rewriter doesn't allow union xpaths

[VladimirAlexiev]

This function

declare function local:rdf_outcome_small ($url as xs:string, $study) {
  if (not(fn:empty ($study/clinical_results/outcome_list))) then ()
  else for $i at $n in $study/(primary_outcome|secondary_outcome|other_outcome) ###
    let $outcome := fn:concat($url,"/outcome/",$n)
      construct {
        <{$url}> cto:outcome <{$outcome}>.
        <{$outcome}> a cto:Outcome;
          dc:type         {functx:capitalize-first(fn:substring-before($i/name(),"_outcome"))};
          dc:title        {$i/measure/text()};
          cto:timeFrame   {$i/time_frame/text()};
          cto:safetyIssue {func:boolean($i/safety_issue/text())};
          dc:description  {$i/description/text()}.
        }
};

causes this error

net/sf/xsparql/rewriter/XQuerySerializer.g: node from line 0:0 mismatched tree node: DOWN expecting <UP>
net/sf/xsparql/rewriter/XQuerySerializer.g: node from line 0:0 mismatched tree node: DOWN expecting <UP>
net/sf/xsparql/rewriter/XQuerySerializer.g: node from line 0:0 mismatched tree node: XPATH expecting <UP>
Parse error: java.lang.Exception: Errors for Serializer. Translation aborted.
java.lang.Exception: Errors for Serializer. Translation aborted.
        at net.sf.xsparql.rewriter.XSPARQLProcessor.process(XSPARQLProcessor.java:257)
        at net.sf.xsparql.Main.rewriteQuery(Main.java:197)
        at net.sf.xsparql.Main.main(Main.java:111)

(Both location and error message are totally useless, so god help you if you write in big chunks).

The culprit is the union xpath at ###. I'm no xpath expert, but according to http://www.freeformatter.com/xpath-tester.html that is valid.

(If I replace with $study/primary_outcome it goes ok, but I need the union!)

[VladimirAlexiev]

This doesn't work either:

$study/(primary_outcome union secondary_outcome union other_outcome)

This works ok:

($study/primary_outcome, $study/secondary_outcome, $study/other_outcome)

[VladimirAlexiev]

#39 is a duplicate