5652 2008-04-22 13:29:11 +0000 Constuctors for union types 2008-04-22 14:07:45 +0000 1 1 1 Unclassified XPath / XQuery / XSLT Functions and Operators 1.0 Recommendation PC Windows XP CLOSED INVALID P2 normal --- 1 nick mike public-qt-comments oldest_to_newest 19903 0 nick 2008-04-22 13:29:11 +0000 Imagine a schema defining my:sizeType <xs:simpleType name="sizeType"> <xs:union memberType="xs:integer xs:string"/> </xs:simpleType> The various specifications seem to suggest such a constructor exists (5.4) but do not appear to be clear as to what the behaviour of a constructor for such a union type should be. So for example, should my:sizeType("123") instance of xs:integer return true, false, or throw an exception (for the constructor being invalid - if so which?). Our thoughts are that the behaviour should be the same as during schema validation (so should map to an xs:integer and hence return true), but are unable to find anything definite in the specification to confirm this. 19904 1 mike 2008-04-22 13:41:19 +0000 (Personal response) Section 5.4 starts: "For every atomic type in the static context that is derived from a primitive type, there is a constructor function..." A union type is not an atomic type; I think it is quite clear that constructor functions are not defined for list and union types. It would be nice if they were, but currently they are not. 19905 2 nick 2008-04-22 14:07:27 +0000 OK. That makes sense. (We were getting confused as were reading "For every atomic type" as "Any type which is a subtype of xs:anyAtomicType", which the union types are, but clearly isn't what is actually being described in 5.4)