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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 01:47:29 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 01:47:29 +0000
commit0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch)
treea31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /intl/icu/source/i18n/unicode/regex.h
parentInitial commit. (diff)
downloadfirefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.tar.xz
firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.zip
Adding upstream version 115.8.0esr.upstream/115.8.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+// © 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 &regex,
+ 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 &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. 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 &regex,
+ 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 &regex,
+ 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 &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.
+ *
+ * @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 &regexp, 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 &regexp, 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 &region(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 &region(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