icuSources/data/brkitr/rules/line_fi.txt

   1 # Copyright (c) 2002-2016  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 35 for Unicode 8.0
   9 #         http://www.unicode.org/reports/tr14/
  10 #         tailored as noted in 2nd paragraph below..
  11 #
  12 #         Includes the Emoji breaking proposals from Unicode L2/16-011R3.
  13 #         http://www.unicode.org/L2/L2016/16011r3-break-prop-emoji.pdf
  14 #
  15 #         TODO:  Rule LB 8 remains as it was in Unicode 5.2
  16 #         This is only because of a limitation of ICU break engine implementation,
  17 #         not because the older behavior is desirable.
  18 #
  19 #         This tailors the line break behavior for Finnish, while otherwise behaving
  20 #         per UAX 14 which corresponds to CSS line-break=strict (BCP47 -u-lb-strict).
  21 #         It sets characters of class CJ to behave like NS.
  22
  23 #
  24 #  Character Classes defined by TR 14.
  25 #
  26
  27 !!chain;
  28
  29 !!lookAheadHardBreak;
  30 #
  31 #  !!lookAheadHardBreak    Described here because it is (as yet) undocumented elsewhere
  32 #                          and only used for the line break rules.
  33 #
  34 #           It is used in the implementation of rule LB 10
  35 #           which says to treat any combining mark that is not attached to a base
  36 #           character as if it were of class AL  (alphabetic).
  37 #
  38 #           The problem occurs in the reverse rules.
  39 #
  40 #           Consider a sequence like, with correct breaks as shown
  41 #               LF  ID  CM  AL  AL
  42 #                  ^       ^       ^
  43 #           Then consider the sequence without the initial ID (ideographic)
  44 #                 LF  CM  AL  AL
  45 #                    ^           ^
  46 #           Our CM, which in the first example was attached to the ideograph,
  47 #           is now unattached, becomes an alpha, and joins in with the other
  48 #           alphas.
  49 #
  50 #           When iterating forwards, these sequences do not present any problems
  51 #           When iterating backwards, we need to look ahead when encountering
  52 #           a CM to see whether it attaches to something further on or not.
  53 #           (Look-ahead in a reverse rule is looking towards the start)
  54 #
  55 #           If the CM is unattached, we need to force a break.
  56 #
  57 #           !!lookAheadHardBreak forces the run time state machine to
  58 #           stop immediately when a look ahead rule ( '/' operator) matches,
  59 #           and set the match position to that of the look-ahead operator,
  60 #           no matter what other rules may be in play at the time.
  61 #
  62 #           See rule LB 19 for an example.
  63 #
  64
  65 # Temporary definitions of Emoji Base and Emoji Modifiers, until properties are available.
  66
  67 $EB = [\u261D\u26F9\u270A-\u270D\U0001F385\U0001F3C2-\U0001F3C4\U0001F3C7\U0001F3CA-\U0001F3CC\U0001F442-\U0001F443\U0001F446-\U0001F450\U0001F466-\U0001F478\U0001F47C\U0001F481-\U0001F483\U0001F485-\U0001F487\U0001F4AA\U0001F574-\U0001F575\U0001F57A\U0001F590\U0001F595-\U0001F596\U0001F645-\U0001F647\U0001F64B-\U0001F64F\U0001F6A3\U0001F6B4-\U0001F6B6\U0001F6C0\U0001F6CC\U0001F918-\U0001F91E\U0001F926\U0001F930\U0001F933-\U0001F939\U0001F93C-\U0001F93E];
  68 $EM = [\U0001F3FB-\U0001F3FF];
  69
  70 $AI = [[:LineBreak =  Ambiguous:] - [\u2640\u2642]];
  71 $AL = [[:LineBreak =  Alphabetic:] - [$EM\u2695\u2696\u2764]];
  72 $BA = [:LineBreak =  Break_After:];
  73 $HH = [\u2010];
  74 $BB = [:LineBreak =  Break_Before:];
  75 $BK = [:LineBreak =  Mandatory_Break:];
  76 $B2 = [:LineBreak =  Break_Both:];
  77 $CB = [:LineBreak =  Contingent_Break:];
  78 $CJ = [:LineBreak =  Conditional_Japanese_Starter:];
  79 $CL = [:LineBreak =  Close_Punctuation:];
  80 $CM = [[:LineBreak =  Combining_Mark:] \u200d];
  81 $CP = [:LineBreak =  Close_Parenthesis:];
  82 $CR = [:LineBreak =  Carriage_Return:];
  83 $EX = [:LineBreak =  Exclamation:];
  84 $GL = [:LineBreak =  Glue:];
  85 $HL = [:LineBreak =  Hebrew_Letter:];
  86 $HY = [:LineBreak =  Hyphen:];
  87 $H2 = [:LineBreak =  H2:];
  88 $H3 = [:LineBreak =  H3:];
  89 $ID = [[:LineBreak =  Ideographic:][\u2640\u2642\u2695\u2696\u2764] - $EB];
  90 $IN = [:LineBreak =  Inseperable:];
  91 $IS = [:LineBreak =  Infix_Numeric:];
  92 $JL = [:LineBreak =  JL:];
  93 $JV = [:LineBreak =  JV:];
  94 $JT = [:LineBreak =  JT:];
  95 $LF = [:LineBreak =  Line_Feed:];
  96 $NL = [:LineBreak =  Next_Line:];
  97 $NS = [[:LineBreak =  Nonstarter:] $CJ];
  98 $NU = [:LineBreak =  Numeric:];
  99 $OP = [:LineBreak =  Open_Punctuation:];
 100 $PO = [:LineBreak =  Postfix_Numeric:];
 101 $PR = [:LineBreak =  Prefix_Numeric:];
 102 $QU = [:LineBreak =  Quotation:];
 103 $RI = [:LineBreak =  Regional_Indicator:];
 104 $SA = [:LineBreak =  Complex_Context:];
 105 $SG = [:LineBreak =  Surrogate:];
 106 $SP = [:LineBreak =  Space:];
 107 $SY = [:LineBreak =  Break_Symbols:];
 108 $WJ = [:LineBreak =  Word_Joiner:];
 109 $XX = [:LineBreak =  Unknown:];
 110 $ZW = [:LineBreak =  ZWSpace:];
 111 $ZWJ = [\u200d];
 112
 113 #   Dictionary character set, for triggering language-based break engines. Currently
 114 #   limited to LineBreak=Complex_Context. Note that this set only works in Unicode
 115 #   5.0 or later as the definition of Complex_Context was corrected to include all
 116 #   characters requiring dictionary break.
 117
 118 $dictionary = [:LineBreak = Complex_Context:];
 119
 120 #
 121 #  Rule LB1.  By default, treat AI  (characters with ambiguous east Asian width),
 122 #                               SA  (South East Asian: Thai, Lao, Khmer)
 123 #                               SG  (Unpaired Surrogates)
 124 #                               XX  (Unknown, unassigned)
 125 #                         as $AL  (Alphabetic)
 126 #
 127 $ALPlus = [$AL $AI $SA $SG $XX];
 128
 129 #
 130 #  Combining Marks.   X $CM*  behaves as if it were X.  Rule LB6.
 131 #
 132 $ALcm = $ALPlus $CM*;
 133 $BAcm = $BA $CM*;
 134 $HHcm = $HH $CM*;
 135 $BBcm = $BB $CM*;
 136 $B2cm = $B2 $CM*;
 137 $CLcm = $CL $CM*;
 138 $CPcm = $CP $CM*;
 139 $EXcm = $EX $CM*;
 140 $GLcm = $GL $CM*;
 141 $HLcm = $HL $CM*;
 142 $HYcm = $HY $CM*;
 143 $H2cm = $H2 $CM*;
 144 $H3cm = $H3 $CM*;
 145 $INcm = $IN $CM*;
 146 $IScm = $IS $CM*;
 147 $JLcm = $JL $CM*;
 148 $JVcm = $JV $CM*;
 149 $JTcm = $JT $CM*;
 150 $NScm = $NS $CM*;
 151 $NUcm = $NU $CM*;
 152 $OPcm = $OP $CM*;
 153 $POcm = $PO $CM*;
 154 $PRcm = $PR $CM*;
 155 $QUcm = $QU $CM*;
 156 $RIcm = $RI $CM*;
 157 $SYcm = $SY $CM*;
 158 $WJcm = $WJ $CM*;
 159
 160 ## -------------------------------------------------
 161
 162 !!forward;
 163
 164 #
 165 #  Each class of character can stand by itself as an unbroken token, with trailing combining stuff
 166 #
 167 $ALPlus $CM+;
 168 $BA $CM+;
 169 $HH $CM+;
 170 $BB $CM+;
 171 $B2 $CM+;
 172 $CL $CM+;
 173 $CP $CM+;
 174 $EB $CM+;
 175 $EM $CM+;
 176 $EX $CM+;
 177 $GL $CM+;
 178 $HL $CM+;
 179 $HY $CM+;
 180 $H2 $CM+;
 181 $H3 $CM+;
 182 $ID $CM+;
 183 $IN $CM+;
 184 $IS $CM+;
 185 $JL $CM+;
 186 $JV $CM+;
 187 $JT $CM+;
 188 $NS $CM+;
 189 $NU $CM+;
 190 $OP $CM+;
 191 $PO $CM+;
 192 $PR $CM+;
 193 $QU $CM+;
 194 $RI $CM+;
 195 $SY $CM+;
 196 $WJ $CM+;
 197
 198 #
 199 # CAN_CM  is the set of characters that may combine with CM combining chars.
 200 #         Note that Linebreak UAX 14's concept of a combining char and the rules
 201 #         for what they can combine with are _very_ different from the rest of Unicode.
 202 #
 203 #         Note that $CM itself is left out of this set.  If CM is needed as a base
 204 #         it must be listed separately in the rule.
 205 #
 206 $CAN_CM  = [^$SP $BK $CR $LF $NL $ZW $CM];       # Bases that can   take CMs
 207 $CANT_CM = [ $SP $BK $CR $LF $NL $ZW $CM];       # Bases that can't take CMs
 208
 209 #
 210 # AL_FOLLOW  set of chars that can unconditionally follow an AL
 211 #            Needed in rules where stand-alone $CM s are treated as AL.
 212 #            Chaining is disabled with CM because it causes other failures,
 213 #            so for this one case we need to manually list out longer sequences.
 214 #
 215 $AL_FOLLOW_NOCM = [$BK $CR $LF $NL $ZW $SP];
 216 $AL_FOLLOW_CM   = [$CL $CP $EX $HL $IS $SY $WJ $GL $OP $QU $BA $HH $HY $NS $IN $NU $ALPlus];
 217 $AL_FOLLOW      = [$AL_FOLLOW_NOCM $AL_FOLLOW_CM];
 218
 219
 220 #
 221 #  Rule LB 4, 5    Mandatory (Hard) breaks.
 222 #
 223 $LB4Breaks    = [$BK $CR $LF $NL];
 224 $LB4NonBreaks = [^$BK $CR $LF $NL $CM];
 225 $CR $LF {100};
 226
 227 #
 228 #  LB 6    Do not break before hard line breaks.
 229 #
 230 $LB4NonBreaks?  $LB4Breaks {100};    # LB 5  do not break before hard breaks.
 231 $CAN_CM $CM*    $LB4Breaks {100};
 232 ^$CM+           $LB4Breaks {100};
 233
 234 # LB 7         x SP
 235 #              x ZW
 236 $LB4NonBreaks [$SP $ZW];
 237 $CAN_CM $CM*  [$SP $ZW];
 238 ^$CM+         [$SP $ZW];
 239
 240 #
 241 # LB 8         Break after zero width space
 242 #              TODO:  ZW SP* <break>
 243 #              An engine change is required to write the reverse rule for this.
 244 #              For now, leave the Unicode 5.2 rule, ZW <break>
 245 #
 246 $LB8Breaks    = [$LB4Breaks $ZW];
 247 $LB8NonBreaks = [[$LB4NonBreaks] - [$ZW]];
 248
 249 # LB 8a        ZWJ x ID    Emoji proposal.
 250 #
 251 $ZWJ ($ID | $EB | $EM);
 252
 253 # LB 9     Combining marks.      X   $CM needs to behave like X, where X is not $SP, $BK $CR $LF $NL
 254 #                                $CM not covered by the above needs to behave like $AL
 255 #                                See definition of $CAN_CM.
 256
 257 $CAN_CM $CM+;                   #  Stick together any combining sequences that don't match other rules.
 258 ^$CM+;
 259
 260 #
 261 # LB 11  Do not break before or after WORD JOINER & related characters.
 262 #
 263 $CAN_CM $CM*  $WJcm;
 264 $LB8NonBreaks $WJcm;
 265 ^$CM+         $WJcm;
 266
 267 $WJcm $CANT_CM;
 268 $WJcm $CAN_CM $CM*;
 269
 270 #
 271 # LB 12  Do not break after NBSP and related characters.
 272 #         GL  x
 273 #
 274 $GLcm $CAN_CM $CM*;
 275 $GLcm $CANT_CM;
 276
 277 #
 278 # LB 12a  Do not break before NBSP and related characters ...
 279 #            [^SP BA HY] x GL
 280 #
 281 [[$LB8NonBreaks] - [$SP $BA $HH $HY]] $CM* $GLcm;
 282 ^$CM+ $GLcm;
 283
 284
 285
 286 #
 287 # LB 13   Don't break before ']' or '!' or ';' or '/', even after spaces.
 288 #
 289 $LB8NonBreaks $CL;
 290 $CAN_CM $CM*  $CL;
 291 ^$CM+         $CL;              # by rule 10, stand-alone CM behaves as AL
 292
 293 $LB8NonBreaks $CP;
 294 $CAN_CM $CM*  $CP;
 295 ^$CM+         $CP;              # by rule 10, stand-alone CM behaves as AL
 296
 297 $LB8NonBreaks $EX;
 298 $CAN_CM $CM*  $EX;
 299 ^$CM+         $EX;              # by rule 10, stand-alone CM behaves as AL
 300
 301 $LB8NonBreaks $IS;
 302 $CAN_CM $CM*  $IS;
 303 ^$CM+         $IS;              # by rule 10, stand-alone CM behaves as AL
 304
 305 $LB8NonBreaks $SY;
 306 $CAN_CM $CM*  $SY;
 307 ^$CM+         $SY;              # by rule 10, stand-alone CM behaves as AL
 308
 309
 310 #
 311 # LB 14  Do not break after OP, even after spaces
 312 #
 313 $OPcm $SP* $CAN_CM $CM*;
 314 $OPcm $SP* $CANT_CM;
 315
 316 $OPcm $SP+ $CM+ $AL_FOLLOW?;    # by rule 10, stand-alone CM behaves as AL
 317
 318 # LB 15
 319 $QUcm $SP* $OPcm;
 320
 321 # LB 16
 322 ($CLcm | $CPcm) $SP* $NScm;
 323
 324 # LB 17
 325 $B2cm $SP* $B2cm;
 326
 327 #
 328 # LB 18  Break after spaces.
 329 #
 330 $LB18NonBreaks = [$LB8NonBreaks - [$SP]];
 331 $LB18Breaks    = [$LB8Breaks $SP];
 332
 333
 334 # LB 19
 335 #         x QU
 336 $LB18NonBreaks $CM* $QUcm;
 337 ^$CM+               $QUcm;
 338
 339 #         QU  x
 340 $QUcm .?;
 341
 342
 343 # LB 20
 344 #        <break>  $CB
 345 #        $CB   <break>
 346
 347 $LB20NonBreaks = [$LB18NonBreaks - $CB];
 348
 349 # LB 20.09 added rule for Finnish tailoring
 350 # LB 21        x   (BA | HY | NS)
 351 #           BB x
 352 #
 353 $LB20NonBreaks $CM* ($BAcm | $HHcm | $HYcm | $NScm) / $AL;
 354 $LB20NonBreaks $CM* ($BAcm | $HHcm | $HYcm | $NScm);
 355 ($HY | $HH) $AL;
 356 ^$CM+ ($BAcm | $HYcm | $HHcm | $NScm);
 357
 358 $BBcm [^$CB];                                  #  $BB  x
 359 $BBcm $LB20NonBreaks $CM*;
 360
 361 # LB 21a Don't break after Hebrew + Hyphen
 362 #   HL (HY | BA) x
 363 #
 364 $HLcm ($HYcm | $BAcm | $HHcm) [^$CB]?;
 365
 366 # LB 21b (forward) Don't break between SY and HL
 367 # (break between HL and SY already disallowed by LB 13 above)
 368 $SYcm $HLcm;
 369
 370 # LB 22
 371 ($ALcm | $HLcm) $INcm;
 372 ^$CM+    $INcm;     #  by rule 10, any otherwise unattached CM behaves as AL
 373 $EXcm    $INcm;
 374 ($ID | $EB | $EM) $CM*  $INcm;
 375 $INcm    $INcm;
 376 $NUcm    $INcm;
 377
 378
 379 # $LB 23
 380 ($ID | $EB | $EM) $CM*  $POcm;
 381 $ALcm  $NUcm;       # includes $LB19
 382 $HLcm  $NUcm;
 383 ^$CM+  $NUcm;       # Rule 10, any otherwise unattached CM behaves as AL
 384 $NUcm  $ALcm;
 385 $NUcm  $HLcm;
 386
 387 #
 388 # LB 24
 389 #
 390 $PRcm ($ID | $EB | $EM);
 391 $PRcm ($ALcm | $HLcm);
 392 $POcm ($ALcm | $HLcm);
 393 ($ALcm | $HLcm) ($PRcm | $POcm);
 394 ^$CM+ ($PRcm | $POcm);       # Rule 10, any otherwise unattached CM behaves as AL
 395
 396 #
 397 # LB 25   Numbers.
 398 #
 399 ($PRcm | $POcm)? ($OPcm | $HYcm)? $NUcm ($NUcm | $SYcm | $IScm)* ($CLcm | $CPcm)? ($PRcm | $POcm)?;
 400
 401 # LB 26  Do not break a Korean syllable
 402 #
 403 $JLcm ($JLcm | $JVcm | $H2cm | $H3cm);
 404 ($JVcm | $H2cm) ($JVcm | $JTcm);
 405 ($JTcm | $H3cm) $JTcm;
 406
 407 # LB 27  Treat korean Syllable Block the same as ID  (don't break it)
 408 ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm) $INcm;
 409 ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm) $POcm;
 410 $PRcm ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm);
 411
 412
 413 # LB 28   Do not break between alphabetics
 414 #
 415 ($ALcm | $HLcm) ($ALcm | $HLcm);
 416 ^$CM+ ($ALcm | $HLcm);      # The $CM+ is from rule 10, an unattached CM is treated as AL
 417
 418 # LB 29
 419 $IScm ($ALcm | $HLcm);
 420
 421 # LB 30
 422 ($ALcm | $HLcm | $NUcm) $OPcm;
 423 ^$CM+ $OPcm;         # The $CM+ is from rule 10, an unattached CM is treated as AL.
 424 $CPcm ($ALcm | $HLcm | $NUcm);
 425
 426 # LB 30a  Do not break between regional indicators. Break after pairs of them.
 427 #         Tricky interaction with LB8a: ZWJ x ID
 428 $RIcm $RI                / [[^$BK $CR $LF $NL $SP $ZW $WJ $CL $CP $EX $IS $SY $GL $QU $BA $HY $NS $CM] {eof}];
 429 $RIcm $RI $CM*  $ZWJ     / [[^$BK $CR $LF $NL $SP $ZW $WJ $CL $CP $EX $IS $SY $GL $QU $BA $HY $NS $CM $ID $EB $EM] {eof}];
 430 $RIcm $RI $CM* [$CM-$ZWJ] / [[^$BK $CR $LF $NL $SP $ZW $WJ $CL $CP $EX $IS $SY $GL $QU $BA $HY $NS $CM] {eof}];
 431
 432 $RIcm $RIcm [$BK $CR $LF $NL $SP $ZW $WJ $CL $CP $EX $IS $SY $GL $QU $BA $HY $NS {eof}];
 433 $RIcm $RIcm $ZWJ ($ID | $EB | $EM);
 434
 435 # LB 30b Do not break between an Emoji Base and an Emoji Modifier
 436 $EB $CM* $EM;
 437
 438 #
 439 #  Reverse Rules.
 440 #
 441 ## -------------------------------------------------
 442
 443 !!reverse;
 444
 445 ^$CM+ $ALPlus;
 446 ^$CM+ $BA;
 447 ^$CM+ $HH;
 448 ^$CM+ $BB;
 449 ^$CM+ $B2;
 450 ^$CM+ $CL;
 451 ^$CM+ $CP;
 452 ^$CM+ $EB;
 453 ^$CM+ $EM;
 454 ^$CM+ $EX;
 455 ^$CM+ $GL;
 456 ^$CM+ $HL;
 457 ^$CM+ $HY;
 458 ^$CM+ $H2;
 459 ^$CM+ $H3;
 460 ^$CM+ $ID;
 461 ^$CM+ $IN;
 462 ^$CM+ $IS;
 463 ^$CM+ $JL;
 464 ^$CM+ $JV;
 465 ^$CM+ $JT;
 466 ^$CM+ $NS;
 467 ^$CM+ $NU;
 468 ^$CM+ $OP;
 469 ^$CM+ $PO;
 470 ^$CM+ $PR;
 471 ^$CM+ $QU;
 472 ^$CM+ $RI;
 473 ^$CM+ $SY;
 474 ^$CM+ $WJ;
 475 ^$CM+;
 476
 477
 478 #
 479 #  Sequences of the form  (shown forwards)
 480 #      [CANT_CM]  <break>  [CM]  [whatever]
 481 #  The CM needs to behave as an AL
 482 #
 483 $AL_FOLLOW $CM+ / (
 484           [$BK $CR $LF $NL $ZW {eof}] |
 485           $SP+ $CM+ $SP |
 486           $SP+ $CM* ([^$OP $CM $SP] | [$AL {eof}]));   # if LB 14 will match, need to surpress this break.
 487                                                #  LB14 says    OP SP* x .
 488                                                #    becomes    OP SP* x AL
 489                                                #    becomes    OP SP* x CM+ AL_FOLLOW
 490                                                #
 491                                                # Further note:  the $AL in [$AL {eof}] is only to work around
 492                                                #                a rule compiler bug which complains about
 493                                                #                empty sets otherwise.
 494
 495 #
 496 #  Sequences of the form  (shown forwards)
 497 #      [CANT_CM]  <break> [CM]  <break>  [PR]
 498 #  The CM needs to behave as an AL
 499 #  This rule is concerned about getting the second of the two <breaks> in place.
 500 #
 501
 502 # Apple early addition, remove this, superseded by LB24
 503 # [$PR   ] / $CM+ [$BK $CR $LF $NL $ZW $SP {eof}];
 504
 505
 506
 507 # LB 4, 5, 6
 508
 509 $LB4Breaks [$LB4NonBreaks-$CM];
 510 $LB4Breaks $CM+ $CAN_CM;
 511 $LF $CR;
 512
 513
 514 # LB 7         x SP
 515 #              x ZW
 516 [$SP $ZW] [$LB4NonBreaks-$CM];
 517 [$SP $ZW] $CM+ $CAN_CM;
 518
 519 # LB 8 ZW SP* <break>
 520 #     TODO: to implement this, we need more than one look-ahead hard break in play at a time.
 521 #           Requires an engine enhancement.
 522 #   / $SP* $ZW
 523
 524 # LB 8a        ZWJ x ID    Unicode Emoji proposal L2/16-011R3
 525 #                          The ZWJ will look like a CM to whatever precedes it.
 526 #
 527 ($ID | $EB | $EM) $ZWJ $CM* $CAN_CM?;
 528
 529
 530 # LB 9,10  Combining marks.
 531 #    X   $CM needs to behave like X, where X is not $SP or controls.
 532 #    $CM not covered by the above needs to behave like $AL
 533 # Stick together any combining sequences that don't match other rules.
 534 ^$CM+ $CAN_CM;
 535
 536
 537 # LB 11
 538 #
 539 $WJ $CM* $CAN_CM;
 540 $WJ      [$LB8NonBreaks-$CM];
 541
 542      $CANT_CM $CM* $WJ;
 543 $CAN_CM  $CM* $WJ;
 544
 545 # LB 12a
 546 #      [^SP BA HY] x GL
 547 #
 548 $GL $CM* [$LB8NonBreaks-[$CM $SP $BA $HH $HY]];
 549
 550 # LB 12
 551 #     GL  x
 552 #
 553 $CANT_CM $CM* $GL;
 554 $CAN_CM $CM* $GL;
 555
 556
 557 # LB 13
 558 $CL $CM+ $CAN_CM;
 559 $CP $CM+ $CAN_CM;
 560 $EX $CM+ $CAN_CM;
 561 $IS $CM+ $CAN_CM;
 562 $SY $CM+ $CAN_CM;
 563
 564 $CL [$LB8NonBreaks-$CM];
 565 $CP [$LB8NonBreaks-$CM];
 566 $EX [$LB8NonBreaks-$CM];
 567 $IS [$LB8NonBreaks-$CM];
 568 $SY [$LB8NonBreaks-$CM];
 569
 570 # Rule 13 & 14 taken together for an edge case.
 571 #   Match this, shown forward
 572 #     OP SP+  ($CM+ behaving as $AL) (CL | CP | EX | IS | IY)
 573 #   This really wants to chain at the $CM+ (which is acting as an $AL)
 574 #   except for $CM chaining being disabled.
 575 [$CL $CP $EX $IS $SY] $CM+ $SP+ $CM* $OP;
 576
 577 # LB 14    OP SP* x
 578 #
 579 $CAN_CM    $SP* $CM* $OP;
 580      $CANT_CM   $SP* $CM* $OP;
 581 $AL_FOLLOW? $CM+  $SP $SP* $CM* $OP;     #  by LB 10, behaves like $AL_FOLLOW? $AL $SP* $CM* $OP
 582
 583      $AL_FOLLOW_NOCM $CM+ $SP+ $CM* $OP;
 584 $AL_FOLLOW_CM   $CM+ $SP+ $CM* $OP;
 585
 586
 587 # LB 15
 588 $OP $SP* $CM* $QU;
 589
 590 # LB 16
 591 $NS $SP* $CM* ($CL | $CP);
 592
 593 # LB 17
 594 $B2 $SP* $CM* $B2;
 595
 596 # LB 18  break after spaces
 597 #        Nothing explicit needed here.
 598
 599
 600 #
 601 # LB 19
 602 #
 603 $QU $CM* $CAN_CM;                                #   . x QU
 604 $QU      $LB18NonBreaks;
 605
 606
 607 $CAN_CM  $CM* $QU;                               #   QU x .
 608      $CANT_CM $CM* $QU;
 609
 610 #
 611 #  LB 20  Break before and after CB.
 612 #         nothing needed here.
 613 #
 614
 615 # LB 20.09 added rule for Finnish tailoring
 616 $AL ($HY | $HH) / $SP;
 617
 618 # LB 21
 619 ($BA | $HH | $HY | $NS) $CM* [$LB20NonBreaks-$CM];     #  . x (BA | HY | NS)
 620
 621 [$LB20NonBreaks-$CM] $CM* $BB;                        #  BB x .
 622 [^$CB] $CM* $BB;                                      #
 623
 624 # LB21a
 625 [^$CB] $CM* ($HY | $BA | $HH) $CM* $HL;
 626
 627 # LB21b (reverse)
 628 $HL $CM* $SY;
 629
 630 # LB 22
 631 $IN $CM* ($ALPlus | $HL);
 632 $IN $CM* $EX;
 633 $IN $CM* ($ID | $EB | $EM);
 634 $IN $CM* $IN;
 635 $IN $CM* $NU;
 636
 637 # LB 23
 638 $PO $CM* ($ID | $EB | $EM);
 639 $NU $CM* ($ALPlus | $HL);
 640 ($ALPlus | $HL) $CM* $NU;
 641
 642 # LB 24
 643 ($ID | $EB | $EM) $CM* $PR;
 644 ($ALPlus | $HL) $CM* $PR;
 645 ($ALPlus | $HL) $CM* $PO;
 646 $CM* ($PR | $PO) $CM* ($ALPlus | $HL);
 647 $CM* ($PR | $PO) $CM+ / [$BK $CR $LF $NL $ZW $SP {eof}];
 648
 649 # LB 25
 650 ($CM* ($PR | $PO))? ($CM* ($CL | $CP))? ($CM* ($NU | $IS | $SY))* $CM* $NU ($CM* ($OP | $HY))? ($CM* ($PR | $PO))?;
 651
 652 # LB 26
 653 ($H3 | $H2 | $JV | $JL) $CM* $JL;
 654 ($JT | $JV) $CM* ($H2 | $JV);
 655 $JT $CM* ($H3 | $JT);
 656
 657 # LB 27
 658 $IN $CM* ($H3 | $H2 | $JT | $JV | $JL);
 659 $PO $CM* ($H3 | $H2 | $JT | $JV | $JL);
 660  ($H3 | $H2 | $JT | $JV | $JL) $CM* $PR;
 661
 662 # LB 28
 663 ($ALPlus | $HL) $CM* ($ALPlus | $HL);
 664
 665
 666 # LB 29
 667 ($ALPlus | $HL) $CM* $IS;
 668
 669 # LB 30
 670 $OP $CM* ($ALPlus | $HL | $NU);
 671 ($ALPlus | $HL | $NU) $CM* $CP;
 672
 673 # LB 30a
 674 #    Pairs of Regional Indicators.
 675 #    The following two rules are nearly identical. The first matches only sequences with an odd number of adjacent RIs,
 676 #    the second with an even number. Stripping away the cruft they look like
 677 #         [^RI] RI / (RI RI)+ ^RI;
 678 #         [^RI] RI RI / (RI RI)+ ^RI;
 679 #
 680 [{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]];
 681 [{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]];
 682
 683 # In general, adjacent RIs stay together. The hard-break rules, above, overide this, forcing in the boundaries between pairs.
 684 $RI $CM* $RI;
 685
 686 #    WJ, GL, QU, etc. are classes with rules like "WJ x "   which includes "WJ x RI".
 687 $RI $CM* ([$WJ $GL $QU $BB] |  (($HY | $BA)$CM* $HL));
 688
 689
 690 # LB 30b Do not break between an Emoji Base and an Emoji Modifier
 691 $EM $CM* $EB;
 692
 693
 694 ## -------------------------------------------------
 695
 696 !!safe_reverse;
 697
 698 # LB 9
 699 ^$CM+ [^$CM $BK $CR $LF $NL $ZW $SP];
 700 ^$CM+ $SP / .;
 701
 702 # LB 14
 703 $SP+ $CM* $OP;
 704
 705 # LB 15
 706 $SP+ $CM* $QU;
 707
 708 # LB 16
 709 $SP+ $CM* ($CL | $CP);
 710
 711 # LB 17
 712 $SP+ $CM* $B2;
 713
 714 # LB 21
 715 $CM* ($HY | $BA | $HH) $CM* $HL;
 716
 717 # LB 25
 718 ($CM* ($IS | $SY))+ $CM* $NU;
 719 ($CL | $CP) $CM* ($NU | $IS | $SY);
 720
 721 #  LB 30
 722 ($CM* $RI)+;
 723
 724 # For dictionary-based break
 725 $dictionary $dictionary;
 726
 727 ## -------------------------------------------------
 728
 729 !!safe_forward;
 730
 731 # Skip forward over all character classes that are involved in
 732 #   rules containing patterns with possibly more than one char
 733 #   of context.
 734 #
 735 #  It might be slightly more efficient to have specific rules
 736 #  instead of one generic one, but only if we could
 737 #  turn off rule chaining.  We don't want to move more
 738 #  than necessary.
 739 #
 740 ^[$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];
 741 $dictionary $dictionary;
 742