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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- W I D E C H A R --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2006, 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- --
-- 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. --
-- --
-- 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. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- Note: this package uses the generic subprograms in System.Wch_Cnv, which
-- completely encapsulate the set of wide character encoding methods, so no
-- modifications are required when adding new encoding methods.
with Opt; use Opt;
with System.WCh_Cnv; use System.WCh_Cnv;
with System.WCh_Con; use System.WCh_Con;
package body Widechar is
---------------------------
-- Is_Start_Of_Wide_Char --
---------------------------
function Is_Start_Of_Wide_Char
(S : Source_Buffer_Ptr;
P : Source_Ptr) return Boolean
is
begin
case Wide_Character_Encoding_Method is
-- For Hex mode, just test for an ESC character. The ESC character
-- cannot appear in any other context in a legal Ada program.
when WCEM_Hex =>
return S (P) = ASCII.ESC;
-- For brackets, just test ["x where x is a hex character. This is
-- sufficient test, since this sequence cannot otherwise appear in a
-- legal Ada program.
when WCEM_Brackets =>
return P <= S'Last - 2
and then S (P) = '['
and then S (P + 1) = '"'
and then (S (P + 2) in '0' .. '9'
or else
S (P + 2) in 'a' .. 'f'
or else
S (P + 2) in 'A' .. 'F');
-- All other encoding methods use the upper bit set in the first
-- character to uniquely represent a wide character.
when WCEM_Upper |
WCEM_Shift_JIS |
WCEM_EUC |
WCEM_UTF8 =>
return S (P) >= Character'Val (16#80#);
end case;
end Is_Start_Of_Wide_Char;
-----------------
-- Length_Wide --
-----------------
function Length_Wide return Nat is
begin
return WC_Longest_Sequence;
end Length_Wide;
---------------
-- Scan_Wide --
---------------
procedure Scan_Wide
(S : Source_Buffer_Ptr;
P : in out Source_Ptr;
C : out Char_Code;
Err : out Boolean)
is
P_Init : constant Source_Ptr := P;
Chr : Character;
function In_Char return Character;
-- Function to obtain characters of wide character escape sequence
-------------
-- In_Char --
-------------
function In_Char return Character is
begin
P := P + 1;
return S (P - 1);
end In_Char;
function WC_In is new Char_Sequence_To_UTF_32 (In_Char);
-- Start of processingf for Scan_Wide
begin
Chr := In_Char;
-- Scan out the wide character. if the first character is a bracket,
-- we allow brackets encoding regardless of the standard encoding
-- method being used, but otherwise we use this standard method.
if Chr = '[' then
C := Char_Code (WC_In (Chr, WCEM_Brackets));
else
C := Char_Code (WC_In (Chr, Wide_Character_Encoding_Method));
end if;
Err := False;
Wide_Char_Byte_Count := Wide_Char_Byte_Count + Nat (P - P_Init - 1);
exception
when Constraint_Error =>
C := Char_Code (0);
P := P - 1;
Err := True;
end Scan_Wide;
--------------
-- Set_Wide --
--------------
procedure Set_Wide
(C : Char_Code;
S : in out String;
P : in out Natural)
is
procedure Out_Char (C : Character);
-- Procedure to store one character of wide character sequence
--------------
-- Out_Char --
--------------
procedure Out_Char (C : Character) is
begin
P := P + 1;
S (P) := C;
end Out_Char;
procedure WC_Out is new UTF_32_To_Char_Sequence (Out_Char);
-- Start of processing for Set_Wide
begin
WC_Out (UTF_32_Code (C), Wide_Character_Encoding_Method);
end Set_Wide;
---------------
-- Skip_Wide --
---------------
procedure Skip_Wide (S : String; P : in out Natural) is
P_Init : constant Natural := P;
function Skip_Char return Character;
-- Function to skip one character of wide character escape sequence
---------------
-- Skip_Char --
---------------
function Skip_Char return Character is
begin
P := P + 1;
return S (P - 1);
end Skip_Char;
function WC_Skip is new Char_Sequence_To_UTF_32 (Skip_Char);
Discard : UTF_32_Code;
pragma Warnings (Off, Discard);
-- Start of processing for Skip_Wide
begin
Discard := WC_Skip (Skip_Char, Wide_Character_Encoding_Method);
Wide_Char_Byte_Count := Wide_Char_Byte_Count + Nat (P - P_Init - 1);
end Skip_Wide;
---------------
-- Skip_Wide --
---------------
procedure Skip_Wide (S : Source_Buffer_Ptr; P : in out Source_Ptr) is
P_Init : constant Source_Ptr := P;
function Skip_Char return Character;
-- Function to skip one character of wide character escape sequence
---------------
-- Skip_Char --
---------------
function Skip_Char return Character is
begin
P := P + 1;
return S (P - 1);
end Skip_Char;
function WC_Skip is new Char_Sequence_To_UTF_32 (Skip_Char);
Discard : UTF_32_Code;
pragma Warnings (Off, Discard);
-- Start of processing for Skip_Wide
begin
Discard := WC_Skip (Skip_Char, Wide_Character_Encoding_Method);
Wide_Char_Byte_Count := Wide_Char_Byte_Count + Nat (P - P_Init - 1);
end Skip_Wide;
end Widechar;
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