In category theory, a functor F is an operator on types. F is also considered to be a polymorphic operator on functions with the type
F : (a -> b) -> (F a -> F b).Functors are a generalisation of the function "map". The type operator in this case takes a type T and returns type "list of T". The map function takes a function and applies it to each element of a list.
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Nearby terms: function inlining « function key « Function Point Analysis « functor » funky » FUNLOG » FunnelWeb