Clojure: High Performance JVM Programming

Summary

Now we understand Clojure's way a little bit better and we have a better grasp of what to look for when we need polymorphism. We understand that when needing a polymorphic function we have several options:

• We can implement multimethods if we need a highly customized dispatching mechanism
• We can implement multimethods if we need to define a complex inheritance structure
• We can implement a protocol and define a custom type that implements that protocol
• We can define a protocol and extend existing Java or Clojure types with our custom functions for each type

Polymorphism in Clojure is very powerful. It allows you to extend the functionality of Clojure or Java types that already exist; it feels like adding methods to an interface. The best thing ...