5791 2008-06-24 11:50:16 +0000 Static Typing: CVS: K-SeqExprInstanceOf-56, 57, 58 2008-06-26 12:05:50 +0000 1 1 1 Unclassified XML Query Test Suite XML Query Test Suite unspecified PC Windows NT CLOSED FIXED P2 normal --- 1 tim frans.englich frans.englich jmdyck public-qt-comments oldest_to_newest 20771 0 tim 2008-06-24 11:50:16 +0000 In addition to expecting an error, this query may also return true because it can be answered purely through static type analysis. Similarly for K-SeqExprInstanceOf-57. K-SeqExprInstanceOf-58 should expect false. (:*******************************************************:) (: Test: K-SeqExprInstanceOf-56 :) (: Written by: Frans Englich :) (: Date: 2007-11-22T11:31:21+01:00 :) (: Purpose: The fn:error() function in combination with 'instance of'. :) (:*******************************************************:) error() instance of xs:integer 20783 1 frans.englich 2008-06-24 12:54:59 +0000 A fix was attempted in CVS. 20792 2 tim 2008-06-24 13:46:27 +0000 I think you may have got the expected results wrong for the first two here. It should be: K-SeqExprInstanceOf-56 -> true K-SeqExprInstanceOf-57 -> true 20796 3 tim 2008-06-24 14:34:48 +0000 ...and (my mistake): K-SeqExprInstanceOf-58 -> false 20807 4 frans.englich 2008-06-24 15:20:40 +0000 I'm not sure I'm following, so K-SeqExprInstanceOf-56: error() instance of xs:integer should return true? none is an instance of xs:integer? 20811 5 tim 2008-06-24 16:30:51 +0000 Though strange, I think that none _is_ an instance of xs:integer. Can someone please confirm this? 'none' is definitely a subtype of xs:integer. 'none' is a subtype of all other types. So this query can be boiled down to the question "is something shich is a subtype of xs:integer always an instance of xs:itneger". 20819 6 jmdyck 2008-06-24 20:58:26 +0000 Is none a subtype of xs:integer? Yes. Is none an instance of xs:integer? It's a bad question, because none denotes a type, not a value. Instead, the proper question is something like: given an expression Expr instance of SequenceType if the static type of Expr is a subtype of (the type denoted by) SequenceType, is an implementation allowed to rewrite the expression as fn:true()? I believe you could prove that, in such a case, the only non-error outcome is the value true, and so (according to the XQuery rewriting rules) the rewrite is allowed. The particular test case is an example of the general case, so I believe returning true is conformant. (However, I'm not familiar with the extent to which the test suite caters to rewrites.) 20840 7 frans.englich 2008-06-25 11:22:39 +0000 Ok, I changed the baselines as per instructed in comments #2 and #3. A lot can be said about XQuery Formal Semantics. 20851 8 tim 2008-06-25 12:37:02 +0000 > A lot can be said about XQuery Formal Semantics. Only nice things I hope :) I'll close this once I've checked the results. CurrentlyI can't connect to CVS - it just hangs. 20895 9 tim 2008-06-26 11:09:09 +0000 K-SeqExprInstanceOf-56 and K-SeqExprInstanceOf-57 are now correct. I've given you the wrong expected result for: K-SeqExprInstanceOf-58 error() instance of empty-sequence() should be true. The reason is that 'empty' is the same as 'none?'. So this is like (something of type T) instance of T? which is true. 20898 10 frans.englich 2008-06-26 11:14:28 +0000 Should be fixed in CVS. 20904 11 tim 2008-06-26 12:05:50 +0000 Thanks.