Natools

                  else
                     High := Data (I);
                     Has_High := True;
                  end if;
               end if;
            end loop;
            if Has_High then
               Result (O) := Decode_Hex (High, 0);
               Result (O) := Decode_Hex (High, Digit_0);
               O := O + 1;
            end if;
            pragma Assert (O - 1 = Result'Last);
         end;
      end return;
   end Decode_Hex;