[xquery-talk] fn:sort: sort for strings in descending order

[Christian Grün]

Hi everyone,

As you may know, XQuery 3.1 introduces an interesting new fn:sort
function, which can be used as alternative for the order by clause in
FLWOR expressions [1]. It can e.g. be used to sort numbers in a
descending order:

  sort(
    1 to 10,
    function($k) { -$k }
  )

I would be interested if anyone has already tried to get the
descending order working for strings?

  sort(
    ('A', 'AA', 'B'),
    function($k) { ... }
  )

I assume that string-to-codepoints could be used, and all Unicode
points could then be negated, and additionally longer Unicode
sequences would need to be preferred over shorter ones… But maybe
there is a more concise solution?

Thanks in advance,
Christian

[1] http://www.w3.org/TR/xpath-functions-31/#func-sort