gcc/ada/s-wchwts.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUNTIME COMPONENTS                          --
   4 --                                                                          --
   5 --                       S Y S T E M . W C H _ W T S                        --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --                            $Revision: 1.1.16.1 $
  10 --                                                                          --
  11 --          Copyright (C) 1992-2000 Free Software Foundation, Inc.          --
  12 --                                                                          --
  13 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  14 -- 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- --
  16 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  17 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  18 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  19 -- 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 --
  21 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  22 -- MA 02111-1307, USA.                                                      --
  23 --                                                                          --
  24 -- 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, --
  26 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  27 -- covered  by the  GNU  General  Public  License.  This exception does not --
  28 -- however invalidate  any other reasons why  the executable file  might be --
  29 -- covered by the  GNU Public License.                                      --
  30 --                                                                          --
  31 -- GNAT was originally developed  by the GNAT team at  New York University. --
  32 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  33 --                                                                          --
  34 ------------------------------------------------------------------------------
  35
  36 with Interfaces;     use Interfaces;
  37 with System.WCh_Con; use System.WCh_Con;
  38 with System.WCh_JIS; use System.WCh_JIS;
  39
  40 package body System.WCh_WtS is
  41
  42    ---------------------------
  43    -- Wide_String_To_String --
  44    ---------------------------
  45
  46    function Wide_String_To_String
  47      (S    : Wide_String;
  48       EM   : WC_Encoding_Method)
  49       return String
  50    is
  51       R  : String (1 .. 5 * S'Length); -- worst case length!
  52       RP : Natural;
  53       C1 : Character;
  54       C2 : Character;
  55
  56    begin
  57       RP := 0;
  58
  59       for SP in S'Range loop
  60          declare
  61             C   : constant Wide_Character := S (SP);
  62             CV  : constant Unsigned_16    := Wide_Character'Pos (C);
  63             Hex : constant array (Unsigned_16 range 0 .. 15) of Character :=
  64                     "0123456789ABCDEF";
  65
  66          begin
  67             if CV <= 127 then
  68                RP := RP + 1;
  69                R (RP) := Character'Val (CV);
  70
  71             else
  72                case EM is
  73
  74                   --  Hex ESC sequence encoding
  75
  76                   when WCEM_Hex =>
  77                      if CV <= 16#FF# then
  78                         RP := RP + 1;
  79                         R (RP) := Character'Val (CV);
  80
  81                      else
  82                         R (RP + 1) := ASCII.ESC;
  83                         R (RP + 2) := Hex (Shift_Right (CV, 12));
  84                         R (RP + 3) := Hex (Shift_Right (CV, 8)  and 16#000F#);
  85                         R (RP + 4) := Hex (Shift_Right (CV, 4)  and 16#000F#);
  86                         R (RP + 5) := Hex (CV                   and 16#000F#);
  87                         RP := RP + 5;
  88                      end if;
  89
  90                   --  Upper bit shift (internal code = external code)
  91
  92                   when WCEM_Upper =>
  93                      R (RP + 1) := Character'Val (Shift_Right (CV, 8));
  94                      R (RP + 2) := Character'Val (CV and 16#FF#);
  95                      RP := RP + 2;
  96
  97                   --  Upper bit shift (EUC)
  98
  99                   when WCEM_EUC =>
 100                      JIS_To_EUC (C, C1, C2);
 101                      R (RP + 1) := C1;
 102                      R (RP + 2) := C2;
 103                      RP := RP + 2;
 104
 105                   --  Upper bit shift (Shift-JIS)
 106
 107                   when WCEM_Shift_JIS =>
 108                      JIS_To_Shift_JIS (C, C1, C2);
 109                      R (RP + 1) := C1;
 110                      R (RP + 2) := C2;
 111                      RP := RP + 2;
 112
 113                   --  Upper bit shift (UTF-8)
 114
 115                   --    16#0080#-16#07ff#: 2#110xxxxx# 2#10xxxxxx#
 116                   --    16#0800#-16#ffff#: 2#1110xxxx# 2#10xxxxxx# 2#10xxxxxx#
 117
 118                   when WCEM_UTF8 =>
 119                      if CV < 16#0800# then
 120                         R (RP + 1) :=
 121                           Character'Val (2#11000000# or Shift_Right (CV, 6));
 122                         R (RP + 2) :=
 123                           Character'Val (2#10000000# or (CV and 2#00111111#));
 124                         RP := RP + 2;
 125
 126                      else
 127                         R (RP + 1) :=
 128                           Character'Val (2#11100000# or Shift_Right (CV, 12));
 129                         R (RP + 2) :=
 130                           Character'Val (2#10000000# or
 131                                           (Shift_Right (CV, 6) and
 132                                                                2#00111111#));
 133                         R (RP + 3) :=
 134                           Character'Val (2#10000000# or (CV and 2#00111111#));
 135                         RP := RP + 3;
 136                      end if;
 137
 138                   --  Brackets encoding
 139
 140                   when WCEM_Brackets =>
 141                      if CV <= 16#FF# then
 142                         RP := RP + 1;
 143                         R (RP) := Character'Val (CV);
 144
 145                      else
 146                         R (RP + 1) := '[';
 147                         R (RP + 2) := '"';
 148                         R (RP + 3) := Hex (Shift_Right (CV, 12));
 149                         R (RP + 4) := Hex (Shift_Right (CV, 8)  and 16#000F#);
 150                         R (RP + 5) := Hex (Shift_Right (CV, 4)  and 16#000F#);
 151                         R (RP + 6) := Hex (CV                   and 16#000F#);
 152                         R (RP + 7) := '"';
 153                         R (RP + 8) := ']';
 154                         RP := RP + 8;
 155                      end if;
 156
 157                end case;
 158             end if;
 159          end;
 160       end loop;
 161
 162       return R (1 .. RP);
 163    end Wide_String_To_String;
 164
 165 end System.WCh_WtS;