The ICU API for processing regular expressions consists of two classes,
* RegexPattern and RegexMatcher.
* RegexPattern objects represent a pre-processed, or compiled
* regular expression. They are created from a regular expression pattern string,
* and can be used to create RegexMatcher objects for the pattern.
Class RegexMatcher bundles together a regular expression
* pattern and a target string to which the search pattern will be applied.
* RegexMatcher includes API for doing plain find or search
* operations, for search and replace operations, and for obtaining detailed
* information about bounds of a match.
Note that by constructing RegexMatcher objects directly from regular
* expression pattern strings application code can be simplified and the explicit
* need for RegexPattern objects can usually be eliminated.
*
RegexPattern represents a compiled regular expression. It includes
* factory methods for creating a RegexPattern object from the source (string) form
* of a regular expression, methods for creating RegexMatchers that allow the pattern
* to be applied to input text, and a few convenience methods for simple common
* uses of regular expressions.
*
* Class RegexPattern is not intended to be subclassed.
* * @stable ICU 2.4 */ class U_I18N_API RegexPattern U_FINAL : public UObject { public: /** * default constructor. Create a RegexPattern object that refers to no actual * pattern. Not normally needed; RegexPattern objects are usually * created using the factory methodcompile().
*
* @stable ICU 2.4
*/
RegexPattern();
/**
* Copy Constructor. Create a new RegexPattern object that is equivalent
* to the source object.
* @param source the pattern object to be copied.
* @stable ICU 2.4
*/
RegexPattern(const RegexPattern &source);
/**
* Destructor. Note that a RegexPattern object must persist so long as any
* RegexMatcher objects that were created from the RegexPattern are active.
* @stable ICU 2.4
*/
virtual ~RegexPattern();
/**
* Comparison operator. Two RegexPattern objects are considered equal if they
* were constructed from identical source patterns using the same match flag
* settings.
* @param that a RegexPattern object to compare with "this".
* @return TRUE if the objects are equivalent.
* @stable ICU 2.4
*/
UBool operator==(const RegexPattern& that) const;
/**
* Comparison operator. Two RegexPattern objects are considered equal if they
* were constructed from identical source patterns using the same match flag
* settings.
* @param that a RegexPattern object to compare with "this".
* @return TRUE if the objects are different.
* @stable ICU 2.4
*/
inline UBool operator!=(const RegexPattern& that) const {return ! operator ==(that);}
/**
* Assignment operator. After assignment, this RegexPattern will behave identically
* to the source object.
* @stable ICU 2.4
*/
RegexPattern &operator =(const RegexPattern &source);
/**
* Create an exact copy of this RegexPattern object. Since RegexPattern is not
* intended to be subclassed, clone() and the copy construction are
* equivalent operations.
* @return the copy of this RegexPattern
* @stable ICU 2.4
*/
virtual RegexPattern *clone() const;
/**
* Compiles the regular expression in string form into a RegexPattern
* object. These compile methods, rather than the constructors, are the usual
* way that RegexPattern objects are created.
*
* Note that RegexPattern objects must not be deleted while RegexMatcher * objects created from the pattern are active. RegexMatchers keep a pointer * back to their pattern, so premature deletion of the pattern is a * catastrophic error.
* *All pattern match mode flags are set to their default values.
* *Note that it is often more convenient to construct a RegexMatcher directly * from a pattern string rather than separately compiling the pattern and * then creating a RegexMatcher object from the pattern.
* * @param regex The regular expression to be compiled. * @param pe Receives the position (line and column nubers) of any error * within the regular expression.) * @param status A reference to a UErrorCode to receive any errors. * @return A regexPattern object for the compiled pattern. * * @stable ICU 2.4 */ static RegexPattern * U_EXPORT2 compile( const UnicodeString ®ex, UParseError &pe, UErrorCode &status); /** * Compiles the regular expression in string form into a RegexPattern * object. These compile methods, rather than the constructors, are the usual * way that RegexPattern objects are created. * *Note that RegexPattern objects must not be deleted while RegexMatcher * objects created from the pattern are active. RegexMatchers keep a pointer * back to their pattern, so premature deletion of the pattern is a * catastrophic error.
* *All pattern match mode flags are set to their default values.
* *Note that it is often more convenient to construct a RegexMatcher directly * from a pattern string rather than separately compiling the pattern and * then creating a RegexMatcher object from the pattern.
* * @param regex The regular expression to be compiled. Note, the text referred * to by this UText must not be deleted during the lifetime of the * RegexPattern object or any RegexMatcher object created from it. * @param pe Receives the position (line and column nubers) of any error * within the regular expression.) * @param status A reference to a UErrorCode to receive any errors. * @return A regexPattern object for the compiled pattern. * * @stable ICU 4.6 */ static RegexPattern * U_EXPORT2 compile( UText *regex, UParseError &pe, UErrorCode &status); /** * Compiles the regular expression in string form into a RegexPattern * object using the specified match mode flags. These compile methods, * rather than the constructors, are the usual way that RegexPattern objects * are created. * *Note that RegexPattern objects must not be deleted while RegexMatcher * objects created from the pattern are active. RegexMatchers keep a pointer * back to their pattern, so premature deletion of the pattern is a * catastrophic error.
* *Note that it is often more convenient to construct a RegexMatcher directly * from a pattern string instead of than separately compiling the pattern and * then creating a RegexMatcher object from the pattern.
* * @param regex The regular expression to be compiled. * @param flags The match mode flags to be used. * @param pe Receives the position (line and column numbers) of any error * within the regular expression.) * @param status A reference to a UErrorCode to receive any errors. * @return A regexPattern object for the compiled pattern. * * @stable ICU 2.4 */ static RegexPattern * U_EXPORT2 compile( const UnicodeString ®ex, uint32_t flags, UParseError &pe, UErrorCode &status); /** * Compiles the regular expression in string form into a RegexPattern * object using the specified match mode flags. These compile methods, * rather than the constructors, are the usual way that RegexPattern objects * are created. * *Note that RegexPattern objects must not be deleted while RegexMatcher * objects created from the pattern are active. RegexMatchers keep a pointer * back to their pattern, so premature deletion of the pattern is a * catastrophic error.
* *Note that it is often more convenient to construct a RegexMatcher directly * from a pattern string instead of than separately compiling the pattern and * then creating a RegexMatcher object from the pattern.
* * @param regex The regular expression to be compiled. Note, the text referred * to by this UText must not be deleted during the lifetime of the * RegexPattern object or any RegexMatcher object created from it. * @param flags The match mode flags to be used. * @param pe Receives the position (line and column numbers) of any error * within the regular expression.) * @param status A reference to a UErrorCode to receive any errors. * @return A regexPattern object for the compiled pattern. * * @stable ICU 4.6 */ static RegexPattern * U_EXPORT2 compile( UText *regex, uint32_t flags, UParseError &pe, UErrorCode &status); /** * Compiles the regular expression in string form into a RegexPattern * object using the specified match mode flags. These compile methods, * rather than the constructors, are the usual way that RegexPattern objects * are created. * *Note that RegexPattern objects must not be deleted while RegexMatcher * objects created from the pattern are active. RegexMatchers keep a pointer * back to their pattern, so premature deletion of the pattern is a * catastrophic error.
* *Note that it is often more convenient to construct a RegexMatcher directly * from a pattern string instead of than separately compiling the pattern and * then creating a RegexMatcher object from the pattern.
* * @param regex The regular expression to be compiled. * @param flags The match mode flags to be used. * @param status A reference to a UErrorCode to receive any errors. * @return A regexPattern object for the compiled pattern. * * @stable ICU 2.6 */ static RegexPattern * U_EXPORT2 compile( const UnicodeString ®ex, uint32_t flags, UErrorCode &status); /** * Compiles the regular expression in string form into a RegexPattern * object using the specified match mode flags. These compile methods, * rather than the constructors, are the usual way that RegexPattern objects * are created. * *Note that RegexPattern objects must not be deleted while RegexMatcher * objects created from the pattern are active. RegexMatchers keep a pointer * back to their pattern, so premature deletion of the pattern is a * catastrophic error.
* *Note that it is often more convenient to construct a RegexMatcher directly * from a pattern string instead of than separately compiling the pattern and * then creating a RegexMatcher object from the pattern.
* * @param regex The regular expression to be compiled. Note, the text referred * to by this UText must not be deleted during the lifetime of the * RegexPattern object or any RegexMatcher object created from it. * @param flags The match mode flags to be used. * @param status A reference to a UErrorCode to receive any errors. * @return A regexPattern object for the compiled pattern. * * @stable ICU 4.6 */ static RegexPattern * U_EXPORT2 compile( UText *regex, uint32_t flags, UErrorCode &status); /** * Get the match mode flags that were used when compiling this pattern. * @return the match mode flags * @stable ICU 2.4 */ virtual uint32_t flags() const; /** * Creates a RegexMatcher that will match the given input against this pattern. The * RegexMatcher can then be used to perform match, find or replace operations * on the input. Note that a RegexPattern object must not be deleted while * RegexMatchers created from it still exist and might possibly be used again. ** The matcher will retain a reference to the supplied input string, and all regexp * pattern matching operations happen directly on this original string. It is * critical that the string not be altered or deleted before use by the regular * expression operations is complete. * * @param input The input string to which the regular expression will be applied. * @param status A reference to a UErrorCode to receive any errors. * @return A RegexMatcher object for this pattern and input. * * @stable ICU 2.4 */ virtual RegexMatcher *matcher(const UnicodeString &input, UErrorCode &status) const; private: /** * Cause a compilation error if an application accidentally attempts to * create a matcher with a (char16_t *) string as input rather than * a UnicodeString. Avoids a dangling reference to a temporary string. *
* To efficiently work with char16_t *strings, wrap the data in a UnicodeString
* using one of the aliasing constructors, such as
* UnicodeString(UBool isTerminated, const char16_t *text, int32_t textLength);
* or in a UText, using
* utext_openUChars(UText *ut, const char16_t *text, int64_t textLength, UErrorCode *status);
*
*/
RegexMatcher *matcher(const char16_t *input,
UErrorCode &status) const;
public:
/**
* Creates a RegexMatcher that will match against this pattern. The
* RegexMatcher can be used to perform match, find or replace operations.
* Note that a RegexPattern object must not be deleted while
* RegexMatchers created from it still exist and might possibly be used again.
*
* @param status A reference to a UErrorCode to receive any errors.
* @return A RegexMatcher object for this pattern and input.
*
* @stable ICU 2.6
*/
virtual RegexMatcher *matcher(UErrorCode &status) const;
/**
* Test whether a string matches a regular expression. This convenience function
* both compiles the regular expression and applies it in a single operation.
* Note that if the same pattern needs to be applied repeatedly, this method will be
* less efficient than creating and reusing a RegexMatcher object.
*
* @param regex The regular expression
* @param input The string data to be matched
* @param pe Receives the position of any syntax errors within the regular expression
* @param status A reference to a UErrorCode to receive any errors.
* @return True if the regular expression exactly matches the full input string.
*
* @stable ICU 2.4
*/
static UBool U_EXPORT2 matches(const UnicodeString ®ex,
const UnicodeString &input,
UParseError &pe,
UErrorCode &status);
/**
* Test whether a string matches a regular expression. This convenience function
* both compiles the regular expression and applies it in a single operation.
* Note that if the same pattern needs to be applied repeatedly, this method will be
* less efficient than creating and reusing a RegexMatcher object.
*
* @param regex The regular expression
* @param input The string data to be matched
* @param pe Receives the position of any syntax errors within the regular expression
* @param status A reference to a UErrorCode to receive any errors.
* @return True if the regular expression exactly matches the full input string.
*
* @stable ICU 4.6
*/
static UBool U_EXPORT2 matches(UText *regex,
UText *input,
UParseError &pe,
UErrorCode &status);
/**
* Returns the regular expression from which this pattern was compiled. This method will work
* even if the pattern was compiled from a UText.
*
* Note: If the pattern was originally compiled from a UText, and that UText was modified,
* the returned string may no longer reflect the RegexPattern object.
* @stable ICU 2.4
*/
virtual UnicodeString pattern() const;
/**
* Returns the regular expression from which this pattern was compiled. This method will work
* even if the pattern was compiled from a UnicodeString.
*
* Note: This is the original input, not a clone. If the pattern was originally compiled from a
* UText, and that UText was modified, the returned UText may no longer reflect the RegexPattern
* object.
*
* @stable ICU 4.6
*/
virtual UText *patternText(UErrorCode &status) const;
/**
* Get the group number corresponding to a named capture group.
* The returned number can be used with any function that access
* capture groups by number.
*
* The function returns an error status if the specified name does not
* appear in the pattern.
*
* @param groupName The capture group name.
* @param status A UErrorCode to receive any errors.
*
* @stable ICU 55
*/
virtual int32_t groupNumberFromName(const UnicodeString &groupName, UErrorCode &status) const;
/**
* Get the group number corresponding to a named capture group.
* The returned number can be used with any function that access
* capture groups by number.
*
* The function returns an error status if the specified name does not
* appear in the pattern.
*
* @param groupName The capture group name,
* platform invariant characters only.
* @param nameLength The length of the name, or -1 if the name is
* nul-terminated.
* @param status A UErrorCode to receive any errors.
*
* @stable ICU 55
*/
virtual int32_t groupNumberFromName(const char *groupName, int32_t nameLength, UErrorCode &status) const;
/**
* Split a string into fields. Somewhat like split() from Perl or Java.
* Pattern matches identify delimiters that separate the input
* into fields. The input data between the delimiters becomes the
* fields themselves.
*
* If the delimiter pattern includes capture groups, the captured text will
* also appear in the destination array of output strings, interspersed
* with the fields. This is similar to Perl, but differs from Java,
* which ignores the presence of capture groups in the pattern.
*
* Trailing empty fields will always be returned, assuming sufficient
* destination capacity. This differs from the default behavior for Java
* and Perl where trailing empty fields are not returned.
*
* The number of strings produced by the split operation is returned.
* This count includes the strings from capture groups in the delimiter pattern.
* This behavior differs from Java, which ignores capture groups.
*
* For the best performance on split() operations,
* RegexMatcher::split is preferable to this function
*
* @param input The string to be split into fields. The field delimiters
* match the pattern (in the "this" object)
* @param dest An array of UnicodeStrings to receive the results of the split.
* This is an array of actual UnicodeString objects, not an
* array of pointers to strings. Local (stack based) arrays can
* work well here.
* @param destCapacity The number of elements in the destination array.
* If the number of fields found is less than destCapacity, the
* extra strings in the destination array are not altered.
* If the number of destination strings is less than the number
* of fields, the trailing part of the input string, including any
* field delimiters, is placed in the last destination string.
* @param status A reference to a UErrorCode to receive any errors.
* @return The number of fields into which the input string was split.
* @stable ICU 2.4
*/
virtual int32_t split(const UnicodeString &input,
UnicodeString dest[],
int32_t destCapacity,
UErrorCode &status) const;
/**
* Split a string into fields. Somewhat like split() from Perl or Java.
* Pattern matches identify delimiters that separate the input
* into fields. The input data between the delimiters becomes the
* fields themselves.
*
* If the delimiter pattern includes capture groups, the captured text will
* also appear in the destination array of output strings, interspersed
* with the fields. This is similar to Perl, but differs from Java,
* which ignores the presence of capture groups in the pattern.
*
* Trailing empty fields will always be returned, assuming sufficient
* destination capacity. This differs from the default behavior for Java
* and Perl where trailing empty fields are not returned.
*
* The number of strings produced by the split operation is returned.
* This count includes the strings from capture groups in the delimiter pattern.
* This behavior differs from Java, which ignores capture groups.
*
* For the best performance on split() operations,
* RegexMatcher::split is preferable to this function
*
* @param input The string to be split into fields. The field delimiters
* match the pattern (in the "this" object)
* @param dest An array of mutable UText structs to receive the results of the split.
* If a field is NULL, a new UText is allocated to contain the results for
* that field. This new UText is not guaranteed to be mutable.
* @param destCapacity The number of elements in the destination array.
* If the number of fields found is less than destCapacity, the
* extra strings in the destination array are not altered.
* If the number of destination strings is less than the number
* of fields, the trailing part of the input string, including any
* field delimiters, is placed in the last destination string.
* @param status A reference to a UErrorCode to receive any errors.
* @return The number of destination strings used.
*
* @stable ICU 4.6
*/
virtual int32_t split(UText *input,
UText *dest[],
int32_t destCapacity,
UErrorCode &status) const;
/**
* ICU "poor man's RTTI", returns a UClassID for the actual class.
*
* @stable ICU 2.4
*/
virtual UClassID getDynamicClassID() const;
/**
* ICU "poor man's RTTI", returns a UClassID for this class.
*
* @stable ICU 2.4
*/
static UClassID U_EXPORT2 getStaticClassID();
private:
//
// Implementation Data
//
UText *fPattern; // The original pattern string.
UnicodeString *fPatternString; // The original pattern UncodeString if relevant
uint32_t fFlags; // The flags used when compiling the pattern.
//
UVector64 *fCompiledPat; // The compiled pattern p-code.
UnicodeString fLiteralText; // Any literal string data from the pattern,
// after un-escaping, for use during the match.
UVector *fSets; // Any UnicodeSets referenced from the pattern.
Regex8BitSet *fSets8; // (and fast sets for latin-1 range.)
UErrorCode fDeferredStatus; // status if some prior error has left this
// RegexPattern in an unusable state.
int32_t fMinMatchLen; // Minimum Match Length. All matches will have length
// >= this value. For some patterns, this calculated
// value may be less than the true shortest
// possible match.
int32_t fFrameSize; // Size of a state stack frame in the
// execution engine.
int32_t fDataSize; // The size of the data needed by the pattern that
// does not go on the state stack, but has just
// a single copy per matcher.
UVector32 *fGroupMap; // Map from capture group number to position of
// the group's variables in the matcher stack frame.
UnicodeSet **fStaticSets; // Ptr to static (shared) sets for predefined
// regex character classes, e.g. Word.
Regex8BitSet *fStaticSets8; // Ptr to the static (shared) latin-1 only
// sets for predefined regex classes.
int32_t fStartType; // Info on how a match must start.
int32_t fInitialStringIdx; //
int32_t fInitialStringLen;
UnicodeSet *fInitialChars;
UChar32 fInitialChar;
Regex8BitSet *fInitialChars8;
UBool fNeedsAltInput;
UHashtable *fNamedCaptureMap; // Map from capture group names to numbers.
friend class RegexCompile;
friend class RegexMatcher;
friend class RegexCImpl;
//
// Implementation Methods
//
void init(); // Common initialization, for use by constructors.
void zap(); // Common cleanup
void dumpOp(int32_t index) const;
public:
#ifndef U_HIDE_INTERNAL_API
/**
* Dump a compiled pattern. Internal debug function.
* @internal
*/
void dumpPattern() const;
#endif /* U_HIDE_INTERNAL_API */
};
/**
* class RegexMatcher bundles together a regular expression pattern and
* input text to which the expression can be applied. It includes methods
* for testing for matches, and for find and replace operations.
*
*
Class RegexMatcher is not intended to be subclassed.
* * @stable ICU 2.4 */ class U_I18N_API RegexMatcher U_FINAL : public UObject { public: /** * Construct a RegexMatcher for a regular expression. * This is a convenience method that avoids the need to explicitly create * a RegexPattern object. Note that if several RegexMatchers need to be * created for the same expression, it will be more efficient to * separately create and cache a RegexPattern object, and use * its matcher() method to create the RegexMatcher objects. * * @param regexp The Regular Expression to be compiled. * @param flags Regular expression options, such as case insensitive matching. * @see UREGEX_CASE_INSENSITIVE * @param status Any errors are reported by setting this UErrorCode variable. * @stable ICU 2.6 */ RegexMatcher(const UnicodeString ®exp, uint32_t flags, UErrorCode &status); /** * Construct a RegexMatcher for a regular expression. * This is a convenience method that avoids the need to explicitly create * a RegexPattern object. Note that if several RegexMatchers need to be * created for the same expression, it will be more efficient to * separately create and cache a RegexPattern object, and use * its matcher() method to create the RegexMatcher objects. * * @param regexp The regular expression to be compiled. * @param flags Regular expression options, such as case insensitive matching. * @see UREGEX_CASE_INSENSITIVE * @param status Any errors are reported by setting this UErrorCode variable. * * @stable ICU 4.6 */ RegexMatcher(UText *regexp, uint32_t flags, UErrorCode &status); /** * Construct a RegexMatcher for a regular expression. * This is a convenience method that avoids the need to explicitly create * a RegexPattern object. Note that if several RegexMatchers need to be * created for the same expression, it will be more efficient to * separately create and cache a RegexPattern object, and use * its matcher() method to create the RegexMatcher objects. ** The matcher will retain a reference to the supplied input string, and all regexp * pattern matching operations happen directly on the original string. It is * critical that the string not be altered or deleted before use by the regular * expression operations is complete. * * @param regexp The Regular Expression to be compiled. * @param input The string to match. The matcher retains a reference to the * caller's string; mo copy is made. * @param flags Regular expression options, such as case insensitive matching. * @see UREGEX_CASE_INSENSITIVE * @param status Any errors are reported by setting this UErrorCode variable. * @stable ICU 2.6 */ RegexMatcher(const UnicodeString ®exp, const UnicodeString &input, uint32_t flags, UErrorCode &status); /** * Construct a RegexMatcher for a regular expression. * This is a convenience method that avoids the need to explicitly create * a RegexPattern object. Note that if several RegexMatchers need to be * created for the same expression, it will be more efficient to * separately create and cache a RegexPattern object, and use * its matcher() method to create the RegexMatcher objects. *
* The matcher will make a shallow clone of the supplied input text, and all regexp * pattern matching operations happen on this clone. While read-only operations on * the supplied text are permitted, it is critical that the underlying string not be * altered or deleted before use by the regular expression operations is complete. * * @param regexp The Regular Expression to be compiled. * @param input The string to match. The matcher retains a shallow clone of the text. * @param flags Regular expression options, such as case insensitive matching. * @see UREGEX_CASE_INSENSITIVE * @param status Any errors are reported by setting this UErrorCode variable. * * @stable ICU 4.6 */ RegexMatcher(UText *regexp, UText *input, uint32_t flags, UErrorCode &status); private: /** * Cause a compilation error if an application accidentally attempts to * create a matcher with a (char16_t *) string as input rather than * a UnicodeString. Avoids a dangling reference to a temporary string. *
* To efficiently work with char16_t *strings, wrap the data in a UnicodeString
* using one of the aliasing constructors, such as
* UnicodeString(UBool isTerminated, const char16_t *text, int32_t textLength);
* or in a UText, using
* utext_openUChars(UText *ut, const char16_t *text, int64_t textLength, UErrorCode *status);
*
*/
RegexMatcher(const UnicodeString ®exp, const char16_t *input,
uint32_t flags, UErrorCode &status);
public:
/**
* Destructor.
*
* @stable ICU 2.4
*/
virtual ~RegexMatcher();
/**
* Attempts to match the entire input region against the pattern.
* @param status A reference to a UErrorCode to receive any errors.
* @return TRUE if there is a match
* @stable ICU 2.4
*/
virtual UBool matches(UErrorCode &status);
/**
* Resets the matcher, then attempts to match the input beginning
* at the specified startIndex, and extending to the end of the input.
* The input region is reset to include the entire input string.
* A successful match must extend to the end of the input.
* @param startIndex The input string (native) index at which to begin matching.
* @param status A reference to a UErrorCode to receive any errors.
* @return TRUE if there is a match
* @stable ICU 2.8
*/
virtual UBool matches(int64_t startIndex, UErrorCode &status);
/**
* Attempts to match the input string, starting from the beginning of the region,
* against the pattern. Like the matches() method, this function
* always starts at the beginning of the input region;
* unlike that function, it does not require that the entire region be matched.
*
*
If the match succeeds then more information can be obtained via the start(),
* end(), and group() functions.
If the match succeeds then more information can be obtained via the start(),
* end(), and group() functions.
start(), end() and group()
* will provide more information regarding the match.
* Note that if the input string is changed by the application, * use find(startPos, status) instead of find(), because the saved starting * position may not be valid with the altered input string.
* @return TRUE if a match is found. * @stable ICU 2.4 */ virtual UBool find(); /** * Find the next pattern match in the input string. * The find begins searching the input at the location following the end of * the previous match, or at the start of the string if there is no previous match. * If a match is found,start(), end() and group()
* will provide more information regarding the match.
* Note that if the input string is changed by the application, * use find(startPos, status) instead of find(), because the saved starting * position may not be valid with the altered input string.
* @param status A reference to a UErrorCode to receive any errors. * @return TRUE if a match is found. * @stable ICU 55 */ virtual UBool find(UErrorCode &status); /** * Resets this RegexMatcher and then attempts to find the next substring of the * input string that matches the pattern, starting at the specified index. * * @param start The (native) index in the input string to begin the search. * @param status A reference to a UErrorCode to receive any errors. * @return TRUE if a match is found. * @stable ICU 2.4 */ virtual UBool find(int64_t start, UErrorCode &status); /** * Returns a string containing the text matched by the previous match. * If the pattern can match an empty string, an empty string may be returned. * @param status A reference to a UErrorCode to receive any errors. * Possible errors are U_REGEX_INVALID_STATE if no match * has been attempted or the last match failed. * @return a string containing the matched input text. * @stable ICU 2.4 */ virtual UnicodeString group(UErrorCode &status) const; /** * Returns a string containing the text captured by the given group * during the previous match operation. Group(0) is the entire match. * * A zero length string is returned both for capture groups that did not * participate in the match and for actual zero length matches. * To distinguish between these two cases use the function start(), * which returns -1 for non-participating groups. * * @param groupNum the capture group number * @param status A reference to a UErrorCode to receive any errors. * Possible errors are U_REGEX_INVALID_STATE if no match * has been attempted or the last match failed and * U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number. * @return the captured text * @stable ICU 2.4 */ virtual UnicodeString group(int32_t groupNum, UErrorCode &status) const; /** * Returns the number of capturing groups in this matcher's pattern. * @return the number of capture groups * @stable ICU 2.4 */ virtual int32_t groupCount() const; /** * Returns a shallow clone of the entire live input string with the UText current native index * set to the beginning of the requested group. * * @param dest The UText into which the input should be cloned, or NULL to create a new UText * @param group_len A reference to receive the length of the desired capture group * @param status A reference to a UErrorCode to receive any errors. * Possible errors are U_REGEX_INVALID_STATE if no match * has been attempted or the last match failed and * U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number. * @return dest if non-NULL, a shallow copy of the input text otherwise * * @stable ICU 4.6 */ virtual UText *group(UText *dest, int64_t &group_len, UErrorCode &status) const; /** * Returns a shallow clone of the entire live input string with the UText current native index * set to the beginning of the requested group. * * A group length of zero is returned both for capture groups that did not * participate in the match and for actual zero length matches. * To distinguish between these two cases use the function start(), * which returns -1 for non-participating groups. * * @param groupNum The capture group number. * @param dest The UText into which the input should be cloned, or NULL to create a new UText. * @param group_len A reference to receive the length of the desired capture group * @param status A reference to a UErrorCode to receive any errors. * Possible errors are U_REGEX_INVALID_STATE if no match * has been attempted or the last match failed and * U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number. * @return dest if non-NULL, a shallow copy of the input text otherwise * * @stable ICU 4.6 */ virtual UText *group(int32_t groupNum, UText *dest, int64_t &group_len, UErrorCode &status) const; /** * Returns the index in the input string of the start of the text matched * during the previous match operation. * @param status a reference to a UErrorCode to receive any errors. * @return The (native) position in the input string of the start of the last match. * @stable ICU 2.4 */ virtual int32_t start(UErrorCode &status) const; /** * Returns the index in the input string of the start of the text matched * during the previous match operation. * @param status a reference to a UErrorCode to receive any errors. * @return The (native) position in the input string of the start of the last match. * @stable ICU 4.6 */ virtual int64_t start64(UErrorCode &status) const; /** * Returns the index in the input string of the start of the text matched by the * specified capture group during the previous match operation. Return -1 if * the capture group exists in the pattern, but was not part of the last match. * * @param group the capture group number * @param status A reference to a UErrorCode to receive any errors. Possible * errors are U_REGEX_INVALID_STATE if no match has been * attempted or the last match failed, and * U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number * @return the (native) start position of substring matched by the specified group. * @stable ICU 2.4 */ virtual int32_t start(int32_t group, UErrorCode &status) const; /** * Returns the index in the input string of the start of the text matched by the * specified capture group during the previous match operation. Return -1 if * the capture group exists in the pattern, but was not part of the last match. * * @param group the capture group number. * @param status A reference to a UErrorCode to receive any errors. Possible * errors are U_REGEX_INVALID_STATE if no match has been * attempted or the last match failed, and * U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number. * @return the (native) start position of substring matched by the specified group. * @stable ICU 4.6 */ virtual int64_t start64(int32_t group, UErrorCode &status) const; /** * Returns the index in the input string of the first character following the * text matched during the previous match operation. * * @param status A reference to a UErrorCode to receive any errors. Possible * errors are U_REGEX_INVALID_STATE if no match has been * attempted or the last match failed. * @return the index of the last character matched, plus one. * The index value returned is a native index, corresponding to * code units for the underlying encoding type, for example, * a byte index for UTF-8. * @stable ICU 2.4 */ virtual int32_t end(UErrorCode &status) const; /** * Returns the index in the input string of the first character following the * text matched during the previous match operation. * * @param status A reference to a UErrorCode to receive any errors. Possible * errors are U_REGEX_INVALID_STATE if no match has been * attempted or the last match failed. * @return the index of the last character matched, plus one. * The index value returned is a native index, corresponding to * code units for the underlying encoding type, for example, * a byte index for UTF-8. * @stable ICU 4.6 */ virtual int64_t end64(UErrorCode &status) const; /** * Returns the index in the input string of the character following the * text matched by the specified capture group during the previous match operation. * * @param group the capture group number * @param status A reference to a UErrorCode to receive any errors. Possible * errors are U_REGEX_INVALID_STATE if no match has been * attempted or the last match failed and * U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number * @return the index of the first character following the text * captured by the specified group during the previous match operation. * Return -1 if the capture group exists in the pattern but was not part of the match. * The index value returned is a native index, corresponding to * code units for the underlying encoding type, for example, * a byte index for UTF8. * @stable ICU 2.4 */ virtual int32_t end(int32_t group, UErrorCode &status) const; /** * Returns the index in the input string of the character following the * text matched by the specified capture group during the previous match operation. * * @param group the capture group number * @param status A reference to a UErrorCode to receive any errors. Possible * errors are U_REGEX_INVALID_STATE if no match has been * attempted or the last match failed and * U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number * @return the index of the first character following the text * captured by the specified group during the previous match operation. * Return -1 if the capture group exists in the pattern but was not part of the match. * The index value returned is a native index, corresponding to * code units for the underlying encoding type, for example, * a byte index for UTF8. * @stable ICU 4.6 */ virtual int64_t end64(int32_t group, UErrorCode &status) const; /** * Resets this matcher. The effect is to remove any memory of previous matches, * and to cause subsequent find() operations to begin at the beginning of * the input string. * * @return this RegexMatcher. * @stable ICU 2.4 */ virtual RegexMatcher &reset(); /** * Resets this matcher, and set the current input position. * The effect is to remove any memory of previous matches, * and to cause subsequent find() operations to begin at * the specified (native) position in the input string. ** The matcher's region is reset to its default, which is the entire * input string. *
* An alternative to this function is to set a match region * beginning at the desired index. * * @return this RegexMatcher. * @stable ICU 2.8 */ virtual RegexMatcher &reset(int64_t index, UErrorCode &status); /** * Resets this matcher with a new input string. This allows instances of RegexMatcher * to be reused, which is more efficient than creating a new RegexMatcher for * each input string to be processed. * @param input The new string on which subsequent pattern matches will operate. * The matcher retains a reference to the callers string, and operates * directly on that. Ownership of the string remains with the caller. * Because no copy of the string is made, it is essential that the * caller not delete the string until after regexp operations on it * are done. * Note that while a reset on the matcher with an input string that is then * modified across/during matcher operations may be supported currently for UnicodeString, * this was not originally intended behavior, and support for this is not guaranteed * in upcoming versions of ICU. * @return this RegexMatcher. * @stable ICU 2.4 */ virtual RegexMatcher &reset(const UnicodeString &input); /** * Resets this matcher with a new input string. This allows instances of RegexMatcher * to be reused, which is more efficient than creating a new RegexMatcher for * each input string to be processed. * @param input The new string on which subsequent pattern matches will operate. * The matcher makes a shallow clone of the given text; ownership of the * original string remains with the caller. Because no deep copy of the * text is made, it is essential that the caller not modify the string * until after regexp operations on it are done. * @return this RegexMatcher. * * @stable ICU 4.6 */ virtual RegexMatcher &reset(UText *input); /** * Set the subject text string upon which the regular expression is looking for matches * without changing any other aspect of the matching state. * The new and previous text strings must have the same content. * * This function is intended for use in environments where ICU is operating on * strings that may move around in memory. It provides a mechanism for notifying * ICU that the string has been relocated, and providing a new UText to access the * string in its new position. * * Note that the regular expression implementation never copies the underlying text * of a string being matched, but always operates directly on the original text * provided by the user. Refreshing simply drops the references to the old text * and replaces them with references to the new. * * Caution: this function is normally used only by very specialized, * system-level code. One example use case is with garbage collection that moves * the text in memory. * * @param input The new (moved) text string. * @param status Receives errors detected by this function. * * @stable ICU 4.8 */ virtual RegexMatcher &refreshInputText(UText *input, UErrorCode &status); private: /** * Cause a compilation error if an application accidentally attempts to * reset a matcher with a (char16_t *) string as input rather than * a UnicodeString. Avoids a dangling reference to a temporary string. *
* To efficiently work with char16_t *strings, wrap the data in a UnicodeString
* using one of the aliasing constructors, such as
* UnicodeString(UBool isTerminated, const char16_t *text, int32_t textLength);
* or in a UText, using
* utext_openUChars(UText *ut, const char16_t *text, int64_t textLength, UErrorCode *status);
*
*/
RegexMatcher &reset(const char16_t *input);
public:
/**
* Returns the input string being matched. Ownership of the string belongs to
* the matcher; it should not be altered or deleted. This method will work even if the input
* was originally supplied as a UText.
* @return the input string
* @stable ICU 2.4
*/
virtual const UnicodeString &input() const;
/**
* Returns the input string being matched. This is the live input text; it should not be
* altered or deleted. This method will work even if the input was originally supplied as
* a UnicodeString.
* @return the input text
*
* @stable ICU 4.6
*/
virtual UText *inputText() const;
/**
* Returns the input string being matched, either by copying it into the provided
* UText parameter or by returning a shallow clone of the live input. Note that copying
* the entire input may cause significant performance and memory issues.
* @param dest The UText into which the input should be copied, or NULL to create a new UText
* @param status error code
* @return dest if non-NULL, a shallow copy of the input text otherwise
*
* @stable ICU 4.6
*/
virtual UText *getInput(UText *dest, UErrorCode &status) const;
/** Sets the limits of this matcher's region.
* The region is the part of the input string that will be searched to find a match.
* Invoking this method resets the matcher, and then sets the region to start
* at the index specified by the start parameter and end at the index specified
* by the end parameter.
*
* Depending on the transparency and anchoring being used (see useTransparentBounds
* and useAnchoringBounds), certain constructs such as anchors may behave differently
* at or around the boundaries of the region
*
* The function will fail if start is greater than limit, or if either index
* is less than zero or greater than the length of the string being matched.
*
* @param start The (native) index to begin searches at.
* @param limit The index to end searches at (exclusive).
* @param status A reference to a UErrorCode to receive any errors.
* @stable ICU 4.0
*/
virtual RegexMatcher ®ion(int64_t start, int64_t limit, UErrorCode &status);
/**
* Identical to region(start, limit, status) but also allows a start position without
* resetting the region state.
* @param regionStart The region start
* @param regionLimit the limit of the region
* @param startIndex The (native) index within the region bounds at which to begin searches.
* @param status A reference to a UErrorCode to receive any errors.
* If startIndex is not within the specified region bounds,
* U_INDEX_OUTOFBOUNDS_ERROR is returned.
* @stable ICU 4.6
*/
virtual RegexMatcher ®ion(int64_t regionStart, int64_t regionLimit, int64_t startIndex, UErrorCode &status);
/**
* Reports the start index of this matcher's region. The searches this matcher
* conducts are limited to finding matches within regionStart (inclusive) and
* regionEnd (exclusive).
*
* @return The starting (native) index of this matcher's region.
* @stable ICU 4.0
*/
virtual int32_t regionStart() const;
/**
* Reports the start index of this matcher's region. The searches this matcher
* conducts are limited to finding matches within regionStart (inclusive) and
* regionEnd (exclusive).
*
* @return The starting (native) index of this matcher's region.
* @stable ICU 4.6
*/
virtual int64_t regionStart64() const;
/**
* Reports the end (limit) index (exclusive) of this matcher's region. The searches
* this matcher conducts are limited to finding matches within regionStart
* (inclusive) and regionEnd (exclusive).
*
* @return The ending point (native) of this matcher's region.
* @stable ICU 4.0
*/
virtual int32_t regionEnd() const;
/**
* Reports the end (limit) index (exclusive) of this matcher's region. The searches
* this matcher conducts are limited to finding matches within regionStart
* (inclusive) and regionEnd (exclusive).
*
* @return The ending point (native) of this matcher's region.
* @stable ICU 4.6
*/
virtual int64_t regionEnd64() const;
/**
* Queries the transparency of region bounds for this matcher.
* See useTransparentBounds for a description of transparent and opaque bounds.
* By default, a matcher uses opaque region boundaries.
*
* @return TRUE if this matcher is using opaque bounds, false if it is not.
* @stable ICU 4.0
*/
virtual UBool hasTransparentBounds() const;
/**
* Sets the transparency of region bounds for this matcher.
* Invoking this function with an argument of true will set this matcher to use transparent bounds.
* If the boolean argument is false, then opaque bounds will be used.
*
* Using transparent bounds, the boundaries of this matcher's region are transparent
* to lookahead, lookbehind, and boundary matching constructs. Those constructs can
* see text beyond the boundaries of the region while checking for a match.
*
* With opaque bounds, no text outside of the matcher's region is visible to lookahead,
* lookbehind, and boundary matching constructs.
*
* By default, a matcher uses opaque bounds.
*
* @param b TRUE for transparent bounds; FALSE for opaque bounds
* @return This Matcher;
* @stable ICU 4.0
**/
virtual RegexMatcher &useTransparentBounds(UBool b);
/**
* Return true if this matcher is using anchoring bounds.
* By default, matchers use anchoring region bounds.
*
* @return TRUE if this matcher is using anchoring bounds.
* @stable ICU 4.0
*/
virtual UBool hasAnchoringBounds() const;
/**
* Set whether this matcher is using Anchoring Bounds for its region.
* With anchoring bounds, pattern anchors such as ^ and $ will match at the start
* and end of the region. Without Anchoring Bounds, anchors will only match at
* the positions they would in the complete text.
*
* Anchoring Bounds are the default for regions.
*
* @param b TRUE if to enable anchoring bounds; FALSE to disable them.
* @return This Matcher
* @stable ICU 4.0
*/
virtual RegexMatcher &useAnchoringBounds(UBool b);
/**
* Return TRUE if the most recent matching operation attempted to access
* additional input beyond the available input text.
* In this case, additional input text could change the results of the match.
*
* hitEnd() is defined for both successful and unsuccessful matches.
* In either case hitEnd() will return TRUE if if the end of the text was
* reached at any point during the matching process.
*
* @return TRUE if the most recent match hit the end of input
* @stable ICU 4.0
*/
virtual UBool hitEnd() const;
/**
* Return TRUE the most recent match succeeded and additional input could cause
* it to fail. If this method returns false and a match was found, then more input
* might change the match but the match won't be lost. If a match was not found,
* then requireEnd has no meaning.
*
* @return TRUE if more input could cause the most recent match to no longer match.
* @stable ICU 4.0
*/
virtual UBool requireEnd() const;
/**
* Returns the pattern that is interpreted by this matcher.
* @return the RegexPattern for this RegexMatcher
* @stable ICU 2.4
*/
virtual const RegexPattern &pattern() const;
/**
* Replaces every substring of the input that matches the pattern
* with the given replacement string. This is a convenience function that
* provides a complete find-and-replace-all operation.
*
* This method first resets this matcher. It then scans the input string
* looking for matches of the pattern. Input that is not part of any
* match is left unchanged; each match is replaced in the result by the
* replacement string. The replacement string may contain references to
* capture groups.
*
* @param replacement a string containing the replacement text.
* @param status a reference to a UErrorCode to receive any errors.
* @return a string containing the results of the find and replace.
* @stable ICU 2.4
*/
virtual UnicodeString replaceAll(const UnicodeString &replacement, UErrorCode &status);
/**
* Replaces every substring of the input that matches the pattern
* with the given replacement string. This is a convenience function that
* provides a complete find-and-replace-all operation.
*
* This method first resets this matcher. It then scans the input string
* looking for matches of the pattern. Input that is not part of any
* match is left unchanged; each match is replaced in the result by the
* replacement string. The replacement string may contain references to
* capture groups.
*
* @param replacement a string containing the replacement text.
* @param dest a mutable UText in which the results are placed.
* If NULL, a new UText will be created (which may not be mutable).
* @param status a reference to a UErrorCode to receive any errors.
* @return a string containing the results of the find and replace.
* If a pre-allocated UText was provided, it will always be used and returned.
*
* @stable ICU 4.6
*/
virtual UText *replaceAll(UText *replacement, UText *dest, UErrorCode &status);
/**
* Replaces the first substring of the input that matches
* the pattern with the replacement string. This is a convenience
* function that provides a complete find-and-replace operation.
*
*
This function first resets this RegexMatcher. It then scans the input string * looking for a match of the pattern. Input that is not part * of the match is appended directly to the result string; the match is replaced * in the result by the replacement string. The replacement string may contain * references to captured groups.
* *The state of the matcher (the position at which a subsequent find() * would begin) after completing a replaceFirst() is not specified. The * RegexMatcher should be reset before doing additional find() operations.
* * @param replacement a string containing the replacement text. * @param status a reference to a UErrorCode to receive any errors. * @return a string containing the results of the find and replace. * @stable ICU 2.4 */ virtual UnicodeString replaceFirst(const UnicodeString &replacement, UErrorCode &status); /** * Replaces the first substring of the input that matches * the pattern with the replacement string. This is a convenience * function that provides a complete find-and-replace operation. * *This function first resets this RegexMatcher. It then scans the input string * looking for a match of the pattern. Input that is not part * of the match is appended directly to the result string; the match is replaced * in the result by the replacement string. The replacement string may contain * references to captured groups.
* *The state of the matcher (the position at which a subsequent find() * would begin) after completing a replaceFirst() is not specified. The * RegexMatcher should be reset before doing additional find() operations.
* * @param replacement a string containing the replacement text. * @param dest a mutable UText in which the results are placed. * If NULL, a new UText will be created (which may not be mutable). * @param status a reference to a UErrorCode to receive any errors. * @return a string containing the results of the find and replace. * If a pre-allocated UText was provided, it will always be used and returned. * * @stable ICU 4.6 */ virtual UText *replaceFirst(UText *replacement, UText *dest, UErrorCode &status); /** * Implements a replace operation intended to be used as part of an * incremental find-and-replace. * *The input string, starting from the end of the previous replacement and ending at * the start of the current match, is appended to the destination string. Then the * replacement string is appended to the output string, * including handling any substitutions of captured text.
* *For simple, prepackaged, non-incremental find-and-replace * operations, see replaceFirst() or replaceAll().
* * @param dest A UnicodeString to which the results of the find-and-replace are appended. * @param replacement A UnicodeString that provides the text to be substituted for * the input text that matched the regexp pattern. The replacement * text may contain references to captured text from the * input. * @param status A reference to a UErrorCode to receive any errors. Possible * errors are U_REGEX_INVALID_STATE if no match has been * attempted or the last match failed, and U_INDEX_OUTOFBOUNDS_ERROR * if the replacement text specifies a capture group that * does not exist in the pattern. * * @return this RegexMatcher * @stable ICU 2.4 * */ virtual RegexMatcher &appendReplacement(UnicodeString &dest, const UnicodeString &replacement, UErrorCode &status); /** * Implements a replace operation intended to be used as part of an * incremental find-and-replace. * *The input string, starting from the end of the previous replacement and ending at * the start of the current match, is appended to the destination string. Then the * replacement string is appended to the output string, * including handling any substitutions of captured text.
* *For simple, prepackaged, non-incremental find-and-replace * operations, see replaceFirst() or replaceAll().
* * @param dest A mutable UText to which the results of the find-and-replace are appended. * Must not be NULL. * @param replacement A UText that provides the text to be substituted for * the input text that matched the regexp pattern. The replacement * text may contain references to captured text from the input. * @param status A reference to a UErrorCode to receive any errors. Possible * errors are U_REGEX_INVALID_STATE if no match has been * attempted or the last match failed, and U_INDEX_OUTOFBOUNDS_ERROR * if the replacement text specifies a capture group that * does not exist in the pattern. * * @return this RegexMatcher * * @stable ICU 4.6 */ virtual RegexMatcher &appendReplacement(UText *dest, UText *replacement, UErrorCode &status); /** * As the final step in a find-and-replace operation, append the remainder * of the input string, starting at the position following the last appendReplacement(), * to the destination string.appendTail() is intended to be invoked after one
* or more invocations of the RegexMatcher::appendReplacement().
*
* @param dest A UnicodeString to which the results of the find-and-replace are appended.
* @return the destination string.
* @stable ICU 2.4
*/
virtual UnicodeString &appendTail(UnicodeString &dest);
/**
* As the final step in a find-and-replace operation, append the remainder
* of the input string, starting at the position following the last appendReplacement(),
* to the destination string. appendTail() is intended to be invoked after one
* or more invocations of the RegexMatcher::appendReplacement().
*
* @param dest A mutable UText to which the results of the find-and-replace are appended.
* Must not be NULL.
* @param status error cod
* @return the destination string.
*
* @stable ICU 4.6
*/
virtual UText *appendTail(UText *dest, UErrorCode &status);
/**
* Split a string into fields. Somewhat like split() from Perl.
* The pattern matches identify delimiters that separate the input
* into fields. The input data between the matches becomes the
* fields themselves.
*
* @param input The string to be split into fields. The field delimiters
* match the pattern (in the "this" object). This matcher
* will be reset to this input string.
* @param dest An array of UnicodeStrings to receive the results of the split.
* This is an array of actual UnicodeString objects, not an
* array of pointers to strings. Local (stack based) arrays can
* work well here.
* @param destCapacity The number of elements in the destination array.
* If the number of fields found is less than destCapacity, the
* extra strings in the destination array are not altered.
* If the number of destination strings is less than the number
* of fields, the trailing part of the input string, including any
* field delimiters, is placed in the last destination string.
* @param status A reference to a UErrorCode to receive any errors.
* @return The number of fields into which the input string was split.
* @stable ICU 2.6
*/
virtual int32_t split(const UnicodeString &input,
UnicodeString dest[],
int32_t destCapacity,
UErrorCode &status);
/**
* Split a string into fields. Somewhat like split() from Perl.
* The pattern matches identify delimiters that separate the input
* into fields. The input data between the matches becomes the
* fields themselves.
*
* @param input The string to be split into fields. The field delimiters
* match the pattern (in the "this" object). This matcher
* will be reset to this input string.
* @param dest An array of mutable UText structs to receive the results of the split.
* If a field is NULL, a new UText is allocated to contain the results for
* that field. This new UText is not guaranteed to be mutable.
* @param destCapacity The number of elements in the destination array.
* If the number of fields found is less than destCapacity, the
* extra strings in the destination array are not altered.
* If the number of destination strings is less than the number
* of fields, the trailing part of the input string, including any
* field delimiters, is placed in the last destination string.
* @param status A reference to a UErrorCode to receive any errors.
* @return The number of fields into which the input string was split.
*
* @stable ICU 4.6
*/
virtual int32_t split(UText *input,
UText *dest[],
int32_t destCapacity,
UErrorCode &status);
/**
* Set a processing time limit for match operations with this Matcher.
*
* Some patterns, when matching certain strings, can run in exponential time.
* For practical purposes, the match operation may appear to be in an
* infinite loop.
* When a limit is set a match operation will fail with an error if the
* limit is exceeded.
* * The units of the limit are steps of the match engine. * Correspondence with actual processor time will depend on the speed * of the processor and the details of the specific pattern, but will * typically be on the order of milliseconds. *
* By default, the matching time is not limited. *
* * @param limit The limit value, or 0 for no limit. * @param status A reference to a UErrorCode to receive any errors. * @stable ICU 4.0 */ virtual void setTimeLimit(int32_t limit, UErrorCode &status); /** * Get the time limit, if any, for match operations made with this Matcher. * * @return the maximum allowed time for a match, in units of processing steps. * @stable ICU 4.0 */ virtual int32_t getTimeLimit() const; /** * Set the amount of heap storage available for use by the match backtracking stack. * The matcher is also reset, discarding any results from previous matches. *
* ICU uses a backtracking regular expression engine, with the backtrack stack * maintained on the heap. This function sets the limit to the amount of memory * that can be used for this purpose. A backtracking stack overflow will * result in an error from the match operation that caused it. *
* A limit is desirable because a malicious or poorly designed pattern can use * excessive memory, potentially crashing the process. A limit is enabled * by default. *
* @param limit The maximum size, in bytes, of the matching backtrack stack. * A value of zero means no limit. * The limit must be greater or equal to zero. * * @param status A reference to a UErrorCode to receive any errors. * * @stable ICU 4.0 */ virtual void setStackLimit(int32_t limit, UErrorCode &status); /** * Get the size of the heap storage available for use by the back tracking stack. * * @return the maximum backtracking stack size, in bytes, or zero if the * stack size is unlimited. * @stable ICU 4.0 */ virtual int32_t getStackLimit() const; /** * Set a callback function for use with this Matcher. * During matching operations the function will be called periodically, * giving the application the opportunity to terminate a long-running * match. * * @param callback A pointer to the user-supplied callback function. * @param context User context pointer. The value supplied at the * time the callback function is set will be saved * and passed to the callback each time that it is called. * @param status A reference to a UErrorCode to receive any errors. * @stable ICU 4.0 */ virtual void setMatchCallback(URegexMatchCallback *callback, const void *context, UErrorCode &status); /** * Get the callback function for this URegularExpression. * * @param callback Out parameter, receives a pointer to the user-supplied * callback function. * @param context Out parameter, receives the user context pointer that * was set when uregex_setMatchCallback() was called. * @param status A reference to a UErrorCode to receive any errors. * @stable ICU 4.0 */ virtual void getMatchCallback(URegexMatchCallback *&callback, const void *&context, UErrorCode &status); /** * Set a progress callback function for use with find operations on this Matcher. * During find operations, the callback will be invoked after each return from a * match attempt, giving the application the opportunity to terminate a long-running * find operation. * * @param callback A pointer to the user-supplied callback function. * @param context User context pointer. The value supplied at the * time the callback function is set will be saved * and passed to the callback each time that it is called. * @param status A reference to a UErrorCode to receive any errors. * @stable ICU 4.6 */ virtual void setFindProgressCallback(URegexFindProgressCallback *callback, const void *context, UErrorCode &status); /** * Get the find progress callback function for this URegularExpression. * * @param callback Out parameter, receives a pointer to the user-supplied * callback function. * @param context Out parameter, receives the user context pointer that * was set when uregex_setFindProgressCallback() was called. * @param status A reference to a UErrorCode to receive any errors. * @stable ICU 4.6 */ virtual void getFindProgressCallback(URegexFindProgressCallback *&callback, const void *&context, UErrorCode &status); #ifndef U_HIDE_INTERNAL_API /** * setTrace Debug function, enable/disable tracing of the matching engine. * For internal ICU development use only. DO NO USE!!!! * @internal */ void setTrace(UBool state); #endif /* U_HIDE_INTERNAL_API */ /** * ICU "poor man's RTTI", returns a UClassID for this class. * * @stable ICU 2.2 */ static UClassID U_EXPORT2 getStaticClassID(); /** * ICU "poor man's RTTI", returns a UClassID for the actual class. * * @stable ICU 2.2 */ virtual UClassID getDynamicClassID() const; private: // Constructors and other object boilerplate are private. // Instances of RegexMatcher can not be assigned, copied, cloned, etc. RegexMatcher(); // default constructor not implemented RegexMatcher(const RegexPattern *pat); RegexMatcher(const RegexMatcher &other); RegexMatcher &operator =(const RegexMatcher &rhs); void init(UErrorCode &status); // Common initialization void init2(UText *t, UErrorCode &e); // Common initialization, part 2. friend class RegexPattern; friend class RegexCImpl; public: #ifndef U_HIDE_INTERNAL_API /** @internal */ void resetPreserveRegion(); // Reset matcher state, but preserve any region. #endif /* U_HIDE_INTERNAL_API */ private: // // MatchAt This is the internal interface to the match engine itself. // Match status comes back in matcher member variables. // void MatchAt(int64_t startIdx, UBool toEnd, UErrorCode &status); inline void backTrack(int64_t &inputIdx, int32_t &patIdx); UBool isWordBoundary(int64_t pos); // perform Perl-like \b test UBool isUWordBoundary(int64_t pos); // perform RBBI based \b test REStackFrame *resetStack(); inline REStackFrame *StateSave(REStackFrame *fp, int64_t savePatIdx, UErrorCode &status); void IncrementTime(UErrorCode &status); // Call user find callback function, if set. Return TRUE if operation should be interrupted. inline UBool findProgressInterrupt(int64_t matchIndex, UErrorCode &status); int64_t appendGroup(int32_t groupNum, UText *dest, UErrorCode &status) const; UBool findUsingChunk(UErrorCode &status); void MatchChunkAt(int32_t startIdx, UBool toEnd, UErrorCode &status); UBool isChunkWordBoundary(int32_t pos); const RegexPattern *fPattern; RegexPattern *fPatternOwned; // Non-NULL if this matcher owns the pattern, and // should delete it when through. const UnicodeString *fInput; // The string being matched. Only used for input() UText *fInputText; // The text being matched. Is never NULL. UText *fAltInputText; // A shallow copy of the text being matched. // Only created if the pattern contains backreferences. int64_t fInputLength; // Full length of the input text. int32_t fFrameSize; // The size of a frame in the backtrack stack. int64_t fRegionStart; // Start of the input region, default = 0. int64_t fRegionLimit; // End of input region, default to input.length. int64_t fAnchorStart; // Region bounds for anchoring operations (^ or $). int64_t fAnchorLimit; // See useAnchoringBounds int64_t fLookStart; // Region bounds for look-ahead/behind and int64_t fLookLimit; // and other boundary tests. See // useTransparentBounds int64_t fActiveStart; // Currently active bounds for matching. int64_t fActiveLimit; // Usually is the same as region, but // is changed to fLookStart/Limit when // entering look around regions. UBool fTransparentBounds; // True if using transparent bounds. UBool fAnchoringBounds; // True if using anchoring bounds. UBool fMatch; // True if the last attempted match was successful. int64_t fMatchStart; // Position of the start of the most recent match int64_t fMatchEnd; // First position after the end of the most recent match // Zero if no previous match, even when a region // is active. int64_t fLastMatchEnd; // First position after the end of the previous match, // or -1 if there was no previous match. int64_t fAppendPosition; // First position after the end of the previous // appendReplacement(). As described by the // JavaDoc for Java Matcher, where it is called // "append position" UBool fHitEnd; // True if the last match touched the end of input. UBool fRequireEnd; // True if the last match required end-of-input // (matched $ or Z) UVector64 *fStack; REStackFrame *fFrame; // After finding a match, the last active stack frame, // which will contain the capture group results. // NOT valid while match engine is running. int64_t *fData; // Data area for use by the compiled pattern. int64_t fSmallData[8]; // Use this for data if it's enough. int32_t fTimeLimit; // Max time (in arbitrary steps) to let the // match engine run. Zero for unlimited. int32_t fTime; // Match time, accumulates while matching. int32_t fTickCounter; // Low bits counter for time. Counts down StateSaves. // Kept separately from fTime to keep as much // code as possible out of the inline // StateSave function. int32_t fStackLimit; // Maximum memory size to use for the backtrack // stack, in bytes. Zero for unlimited. URegexMatchCallback *fCallbackFn; // Pointer to match progress callback funct. // NULL if there is no callback. const void *fCallbackContext; // User Context ptr for callback function. URegexFindProgressCallback *fFindProgressCallbackFn; // Pointer to match progress callback funct. // NULL if there is no callback. const void *fFindProgressCallbackContext; // User Context ptr for callback function. UBool fInputUniStrMaybeMutable; // Set when fInputText wraps a UnicodeString that may be mutable - compatibility. UBool fTraceDebug; // Set true for debug tracing of match engine. UErrorCode fDeferredStatus; // Save error state that cannot be immediately // reported, or that permanently disables this matcher. RuleBasedBreakIterator *fWordBreakItr; }; U_NAMESPACE_END #endif // UCONFIG_NO_REGULAR_EXPRESSIONS #endif