* 仕様書

[REFS[
- [1] [CITE@en-us[UAX #44: Unicode Character Database]] 
-- [8] <https://www.unicode.org/reports/tr44/#Default_Values_Table>
-- [9] <https://www.unicode.org/reports/tr44/#Complex_Default_Values>
-- [2] <https://www.unicode.org/reports/tr44/#Bidi_Class>
-- [3] <https://www.unicode.org/reports/tr44/#Extracted_Properties_Table>
-- [4] <https://www.unicode.org/reports/tr44/#Bidi_Class_Values>
- [5] [CITE@en-us[UAX #9: Unicode Bidirectional Algorithm]]
<https://www.unicode.org/reports/tr9/#Bidirectional_Character_Types>
- [7] ([TIME[2019-03-12 02:21:22 +09:00]]) <https://unicode.org/Public/UCD/latest/ucd/extracted/DerivedBidiClass.txt>
-- [6] 旧: <https://www.unicode.org/Public/UNIDATA/extracted/DerivedBidiClass.txt>
]REFS]

* データファイル

[10] 
[[UCD]]
の
[CODE[UnicodeData.txt]]
に含まれています。


[11] 
[[UCD]]
の
[DFN[[CODE[DerivedBidiClass.txt]]]] [SRC[>>7]]
にも含まれています。
こちらの方が使いやすい形式かもしれません。

* 値

[12] [CODE[Bidi_Class]] には次の種類があります。

[FIG(table)[

:c:[RUBYB[分類][Category]] [SRC[>>5]]
:t:[RUBYB[型][Type]] [SRC[>>5]] ([CODE[Bidi_Class]])
:list:一覧

:c: [RUBYB[強][Strong]]
:t: [CODE[L]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3AL>

:c: [RUBYB[強][Strong]]
:t: [CODE[R]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3AR>

:c: [RUBYB[強][Strong]]
:t: [CODE[AL]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3AAL>

:c: [RUBYB[弱][Weak]]
:t: [CODE[EN]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3AEN>

:c: [RUBYB[弱][Weak]]
:t: [CODE[ES]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3AES>

:c: [RUBYB[弱][Weak]]
:t: [CODE[ET]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3AET>

:c: [RUBYB[弱][Weak]]
:t: [CODE[AN]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3AAN>

:c: [RUBYB[弱][Weak]]
:t: [CODE[CS]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3ACS>

:c: [RUBYB[弱][Weak]]
:t: [CODE[NSM]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3ANSM>

:c: [RUBYB[弱][Weak]]
:t: [CODE[BN]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3ABN>

:c: [RUBYB[中立][Neutral]]
:t: [CODE[B]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3AB>

:c: [RUBYB[中立][Neutral]]
:t: [CODE[S]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3AS>

:c: [RUBYB[中立][Neutral]]
:t: [CODE[WS]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3AWS>

:c: [RUBYB[中立][Neutral]]
:t: [CODE[ON]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3AON>

:c: [RUBYB[明示的書式付け][Explicit Formatting]]
:t: [CODE[LRE]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3ALRE>

:c: [RUBYB[明示的書式付け][Explicit Formatting]]
:t: [CODE[LRC]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3ALRC>

:c: [RUBYB[明示的書式付け][Explicit Formatting]]
:t: [CODE[RLE]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3ARLE>

:c: [RUBYB[明示的書式付け][Explicit Formatting]]
:t: [CODE[RLC]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3ARLC>

:c: [RUBYB[明示的書式付け][Explicit Formatting]]
:t: [CODE[PDF]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3APDF>

:c: [RUBYB[明示的書式付け][Explicit Formatting]]
:t: [CODE[LRI]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3ALRI>

:c: [RUBYB[明示的書式付け][Explicit Formatting]]
:t: [CODE[RLI]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3ARLI>

:c: [RUBYB[明示的書式付け][Explicit Formatting]]
:t: [CODE[FSI]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3AFSI>

:c: [RUBYB[明示的書式付け][Explicit Formatting]]
:t: [CODE[PDI]]
:list:<https://chars.suikawiki.org/set/%24unicode%3ABidi_Class%3APDI>

]FIG]

[13] 
[[文字]]が割り当てられている[[符号位置]]だけでなく、
[[未割当符号位置]]にもいずれかの値が決められています。
[[アラビア文字]]の[[ブロック]]の空き位置は[[アラビア文字]]用の値、
というように[[ブロック]]ごとの値が予め決められています。


* メモ