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xpath2 functions returning ()

Subject: xpath2 functions returning ()
From: David Carlisle <davidc@xxxxxxxxx>
Date: Fri, 4 Jan 2002 15:14:27 GMT
 xpath2 functions returning ()

> I think that rubs up against the problem that the name() function
> actually returns an empty sequence for the document node (new
> terminology 'root node' is 'document node' in XPath 2.0), rather than
> an empty string

Yet another example of the rather bizarre affection and special
attention shown to empty sequences in X*2.

In Xpath 1 an empty node set was just a node set that happened to be
empty and had no special semantics, although did coerce to false rather
than true.

Xpath 2 seems to want to treat () special in many contexts. Most of which
seem unfortunate:-) The example above is one, sum() returning the empty
sequence instead of 0 is another (that seems to be much worse, and will
mean that you will almost always have to special case any value returned
from sum() to check if it is empty and if so replace it with 0)


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