functor

1. A function word.

2. A function object.

3. A category homomorphism; a morphism from a source category to a target category which maps objects to objects and arrows to arrows (either covariantly or contravariantly), in such a way as to preserve morphism composition and identities.

   In the category of categories #92;mathbf#123;Cat#125; the objects are categories and the morphisms are functors.

   Funktor

   функторfunktor

4. A structure allowing a function to apply within a generic type, in a way that is conceptually similar to a functor in category theory.

regular