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Data.Functor | Portability | portable | Stability | provisional | Maintainer | libraries@haskell.org |
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Description |
Functors: uniform action over a parameterized type, generalizing the
map function on lists.
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Synopsis |
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Documentation |
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class Functor f where |
The Functor class is used for types that can be mapped over.
Instances of Functor should satisfy the following laws:
fmap id == id
fmap (f . g) == fmap f . fmap g
The instances of Functor for lists, Data.Maybe.Maybe and System.IO.IO
defined in the Prelude satisfy these laws.
| | Methods | fmap :: (a -> b) -> f a -> f b | | (<$) :: a -> f b -> f a | Replace all locations in the input with the same value.
The default definition is fmap . const, but this may be
overridden with a more efficient version.
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(<$>) :: Functor f => (a -> b) -> f a -> f b |
An infix synonym for fmap.
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Produced by Haddock version 2.6.1 |