I've not got time yet to write this up formally, but....
There's no difference between calling a sub PMC with parameters and
invoking a return continuation with return values. The return values for
that continuation are just sent as parameters, as if you were calling it
as a function.
Yes, that means that if you do:
$return_cont->(1, 2, 3);
it's the same as:
return (1,2,3);
assuming $return_cont has your return continuation in it. If programs want
to specify the types of the return values they can attach a prototype
property to their return continuation, which can be queried the same (and
yes, I know its unspecified) way that you can do it if you have a sub PMC.
I'll update the PDD as soon as I can get time and some working brain
cells.
Dan