gcc/ada/s-wchcnv.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                       S Y S T E M . W C H _ C N V                        --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2007, 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 2,  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.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  This package contains generic subprograms used for converting between
  35 --  sequences of Character and Wide_Character. All access to wide character
  36 --  sequences is isolated in this unit.
  37
  38 --  This unit may be used directly from an application program by providing
  39 --  an appropriate WITH, and the interface can be expected to remain stable.
  40
  41 pragma Warnings (Off);
  42 pragma Compiler_Unit;
  43 pragma Warnings (On);
  44
  45 with System.WCh_Con;
  46
  47 package System.WCh_Cnv is
  48    pragma Pure;
  49
  50    type UTF_32_Code is range 0 .. 16#7FFF_FFFF#;
  51    for UTF_32_Code'Size use 32;
  52    --  Range of allowed UTF-32 encoding values
  53
  54    generic
  55       with function In_Char return Character;
  56    function Char_Sequence_To_Wide_Char
  57      (C  : Character;
  58       EM : System.WCh_Con.WC_Encoding_Method) return Wide_Character;
  59    --  C is the first character of a sequence of one or more characters which
  60    --  represent a wide character sequence. Calling the function In_Char for
  61    --  additional characters as required, Char_To_Wide_Char returns the
  62    --  corresponding wide character value. Constraint_Error is raised if the
  63    --  sequence of characters encountered is not a valid wide character
  64    --  sequence for the given encoding method.
  65
  66    generic
  67       with function In_Char return Character;
  68    function Char_Sequence_To_UTF_32
  69      (C  : Character;
  70       EM : System.WCh_Con.WC_Encoding_Method) return UTF_32_Code;
  71    --  This is similar to the above, but the function returns a code from
  72    --  the full UTF_32 code set, which covers the full range of possible
  73    --  values in Wide_Wide_Character. The result can be converted to
  74    --  Wide_Wide_Character form using Wide_Wide_Character'Val.
  75
  76    generic
  77       with procedure Out_Char (C : Character);
  78    procedure Wide_Char_To_Char_Sequence
  79      (WC : Wide_Character;
  80       EM : System.WCh_Con.WC_Encoding_Method);
  81    --  Given a wide character, converts it into a sequence of one or
  82    --  more characters, calling the given Out_Char procedure for each.
  83    --  Constraint_Error is raised if the given wide character value is
  84    --  not a valid value for the given encoding method.
  85
  86    generic
  87       with procedure Out_Char (C : Character);
  88    procedure UTF_32_To_Char_Sequence
  89      (Val : UTF_32_Code;
  90       EM  : System.WCh_Con.WC_Encoding_Method);
  91    --  This is similar to the above, but the input value is a code from the
  92    --  full UTF_32 code set, which covers the full range of possible values
  93    --  in Wide_Wide_Character. To convert a Wide_Wide_Character value, the
  94    --  caller can use Wide_Wide_Character'Pos in the call.
  95
  96 end System.WCh_Cnv;