README
1 To generate or modify mapping headers
2 -------------------------------------
3 Mapping headers are imported from CJKCodecs as pre-generated form.
4 If you need to tweak or add something on it, please look at tools/
5 subdirectory of CJKCodecs' distribution.
6
7
8
9 Notes on implmentation characteristics of each codecs
10 -----------------------------------------------------
11
12 1) Big5 codec
13
14 The big5 codec maps the following characters as cp950 does rather
15 than conforming Unicode.org's that maps to 0xFFFD.
16
17 BIG5 Unicode Description
18
19 0xA15A 0x2574 SPACING UNDERSCORE
20 0xA1C3 0xFFE3 SPACING HEAVY OVERSCORE
21 0xA1C5 0x02CD SPACING HEAVY UNDERSCORE
22 0xA1FE 0xFF0F LT DIAG UP RIGHT TO LOW LEFT
23 0xA240 0xFF3C LT DIAG UP LEFT TO LOW RIGHT
24 0xA2CC 0x5341 HANGZHOU NUMERAL TEN
25 0xA2CE 0x5345 HANGZHOU NUMERAL THIRTY
26
27 Because unicode 0x5341, 0x5345, 0xFF0F, 0xFF3C is mapped to another
28 big5 codes already, a roundtrip compatibility is not guaranteed for
29 them.
30
31
32 2) cp932 codec
33
34 To conform to Windows's real mapping, cp932 codec maps the following
35 codepoints in addition of the official cp932 mapping.
36
37 CP932 Unicode Description
38
39 0x80 0x80 UNDEFINED
40 0xA0 0xF8F0 UNDEFINED
41 0xFD 0xF8F1 UNDEFINED
42 0xFE 0xF8F2 UNDEFINED
43 0xFF 0xF8F3 UNDEFINED
44
45
46 3) euc-jisx0213 codec
47
48 The euc-jisx0213 codec maps JIS X 0213 Plane 1 code 0x2140 into
49 unicode U+FF3C instead of U+005C as on unicode.org's mapping.
50 Because euc-jisx0213 has REVERSE SOLIDUS on 0x5c already and A140
51 is shown as a full width character, mapping to U+FF3C can make
52 more sense.
53
54 The euc-jisx0213 codec is enabled to decode JIS X 0212 codes on
55 codeset 2. Because JIS X 0212 and JIS X 0213 Plane 2 don't have
56 overlapped by each other, it doesn't bother standard conformations
57 (and JIS X 0213 Plane 2 is intended to use so.) On encoding
58 sessions, the codec will try to encode kanji characters in this
59 order:
60
61 JIS X 0213 Plane 1 -> JIS X 0213 Plane 2 -> JIS X 0212
62
63
64 4) euc-jp codec
65
66 The euc-jp codec is a compatibility instance on these points:
67 - U+FF3C FULLWIDTH REVERSE SOLIDUS is mapped to EUC-JP A1C0 (vice versa)
68 - U+00A5 YEN SIGN is mapped to EUC-JP 0x5c. (one way)
69 - U+203E OVERLINE is mapped to EUC-JP 0x7e. (one way)
70
71
72 5) shift-jis codec
73
74 The shift-jis codec is mapping 0x20-0x7e area to U+20-U+7E directly
75 instead of using JIS X 0201 for compatibility. The differences are:
76 - U+005C REVERSE SOLIDUS is mapped to SHIFT-JIS 0x5c.
77 - U+007E TILDE is mapped to SHIFT-JIS 0x7e.
78 - U+FF3C FULL-WIDTH REVERSE SOLIDUS is mapped to SHIFT-JIS 815f.
79
80