Implementing natural sort in XQuery on MarkLogic - xpath

Question

I wasn't finding any readily-available natural sort implementations in XQuery and thought I'd give it a shot. Using stuff found here as a reference, this is what I came up with:
xquery version "1.0-ml";
declare namespace xf = "http://www.w3.org/2005/xpath-functions";
declare namespace nat-sort = "https://github.com/JKesMc9tqIQe9M/xquery-natural-sort";
import module namespace functx = "http://www.functx.com" at "/MarkLogic/functx/functx-1.0-nodoc-2007-01.xqy";
declare %public function nat-sort:nat-sort($s as item()*) as item()* {
let $pad-length := fn:max($s ! fn:analyze-string(., '([0-9]+)')/xf:match ! fn:string-length(.)) + 1
for $item in $s
let $sort-key := fn:string-join(
let $decomposed := fn:analyze-string($item, '([0-9]+)')/xf:*
for $i in $decomposed
return
if ($i/self::xf:match)
then fn:string(functx:pad-integer-to-length(fn:number($i), $pad-length))
else fn:string($i),
'')
order by $sort-key
return $item
};
It seems to work, at least with the few test cases I have constructed, but I'm wondering if (1) there's a more concise way to do it (2) there's an existing/standard way to do it I'm unaware of (3) there are obvious problems with this approach. Thanks!

Answer 1

The set of collations available in XQuery depends on your XQuery implementation. You can choose a collation as an option in the "order by" clause. XQuery 3.1 brings support for the Unicode Collation Algorithm, which allows you to request the sort order you are asking for using the collation URI
http://www.w3.org/2013/collation/UCA?numeric=yes
but with XQuery 1.0 or 3.0 implementations, you'll have to check the documentation for your chosen product. Saxon has an alphanumeric collation which fits the bill, but I don't know about MarkLogic.