[Oberon] Module contexts in Original Oberon 2013

[Andreas Pirklbauer]

     > > For those who want to play around with "module contexts", they are now 
     > > also available in Original Oberon 2013:
     > >
     > >    http://github.com/andreaspirklbauer/Oberon-module-contexts
     > >
     > > This test implementation more or less follows the conventions described in:
     > >
     > >    http://www.ocp.inf.ethz.ch/wiki/Documentation/Language?action=download&upname=contexts.pdf
     > >
 
   > Great, module namespaces help a lot in very large projects.
   > However I'm not really convinced about the syntax, expecially IMPORT .. IN.
   > --
   > Diego Sardina

I decided not to meddle with the syntax, as defined in the above spec and as used in A2.

However, I deliberately introduced a few restrictions that greatly simplified the implementation.
I'd be interested in hearing whether these are in fact TOO restrictive.

For example, the original proposal allows to use “A2" modules from within “Oberon” and
vice versa. In the Oberon 2013 implementation, mixing modules from different contexts is
not possible (a minor restriction as one always just make a copy) - which allowed me to
leave symbol files, object files and runtime module descriptor completely untouched.

-ap