1 // © 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 * [UTS #10 Unicode Collation Algorithm](http://www.unicode.org/reports/tr10/#Asymmetric_Search), 261 * but also allows unmarked characters in the searched text to match 262 * marked or unmarked versions of that character in the pattern. 263 * 264 * @stable ICU 4.4 265 */ 266 USEARCH_ANY_BASE_WEIGHT_IS_WILDCARD, 267 268 #ifndef U_HIDE_DEPRECATED_API 269 /** 270 * One more than the highest normal USearchAttributeValue value. 271 * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420. 272 */ 273 USEARCH_ATTRIBUTE_VALUE_COUNT 274 #endif /* U_HIDE_DEPRECATED_API */ 275 } USearchAttributeValue; 276 277 /* open and close ------------------------------------------------------ */ 278 279 /** 280 * Creating a search iterator data struct using the argument locale language 281 * rule set. A collator will be created in the process, which will be owned by 282 * this search and will be deleted in <tt>usearch_close</tt>. 283 * @param pattern for matching 284 * @param patternlength length of the pattern, -1 for null-termination 285 * @param text text string 286 * @param textlength length of the text string, -1 for null-termination 287 * @param locale name of locale for the rules to be used 288 * @param breakiter A BreakIterator that will be used to restrict the points 289 * at which matches are detected. If a match is found, but 290 * the match's start or end index is not a boundary as 291 * determined by the <tt>BreakIterator</tt>, the match will 292 * be rejected and another will be searched for. 293 * If this parameter is <tt>NULL</tt>, no break detection is 294 * attempted. 295 * @param status for errors if it occurs. If pattern or text is NULL, or if 296 * patternlength or textlength is 0 then an 297 * U_ILLEGAL_ARGUMENT_ERROR is returned. 298 * @return search iterator data structure, or NULL if there is an error. 299 * @stable ICU 2.4 300 */ 301 U_STABLE UStringSearch * U_EXPORT2 usearch_open(const UChar *pattern, 302 int32_t patternlength, 303 const UChar *text, 304 int32_t textlength, 305 const char *locale, 306 UBreakIterator *breakiter, 307 UErrorCode *status); 308 309 /** 310 * Creating a search iterator data struct using the argument collator language 311 * rule set. Note, user retains the ownership of this collator, thus the 312 * responsibility of deletion lies with the user. 313 * NOTE: string search cannot be instantiated from a collator that has 314 * collate digits as numbers (CODAN) turned on. 315 * @param pattern for matching 316 * @param patternlength length of the pattern, -1 for null-termination 317 * @param text text string 318 * @param textlength length of the text string, -1 for null-termination 319 * @param collator used for the language rules 320 * @param breakiter A BreakIterator that will be used to restrict the points 321 * at which matches are detected. If a match is found, but 322 * the match's start or end index is not a boundary as 323 * determined by the <tt>BreakIterator</tt>, the match will 324 * be rejected and another will be searched for. 325 * If this parameter is <tt>NULL</tt>, no break detection is 326 * attempted. 327 * @param status for errors if it occurs. If collator, pattern or text is NULL, 328 * or if patternlength or textlength is 0 then an 329 * U_ILLEGAL_ARGUMENT_ERROR is returned. 330 * @return search iterator data structure, or NULL if there is an error. 331 * @stable ICU 2.4 332 */ 333 U_STABLE UStringSearch * U_EXPORT2 usearch_openFromCollator( 334 const UChar *pattern, 335 int32_t patternlength, 336 const UChar *text, 337 int32_t textlength, 338 const UCollator *collator, 339 UBreakIterator *breakiter, 340 UErrorCode *status); 341 342 /** 343 * Destroying and cleaning up the search iterator data struct. 344 * If a collator is created in <tt>usearch_open</tt>, it will be destroyed here. 345 * @param searchiter data struct to clean up 346 * @stable ICU 2.4 347 */ 348 U_STABLE void U_EXPORT2 usearch_close(UStringSearch *searchiter); 349 350 #if U_SHOW_CPLUSPLUS_API 351 352 U_NAMESPACE_BEGIN 353 354 /** 355 * \class LocalUStringSearchPointer 356 * "Smart pointer" class, closes a UStringSearch via usearch_close(). 357 * For most methods see the LocalPointerBase base class. 358 * 359 * @see LocalPointerBase 360 * @see LocalPointer 361 * @stable ICU 4.4 362 */ 363 U_DEFINE_LOCAL_OPEN_POINTER(LocalUStringSearchPointer, UStringSearch, usearch_close); 364 365 U_NAMESPACE_END 366 367 #endif 368 369 /* get and set methods -------------------------------------------------- */ 370 371 /** 372 * Sets the current position in the text string which the next search will 373 * start from. Clears previous states. 374 * This method takes the argument index and sets the position in the text 375 * string accordingly without checking if the index is pointing to a 376 * valid starting point to begin searching. 377 * Search positions that may render incorrect results are highlighted in the 378 * header comments 379 * @param strsrch search iterator data struct 380 * @param position position to start next search from. If position is less 381 * than or greater than the text range for searching, 382 * an U_INDEX_OUTOFBOUNDS_ERROR will be returned 383 * @param status error status if any. 384 * @stable ICU 2.4 385 */ 386 U_STABLE void U_EXPORT2 usearch_setOffset(UStringSearch *strsrch, 387 int32_t position, 388 UErrorCode *status); 389 390 /** 391 * Return the current index in the string text being searched. 392 * If the iteration has gone past the end of the text (or past the beginning 393 * for a backwards search), <tt>USEARCH_DONE</tt> is returned. 394 * @param strsrch search iterator data struct 395 * @see #USEARCH_DONE 396 * @stable ICU 2.4 397 */ 398 U_STABLE int32_t U_EXPORT2 usearch_getOffset(const UStringSearch *strsrch); 399 400 /** 401 * Sets the text searching attributes located in the enum USearchAttribute 402 * with values from the enum USearchAttributeValue. 403 * <tt>USEARCH_DEFAULT</tt> can be used for all attributes for resetting. 404 * @param strsrch search iterator data struct 405 * @param attribute text attribute to be set 406 * @param value text attribute value 407 * @param status for errors if it occurs 408 * @see #usearch_getAttribute 409 * @stable ICU 2.4 410 */ 411 U_STABLE void U_EXPORT2 usearch_setAttribute(UStringSearch *strsrch, 412 USearchAttribute attribute, 413 USearchAttributeValue value, 414 UErrorCode *status); 415 416 /** 417 * Gets the text searching attributes. 418 * @param strsrch search iterator data struct 419 * @param attribute text attribute to be retrieve 420 * @return text attribute value 421 * @see #usearch_setAttribute 422 * @stable ICU 2.4 423 */ 424 U_STABLE USearchAttributeValue U_EXPORT2 usearch_getAttribute( 425 const UStringSearch *strsrch, 426 USearchAttribute attribute); 427 428 /** 429 * Returns the index to the match in the text string that was searched. 430 * This call returns a valid result only after a successful call to 431 * <tt>usearch_first</tt>, <tt>usearch_next</tt>, <tt>usearch_previous</tt>, 432 * or <tt>usearch_last</tt>. 433 * Just after construction, or after a searching method returns 434 * <tt>USEARCH_DONE</tt>, this method will return <tt>USEARCH_DONE</tt>. 435 * <p> 436 * Use <tt>usearch_getMatchedLength</tt> to get the matched string length. 437 * @param strsrch search iterator data struct 438 * @return index to a substring within the text string that is being 439 * searched. 440 * @see #usearch_first 441 * @see #usearch_next 442 * @see #usearch_previous 443 * @see #usearch_last 444 * @see #USEARCH_DONE 445 * @stable ICU 2.4 446 */ 447 U_STABLE int32_t U_EXPORT2 usearch_getMatchedStart( 448 const UStringSearch *strsrch); 449 450 /** 451 * Returns the length of text in the string which matches the search pattern. 452 * This call returns a valid result only after a successful call to 453 * <tt>usearch_first</tt>, <tt>usearch_next</tt>, <tt>usearch_previous</tt>, 454 * or <tt>usearch_last</tt>. 455 * Just after construction, or after a searching method returns 456 * <tt>USEARCH_DONE</tt>, this method will return 0. 457 * @param strsrch search iterator data struct 458 * @return The length of the match in the string text, or 0 if there is no 459 * match currently. 460 * @see #usearch_first 461 * @see #usearch_next 462 * @see #usearch_previous 463 * @see #usearch_last 464 * @see #USEARCH_DONE 465 * @stable ICU 2.4 466 */ 467 U_STABLE int32_t U_EXPORT2 usearch_getMatchedLength( 468 const UStringSearch *strsrch); 469 470 /** 471 * Returns the text that was matched by the most recent call to 472 * <tt>usearch_first</tt>, <tt>usearch_next</tt>, <tt>usearch_previous</tt>, 473 * or <tt>usearch_last</tt>. 474 * If the iterator is not pointing at a valid match (e.g. just after 475 * construction or after <tt>USEARCH_DONE</tt> has been returned, returns 476 * an empty string. If result is not large enough to store the matched text, 477 * result will be filled with the partial text and an U_BUFFER_OVERFLOW_ERROR 478 * will be returned in status. result will be null-terminated whenever 479 * possible. If the buffer fits the matched text exactly, a null-termination 480 * is not possible, then a U_STRING_NOT_TERMINATED_ERROR set in status. 481 * Pre-flighting can be either done with length = 0 or the API 482 * <tt>usearch_getMatchLength</tt>. 483 * @param strsrch search iterator data struct 484 * @param result UChar buffer to store the matched string 485 * @param resultCapacity length of the result buffer 486 * @param status error returned if result is not large enough 487 * @return exact length of the matched text, not counting the null-termination 488 * @see #usearch_first 489 * @see #usearch_next 490 * @see #usearch_previous 491 * @see #usearch_last 492 * @see #USEARCH_DONE 493 * @stable ICU 2.4 494 */ 495 U_STABLE int32_t U_EXPORT2 usearch_getMatchedText(const UStringSearch *strsrch, 496 UChar *result, 497 int32_t resultCapacity, 498 UErrorCode *status); 499 500 #if !UCONFIG_NO_BREAK_ITERATION 501 502 /** 503 * Set the BreakIterator that will be used to restrict the points at which 504 * matches are detected. 505 * @param strsrch search iterator data struct 506 * @param breakiter A BreakIterator that will be used to restrict the points 507 * at which matches are detected. If a match is found, but 508 * the match's start or end index is not a boundary as 509 * determined by the <tt>BreakIterator</tt>, the match will 510 * be rejected and another will be searched for. 511 * If this parameter is <tt>NULL</tt>, no break detection is 512 * attempted. 513 * @param status for errors if it occurs 514 * @see #usearch_getBreakIterator 515 * @stable ICU 2.4 516 */ 517 U_STABLE void U_EXPORT2 usearch_setBreakIterator(UStringSearch *strsrch, 518 UBreakIterator *breakiter, 519 UErrorCode *status); 520 521 /** 522 * Returns the BreakIterator that is used to restrict the points at which 523 * matches are detected. This will be the same object that was passed to the 524 * constructor or to <tt>usearch_setBreakIterator</tt>. Note that 525 * <tt>NULL</tt> 526 * is a legal value; it means that break detection should not be attempted. 527 * @param strsrch search iterator data struct 528 * @return break iterator used 529 * @see #usearch_setBreakIterator 530 * @stable ICU 2.4 531 */ 532 U_STABLE const UBreakIterator * U_EXPORT2 usearch_getBreakIterator( 533 const UStringSearch *strsrch); 534 535 #endif 536 537 /** 538 * Set the string text to be searched. Text iteration will hence begin at the 539 * start of the text string. This method is useful if you want to re-use an 540 * iterator to search for the same pattern within a different body of text. 541 * @param strsrch search iterator data struct 542 * @param text new string to look for match 543 * @param textlength length of the new string, -1 for null-termination 544 * @param status for errors if it occurs. If text is NULL, or textlength is 0 545 * then an U_ILLEGAL_ARGUMENT_ERROR is returned with no change 546 * done to strsrch. 547 * @see #usearch_getText 548 * @stable ICU 2.4 549 */ 550 U_STABLE void U_EXPORT2 usearch_setText( UStringSearch *strsrch, 551 const UChar *text, 552 int32_t textlength, 553 UErrorCode *status); 554 555 /** 556 * Return the string text to be searched. 557 * @param strsrch search iterator data struct 558 * @param length returned string text length 559 * @return string text 560 * @see #usearch_setText 561 * @stable ICU 2.4 562 */ 563 U_STABLE const UChar * U_EXPORT2 usearch_getText(const UStringSearch *strsrch, 564 int32_t *length); 565 566 /** 567 * Gets the collator used for the language rules. 568 * <p> 569 * Deleting the returned <tt>UCollator</tt> before calling 570 * <tt>usearch_close</tt> would cause the string search to fail. 571 * <tt>usearch_close</tt> will delete the collator if this search owns it. 572 * @param strsrch search iterator data struct 573 * @return collator 574 * @stable ICU 2.4 575 */ 576 U_STABLE UCollator * U_EXPORT2 usearch_getCollator( 577 const UStringSearch *strsrch); 578 579 /** 580 * Sets the collator used for the language rules. User retains the ownership 581 * of this collator, thus the responsibility of deletion lies with the user. 582 * This method causes internal data such as Boyer-Moore shift tables to 583 * be recalculated, but the iterator's position is unchanged. 584 * @param strsrch search iterator data struct 585 * @param collator to be used 586 * @param status for errors if it occurs 587 * @stable ICU 2.4 588 */ 589 U_STABLE void U_EXPORT2 usearch_setCollator( UStringSearch *strsrch, 590 const UCollator *collator, 591 UErrorCode *status); 592 593 /** 594 * Sets the pattern used for matching. 595 * Internal data like the Boyer Moore table will be recalculated, but the 596 * iterator's position is unchanged. 597 * @param strsrch search iterator data struct 598 * @param pattern string 599 * @param patternlength pattern length, -1 for null-terminated string 600 * @param status for errors if it occurs. If text is NULL, or textlength is 0 601 * then an U_ILLEGAL_ARGUMENT_ERROR is returned with no change 602 * done to strsrch. 603 * @stable ICU 2.4 604 */ 605 U_STABLE void U_EXPORT2 usearch_setPattern( UStringSearch *strsrch, 606 const UChar *pattern, 607 int32_t patternlength, 608 UErrorCode *status); 609 610 /** 611 * Gets the search pattern 612 * @param strsrch search iterator data struct 613 * @param length return length of the pattern, -1 indicates that the pattern 614 * is null-terminated 615 * @return pattern string 616 * @stable ICU 2.4 617 */ 618 U_STABLE const UChar * U_EXPORT2 usearch_getPattern( 619 const UStringSearch *strsrch, 620 int32_t *length); 621 622 /* methods ------------------------------------------------------------- */ 623 624 /** 625 * Returns the first index at which the string text matches the search 626 * pattern. 627 * The iterator is adjusted so that its current index (as returned by 628 * <tt>usearch_getOffset</tt>) is the match position if one was found. 629 * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and 630 * the iterator will be adjusted to the index <tt>USEARCH_DONE</tt>. 631 * @param strsrch search iterator data struct 632 * @param status for errors if it occurs 633 * @return The character index of the first match, or 634 * <tt>USEARCH_DONE</tt> if there are no matches. 635 * @see #usearch_getOffset 636 * @see #USEARCH_DONE 637 * @stable ICU 2.4 638 */ 639 U_STABLE int32_t U_EXPORT2 usearch_first(UStringSearch *strsrch, 640 UErrorCode *status); 641 642 /** 643 * Returns the first index equal or greater than <tt>position</tt> at which 644 * the string text 645 * matches the search pattern. The iterator is adjusted so that its current 646 * index (as returned by <tt>usearch_getOffset</tt>) is the match position if 647 * one was found. 648 * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and 649 * the iterator will be adjusted to the index <tt>USEARCH_DONE</tt> 650 * <p> 651 * Search positions that may render incorrect results are highlighted in the 652 * header comments. If position is less than or greater than the text range 653 * for searching, an U_INDEX_OUTOFBOUNDS_ERROR will be returned 654 * @param strsrch search iterator data struct 655 * @param position to start the search at 656 * @param status for errors if it occurs 657 * @return The character index of the first match following <tt>pos</tt>, 658 * or <tt>USEARCH_DONE</tt> if there are no matches. 659 * @see #usearch_getOffset 660 * @see #USEARCH_DONE 661 * @stable ICU 2.4 662 */ 663 U_STABLE int32_t U_EXPORT2 usearch_following(UStringSearch *strsrch, 664 int32_t position, 665 UErrorCode *status); 666 667 /** 668 * Returns the last index in the target text at which it matches the search 669 * pattern. The iterator is adjusted so that its current 670 * index (as returned by <tt>usearch_getOffset</tt>) is the match position if 671 * one was found. 672 * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and 673 * the iterator will be adjusted to the index <tt>USEARCH_DONE</tt>. 674 * @param strsrch search iterator data struct 675 * @param status for errors if it occurs 676 * @return The index of the first match, or <tt>USEARCH_DONE</tt> if there 677 * are no matches. 678 * @see #usearch_getOffset 679 * @see #USEARCH_DONE 680 * @stable ICU 2.4 681 */ 682 U_STABLE int32_t U_EXPORT2 usearch_last(UStringSearch *strsrch, 683 UErrorCode *status); 684 685 /** 686 * Returns the first index less than <tt>position</tt> at which the string text 687 * matches the search pattern. The iterator is adjusted so that its current 688 * index (as returned by <tt>usearch_getOffset</tt>) is the match position if 689 * one was found. 690 * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and 691 * the iterator will be adjusted to the index <tt>USEARCH_DONE</tt> 692 * <p> 693 * Search positions that may render incorrect results are highlighted in the 694 * header comments. If position is less than or greater than the text range 695 * for searching, an U_INDEX_OUTOFBOUNDS_ERROR will be returned. 696 * <p> 697 * When <tt>USEARCH_OVERLAP</tt> option is off, the last index of the 698 * result match is always less than <tt>position</tt>. 699 * When <tt>USERARCH_OVERLAP</tt> is on, the result match may span across 700 * <tt>position</tt>. 701 * @param strsrch search iterator data struct 702 * @param position index position the search is to begin at 703 * @param status for errors if it occurs 704 * @return The character index of the first match preceding <tt>pos</tt>, 705 * or <tt>USEARCH_DONE</tt> if there are no matches. 706 * @see #usearch_getOffset 707 * @see #USEARCH_DONE 708 * @stable ICU 2.4 709 */ 710 U_STABLE int32_t U_EXPORT2 usearch_preceding(UStringSearch *strsrch, 711 int32_t position, 712 UErrorCode *status); 713 714 /** 715 * Returns the index of the next point at which the string text matches the 716 * search pattern, starting from the current position. 717 * The iterator is adjusted so that its current 718 * index (as returned by <tt>usearch_getOffset</tt>) is the match position if 719 * one was found. 720 * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and 721 * the iterator will be adjusted to the index <tt>USEARCH_DONE</tt> 722 * @param strsrch search iterator data struct 723 * @param status for errors if it occurs 724 * @return The index of the next match after the current position, or 725 * <tt>USEARCH_DONE</tt> if there are no more matches. 726 * @see #usearch_first 727 * @see #usearch_getOffset 728 * @see #USEARCH_DONE 729 * @stable ICU 2.4 730 */ 731 U_STABLE int32_t U_EXPORT2 usearch_next(UStringSearch *strsrch, 732 UErrorCode *status); 733 734 /** 735 * Returns the index of the previous point at which the string text matches 736 * the search pattern, starting at the current position. 737 * The iterator is adjusted so that its current 738 * index (as returned by <tt>usearch_getOffset</tt>) is the match position if 739 * one was found. 740 * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and 741 * the iterator will be adjusted to the index <tt>USEARCH_DONE</tt> 742 * @param strsrch search iterator data struct 743 * @param status for errors if it occurs 744 * @return The index of the previous match before the current position, 745 * or <tt>USEARCH_DONE</tt> if there are no more matches. 746 * @see #usearch_last 747 * @see #usearch_getOffset 748 * @see #USEARCH_DONE 749 * @stable ICU 2.4 750 */ 751 U_STABLE int32_t U_EXPORT2 usearch_previous(UStringSearch *strsrch, 752 UErrorCode *status); 753 754 /** 755 * Reset the iteration. 756 * Search will begin at the start of the text string if a forward iteration 757 * is initiated before a backwards iteration. Otherwise if a backwards 758 * iteration is initiated before a forwards iteration, the search will begin 759 * at the end of the text string. 760 * @param strsrch search iterator data struct 761 * @see #usearch_first 762 * @stable ICU 2.4 763 */ 764 U_STABLE void U_EXPORT2 usearch_reset(UStringSearch *strsrch); 765 766 #ifndef U_HIDE_INTERNAL_API 767 /** 768 * Simple forward search for the pattern, starting at a specified index, 769 * and using using a default set search options. 770 * 771 * This is an experimental function, and is not an official part of the 772 * ICU API. 773 * 774 * The collator options, such as UCOL_STRENGTH and UCOL_NORMALIZTION, are honored. 775 * 776 * The UStringSearch options USEARCH_CANONICAL_MATCH, USEARCH_OVERLAP and 777 * any Break Iterator are ignored. 778 * 779 * Matches obey the following constraints: 780 * 781 * Characters at the start or end positions of a match that are ignorable 782 * for collation are not included as part of the match, unless they 783 * are part of a combining sequence, as described below. 784 * 785 * A match will not include a partial combining sequence. Combining 786 * character sequences are considered to be inseperable units, 787 * and either match the pattern completely, or are considered to not match 788 * at all. Thus, for example, an A followed a combining accent mark will 789 * not be found when searching for a plain (unaccented) A. (unless 790 * the collation strength has been set to ignore all accents). 791 * 792 * When beginning a search, the initial starting position, startIdx, 793 * is assumed to be an acceptable match boundary with respect to 794 * combining characters. A combining sequence that spans across the 795 * starting point will not supress a match beginning at startIdx. 796 * 797 * Characters that expand to multiple collation elements 798 * (German sharp-S becoming 'ss', or the composed forms of accented 799 * characters, for example) also must match completely. 800 * Searching for a single 's' in a string containing only a sharp-s will 801 * find no match. 802 * 803 * 804 * @param strsrch the UStringSearch struct, which references both 805 * the text to be searched and the pattern being sought. 806 * @param startIdx The index into the text to begin the search. 807 * @param matchStart An out parameter, the starting index of the matched text. 808 * This parameter may be NULL. 809 * A value of -1 will be returned if no match was found. 810 * @param matchLimit Out parameter, the index of the first position following the matched text. 811 * The matchLimit will be at a suitable position for beginning a subsequent search 812 * in the input text. 813 * This parameter may be NULL. 814 * A value of -1 will be returned if no match was found. 815 * 816 * @param status Report any errors. Note that no match found is not an error. 817 * @return TRUE if a match was found, FALSE otherwise. 818 * 819 * @internal 820 */ 821 U_INTERNAL UBool U_EXPORT2 usearch_search(UStringSearch *strsrch, 822 int32_t startIdx, 823 int32_t *matchStart, 824 int32_t *matchLimit, 825 UErrorCode *status); 826 827 /** 828 * Simple backwards search for the pattern, starting at a specified index, 829 * and using using a default set search options. 830 * 831 * This is an experimental function, and is not an official part of the 832 * ICU API. 833 * 834 * The collator options, such as UCOL_STRENGTH and UCOL_NORMALIZTION, are honored. 835 * 836 * The UStringSearch options USEARCH_CANONICAL_MATCH, USEARCH_OVERLAP and 837 * any Break Iterator are ignored. 838 * 839 * Matches obey the following constraints: 840 * 841 * Characters at the start or end positions of a match that are ignorable 842 * for collation are not included as part of the match, unless they 843 * are part of a combining sequence, as described below. 844 * 845 * A match will not include a partial combining sequence. Combining 846 * character sequences are considered to be inseperable units, 847 * and either match the pattern completely, or are considered to not match 848 * at all. Thus, for example, an A followed a combining accent mark will 849 * not be found when searching for a plain (unaccented) A. (unless 850 * the collation strength has been set to ignore all accents). 851 * 852 * When beginning a search, the initial starting position, startIdx, 853 * is assumed to be an acceptable match boundary with respect to 854 * combining characters. A combining sequence that spans across the 855 * starting point will not supress a match beginning at startIdx. 856 * 857 * Characters that expand to multiple collation elements 858 * (German sharp-S becoming 'ss', or the composed forms of accented 859 * characters, for example) also must match completely. 860 * Searching for a single 's' in a string containing only a sharp-s will 861 * find no match. 862 * 863 * 864 * @param strsrch the UStringSearch struct, which references both 865 * the text to be searched and the pattern being sought. 866 * @param startIdx The index into the text to begin the search. 867 * @param matchStart An out parameter, the starting index of the matched text. 868 * This parameter may be NULL. 869 * A value of -1 will be returned if no match was found. 870 * @param matchLimit Out parameter, the index of the first position following the matched text. 871 * The matchLimit will be at a suitable position for beginning a subsequent search 872 * in the input text. 873 * This parameter may be NULL. 874 * A value of -1 will be returned if no match was found. 875 * 876 * @param status Report any errors. Note that no match found is not an error. 877 * @return TRUE if a match was found, FALSE otherwise. 878 * 879 * @internal 880 */ 881 U_INTERNAL UBool U_EXPORT2 usearch_searchBackwards(UStringSearch *strsrch, 882 int32_t startIdx, 883 int32_t *matchStart, 884 int32_t *matchLimit, 885 UErrorCode *status); 886 #endif /* U_HIDE_INTERNAL_API */ 887 888 #endif /* #if !UCONFIG_NO_COLLATION && !UCONFIG_NO_BREAK_ITERATION */ 889 890 #endif 891