gcc/ada/libgnat/s-wchwts.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                       S Y S T E M . W C H _ W T S                        --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2018, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  17 --                                                                          --
  18 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 with System.WCh_Con; use System.WCh_Con;
  33 with System.WCh_Cnv; use System.WCh_Cnv;
  34
  35 package body System.WCh_WtS is
  36
  37    -----------------------
  38    -- Local Subprograms --
  39    -----------------------
  40
  41    procedure Store_UTF_32_Character
  42      (U  : UTF_32_Code;
  43       S  : out String;
  44       P  : in out Integer;
  45       EM : WC_Encoding_Method);
  46    --  Stores the string representation of the wide or wide wide character
  47    --  whose code is given as U, starting at S (P + 1). P is incremented to
  48    --  point to the last character stored. Raises CE if character cannot be
  49    --  stored using the given encoding method.
  50
  51    ----------------------------
  52    -- Store_UTF_32_Character --
  53    ----------------------------
  54
  55    procedure Store_UTF_32_Character
  56      (U  : UTF_32_Code;
  57       S  : out String;
  58       P  : in out Integer;
  59       EM : WC_Encoding_Method)
  60    is
  61       procedure Out_Char (C : Character);
  62       pragma Inline (Out_Char);
  63       --  Procedure to increment P and store C at S (P)
  64
  65       procedure Store_Chars is new UTF_32_To_Char_Sequence (Out_Char);
  66
  67       --------------
  68       -- Out_Char --
  69       --------------
  70
  71       procedure Out_Char (C : Character) is
  72       begin
  73          P := P + 1;
  74          S (P) := C;
  75       end Out_Char;
  76
  77    begin
  78       Store_Chars (U, EM);
  79    end Store_UTF_32_Character;
  80
  81    ---------------------------
  82    -- Wide_String_To_String --
  83    ---------------------------
  84
  85    function Wide_String_To_String
  86      (S  : Wide_String;
  87       EM : WC_Encoding_Method) return String
  88    is
  89       Max_Chars : constant Natural := WC_Longest_Sequences (EM);
  90
  91       Result     : String (S'First .. S'First + Max_Chars * S'Length);
  92       Result_Idx : Natural;
  93
  94    begin
  95       Result_Idx := Result'First - 1;
  96
  97       for S_Idx in S'Range loop
  98          Store_UTF_32_Character
  99            (U  => Wide_Character'Pos (S (S_Idx)),
 100             S  => Result,
 101             P  => Result_Idx,
 102             EM => EM);
 103       end loop;
 104
 105       return Result (Result'First .. Result_Idx);
 106    end Wide_String_To_String;
 107
 108    --------------------------------
 109    -- Wide_Wide_String_To_String --
 110    --------------------------------
 111
 112    function Wide_Wide_String_To_String
 113      (S  : Wide_Wide_String;
 114       EM : WC_Encoding_Method) return String
 115    is
 116       Max_Chars : constant Natural := WC_Longest_Sequences (EM);
 117
 118       Result     : String (S'First .. S'First + Max_Chars * S'Length);
 119       Result_Idx : Natural;
 120
 121    begin
 122       Result_Idx := Result'First - 1;
 123
 124       for S_Idx in S'Range loop
 125          Store_UTF_32_Character
 126            (U  => Wide_Wide_Character'Pos (S (S_Idx)),
 127             S  => Result,
 128             P  => Result_Idx,
 129             EM => EM);
 130       end loop;
 131
 132       return Result (Result'First .. Result_Idx);
 133    end Wide_Wide_String_To_String;
 134
 135 end System.WCh_WtS;