New issue: Layers are strictly hierarchical

[David M. Lloyd]

If there is any expectation of moving existing systems over to Jigsaw, I 
think that the strict hierarchical layer system should be abandoned in 
favor of a graph-oriented system.  This allows containers to maintain 
separate module graphs with separate namespaces which nevertheless 
interconnect.

I believe that this is a necessary requirement if (in particular) there 
is an expectation that Java EE 9 (or another Java EE specification) 
would be reframed in terms of Jigsaw-style modules, since Java EE module 
names have many fewer restrictions, and it is possible for (for example) 
more than one application to contain modules of the same name.

If on the other hand there is an expectation that Java EE is not going 
to be retrofitted in a way which maps EE applications and modules to 
Jigsaw modules, then this should be clearly declared.

-- 
- DML