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      1 # Copyright (c) 2002-2013  International Business Machines Corporation and
      2 # others. All Rights Reserved.
      3 #
      4 #  file:  line_fi.txt
      5 #
      6 #         Line Breaking Rules
      7 #         Implement default line breaking as defined by 
      8 #         Unicode Standard Annex #14 Revision 29 for Unicode 6.2
      9 #         http://www.unicode.org/reports/tr14/
     10 #
     11 #         TODO:  Rule LB 8 remains as it was in Unicode 5.2
     12 #         This is only because of a limitation of ICU break engine implementation,
     13 #         not because the older behavior is desirable.
     14 
     15 #
     16 #  Character Classes defined by TR 14.
     17 #
     18 
     19 !!chain;
     20 !!LBCMNoChain;
     21 
     22 
     23 !!lookAheadHardBreak;
     24 #
     25 #  !!lookAheadHardBreak    Described here because it is (as yet) undocumented elsewhere
     26 #                          and only used for the line break rules.
     27 #
     28 #           It is used in the implementation of rule LB 10
     29 #           which says to treat any combining mark that is not attached to a base
     30 #           character as if it were of class AL  (alphabetic).
     31 #
     32 #           The problem occurs in the reverse rules.
     33 #
     34 #           Consider a sequence like, with correct breaks as shown
     35 #               LF  ID  CM  AL  AL
     36 #                  ^       ^       ^
     37 #           Then consider the sequence without the initial ID (ideographic)
     38 #                 LF  CM  AL  AL
     39 #                    ^           ^
     40 #           Our CM, which in the first example was attached to the ideograph,
     41 #           is now unattached, becomes an alpha, and joins in with the other
     42 #           alphas.
     43 #
     44 #           When iterating forwards, these sequences do not present any problems
     45 #           When iterating backwards, we need to look ahead when encountering
     46 #           a CM to see whether it attaches to something further on or not.
     47 #           (Look-ahead in a reverse rule is looking towards the start)
     48 #
     49 #           If the CM is unattached, we need to force a break.
     50 #
     51 #           !!lookAheadHardBreak forces the run time state machine to
     52 #           stop immediately when a look ahead rule ( '/' operator) matches,
     53 #           and set the match position to that of the look-ahead operator,
     54 #           no matter what other rules may be in play at the time.
     55 #
     56 #           See rule LB 19 for an example.
     57 #
     58 
     59 $AI = [:LineBreak =  Ambiguous:];
     60 $AL = [:LineBreak =  Alphabetic:];
     61 $BA = [[:LineBreak =  Break_After:] - [\u2010]];
     62 $HH = [\u2010];
     63 $BB = [:LineBreak =  Break_Before:];
     64 $BK = [:LineBreak =  Mandatory_Break:];
     65 $B2 = [:LineBreak =  Break_Both:];
     66 $CB = [:LineBreak =  Contingent_Break:];
     67 $CJ = [:LineBreak =  Conditional_Japanese_Starter:];
     68 $CL = [:LineBreak =  Close_Punctuation:];
     69 $CM = [:LineBreak =  Combining_Mark:];
     70 $CP = [:LineBreak =  Close_Parenthesis:];
     71 $CR = [:LineBreak =  Carriage_Return:];
     72 $EX = [:LineBreak =  Exclamation:];
     73 $GL = [:LineBreak =  Glue:];
     74 $HL = [:LineBreak =  Hebrew_Letter:];
     75 $HY = [:LineBreak =  Hyphen:];
     76 $H2 = [:LineBreak =  H2:];
     77 $H3 = [:LineBreak =  H3:];
     78 $ID = [:LineBreak =  Ideographic:];
     79 $IN = [:LineBreak =  Inseperable:];
     80 $IS = [:LineBreak =  Infix_Numeric:];
     81 $JL = [:LineBreak =  JL:];
     82 $JV = [:LineBreak =  JV:];
     83 $JT = [:LineBreak =  JT:];
     84 $LF = [:LineBreak =  Line_Feed:];
     85 $NL = [:LineBreak =  Next_Line:];
     86 $NS = [[:LineBreak =  Nonstarter:] $CJ];
     87 $NU = [:LineBreak =  Numeric:];
     88 $OP = [:LineBreak =  Open_Punctuation:];
     89 $PO = [:LineBreak =  Postfix_Numeric:];
     90 $PR = [:LineBreak =  Prefix_Numeric:];
     91 $QU = [:LineBreak =  Quotation:];
     92 $RI = [:LineBreak =  Regional_Indicator:];
     93 $SA = [:LineBreak =  Complex_Context:];
     94 $SG = [:LineBreak =  Surrogate:];
     95 $SP = [:LineBreak =  Space:];
     96 $SY = [:LineBreak =  Break_Symbols:];
     97 $WJ = [:LineBreak =  Word_Joiner:];
     98 $XX = [:LineBreak =  Unknown:];
     99 $ZW = [:LineBreak =  ZWSpace:];
    100 
    101 #   Dictionary character set, for triggering language-based break engines. Currently
    102 #   limited to LineBreak=Complex_Context. Note that this set only works in Unicode
    103 #   5.0 or later as the definition of Complex_Context was corrected to include all
    104 #   characters requiring dictionary break.
    105 
    106 $dictionary = [:LineBreak = Complex_Context:];
    107 
    108 #
    109 #  Rule LB1.  By default, treat AI  (characters with ambiguous east Asian width),
    110 #                               SA  (South East Asian: Thai, Lao, Khmer)
    111 #                               SG  (Unpaired Surrogates)
    112 #                               XX  (Unknown, unassigned)
    113 #                         as $AL  (Alphabetic)
    114 #
    115 $ALPlus = [$AL $AI $SA $SG $XX];
    116 
    117 #
    118 #  Combining Marks.   X $CM*  behaves as if it were X.  Rule LB6.
    119 #
    120 $ALcm = $ALPlus $CM*;
    121 $BAcm = $BA $CM*;
    122 $HHcm = $HH $CM*;
    123 $BBcm = $BB $CM*;
    124 $B2cm = $B2 $CM*;
    125 $CLcm = $CL $CM*;
    126 $CPcm = $CP $CM*;
    127 $EXcm = $EX $CM*;
    128 $GLcm = $GL $CM*;
    129 $HLcm = $HL $CM*;
    130 $HYcm = $HY $CM*;
    131 $H2cm = $H2 $CM*;
    132 $H3cm = $H3 $CM*;
    133 $IDcm = $ID $CM*;
    134 $INcm = $IN $CM*;
    135 $IScm = $IS $CM*;
    136 $JLcm = $JL $CM*;
    137 $JVcm = $JV $CM*;
    138 $JTcm = $JT $CM*;
    139 $NScm = $NS $CM*;
    140 $NUcm = $NU $CM*;
    141 $OPcm = $OP $CM*;
    142 $POcm = $PO $CM*;
    143 $PRcm = $PR $CM*;
    144 $QUcm = $QU $CM*;
    145 $RIcm = $RI $CM*;
    146 $SYcm = $SY $CM*;
    147 $WJcm = $WJ $CM*;
    148 
    149 ## -------------------------------------------------
    150 
    151 !!forward;
    152 
    153 #
    154 #  Each class of character can stand by itself as an unbroken token, with trailing combining stuff
    155 #
    156 $ALPlus $CM+;
    157 $BA $CM+;
    158 $HH $CM+;
    159 $BB $CM+;
    160 $B2 $CM+;
    161 $CL $CM+;
    162 $CP $CM+;
    163 $EX $CM+;
    164 $GL $CM+;
    165 $HL $CM+;
    166 $HY $CM+;
    167 $H2 $CM+;
    168 $H3 $CM+;
    169 $ID $CM+;
    170 $IN $CM+;
    171 $IS $CM+;
    172 $JL $CM+;
    173 $JV $CM+;
    174 $JT $CM+;
    175 $NS $CM+;
    176 $NU $CM+;
    177 $OP $CM+;
    178 $PO $CM+;
    179 $PR $CM+;
    180 $QU $CM+;
    181 $RI $CM+;
    182 $SY $CM+;
    183 $WJ $CM+;
    184 
    185 #
    186 # CAN_CM  is the set of characters that may combine with CM combining chars.
    187 #         Note that Linebreak UAX 14's concept of a combining char and the rules
    188 #         for what they can combine with are _very_ different from the rest of Unicode.
    189 #
    190 #         Note that $CM itself is left out of this set.  If CM is needed as a base
    191 #         it must be listed separately in the rule.
    192 #
    193 $CAN_CM  = [^$SP $BK $CR $LF $NL $ZW $CM];       # Bases that can   take CMs
    194 $CANT_CM = [ $SP $BK $CR $LF $NL $ZW $CM];       # Bases that can't take CMs
    195 
    196 #
    197 # AL_FOLLOW  set of chars that can unconditionally follow an AL
    198 #            Needed in rules where stand-alone $CM s are treated as AL.
    199 #            Chaining is disabled with CM because it causes other failures,
    200 #            so for this one case we need to manually list out longer sequences.
    201 #
    202 $AL_FOLLOW_NOCM = [$BK $CR $LF $NL $ZW $SP];
    203 $AL_FOLLOW_CM   = [$CL $CP $EX $HL $IS $SY $WJ $GL $OP $QU $BA $HH $HY $NS $IN $NU $ALPlus];
    204 $AL_FOLLOW      = [$AL_FOLLOW_NOCM $AL_FOLLOW_CM];
    205 
    206 
    207 #
    208 #  Rule LB 4, 5    Mandatory (Hard) breaks.
    209 #
    210 $LB4Breaks    = [$BK $CR $LF $NL];
    211 $LB4NonBreaks = [^$BK $CR $LF $NL];
    212 $CR $LF {100};
    213 
    214 #
    215 #  LB 6    Do not break before hard line breaks.
    216 #
    217 $LB4NonBreaks?  $LB4Breaks {100};    # LB 5  do not break before hard breaks.
    218 $CAN_CM $CM*    $LB4Breaks {100};
    219 $CM+            $LB4Breaks {100};
    220 
    221 # LB 7         x SP
    222 #              x ZW
    223 $LB4NonBreaks [$SP $ZW];
    224 $CAN_CM $CM*  [$SP $ZW];
    225 $CM+          [$SP $ZW];
    226 
    227 #
    228 # LB 8         Break after zero width space
    229 #              TODO:  ZW SP* <break>
    230 #              An engine change is required to write the reverse rule for this.
    231 #              For now, leave the Unicode 5.2 rule, ZW <break>
    232 #
    233 $LB8Breaks    = [$LB4Breaks $ZW];
    234 $LB8NonBreaks = [[$LB4NonBreaks] - [$ZW]];
    235 
    236 
    237 # LB 9     Combining marks.      X   $CM needs to behave like X, where X is not $SP, $BK $CR $LF $NL 
    238 #                                $CM not covered by the above needs to behave like $AL   
    239 #                                See definition of $CAN_CM.
    240 
    241 $CAN_CM $CM+;                   #  Stick together any combining sequences that don't match other rules.
    242 $CM+;
    243 
    244 #
    245 # LB 11  Do not break before or after WORD JOINER & related characters.
    246 #
    247 $CAN_CM $CM*  $WJcm;
    248 $LB8NonBreaks $WJcm;
    249 $CM+          $WJcm;
    250 
    251 $WJcm $CANT_CM;
    252 $WJcm $CAN_CM $CM*;
    253 
    254 #
    255 # LB 12  Do not break after NBSP and related characters.
    256 #         GL  x
    257 #
    258 $GLcm $CAN_CM $CM*;
    259 $GLcm $CANT_CM;
    260  
    261 #
    262 # LB 12a  Do not break before NBSP and related characters ...
    263 #            [^SP BA HY] x GL
    264 #
    265 [[$LB8NonBreaks] - [$SP $BA $HH $HY]] $CM* $GLcm;
    266 $CM+ GLcm;
    267 
    268 
    269 
    270 #
    271 # LB 13   Don't break before ']' or '!' or ';' or '/', even after spaces.
    272 #
    273 $LB8NonBreaks $CL;
    274 $CAN_CM $CM*  $CL;
    275 $CM+          $CL;              # by rule 10, stand-alone CM behaves as AL
    276 
    277 $LB8NonBreaks $CP;
    278 $CAN_CM $CM*  $CP;
    279 $CM+          $CP;              # by rule 10, stand-alone CM behaves as AL
    280 
    281 $LB8NonBreaks $EX;
    282 $CAN_CM $CM*  $EX;
    283 $CM+          $EX;              # by rule 10, stand-alone CM behaves as AL
    284 
    285 $LB8NonBreaks $IS;
    286 $CAN_CM $CM*  $IS;
    287 $CM+          $IS;              # by rule 10, stand-alone CM behaves as AL
    288 
    289 $LB8NonBreaks $SY;
    290 $CAN_CM $CM*  $SY;
    291 $CM+          $SY;              # by rule 10, stand-alone CM behaves as AL
    292 
    293 
    294 #
    295 # LB 14  Do not break after OP, even after spaces
    296 #
    297 $OPcm $SP* $CAN_CM $CM*;
    298 $OPcm $SP* $CANT_CM;
    299 
    300 $OPcm $SP+ $CM+ $AL_FOLLOW?;    # by rule 10, stand-alone CM behaves as AL
    301 
    302 # LB 15
    303 $QUcm $SP* $OPcm;
    304 
    305 # LB 16
    306 ($CLcm | $CPcm) $SP* $NScm;
    307 
    308 # LB 17
    309 $B2cm $SP* $B2cm;
    310 
    311 #
    312 # LB 18  Break after spaces.
    313 #
    314 $LB18NonBreaks = [$LB8NonBreaks - [$SP]];
    315 $LB18Breaks    = [$LB8Breaks $SP];
    316 
    317 
    318 # LB 19
    319 #         x QU
    320 $LB18NonBreaks $CM* $QUcm;
    321 $CM+                $QUcm;
    322 
    323 #         QU  x
    324 $QUcm .?;
    325 $QUcm $LB18NonBreaks $CM*;    # Don't let a combining mark go onto $CR, $BK, etc.
    326                               #  TODO:  I don't think this rule is needed.
    327 
    328 
    329 # LB 20
    330 #        <break>  $CB
    331 #        $CB   <break>
    332 
    333 $LB20NonBreaks = [$LB18NonBreaks - $CB];
    334 
    335 # LB 20.09 added rule for Finnish tailoring
    336 # LB 21        x   (BA | HY | NS)
    337 #           BB x
    338 #
    339 $LB20NonBreaks $CM* ($BAcm | $HHcm | $HYcm | $NScm) / $AL; 
    340 $LB20NonBreaks $CM* ($BAcm | $HHcm | $HYcm | $NScm); 
    341 ($HY | $HH) $AL;
    342 
    343 $BBcm [^$CB];                                  #  $BB  x
    344 $BBcm $LB20NonBreaks $CM*;
    345 
    346 # LB 21a Don't break after Hebrew + Hyphen
    347 #   HL (HY | BA) x
    348 #  
    349 $HLcm ($HYcm | $BAcm | $HHcm) [^$CB]?;
    350 
    351 # LB 21b (forward) Don't break between SY and HL
    352 # (break between HL and SY already disallowed by LB 13 above)
    353 $SYcm $HLcm;
    354 
    355 # LB 22
    356 ($ALcm | $HLcm) $INcm;
    357 $CM+     $INcm;     #  by rule 10, any otherwise unattached CM behaves as AL
    358 $IDcm    $INcm;
    359 $INcm    $INcm;
    360 $NUcm    $INcm;
    361 
    362 
    363 # $LB 23
    364 $IDcm  $POcm;
    365 $ALcm  $NUcm;       # includes $LB19
    366 $HLcm  $NUcm;
    367 $CM+   $NUcm;       # Rule 10, any otherwise unattached CM behaves as AL
    368 $NUcm  $ALcm;
    369 $NUcm  $HLcm;
    370 
    371 #
    372 # LB 24
    373 #
    374 $PRcm $IDcm;
    375 $PRcm ($ALcm | $HLcm);
    376 $POcm ($ALcm | $HLcm);
    377 
    378 #
    379 # LB 25   Numbers.
    380 #
    381 ($PRcm | $POcm)? ($OPcm | $HYcm)? $NUcm ($NUcm | $SYcm | $IScm)* ($CLcm | $CPcm)? ($PRcm | $POcm)?;
    382 
    383 # LB 26  Do not break a Korean syllable
    384 #
    385 $JLcm ($JLcm | $JVcm | $H2cm | $H3cm);
    386 ($JVcm | $H2cm) ($JVcm | $JTcm);
    387 ($JTcm | $H3cm) $JTcm;
    388 
    389 # LB 27  Treat korean Syllable Block the same as ID  (don't break it)
    390 ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm) $INcm;
    391 ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm) $POcm;
    392 $PRcm ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm);
    393 
    394 
    395 # LB 28   Do not break between alphabetics
    396 #
    397 ($ALcm | $HLcm) ($ALcm | $HLcm);
    398 $CM+ ($ALcm | $HLcm);      # The $CM+ is from rule 10, an unattached CM is treated as AL
    399 
    400 # LB 29
    401 $IScm ($ALcm | $HLcm);
    402 
    403 # LB 30
    404 ($ALcm | $HLcm | $NUcm) $OPcm;
    405 $CM+ $OPcm;         # The $CM+ is from rule 10, an unattached CM is treated as AL.          
    406 $CPcm ($ALcm | $HLcm | $NUcm);
    407 
    408 # LB 30a  Do not break between regional indicators.
    409 $RIcm $RIcm;
    410 
    411 #
    412 #  Reverse Rules.
    413 #
    414 ## -------------------------------------------------
    415 
    416 !!reverse;
    417 
    418 $CM+ $ALPlus;
    419 $CM+ $BA;
    420 $CM+ $HH;
    421 $CM+ $BB;
    422 $CM+ $B2;
    423 $CM+ $CL;
    424 $CM+ $CP;
    425 $CM+ $EX;
    426 $CM+ $GL;
    427 $CM+ $HL;
    428 $CM+ $HY;
    429 $CM+ $H2;
    430 $CM+ $H3;
    431 $CM+ $ID;
    432 $CM+ $IN;
    433 $CM+ $IS;
    434 $CM+ $JL;
    435 $CM+ $JV;
    436 $CM+ $JT;
    437 $CM+ $NS;
    438 $CM+ $NU;
    439 $CM+ $OP;
    440 $CM+ $PO;
    441 $CM+ $PR;
    442 $CM+ $QU;
    443 $CM+ $RI;
    444 $CM+ $SY;
    445 $CM+ $WJ;
    446 $CM+;
    447 
    448 
    449 #
    450 #  Sequences of the form  (shown forwards)
    451 #      [CANT_CM]  <break>  [CM]  [whatever]
    452 #  The CM needs to behave as an AL
    453 #
    454 $AL_FOLLOW $CM+ / (
    455           [$BK $CR $LF $NL $ZW {eof}] |
    456           $SP+ $CM+ $SP |
    457           $SP+ $CM* ([^$OP $CM $SP] | [$AL {eof}]));   # if LB 14 will match, need to surpress this break.
    458                                                #  LB14 says    OP SP* x .        
    459                                                #    becomes    OP SP* x AL
    460                                                #    becomes    OP SP* x CM+ AL_FOLLOW
    461                                                #
    462                                                # Further note:  the $AL in [$AL {eof}] is only to work around
    463                                                #                a rule compiler bug which complains about
    464                                                #                empty sets otherwise.
    465           
    466 #
    467 #  Sequences of the form  (shown forwards)
    468 #      [CANT_CM]  <break> [CM]  <break>  [PR]
    469 #  The CM needs to behave as an AL
    470 #  This rule is concerned about getting the second of the two <breaks> in place.
    471 #
    472 
    473 [$PR   ] / $CM+ [$BK $CR $LF $NL $ZW $SP {eof}];
    474 
    475 
    476 
    477 # LB 4, 5, 5
    478 
    479 $LB4Breaks [$LB4NonBreaks-$CM];
    480 $LB4Breaks $CM+ $CAN_CM;
    481 $LF $CR;
    482 
    483 
    484 # LB 7         x SP
    485 #              x ZW
    486 [$SP $ZW] [$LB4NonBreaks-$CM];
    487 [$SP $ZW] $CM+ $CAN_CM;
    488 
    489 # LB 8 ZW SP* <break>
    490 #     TODO: to implement this, we need more than one look-ahead hard break in play at a time.
    491 #           Requires an engine enhancement.
    492 #   / $SP* $ZW
    493 
    494 # LB 9,10  Combining marks.
    495 #    X   $CM needs to behave like X, where X is not $SP or controls.
    496 #    $CM not covered by the above needs to behave like $AL
    497 # Stick together any combining sequences that don't match other rules.
    498 $CM+ $CAN_CM;
    499 
    500 
    501 # LB 11
    502 $CM* $WJ $CM* $CAN_CM;
    503 $CM* $WJ      [$LB8NonBreaks-$CM];
    504 
    505      $CANT_CM $CM* $WJ;
    506 $CM* $CAN_CM  $CM* $WJ;
    507 
    508 # LB 12a
    509 #      [^SP BA HY] x GL
    510 #
    511 $CM* $GL $CM* [$LB8NonBreaks-[$CM $SP $BA $HH $HY]];
    512 
    513 # LB 12
    514 #     GL  x
    515 #
    516 $CANT_CM $CM* $GL;
    517 $CM* $CAN_CM $CM* $GL;
    518 
    519 
    520 # LB 13
    521 $CL $CM+ $CAN_CM;
    522 $CP $CM+ $CAN_CM;
    523 $EX $CM+ $CAN_CM;
    524 $IS $CM+ $CAN_CM;
    525 $SY $CM+ $CAN_CM;
    526 
    527 $CL [$LB8NonBreaks-$CM];
    528 $CP [$LB8NonBreaks-$CM];
    529 $EX [$LB8NonBreaks-$CM];
    530 $IS [$LB8NonBreaks-$CM];
    531 $SY [$LB8NonBreaks-$CM];
    532 
    533 # Rule 13 & 14 taken together for an edge case.
    534 #   Match this, shown forward
    535 #     OP SP+  ($CM+ behaving as $AL) (CL | CP | EX | IS | IY)
    536 #   This really wants to chain at the $CM+ (which is acting as an $AL)
    537 #   except for $CM chaining being disabled.
    538 [$CL $CP $EX $IS $SY] $CM+ $SP+ $CM* $OP;  
    539 
    540 # LB 14    OP SP* x
    541 #
    542 $CM* $CAN_CM    $SP* $CM* $OP;
    543      $CANT_CM   $SP* $CM* $OP;
    544 $AL_FOLLOW? $CM+  $SP $SP* $CM* $OP;     #  by LB 10, behaves like $AL_FOLLOW? $AL $SP* $CM* $OP
    545      
    546      $AL_FOLLOW_NOCM $CM+ $SP+ $CM* $OP;
    547 $CM* $AL_FOLLOW_CM   $CM+ $SP+ $CM* $OP;
    548 $SY $CM $SP+ $OP;   # TODO:  Experiment.  Remove.
    549 
    550 
    551 
    552 # LB 15
    553 $CM* $OP $SP* $CM* $QU;
    554 
    555 # LB 16
    556 $CM* $NS $SP* $CM* ($CL | $CP);
    557 
    558 # LB 17
    559 $CM* $B2 $SP* $CM* $B2;
    560 
    561 # LB 18  break after spaces
    562 #        Nothing explicit needed here.
    563 
    564 
    565 #
    566 # LB 19
    567 #
    568 $CM* $QU $CM* $CAN_CM;                                #   . x QU
    569 $CM* $QU      $LB18NonBreaks;
    570 
    571 
    572 $CM* $CAN_CM  $CM* $QU;                               #   QU x .
    573      $CANT_CM $CM* $QU;
    574      
    575 #
    576 #  LB 20  Break before and after CB.
    577 #         nothing needed here.
    578 #
    579 
    580 # LB 20.09 added rule for Finnish tailoring
    581 $AL ($HY | $HH) / $SP;
    582 
    583 # LB 21
    584 $CM* ($BA | $HH | $HY | $NS) $CM* [$LB20NonBreaks-$CM];     #  . x (BA | HY | NS)
    585 
    586 $CM* [$LB20NonBreaks-$CM] $CM* $BB;                   #  BB x .
    587 [^$CB] $CM* $BB;                                      # 
    588 
    589 # LB21a
    590 [^$CB] $CM* ($HY | $BA | $HH) $CM* $HL;
    591 
    592 # LB21b (reverse)
    593 $CM* $HL $CM* $SY;
    594 
    595 # LB 22
    596 $CM* $IN $CM* ($ALPlus | $HL);
    597 $CM* $IN $CM* $ID;
    598 $CM* $IN $CM* $IN;
    599 $CM* $IN $CM* $NU;
    600 
    601 # LB 23
    602 $CM* $PO $CM* $ID;
    603 $CM* $NU $CM* ($ALPlus | $HL);
    604 $CM* ($ALPlus | $HL) $CM* $NU;
    605 
    606 # LB 24
    607 $CM* $ID $CM* $PR;
    608 $CM* ($ALPlus | $HL) $CM* $PR;
    609 $CM* ($ALPlus | $HL) $CM* $PO;
    610 
    611 
    612 # LB 25
    613 ($CM* ($PR | $PO))? ($CM* ($CL | $CP))? ($CM* ($NU | $IS | $SY))* $CM* $NU ($CM* ($OP | $HY))? ($CM* ($PR | $PO))?;
    614 
    615 # LB 26
    616 $CM* ($H3 | $H2 | $JV | $JL) $CM* $JL;
    617 $CM* ($JT | $JV) $CM* ($H2 | $JV);
    618 $CM* $JT $CM* ($H3 | $JT);
    619 
    620 # LB 27
    621 $CM* $IN $CM* ($H3 | $H2 | $JT | $JV | $JL);
    622 $CM* $PO $CM* ($H3 | $H2 | $JT | $JV | $JL);
    623 $CM* ($H3 | $H2 | $JT | $JV | $JL) $CM* $PR;
    624 
    625 # LB 28
    626 $CM* ($ALPlus | $HL) $CM* ($ALPlus | $HL);
    627 
    628 
    629 # LB 29
    630 $CM* ($ALPlus | $HL) $CM* $IS;
    631 
    632 # LB 30
    633 $CM* $OP $CM* ($ALPlus | $HL | $NU);
    634 $CM* ($ALPlus | $HL | $NU) $CM* $CP;
    635 
    636 # LB 30a
    637 $CM* $RI $CM* $RI;
    638 
    639 ## -------------------------------------------------
    640 
    641 !!safe_reverse;
    642 
    643 # LB 9
    644 $CM+ [^$CM $BK $CR $LF $NL $ZW $SP];
    645 $CM+ $SP / .;
    646 
    647 # LB 14
    648 $SP+ $CM* $OP;
    649 
    650 # LB 15
    651 $SP+ $CM* $QU;
    652 
    653 # LB 16
    654 $SP+ $CM* ($CL | $CP);
    655 
    656 # LB 17
    657 $SP+ $CM* $B2;
    658 
    659 # LB 21
    660 $CM* ($HY | $BA | $HH) $CM* $HL;
    661 
    662 # LB 25
    663 ($CM* ($IS | $SY))+ $CM* $NU;
    664 ($CL | $CP) $CM* ($NU | $IS | $SY);
    665 
    666 # For dictionary-based break
    667 $dictionary $dictionary;
    668 
    669 ## -------------------------------------------------
    670 
    671 !!safe_forward;
    672 
    673 # Skip forward over all character classes that are involved in
    674 #   rules containing patterns with possibly more than one char
    675 #   of context.
    676 #
    677 #  It might be slightly more efficient to have specific rules
    678 #  instead of one generic one, but only if we could
    679 #  turn off rule chaining.  We don't want to move more
    680 #  than necessary.
    681 #
    682 [$CM $OP $QU $CL $CP $B2 $PR $HY $BA $SP $dictionary]+ [^$CM $OP $QU $CL $CP $B2 $PR $HY $BA $dictionary];
    683 $dictionary $dictionary;
    684 
    685