functor
- Understanding contravariance
- Functortown: A Map of the Territory
- Functortown: Functor and Bifunctor
- Python mapping
the Functor typeclass
- Beginner crash course: Functor
- Functor and Bifunctor, lesson 5: Two maps in one
- Functor and Bifunctor, lesson 4: Breaking the laws!
- Functor and Bifunctor, lesson 2: More common functors
- Functortown: Functor and Bifunctor
- Functor and Bifunctor, lesson 1: Introduction to mapping
- Functor and Bifunctor, lesson 3: Laws and orders
- Functor and Bifunctor, lesson 6: More than a sum