Обратите внимание, что файл Unicode NamesList содержит следующие комментарии:
➡ 27A1 BLACK RIGHTWARDS ARROW
* fonts may harmonize this glyph with the style for other black arrows
x (leftwards black arrow - 2B05)
⬅ 2B05 LEFTWARDS BLACK ARROW
x (black rightwards arrow - 27A1)
Так что это говорит о том, что шрифты приветствуются, но не обязательны, чтобы они выглядели как другие черные стрелки.Вот как проверить все черные стрелки с помощью сценария uninames :
$ uninames BLACK WARDS ARROW
➡ 27A1 BLACK RIGHTWARDS ARROW
* fonts may harmonize this glyph with the style for other black arrows
x (leftwards black arrow - 2B05)
➤ 27A4 BLACK RIGHTWARDS ARROWHEAD
➥ 27A5 HEAVY BLACK CURVED DOWNWARDS AND RIGHTWARDS ARROW
➦ 27A6 HEAVY BLACK CURVED UPWARDS AND RIGHTWARDS ARROW
➧ 27A7 SQUAT BLACK RIGHTWARDS ARROW
➨ 27A8 HEAVY CONCAVE-POINTED BLACK RIGHTWARDS ARROW
➵ 27B5 BLACK-FEATHERED RIGHTWARDS ARROW
➸ 27B8 HEAVY BLACK-FEATHERED RIGHTWARDS ARROW
⤝ 291D LEFTWARDS ARROW TO BLACK DIAMOND
⤞ 291E RIGHTWARDS ARROW TO BLACK DIAMOND
⤟ 291F LEFTWARDS ARROW FROM BAR TO BLACK DIAMOND
⤠ 2920 RIGHTWARDS ARROW FROM BAR TO BLACK DIAMOND
⬅ 2B05 LEFTWARDS BLACK ARROW
x (black rightwards arrow - 27A1)
⬆ 2B06 UPWARDS BLACK ARROW
⬇ 2B07 DOWNWARDS BLACK ARROW
Также обратите внимание, что эти кодовые точки не помечены как двунаправленные.Они не встречаются в файле BidiMirroring, в котором есть только эти:
$ grep ARROW BidiMirroring.txt
# 29A8; MEASURED ANGLE WITH OPEN ARM ENDING IN ARROW POINTING UP AND RIGHT
# 29A9; MEASURED ANGLE WITH OPEN ARM ENDING IN ARROW POINTING UP AND LEFT
# 29AA; MEASURED ANGLE WITH OPEN ARM ENDING IN ARROW POINTING DOWN AND RIGHT
# 29AB; MEASURED ANGLE WITH OPEN ARM ENDING IN ARROW POINTING DOWN AND LEFT
# 29AC; MEASURED ANGLE WITH OPEN ARM ENDING IN ARROW POINTING RIGHT AND UP
# 29AD; MEASURED ANGLE WITH OPEN ARM ENDING IN ARROW POINTING LEFT AND UP
# 29AE; MEASURED ANGLE WITH OPEN ARM ENDING IN ARROW POINTING RIGHT AND DOWN
# 29AF; MEASURED ANGLE WITH OPEN ARM ENDING IN ARROW POINTING LEFT AND DOWN
# 2A17; INTEGRAL WITH LEFTWARDS ARROW WITH HOOK
Если вы проверите свойства этих двух кодовых точек с помощью uniprops script , выпосмотрим, где они немного отличаются:
$ uniprops -a 27A1 2B05
U+27A1 ‹➡› \N{BLACK RIGHTWARDS ARROW}
\pS \p{So}
All Any Assigned InDingbats Common Zyyy Dingbats So S Gr_Base Grapheme_Base Graph GrBase Other_Symbol Pat_Syn Pattern_Syntax PatSyn Print Symbol
X_POSIX_Graph X_POSIX_Print
Age=1.1 Bidi_Class=ON Bidi_Class=Other_Neutral BC=ON Block=Dingbats Canonical_Combining_Class=0 Canonical_Combining_Class=Not_Reordered CCC=NR
Canonical_Combining_Class=NR Script=Common Decomposition_Type=None DT=None East_Asian_Width=Neutral Grapheme_Cluster_Break=Other GCB=XX
Grapheme_Cluster_Break=XX Hangul_Syllable_Type=NA Hangul_Syllable_Type=Not_Applicable HST=NA Joining_Group=No_Joining_Group JG=NoJoiningGroup
Joining_Type=Non_Joining JT=U Joining_Type=U Line_Break=AL Line_Break=Alphabetic LB=AL Numeric_Type=None NT=None Numeric_Value=NaN NV=NaN
Present_In=1.1 IN=1.1 Present_In=2.0 IN=2.0 Present_In=2.1 IN=2.1 Present_In=3.0 IN=3.0 Present_In=3.1 IN=3.1 Present_In=3.2 IN=3.2 Present_In=4.0
IN=4.0 Present_In=4.1 IN=4.1 Present_In=5.0 IN=5.0 Present_In=5.1 IN=5.1 Present_In=5.2 IN=5.2 Present_In=6.0 IN=6.0 SC=Zyyy Script=Zyyy
Sentence_Break=Other SB=XX Sentence_Break=XX Word_Break=Other WB=XX Word_Break=XX
U+2B05 ‹⬅› \N{LEFTWARDS BLACK ARROW}
\pS \p{So}
All Any Assigned InMiscellaneousSymbolsAndArrows Common Zyyy So S Gr_Base Grapheme_Base Graph GrBase Miscellaneous_Symbols_And_Arrows Other_Symbol
Pat_Syn Pattern_Syntax PatSyn Print Symbol X_POSIX_Graph X_POSIX_Print
Age=4.0 Bidi_Class=ON Bidi_Class=Other_Neutral BC=ON Block=Miscellaneous_Symbols_And_Arrows Canonical_Combining_Class=0
Canonical_Combining_Class=Not_Reordered CCC=NR Canonical_Combining_Class=NR Script=Common Decomposition_Type=None DT=None East_Asian_Width=Neutral
Grapheme_Cluster_Break=Other GCB=XX Grapheme_Cluster_Break=XX Hangul_Syllable_Type=NA Hangul_Syllable_Type=Not_Applicable HST=NA
Joining_Group=No_Joining_Group JG=NoJoiningGroup Joining_Type=Non_Joining JT=U Joining_Type=U Line_Break=AL Line_Break=Alphabetic LB=AL
Numeric_Type=None NT=None Numeric_Value=NaN NV=NaN Present_In=4.0 IN=4.0 Present_In=4.1 IN=4.1 Present_In=5.0 IN=5.0 Present_In=5.1 IN=5.1
Present_In=5.2 IN=5.2 Present_In=6.0 IN=6.0 SC=Zyyy Script=Zyyy Sentence_Break=Other SB=XX Sentence_Break=XX Word_Break=Other WB=XX Word_Break=XX