1# Copyright (c) 2002-2010  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 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$BA = [[:LineBreak =  Break_After:] - [\u2010]];
62$HH = [\u2010];
63$BB = [:LineBreak =  Break_Before:];
64$BK = [:LineBreak =  Mandatory_Break:];
65$B2 = [:LineBreak =  Break_Both:];
66$CB = [:LineBreak =  Contingent_Break:];
67$CL = [:LineBreak =  Close_Punctuation:];
68$CM = [:LineBreak =  Combining_Mark:];
69$CP = [:LineBreak =  Close_Parenthesis:];
70$CR = [:LineBreak =  Carriage_Return:];
71$EX = [:LineBreak =  Exclamation:];
72$GL = [:LineBreak =  Glue:];
73$HY = [:LineBreak =  Hyphen:];
74$H2 = [:LineBreak =  H2:];
75$H3 = [:LineBreak =  H3:];
76$ID = [:LineBreak =  Ideographic:];
77$IN = [:LineBreak =  Inseperable:];
78$IS = [:LineBreak =  Infix_Numeric:];
79$JL = [:LineBreak =  JL:];
80$JV = [:LineBreak =  JV:];
81$JT = [:LineBreak =  JT:];
82$LF = [:LineBreak =  Line_Feed:];
83$NL = [:LineBreak =  Next_Line:];
84$NS = [:LineBreak =  Nonstarter:];
85$NU = [:LineBreak =  Numeric:];
86$OP = [:LineBreak =  Open_Punctuation:];
87$PO = [:LineBreak =  Postfix_Numeric:];
88$PR = [:LineBreak =  Prefix_Numeric:];
89$QU = [:LineBreak =  Quotation:];
90$SA = [:LineBreak =  Complex_Context:];
91$SG = [:LineBreak =  Surrogate:];
92$SP = [:LineBreak =  Space:];
93$SY = [:LineBreak =  Break_Symbols:];
94$WJ = [:LineBreak =  Word_Joiner:];
95$XX = [:LineBreak =  Unknown:];
96$ZW = [:LineBreak =  ZWSpace:];
97
98#   Dictionary character set, for triggering language-based break engines. Currently
99#   limited to LineBreak=Complex_Context. Note that this set only works in Unicode
100#   5.0 or later as the definition of Complex_Context was corrected to include all
101#   characters requiring dictionary break.
102
103$dictionary = [:LineBreak = Complex_Context:];
104
105#
106#  Rule LB1.  By default, treat AI  (characters with ambiguous east Asian width),
107#                               SA  (South East Asian: Thai, Lao, Khmer)
108#                               SG  (Unpaired Surrogates)
109#                               XX  (Unknown, unassigned)
110#                         as $AL  (Alphabetic)
111#
112$ALPlus = [$AL $AI $SA $SG $XX];
113
114#
115#  Combining Marks.   X $CM*  behaves as if it were X.  Rule LB6.
116#
117$ALcm = $ALPlus $CM*;
118$BAcm = $BA $CM*;
119$HHcm = $HH $CM*;
120$BBcm = $BB $CM*;
121$B2cm = $B2 $CM*;
122$CLcm = $CL $CM*;
123$CPcm = $CP $CM*;
124$EXcm = $EX $CM*;
125$GLcm = $GL $CM*;
126$HYcm = $HY $CM*;
127$H2cm = $H2 $CM*;
128$H3cm = $H3 $CM*;
129$IDcm = $ID $CM*;
130$INcm = $IN $CM*;
131$IScm = $IS $CM*;
132$JLcm = $JL $CM*;
133$JVcm = $JV $CM*;
134$JTcm = $JT $CM*;
135$NScm = $NS $CM*;
136$NUcm = $NU $CM*;
137$OPcm = $OP $CM*;
138$POcm = $PO $CM*;
139$PRcm = $PR $CM*;
140$QUcm = $QU $CM*;
141$SYcm = $SY $CM*;
142$WJcm = $WJ $CM*;
143
144## -------------------------------------------------
145
146!!forward;
147
148#
149#  Each class of character can stand by itself as an unbroken token, with trailing combining stuff
150#
151$ALPlus $CM+;
152$BA $CM+;
153$HH $CM+;
154$BB $CM+;
155$B2 $CM+;
156$CL $CM+;
157$CP $CM+;
158$EX $CM+;
159$GL $CM+;
160$HY $CM+;
161$H2 $CM+;
162$H3 $CM+;
163$ID $CM+;
164$IN $CM+;
165$IS $CM+;
166$JL $CM+;
167$JV $CM+;
168$JT $CM+;
169$NS $CM+;
170$NU $CM+;
171$OP $CM+;
172$PO $CM+;
173$PR $CM+;
174$QU $CM+;
175$SY $CM+;
176$WJ $CM+;
177
178#
179# CAN_CM  is the set of characters that may combine with CM combining chars.
180#         Note that Linebreak UAX 14's concept of a combining char and the rules
181#         for what they can combine with are _very_ different from the rest of Unicode.
182#
183#         Note that $CM itself is left out of this set.  If CM is needed as a base
184#         it must be listed separately in the rule.
185#
186$CAN_CM  = [^$SP $BK $CR $LF $NL $ZW $CM];       # Bases that can   take CMs
187$CANT_CM = [ $SP $BK $CR $LF $NL $ZW $CM];       # Bases that can't take CMs
188
189#
190# AL_FOLLOW  set of chars that can unconditionally follow an AL
191#            Needed in rules where stand-alone $CM s are treated as AL.
192#            Chaining is disabled with CM because it causes other failures,
193#            so for this one case we need to manually list out longer sequences.
194#
195$AL_FOLLOW_NOCM = [$BK $CR $LF $NL $ZW $SP];
196$AL_FOLLOW_CM   = [$CL $CP $EX $IS $SY $WJ $GL $OP $QU $BA $HH $HY $NS $IN $NU $ALPlus];
197$AL_FOLLOW      = [$AL_FOLLOW_NOCM $AL_FOLLOW_CM];
198
199
200#
201#  Rule LB 4, 5    Mandatory (Hard) breaks.
202#
203$LB4Breaks    = [$BK $CR $LF $NL];
204$LB4NonBreaks = [^$BK $CR $LF $NL];
205$CR $LF {100};
206
207#
208#  LB 6    Do not break before hard line breaks.
209#
210$LB4NonBreaks?  $LB4Breaks {100};    # LB 5  do not break before hard breaks.
211$CAN_CM $CM*    $LB4Breaks {100};
212$CM+            $LB4Breaks {100};
213
214# LB 7         x SP
215#              x ZW
216$LB4NonBreaks [$SP $ZW];
217$CAN_CM $CM*  [$SP $ZW];
218$CM+          [$SP $ZW];
219
220#
221# LB 8         Break after zero width space
222#              TODO:  ZW SP* <break>
223#              An engine change is required to write the reverse rule for this.
224#              For now, leave the Unicode 5.2 rule, ZW <break>
225#
226$LB8Breaks    = [$LB4Breaks $ZW];
227$LB8NonBreaks = [[$LB4NonBreaks] - [$ZW]];
228
229
230# LB 9     Combining marks.      X   $CM needs to behave like X, where X is not $SP, $BK $CR $LF $NL 
231#                                $CM not covered by the above needs to behave like $AL   
232#                                See definition of $CAN_CM.
233
234$CAN_CM $CM+;                   #  Stick together any combining sequences that don't match other rules.
235$CM+;
236
237#
238# LB 11  Do not break before or after WORD JOINER & related characters.
239#
240$CAN_CM $CM*  $WJcm;
241$LB8NonBreaks $WJcm;
242$CM+          $WJcm;
243
244$WJcm $CANT_CM;
245$WJcm $CAN_CM $CM*;
246
247#
248# LB 12  Do not break after NBSP and related characters.
249#         GL  x
250#
251$GLcm $CAN_CM $CM*;
252$GLcm $CANT_CM;
253 
254#
255# LB 12a  Do not break before NBSP and related characters ...
256#            [^SP BA HY] x GL
257#
258[[$LB8NonBreaks] - [$SP $BA $HH $HY]] $CM* $GLcm;
259$CM+ GLcm;
260
261
262
263#
264# LB 13   Don't break before ']' or '!' or ';' or '/', even after spaces.
265#
266$LB8NonBreaks $CL;
267$CAN_CM $CM*  $CL;
268$CM+          $CL;              # by rule 10, stand-alone CM behaves as AL
269
270$LB8NonBreaks $CP;
271$CAN_CM $CM*  $CP;
272$CM+          $CP;              # by rule 10, stand-alone CM behaves as AL
273
274$LB8NonBreaks $EX;
275$CAN_CM $CM*  $EX;
276$CM+          $EX;              # by rule 10, stand-alone CM behaves as AL
277
278$LB8NonBreaks $IS;
279$CAN_CM $CM*  $IS;
280$CM+          $IS;              # by rule 10, stand-alone CM behaves as AL
281
282$LB8NonBreaks $SY;
283$CAN_CM $CM*  $SY;
284$CM+          $SY;              # by rule 10, stand-alone CM behaves as AL
285
286
287#
288# LB 14  Do not break after OP, even after spaces
289#
290$OPcm $SP* $CAN_CM $CM*;
291$OPcm $SP* $CANT_CM;
292
293$OPcm $SP+ $CM+ $AL_FOLLOW?;    # by rule 10, stand-alone CM behaves as AL
294
295# LB 15
296$QUcm $SP* $OPcm;
297
298# LB 16
299($CLcm | $CPcm) $SP* $NScm;
300
301# LB 17
302$B2cm $SP* $B2cm;
303
304#
305# LB 18  Break after spaces.
306#
307$LB18NonBreaks = [$LB8NonBreaks - [$SP]];
308$LB18Breaks    = [$LB8Breaks $SP];
309
310
311# LB 19
312#         x QU
313$LB18NonBreaks $CM* $QUcm;
314$CM+                $QUcm;
315
316#         QU  x
317$QUcm .?;
318$QUcm $LB18NonBreaks $CM*;    # Don't let a combining mark go onto $CR, $BK, etc.
319                              #  TODO:  I don't think this rule is needed.
320
321
322# LB 20
323#        <break>  $CB
324#        $CB   <break>
325
326$LB20NonBreaks = [$LB18NonBreaks - $CB];
327
328# LB 20.09 added rule for Finnish tailoring
329# LB 21        x   (BA | HY | NS)
330#           BB x
331#
332$LB20NonBreaks $CM* ($BAcm | $HHcm | $HYcm | $NScm) / $AL; 
333$LB20NonBreaks $CM* ($BAcm | $HHcm | $HYcm | $NScm); 
334($HY | $HH) $AL;
335
336$BBcm [^$CB];                                  #  $BB  x
337$BBcm $LB20NonBreaks $CM*;
338
339# LB 22
340$ALcm    $INcm;
341$CM+     $INcm;     #  by rule 10, any otherwise unattached CM behaves as AL
342$IDcm    $INcm;
343$INcm    $INcm;
344$NUcm    $INcm;
345
346
347# $LB 23
348$IDcm  $POcm;
349$ALcm  $NUcm;       # includes $LB19
350$CM+   $NUcm;       # Rule 10, any otherwise unattached CM behaves as AL
351$NUcm  $ALcm;
352
353#
354# LB 24
355#
356$PRcm $IDcm;
357$PRcm $ALcm;
358$POcm $ALcm;
359
360#
361# LB 25   Numbers.
362#
363($PRcm | $POcm)? ($OPcm | $HYcm)? $NUcm ($NUcm | $SYcm | $IScm)* ($CLcm | $CPcm)? ($PRcm | $POcm)?;
364
365# LB 26  Do not break a Korean syllable
366#
367$JLcm ($JLcm | $JVcm | $H2cm | $H3cm);
368($JVcm | $H2cm) ($JVcm | $JTcm);
369($JTcm | $H3cm) $JTcm;
370
371# LB 27  Treat korean Syllable Block the same as ID  (don't break it)
372($JLcm | $JVcm | $JTcm | $H2cm | $H3cm) $INcm;
373($JLcm | $JVcm | $JTcm | $H2cm | $H3cm) $POcm;
374$PRcm ($JLcm | $JVcm | $JTcm | $H2cm | $H3cm);
375
376
377# LB 28   Do not break between alphabetics
378#
379$ALcm $ALcm;
380$CM+ $ALcm;      # The $CM+ is from rule 10, an unattached CM is treated as AL
381
382# LB 29
383$IScm $ALcm;
384
385# LB 30
386($ALcm | $NUcm) $OPcm;
387$CM+ $OPcm;         # The $CM+ is from rule 10, an unattached CM is treated as AL.          
388$CPcm ($ALcm | $NUcm);
389
390
391#
392#  Reverse Rules.
393#
394## -------------------------------------------------
395
396!!reverse;
397
398$CM+ $ALPlus;
399$CM+ $BA;
400$CM+ $HH;
401$CM+ $BB;
402$CM+ $B2;
403$CM+ $CL;
404$CM+ $CP;
405$CM+ $EX;
406$CM+ $GL;
407$CM+ $HY;
408$CM+ $H2;
409$CM+ $H3;
410$CM+ $ID;
411$CM+ $IN;
412$CM+ $IS;
413$CM+ $JL;
414$CM+ $JV;
415$CM+ $JT;
416$CM+ $NS;
417$CM+ $NU;
418$CM+ $OP;
419$CM+ $PO;
420$CM+ $PR;
421$CM+ $QU;
422$CM+ $SY;
423$CM+ $WJ;
424$CM+;
425
426
427#
428#  Sequences of the form  (shown forwards)
429#      [CANT_CM]  <break>  [CM]  [whatever]
430#  The CM needs to behave as an AL
431#
432$AL_FOLLOW $CM+ / (
433          [$BK $CR $LF $NL $ZW {eof}] |
434          $SP+ $CM+ $SP |
435          $SP+ $CM* ([^$OP $CM $SP] | [$AL {eof}]));   # if LB 14 will match, need to surpress this break.
436                                               #  LB14 says    OP SP* x .        
437                                               #    becomes    OP SP* x AL
438                                               #    becomes    OP SP* x CM+ AL_FOLLOW
439                                               #
440                                               # Further note:  the $AL in [$AL {eof}] is only to work around
441                                               #                a rule compiler bug which complains about
442                                               #                empty sets otherwise.
443          
444#
445#  Sequences of the form  (shown forwards)
446#      [CANT_CM]  <break> [CM]  <break>  [PR]
447#  The CM needs to behave as an AL
448#  This rule is concerned about getting the second of the two <breaks> in place.
449#
450
451[$PR   ] / $CM+ [$BK $CR $LF $NL $ZW $SP {eof}];
452
453
454
455# LB 4, 5, 5
456
457$LB4Breaks [$LB4NonBreaks-$CM];
458$LB4Breaks $CM+ $CAN_CM;
459$LF $CR;
460
461
462# LB 7         x SP
463#              x ZW
464[$SP $ZW] [$LB4NonBreaks-$CM];
465[$SP $ZW] $CM+ $CAN_CM;
466
467# LB 8 ZW SP* <break>
468#     TODO: to implement this, we need more than one look-ahead hard break in play at a time.
469#           Requires an engine enhancement.
470#   / $SP* $ZW
471
472# LB 9,10  Combining marks.
473#    X   $CM needs to behave like X, where X is not $SP or controls.
474#    $CM not covered by the above needs to behave like $AL
475# Stick together any combining sequences that don't match other rules.
476$CM+ $CAN_CM;
477
478
479# LB 11
480$CM* $WJ $CM* $CAN_CM;
481$CM* $WJ      [$LB8NonBreaks-$CM];
482
483     $CANT_CM $CM* $WJ;
484$CM* $CAN_CM  $CM* $WJ;
485
486# LB 12a
487#      [^SP BA HY] x GL
488#
489$CM* $GL $CM* [$LB8NonBreaks-[$CM $SP $BA $HH $HY]];
490
491# LB 12
492#     GL  x
493#
494$CANT_CM $CM* $GL;
495$CM* $CAN_CM $CM* $GL;
496
497
498# LB 13
499$CL $CM+ $CAN_CM;
500$CP $CM+ $CAN_CM;
501$EX $CM+ $CAN_CM;
502$IS $CM+ $CAN_CM;
503$SY $CM+ $CAN_CM;
504
505$CL [$LB8NonBreaks-$CM];
506$CP [$LB8NonBreaks-$CM];
507$EX [$LB8NonBreaks-$CM];
508$IS [$LB8NonBreaks-$CM];
509$SY [$LB8NonBreaks-$CM];
510
511# Rule 13 & 14 taken together for an edge case.
512#   Match this, shown forward
513#     OP SP+  ($CM+ behaving as $AL) (CL | CP | EX | IS | IY)
514#   This really wants to chain at the $CM+ (which is acting as an $AL)
515#   except for $CM chaining being disabled.
516[$CL $CP $EX $IS $SY] $CM+ $SP+ $CM* $OP;  
517
518# LB 14    OP SP* x
519#
520$CM* $CAN_CM    $SP* $CM* $OP;
521     $CANT_CM   $SP* $CM* $OP;
522$AL_FOLLOW? $CM+  $SP $SP* $CM* $OP;     #  by LB 10, behaves like $AL_FOLLOW? $AL $SP* $CM* $OP
523     
524     $AL_FOLLOW_NOCM $CM+ $SP+ $CM* $OP;
525$CM* $AL_FOLLOW_CM   $CM+ $SP+ $CM* $OP;
526$SY $CM $SP+ $OP;   # TODO:  Experiment.  Remove.
527
528
529
530# LB 15
531$CM* $OP $SP* $CM* $QU;
532
533# LB 16
534$CM* $NS $SP* $CM* ($CL | $CP);
535
536# LB 17
537$CM* $B2 $SP* $CM* $B2;
538
539# LB 18  break after spaces
540#        Nothing explicit needed here.
541
542
543#
544# LB 19
545#
546$CM* $QU $CM* $CAN_CM;                                #   . x QU
547$CM* $QU      $LB18NonBreaks;
548
549
550$CM* $CAN_CM  $CM* $QU;                               #   QU x .
551     $CANT_CM $CM* $QU;
552     
553#
554#  LB 20  Break before and after CB.
555#         nothing needed here.
556#
557
558# LB 20.09 added rule for Finnish tailoring
559$AL ($HY | $HH) / $SP;
560
561# LB 21
562$CM* ($BA | $HH | $HY | $NS) $CM* [$LB20NonBreaks-$CM];     #  . x (BA | HY | NS)
563
564$CM* [$LB20NonBreaks-$CM] $CM* $BB;                   #  BB x .
565[^$CB] $CM* $BB;                                      # 
566
567
568
569# LB 22
570$CM* $IN $CM* $ALPlus;
571$CM* $IN $CM* $ID;
572$CM* $IN $CM* $IN;
573$CM* $IN $CM* $NU;
574
575# LB 23
576$CM* $PO $CM* $ID;
577$CM* $NU $CM* $ALPlus;
578$CM* $ALPlus $CM* $NU;
579
580# LB 24
581$CM* $ID $CM* $PR;
582$CM* $ALPlus $CM* $PR;
583$CM* $ALPlus $CM* $PO;
584
585
586# LB 25
587($CM* ($PR | $PO))? ($CM* ($CL | $CP))? ($CM* ($NU | $IS | $SY))* $CM* $NU ($CM* ($OP | $HY))? ($CM* ($PR | $PO))?;
588
589# LB 26
590$CM* ($H3 | $H2 | $JV | $JL) $CM* $JL;
591$CM* ($JT | $JV) $CM* ($H2 | $JV);
592$CM* $JT $CM* ($H3 | $JT);
593
594# LB 27
595$CM* $IN $CM* ($H3 | $H2 | $JT | $JV | $JL);
596$CM* $PO $CM* ($H3 | $H2 | $JT | $JV | $JL);
597$CM* ($H3 | $H2 | $JT | $JV | $JL) $CM* $PR;
598
599# LB 28
600$CM* $ALPlus $CM* $ALPlus;
601
602
603# LB 29
604$CM* $ALPlus $CM* $IS;
605
606# LB 30
607$CM* $OP $CM* ($ALPlus | $NU);
608$CM* ($ALPlus | $NU) $CM* $CP;
609
610
611## -------------------------------------------------
612
613!!safe_reverse;
614
615# LB 9
616$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
654