Functional Classes Guide Use of Design Patterns in Implementing Mediators

In this paper, we study how functional classes guide use of design patterns when implementing mediators. Functional classes is a design style that merges both object-oriented and functional programming paradigms. A functional class is a class without variables having pure functions as methods. Therefore, method calls in functional classes are function calls also in the formal sense. As a result, a functional class is naturally a mediator. In this paper, as the main contribution, we show that functional classes lead to proper use of certain specific design patterns, like Singleton, Adapter, Abstract Factory, and Strategy. We exemplify this with a data mediator implementation called JavaTableFC