Natools

   procedure Find_Token (Source : in     Chunked_String;
                         Set    : in     Maps.Character_Set;
                         Test   : in     Ada.Strings.Membership;
                         First  :    out Positive;
                         Last   :    out Natural)
   is
      function Invert (M : Ada.Strings.Membership)
         return Ada.Strings.Membership;
      pragma Inline (Invert);
      Invert : constant array (Ada.Strings.Membership)
        of Ada.Strings.Membership
        := (Ada.Strings.Inside  => Ada.Strings.Outside,
            Ada.Strings.Outside => Ada.Strings.Inside);

      N : Natural;

      function Invert (M : Ada.Strings.Membership)
         return Ada.Strings.Membership
      is
         use Ada.Strings;
      begin
         case M is
            when Inside  => return Outside;
            when Outside => return Inside;
         end case;
      end Invert;
   begin
      N := Index (Source, Set, Test);

      if N = 0 then
         First := 1;
         Last := 0;
      else