Smashing Swift
I don't understand what a functor is or why an array is a functor. Can anyone please explain? I did the wikipedia article for category theory and I read some stack overflow questions and I'm not sure I understand why an array is a functor. It seems some languages have their own meaning for what a "functor" is, confusing the issue.<p>My initial guess is that a functor is just sort of like a function that casts or does something like return an interface type from a type that implements the interface or a base class. Is that right? I still don't understand why an array is a functor though, I'd imagine it would at least have to be a function?<p>Edit:<p>Actually I think he's talking about Haskell's version of an iterable, and it would then make sense to call an array a functor.<p><a href="https://en.wikibooks.org/wiki/Haskell/The_Functor_class" rel="nofollow">https://en.wikibooks.org/wiki/Haskell/The_Functor_class</a><p>Why is that called a functor instead of an iterable or enumerable though?