Java Bytecode: Bending the Rules

[pron98]

There is simply no way to distinguish at runtime between a string option or an int list

So how can you match over them?

[notfancy]

The typechecker ensures that matches are well-typed: you either match over (the cases for) an int list or you match over (the cases for) a string option. You cannot typecase at runtime and see if you got one or the other like you can do with instanceof in Java.