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
|
------------------------------------------------------------------------------
-- --
-- GNAT RUNTIME COMPONENTS --
-- --
-- S Y S T E M . W C H _ J I S --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992,1993,1994 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, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, 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. --
-- --
------------------------------------------------------------------------------
package body System.WCh_JIS is
type Byte is mod 256;
EUC_Hankaku_Kana : constant Byte := 16#8E#;
-- Prefix byte in EUC for Hankaku Kana (small Katakana). Such characters
-- in EUC are represented by a prefix byte followed by the code, which
-- is in the upper half (the corresponding JIS internal code is in the
-- range 16#0080# - 16#00FF#).
function EUC_To_JIS (EUC1, EUC2 : Character) return Wide_Character is
EUC1B : constant Byte := Character'Pos (EUC1);
EUC2B : constant Byte := Character'Pos (EUC2);
begin
if EUC2B not in 16#A0# .. 16#FE# then
raise Constraint_Error;
end if;
if EUC1B = EUC_Hankaku_Kana then
return Wide_Character'Val (EUC2B);
else
if EUC1B not in 16#A0# .. 16#FE# then
raise Constraint_Error;
else
return Wide_Character'Val
(256 * Natural (EUC1B and 16#7F#) + Natural (EUC2B and 16#7F#));
end if;
end if;
end EUC_To_JIS;
----------------
-- JIS_To_EUC --
----------------
procedure JIS_To_EUC
(J : in Wide_Character;
EUC1 : out Character;
EUC2 : out Character)
is
JIS1 : constant Natural := Wide_Character'Pos (J) / 256;
JIS2 : constant Natural := Wide_Character'Pos (J) rem 256;
begin
if JIS1 = 0 then
EUC1 := Character'Val (EUC_Hankaku_Kana);
EUC2 := Character'Val (JIS2);
else
EUC1 := Character'Val (JIS1 + 16#80#);
EUC2 := Character'Val (JIS2 + 16#80#);
end if;
end JIS_To_EUC;
----------------------
-- JIS_To_Shift_JIS --
----------------------
procedure JIS_To_Shift_JIS
(J : in Wide_Character;
SJ1 : out Character;
SJ2 : out Character)
is
JIS1 : Byte;
JIS2 : Byte;
begin
-- The following is the required algorithm, it's hard to make any
-- more intelligent comments! This was copied from a public domain
-- C program called etos.c (author unknown).
JIS1 := Byte (Natural (Wide_Character'Pos (J) / 256));
JIS2 := Byte (Natural (Wide_Character'Pos (J) rem 256));
if JIS1 > 16#5F# then
JIS1 := JIS1 + 16#80#;
end if;
if (JIS1 mod 2) = 0 then
SJ1 := Character'Val ((JIS1 - 16#30#) / 2 + 16#88#);
SJ2 := Character'Val (JIS2 + 16#7E#);
else
if JIS2 >= 16#60# then
JIS2 := JIS2 + 16#01#;
end if;
SJ1 := Character'Val ((JIS1 - 16#31#) / 2 + 16#89#);
SJ2 := Character'Val (JIS2 + 16#1F#);
end if;
end JIS_To_Shift_JIS;
----------------------
-- Shift_JIS_To_JIS --
----------------------
function Shift_JIS_To_JIS (SJ1, SJ2 : Character) return Wide_Character is
SJIS1 : Byte;
SJIS2 : Byte;
JIS1 : Byte;
JIS2 : Byte;
begin
-- The following is the required algorithm, it's hard to make any
-- more intelligent comments! This was copied from a public domain
-- C program called stoj.c written by shige@csk.JUNET.
SJIS1 := Character'Pos (SJ1);
SJIS2 := Character'Pos (SJ2);
if SJIS1 >= 16#E0# then
SJIS1 := SJIS1 - 16#40#;
end if;
if SJIS2 >= 16#9F# then
JIS1 := (SJIS1 - 16#88#) * 2 + 16#30#;
JIS2 := SJIS2 - 16#7E#;
else
if SJIS2 >= 16#7F# then
SJIS2 := SJIS2 - 16#01#;
end if;
JIS1 := (SJIS1 - 16#89#) * 2 + 16#31#;
JIS2 := SJIS2 - 16#1F#;
end if;
if JIS1 not in 16#20# .. 16#7E#
or else JIS2 not in 16#20# .. 16#7E#
then
raise Constraint_Error;
else
return Wide_Character'Val (256 * Natural (JIS1) + Natural (JIS2));
end if;
end Shift_JIS_To_JIS;
end System.WCh_JIS;
|
