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haiku/headers/libs/icu/unicode/regex.h
Oliver Tappe 75f1522155 * reintegrated gsoc-locale-kit branch into trunk - there's more 
work to do, but it's about time to give this code more exposure.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33176 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-09-18 22:23:34 +00:00

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/*
**********************************************************************
* Copyright (C) 2002-2009, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
* file name: regex.h
* encoding: US-ASCII
* 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
*
* <h2>Regular Expression API</h2>
*
* <p>The ICU API for processing regular expressions consists of two classes,
* <code>RegexPattern</code> and <code>RegexMatcher</code>.
* <code>RegexPattern</code> objects represent a pre-processed, or compiled
* regular expression. They are created from a regular expression pattern string,
* and can be used to create <code>RegexMatcher</code> objects for the pattern.</p>
*
* <p>Class <code>RegexMatcher</code> bundles together a regular expression
* pattern and a target string to which the search pattern will be applied.
* <code>RegexMatcher</code> includes API for doing plain find or search
* operations, for search and replace operations, and for obtaining detailed
* information about bounds of a match. </p>
*
* <p>Note that by constructing <code>RegexMatcher</code> objects directly from regular
* expression pattern strings application code can be simplified and the explicit
* need for <code>RegexPattern</code> objects can usually be eliminated.
* </p>
*/
#include "unicode/utypes.h"
#if !UCONFIG_NO_REGULAR_EXPRESSIONS
#include "unicode/uobject.h"
#include "unicode/unistr.h"
#include "unicode/parseerr.h"
#include "unicode/uregex.h"
U_NAMESPACE_BEGIN
// Forward Declarations...
class RegexMatcher;
class RegexPattern;
class UVector;
class UVector32;
class UnicodeSet;
struct REStackFrame;
struct Regex8BitSet;
class RuleBasedBreakIterator;
class RegexCImpl;
/**
* RBBIPatternDump Debug function, displays the compiled form of a pattern.
* @internal
*/
#ifdef REGEX_DEBUG
U_INTERNAL void U_EXPORT2
RegexPatternDump(const RegexPattern *pat);
#else
#define RegexPatternDump(pat)
#endif
/**
* Class <code>RegexPattern</code> 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.
*
* <p>Class RegexPattern is not intended to be subclassed.</p>
*
* @stable ICU 2.4
*/
class U_I18N_API RegexPattern: public UObject {
public:
/**
* default constructor. Create a RegexPattern object that refers to no actual
* pattern. Not normally needed; RegexPattern objects are usually
* created using the factory method <code>compile()</code>.
*
* @stable ICU 2.4
*/
RegexPattern();
/**
* Copy Constructor. Create a new RegexPattern object that is equivalent
* to the source object.
* @param source the pattern object to be copied.
* @stable ICU 2.4
*/
RegexPattern(const RegexPattern &source);
/**
* Destructor. Note that a RegexPattern object must persist so long as any
* RegexMatcher objects that were created from the RegexPattern are active.
* @stable ICU 2.4
*/
virtual ~RegexPattern();
/**
* Comparison operator. Two RegexPattern objects are considered equal if they
* were constructed from identical source patterns using the same match flag
* settings.
* @param that a RegexPattern object to compare with "this".
* @return TRUE if the objects are equivalent.
* @stable ICU 2.4
*/
UBool operator==(const RegexPattern& that) const;
/**
* Comparison operator. Two RegexPattern objects are considered equal if they
* were constructed from identical source patterns using the same match flag
* settings.
* @param that a RegexPattern object to compare with "this".
* @return TRUE if the objects are different.
* @stable ICU 2.4
*/
inline UBool operator!=(const RegexPattern& that) const {return ! operator ==(that);};
/**
* Assignment operator. After assignment, this RegexPattern will behave identically
* to the source object.
* @stable ICU 2.4
*/
RegexPattern &operator =(const RegexPattern &source);
/**
* Create an exact copy of this RegexPattern object. Since RegexPattern is not
* intended to be subclasses, <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.
*
* <p>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.</p>
*
* <p>All pattern match mode flags are set to their default values.</p>
*
* <p>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.</p>
*
* @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 using the specified match mode flags. These compile methods,
* rather than the constructors, are the usual way that RegexPattern objects
* are created.
*
* <p>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.</p>
*
* <p>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.</p>
*
* @param regex The regular expression to be compiled.
* @param flags The match mode flags to be used.
* @param pe Receives the position (line and column nubers) of any error
* within the regular expression.)
* @param status A reference to a UErrorCode to receive any errors.
* @return A regexPattern object for the compiled pattern.
*
* @stable ICU 2.4
*/
static RegexPattern * U_EXPORT2 compile( const UnicodeString &regex,
uint32_t flags,
UParseError &pe,
UErrorCode &status);
/**
* Compiles the regular expression in string form into a RegexPattern
* object using the specified match mode flags. These compile methods,
* rather than the constructors, are the usual way that RegexPattern objects
* are created.
*
* <p>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.</p>
*
* <p>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.</p>
*
* @param regex The regular expression to be compiled.
* @param flags The match mode flags to be used.
* @param status A reference to a UErrorCode to receive any errors.
* @return A regexPattern object for the compiled pattern.
*
* @stable ICU 2.6
*/
static RegexPattern * U_EXPORT2 compile( const UnicodeString &regex,
uint32_t flags,
UErrorCode &status);
/**
* Get the match mode flags that were used when compiling this pattern.
* @return the match mode flags
* @stable ICU 2.4
*/
virtual uint32_t flags() const;
/**
* Creates a RegexMatcher that will match the given input against this pattern. The
* RegexMatcher can then be used to perform match, find or replace operations
* on the input. Note that a RegexPattern object must not be deleted while
* RegexMatchers created from it still exist and might possibly be used again.
* <p>
* The matcher will retain a reference to the supplied input string, and all regexp
* pattern matching operations happen directly on this original string. It is
* critical that the string not be altered or deleted before use by the regular
* expression operations is complete.
*
* @param input The input string to which the regular expression will be applied.
* @param status A reference to a UErrorCode to receive any errors.
* @return A RegexMatcher object for this pattern and input.
*
* @stable ICU 2.4
*/
virtual RegexMatcher *matcher(const UnicodeString &input,
UErrorCode &status) const;
private:
/**
* Cause a compilation error if an application accidently attempts to
* create a matcher with a (UChar *) string as input rather than
* a UnicodeString. Avoids a dangling reference to a temporary string.
* <p>
* To efficiently work with UChar *strings, wrap the data in a UnicodeString
* using one of the aliasing constructors, such as
* <code>UnicodeString(UBool isTerminated, const UChar *text, int32_t textLength);</code>
*
* @internal
*/
RegexMatcher *matcher(const UChar *input,
UErrorCode &status) const;
public:
/**
* Creates a RegexMatcher that will match against this pattern. The
* RegexMatcher can be used to perform match, find or replace operations.
* Note that a RegexPattern object must not be deleted while
* RegexMatchers created from it still exist and might possibly be used again.
*
* @param status A reference to a UErrorCode to receive any errors.
* @return A RegexMatcher object for this pattern and input.
*
* @stable ICU 2.6
*/
virtual RegexMatcher *matcher(UErrorCode &status) const;
/**
* Test whether a string matches a regular expression. This convenience function
* both compiles the reguluar expression and applies it in a single operation.
* Note that if the same pattern needs to be applied repeatedly, this method will be
* less efficient than creating and reusing a RegexMatcher object.
*
* @param regex The regular expression
* @param input The string data to be matched
* @param pe Receives the position of any syntax errors within the regular expression
* @param status A reference to a UErrorCode to receive any errors.
* @return True if the regular expression exactly matches the full input string.
*
* @stable ICU 2.4
*/
static UBool U_EXPORT2 matches(const UnicodeString &regex,
const UnicodeString &input,
UParseError &pe,
UErrorCode &status);
/**
* Returns the regular expression from which this pattern was compiled.
* @stable ICU 2.4
*/
virtual UnicodeString pattern() const;
/**
* Split a string into fields. Somewhat like split() from Perl.
* The pattern matches identify delimiters that separate the input
* into fields. The input data between the matches becomes the
* fields themselves.
* <p>
* For the best performance on split() operations,
* <code>RegexMatcher::split</code> is perferable to this function
*
* @param input The string to be split into fields. The field delimiters
* match the pattern (in the "this" object)
* @param dest An array of UnicodeStrings to receive the results of the split.
* This is an array of actual UnicodeString objects, not an
* array of pointers to strings. Local (stack based) arrays can
* work well here.
* @param destCapacity The number of elements in the destination array.
* If the number of fields found is less than destCapacity, the
* extra strings in the destination array are not altered.
* If the number of destination strings is less than the number
* of fields, the trailing part of the input string, including any
* field delimiters, is placed in the last destination string.
* @param status A reference to a UErrorCode to receive any errors.
* @return The number of fields into which the input string was split.
* @stable ICU 2.4
*/
virtual int32_t split(const UnicodeString &input,
UnicodeString dest[],
int32_t destCapacity,
UErrorCode &status) const;
/**
* ICU "poor man's RTTI", returns a UClassID for the actual class.
*
* @stable ICU 2.4
*/
virtual UClassID getDynamicClassID() const;
/**
* ICU "poor man's RTTI", returns a UClassID for this class.
*
* @stable ICU 2.4
*/
static UClassID U_EXPORT2 getStaticClassID();
private:
//
// Implementation Data
//
UnicodeString fPattern; // The original pattern string.
uint32_t fFlags; // The flags used when compiling the pattern.
//
UVector32 *fCompiledPat; // The compiled pattern p-code.
UnicodeString fLiteralText; // Any literal string data from the pattern,
// after un-escaping, for use during the match.
UVector *fSets; // Any UnicodeSets referenced from the pattern.
Regex8BitSet *fSets8; // (and fast sets for latin-1 range.)
UErrorCode fDeferredStatus; // status if some prior error has left this
// RegexPattern in an unusable state.
int32_t fMinMatchLen; // Minimum Match Length. All matches will have length
// >= this value. For some patterns, this calculated
// value may be less than the true shortest
// possible match.
int32_t fFrameSize; // Size of a state stack frame in the
// execution engine.
int32_t fDataSize; // The size of the data needed by the pattern that
// does not go on the state stack, but has just
// a single copy per matcher.
UVector32 *fGroupMap; // Map from capture group number to position of
// the group's variables in the matcher stack frame.
int32_t fMaxCaptureDigits;
UnicodeSet **fStaticSets; // Ptr to static (shared) sets for predefined
// regex character classes, e.g. Word.
Regex8BitSet *fStaticSets8; // Ptr to the static (shared) latin-1 only
// sets for predefined regex classes.
int32_t fStartType; // Info on how a match must start.
int32_t fInitialStringIdx; //
int32_t fInitialStringLen;
UnicodeSet *fInitialChars;
UChar32 fInitialChar;
Regex8BitSet *fInitialChars8;
friend class RegexCompile;
friend class RegexMatcher;
friend class RegexCImpl;
//
// Implementation Methods
//
void init(); // Common initialization, for use by constructors.
void zap(); // Common cleanup
#ifdef REGEX_DEBUG
void dumpOp(int32_t index) const;
friend void U_EXPORT2 RegexPatternDump(const RegexPattern *);
#endif
};
/**
* class RegexMatcher bundles together a reular expression pattern and
* input text to which the expression can be applied. It includes methods
* for testing for matches, and for find and replace operations.
*
* <p>Class RegexMatcher is not intended to be subclassed.</p>
*
* @stable ICU 2.4
*/
class U_I18N_API RegexMatcher: public UObject {
public:
/**
* Construct a RegexMatcher for a regular expression.
* This is a convenience method that avoids the need to explicitly create
* a RegexPattern object. Note that if several RegexMatchers need to be
* created for the same expression, it will be more efficient to
* separately create and cache a RegexPattern object, and use
* its matcher() method to create the RegexMatcher objects.
*
* @param regexp The Regular Expression to be compiled.
* @param flags Regular expression options, such as case insensitive matching.
* @see UREGEX_CASE_INSENSITIVE
* @param status Any errors are reported by setting this UErrorCode variable.
* @stable ICU 2.6
*/
RegexMatcher(const UnicodeString &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.
* <p>
* The matcher will retain a reference to the supplied input string, and all regexp
* pattern matching operations happen directly on the original string. It is
* critical that the string not be altered or deleted before use by the regular
* expression operations is complete.
*
* @param regexp The Regular Expression to be compiled.
* @param input The string to match. The matcher retains a reference to the
* caller's string; mo copy is made.
* @param flags Regular expression options, such as case insensitive matching.
* @see UREGEX_CASE_INSENSITIVE
* @param status Any errors are reported by setting this UErrorCode variable.
* @stable ICU 2.6
*/
RegexMatcher(const UnicodeString &regexp, const UnicodeString &input,
uint32_t flags, UErrorCode &status);
private:
/**
* Cause a compilation error if an application accidently attempts to
* create a matcher with a (UChar *) string as input rather than
* a UnicodeString. Avoids a dangling reference to a temporary string.
* <p>
* To efficiently work with UChar *strings, wrap the data in a UnicodeString
* using one of the aliasing constructors, such as
* <code>UnicodeString(UBool isTerminated, const UChar *text, int32_t textLength);</code>
*
* @internal
*/
RegexMatcher(const UnicodeString &regexp, const UChar *input,
uint32_t flags, UErrorCode &status);
public:
/**
* Destructor.
*
* @stable ICU 2.4
*/
virtual ~RegexMatcher();
/**
* Attempts to match the entire input region against the pattern.
* @param status A reference to a UErrorCode to receive any errors.
* @return TRUE if there is a match
* @stable ICU 2.4
*/
virtual UBool matches(UErrorCode &status);
/**
* Resets the matcher, then attempts to match the input beginning
* at the specified startIndex, and extending to the end of the input.
* The input region is reset to include the entire input string.
* A successful match must extend to the end of the input.
* @param startIndex The input string index at which to begin matching.
* @param status A reference to a UErrorCode to receive any errors.
* @return TRUE if there is a match
* @stable ICU 2.8
*/
virtual UBool matches(int32_t startIndex, UErrorCode &status);
/**
* Attempts to match the input string, starting from the beginning of the region,
* against the pattern. Like the matches() method, this function
* always starts at the beginning of the input region;
* unlike that function, it does not require that the entire region be matched.
*
* <p>If the match succeeds then more information can be obtained via the <code>start()</code>,
* <code>end()</code>, and <code>group()</code> functions.</p>
*
* @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().
*
* <p>If the match succeeds then more information can be obtained via the <code>start()</code>,
* <code>end()</code>, and <code>group()</code> functions.</p>
*
* @param startIndex The input string index at which to begin matching.
* @param status A reference to a UErrorCode to receive any errors.
* @return TRUE if there is a match.
* @stable ICU 2.8
*/
virtual UBool lookingAt(int32_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, <code>start(), end()</code> and <code>group()</code>
* will provide more information regarding the match.
* <p>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.</p>
* @return TRUE if a match is found.
* @stable ICU 2.4
*/
virtual UBool find();
/**
* Resets this RegexMatcher and then attempts to find the next substring of the
* input string that matches the pattern, starting at the specified index.
*
* @param start the position in the input string to begin the search
* @param status A reference to a UErrorCode to receive any errors.
* @return TRUE if a match is found.
* @stable ICU 2.4
*/
virtual UBool find(int32_t start, UErrorCode &status);
/**
* Returns a string containing the text matched by the previous match.
* If the pattern can match an empty string, an empty string may be returned.
* @param status A reference to a UErrorCode to receive any errors.
* Possible errors are U_REGEX_INVALID_STATE if no match
* has been attempted or the last match failed.
* @return a string containing the matched input text.
* @stable ICU 2.4
*/
virtual UnicodeString group(UErrorCode &status) const;
/**
* Returns a string containing the text captured by the given group
* during the previous match operation. Group(0) is the entire match.
*
* @param groupNum the capture group number
* @param status A reference to a UErrorCode to receive any errors.
* Possible errors are U_REGEX_INVALID_STATE if no match
* has been attempted or the last match failed and
* U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number.
* @return the captured text
* @stable ICU 2.4
*/
virtual UnicodeString group(int32_t groupNum, UErrorCode &status) const;
/**
* Returns the number of capturing groups in this matcher's pattern.
* @return the number of capture groups
* @stable ICU 2.4
*/
virtual int32_t groupCount() const;
/**
* Returns the index in the input string of the start of the text matched
* during the previous match operation.
* @param status a reference to a UErrorCode to receive any errors.
* @return The position in the input string of the start of the last match.
* @stable ICU 2.4
*/
virtual int32_t start(UErrorCode &status) const;
/**
* Returns the index in the input string of the start of the text matched by the
* specified capture group during the previous match operation. Return -1 if
* the capture group exists in the pattern, but was not part of the last match.
*
* @param group the capture group number
* @param status A reference to a UErrorCode to receive any errors. Possible
* errors are U_REGEX_INVALID_STATE if no match has been
* attempted or the last match failed, and
* U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number
* @return the start position of substring matched by the specified group.
* @stable ICU 2.4
*/
virtual int32_t start(int32_t group, UErrorCode &status) const;
/**
* Returns the index in the input string of the first character following the
* text matched during the previous match operation.
* @param status A reference to a UErrorCode to receive any errors. Possible
* errors are U_REGEX_INVALID_STATE if no match has been
* attempted or the last match failed.
* @return the index of the last character matched, plus one.
* @stable ICU 2.4
*/
virtual int32_t end(UErrorCode &status) const;
/**
* Returns the index in the input string of the character following the
* text matched by the specified capture group during the previous match operation.
* @param group the capture group number
* @param status A reference to a UErrorCode to receive any errors. Possible
* errors are U_REGEX_INVALID_STATE if no match has been
* attempted or the last match failed and
* U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number
* @return the index of the first character following the text
* captured by the specifed group during the previous match operation.
* Return -1 if the capture group exists in the pattern but was not part of the match.
* @stable ICU 2.4
*/
virtual int32_t end(int32_t group, UErrorCode &status) const;
/**
* Resets this matcher. The effect is to remove any memory of previous matches,
* and to cause subsequent find() operations to begin at the beginning of
* the input string.
*
* @return this RegexMatcher.
* @stable ICU 2.4
*/
virtual RegexMatcher &reset();
/**
* Resets this matcher, and set the current input position.
* The effect is to remove any memory of previous matches,
* and to cause subsequent find() operations to begin at
* the specified position in the input string.
* <p>
* The matcher's region is reset to its default, which is the entire
* input string.
* <p>
* An alternative to this function is to set a match region
* beginning at the desired index.
*
* @return this RegexMatcher.
* @stable ICU 2.8
*/
virtual RegexMatcher &reset(int32_t index, UErrorCode &status);
/**
* Resets this matcher with a new input string. This allows instances of RegexMatcher
* to be reused, which is more efficient than creating a new RegexMatcher for
* each input string to be processed.
* @param input The new string on which subsequent pattern matches will operate.
* The matcher retains a reference to the callers string, and operates
* directly on that. Ownership of the string remains with the caller.
* Because no copy of the string is made, it is essential that the
* caller not delete the string until after regexp operations on it
* are done.
* @return this RegexMatcher.
* @stable ICU 2.4
*/
virtual RegexMatcher &reset(const UnicodeString &input);
private:
/**
* Cause a compilation error if an application accidently attempts to
* reset a matcher with a (UChar *) string as input rather than
* a UnicodeString. Avoids a dangling reference to a temporary string.
* <p>
* To efficiently work with UChar *strings, wrap the data in a UnicodeString
* using one of the aliasing constructors, such as
* <code>UnicodeString(UBool isTerminated, const UChar *text, int32_t textLength);</code>
*
* @internal
*/
RegexMatcher &reset(const UChar *input);
public:
/**
* Returns the input string being matched. The returned string is not a copy,
* but the live input string. It should not be altered or deleted.
* @return the input string
* @stable ICU 2.4
*/
virtual const UnicodeString &input() const;
/** Sets the limits of this matcher's region.
* The region is the part of the input string that will be searched to find a match.
* Invoking this method resets the matcher, and then sets the region to start
* at the index specified by the start parameter and end at the index specified
* by the end parameter.
*
* Depending on the transparency and anchoring being used (see useTransparentBounds
* and useAnchoringBounds), certain constructs such as anchors may behave differently
* at or around the boundaries of the region
*
* The function will fail if start is greater than limit, or if either index
* is less than zero or greater than the length of the string being matched.
*
* @param start The index to begin searches at.
* @param limit The index to end searches at (exclusive).
* @param status A reference to a UErrorCode to receive any errors.
* @stable ICU 4.0
*/
virtual RegexMatcher &region(int32_t start, int32_t limit, UErrorCode &status);
/**
* Reports the start index of this matcher's region. The searches this matcher
* conducts are limited to finding matches within regionStart (inclusive) and
* regionEnd (exclusive).
*
* @return The starting index of this matcher's region.
* @stable ICU 4.0
*/
virtual int32_t regionStart() const;
/**
* Reports the end (limit) index (exclusive) of this matcher's region. The searches
* this matcher conducts are limited to finding matches within regionStart
* (inclusive) and regionEnd (exclusive).
*
* @return The ending point of this matcher's region.
* @stable ICU 4.0
*/
virtual int32_t regionEnd() const;
/**
* Queries the transparency of region bounds for this matcher.
* See useTransparentBounds for a description of transparent and opaque bounds.
* By default, a matcher uses opaque region boundaries.
*
* @return TRUE if this matcher is using opaque bounds, false if it is not.
* @stable ICU 4.0
*/
virtual UBool hasTransparentBounds() const;
/**
* Sets the transparency of region bounds for this matcher.
* Invoking this function with an argument of true will set this matcher to use transparent bounds.
* If the boolean argument is false, then opaque bounds will be used.
*
* Using transparent bounds, the boundaries of this matcher's region are transparent
* to lookahead, lookbehind, and boundary matching constructs. Those constructs can
* see text beyond the boundaries of the region while checking for a match.
*
* With opaque bounds, no text outside of the matcher's region is visible to lookahead,
* lookbehind, and boundary matching constructs.
*
* By default, a matcher uses opaque bounds.
*
* @param b TRUE for transparent bounds; FALSE for opaque bounds
* @return This Matcher;
* @stable ICU 4.0
**/
virtual RegexMatcher &useTransparentBounds(UBool b);
/**
* Return true if this matcher is using anchoring bounds.
* By default, matchers use anchoring region boounds.
*
* @return TRUE if this matcher is using anchoring bounds.
* @stable ICU 4.0
*/
virtual UBool hasAnchoringBounds() const;
/**
* Set whether this matcher is using Anchoring Bounds for its region.
* With anchoring bounds, pattern anchors such as ^ and $ will match at the start
* and end of the region. Without Anchoring Bounds, anchors will only match at
* the positions they would in the complete text.
*
* Anchoring Bounds are the default for regions.
*
* @param b TRUE if to enable anchoring bounds; FALSE to disable them.
* @return This Matcher
* @stable ICU 4.0
*/
virtual RegexMatcher &useAnchoringBounds(UBool b);
/**
* Return TRUE if the most recent matching operation touched the
* end of the text being processed. In this case, additional input text could
* change the results of that match.
*
* hitEnd() is defined for both successful and unsuccessful matches.
* In either case hitEnd() will return TRUE if if the end of the text was
* reached at any point during the matching process.
*
* @return TRUE if the most recent match hit the end of input
* @stable ICU 4.0
*/
virtual UBool hitEnd() const;
/**
* Return TRUE the most recent match succeeded and additional input could cause
* it to fail. If this method returns false and a match was found, then more input
* might change the match but the match won't be lost. If a match was not found,
* then requireEnd has no meaning.
*
* @return TRUE if more input could cause the most recent match to no longer match.
* @stable ICU 4.0
*/
virtual UBool requireEnd() const;
/**
* Returns the pattern that is interpreted by this matcher.
* @return the RegexPattern for this RegexMatcher
* @stable ICU 2.4
*/
virtual const RegexPattern &pattern() const;
/**
* Replaces every substring of the input that matches the pattern
* with the given replacement string. This is a convenience function that
* provides a complete find-and-replace-all operation.
*
* This method first resets this matcher. It then scans the input string
* looking for matches of the pattern. Input that is not part of any
* match is left unchanged; each match is replaced in the result by the
* replacement string. The replacement string may contain references to
* capture groups.
*
* @param replacement a string containing the replacement text.
* @param status a reference to a UErrorCode to receive any errors.
* @return a string containing the results of the find and replace.
* @stable ICU 2.4
*/
virtual UnicodeString replaceAll(const UnicodeString &replacement, UErrorCode &status);
/**
* Replaces the first substring of the input that matches
* the pattern with the replacement string. This is a convenience
* function that provides a complete find-and-replace operation.
*
* <p>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.</p>
*
* <p>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.</p>
*
* @param replacement a string containing the replacement text.
* @param status a reference to a UErrorCode to receive any errors.
* @return a string containing the results of the find and replace.
* @stable ICU 2.4
*/
virtual UnicodeString replaceFirst(const UnicodeString &replacement, UErrorCode &status);
/**
* Implements a replace operation intended to be used as part of an
* incremental find-and-replace.
*
* <p>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.</p>
*
* <p>For simple, prepackaged, non-incremental find-and-replace
* operations, see replaceFirst() or replaceAll().</p>
*
* @param dest A UnicodeString to which the results of the find-and-replace are appended.
* @param replacement A UnicodeString that provides the text to be substituted for
* the input text that matched the regexp pattern. The replacement
* text may contain references to captured text from the
* input.
* @param status A reference to a UErrorCode to receive any errors. Possible
* errors are U_REGEX_INVALID_STATE if no match has been
* attempted or the last match failed, and U_INDEX_OUTOFBOUNDS_ERROR
* if the replacement text specifies a capture group that
* does not exist in the pattern.
*
* @return this RegexMatcher
* @stable ICU 2.4
*
*/
virtual RegexMatcher &appendReplacement(UnicodeString &dest,
const UnicodeString &replacement, UErrorCode &status);
/**
* As the final step in a find-and-replace operation, append the remainder
* of the input string, starting at the position following the last appendReplacement(),
* to the destination string. <code>appendTail()</code> is intended to be invoked after one
* or more invocations of the <code>RegexMatcher::appendReplacement()</code>.
*
* @param dest A UnicodeString to which the results of the find-and-replace are appended.
* @return the destination string.
* @stable ICU 2.4
*/
virtual UnicodeString &appendTail(UnicodeString &dest);
/**
* Split a string into fields. Somewhat like split() from Perl.
* The pattern matches identify delimiters that separate the input
* into fields. The input data between the matches becomes the
* fields themselves.
* <p>
*
* @param input The string to be split into fields. The field delimiters
* match the pattern (in the "this" object). This matcher
* will be reset to this input string.
* @param dest An array of UnicodeStrings to receive the results of the split.
* This is an array of actual UnicodeString objects, not an
* array of pointers to strings. Local (stack based) arrays can
* work well here.
* @param destCapacity The number of elements in the destination array.
* If the number of fields found is less than destCapacity, the
* extra strings in the destination array are not altered.
* If the number of destination strings is less than the number
* of fields, the trailing part of the input string, including any
* field delimiters, is placed in the last destination string.
* @param status A reference to a UErrorCode to receive any errors.
* @return The number of fields into which the input string was split.
* @stable ICU 2.6
*/
virtual int32_t split(const UnicodeString &input,
UnicodeString dest[],
int32_t destCapacity,
UErrorCode &status);
/**
* Set a processing time limit for match operations with this Matcher.
*
* Some patterns, when matching certain strings, can run in exponential time.
* For practical purposes, the match operation may appear to be in an
* infinite loop.
* When a limit is set a match operation will fail with an error if the
* limit is exceeded.
* <p>
* 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.
* <p>
* By default, the matching time is not limited.
* <p>
*
* @param limit The limit value, or 0 for no limit.
* @param status A reference to a UErrorCode to receive any errors.
* @stable ICU 4.0
*/
virtual void setTimeLimit(int32_t limit, UErrorCode &status);
/**
* Get the time limit, if any, for match operations made with this Matcher.
*
* @return the maximum allowed time for a match, in units of processing steps.
* @stable ICU 4.0
*/
virtual int32_t getTimeLimit() const;
/**
* Set the amount of heap storage avaliable for use by the match backtracking stack.
* The matcher is also reset, discarding any results from previous matches.
* <p>
* 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.
* <p>
* 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.
* <p>
* @param limit The maximum size, in bytes, of the matching backtrack stack.
* A value of zero means no limit.
* The limit must be greater or equal to zero.
*
* @param status A reference to a UErrorCode to receive any errors.
*
* @stable ICU 4.0
*/
virtual void setStackLimit(int32_t limit, UErrorCode &status);
/**
* Get the size of the heap storage available for use by the back tracking stack.
*
* @return the maximum backtracking stack size, in bytes, or zero if the
* stack size is unlimited.
* @stable ICU 4.0
*/
virtual int32_t getStackLimit() const;
/**
* Set a callback function for use with this Matcher.
* During matching operations the function will be called periodically,
* giving the application the opportunity to terminate a long-running
* match.
*
* @param callback A pointer to the user-supplied callback function.
* @param context User context pointer. The value supplied at the
* time the callback function is set will be saved
* and passed to the callback each time that it is called.
* @param status A reference to a UErrorCode to receive any errors.
* @stable ICU 4.0
*/
virtual void setMatchCallback(URegexMatchCallback *callback,
const void *context,
UErrorCode &status);
/**
* Get the callback function for this URegularExpression.
*
* @param callback Out paramater, receives a pointer to the user-supplied
* callback function.
* @param context Out parameter, receives the user context pointer that
* was set when uregex_setMatchCallback() was called.
* @param status A reference to a UErrorCode to receive any errors.
* @stable ICU 4.0
*/
virtual void getMatchCallback(URegexMatchCallback *&callback,
const void *&context,
UErrorCode &status);
/**
* setTrace Debug function, enable/disable tracing of the matching engine.
* For internal ICU development use only. DO NO USE!!!!
* @internal
*/
void setTrace(UBool state);
/**
* ICU "poor man's RTTI", returns a UClassID for this class.
*
* @stable ICU 2.2
*/
static UClassID U_EXPORT2 getStaticClassID();
/**
* ICU "poor man's RTTI", returns a UClassID for the actual class.
*
* @stable ICU 2.2
*/
virtual UClassID getDynamicClassID() const;
private:
// Constructors and other object boilerplate are private.
// Instances of RegexMatcher can not be assigned, copied, cloned, etc.
RegexMatcher(); // default constructor not implemented
RegexMatcher(const RegexPattern *pat);
RegexMatcher(const RegexMatcher &other);
RegexMatcher &operator =(const RegexMatcher &rhs);
void init(UErrorCode &status); // Common initialization
void init2(const UnicodeString &s, UErrorCode &e); // Common initialization, part 2.
friend class RegexPattern;
friend class RegexCImpl;
public:
/** @internal */
void resetPreserveRegion(); // Reset matcher state, but preserve any region.
private:
//
// MatchAt This is the internal interface to the match engine itself.
// Match status comes back in matcher member variables.
//
void MatchAt(int32_t startIdx, UBool toEnd, UErrorCode &status);
inline void backTrack(int32_t &inputIdx, int32_t &patIdx);
UBool isWordBoundary(int32_t pos); // perform Perl-like \b test
UBool isUWordBoundary(int32_t pos); // perform RBBI based \b test
REStackFrame *resetStack();
inline REStackFrame *StateSave(REStackFrame *fp, int32_t savePatIdx, UErrorCode &status);
void IncrementTime(UErrorCode &status);
const RegexPattern *fPattern;
RegexPattern *fPatternOwned; // Non-NULL if this matcher owns the pattern, and
// should delete it when through.
const UnicodeString *fInput; // The text being matched. Is never NULL.
int32_t fFrameSize; // The size of a frame in the backtrack stack.
int32_t fRegionStart; // Start of the input region, default = 0.
int32_t fRegionLimit; // End of input region, default to input.length.
int32_t fAnchorStart; // Region bounds for anchoring operations (^ or $).
int32_t fAnchorLimit; // See useAnchoringBounds
int32_t fLookStart; // Region bounds for look-ahead/behind and
int32_t fLookLimit; // and other boundary tests. See
// useTransparentBounds
int32_t fActiveStart; // Currently active bounds for matching.
int32_t fActiveLimit; // Usually is the same as region, but
// is changed to fLookStart/Limit when
// entering look around regions.
UBool fTransparentBounds; // True if using transparent bounds.
UBool fAnchoringBounds; // True if using anchoring bounds.
UBool fMatch; // True if the last attempted match was successful.
int32_t fMatchStart; // Position of the start of the most recent match
int32_t fMatchEnd; // First position after the end of the most recent match
// Zero if no previous match, even when a region
// is active.
int32_t fLastMatchEnd; // First position after the end of the previous match,
// or -1 if there was no previous match.
int32_t fAppendPosition; // First position after the end of the previous
// appendReplacement(). As described by the
// JavaDoc for Java Matcher, where it is called
// "append position"
UBool fHitEnd; // True if the last match touched the end of input.
UBool fRequireEnd; // True if the last match required end-of-input
// (matched $ or Z)
UVector32 *fStack;
REStackFrame *fFrame; // After finding a match, the last active stack frame,
// which will contain the capture group results.
// NOT valid while match engine is running.
int32_t *fData; // Data area for use by the compiled pattern.
int32_t fSmallData[8]; // Use this for data if it's enough.
int32_t fTimeLimit; // Max time (in arbitrary steps) to let the
// match engine run. Zero for unlimited.
int32_t fTime; // Match time, accumulates while matching.
int32_t fTickCounter; // Low bits counter for time. Counts down StateSaves.
// Kept separately from fTime to keep as much
// code as possible out of the inline
// StateSave function.
int32_t fStackLimit; // Maximum memory size to use for the backtrack
// stack, in bytes. Zero for unlimited.
URegexMatchCallback *fCallbackFn; // Pointer to match progress callback funct.
// NULL if there is no callback.
const void *fCallbackContext; // User Context ptr for callback function.
UBool fTraceDebug; // Set true for debug tracing of match engine.
UErrorCode fDeferredStatus; // Save error state that cannot be immediately
// reported, or that permanently disables this matcher.
RuleBasedBreakIterator *fWordBreakItr;
};
U_NAMESPACE_END
#endif // UCONFIG_NO_REGULAR_EXPRESSIONS
#endif
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