1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
|
------------------------------------------------------------------------------
-- --
-- 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) 2007-2012, 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 := S'First;
for J in S'Range loop
Encode_Wide_Character (S (J), Result, Ptr);
end loop;
Length := Ptr - S'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 := S'First;
for J in S'Range loop
Encode_Wide_Wide_Character (S (J), Result, Ptr);
end loop;
Length := Ptr - S'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;
|
