1 /*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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10 *
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25
26 /*
27 * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
28 * (C) Copyright IBM Corp. 1996-1998 - All Rights Reserved
29 *
30 * The original version of this source code and documentation is copyrighted
31 * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
32 * materials are provided under terms of a License Agreement between Taligent
33 * and Sun. This technology is protected by multiple US and International
34 * patents. This notice and attribution to Taligent may not be removed.
35 * Taligent is a registered trademark of Taligent, Inc.
36 *
37 */
38
39 package java.text;
40
41 import java.text.Normalizer;
42 import java.util.Vector;
43 import java.util.Locale;
44
45 /**
46 * The <code>RuleBasedCollator</code> class is a concrete subclass of
47 * <code>Collator</code> that provides a simple, data-driven, table
48 * collator. With this class you can create a customized table-based
49 * <code>Collator</code>. <code>RuleBasedCollator</code> maps
50 * characters to sort keys.
51 *
52 * <p>
53 * <code>RuleBasedCollator</code> has the following restrictions
54 * for efficiency (other subclasses may be used for more complex languages) :
55 * <ol>
56 * <li>If a special collation rule controlled by a <modifier> is
57 specified it applies to the whole collator object.
58 * <li>All non-mentioned characters are at the end of the
59 * collation order.
60 * </ol>
61 *
62 * <p>
63 * The collation table is composed of a list of collation rules, where each
64 * rule is of one of three forms:
65 * <pre>
66 * <modifier>
67 * <relation> <text-argument>
68 * <reset> <text-argument>
69 * </pre>
70 * The definitions of the rule elements is as follows:
71 * <UL>
72 * <LI><strong>Text-Argument</strong>: A text-argument is any sequence of
73 * characters, excluding special characters (that is, common
74 * whitespace characters [0009-000D, 0020] and rule syntax characters
75 * [0021-002F, 003A-0040, 005B-0060, 007B-007E]). If those
76 * characters are desired, you can put them in single quotes
77 * (e.g. ampersand => '&'). Note that unquoted white space characters
78 * are ignored; e.g. <code>b c</code> is treated as <code>bc</code>.
79 * <LI><strong>Modifier</strong>: There are currently two modifiers that
80 * turn on special collation rules.
81 * <UL>
82 * <LI>'@' : Turns on backwards sorting of accents (secondary
83 * differences), as in French.
84 * <LI>'!' : Turns on Thai/Lao vowel-consonant swapping. If this
85 * rule is in force when a Thai vowel of the range
86 * \U0E40-\U0E44 precedes a Thai consonant of the range
87 * \U0E01-\U0E2E OR a Lao vowel of the range \U0EC0-\U0EC4
88 * precedes a Lao consonant of the range \U0E81-\U0EAE then
89 * the vowel is placed after the consonant for collation
90 * purposes.
91 * </UL>
92 * <p>'@' : Indicates that accents are sorted backwards, as in French.
93 * <LI><strong>Relation</strong>: The relations are the following:
94 * <UL>
95 * <LI>'<' : Greater, as a letter difference (primary)
96 * <LI>';' : Greater, as an accent difference (secondary)
97 * <LI>',' : Greater, as a case difference (tertiary)
98 * <LI>'=' : Equal
99 * </UL>
100 * <LI><strong>Reset</strong>: There is a single reset
101 * which is used primarily for contractions and expansions, but which
102 * can also be used to add a modification at the end of a set of rules.
103 * <p>'&' : Indicates that the next rule follows the position to where
104 * the reset text-argument would be sorted.
105 * </UL>
106 *
107 * <p>
108 * This sounds more complicated than it is in practice. For example, the
109 * following are equivalent ways of expressing the same thing:
110 * <blockquote>
111 * <pre>
112 * a < b < c
113 * a < b & b < c
114 * a < c & a < b
115 * </pre>
116 * </blockquote>
117 * Notice that the order is important, as the subsequent item goes immediately
118 * after the text-argument. The following are not equivalent:
119 * <blockquote>
120 * <pre>
121 * a < b & a < c
122 * a < c & a < b
123 * </pre>
124 * </blockquote>
125 * Either the text-argument must already be present in the sequence, or some
126 * initial substring of the text-argument must be present. (e.g. "a < b & ae <
127 * e" is valid since "a" is present in the sequence before "ae" is reset). In
128 * this latter case, "ae" is not entered and treated as a single character;
129 * instead, "e" is sorted as if it were expanded to two characters: "a"
130 * followed by an "e". This difference appears in natural languages: in
131 * traditional Spanish "ch" is treated as though it contracts to a single
132 * character (expressed as "c < ch < d"), while in traditional German
133 * a-umlaut is treated as though it expanded to two characters
134 * (expressed as "a,A < b,B ... &ae;\u00e3&AE;\u00c3").
135 * [\u00e3 and \u00c3 are, of course, the escape sequences for a-umlaut.]
136 * <p>
137 * <strong>Ignorable Characters</strong>
138 * <p>
139 * For ignorable characters, the first rule must start with a relation (the
140 * examples we have used above are really fragments; "a < b" really should be
141 * "< a < b"). If, however, the first relation is not "<", then all the all
142 * text-arguments up to the first "<" are ignorable. For example, ", - < a < b"
143 * makes "-" an ignorable character, as we saw earlier in the word
144 * "black-birds". In the samples for different languages, you see that most
145 * accents are ignorable.
146 *
147 * <p><strong>Normalization and Accents</strong>
148 * <p>
149 * <code>RuleBasedCollator</code> automatically processes its rule table to
150 * include both pre-composed and combining-character versions of
151 * accented characters. Even if the provided rule string contains only
152 * base characters and separate combining accent characters, the pre-composed
153 * accented characters matching all canonical combinations of characters from
154 * the rule string will be entered in the table.
155 * <p>
156 * This allows you to use a RuleBasedCollator to compare accented strings
157 * even when the collator is set to NO_DECOMPOSITION. There are two caveats,
158 * however. First, if the strings to be collated contain combining
159 * sequences that may not be in canonical order, you should set the collator to
160 * CANONICAL_DECOMPOSITION or FULL_DECOMPOSITION to enable sorting of
161 * combining sequences. Second, if the strings contain characters with
162 * compatibility decompositions (such as full-width and half-width forms),
163 * you must use FULL_DECOMPOSITION, since the rule tables only include
164 * canonical mappings.
165 *
166 * <p><strong>Errors</strong>
167 * <p>
168 * The following are errors:
169 * <UL>
170 * <LI>A text-argument contains unquoted punctuation symbols
171 * (e.g. "a < b-c < d").
172 * <LI>A relation or reset character not followed by a text-argument
173 * (e.g. "a < ,b").
174 * <LI>A reset where the text-argument (or an initial substring of the
175 * text-argument) is not already in the sequence.
176 * (e.g. "a < b & e < f")
177 * </UL>
178 * If you produce one of these errors, a <code>RuleBasedCollator</code> throws
179 * a <code>ParseException</code>.
180 *
181 * <p><strong>Examples</strong>
182 * <p>Simple: "< a < b < c < d"
183 * <p>Norwegian: "< a, A < b, B < c, C < d, D < e, E < f, F
184 * < g, G < h, H < i, I < j, J < k, K < l, L
185 * < m, M < n, N < o, O < p, P < q, Q < r, R
186 * < s, S < t, T < u, U < v, V < w, W < x, X
187 * < y, Y < z, Z
188 * < \u00E6, \u00C6
189 * < \u00F8, \u00D8
190 * < \u00E5 = a\u030A, \u00C5 = A\u030A;
191 * aa, AA"
192 *
193 * <p>
194 * To create a <code>RuleBasedCollator</code> object with specialized
195 * rules tailored to your needs, you construct the <code>RuleBasedCollator</code>
196 * with the rules contained in a <code>String</code> object. For example:
197 * <blockquote>
198 * <pre>
199 * String simple = "< a< b< c< d";
200 * RuleBasedCollator mySimple = new RuleBasedCollator(simple);
201 * </pre>
202 * </blockquote>
203 * Or:
204 * <blockquote>
205 * <pre>
206 * String Norwegian = "< a, A < b, B < c, C < d, D < e, E < f, F < g, G < h, H < i, I" +
207 * "< j, J < k, K < l, L < m, M < n, N < o, O < p, P < q, Q < r, R" +
208 * "< s, S < t, T < u, U < v, V < w, W < x, X < y, Y < z, Z" +
209 * "< \u00E6, \u00C6" + // Latin letter ae & AE
210 * "< \u00F8, \u00D8" + // Latin letter o & O with stroke
211 * "< \u00E5 = a\u030A," + // Latin letter a with ring above
212 * " \u00C5 = A\u030A;" + // Latin letter A with ring above
213 * " aa, AA";
214 * RuleBasedCollator myNorwegian = new RuleBasedCollator(Norwegian);
215 * </pre>
216 * </blockquote>
217 *
218 * <p>
219 * A new collation rules string can be created by concatenating rules
220 * strings. For example, the rules returned by {@link #getRules()} could
221 * be concatenated to combine multiple <code>RuleBasedCollator</code>s.
222 *
223 * <p>
224 * The following example demonstrates how to change the order of
225 * non-spacing accents,
226 * <blockquote>
227 * <pre>
228 * // old rule
229 * String oldRules = "=\u0301;\u0300;\u0302;\u0308" // main accents
230 * + ";\u0327;\u0303;\u0304;\u0305" // main accents
231 * + ";\u0306;\u0307;\u0309;\u030A" // main accents
232 * + ";\u030B;\u030C;\u030D;\u030E" // main accents
233 * + ";\u030F;\u0310;\u0311;\u0312" // main accents
234 * + "< a , A ; ae, AE ; \u00e6 , \u00c6"
235 * + "< b , B < c, C < e, E & C < d, D";
236 * // change the order of accent characters
237 * String addOn = "& \u0300 ; \u0308 ; \u0302";
238 * RuleBasedCollator myCollator = new RuleBasedCollator(oldRules + addOn);
239 * </pre>
240 * </blockquote>
241 *
242 * @see Collator
243 * @see CollationElementIterator
244 * @author Helena Shih, Laura Werner, Richard Gillam
245 */
246 public class RuleBasedCollator extends Collator{
247 // IMPLEMENTATION NOTES: The implementation of the collation algorithm is
248 // divided across three classes: RuleBasedCollator, RBCollationTables, and
249 // CollationElementIterator. RuleBasedCollator contains the collator's
250 // transient state and includes the code that uses the other classes to
251 // implement comparison and sort-key building. RuleBasedCollator also
252 // contains the logic to handle French secondary accent sorting.
253 // A RuleBasedCollator has two CollationElementIterators. State doesn't
254 // need to be preserved in these objects between calls to compare() or
255 // getCollationKey(), but the objects persist anyway to avoid wasting extra
256 // creation time. compare() and getCollationKey() are synchronized to ensure
257 // thread safety with this scheme. The CollationElementIterator is responsible
258 // for generating collation elements from strings and returning one element at
259 // a time (sometimes there's a one-to-many or many-to-one mapping between
260 // characters and collation elements-- this class handles that).
261 // CollationElementIterator depends on RBCollationTables, which contains the
262 // collator's static state. RBCollationTables contains the actual data
263 // tables specifying the collation order of characters for a particular locale
264 // or use. It also contains the base logic that CollationElementIterator
265 // uses to map from characters to collation elements. A single RBCollationTables
266 // object is shared among all RuleBasedCollators for the same locale, and
267 // thus by all the CollationElementIterators they create.
268
269 /**
270 * RuleBasedCollator constructor. This takes the table rules and builds
271 * a collation table out of them. Please see RuleBasedCollator class
272 * description for more details on the collation rule syntax.
273 * @see java.util.Locale
274 * @param rules the collation rules to build the collation table from.
275 * @exception ParseException A format exception
276 * will be thrown if the build process of the rules fails. For
277 * example, build rule "a < ? < d" will cause the constructor to
278 * throw the ParseException because the '?' is not quoted.
279 */
280 public RuleBasedCollator(String rules) throws ParseException {
281 this(rules, Collator.CANONICAL_DECOMPOSITION);
282 }
283
284 /**
285 * RuleBasedCollator constructor. This takes the table rules and builds
286 * a collation table out of them. Please see RuleBasedCollator class
287 * description for more details on the collation rule syntax.
288 * @see java.util.Locale
289 * @param rules the collation rules to build the collation table from.
290 * @param decomp the decomposition strength used to build the
291 * collation table and to perform comparisons.
292 * @exception ParseException A format exception
293 * will be thrown if the build process of the rules fails. For
294 * example, build rule "a < ? < d" will cause the constructor to
295 * throw the ParseException because the '?' is not quoted.
296 */
297 RuleBasedCollator(String rules, int decomp) throws ParseException {
298 setStrength(Collator.TERTIARY);
299 setDecomposition(decomp);
300 tables = new RBCollationTables(rules, decomp);
301 }
302
303 /**
304 * "Copy constructor." Used in clone() for performance.
305 */
306 private RuleBasedCollator(RuleBasedCollator that) {
307 setStrength(that.getStrength());
308 setDecomposition(that.getDecomposition());
309 tables = that.tables;
310 }
311
312 /**
313 * Gets the table-based rules for the collation object.
314 * @return returns the collation rules that the table collation object
315 * was created from.
316 */
317 public String getRules()
318 {
319 return tables.getRules();
320 }
321
322 /**
323 * Returns a CollationElementIterator for the given String.
324 *
325 * @param source the string to be collated
326 * @return a {@code CollationElementIterator} object
327 * @see java.text.CollationElementIterator
328 */
329 public CollationElementIterator getCollationElementIterator(String source) {
330 return new CollationElementIterator( source, this );
331 }
332
333 /**
334 * Returns a CollationElementIterator for the given CharacterIterator.
335 *
336 * @param source the character iterator to be collated
337 * @return a {@code CollationElementIterator} object
338 * @see java.text.CollationElementIterator
339 * @since 1.2
340 */
341 public CollationElementIterator getCollationElementIterator(
342 CharacterIterator source) {
343 return new CollationElementIterator( source, this );
344 }
345
346 /**
347 * Compares the character data stored in two different strings based on the
348 * collation rules. Returns information about whether a string is less
349 * than, greater than or equal to another string in a language.
350 * This can be overriden in a subclass.
351 *
352 * @exception NullPointerException if <code>source</code> or <code>target</code> is null.
353 */
354 public synchronized int compare(String source, String target)
355 {
356 if (source == null || target == null) {
357 throw new NullPointerException();
358 }
359
360 // The basic algorithm here is that we use CollationElementIterators
361 // to step through both the source and target strings. We compare each
362 // collation element in the source string against the corresponding one
363 // in the target, checking for differences.
364 //
365 // If a difference is found, we set <result> to LESS or GREATER to
366 // indicate whether the source string is less or greater than the target.
367 //
368 // However, it's not that simple. If we find a tertiary difference
369 // (e.g. 'A' vs. 'a') near the beginning of a string, it can be
370 // overridden by a primary difference (e.g. "A" vs. "B") later in
371 // the string. For example, "AA" < "aB", even though 'A' > 'a'.
372 //
373 // To keep track of this, we use strengthResult to keep track of the
374 // strength of the most significant difference that has been found
375 // so far. When we find a difference whose strength is greater than
376 // strengthResult, it overrides the last difference (if any) that
377 // was found.
378
379 int result = Collator.EQUAL;
380
381 if (sourceCursor == null) {
382 sourceCursor = getCollationElementIterator(source);
383 } else {
384 sourceCursor.setText(source);
385 }
386 if (targetCursor == null) {
387 targetCursor = getCollationElementIterator(target);
388 } else {
389 targetCursor.setText(target);
390 }
391
392 int sOrder = 0, tOrder = 0;
393
394 boolean initialCheckSecTer = getStrength() >= Collator.SECONDARY;
395 boolean checkSecTer = initialCheckSecTer;
396 boolean checkTertiary = getStrength() >= Collator.TERTIARY;
397
398 boolean gets = true, gett = true;
399
400 while(true) {
401 // Get the next collation element in each of the strings, unless
402 // we've been requested to skip it.
403 if (gets) sOrder = sourceCursor.next(); else gets = true;
404 if (gett) tOrder = targetCursor.next(); else gett = true;
405
406 // If we've hit the end of one of the strings, jump out of the loop
407 if ((sOrder == CollationElementIterator.NULLORDER)||
408 (tOrder == CollationElementIterator.NULLORDER))
409 break;
410
411 int pSOrder = CollationElementIterator.primaryOrder(sOrder);
412 int pTOrder = CollationElementIterator.primaryOrder(tOrder);
413
414 // If there's no difference at this position, we can skip it
415 if (sOrder == tOrder) {
416 if (tables.isFrenchSec() && pSOrder != 0) {
417 if (!checkSecTer) {
418 // in french, a secondary difference more to the right is stronger,
419 // so accents have to be checked with each base element
420 checkSecTer = initialCheckSecTer;
421 // but tertiary differences are less important than the first
422 // secondary difference, so checking tertiary remains disabled
423 checkTertiary = false;
424 }
425 }
426 continue;
427 }
428
429 // Compare primary differences first.
430 if ( pSOrder != pTOrder )
431 {
432 if (sOrder == 0) {
433 // The entire source element is ignorable.
434 // Skip to the next source element, but don't fetch another target element.
435 gett = false;
436 continue;
437 }
438 if (tOrder == 0) {
439 gets = false;
440 continue;
441 }
442
443 // The source and target elements aren't ignorable, but it's still possible
444 // for the primary component of one of the elements to be ignorable....
445
446 if (pSOrder == 0) // primary order in source is ignorable
447 {
448 // The source's primary is ignorable, but the target's isn't. We treat ignorables
449 // as a secondary difference, so remember that we found one.
450 if (checkSecTer) {
451 result = Collator.GREATER; // (strength is SECONDARY)
452 checkSecTer = false;
453 }
454 // Skip to the next source element, but don't fetch another target element.
455 gett = false;
456 }
457 else if (pTOrder == 0)
458 {
459 // record differences - see the comment above.
460 if (checkSecTer) {
461 result = Collator.LESS; // (strength is SECONDARY)
462 checkSecTer = false;
463 }
464 // Skip to the next source element, but don't fetch another target element.
465 gets = false;
466 } else {
467 // Neither of the orders is ignorable, and we already know that the primary
468 // orders are different because of the (pSOrder != pTOrder) test above.
469 // Record the difference and stop the comparison.
470 if (pSOrder < pTOrder) {
471 return Collator.LESS; // (strength is PRIMARY)
472 } else {
473 return Collator.GREATER; // (strength is PRIMARY)
474 }
475 }
476 } else { // else of if ( pSOrder != pTOrder )
477 // primary order is the same, but complete order is different. So there
478 // are no base elements at this point, only ignorables (Since the strings are
479 // normalized)
480
481 if (checkSecTer) {
482 // a secondary or tertiary difference may still matter
483 short secSOrder = CollationElementIterator.secondaryOrder(sOrder);
484 short secTOrder = CollationElementIterator.secondaryOrder(tOrder);
485 if (secSOrder != secTOrder) {
486 // there is a secondary difference
487 result = (secSOrder < secTOrder) ? Collator.LESS : Collator.GREATER;
488 // (strength is SECONDARY)
489 checkSecTer = false;
490 // (even in french, only the first secondary difference within
491 // a base character matters)
492 } else {
493 if (checkTertiary) {
494 // a tertiary difference may still matter
495 short terSOrder = CollationElementIterator.tertiaryOrder(sOrder);
496 short terTOrder = CollationElementIterator.tertiaryOrder(tOrder);
497 if (terSOrder != terTOrder) {
498 // there is a tertiary difference
499 result = (terSOrder < terTOrder) ? Collator.LESS : Collator.GREATER;
500 // (strength is TERTIARY)
501 checkTertiary = false;
502 }
503 }
504 }
505 } // if (checkSecTer)
506
507 } // if ( pSOrder != pTOrder )
508 } // while()
509
510 if (sOrder != CollationElementIterator.NULLORDER) {
511 // (tOrder must be CollationElementIterator::NULLORDER,
512 // since this point is only reached when sOrder or tOrder is NULLORDER.)
513 // The source string has more elements, but the target string hasn't.
514 do {
515 if (CollationElementIterator.primaryOrder(sOrder) != 0) {
516 // We found an additional non-ignorable base character in the source string.
517 // This is a primary difference, so the source is greater
518 return Collator.GREATER; // (strength is PRIMARY)
519 }
520 else if (CollationElementIterator.secondaryOrder(sOrder) != 0) {
521 // Additional secondary elements mean the source string is greater
522 if (checkSecTer) {
523 result = Collator.GREATER; // (strength is SECONDARY)
524 checkSecTer = false;
525 }
526 }
527 } while ((sOrder = sourceCursor.next()) != CollationElementIterator.NULLORDER);
528 }
529 else if (tOrder != CollationElementIterator.NULLORDER) {
530 // The target string has more elements, but the source string hasn't.
531 do {
532 if (CollationElementIterator.primaryOrder(tOrder) != 0)
533 // We found an additional non-ignorable base character in the target string.
534 // This is a primary difference, so the source is less
535 return Collator.LESS; // (strength is PRIMARY)
536 else if (CollationElementIterator.secondaryOrder(tOrder) != 0) {
537 // Additional secondary elements in the target mean the source string is less
538 if (checkSecTer) {
539 result = Collator.LESS; // (strength is SECONDARY)
540 checkSecTer = false;
541 }
542 }
543 } while ((tOrder = targetCursor.next()) != CollationElementIterator.NULLORDER);
544 }
545
546 // For IDENTICAL comparisons, we use a bitwise character comparison
547 // as a tiebreaker if all else is equal
548 if (result == 0 && getStrength() == IDENTICAL) {
549 int mode = getDecomposition();
550 Normalizer.Form form;
551 if (mode == CANONICAL_DECOMPOSITION) {
552 form = Normalizer.Form.NFD;
553 } else if (mode == FULL_DECOMPOSITION) {
554 form = Normalizer.Form.NFKD;
555 } else {
556 return source.compareTo(target);
557 }
558
559 String sourceDecomposition = Normalizer.normalize(source, form);
560 String targetDecomposition = Normalizer.normalize(target, form);
561 return sourceDecomposition.compareTo(targetDecomposition);
562 }
563 return result;
564 }
565
566 /**
567 * Transforms the string into a series of characters that can be compared
568 * with CollationKey.compareTo. This overrides java.text.Collator.getCollationKey.
569 * It can be overriden in a subclass.
570 */
571 public synchronized CollationKey getCollationKey(String source)
572 {
573 //
574 // The basic algorithm here is to find all of the collation elements for each
575 // character in the source string, convert them to a char representation,
576 // and put them into the collation key. But it's trickier than that.
577 // Each collation element in a string has three components: primary (A vs B),
578 // secondary (A vs A-acute), and tertiary (A' vs a); and a primary difference
579 // at the end of a string takes precedence over a secondary or tertiary
580 // difference earlier in the string.
581 //
582 // To account for this, we put all of the primary orders at the beginning of the
583 // string, followed by the secondary and tertiary orders, separated by nulls.
584 //
585 // Here's a hypothetical example, with the collation element represented as
586 // a three-digit number, one digit for primary, one for secondary, etc.
587 //
588 // String: A a B \u00e9 <--(e-acute)
589 // Collation Elements: 101 100 201 510
590 //
591 // Collation Key: 1125<null>0001<null>1010
592 //
593 // To make things even trickier, secondary differences (accent marks) are compared
594 // starting at the *end* of the string in languages with French secondary ordering.
595 // But when comparing the accent marks on a single base character, they are compared
596 // from the beginning. To handle this, we reverse all of the accents that belong
597 // to each base character, then we reverse the entire string of secondary orderings
598 // at the end. Taking the same example above, a French collator might return
599 // this instead:
600 //
601 // Collation Key: 1125<null>1000<null>1010
602 //
603 if (source == null)
604 return null;
605
606 if (primResult == null) {
607 primResult = new StringBuffer();
608 secResult = new StringBuffer();
609 terResult = new StringBuffer();
610 } else {
611 primResult.setLength(0);
612 secResult.setLength(0);
613 terResult.setLength(0);
614 }
615 int order = 0;
616 boolean compareSec = (getStrength() >= Collator.SECONDARY);
617 boolean compareTer = (getStrength() >= Collator.TERTIARY);
618 int secOrder = CollationElementIterator.NULLORDER;
619 int terOrder = CollationElementIterator.NULLORDER;
620 int preSecIgnore = 0;
621
622 if (sourceCursor == null) {
623 sourceCursor = getCollationElementIterator(source);
624 } else {
625 sourceCursor.setText(source);
626 }
627
628 // walk through each character
629 while ((order = sourceCursor.next()) !=
630 CollationElementIterator.NULLORDER)
631 {
632 secOrder = CollationElementIterator.secondaryOrder(order);
633 terOrder = CollationElementIterator.tertiaryOrder(order);
634 if (!CollationElementIterator.isIgnorable(order))
635 {
636 primResult.append((char) (CollationElementIterator.primaryOrder(order)
637 + COLLATIONKEYOFFSET));
638
639 if (compareSec) {
640 //
641 // accumulate all of the ignorable/secondary characters attached
642 // to a given base character
643 //
644 if (tables.isFrenchSec() && preSecIgnore < secResult.length()) {
645 //
646 // We're doing reversed secondary ordering and we've hit a base
647 // (non-ignorable) character. Reverse any secondary orderings
648 // that applied to the last base character. (see block comment above.)
649 //
650 RBCollationTables.reverse(secResult, preSecIgnore, secResult.length());
651 }
652 // Remember where we are in the secondary orderings - this is how far
653 // back to go if we need to reverse them later.
654 secResult.append((char)(secOrder+ COLLATIONKEYOFFSET));
655 preSecIgnore = secResult.length();
656 }
657 if (compareTer) {
658 terResult.append((char)(terOrder+ COLLATIONKEYOFFSET));
659 }
660 }
661 else
662 {
663 if (compareSec && secOrder != 0)
664 secResult.append((char)
665 (secOrder + tables.getMaxSecOrder() + COLLATIONKEYOFFSET));
666 if (compareTer && terOrder != 0)
667 terResult.append((char)
668 (terOrder + tables.getMaxTerOrder() + COLLATIONKEYOFFSET));
669 }
670 }
671 if (tables.isFrenchSec())
672 {
673 if (preSecIgnore < secResult.length()) {
674 // If we've accumulated any secondary characters after the last base character,
675 // reverse them.
676 RBCollationTables.reverse(secResult, preSecIgnore, secResult.length());
677 }
678 // And now reverse the entire secResult to get French secondary ordering.
679 RBCollationTables.reverse(secResult, 0, secResult.length());
680 }
681 primResult.append((char)0);
682 secResult.append((char)0);
683 secResult.append(terResult.toString());
684 primResult.append(secResult.toString());
685
686 if (getStrength() == IDENTICAL) {
687 primResult.append((char)0);
688 int mode = getDecomposition();
689 if (mode == CANONICAL_DECOMPOSITION) {
690 primResult.append(Normalizer.normalize(source, Normalizer.Form.NFD));
691 } else if (mode == FULL_DECOMPOSITION) {
692 primResult.append(Normalizer.normalize(source, Normalizer.Form.NFKD));
693 } else {
694 primResult.append(source);
695 }
696 }
697 return new RuleBasedCollationKey(source, primResult.toString());
698 }
699
700 /**
701 * Standard override; no change in semantics.
702 */
703 public Object clone() {
704 // if we know we're not actually a subclass of RuleBasedCollator
705 // (this class really should have been made final), bypass
706 // Object.clone() and use our "copy constructor". This is faster.
707 if (getClass() == RuleBasedCollator.class) {
708 return new RuleBasedCollator(this);
709 }
710 else {
711 RuleBasedCollator result = (RuleBasedCollator) super.clone();
712 result.primResult = null;
713 result.secResult = null;
714 result.terResult = null;
715 result.sourceCursor = null;
716 result.targetCursor = null;
717 return result;
718 }
719 }
720
721 /**
722 * Compares the equality of two collation objects.
723 * @param obj the table-based collation object to be compared with this.
724 * @return true if the current table-based collation object is the same
725 * as the table-based collation object obj; false otherwise.
726 */
727 public boolean equals(Object obj) {
728 if (obj == null) return false;
729 if (!super.equals(obj)) return false; // super does class check
730 RuleBasedCollator other = (RuleBasedCollator) obj;
731 // all other non-transient information is also contained in rules.
732 return (getRules().equals(other.getRules()));
733 }
734
735 /**
736 * Generates the hash code for the table-based collation object
737 */
738 public int hashCode() {
739 return getRules().hashCode();
740 }
741
742 /**
743 * Allows CollationElementIterator access to the tables object
744 */
745 RBCollationTables getTables() {
746 return tables;
747 }
748
749 // ==============================================================
750 // private
751 // ==============================================================
752
753 static final int CHARINDEX = 0x70000000; // need look up in .commit()
754 static final int EXPANDCHARINDEX = 0x7E000000; // Expand index follows
755 static final int CONTRACTCHARINDEX = 0x7F000000; // contract indexes follow
756 static final int UNMAPPED = 0xFFFFFFFF;
757
758 private static final int COLLATIONKEYOFFSET = 1;
759
760 private RBCollationTables tables = null;
761
762 // Internal objects that are cached across calls so that they don't have to
763 // be created/destroyed on every call to compare() and getCollationKey()
764 private StringBuffer primResult = null;
765 private StringBuffer secResult = null;
766 private StringBuffer terResult = null;
767 private CollationElementIterator sourceCursor = null;
768 private CollationElementIterator targetCursor = null;
769 }