icuSources/i18n/collationsets.cpp

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /*
   4 *******************************************************************************
   5 * Copyright (C) 2013-2014, International Business Machines
   6 * Corporation and others.  All Rights Reserved.
   7 *******************************************************************************
   8 * collationsets.cpp
   9 *
  10 * created on: 2013feb09
  11 * created by: Markus W. Scherer
  12 */
  13
  14 #include "unicode/utypes.h"
  15
  16 #if !UCONFIG_NO_COLLATION
  17
  18 #include "unicode/ucharstrie.h"
  19 #include "unicode/uniset.h"
  20 #include "unicode/unistr.h"
  21 #include "unicode/ustringtrie.h"
  22 #include "collation.h"
  23 #include "collationdata.h"
  24 #include "collationsets.h"
  25 #include "normalizer2impl.h"
  26 #include "uassert.h"
  27 #include "utf16collationiterator.h"
  28 #include "utrie2.h"
  29
  30 U_NAMESPACE_BEGIN
  31
  32 U_CDECL_BEGIN
  33
  34 static UBool U_CALLCONV
  35 enumTailoredRange(const void *context, UChar32 start, UChar32 end, uint32_t ce32) {
  36     if(ce32 == Collation::FALLBACK_CE32) {
  37         return TRUE;  // fallback to base, not tailored
  38     }
  39     TailoredSet *ts = (TailoredSet *)context;
  40     return ts->handleCE32(start, end, ce32);
  41 }
  42
  43 U_CDECL_END
  44
  45 void
  46 TailoredSet::forData(const CollationData *d, UErrorCode &ec) {
  47     if(U_FAILURE(ec)) { return; }
  48     errorCode = ec;  // Preserve info & warning codes.
  49     data = d;
  50     baseData = d->base;
  51     U_ASSERT(baseData != NULL);
  52     utrie2_enum(data->trie, NULL, enumTailoredRange, this);
  53     ec = errorCode;
  54 }
  55
  56 UBool
  57 TailoredSet::handleCE32(UChar32 start, UChar32 end, uint32_t ce32) {
  58     U_ASSERT(ce32 != Collation::FALLBACK_CE32);
  59     if(Collation::isSpecialCE32(ce32)) {
  60         ce32 = data->getIndirectCE32(ce32);
  61         if(ce32 == Collation::FALLBACK_CE32) {
  62             return U_SUCCESS(errorCode);
  63         }
  64     }
  65     do {
  66         uint32_t baseCE32 = baseData->getFinalCE32(baseData->getCE32(start));
  67         // Do not just continue if ce32 == baseCE32 because
  68         // contractions and expansions in different data objects
  69         // normally differ even if they have the same data offsets.
  70         if(Collation::isSelfContainedCE32(ce32) && Collation::isSelfContainedCE32(baseCE32)) {
  71             // fastpath
  72             if(ce32 != baseCE32) {
  73                 tailored->add(start);
  74             }
  75         } else {
  76             compare(start, ce32, baseCE32);
  77         }
  78     } while(++start <= end);
  79     return U_SUCCESS(errorCode);
  80 }
  81
  82 void
  83 TailoredSet::compare(UChar32 c, uint32_t ce32, uint32_t baseCE32) {
  84     if(Collation::isPrefixCE32(ce32)) {
  85         const UChar *p = data->contexts + Collation::indexFromCE32(ce32);
  86         ce32 = data->getFinalCE32(CollationData::readCE32(p));
  87         if(Collation::isPrefixCE32(baseCE32)) {
  88             const UChar *q = baseData->contexts + Collation::indexFromCE32(baseCE32);
  89             baseCE32 = baseData->getFinalCE32(CollationData::readCE32(q));
  90             comparePrefixes(c, p + 2, q + 2);
  91         } else {
  92             addPrefixes(data, c, p + 2);
  93         }
  94     } else if(Collation::isPrefixCE32(baseCE32)) {
  95         const UChar *q = baseData->contexts + Collation::indexFromCE32(baseCE32);
  96         baseCE32 = baseData->getFinalCE32(CollationData::readCE32(q));
  97         addPrefixes(baseData, c, q + 2);
  98     }
  99
 100     if(Collation::isContractionCE32(ce32)) {
 101         const UChar *p = data->contexts + Collation::indexFromCE32(ce32);
 102         if((ce32 & Collation::CONTRACT_SINGLE_CP_NO_MATCH) != 0) {
 103             ce32 = Collation::NO_CE32;
 104         } else {
 105             ce32 = data->getFinalCE32(CollationData::readCE32(p));
 106         }
 107         if(Collation::isContractionCE32(baseCE32)) {
 108             const UChar *q = baseData->contexts + Collation::indexFromCE32(baseCE32);
 109             if((baseCE32 & Collation::CONTRACT_SINGLE_CP_NO_MATCH) != 0) {
 110                 baseCE32 = Collation::NO_CE32;
 111             } else {
 112                 baseCE32 = baseData->getFinalCE32(CollationData::readCE32(q));
 113             }
 114             compareContractions(c, p + 2, q + 2);
 115         } else {
 116             addContractions(c, p + 2);
 117         }
 118     } else if(Collation::isContractionCE32(baseCE32)) {
 119         const UChar *q = baseData->contexts + Collation::indexFromCE32(baseCE32);
 120         baseCE32 = baseData->getFinalCE32(CollationData::readCE32(q));
 121         addContractions(c, q + 2);
 122     }
 123
 124     int32_t tag;
 125     if(Collation::isSpecialCE32(ce32)) {
 126         tag = Collation::tagFromCE32(ce32);
 127         U_ASSERT(tag != Collation::PREFIX_TAG);
 128         U_ASSERT(tag != Collation::CONTRACTION_TAG);
 129         // Currently, the tailoring data builder does not write offset tags.
 130         // They might be useful for saving space,
 131         // but they would complicate the builder,
 132         // and in tailorings we assume that performance of tailored characters is more important.
 133         U_ASSERT(tag != Collation::OFFSET_TAG);
 134     } else {
 135         tag = -1;
 136     }
 137     int32_t baseTag;
 138     if(Collation::isSpecialCE32(baseCE32)) {
 139         baseTag = Collation::tagFromCE32(baseCE32);
 140         U_ASSERT(baseTag != Collation::PREFIX_TAG);
 141         U_ASSERT(baseTag != Collation::CONTRACTION_TAG);
 142     } else {
 143         baseTag = -1;
 144     }
 145
 146     // Non-contextual mappings, expansions, etc.
 147     if(baseTag == Collation::OFFSET_TAG) {
 148         // We might be comparing a tailoring CE which is a copy of
 149         // a base offset-tag CE, via the [optimize [set]] syntax
 150         // or when a single-character mapping was copied for tailored contractions.
 151         // Offset tags always result in long-primary CEs,
 152         // with common secondary/tertiary weights.
 153         if(!Collation::isLongPrimaryCE32(ce32)) {
 154             add(c);
 155             return;
 156         }
 157         int64_t dataCE = baseData->ces[Collation::indexFromCE32(baseCE32)];
 158         uint32_t p = Collation::getThreeBytePrimaryForOffsetData(c, dataCE);
 159         if(Collation::primaryFromLongPrimaryCE32(ce32) != p) {
 160             add(c);
 161             return;
 162         }
 163     }
 164
 165     if(tag != baseTag) {
 166         add(c);
 167         return;
 168     }
 169
 170     if(tag == Collation::EXPANSION32_TAG) {
 171         const uint32_t *ce32s = data->ce32s + Collation::indexFromCE32(ce32);
 172         int32_t length = Collation::lengthFromCE32(ce32);
 173
 174         const uint32_t *baseCE32s = baseData->ce32s + Collation::indexFromCE32(baseCE32);
 175         int32_t baseLength = Collation::lengthFromCE32(baseCE32);
 176
 177         if(length != baseLength) {
 178             add(c);
 179             return;
 180         }
 181         for(int32_t i = 0; i < length; ++i) {
 182             if(ce32s[i] != baseCE32s[i]) {
 183                 add(c);
 184                 break;
 185             }
 186         }
 187     } else if(tag == Collation::EXPANSION_TAG) {
 188         const int64_t *ces = data->ces + Collation::indexFromCE32(ce32);
 189         int32_t length = Collation::lengthFromCE32(ce32);
 190
 191         const int64_t *baseCEs = baseData->ces + Collation::indexFromCE32(baseCE32);
 192         int32_t baseLength = Collation::lengthFromCE32(baseCE32);
 193
 194         if(length != baseLength) {
 195             add(c);
 196             return;
 197         }
 198         for(int32_t i = 0; i < length; ++i) {
 199             if(ces[i] != baseCEs[i]) {
 200                 add(c);
 201                 break;
 202             }
 203         }
 204     } else if(tag == Collation::HANGUL_TAG) {
 205         UChar jamos[3];
 206         int32_t length = Hangul::decompose(c, jamos);
 207         if(tailored->contains(jamos[0]) || tailored->contains(jamos[1]) ||
 208                 (length == 3 && tailored->contains(jamos[2]))) {
 209             add(c);
 210         }
 211     } else if(ce32 != baseCE32) {
 212         add(c);
 213     }
 214 }
 215
 216 void
 217 TailoredSet::comparePrefixes(UChar32 c, const UChar *p, const UChar *q) {
 218     // Parallel iteration over prefixes of both tables.
 219     UCharsTrie::Iterator prefixes(p, 0, errorCode);
 220     UCharsTrie::Iterator basePrefixes(q, 0, errorCode);
 221     const UnicodeString *tp = NULL;  // Tailoring prefix.
 222     const UnicodeString *bp = NULL;  // Base prefix.
 223     // Use a string with a U+FFFF as the limit sentinel.
 224     // U+FFFF is untailorable and will not occur in prefixes.
 225     UnicodeString none((UChar)0xffff);
 226     for(;;) {
 227         if(tp == NULL) {
 228             if(prefixes.next(errorCode)) {
 229                 tp = &prefixes.getString();
 230             } else {
 231                 tp = &none;
 232             }
 233         }
 234         if(bp == NULL) {
 235             if(basePrefixes.next(errorCode)) {
 236                 bp = &basePrefixes.getString();
 237             } else {
 238                 bp = &none;
 239             }
 240         }
 241         if(tp == &none && bp == &none) { break; }
 242         int32_t cmp = tp->compare(*bp);
 243         if(cmp < 0) {
 244             // tp occurs in the tailoring but not in the base.
 245             addPrefix(data, *tp, c, (uint32_t)prefixes.getValue());
 246             tp = NULL;
 247         } else if(cmp > 0) {
 248             // bp occurs in the base but not in the tailoring.
 249             addPrefix(baseData, *bp, c, (uint32_t)basePrefixes.getValue());
 250             bp = NULL;
 251         } else {
 252             setPrefix(*tp);
 253             compare(c, (uint32_t)prefixes.getValue(), (uint32_t)basePrefixes.getValue());
 254             resetPrefix();
 255             tp = NULL;
 256             bp = NULL;
 257         }
 258     }
 259 }
 260
 261 void
 262 TailoredSet::compareContractions(UChar32 c, const UChar *p, const UChar *q) {
 263     // Parallel iteration over suffixes of both tables.
 264     UCharsTrie::Iterator suffixes(p, 0, errorCode);
 265     UCharsTrie::Iterator baseSuffixes(q, 0, errorCode);
 266     const UnicodeString *ts = NULL;  // Tailoring suffix.
 267     const UnicodeString *bs = NULL;  // Base suffix.
 268     // Use a string with two U+FFFF as the limit sentinel.
 269     // U+FFFF is untailorable and will not occur in contractions except maybe
 270     // as a single suffix character for a root-collator boundary contraction.
 271     UnicodeString none((UChar)0xffff);
 272     none.append((UChar)0xffff);
 273     for(;;) {
 274         if(ts == NULL) {
 275             if(suffixes.next(errorCode)) {
 276                 ts = &suffixes.getString();
 277             } else {
 278                 ts = &none;
 279             }
 280         }
 281         if(bs == NULL) {
 282             if(baseSuffixes.next(errorCode)) {
 283                 bs = &baseSuffixes.getString();
 284             } else {
 285                 bs = &none;
 286             }
 287         }
 288         if(ts == &none && bs == &none) { break; }
 289         int32_t cmp = ts->compare(*bs);
 290         if(cmp < 0) {
 291             // ts occurs in the tailoring but not in the base.
 292             addSuffix(c, *ts);
 293             ts = NULL;
 294         } else if(cmp > 0) {
 295             // bs occurs in the base but not in the tailoring.
 296             addSuffix(c, *bs);
 297             bs = NULL;
 298         } else {
 299             suffix = ts;
 300             compare(c, (uint32_t)suffixes.getValue(), (uint32_t)baseSuffixes.getValue());
 301             suffix = NULL;
 302             ts = NULL;
 303             bs = NULL;
 304         }
 305     }
 306 }
 307
 308 void
 309 TailoredSet::addPrefixes(const CollationData *d, UChar32 c, const UChar *p) {
 310     UCharsTrie::Iterator prefixes(p, 0, errorCode);
 311     while(prefixes.next(errorCode)) {
 312         addPrefix(d, prefixes.getString(), c, (uint32_t)prefixes.getValue());
 313     }
 314 }
 315
 316 void
 317 TailoredSet::addPrefix(const CollationData *d, const UnicodeString &pfx, UChar32 c, uint32_t ce32) {
 318     setPrefix(pfx);
 319     ce32 = d->getFinalCE32(ce32);
 320     if(Collation::isContractionCE32(ce32)) {
 321         const UChar *p = d->contexts + Collation::indexFromCE32(ce32);
 322         addContractions(c, p + 2);
 323     }
 324     tailored->add(UnicodeString(unreversedPrefix).append(c));
 325     resetPrefix();
 326 }
 327
 328 void
 329 TailoredSet::addContractions(UChar32 c, const UChar *p) {
 330     UCharsTrie::Iterator suffixes(p, 0, errorCode);
 331     while(suffixes.next(errorCode)) {
 332         addSuffix(c, suffixes.getString());
 333     }
 334 }
 335
 336 void
 337 TailoredSet::addSuffix(UChar32 c, const UnicodeString &sfx) {
 338     tailored->add(UnicodeString(unreversedPrefix).append(c).append(sfx));
 339 }
 340
 341 void
 342 TailoredSet::add(UChar32 c) {
 343     if(unreversedPrefix.isEmpty() && suffix == NULL) {
 344         tailored->add(c);
 345     } else {
 346         UnicodeString s(unreversedPrefix);
 347         s.append(c);
 348         if(suffix != NULL) {
 349             s.append(*suffix);
 350         }
 351         tailored->add(s);
 352     }
 353 }
 354
 355 ContractionsAndExpansions::CESink::~CESink() {}
 356
 357 U_CDECL_BEGIN
 358
 359 static UBool U_CALLCONV
 360 enumCnERange(const void *context, UChar32 start, UChar32 end, uint32_t ce32) {
 361     ContractionsAndExpansions *cne = (ContractionsAndExpansions *)context;
 362     if(cne->checkTailored == 0) {
 363         // There is no tailoring.
 364         // No need to collect nor check the tailored set.
 365     } else if(cne->checkTailored < 0) {
 366         // Collect the set of code points with mappings in the tailoring data.
 367         if(ce32 == Collation::FALLBACK_CE32) {
 368             return TRUE;  // fallback to base, not tailored
 369         } else {
 370             cne->tailored.add(start, end);
 371         }
 372         // checkTailored > 0: Exclude tailored ranges from the base data enumeration.
 373     } else if(start == end) {
 374         if(cne->tailored.contains(start)) {
 375             return TRUE;
 376         }
 377     } else if(cne->tailored.containsSome(start, end)) {
 378         cne->ranges.set(start, end).removeAll(cne->tailored);
 379         int32_t count = cne->ranges.getRangeCount();
 380         for(int32_t i = 0; i < count; ++i) {
 381             cne->handleCE32(cne->ranges.getRangeStart(i), cne->ranges.getRangeEnd(i), ce32);
 382         }
 383         return U_SUCCESS(cne->errorCode);
 384     }
 385     cne->handleCE32(start, end, ce32);
 386     return U_SUCCESS(cne->errorCode);
 387 }
 388
 389 U_CDECL_END
 390
 391 void
 392 ContractionsAndExpansions::forData(const CollationData *d, UErrorCode &ec) {
 393     if(U_FAILURE(ec)) { return; }
 394     errorCode = ec;  // Preserve info & warning codes.
 395     // Add all from the data, can be tailoring or base.
 396     if(d->base != NULL) {
 397         checkTailored = -1;
 398     }
 399     data = d;
 400     utrie2_enum(data->trie, NULL, enumCnERange, this);
 401     if(d->base == NULL || U_FAILURE(errorCode)) {
 402         ec = errorCode;
 403         return;
 404     }
 405     // Add all from the base data but only for un-tailored code points.
 406     tailored.freeze();
 407     checkTailored = 1;
 408     data = d->base;
 409     utrie2_enum(data->trie, NULL, enumCnERange, this);
 410     ec = errorCode;
 411 }
 412
 413 void
 414 ContractionsAndExpansions::forCodePoint(const CollationData *d, UChar32 c, UErrorCode &ec) {
 415     if(U_FAILURE(ec)) { return; }
 416     errorCode = ec;  // Preserve info & warning codes.
 417     uint32_t ce32 = d->getCE32(c);
 418     if(ce32 == Collation::FALLBACK_CE32) {
 419         d = d->base;
 420         ce32 = d->getCE32(c);
 421     }
 422     data = d;
 423     handleCE32(c, c, ce32);
 424     ec = errorCode;
 425 }
 426
 427 void
 428 ContractionsAndExpansions::handleCE32(UChar32 start, UChar32 end, uint32_t ce32) {
 429     for(;;) {
 430         if((ce32 & 0xff) < Collation::SPECIAL_CE32_LOW_BYTE) {
 431             // !isSpecialCE32()
 432             if(sink != NULL) {
 433                 sink->handleCE(Collation::ceFromSimpleCE32(ce32));
 434             }
 435             return;
 436         }
 437         switch(Collation::tagFromCE32(ce32)) {
 438         case Collation::FALLBACK_TAG:
 439             return;
 440         case Collation::RESERVED_TAG_3:
 441         case Collation::BUILDER_DATA_TAG:
 442         case Collation::LEAD_SURROGATE_TAG:
 443             if(U_SUCCESS(errorCode)) { errorCode = U_INTERNAL_PROGRAM_ERROR; }
 444             return;
 445         case Collation::LONG_PRIMARY_TAG:
 446             if(sink != NULL) {
 447                 sink->handleCE(Collation::ceFromLongPrimaryCE32(ce32));
 448             }
 449             return;
 450         case Collation::LONG_SECONDARY_TAG:
 451             if(sink != NULL) {
 452                 sink->handleCE(Collation::ceFromLongSecondaryCE32(ce32));
 453             }
 454             return;
 455         case Collation::LATIN_EXPANSION_TAG:
 456             if(sink != NULL) {
 457                 ces[0] = Collation::latinCE0FromCE32(ce32);
 458                 ces[1] = Collation::latinCE1FromCE32(ce32);
 459                 sink->handleExpansion(ces, 2);
 460             }
 461             // Optimization: If we have a prefix,
 462             // then the relevant strings have been added already.
 463             if(unreversedPrefix.isEmpty()) {
 464                 addExpansions(start, end);
 465             }
 466             return;
 467         case Collation::EXPANSION32_TAG:
 468             if(sink != NULL) {
 469                 const uint32_t *ce32s = data->ce32s + Collation::indexFromCE32(ce32);
 470                 int32_t length = Collation::lengthFromCE32(ce32);
 471                 for(int32_t i = 0; i < length; ++i) {
 472                     ces[i] = Collation::ceFromCE32(*ce32s++);
 473                 }
 474                 sink->handleExpansion(ces, length);
 475             }
 476             // Optimization: If we have a prefix,
 477             // then the relevant strings have been added already.
 478             if(unreversedPrefix.isEmpty()) {
 479                 addExpansions(start, end);
 480             }
 481             return;
 482         case Collation::EXPANSION_TAG:
 483             if(sink != NULL) {
 484                 int32_t length = Collation::lengthFromCE32(ce32);
 485                 sink->handleExpansion(data->ces + Collation::indexFromCE32(ce32), length);
 486             }
 487             // Optimization: If we have a prefix,
 488             // then the relevant strings have been added already.
 489             if(unreversedPrefix.isEmpty()) {
 490                 addExpansions(start, end);
 491             }
 492             return;
 493         case Collation::PREFIX_TAG:
 494             handlePrefixes(start, end, ce32);
 495             return;
 496         case Collation::CONTRACTION_TAG:
 497             handleContractions(start, end, ce32);
 498             return;
 499         case Collation::DIGIT_TAG:
 500             // Fetch the non-numeric-collation CE32 and continue.
 501             ce32 = data->ce32s[Collation::indexFromCE32(ce32)];
 502             break;
 503         case Collation::U0000_TAG:
 504             U_ASSERT(start == 0 && end == 0);
 505             // Fetch the normal ce32 for U+0000 and continue.
 506             ce32 = data->ce32s[0];
 507             break;
 508         case Collation::HANGUL_TAG:
 509             if(sink != NULL) {
 510                 // TODO: This should be optimized,
 511                 // especially if [start..end] is the complete Hangul range. (assert that)
 512                 UTF16CollationIterator iter(data, FALSE, NULL, NULL, NULL);
 513                 UChar hangul[1] = { 0 };
 514                 for(UChar32 c = start; c <= end; ++c) {
 515                     hangul[0] = (UChar)c;
 516                     iter.setText(hangul, hangul + 1);
 517                     int32_t length = iter.fetchCEs(errorCode);
 518                     if(U_FAILURE(errorCode)) { return; }
 519                     // Ignore the terminating non-CE.
 520                     U_ASSERT(length >= 2 && iter.getCE(length - 1) == Collation::NO_CE);
 521                     sink->handleExpansion(iter.getCEs(), length - 1);
 522                 }
 523             }
 524             // Optimization: If we have a prefix,
 525             // then the relevant strings have been added already.
 526             if(unreversedPrefix.isEmpty()) {
 527                 addExpansions(start, end);
 528             }
 529             return;
 530         case Collation::OFFSET_TAG:
 531             // Currently no need to send offset CEs to the sink.
 532             return;
 533         case Collation::IMPLICIT_TAG:
 534             // Currently no need to send implicit CEs to the sink.
 535             return;
 536         }
 537     }
 538 }
 539
 540 void
 541 ContractionsAndExpansions::handlePrefixes(
 542         UChar32 start, UChar32 end, uint32_t ce32) {
 543     const UChar *p = data->contexts + Collation::indexFromCE32(ce32);
 544     ce32 = CollationData::readCE32(p);  // Default if no prefix match.
 545     handleCE32(start, end, ce32);
 546     if(!addPrefixes) { return; }
 547     UCharsTrie::Iterator prefixes(p + 2, 0, errorCode);
 548     while(prefixes.next(errorCode)) {
 549         setPrefix(prefixes.getString());
 550         // Prefix/pre-context mappings are special kinds of contractions
 551         // that always yield expansions.
 552         addStrings(start, end, contractions);
 553         addStrings(start, end, expansions);
 554         handleCE32(start, end, (uint32_t)prefixes.getValue());
 555     }
 556     resetPrefix();
 557 }
 558
 559 void
 560 ContractionsAndExpansions::handleContractions(
 561         UChar32 start, UChar32 end, uint32_t ce32) {
 562     const UChar *p = data->contexts + Collation::indexFromCE32(ce32);
 563     if((ce32 & Collation::CONTRACT_SINGLE_CP_NO_MATCH) != 0) {
 564         // No match on the single code point.
 565         // We are underneath a prefix, and the default mapping is just
 566         // a fallback to the mappings for a shorter prefix.
 567         U_ASSERT(!unreversedPrefix.isEmpty());
 568     } else {
 569         ce32 = CollationData::readCE32(p);  // Default if no suffix match.
 570         U_ASSERT(!Collation::isContractionCE32(ce32));
 571         handleCE32(start, end, ce32);
 572     }
 573     UCharsTrie::Iterator suffixes(p + 2, 0, errorCode);
 574     while(suffixes.next(errorCode)) {
 575         suffix = &suffixes.getString();
 576         addStrings(start, end, contractions);
 577         if(!unreversedPrefix.isEmpty()) {
 578             addStrings(start, end, expansions);
 579         }
 580         handleCE32(start, end, (uint32_t)suffixes.getValue());
 581     }
 582     suffix = NULL;
 583 }
 584
 585 void
 586 ContractionsAndExpansions::addExpansions(UChar32 start, UChar32 end) {
 587     if(unreversedPrefix.isEmpty() && suffix == NULL) {
 588         if(expansions != NULL) {
 589             expansions->add(start, end);
 590         }
 591     } else {
 592         addStrings(start, end, expansions);
 593     }
 594 }
 595
 596 void
 597 ContractionsAndExpansions::addStrings(UChar32 start, UChar32 end, UnicodeSet *set) {
 598     if(set == NULL) { return; }
 599     UnicodeString s(unreversedPrefix);
 600     do {
 601         s.append(start);
 602         if(suffix != NULL) {
 603             s.append(*suffix);
 604         }
 605         set->add(s);
 606         s.truncate(unreversedPrefix.length());
 607     } while(++start <= end);
 608 }
 609
 610 U_NAMESPACE_END
 611
 612 #endif  // !UCONFIG_NO_COLLATION