# Copyright (c) 2002-2015 International Business Machines Corporation and # others. All Rights Reserved. # # file: line_normal_cj.txt # # Line Breaking Rules # Implement default line breaking as defined by # Unicode Standard Annex #14 Revision 29 for Unicode 6.2 # http://www.unicode.org/reports/tr14/ # 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=normal (BCP47 -u-lb-normal) as defined for Chinese & Japanese. # It sets characters of class CJ to behave like ID. # In addition, it allows breaks: # * before hyphens 2010 & 2013 (both BA) and 301C, 30A0 (both NS) # # Character Classes defined by TR 14. # !!chain; !!LBCMNoChain; !!lookAheadHardBreak; # # !!lookAheadHardBreak Described here because it is (as yet) undocumented elsewhere # and only used for the line break rules. # # It is used in the implementation of rule LB 10 # which says to treat any combining mark that is not attached to a base # character as if it were of class AL (alphabetic). # # The problem occurs in the reverse rules. # # Consider a sequence like, with correct breaks as shown # LF ID CM AL AL # ^ ^ ^ # Then consider the sequence without the initial ID (ideographic) # LF CM AL AL # ^ ^ # Our CM, which in the first example was attached to the ideograph, # is now unattached, becomes an alpha, and joins in with the other # alphas. # # When iterating forwards, these sequences do not present any problems # When iterating backwards, we need to look ahead when encountering # a CM to see whether it attaches to something further on or not. # (Look-ahead in a reverse rule is looking towards the start) # # If the CM is unattached, we need to force a break. # # !!lookAheadHardBreak forces the run time state machine to # stop immediately when a look ahead rule ( '/' operator) matches, # and set the match position to that of the look-ahead operator, # no matter what other rules may be in play at the time. # # See rule LB 19 for an example. # $AI = [:LineBreak = Ambiguous:]; $AL = [:LineBreak = Alphabetic:]; $BAX = [\u2010 \u2013]; $BA = [[:LineBreak = Break_After:] - $BAX]; $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:]; $EX = [:LineBreak = Exclamation:]; $GL = [:LineBreak = Glue:]; $HL = [:LineBreak = Hebrew_Letter:]; $HY = [:LineBreak = Hyphen:]; $H2 = [:LineBreak = H2:]; $H3 = [:LineBreak = H3:]; $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 = [\u301C \u30A0]; $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:]; # Dictionary character set, for triggering language-based break engines. Currently # limited to LineBreak=Complex_Context. Note that this set only works in Unicode # 5.0 or later as the definition of Complex_Context was corrected to include all # characters requiring dictionary break. $dictionary = [:LineBreak = Complex_Context:]; # # Rule LB1. By default, treat AI (characters with ambiguous east Asian width), # SA (South East Asian: Thai, Lao, Khmer) # SG (Unpaired Surrogates) # XX (Unknown, unassigned) # as $AL (Alphabetic) # $ALPlus = [$AL $AI $SA $SG $XX]; # # Combining Marks. X $CM* behaves as if it were X. Rule LB6. # $ALcm = $ALPlus $CM*; $BAcm = $BA $CM*; $BAXcm = $BAX $CM*; $BBcm = $BB $CM*; $B2cm = $B2 $CM*; $CLcm = $CL $CM*; $CPcm = $CP $CM*; $EXcm = $EX $CM*; $GLcm = $GL $CM*; $HLcm = $HL $CM*; $HYcm = $HY $CM*; $H2cm = $H2 $CM*; $H3cm = $H3 $CM*; $IDcm = $ID $CM*; $INcm = $IN $CM*; $IScm = $IS $CM*; $JLcm = $JL $CM*; $JVcm = $JV $CM*; $JTcm = $JT $CM*; $NScm = $NS $CM*; $NSXcm = $NSX $CM*; $NUcm = $NU $CM*; $OPcm = $OP $CM*; $POcm = $PO $CM*; $PRcm = $PR $CM*; $QUcm = $QU $CM*; $RIcm = $RI $CM*; $SYcm = $SY $CM*; $WJcm = $WJ $CM*; ## ------------------------------------------------- !!forward; # # Each class of character can stand by itself as an unbroken token, with trailing combining stuff # $ALPlus $CM+; $BA $CM+; $BAX $CM+; $BB $CM+; $B2 $CM+; $CL $CM+; $CP $CM+; $EX $CM+; $GL $CM+; $HL $CM+; $HY $CM+; $H2 $CM+; $H3 $CM+; $ID $CM+; $IN $CM+; $IS $CM+; $JL $CM+; $JV $CM+; $JT $CM+; $NS $CM+; $NSX $CM+; $NU $CM+; $OP $CM+; $PO $CM+; $PR $CM+; $QU $CM+; $RI $CM+; $SY $CM+; $WJ $CM+; # # 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. # Chaining is disabled with CM because it causes other failures, # so for this one case we need to manually list out longer sequences. # $AL_FOLLOW_NOCM = [$BK $CR $LF $NL $ZW $SP]; $AL_FOLLOW_CM = [$CL $CP $EX $HL $IS $SY $WJ $GL $OP $QU $BA $BAX $HY $NS $NSX $IN $NU $ALPlus]; $AL_FOLLOW = [$AL_FOLLOW_NOCM $AL_FOLLOW_CM]; # # Rule LB 4, 5 Mandatory (Hard) breaks. # $LB4Breaks = [$BK $CR $LF $NL]; $LB4NonBreaks = [^$BK $CR $LF $NL]; $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* <break> # An engine change is required to write the reverse rule for this. # For now, leave the Unicode 5.2 rule, ZW <break> # $LB8Breaks = [$LB4Breaks $ZW]; $LB8NonBreaks = [[$LB4NonBreaks] - [$ZW]]; # 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* $WJcm; $LB8NonBreaks $WJcm; $CM+ $WJcm; $WJcm $CANT_CM; $WJcm $CAN_CM $CM*; # # LB 12 Do not break after NBSP and related characters. # GL x # $GLcm $CAN_CM $CM*; $GLcm $CANT_CM; # # LB 12a Do not break before NBSP and related characters ... # [^SP BA HY] x GL # [[$LB8NonBreaks] - [$SP $BA $BAX $HY]] $CM* $GLcm; $CM+ GLcm; # # 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 # $OPcm $SP* $CAN_CM $CM*; $OPcm $SP* $CANT_CM; $OPcm $SP+ $CM+ $AL_FOLLOW?; # by rule 10, stand-alone CM behaves as AL # LB 15 $QUcm $SP* $OPcm; # LB 16 # Do not break between closing punctuation and $NS, even with intervening spaces # But DO allow a break between closing punctuation and $NSX, don't include it here ($CLcm | $CPcm) $SP* $NScm; # LB 17 $B2cm $SP* $B2cm; # # LB 18 Break after spaces. # $LB18NonBreaks = [$LB8NonBreaks - [$SP]]; $LB18Breaks = [$LB8Breaks $SP]; # LB 19 # x QU $LB18NonBreaks $CM* $QUcm; $CM+ $QUcm; # QU x $QUcm .?; $QUcm $LB18NonBreaks $CM*; # Don't let a combining mark go onto $CR, $BK, etc. # TODO: I don't think this rule is needed. # LB 20 # <break> $CB # $CB <break> $LB20NonBreaks = [$LB18NonBreaks - $CB]; # LB 21 x (BA | HY | NS) # BB x # # DO allow breaks here before $BAXcm and $NSXcm, so don't include them $LB20NonBreaks $CM* ($BAcm | $HYcm | $NScm); $BBcm [^$CB]; # $BB x $BBcm $LB20NonBreaks $CM*; # LB 21a Don't break after Hebrew + Hyphen # HL (HY | BA) x # $HLcm ($HYcm | $BAcm | $BAXcm) [^$CB]?; # LB 21b (forward) Don't break between SY and HL # (break between HL and SY already disallowed by LB 13 above) $SYcm $HLcm; # LB 22 ($ALcm | $HLcm) $INcm; $CM+ $INcm; # by rule 10, any otherwise unattached CM behaves as AL $IDcm $INcm; $INcm $INcm; $NUcm $INcm; # $LB 23 $IDcm $POcm; $ALcm $NUcm; # includes $LB19 $HLcm $NUcm; $CM+ $NUcm; # Rule 10, any otherwise unattached CM behaves as AL $NUcm $ALcm; $NUcm $HLcm; # # LB 24 # $PRcm $IDcm; $PRcm ($ALcm | $HLcm); $POcm ($ALcm | $HLcm); # # LB 25 Numbers. # ($PRcm | $POcm)? ($OPcm | $HYcm)? $NUcm ($NUcm | $SYcm | $IScm)* ($CLcm | $CPcm)? ($PRcm | $POcm)?; # LB 26 Do not break a Korean syllable # $JLcm ($JLcm | $JVcm | $H2cm | $H3cm); ($JVcm | $H2cm) ($JVcm | $JTcm); ($JTcm | $H3cm) $JTcm; # LB 27 Treat korean Syllable Block the same as ID (don't break it) ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm) $INcm; ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm) $POcm; $PRcm ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm); # LB 28 Do not break between alphabetics # ($ALcm | $HLcm) ($ALcm | $HLcm); $CM+ ($ALcm | $HLcm); # The $CM+ is from rule 10, an unattached CM is treated as AL # LB 29 $IScm ($ALcm | $HLcm); # LB 30 ($ALcm | $HLcm | $NUcm) $OPcm; $CM+ $OPcm; # The $CM+ is from rule 10, an unattached CM is treated as AL. $CPcm ($ALcm | $HLcm | $NUcm); # LB 30a Do not break between regional indicators. $RIcm $RIcm; # # Reverse Rules. # ## ------------------------------------------------- !!reverse; $CM+ $ALPlus; $CM+ $BA; $CM+ $BAX; $CM+ $BB; $CM+ $B2; $CM+ $CL; $CM+ $CP; $CM+ $EX; $CM+ $GL; $CM+ $HL; $CM+ $HY; $CM+ $H2; $CM+ $H3; $CM+ $ID; $CM+ $IN; $CM+ $IS; $CM+ $JL; $CM+ $JV; $CM+ $JT; $CM+ $NS; $CM+ $NSX; $CM+ $NU; $CM+ $OP; $CM+ $PO; $CM+ $PR; $CM+ $QU; $CM+ $RI; $CM+ $SY; $CM+ $WJ; $CM+; # # Sequences of the form (shown forwards) # [CANT_CM] <break> [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. # # Sequences of the form (shown forwards) # [CANT_CM] <break> [CM] <break> [PR] # The CM needs to behave as an AL # This rule is concerned about getting the second of the two <breaks> in place. # [$PR ] / $CM+ [$BK $CR $LF $NL $ZW $SP {eof}]; # LB 4, 5, 5 $LB4Breaks [$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* <break> # 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 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 $CM* $WJ $CM* $CAN_CM; $CM* $WJ [$LB8NonBreaks-$CM]; $CANT_CM $CM* $WJ; $CM* $CAN_CM $CM* $WJ; # LB 12a # [^SP BA HY] x GL # $CM* $GL $CM* [$LB8NonBreaks-[$CM $SP $BA $BAX $HY]]; # LB 12 # GL x # $CANT_CM $CM* $GL; $CM* $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-$CM]; # Rule 13 & 14 taken together for an edge case. # Match this, shown forward # OP SP+ ($CM+ behaving as $AL) (CL | CP | EX | IS | IY) # This really wants to chain at the $CM+ (which is acting as an $AL) # except for $CM chaining being disabled. [$CL $CP $EX $IS $SY] $CM+ $SP+ $CM* $OP; # LB 14 OP SP* x # $CM* $CAN_CM $SP* $CM* $OP; $CANT_CM $SP* $CM* $OP; $AL_FOLLOW? $CM+ $SP $SP* $CM* $OP; # by LB 10, behaves like $AL_FOLLOW? $AL $SP* $CM* $OP $AL_FOLLOW_NOCM $CM+ $SP+ $CM* $OP; $CM* $AL_FOLLOW_CM $CM+ $SP+ $CM* $OP; $SY $CM $SP+ $OP; # TODO: Experiment. Remove. # LB 15 $CM* $OP $SP* $CM* $QU; # LB 16 # Don't include $NSX here $CM* $NS $SP* $CM* ($CL | $CP); # LB 17 $CM* $B2 $SP* $CM* $B2; # LB 18 break after spaces # Nothing explicit needed here. # # LB 19 # $CM* $QU $CM* $CAN_CM; # . x QU $CM* $QU $LB18NonBreaks; $CM* $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 $BAX or $NSX here $CM* ($BA | $HY | $NS) $CM* [$LB20NonBreaks-$CM]; # . x (BA | HY | NS) $CM* [$LB20NonBreaks-$CM] $CM* $BB; # BB x . [^$CB] $CM* $BB; # # LB21a [^$CB] $CM* ($HY | $BA | $BAX) $CM* $HL; # LB21b (reverse) $CM* $HL $CM* $SY; # LB 22 $CM* $IN $CM* ($ALPlus | $HL); $CM* $IN $CM* $ID; $CM* $IN $CM* $IN; $CM* $IN $CM* $NU; # LB 23 $CM* $PO $CM* $ID; $CM* $NU $CM* ($ALPlus | $HL); $CM* ($ALPlus | $HL) $CM* $NU; # LB 24 $CM* $ID $CM* $PR; $CM* ($ALPlus | $HL) $CM* $PR; $CM* ($ALPlus | $HL) $CM* $PO; # LB 25 ($CM* ($PR | $PO))? ($CM* ($CL | $CP))? ($CM* ($NU | $IS | $SY))* $CM* $NU ($CM* ($OP | $HY))? ($CM* ($PR | $PO))?; # LB 26 $CM* ($H3 | $H2 | $JV | $JL) $CM* $JL; $CM* ($JT | $JV) $CM* ($H2 | $JV); $CM* $JT $CM* ($H3 | $JT); # LB 27 $CM* $IN $CM* ($H3 | $H2 | $JT | $JV | $JL); $CM* $PO $CM* ($H3 | $H2 | $JT | $JV | $JL); $CM* ($H3 | $H2 | $JT | $JV | $JL) $CM* $PR; # LB 28 $CM* ($ALPlus | $HL) $CM* ($ALPlus | $HL); # LB 29 $CM* ($ALPlus | $HL) $CM* $IS; # LB 30 $CM* $OP $CM* ($ALPlus | $HL | $NU); $CM* ($ALPlus | $HL | $NU) $CM* $CP; # LB 30a $CM* $RI $CM* $RI; ## ------------------------------------------------- !!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); # 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 $dictionary]+ [^$CM $OP $QU $CL $CP $B2 $PR $HY $BA $dictionary]; $dictionary $dictionary;