For purposes of discussion, suppose that you
arbitrarily split sequence serialization from single-item serialization into
non-XML formats because I believe they are actually qualitatively different
problems. Referring only to the sequence serialization side of the problem here,
I think the question is whether XML sequence serialization and parsing has to in
fact be consumable by an XML parser. As I see it, you either end up specifying
some arbitrary set of privileged xml sequence tags:
<?xml
version="1.0" encoding="UTF-8"?>
<xml:sequence xmlns:xs="
http://www.w3.org/2001/XMLSchema">
<xml:item value="foo" type="xs:string"/>
<xml:item value="5" type="xs:positiveInteger"/>
<xml:item
type="document"><bar><bat/></bar></xml:item>
<xml:item
type="comment">foo</xml:item>
</xml:sequence>
or you
work with a direct serialization as described earlier, possibly with RDF
encodings for type:
(<?xml version="1.0"
encoding="UTF-8"?>,"foo",5^positiveInteger,<bar><bat/></bar>,<!--
foo -->)
