icuSources/data/brkitr/line.txt

   1 # Copyright (c) 2002-2010  International Business Machines Corporation and
   2 # others. All Rights Reserved.
   3 #
   4 #  file:  line.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:];
  61 $BA = [:LineBreak =  Break_After:];
  62 $BB = [:LineBreak =  Break_Before:];
  63 $BK = [:LineBreak =  Mandatory_Break:];
  64 $B2 = [:LineBreak =  Break_Both:];
  65 $CB = [:LineBreak =  Contingent_Break:];
  66 $CL = [:LineBreak =  Close_Punctuation:];
  67 $CM = [:LineBreak =  Combining_Mark:];
  68 $CP = [:LineBreak =  Close_Parenthesis:];
  69 $CR = [:LineBreak =  Carriage_Return:];
  70 $EX = [:LineBreak =  Exclamation:];
  71 $GL = [:LineBreak =  Glue:];
  72 $HY = [:LineBreak =  Hyphen:];
  73 $H2 = [:LineBreak =  H2:];
  74 $H3 = [:LineBreak =  H3:];
  75 $ID = [:LineBreak =  Ideographic:];
  76 $IN = [:LineBreak =  Inseperable:];
  77 $IS = [:LineBreak =  Infix_Numeric:];
  78 $JL = [:LineBreak =  JL:];
  79 $JV = [:LineBreak =  JV:];
  80 $JT = [:LineBreak =  JT:];
  81 $LF = [:LineBreak =  Line_Feed:];
  82 $NL = [:LineBreak =  Next_Line:];
  83 $NS = [:LineBreak =  Nonstarter:];
  84 $NU = [:LineBreak =  Numeric:];
  85 $OP = [:LineBreak =  Open_Punctuation:];
  86 $PO = [:LineBreak =  Postfix_Numeric:];
  87 $PR = [:LineBreak =  Prefix_Numeric:];
  88 $QU = [:LineBreak =  Quotation:];
  89 $SA = [:LineBreak =  Complex_Context:];
  90 $SG = [:LineBreak =  Surrogate:];
  91 $SP = [:LineBreak =  Space:];
  92 $SY = [:LineBreak =  Break_Symbols:];
  93 $WJ = [:LineBreak =  Word_Joiner:];
  94 $XX = [:LineBreak =  Unknown:];
  95 $ZW = [:LineBreak =  ZWSpace:];
  96
  97 #   Dictionary character set, for triggering language-based break engines. Currently
  98 #   limited to LineBreak=Complex_Context. Note that this set only works in Unicode
  99 #   5.0 or later as the definition of Complex_Context was corrected to include all
 100 #   characters requiring dictionary break.
 101
 102 $dictionary = [:LineBreak = Complex_Context:];
 103
 104 #
 105 #  Rule LB1.  By default, treat AI  (characters with ambiguous east Asian width),
 106 #                               SA  (South East Asian: Thai, Lao, Khmer)
 107 #                               SG  (Unpaired Surrogates)
 108 #                               XX  (Unknown, unassigned)
 109 #                         as $AL  (Alphabetic)
 110 #
 111 $ALPlus = [$AL $AI $SA $SG $XX];
 112
 113 #
 114 #  Combining Marks.   X $CM*  behaves as if it were X.  Rule LB6.
 115 #
 116 $ALcm = $ALPlus $CM*;
 117 $BAcm = $BA $CM*;
 118 $BBcm = $BB $CM*;
 119 $B2cm = $B2 $CM*;
 120 $CLcm = $CL $CM*;
 121 $CPcm = $CP $CM*;
 122 $EXcm = $EX $CM*;
 123 $GLcm = $GL $CM*;
 124 $HYcm = $HY $CM*;
 125 $H2cm = $H2 $CM*;
 126 $H3cm = $H3 $CM*;
 127 $IDcm = $ID $CM*;
 128 $INcm = $IN $CM*;
 129 $IScm = $IS $CM*;
 130 $JLcm = $JL $CM*;
 131 $JVcm = $JV $CM*;
 132 $JTcm = $JT $CM*;
 133 $NScm = $NS $CM*;
 134 $NUcm = $NU $CM*;
 135 $OPcm = $OP $CM*;
 136 $POcm = $PO $CM*;
 137 $PRcm = $PR $CM*;
 138 $QUcm = $QU $CM*;
 139 $SYcm = $SY $CM*;
 140 $WJcm = $WJ $CM*;
 141
 142 ## -------------------------------------------------
 143
 144 !!forward;
 145
 146 #
 147 #  Each class of character can stand by itself as an unbroken token, with trailing combining stuff
 148 #
 149 $ALPlus $CM+;
 150 $BA $CM+;
 151 $BB $CM+;
 152 $B2 $CM+;
 153 $CL $CM+;
 154 $CP $CM+;
 155 $EX $CM+;
 156 $GL $CM+;
 157 $HY $CM+;
 158 $H2 $CM+;
 159 $H3 $CM+;
 160 $ID $CM+;
 161 $IN $CM+;
 162 $IS $CM+;
 163 $JL $CM+;
 164 $JV $CM+;
 165 $JT $CM+;
 166 $NS $CM+;
 167 $NU $CM+;
 168 $OP $CM+;
 169 $PO $CM+;
 170 $PR $CM+;
 171 $QU $CM+;
 172 $SY $CM+;
 173 $WJ $CM+;
 174
 175 #
 176 # CAN_CM  is the set of characters that may combine with CM combining chars.
 177 #         Note that Linebreak UAX 14's concept of a combining char and the rules
 178 #         for what they can combine with are _very_ different from the rest of Unicode.
 179 #
 180 #         Note that $CM itself is left out of this set.  If CM is needed as a base
 181 #         it must be listed separately in the rule.
 182 #
 183 $CAN_CM  = [^$SP $BK $CR $LF $NL $ZW $CM];       # Bases that can   take CMs
 184 $CANT_CM = [ $SP $BK $CR $LF $NL $ZW $CM];       # Bases that can't take CMs
 185
 186 #
 187 # AL_FOLLOW  set of chars that can unconditionally follow an AL
 188 #            Needed in rules where stand-alone $CM s are treated as AL.
 189 #            Chaining is disabled with CM because it causes other failures,
 190 #            so for this one case we need to manually list out longer sequences.
 191 #
 192 $AL_FOLLOW_NOCM = [$BK $CR $LF $NL $ZW $SP];
 193 $AL_FOLLOW_CM   = [$CL $CP $EX $IS $SY $WJ $GL $OP $QU $BA $HY $NS $IN $NU $ALPlus];
 194 $AL_FOLLOW      = [$AL_FOLLOW_NOCM $AL_FOLLOW_CM];
 195
 196
 197 #
 198 #  Rule LB 4, 5    Mandatory (Hard) breaks.
 199 #
 200 $LB4Breaks    = [$BK $CR $LF $NL];
 201 $LB4NonBreaks = [^$BK $CR $LF $NL];
 202 $CR $LF {100};
 203
 204 #
 205 #  LB 6    Do not break before hard line breaks.
 206 #
 207 $LB4NonBreaks?  $LB4Breaks {100};    # LB 5  do not break before hard breaks.
 208 $CAN_CM $CM*    $LB4Breaks {100};
 209 $CM+            $LB4Breaks {100};
 210
 211 # LB 7         x SP
 212 #              x ZW
 213 $LB4NonBreaks [$SP $ZW];
 214 $CAN_CM $CM*  [$SP $ZW];
 215 $CM+          [$SP $ZW];
 216
 217 #
 218 # LB 8         Break after zero width space
 219 #              TODO:  ZW SP* <break>
 220 #              An engine change is required to write the reverse rule for this.
 221 #              For now, leave the Unicode 5.2 rule, ZW <break>
 222 #
 223 $LB8Breaks    = [$LB4Breaks $ZW];
 224 $LB8NonBreaks = [[$LB4NonBreaks] - [$ZW]];
 225
 226
 227 # LB 9     Combining marks.      X   $CM needs to behave like X, where X is not $SP, $BK $CR $LF $NL
 228 #                                $CM not covered by the above needs to behave like $AL
 229 #                                See definition of $CAN_CM.
 230
 231 $CAN_CM $CM+;                   #  Stick together any combining sequences that don't match other rules.
 232 $CM+;
 233
 234 #
 235 # LB 11  Do not break before or after WORD JOINER & related characters.
 236 #
 237 $CAN_CM $CM*  $WJcm;
 238 $LB8NonBreaks $WJcm;
 239 $CM+          $WJcm;
 240
 241 $WJcm $CANT_CM;
 242 $WJcm $CAN_CM $CM*;
 243
 244 #
 245 # LB 12  Do not break after NBSP and related characters.
 246 #         GL  x
 247 #
 248 $GLcm $CAN_CM $CM*;
 249 $GLcm $CANT_CM;
 250
 251 #
 252 # LB 12a  Do not break before NBSP and related characters ...
 253 #            [^SP BA HY] x GL
 254 #
 255 [[$LB8NonBreaks] - [$SP $BA $HY]] $CM* $GLcm;
 256 $CM+ GLcm;
 257
 258
 259
 260 #
 261 # LB 13   Don't break before ']' or '!' or ';' or '/', even after spaces.
 262 #
 263 $LB8NonBreaks $CL;
 264 $CAN_CM $CM*  $CL;
 265 $CM+          $CL;              # by rule 10, stand-alone CM behaves as AL
 266
 267 $LB8NonBreaks $CP;
 268 $CAN_CM $CM*  $CP;
 269 $CM+          $CP;              # by rule 10, stand-alone CM behaves as AL
 270
 271 $LB8NonBreaks $EX;
 272 $CAN_CM $CM*  $EX;
 273 $CM+          $EX;              # by rule 10, stand-alone CM behaves as AL
 274
 275 $LB8NonBreaks $IS;
 276 $CAN_CM $CM*  $IS;
 277 $CM+          $IS;              # by rule 10, stand-alone CM behaves as AL
 278
 279 $LB8NonBreaks $SY;
 280 $CAN_CM $CM*  $SY;
 281 $CM+          $SY;              # by rule 10, stand-alone CM behaves as AL
 282
 283
 284 #
 285 # LB 14  Do not break after OP, even after spaces
 286 #
 287 $OPcm $SP* $CAN_CM $CM*;
 288 $OPcm $SP* $CANT_CM;
 289
 290 $OPcm $SP+ $CM+ $AL_FOLLOW?;    # by rule 10, stand-alone CM behaves as AL
 291
 292 # LB 15
 293 $QUcm $SP* $OPcm;
 294
 295 # LB 16
 296 ($CLcm | $CPcm) $SP* $NScm;
 297
 298 # LB 17
 299 $B2cm $SP* $B2cm;
 300
 301 #
 302 # LB 18  Break after spaces.
 303 #
 304 $LB18NonBreaks = [$LB8NonBreaks - [$SP]];
 305 $LB18Breaks    = [$LB8Breaks $SP];
 306
 307
 308 # LB 19
 309 #         x QU
 310 $LB18NonBreaks $CM* $QUcm;
 311 $CM+                $QUcm;
 312
 313 #         QU  x
 314 $QUcm .?;
 315 $QUcm $LB18NonBreaks $CM*;    # Don't let a combining mark go onto $CR, $BK, etc.
 316                               #  TODO:  I don't think this rule is needed.
 317
 318
 319 # LB 20
 320 #        <break>  $CB
 321 #        $CB   <break>
 322
 323 $LB20NonBreaks = [$LB18NonBreaks - $CB];
 324
 325 # LB 21        x   (BA | HY | NS)
 326 #           BB x
 327 #
 328 $LB20NonBreaks $CM* ($BAcm | $HYcm | $NScm);
 329
 330 $BBcm [^$CB];                                  #  $BB  x
 331 $BBcm $LB20NonBreaks $CM*;
 332
 333 # LB 22
 334 $ALcm    $INcm;
 335 $CM+     $INcm;     #  by rule 10, any otherwise unattached CM behaves as AL
 336 $IDcm    $INcm;
 337 $INcm    $INcm;
 338 $NUcm    $INcm;
 339
 340
 341 # $LB 23
 342 $IDcm  $POcm;
 343 $ALcm  $NUcm;       # includes $LB19
 344 $CM+   $NUcm;       # Rule 10, any otherwise unattached CM behaves as AL
 345 $NUcm  $ALcm;
 346
 347 #
 348 # LB 24
 349 #
 350 $PRcm $IDcm;
 351 $PRcm $ALcm;
 352 $POcm $ALcm;
 353
 354 #
 355 # LB 25   Numbers.
 356 #
 357 ($PRcm | $POcm)? ($OPcm | $HYcm)? $NUcm ($NUcm | $SYcm | $IScm)* ($CLcm | $CPcm)? ($PRcm | $POcm)?;
 358
 359 # LB 26  Do not break a Korean syllable
 360 #
 361 $JLcm ($JLcm | $JVcm | $H2cm | $H3cm);
 362 ($JVcm | $H2cm) ($JVcm | $JTcm);
 363 ($JTcm | $H3cm) $JTcm;
 364
 365 # LB 27  Treat korean Syllable Block the same as ID  (don't break it)
 366 ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm) $INcm;
 367 ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm) $POcm;
 368 $PRcm ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm);
 369
 370
 371 # LB 28   Do not break between alphabetics
 372 #
 373 $ALcm $ALcm;
 374 $CM+ $ALcm;      # The $CM+ is from rule 10, an unattached CM is treated as AL
 375
 376 # LB 29
 377 $IScm $ALcm;
 378
 379 # LB 30
 380 ($ALcm | $NUcm) $OPcm;
 381 $CM+ $OPcm;         # The $CM+ is from rule 10, an unattached CM is treated as AL.
 382 $CPcm ($ALcm | $NUcm);
 383
 384
 385 #
 386 #  Reverse Rules.
 387 #
 388 ## -------------------------------------------------
 389
 390 !!reverse;
 391
 392 $CM+ $ALPlus;
 393 $CM+ $BA;
 394 $CM+ $BB;
 395 $CM+ $B2;
 396 $CM+ $CL;
 397 $CM+ $CP;
 398 $CM+ $EX;
 399 $CM+ $GL;
 400 $CM+ $HY;
 401 $CM+ $H2;
 402 $CM+ $H3;
 403 $CM+ $ID;
 404 $CM+ $IN;
 405 $CM+ $IS;
 406 $CM+ $JL;
 407 $CM+ $JV;
 408 $CM+ $JT;
 409 $CM+ $NS;
 410 $CM+ $NU;
 411 $CM+ $OP;
 412 $CM+ $PO;
 413 $CM+ $PR;
 414 $CM+ $QU;
 415 $CM+ $SY;
 416 $CM+ $WJ;
 417 $CM+;
 418
 419
 420 #
 421 #  Sequences of the form  (shown forwards)
 422 #      [CANT_CM]  <break>  [CM]  [whatever]
 423 #  The CM needs to behave as an AL
 424 #
 425 $AL_FOLLOW $CM+ / (
 426           [$BK $CR $LF $NL $ZW {eof}] |
 427           $SP+ $CM+ $SP |
 428           $SP+ $CM* ([^$OP $CM $SP] | [$AL {eof}]));   # if LB 14 will match, need to surpress this break.
 429                                                #  LB14 says    OP SP* x .
 430                                                #    becomes    OP SP* x AL
 431                                                #    becomes    OP SP* x CM+ AL_FOLLOW
 432                                                #
 433                                                # Further note:  the $AL in [$AL {eof}] is only to work around
 434                                                #                a rule compiler bug which complains about
 435                                                #                empty sets otherwise.
 436
 437 #
 438 #  Sequences of the form  (shown forwards)
 439 #      [CANT_CM]  <break> [CM]  <break>  [PR]
 440 #  The CM needs to behave as an AL
 441 #  This rule is concerned about getting the second of the two <breaks> in place.
 442 #
 443
 444 [$PR   ] / $CM+ [$BK $CR $LF $NL $ZW $SP {eof}];
 445
 446
 447
 448 # LB 4, 5, 5
 449
 450 $LB4Breaks [$LB4NonBreaks-$CM];
 451 $LB4Breaks $CM+ $CAN_CM;
 452 $LF $CR;
 453
 454
 455 # LB 7         x SP
 456 #              x ZW
 457 [$SP $ZW] [$LB4NonBreaks-$CM];
 458 [$SP $ZW] $CM+ $CAN_CM;
 459
 460 # LB 8 ZW SP* <break>
 461 #     TODO: to implement this, we need more than one look-ahead hard break in play at a time.
 462 #           Requires an engine enhancement.
 463 #   / $SP* $ZW
 464
 465 # LB 9,10  Combining marks.
 466 #    X   $CM needs to behave like X, where X is not $SP or controls.
 467 #    $CM not covered by the above needs to behave like $AL
 468 # Stick together any combining sequences that don't match other rules.
 469 $CM+ $CAN_CM;
 470
 471
 472 # LB 11
 473 $CM* $WJ $CM* $CAN_CM;
 474 $CM* $WJ      [$LB8NonBreaks-$CM];
 475
 476      $CANT_CM $CM* $WJ;
 477 $CM* $CAN_CM  $CM* $WJ;
 478
 479 # LB 12a
 480 #      [^SP BA HY] x GL
 481 #
 482 $CM* $GL $CM* [$LB8NonBreaks-[$CM $SP $BA $HY]];
 483
 484 # LB 12
 485 #     GL  x
 486 #
 487 $CANT_CM $CM* $GL;
 488 $CM* $CAN_CM $CM* $GL;
 489
 490
 491 # LB 13
 492 $CL $CM+ $CAN_CM;
 493 $CP $CM+ $CAN_CM;
 494 $EX $CM+ $CAN_CM;
 495 $IS $CM+ $CAN_CM;
 496 $SY $CM+ $CAN_CM;
 497
 498 $CL [$LB8NonBreaks-$CM];
 499 $CP [$LB8NonBreaks-$CM];
 500 $EX [$LB8NonBreaks-$CM];
 501 $IS [$LB8NonBreaks-$CM];
 502 $SY [$LB8NonBreaks-$CM];
 503
 504 # Rule 13 & 14 taken together for an edge case.
 505 #   Match this, shown forward
 506 #     OP SP+  ($CM+ behaving as $AL) (CL | CP | EX | IS | IY)
 507 #   This really wants to chain at the $CM+ (which is acting as an $AL)
 508 #   except for $CM chaining being disabled.
 509 [$CL $CP $EX $IS $SY] $CM+ $SP+ $CM* $OP;
 510
 511 # LB 14    OP SP* x
 512 #
 513 $CM* $CAN_CM    $SP* $CM* $OP;
 514      $CANT_CM   $SP* $CM* $OP;
 515 $AL_FOLLOW? $CM+  $SP $SP* $CM* $OP;     #  by LB 10, behaves like $AL_FOLLOW? $AL $SP* $CM* $OP
 516
 517      $AL_FOLLOW_NOCM $CM+ $SP+ $CM* $OP;
 518 $CM* $AL_FOLLOW_CM   $CM+ $SP+ $CM* $OP;
 519 $SY $CM $SP+ $OP;   # TODO:  Experiment.  Remove.
 520
 521
 522
 523 # LB 15
 524 $CM* $OP $SP* $CM* $QU;
 525
 526 # LB 16
 527 $CM* $NS $SP* $CM* ($CL | $CP);
 528
 529 # LB 17
 530 $CM* $B2 $SP* $CM* $B2;
 531
 532 # LB 18  break after spaces
 533 #        Nothing explicit needed here.
 534
 535
 536 #
 537 # LB 19
 538 #
 539 $CM* $QU $CM* $CAN_CM;                                #   . x QU
 540 $CM* $QU      $LB18NonBreaks;
 541
 542
 543 $CM* $CAN_CM  $CM* $QU;                               #   QU x .
 544      $CANT_CM $CM* $QU;
 545
 546 #
 547 #  LB 20  Break before and after CB.
 548 #         nothing needed here.
 549 #
 550
 551 # LB 21
 552 $CM* ($BA | $HY | $NS) $CM* [$LB20NonBreaks-$CM];     #  . x (BA | HY | NS)
 553
 554 $CM* [$LB20NonBreaks-$CM] $CM* $BB;                   #  BB x .
 555 [^$CB] $CM* $BB;                                      #
 556
 557
 558
 559 # LB 22
 560 $CM* $IN $CM* $ALPlus;
 561 $CM* $IN $CM* $ID;
 562 $CM* $IN $CM* $IN;
 563 $CM* $IN $CM* $NU;
 564
 565 # LB 23
 566 $CM* $PO $CM* $ID;
 567 $CM* $NU $CM* $ALPlus;
 568 $CM* $ALPlus $CM* $NU;
 569
 570 # LB 24
 571 $CM* $ID $CM* $PR;
 572 $CM* $ALPlus $CM* $PR;
 573 $CM* $ALPlus $CM* $PO;
 574
 575
 576 # LB 25
 577 ($CM* ($PR | $PO))? ($CM* ($CL | $CP))? ($CM* ($NU | $IS | $SY))* $CM* $NU ($CM* ($OP | $HY))? ($CM* ($PR | $PO))?;
 578
 579 # LB 26
 580 $CM* ($H3 | $H2 | $JV | $JL) $CM* $JL;
 581 $CM* ($JT | $JV) $CM* ($H2 | $JV);
 582 $CM* $JT $CM* ($H3 | $JT);
 583
 584 # LB 27
 585 $CM* $IN $CM* ($H3 | $H2 | $JT | $JV | $JL);
 586 $CM* $PO $CM* ($H3 | $H2 | $JT | $JV | $JL);
 587 $CM* ($H3 | $H2 | $JT | $JV | $JL) $CM* $PR;
 588
 589 # LB 28
 590 $CM* $ALPlus $CM* $ALPlus;
 591
 592
 593 # LB 29
 594 $CM* $ALPlus $CM* $IS;
 595
 596 # LB 30
 597 $CM* $OP $CM* ($ALPlus | $NU);
 598 $CM* ($ALPlus | $NU) $CM* $CP;
 599
 600
 601 ## -------------------------------------------------
 602
 603 !!safe_reverse;
 604
 605 # LB 9
 606 $CM+ [^$CM $BK $CR $LF $NL $ZW $SP];
 607 $CM+ $SP / .;
 608
 609 # LB 14
 610 $SP+ $CM* $OP;
 611
 612 # LB 15
 613 $SP+ $CM* $QU;
 614
 615 # LB 16
 616 $SP+ $CM* ($CL | $CP);
 617
 618 # LB 17
 619 $SP+ $CM* $B2;
 620
 621 # LB 25
 622 ($CM* ($IS | $SY))+ $CM* $NU;
 623 ($CL | $CP) $CM* ($NU | $IS | $SY);
 624
 625 # For dictionary-based break
 626 $dictionary $dictionary;
 627
 628 ## -------------------------------------------------
 629
 630 !!safe_forward;
 631
 632 # Skip forward over all character classes that are involved in
 633 #   rules containing patterns with possibly more than one char
 634 #   of context.
 635 #
 636 #  It might be slightly more efficient to have specific rules
 637 #  instead of one generic one, but only if we could
 638 #  turn off rule chaining.  We don't want to move more
 639 #  than necessary.
 640 #
 641 [$CM $OP $QU $CL $CP $B2 $PR $HY $SP $dictionary]+ [^$CM $OP $QU $CL $CP $B2 $PR $HY $dictionary];
 642 $dictionary $dictionary;
 643