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At 5:07 PM -0400 4/11/04, Bob Wyman wrote:
> Just as XML works well in both "schema-based" and
>"schema-free" environments, it is critical that any alternative binary
>encoding do the same. But, it is also useful to recognize that when
>you're working with XML, you are never really in a "schema-free"
>environment... Even if you don't have an application-specific schema,
>you've still got the schema for XML itself -- the InfoSet .
No, many applications and tools have been written on top of real XML
without concern for the Infoset. Most technologies such as SAX, DOM,
XOM, XSLT, JDOM, XPath, etc. subset the Infoset to achieve their
goals. Quite a few tools (JAXB, etc.) really don't present an infoset
representation of XML at all. Different local uses have different
implicit schemas and data models. Some well-formed XML documents
don't have infosets (though these documents can be processed by DOM,
SAX, and other tools) and many infosets have no corresponding
representation as a well-formed XML document.
Remember: the infoset is explicitly not the canonical data model for
XML. It is nothing more than "a set of definitions for use in other
specifications that need to refer to the information in an XML
Elliotte Rusty Harold
Effective XML (Addison-Wesley, 2003)