Anamorphism in 1 minute

An Anamorphism (from the Greek ἀνά "upwards" and μορφή "form, shape) over a type T is a function of type U → T that destructs the U in some way into a number of components. On the components that are of type U, it applies recursion to convert theme to T 's. After that it combines the recursive results with the other components to a T , by means of the constructor functions of T .

For example if we want to build List(N, N-1, …, 1) from N we would use anamorphism from Int to List[Int]. It’s the opposite operation to fold - unfold.