1709 2005-07-18 07:23:47 +0000 [FS] (editorial) recommendation for static typing extensions 2005-09-06 13:07:20 +0000 1 1 1 Unclassified XPath / XQuery / XSLT Formal Semantics 1.0 Last Call drafts All All CLOSED DUPLICATE 1708 P4 normal --- 1 dflorescu simeon public-qt-comments oldest_to_newest 4795 0 dflorescu 2005-07-18 07:23:47 +0000 In 6.1 Static Typing Extensions, the FS specification states the following: "It is not recommended for a static typing extension to change the static typing behavior of expressions that specify a type explicitely (treat as, cast as, typeswitch, function parameters, and type declarations in variable bindings), since the purpose of those expressions is to impose a specific type." This kind of recommendation is not appropriate for a standard specification. In fact, many desirable static typing extensions will violate this recommendation. This is likely to happen if the specified type is a supertype of the static type result. Consider the following example: declare function local:f($x as xs:decimal) as item* {$x}; local:f(3)+4 The static type analysis can infer that the function retun type is xs:decimal, which is more specific than item*. So an implementation may correctly infer xs:decimal as the static type of local:f() such that that the subsequent static type analysis of addition will be OK. Otherwise, this query will unnecessarily yield pessimestic type errors. 4802 1 mrys 2005-07-18 09:54:14 +0000 You may be correct for most of the given expressions. But note that a treat as has the explicit purpose to set the static type... Michael (personal response) 4962 2 pcotton 2005-07-20 00:35:55 +0000 *** This bug has been marked as a duplicate of 1708 ***