AppPkg/Applications/Python/Python-2.7.10/Modules/cjkcodecs/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