diff options
Diffstat (limited to 'intl/icu/source/i18n/unicode/regex.h')
| -rw-r--r-- | intl/icu/source/i18n/unicode/regex.h | 1882 |
1 files changed, 1882 insertions, 0 deletions
diff --git a/intl/icu/source/i18n/unicode/regex.h b/intl/icu/source/i18n/unicode/regex.h new file mode 100644 index 0000000000..cc2f924929 --- /dev/null +++ b/intl/icu/source/i18n/unicode/regex.h @@ -0,0 +1,1882 @@ +// © 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* +********************************************************************** +* Copyright (C) 2002-2016, International Business Machines +* Corporation and others. All Rights Reserved. +********************************************************************** +* file name: regex.h +* encoding: UTF-8 +* indentation:4 +* +* created on: 2002oct22 +* created by: Andy Heninger +* +* ICU Regular Expressions, API for C++ +*/ + +#ifndef REGEX_H +#define REGEX_H + +//#define REGEX_DEBUG + +/** + * \file + * \brief C++ API: Regular Expressions + * + * 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. + * + */ + +#include "unicode/utypes.h" + +#if U_SHOW_CPLUSPLUS_API + +#if !UCONFIG_NO_REGULAR_EXPRESSIONS + +#include "unicode/uobject.h" +#include "unicode/unistr.h" +#include "unicode/utext.h" +#include "unicode/parseerr.h" + +#include "unicode/uregex.h" + +// Forward Declarations + +struct UHashtable; + +U_NAMESPACE_BEGIN + +struct Regex8BitSet; +class RegexCImpl; +class RegexMatcher; +class RegexPattern; +struct REStackFrame; +class BreakIterator; +class UnicodeSet; +class UVector; +class UVector32; +class UVector64; + + +/** + * Class `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 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 method `compile()`. + * + * @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 #URegexpFlag + * settings. + * @param that a RegexPattern object to compare with "this". + * @return true if the objects are equivalent. + * @stable ICU 2.4 + */ + bool operator==(const RegexPattern& that) const; + + /** + * Comparison operator. Two RegexPattern objects are considered equal if they + * were constructed from identical source patterns using the same #URegexpFlag + * settings. + * @param that a RegexPattern object to compare with "this". + * @return true if the objects are different. + * @stable ICU 2.4 + */ + inline bool 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, <code>clone()</code> 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 #URegexpFlag 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 #URegexpFlag 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 #URegexpFlag 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 #URegexpFlag match mode flags to be used, e.g. #UREGEX_CASE_INSENSITIVE. + * @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 #URegexpFlag 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 #URegexpFlag match mode flags to be used, e.g. #UREGEX_CASE_INSENSITIVE. + * @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 #URegexpFlag 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 #URegexpFlag match mode flags to be used, e.g. #UREGEX_CASE_INSENSITIVE. + * @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 #URegexpFlag 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 #URegexpFlag match mode flags to be used, e.g. #UREGEX_CASE_INSENSITIVE. + * @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 #URegexpFlag match mode flags that were used when compiling this pattern. + * @return the #URegexpFlag 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 = delete; +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, + * <code>RegexMatcher::split</code> 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 nullptr, 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 override; + + /** + * 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. + + 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. + bool initNamedCaptureMap(); // Lazy init for fNamedCaptureMap. + 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. + * + * <p>Class RegexMatcher is not intended to be subclassed.</p> + * + * @stable ICU 2.4 + */ +class U_I18N_API RegexMatcher 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 #URegexpFlag options, such as #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 #URegexpFlag options, such as #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 #URegexpFlag options, such as #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 #URegexpFlag options, such as #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) = delete; +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. + * + * @param status A reference to a UErrorCode to receive any errors. + * @return true if there is a match at the start of the input string. + * @stable ICU 2.4 + */ + virtual UBool lookingAt(UErrorCode &status); + + + /** + * Attempts to match the input string, starting from the specified index, against the pattern. + * The match may be of any length, and is not required to extend to the end + * of the input string. Contrast with match(). + * + * If the match succeeds then more information can be obtained via the start(), + * end(), and group() functions. + * + * @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 lookingAt(int64_t startIndex, UErrorCode &status); + + + /** + * 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. + * @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 nullptr 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-nullptr, 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 nullptr 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-nullptr, 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) = delete; +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 nullptr to create a new UText + * @param status error code + * @return dest if non-nullptr, 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 nullptr, 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 nullptr, 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 nullptr. + * @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 nullptr. + * @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 nullptr, 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 override; + +private: + // Constructors and other object boilerplate are private. + // Instances of RegexMatcher can not be assigned, copied, cloned, etc. + RegexMatcher() = delete; // default constructor not implemented + RegexMatcher(const RegexPattern *pat); + RegexMatcher(const RegexMatcher &other) = delete; + RegexMatcher &operator =(const RegexMatcher &rhs) = delete; + 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, UErrorCode &status); // perform RBBI based \b test + // Find a grapheme cluster boundary using a break iterator. For handling \X in regexes. + int64_t followingGCBoundary(int64_t pos, UErrorCode &status); + 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-nullptr 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 nullptr. + 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. + // nullptr if there is no callback. + const void *fCallbackContext; // User Context ptr for callback function. + + URegexFindProgressCallback *fFindProgressCallbackFn; // Pointer to match progress callback funct. + // nullptr 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. + + BreakIterator *fWordBreakItr; + BreakIterator *fGCBreakItr; +}; + +U_NAMESPACE_END +#endif // UCONFIG_NO_REGULAR_EXPRESSIONS + +#endif /* U_SHOW_CPLUSPLUS_API */ + +#endif |