Dynamic loading for Java

Created by: eliotmoss

So Adam and I have run into an interesting question about how to do dynamic loading for Java. The thing is, one does not know all the details of a class in advance. Therefore, it is hard to give things signatures. Consider, for example, the vtable. We need to have Mu types for all the classes mentioned in all the methods -- the vtable will be a struct of function pointers, each pointer specifically typed. But that would force eager loading of the entire universe to figure out the types!

The only alternative seems to be to refcast all over the place at run time. Is that the intent? (Coming from Java I had a (mistaken) bias that this involves a cost, but I see on referring to the spec that refcast does not involve any run-time work.)