[Bug 5315] [UPD] Rename multiple nodes

http://www.w3.org/Bugs/Public/show_bug.cgi?id=5315





------- Comment #1 from chamberl@almaden.ibm.com  2007-12-17 18:37 -------
Michael,
I am not enthusiastic about allowing all our updating expressions to operate on
multiple target nodes. The semantics of such a feature would be quite complex.
In general, the target expression of an update may return a mixed sequence of
different kinds of nodes (elements, attributes, etc.) The semantics of updates
for the various types of nodes are different (for example, you can insert into
an element but not into an attribute; you can replace an attribute only with
another attribute; renaming an attribute may need special rules for namespaces
as you observed in Bug 5316; etc.) Specifying the semantics of updates on
sequences of nodes would be a nightmare. It would also contradict the XQuery
philosophy (frequently espoused by you, Michael) of simple, composable
expressions (e.g., use a FLWOR to update multiple nodes.)

You might reasonably argue that, for consistency, we should not allow a delete
expression to operate on multiple nodes, even though the semantics of multiple
deletions are harmless and straightforward. I would be inclined to retain
multiple deletions since they have been in the spec for a long time and are
well understood. The work of removing them from the spec and the test suite at
this point seems to have a pretty low return on investment. But if consistency
is our highest priority, I would much rather remove multiple deletions than try
to specify the semantics of multiple-everything-else.

--Don Chamberlin (speaking for myself)

Received on Monday, 17 December 2007 18:37:09 UTC