| Notes on cjkcodecs |
| ------------------- |
| This directory contains source files for cjkcodecs extension modules. |
| They are based on CJKCodecs (http://cjkpython.i18n.org/#CJKCodecs) |
| as of Aug 20 2004 currently. |
| |
| |
| |
| To generate or modify mapping headers |
| ------------------------------------- |
| Mapping headers are imported from CJKCodecs as pre-generated form. |
| If you need to tweak or add something on it, please look at tools/ |
| subdirectory of CJKCodecs' distribution. |
| |
| |
| |
| Notes on implmentation characteristics of each codecs |
| ----------------------------------------------------- |
| |
| 1) Big5 codec |
| |
| The big5 codec maps the following characters as cp950 does rather |
| than conforming Unicode.org's that maps to 0xFFFD. |
| |
| BIG5 Unicode Description |
| |
| 0xA15A 0x2574 SPACING UNDERSCORE |
| 0xA1C3 0xFFE3 SPACING HEAVY OVERSCORE |
| 0xA1C5 0x02CD SPACING HEAVY UNDERSCORE |
| 0xA1FE 0xFF0F LT DIAG UP RIGHT TO LOW LEFT |
| 0xA240 0xFF3C LT DIAG UP LEFT TO LOW RIGHT |
| 0xA2CC 0x5341 HANGZHOU NUMERAL TEN |
| 0xA2CE 0x5345 HANGZHOU NUMERAL THIRTY |
| |
| Because unicode 0x5341, 0x5345, 0xFF0F, 0xFF3C is mapped to another |
| big5 codes already, a roundtrip compatibility is not guaranteed for |
| them. |
| |
| |
| 2) cp932 codec |
| |
| To conform to Windows's real mapping, cp932 codec maps the following |
| codepoints in addition of the official cp932 mapping. |
| |
| CP932 Unicode Description |
| |
| 0x80 0x80 UNDEFINED |
| 0xA0 0xF8F0 UNDEFINED |
| 0xFD 0xF8F1 UNDEFINED |
| 0xFE 0xF8F2 UNDEFINED |
| 0xFF 0xF8F3 UNDEFINED |
| |
| |
| 3) euc-jisx0213 codec |
| |
| The euc-jisx0213 codec maps JIS X 0213 Plane 1 code 0x2140 into |
| unicode U+FF3C instead of U+005C as on unicode.org's mapping. |
| Because euc-jisx0213 has REVERSE SOLIDUS on 0x5c already and A140 |
| is shown as a full width character, mapping to U+FF3C can make |
| more sense. |
| |
| The euc-jisx0213 codec is enabled to decode JIS X 0212 codes on |
| codeset 2. Because JIS X 0212 and JIS X 0213 Plane 2 don't have |
| overlapped by each other, it doesn't bother standard conformations |
| (and JIS X 0213 Plane 2 is intended to use so.) On encoding |
| sessions, the codec will try to encode kanji characters in this |
| order: |
| |
| JIS X 0213 Plane 1 -> JIS X 0213 Plane 2 -> JIS X 0212 |
| |
| |
| 4) euc-jp codec |
| |
| The euc-jp codec is a compatibility instance on these points: |
| - U+FF3C FULLWIDTH REVERSE SOLIDUS is mapped to EUC-JP A1C0 (vice versa) |
| - U+00A5 YEN SIGN is mapped to EUC-JP 0x5c. (one way) |
| - U+203E OVERLINE is mapped to EUC-JP 0x7e. (one way) |
| |
| |
| 5) shift-jis codec |
| |
| The shift-jis codec is mapping 0x20-0x7e area to U+20-U+7E directly |
| instead of using JIS X 0201 for compatibility. The differences are: |
| - U+005C REVERSE SOLIDUS is mapped to SHIFT-JIS 0x5c. |
| - U+007E TILDE is mapped to SHIFT-JIS 0x7e. |
| - U+FF3C FULL-WIDTH REVERSE SOLIDUS is mapped to SHIFT-JIS 815f. |
| |