Data.Functor.Constant

The constant functor.

Documentation

newtype Constant a b

Constant functor.

Constructors

Constant

Fields

• getConstant :: a

Instances

Bifunctor (Constant *)

Methods

bimap :: (a -> b) -> (c -> d) -> Constant * a c -> Constant * b d

first :: (a -> b) -> Constant * a c -> Constant * b c

second :: (b -> c) -> Constant * a b -> Constant * a c

Eq2 (Constant *)

Methods

liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> Constant * a c -> Constant * b d -> Bool

Ord2 (Constant *)

Methods

liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> Constant * a c -> Constant * b d -> Ordering

Read2 (Constant *)

Methods

liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Constant * a b)

liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Constant * a b]

liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Constant * a b)

liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Constant * a b]

Show2 (Constant *)

Methods

liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> Constant * a b -> ShowS

liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [Constant * a b] -> ShowS

Functor (Constant * a)

Methods

fmap :: (a -> b) -> Constant * a a -> Constant * a b

(<$) :: a -> Constant * a b -> Constant * a a

Monoid a => Applicative (Constant * a)

Methods

pure :: a -> Constant * a a

(<*>) :: Constant * a (a -> b) -> Constant * a a -> Constant * a b

liftA2 :: (a -> b -> c) -> Constant * a a -> Constant * a b -> Constant * a c

(*>) :: Constant * a a -> Constant * a b -> Constant * a b

(<*) :: Constant * a a -> Constant * a b -> Constant * a a

Foldable (Constant * a)

Methods

fold :: Monoid m => Constant * a m -> m

foldMap :: Monoid m => (a -> m) -> Constant * a a -> m

foldr :: (a -> b -> b) -> b -> Constant * a a -> b

foldr' :: (a -> b -> b) -> b -> Constant * a a -> b

foldl :: (b -> a -> b) -> b -> Constant * a a -> b

foldl' :: (b -> a -> b) -> b -> Constant * a a -> b

foldr1 :: (a -> a -> a) -> Constant * a a -> a

foldl1 :: (a -> a -> a) -> Constant * a a -> a

toList :: Constant * a a -> [a]

null :: Constant * a a -> Bool

length :: Constant * a a -> Int

elem :: Eq a => a -> Constant * a a -> Bool

maximum :: Ord a => Constant * a a -> a

minimum :: Ord a => Constant * a a -> a

sum :: Num a => Constant * a a -> a

product :: Num a => Constant * a a -> a

Traversable (Constant * a)

Methods

traverse :: Applicative f => (a -> f b) -> Constant * a a -> f (Constant * a b)

sequenceA :: Applicative f => Constant * a (f a) -> f (Constant * a a)

mapM :: Monad m => (a -> m b) -> Constant * a a -> m (Constant * a b)

sequence :: Monad m => Constant * a (m a) -> m (Constant * a a)

Eq a => Eq1 (Constant * a)

Methods

liftEq :: (a -> b -> Bool) -> Constant * a a -> Constant * a b -> Bool

Ord a => Ord1 (Constant * a)

Methods

liftCompare :: (a -> b -> Ordering) -> Constant * a a -> Constant * a b -> Ordering

Read a => Read1 (Constant * a)

Methods

liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Constant * a a)

liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Constant * a a]

liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Constant * a a)

liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Constant * a a]

Show a => Show1 (Constant * a)

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Constant * a a -> ShowS

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Constant * a a] -> ShowS

Eq a => Eq (Constant k a b)

Methods

(==) :: Constant k a b -> Constant k a b -> Bool

(/=) :: Constant k a b -> Constant k a b -> Bool

Ord a => Ord (Constant k a b)

Methods

compare :: Constant k a b -> Constant k a b -> Ordering

(<) :: Constant k a b -> Constant k a b -> Bool

(<=) :: Constant k a b -> Constant k a b -> Bool

(>) :: Constant k a b -> Constant k a b -> Bool

(>=) :: Constant k a b -> Constant k a b -> Bool

max :: Constant k a b -> Constant k a b -> Constant k a b

min :: Constant k a b -> Constant k a b -> Constant k a b

Read a => Read (Constant k a b)

Methods

readsPrec :: Int -> ReadS (Constant k a b)

readList :: ReadS [Constant k a b]

readPrec :: ReadPrec (Constant k a b)

readListPrec :: ReadPrec [Constant k a b]

Show a => Show (Constant k a b)

Methods

showsPrec :: Int -> Constant k a b -> ShowS

show :: Constant k a b -> String

showList :: [Constant k a b] -> ShowS

Monoid a => Monoid (Constant k a b)

Methods

mempty :: Constant k a b

mappend :: Constant k a b -> Constant k a b -> Constant k a b

mconcat :: [Constant k a b] -> Constant k a b