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1 /*
2 **********************************************************************
3 *   Copyright (C) 2004-2011, International Business Machines
4 *   Corporation and others.  All Rights Reserved.
5 **********************************************************************
6 *   file name:  uregex.h
7 *   encoding:   US-ASCII
8 *   indentation:4
9 *
10 *   created on: 2004mar09
11 *   created by: Andy Heninger
12 *
13 *   ICU Regular Expressions, API for C
14 */
15 
16 /**
17  * \file
18  * \brief C API: Regular Expressions
19  *
20  * <p>This is a C wrapper around the C++ RegexPattern and RegexMatcher classes.</p>
21  */
22 
23 #ifndef UREGEX_H
24 #define UREGEX_H
25 
26 #include "unicode/utext.h"
27 #include "unicode/utypes.h"
28 
29 #if !UCONFIG_NO_REGULAR_EXPRESSIONS
30 
31 #include "unicode/localpointer.h"
32 #include "unicode/parseerr.h"
33 
34 struct URegularExpression;
35 /**
36   * Structure representing a compiled regular expression, plus the results
37   *    of a match operation.
38   * @stable ICU 3.0
39   */
40 typedef struct URegularExpression URegularExpression;
41 
42 
43 /**
44  * Constants for Regular Expression Match Modes.
45  * @stable ICU 2.4
46  */
47 typedef enum URegexpFlag{
48 
49 #ifndef U_HIDE_DRAFT_API
50     /** Forces normalization of pattern and strings.
51     Not implemented yet, just a placeholder, hence draft.
52     @draft ICU 2.4 */
53     UREGEX_CANON_EQ         = 128,
54 #endif
55     /**  Enable case insensitive matching.  @stable ICU 2.4 */
56     UREGEX_CASE_INSENSITIVE = 2,
57 
58     /**  Allow white space and comments within patterns  @stable ICU 2.4 */
59     UREGEX_COMMENTS         = 4,
60 
61     /**  If set, '.' matches line terminators,  otherwise '.' matching stops at line end.
62       *  @stable ICU 2.4 */
63     UREGEX_DOTALL           = 32,
64 
65     /**  If set, treat the entire pattern as a literal string.
66       *  Metacharacters or escape sequences in the input sequence will be given
67       *  no special meaning. Not implemented yet as of ICU 4.4.
68       *
69       *  The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact
70       *  on matching when used in conjunction with this flag.
71       *  The other flags become superfluous.
72       *  TODO:  say which escapes are still handled; anything Java does
73       *         early (\\u) we should still do.
74       * @stable ICU 4.0
75       */
76     UREGEX_LITERAL = 16,
77 
78     /**   Control behavior of "$" and "^"
79       *    If set, recognize line terminators within string,
80       *    otherwise, match only at start and end of input string.
81       *   @stable ICU 2.4 */
82     UREGEX_MULTILINE        = 8,
83 
84     /**   Unix-only line endings.
85       *   When this mode is enabled, only \\u000a is recognized as a line ending
86       *    in the behavior of ., ^, and $.
87       *   @stable ICU 4.0
88       */
89     UREGEX_UNIX_LINES = 1,
90 
91     /**  Unicode word boundaries.
92       *     If set, \b uses the Unicode TR 29 definition of word boundaries.
93       *     Warning: Unicode word boundaries are quite different from
94       *     traditional regular expression word boundaries.  See
95       *     http://unicode.org/reports/tr29/#Word_Boundaries
96       *     @stable ICU 2.8
97       */
98     UREGEX_UWORD            = 256,
99 
100      /**  Error on Unrecognized backslash escapes.
101        *     If set, fail with an error on patterns that contain
102        *     backslash-escaped ASCII letters without a known special
103        *     meaning.  If this flag is not set, these
104        *     escaped letters represent themselves.
105        *     @stable ICU 4.0
106        */
107      UREGEX_ERROR_ON_UNKNOWN_ESCAPES = 512
108 
109 }  URegexpFlag;
110 
111 /**
112   *  Open (compile) an ICU regular expression.  Compiles the regular expression in
113   *  string form into an internal representation using the specified match mode flags.
114   *  The resulting regular expression handle can then be used to perform various
115   *   matching operations.
116   *
117   *
118   * @param pattern        The Regular Expression pattern to be compiled.
119   * @param patternLength  The length of the pattern, or -1 if the pattern is
120   *                       NUL terminated.
121   * @param flags          Flags that alter the default matching behavior for
122   *                       the regular expression, UREGEX_CASE_INSENSITIVE, for
123   *                       example.  For default behavior, set this parameter to zero.
124   *                       See <code>enum URegexpFlag</code>.  All desired flags
125   *                       are bitwise-ORed together.
126   * @param pe             Receives the position (line and column numbers) of any syntax
127   *                       error within the source regular expression string.  If this
128   *                       information is not wanted, pass NULL for this parameter.
129   * @param status         Receives error detected by this function.
130   * @stable ICU 3.0
131   *
132   */
133 U_STABLE URegularExpression * U_EXPORT2
134 uregex_open( const  UChar          *pattern,
135                     int32_t         patternLength,
136                     uint32_t        flags,
137                     UParseError    *pe,
138                     UErrorCode     *status);
139 
140 /**
141   *  Open (compile) an ICU regular expression.  Compiles the regular expression in
142   *  string form into an internal representation using the specified match mode flags.
143   *  The resulting regular expression handle can then be used to perform various
144   *   matching operations.
145   *  <p>
146   *  The contents of the pattern UText will be extracted and saved. Ownership of the
147   *   UText struct itself remains with the caller. This is to match the behavior of
148   *   uregex_open().
149   *
150   * @param pattern        The Regular Expression pattern to be compiled.
151   * @param flags          Flags that alter the default matching behavior for
152   *                       the regular expression, UREGEX_CASE_INSENSITIVE, for
153   *                       example.  For default behavior, set this parameter to zero.
154   *                       See <code>enum URegexpFlag</code>.  All desired flags
155   *                       are bitwise-ORed together.
156   * @param pe             Receives the position (line and column numbers) of any syntax
157   *                       error within the source regular expression string.  If this
158   *                       information is not wanted, pass NULL for this parameter.
159   * @param status         Receives error detected by this function.
160   *
161   * @draft ICU 4.6
162   */
163 U_DRAFT URegularExpression *  U_EXPORT2
164 uregex_openUText(UText          *pattern,
165                  uint32_t        flags,
166                  UParseError    *pe,
167                  UErrorCode     *status);
168 
169 /**
170   *  Open (compile) an ICU regular expression.  The resulting regular expression
171   *   handle can then be used to perform various matching operations.
172   *  <p>
173   *   This function is the same as uregex_open, except that the pattern
174   *   is supplied as an 8 bit char * string in the default code page.
175   *
176   * @param pattern        The Regular Expression pattern to be compiled,
177   *                       NUL terminated.
178   * @param flags          Flags that alter the default matching behavior for
179   *                       the regular expression, UREGEX_CASE_INSENSITIVE, for
180   *                       example.  For default behavior, set this parameter to zero.
181   *                       See <code>enum URegexpFlag</code>.  All desired flags
182   *                       are bitwise-ORed together.
183   * @param pe             Receives the position (line and column numbers) of any syntax
184   *                       error within the source regular expression string.  If this
185   *                       information is not wanted, pass NULL for this parameter.
186   * @param status         Receives errors detected by this function.
187   * @return               The URegularExpression object representing the compiled
188   *                       pattern.
189   *
190   * @stable ICU 3.0
191   */
192 #if !UCONFIG_NO_CONVERSION
193 U_STABLE URegularExpression * U_EXPORT2
194 uregex_openC( const char           *pattern,
195                     uint32_t        flags,
196                     UParseError    *pe,
197                     UErrorCode     *status);
198 #endif
199 
200 
201 
202 /**
203   *  Close the regular expression, recovering all resources (memory) it
204   *   was holding.
205   *
206   * @param regexp   The regular expression to be closed.
207   * @stable ICU 3.0
208   */
209 U_STABLE void U_EXPORT2
210 uregex_close(URegularExpression *regexp);
211 
212 #if U_SHOW_CPLUSPLUS_API
213 
214 U_NAMESPACE_BEGIN
215 
216 /**
217  * \class LocalURegularExpressionPointer
218  * "Smart pointer" class, closes a URegularExpression via uregex_close().
219  * For most methods see the LocalPointerBase base class.
220  *
221  * @see LocalPointerBase
222  * @see LocalPointer
223  * @stable ICU 4.4
224  */
225 U_DEFINE_LOCAL_OPEN_POINTER(LocalURegularExpressionPointer, URegularExpression, uregex_close);
226 
227 U_NAMESPACE_END
228 
229 #endif
230 
231 /**
232  * Make a copy of a compiled regular expression.  Cloning a regular
233  * expression is faster than opening a second instance from the source
234  * form of the expression, and requires less memory.
235  * <p>
236  * Note that the current input string and the position of any matched text
237  *  within it are not cloned; only the pattern itself and the
238  *  match mode flags are copied.
239  * <p>
240  * Cloning can be particularly useful to threaded applications that perform
241  * multiple match operations in parallel.  Each concurrent RE
242  * operation requires its own instance of a URegularExpression.
243  *
244  * @param regexp   The compiled regular expression to be cloned.
245  * @param status   Receives indication of any errors encountered
246  * @return the cloned copy of the compiled regular expression.
247  * @stable ICU 3.0
248  */
249 U_STABLE URegularExpression * U_EXPORT2
250 uregex_clone(const URegularExpression *regexp, UErrorCode *status);
251 
252 /**
253  *  Returns a pointer to the source form of the pattern for this regular expression.
254  *  This function will work even if the pattern was originally specified as a UText.
255  *
256  * @param regexp     The compiled regular expression.
257  * @param patLength  This output parameter will be set to the length of the
258  *                   pattern string.  A NULL pointer may be used here if the
259  *                   pattern length is not needed, as would be the case if
260  *                   the pattern is known in advance to be a NUL terminated
261  *                   string.
262  * @param status     Receives errors detected by this function.
263  * @return a pointer to the pattern string.  The storage for the string is
264  *                   owned by the regular expression object, and must not be
265  *                   altered or deleted by the application.  The returned string
266  *                   will remain valid until the regular expression is closed.
267  * @stable ICU 3.0
268  */
269 U_STABLE const UChar * U_EXPORT2
270 uregex_pattern(const URegularExpression *regexp,
271                      int32_t            *patLength,
272                      UErrorCode         *status);
273 
274 /**
275  *  Returns the source text of the pattern for this regular expression.
276  *  This function will work even if the pattern was originally specified as a UChar string.
277  *
278  * @param regexp     The compiled regular expression.
279  * @param status     Receives errors detected by this function.
280  * @return the pattern text.  The storage for the text is owned by the regular expression
281  *                   object, and must not be altered or deleted.
282  *
283  * @draft ICU 4.6
284  */
285 U_DRAFT UText * U_EXPORT2
286 uregex_patternUText(const URegularExpression *regexp,
287                           UErrorCode         *status);
288 
289 
290 /**
291   * Get the match mode flags that were specified when compiling this regular expression.
292   * @param status   Receives errors detected by this function.
293   * @param regexp   The compiled regular expression.
294   * @return         The match mode flags
295   * @see URegexpFlag
296   * @stable ICU 3.0
297   */
298 U_STABLE int32_t U_EXPORT2
299 uregex_flags(const  URegularExpression   *regexp,
300                     UErrorCode           *status);
301 
302 
303 /**
304   *  Set the subject text string upon which the regular expression will look for matches.
305   *  This function may be called any number of times, allowing the regular
306   *  expression pattern to be applied to different strings.
307   *  <p>
308   *  Regular expression matching operations work directly on the application's
309   *  string data.  No copy is made.  The subject string data must not be
310   *  altered after calling this function until after all regular expression
311   *  operations involving this string data are completed.
312   *  <p>
313   *  Zero length strings are permitted.  In this case, no subsequent match
314   *  operation will dereference the text string pointer.
315   *
316   * @param regexp     The compiled regular expression.
317   * @param text       The subject text string.
318   * @param textLength The length of the subject text, or -1 if the string
319   *                   is NUL terminated.
320   * @param status     Receives errors detected by this function.
321   * @stable ICU 3.0
322   */
323 U_STABLE void U_EXPORT2
324 uregex_setText(URegularExpression *regexp,
325                const UChar        *text,
326                int32_t             textLength,
327                UErrorCode         *status);
328 
329 
330 /**
331   *  Set the subject text string upon which the regular expression will look for matches.
332   *  This function may be called any number of times, allowing the regular
333   *  expression pattern to be applied to different strings.
334   *  <p>
335   *  Regular expression matching operations work directly on the application's
336   *  string data; only a shallow clone is made.  The subject string data must not be
337   *  altered after calling this function until after all regular expression
338   *  operations involving this string data are completed.
339   *
340   * @param regexp     The compiled regular expression.
341   * @param text       The subject text string.
342   * @param status     Receives errors detected by this function.
343   *
344   * @draft ICU 4.6
345   */
346 U_DRAFT void U_EXPORT2
347 uregex_setUText(URegularExpression *regexp,
348                 UText              *text,
349                 UErrorCode         *status);
350 
351 /**
352   *  Get the subject text that is currently associated with this
353   *   regular expression object.  If the input was supplied using uregex_setText(),
354   *   that pointer will be returned.  Otherwise, the characters in the input will
355   *   be extracted to a buffer and returned.  In either case, ownership remains
356   *   with the regular expression object.
357   *
358   *  This function will work even if the input was originally specified as a UText.
359   *
360   * @param regexp      The compiled regular expression.
361   * @param textLength  The length of the string is returned in this output parameter.
362   *                    A NULL pointer may be used here if the
363   *                    text length is not needed, as would be the case if
364   *                    the text is known in advance to be a NUL terminated
365   *                    string.
366   * @param status      Receives errors detected by this function.
367   * @return            Pointer to the subject text string currently associated with
368   *                    this regular expression.
369   * @stable ICU 3.0
370   */
371 U_STABLE const UChar * U_EXPORT2
372 uregex_getText(URegularExpression *regexp,
373                int32_t            *textLength,
374                UErrorCode         *status);
375 
376 
377 /**
378   *  Get the subject text that is currently associated with this
379   *   regular expression object.
380   *
381   *  This function will work even if the input was originally specified as a UChar string.
382   *
383   * @param regexp      The compiled regular expression.
384   * @param dest        A mutable UText in which to store the current input.
385   *                    If NULL, a new UText will be created as an immutable shallow clone
386   *                    of the actual input string.
387   * @param status      Receives errors detected by this function.
388   * @return            The subject text currently associated with this regular expression.
389   *                    If a pre-allocated UText was provided, it will always be used and returned.
390   *
391   * @draft ICU 4.6
392   */
393 U_DRAFT UText * U_EXPORT2
394 uregex_getUText(URegularExpression *regexp,
395                 UText              *dest,
396                 UErrorCode         *status);
397 
398 /**
399   *  Set the subject text string upon which the regular expression is looking for matches
400   *  without changing any other aspect of the matching state.
401   *  The new and previous text strings must have the same content.
402   *
403   *  This function is intended for use in environments where ICU is operating on
404   *  strings that may move around in memory.  It provides a mechanism for notifying
405   *  ICU that the string has been relocated, and providing a new UText to access the
406   *  string in its new position.
407   *
408   *  Note that the regular expression implementation never copies the underlying text
409   *  of a string being matched, but always operates directly on the original text
410   *  provided by the user. Refreshing simply drops the references to the old text
411   *  and replaces them with references to the new.
412   *
413   *  Caution:  this function is normally used only by very specialized
414   *            system-level code.   One example use case is with garbage collection
415   *            that moves the text in memory.
416   *
417   * @param regexp     The compiled regular expression.
418   * @param text       The new (moved) text string.
419   * @param status     Receives errors detected by this function.
420   *
421   * @draft ICU 4.8
422   */
423 U_DRAFT void U_EXPORT2
424 uregex_refreshUText(URegularExpression *regexp,
425                     UText              *text,
426                     UErrorCode         *status);
427 
428 /**
429   *   Attempts to match the input string against the pattern.
430   *   To succeed, the match must extend to the end of the string,
431   *   or cover the complete match region.
432   *
433   *   If startIndex >= zero the match operation starts at the specified
434   *   index and must extend to the end of the input string.  Any region
435   *   that has been specified is reset.
436   *
437   *   If startIndex == -1 the match must cover the input region, or the entire
438   *   input string if no region has been set.  This directly corresponds to
439   *   Matcher.matches() in Java
440   *
441   *    @param  regexp      The compiled regular expression.
442   *    @param  startIndex  The input string (native) index at which to begin matching, or -1
443   *                        to match the input Region.
444   *    @param  status      Receives errors detected by this function.
445   *    @return             TRUE if there is a match
446   *    @stable ICU 3.0
447   */
448 U_STABLE UBool U_EXPORT2
449 uregex_matches(URegularExpression *regexp,
450                 int32_t            startIndex,
451                 UErrorCode        *status);
452 
453 /**
454   *   64bit version of uregex_matches.
455   *   Attempts to match the input string against the pattern.
456   *   To succeed, the match must extend to the end of the string,
457   *   or cover the complete match region.
458   *
459   *   If startIndex >= zero the match operation starts at the specified
460   *   index and must extend to the end of the input string.  Any region
461   *   that has been specified is reset.
462   *
463   *   If startIndex == -1 the match must cover the input region, or the entire
464   *   input string if no region has been set.  This directly corresponds to
465   *   Matcher.matches() in Java
466   *
467   *    @param  regexp      The compiled regular expression.
468   *    @param  startIndex  The input string (native) index at which to begin matching, or -1
469   *                        to match the input Region.
470   *    @param  status      Receives errors detected by this function.
471   *    @return             TRUE if there is a match
472   *   @draft ICU 4.6
473   */
474 U_DRAFT UBool U_EXPORT2
475 uregex_matches64(URegularExpression *regexp,
476                  int64_t            startIndex,
477                  UErrorCode        *status);
478 
479 /**
480   *   Attempts to match the input string, starting from the specified index, against the pattern.
481   *   The match may be of any length, and is not required to extend to the end
482   *   of the input string.  Contrast with uregex_matches().
483   *
484   *   <p>If startIndex is >= 0 any input region that was set for this
485   *   URegularExpression is reset before the operation begins.
486   *
487   *   <p>If the specified starting index == -1 the match begins at the start of the input
488   *   region, or at the start of the full string if no region has been specified.
489   *   This corresponds directly with Matcher.lookingAt() in Java.
490   *
491   *   <p>If the match succeeds then more information can be obtained via the
492   *    <code>uregexp_start()</code>, <code>uregexp_end()</code>,
493   *    and <code>uregexp_group()</code> functions.</p>
494   *
495   *    @param   regexp      The compiled regular expression.
496   *    @param   startIndex  The input string (native) index at which to begin matching, or
497   *                         -1 to match the Input Region
498   *    @param   status      A reference to a UErrorCode to receive any errors.
499   *    @return  TRUE if there is a match.
500   *    @stable ICU 3.0
501   */
502 U_STABLE UBool U_EXPORT2
503 uregex_lookingAt(URegularExpression *regexp,
504                  int32_t             startIndex,
505                  UErrorCode         *status);
506 
507 /**
508   *   64bit version of uregex_lookingAt.
509   *   Attempts to match the input string, starting from the specified index, against the pattern.
510   *   The match may be of any length, and is not required to extend to the end
511   *   of the input string.  Contrast with uregex_matches().
512   *
513   *   <p>If startIndex is >= 0 any input region that was set for this
514   *   URegularExpression is reset before the operation begins.
515   *
516   *   <p>If the specified starting index == -1 the match begins at the start of the input
517   *   region, or at the start of the full string if no region has been specified.
518   *   This corresponds directly with Matcher.lookingAt() in Java.
519   *
520   *   <p>If the match succeeds then more information can be obtained via the
521   *    <code>uregexp_start()</code>, <code>uregexp_end()</code>,
522   *    and <code>uregexp_group()</code> functions.</p>
523   *
524   *    @param   regexp      The compiled regular expression.
525   *    @param   startIndex  The input string (native) index at which to begin matching, or
526   *                         -1 to match the Input Region
527   *    @param   status      A reference to a UErrorCode to receive any errors.
528   *    @return  TRUE if there is a match.
529   *    @draft ICU 4.6
530   */
531 U_DRAFT UBool U_EXPORT2
532 uregex_lookingAt64(URegularExpression *regexp,
533                    int64_t             startIndex,
534                    UErrorCode         *status);
535 
536 /**
537   *   Find the first matching substring of the input string that matches the pattern.
538   *   If startIndex is >= zero the search for a match begins at the specified index,
539   *          and any match region is reset.  This corresponds directly with
540   *          Matcher.find(startIndex) in Java.
541   *
542   *   If startIndex == -1 the search begins at the start of the input region,
543   *           or at the start of the full string if no region has been specified.
544   *
545   *   If a match is found, <code>uregex_start(), uregex_end()</code>, and
546   *   <code>uregex_group()</code> will provide more information regarding the match.
547   *
548   *   @param   regexp      The compiled regular expression.
549   *   @param   startIndex  The position (native) in the input string to begin the search, or
550   *                        -1 to search within the Input Region.
551   *   @param   status      A reference to a UErrorCode to receive any errors.
552   *   @return              TRUE if a match is found.
553   *   @stable ICU 3.0
554   */
555 U_STABLE UBool U_EXPORT2
556 uregex_find(URegularExpression *regexp,
557             int32_t             startIndex,
558             UErrorCode         *status);
559 
560 /**
561   *   64bit version of uregex_find.
562   *   Find the first matching substring of the input string that matches the pattern.
563   *   If startIndex is >= zero the search for a match begins at the specified index,
564   *          and any match region is reset.  This corresponds directly with
565   *          Matcher.find(startIndex) in Java.
566   *
567   *   If startIndex == -1 the search begins at the start of the input region,
568   *           or at the start of the full string if no region has been specified.
569   *
570   *   If a match is found, <code>uregex_start(), uregex_end()</code>, and
571   *   <code>uregex_group()</code> will provide more information regarding the match.
572   *
573   *   @param   regexp      The compiled regular expression.
574   *   @param   startIndex  The position (native) in the input string to begin the search, or
575   *                        -1 to search within the Input Region.
576   *   @param   status      A reference to a UErrorCode to receive any errors.
577   *   @return              TRUE if a match is found.
578   *   @draft ICU 4.6
579   */
580 U_DRAFT UBool U_EXPORT2
581 uregex_find64(URegularExpression *regexp,
582               int64_t             startIndex,
583               UErrorCode         *status);
584 
585 /**
586   *  Find the next pattern match in the input string.  Begin searching
587   *  the input at the location following the end of he previous match,
588   *  or at the start of the string (or region) if there is no
589   *  previous match.  If a match is found, <code>uregex_start(), uregex_end()</code>, and
590   *  <code>uregex_group()</code> will provide more information regarding the match.
591   *
592   *  @param   regexp      The compiled regular expression.
593   *  @param   status      A reference to a UErrorCode to receive any errors.
594   *  @return              TRUE if a match is found.
595   *  @see uregex_reset
596   *  @stable ICU 3.0
597   */
598 U_STABLE UBool U_EXPORT2
599 uregex_findNext(URegularExpression *regexp,
600                 UErrorCode         *status);
601 
602 /**
603   *   Get the number of capturing groups in this regular expression's pattern.
604   *   @param   regexp      The compiled regular expression.
605   *   @param   status      A reference to a UErrorCode to receive any errors.
606   *   @return the number of capture groups
607   *   @stable ICU 3.0
608   */
609 U_STABLE int32_t U_EXPORT2
610 uregex_groupCount(URegularExpression *regexp,
611                   UErrorCode         *status);
612 
613 /** Extract the string for the specified matching expression or subexpression.
614   * Group #0 is the complete string of matched text.
615   * Group #1 is the text matched by the first set of capturing parentheses.
616   *
617   *   @param   regexp       The compiled regular expression.
618   *   @param   groupNum     The capture group to extract.  Group 0 is the complete
619   *                         match.  The value of this parameter must be
620   *                         less than or equal to the number of capture groups in
621   *                         the pattern.
622   *   @param   dest         Buffer to receive the matching string data
623   *   @param   destCapacity Capacity of the dest buffer.
624   *   @param   status       A reference to a UErrorCode to receive any errors.
625   *   @return               Length of matching data,
626   *                         or -1 if no applicable match.
627   *   @stable ICU 3.0
628   */
629 U_STABLE int32_t U_EXPORT2
630 uregex_group(URegularExpression *regexp,
631              int32_t             groupNum,
632              UChar              *dest,
633              int32_t             destCapacity,
634              UErrorCode          *status);
635 
636 
637 /** Returns a shallow immutable clone of the entire input string.  The returned UText current native index
638   *   is set to the beginning of the requested capture group.  The capture group length is also
639   *   returned via groupLength.
640   * Group #0 is the complete string of matched text.
641   * Group #1 is the text matched by the first set of capturing parentheses.
642   *
643   *   @param   regexp       The compiled regular expression.
644   *   @param   groupNum     The capture group to extract.  Group 0 is the complete
645   *                         match.  The value of this parameter must be
646   *                         less than or equal to the number of capture groups in
647   *                         the pattern.
648   *   @param   dest         A mutable UText in which to store the current input.
649   *                         If NULL, a new UText will be created as an immutable shallow clone
650   *                         of the entire input string.
651   *   @param   groupLength  The group length of the desired capture group.
652   *   @param   status       A reference to a UErrorCode to receive any errors.
653   *   @return               The subject text currently associated with this regular expression.
654   *                         If a pre-allocated UText was provided, it will always be used and returned.
655 
656   *
657   *   @draft ICU 4.6
658   */
659 U_DRAFT UText * U_EXPORT2
660 uregex_groupUText(URegularExpression *regexp,
661                   int32_t             groupNum,
662                   UText              *dest,
663                   int64_t            *groupLength,
664                   UErrorCode         *status);
665 
666 
667 /** Extract the string for the specified matching expression or subexpression.
668   * Group #0 is the complete string of matched text.
669   * Group #1 is the text matched by the first set of capturing parentheses.
670   *
671   *   @param   regexp       The compiled regular expression.
672   *   @param   groupNum     The capture group to extract.  Group 0 is the complete
673   *                         match.  The value of this parameter must be
674   *                         less than or equal to the number of capture groups in
675   *                         the pattern.
676   *   @param   dest         Mutable UText to receive the matching string data.
677   *                         If NULL, a new UText will be created (which may not be mutable).
678   *   @param   status       A reference to a UErrorCode to receive any errors.
679   *   @return               The matching string data. If a pre-allocated UText was provided,
680   *                          it will always be used and returned.
681   *
682   *   @internal ICU 4.4 technology preview
683   */
684 U_INTERNAL UText * U_EXPORT2
685 uregex_groupUTextDeep(URegularExpression *regexp,
686                   int32_t             groupNum,
687                   UText              *dest,
688                   UErrorCode         *status);
689 
690 /**
691   *   Returns the index in the input string of the start of the text matched by the
692   *   specified capture group during the previous match operation.  Return -1 if
693   *   the capture group was not part of the last match.
694   *   Group #0 refers to the complete range of matched text.
695   *   Group #1 refers to the text matched by the first set of capturing parentheses.
696   *
697   *    @param   regexp      The compiled regular expression.
698   *    @param   groupNum    The capture group number
699   *    @param   status      A reference to a UErrorCode to receive any errors.
700   *    @return              the starting (native) position in the input of the text matched
701   *                         by the specified group.
702   *    @stable ICU 3.0
703   */
704 U_STABLE int32_t U_EXPORT2
705 uregex_start(URegularExpression *regexp,
706              int32_t             groupNum,
707              UErrorCode          *status);
708 
709 /**
710   *   64bit version of uregex_start.
711   *   Returns the index in the input string of the start of the text matched by the
712   *   specified capture group during the previous match operation.  Return -1 if
713   *   the capture group was not part of the last match.
714   *   Group #0 refers to the complete range of matched text.
715   *   Group #1 refers to the text matched by the first set of capturing parentheses.
716   *
717   *    @param   regexp      The compiled regular expression.
718   *    @param   groupNum    The capture group number
719   *    @param   status      A reference to a UErrorCode to receive any errors.
720   *    @return              the starting (native) position in the input of the text matched
721   *                         by the specified group.
722   *   @draft ICU 4.6
723   */
724 U_DRAFT int64_t U_EXPORT2
725 uregex_start64(URegularExpression *regexp,
726                int32_t             groupNum,
727                UErrorCode          *status);
728 
729 /**
730   *   Returns the index in the input string of the position following the end
731   *   of the text matched by the specified capture group.
732   *   Return -1 if the capture group was not part of the last match.
733   *   Group #0 refers to the complete range of matched text.
734   *   Group #1 refers to the text matched by the first set of capturing parentheses.
735   *
736   *    @param   regexp      The compiled regular expression.
737   *    @param   groupNum    The capture group number
738   *    @param   status      A reference to a UErrorCode to receive any errors.
739   *    @return              the (native) index of the position following the last matched character.
740   *    @stable ICU 3.0
741   */
742 U_STABLE int32_t U_EXPORT2
743 uregex_end(URegularExpression   *regexp,
744            int32_t               groupNum,
745            UErrorCode           *status);
746 
747 /**
748   *   64bit version of uregex_end.
749   *   Returns the index in the input string of the position following the end
750   *   of the text matched by the specified capture group.
751   *   Return -1 if the capture group was not part of the last match.
752   *   Group #0 refers to the complete range of matched text.
753   *   Group #1 refers to the text matched by the first set of capturing parentheses.
754   *
755   *    @param   regexp      The compiled regular expression.
756   *    @param   groupNum    The capture group number
757   *    @param   status      A reference to a UErrorCode to receive any errors.
758   *    @return              the (native) index of the position following the last matched character.
759   *   @draft ICU 4.6
760   */
761 U_DRAFT int64_t U_EXPORT2
762 uregex_end64(URegularExpression *regexp,
763              int32_t               groupNum,
764              UErrorCode           *status);
765 
766 /**
767   *  Reset any saved state from the previous match.  Has the effect of
768   *  causing uregex_findNext to begin at the specified index, and causing
769   *  uregex_start(), uregex_end() and uregex_group() to return an error
770   *  indicating that there is no match information available.  Clears any
771   *  match region that may have been set.
772   *
773   *    @param   regexp      The compiled regular expression.
774   *    @param   index       The position (native) in the text at which a
775   *                         uregex_findNext() should begin searching.
776   *    @param   status      A reference to a UErrorCode to receive any errors.
777   *    @stable ICU 3.0
778   */
779 U_STABLE void U_EXPORT2
780 uregex_reset(URegularExpression    *regexp,
781              int32_t               index,
782              UErrorCode            *status);
783 
784 /**
785   *  64bit version of uregex_reset.
786   *  Reset any saved state from the previous match.  Has the effect of
787   *  causing uregex_findNext to begin at the specified index, and causing
788   *  uregex_start(), uregex_end() and uregex_group() to return an error
789   *  indicating that there is no match information available.  Clears any
790   *  match region that may have been set.
791   *
792   *    @param   regexp      The compiled regular expression.
793   *    @param   index       The position (native) in the text at which a
794   *                         uregex_findNext() should begin searching.
795   *    @param   status      A reference to a UErrorCode to receive any errors.
796   *    @draft ICU 4.6
797   */
798 U_DRAFT void U_EXPORT2
799 uregex_reset64(URegularExpression  *regexp,
800                int64_t               index,
801                UErrorCode            *status);
802 
803 /**
804   * Sets the limits of the matching region for this URegularExpression.
805   * The region is the part of the input string that will be considered when matching.
806   * Invoking this method resets any saved state from the previous match,
807   * then sets the region to start at the index specified by the start parameter
808   * and end at the index specified by the end parameter.
809   *
810   * Depending on the transparency and anchoring being used (see useTransparentBounds
811   * and useAnchoringBounds), certain constructs such as anchors may behave differently
812   * at or around the boundaries of the region
813   *
814   * The function will fail if start is greater than limit, or if either index
815   *  is less than zero or greater than the length of the string being matched.
816   *
817   * @param regexp The compiled regular expression.
818   * @param regionStart  The (native) index to begin searches at.
819   * @param regionLimit  The (native) index to end searches at (exclusive).
820   * @param status A pointer to a UErrorCode to receive any errors.
821   * @stable ICU 4.0
822   */
823 U_STABLE void U_EXPORT2
824 uregex_setRegion(URegularExpression   *regexp,
825                  int32_t               regionStart,
826                  int32_t               regionLimit,
827                  UErrorCode           *status);
828 
829 /**
830   * 64bit version of uregex_setRegion.
831   * Sets the limits of the matching region for this URegularExpression.
832   * The region is the part of the input string that will be considered when matching.
833   * Invoking this method resets any saved state from the previous match,
834   * then sets the region to start at the index specified by the start parameter
835   * and end at the index specified by the end parameter.
836   *
837   * Depending on the transparency and anchoring being used (see useTransparentBounds
838   * and useAnchoringBounds), certain constructs such as anchors may behave differently
839   * at or around the boundaries of the region
840   *
841   * The function will fail if start is greater than limit, or if either index
842   *  is less than zero or greater than the length of the string being matched.
843   *
844   * @param regexp The compiled regular expression.
845   * @param regionStart  The (native) index to begin searches at.
846   * @param regionLimit  The (native) index to end searches at (exclusive).
847   * @param status A pointer to a UErrorCode to receive any errors.
848   * @draft ICU 4.6
849   */
850 U_DRAFT void U_EXPORT2
851 uregex_setRegion64(URegularExpression *regexp,
852                  int64_t               regionStart,
853                  int64_t               regionLimit,
854                  UErrorCode           *status);
855 
856 /**
857   *  Set the matching region and the starting index for subsequent matches
858   *  in a single operation.
859   *  This is useful because the usual function for setting the starting
860   *  index, urgex_reset(), also resets any region limits.
861   *
862   * @param regexp The compiled regular expression.
863   * @param regionStart  The (native) index to begin searches at.
864   * @param regionLimit  The (native) index to end searches at (exclusive).
865   * @param startIndex   The index in the input text at which the next
866   *                     match operation should begin.
867   * @param status A pointer to a UErrorCode to receive any errors.
868   * @draft ICU 4.6
869   */
870 U_DRAFT void U_EXPORT2
871 uregex_setRegionAndStart(URegularExpression *regexp,
872                  int64_t               regionStart,
873                  int64_t               regionLimit,
874                  int64_t               startIndex,
875                  UErrorCode           *status);
876 
877 /**
878   * Reports the start index of the matching region. Any matches found are limited to
879   * to the region bounded by regionStart (inclusive) and regionEnd (exclusive).
880   *
881   * @param regexp The compiled regular expression.
882   * @param status A pointer to a UErrorCode to receive any errors.
883   * @return The starting (native) index of this matcher's region.
884   * @stable ICU 4.0
885   */
886 U_STABLE int32_t U_EXPORT2
887 uregex_regionStart(const  URegularExpression   *regexp,
888                           UErrorCode           *status);
889 
890 /**
891   * 64bit version of uregex_regionStart.
892   * Reports the start index of the matching region. Any matches found are limited to
893   * to the region bounded by regionStart (inclusive) and regionEnd (exclusive).
894   *
895   * @param regexp The compiled regular expression.
896   * @param status A pointer to a UErrorCode to receive any errors.
897   * @return The starting (native) index of this matcher's region.
898   * @draft ICU 4.6
899   */
900 U_DRAFT int64_t U_EXPORT2
901 uregex_regionStart64(const  URegularExpression   *regexp,
902                             UErrorCode           *status);
903 
904 /**
905   * Reports the end index (exclusive) of the matching region for this URegularExpression.
906   * Any matches found are limited to to the region bounded by regionStart (inclusive)
907   * and regionEnd (exclusive).
908   *
909   * @param regexp The compiled regular expression.
910   * @param status A pointer to a UErrorCode to receive any errors.
911   * @return The ending point (native) of this matcher's region.
912   * @stable ICU 4.0
913   */
914 U_STABLE int32_t U_EXPORT2
915 uregex_regionEnd(const  URegularExpression   *regexp,
916                         UErrorCode           *status);
917 
918 /**
919   * 64bit version of uregex_regionEnd.
920   * Reports the end index (exclusive) of the matching region for this URegularExpression.
921   * Any matches found are limited to to the region bounded by regionStart (inclusive)
922   * and regionEnd (exclusive).
923   *
924   * @param regexp The compiled regular expression.
925   * @param status A pointer to a UErrorCode to receive any errors.
926   * @return The ending point (native) of this matcher's region.
927   * @draft ICU 4.6
928   */
929 U_DRAFT int64_t U_EXPORT2
930 uregex_regionEnd64(const  URegularExpression   *regexp,
931                           UErrorCode           *status);
932 
933 /**
934   * Queries the transparency of region bounds for this URegularExpression.
935   * See useTransparentBounds for a description of transparent and opaque bounds.
936   * By default, matching boundaries are opaque.
937   *
938   * @param regexp The compiled regular expression.
939   * @param status A pointer to a UErrorCode to receive any errors.
940   * @return TRUE if this matcher is using opaque bounds, false if it is not.
941   * @stable ICU 4.0
942   */
943 U_STABLE UBool U_EXPORT2
944 uregex_hasTransparentBounds(const  URegularExpression   *regexp,
945                                    UErrorCode           *status);
946 
947 
948 /**
949   * Sets the transparency of region bounds for this URegularExpression.
950   * Invoking this function with an argument of TRUE will set matches to use transparent bounds.
951   * If the boolean argument is FALSE, then opaque bounds will be used.
952   *
953   * Using transparent bounds, the boundaries of the matching region are transparent
954   * to lookahead, lookbehind, and boundary matching constructs. Those constructs can
955   * see text beyond the boundaries of the region while checking for a match.
956   *
957   * With opaque bounds, no text outside of the matching region is visible to lookahead,
958   * lookbehind, and boundary matching constructs.
959   *
960   * By default, opaque bounds are used.
961   *
962   * @param   regexp The compiled regular expression.
963   * @param   b      TRUE for transparent bounds; FALSE for opaque bounds
964   * @param   status A pointer to a UErrorCode to receive any errors.
965   * @stable ICU 4.0
966   **/
967 U_STABLE void U_EXPORT2
968 uregex_useTransparentBounds(URegularExpression   *regexp,
969                             UBool                b,
970                             UErrorCode           *status);
971 
972 
973 /**
974   * Return true if this URegularExpression is using anchoring bounds.
975   * By default, anchoring region bounds are used.
976   *
977   * @param  regexp The compiled regular expression.
978   * @param  status A pointer to a UErrorCode to receive any errors.
979   * @return TRUE if this matcher is using anchoring bounds.
980   * @stable ICU 4.0
981   */
982 U_STABLE UBool U_EXPORT2
983 uregex_hasAnchoringBounds(const  URegularExpression   *regexp,
984                                  UErrorCode           *status);
985 
986 
987 /**
988   * Set whether this URegularExpression is using Anchoring Bounds for its region.
989   * With anchoring bounds, pattern anchors such as ^ and $ will match at the start
990   * and end of the region.  Without Anchoring Bounds, anchors will only match at
991   * the positions they would in the complete text.
992   *
993   * Anchoring Bounds are the default for regions.
994   *
995   * @param regexp The compiled regular expression.
996   * @param b      TRUE if to enable anchoring bounds; FALSE to disable them.
997   * @param status A pointer to a UErrorCode to receive any errors.
998   * @stable ICU 4.0
999   */
1000 U_STABLE void U_EXPORT2
1001 uregex_useAnchoringBounds(URegularExpression   *regexp,
1002                           UBool                 b,
1003                           UErrorCode           *status);
1004 
1005 /**
1006   * Return TRUE if the most recent matching operation touched the
1007   *  end of the text being processed.  In this case, additional input text could
1008   *  change the results of that match.
1009   *
1010   *  @param regexp The compiled regular expression.
1011   *  @param status A pointer to a UErrorCode to receive any errors.
1012   *  @return  TRUE if the most recent match hit the end of input
1013   *  @stable ICU 4.0
1014   */
1015 U_STABLE UBool U_EXPORT2
1016 uregex_hitEnd(const  URegularExpression   *regexp,
1017                      UErrorCode           *status);
1018 
1019 /**
1020   * Return TRUE the most recent match succeeded and additional input could cause
1021   * it to fail. If this function returns false and a match was found, then more input
1022   * might change the match but the match won't be lost. If a match was not found,
1023   * then requireEnd has no meaning.
1024   *
1025   * @param regexp The compiled regular expression.
1026   * @param status A pointer to a UErrorCode to receive any errors.
1027   * @return TRUE  if more input could cause the most recent match to no longer match.
1028   * @stable ICU 4.0
1029   */
1030 U_STABLE UBool U_EXPORT2
1031 uregex_requireEnd(const  URegularExpression   *regexp,
1032                          UErrorCode           *status);
1033 
1034 
1035 
1036 
1037 
1038 /**
1039   *    Replaces every substring of the input that matches the pattern
1040   *    with the given replacement string.  This is a convenience function that
1041   *    provides a complete find-and-replace-all operation.
1042   *
1043   *    This method scans the input string looking for matches of the pattern.
1044   *    Input that is not part of any match is copied unchanged to the
1045   *    destination buffer.  Matched regions are replaced in the output
1046   *    buffer by the replacement string.   The replacement string may contain
1047   *    references to capture groups; these take the form of $1, $2, etc.
1048   *
1049   *    @param   regexp             The compiled regular expression.
1050   *    @param   replacementText    A string containing the replacement text.
1051   *    @param   replacementLength  The length of the replacement string, or
1052   *                                -1 if it is NUL terminated.
1053   *    @param   destBuf            A (UChar *) buffer that will receive the result.
1054   *    @param   destCapacity       The capacity of the destination buffer.
1055   *    @param   status             A reference to a UErrorCode to receive any errors.
1056   *    @return                     The length of the string resulting from the find
1057   *                                and replace operation.  In the event that the
1058   *                                destination capacity is inadequate, the return value
1059   *                                is still the full length of the untruncated string.
1060   *    @stable ICU 3.0
1061   */
1062 U_STABLE int32_t U_EXPORT2
1063 uregex_replaceAll(URegularExpression    *regexp,
1064                   const UChar           *replacementText,
1065                   int32_t                replacementLength,
1066                   UChar                 *destBuf,
1067                   int32_t                destCapacity,
1068                   UErrorCode            *status);
1069 
1070 /**
1071   *    Replaces every substring of the input that matches the pattern
1072   *    with the given replacement string.  This is a convenience function that
1073   *    provides a complete find-and-replace-all operation.
1074   *
1075   *    This method scans the input string looking for matches of the pattern.
1076   *    Input that is not part of any match is copied unchanged to the
1077   *    destination buffer.  Matched regions are replaced in the output
1078   *    buffer by the replacement string.   The replacement string may contain
1079   *    references to capture groups; these take the form of $1, $2, etc.
1080   *
1081   *    @param   regexp         The compiled regular expression.
1082   *    @param   replacement    A string containing the replacement text.
1083   *    @param   dest           A mutable UText that will receive the result.
1084   *                             If NULL, a new UText will be created (which may not be mutable).
1085   *    @param   status         A reference to a UErrorCode to receive any errors.
1086   *    @return                 A UText containing the results of the find and replace.
1087   *                             If a pre-allocated UText was provided, it will always be used and returned.
1088   *
1089   *    @draft ICU 4.6
1090   */
1091 U_DRAFT UText * U_EXPORT2
1092 uregex_replaceAllUText(URegularExpression *regexp,
1093                        UText              *replacement,
1094                        UText              *dest,
1095                        UErrorCode         *status);
1096 
1097 /**
1098   *    Replaces the first substring of the input that matches the pattern
1099   *    with the given replacement string.  This is a convenience function that
1100   *    provides a complete find-and-replace operation.
1101   *
1102   *    This method scans the input string looking for a match of the pattern.
1103   *    All input that is not part of the match is copied unchanged to the
1104   *    destination buffer.  The matched region is replaced in the output
1105   *    buffer by the replacement string.   The replacement string may contain
1106   *    references to capture groups; these take the form of $1, $2, etc.
1107   *
1108   *    @param   regexp             The compiled regular expression.
1109   *    @param   replacementText    A string containing the replacement text.
1110   *    @param   replacementLength  The length of the replacement string, or
1111   *                                -1 if it is NUL terminated.
1112   *    @param   destBuf            A (UChar *) buffer that will receive the result.
1113   *    @param   destCapacity       The capacity of the destination buffer.
1114   *    @param   status             a reference to a UErrorCode to receive any errors.
1115   *    @return                     The length of the string resulting from the find
1116   *                                and replace operation.  In the event that the
1117   *                                destination capacity is inadequate, the return value
1118   *                                is still the full length of the untruncated string.
1119   *    @stable ICU 3.0
1120   */
1121 U_STABLE int32_t U_EXPORT2
1122 uregex_replaceFirst(URegularExpression  *regexp,
1123                     const UChar         *replacementText,
1124                     int32_t              replacementLength,
1125                     UChar               *destBuf,
1126                     int32_t              destCapacity,
1127                     UErrorCode          *status);
1128 
1129 /**
1130   *    Replaces the first substring of the input that matches the pattern
1131   *    with the given replacement string.  This is a convenience function that
1132   *    provides a complete find-and-replace operation.
1133   *
1134   *    This method scans the input string looking for a match of the pattern.
1135   *    All input that is not part of the match is copied unchanged to the
1136   *    destination buffer.  The matched region is replaced in the output
1137   *    buffer by the replacement string.   The replacement string may contain
1138   *    references to capture groups; these take the form of $1, $2, etc.
1139   *
1140   *    @param   regexp         The compiled regular expression.
1141   *    @param   replacement    A string containing the replacement text.
1142   *    @param   dest           A mutable UText that will receive the result.
1143   *                             If NULL, a new UText will be created (which may not be mutable).
1144   *    @param   status         A reference to a UErrorCode to receive any errors.
1145   *    @return                 A UText containing the results of the find and replace.
1146   *                             If a pre-allocated UText was provided, it will always be used and returned.
1147   *
1148   *    @draft ICU 4.6
1149   */
1150 U_DRAFT UText * U_EXPORT2
1151 uregex_replaceFirstUText(URegularExpression *regexp,
1152                          UText              *replacement,
1153                          UText              *dest,
1154                          UErrorCode         *status);
1155 
1156 
1157 /**
1158   *   Implements a replace operation intended to be used as part of an
1159   *   incremental find-and-replace.
1160   *
1161   *   <p>The input string, starting from the end of the previous match and ending at
1162   *   the start of the current match, is appended to the destination string.  Then the
1163   *   replacement string is appended to the output string,
1164   *   including handling any substitutions of captured text.</p>
1165   *
1166   *   <p>A note on preflight computation of buffersize and error handling:
1167   *   Calls to uregex_appendReplacement() and uregex_appendTail() are
1168   *   designed to be chained, one after another, with the destination
1169   *   buffer pointer and buffer capacity updated after each in preparation
1170   *   to for the next.  If the destination buffer is exhausted partway through such a
1171   *   sequence, a U_BUFFER_OVERFLOW_ERROR status will be returned.  Normal
1172   *   ICU conventions are for a function to perform no action if it is
1173   *   called with an error status, but for this one case, uregex_appendRepacement()
1174   *   will operate normally so that buffer size computations will complete
1175   *   correctly.
1176   *
1177   *   <p>For simple, prepackaged, non-incremental find-and-replace
1178   *      operations, see replaceFirst() or replaceAll().</p>
1179   *
1180   *   @param   regexp      The regular expression object.
1181   *   @param   replacementText The string that will replace the matched portion of the
1182   *                        input string as it is copied to the destination buffer.
1183   *                        The replacement text may contain references ($1, for
1184   *                        example) to capture groups from the match.
1185   *   @param   replacementLength  The length of the replacement text string,
1186   *                        or -1 if the string is NUL terminated.
1187   *   @param   destBuf     The buffer into which the results of the
1188   *                        find-and-replace are placed.  On return, this pointer
1189   *                        will be updated to refer to the beginning of the
1190   *                        unused portion of buffer, leaving it in position for
1191   *                        a subsequent call to this function.
1192   *   @param   destCapacity The size of the output buffer,  On return, this
1193   *                        parameter will be updated to reflect the space remaining
1194   *                        unused in the output buffer.
1195   *   @param   status      A reference to a UErrorCode to receive any errors.
1196   *   @return              The length of the result string.  In the event that
1197   *                        destCapacity is inadequate, the full length of the
1198   *                        untruncated output string is returned.
1199   *
1200   *   @stable ICU 3.0
1201   *
1202   */
1203 U_STABLE int32_t U_EXPORT2
1204 uregex_appendReplacement(URegularExpression    *regexp,
1205                          const UChar           *replacementText,
1206                          int32_t                replacementLength,
1207                          UChar                **destBuf,
1208                          int32_t               *destCapacity,
1209                          UErrorCode            *status);
1210 
1211 
1212 /**
1213   *   Implements a replace operation intended to be used as part of an
1214   *   incremental find-and-replace.
1215   *
1216   *   <p>The input string, starting from the end of the previous match and ending at
1217   *   the start of the current match, is appended to the destination string.  Then the
1218   *   replacement string is appended to the output string,
1219   *   including handling any substitutions of captured text.</p>
1220   *
1221   *   <p>For simple, prepackaged, non-incremental find-and-replace
1222   *      operations, see replaceFirst() or replaceAll().</p>
1223   *
1224   *   @param   regexp      The regular expression object.
1225   *   @param   replacementText The string that will replace the matched portion of the
1226   *                        input string as it is copied to the destination buffer.
1227   *                        The replacement text may contain references ($1, for
1228   *                        example) to capture groups from the match.
1229   *   @param   dest        A mutable UText that will receive the result. Must not be NULL.
1230   *   @param   status      A reference to a UErrorCode to receive any errors.
1231   *
1232   *   @draft ICU 4.6
1233   */
1234 U_DRAFT void U_EXPORT2
1235 uregex_appendReplacementUText(URegularExpression    *regexp,
1236                               UText                 *replacementText,
1237                               UText                 *dest,
1238                               UErrorCode            *status);
1239 
1240 
1241 /**
1242   * As the final step in a find-and-replace operation, append the remainder
1243   * of the input string, starting at the position following the last match,
1244   * to the destination string. <code>uregex_appendTail()</code> is intended
1245   *  to be invoked after one or more invocations of the
1246   *  <code>uregex_appendReplacement()</code> function.
1247   *
1248   *   @param   regexp      The regular expression object.  This is needed to
1249   *                        obtain the input string and with the position
1250   *                        of the last match within it.
1251   *   @param   destBuf     The buffer in which the results of the
1252   *                        find-and-replace are placed.  On return, the pointer
1253   *                        will be updated to refer to the beginning of the
1254   *                        unused portion of buffer.
1255   *   @param   destCapacity The size of the output buffer,  On return, this
1256   *                        value will be updated to reflect the space remaining
1257   *                        unused in the output buffer.
1258   *   @param   status      A reference to a UErrorCode to receive any errors.
1259   *   @return              The length of the result string.  In the event that
1260   *                        destCapacity is inadequate, the full length of the
1261   *                        untruncated output string is returned.
1262   *
1263   *   @stable ICU 3.0
1264   */
1265 U_STABLE int32_t U_EXPORT2
1266 uregex_appendTail(URegularExpression    *regexp,
1267                   UChar                **destBuf,
1268                   int32_t               *destCapacity,
1269                   UErrorCode            *status);
1270 
1271 
1272 /**
1273   * As the final step in a find-and-replace operation, append the remainder
1274   * of the input string, starting at the position following the last match,
1275   * to the destination string. <code>uregex_appendTailUText()</code> is intended
1276   *  to be invoked after one or more invocations of the
1277   *  <code>uregex_appendReplacementUText()</code> function.
1278   *
1279   *   @param   regexp      The regular expression object.  This is needed to
1280   *                        obtain the input string and with the position
1281   *                        of the last match within it.
1282   *   @param   dest        A mutable UText that will receive the result. Must not be NULL.
1283   *
1284   *   @param status        Error code
1285   *
1286   *   @return              The destination UText.
1287   *
1288   *   @draft ICU 4.6
1289   */
1290 U_DRAFT UText * U_EXPORT2
1291 uregex_appendTailUText(URegularExpression    *regexp,
1292                        UText                 *dest,
1293                        UErrorCode            *status);
1294 
1295 
1296 
1297  /**
1298    * Split a string into fields.  Somewhat like split() from Perl.
1299    *  The pattern matches identify delimiters that separate the input
1300    *  into fields.  The input data between the matches becomes the
1301    *  fields themselves.
1302    *
1303    *  Each of the fields is copied from the input string to the destination
1304    *  buffer, and NUL terminated.  The position of each field within
1305    *  the destination buffer is returned in the destFields array.
1306    *
1307    *  If the delimiter pattern includes capture groups, the captured text will
1308    *  also appear in the destination array of output strings, interspersed
1309    *  with the fields.  This is similar to Perl, but differs from Java,
1310    *  which ignores the presence of capture groups in the pattern.
1311    *
1312    *  Trailing empty fields will always be returned, assuming sufficient
1313    *  destination capacity.  This differs from the default behavior for Java
1314    *  and Perl where trailing empty fields are not returned.
1315    *
1316    *  The number of strings produced by the split operation is returned.
1317    *  This count includes the strings from capture groups in the delimiter pattern.
1318    *  This behavior differs from Java, which ignores capture groups.
1319    *
1320    *    @param   regexp      The compiled regular expression.
1321    *    @param   destBuf     A (UChar *) buffer to receive the fields that
1322    *                         are extracted from the input string. These
1323    *                         field pointers will refer to positions within the
1324    *                         destination buffer supplied by the caller.  Any
1325    *                         extra positions within the destFields array will be
1326    *                         set to NULL.
1327    *    @param   destCapacity The capacity of the destBuf.
1328    *    @param   requiredCapacity  The actual capacity required of the destBuf.
1329    *                         If destCapacity is too small, requiredCapacity will return
1330    *                         the total capacity required to hold all of the output, and
1331    *                         a U_BUFFER_OVERFLOW_ERROR will be returned.
1332    *    @param   destFields  An array to be filled with the position of each
1333    *                         of the extracted fields within destBuf.
1334    *    @param   destFieldsCapacity  The number of elements in the destFields array.
1335    *                If the number of fields found is less than destFieldsCapacity,
1336    *                the extra destFields elements are set to zero.
1337    *                If destFieldsCapacity is too small, the trailing part of the
1338    *                input, including any field delimiters, is treated as if it
1339    *                were the last field - it is copied to the destBuf, and
1340    *                its position is in the destBuf is stored in the last element
1341    *                of destFields.  This behavior mimics that of Perl.  It is not
1342    *                an error condition, and no error status is returned when all destField
1343    *                positions are used.
1344    * @param status  A reference to a UErrorCode to receive any errors.
1345    * @return        The number of fields into which the input string was split.
1346    * @stable ICU 3.0
1347    */
1348 U_STABLE int32_t U_EXPORT2
1349 uregex_split(   URegularExpression      *regexp,
1350                   UChar                 *destBuf,
1351                   int32_t                destCapacity,
1352                   int32_t               *requiredCapacity,
1353                   UChar                 *destFields[],
1354                   int32_t                destFieldsCapacity,
1355                   UErrorCode            *status);
1356 
1357 
1358   /**
1359    * Split a string into fields.  Somewhat like split() from Perl.
1360    * The pattern matches identify delimiters that separate the input
1361    *  into fields.  The input data between the matches becomes the
1362    *  fields themselves.
1363    * <p>
1364    * The behavior of this function is not very closely aligned with uregex_split();
1365    * instead, it is based on (and implemented directly on top of) the C++ split method.
1366    *
1367    * @param regexp  The compiled regular expression.
1368    * @param destFields    An array of mutable UText structs to receive the results of the split.
1369    *                If a field is NULL, a new UText is allocated to contain the results for
1370    *                that field. This new UText is not guaranteed to be mutable.
1371    * @param destFieldsCapacity  The number of elements in the destination array.
1372    *                If the number of fields found is less than destCapacity, the
1373    *                extra strings in the destination array are not altered.
1374    *                If the number of destination strings is less than the number
1375    *                of fields, the trailing part of the input string, including any
1376    *                field delimiters, is placed in the last destination string.
1377    *                This behavior mimics that of Perl.  It is not  an error condition, and no
1378    *                error status is returned when all destField positions are used.
1379    * @param status  A reference to a UErrorCode to receive any errors.
1380    * @return        The number of fields into which the input string was split.
1381    *
1382    * @draft ICU 4.6
1383    */
1384 U_DRAFT int32_t U_EXPORT2
1385 uregex_splitUText(URegularExpression    *regexp,
1386                   UText                 *destFields[],
1387                   int32_t                destFieldsCapacity,
1388                   UErrorCode            *status);
1389 
1390 
1391 
1392 
1393 /**
1394  * Set a processing time limit for match operations with this URegularExpression.
1395  *
1396  * Some patterns, when matching certain strings, can run in exponential time.
1397  * For practical purposes, the match operation may appear to be in an
1398  * infinite loop.
1399  * When a limit is set a match operation will fail with an error if the
1400  * limit is exceeded.
1401  * <p>
1402  * The units of the limit are steps of the match engine.
1403  * Correspondence with actual processor time will depend on the speed
1404  * of the processor and the details of the specific pattern, but will
1405  * typically be on the order of milliseconds.
1406  * <p>
1407  * By default, the matching time is not limited.
1408  * <p>
1409  *
1410  * @param   regexp      The compiled regular expression.
1411  * @param   limit       The limit value, or 0 for no limit.
1412  * @param   status      A reference to a UErrorCode to receive any errors.
1413  * @stable ICU 4.0
1414  */
1415 U_STABLE void U_EXPORT2
1416 uregex_setTimeLimit(URegularExpression      *regexp,
1417                     int32_t                  limit,
1418                     UErrorCode              *status);
1419 
1420 /**
1421  * Get the time limit for for matches with this URegularExpression.
1422  * A return value of zero indicates that there is no limit.
1423  *
1424  * @param   regexp      The compiled regular expression.
1425  * @param   status      A reference to a UErrorCode to receive any errors.
1426  * @return the maximum allowed time for a match, in units of processing steps.
1427  * @stable ICU 4.0
1428  */
1429 U_STABLE int32_t U_EXPORT2
1430 uregex_getTimeLimit(const URegularExpression      *regexp,
1431                           UErrorCode              *status);
1432 
1433 /**
1434  * Set the amount of heap storage available for use by the match backtracking stack.
1435  * <p>
1436  * ICU uses a backtracking regular expression engine, with the backtrack stack
1437  * maintained on the heap.  This function sets the limit to the amount of memory
1438  * that can be used  for this purpose.  A backtracking stack overflow will
1439  * result in an error from the match operation that caused it.
1440  * <p>
1441  * A limit is desirable because a malicious or poorly designed pattern can use
1442  * excessive memory, potentially crashing the process.  A limit is enabled
1443  * by default.
1444  * <p>
1445  * @param   regexp      The compiled regular expression.
1446  * @param   limit       The maximum size, in bytes, of the matching backtrack stack.
1447  *                      A value of -1 means no limit.
1448  *                      The limit must be greater than zero, or -1.
1449  * @param   status      A reference to a UErrorCode to receive any errors.
1450  *
1451  * @stable ICU 4.0
1452  */
1453 U_STABLE void U_EXPORT2
1454 uregex_setStackLimit(URegularExpression      *regexp,
1455                      int32_t                  limit,
1456                      UErrorCode              *status);
1457 
1458 /**
1459  * Get the size of the heap storage available for use by the back tracking stack.
1460  *
1461  * @return  the maximum backtracking stack size, in bytes, or zero if the
1462  *          stack size is unlimited.
1463  * @stable ICU 4.0
1464  */
1465 U_STABLE int32_t U_EXPORT2
1466 uregex_getStackLimit(const URegularExpression      *regexp,
1467                            UErrorCode              *status);
1468 
1469 
1470 /**
1471  * Function pointer for a regular expression matching callback function.
1472  * When set, a callback function will be called periodically during matching
1473  * operations.  If the call back function returns FALSE, the matching
1474  * operation will be terminated early.
1475  *
1476  * Note:  the callback function must not call other functions on this
1477  *        URegularExpression.
1478  *
1479  * @param context  context pointer.  The callback function will be invoked
1480  *                 with the context specified at the time that
1481  *                 uregex_setMatchCallback() is called.
1482  * @param steps    the accumulated processing time, in match steps,
1483  *                 for this matching operation.
1484  * @return         TRUE to continue the matching operation.
1485  *                 FALSE to terminate the matching operation.
1486  * @stable ICU 4.0
1487  */
1488 U_CDECL_BEGIN
1489 typedef UBool U_CALLCONV URegexMatchCallback (
1490                    const void *context,
1491                    int32_t     steps);
1492 U_CDECL_END
1493 
1494 /**
1495  * Set a callback function for this URegularExpression.
1496  * During matching operations the function will be called periodically,
1497  * giving the application the opportunity to terminate a long-running
1498  * match.
1499  *
1500  * @param   regexp      The compiled regular expression.
1501  * @param   callback    A pointer to the user-supplied callback function.
1502  * @param   context     User context pointer.  The value supplied at the
1503  *                      time the callback function is set will be saved
1504  *                      and passed to the callback each time that it is called.
1505  * @param   status      A reference to a UErrorCode to receive any errors.
1506  * @stable ICU 4.0
1507  */
1508 U_STABLE void U_EXPORT2
1509 uregex_setMatchCallback(URegularExpression      *regexp,
1510                         URegexMatchCallback     *callback,
1511                         const void              *context,
1512                         UErrorCode              *status);
1513 
1514 
1515 /**
1516  *  Get the callback function for this URegularExpression.
1517  *
1518  * @param   regexp      The compiled regular expression.
1519  * @param   callback    Out parameter, receives a pointer to the user-supplied
1520  *                      callback function.
1521  * @param   context     Out parameter, receives the user context pointer that
1522  *                      was set when uregex_setMatchCallback() was called.
1523  * @param   status      A reference to a UErrorCode to receive any errors.
1524  * @stable ICU 4.0
1525  */
1526 U_STABLE void U_EXPORT2
1527 uregex_getMatchCallback(const URegularExpression    *regexp,
1528                         URegexMatchCallback        **callback,
1529                         const void                 **context,
1530                         UErrorCode                  *status);
1531 
1532 
1533 /**
1534  * Function pointer for a regular expression find callback function.
1535  *
1536  * When set, a callback function will be called during a find operation
1537  * and for operations that depend on find, such as findNext, split and some replace
1538  * operations like replaceFirst.
1539  * The callback will usually be called after each attempt at a match, but this is not a
1540  * guarantee that the callback will be invoked at each character.  For finds where the
1541  * match engine is invoked at each character, this may be close to true, but less likely
1542  * for more optimized loops where the pattern is known to only start, and the match
1543  * engine invoked, at certain characters.
1544  * When invoked, this callback will specify the index at which a match operation is about
1545  * to be attempted, giving the application the opportunity to terminate a long-running
1546  * find operation.
1547  *
1548  * If the call back function returns FALSE, the find operation will be terminated early.
1549  *
1550  * Note:  the callback function must not call other functions on this
1551  *        URegularExpression
1552  *
1553  * @param context  context pointer.  The callback function will be invoked
1554  *                 with the context specified at the time that
1555  *                 uregex_setFindProgressCallback() is called.
1556  * @param matchIndex  the next index at which a match attempt will be attempted for this
1557  *                 find operation.  If this callback interrupts the search, this is the
1558  *                 index at which a find/findNext operation may be re-initiated.
1559  * @return         TRUE to continue the matching operation.
1560  *                 FALSE to terminate the matching operation.
1561  * @draft ICU 4.6
1562  */
1563 U_CDECL_BEGIN
1564 typedef UBool U_CALLCONV URegexFindProgressCallback (
1565                    const void *context,
1566                    int64_t     matchIndex);
1567 U_CDECL_END
1568 
1569 /**
1570  *  Set the find progress callback function for this URegularExpression.
1571  *
1572  * @param   regexp      The compiled regular expression.
1573  * @param   callback    A pointer to the user-supplied callback function.
1574  * @param   context     User context pointer.  The value supplied at the
1575  *                      time the callback function is set will be saved
1576  *                      and passed to the callback each time that it is called.
1577  * @param   status      A reference to a UErrorCode to receive any errors.
1578  * @draft ICU 4.6
1579  */
1580 U_DRAFT void U_EXPORT2
1581 uregex_setFindProgressCallback(URegularExpression              *regexp,
1582                                 URegexFindProgressCallback      *callback,
1583                                 const void                      *context,
1584                                 UErrorCode                      *status);
1585 
1586 
1587 /**
1588  *  Get the find progress callback function for this URegularExpression.
1589  *
1590  * @param   regexp      The compiled regular expression.
1591  * @param   callback    Out parameter, receives a pointer to the user-supplied
1592  *                      callback function.
1593  * @param   context     Out parameter, receives the user context pointer that
1594  *                      was set when uregex_setFindProgressCallback() was called.
1595  * @param   status      A reference to a UErrorCode to receive any errors.
1596  * @draft ICU 4.6
1597  */
1598 U_DRAFT void U_EXPORT2
1599 uregex_getFindProgressCallback(const URegularExpression          *regexp,
1600                                 URegexFindProgressCallback        **callback,
1601                                 const void                        **context,
1602                                 UErrorCode                        *status);
1603 
1604 #endif   /*  !UCONFIG_NO_REGULAR_EXPRESSIONS  */
1605 #endif   /*  UREGEX_H  */
1606