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Functor

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  fmap (p . q) = (fmap p) . (fmap q)
 
  fmap (p . q) = (fmap p) . (fmap q)
  
[[Category:Standard classes]]
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== More reading ==
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* [http://www.haskellforall.com/2012/09/the-functor-design-pattern.html The functor design pattern]
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[[Category:Functor|*]]

Revision as of 18:52, 19 September 2012

Functor class (base)
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)


More reading