(1): No support, some monad or early-error-return sugar used to be considered but effects cover most of the usecases of monads and are easier to use so I plan on emphasizing them. As for arrows, I have to say here that I've actually never used them in haskell so I don't know how useful they'd be.

(2): Thanks for the resource, I'll look it over :). I remember seeing a vaguely related note that multicore OCaml used to provide a `Obj.clone_continuation` function but no longer does. Of course, ante's algebraic effects design is rather different so that may not apply anyway. It may depend on the Generator whether it is cloneable or not. Some generators are just functions that can be arbitrarily cloned, but others are closures which may have restrictions in whether their environment is cloneable. Ante's clone story in general needs more work.