Natools

      Has_Value : out Boolean);
      --  Decode a screen offset from a S-expression

   procedure Update_Casing
     (Casing : in out Encodings.Hex_Casing;
      Name : in Atom);

   function To_Atom (Value : in Screen_Offset) return Atom;
   function To_Atom (Before, After : in Entity) return Atom;

   function To_String (Value : in Entity) return String;



   ------------------------------

         end loop;

         Has_Value := True;
         Value := Result;
      end;
   end Read_Screen_Offset;


   function To_Atom (Value : in Screen_Offset) return Atom is
      Length : Count;
   begin
      Compute_Length : declare
         Left : Screen_Offset := Value;
      begin
         Length := 1;
         while Left >= 10 loop
            Length := Length + 1;
            Left := Left / 10;
         end loop;
      end Compute_Length;

      return Result : Atom (0 .. Length - 1) do
         declare
            I : Offset := Result'Last;
            Left : Screen_Offset := Value;
         begin
            loop
               Result (I) := Encodings.Digit_0 + Octet (Left mod 10);
               I := I - 1;
               Left := Left / 10;
               exit when Left = 0;
            end loop;
            pragma Assert (I + 1 = Result'First);
         end;
      end return;
   end To_Atom;


   function To_Atom (Before, After : in Entity) return Atom is
   begin
      return To_Atom (To_String (Before) & "-" & To_String (After));
   end To_Atom;

   end Update_Casing;



   ---------------------------------
   -- Public High Level Interface --
   ---------------------------------

   procedure Print
     (Output : in out Printers.Printer'Class;
      Param : in Parameters) is
   begin
      --  Newline_At and Newline

      Output.Open_List;
      Output.Append_Atom (To_Atom ("newline"));
      case Param.Newline is
         when CR =>    Output.Append_Atom (To_Atom ("cr"));
         when LF =>    Output.Append_Atom (To_Atom ("lf"));
         when CR_LF => Output.Append_Atom (To_Atom ("cr-lf"));
         when LF_CR => Output.Append_Atom (To_Atom ("lf-cr"));
      end case;

      if Param.Newline_At = Entity_Separator'(others => (others => True)) then
         Output.Append_Atom (To_Atom ("all"));
      else
         Output.Append_Atom (To_Atom ("none"));
         for Before in Entity loop
            for After in Entity loop
               if Param.Newline_At (Before, After) then
                  Output.Append_Atom (To_Atom (Before, After));
               end if;
            end loop;
         end loop;
      end if;
      Output.Close_List;

      --  Space_At

      Output.Open_List;
      Output.Append_Atom (To_Atom ("space"));
      if Param.Space_At = Entity_Separator'(others => (others => True)) then
         Output.Append_Atom (To_Atom ("all"));
      else
         Output.Append_Atom (To_Atom ("none"));
         for Before in Entity loop
            for After in Entity loop
               if Param.Space_At (Before, After) then
                  Output.Append_Atom (To_Atom (Before, After));
               end if;
            end loop;
         end loop;
      end if;
      Output.Close_List;

      --  Tab_Stop

      Output.Open_List;
      Output.Append_Atom (To_Atom ("tab-stop"));
      Output.Append_Atom (To_Atom (Param.Tab_Stop));
      Output.Close_List;

      --  Width

      if Param.Width > 0 then
         Output.Open_List;
         Output.Append_Atom (To_Atom ("width"));
         Output.Append_Atom (To_Atom (Param.Width));
         Output.Close_List;
      else
         Output.Append_Atom (To_Atom ("no-width"));
      end if;

      --  Indentation and Indent

      if Param.Indentation = 0 then
         Output.Append_Atom (To_Atom ("no-indentation"));
      else
         Output.Open_List;
         Output.Append_Atom (To_Atom ("indentation"));
         Output.Append_Atom (To_Atom (Param.Indentation));
         if Param.Indentation > 1 then
            case Param.Indent is
               when Spaces =>
                  Output.Append_Atom (To_Atom ("spaces"));
               when Tabs =>
                  Output.Append_Atom (To_Atom ("tabs"));
               when Tabs_And_Spaces =>
                  Output.Append_Atom (To_Atom ("tabbed-spaces"));
            end case;
         else
            case Param.Indent is
               when Spaces =>
                  Output.Append_Atom (To_Atom ("space"));
               when Tabs =>
                  Output.Append_Atom (To_Atom ("tab"));
               when Tabs_And_Spaces =>
                  Output.Append_Atom (To_Atom ("tabbed-space"));
            end case;
         end if;
         Output.Close_List;
      end if;

      --  Quoted

      case Param.Quoted is
         when No_Quoted    =>
            Output.Append_Atom (To_Atom ("no-quoted-string"));
         when Single_Line  =>
            Output.Append_Atom (To_Atom ("single-line-quoted-string"));
         when When_Shorter =>
            Output.Append_Atom (To_Atom ("quoted-string-when-shorter"));
      end case;

      --  Quoted_Escape

      Output.Open_List;
      Output.Append_Atom (To_Atom ("escape"));
      case Param.Quoted_Escape is
         when Octal_Escape => Output.Append_Atom (To_Atom ("octal"));
         when Hex_Escape   => Output.Append_Atom (To_Atom ("hexadecimal"));
      end case;
      Output.Close_List;

      --  Token

      Output.Open_List;
      Output.Append_Atom (To_Atom ("token"));
      case Param.Token is
         when No_Token       => Output.Append_Atom (To_Atom ("never"));
         when Extended_Token => Output.Append_Atom (To_Atom ("extended"));
         when Standard_Token => Output.Append_Atom (To_Atom ("standard"));
      end case;
      Output.Close_List;

      --  Char_Encoding

      case Param.Char_Encoding is
         when UTF_8 => Output.Append_Atom (To_Atom ("utf-8"));
         when ASCII => Output.Append_Atom (To_Atom ("ascii"));
         when Latin => Output.Append_Atom (To_Atom ("latin-1"));
      end case;

      --  Hex_Casing

      case Param.Hex_Casing is
         when Encodings.Upper => Output.Append_Atom (To_Atom ("upper-case"));
         when Encodings.Lower => Output.Append_Atom (To_Atom ("lower-case"));
      end case;

      --  Fallback

      case Param.Fallback is
         when Base64      => Output.Append_Atom (To_Atom ("base-64"));
         when Hexadecimal => Output.Append_Atom (To_Atom ("hexadecimal"));
         when Verbatim    => Output.Append_Atom (To_Atom ("verbatim"));
      end case;
   end Print;


   procedure Update
     (Param : in out Parameters;
      Expression : in out Lockable.Descriptor'Class)
   is
      Interpreter : Interpreters.Interpreter := Config_Interpreter;
   begin