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