #

Ord2 These Source #

Since: 1.1.1

Instance details

Defined in Data.These

Methods

liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> These a c -> These b d -> Ordering #

Read2 These Source #

Since: 1.1.1

Instance details

Defined in Data.These

Methods

liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (These a b) #

liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [These a b] #

liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (These a b) #

liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [These a b] #

Show2 These Source #

Since: 1.1.1

Instance details

Defined in Data.These

Methods

liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> These a b -> ShowS #

liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [These a b] -> ShowS #

NFData2 These Source #

Since: 1.1.1

Instance details

Defined in Data.These

Methods

liftRnf2 :: (a -> ()) -> (b -> ()) -> These a b -> () #

Hashable2 These Source #

Since: 1.1.1

Instance details

Defined in Data.These

Methods

liftHashWithSalt2 :: (Int -> a -> Int) -> (Int -> b -> Int) -> Int -> These a b -> Int #

Generic1 (These a :: Type -> Type) Source # 
Instance details

Defined in Data.These

Associated Types

type Rep1 (These a :: Type -> Type) 
Instance details

Defined in Data.These

type Rep1 (These a :: Type -> Type) = D1 ('MetaData "These" "Data.These" "these-1.2.1-9ohI0r8b6M98gOYK8QHI1w" '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) Par1) :+: C1 ('MetaCons "These" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1)))

Methods

from1 :: These a a0 -> Rep1 (These a) a0 #

to1 :: Rep1 (These a) a0 -> 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 #

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 #

Eq a => Eq1 (These a) Source #

Since: 1.1.1

Instance details

Defined in Data.These

Methods

liftEq :: (a0 -> b -> Bool) -> These a a0 -> These a b -> Bool #

Ord a => Ord1 (These a) Source #

Since: 1.1.1

Instance details

Defined in Data.These

Methods

liftCompare :: (a0 -> b -> Ordering) -> These a a0 -> These a b -> Ordering #

Read a => Read1 (These a) Source #

Since: 1.1.1

Instance details

Defined in Data.These

Methods

liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (These a a0) #

liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [These a a0] #

liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (These a a0) #

liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [These a a0] #

Show a => Show1 (These a) Source #

Since: 1.1.1

Instance details

Defined in Data.These

Methods

liftShowsPrec :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> Int -> These a a0 -> ShowS #

liftShowList :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> [These a a0] -> ShowS #

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) #

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 #

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 => 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 #

NFData a => NFData1 (These a) Source #

Since: 1.1.1

Instance details

Defined in Data.These

Methods

liftRnf :: (a0 -> ()) -> These a a0 -> () #

Hashable a => Hashable1 (These a) Source #

Since: 1.1.1

Instance details

Defined in Data.These

Methods

liftHashWithSalt :: (Int -> a0 -> Int) -> Int -> These a a0 -> Int #

(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 :: forall r r'. (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) #

(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 #

Generic (These a b) Source # 
Instance details

Defined in Data.These

Associated Types

type Rep (These a b) 
Instance details

Defined in Data.These

type Rep (These a b) = D1 ('MetaData "These" "Data.These" "these-1.2.1-9ohI0r8b6M98gOYK8QHI1w" '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))))

Methods

from :: These a b -> Rep (These a b) x #

to :: Rep (These a b) x -> 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 #

(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 -> () #

(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 #

(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 #

(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 #

type Rep1 (These a :: Type -> Type) Source # 
Instance details

Defined in Data.These

type Rep1 (These a :: Type -> Type) = D1 ('MetaData "These" "Data.These" "these-1.2.1-9ohI0r8b6M98gOYK8QHI1w" '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) Par1) :+: C1 ('MetaCons "These" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1)))
type Rep (These a b) Source # 
Instance details

Defined in Data.These

type Rep (These a b) = D1 ('MetaData "These" "Data.These" "these-1.2.1-9ohI0r8b6M98gOYK8QHI1w" '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

partitionEithersNE :: NonEmpty (Either a b) -> These (NonEmpty a) (NonEmpty b) Source #

Like partitionEithers but for NonEmpty types.

Note: this is not online algorithm. In the worst case it will traverse the whole list before deciding the result constructor.

>>> partitionEithersNE $ Left 'x' :| [Right 'y']
These ('x' :| "") ('y' :| "")

>>> partitionEithersNE $ Left 'x' :| map Left "yz"
This ('x' :| "yz")

Since: 1.0.1

Distributivity

These distributivity combinators aren't isomorphisms!

distrThesePair :: These (a, b) c -> (These a c, These b c) Source #

undistrThesePair :: (These a c, These b c) -> These (a, b) c Source #

distrPairThese :: (These a b, c) -> These (a, c) (b, c) Source #

undistrPairThese :: These (a, c) (b, c) -> (These a b, c) Source #