kata17

kata17

version of the Kata using Java 17 features

Toward Using Java 17 with the preview features enabled

1. JEP 406 enhances the switch to support switching on any objects. We can leverage that to simplify the code by transforming the polymorphic method Exp.eval() into a switch. I will make the algorithm clearer by having all bits in once place instead of having each parts declared in the implementation classes. Note: we can do that because the hierarchy is closed so we control all implementations

   There is a nice interaction between sealed and switch() if a hierarchy is sealed, the compiler will not allow a default. Which is nice because it means that if a subtype is added, the compiler will force you to add a new case.

2. That's all for now, soon JEP 405 will be implemented, this will avoid to use accessors in the switch, but there is no available prototype implementing that JEP yet.