04-08 Type Class Overview: Functor, Foldable (Introduction to Haskell)

We continue our overview of important type classes by discussing two classes that define interfaces on type constructors (parameterised datatypes), namely Functor and Foldable. The Functor class generalises the concept of types that have a map function, and the Foldable class is for types which contain elements in a clear order, meaning in particular that their elements can be extracted as a list.
Course site with self-test questions: teaching.well-...