File : s-imgbiu.adb


     ------------------------------------------------------------------------------
     --                                                                          --
     --                         GNAT RUNTIME COMPONENTS                          --
     --                                                                          --
   5 --                       S Y S T E M . I M G _ B I U                        --
     --                                                                          --
     --                                 B o d y                                  --
     --                                                                          --
     --                            $Revision: 1.6 $                              --
  10 --                                                                          --
     --     Copyright (C) 1992,1993,1994,1995 Free Software Foundation, Inc.     --
     --                                                                          --
     -- GNAT is free software;  you can  redistribute it  and/or modify it under --
     -- terms of the  GNU General Public License as published  by the Free Soft- --
  15 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
     -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
     -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
     -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
     -- for  more details.  You should have  received  a copy of the GNU General --
  20 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
     -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
     -- MA 02111-1307, USA.                                                      --
     --                                                                          --
     -- As a special exception,  if other files  instantiate  generics from this --
  25 -- unit, or you link  this unit with other files  to produce an executable, --
     -- this  unit  does not  by itself cause  the resulting  executable  to  be --
     -- covered  by the  GNU  General  Public  License.  This exception does not --
     -- however invalidate  any other reasons why  the executable file  might be --
     -- covered by the  GNU Public License.                                      --
  30 --                                                                          --
     -- GNAT was originally developed  by the GNAT team at  New York University. --
     -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
     --                                                                          --
     ------------------------------------------------------------------------------
  35 
     with System.Unsigned_Types; use System.Unsigned_Types;
     
     package body System.Img_BIU is
     
  40    -----------------------------
        -- Set_Image_Based_Integer --
        -----------------------------
     
        procedure Set_Image_Based_Integer
  45      (V : Integer;
           B : Natural;
           W : Integer;
           S : out String;
           P : in out Natural)
  50    is
           Start : Natural;
     
        begin
           --  Positive case can just use the unsigned circuit directly
  55 
           if V >= 0 then
              Set_Image_Based_Unsigned (Unsigned (V), B, W, S, P);
     
           --  Negative case has to set a minus sign. Note also that we have to be
  60       --  careful not to generate overflow with the largest negative number.
     
           else
              P := P + 1;
              S (P) := ' ';
  65          Start := P;
     
              declare
                 pragma Suppress (Overflow_Check);
                 pragma Suppress (Range_Check);
  70          begin
                 Set_Image_Based_Unsigned (Unsigned (-V), B, W - 1, S, P);
              end;
     
              --  Set minus sign in last leading blank location. Because of the
  75          --  code above, there must be at least one such location.
     
              while S (Start + 1) = ' ' loop
                 Start := Start + 1;
              end loop;
  80 
              S (Start) := '-';
           end if;
     
        end Set_Image_Based_Integer;
  85 
        ------------------------------
        -- Set_Image_Based_Unsigned --
        ------------------------------
     
  90    procedure Set_Image_Based_Unsigned
          (V : Unsigned;
           B : Natural;
           W : Integer;
           S : out String;
  95       P : in out Natural)
        is
           Start : constant Natural := P;
           F, T  : Natural;
           BU    : constant Unsigned := Unsigned (B);
 100       Hex   : constant array
                     (Unsigned range 0 .. 15) of Character := "0123456789ABCDEF";
     
           procedure Set_Digits (T : Unsigned);
           --  Set digits of absolute value of T
 105 
           procedure Set_Digits (T : Unsigned) is
           begin
              if T >= BU then
                 Set_Digits (T / BU);
 110             P := P + 1;
                 S (P) := Hex (T mod BU);
              else
                 P := P + 1;
                 S (P) := Hex (T);
 115          end if;
           end Set_Digits;
     
        --  Start of processing for Set_Image_Based_Unsigned
     
 120    begin
     
           if B >= 10 then
              P := P + 1;
              S (P) := '1';
 125       end if;
     
           P := P + 1;
           S (P) := Character'Val (Character'Pos ('0') + B mod 10);
     
 130       P := P + 1;
           S (P) := '#';
     
           Set_Digits (V);
     
 135       P := P + 1;
           S (P) := '#';
     
           --  Add leading spaces if required by width parameter
     
 140       if P - Start < W then
              F := P;
              P := Start + W;
              T := P;
     
 145          while F > Start loop
                 S (T) := S (F);
                 T := T - 1;
                 F := F - 1;
              end loop;
 150 
              for J in Start + 1 .. T loop
                 S (J) := ' ';
              end loop;
           end if;
 155 
        end Set_Image_Based_Unsigned;
     
     end System.Img_BIU;