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1 /*
2 **********************************************************************
3 *   Copyright (C) 2004-2010, 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 rexpression, 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 specail
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 termintated.
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 nubers) 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 nubers) 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   * @internal ICU 4.4 technology preview
162   */
163 U_INTERNAL 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 termintated.
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 nubers) 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  * @draft 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 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  * @internal ICU 4.4 technology preview
284  */
285 U_INTERNAL 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   * @internal ICU 4.4 technology preview
345   */
346 U_INTERNAL 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   * @internal ICU 4.4 technology preview
392   */
393 U_INTERNAL UText * U_EXPORT2
394 uregex_getUText(URegularExpression *regexp,
395                 UText              *dest,
396                 UErrorCode         *status);
397 
398 // BEGIN android-added
399 // Removed it after Android upgrade to ICU4.6.
400 /**
401   *  Set the subject text string upon which the regular expression is looking for matches
402   *  without changing any other aspect of the matching state.
403   *  The new and previous text strings must have the same content.
404   *
405   *  This function is intended for use in environments where ICU is operating on
406   *  strings that may move around in memory.  It provides a mechanism for notifying
407   *  ICU that the string has been relocated, and providing a new UText to access the
408   *  string in its new position.
409   *
410   *   Caution:  this function is normally used only by very specialized
411   *             system-level code.
412   *
413   * @param regexp     The compiled regular expression.
414   * @param text       The new (moved) text string.
415   * @param status     Receives errors detected by this function.
416   *
417   * @internal ICU 4.6
418   */
419 U_INTERNAL void U_EXPORT2
420 uregex_refreshUText(URegularExpression *regexp,
421                     UText              *text,
422                     UErrorCode         *status);
423 // END android-added
424 
425 /**
426   *   Attempts to match the input string against the pattern.
427   *   To succeed, the match must extend to the end of the string,
428   *   or cover the complete match region.
429   *
430   *   If startIndex >= zero the match operation starts at the specified
431   *   index and must extend to the end of the input string.  Any region
432   *   that has been specified is reset.
433   *
434   *   If startIndex == -1 the match must cover the input region, or the entire
435   *   input string if no region has been set.  This directly corresponds to
436   *   Matcher.matches() in Java
437   *
438   *    @param  regexp      The compiled regular expression.
439   *    @param  startIndex  The input string index at which to begin matching, or -1
440   *                        to match the input Region.
441   *    @param  status      Receives errors detected by this function.
442   *    @return             TRUE if there is a match
443   *    @stable ICU 3.0
444   */
445 U_STABLE UBool U_EXPORT2
446 uregex_matches(URegularExpression *regexp,
447                 int32_t            startIndex,
448                 UErrorCode        *status);
449 
450 /**
451   *   Attempts to match the input string, starting from the specified index, against the pattern.
452   *   The match may be of any length, and is not required to extend to the end
453   *   of the input string.  Contrast with uregex_matches().
454   *
455   *   <p>If startIndex is >= 0 any input region that was set for this
456   *   URegularExpression is reset before the operation begins.
457   *
458   *   <p>If the specified starting index == -1 the match begins at the start of the input
459   *   region, or at the start of the full string if no region has been specified.
460   *   This corresponds directly with Matcher.lookingAt() in Java.
461   *
462   *   <p>If the match succeeds then more information can be obtained via the
463   *    <code>uregexp_start()</code>, <code>uregexp_end()</code>,
464   *    and <code>uregexp_group()</code> functions.</p>
465   *
466   *    @param   regexp      The compiled regular expression.
467   *    @param   startIndex  The input string index at which to begin matching, or
468   *                         -1 to match the Input Region
469   *    @param   status      A reference to a UErrorCode to receive any errors.
470   *    @return  TRUE if there is a match.
471   *    @stable ICU 3.0
472   */
473 U_STABLE UBool U_EXPORT2
474 uregex_lookingAt(URegularExpression *regexp,
475                  int32_t             startIndex,
476                  UErrorCode         *status);
477 
478 /**
479   *   Find the first matching substring of the input string that matches the pattern.
480   *   If startIndex is >= zero the search for a match begins at the specified index,
481   *          and any match region is reset.  This corresponds directly with
482   *          Matcher.find(startIndex) in Java.
483   *
484   *   If startIndex == -1 the search begins at the start of the input region,
485   *           or at the start of the full string if no region has been specified.
486   *
487   *   If a match is found, <code>uregex_start(), uregex_end()</code>, and
488   *   <code>uregex_group()</code> will provide more information regarding the match.
489   *
490   *   @param   regexp      The compiled regular expression.
491   *   @param   startIndex  The position in the input string to begin the search, or
492   *                        -1 to search within the Input Region.
493   *   @param   status      A reference to a UErrorCode to receive any errors.
494   *   @return              TRUE if a match is found.
495   *   @stable ICU 3.0
496   */
497 U_STABLE UBool U_EXPORT2
498 uregex_find(URegularExpression *regexp,
499             int32_t             startIndex,
500             UErrorCode         *status);
501 
502 /**
503   *  Find the next pattern match in the input string.  Begin searching
504   *  the input at the location following the end of he previous match,
505   *  or at the start of the string (or region) if there is no
506   *  previous match.  If a match is found, <code>uregex_start(), uregex_end()</code>, and
507   *  <code>uregex_group()</code> will provide more information regarding the match.
508   *
509   *  @param   regexp      The compiled regular expression.
510   *  @param   status      A reference to a UErrorCode to receive any errors.
511   *  @return              TRUE if a match is found.
512   *  @see uregex_reset
513   *  @stable ICU 3.0
514   */
515 U_STABLE UBool U_EXPORT2
516 uregex_findNext(URegularExpression *regexp,
517                 UErrorCode         *status);
518 
519 /**
520   *   Get the number of capturing groups in this regular expression's pattern.
521   *   @param   regexp      The compiled regular expression.
522   *   @param   status      A reference to a UErrorCode to receive any errors.
523   *   @return the number of capture groups
524   *   @stable ICU 3.0
525   */
526 U_STABLE int32_t U_EXPORT2
527 uregex_groupCount(URegularExpression *regexp,
528                   UErrorCode         *status);
529 
530 /** Extract the string for the specified matching expression or subexpression.
531   * Group #0 is the complete string of matched text.
532   * Group #1 is the text matched by the first set of capturing parentheses.
533   *
534   *   @param   regexp       The compiled regular expression.
535   *   @param   groupNum     The capture group to extract.  Group 0 is the complete
536   *                         match.  The value of this parameter must be
537   *                         less than or equal to the number of capture groups in
538   *                         the pattern.
539   *   @param   dest         Buffer to receive the matching string data
540   *   @param   destCapacity Capacity of the dest buffer.
541   *   @param   status       A reference to a UErrorCode to receive any errors.
542   *   @return               Length of matching data,
543   *                         or -1 if no applicable match.
544   *   @stable ICU 3.0
545   */
546 U_STABLE int32_t U_EXPORT2
547 uregex_group(URegularExpression *regexp,
548              int32_t             groupNum,
549              UChar              *dest,
550              int32_t             destCapacity,
551              UErrorCode          *status);
552 
553 /** Extract the string for the specified matching expression or subexpression.
554   * Group #0 is the complete string of matched text.
555   * Group #1 is the text matched by the first set of capturing parentheses.
556   *
557   *   @param   regexp       The compiled regular expression.
558   *   @param   groupNum     The capture group to extract.  Group 0 is the complete
559   *                         match.  The value of this parameter must be
560   *                         less than or equal to the number of capture groups in
561   *                         the pattern.
562   *   @param   dest         Mutable UText to receive the matching string data.
563   *                         If NULL, a new UText will be created (which may not be mutable).
564   *   @param   status       A reference to a UErrorCode to receive any errors.
565   *   @return               The matching string data. If a pre-allocated UText was provided,
566   *                          it will always be used and returned.
567   *
568   *   @internal ICU 4.4 technology preview
569   */
570 U_INTERNAL UText * U_EXPORT2
571 uregex_groupUText(URegularExpression *regexp,
572                   int32_t             groupNum,
573                   UText              *dest,
574                   UErrorCode         *status);
575 
576 
577 /**
578   *   Returns the index in the input string of the start of the text matched by the
579   *   specified capture group during the previous match operation.  Return -1 if
580   *   the capture group was not part of the last match.
581   *   Group #0 refers to the complete range of matched text.
582   *   Group #1 refers to the text matched by the first set of capturing parentheses.
583   *
584   *    @param   regexp      The compiled regular expression.
585   *    @param   groupNum    The capture group number
586   *    @param   status      A reference to a UErrorCode to receive any errors.
587   *    @return              the starting position in the input of the text matched
588   *                         by the specified group.
589   *    @stable ICU 3.0
590   */
591 U_STABLE int32_t U_EXPORT2
592 uregex_start(URegularExpression *regexp,
593              int32_t             groupNum,
594              UErrorCode          *status);
595 
596 /**
597   *   Returns the index in the input string of the position following the end
598   *   of the text matched by the specified capture group.
599   *   Return -1 if the capture group was not part of the last match.
600   *   Group #0 refers to the complete range of matched text.
601   *   Group #1 refers to the text matched by the first set of capturing parentheses.
602   *
603   *    @param   regexp      The compiled regular expression.
604   *    @param   groupNum    The capture group number
605   *    @param   status      A reference to a UErrorCode to receive any errors.
606   *    @return              the index of the position following the last matched character.
607   *    @stable ICU 3.0
608   */
609 U_STABLE int32_t U_EXPORT2
610 uregex_end(URegularExpression   *regexp,
611            int32_t               groupNum,
612            UErrorCode           *status);
613 
614 /**
615   *  Reset any saved state from the previous match.  Has the effect of
616   *  causing uregex_findNext to begin at the specified index, and causing
617   *  uregex_start(), uregex_end() and uregex_group() to return an error
618   *  indicating that there is no match information available.  Clears any
619   *  match region that may have been set.
620   *
621   *    @param   regexp      The compiled regular expression.
622   *    @param   index       The position in the text at which a
623   *                         uregex_findNext() should begin searching.
624   *    @param   status      A reference to a UErrorCode to receive any errors.
625   *    @stable ICU 3.0
626   */
627 U_STABLE void U_EXPORT2
628 uregex_reset(URegularExpression    *regexp,
629              int32_t               index,
630              UErrorCode            *status);
631 
632 
633 /** Sets the limits of the matching region for this URegularExpression.
634   * The region is the part of the input string that will be considered when matching.
635   * Invoking this method resets any saved state from the previous match,
636   * then sets the region to start at the index specified by the start parameter
637   * and end at the index specified by the end parameter.
638   *
639   * Depending on the transparency and anchoring being used (see useTransparentBounds
640   * and useAnchoringBounds), certain constructs such as anchors may behave differently
641   * at or around the boundaries of the region
642   *
643   * The function will fail if start is greater than limit, or if either index
644   *  is less than zero or greater than the length of the string being matched.
645   *
646   * @param regexp The compiled regular expression.
647   * @param regionStart  The index to begin searches at.
648   * @param regionLimit  The index to end searches at (exclusive).
649   * @param status A pointer to a UErrorCode to receive any errors.
650   * @stable ICU 4.0
651   */
652 U_STABLE void U_EXPORT2
653 uregex_setRegion(URegularExpression   *regexp,
654                  int32_t               regionStart,
655                  int32_t               regionLimit,
656                  UErrorCode           *status);
657 
658 /**
659   * Reports the start index of the matching region. Any matches found are limited to
660   * to the region bounded by regionStart (inclusive) and regionEnd (exclusive).
661   *
662   * @param regexp The compiled regular expression.
663   * @param status A pointer to a UErrorCode to receive any errors.
664   * @return The starting index of this matcher's region.
665   * @stable ICU 4.0
666   */
667 U_STABLE int32_t U_EXPORT2
668 uregex_regionStart(const  URegularExpression   *regexp,
669                           UErrorCode           *status);
670 
671 
672 
673 /**
674   * Reports the end index (exclusive) of the matching region for this URegularExpression.
675   * Any matches found are limited to to the region bounded by regionStart (inclusive)
676   * and regionEnd (exclusive).
677   *
678   * @param regexp The compiled regular expression.
679   * @param status A pointer to a UErrorCode to receive any errors.
680   * @return The ending point of this matcher's region.
681   * @stable ICU 4.0
682   */
683 U_STABLE int32_t U_EXPORT2
684 uregex_regionEnd(const  URegularExpression   *regexp,
685                         UErrorCode           *status);
686 
687 /**
688   * Queries the transparency of region bounds for this URegularExpression.
689   * See useTransparentBounds for a description of transparent and opaque bounds.
690   * By default, matching boundaries are opaque.
691   *
692   * @param regexp The compiled regular expression.
693   * @param status A pointer to a UErrorCode to receive any errors.
694   * @return TRUE if this matcher is using opaque bounds, false if it is not.
695   * @stable ICU 4.0
696   */
697 U_STABLE UBool U_EXPORT2
698 uregex_hasTransparentBounds(const  URegularExpression   *regexp,
699                                    UErrorCode           *status);
700 
701 
702 /**
703   * Sets the transparency of region bounds for this URegularExpression.
704   * Invoking this function with an argument of TRUE will set matches to use transparent bounds.
705   * If the boolean argument is FALSE, then opaque bounds will be used.
706   *
707   * Using transparent bounds, the boundaries of the matching region are transparent
708   * to lookahead, lookbehind, and boundary matching constructs. Those constructs can
709   * see text beyond the boundaries of the region while checking for a match.
710   *
711   * With opaque bounds, no text outside of the matching region is visible to lookahead,
712   * lookbehind, and boundary matching constructs.
713   *
714   * By default, opaque bounds are used.
715   *
716   * @param   regexp The compiled regular expression.
717   * @param   b      TRUE for transparent bounds; FALSE for opaque bounds
718   * @param   status A pointer to a UErrorCode to receive any errors.
719   * @stable ICU 4.0
720   **/
721 U_STABLE void U_EXPORT2
722 uregex_useTransparentBounds(URegularExpression   *regexp,
723                             UBool                b,
724                             UErrorCode           *status);
725 
726 
727 /**
728   * Return true if this URegularExpression is using anchoring bounds.
729   * By default, anchoring region bounds are used.
730   *
731   * @param  regexp The compiled regular expression.
732   * @param  status A pointer to a UErrorCode to receive any errors.
733   * @return TRUE if this matcher is using anchoring bounds.
734   * @stable ICU 4.0
735   */
736 U_STABLE UBool U_EXPORT2
737 uregex_hasAnchoringBounds(const  URegularExpression   *regexp,
738                                  UErrorCode           *status);
739 
740 
741 /**
742   * Set whether this URegularExpression is using Anchoring Bounds for its region.
743   * With anchoring bounds, pattern anchors such as ^ and $ will match at the start
744   * and end of the region.  Without Anchoring Bounds, anchors will only match at
745   * the positions they would in the complete text.
746   *
747   * Anchoring Bounds are the default for regions.
748   *
749   * @param regexp The compiled regular expression.
750   * @param b      TRUE if to enable anchoring bounds; FALSE to disable them.
751   * @param status A pointer to a UErrorCode to receive any errors.
752   * @stable ICU 4.0
753   */
754 U_STABLE void U_EXPORT2
755 uregex_useAnchoringBounds(URegularExpression   *regexp,
756                           UBool                 b,
757                           UErrorCode           *status);
758 
759 /**
760   * Return TRUE if the most recent matching operation touched the
761   *  end of the text being processed.  In this case, additional input text could
762   *  change the results of that match.
763   *
764   *  @param regexp The compiled regular expression.
765   *  @param status A pointer to a UErrorCode to receive any errors.
766   *  @return  TRUE if the most recent match hit the end of input
767   *  @stable ICU 4.0
768   */
769 U_STABLE UBool U_EXPORT2
770 uregex_hitEnd(const  URegularExpression   *regexp,
771                      UErrorCode           *status);
772 
773 /**
774   * Return TRUE the most recent match succeeded and additional input could cause
775   * it to fail. If this function returns false and a match was found, then more input
776   * might change the match but the match won't be lost. If a match was not found,
777   * then requireEnd has no meaning.
778   *
779   * @param regexp The compiled regular expression.
780   * @param status A pointer to a UErrorCode to receive any errors.
781   * @return TRUE  if more input could cause the most recent match to no longer match.
782   * @stable ICU 4.0
783   */
784 U_STABLE UBool U_EXPORT2
785 uregex_requireEnd(const  URegularExpression   *regexp,
786                          UErrorCode           *status);
787 
788 
789 
790 
791 
792 /**
793   *    Replaces every substring of the input that matches the pattern
794   *    with the given replacement string.  This is a convenience function that
795   *    provides a complete find-and-replace-all operation.
796   *
797   *    This method scans the input string looking for matches of the pattern.
798   *    Input that is not part of any match is copied unchanged to the
799   *    destination buffer.  Matched regions are replaced in the output
800   *    buffer by the replacement string.   The replacement string may contain
801   *    references to capture groups; these take the form of $1, $2, etc.
802   *
803   *    @param   regexp             The compiled regular expression.
804   *    @param   replacementText    A string containing the replacement text.
805   *    @param   replacementLength  The length of the replacement string, or
806   *                                -1 if it is NUL terminated.
807   *    @param   destBuf            A (UChar *) buffer that will receive the result.
808   *    @param   destCapacity       The capacity of the desitnation buffer.
809   *    @param   status             A reference to a UErrorCode to receive any errors.
810   *    @return                     The length of the string resulting from the find
811   *                                and replace operation.  In the event that the
812   *                                destination capacity is inadequate, the return value
813   *                                is still the full length of the untruncated string.
814   *    @stable ICU 3.0
815   */
816 U_STABLE int32_t U_EXPORT2
817 uregex_replaceAll(URegularExpression    *regexp,
818                   const UChar           *replacementText,
819                   int32_t                replacementLength,
820                   UChar                 *destBuf,
821                   int32_t                destCapacity,
822                   UErrorCode            *status);
823 
824 /**
825   *    Replaces every substring of the input that matches the pattern
826   *    with the given replacement string.  This is a convenience function that
827   *    provides a complete find-and-replace-all operation.
828   *
829   *    This method scans the input string looking for matches of the pattern.
830   *    Input that is not part of any match is copied unchanged to the
831   *    destination buffer.  Matched regions are replaced in the output
832   *    buffer by the replacement string.   The replacement string may contain
833   *    references to capture groups; these take the form of $1, $2, etc.
834   *
835   *    @param   regexp         The compiled regular expression.
836   *    @param   replacement    A string containing the replacement text.
837   *    @param   dest           A mutable UText that will receive the result.
838   *                             If NULL, a new UText will be created (which may not be mutable).
839   *    @param   status         A reference to a UErrorCode to receive any errors.
840   *    @return                 A UText containing the results of the find and replace.
841   *                             If a pre-allocated UText was provided, it will always be used and returned.
842   *
843   *    @internal ICU 4.4 technology preview
844   */
845 U_INTERNAL UText * U_EXPORT2
846 uregex_replaceAllUText(URegularExpression *regexp,
847                        UText              *replacement,
848                        UText              *dest,
849                        UErrorCode         *status);
850 
851 /**
852   *    Replaces the first substring of the input that matches the pattern
853   *    with the given replacement string.  This is a convenience function that
854   *    provides a complete find-and-replace operation.
855   *
856   *    This method scans the input string looking for a match of the pattern.
857   *    All input that is not part of the match is copied unchanged to the
858   *    destination buffer.  The matched region is replaced in the output
859   *    buffer by the replacement string.   The replacement string may contain
860   *    references to capture groups; these take the form of $1, $2, etc.
861   *
862   *    @param   regexp             The compiled regular expression.
863   *    @param   replacementText    A string containing the replacement text.
864   *    @param   replacementLength  The length of the replacement string, or
865   *                                -1 if it is NUL terminated.
866   *    @param   destBuf            A (UChar *) buffer that will receive the result.
867   *    @param   destCapacity       The capacity of the desitnation buffer.
868   *    @param   status             a reference to a UErrorCode to receive any errors.
869   *    @return                     The length of the string resulting from the find
870   *                                and replace operation.  In the event that the
871   *                                destination capacity is inadequate, the return value
872   *                                is still the full length of the untruncated string.
873   *    @stable ICU 3.0
874   */
875 U_STABLE int32_t U_EXPORT2
876 uregex_replaceFirst(URegularExpression  *regexp,
877                     const UChar         *replacementText,
878                     int32_t              replacementLength,
879                     UChar               *destBuf,
880                     int32_t              destCapacity,
881                     UErrorCode          *status);
882 
883 /**
884   *    Replaces the first substring of the input that matches the pattern
885   *    with the given replacement string.  This is a convenience function that
886   *    provides a complete find-and-replace operation.
887   *
888   *    This method scans the input string looking for a match of the pattern.
889   *    All input that is not part of the match is copied unchanged to the
890   *    destination buffer.  The matched region is replaced in the output
891   *    buffer by the replacement string.   The replacement string may contain
892   *    references to capture groups; these take the form of $1, $2, etc.
893   *
894   *    @param   regexp         The compiled regular expression.
895   *    @param   replacement    A string containing the replacement text.
896   *    @param   dest           A mutable UText that will receive the result.
897   *                             If NULL, a new UText will be created (which may not be mutable).
898   *    @param   status         A reference to a UErrorCode to receive any errors.
899   *    @return                 A UText containing the results of the find and replace.
900   *                             If a pre-allocated UText was provided, it will always be used and returned.
901   *
902   *    @internal ICU 4.4 technology preview
903   */
904 U_INTERNAL UText * U_EXPORT2
905 uregex_replaceFirstUText(URegularExpression *regexp,
906                          UText              *replacement,
907                          UText              *dest,
908                          UErrorCode         *status);
909 
910 
911 /**
912   *   Implements a replace operation intended to be used as part of an
913   *   incremental find-and-replace.
914   *
915   *   <p>The input string, starting from the end of the previous match and ending at
916   *   the start of the current match, is appended to the destination string.  Then the
917   *   replacement string is appended to the output string,
918   *   including handling any substitutions of captured text.</p>
919   *
920   *   <p>A note on preflight computation of buffersize and error handling:
921   *   Calls to uregex_appendReplacement() and uregex_appendTail() are
922   *   designed to be chained, one after another, with the destination
923   *   buffer pointer and buffer capacity updated after each in preparation
924   *   to for the next.  If the destination buffer is exhausted partway through such a
925   *   sequence, a U_BUFFER_OVERFLOW_ERROR status will be returned.  Normal
926   *   ICU conventions are for a function to perform no action if it is
927   *   called with an error status, but for this one case, uregex_appendRepacement()
928   *   will operate normally so that buffer size computations will complete
929   *   correctly.
930   *
931   *   <p>For simple, prepackaged, non-incremental find-and-replace
932   *      operations, see replaceFirst() or replaceAll().</p>
933   *
934   *   @param   regexp      The regular expression object.
935   *   @param   replacementText The string that will replace the matched portion of the
936   *                        input string as it is copied to the destination buffer.
937   *                        The replacement text may contain references ($1, for
938   *                        example) to capture groups from the match.
939   *   @param   replacementLength  The length of the replacement text string,
940   *                        or -1 if the string is NUL terminated.
941   *   @param   destBuf     The buffer into which the results of the
942   *                        find-and-replace are placed.  On return, this pointer
943   *                        will be updated to refer to the beginning of the
944   *                        unused portion of buffer, leaving it in position for
945   *                        a subsequent call to this function.
946   *   @param   destCapacity The size of the output buffer,  On return, this
947   *                        parameter will be updated to reflect the space remaining
948   *                        unused in the output buffer.
949   *   @param   status      A reference to a UErrorCode to receive any errors.
950   *   @return              The length of the result string.  In the event that
951   *                        destCapacity is inadequate, the full length of the
952   *                        untruncated output string is returned.
953   *
954   *   @stable ICU 3.0
955   *
956   */
957 U_STABLE int32_t U_EXPORT2
958 uregex_appendReplacement(URegularExpression    *regexp,
959                          const UChar           *replacementText,
960                          int32_t                replacementLength,
961                          UChar                **destBuf,
962                          int32_t               *destCapacity,
963                          UErrorCode            *status);
964 
965 
966 /**
967   *   Implements a replace operation intended to be used as part of an
968   *   incremental find-and-replace.
969   *
970   *   <p>The input string, starting from the end of the previous match and ending at
971   *   the start of the current match, is appended to the destination string.  Then the
972   *   replacement string is appended to the output string,
973   *   including handling any substitutions of captured text.</p>
974   *
975   *   <p>For simple, prepackaged, non-incremental find-and-replace
976   *      operations, see replaceFirst() or replaceAll().</p>
977   *
978   *   @param   regexp      The regular expression object.
979   *   @param   replacementText The string that will replace the matched portion of the
980   *                        input string as it is copied to the destination buffer.
981   *                        The replacement text may contain references ($1, for
982   *                        example) to capture groups from the match.
983   *   @param   dest        A mutable UText that will receive the result. Must not be NULL.
984   *   @param   status      A reference to a UErrorCode to receive any errors.
985   *
986   *   @internal ICU 4.4 technology preview
987   */
988 U_INTERNAL void U_EXPORT2
989 uregex_appendReplacementUText(URegularExpression    *regexp,
990                               UText                 *replacementText,
991                               UText                 *dest,
992                               UErrorCode            *status);
993 
994 
995 /**
996   * As the final step in a find-and-replace operation, append the remainder
997   * of the input string, starting at the position following the last match,
998   * to the destination string. <code>uregex_appendTail()</code> is intended
999   *  to be invoked after one or more invocations of the
1000   *  <code>uregex_appendReplacement()</code> function.
1001   *
1002   *   @param   regexp      The regular expression object.  This is needed to
1003   *                        obtain the input string and with the position
1004   *                        of the last match within it.
1005   *   @param   destBuf     The buffer in which the results of the
1006   *                        find-and-replace are placed.  On return, the pointer
1007   *                        will be updated to refer to the beginning of the
1008   *                        unused portion of buffer.
1009   *   @param   destCapacity The size of the output buffer,  On return, this
1010   *                        value will be updated to reflect the space remaining
1011   *                        unused in the output buffer.
1012   *   @param   status      A reference to a UErrorCode to receive any errors.
1013   *   @return              The length of the result string.  In the event that
1014   *                        destCapacity is inadequate, the full length of the
1015   *                        untruncated output string is returned.
1016   *
1017   *   @stable ICU 3.0
1018   */
1019 U_STABLE int32_t U_EXPORT2
1020 uregex_appendTail(URegularExpression    *regexp,
1021                   UChar                **destBuf,
1022                   int32_t               *destCapacity,
1023                   UErrorCode            *status);
1024 
1025 
1026 /**
1027   * As the final step in a find-and-replace operation, append the remainder
1028   * of the input string, starting at the position following the last match,
1029   * to the destination string. <code>uregex_appendTailUText()</code> is intended
1030   *  to be invoked after one or more invocations of the
1031   *  <code>uregex_appendReplacementUText()</code> function.
1032   *
1033   *   @param   regexp      The regular expression object.  This is needed to
1034   *                        obtain the input string and with the position
1035   *                        of the last match within it.
1036   *   @param   dest        A mutable UText that will receive the result. Must not be NULL.
1037   *   @return              The destination UText.
1038   *
1039   *   @internal ICU 4.4 technology preview
1040   */
1041 U_INTERNAL UText * U_EXPORT2
1042 uregex_appendTailUText(URegularExpression    *regexp,
1043                        UText                 *dest);
1044 
1045 
1046 
1047  /**
1048    * Split a string into fields.  Somewhat like split() from Perl.
1049    *  The pattern matches identify delimiters that separate the input
1050    *  into fields.  The input data between the matches becomes the
1051    *  fields themselves.
1052    * <p>
1053    *  Each of the fields is copied from the input string to the destination
1054    *  buffer, and NUL terminated.  The position of each field within
1055    *  the destination buffer is returned in the destFields array.
1056    *
1057    *  Note:  another choice for the design of this function would be to not
1058    *         copy the resulting fields at all, but to return indexes and
1059    *         lengths within the source text.
1060    *           Advantages would be
1061    *             o  Faster.  No Copying.
1062    *             o  Nothing extra needed when field data may contain embedded NUL chars.
1063    *             o  Less memory needed if working on large data.
1064    *           Disadvantages
1065    *             o  Less consistent with C++ split, which copies into an
1066    *                array of UnicodeStrings.
1067    *             o  No NUL termination, extracted fields would be less convenient
1068    *                to use in most cases.
1069    *             o  Possible problems in the future, when support Unicode Normalization
1070    *                could cause the fields to not correspond exactly to
1071    *                a range of the source text.
1072    *
1073    *    @param   regexp      The compiled regular expression.
1074    *    @param   destBuf     A (UChar *) buffer to receive the fields that
1075    *                         are extracted from the input string. These
1076    *                         field pointers will refer to positions within the
1077    *                         destination buffer supplied by the caller.  Any
1078    *                         extra positions within the destFields array will be
1079    *                         set to NULL.
1080    *    @param   destCapacity The capacity of the destBuf.
1081    *    @param   requiredCapacity  The actual capacity required of the destBuf.
1082    *                         If destCapacity is too small, requiredCapacity will return
1083    *                         the total capacity required to hold all of the output, and
1084    *                         a U_BUFFER_OVERFLOW_ERROR will be returned.
1085    *    @param   destFields  An array to be filled with the position of each
1086    *                         of the extracted fields within destBuf.
1087    *    @param   destFieldsCapacity  The number of elements in the destFields array.
1088    *                If the number of fields found is less than destFieldsCapacity,
1089    *                the extra destFields elements are set to zero.
1090    *                If destFieldsCapacity is too small, the trailing part of the
1091    *                input, including any field delimiters, is treated as if it
1092    *                were the last field - it is copied to the destBuf, and
1093    *                its position is in the destBuf is stored in the last element
1094    *                of destFields.  This behavior mimics that of Perl.  It is not
1095    *                an error condition, and no error status is returned when all destField
1096    *                positions are used.
1097    * @param status  A reference to a UErrorCode to receive any errors.
1098    * @return        The number of fields into which the input string was split.
1099    * @stable ICU 3.0
1100    */
1101 U_STABLE int32_t U_EXPORT2
1102 uregex_split(   URegularExpression      *regexp,
1103                   UChar                 *destBuf,
1104                   int32_t                destCapacity,
1105                   int32_t               *requiredCapacity,
1106                   UChar                 *destFields[],
1107                   int32_t                destFieldsCapacity,
1108                   UErrorCode            *status);
1109 
1110 
1111   /**
1112    * Split a string into fields.  Somewhat like split() from Perl.
1113    * The pattern matches identify delimiters that separate the input
1114    *  into fields.  The input data between the matches becomes the
1115    *  fields themselves.
1116    * <p>
1117    * The behavior of this function is not very closely aligned with uregex_split();
1118    * instead, it is based on (and implemented directly on top of) the C++ split method.
1119    *
1120    * @param regexp  The compiled regular expression.
1121    * @param destFields    An array of mutable UText structs to receive the results of the split.
1122    *                If a field is NULL, a new UText is allocated to contain the results for
1123    *                that field. This new UText is not guaranteed to be mutable.
1124    * @param destFieldsCapacity  The number of elements in the destination array.
1125    *                If the number of fields found is less than destCapacity, the
1126    *                extra strings in the destination array are not altered.
1127    *                If the number of destination strings is less than the number
1128    *                of fields, the trailing part of the input string, including any
1129    *                field delimiters, is placed in the last destination string.
1130    *                This behavior mimics that of Perl.  It is not  an error condition, and no
1131    *                error status is returned when all destField positions are used.
1132    * @param status  A reference to a UErrorCode to receive any errors.
1133    * @return        The number of fields into which the input string was split.
1134    *
1135    * @internal ICU 4.4 technology preview
1136    */
1137 U_INTERNAL int32_t U_EXPORT2
1138 uregex_splitUText(URegularExpression    *regexp,
1139                   UText                 *destFields[],
1140                   int32_t                destFieldsCapacity,
1141                   UErrorCode            *status);
1142 
1143 
1144 
1145 
1146 /**
1147  * Set a processing time limit for match operations with this URegularExpression.
1148  *
1149  * Some patterns, when matching certain strings, can run in exponential time.
1150  * For practical purposes, the match operation may appear to be in an
1151  * infinite loop.
1152  * When a limit is set a match operation will fail with an error if the
1153  * limit is exceeded.
1154  * <p>
1155  * The units of the limit are steps of the match engine.
1156  * Correspondence with actual processor time will depend on the speed
1157  * of the processor and the details of the specific pattern, but will
1158  * typically be on the order of milliseconds.
1159  * <p>
1160  * By default, the matching time is not limited.
1161  * <p>
1162  *
1163  * @param   regexp      The compiled regular expression.
1164  * @param   limit       The limit value, or 0 for no limit.
1165  * @param   status      A reference to a UErrorCode to receive any errors.
1166  * @stable ICU 4.0
1167  */
1168 U_STABLE void U_EXPORT2
1169 uregex_setTimeLimit(URegularExpression      *regexp,
1170                     int32_t                  limit,
1171                     UErrorCode              *status);
1172 
1173 /**
1174  * Get the time limit for for matches with this URegularExpression.
1175  * A return value of zero indicates that there is no limit.
1176  *
1177  * @param   regexp      The compiled regular expression.
1178  * @param   status      A reference to a UErrorCode to receive any errors.
1179  * @return the maximum allowed time for a match, in units of processing steps.
1180  * @stable ICU 4.0
1181  */
1182 U_STABLE int32_t U_EXPORT2
1183 uregex_getTimeLimit(const URegularExpression      *regexp,
1184                           UErrorCode              *status);
1185 
1186 /**
1187  * Set the amount of heap storage avaliable for use by the match backtracking stack.
1188  * <p>
1189  * ICU uses a backtracking regular expression engine, with the backtrack stack
1190  * maintained on the heap.  This function sets the limit to the amount of memory
1191  * that can be used  for this purpose.  A backtracking stack overflow will
1192  * result in an error from the match operation that caused it.
1193  * <p>
1194  * A limit is desirable because a malicious or poorly designed pattern can use
1195  * excessive memory, potentially crashing the process.  A limit is enabled
1196  * by default.
1197  * <p>
1198  * @param   regexp      The compiled regular expression.
1199  * @param   limit       The maximum size, in bytes, of the matching backtrack stack.
1200  *                      A value of -1 means no limit.
1201  *                      The limit must be greater than zero, or -1.
1202  * @param   status      A reference to a UErrorCode to receive any errors.
1203  *
1204  * @stable ICU 4.0
1205  */
1206 U_STABLE void U_EXPORT2
1207 uregex_setStackLimit(URegularExpression      *regexp,
1208                      int32_t                  limit,
1209                      UErrorCode              *status);
1210 
1211 /**
1212  * Get the size of the heap storage available for use by the back tracking stack.
1213  *
1214  * @return  the maximum backtracking stack size, in bytes, or zero if the
1215  *          stack size is unlimited.
1216  * @stable ICU 4.0
1217  */
1218 U_STABLE int32_t U_EXPORT2
1219 uregex_getStackLimit(const URegularExpression      *regexp,
1220                            UErrorCode              *status);
1221 
1222 
1223 /**
1224  * Function pointer for a regular expression matching callback function.
1225  * When set, a callback function will be called periodically during matching
1226  * operations.  If the call back function returns FALSE, the matching
1227  * operation will be terminated early.
1228  *
1229  * Note:  the callback function must not call other functions on this
1230  *        URegularExpression.
1231  *
1232  * @param context  context pointer.  The callback function will be invoked
1233  *                 with the context specified at the time that
1234  *                 uregex_setMatchCallback() is called.
1235  * @param steps    the accumulated processing time, in match steps,
1236  *                 for this matching operation.
1237  * @return         TRUE to continue the matching operation.
1238  *                 FALSE to terminate the matching operation.
1239  * @stable ICU 4.0
1240  */
1241 U_CDECL_BEGIN
1242 typedef UBool U_CALLCONV URegexMatchCallback (
1243                    const void *context,
1244                    int32_t     steps);
1245 U_CDECL_END
1246 
1247 /**
1248  * Set a callback function for this URegularExpression.
1249  * During matching operations the function will be called periodically,
1250  * giving the application the opportunity to terminate a long-running
1251  * match.
1252  *
1253  * @param   regexp      The compiled regular expression.
1254  * @param   callback    A pointer to the user-supplied callback function.
1255  * @param   context     User context pointer.  The value supplied at the
1256  *                      time the callback function is set will be saved
1257  *                      and passed to the callback each time that it is called.
1258  * @param   status      A reference to a UErrorCode to receive any errors.
1259  * @stable ICU 4.0
1260  */
1261 U_STABLE void U_EXPORT2
1262 uregex_setMatchCallback(URegularExpression      *regexp,
1263                         URegexMatchCallback     *callback,
1264                         const void              *context,
1265                         UErrorCode              *status);
1266 
1267 
1268 /**
1269  *  Get the callback function for this URegularExpression.
1270  *
1271  * @param   regexp      The compiled regular expression.
1272  * @param   callback    Out paramater, receives a pointer to the user-supplied
1273  *                      callback function.
1274  * @param   context     Out parameter, receives the user context pointer that
1275  *                      was set when uregex_setMatchCallback() was called.
1276  * @param   status      A reference to a UErrorCode to receive any errors.
1277  * @stable ICU 4.0
1278  */
1279 U_STABLE void U_EXPORT2
1280 uregex_getMatchCallback(const URegularExpression    *regexp,
1281                         URegexMatchCallback        **callback,
1282                         const void                 **context,
1283                         UErrorCode                  *status);
1284 
1285 
1286 
1287 #endif   /*  !UCONFIG_NO_REGULAR_EXPRESSIONS  */
1288 #endif   /*  UREGEX_H  */
1289