icuSources/data/brkitr/line_he.txt

   1 # Copyright (c) 2002-2010  International Business Machines Corporation and
   2 # others. All Rights Reserved.
   3 #
   4 #  file:  line_he.txt
   5 #
   6 #         Line Breaking Rules
   7 #         Implement default line breaking as defined by
   8 #         Unicode Standard Annex #14 Revision 24 for Unicode 6.0
   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:] - [[:Hebrew:] & [:Letter:]]];
  61 $HL = [[:Hebrew:] & [:Letter:]];
  62 $BA = [[:LineBreak =  Break_After:] - [\u2010]];
  63 $HH = [\u2010];
  64 $BB = [:LineBreak =  Break_Before:];
  65 $BK = [:LineBreak =  Mandatory_Break:];
  66 $B2 = [:LineBreak =  Break_Both:];
  67 $CB = [:LineBreak =  Contingent_Break:];
  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 $HY = [:LineBreak =  Hyphen:];
  75 $H2 = [:LineBreak =  H2:];
  76 $H3 = [:LineBreak =  H3:];
  77 $ID = [:LineBreak =  Ideographic:];
  78 $IN = [:LineBreak =  Inseperable:];
  79 $IS = [:LineBreak =  Infix_Numeric:];
  80 $JL = [:LineBreak =  JL:];
  81 $JV = [:LineBreak =  JV:];
  82 $JT = [:LineBreak =  JT:];
  83 $LF = [:LineBreak =  Line_Feed:];
  84 $NL = [:LineBreak =  Next_Line:];
  85 $NS = [:LineBreak =  Nonstarter:];
  86 $NU = [:LineBreak =  Numeric:];
  87 $OP = [:LineBreak =  Open_Punctuation:];
  88 $PO = [:LineBreak =  Postfix_Numeric:];
  89 $PR = [:LineBreak =  Prefix_Numeric:];
  90 $QU = [:LineBreak =  Quotation:];
  91 $SA = [:LineBreak =  Complex_Context:];
  92 $SG = [:LineBreak =  Surrogate:];
  93 $SP = [:LineBreak =  Space:];
  94 $SY = [:LineBreak =  Break_Symbols:];
  95 $WJ = [:LineBreak =  Word_Joiner:];
  96 $XX = [:LineBreak =  Unknown:];
  97 $ZW = [:LineBreak =  ZWSpace:];
  98
  99 #   Dictionary character set, for triggering language-based break engines. Currently
 100 #   limited to LineBreak=Complex_Context. Note that this set only works in Unicode
 101 #   5.0 or later as the definition of Complex_Context was corrected to include all
 102 #   characters requiring dictionary break.
 103
 104 $dictionary = [:LineBreak = Complex_Context:];
 105
 106 #
 107 #  Rule LB1.  By default, treat AI  (characters with ambiguous east Asian width),
 108 #                               SA  (South East Asian: Thai, Lao, Khmer)
 109 #                               SG  (Unpaired Surrogates)
 110 #                               XX  (Unknown, unassigned)
 111 #                         as $AL  (Alphabetic)
 112 #
 113 $ALPlus = [$AL $HL $AI $SA $SG $XX];
 114
 115 #
 116 #  Combining Marks.   X $CM*  behaves as if it were X.  Rule LB6.
 117 #
 118 $ALcm = $ALPlus $CM*;
 119 $HLcm = $HL $CM*;
 120 $BAcm = $BA $CM*;
 121 $HHcm = $HH $CM*;
 122 $BBcm = $BB $CM*;
 123 $B2cm = $B2 $CM*;
 124 $CLcm = $CL $CM*;
 125 $CPcm = $CP $CM*;
 126 $EXcm = $EX $CM*;
 127 $GLcm = $GL $CM*;
 128 $HYcm = $HY $CM*;
 129 $H2cm = $H2 $CM*;
 130 $H3cm = $H3 $CM*;
 131 $IDcm = $ID $CM*;
 132 $INcm = $IN $CM*;
 133 $IScm = $IS $CM*;
 134 $JLcm = $JL $CM*;
 135 $JVcm = $JV $CM*;
 136 $JTcm = $JT $CM*;
 137 $NScm = $NS $CM*;
 138 $NUcm = $NU $CM*;
 139 $OPcm = $OP $CM*;
 140 $POcm = $PO $CM*;
 141 $PRcm = $PR $CM*;
 142 $QUcm = $QU $CM*;
 143 $SYcm = $SY $CM*;
 144 $WJcm = $WJ $CM*;
 145
 146 ## -------------------------------------------------
 147
 148 !!forward;
 149
 150 #
 151 #  Each class of character can stand by itself as an unbroken token, with trailing combining stuff
 152 #
 153 $ALPlus $CM+;
 154 $BA $CM+;
 155 $HH $CM+;
 156 $BB $CM+;
 157 $B2 $CM+;
 158 $CL $CM+;
 159 $CP $CM+;
 160 $EX $CM+;
 161 $GL $CM+;
 162 $HY $CM+;
 163 $H2 $CM+;
 164 $H3 $CM+;
 165 $ID $CM+;
 166 $IN $CM+;
 167 $IS $CM+;
 168 $JL $CM+;
 169 $JV $CM+;
 170 $JT $CM+;
 171 $NS $CM+;
 172 $NU $CM+;
 173 $OP $CM+;
 174 $PO $CM+;
 175 $PR $CM+;
 176 $QU $CM+;
 177 $SY $CM+;
 178 $WJ $CM+;
 179
 180 #
 181 # CAN_CM  is the set of characters that may combine with CM combining chars.
 182 #         Note that Linebreak UAX 14's concept of a combining char and the rules
 183 #         for what they can combine with are _very_ different from the rest of Unicode.
 184 #
 185 #         Note that $CM itself is left out of this set.  If CM is needed as a base
 186 #         it must be listed separately in the rule.
 187 #
 188 $CAN_CM  = [^$SP $BK $CR $LF $NL $ZW $CM];       # Bases that can   take CMs
 189 $CANT_CM = [ $SP $BK $CR $LF $NL $ZW $CM];       # Bases that can't take CMs
 190
 191 #
 192 # AL_FOLLOW  set of chars that can unconditionally follow an AL
 193 #            Needed in rules where stand-alone $CM s are treated as AL.
 194 #            Chaining is disabled with CM because it causes other failures,
 195 #            so for this one case we need to manually list out longer sequences.
 196 #
 197 $AL_FOLLOW_NOCM = [$BK $CR $LF $NL $ZW $SP];
 198 $AL_FOLLOW_CM   = [$CL $CP $EX $IS $SY $WJ $GL $OP $QU $BA $HH $HY $NS $IN $NU $ALPlus];
 199 $AL_FOLLOW      = [$AL_FOLLOW_NOCM $AL_FOLLOW_CM];
 200
 201
 202 #
 203 #  Rule LB 4, 5    Mandatory (Hard) breaks.
 204 #
 205 $LB4Breaks    = [$BK $CR $LF $NL];
 206 $LB4NonBreaks = [^$BK $CR $LF $NL];
 207 $CR $LF {100};
 208
 209 #
 210 #  LB 6    Do not break before hard line breaks.
 211 #
 212 $LB4NonBreaks?  $LB4Breaks {100};    # LB 5  do not break before hard breaks.
 213 $CAN_CM $CM*    $LB4Breaks {100};
 214 $CM+            $LB4Breaks {100};
 215
 216 # LB 7         x SP
 217 #              x ZW
 218 $LB4NonBreaks [$SP $ZW];
 219 $CAN_CM $CM*  [$SP $ZW];
 220 $CM+          [$SP $ZW];
 221
 222 #
 223 # LB 8         Break after zero width space
 224 #              TODO:  ZW SP* <break>
 225 #              An engine change is required to write the reverse rule for this.
 226 #              For now, leave the Unicode 5.2 rule, ZW <break>
 227 #
 228 $LB8Breaks    = [$LB4Breaks $ZW];
 229 $LB8NonBreaks = [[$LB4NonBreaks] - [$ZW]];
 230
 231
 232 # LB 9     Combining marks.      X   $CM needs to behave like X, where X is not $SP, $BK $CR $LF $NL
 233 #                                $CM not covered by the above needs to behave like $AL
 234 #                                See definition of $CAN_CM.
 235
 236 $CAN_CM $CM+;                   #  Stick together any combining sequences that don't match other rules.
 237 $CM+;
 238
 239 #
 240 # LB 11  Do not break before or after WORD JOINER & related characters.
 241 #
 242 $CAN_CM $CM*  $WJcm;
 243 $LB8NonBreaks $WJcm;
 244 $CM+          $WJcm;
 245
 246 $WJcm $CANT_CM;
 247 $WJcm $CAN_CM $CM*;
 248
 249 #
 250 # LB 12  Do not break after NBSP and related characters.
 251 #         GL  x
 252 #
 253 $GLcm $CAN_CM $CM*;
 254 $GLcm $CANT_CM;
 255
 256 #
 257 # LB 12a  Do not break before NBSP and related characters ...
 258 #            [^SP BA HY] x GL
 259 #
 260 [[$LB8NonBreaks] - [$SP $BA $HH $HY]] $CM* $GLcm;
 261 $CM+ GLcm;
 262
 263
 264
 265 #
 266 # LB 13   Don't break before ']' or '!' or ';' or '/', even after spaces.
 267 #
 268 $LB8NonBreaks $CL;
 269 $CAN_CM $CM*  $CL;
 270 $CM+          $CL;              # by rule 10, stand-alone CM behaves as AL
 271
 272 $LB8NonBreaks $CP;
 273 $CAN_CM $CM*  $CP;
 274 $CM+          $CP;              # by rule 10, stand-alone CM behaves as AL
 275
 276 $LB8NonBreaks $EX;
 277 $CAN_CM $CM*  $EX;
 278 $CM+          $EX;              # by rule 10, stand-alone CM behaves as AL
 279
 280 $LB8NonBreaks $IS;
 281 $CAN_CM $CM*  $IS;
 282 $CM+          $IS;              # by rule 10, stand-alone CM behaves as AL
 283
 284 $LB8NonBreaks $SY;
 285 $CAN_CM $CM*  $SY;
 286 $CM+          $SY;              # by rule 10, stand-alone CM behaves as AL
 287
 288
 289 #
 290 # LB 14  Do not break after OP, even after spaces
 291 #
 292 $OPcm $SP* $CAN_CM $CM*;
 293 $OPcm $SP* $CANT_CM;
 294
 295 $OPcm $SP+ $CM+ $AL_FOLLOW?;    # by rule 10, stand-alone CM behaves as AL
 296
 297 # LB 15
 298 $QUcm $SP* $OPcm;
 299
 300 # LB 16
 301 ($CLcm | $CPcm) $SP* $NScm;
 302
 303 # LB 17
 304 $B2cm $SP* $B2cm;
 305
 306 #
 307 # LB 18  Break after spaces.
 308 #
 309 $LB18NonBreaks = [$LB8NonBreaks - [$SP]];
 310 $LB18Breaks    = [$LB8Breaks $SP];
 311
 312
 313 # LB 19
 314 #         x QU
 315 $LB18NonBreaks $CM* $QUcm;
 316 $CM+                $QUcm;
 317
 318 #         QU  x
 319 $QUcm .?;
 320 $QUcm $LB18NonBreaks $CM*;    # Don't let a combining mark go onto $CR, $BK, etc.
 321                               #  TODO:  I don't think this rule is needed.
 322
 323
 324 # LB 20
 325 #        <break>  $CB
 326 #        $CB   <break>
 327
 328 $LB20NonBreaks = [$LB18NonBreaks - $CB];
 329
 330 # LB 21        x   (BA | HY | NS)
 331 #           BB x
 332 #
 333 $LB20NonBreaks $CM* ($BAcm | $HHcm | $HYcm | $NScm);
 334
 335 $BBcm [^$CB];                                  #  $BB  x
 336 $BBcm $LB20NonBreaks $CM*;
 337
 338 # LB 22
 339 $ALcm    $INcm;
 340 $CM+     $INcm;     #  by rule 10, any otherwise unattached CM behaves as AL
 341 $IDcm    $INcm;
 342 $INcm    $INcm;
 343 $NUcm    $INcm;
 344
 345
 346 # $LB 23
 347 $IDcm  $POcm;
 348 $ALcm  $NUcm;       # includes $LB19
 349 $CM+   $NUcm;       # Rule 10, any otherwise unattached CM behaves as AL
 350 $NUcm  $ALcm;
 351
 352 #
 353 # LB 24
 354 #
 355 $PRcm $IDcm;
 356 $PRcm $ALcm;
 357 $POcm $ALcm;
 358
 359 #
 360 # LB 25   Numbers.
 361 #
 362 ($PRcm | $POcm)? ($OPcm | $HYcm)? $NUcm ($NUcm | $SYcm | $IScm)* ($CLcm | $CPcm)? ($PRcm | $POcm)?;
 363
 364 # LB 26  Do not break a Korean syllable
 365 #
 366 $JLcm ($JLcm | $JVcm | $H2cm | $H3cm);
 367 ($JVcm | $H2cm) ($JVcm | $JTcm);
 368 ($JTcm | $H3cm) $JTcm;
 369
 370 # LB 27  Treat korean Syllable Block the same as ID  (don't break it)
 371 ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm) $INcm;
 372 ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm) $POcm;
 373 $PRcm ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm);
 374
 375
 376 # LB 28   Do not break between alphabetics
 377 #
 378 $ALcm $ALcm;
 379 $CM+ $ALcm;      # The $CM+ is from rule 10, an unattached CM is treated as AL
 380
 381 # LB 29
 382 $IScm $ALcm;
 383
 384 # LB 30
 385 ($ALcm | $NUcm) $OPcm;
 386 $CM+ $OPcm;         # The $CM+ is from rule 10, an unattached CM is treated as AL.
 387 $CPcm ($ALcm | $NUcm);
 388
 389 # (LB 31) Add new rule to prevent the break we do not want, this is the behavior change
 390 $HLcm ($HY | $HH) $ALcm;
 391
 392 #
 393 #  Reverse Rules.
 394 #
 395 ## -------------------------------------------------
 396
 397 !!reverse;
 398
 399 $CM+ $ALPlus;
 400 $CM+ $BA;
 401 $CM+ $HH;
 402 $CM+ $BB;
 403 $CM+ $B2;
 404 $CM+ $CL;
 405 $CM+ $CP;
 406 $CM+ $EX;
 407 $CM+ $GL;
 408 $CM+ $HY;
 409 $CM+ $H2;
 410 $CM+ $H3;
 411 $CM+ $ID;
 412 $CM+ $IN;
 413 $CM+ $IS;
 414 $CM+ $JL;
 415 $CM+ $JV;
 416 $CM+ $JT;
 417 $CM+ $NS;
 418 $CM+ $NU;
 419 $CM+ $OP;
 420 $CM+ $PO;
 421 $CM+ $PR;
 422 $CM+ $QU;
 423 $CM+ $SY;
 424 $CM+ $WJ;
 425 $CM+;
 426
 427
 428 #
 429 #  Sequences of the form  (shown forwards)
 430 #      [CANT_CM]  <break>  [CM]  [whatever]
 431 #  The CM needs to behave as an AL
 432 #
 433 $AL_FOLLOW $CM+ / (
 434           [$BK $CR $LF $NL $ZW {eof}] |
 435           $SP+ $CM+ $SP |
 436           $SP+ $CM* ([^$OP $CM $SP] | [$AL {eof}]));   # if LB 14 will match, need to surpress this break.
 437                                                #  LB14 says    OP SP* x .
 438                                                #    becomes    OP SP* x AL
 439                                                #    becomes    OP SP* x CM+ AL_FOLLOW
 440                                                #
 441                                                # Further note:  the $AL in [$AL {eof}] is only to work around
 442                                                #                a rule compiler bug which complains about
 443                                                #                empty sets otherwise.
 444
 445 #
 446 #  Sequences of the form  (shown forwards)
 447 #      [CANT_CM]  <break> [CM]  <break>  [PR]
 448 #  The CM needs to behave as an AL
 449 #  This rule is concerned about getting the second of the two <breaks> in place.
 450 #
 451
 452 [$PR   ] / $CM+ [$BK $CR $LF $NL $ZW $SP {eof}];
 453
 454
 455
 456 # LB 4, 5, 5
 457
 458 $LB4Breaks [$LB4NonBreaks-$CM];
 459 $LB4Breaks $CM+ $CAN_CM;
 460 $LF $CR;
 461
 462
 463 # LB 7         x SP
 464 #              x ZW
 465 [$SP $ZW] [$LB4NonBreaks-$CM];
 466 [$SP $ZW] $CM+ $CAN_CM;
 467
 468 # LB 8 ZW SP* <break>
 469 #     TODO: to implement this, we need more than one look-ahead hard break in play at a time.
 470 #           Requires an engine enhancement.
 471 #   / $SP* $ZW
 472
 473 # LB 9,10  Combining marks.
 474 #    X   $CM needs to behave like X, where X is not $SP or controls.
 475 #    $CM not covered by the above needs to behave like $AL
 476 # Stick together any combining sequences that don't match other rules.
 477 $CM+ $CAN_CM;
 478
 479
 480 # LB 11
 481 $CM* $WJ $CM* $CAN_CM;
 482 $CM* $WJ      [$LB8NonBreaks-$CM];
 483
 484      $CANT_CM $CM* $WJ;
 485 $CM* $CAN_CM  $CM* $WJ;
 486
 487 # LB 12a
 488 #      [^SP BA HY] x GL
 489 #
 490 $CM* $GL $CM* [$LB8NonBreaks-[$CM $SP $BA $HH $HY]];
 491
 492 # LB 12
 493 #     GL  x
 494 #
 495 $CANT_CM $CM* $GL;
 496 $CM* $CAN_CM $CM* $GL;
 497
 498
 499 # LB 13
 500 $CL $CM+ $CAN_CM;
 501 $CP $CM+ $CAN_CM;
 502 $EX $CM+ $CAN_CM;
 503 $IS $CM+ $CAN_CM;
 504 $SY $CM+ $CAN_CM;
 505
 506 $CL [$LB8NonBreaks-$CM];
 507 $CP [$LB8NonBreaks-$CM];
 508 $EX [$LB8NonBreaks-$CM];
 509 $IS [$LB8NonBreaks-$CM];
 510 $SY [$LB8NonBreaks-$CM];
 511
 512 # Rule 13 & 14 taken together for an edge case.
 513 #   Match this, shown forward
 514 #     OP SP+  ($CM+ behaving as $AL) (CL | CP | EX | IS | IY)
 515 #   This really wants to chain at the $CM+ (which is acting as an $AL)
 516 #   except for $CM chaining being disabled.
 517 [$CL $CP $EX $IS $SY] $CM+ $SP+ $CM* $OP;
 518
 519 # LB 14    OP SP* x
 520 #
 521 $CM* $CAN_CM    $SP* $CM* $OP;
 522      $CANT_CM   $SP* $CM* $OP;
 523 $AL_FOLLOW? $CM+  $SP $SP* $CM* $OP;     #  by LB 10, behaves like $AL_FOLLOW? $AL $SP* $CM* $OP
 524
 525      $AL_FOLLOW_NOCM $CM+ $SP+ $CM* $OP;
 526 $CM* $AL_FOLLOW_CM   $CM+ $SP+ $CM* $OP;
 527 $SY $CM $SP+ $OP;   # TODO:  Experiment.  Remove.
 528
 529
 530
 531 # LB 15
 532 $CM* $OP $SP* $CM* $QU;
 533
 534 # LB 16
 535 $CM* $NS $SP* $CM* ($CL | $CP);
 536
 537 # LB 17
 538 $CM* $B2 $SP* $CM* $B2;
 539
 540 # LB 18  break after spaces
 541 #        Nothing explicit needed here.
 542
 543
 544 #
 545 # LB 19
 546 #
 547 $CM* $QU $CM* $CAN_CM;                                #   . x QU
 548 $CM* $QU      $LB18NonBreaks;
 549
 550
 551 $CM* $CAN_CM  $CM* $QU;                               #   QU x .
 552      $CANT_CM $CM* $QU;
 553
 554 #
 555 #  LB 20  Break before and after CB.
 556 #         nothing needed here.
 557 #
 558
 559 # LB 21
 560 $CM* ($BA | $HH | $HY | $NS) $CM* [$LB20NonBreaks-$CM];     #  . x (BA | HY | NS)
 561
 562 $CM* [$LB20NonBreaks-$CM] $CM* $BB;                   #  BB x .
 563 [^$CB] $CM* $BB;                                      #
 564
 565
 566
 567 # LB 22
 568 $CM* $IN $CM* $ALPlus;
 569 $CM* $IN $CM* $ID;
 570 $CM* $IN $CM* $IN;
 571 $CM* $IN $CM* $NU;
 572
 573 # LB 23
 574 $CM* $PO $CM* $ID;
 575 $CM* $NU $CM* $ALPlus;
 576 $CM* $ALPlus $CM* $NU;
 577
 578 # LB 24
 579 $CM* $ID $CM* $PR;
 580 $CM* $ALPlus $CM* $PR;
 581 $CM* $ALPlus $CM* $PO;
 582
 583
 584 # LB 25
 585 ($CM* ($PR | $PO))? ($CM* ($CL | $CP))? ($CM* ($NU | $IS | $SY))* $CM* $NU ($CM* ($OP | $HY))? ($CM* ($PR | $PO))?;
 586
 587 # LB 26
 588 $CM* ($H3 | $H2 | $JV | $JL) $CM* $JL;
 589 $CM* ($JT | $JV) $CM* ($H2 | $JV);
 590 $CM* $JT $CM* ($H3 | $JT);
 591
 592 # LB 27
 593 $CM* $IN $CM* ($H3 | $H2 | $JT | $JV | $JL);
 594 $CM* $PO $CM* ($H3 | $H2 | $JT | $JV | $JL);
 595 $CM* ($H3 | $H2 | $JT | $JV | $JL) $CM* $PR;
 596
 597 # LB 28
 598 $CM* $ALPlus $CM* $ALPlus;
 599
 600
 601 # LB 29
 602 $CM* $ALPlus $CM* $IS;
 603
 604 # LB 30
 605 $CM* $OP $CM* ($ALPlus | $NU);
 606 $CM* ($ALPlus | $NU) $CM* $CP;
 607
 608 # (LB 31) Add new rule to prevent the break we do not want, this is the behavior change
 609 $CM* $ALPlus ($HY | $HH) $CM* $HL;
 610
 611 ## -------------------------------------------------
 612
 613 !!safe_reverse;
 614
 615 # LB 9
 616 $CM+ [^$CM $BK $CR $LF $NL $ZW $SP];
 617 $CM+ $SP / .;
 618
 619 # LB 14
 620 $SP+ $CM* $OP;
 621
 622 # LB 15
 623 $SP+ $CM* $QU;
 624
 625 # LB 16
 626 $SP+ $CM* ($CL | $CP);
 627
 628 # LB 17
 629 $SP+ $CM* $B2;
 630
 631 # LB 25
 632 ($CM* ($IS | $SY))+ $CM* $NU;
 633 ($CL | $CP) $CM* ($NU | $IS | $SY);
 634
 635 # For dictionary-based break
 636 $dictionary $dictionary;
 637
 638 ## -------------------------------------------------
 639
 640 !!safe_forward;
 641
 642 # Skip forward over all character classes that are involved in
 643 #   rules containing patterns with possibly more than one char
 644 #   of context.
 645 #
 646 #  It might be slightly more efficient to have specific rules
 647 #  instead of one generic one, but only if we could
 648 #  turn off rule chaining.  We don't want to move more
 649 #  than necessary.
 650 #
 651 [$CM $OP $QU $CL $CP $B2 $PR $HY $SP $dictionary]+ [^$CM $OP $QU $CL $CP $B2 $PR $HY $dictionary];
 652 $dictionary $dictionary;
 653