[xquery-talk] OJXQI -- seems fundamentally broken

Per Bothner per at bothner.com
Thu May 22 09:50:11 PDT 2003

Paul Pedersen wrote:

> What's wrong in this picture?  Simply that XQuery returns
> "items" not nodes.  An XQuery expression can return an
> arbitrary sequence of primitive datatypes, Schema types,
> disembodied attributes, text nodes, element nodes, etc.
> So I don't quite see how the interface as shown can be
> considered an "XQuery" interface. Cerisent constructed
> an XQuery interface called XDBC (by analogy with JDBC),
> and handling heterogeneous item sequences was the >main<
> problem.

A useful API would be that of a "pull parser",
or a tree iterator.  You'd ask the iterator what's
next, and the client can extract it using various
methods, skip it, traversing recursively, or send the next
object to a "push" SAX-like consumer.

The Qexo implementation provides something like that,
but it's not as smooth or complete as it should be.
	--Per Bothner
per at bothner.com   http://per.bothner.com/

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