Functional Programming – 22: Functor

In Functional Programming, Functor is simply a structure that can be mapped over. The concept is borrowed from Category Theory. In Category Theory, Functor is a mapping between Categories.

This mapping involves:
– mapping of objects (types)
– mapping of arrows (functions)

It should also:
– preserve composition law
– preserve identity law

In this Video:
– Functor
– Endofunctor
– Option Functor
– List Functor
– Either Functor

Links:
– Category Theory by Bartosz Milewski – https://www.youtube.com/watch?v=FyoQjkwsy7o