Data.Ord.Ala

Creating Ord instance by a key function

Documentation

newtype Ala k a

Also known as store comonad

Constructors

Ala (a -> k, a)

Instances

Eq k => Eq (Ala k a)

Ord k => Ord (Ala k a)

ordBy :: Ord k => (a -> k) -> a -> Ala k a

Make Ord instance from the key function.

unAla :: Ala k a -> a

Extract the original value from Ala.

keyAla :: Ala k a -> k

Extract the key from Ala.

mapAla :: (j -> k) -> Ala j a -> Ala k a