gcc/ada/libgnat/g-encstr.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                    G N A T . E N C O D E _ S T R I N G                   --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --                     Copyright (C) 2007-2023, AdaCore                     --
  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 --  This generic package provides utility routines for converting from
  33 --  Wide_String or Wide_Wide_String to encoded String using a specified
  34 --  encoding convention, which is supplied as the generic parameter. If
  35 --  this parameter is a known at compile time constant (e.g. a constant
  36 --  defined in System.WCh_Con), the instantiation is specialized so that
  37 --  it applies only to this specified coding.
  38
  39 --  Note: this package is only about encoding sequences of 16- or 32-bit
  40 --  characters into a sequence of 8-bit codes. It knows nothing at all about
  41 --  the character encodings being used for the input Wide_Character and
  42 --  Wide_Wide_Character values, although some of the encoding methods (notably
  43 --  JIS and EUC) have built in assumptions about the range of possible input
  44 --  code values. Most often the input will be Unicode/ISO-10646 as specified by
  45 --  the Ada RM, but this package does not make any assumptions about the
  46 --  character coding, and in the case of UTF-8 all possible code values can be
  47 --  encoded. See also the packages Ada.Wide_[Wide_]Characters.Unicode for
  48 --  unicode specific functions.
  49
  50 --  Note on brackets encoding (WCEM_Brackets). On input, upper half characters
  51 --  can be represented as ["hh"] but the routines in this package will only use
  52 --  brackets encodings for codes higher than 16#FF#, so upper half characters
  53 --  will be output as single Character values.
  54
  55 with System.WCh_Con;
  56
  57 generic
  58    Encoding_Method : System.WCh_Con.WC_Encoding_Method;
  59
  60 package GNAT.Encode_String is
  61    pragma Pure;
  62
  63    function Encode_Wide_String (S : Wide_String) return String;
  64    pragma Inline (Encode_Wide_String);
  65    --  Encode the given Wide_String, returning a String encoded using the
  66    --  given encoding method. Constraint_Error will be raised if the encoding
  67    --  method cannot accommodate the input data.
  68
  69    procedure Encode_Wide_String
  70      (S      : Wide_String;
  71       Result : out String;
  72       Length : out Natural);
  73    --  Encode the given Wide_String, storing the encoded string in Result,
  74    --  with Length being set to the length of the encoded string. The caller
  75    --  must ensure that Result is long enough (see useful constants defined
  76    --  in System.WCh_Con: WC_Longest_Sequence, WC_Longest_Sequences). If the
  77    --  length of Result is insufficient Constraint_Error will be raised.
  78    --  Constraint_Error will also be raised if the encoding method cannot
  79    --  accommodate the input data.
  80
  81    function Encode_Wide_Wide_String (S : Wide_Wide_String) return String;
  82    pragma Inline (Encode_Wide_Wide_String);
  83    --  Same as above function but for Wide_Wide_String input
  84
  85    procedure Encode_Wide_Wide_String
  86      (S      : Wide_Wide_String;
  87       Result : out String;
  88       Length : out Natural);
  89    --  Same as above procedure, but for Wide_Wide_String input
  90
  91    procedure Encode_Wide_Character
  92      (Char   : Wide_Character;
  93       Result : in out String;
  94       Ptr    : in out Natural);
  95    pragma Inline (Encode_Wide_Character);
  96    --  This is a lower level procedure that encodes the single character Char.
  97    --  The output is stored in Result starting at Result (Ptr), and Ptr is
  98    --  updated past the stored value. Constraint_Error is raised if Result
  99    --  is not long enough to accommodate the result, or if the encoding method
 100    --  specified does not accommodate the input character value, or if Ptr is
 101    --  outside the bounds of the Result string.
 102
 103    procedure Encode_Wide_Wide_Character
 104      (Char   : Wide_Wide_Character;
 105       Result : in out String;
 106       Ptr    : in out Natural);
 107    --  Same as above procedure but with Wide_Wide_Character input
 108
 109 end GNAT.Encode_String;