FUNCTIONAL PROGRAMMING WITH APOMORPHISMS (CORECURSION)

Abstract

In the mainstream categorical approach to typed (total) functional programming, functions with inductive source types defined by primitive recursion are called paramorphisms; the utility of primitive recursion as a scheme for defining functions in programming is well known. We draw attention to the dual notion of apomorphisms — functions with coinductive target types defined by primitive corecursion and show on examples that primitive corecursion is useful in programming.