Functional Patterns

The objective of this chapter is to learn about functional patterns and the changes to the traditional patterns added by the introduction of a functional style of programming that is now possible in the most important programming languages. Java 8 brought in functional features that added a new level of abstraction, affecting the way we write some of the object-oriented design patterns, even making some of them irrelevant. In this chapter, we will see how design patterns are changed, or even replaced, by the new language features. In his paper, Design Patterns in Dynamic Languages, Peter Norvig noticed that 16 out of the 23 design patterns are simpler or replaced by existing language features in dynamic languages, such as Dylan. The full paper is available at http://norvig.com/design-patterns/. In this chapter, we are going to see what can be replaced...