collection-node()

[Michael Kay]

> 
> Why does XQuery not have a collection node?
> 

We did consider at one time making collections into first-class objects. I
think the reason it didn't happen was simply that it looked like a lot of
work for a relatively small advantage.

If a collection is a node, then it's rather different from other kinds of
node. Documents can belong to more than one collection, and the documents in
a collection are unordered. (Would the documents in a collection be children
of the collection node? In that case, would they be siblings of each
other?...)

One of the questions we didn't want to answer was whether collections can
contain other collections. Different XML databases have different answers to
that question and it would therefore have absorbed a lot of WG time.

Someone suggested, wisely I think, that it would be a good idea to see what
implementors did with the concept of a collection, see what kind of
consensus emerged, and if there was enough commonality, the WG could then
consider standardizing the functionality further.

Michael Kay
http://www.saxonica.com/