-- --
-- S p e c --
-- --
--- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
--- ware Foundation; either version 2, or (at your option) any later ver- --
+-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
--- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
--- for more details. You should have received a copy of the GNU General --
--- Public License distributed with GNAT; see file COPYING. If not, write --
--- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
--- Boston, MA 02110-1301, USA. --
+-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
--- As a special exception, if other files instantiate generics from this --
--- unit, or you link this unit with other files to produce an executable, --
--- this unit does not by itself cause the resulting executable to be --
--- covered by the GNU General Public License. This exception does not --
--- however invalidate any other reasons why the executable file might be --
--- covered by the GNU Public License. --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception, --
+-- version 3.1, as published by the Free Software Foundation. --
+-- --
+-- You should have received a copy of the GNU General Public License and --
+-- a copy of the GCC Runtime Library Exception along with this program; --
+-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
+-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- This unit may be used directly from an application program by providing
-- an appropriate WITH, and the interface can be expected to remain stable.
+pragma Compiler_Unit;
+
package System.WCh_Con is
pragma Pure;
-- 4. Adjust definition of WC_Longest_Sequence if necessary
-- 5. Add an entry in WC_Encoding_Letters for the new method
-- 6. Add proper code to s-wchstw.adb, s-wchwts.adb, s-widwch.adb
+ -- 7. Update documentation (remember section on form strings)
-- Note that the WC_Encoding_Method values must be kept ordered so that
-- the definitions of the subtypes WC_Upper_Half_Encoding_Method and
-- sequence ESC a b c d (five characters, where abcd are ASCII hex
-- characters, using upper case for letters). This method is easy
-- to deal with in external environments that do not support wide
- -- characters, and covers the whole BMP. This is the default encoding
- -- method.
+ -- characters, and covers the whole 16-bit BMP. Codes larger than
+ -- 16#FFFF# are not representable using this encoding method.
WCEM_Upper : constant WC_Encoding_Method := 2;
-- The wide character with encoding 16#abcd#, where the upper bit is on
-- 16#cd#. The second byte may never be a format control character, but
-- is not required to be in the upper half. This method can be also used
-- for shift-JIS or EUC where the internal coding matches the external
- -- coding.
+ -- coding. Codes larger than 16#FFFF# are not representable using this
+ -- encoding method.
WCEM_Shift_JIS : constant WC_Encoding_Method := 3;
-- A wide character is represented by a two character sequence 16#ab#
-- as described above. The internal character code is the corresponding
-- JIS character according to the standard algorithm for Shift-JIS
-- conversion. See the body of package System.JIS_Conversions for
- -- further details.
+ -- further details. Codes larger than 16#FFFF are not representable
+ -- using this encoding method.
WCEM_EUC : constant WC_Encoding_Method := 4;
-- A wide character is represented by a two character sequence 16#ab# and
-- 16#cd#, with both characters being in the upper half set. The internal
-- character code is the corresponding JIS character according to the EUC
-- encoding algorithm. See the body of package System.JIS_Conversions for
- -- further details.
+ -- further details. Codes larger than 16#FFFF# are not representable using
+ -- this encoding method.
WCEM_UTF8 : constant WC_Encoding_Method := 5;
- -- An ISO 10646-1 BMP/Unicode wide character is represented in
- -- UCS Transformation Format 8 (UTF-8) as defined in Annex R of ISO
- -- 10646-1/Am.2. Depending on the character value, a Unicode character
+ -- An ISO 10646-1 BMP/Unicode wide character is represented in UCS
+ -- Transformation Format 8 (UTF-8), as defined in Annex R of ISO
+ -- 10646-1/Am.2. Depending on the character value, a Unicode character
-- is represented as the one to six byte sequence.
--
-- 16#0000_0000#-16#0000_007f#: 2#0xxxxxxx#
-- where the xxx bits correspond to the left-padded bits of the
-- 16-bit character value. Note that all lower half ASCII characters
-- are represented as ASCII bytes and all upper half characters and
- -- other wide characters are represented as sequences of upper-half.
+ -- other wide characters are represented as sequences of upper-half. This
+ -- encoding method can represent the entire range of Wide_Wide_Character.
WCEM_Brackets : constant WC_Encoding_Method := 6;
-- A wide character is represented using one of the following sequences:
-- ["xxxxxx"]
-- ["xxxxxxxx"]
--
- -- where xx are hexadecimal digits representing the character code.
+ -- where xx are hexadecimal digits representing the character code. This
+ -- encoding method can represent the entire range of Wide_Wide_Character
+ -- but in the general case results in ambiguous representations (there is
+ -- no ambiguity in Ada sources, since the above sequences are illegal Ada).
WC_Encoding_Letters : constant array (WC_Encoding_Method) of Character :=
(WCEM_Hex => 'h',
-- Encoding methods using an upper half character (16#80#..16#FF) at
-- the start of the sequence.
- WC_Longest_Sequence : constant := 10;
+ WC_Longest_Sequence : constant := 12;
-- The longest number of characters that can be used for a wide character
-- or wide wide character sequence for any of the active encoding methods.
+ WC_Longest_Sequences : constant array (WC_Encoding_Method) of Natural :=
+ (WCEM_Hex => 5,
+ WCEM_Upper => 2,
+ WCEM_Shift_JIS => 2,
+ WCEM_EUC => 2,
+ WCEM_UTF8 => 6,
+ WCEM_Brackets => 12);
+ -- The longest number of characters that can be used for a wide character
+ -- or wide wide character sequence using the given encoding method.
+
function Get_WC_Encoding_Method (C : Character) return WC_Encoding_Method;
-- Given a character C, returns corresponding encoding method (see array
-- WC_Encoding_Letters above). Raises Constraint_Error if not in list.
-- utf8, brackets, return the corresponding encoding method. Raises
-- Constraint_Error if not in list.
+ function Is_Start_Of_Encoding
+ (C : Character;
+ EM : WC_Encoding_Method) return Boolean;
+ pragma Inline (Is_Start_Of_Encoding);
+ -- Returns True if the Character C is the start of a multi-character
+ -- encoding sequence for the given encoding method EM. If EM is set to
+ -- WCEM_Brackets, this function always returns False.
+
end System.WCh_Con;
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