Jun 29, 2018 · I keep hearing a lot about functors in C++. Can someone give me an overview as to what they are and in what cases they would be useful?

Jan 9, 2010 · The word "functor" comes from category theory, which is a very general, very abstract branch of mathematics. It has been borrowed by designers of functional languages in at least two …

Aug 28, 2011 · A functor that is Applicative but not a Monad because laws cannot be satisfied even though the type signature of bind can be implemented. This example has generated quite a bit of …

Jun 20, 2022 · The takeaway is as follows: It’s safe to think of a representable functor as being a hom functor for the purpose of almost any proof or construction. The interesting thing about representable …

Sep 24, 2023 · In sum, the question is whether or not to mean functor as a property of couples of functions or as to couple of functions with built-in domain and codomain (which are categories). I …

Dec 15, 2021 · The deformation as a functor Ask Question Asked 4 years, 3 months ago Modified 3 years, 10 months ago

Feb 11, 2018 · So, you can think about a functor as a "function" (which indeed is not) between both objects and morphisms. For your another confusion, in axiomatic set theory, the sets are the most …

For one, the functor can contain internal state; a state that is valid for this invocation of the function object only. You could add static variables to your function, but those would be used for any …

Jul 22, 2017 · A functor takes a pure function (and a functorial value) whereas a monad takes a Kleisli arrow, i.e. a function that returns a monad (and a monadic value). Hence you can chain two monads …

Feb 13, 2017 · I wonder where should we use lambda expression over functor in C++. To me, these two techniques are basically the same, even functor is more elegant and cleaner than lambda. For …