I encountered an unexpected error today when applying "Format & Indent" to a valid XQuery file. The error is:

The XQuery is as follows, and line 21, column 33 corresponds to the nested array constructors [[]] :

xquery version "3.1";

declare namespace array="http://www.w3.org/2005/xpath-functions/array";

let $permArray := function($myAr as array(*))  
{ 
  let $extend := function($ar as array(*), $mem as item()*)
                 {
                   array{    
                          for $i in 1 to (array:size($ar) +1)
                            return                    
                               array:insert-before($ar, $i, $mem)
                        }  
                 },
      $extendAllSubArrays :=  function($zero as array(*), $mem as item()*)
                              {
                                array:join(
                                            for $i in 1 to array:size($zero)
                                             return $extend($zero($i), $mem)
                                           )
                               }
     return
       array:fold-left($myAr, [[]],  $extendAllSubArrays) 
}
return $permArray([1, 2, 3]) => serialize(map { "method": "json" })

The query was shared on the XML.com Slack at https://xmlcom.slack.com/archives/C011NLXE4DU/p1659114945879269?thread_ts=1658881670.454309&cid=C011NLXE4DU.

Using the XQuery debugger, oXygen returns the expected results: 

But for some reason oXygen is unable to perform "format & indent" on the source XQuery. Could you please investigate this "lexical error"?

Thank you,

Joe