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: 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 subclasses, 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 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 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, 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); /** * 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 accidently attempts to * create a matcher with a (UChar *) string as input rather than * a UnicodeString. Avoids a dangling reference to a temporary string. *
* To efficiently work with UChar *strings, wrap the data in a UnicodeString
* using one of the aliasing constructors, such as
* UnicodeString(UBool isTerminated, const UChar *text, int32_t textLength);
*
* @internal
*/
RegexMatcher *matcher(const UChar *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 reguluar 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);
/**
* Returns the regular expression from which this pattern was compiled.
* @stable ICU 2.4
*/
virtual UnicodeString pattern() const;
/**
* 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.
*
* For the best performance on split() operations,
* RegexMatcher::split is perferable 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;
/**
* 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
//
UnicodeString fPattern; // The original pattern string.
uint32_t fFlags; // The flags used when compiling the pattern.
//
UVector32 *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.
int32_t fMaxCaptureDigits;
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;
friend class RegexCompile;
friend class RegexMatcher;
friend class RegexCImpl;
//
// Implementation Methods
//
void init(); // Common initialization, for use by constructors.
void zap(); // Common cleanup
#ifdef REGEX_DEBUG
void dumpOp(int32_t index) const;
friend void U_EXPORT2 RegexPatternDump(const RegexPattern *);
#endif
};
/**
* class RegexMatcher bundles together a reular 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: 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. ** 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); private: /** * Cause a compilation error if an application accidently attempts to * create a matcher with a (UChar *) string as input rather than * a UnicodeString. Avoids a dangling reference to a temporary string. *
* To efficiently work with UChar *strings, wrap the data in a UnicodeString
* using one of the aliasing constructors, such as
* UnicodeString(UBool isTerminated, const UChar *text, int32_t textLength);
*
* @internal
*/
RegexMatcher(const UnicodeString ®exp, const UChar *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 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(int32_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(); /** * 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 position 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(int32_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. * * @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 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 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 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 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 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. * @stable ICU 2.4 */ virtual int32_t end(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 specifed group during the previous match operation. * Return -1 if the capture group exists in the pattern but was not part of the match. * @stable ICU 2.4 */ virtual int32_t end(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 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(int32_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. * @return this RegexMatcher. * @stable ICU 2.4 */ virtual RegexMatcher &reset(const UnicodeString &input); private: /** * Cause a compilation error if an application accidently attempts to * reset a matcher with a (UChar *) string as input rather than * a UnicodeString. Avoids a dangling reference to a temporary string. *
* To efficiently work with UChar *strings, wrap the data in a UnicodeString
* using one of the aliasing constructors, such as
* UnicodeString(UBool isTerminated, const UChar *text, int32_t textLength);
*
* @internal
*/
RegexMatcher &reset(const UChar *input);
public:
/**
* Returns the input string being matched. The returned string is not a copy,
* but the live input string. It should not be altered or deleted.
* @return the input string
* @stable ICU 2.4
*/
virtual const UnicodeString &input() 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 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(int32_t start, int32_t limit, 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 index of this matcher's region.
* @stable ICU 4.0
*/
virtual int32_t regionStart() 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 of this matcher's region.
* @stable ICU 4.0
*/
virtual int32_t regionEnd() 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 boounds.
*
* @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 touched the
* end of the text being processed. In this case, additional input text could
* change the results of that 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 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); /** * 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); /** * 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);
/**
* 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); /** * 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 avaliable 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 paramater, 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); /** * setTrace Debug function, enable/disable tracing of the matching engine. * For internal ICU development use only. DO NO USE!!!! * @internal */ void setTrace(UBool state); /** * 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(const UnicodeString &s, UErrorCode &e); // Common initialization, part 2. friend class RegexPattern; friend class RegexCImpl; public: /** @internal */ void resetPreserveRegion(); // Reset matcher state, but preserve any region. private: // // MatchAt This is the internal interface to the match engine itself. // Match status comes back in matcher member variables. // void MatchAt(int32_t startIdx, UBool toEnd, UErrorCode &status); inline void backTrack(int32_t &inputIdx, int32_t &patIdx); UBool isWordBoundary(int32_t pos); // perform Perl-like \b test UBool isUWordBoundary(int32_t pos); // perform RBBI based \b test REStackFrame *resetStack(); inline REStackFrame *StateSave(REStackFrame *fp, int32_t savePatIdx, UErrorCode &status); void IncrementTime(UErrorCode &status); const RegexPattern *fPattern; RegexPattern *fPatternOwned; // Non-NULL if this matcher owns the pattern, and // should delete it when through. const UnicodeString *fInput; // The text being matched. Is never NULL. int32_t fFrameSize; // The size of a frame in the backtrack stack. int32_t fRegionStart; // Start of the input region, default = 0. int32_t fRegionLimit; // End of input region, default to input.length. int32_t fAnchorStart; // Region bounds for anchoring operations (^ or $). int32_t fAnchorLimit; // See useAnchoringBounds int32_t fLookStart; // Region bounds for look-ahead/behind and int32_t fLookLimit; // and other boundary tests. See // useTransparentBounds int32_t fActiveStart; // Currently active bounds for matching. int32_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. int32_t fMatchStart; // Position of the start of the most recent match int32_t fMatchEnd; // First position after the end of the most recent match // Zero if no previous match, even when a region // is active. int32_t fLastMatchEnd; // First position after the end of the previous match, // or -1 if there was no previous match. int32_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) UVector32 *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. int32_t *fData; // Data area for use by the compiled pattern. int32_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. 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