Jigsaw spec clarifications

[Jonathan Gibbons]

1. The uniqueness rule for provides services (It is a compile-time error 
if more than one |provides| clause in a view indicates the same module 
name or service name) is somewhat unclear about which of the names must 
be unique.

What about
     provides service S with S_A;
     provides service S with S_B;

What about
     provides service S1 with S;
     provides service S2 with S;

Both of these would seem to be reasonable use cases.

2. The same rule for modules, can you provide different versions of a 
module?
     provides M @ 1.0;
     provides M @ 2.0;
The spec implies not, which seems surprising for an alias mechanism.

3. I presume, but the spec does not say, that in "provides service S 
with S_A" S_A should be a subtype of S.


-- Jon