Re: [Bug 12184] Circularity in xs:override

[Still working on clearing away the underbrush to try to get at the
underlying principles]

I take it that one very important underlying goal is that someone who
writes an override should be 

 a) Free from having to understand the details of how the schema
    corresponding to the overriden schema document is constructed;
 b) Insulated from any _changes_ in that construction.

This naturally leads to two parallel-but-distinct sub-requirements,
one wrt includes (in the target) and the other wrt overrides (in the
target).

So, a thought experiment.  Instead of converting includes into
overrides, why not start by _eliminating_ includes, thereby reducing
the complexity of the situation we have to get our heads around, and
exploiting our existing understanding of how to manage re-entrancy and
circularity in the include graph?

I think I have an algorithm in mind, aimed at replacing the one at the
beginning of appendix F.2.  Attached is a preliminary step towards
specifying that algorithm, which _just_ addresses the include issue.

ht

-- 
       Henry S. Thompson, School of Informatics, University of Edinburgh
      10 Crichton Street, Edinburgh EH8 9AB, SCOTLAND -- (44) 131 650-4440
                Fax: (44) 131 651-1426, e-mail: ht@inf.ed.ac.uk
                       URL: http://www.ltg.ed.ac.uk/~ht/
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