Saxon

Legacy ID: #5232357 Legacy Poster: antbo (antbo)

Hello, I'm using Saxon B8.8. I'm calling a Java extension function from an XQuery. For instance: declare namespace test='java:my.package.Test'; let $list1 := ('a1','b1') let $list2 := ($list1,'a2','b2') return test:myFunc($list2) Question: What I would like is to receive into myFunc a List containing a List and 2 Strings: {{'a1','b1'},'a2','b2'}. But myFunc is actually receiving a List containing 4 Strings: {'a1','b1','a2','b2'}. Am I doing something wrong? (I may understand this behavior is correct as doing a "for" loop over $list2 iterates onto each single String) Is there another way to achieve what I want? Problem: To achieve my goal, I tried to introduce a wrapping method creating an object hiding the List. This object has only one member attribute: the List object it receives into its constructor: declare namespace test='java:my.package.Test'; let $list1 := ('a1','b1') let $list2 := (test:wrapList($list1),'a2','b2') return test:myFunc($list2) This works fine: myFunc is receiving a List containing {ListWrapper,'a2','b2'}, and ListWrapper contains {'a1','b1'}. But the problem arises when the ListWrapper is returned by the query. For example: let $list1 := ('a1','b1') return test:wrapList($list1) Here I get a NPE into net.sf.saxon.value.ObjectValue.getItemType() because the TypeHierarchy parameter is null. The call stack is: java.lang.NullPointerException at net.sf.saxon.value.ObjectValue.getItemType() at net.sf.saxon.value.Value.convert() at net.sf.saxon.query.XQueryExpression.evaluate() ... Am I missing something? Thanks for your help.