Pascal samples. Script-defined callback functions.

uses Classes;

function Compare(Item1, Item2: Pointer): Integer; register;
begin
  if Integer(Item1) > Integer(Item2) then
    result := 1
  else if Integer(Item1) < Integer(Item2) then
    result := -1
  else
   result := 0;
end;

var
  L: TList;
  I: Integer;
begin
  L := TList.Create;
  L.Add(Pointer(3));
  L.Add(Pointer(1));
  L.Add(Pointer(2));
  L.Add(Pointer(6));
  L.Add(Pointer(4));
  L.Add(Pointer(5));
  L.Sort(@Compare);
  for I:=0 to L.Count - 1 do
    writeln(Integer(L[I]));
  L.Free;
end.