ICU 60.0.1  60.0.1
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icu::RegexPattern Class Referencefinal

Class RegexPattern represents a compiled regular expression. More...

#include <regex.h>

Inheritance diagram for icu::RegexPattern:
icu::UObject icu::UMemory

Public Member Functions

 RegexPattern ()
 default constructor. More...
 
 RegexPattern (const RegexPattern &source)
 Copy Constructor. More...
 
virtual ~RegexPattern ()
 Destructor. More...
 
UBool operator== (const RegexPattern &that) const
 Comparison operator. More...
 
UBool operator!= (const RegexPattern &that) const
 Comparison operator. More...
 
RegexPatternoperator= (const RegexPattern &source)
 Assignment operator. More...
 
virtual RegexPatternclone () const
 Create an exact copy of this RegexPattern object. More...
 
virtual uint32_t flags () const
 Get the match mode flags that were used when compiling this pattern. More...
 
virtual RegexMatchermatcher (const UnicodeString &input, UErrorCode &status) const
 Creates a RegexMatcher that will match the given input against this pattern. More...
 
virtual RegexMatchermatcher (UErrorCode &status) const
 Creates a RegexMatcher that will match against this pattern. More...
 
virtual UnicodeString pattern () const
 Returns the regular expression from which this pattern was compiled. More...
 
virtual UTextpatternText (UErrorCode &status) const
 Returns the regular expression from which this pattern was compiled. More...
 
virtual int32_t groupNumberFromName (const UnicodeString &groupName, UErrorCode &status) const
 Get the group number corresponding to a named capture group. More...
 
virtual int32_t groupNumberFromName (const char *groupName, int32_t nameLength, UErrorCode &status) const
 Get the group number corresponding to a named capture group. More...
 
virtual int32_t split (const UnicodeString &input, UnicodeString dest[], int32_t destCapacity, UErrorCode &status) const
 Split a string into fields. More...
 
virtual int32_t split (UText *input, UText *dest[], int32_t destCapacity, UErrorCode &status) const
 Split a string into fields. More...
 
virtual UClassID getDynamicClassID () const
 ICU "poor man's RTTI", returns a UClassID for the actual class. More...
 
void dumpPattern () const
 Dump a compiled pattern. More...
 
- Public Member Functions inherited from icu::UObject
virtual ~UObject ()
 Destructor. More...
 

Static Public Member Functions

static RegexPatterncompile (const UnicodeString &regex, UParseError &pe, UErrorCode &status)
 Compiles the regular expression in string form into a RegexPattern object. More...
 
static RegexPatterncompile (UText *regex, UParseError &pe, UErrorCode &status)
 Compiles the regular expression in string form into a RegexPattern object. More...
 
static RegexPatterncompile (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. More...
 
static RegexPatterncompile (UText *regex, uint32_t flags, UParseError &pe, UErrorCode &status)
 Compiles the regular expression in string form into a RegexPattern object using the specified match mode flags. More...
 
static RegexPatterncompile (const UnicodeString &regex, uint32_t flags, UErrorCode &status)
 Compiles the regular expression in string form into a RegexPattern object using the specified match mode flags. More...
 
static RegexPatterncompile (UText *regex, uint32_t flags, UErrorCode &status)
 Compiles the regular expression in string form into a RegexPattern object using the specified match mode flags. More...
 
static UBool matches (const UnicodeString &regex, const UnicodeString &input, UParseError &pe, UErrorCode &status)
 Test whether a string matches a regular expression. More...
 
static UBool matches (UText *regex, UText *input, UParseError &pe, UErrorCode &status)
 Test whether a string matches a regular expression. More...
 
static UClassID getStaticClassID ()
 ICU "poor man's RTTI", returns a UClassID for this class. More...
 

Friends

class RegexCompile
 
class RegexMatcher
 
class RegexCImpl
 

Detailed Description

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

Definition at line 87 of file regex.h.

Constructor & Destructor Documentation

icu::RegexPattern::RegexPattern ( )

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
icu::RegexPattern::RegexPattern ( const RegexPattern source)

Copy Constructor.

Create a new RegexPattern object that is equivalent to the source object.

Parameters
sourcethe pattern object to be copied.
Stable:
ICU 2.4
virtual icu::RegexPattern::~RegexPattern ( )
virtual

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

Member Function Documentation

virtual RegexPattern* icu::RegexPattern::clone ( ) const
virtual

Create an exact copy of this RegexPattern object.

Since RegexPattern is not intended to be subclassed, clone() and the copy construction are equivalent operations.

Returns
the copy of this RegexPattern
Stable:
ICU 2.4
static RegexPattern* icu::RegexPattern::compile ( const UnicodeString regex,
UParseError pe,
UErrorCode status 
)
static

Compiles the regular expression in string form into a RegexPattern object.

These compile methods, rather than the constructors, are the usual way that RegexPattern objects are created.

Note that RegexPattern objects must not be deleted while RegexMatcher objects created from the pattern are active. RegexMatchers keep a pointer back to their pattern, so premature deletion of the pattern is a catastrophic error.

All pattern match mode flags are set to their default values.

Note that it is often more convenient to construct a RegexMatcher directly from a pattern string rather than separately compiling the pattern and then creating a RegexMatcher object from the pattern.

Parameters
regexThe regular expression to be compiled.
peReceives the position (line and column nubers) of any error within the regular expression.)
statusA reference to a UErrorCode to receive any errors.
Returns
A regexPattern object for the compiled pattern.
Stable:
ICU 2.4
static RegexPattern* icu::RegexPattern::compile ( UText regex,
UParseError pe,
UErrorCode status 
)
static

Compiles the regular expression in string form into a RegexPattern object.

These compile methods, rather than the constructors, are the usual way that RegexPattern objects are created.

Note that RegexPattern objects must not be deleted while RegexMatcher objects created from the pattern are active. RegexMatchers keep a pointer back to their pattern, so premature deletion of the pattern is a catastrophic error.

All pattern match mode flags are set to their default values.

Note that it is often more convenient to construct a RegexMatcher directly from a pattern string rather than separately compiling the pattern and then creating a RegexMatcher object from the pattern.

Parameters
regexThe 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.
peReceives the position (line and column nubers) of any error within the regular expression.)
statusA reference to a UErrorCode to receive any errors.
Returns
A regexPattern object for the compiled pattern.
Stable:
ICU 4.6
static RegexPattern* icu::RegexPattern::compile ( const UnicodeString regex,
uint32_t  flags,
UParseError pe,
UErrorCode status 
)
static

Compiles the regular expression in string form into a RegexPattern object using the specified match mode flags.

These compile methods, rather than the constructors, are the usual way that RegexPattern objects are created.

Note that RegexPattern objects must not be deleted while RegexMatcher objects created from the pattern are active. RegexMatchers keep a pointer back to their pattern, so premature deletion of the pattern is a catastrophic error.

Note that it is often more convenient to construct a RegexMatcher directly from a pattern string instead of than separately compiling the pattern and then creating a RegexMatcher object from the pattern.

Parameters
regexThe regular expression to be compiled.
flagsThe match mode flags to be used.
peReceives the position (line and column numbers) of any error within the regular expression.)
statusA reference to a UErrorCode to receive any errors.
Returns
A regexPattern object for the compiled pattern.
Stable:
ICU 2.4
static RegexPattern* icu::RegexPattern::compile ( UText regex,
uint32_t  flags,
UParseError pe,
UErrorCode status 
)
static

Compiles the regular expression in string form into a RegexPattern object using the specified match mode flags.

These compile methods, rather than the constructors, are the usual way that RegexPattern objects are created.

Note that RegexPattern objects must not be deleted while RegexMatcher objects created from the pattern are active. RegexMatchers keep a pointer back to their pattern, so premature deletion of the pattern is a catastrophic error.

Note that it is often more convenient to construct a RegexMatcher directly from a pattern string instead of than separately compiling the pattern and then creating a RegexMatcher object from the pattern.

Parameters
regexThe 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.
flagsThe match mode flags to be used.
peReceives the position (line and column numbers) of any error within the regular expression.)
statusA reference to a UErrorCode to receive any errors.
Returns
A regexPattern object for the compiled pattern.
Stable:
ICU 4.6
static RegexPattern* icu::RegexPattern::compile ( const UnicodeString regex,
uint32_t  flags,
UErrorCode status 
)
static

Compiles the regular expression in string form into a RegexPattern object using the specified match mode flags.

These compile methods, rather than the constructors, are the usual way that RegexPattern objects are created.

Note that RegexPattern objects must not be deleted while RegexMatcher objects created from the pattern are active. RegexMatchers keep a pointer back to their pattern, so premature deletion of the pattern is a catastrophic error.

Note that it is often more convenient to construct a RegexMatcher directly from a pattern string instead of than separately compiling the pattern and then creating a RegexMatcher object from the pattern.

Parameters
regexThe regular expression to be compiled.
flagsThe match mode flags to be used.
statusA reference to a UErrorCode to receive any errors.
Returns
A regexPattern object for the compiled pattern.
Stable:
ICU 2.6
static RegexPattern* icu::RegexPattern::compile ( UText regex,
uint32_t  flags,
UErrorCode status 
)
static

Compiles the regular expression in string form into a RegexPattern object using the specified match mode flags.

These compile methods, rather than the constructors, are the usual way that RegexPattern objects are created.

Note that RegexPattern objects must not be deleted while RegexMatcher objects created from the pattern are active. RegexMatchers keep a pointer back to their pattern, so premature deletion of the pattern is a catastrophic error.

Note that it is often more convenient to construct a RegexMatcher directly from a pattern string instead of than separately compiling the pattern and then creating a RegexMatcher object from the pattern.

Parameters
regexThe 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.
flagsThe match mode flags to be used.
statusA reference to a UErrorCode to receive any errors.
Returns
A regexPattern object for the compiled pattern.
Stable:
ICU 4.6
void icu::RegexPattern::dumpPattern ( ) const

Dump a compiled pattern.

Internal debug function.

Internal:
Do not use. This API is for internal use only.
virtual uint32_t icu::RegexPattern::flags ( ) const
virtual

Get the match mode flags that were used when compiling this pattern.

Returns
the match mode flags
Stable:
ICU 2.4
virtual UClassID icu::RegexPattern::getDynamicClassID ( ) const
virtual

ICU "poor man's RTTI", returns a UClassID for the actual class.

Stable:
ICU 2.4

Reimplemented from icu::UObject.

static UClassID icu::RegexPattern::getStaticClassID ( )
static

ICU "poor man's RTTI", returns a UClassID for this class.

Stable:
ICU 2.4
virtual int32_t icu::RegexPattern::groupNumberFromName ( const UnicodeString groupName,
UErrorCode status 
) const
virtual

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.

Parameters
groupNameThe capture group name.
statusA UErrorCode to receive any errors.
Stable:
ICU 55
virtual int32_t icu::RegexPattern::groupNumberFromName ( const char *  groupName,
int32_t  nameLength,
UErrorCode status 
) const
virtual

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.

Parameters
groupNameThe capture group name, platform invariant characters only.
nameLengthThe length of the name, or -1 if the name is nul-terminated.
statusA UErrorCode to receive any errors.
Stable:
ICU 55
virtual RegexMatcher* icu::RegexPattern::matcher ( const UnicodeString input,
UErrorCode status 
) const
virtual

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.

Parameters
inputThe input string to which the regular expression will be applied.
statusA reference to a UErrorCode to receive any errors.
Returns
A RegexMatcher object for this pattern and input.
Stable:
ICU 2.4
virtual RegexMatcher* icu::RegexPattern::matcher ( UErrorCode status) const
virtual

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.

Parameters
statusA reference to a UErrorCode to receive any errors.
Returns
A RegexMatcher object for this pattern and input.
Stable:
ICU 2.6
static UBool icu::RegexPattern::matches ( const UnicodeString regex,
const UnicodeString input,
UParseError pe,
UErrorCode status 
)
static

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.

Parameters
regexThe regular expression
inputThe string data to be matched
peReceives the position of any syntax errors within the regular expression
statusA reference to a UErrorCode to receive any errors.
Returns
True if the regular expression exactly matches the full input string.
Stable:
ICU 2.4
static UBool icu::RegexPattern::matches ( UText regex,
UText input,
UParseError pe,
UErrorCode status 
)
static

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.

Parameters
regexThe regular expression
inputThe string data to be matched
peReceives the position of any syntax errors within the regular expression
statusA reference to a UErrorCode to receive any errors.
Returns
True if the regular expression exactly matches the full input string.
Stable:
ICU 4.6
UBool icu::RegexPattern::operator!= ( const RegexPattern that) const
inline

Comparison operator.

Two RegexPattern objects are considered equal if they were constructed from identical source patterns using the same match flag settings.

Parameters
thata RegexPattern object to compare with "this".
Returns
TRUE if the objects are different.
Stable:
ICU 2.4

Definition at line 132 of file regex.h.

References icu::UObject::getDynamicClassID(), and icu::operator==().

RegexPattern& icu::RegexPattern::operator= ( const RegexPattern source)

Assignment operator.

After assignment, this RegexPattern will behave identically to the source object.

Stable:
ICU 2.4
UBool icu::RegexPattern::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.

Parameters
thata RegexPattern object to compare with "this".
Returns
TRUE if the objects are equivalent.
Stable:
ICU 2.4
virtual UnicodeString icu::RegexPattern::pattern ( ) const
virtual

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 UText* icu::RegexPattern::patternText ( UErrorCode status) const
virtual

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 int32_t icu::RegexPattern::split ( const UnicodeString input,
UnicodeString  dest[],
int32_t  destCapacity,
UErrorCode status 
) const
virtual

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

Parameters
inputThe string to be split into fields. The field delimiters match the pattern (in the "this" object)
destAn 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.
destCapacityThe 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.
statusA reference to a UErrorCode to receive any errors.
Returns
The number of fields into which the input string was split.
Stable:
ICU 2.4
virtual int32_t icu::RegexPattern::split ( UText input,
UText dest[],
int32_t  destCapacity,
UErrorCode status 
) const
virtual

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

Parameters
inputThe string to be split into fields. The field delimiters match the pattern (in the "this" object)
destAn array of mutable UText structs to receive the results of the split. If a field is NULL, a new UText is allocated to contain the results for that field. This new UText is not guaranteed to be mutable.
destCapacityThe 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.
statusA reference to a UErrorCode to receive any errors.
Returns
The number of destination strings used.
Stable:
ICU 4.6

The documentation for this class was generated from the following file: