Implied readability + layers

[Alex Buckley]

On 11/5/2015 2:30 PM, Ali Ebrahimi wrote:
> On Fri, Nov 6, 2015 at 1:09 AM, Alex Buckley <alex.buckley at oracle.com
> <mailto:alex.buckley at oracle.com>> wrote:
>
>     A single version of com.bar in a program is strongly presumed to be
>     better than multiple versions of com.bar in a program.
>
> In Ideal world this would be perfect.
>
> But, If you use many modules from different third-parties with different
> release cycles, things may change and finding this single version may be
> impossible.

Disagree. Since JDK 1.0, people have been finding this single version by 
putting it earlier on the classpath than other versions. And if other 
versions have been shaded so as to co-exist on the classpath with the 
primary version, then that technique will still work in modules.

There is a requirement to support modules from different third parties: 
http://openjdk.java.net/projects/jigsaw/spec/reqs/#alternate-module-versions-in-dynamic-configurations 
-- but that doesn't mean arbitrary combinations like a module in a child 
layer overriding a module in a parent layer.

Alex