[XQuery] SAG-XQ-002 Input collection

SAG-XQ-002 Input collection

We regret that there is no simple intuitive way of writing a query whose
input is some implicit (context-defined) collection of documents.

The input() function went some way to meeting this need, but this has
disappeared.

The context item is restricted to a single node or value, which sends the
wrong message about the purpose of XQuery, which is that it is designed
primarily to process large collections of documents, unlike XPath, which is
designed primarily to locate nodes within a single document.

Other mechanisms for supplying a collection as input to the query (using
parameter variables, and using the collection() function) are syntactically
cumbersome.

We think that for XQuery (as distinct from XPath and XSLT) the concept of an
implicit input collection is a useful one, and that there should be a
convenient syntax to refer to it. (How about "~", or perhaps "$$"?)

Michael Kay
for Software AG