Functor
From HaskellWiki
(Difference between revisions)
m (Remove Category:Standard classes - now in template) |
(Added section "More reading" with a link to "The functor design pattern") |
||
| (One intermediate revision not shown.) | |||
| Line 10: | Line 10: | ||
fmap (p . q) = (fmap p) . (fmap q) | fmap (p . q) = (fmap p) . (fmap q) | ||
| - | [[Category: | + | |
| + | == More reading == | ||
| + | |||
| + | * [http://www.haskellforall.com/2012/09/the-functor-design-pattern.html The functor design pattern] | ||
| + | |||
| + | |||
| + | |||
| + | [[Category:Functor|*]] | ||
Current revision
| 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)
