1 // Copyright (C) 2016 and later: Unicode, Inc. and others. 2 // License & terms of use: http://www.unicode.org/copyright.html 3 /* 4 ********************************************************************** 5 * Copyright (C) 2001-2011,2014 IBM and others. All rights reserved. 6 ********************************************************************** 7 * Date Name Description 8 * 06/28/2001 synwee Creation. 9 ********************************************************************** 10 */ 11 #ifndef USEARCH_H 12 #define USEARCH_H 13 14 #include "unicode/utypes.h" 15 16 #if !UCONFIG_NO_COLLATION && !UCONFIG_NO_BREAK_ITERATION 17 18 #include "unicode/localpointer.h" 19 #include "unicode/ucol.h" 20 #include "unicode/ucoleitr.h" 21 #include "unicode/ubrk.h" 22 23 /** 24 * \file 25 * \brief C API: StringSearch 26 * 27 * C Apis for an engine that provides language-sensitive text searching based 28 * on the comparison rules defined in a <tt>UCollator</tt> data struct, 29 * see <tt>ucol.h</tt>. This ensures that language eccentricity can be 30 * handled, e.g. for the German collator, characters ß and SS will be matched 31 * if case is chosen to be ignored. 32 * See the <a href="http://source.icu-project.org/repos/icu/icuhtml/trunk/design/collation/ICU_collation_design.htm"> 33 * "ICU Collation Design Document"</a> for more information. 34 * <p> 35 * The implementation may use a linear search or a modified form of the Boyer-Moore 36 * search; for more information on the latter see 37 * <a href="http://icu-project.org/docs/papers/efficient_text_searching_in_java.html"> 38 * "Efficient Text Searching in Java"</a>, published in <i>Java Report</i> 39 * in February, 1999. 40 * <p> 41 * There are 2 match options for selection:<br> 42 * Let S' be the sub-string of a text string S between the offsets start and 43 * end <start, end>. 44 * <br> 45 * A pattern string P matches a text string S at the offsets <start, end> 46 * if 47 * <pre> 48 * option 1. Some canonical equivalent of P matches some canonical equivalent 49 * of S' 50 * option 2. P matches S' and if P starts or ends with a combining mark, 51 * there exists no non-ignorable combining mark before or after S' 52 * in S respectively. 53 * </pre> 54 * Option 2. will be the default. 55 * <p> 56 * This search has APIs similar to that of other text iteration mechanisms 57 * such as the break iterators in <tt>ubrk.h</tt>. Using these 58 * APIs, it is easy to scan through text looking for all occurances of 59 * a given pattern. This search iterator allows changing of direction by 60 * calling a <tt>reset</tt> followed by a <tt>next</tt> or <tt>previous</tt>. 61 * Though a direction change can occur without calling <tt>reset</tt> first, 62 * this operation comes with some speed penalty. 63 * Generally, match results in the forward direction will match the result 64 * matches in the backwards direction in the reverse order 65 * <p> 66 * <tt>usearch.h</tt> provides APIs to specify the starting position 67 * within the text string to be searched, e.g. <tt>usearch_setOffset</tt>, 68 * <tt>usearch_preceding</tt> and <tt>usearch_following</tt>. Since the 69 * starting position will be set as it is specified, please take note that 70 * there are some dangerous positions which the search may render incorrect 71 * results: 72 * <ul> 73 * <li> The midst of a substring that requires normalization. 74 * <li> If the following match is to be found, the position should not be the 75 * second character which requires to be swapped with the preceding 76 * character. Vice versa, if the preceding match is to be found, 77 * position to search from should not be the first character which 78 * requires to be swapped with the next character. E.g certain Thai and 79 * Lao characters require swapping. 80 * <li> If a following pattern match is to be found, any position within a 81 * contracting sequence except the first will fail. Vice versa if a 82 * preceding pattern match is to be found, a invalid starting point 83 * would be any character within a contracting sequence except the last. 84 * </ul> 85 * <p> 86 * A breakiterator can be used if only matches at logical breaks are desired. 87 * Using a breakiterator will only give you results that exactly matches the 88 * boundaries given by the breakiterator. For instance the pattern "e" will 89 * not be found in the string "\u00e9" if a character break iterator is used. 90 * <p> 91 * Options are provided to handle overlapping matches. 92 * E.g. In English, overlapping matches produces the result 0 and 2 93 * for the pattern "abab" in the text "ababab", where else mutually 94 * exclusive matches only produce the result of 0. 95 * <p> 96 * Options are also provided to implement "asymmetric search" as described in 97 * <a href="http://www.unicode.org/reports/tr10/#Asymmetric_Search"> 98 * UTS #10 Unicode Collation Algorithm</a>, specifically the USearchAttribute 99 * USEARCH_ELEMENT_COMPARISON and its values. 100 * <p> 101 * Though collator attributes will be taken into consideration while 102 * performing matches, there are no APIs here for setting and getting the 103 * attributes. These attributes can be set by getting the collator 104 * from <tt>usearch_getCollator</tt> and using the APIs in <tt>ucol.h</tt>. 105 * Lastly to update String Search to the new collator attributes, 106 * usearch_reset() has to be called. 107 * <p> 108 * Restriction: <br> 109 * Currently there are no composite characters that consists of a 110 * character with combining class > 0 before a character with combining 111 * class == 0. However, if such a character exists in the future, the 112 * search mechanism does not guarantee the results for option 1. 113 * 114 * <p> 115 * Example of use:<br> 116 * <pre><code> 117 * char *tgtstr = "The quick brown fox jumped over the lazy fox"; 118 * char *patstr = "fox"; 119 * UChar target[64]; 120 * UChar pattern[16]; 121 * UErrorCode status = U_ZERO_ERROR; 122 * u_uastrcpy(target, tgtstr); 123 * u_uastrcpy(pattern, patstr); 124 * 125 * UStringSearch *search = usearch_open(pattern, -1, target, -1, "en_US", 126 * NULL, &status); 127 * if (U_SUCCESS(status)) { 128 * for (int pos = usearch_first(search, &status); 129 * pos != USEARCH_DONE; 130 * pos = usearch_next(search, &status)) 131 * { 132 * printf("Found match at %d pos, length is %d\n", pos, 133 * usearch_getMatchLength(search)); 134 * } 135 * } 136 * 137 * usearch_close(search); 138 * </code></pre> 139 * @stable ICU 2.4 140 */ 141 142 /** 143 * DONE is returned by previous() and next() after all valid matches have 144 * been returned, and by first() and last() if there are no matches at all. 145 * @stable ICU 2.4 146 */ 147 #define USEARCH_DONE -1 148 149 /** 150 * Data structure for searching 151 * @stable ICU 2.4 152 */ 153 struct UStringSearch; 154 /** 155 * Data structure for searching 156 * @stable ICU 2.4 157 */ 158 typedef struct UStringSearch UStringSearch; 159 160 /** 161 * @stable ICU 2.4 162 */ 163 typedef enum { 164 /** 165 * Option for overlapping matches 166 * @stable ICU 2.4 167 */ 168 USEARCH_OVERLAP = 0, 169 #ifndef U_HIDE_DEPRECATED_API 170 /** 171 * Option for canonical matches; option 1 in header documentation. 172 * The default value will be USEARCH_OFF. 173 * Note: Setting this option to USEARCH_ON currently has no effect on 174 * search behavior, and this option is deprecated. Instead, to control 175 * canonical match behavior, you must set UCOL_NORMALIZATION_MODE 176 * appropriately (to UCOL_OFF or UCOL_ON) in the UCollator used by 177 * the UStringSearch object. 178 * @see usearch_openFromCollator 179 * @see usearch_getCollator 180 * @see usearch_setCollator 181 * @see ucol_getAttribute 182 * @deprecated ICU 53 183 */ 184 USEARCH_CANONICAL_MATCH = 1, 185 #endif /* U_HIDE_DEPRECATED_API */ 186 /** 187 * Option to control how collation elements are compared. 188 * The default value will be USEARCH_STANDARD_ELEMENT_COMPARISON. 189 * @stable ICU 4.4 190 */ 191 USEARCH_ELEMENT_COMPARISON = 2, 192 193 #ifndef U_HIDE_DEPRECATED_API 194 /** 195 * One more than the highest normal USearchAttribute value. 196 * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420. 197 */ 198 USEARCH_ATTRIBUTE_COUNT = 3 199 #endif // U_HIDE_DEPRECATED_API 200 } USearchAttribute; 201 202 /** 203 * @stable ICU 2.4 204 */ 205 typedef enum { 206 /** 207 * Default value for any USearchAttribute 208 * @stable ICU 2.4 209 */ 210 USEARCH_DEFAULT = -1, 211 /** 212 * Value for USEARCH_OVERLAP and USEARCH_CANONICAL_MATCH 213 * @stable ICU 2.4 214 */ 215 USEARCH_OFF, 216 /** 217 * Value for USEARCH_OVERLAP and USEARCH_CANONICAL_MATCH 218 * @stable ICU 2.4 219 */ 220 USEARCH_ON, 221 /** 222 * Value (default) for USEARCH_ELEMENT_COMPARISON; 223 * standard collation element comparison at the specified collator 224 * strength. 225 * @stable ICU 4.4 226 */ 227 USEARCH_STANDARD_ELEMENT_COMPARISON, 228 /** 229 * Value for USEARCH_ELEMENT_COMPARISON; 230 * collation element comparison is modified to effectively provide 231 * behavior between the specified strength and strength - 1. Collation 232 * elements in the pattern that have the base weight for the specified 233 * strength are treated as "wildcards" that match an element with any 234 * other weight at that collation level in the searched text. For 235 * example, with a secondary-strength English collator, a plain 'e' in 236 * the pattern will match a plain e or an e with any diacritic in the 237 * searched text, but an e with diacritic in the pattern will only 238 * match an e with the same diacritic in the searched text. 239 * 240 * This supports "asymmetric search" as described in 241 * <a href="http://www.unicode.org/reports/tr10/#Asymmetric_Search"> 242 * UTS #10 Unicode Collation Algorithm</a>. 243 * 244 * @stable ICU 4.4 245 */ 246 USEARCH_PATTERN_BASE_WEIGHT_IS_WILDCARD, 247 /** 248 * Value for USEARCH_ELEMENT_COMPARISON. 249 * collation element comparison is modified to effectively provide 250 * behavior between the specified strength and strength - 1. Collation 251 * elements in either the pattern or the searched text that have the 252 * base weight for the specified strength are treated as "wildcards" 253 * that match an element with any other weight at that collation level. 254 * For example, with a secondary-strength English collator, a plain 'e' 255 * in the pattern will match a plain e or an e with any diacritic in the 256 * searched text, but an e with diacritic in the pattern will only 257 * match an e with the same diacritic or a plain e in the searched text. 258 * 259 * This option is similar to "asymmetric search" as described in 260 * <a href="http://www.unicode.org/reports/tr10/#Asymmetric_Search"> 261 * UTS #10 Unicode Collation Algorithm</a, but also allows unmarked 262 * characters in the searched text to match marked or unmarked versions of 263 * that character in the pattern. 264 * 265 * @stable ICU 4.4 266 */ 267 USEARCH_ANY_BASE_WEIGHT_IS_WILDCARD, 268 269 #ifndef U_HIDE_DEPRECATED_API 270 /** 271 * One more than the highest normal USearchAttributeValue value. 272 * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420. 273 */ 274 USEARCH_ATTRIBUTE_VALUE_COUNT 275 #endif // U_HIDE_DEPRECATED_API 276 } USearchAttributeValue; 277 278 /* open and close ------------------------------------------------------ */ 279 280 /** 281 * Creating a search iterator data struct using the argument locale language 282 * rule set. A collator will be created in the process, which will be owned by 283 * this search and will be deleted in <tt>usearch_close</tt>. 284 * @param pattern for matching 285 * @param patternlength length of the pattern, -1 for null-termination 286 * @param text text string 287 * @param textlength length of the text string, -1 for null-termination 288 * @param locale name of locale for the rules to be used 289 * @param breakiter A BreakIterator that will be used to restrict the points 290 * at which matches are detected. If a match is found, but 291 * the match's start or end index is not a boundary as 292 * determined by the <tt>BreakIterator</tt>, the match will 293 * be rejected and another will be searched for. 294 * If this parameter is <tt>NULL</tt>, no break detection is 295 * attempted. 296 * @param status for errors if it occurs. If pattern or text is NULL, or if 297 * patternlength or textlength is 0 then an 298 * U_ILLEGAL_ARGUMENT_ERROR is returned. 299 * @return search iterator data structure, or NULL if there is an error. 300 * @stable ICU 2.4 301 */ 302 U_STABLE UStringSearch * U_EXPORT2 usearch_open(const UChar *pattern, 303 int32_t patternlength, 304 const UChar *text, 305 int32_t textlength, 306 const char *locale, 307 UBreakIterator *breakiter, 308 UErrorCode *status); 309 310 /** 311 * Creating a search iterator data struct using the argument collator language 312 * rule set. Note, user retains the ownership of this collator, thus the 313 * responsibility of deletion lies with the user. 314 * NOTE: string search cannot be instantiated from a collator that has 315 * collate digits as numbers (CODAN) turned on. 316 * @param pattern for matching 317 * @param patternlength length of the pattern, -1 for null-termination 318 * @param text text string 319 * @param textlength length of the text string, -1 for null-termination 320 * @param collator used for the language rules 321 * @param breakiter A BreakIterator that will be used to restrict the points 322 * at which matches are detected. If a match is found, but 323 * the match's start or end index is not a boundary as 324 * determined by the <tt>BreakIterator</tt>, the match will 325 * be rejected and another will be searched for. 326 * If this parameter is <tt>NULL</tt>, no break detection is 327 * attempted. 328 * @param status for errors if it occurs. If collator, pattern or text is NULL, 329 * or if patternlength or textlength is 0 then an 330 * U_ILLEGAL_ARGUMENT_ERROR is returned. 331 * @return search iterator data structure, or NULL if there is an error. 332 * @stable ICU 2.4 333 */ 334 U_STABLE UStringSearch * U_EXPORT2 usearch_openFromCollator( 335 const UChar *pattern, 336 int32_t patternlength, 337 const UChar *text, 338 int32_t textlength, 339 const UCollator *collator, 340 UBreakIterator *breakiter, 341 UErrorCode *status); 342 343 /** 344 * Destroying and cleaning up the search iterator data struct. 345 * If a collator is created in <tt>usearch_open</tt>, it will be destroyed here. 346 * @param searchiter data struct to clean up 347 * @stable ICU 2.4 348 */ 349 U_STABLE void U_EXPORT2 usearch_close(UStringSearch *searchiter); 350 351 #if U_SHOW_CPLUSPLUS_API 352 353 U_NAMESPACE_BEGIN 354 355 /** 356 * \class LocalUStringSearchPointer 357 * "Smart pointer" class, closes a UStringSearch via usearch_close(). 358 * For most methods see the LocalPointerBase base class. 359 * 360 * @see LocalPointerBase 361 * @see LocalPointer 362 * @stable ICU 4.4 363 */ 364 U_DEFINE_LOCAL_OPEN_POINTER(LocalUStringSearchPointer, UStringSearch, usearch_close); 365 366 U_NAMESPACE_END 367 368 #endif 369 370 /* get and set methods -------------------------------------------------- */ 371 372 /** 373 * Sets the current position in the text string which the next search will 374 * start from. Clears previous states. 375 * This method takes the argument index and sets the position in the text 376 * string accordingly without checking if the index is pointing to a 377 * valid starting point to begin searching. 378 * Search positions that may render incorrect results are highlighted in the 379 * header comments 380 * @param strsrch search iterator data struct 381 * @param position position to start next search from. If position is less 382 * than or greater than the text range for searching, 383 * an U_INDEX_OUTOFBOUNDS_ERROR will be returned 384 * @param status error status if any. 385 * @stable ICU 2.4 386 */ 387 U_STABLE void U_EXPORT2 usearch_setOffset(UStringSearch *strsrch, 388 int32_t position, 389 UErrorCode *status); 390 391 /** 392 * Return the current index in the string text being searched. 393 * If the iteration has gone past the end of the text (or past the beginning 394 * for a backwards search), <tt>USEARCH_DONE</tt> is returned. 395 * @param strsrch search iterator data struct 396 * @see #USEARCH_DONE 397 * @stable ICU 2.4 398 */ 399 U_STABLE int32_t U_EXPORT2 usearch_getOffset(const UStringSearch *strsrch); 400 401 /** 402 * Sets the text searching attributes located in the enum USearchAttribute 403 * with values from the enum USearchAttributeValue. 404 * <tt>USEARCH_DEFAULT</tt> can be used for all attributes for resetting. 405 * @param strsrch search iterator data struct 406 * @param attribute text attribute to be set 407 * @param value text attribute value 408 * @param status for errors if it occurs 409 * @see #usearch_getAttribute 410 * @stable ICU 2.4 411 */ 412 U_STABLE void U_EXPORT2 usearch_setAttribute(UStringSearch *strsrch, 413 USearchAttribute attribute, 414 USearchAttributeValue value, 415 UErrorCode *status); 416 417 /** 418 * Gets the text searching attributes. 419 * @param strsrch search iterator data struct 420 * @param attribute text attribute to be retrieve 421 * @return text attribute value 422 * @see #usearch_setAttribute 423 * @stable ICU 2.4 424 */ 425 U_STABLE USearchAttributeValue U_EXPORT2 usearch_getAttribute( 426 const UStringSearch *strsrch, 427 USearchAttribute attribute); 428 429 /** 430 * Returns the index to the match in the text string that was searched. 431 * This call returns a valid result only after a successful call to 432 * <tt>usearch_first</tt>, <tt>usearch_next</tt>, <tt>usearch_previous</tt>, 433 * or <tt>usearch_last</tt>. 434 * Just after construction, or after a searching method returns 435 * <tt>USEARCH_DONE</tt>, this method will return <tt>USEARCH_DONE</tt>. 436 * <p> 437 * Use <tt>usearch_getMatchedLength</tt> to get the matched string length. 438 * @param strsrch search iterator data struct 439 * @return index to a substring within the text string that is being 440 * searched. 441 * @see #usearch_first 442 * @see #usearch_next 443 * @see #usearch_previous 444 * @see #usearch_last 445 * @see #USEARCH_DONE 446 * @stable ICU 2.4 447 */ 448 U_STABLE int32_t U_EXPORT2 usearch_getMatchedStart( 449 const UStringSearch *strsrch); 450 451 /** 452 * Returns the length of text in the string which matches the search pattern. 453 * This call returns a valid result only after a successful call to 454 * <tt>usearch_first</tt>, <tt>usearch_next</tt>, <tt>usearch_previous</tt>, 455 * or <tt>usearch_last</tt>. 456 * Just after construction, or after a searching method returns 457 * <tt>USEARCH_DONE</tt>, this method will return 0. 458 * @param strsrch search iterator data struct 459 * @return The length of the match in the string text, or 0 if there is no 460 * match currently. 461 * @see #usearch_first 462 * @see #usearch_next 463 * @see #usearch_previous 464 * @see #usearch_last 465 * @see #USEARCH_DONE 466 * @stable ICU 2.4 467 */ 468 U_STABLE int32_t U_EXPORT2 usearch_getMatchedLength( 469 const UStringSearch *strsrch); 470 471 /** 472 * Returns the text that was matched by the most recent call to 473 * <tt>usearch_first</tt>, <tt>usearch_next</tt>, <tt>usearch_previous</tt>, 474 * or <tt>usearch_last</tt>. 475 * If the iterator is not pointing at a valid match (e.g. just after 476 * construction or after <tt>USEARCH_DONE</tt> has been returned, returns 477 * an empty string. If result is not large enough to store the matched text, 478 * result will be filled with the partial text and an U_BUFFER_OVERFLOW_ERROR 479 * will be returned in status. result will be null-terminated whenever 480 * possible. If the buffer fits the matched text exactly, a null-termination 481 * is not possible, then a U_STRING_NOT_TERMINATED_ERROR set in status. 482 * Pre-flighting can be either done with length = 0 or the API 483 * <tt>usearch_getMatchLength</tt>. 484 * @param strsrch search iterator data struct 485 * @param result UChar buffer to store the matched string 486 * @param resultCapacity length of the result buffer 487 * @param status error returned if result is not large enough 488 * @return exact length of the matched text, not counting the null-termination 489 * @see #usearch_first 490 * @see #usearch_next 491 * @see #usearch_previous 492 * @see #usearch_last 493 * @see #USEARCH_DONE 494 * @stable ICU 2.4 495 */ 496 U_STABLE int32_t U_EXPORT2 usearch_getMatchedText(const UStringSearch *strsrch, 497 UChar *result, 498 int32_t resultCapacity, 499 UErrorCode *status); 500 501 #if !UCONFIG_NO_BREAK_ITERATION 502 503 /** 504 * Set the BreakIterator that will be used to restrict the points at which 505 * matches are detected. 506 * @param strsrch search iterator data struct 507 * @param breakiter A BreakIterator that will be used to restrict the points 508 * at which matches are detected. If a match is found, but 509 * the match's start or end index is not a boundary as 510 * determined by the <tt>BreakIterator</tt>, the match will 511 * be rejected and another will be searched for. 512 * If this parameter is <tt>NULL</tt>, no break detection is 513 * attempted. 514 * @param status for errors if it occurs 515 * @see #usearch_getBreakIterator 516 * @stable ICU 2.4 517 */ 518 U_STABLE void U_EXPORT2 usearch_setBreakIterator(UStringSearch *strsrch, 519 UBreakIterator *breakiter, 520 UErrorCode *status); 521 522 /** 523 * Returns the BreakIterator that is used to restrict the points at which 524 * matches are detected. This will be the same object that was passed to the 525 * constructor or to <tt>usearch_setBreakIterator</tt>. Note that 526 * <tt>NULL</tt> 527 * is a legal value; it means that break detection should not be attempted. 528 * @param strsrch search iterator data struct 529 * @return break iterator used 530 * @see #usearch_setBreakIterator 531 * @stable ICU 2.4 532 */ 533 U_STABLE const UBreakIterator * U_EXPORT2 usearch_getBreakIterator( 534 const UStringSearch *strsrch); 535 536 #endif 537 538 /** 539 * Set the string text to be searched. Text iteration will hence begin at the 540 * start of the text string. This method is useful if you want to re-use an 541 * iterator to search for the same pattern within a different body of text. 542 * @param strsrch search iterator data struct 543 * @param text new string to look for match 544 * @param textlength length of the new string, -1 for null-termination 545 * @param status for errors if it occurs. If text is NULL, or textlength is 0 546 * then an U_ILLEGAL_ARGUMENT_ERROR is returned with no change 547 * done to strsrch. 548 * @see #usearch_getText 549 * @stable ICU 2.4 550 */ 551 U_STABLE void U_EXPORT2 usearch_setText( UStringSearch *strsrch, 552 const UChar *text, 553 int32_t textlength, 554 UErrorCode *status); 555 556 /** 557 * Return the string text to be searched. 558 * @param strsrch search iterator data struct 559 * @param length returned string text length 560 * @return string text 561 * @see #usearch_setText 562 * @stable ICU 2.4 563 */ 564 U_STABLE const UChar * U_EXPORT2 usearch_getText(const UStringSearch *strsrch, 565 int32_t *length); 566 567 /** 568 * Gets the collator used for the language rules. 569 * <p> 570 * Deleting the returned <tt>UCollator</tt> before calling 571 * <tt>usearch_close</tt> would cause the string search to fail. 572 * <tt>usearch_close</tt> will delete the collator if this search owns it. 573 * @param strsrch search iterator data struct 574 * @return collator 575 * @stable ICU 2.4 576 */ 577 U_STABLE UCollator * U_EXPORT2 usearch_getCollator( 578 const UStringSearch *strsrch); 579 580 /** 581 * Sets the collator used for the language rules. User retains the ownership 582 * of this collator, thus the responsibility of deletion lies with the user. 583 * This method causes internal data such as Boyer-Moore shift tables to 584 * be recalculated, but the iterator's position is unchanged. 585 * @param strsrch search iterator data struct 586 * @param collator to be used 587 * @param status for errors if it occurs 588 * @stable ICU 2.4 589 */ 590 U_STABLE void U_EXPORT2 usearch_setCollator( UStringSearch *strsrch, 591 const UCollator *collator, 592 UErrorCode *status); 593 594 /** 595 * Sets the pattern used for matching. 596 * Internal data like the Boyer Moore table will be recalculated, but the 597 * iterator's position is unchanged. 598 * @param strsrch search iterator data struct 599 * @param pattern string 600 * @param patternlength pattern length, -1 for null-terminated string 601 * @param status for errors if it occurs. If text is NULL, or textlength is 0 602 * then an U_ILLEGAL_ARGUMENT_ERROR is returned with no change 603 * done to strsrch. 604 * @stable ICU 2.4 605 */ 606 U_STABLE void U_EXPORT2 usearch_setPattern( UStringSearch *strsrch, 607 const UChar *pattern, 608 int32_t patternlength, 609 UErrorCode *status); 610 611 /** 612 * Gets the search pattern 613 * @param strsrch search iterator data struct 614 * @param length return length of the pattern, -1 indicates that the pattern 615 * is null-terminated 616 * @return pattern string 617 * @stable ICU 2.4 618 */ 619 U_STABLE const UChar * U_EXPORT2 usearch_getPattern( 620 const UStringSearch *strsrch, 621 int32_t *length); 622 623 /* methods ------------------------------------------------------------- */ 624 625 /** 626 * Returns the first index at which the string text matches the search 627 * pattern. 628 * The iterator is adjusted so that its current index (as returned by 629 * <tt>usearch_getOffset</tt>) is the match position if one was found. 630 * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and 631 * the iterator will be adjusted to the index <tt>USEARCH_DONE</tt>. 632 * @param strsrch search iterator data struct 633 * @param status for errors if it occurs 634 * @return The character index of the first match, or 635 * <tt>USEARCH_DONE</tt> if there are no matches. 636 * @see #usearch_getOffset 637 * @see #USEARCH_DONE 638 * @stable ICU 2.4 639 */ 640 U_STABLE int32_t U_EXPORT2 usearch_first(UStringSearch *strsrch, 641 UErrorCode *status); 642 643 /** 644 * Returns the first index equal or greater than <tt>position</tt> at which 645 * the string text 646 * matches the search pattern. The iterator is adjusted so that its current 647 * index (as returned by <tt>usearch_getOffset</tt>) is the match position if 648 * one was found. 649 * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and 650 * the iterator will be adjusted to the index <tt>USEARCH_DONE</tt> 651 * <p> 652 * Search positions that may render incorrect results are highlighted in the 653 * header comments. If position is less than or greater than the text range 654 * for searching, an U_INDEX_OUTOFBOUNDS_ERROR will be returned 655 * @param strsrch search iterator data struct 656 * @param position to start the search at 657 * @param status for errors if it occurs 658 * @return The character index of the first match following <tt>pos</tt>, 659 * or <tt>USEARCH_DONE</tt> if there are no matches. 660 * @see #usearch_getOffset 661 * @see #USEARCH_DONE 662 * @stable ICU 2.4 663 */ 664 U_STABLE int32_t U_EXPORT2 usearch_following(UStringSearch *strsrch, 665 int32_t position, 666 UErrorCode *status); 667 668 /** 669 * Returns the last index in the target text at which it matches the search 670 * pattern. The iterator is adjusted so that its current 671 * index (as returned by <tt>usearch_getOffset</tt>) is the match position if 672 * one was found. 673 * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and 674 * the iterator will be adjusted to the index <tt>USEARCH_DONE</tt>. 675 * @param strsrch search iterator data struct 676 * @param status for errors if it occurs 677 * @return The index of the first match, or <tt>USEARCH_DONE</tt> if there 678 * are no matches. 679 * @see #usearch_getOffset 680 * @see #USEARCH_DONE 681 * @stable ICU 2.4 682 */ 683 U_STABLE int32_t U_EXPORT2 usearch_last(UStringSearch *strsrch, 684 UErrorCode *status); 685 686 /** 687 * Returns the first index less than <tt>position</tt> at which the string text 688 * matches the search pattern. The iterator is adjusted so that its current 689 * index (as returned by <tt>usearch_getOffset</tt>) is the match position if 690 * one was found. 691 * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and 692 * the iterator will be adjusted to the index <tt>USEARCH_DONE</tt> 693 * <p> 694 * Search positions that may render incorrect results are highlighted in the 695 * header comments. If position is less than or greater than the text range 696 * for searching, an U_INDEX_OUTOFBOUNDS_ERROR will be returned. 697 * <p> 698 * When <tt>USEARCH_OVERLAP</tt> option is off, the last index of the 699 * result match is always less than <tt>position</tt>. 700 * When <tt>USERARCH_OVERLAP</tt> is on, the result match may span across 701 * <tt>position</tt>. 702 * @param strsrch search iterator data struct 703 * @param position index position the search is to begin at 704 * @param status for errors if it occurs 705 * @return The character index of the first match preceding <tt>pos</tt>, 706 * or <tt>USEARCH_DONE</tt> if there are no matches. 707 * @see #usearch_getOffset 708 * @see #USEARCH_DONE 709 * @stable ICU 2.4 710 */ 711 U_STABLE int32_t U_EXPORT2 usearch_preceding(UStringSearch *strsrch, 712 int32_t position, 713 UErrorCode *status); 714 715 /** 716 * Returns the index of the next point at which the string text matches the 717 * search pattern, starting from the current position. 718 * The iterator is adjusted so that its current 719 * index (as returned by <tt>usearch_getOffset</tt>) is the match position if 720 * one was found. 721 * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and 722 * the iterator will be adjusted to the index <tt>USEARCH_DONE</tt> 723 * @param strsrch search iterator data struct 724 * @param status for errors if it occurs 725 * @return The index of the next match after the current position, or 726 * <tt>USEARCH_DONE</tt> if there are no more matches. 727 * @see #usearch_first 728 * @see #usearch_getOffset 729 * @see #USEARCH_DONE 730 * @stable ICU 2.4 731 */ 732 U_STABLE int32_t U_EXPORT2 usearch_next(UStringSearch *strsrch, 733 UErrorCode *status); 734 735 /** 736 * Returns the index of the previous point at which the string text matches 737 * the search pattern, starting at the current position. 738 * The iterator is adjusted so that its current 739 * index (as returned by <tt>usearch_getOffset</tt>) is the match position if 740 * one was found. 741 * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and 742 * the iterator will be adjusted to the index <tt>USEARCH_DONE</tt> 743 * @param strsrch search iterator data struct 744 * @param status for errors if it occurs 745 * @return The index of the previous match before the current position, 746 * or <tt>USEARCH_DONE</tt> if there are no more matches. 747 * @see #usearch_last 748 * @see #usearch_getOffset 749 * @see #USEARCH_DONE 750 * @stable ICU 2.4 751 */ 752 U_STABLE int32_t U_EXPORT2 usearch_previous(UStringSearch *strsrch, 753 UErrorCode *status); 754 755 /** 756 * Reset the iteration. 757 * Search will begin at the start of the text string if a forward iteration 758 * is initiated before a backwards iteration. Otherwise if a backwards 759 * iteration is initiated before a forwards iteration, the search will begin 760 * at the end of the text string. 761 * @param strsrch search iterator data struct 762 * @see #usearch_first 763 * @stable ICU 2.4 764 */ 765 U_STABLE void U_EXPORT2 usearch_reset(UStringSearch *strsrch); 766 767 #ifndef U_HIDE_INTERNAL_API 768 /** 769 * Simple forward search for the pattern, starting at a specified index, 770 * and using using a default set search options. 771 * 772 * This is an experimental function, and is not an official part of the 773 * ICU API. 774 * 775 * The collator options, such as UCOL_STRENGTH and UCOL_NORMALIZTION, are honored. 776 * 777 * The UStringSearch options USEARCH_CANONICAL_MATCH, USEARCH_OVERLAP and 778 * any Break Iterator are ignored. 779 * 780 * Matches obey the following constraints: 781 * 782 * Characters at the start or end positions of a match that are ignorable 783 * for collation are not included as part of the match, unless they 784 * are part of a combining sequence, as described below. 785 * 786 * A match will not include a partial combining sequence. Combining 787 * character sequences are considered to be inseperable units, 788 * and either match the pattern completely, or are considered to not match 789 * at all. Thus, for example, an A followed a combining accent mark will 790 * not be found when searching for a plain (unaccented) A. (unless 791 * the collation strength has been set to ignore all accents). 792 * 793 * When beginning a search, the initial starting position, startIdx, 794 * is assumed to be an acceptable match boundary with respect to 795 * combining characters. A combining sequence that spans across the 796 * starting point will not supress a match beginning at startIdx. 797 * 798 * Characters that expand to multiple collation elements 799 * (German sharp-S becoming 'ss', or the composed forms of accented 800 * characters, for example) also must match completely. 801 * Searching for a single 's' in a string containing only a sharp-s will 802 * find no match. 803 * 804 * 805 * @param strsrch the UStringSearch struct, which references both 806 * the text to be searched and the pattern being sought. 807 * @param startIdx The index into the text to begin the search. 808 * @param matchStart An out parameter, the starting index of the matched text. 809 * This parameter may be NULL. 810 * A value of -1 will be returned if no match was found. 811 * @param matchLimit Out parameter, the index of the first position following the matched text. 812 * The matchLimit will be at a suitable position for beginning a subsequent search 813 * in the input text. 814 * This parameter may be NULL. 815 * A value of -1 will be returned if no match was found. 816 * 817 * @param status Report any errors. Note that no match found is not an error. 818 * @return TRUE if a match was found, FALSE otherwise. 819 * 820 * @internal 821 */ 822 U_INTERNAL UBool U_EXPORT2 usearch_search(UStringSearch *strsrch, 823 int32_t startIdx, 824 int32_t *matchStart, 825 int32_t *matchLimit, 826 UErrorCode *status); 827 828 /** 829 * Simple backwards search for the pattern, starting at a specified index, 830 * and using using a default set search options. 831 * 832 * This is an experimental function, and is not an official part of the 833 * ICU API. 834 * 835 * The collator options, such as UCOL_STRENGTH and UCOL_NORMALIZTION, are honored. 836 * 837 * The UStringSearch options USEARCH_CANONICAL_MATCH, USEARCH_OVERLAP and 838 * any Break Iterator are ignored. 839 * 840 * Matches obey the following constraints: 841 * 842 * Characters at the start or end positions of a match that are ignorable 843 * for collation are not included as part of the match, unless they 844 * are part of a combining sequence, as described below. 845 * 846 * A match will not include a partial combining sequence. Combining 847 * character sequences are considered to be inseperable units, 848 * and either match the pattern completely, or are considered to not match 849 * at all. Thus, for example, an A followed a combining accent mark will 850 * not be found when searching for a plain (unaccented) A. (unless 851 * the collation strength has been set to ignore all accents). 852 * 853 * When beginning a search, the initial starting position, startIdx, 854 * is assumed to be an acceptable match boundary with respect to 855 * combining characters. A combining sequence that spans across the 856 * starting point will not supress a match beginning at startIdx. 857 * 858 * Characters that expand to multiple collation elements 859 * (German sharp-S becoming 'ss', or the composed forms of accented 860 * characters, for example) also must match completely. 861 * Searching for a single 's' in a string containing only a sharp-s will 862 * find no match. 863 * 864 * 865 * @param strsrch the UStringSearch struct, which references both 866 * the text to be searched and the pattern being sought. 867 * @param startIdx The index into the text to begin the search. 868 * @param matchStart An out parameter, the starting index of the matched text. 869 * This parameter may be NULL. 870 * A value of -1 will be returned if no match was found. 871 * @param matchLimit Out parameter, the index of the first position following the matched text. 872 * The matchLimit will be at a suitable position for beginning a subsequent search 873 * in the input text. 874 * This parameter may be NULL. 875 * A value of -1 will be returned if no match was found. 876 * 877 * @param status Report any errors. Note that no match found is not an error. 878 * @return TRUE if a match was found, FALSE otherwise. 879 * 880 * @internal 881 */ 882 U_INTERNAL UBool U_EXPORT2 usearch_searchBackwards(UStringSearch *strsrch, 883 int32_t startIdx, 884 int32_t *matchStart, 885 int32_t *matchLimit, 886 UErrorCode *status); 887 #endif /* U_HIDE_INTERNAL_API */ 888 889 #endif /* #if !UCONFIG_NO_COLLATION && !UCONFIG_NO_BREAK_ITERATION */ 890 891 #endif 892
