This simple module defines the const functor known from Haskell's base libraries. It defines a wrapper around a constant value that "ignores" functions mapped over it.
newtype Const a _
The Const
functor which returns a constant for any fmap, i.e.,
a wrapper around a constant value that ignores functions mapped over it.
Example:
> fmap (++ "world") (Const "Hello") Const "Hello"
Constructor:
Const
:: a -> Const a _
Fields:
getConst
:: a
Known instances:
Functor (Const a)
(Eq a, Eq _) => Eq (Const a _)
(Ord a, Ord _) => Ord (Const a _)
(Read a, Read _) => Read (Const a _)
(Show a, Show _) => Show (Const a _)