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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- G N A T . E N C O D E _ S T R I N G --
-- --
-- B o d y --
-- --
-- Copyright (C) 2007-2024, 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 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. --
-- --
-- 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. --
-- --
------------------------------------------------------------------------------
with Interfaces; use Interfaces;
with System.WCh_Con; use System.WCh_Con;
with System.WCh_Cnv; use System.WCh_Cnv;
package body GNAT.Encode_String is
-----------------------
-- Local Subprograms --
-----------------------
procedure Bad;
pragma No_Return (Bad);
-- Raise error for bad character code
procedure Past_End;
pragma No_Return (Past_End);
-- Raise error for off end of string
---------
-- Bad --
---------
procedure Bad is
begin
raise Constraint_Error with
"character cannot be encoded with given Encoding_Method";
end Bad;
------------------------
-- Encode_Wide_String --
------------------------
function Encode_Wide_String (S : Wide_String) return String is
Long : constant Natural := WC_Longest_Sequences (Encoding_Method);
Result : String (1 .. S'Length * Long);
Length : Natural;
begin
Encode_Wide_String (S, Result, Length);
return Result (1 .. Length);
end Encode_Wide_String;
procedure Encode_Wide_String
(S : Wide_String;
Result : out String;
Length : out Natural)
is
Ptr : Natural;
begin
Ptr := Result'First;
for J in S'Range loop
Encode_Wide_Character (S (J), Result, Ptr);
end loop;
Length := Ptr - Result'First;
end Encode_Wide_String;
-----------------------------
-- Encode_Wide_Wide_String --
-----------------------------
function Encode_Wide_Wide_String (S : Wide_Wide_String) return String is
Long : constant Natural := WC_Longest_Sequences (Encoding_Method);
Result : String (1 .. S'Length * Long);
Length : Natural;
begin
Encode_Wide_Wide_String (S, Result, Length);
return Result (1 .. Length);
end Encode_Wide_Wide_String;
procedure Encode_Wide_Wide_String
(S : Wide_Wide_String;
Result : out String;
Length : out Natural)
is
Ptr : Natural;
begin
Ptr := Result'First;
for J in S'Range loop
Encode_Wide_Wide_Character (S (J), Result, Ptr);
end loop;
Length := Ptr - Result'First;
end Encode_Wide_Wide_String;
---------------------------
-- Encode_Wide_Character --
---------------------------
procedure Encode_Wide_Character
(Char : Wide_Character;
Result : in out String;
Ptr : in out Natural)
is
begin
Encode_Wide_Wide_Character
(Wide_Wide_Character'Val (Wide_Character'Pos (Char)), Result, Ptr);
exception
when Constraint_Error =>
Bad;
end Encode_Wide_Character;
--------------------------------
-- Encode_Wide_Wide_Character --
--------------------------------
procedure Encode_Wide_Wide_Character
(Char : Wide_Wide_Character;
Result : in out String;
Ptr : in out Natural)
is
U : Unsigned_32;
procedure Out_Char (C : Character);
pragma Inline (Out_Char);
-- Procedure to store one character for instantiation below
--------------
-- Out_Char --
--------------
procedure Out_Char (C : Character) is
begin
if Ptr > Result'Last then
Past_End;
else
Result (Ptr) := C;
Ptr := Ptr + 1;
end if;
end Out_Char;
-- Start of processing for Encode_Wide_Wide_Character;
begin
-- Efficient code for UTF-8 case
if Encoding_Method = WCEM_UTF8 then
-- Note: for details of UTF8 encoding see RFC 3629
U := Unsigned_32 (Wide_Wide_Character'Pos (Char));
-- 16#00_0000#-16#00_007F#: 0xxxxxxx
if U <= 16#00_007F# then
Out_Char (Character'Val (U));
-- 16#00_0080#-16#00_07FF#: 110xxxxx 10xxxxxx
elsif U <= 16#00_07FF# then
Out_Char (Character'Val (2#11000000# or Shift_Right (U, 6)));
Out_Char (Character'Val (2#10000000# or (U and 2#00111111#)));
-- 16#00_0800#-16#00_FFFF#: 1110xxxx 10xxxxxx 10xxxxxx
elsif U <= 16#00_FFFF# then
Out_Char (Character'Val (2#11100000# or Shift_Right (U, 12)));
Out_Char (Character'Val (2#10000000# or (Shift_Right (U, 6)
and 2#00111111#)));
Out_Char (Character'Val (2#10000000# or (U and 2#00111111#)));
-- 16#01_0000#-16#10_FFFF#: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
elsif U <= 16#10_FFFF# then
Out_Char (Character'Val (2#11110000# or Shift_Right (U, 18)));
Out_Char (Character'Val (2#10000000# or (Shift_Right (U, 12)
and 2#00111111#)));
Out_Char (Character'Val (2#10000000# or (Shift_Right (U, 6)
and 2#00111111#)));
Out_Char (Character'Val (2#10000000# or (U and 2#00111111#)));
-- 16#0020_0000#-16#03FF_FFFF#: 111110xx 10xxxxxx 10xxxxxx
-- 10xxxxxx 10xxxxxx
elsif U <= 16#03FF_FFFF# then
Out_Char (Character'Val (2#11111000# or Shift_Right (U, 24)));
Out_Char (Character'Val (2#10000000# or (Shift_Right (U, 18)
and 2#00111111#)));
Out_Char (Character'Val (2#10000000# or (Shift_Right (U, 12)
and 2#00111111#)));
Out_Char (Character'Val (2#10000000# or (Shift_Right (U, 6)
and 2#00111111#)));
Out_Char (Character'Val (2#10000000# or (U and 2#00111111#)));
-- All other cases are invalid character codes, not this includes:
-- 16#0400_0000#-16#7FFF_FFFF#: 1111110x 10xxxxxx 10xxxxxx
-- 10xxxxxx 10xxxxxx 10xxxxxx
-- since Wide_Wide_Character values cannot exceed 16#3F_FFFF#
else
Bad;
end if;
-- All encoding methods other than UTF-8
else
Non_UTF8 : declare
procedure UTF_32_To_String is
new UTF_32_To_Char_Sequence (Out_Char);
-- Instantiate conversion procedure with above Out_Char routine
begin
UTF_32_To_String
(UTF_32_Code (Wide_Wide_Character'Pos (Char)), Encoding_Method);
exception
when Constraint_Error =>
Bad;
end Non_UTF8;
end if;
end Encode_Wide_Wide_Character;
--------------
-- Past_End --
--------------
procedure Past_End is
begin
raise Constraint_Error with "past end of string";
end Past_End;
end GNAT.Encode_String;
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