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