[basex-talk] Error XUST0001 for fold-left ?

[Maximilian Gärber]

Hi,

I just tried a previously (7.8-Snapshot) working application with
8.0-Snapshot and got:

  Stopped at /intersect-nodes.xqm, 22/13:
[XUST0001] fn:fold-left(items,zero,function): all expressions must be
updating or return an empty sequence.

but there are no updates applied in this function (or ones calling
this function):

declare %public function _:intersect(
    $map as map(*))
    as node()*
{
  fold-left(
    map:keys($map),
    $_:ALL,
    function($s1, $key as item()*) {
      let $s2 := $map($key),
          $a1 := _:all($s1),
          $a2 := _:all($s2)
      return if($a1)
        then if($a2) then $_:ALL else $s2
        else if($a2) then $s1 else $s1 intersect $s2
    }
  )

Any ideas?

Regards, Max