[relaxng-user] Is a deterministic schema possible for my index model?

[David Sewell]

On Fri, 17 Dec 2004, Fredrik Lindgren wrote:

> I have not verified it, but what about specifying the pattern as:
> pages = (pgrom+, pg*) | pg+
> This pattern should be equivalent to the initial pattern since any sequence
> that starts with a pgrom will be handled by the first choice, while the second
> choice takes care of the rest.
> The non-deterministic thing is due to the possibility of a pgrom element
> matching either choice in the generated fragment.

Thanks, that's perfect. As they say, "why didn't I think of that?" The
DTD and XSD versions work as expected.

Thanks also to David Pawson for the pointer to the DocBook index
model--it's more complex than needed for my purposes, though.

DS

> Fredrik Lindgren
> On Thu, 16 Dec 2004 14:29:07 -0500 (EST), David Sewell <dsewell at virginia.edu>
> wrote:
>
> > (First post from me)
> >
> > I'm developing a RelaxNG schema to mark up back-of-the-book indexes.
> > Leaving out refinements like "see also" references and nested
> > subentries, an index consists of multiple entries. Each entry has a
> > heading, and one or more page references. I want to use distinct XML
> > elements for front-matter (roman) pages and body (arabic) pages.
> > The relevant part of the schema (compact syntax) is this definition:
> >
> > 	pages = (pgrom+, pg*) | (pgrom*, pg+)
> >
> > I.e., there has to be at least one front-matter page or one body page.
> >
> > Trang turns this into the following DTD fragment:
> >
> > 	<!ENTITY % pages "(pgrom+,pg*)|(pgrom*,pg+)">
> >
> > while the XML schema equivalent is a group containing a choice between
> > two <xs:sequence> elements. In either case if I attempt to validate a
> > document instance I get a complaint about a non-deterministic content
> > model.
> >
> > Is this just one of those places where Relax NG does something that you
> > can't do with a DTD or W3C schema? If I want a translatable index
> > schema, will I have to write
> >
> > 	pages = pgrom*, pg*
> >
> > and therefore permit empty content for "pages"?
> >
> > David S.
> >
>

-- 
David Sewell, Editorial and Technical Manager
Electronic Imprint, The University of Virginia Press
PO Box 400318, Charlottesville, VA 22904-4318 USA
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Email: dsewell at virginia.edu   Tel: +1 434 924 9973
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