Hej,
just looking at the working draft on the array section. I know this is work in progress. However I’d like to know how the signature of array:fold-right (and left) is motivated.
Present signature is …

Section 17.3.13 array:fold-right
array:fold-right(
	$array	 as array(*),
	$zero	 as item()*,
	$function	as function(item()*) as item()*
) as array(*)


I’d expect an array:fold-right to be equivalent to the query:


declare function array:fold-right(
        $array	 as array(*),
	$zero	 as item()*,
        $function	 as function(item()*, item()*) as item()*
) as item()* {
  if (array:size($seq) = 0)
  then $zero
  else $function(array:head($array), fn:fold-right(array:tail($array), $zero, $function))
};

Hence the signature to be different to the one presently mentioned in the draft. This signature then would be in analogy to fn:fold-right.