[Bug 4841] [FS] Use of fn:subsequence in relation to normalization rules for filter expressions in FS

http://www.w3.org/Bugs/Public/show_bug.cgi?id=4841





------- Comment #4 from mike@saxonica.com  2007-07-11 10:23 -------
>This would affect conformance of implementations ...

I'm not sure how far you want to go here. Saxon, given the expression A[3.4],
will normalize it to () and then infer a type of empty-sequence (which under
Saxon's optimistic static typing results in a warning). The FS has been
reluctant to introduce normalization rules that take account of the value, as
distinct from the type, of the operands: and normalizing to empty-sequence is
undesirable as it makes the expression an error. I suppose that the fix that
makes most sense is one that infers a cardinality of zero-or-one for any
predicate value that is a numeric literal, without doing the incorrect
normalization to subsequence().

Received on Wednesday, 11 July 2007 10:23:15 UTC