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Note: ... in this posting is a metasymbol meaning "anything syntactically
correct", not a part of RELAX NG compact syntax.
Dare Obasanjo scripsit:
> Extensible types are a major feature of W3C XML Schema and I don't think
> I've seen many schemas that do not use them. A RELAX NG mapping of an
> XSD document that doesn't replicate this functionality one way or the
> other is a non-starter for most of the uses of XSD that I've seen.
How's this:
basicNameType =
element firstName { text },
element MI { text }?,
element lastName { text }
extendedNameType =
basicNameType,
element generation { "Jr." | "Sr." | "II" | "III" | "IV" | "V" }?,
element title { "Mr." | "Mrs." | "Miss" | "Ms." | "Dr." }?
Does that replicate the functionality sufficiently? Of course the definitions
can be in separate schema files.
> A lot of functionality falls under extensible types including
> polymorphism via substitution groups and xsi:type which I do not see
> RELAX NG being able to do.
h1 = element h1 { ... }
h2 = element h2 { ... }
h3 = element h3 { ... }
h = h1 | h2 | h3 | ...
Wherever h is referenced, an h1 or h2 or ... element may appear. There
is no constraint that they have compatible content models, though.
> I also don't see any RELAX NG equivalent to the identity constraints
> xs:unique, xs:keyref and xs:key.
Quite correct. RELAX NG understands only DTD-equivalent identity constraints;
viz: attributes of type xsd:ID, xsd:IDREF, and xsd:IDREFS.
> Is there anything akin to xs:redefine in RELAX NG? I couldn't find it in
> a cursory reading of the tutorial or the spec.
Yes. If you say:
include "subspec" {
foo = ...
bar = ...
baz = ...
}
then any definitions for foo, bar, and baz in "subspec" are redefined.
Furthermore, you can write:
foo = ...
foo |= ...
foo |= ...
and the three definitions (which may reside in different files) will be
or'd (choice'd) together. Ditto for "&=" definitions, but they are
interleaved.
--
John Cowan <jcowan@reutershealth.com> http://www.reutershealth.com
I amar prestar aen, han mathon ne nen, http://www.ccil.org/~cowan
han mathon ne chae, a han noston ne 'wilith. --Galadriel, _LOTR:FOTR_
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