Andreas Rossberg

My feeling is that pushing defaultability further is just gonna metastasise in ugly ways and lead to unnecessary ad-hoc complexity. I'd suggest we treat it as a limited shorthand for...

I agree with @conrad-watt. Getting rid of the intrusive new form of non-determinism (a.k.a. implementation-dependent semantics) would make me much less concerned about this proposal.

Thanks, done, see #15. But note that some bits still require some resolution, in particular, how we enforce def-use ordering between type and import sections. I also remove Eq constraints...

Yes, a module with type imports is similar to a polymorphic definition, i.e., the instantiation types determine the types of exports. FWIW, table types don't matter for call_indirect, they are...

Unfortunately, importing non-reference types would pretty much break (separate) compilation of Wasm modules, since the engine could not know what the space and storage constraints for values of an imported...

The obvious alternative is boxing all capability values, which might well be the simplest solution.

Yes, abstract types (which haven't originally been a priority) still need some design. I agree that something between Haskell's newtype and ML-style module sealing semantics is probably where we will...

@RossTate, it is straightforward to extend ML-style sealing with bounds. In fact, ML already has equality bounds, we just add subtyping bounds. There is precedence for this, e.g., in Fisher...

There is no casting in this proposal. With GC types, which introduce it, casting is controlled by RTTs, which are intentionally explicit. A value's more specific type can only be...

I agree that we probably want to allow (declared) subtyping on continuations. However, it is important to note that this by no means implies that we also support downcasts on...