> That's true (and will be addressed) Glad to hear it! It's probably the biggest issue trying to do functional programming on the JVM. > There is no difficult

> That's true (and will be addressed) Glad to hear it! It's probably the biggest issue trying to do functional programming on the JVM. > There is no difficulty supporting that. In fact, the Java language is about to get that without JVM changes. The technique to implement ADTs in functional languages on the JVM has often been to add an integer tag to every subtype and switch on that, but it's ugly enough for interop that IIRC Scala doesn't do it (and is thus less efficient).