# Copyright (C) 2016 and later: Unicode, Inc. and others. # License & terms of use: http://www.unicode.org/copyright.html # Copyright (c) 2002-2016 International Business Machines Corporation and # others. All Rights Reserved. # # file: line_loose.txt # # Line Breaking Rules # Implement default line breaking as defined by # Unicode Standard Annex #14 Revision 37 for Unicode 9.0 # http://www.unicode.org/reports/tr14/ # # Includes extensions to the handling of emoji ZWJ sequences from # https://goo.gl/cluFCn # # tailored as noted in 2nd paragraph below. # # TODO: Rule LB 8 remains as it was in Unicode 5.2 # This is only because of a limitation of ICU break engine implementation, # not because the older behavior is desirable. # # This tailors the line break behavior to correspond to CSS # line-break=loose (BCP47 -u-lb-loose) as defined for languages other than # Chinese & Japanese. # It sets characters of class CJ to behave like ID. # In addition, it allows breaks: # * before iteration marks 3005, 303B, 309D, 309E, 30FD, 30FE (all NS) # * between characters of LineBreak class IN # # Character Classes defined by TR 14. # !!chain; $AI = [:LineBreak = Ambiguous:]; $AL = [:LineBreak = Alphabetic:]; $BA = [:LineBreak = Break_After:]; $BB = [:LineBreak = Break_Before:]; $BK = [:LineBreak = Mandatory_Break:]; $B2 = [:LineBreak = Break_Both:]; $CB = [:LineBreak = Contingent_Break:]; $CJ = [:LineBreak = Conditional_Japanese_Starter:]; $CL = [:LineBreak = Close_Punctuation:]; # $CM = [:LineBreak = Combining_Mark:]; $CP = [:LineBreak = Close_Parenthesis:]; $CR = [:LineBreak = Carriage_Return:]; $EB = [[:LineBreak = EB:]\U0001F3C2\U0001F3C7\U0001F3CC\U0001F46A-\U0001F46D\U0001F46F\U0001F574\U0001F6CC]; $EM = [:LineBreak = EM:]; $EX = [:LineBreak = Exclamation:]; $GL = [:LineBreak = Glue:]; $HL = [:LineBreak = Hebrew_Letter:]; $HY = [:LineBreak = Hyphen:]; $H2 = [:LineBreak = H2:]; $H3 = [:LineBreak = H3:]; # CSS Loose tailoring: CJ resolves to ID $ID = [[:LineBreak = Ideographic:] $CJ]; $IN = [:LineBreak = Inseperable:]; $IS = [:LineBreak = Infix_Numeric:]; $JL = [:LineBreak = JL:]; $JV = [:LineBreak = JV:]; $JT = [:LineBreak = JT:]; $LF = [:LineBreak = Line_Feed:]; $NL = [:LineBreak = Next_Line:]; $NSX = [\u3005 \u303B \u309D \u309E \u30FD \u30FE]; $NS = [[:LineBreak = Nonstarter:] - $NSX]; $NU = [:LineBreak = Numeric:]; $OP = [:LineBreak = Open_Punctuation:]; $PO = [:LineBreak = Postfix_Numeric:]; $PR = [:LineBreak = Prefix_Numeric:]; $QU = [:LineBreak = Quotation:]; $RI = [:LineBreak = Regional_Indicator:]; $SA = [:LineBreak = Complex_Context:]; $SG = [:LineBreak = Surrogate:]; $SP = [:LineBreak = Space:]; $SY = [:LineBreak = Break_Symbols:]; $WJ = [:LineBreak = Word_Joiner:]; $XX = [:LineBreak = Unknown:]; $ZW = [:LineBreak = ZWSpace:]; $ZWJ = [:LineBreak = ZWJ:]; $EmojiNRK = [[\p{Emoji}] - [$RI \u002a\u00230-9©®™〰〽]]; # Data for Extended Pictographic scraped from CLDR common/properties/ExtendedPictographic.txt, r12773 $Extended_Pict = [\U0001F774-\U0001F77F\u2700-\u2701\u2703-\u2704\u270E\u2710-\u2711\u2765-\u2767\U0001F030-\U0001F093\U0001F094-\U0001F09F\U0001F10D-\U0001F10F\U0001F12F\U0001F16C-\U0001F16F\U0001F1AD-\U0001F1E5\U0001F203-\U0001F20F\U0001F23C-\U0001F23F\U0001F249-\U0001F24F\U0001F252-\U0001F2FF\U0001F7D5-\U0001F7FF\U0001F000-\U0001F003\U0001F005-\U0001F02B\U0001F02C-\U0001F02F\U0001F322-\U0001F323\U0001F394-\U0001F395\U0001F398\U0001F39C-\U0001F39D\U0001F3F1-\U0001F3F2\U0001F3F6\U0001F4FE\U0001F53E-\U0001F548\U0001F54F\U0001F568-\U0001F56E\U0001F571-\U0001F572\U0001F57B-\U0001F586\U0001F588-\U0001F589\U0001F58E-\U0001F58F\U0001F591-\U0001F594\U0001F597-\U0001F5A3\U0001F5A6-\U0001F5A7\U0001F5A9-\U0001F5B0\U0001F5B3-\U0001F5BB\U0001F5BD-\U0001F5C1\U0001F5C5-\U0001F5D0\U0001F5D4-\U0001F5DB\U0001F5DF-\U0001F5E0\U0001F5E2\U0001F5E4-\U0001F5E7\U0001F5E9-\U0001F5EE\U0001F5F0-\U0001F5F2\U0001F5F4-\U0001F5F9\u2605\u2607-\u260D\u260F-\u2610\u2612\u2616-\u2617\u2619-\u261C\u261E-\u261F\u2621\u2624-\u2625\u2627-\u2629\u262B-\u262D\u2630-\u2637\u263B-\u2647\u2654-\u265F\u2661-\u2662\u2664\u2667\u2669-\u267A\u267C-\u267E\u2680-\u2691\u2695\u2698\u269A\u269D-\u269F\u26A2-\u26A9\u26AC-\u26AF\u26B2-\u26BC\u26BF-\u26C3\u26C6-\u26C7\u26C9-\u26CD\u26D0\u26D2\u26D5-\u26E8\u26EB-\u26EF\u26F6\u26FB-\u26FC\u26FE-\u26FF\u2388\U0001FA00-\U0001FFFD\U0001F0A0-\U0001F0AE\U0001F0B1-\U0001F0BF\U0001F0C1-\U0001F0CF\U0001F0D1-\U0001F0F5\U0001F0AF-\U0001F0B0\U0001F0C0\U0001F0D0\U0001F0F6-\U0001F0FF\U0001F80C-\U0001F80F\U0001F848-\U0001F84F\U0001F85A-\U0001F85F\U0001F888-\U0001F88F\U0001F8AE-\U0001F8FF\U0001F900-\U0001F90F\U0001F91F\U0001F928-\U0001F92F\U0001F931-\U0001F932\U0001F93F\U0001F94C-\U0001F94F\U0001F95F-\U0001F97F\U0001F992-\U0001F9BF\U0001F9C1-\U0001F9FF\U0001F6C6-\U0001F6CA\U0001F6E6-\U0001F6E8\U0001F6EA\U0001F6F1-\U0001F6F2\U0001F6D3-\U0001F6DF\U0001F6ED-\U0001F6EF\U0001F6F7-\U0001F6FF]; # By LB9, a ZWJ also behaves as a CM. Including it in the definition of CM avoids having to explicitly # list it in the numerous rules that use CM. # By LB1, SA characters with general categor of Mn or Mc also resolve to CM. $CM = [[:LineBreak = Combining_Mark:] $ZWJ [$SA & [[:Mn:][:Mc:]]]]; # Dictionary character set, for triggering language-based break engines. Currently # limited to LineBreak=Complex_Context (SA). $dictionary = [$SA]; # # Rule LB1. By default, treat AI (characters with ambiguous east Asian width), # SA (Dictionary chars, excluding Mn and Mc) # SG (Unpaired Surrogates) # XX (Unknown, unassigned) # as $AL (Alphabetic) # $ALPlus = [$AL $AI $SG $XX [$SA-[[:Mn:][:Mc:]]]]; ## ------------------------------------------------- !!forward; # # CAN_CM is the set of characters that may combine with CM combining chars. # Note that Linebreak UAX 14's concept of a combining char and the rules # for what they can combine with are _very_ different from the rest of Unicode. # # Note that $CM itself is left out of this set. If CM is needed as a base # it must be listed separately in the rule. # $CAN_CM = [^$SP $BK $CR $LF $NL $ZW $CM]; # Bases that can take CMs $CANT_CM = [ $SP $BK $CR $LF $NL $ZW $CM]; # Bases that can't take CMs # # AL_FOLLOW set of chars that can unconditionally follow an AL # Needed in rules where stand-alone $CM s are treated as AL. # $AL_FOLLOW = [$BK $CR $LF $NL $ZW $SP $CL $CP $EX $HL $IS $SY $WJ $GL $OP $QU $BA $HY $NS $IN $NU $PR $PO $ALPlus]; # # Rule LB 4, 5 Mandatory (Hard) breaks. # $LB4Breaks = [$BK $CR $LF $NL]; $LB4NonBreaks = [^$BK $CR $LF $NL $CM]; $CR $LF {100}; # # LB 6 Do not break before hard line breaks. # $LB4NonBreaks? $LB4Breaks {100}; # LB 5 do not break before hard breaks. $CAN_CM $CM* $LB4Breaks {100}; ^$CM+ $LB4Breaks {100}; # LB 7 x SP # x ZW $LB4NonBreaks [$SP $ZW]; $CAN_CM $CM* [$SP $ZW]; ^$CM+ [$SP $ZW]; # # LB 8 Break after zero width space # TODO: ZW SP* # An engine change is required to write the reverse rule for this. # For now, leave the Unicode 5.2 rule, ZW # $LB8Breaks = [$LB4Breaks $ZW]; $LB8NonBreaks = [[$LB4NonBreaks] - [$ZW]]; # LB 8a ZWJ x (ID | Extended_Pict | EmojiNRK) Emoji ZWJ sequences. # $ZWJ ($ID | $Extended_Pict | $EmojiNRK); # LB 9 Combining marks. X $CM needs to behave like X, where X is not $SP, $BK $CR $LF $NL # $CM not covered by the above needs to behave like $AL # See definition of $CAN_CM. $CAN_CM $CM+; # Stick together any combining sequences that don't match other rules. ^$CM+; # # LB 11 Do not break before or after WORD JOINER & related characters. # $CAN_CM $CM* $WJ; $LB8NonBreaks $WJ; ^$CM+ $WJ; $WJ $CM* .; # # LB 12 Do not break after NBSP and related characters. # GL x # $GL $CM* .; # # LB 12a Do not break before NBSP and related characters ... # [^SP BA HY] x GL # [[$LB8NonBreaks] - [$SP $BA $HY]] $CM* $GL; ^$CM+ $GL; # # LB 13 Don't break before ']' or '!' or ';' or '/', even after spaces. # $LB8NonBreaks $CL; $CAN_CM $CM* $CL; ^$CM+ $CL; # by rule 10, stand-alone CM behaves as AL $LB8NonBreaks $CP; $CAN_CM $CM* $CP; ^$CM+ $CP; # by rule 10, stand-alone CM behaves as AL $LB8NonBreaks $EX; $CAN_CM $CM* $EX; ^$CM+ $EX; # by rule 10, stand-alone CM behaves as AL $LB8NonBreaks $IS; $CAN_CM $CM* $IS; ^$CM+ $IS; # by rule 10, stand-alone CM behaves as AL $LB8NonBreaks $SY; $CAN_CM $CM* $SY; ^$CM+ $SY; # by rule 10, stand-alone CM behaves as AL # # LB 14 Do not break after OP, even after spaces # $OP $CM* $SP* .; $OP $CM* $SP+ $CM+ $AL_FOLLOW?; # by rule 10, stand-alone CM behaves as AL # by rule 8, CM following a SP is stand-alone. # LB 15 $QU $CM* $SP* $OP; # LB 16 # Do not break between closing punctuation and $NS, even with intervening spaces # But DO allow a break between closing punctuation and $NSX, don't include it here ($CL | $CP) $CM* $SP* $NS; # LB 17 $B2 $CM* $SP* $B2; # # LB 18 Break after spaces. # $LB18NonBreaks = [$LB8NonBreaks - [$SP]]; $LB18Breaks = [$LB8Breaks $SP]; # LB 19 # x QU $LB18NonBreaks $CM* $QU; ^$CM+ $QU; # QU x $QU $CM* .; # LB 20 # $CB # $CB $LB20NonBreaks = [$LB18NonBreaks - $CB]; # LB 21 x (BA | HY | NS) # BB x # # DO allow breaks here before NSX, so don't include it $LB20NonBreaks $CM* ($BA | $HY | $NS); ^$CM+ ($BA | $HY | $NS); $BB $CM* [^$CB]; # $BB x $BB $CM* $LB20NonBreaks; # LB 21a Don't break after Hebrew + Hyphen # HL (HY | BA) x # $HL $CM* ($HY | $BA) $CM* [^$CB]?; # LB 21b (forward) Don't break between SY and HL # (break between HL and SY already disallowed by LB 13 above) $SY $CM* $HL; # LB 22 ($ALPlus | $HL) $CM* $IN; ^$CM+ $IN; # by rule 10, any otherwise unattached CM behaves as AL $EX $CM* $IN; ($ID | $EB | $EM) $CM* $IN; # $IN $CM* $IN; # delete this rule for CSS loose $NU $CM* $IN; # $LB 23 # ($ALPlus | $HL) $CM* $NU; ^$CM+ $NU; # Rule 10, any otherwise unattached CM behaves as AL $NU $CM* ($ALPlus | $HL); # LB 23a # $PR $CM* ($ID | $EB | $EM); ($ID | $EB | $EM) $CM* $PO; # # LB 24 # ($PR | $PO) $CM* ($ALPlus | $HL); ($ALPlus | $HL) $CM* ($PR | $PO); ^$CM+ ($PR | $PO); # Rule 10, any otherwise unattached CM behaves as AL # # LB 25 Numbers. # (($PR | $PO) $CM*)? (($OP | $HY) $CM*)? $NU ($CM* ($NU | $SY | $IS))* ($CM* ($CL | $CP))? ($CM* ($PR | $PO))?; # LB 26 Do not break a Korean syllable # $JL $CM* ($JL | $JV | $H2 | $H3); ($JV | $H2) $CM* ($JV | $JT); ($JT | $H3) $CM* $JT; # LB 27 Treat korean Syllable Block the same as ID (don't break it) ($JL | $JV | $JT | $H2 | $H3) $CM* $IN; ($JL | $JV | $JT | $H2 | $H3) $CM* $PO; $PR $CM* ($JL | $JV | $JT | $H2 | $H3); # LB 28 Do not break between alphabetics # ($ALPlus | $HL) $CM* ($ALPlus | $HL); ^$CM+ ($ALPlus | $HL); # The $CM+ is from rule 10, an unattached CM is treated as AL # LB 29 $IS $CM* ($ALPlus | $HL); # LB 30 ($ALPlus | $HL | $NU) $CM* $OP; ^$CM+ $OP; # The $CM+ is from rule 10, an unattached CM is treated as AL. $CP $CM* ($ALPlus | $HL | $NU); # LB 30a Do not break between regional indicators. Break after pairs of them. # Tricky interaction with LB8a: ZWJ x ID $RI $CM* $RI / [[^$BK $CR $LF $NL $SP $ZW $WJ $CL $CP $EX $IS $SY $GL $QU $BA $HY $NS $CM] {eof}]; $RI $CM* $RI $CM* $ZWJ / [[^$BK $CR $LF $NL $SP $ZW $WJ $CL $CP $EX $IS $SY $GL $QU $BA $HY $NS $CM $ID $Extended_Pict $EmojiNRK] {eof}]; $RI $CM* $RI $CM* [$CM-$ZWJ] / [[^$BK $CR $LF $NL $SP $ZW $WJ $CL $CP $EX $IS $SY $GL $QU $BA $HY $NS $CM] {eof}]; $RI $CM* $RI $CM* [$BK $CR $LF $NL $SP $ZW $WJ $CL $CP $EX $IS $SY $GL $QU $BA $HY $NS {eof}]; $RI $CM* $RI $CM* $ZWJ ($ID | $Extended_Pict | $EmojiNRK); # LB 30b Do not break between an Emoji Base and an Emoji Modifier $EB $CM* $EM; # # Reverse Rules. # ## ------------------------------------------------- !!reverse; # LB 9 Combining Marks. # Stick together any combining sequences that don't match other rules. ^$CM+ $CAN_CM?; # # Sequences of the form (shown forwards) # [CANT_CM] [CM] [whatever] # The CM needs to behave as an AL # $AL_FOLLOW $CM+ / ( [$BK $CR $LF $NL $ZW {eof}] | $SP+ $CM+ $SP | $SP+ $CM* ([^$OP $CM $SP] | [$AL {eof}])); # if LB 14 will match, need to surpress this break. # LB14 says OP SP* x . # becomes OP SP* x AL # becomes OP SP* x CM+ AL_FOLLOW # # Further note: the $AL in [$AL {eof}] is only to work around # a rule compiler bug which complains about # empty sets otherwise. # LB 4, 5, 6 $LB4Breaks [$LB4NonBreaks-$CM]; $LB4Breaks $CM+ $CAN_CM; $LF $CR; # LB 7 x SP # x ZW [$SP $ZW] [$LB4NonBreaks-$CM]; [$SP $ZW] $CM+ $CAN_CM; # LB 8 ZW SP* # TODO: to implement this, we need more than one look-ahead hard break in play at a time. # Requires an engine enhancement. # / $SP* $ZW # LB 8a ZWJ x (ID | Extended_Pict | EmojiNRK) # ($ID | $Extended_Pict | $EmojiNRK) $ZWJ $CM* $CAN_CM?; # LB 9,10 Combining marks. # X $CM needs to behave like X, where X is not $SP or controls. # $CM not covered by the above needs to behave like $AL # Stick together any combining sequences that don't match other rules. ^$CM+ $CAN_CM; # LB 11 # $WJ $CM* $CAN_CM; $WJ [$LB8NonBreaks-$CM]; $CANT_CM $CM* $WJ; $CAN_CM $CM* $WJ; # LB 12a # [^SP BA HY] x GL # $GL $CM* [$LB8NonBreaks-[$CM $SP $BA $HY]]; # LB 12 # GL x # $CANT_CM $CM* $GL; $CAN_CM $CM* $GL; # LB 13 $CL $CM+ $CAN_CM; $CP $CM+ $CAN_CM; $EX $CM+ $CAN_CM; $IS $CM+ $CAN_CM; $SY $CM+ $CAN_CM; $CL [$LB8NonBreaks-$CM]; $CP [$LB8NonBreaks-$CM]; $EX [$LB8NonBreaks-$CM]; $IS [$LB8NonBreaks-$CM]; $SY [$LB8NonBreaks-$CM]; # LB 14 OP SP* x # . $SP* $CM* $OP; $AL_FOLLOW? $CM+ $SP+ $CM* $OP; # by LB 10, behaves like $AL_FOLLOW? $AL $SP+ $CM* $OP # LB 15 $OP $SP* $CM* $QU; # LB 16 # Don't include $NSX here $NS $SP* $CM* ($CL | $CP); # LB 17 $B2 $SP* $CM* $B2; # LB 18 break after spaces # Nothing explicit needed here. # # LB 19 # $QU $CM* $CAN_CM; # . x QU $QU $LB18NonBreaks; $CAN_CM $CM* $QU; # QU x . $CANT_CM $CM* $QU; # # LB 20 Break before and after CB. # nothing needed here. # # LB 21 # Don't include $NSX here ($BA | $HY | $NS) $CM* [$LB20NonBreaks-$CM]; # . x (BA | HY | NS) [$LB20NonBreaks-$CM] $CM* $BB; # BB x . [^$CB] $CM* $BB; # # LB21a [^$CB] $CM* ($HY | $BA) $CM* $HL; # LB21b (reverse) $HL $CM* $SY; # LB 22 $IN $CM* ($ALPlus | $HL); $IN $CM* $EX; $IN $CM* ($ID | $EB | $EM); # $IN $CM* $IN; # delete this rule for CSS loose $IN $CM* $NU; # LB 23 $NU $CM* ($ALPlus | $HL); ($ALPlus | $HL) $CM* $NU; # LB23a ($ID | $EB | $EM) $CM* $PR; $PO $CM* ($ID | $EB | $EM); # LB 24 ($ALPlus | $HL) $CM* ($PR | $PO); ($PR | $PO) $CM* ($ALPlus | $HL); # LB 25 ($CM* ($PR | $PO))? ($CM* ($CL | $CP))? ($CM* ($NU | $IS | $SY))* $CM* $NU ($CM* ($OP | $HY))? ($CM* ($PR | $PO))?; # LB 26 ($H3 | $H2 | $JV | $JL) $CM* $JL; ($JT | $JV) $CM* ($H2 | $JV); $JT $CM* ($H3 | $JT); # LB 27 $IN $CM* ($H3 | $H2 | $JT | $JV | $JL); $PO $CM* ($H3 | $H2 | $JT | $JV | $JL); ($H3 | $H2 | $JT | $JV | $JL) $CM* $PR; # LB 28 ($ALPlus | $HL) $CM* ($ALPlus | $HL); # LB 29 ($ALPlus | $HL) $CM* $IS; # LB 30 $OP $CM* ($ALPlus | $HL | $NU); ($ALPlus | $HL | $NU) $CM* $CP; # LB 30a # Pairs of Regional Indicators. # The following two rules are nearly identical. The first matches only sequences with an odd number of adjacent RIs, # the second with an even number. Stripping away the cruft they look like # [^RI] RI / (RI RI)+ ^RI; # [^RI] RI RI / (RI RI)+ ^RI; # # Line Loose tailoring: Don't include NSX here. [{bof} $NS $HY $BA $QU $CL $CP $EX $IS $SY $WJ $GL $ZW $SP $BK $CR $LF $NL $ZWJ] $CM* $RI / ($CM* $RI $CM* $RI)+ $CM* [{eof}[^$RI $CM]]; [{bof} $NS $HY $BA $QU $CL $CP $EX $IS $SY $WJ $GL $ZW $SP $BK $CR $LF $NL $ZWJ] $CM* $RI $CM* $RI / ($CM* $RI $CM* $RI)+ $CM* [{eof}[^$RI $CM]]; # In general, adjacent RIs stay together. The hard-break rules, above, overide this, forcing in the boundaries between pairs. $RI $CM* $RI; # WJ, GL, QU, etc. are classes with rules like "WJ x " which includes "WJ x RI". $RI $CM* ([$WJ $GL $QU $BB] | (($HY | $BA)$CM* $HL)); # LB 30b Do not break between an Emoji Base and an Emoji Modifier $EM $CM* $EB; ## ------------------------------------------------- !!safe_reverse; # LB 9 ^$CM+ [^$CM $BK $CR $LF $NL $ZW $SP]; ^$CM+ $SP / .; # LB 14 $SP+ $CM* $OP; # LB 15 $SP+ $CM* $QU; # LB 16 $SP+ $CM* ($CL | $CP); # LB 17 $SP+ $CM* $B2; # LB 21 $CM* ($HY | $BA) $CM* $HL; # LB 25 ($CM* ($IS | $SY))+ $CM* $NU; ($CL | $CP) $CM* ($NU | $IS | $SY); # LB 30 ($CM* $RI)+; # For dictionary-based break $dictionary $dictionary; ## ------------------------------------------------- !!safe_forward; # Skip forward over all character classes that are involved in # rules containing patterns with possibly more than one char # of context. # # It might be slightly more efficient to have specific rules # instead of one generic one, but only if we could # turn off rule chaining. We don't want to move more # than necessary. # ^[$CM $OP $QU $CL $CP $B2 $PR $HY $BA $SP $RI $ZWJ $dictionary]+ [^$CM $OP $QU $CL $CP $B2 $PR $HY $BA $RI $ZWJ $dictionary]; $dictionary $dictionary;