Functor
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[[Category:Standard classes]] |
[[Category:Standard classes]] |
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Revision as of 18:27, 7 October 2006
import Control.Monad |
The Functor class is defined like this:
class Functor f where fmap :: (a -> b) -> f a -> f b
All instances of Functor should obey:
fmap id = id fmap (p . q) = (fmap p) . (fmap q)