ICU 3.8.1: uregex.h File Reference

typedef struct URegularExpression URegularExpression

Structure represeting a compiled regular rexpression, plus the results of a match operation.

Stable:: ICU 3.0

Definition at line 38 of file uregex.h.

Constants for Regular Expression Match Modes.

Stable:: ICU 2.4

Enumerator:

UREGEX_CANON_EQ	Forces normalization of pattern and strings. Not implemented yet, just a placeholder, hence draft. Draft: This API may be changed in the future versions and was introduced in ICU 2.4
UREGEX_CASE_INSENSITIVE	Enable case insensitive matching. Stable: ICU 2.4
UREGEX_COMMENTS	Allow white space and comments within patterns. Stable: ICU 2.4
UREGEX_DOTALL	If set, '. ' matches line terminators, otherwise '.' matching stops at line end. Stable: ICU 2.4
UREGEX_MULTILINE	Control behavior of "$" and "^" If set, recognize line terminators within string, otherwise, match only at start and end of input string. Stable: ICU 2.4
UREGEX_UWORD	Unicode word boundaries. If set, uses the Unicode TR 29 definition of word boundaries. Warning: Unicode word boundaries are quite different from traditional regular expression word boundaries. See http://unicode.org/reports/tr29/#Word_Boundaries Stable: ICU 2.8

Definition at line 45 of file uregex.h.

int32_t uregex_appendReplacement	(	URegularExpression *	regexp,
		const UChar *	replacementText,
		int32_t	replacementLength,
		UChar **	destBuf,
		int32_t *	destCapacity,
		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 match 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.

A note on preflight computation of buffersize and error handling: Calls to uregex_appendReplacement() and uregex_appendTail() are designed to be chained, one after another, with the destination buffer pointer and buffer capacity updated after each in preparation to for the next. If the destination buffer is exhausted partway through such a sequence, a U_BUFFER_OVERFLOW_ERROR status will be returned. Normal ICU conventions are for a function to perform no action if it is called with an error status, but for this one case, uregex_appendRepacement() will operate normally so that buffer size computations will complete correctly.

For simple, prepackaged, non-incremental find-and-replace operations, see replaceFirst() or replaceAll().

Parameters:

	regexp	The regular expression object.
	replacementText	The string that will replace the matched portion of the input string as it is copied to the destination buffer. The replacement text may contain references ($1, for example) to capture groups from the match.
	replacementLength	The length of the replacement text string, or -1 if the string is NUL terminated.
	destBuf	The buffer into which the results of the find-and-replace are placed. On return, this pointer will be updated to refer to the beginning of the unused portion of buffer, leaving it in position for a subsequent call to this function.
	destCapacity	The size of the output buffer, On return, this parameter will be updated to reflect the space remaining unused in the output buffer.
	status	A reference to a UErrorCode to receive any errors.

Returns:: The length of the result string. In the event that destCapacity is inadequate, the full length of the untruncated output string is returned.

Stable:: ICU 3.0

int32_t uregex_appendTail	(	URegularExpression *	regexp,
		UChar **	destBuf,
		int32_t *	destCapacity,
		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 match, to the destination string.

uregex_appendTail() is intended to be invoked after one or more invocations of the uregex_appendReplacement() function.

Parameters:

	regexp	The regular expression object. This is needed to obtain the input string and with the position of the last match within it.
	destBuf	The buffer in which the results of the find-and-replace are placed. On return, the pointer will be updated to refer to the beginning of the unused portion of buffer.
	destCapacity	The size of the output buffer, On return, this value will be updated to reflect the space remaining unused in the output buffer.
	status	A reference to a UErrorCode to receive any errors.

Returns:: The length of the result string. In the event that destCapacity is inadequate, the full length of the untruncated output string is returned.

Stable:: ICU 3.0

URegularExpression* uregex_clone	(	const URegularExpression *	regexp,
		UErrorCode *	status
	)

Make a copy of a compiled regular expression.

Cloning a regular expression is faster than opening a second instance from the source form of the expression, and requires less memory.

Note that the current input string and the position of any matched text within it are not cloned; only the pattern itself and and the match mode flags are copied.

Cloning can be particularly useful to threaded applications that perform multiple match operations in parallel. Each concurrent RE operation requires its own instance of a URegularExpression.

Parameters:

	regexp	The compiled regular expression to be cloned.
	status	Receives indication of any errors encountered

Returns:: the cloned copy of the compiled regular expression.

Stable:: ICU 3.0

void uregex_close ( URegularExpression * regexp )

Close the regular expression, recovering all resources (memory) it was holding.

Parameters:

regexp

The regular expression to be closed.

Stable:: ICU 3.0

int32_t uregex_end	(	URegularExpression *	regexp,
		int32_t	groupNum,
		UErrorCode *	status
	)

Returns the index in the input string of the position following the end of the text matched by the specified capture group.

Return -1 if the capture group was not part of the last match. Group #0 refers to the complete range of matched text. Group #1 refers to the text matched by the first set of capturing parentheses.

Parameters:

	regexp	The compiled regular expression.
	groupNum	The capture group number
	status	A reference to a UErrorCode to receive any errors.

Returns:: the index of the position following the last matched character.

Stable:: ICU 3.0

UBool uregex_find	(	URegularExpression *	regexp,
		int32_t	startIndex,
		UErrorCode *	status
	)

Find the first matching substring of the input string that matches the pattern.

The search for a match begins at the specified index. If a match is found, uregex_start(), uregex_end(), and uregex_group() will provide more information regarding the match.

Parameters:

	regexp	The compiled regular expression.
	startIndex	The position in the input string to begin the search
	status	A reference to a UErrorCode to receive any errors.

Returns:: TRUE if a match is found.

Stable:: ICU 3.0

UBool uregex_findNext	(	URegularExpression *	regexp,
		UErrorCode *	status
	)

Find the next pattern match in the input string.

Begin 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, uregex_start(), uregex_end(), and uregex_group() will provide more information regarding the match.

Parameters:

	regexp	The compiled regular expression.
	status	A reference to a UErrorCode to receive any errors.

Returns:: TRUE if a match is found.

See also:: uregex_reset

Stable:: ICU 3.0

int32_t uregex_flags	(	const URegularExpression *	regexp,
		UErrorCode *	status
	)

Get the match mode flags that were specified when compiling this regular expression.

Parameters:

	status	Receives errors detected by this function.
	regexp	The compiled regular expression.

Returns:: The match mode flags

See also:: URegexpFlag

Stable:: ICU 3.0

const UChar* uregex_getText	(	URegularExpression *	regexp,
		int32_t *	textLength,
		UErrorCode *	status
	)

Get the subject text that is currently associated with this regular expression object.

This simply returns whatever string pointer was previously supplied via uregex_setText().

Parameters:

	regexp	The compiled regular expression.
	textLength	The length of the string is returned in this output parameter. A NULL pointer may be used here if the text length is not needed, as would be the case if the text is known in advance to be a NUL terminated string.
	status	Receives errors detected by this function.

Returns:: Poiner to the subject text string currently associated with this regular expression.

Stable:: ICU 3.0

int32_t uregex_group	(	URegularExpression *	regexp,
		int32_t	groupNum,
		UChar *	dest,
		int32_t	destCapacity,
		UErrorCode *	status
	)

Extract the string for the specified matching expression or subexpression.

Group #0 is the complete string of matched text. Group #1 is the text matched by the first set of capturing parentheses.

Parameters:

	regexp	The compiled regular expression.
	groupNum	The capture group to extract. Group 0 is the complete match. The value of this parameter must be less than or equal to the number of capture groups in the pattern.
	dest	Buffer to receive the matching string data
	destCapacity	Capacity of the dest buffer.
	status	A reference to a UErrorCode to receive any errors.

Returns:: Length of matching data, or -1 if no applicable match.

Stable:: ICU 3.0

int32_t uregex_groupCount	(	URegularExpression *	regexp,
		UErrorCode *	status
	)

Get the number of capturing groups in this regular expression's pattern.

Parameters:

	regexp	The compiled regular expression.
	status	A reference to a UErrorCode to receive any errors.

Returns:: the number of capture groups

Stable:: ICU 3.0

UBool uregex_lookingAt	(	URegularExpression *	regexp,
		int32_t	startIndex,
		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 uregex_matches().

If the match succeeds then more information can be obtained via the uregexp_start(), uregexp_end(), and uregexp_group() functions.

Parameters:

	regexp	The compiled regular expression.
	startIndex	The input string index at which to begin matching.
	status	A reference to a UErrorCode to receive any errors.

Returns:: TRUE if there is a match.

Stable:: ICU 3.0

UBool uregex_matches	(	URegularExpression *	regexp,
		int32_t	startIndex,
		UErrorCode *	status
	)

Attempts to match the input string, beginning at startIndex, against the pattern.

To succeed, the match must extend to the end of the input string.

Parameters:

	regexp	The compiled regular expression.
	startIndex	The input string index at which to begin matching.
	status	Receives errors detected by this function.

Returns:: TRUE if there is a match

Stable:: ICU 3.0

URegularExpression* uregex_open	(	const UChar *	pattern,
		int32_t	patternLength,
		uint32_t	flags,
		UParseError *	pe,
		UErrorCode *	status
	)

Open (compile) an ICU regular expression.

Compiles the regular expression in string form into an internal representation using the specified match mode flags. The resulting regular expression handle can then be used to perform various matching operations.

Parameters:

	pattern	The Regular Expression pattern to be compiled.
	patternLength	The length of the pattern, or -1 if the pattern is NUL termintated.
	flags	Flags that alter the default matching behavior for the regular expression, UREGEX_CASE_INSENSITIVE, for example. For default behavior, set this parameter to zero. See `enum URegexpFlag`. All desired flags are bitwise-ORed together.
	pe	Receives the position (line and column nubers) of any syntax error within the source regular expression string. If this information is not wanted, pass NULL for this parameter.
	status	Receives error detected by this function.

Stable:: ICU 3.0

URegularExpression* uregex_openC	(	const char *	pattern,
		uint32_t	flags,
		UParseError *	pe,
		UErrorCode *	status
	)

Open (compile) an ICU regular expression.

The resulting regular expression handle can then be used to perform various matching operations.

This function is the same as uregex_open, except that the pattern is supplied as an 8 bit char * string in the default code page.

Parameters:

	pattern	The Regular Expression pattern to be compiled, NUL termintated.
	flags	Flags that alter the default matching behavior for the regular expression, UREGEX_CASE_INSENSITIVE, for example. For default behavior, set this parameter to zero. See `enum URegexpFlag`. All desired flags are bitwise-ORed together.
	pe	Receives the position (line and column nubers) of any syntax error within the source regular expression string. If this information is not wanted, pass NULL for this parameter.
	status	Receives errors detected by this function.

Returns:: The URegularExpression object representing the compiled pattern.

Stable:: ICU 3.0

const UChar* uregex_pattern	(	const URegularExpression *	regexp,
		int32_t *	patLength,
		UErrorCode *	status
	)

Return a pointer to the source form of the pattern for this regular expression.

Parameters:

	regexp	The compiled regular expression.
	patLength	This output parameter will be set to the length of the pattern string. A NULL pointer may be used here if the pattern length is not needed, as would be the case if the pattern is known in advance to be a NUL terminated string.
	status	Receives errors detected by this function.

Returns:: a pointer to the pattern string. The storage for the string is owned by the regular expression object, and must not be altered or deleted by the application. The returned string will remain valid until the regular expression is closed.

Stable:: ICU 3.0

int32_t uregex_replaceAll	(	URegularExpression *	regexp,
		const UChar *	replacementText,
		int32_t	replacementLength,
		UChar *	destBuf,
		int32_t	destCapacity,
		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 scans the input string looking for matches of the pattern. Input that is not part of any match is copied unchanged to the destination buffer. Matched regions are replaced in the output buffer by the replacement string. The replacement string may contain references to capture groups; these take the form of $1, $2, etc.

Parameters:

	regexp	The compiled regular expression.
	replacementText	A string containing the replacement text.
	replacementLength	The length of the replacement string, or -1 if it is NUL terminated.
	destBuf	A (UChar *) buffer that will receive the result.
	destCapacity	The capacity of the desitnation buffer.
	status	A reference to a UErrorCode to receive any errors.

Returns:: The length of the string resulting from the find and replace operation. In the event that the destination capacity is inadequate, the return value is still the full length of the untruncated string.

Stable:: ICU 3.0

int32_t uregex_replaceFirst	(	URegularExpression *	regexp,
		const UChar *	replacementText,
		int32_t	replacementLength,
		UChar *	destBuf,
		int32_t	destCapacity,
		UErrorCode *	status
	)

Replaces the first 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 operation.

This method scans the input string looking for a match of the pattern. All input that is not part of the match is copied unchanged to the destination buffer. The matched region is replaced in the output buffer by the replacement string. The replacement string may contain references to capture groups; these take the form of $1, $2, etc.

Parameters:

	regexp	The compiled regular expression.
	replacementText	A string containing the replacement text.
	replacementLength	The length of the replacement string, or -1 if it is NUL terminated.
	destBuf	A (UChar *) buffer that will receive the result.
	destCapacity	The capacity of the desitnation buffer.
	status	a reference to a UErrorCode to receive any errors.

Returns:: The length of the string resulting from the find and replace operation. In the event that the destination capacity is inadequate, the return value is still the full length of the untruncated string.

Stable:: ICU 3.0

void uregex_reset	(	URegularExpression *	regexp,
		int32_t	index,
		UErrorCode *	status
	)

Reset any saved state from the previous match.

Has the effect of causing uregex_findNext to begin at the specified index, and causing uregex_start(), uregex_end() and uregex_group() to return an error indicating that there is no match information available.

Parameters:

	regexp	The compiled regular expression.
	index	The position in the text at which a uregex_findNext() should begin searching.
	status	A reference to a UErrorCode to receive any errors.

Stable:: ICU 3.0

void uregex_setText	(	URegularExpression *	regexp,
		const UChar *	text,
		int32_t	textLength,
		UErrorCode *	status
	)

Set the subject text string upon which the regular expression will look for matches.

This function may be called any number of times, allowing the regular expression pattern to be applied to different strings.

Regular expression matching operations work directly on the application's string data. No copy is made. The subject string data must not be altered after calling this function until after all regular expression operations involving this string data are completed.

Zero length strings are permitted. In this case, no subsequent match operation will dereference the text string pointer.

Parameters:

	regexp	The compiled regular expression.
	text	The subject text string.
	textLength	The length of the subject text, or -1 if the string is NUL terminated.
	status	Receives errors detected by this function.

Stable:: ICU 3.0

int32_t uregex_split	(	URegularExpression *	regexp,
		UChar *	destBuf,
		int32_t	destCapacity,
		int32_t *	requiredCapacity,
		UChar *	destFields[],
		int32_t	destFieldsCapacity,
		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.

Each of the fields is copied from the input string to the destination buffer, and the NUL terminated. The position of each field within the destination buffer is returned in the destFields array.

Note: another choice for the design of this function would be to not copy the resulting fields at all, but to return indexes and lengths within the source text. Advantages would be o Faster. No Copying. o Nothing extra needed when field data may contain embedded NUL chars. o Less memory needed if working on large data. Disadvantages o Less consistent with C++ split, which copies into an array of UnicodeStrings. o No NUL termination, extracted fields would be less convenient to use in most cases. o Possible problems in the future, when support Unicode Normalization could cause the fields to not correspond exactly to a range of the source text.

Parameters:

	regexp	The compiled regular expression.
	destBuf	A (UChar *) buffer to receive the fields that are extracted from the input string. These field pointers will refer to positions within the destination buffer supplied by the caller. Any extra positions within the destFields array will be set to NULL.
	destCapacity	The capacity of the destBuf.
	requiredCapacity	The actual capacity required of the destBuf. If destCapacity is too small, requiredCapacity will return the total capacity required to hold all of the output, and a U_BUFFER_OVERFLOW_ERROR will be returned.
	destFields	An array to be filled with the position of each of the extracted fields within destBuf.
	destFieldsCapacity	The number of elements in the destFields array. If the number of fields found is less than destFieldsCapacity, the extra destFields elements are set to zero. If destFieldsCapacity is too small, the trailing part of the input, including any field delimiters, is treated as if it were the last field - it is copied to the destBuf, and its position is in the destBuf is stored in the last element of destFields. This behavior mimics that of Perl. It is not an error condition, and no error status is returned when all destField positions are used.
	status	A reference to a UErrorCode to receive any errors.

Returns:: The number of fields into which the input string was split.

Stable:: ICU 3.0

int32_t uregex_start	(	URegularExpression *	regexp,
		int32_t	groupNum,
		UErrorCode *	status
	)

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 was not part of the last match. Group #0 refers to the complete range of matched text. Group #1 refers to the text matched by the first set of capturing parentheses.

Parameters:

	regexp	The compiled regular expression.
	groupNum	The capture group number
	status	A reference to a UErrorCode to receive any errors.

Returns:: the starting position in the input of the text matched by the specified group.

Stable:: ICU 3.0

uregex.h File Reference

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation

Enumeration Type Documentation

Function Documentation


Typedefs
typedef URegularExpression	URegularExpression
	Structure represeting a compiled regular rexpression, plus the results of a match operation.
Enumerations
enum	URegexpFlag { UREGEX_CANON_EQ = 128, UREGEX_CASE_INSENSITIVE = 2, UREGEX_COMMENTS = 4, UREGEX_DOTALL = 32, UREGEX_MULTILINE = 8, UREGEX_UWORD = 256 }
	Constants for Regular Expression Match Modes. More...
Functions
URegularExpression *	uregex_open (const UChar pattern, int32_t patternLength, uint32_t flags, UParseError pe, UErrorCode *status)
	Open (compile) an ICU regular expression.
URegularExpression *	uregex_openC (const char pattern, uint32_t flags, UParseError pe, UErrorCode *status)
	Open (compile) an ICU regular expression.
void	uregex_close (URegularExpression *regexp)
	Close the regular expression, recovering all resources (memory) it was holding.
URegularExpression *	uregex_clone (const URegularExpression regexp, UErrorCode status)
	Make a copy of a compiled regular expression.
const UChar *	uregex_pattern (const URegularExpression regexp, int32_t patLength, UErrorCode *status)
	Return a pointer to the source form of the pattern for this regular expression.
int32_t	uregex_flags (const URegularExpression regexp, UErrorCode status)
	Get the match mode flags that were specified when compiling this regular expression.
void	uregex_setText (URegularExpression regexp, const UChar text, int32_t textLength, UErrorCode *status)
	Set the subject text string upon which the regular expression will look for matches.
const UChar *	uregex_getText (URegularExpression regexp, int32_t textLength, UErrorCode *status)
	Get the subject text that is currently associated with this regular expression object.
UBool	uregex_matches (URegularExpression regexp, int32_t startIndex, UErrorCode status)
	Attempts to match the input string, beginning at startIndex, against the pattern.
UBool	uregex_lookingAt (URegularExpression regexp, int32_t startIndex, UErrorCode status)
	Attempts to match the input string, starting from the specified index, against the pattern.
UBool	uregex_find (URegularExpression regexp, int32_t startIndex, UErrorCode status)
	Find the first matching substring of the input string that matches the pattern.
UBool	uregex_findNext (URegularExpression regexp, UErrorCode status)
	Find the next pattern match in the input string.
int32_t	uregex_groupCount (URegularExpression regexp, UErrorCode status)
	Get the number of capturing groups in this regular expression's pattern.
int32_t	uregex_group (URegularExpression regexp, int32_t groupNum, UChar dest, int32_t destCapacity, UErrorCode *status)
	Extract the string for the specified matching expression or subexpression.
int32_t	uregex_start (URegularExpression regexp, int32_t groupNum, UErrorCode status)
	Returns the index in the input string of the start of the text matched by the specified capture group during the previous match operation.
int32_t	uregex_end (URegularExpression regexp, int32_t groupNum, UErrorCode status)
	Returns the index in the input string of the position following the end of the text matched by the specified capture group.
void	uregex_reset (URegularExpression regexp, int32_t index, UErrorCode status)
	Reset any saved state from the previous match.
int32_t	uregex_replaceAll (URegularExpression regexp, const UChar replacementText, int32_t replacementLength, UChar destBuf, int32_t destCapacity, UErrorCode status)
	Replaces every substring of the input that matches the pattern with the given replacement string.
int32_t	uregex_replaceFirst (URegularExpression regexp, const UChar replacementText, int32_t replacementLength, UChar destBuf, int32_t destCapacity, UErrorCode status)
	Replaces the first substring of the input that matches the pattern with the given replacement string.
int32_t	uregex_appendReplacement (URegularExpression regexp, const UChar replacementText, int32_t replacementLength, UChar *destBuf, int32_t destCapacity, UErrorCode *status)
	Implements a replace operation intended to be used as part of an incremental find-and-replace.
int32_t	uregex_appendTail (URegularExpression regexp, UChar destBuf, int32_t destCapacity, 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 match, to the destination string.
int32_t	uregex_split (URegularExpression regexp, UChar destBuf, int32_t destCapacity, int32_t requiredCapacity, UChar destFields[], int32_t destFieldsCapacity, UErrorCode *status)
	Split a string into fields.