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      1 /*
      2 **********************************************************************
      3 *   Copyright (C) 2004-2013, 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 /* U_HIDE_DRAFT_API */
     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.
     68       *
     69       *  The flag UREGEX_CASE_INSENSITIVE retains its impact
     70       *  on matching when used in conjunction with this flag.
     71       *  The other flags become superfluous.
     72       *
     73       * @stable ICU 4.0
     74       */
     75     UREGEX_LITERAL = 16,
     76 
     77     /**   Control behavior of "$" and "^"
     78       *    If set, recognize line terminators within string,
     79       *    otherwise, match only at start and end of input string.
     80       *   @stable ICU 2.4 */
     81     UREGEX_MULTILINE        = 8,
     82 
     83     /**   Unix-only line endings.
     84       *   When this mode is enabled, only \\u000a is recognized as a line ending
     85       *    in the behavior of ., ^, and $.
     86       *   @stable ICU 4.0
     87       */
     88     UREGEX_UNIX_LINES = 1,
     89 
     90     /**  Unicode word boundaries.
     91       *     If set, \b uses the Unicode TR 29 definition of word boundaries.
     92       *     Warning: Unicode word boundaries are quite different from
     93       *     traditional regular expression word boundaries.  See
     94       *     http://unicode.org/reports/tr29/#Word_Boundaries
     95       *     @stable ICU 2.8
     96       */
     97     UREGEX_UWORD            = 256,
     98 
     99      /**  Error on Unrecognized backslash escapes.
    100        *     If set, fail with an error on patterns that contain
    101        *     backslash-escaped ASCII letters without a known special
    102        *     meaning.  If this flag is not set, these
    103        *     escaped letters represent themselves.
    104        *     @stable ICU 4.0
    105        */
    106      UREGEX_ERROR_ON_UNKNOWN_ESCAPES = 512
    107 
    108 }  URegexpFlag;
    109 
    110 /**
    111   *  Open (compile) an ICU regular expression.  Compiles the regular expression in
    112   *  string form into an internal representation using the specified match mode flags.
    113   *  The resulting regular expression handle can then be used to perform various
    114   *   matching operations.
    115   *
    116   *
    117   * @param pattern        The Regular Expression pattern to be compiled.
    118   * @param patternLength  The length of the pattern, or -1 if the pattern is
    119   *                       NUL terminated.
    120   * @param flags          Flags that alter the default matching behavior for
    121   *                       the regular expression, UREGEX_CASE_INSENSITIVE, for
    122   *                       example.  For default behavior, set this parameter to zero.
    123   *                       See <code>enum URegexpFlag</code>.  All desired flags
    124   *                       are bitwise-ORed together.
    125   * @param pe             Receives the position (line and column numbers) of any syntax
    126   *                       error within the source regular expression string.  If this
    127   *                       information is not wanted, pass NULL for this parameter.
    128   * @param status         Receives error detected by this function.
    129   * @stable ICU 3.0
    130   *
    131   */
    132 U_STABLE URegularExpression * U_EXPORT2
    133 uregex_open( const  UChar          *pattern,
    134                     int32_t         patternLength,
    135                     uint32_t        flags,
    136                     UParseError    *pe,
    137                     UErrorCode     *status);
    138 
    139 /**
    140   *  Open (compile) an ICU regular expression.  Compiles the regular expression in
    141   *  string form into an internal representation using the specified match mode flags.
    142   *  The resulting regular expression handle can then be used to perform various
    143   *   matching operations.
    144   *  <p>
    145   *  The contents of the pattern UText will be extracted and saved. Ownership of the
    146   *   UText struct itself remains with the caller. This is to match the behavior of
    147   *   uregex_open().
    148   *
    149   * @param pattern        The Regular Expression pattern to be compiled.
    150   * @param flags          Flags that alter the default matching behavior for
    151   *                       the regular expression, UREGEX_CASE_INSENSITIVE, for
    152   *                       example.  For default behavior, set this parameter to zero.
    153   *                       See <code>enum URegexpFlag</code>.  All desired flags
    154   *                       are bitwise-ORed together.
    155   * @param pe             Receives the position (line and column numbers) of any syntax
    156   *                       error within the source regular expression string.  If this
    157   *                       information is not wanted, pass NULL for this parameter.
    158   * @param status         Receives error detected by this function.
    159   *
    160   * @stable ICU 4.6
    161   */
    162 U_STABLE URegularExpression *  U_EXPORT2
    163 uregex_openUText(UText          *pattern,
    164                  uint32_t        flags,
    165                  UParseError    *pe,
    166                  UErrorCode     *status);
    167 
    168 /**
    169   *  Open (compile) an ICU regular expression.  The resulting regular expression
    170   *   handle can then be used to perform various matching operations.
    171   *  <p>
    172   *   This function is the same as uregex_open, except that the pattern
    173   *   is supplied as an 8 bit char * string in the default code page.
    174   *
    175   * @param pattern        The Regular Expression pattern to be compiled,
    176   *                       NUL terminated.
    177   * @param flags          Flags that alter the default matching behavior for
    178   *                       the regular expression, UREGEX_CASE_INSENSITIVE, for
    179   *                       example.  For default behavior, set this parameter to zero.
    180   *                       See <code>enum URegexpFlag</code>.  All desired flags
    181   *                       are bitwise-ORed together.
    182   * @param pe             Receives the position (line and column numbers) of any syntax
    183   *                       error within the source regular expression string.  If this
    184   *                       information is not wanted, pass NULL for this parameter.
    185   * @param status         Receives errors detected by this function.
    186   * @return               The URegularExpression object representing the compiled
    187   *                       pattern.
    188   *
    189   * @stable ICU 3.0
    190   */
    191 #if !UCONFIG_NO_CONVERSION
    192 U_STABLE URegularExpression * U_EXPORT2
    193 uregex_openC( const char           *pattern,
    194                     uint32_t        flags,
    195                     UParseError    *pe,
    196                     UErrorCode     *status);
    197 #endif
    198 
    199 
    200 
    201 /**
    202   *  Close the regular expression, recovering all resources (memory) it
    203   *   was holding.
    204   *
    205   * @param regexp   The regular expression to be closed.
    206   * @stable ICU 3.0
    207   */
    208 U_STABLE void U_EXPORT2
    209 uregex_close(URegularExpression *regexp);
    210 
    211 #if U_SHOW_CPLUSPLUS_API
    212 
    213 U_NAMESPACE_BEGIN
    214 
    215 /**
    216  * \class LocalURegularExpressionPointer
    217  * "Smart pointer" class, closes a URegularExpression via uregex_close().
    218  * For most methods see the LocalPointerBase base class.
    219  *
    220  * @see LocalPointerBase
    221  * @see LocalPointer
    222  * @stable ICU 4.4
    223  */
    224 U_DEFINE_LOCAL_OPEN_POINTER(LocalURegularExpressionPointer, URegularExpression, uregex_close);
    225 
    226 U_NAMESPACE_END
    227 
    228 #endif
    229 
    230 /**
    231  * Make a copy of a compiled regular expression.  Cloning a regular
    232  * expression is faster than opening a second instance from the source
    233  * form of the expression, and requires less memory.
    234  * <p>
    235  * Note that the current input string and the position of any matched text
    236  *  within it are not cloned; only the pattern itself and the
    237  *  match mode flags are copied.
    238  * <p>
    239  * Cloning can be particularly useful to threaded applications that perform
    240  * multiple match operations in parallel.  Each concurrent RE
    241  * operation requires its own instance of a URegularExpression.
    242  *
    243  * @param regexp   The compiled regular expression to be cloned.
    244  * @param status   Receives indication of any errors encountered
    245  * @return the cloned copy of the compiled regular expression.
    246  * @stable ICU 3.0
    247  */
    248 U_STABLE URegularExpression * U_EXPORT2
    249 uregex_clone(const URegularExpression *regexp, UErrorCode *status);
    250 
    251 /**
    252  *  Returns a pointer to the source form of the pattern for this regular expression.
    253  *  This function will work even if the pattern was originally specified as a UText.
    254  *
    255  * @param regexp     The compiled regular expression.
    256  * @param patLength  This output parameter will be set to the length of the
    257  *                   pattern string.  A NULL pointer may be used here if the
    258  *                   pattern length is not needed, as would be the case if
    259  *                   the pattern is known in advance to be a NUL terminated
    260  *                   string.
    261  * @param status     Receives errors detected by this function.
    262  * @return a pointer to the pattern string.  The storage for the string is
    263  *                   owned by the regular expression object, and must not be
    264  *                   altered or deleted by the application.  The returned string
    265  *                   will remain valid until the regular expression is closed.
    266  * @stable ICU 3.0
    267  */
    268 U_STABLE const UChar * U_EXPORT2
    269 uregex_pattern(const URegularExpression *regexp,
    270                      int32_t            *patLength,
    271                      UErrorCode         *status);
    272 
    273 /**
    274  *  Returns the source text of the pattern for this regular expression.
    275  *  This function will work even if the pattern was originally specified as a UChar string.
    276  *
    277  * @param regexp     The compiled regular expression.
    278  * @param status     Receives errors detected by this function.
    279  * @return the pattern text.  The storage for the text is owned by the regular expression
    280  *                   object, and must not be altered or deleted.
    281  *
    282  * @stable ICU 4.6
    283  */
    284 U_STABLE UText * U_EXPORT2
    285 uregex_patternUText(const URegularExpression *regexp,
    286                           UErrorCode         *status);
    287 
    288 /**
    289   * Get the match mode flags that were specified when compiling this regular expression.
    290   * @param status   Receives errors detected by this function.
    291   * @param regexp   The compiled regular expression.
    292   * @return         The match mode flags
    293   * @see URegexpFlag
    294   * @stable ICU 3.0
    295   */
    296 U_STABLE int32_t U_EXPORT2
    297 uregex_flags(const  URegularExpression   *regexp,
    298                     UErrorCode           *status);
    299 
    300 
    301 /**
    302   *  Set the subject text string upon which the regular expression will look for matches.
    303   *  This function may be called any number of times, allowing the regular
    304   *  expression pattern to be applied to different strings.
    305   *  <p>
    306   *  Regular expression matching operations work directly on the application's
    307   *  string data.  No copy is made.  The subject string data must not be
    308   *  altered after calling this function until after all regular expression
    309   *  operations involving this string data are completed.
    310   *  <p>
    311   *  Zero length strings are permitted.  In this case, no subsequent match
    312   *  operation will dereference the text string pointer.
    313   *
    314   * @param regexp     The compiled regular expression.
    315   * @param text       The subject text string.
    316   * @param textLength The length of the subject text, or -1 if the string
    317   *                   is NUL terminated.
    318   * @param status     Receives errors detected by this function.
    319   * @stable ICU 3.0
    320   */
    321 U_STABLE void U_EXPORT2
    322 uregex_setText(URegularExpression *regexp,
    323                const UChar        *text,
    324                int32_t             textLength,
    325                UErrorCode         *status);
    326 
    327 
    328 /**
    329   *  Set the subject text string upon which the regular expression will look for matches.
    330   *  This function may be called any number of times, allowing the regular
    331   *  expression pattern to be applied to different strings.
    332   *  <p>
    333   *  Regular expression matching operations work directly on the application's
    334   *  string data; only a shallow clone is made.  The subject string data must not be
    335   *  altered after calling this function until after all regular expression
    336   *  operations involving this string data are completed.
    337   *
    338   * @param regexp     The compiled regular expression.
    339   * @param text       The subject text string.
    340   * @param status     Receives errors detected by this function.
    341   *
    342   * @stable ICU 4.6
    343   */
    344 U_STABLE void U_EXPORT2
    345 uregex_setUText(URegularExpression *regexp,
    346                 UText              *text,
    347                 UErrorCode         *status);
    348 
    349 /**
    350   *  Get the subject text that is currently associated with this
    351   *   regular expression object.  If the input was supplied using uregex_setText(),
    352   *   that pointer will be returned.  Otherwise, the characters in the input will
    353   *   be extracted to a buffer and returned.  In either case, ownership remains
    354   *   with the regular expression object.
    355   *
    356   *  This function will work even if the input was originally specified as a UText.
    357   *
    358   * @param regexp      The compiled regular expression.
    359   * @param textLength  The length of the string is returned in this output parameter.
    360   *                    A NULL pointer may be used here if the
    361   *                    text length is not needed, as would be the case if
    362   *                    the text is known in advance to be a NUL terminated
    363   *                    string.
    364   * @param status      Receives errors detected by this function.
    365   * @return            Pointer to the subject text string currently associated with
    366   *                    this regular expression.
    367   * @stable ICU 3.0
    368   */
    369 U_STABLE const UChar * U_EXPORT2
    370 uregex_getText(URegularExpression *regexp,
    371                int32_t            *textLength,
    372                UErrorCode         *status);
    373 
    374 /**
    375   *  Get the subject text that is currently associated with this
    376   *   regular expression object.
    377   *
    378   *  This function will work even if the input was originally specified as a UChar string.
    379   *
    380   * @param regexp      The compiled regular expression.
    381   * @param dest        A mutable UText in which to store the current input.
    382   *                    If NULL, a new UText will be created as an immutable shallow clone
    383   *                    of the actual input string.
    384   * @param status      Receives errors detected by this function.
    385   * @return            The subject text currently associated with this regular expression.
    386   *                    If a pre-allocated UText was provided, it will always be used and returned.
    387   *
    388   * @stable ICU 4.6
    389   */
    390 U_STABLE UText * U_EXPORT2
    391 uregex_getUText(URegularExpression *regexp,
    392                 UText              *dest,
    393                 UErrorCode         *status);
    394 
    395 /**
    396   *  Set the subject text string upon which the regular expression is looking for matches
    397   *  without changing any other aspect of the matching state.
    398   *  The new and previous text strings must have the same content.
    399   *
    400   *  This function is intended for use in environments where ICU is operating on
    401   *  strings that may move around in memory.  It provides a mechanism for notifying
    402   *  ICU that the string has been relocated, and providing a new UText to access the
    403   *  string in its new position.
    404   *
    405   *  Note that the regular expression implementation never copies the underlying text
    406   *  of a string being matched, but always operates directly on the original text
    407   *  provided by the user. Refreshing simply drops the references to the old text
    408   *  and replaces them with references to the new.
    409   *
    410   *  Caution:  this function is normally used only by very specialized
    411   *            system-level code.   One example use case is with garbage collection
    412   *            that moves the text in memory.
    413   *
    414   * @param regexp     The compiled regular expression.
    415   * @param text       The new (moved) text string.
    416   * @param status     Receives errors detected by this function.
    417   *
    418   * @stable ICU 4.8
    419   */
    420 U_STABLE void U_EXPORT2
    421 uregex_refreshUText(URegularExpression *regexp,
    422                     UText              *text,
    423                     UErrorCode         *status);
    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 (native) 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   *   64bit version of uregex_matches.
    452   *   Attempts to match the input string against the pattern.
    453   *   To succeed, the match must extend to the end of the string,
    454   *   or cover the complete match region.
    455   *
    456   *   If startIndex >= zero the match operation starts at the specified
    457   *   index and must extend to the end of the input string.  Any region
    458   *   that has been specified is reset.
    459   *
    460   *   If startIndex == -1 the match must cover the input region, or the entire
    461   *   input string if no region has been set.  This directly corresponds to
    462   *   Matcher.matches() in Java
    463   *
    464   *    @param  regexp      The compiled regular expression.
    465   *    @param  startIndex  The input string (native) index at which to begin matching, or -1
    466   *                        to match the input Region.
    467   *    @param  status      Receives errors detected by this function.
    468   *    @return             TRUE if there is a match
    469   *   @stable ICU 4.6
    470   */
    471 U_STABLE UBool U_EXPORT2
    472 uregex_matches64(URegularExpression *regexp,
    473                  int64_t            startIndex,
    474                  UErrorCode        *status);
    475 
    476 /**
    477   *   Attempts to match the input string, starting from the specified index, against the pattern.
    478   *   The match may be of any length, and is not required to extend to the end
    479   *   of the input string.  Contrast with uregex_matches().
    480   *
    481   *   <p>If startIndex is >= 0 any input region that was set for this
    482   *   URegularExpression is reset before the operation begins.
    483   *
    484   *   <p>If the specified starting index == -1 the match begins at the start of the input
    485   *   region, or at the start of the full string if no region has been specified.
    486   *   This corresponds directly with Matcher.lookingAt() in Java.
    487   *
    488   *   <p>If the match succeeds then more information can be obtained via the
    489   *    <code>uregexp_start()</code>, <code>uregexp_end()</code>,
    490   *    and <code>uregexp_group()</code> functions.</p>
    491   *
    492   *    @param   regexp      The compiled regular expression.
    493   *    @param   startIndex  The input string (native) index at which to begin matching, or
    494   *                         -1 to match the Input Region
    495   *    @param   status      A reference to a UErrorCode to receive any errors.
    496   *    @return  TRUE if there is a match.
    497   *    @stable ICU 3.0
    498   */
    499 U_STABLE UBool U_EXPORT2
    500 uregex_lookingAt(URegularExpression *regexp,
    501                  int32_t             startIndex,
    502                  UErrorCode         *status);
    503 
    504 /**
    505   *   64bit version of uregex_lookingAt.
    506   *   Attempts to match the input string, starting from the specified index, against the pattern.
    507   *   The match may be of any length, and is not required to extend to the end
    508   *   of the input string.  Contrast with uregex_matches().
    509   *
    510   *   <p>If startIndex is >= 0 any input region that was set for this
    511   *   URegularExpression is reset before the operation begins.
    512   *
    513   *   <p>If the specified starting index == -1 the match begins at the start of the input
    514   *   region, or at the start of the full string if no region has been specified.
    515   *   This corresponds directly with Matcher.lookingAt() in Java.
    516   *
    517   *   <p>If the match succeeds then more information can be obtained via the
    518   *    <code>uregexp_start()</code>, <code>uregexp_end()</code>,
    519   *    and <code>uregexp_group()</code> functions.</p>
    520   *
    521   *    @param   regexp      The compiled regular expression.
    522   *    @param   startIndex  The input string (native) index at which to begin matching, or
    523   *                         -1 to match the Input Region
    524   *    @param   status      A reference to a UErrorCode to receive any errors.
    525   *    @return  TRUE if there is a match.
    526   *    @stable ICU 4.6
    527   */
    528 U_STABLE UBool U_EXPORT2
    529 uregex_lookingAt64(URegularExpression *regexp,
    530                    int64_t             startIndex,
    531                    UErrorCode         *status);
    532 
    533 /**
    534   *   Find the first matching substring of the input string that matches the pattern.
    535   *   If startIndex is >= zero the search for a match begins at the specified index,
    536   *          and any match region is reset.  This corresponds directly with
    537   *          Matcher.find(startIndex) in Java.
    538   *
    539   *   If startIndex == -1 the search begins at the start of the input region,
    540   *           or at the start of the full string if no region has been specified.
    541   *
    542   *   If a match is found, <code>uregex_start(), uregex_end()</code>, and
    543   *   <code>uregex_group()</code> will provide more information regarding the match.
    544   *
    545   *   @param   regexp      The compiled regular expression.
    546   *   @param   startIndex  The position (native) in the input string to begin the search, or
    547   *                        -1 to search within the Input Region.
    548   *   @param   status      A reference to a UErrorCode to receive any errors.
    549   *   @return              TRUE if a match is found.
    550   *   @stable ICU 3.0
    551   */
    552 U_STABLE UBool U_EXPORT2
    553 uregex_find(URegularExpression *regexp,
    554             int32_t             startIndex,
    555             UErrorCode         *status);
    556 
    557 /**
    558   *   64bit version of uregex_find.
    559   *   Find the first matching substring of the input string that matches the pattern.
    560   *   If startIndex is >= zero the search for a match begins at the specified index,
    561   *          and any match region is reset.  This corresponds directly with
    562   *          Matcher.find(startIndex) in Java.
    563   *
    564   *   If startIndex == -1 the search begins at the start of the input region,
    565   *           or at the start of the full string if no region has been specified.
    566   *
    567   *   If a match is found, <code>uregex_start(), uregex_end()</code>, and
    568   *   <code>uregex_group()</code> will provide more information regarding the match.
    569   *
    570   *   @param   regexp      The compiled regular expression.
    571   *   @param   startIndex  The position (native) in the input string to begin the search, or
    572   *                        -1 to search within the Input Region.
    573   *   @param   status      A reference to a UErrorCode to receive any errors.
    574   *   @return              TRUE if a match is found.
    575   *   @stable ICU 4.6
    576   */
    577 U_STABLE UBool U_EXPORT2
    578 uregex_find64(URegularExpression *regexp,
    579               int64_t             startIndex,
    580               UErrorCode         *status);
    581 
    582 /**
    583   *  Find the next pattern match in the input string.  Begin searching
    584   *  the input at the location following the end of he previous match,
    585   *  or at the start of the string (or region) if there is no
    586   *  previous match.  If a match is found, <code>uregex_start(), uregex_end()</code>, and
    587   *  <code>uregex_group()</code> will provide more information regarding the match.
    588   *
    589   *  @param   regexp      The compiled regular expression.
    590   *  @param   status      A reference to a UErrorCode to receive any errors.
    591   *  @return              TRUE if a match is found.
    592   *  @see uregex_reset
    593   *  @stable ICU 3.0
    594   */
    595 U_STABLE UBool U_EXPORT2
    596 uregex_findNext(URegularExpression *regexp,
    597                 UErrorCode         *status);
    598 
    599 /**
    600   *   Get the number of capturing groups in this regular expression's pattern.
    601   *   @param   regexp      The compiled regular expression.
    602   *   @param   status      A reference to a UErrorCode to receive any errors.
    603   *   @return the number of capture groups
    604   *   @stable ICU 3.0
    605   */
    606 U_STABLE int32_t U_EXPORT2
    607 uregex_groupCount(URegularExpression *regexp,
    608                   UErrorCode         *status);
    609 
    610 /** Extract the string for the specified matching expression or subexpression.
    611   * Group #0 is the complete string of matched text.
    612   * Group #1 is the text matched by the first set of capturing parentheses.
    613   *
    614   *   @param   regexp       The compiled regular expression.
    615   *   @param   groupNum     The capture group to extract.  Group 0 is the complete
    616   *                         match.  The value of this parameter must be
    617   *                         less than or equal to the number of capture groups in
    618   *                         the pattern.
    619   *   @param   dest         Buffer to receive the matching string data
    620   *   @param   destCapacity Capacity of the dest buffer.
    621   *   @param   status       A reference to a UErrorCode to receive any errors.
    622   *   @return               Length of matching data,
    623   *                         or -1 if no applicable match.
    624   *   @stable ICU 3.0
    625   */
    626 U_STABLE int32_t U_EXPORT2
    627 uregex_group(URegularExpression *regexp,
    628              int32_t             groupNum,
    629              UChar              *dest,
    630              int32_t             destCapacity,
    631              UErrorCode          *status);
    632 
    633 /** Returns a shallow immutable clone of the entire input string.  The returned UText current native index
    634   *   is set to the beginning of the requested capture group.  The capture group length is also
    635   *   returned via groupLength.
    636   * Group #0 is the complete string of matched text.
    637   * Group #1 is the text matched by the first set of capturing parentheses.
    638   *
    639   *   @param   regexp       The compiled regular expression.
    640   *   @param   groupNum     The capture group to extract.  Group 0 is the complete
    641   *                         match.  The value of this parameter must be
    642   *                         less than or equal to the number of capture groups in
    643   *                         the pattern.
    644   *   @param   dest         A mutable UText in which to store the current input.
    645   *                         If NULL, a new UText will be created as an immutable shallow clone
    646   *                         of the entire input string.
    647   *   @param   groupLength  The group length of the desired capture group.
    648   *   @param   status       A reference to a UErrorCode to receive any errors.
    649   *   @return               The subject text currently associated with this regular expression.
    650   *                         If a pre-allocated UText was provided, it will always be used and returned.
    651 
    652   *
    653   *   @stable ICU 4.6
    654   */
    655 U_STABLE UText * U_EXPORT2
    656 uregex_groupUText(URegularExpression *regexp,
    657                   int32_t             groupNum,
    658                   UText              *dest,
    659                   int64_t            *groupLength,
    660                   UErrorCode         *status);
    661 
    662 #ifndef U_HIDE_INTERNAL_API
    663 /** Extract the string for the specified matching expression or subexpression.
    664   * Group #0 is the complete string of matched text.
    665   * Group #1 is the text matched by the first set of capturing parentheses.
    666   *
    667   *   @param   regexp       The compiled regular expression.
    668   *   @param   groupNum     The capture group to extract.  Group 0 is the complete
    669   *                         match.  The value of this parameter must be
    670   *                         less than or equal to the number of capture groups in
    671   *                         the pattern.
    672   *   @param   dest         Mutable UText to receive the matching string data.
    673   *                         If NULL, a new UText will be created (which may not be mutable).
    674   *   @param   status       A reference to a UErrorCode to receive any errors.
    675   *   @return               The matching string data. If a pre-allocated UText was provided,
    676   *                          it will always be used and returned.
    677   *
    678   *   @internal ICU 4.4 technology preview
    679   */
    680 U_INTERNAL UText * U_EXPORT2
    681 uregex_groupUTextDeep(URegularExpression *regexp,
    682                   int32_t             groupNum,
    683                   UText              *dest,
    684                   UErrorCode         *status);
    685 #endif  /* U_HIDE_INTERNAL_API */
    686 
    687 /**
    688   *   Returns the index in the input string of the start of the text matched by the
    689   *   specified capture group during the previous match operation.  Return -1 if
    690   *   the capture group was not part of the last match.
    691   *   Group #0 refers to the complete range of matched text.
    692   *   Group #1 refers to the text matched by the first set of capturing parentheses.
    693   *
    694   *    @param   regexp      The compiled regular expression.
    695   *    @param   groupNum    The capture group number
    696   *    @param   status      A reference to a UErrorCode to receive any errors.
    697   *    @return              the starting (native) position in the input of the text matched
    698   *                         by the specified group.
    699   *    @stable ICU 3.0
    700   */
    701 U_STABLE int32_t U_EXPORT2
    702 uregex_start(URegularExpression *regexp,
    703              int32_t             groupNum,
    704              UErrorCode          *status);
    705 
    706 /**
    707   *   64bit version of uregex_start.
    708   *   Returns the index in the input string of the start of the text matched by the
    709   *   specified capture group during the previous match operation.  Return -1 if
    710   *   the capture group was not part of the last match.
    711   *   Group #0 refers to the complete range of matched text.
    712   *   Group #1 refers to the text matched by the first set of capturing parentheses.
    713   *
    714   *    @param   regexp      The compiled regular expression.
    715   *    @param   groupNum    The capture group number
    716   *    @param   status      A reference to a UErrorCode to receive any errors.
    717   *    @return              the starting (native) position in the input of the text matched
    718   *                         by the specified group.
    719   *   @stable ICU 4.6
    720   */
    721 U_STABLE int64_t U_EXPORT2
    722 uregex_start64(URegularExpression *regexp,
    723                int32_t             groupNum,
    724                UErrorCode          *status);
    725 
    726 /**
    727   *   Returns the index in the input string of the position following the end
    728   *   of the text matched by the specified capture group.
    729   *   Return -1 if the capture group was not part of the last match.
    730   *   Group #0 refers to the complete range of matched text.
    731   *   Group #1 refers to the text matched by the first set of capturing parentheses.
    732   *
    733   *    @param   regexp      The compiled regular expression.
    734   *    @param   groupNum    The capture group number
    735   *    @param   status      A reference to a UErrorCode to receive any errors.
    736   *    @return              the (native) index of the position following the last matched character.
    737   *    @stable ICU 3.0
    738   */
    739 U_STABLE int32_t U_EXPORT2
    740 uregex_end(URegularExpression   *regexp,
    741            int32_t               groupNum,
    742            UErrorCode           *status);
    743 
    744 /**
    745   *   64bit version of uregex_end.
    746   *   Returns the index in the input string of the position following the end
    747   *   of the text matched by the specified capture group.
    748   *   Return -1 if the capture group was not part of the last match.
    749   *   Group #0 refers to the complete range of matched text.
    750   *   Group #1 refers to the text matched by the first set of capturing parentheses.
    751   *
    752   *    @param   regexp      The compiled regular expression.
    753   *    @param   groupNum    The capture group number
    754   *    @param   status      A reference to a UErrorCode to receive any errors.
    755   *    @return              the (native) index of the position following the last matched character.
    756   *   @stable ICU 4.6
    757   */
    758 U_STABLE int64_t U_EXPORT2
    759 uregex_end64(URegularExpression *regexp,
    760              int32_t               groupNum,
    761              UErrorCode           *status);
    762 
    763 /**
    764   *  Reset any saved state from the previous match.  Has the effect of
    765   *  causing uregex_findNext to begin at the specified index, and causing
    766   *  uregex_start(), uregex_end() and uregex_group() to return an error
    767   *  indicating that there is no match information available.  Clears any
    768   *  match region that may have been set.
    769   *
    770   *    @param   regexp      The compiled regular expression.
    771   *    @param   index       The position (native) in the text at which a
    772   *                         uregex_findNext() should begin searching.
    773   *    @param   status      A reference to a UErrorCode to receive any errors.
    774   *    @stable ICU 3.0
    775   */
    776 U_STABLE void U_EXPORT2
    777 uregex_reset(URegularExpression    *regexp,
    778              int32_t               index,
    779              UErrorCode            *status);
    780 
    781 /**
    782   *  64bit version of uregex_reset.
    783   *  Reset any saved state from the previous match.  Has the effect of
    784   *  causing uregex_findNext to begin at the specified index, and causing
    785   *  uregex_start(), uregex_end() and uregex_group() to return an error
    786   *  indicating that there is no match information available.  Clears any
    787   *  match region that may have been set.
    788   *
    789   *    @param   regexp      The compiled regular expression.
    790   *    @param   index       The position (native) in the text at which a
    791   *                         uregex_findNext() should begin searching.
    792   *    @param   status      A reference to a UErrorCode to receive any errors.
    793   *    @stable ICU 4.6
    794   */
    795 U_STABLE void U_EXPORT2
    796 uregex_reset64(URegularExpression  *regexp,
    797                int64_t               index,
    798                UErrorCode            *status);
    799 
    800 /**
    801   * Sets the limits of the matching region for this URegularExpression.
    802   * The region is the part of the input string that will be considered when matching.
    803   * Invoking this method resets any saved state from the previous match,
    804   * then sets the region to start at the index specified by the start parameter
    805   * and end at the index specified by the end parameter.
    806   *
    807   * Depending on the transparency and anchoring being used (see useTransparentBounds
    808   * and useAnchoringBounds), certain constructs such as anchors may behave differently
    809   * at or around the boundaries of the region
    810   *
    811   * The function will fail if start is greater than limit, or if either index
    812   *  is less than zero or greater than the length of the string being matched.
    813   *
    814   * @param regexp The compiled regular expression.
    815   * @param regionStart  The (native) index to begin searches at.
    816   * @param regionLimit  The (native) index to end searches at (exclusive).
    817   * @param status A pointer to a UErrorCode to receive any errors.
    818   * @stable ICU 4.0
    819   */
    820 U_STABLE void U_EXPORT2
    821 uregex_setRegion(URegularExpression   *regexp,
    822                  int32_t               regionStart,
    823                  int32_t               regionLimit,
    824                  UErrorCode           *status);
    825 
    826 /**
    827   * 64bit version of uregex_setRegion.
    828   * Sets the limits of the matching region for this URegularExpression.
    829   * The region is the part of the input string that will be considered when matching.
    830   * Invoking this method resets any saved state from the previous match,
    831   * then sets the region to start at the index specified by the start parameter
    832   * and end at the index specified by the end parameter.
    833   *
    834   * Depending on the transparency and anchoring being used (see useTransparentBounds
    835   * and useAnchoringBounds), certain constructs such as anchors may behave differently
    836   * at or around the boundaries of the region
    837   *
    838   * The function will fail if start is greater than limit, or if either index
    839   *  is less than zero or greater than the length of the string being matched.
    840   *
    841   * @param regexp The compiled regular expression.
    842   * @param regionStart  The (native) index to begin searches at.
    843   * @param regionLimit  The (native) index to end searches at (exclusive).
    844   * @param status A pointer to a UErrorCode to receive any errors.
    845   * @stable ICU 4.6
    846   */
    847 U_STABLE void U_EXPORT2
    848 uregex_setRegion64(URegularExpression *regexp,
    849                  int64_t               regionStart,
    850                  int64_t               regionLimit,
    851                  UErrorCode           *status);
    852 
    853 /**
    854   *  Set the matching region and the starting index for subsequent matches
    855   *  in a single operation.
    856   *  This is useful because the usual function for setting the starting
    857   *  index, urgex_reset(), also resets any region limits.
    858   *
    859   * @param regexp The compiled regular expression.
    860   * @param regionStart  The (native) index to begin searches at.
    861   * @param regionLimit  The (native) index to end searches at (exclusive).
    862   * @param startIndex   The index in the input text at which the next
    863   *                     match operation should begin.
    864   * @param status A pointer to a UErrorCode to receive any errors.
    865   * @stable ICU 4.6
    866   */
    867 U_STABLE void U_EXPORT2
    868 uregex_setRegionAndStart(URegularExpression *regexp,
    869                  int64_t               regionStart,
    870                  int64_t               regionLimit,
    871                  int64_t               startIndex,
    872                  UErrorCode           *status);
    873 
    874 /**
    875   * Reports the start index of the matching region. Any matches found are limited to
    876   * to the region bounded by regionStart (inclusive) and regionEnd (exclusive).
    877   *
    878   * @param regexp The compiled regular expression.
    879   * @param status A pointer to a UErrorCode to receive any errors.
    880   * @return The starting (native) index of this matcher's region.
    881   * @stable ICU 4.0
    882   */
    883 U_STABLE int32_t U_EXPORT2
    884 uregex_regionStart(const  URegularExpression   *regexp,
    885                           UErrorCode           *status);
    886 
    887 /**
    888   * 64bit version of uregex_regionStart.
    889   * Reports the start index of the matching region. Any matches found are limited to
    890   * to the region bounded by regionStart (inclusive) and regionEnd (exclusive).
    891   *
    892   * @param regexp The compiled regular expression.
    893   * @param status A pointer to a UErrorCode to receive any errors.
    894   * @return The starting (native) index of this matcher's region.
    895   * @stable ICU 4.6
    896   */
    897 U_STABLE int64_t U_EXPORT2
    898 uregex_regionStart64(const  URegularExpression   *regexp,
    899                             UErrorCode           *status);
    900 
    901 /**
    902   * Reports the end index (exclusive) of the matching region for this URegularExpression.
    903   * Any matches found are limited to to the region bounded by regionStart (inclusive)
    904   * and regionEnd (exclusive).
    905   *
    906   * @param regexp The compiled regular expression.
    907   * @param status A pointer to a UErrorCode to receive any errors.
    908   * @return The ending point (native) of this matcher's region.
    909   * @stable ICU 4.0
    910   */
    911 U_STABLE int32_t U_EXPORT2
    912 uregex_regionEnd(const  URegularExpression   *regexp,
    913                         UErrorCode           *status);
    914 
    915 /**
    916   * 64bit version of uregex_regionEnd.
    917   * Reports the end index (exclusive) of the matching region for this URegularExpression.
    918   * Any matches found are limited to to the region bounded by regionStart (inclusive)
    919   * and regionEnd (exclusive).
    920   *
    921   * @param regexp The compiled regular expression.
    922   * @param status A pointer to a UErrorCode to receive any errors.
    923   * @return The ending point (native) of this matcher's region.
    924   * @stable ICU 4.6
    925   */
    926 U_STABLE int64_t U_EXPORT2
    927 uregex_regionEnd64(const  URegularExpression   *regexp,
    928                           UErrorCode           *status);
    929 
    930 /**
    931   * Queries the transparency of region bounds for this URegularExpression.
    932   * See useTransparentBounds for a description of transparent and opaque bounds.
    933   * By default, matching boundaries are opaque.
    934   *
    935   * @param regexp The compiled regular expression.
    936   * @param status A pointer to a UErrorCode to receive any errors.
    937   * @return TRUE if this matcher is using opaque bounds, false if it is not.
    938   * @stable ICU 4.0
    939   */
    940 U_STABLE UBool U_EXPORT2
    941 uregex_hasTransparentBounds(const  URegularExpression   *regexp,
    942                                    UErrorCode           *status);
    943 
    944 
    945 /**
    946   * Sets the transparency of region bounds for this URegularExpression.
    947   * Invoking this function with an argument of TRUE will set matches to use transparent bounds.
    948   * If the boolean argument is FALSE, then opaque bounds will be used.
    949   *
    950   * Using transparent bounds, the boundaries of the matching region are transparent
    951   * to lookahead, lookbehind, and boundary matching constructs. Those constructs can
    952   * see text beyond the boundaries of the region while checking for a match.
    953   *
    954   * With opaque bounds, no text outside of the matching region is visible to lookahead,
    955   * lookbehind, and boundary matching constructs.
    956   *
    957   * By default, opaque bounds are used.
    958   *
    959   * @param   regexp The compiled regular expression.
    960   * @param   b      TRUE for transparent bounds; FALSE for opaque bounds
    961   * @param   status A pointer to a UErrorCode to receive any errors.
    962   * @stable ICU 4.0
    963   **/
    964 U_STABLE void U_EXPORT2
    965 uregex_useTransparentBounds(URegularExpression   *regexp,
    966                             UBool                b,
    967                             UErrorCode           *status);
    968 
    969 
    970 /**
    971   * Return true if this URegularExpression is using anchoring bounds.
    972   * By default, anchoring region bounds are used.
    973   *
    974   * @param  regexp The compiled regular expression.
    975   * @param  status A pointer to a UErrorCode to receive any errors.
    976   * @return TRUE if this matcher is using anchoring bounds.
    977   * @stable ICU 4.0
    978   */
    979 U_STABLE UBool U_EXPORT2
    980 uregex_hasAnchoringBounds(const  URegularExpression   *regexp,
    981                                  UErrorCode           *status);
    982 
    983 
    984 /**
    985   * Set whether this URegularExpression is using Anchoring Bounds for its region.
    986   * With anchoring bounds, pattern anchors such as ^ and $ will match at the start
    987   * and end of the region.  Without Anchoring Bounds, anchors will only match at
    988   * the positions they would in the complete text.
    989   *
    990   * Anchoring Bounds are the default for regions.
    991   *
    992   * @param regexp The compiled regular expression.
    993   * @param b      TRUE if to enable anchoring bounds; FALSE to disable them.
    994   * @param status A pointer to a UErrorCode to receive any errors.
    995   * @stable ICU 4.0
    996   */
    997 U_STABLE void U_EXPORT2
    998 uregex_useAnchoringBounds(URegularExpression   *regexp,
    999                           UBool                 b,
   1000                           UErrorCode           *status);
   1001 
   1002 /**
   1003   * Return TRUE if the most recent matching operation touched the
   1004   *  end of the text being processed.  In this case, additional input text could
   1005   *  change the results of that match.
   1006   *
   1007   *  @param regexp The compiled regular expression.
   1008   *  @param status A pointer to a UErrorCode to receive any errors.
   1009   *  @return  TRUE if the most recent match hit the end of input
   1010   *  @stable ICU 4.0
   1011   */
   1012 U_STABLE UBool U_EXPORT2
   1013 uregex_hitEnd(const  URegularExpression   *regexp,
   1014                      UErrorCode           *status);
   1015 
   1016 /**
   1017   * Return TRUE the most recent match succeeded and additional input could cause
   1018   * it to fail. If this function returns false and a match was found, then more input
   1019   * might change the match but the match won't be lost. If a match was not found,
   1020   * then requireEnd has no meaning.
   1021   *
   1022   * @param regexp The compiled regular expression.
   1023   * @param status A pointer to a UErrorCode to receive any errors.
   1024   * @return TRUE  if more input could cause the most recent match to no longer match.
   1025   * @stable ICU 4.0
   1026   */
   1027 U_STABLE UBool U_EXPORT2
   1028 uregex_requireEnd(const  URegularExpression   *regexp,
   1029                          UErrorCode           *status);
   1030 
   1031 
   1032 
   1033 
   1034 
   1035 /**
   1036   *    Replaces every substring of the input that matches the pattern
   1037   *    with the given replacement string.  This is a convenience function that
   1038   *    provides a complete find-and-replace-all operation.
   1039   *
   1040   *    This method scans the input string looking for matches of the pattern.
   1041   *    Input that is not part of any match is copied unchanged to the
   1042   *    destination buffer.  Matched regions are replaced in the output
   1043   *    buffer by the replacement string.   The replacement string may contain
   1044   *    references to capture groups; these take the form of $1, $2, etc.
   1045   *
   1046   *    @param   regexp             The compiled regular expression.
   1047   *    @param   replacementText    A string containing the replacement text.
   1048   *    @param   replacementLength  The length of the replacement string, or
   1049   *                                -1 if it is NUL terminated.
   1050   *    @param   destBuf            A (UChar *) buffer that will receive the result.
   1051   *    @param   destCapacity       The capacity of the destination buffer.
   1052   *    @param   status             A reference to a UErrorCode to receive any errors.
   1053   *    @return                     The length of the string resulting from the find
   1054   *                                and replace operation.  In the event that the
   1055   *                                destination capacity is inadequate, the return value
   1056   *                                is still the full length of the untruncated string.
   1057   *    @stable ICU 3.0
   1058   */
   1059 U_STABLE int32_t U_EXPORT2
   1060 uregex_replaceAll(URegularExpression    *regexp,
   1061                   const UChar           *replacementText,
   1062                   int32_t                replacementLength,
   1063                   UChar                 *destBuf,
   1064                   int32_t                destCapacity,
   1065                   UErrorCode            *status);
   1066 
   1067 /**
   1068   *    Replaces every substring of the input that matches the pattern
   1069   *    with the given replacement string.  This is a convenience function that
   1070   *    provides a complete find-and-replace-all operation.
   1071   *
   1072   *    This method scans the input string looking for matches of the pattern.
   1073   *    Input that is not part of any match is copied unchanged to the
   1074   *    destination buffer.  Matched regions are replaced in the output
   1075   *    buffer by the replacement string.   The replacement string may contain
   1076   *    references to capture groups; these take the form of $1, $2, etc.
   1077   *
   1078   *    @param   regexp         The compiled regular expression.
   1079   *    @param   replacement    A string containing the replacement text.
   1080   *    @param   dest           A mutable UText that will receive the result.
   1081   *                             If NULL, a new UText will be created (which may not be mutable).
   1082   *    @param   status         A reference to a UErrorCode to receive any errors.
   1083   *    @return                 A UText containing the results of the find and replace.
   1084   *                             If a pre-allocated UText was provided, it will always be used and returned.
   1085   *
   1086   *    @stable ICU 4.6
   1087   */
   1088 U_STABLE UText * U_EXPORT2
   1089 uregex_replaceAllUText(URegularExpression *regexp,
   1090                        UText              *replacement,
   1091                        UText              *dest,
   1092                        UErrorCode         *status);
   1093 
   1094 /**
   1095   *    Replaces the first substring of the input that matches the pattern
   1096   *    with the given replacement string.  This is a convenience function that
   1097   *    provides a complete find-and-replace operation.
   1098   *
   1099   *    This method scans the input string looking for a match of the pattern.
   1100   *    All input that is not part of the match is copied unchanged to the
   1101   *    destination buffer.  The matched region is replaced in the output
   1102   *    buffer by the replacement string.   The replacement string may contain
   1103   *    references to capture groups; these take the form of $1, $2, etc.
   1104   *
   1105   *    @param   regexp             The compiled regular expression.
   1106   *    @param   replacementText    A string containing the replacement text.
   1107   *    @param   replacementLength  The length of the replacement string, or
   1108   *                                -1 if it is NUL terminated.
   1109   *    @param   destBuf            A (UChar *) buffer that will receive the result.
   1110   *    @param   destCapacity       The capacity of the destination buffer.
   1111   *    @param   status             a reference to a UErrorCode to receive any errors.
   1112   *    @return                     The length of the string resulting from the find
   1113   *                                and replace operation.  In the event that the
   1114   *                                destination capacity is inadequate, the return value
   1115   *                                is still the full length of the untruncated string.
   1116   *    @stable ICU 3.0
   1117   */
   1118 U_STABLE int32_t U_EXPORT2
   1119 uregex_replaceFirst(URegularExpression  *regexp,
   1120                     const UChar         *replacementText,
   1121                     int32_t              replacementLength,
   1122                     UChar               *destBuf,
   1123                     int32_t              destCapacity,
   1124                     UErrorCode          *status);
   1125 
   1126 /**
   1127   *    Replaces the first substring of the input that matches the pattern
   1128   *    with the given replacement string.  This is a convenience function that
   1129   *    provides a complete find-and-replace operation.
   1130   *
   1131   *    This method scans the input string looking for a match of the pattern.
   1132   *    All input that is not part of the match is copied unchanged to the
   1133   *    destination buffer.  The matched region is replaced in the output
   1134   *    buffer by the replacement string.   The replacement string may contain
   1135   *    references to capture groups; these take the form of $1, $2, etc.
   1136   *
   1137   *    @param   regexp         The compiled regular expression.
   1138   *    @param   replacement    A string containing the replacement text.
   1139   *    @param   dest           A mutable UText that will receive the result.
   1140   *                             If NULL, a new UText will be created (which may not be mutable).
   1141   *    @param   status         A reference to a UErrorCode to receive any errors.
   1142   *    @return                 A UText containing the results of the find and replace.
   1143   *                             If a pre-allocated UText was provided, it will always be used and returned.
   1144   *
   1145   *    @stable ICU 4.6
   1146   */
   1147 U_STABLE UText * U_EXPORT2
   1148 uregex_replaceFirstUText(URegularExpression *regexp,
   1149                          UText              *replacement,
   1150                          UText              *dest,
   1151                          UErrorCode         *status);
   1152 
   1153 /**
   1154   *   Implements a replace operation intended to be used as part of an
   1155   *   incremental find-and-replace.
   1156   *
   1157   *   <p>The input string, starting from the end of the previous match and ending at
   1158   *   the start of the current match, is appended to the destination string.  Then the
   1159   *   replacement string is appended to the output string,
   1160   *   including handling any substitutions of captured text.</p>
   1161   *
   1162   *   <p>A note on preflight computation of buffersize and error handling:
   1163   *   Calls to uregex_appendReplacement() and uregex_appendTail() are
   1164   *   designed to be chained, one after another, with the destination
   1165   *   buffer pointer and buffer capacity updated after each in preparation
   1166   *   to for the next.  If the destination buffer is exhausted partway through such a
   1167   *   sequence, a U_BUFFER_OVERFLOW_ERROR status will be returned.  Normal
   1168   *   ICU conventions are for a function to perform no action if it is
   1169   *   called with an error status, but for this one case, uregex_appendRepacement()
   1170   *   will operate normally so that buffer size computations will complete
   1171   *   correctly.
   1172   *
   1173   *   <p>For simple, prepackaged, non-incremental find-and-replace
   1174   *      operations, see replaceFirst() or replaceAll().</p>
   1175   *
   1176   *   @param   regexp      The regular expression object.
   1177   *   @param   replacementText The string that will replace the matched portion of the
   1178   *                        input string as it is copied to the destination buffer.
   1179   *                        The replacement text may contain references ($1, for
   1180   *                        example) to capture groups from the match.
   1181   *   @param   replacementLength  The length of the replacement text string,
   1182   *                        or -1 if the string is NUL terminated.
   1183   *   @param   destBuf     The buffer into which the results of the
   1184   *                        find-and-replace are placed.  On return, this pointer
   1185   *                        will be updated to refer to the beginning of the
   1186   *                        unused portion of buffer, leaving it in position for
   1187   *                        a subsequent call to this function.
   1188   *   @param   destCapacity The size of the output buffer,  On return, this
   1189   *                        parameter will be updated to reflect the space remaining
   1190   *                        unused in the output buffer.
   1191   *   @param   status      A reference to a UErrorCode to receive any errors.
   1192   *   @return              The length of the result string.  In the event that
   1193   *                        destCapacity is inadequate, the full length of the
   1194   *                        untruncated output string is returned.
   1195   *
   1196   *   @stable ICU 3.0
   1197   *
   1198   */
   1199 U_STABLE int32_t U_EXPORT2
   1200 uregex_appendReplacement(URegularExpression    *regexp,
   1201                          const UChar           *replacementText,
   1202                          int32_t                replacementLength,
   1203                          UChar                **destBuf,
   1204                          int32_t               *destCapacity,
   1205                          UErrorCode            *status);
   1206 
   1207 /**
   1208   *   Implements a replace operation intended to be used as part of an
   1209   *   incremental find-and-replace.
   1210   *
   1211   *   <p>The input string, starting from the end of the previous match and ending at
   1212   *   the start of the current match, is appended to the destination string.  Then the
   1213   *   replacement string is appended to the output string,
   1214   *   including handling any substitutions of captured text.</p>
   1215   *
   1216   *   <p>For simple, prepackaged, non-incremental find-and-replace
   1217   *      operations, see replaceFirst() or replaceAll().</p>
   1218   *
   1219   *   @param   regexp      The regular expression object.
   1220   *   @param   replacementText The string that will replace the matched portion of the
   1221   *                        input string as it is copied to the destination buffer.
   1222   *                        The replacement text may contain references ($1, for
   1223   *                        example) to capture groups from the match.
   1224   *   @param   dest        A mutable UText that will receive the result. Must not be NULL.
   1225   *   @param   status      A reference to a UErrorCode to receive any errors.
   1226   *
   1227   *   @stable ICU 4.6
   1228   */
   1229 U_STABLE void U_EXPORT2
   1230 uregex_appendReplacementUText(URegularExpression    *regexp,
   1231                               UText                 *replacementText,
   1232                               UText                 *dest,
   1233                               UErrorCode            *status);
   1234 
   1235 /**
   1236   * As the final step in a find-and-replace operation, append the remainder
   1237   * of the input string, starting at the position following the last match,
   1238   * to the destination string. <code>uregex_appendTail()</code> is intended
   1239   *  to be invoked after one or more invocations of the
   1240   *  <code>uregex_appendReplacement()</code> function.
   1241   *
   1242   *   @param   regexp      The regular expression object.  This is needed to
   1243   *                        obtain the input string and with the position
   1244   *                        of the last match within it.
   1245   *   @param   destBuf     The buffer in which the results of the
   1246   *                        find-and-replace are placed.  On return, the pointer
   1247   *                        will be updated to refer to the beginning of the
   1248   *                        unused portion of buffer.
   1249   *   @param   destCapacity The size of the output buffer,  On return, this
   1250   *                        value will be updated to reflect the space remaining
   1251   *                        unused in the output buffer.
   1252   *   @param   status      A reference to a UErrorCode to receive any errors.
   1253   *   @return              The length of the result string.  In the event that
   1254   *                        destCapacity is inadequate, the full length of the
   1255   *                        untruncated output string is returned.
   1256   *
   1257   *   @stable ICU 3.0
   1258   */
   1259 U_STABLE int32_t U_EXPORT2
   1260 uregex_appendTail(URegularExpression    *regexp,
   1261                   UChar                **destBuf,
   1262                   int32_t               *destCapacity,
   1263                   UErrorCode            *status);
   1264 
   1265 /**
   1266   * As the final step in a find-and-replace operation, append the remainder
   1267   * of the input string, starting at the position following the last match,
   1268   * to the destination string. <code>uregex_appendTailUText()</code> is intended
   1269   *  to be invoked after one or more invocations of the
   1270   *  <code>uregex_appendReplacementUText()</code> function.
   1271   *
   1272   *   @param   regexp      The regular expression object.  This is needed to
   1273   *                        obtain the input string and with the position
   1274   *                        of the last match within it.
   1275   *   @param   dest        A mutable UText that will receive the result. Must not be NULL.
   1276   *
   1277   *   @param status        Error code
   1278   *
   1279   *   @return              The destination UText.
   1280   *
   1281   *   @stable ICU 4.6
   1282   */
   1283 U_STABLE UText * U_EXPORT2
   1284 uregex_appendTailUText(URegularExpression    *regexp,
   1285                        UText                 *dest,
   1286                        UErrorCode            *status);
   1287 
   1288  /**
   1289    * Split a string into fields.  Somewhat like split() from Perl.
   1290    *  The pattern matches identify delimiters that separate the input
   1291    *  into fields.  The input data between the matches becomes the
   1292    *  fields themselves.
   1293    *
   1294    *  Each of the fields is copied from the input string to the destination
   1295    *  buffer, and NUL terminated.  The position of each field within
   1296    *  the destination buffer is returned in the destFields array.
   1297    *
   1298    *  If the delimiter pattern includes capture groups, the captured text will
   1299    *  also appear in the destination array of output strings, interspersed
   1300    *  with the fields.  This is similar to Perl, but differs from Java,
   1301    *  which ignores the presence of capture groups in the pattern.
   1302    *
   1303    *  Trailing empty fields will always be returned, assuming sufficient
   1304    *  destination capacity.  This differs from the default behavior for Java
   1305    *  and Perl where trailing empty fields are not returned.
   1306    *
   1307    *  The number of strings produced by the split operation is returned.
   1308    *  This count includes the strings from capture groups in the delimiter pattern.
   1309    *  This behavior differs from Java, which ignores capture groups.
   1310    *
   1311    *    @param   regexp      The compiled regular expression.
   1312    *    @param   destBuf     A (UChar *) buffer to receive the fields that
   1313    *                         are extracted from the input string. These
   1314    *                         field pointers will refer to positions within the
   1315    *                         destination buffer supplied by the caller.  Any
   1316    *                         extra positions within the destFields array will be
   1317    *                         set to NULL.
   1318    *    @param   destCapacity The capacity of the destBuf.
   1319    *    @param   requiredCapacity  The actual capacity required of the destBuf.
   1320    *                         If destCapacity is too small, requiredCapacity will return
   1321    *                         the total capacity required to hold all of the output, and
   1322    *                         a U_BUFFER_OVERFLOW_ERROR will be returned.
   1323    *    @param   destFields  An array to be filled with the position of each
   1324    *                         of the extracted fields within destBuf.
   1325    *    @param   destFieldsCapacity  The number of elements in the destFields array.
   1326    *                If the number of fields found is less than destFieldsCapacity,
   1327    *                the extra destFields elements are set to zero.
   1328    *                If destFieldsCapacity is too small, the trailing part of the
   1329    *                input, including any field delimiters, is treated as if it
   1330    *                were the last field - it is copied to the destBuf, and
   1331    *                its position is in the destBuf is stored in the last element
   1332    *                of destFields.  This behavior mimics that of Perl.  It is not
   1333    *                an error condition, and no error status is returned when all destField
   1334    *                positions are used.
   1335    * @param status  A reference to a UErrorCode to receive any errors.
   1336    * @return        The number of fields into which the input string was split.
   1337    * @stable ICU 3.0
   1338    */
   1339 U_STABLE int32_t U_EXPORT2
   1340 uregex_split(   URegularExpression      *regexp,
   1341                   UChar                 *destBuf,
   1342                   int32_t                destCapacity,
   1343                   int32_t               *requiredCapacity,
   1344                   UChar                 *destFields[],
   1345                   int32_t                destFieldsCapacity,
   1346                   UErrorCode            *status);
   1347 
   1348   /**
   1349    * Split a string into fields.  Somewhat like split() from Perl.
   1350    * The pattern matches identify delimiters that separate the input
   1351    *  into fields.  The input data between the matches becomes the
   1352    *  fields themselves.
   1353    * <p>
   1354    * The behavior of this function is not very closely aligned with uregex_split();
   1355    * instead, it is based on (and implemented directly on top of) the C++ split method.
   1356    *
   1357    * @param regexp  The compiled regular expression.
   1358    * @param destFields    An array of mutable UText structs to receive the results of the split.
   1359    *                If a field is NULL, a new UText is allocated to contain the results for
   1360    *                that field. This new UText is not guaranteed to be mutable.
   1361    * @param destFieldsCapacity  The number of elements in the destination array.
   1362    *                If the number of fields found is less than destCapacity, the
   1363    *                extra strings in the destination array are not altered.
   1364    *                If the number of destination strings is less than the number
   1365    *                of fields, the trailing part of the input string, including any
   1366    *                field delimiters, is placed in the last destination string.
   1367    *                This behavior mimics that of Perl.  It is not  an error condition, and no
   1368    *                error status is returned when all destField positions are used.
   1369    * @param status  A reference to a UErrorCode to receive any errors.
   1370    * @return        The number of fields into which the input string was split.
   1371    *
   1372    * @stable ICU 4.6
   1373    */
   1374 U_STABLE int32_t U_EXPORT2
   1375 uregex_splitUText(URegularExpression    *regexp,
   1376                   UText                 *destFields[],
   1377                   int32_t                destFieldsCapacity,
   1378                   UErrorCode            *status);
   1379 
   1380 /**
   1381  * Set a processing time limit for match operations with this URegularExpression.
   1382  *
   1383  * Some patterns, when matching certain strings, can run in exponential time.
   1384  * For practical purposes, the match operation may appear to be in an
   1385  * infinite loop.
   1386  * When a limit is set a match operation will fail with an error if the
   1387  * limit is exceeded.
   1388  * <p>
   1389  * The units of the limit are steps of the match engine.
   1390  * Correspondence with actual processor time will depend on the speed
   1391  * of the processor and the details of the specific pattern, but will
   1392  * typically be on the order of milliseconds.
   1393  * <p>
   1394  * By default, the matching time is not limited.
   1395  * <p>
   1396  *
   1397  * @param   regexp      The compiled regular expression.
   1398  * @param   limit       The limit value, or 0 for no limit.
   1399  * @param   status      A reference to a UErrorCode to receive any errors.
   1400  * @stable ICU 4.0
   1401  */
   1402 U_STABLE void U_EXPORT2
   1403 uregex_setTimeLimit(URegularExpression      *regexp,
   1404                     int32_t                  limit,
   1405                     UErrorCode              *status);
   1406 
   1407 /**
   1408  * Get the time limit for for matches with this URegularExpression.
   1409  * A return value of zero indicates that there is no limit.
   1410  *
   1411  * @param   regexp      The compiled regular expression.
   1412  * @param   status      A reference to a UErrorCode to receive any errors.
   1413  * @return the maximum allowed time for a match, in units of processing steps.
   1414  * @stable ICU 4.0
   1415  */
   1416 U_STABLE int32_t U_EXPORT2
   1417 uregex_getTimeLimit(const URegularExpression      *regexp,
   1418                           UErrorCode              *status);
   1419 
   1420 /**
   1421  * Set the amount of heap storage available for use by the match backtracking stack.
   1422  * <p>
   1423  * ICU uses a backtracking regular expression engine, with the backtrack stack
   1424  * maintained on the heap.  This function sets the limit to the amount of memory
   1425  * that can be used  for this purpose.  A backtracking stack overflow will
   1426  * result in an error from the match operation that caused it.
   1427  * <p>
   1428  * A limit is desirable because a malicious or poorly designed pattern can use
   1429  * excessive memory, potentially crashing the process.  A limit is enabled
   1430  * by default.
   1431  * <p>
   1432  * @param   regexp      The compiled regular expression.
   1433  * @param   limit       The maximum size, in bytes, of the matching backtrack stack.
   1434  *                      A value of zero means no limit.
   1435  *                      The limit must be greater than or equal to zero.
   1436  * @param   status      A reference to a UErrorCode to receive any errors.
   1437  *
   1438  * @stable ICU 4.0
   1439  */
   1440 U_STABLE void U_EXPORT2
   1441 uregex_setStackLimit(URegularExpression      *regexp,
   1442                      int32_t                  limit,
   1443                      UErrorCode              *status);
   1444 
   1445 /**
   1446  * Get the size of the heap storage available for use by the back tracking stack.
   1447  *
   1448  * @return  the maximum backtracking stack size, in bytes, or zero if the
   1449  *          stack size is unlimited.
   1450  * @stable ICU 4.0
   1451  */
   1452 U_STABLE int32_t U_EXPORT2
   1453 uregex_getStackLimit(const URegularExpression      *regexp,
   1454                            UErrorCode              *status);
   1455 
   1456 
   1457 /**
   1458  * Function pointer for a regular expression matching callback function.
   1459  * When set, a callback function will be called periodically during matching
   1460  * operations.  If the call back function returns FALSE, the matching
   1461  * operation will be terminated early.
   1462  *
   1463  * Note:  the callback function must not call other functions on this
   1464  *        URegularExpression.
   1465  *
   1466  * @param context  context pointer.  The callback function will be invoked
   1467  *                 with the context specified at the time that
   1468  *                 uregex_setMatchCallback() is called.
   1469  * @param steps    the accumulated processing time, in match steps,
   1470  *                 for this matching operation.
   1471  * @return         TRUE to continue the matching operation.
   1472  *                 FALSE to terminate the matching operation.
   1473  * @stable ICU 4.0
   1474  */
   1475 U_CDECL_BEGIN
   1476 typedef UBool U_CALLCONV URegexMatchCallback (
   1477                    const void *context,
   1478                    int32_t     steps);
   1479 U_CDECL_END
   1480 
   1481 /**
   1482  * Set a callback function for this URegularExpression.
   1483  * During matching operations the function will be called periodically,
   1484  * giving the application the opportunity to terminate a long-running
   1485  * match.
   1486  *
   1487  * @param   regexp      The compiled regular expression.
   1488  * @param   callback    A pointer to the user-supplied callback function.
   1489  * @param   context     User context pointer.  The value supplied at the
   1490  *                      time the callback function is set will be saved
   1491  *                      and passed to the callback each time that it is called.
   1492  * @param   status      A reference to a UErrorCode to receive any errors.
   1493  * @stable ICU 4.0
   1494  */
   1495 U_STABLE void U_EXPORT2
   1496 uregex_setMatchCallback(URegularExpression      *regexp,
   1497                         URegexMatchCallback     *callback,
   1498                         const void              *context,
   1499                         UErrorCode              *status);
   1500 
   1501 
   1502 /**
   1503  *  Get the callback function for this URegularExpression.
   1504  *
   1505  * @param   regexp      The compiled regular expression.
   1506  * @param   callback    Out parameter, receives a pointer to the user-supplied
   1507  *                      callback function.
   1508  * @param   context     Out parameter, receives the user context pointer that
   1509  *                      was set when uregex_setMatchCallback() was called.
   1510  * @param   status      A reference to a UErrorCode to receive any errors.
   1511  * @stable ICU 4.0
   1512  */
   1513 U_STABLE void U_EXPORT2
   1514 uregex_getMatchCallback(const URegularExpression    *regexp,
   1515                         URegexMatchCallback        **callback,
   1516                         const void                 **context,
   1517                         UErrorCode                  *status);
   1518 
   1519 /**
   1520  * Function pointer for a regular expression find callback function.
   1521  *
   1522  * When set, a callback function will be called during a find operation
   1523  * and for operations that depend on find, such as findNext, split and some replace
   1524  * operations like replaceFirst.
   1525  * The callback will usually be called after each attempt at a match, but this is not a
   1526  * guarantee that the callback will be invoked at each character.  For finds where the
   1527  * match engine is invoked at each character, this may be close to true, but less likely
   1528  * for more optimized loops where the pattern is known to only start, and the match
   1529  * engine invoked, at certain characters.
   1530  * When invoked, this callback will specify the index at which a match operation is about
   1531  * to be attempted, giving the application the opportunity to terminate a long-running
   1532  * find operation.
   1533  *
   1534  * If the call back function returns FALSE, the find operation will be terminated early.
   1535  *
   1536  * Note:  the callback function must not call other functions on this
   1537  *        URegularExpression
   1538  *
   1539  * @param context  context pointer.  The callback function will be invoked
   1540  *                 with the context specified at the time that
   1541  *                 uregex_setFindProgressCallback() is called.
   1542  * @param matchIndex  the next index at which a match attempt will be attempted for this
   1543  *                 find operation.  If this callback interrupts the search, this is the
   1544  *                 index at which a find/findNext operation may be re-initiated.
   1545  * @return         TRUE to continue the matching operation.
   1546  *                 FALSE to terminate the matching operation.
   1547  * @stable ICU 4.6
   1548  */
   1549 U_CDECL_BEGIN
   1550 typedef UBool U_CALLCONV URegexFindProgressCallback (
   1551                    const void *context,
   1552                    int64_t     matchIndex);
   1553 U_CDECL_END
   1554 
   1555 
   1556 /**
   1557  *  Set the find progress callback function for this URegularExpression.
   1558  *
   1559  * @param   regexp      The compiled regular expression.
   1560  * @param   callback    A pointer to the user-supplied callback function.
   1561  * @param   context     User context pointer.  The value supplied at the
   1562  *                      time the callback function is set will be saved
   1563  *                      and passed to the callback each time that it is called.
   1564  * @param   status      A reference to a UErrorCode to receive any errors.
   1565  * @stable ICU 4.6
   1566  */
   1567 U_STABLE void U_EXPORT2
   1568 uregex_setFindProgressCallback(URegularExpression              *regexp,
   1569                                 URegexFindProgressCallback      *callback,
   1570                                 const void                      *context,
   1571                                 UErrorCode                      *status);
   1572 
   1573 /**
   1574  *  Get the find progress callback function for this URegularExpression.
   1575  *
   1576  * @param   regexp      The compiled regular expression.
   1577  * @param   callback    Out parameter, receives a pointer to the user-supplied
   1578  *                      callback function.
   1579  * @param   context     Out parameter, receives the user context pointer that
   1580  *                      was set when uregex_setFindProgressCallback() was called.
   1581  * @param   status      A reference to a UErrorCode to receive any errors.
   1582  * @stable ICU 4.6
   1583  */
   1584 U_STABLE void U_EXPORT2
   1585 uregex_getFindProgressCallback(const URegularExpression          *regexp,
   1586                                 URegexFindProgressCallback        **callback,
   1587                                 const void                        **context,
   1588                                 UErrorCode                        *status);
   1589 
   1590 #endif   /*  !UCONFIG_NO_REGULAR_EXPRESSIONS  */
   1591 #endif   /*  UREGEX_H  */
   1592