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/*
**********************************************************************
* Copyright (C) 2004-2009, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
* file name: regex.h
* encoding: US-ASCII
* indentation:4
*
* created on: 2004mar09
* created by: Andy Heninger
*
* ICU Regular Expressions, API for C
*/
/**
* \file
* \brief C API: Regular Expressions
*
* <p>This is a C wrapper around the C++ RegexPattern and RegexMatcher classes.</p>
*/
#ifndef UREGEX_H
#define UREGEX_H
#include "unicode/utypes.h"
#if !UCONFIG_NO_REGULAR_EXPRESSIONS
#include "unicode/parseerr.h"
struct URegularExpression;
/**
* Structure representing a compiled regular rexpression, plus the results
* of a match operation.
* @stable ICU 3.0
*/
typedef struct URegularExpression URegularExpression;
/**
* Constants for Regular Expression Match Modes.
* @stable ICU 2.4
*/
typedef enum URegexpFlag{
#ifndef U_HIDE_DRAFT_API
/** Forces normalization of pattern and strings.
Not implemented yet, just a placeholder, hence draft.
@draft ICU 2.4 */
UREGEX_CANON_EQ = 128,
#endif
/** Enable case insensitive matching. @stable ICU 2.4 */
UREGEX_CASE_INSENSITIVE = 2,
/** Allow white space and comments within patterns @stable ICU 2.4 */
UREGEX_COMMENTS = 4,
/** If set, '.' matches line terminators, otherwise '.' matching stops at line end.
* @stable ICU 2.4 */
UREGEX_DOTALL = 32,
/** If set, treat the entire pattern as a literal string.
* Metacharacters or escape sequences in the input sequence will be given
* no special meaning.
*
* The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact
* on matching when used in conjunction with this flag.
* The other flags become superfluous.
* TODO: say which escapes are still handled; anything Java does
* early (\\u) we should still do.
* @stable ICU 4.0
*/
UREGEX_LITERAL = 16,
/** 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_MULTILINE = 8,
/** Unix-only line endings.
* When this mode is enabled, only \\u000a is recognized as a line ending
* in the behavior of ., ^, and $.
* @stable ICU 4.0
*/
UREGEX_UNIX_LINES = 1,
/** Unicode word boundaries.
* If set, \b 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
*/
UREGEX_UWORD = 256,
/** Error on Unrecognized backslash escapes.
* If set, fail with an error on patterns that contain
* backslash-escaped ASCII letters without a known specail
* meaning. If this flag is not set, these
* escaped letters represent themselves.
* @stable ICU 4.0
*/
UREGEX_ERROR_ON_UNKNOWN_ESCAPES = 512
} URegexpFlag;
/**
* 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.
*
* @param pattern The Regular Expression pattern to be compiled.
* @param patternLength The length of the pattern, or -1 if the pattern is
* NUL termintated.
* @param 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 <code>enum URegexpFlag</code>. All desired flags
* are bitwise-ORed together.
* @param 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.
* @param status Receives error detected by this function.
* @stable ICU 3.0
*
*/
U_STABLE URegularExpression * U_EXPORT2
uregex_open( const UChar *pattern,
int32_t patternLength,
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.
* <p>
* 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.
*
* @param pattern The Regular Expression pattern to be compiled,
* NUL termintated.
* @param 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 <code>enum URegexpFlag</code>. All desired flags
* are bitwise-ORed together.
* @param 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.
* @param status Receives errors detected by this function.
* @return The URegularExpression object representing the compiled
* pattern.
*
* @stable ICU 3.0
*/
#if !UCONFIG_NO_CONVERSION
U_STABLE URegularExpression * U_EXPORT2
uregex_openC( const char *pattern,
uint32_t flags,
UParseError *pe,
UErrorCode *status);
#endif
/**
* Close the regular expression, recovering all resources (memory) it
* was holding.
*
* @param regexp The regular expression to be closed.
* @stable ICU 3.0
*/
U_STABLE void U_EXPORT2
uregex_close(URegularExpression *regexp);
/**
* 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.
* <p>
* 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.
* <p>
* 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.
*
* @param regexp The compiled regular expression to be cloned.
* @param status Receives indication of any errors encountered
* @return the cloned copy of the compiled regular expression.
* @stable ICU 3.0
*/
U_STABLE URegularExpression * U_EXPORT2
uregex_clone(const URegularExpression *regexp, UErrorCode *status);
/**
* Return a pointer to the source form of the pattern for this regular expression.
*
* @param regexp The compiled regular expression.
* @param 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.
* @param status Receives errors detected by this function.
* @return 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
*/
U_STABLE const UChar * U_EXPORT2
uregex_pattern(const URegularExpression *regexp,
int32_t *patLength,
UErrorCode *status);
/**
* Get the match mode flags that were specified when compiling this regular expression.
* @param status Receives errors detected by this function.
* @param regexp The compiled regular expression.
* @return The match mode flags
* @see URegexpFlag
* @stable ICU 3.0
*/
U_STABLE int32_t U_EXPORT2
uregex_flags(const URegularExpression *regexp,
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.
* <p>
* 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.
* <p>
* Zero length strings are permitted. In this case, no subsequent match
* operation will dereference the text string pointer.
*
* @param regexp The compiled regular expression.
* @param text The subject text string.
* @param textLength The length of the subject text, or -1 if the string
* is NUL terminated.
* @param status Receives errors detected by this function.
* @stable ICU 3.0
*/
U_STABLE void U_EXPORT2
uregex_setText(URegularExpression *regexp,
const UChar *text,
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().
*
* @param regexp The compiled regular expression.
* @param 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.
* @param status Receives errors detected by this function.
* @return Poiner to the subject text string currently associated with
* this regular expression.
* @stable ICU 3.0
*/
U_STABLE const UChar * U_EXPORT2
uregex_getText(URegularExpression *regexp,
int32_t *textLength,
UErrorCode *status);
/**
* Attempts to match the input string against the pattern.
* To succeed, the match must extend to the end of the string,
* or cover the complete match region.
*
* If startIndex >= zero the match operation starts at the specified
* index and must extend to the end of the input string. Any region
* that has been specified is reset.
*
* If startIndex == -1 the match must cover the input region, or the entire
* input string if no region has been set. This directly corresponds to
* Matcher.matches() in Java
*
* @param regexp The compiled regular expression.
* @param startIndex The input string index at which to begin matching, or -1
* to match the input Region.
* @param status Receives errors detected by this function.
* @return TRUE if there is a match
* @stable ICU 3.0
*/
U_STABLE UBool U_EXPORT2
uregex_matches(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().
*
* <p>If startIndex is >= 0 any input region that was set for this
* URegularExpression is reset before the operation begins.
*
* <p>If the specified starting index == -1 the match begins at the start of the input
* region, or at the start of the full string if no region has been specified.
* This corresponds directly with Matcher.lookingAt() in Java.
*
* <p>If the match succeeds then more information can be obtained via the
* <code>uregexp_start()</code>, <code>uregexp_end()</code>,
* and <code>uregexp_group()</code> functions.</p>
*
* @param regexp The compiled regular expression.
* @param startIndex The input string index at which to begin matching, or
* -1 to match the Input Region
* @param status A reference to a UErrorCode to receive any errors.
* @return TRUE if there is a match.
* @stable ICU 3.0
*/
U_STABLE UBool U_EXPORT2
uregex_lookingAt(URegularExpression *regexp,
int32_t startIndex,
UErrorCode *status);
/**
* Find the first matching substring of the input string that matches the pattern.
* If startIndex is >= zero the search for a match begins at the specified index,
* and any match region is reset. This corresponds directly with
* Matcher.find(startIndex) in Java.
*
* If startIndex == -1 the search begins at the start of the input region,
* or at the start of the full string if no region has been specified.
*
* If a match is found, <code>uregex_start(), uregex_end()</code>, and
* <code>uregex_group()</code> will provide more information regarding the match.
*
* @param regexp The compiled regular expression.
* @param startIndex The position in the input string to begin the search, or
* -1 to search within the Input Region.
* @param status A reference to a UErrorCode to receive any errors.
* @return TRUE if a match is found.
* @stable ICU 3.0
*/
U_STABLE UBool U_EXPORT2
uregex_find(URegularExpression *regexp,
int32_t startIndex,
UErrorCode *status);
/**
* Find the next pattern match in the input string. Begin searching
* the input at the location following the end of he previous match,
* or at the start of the string (or region) if there is no
* previous match. If a match is found, <code>uregex_start(), uregex_end()</code>, and
* <code>uregex_group()</code> will provide more information regarding the match.
*
* @param regexp The compiled regular expression.
* @param status A reference to a UErrorCode to receive any errors.
* @return TRUE if a match is found.
* @see uregex_reset
* @stable ICU 3.0
*/
U_STABLE UBool U_EXPORT2
uregex_findNext(URegularExpression *regexp,
UErrorCode *status);
/**
* Get the number of capturing groups in this regular expression's pattern.
* @param regexp The compiled regular expression.
* @param status A reference to a UErrorCode to receive any errors.
* @return the number of capture groups
* @stable ICU 3.0
*/
U_STABLE int32_t U_EXPORT2
uregex_groupCount(URegularExpression *regexp,
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.
*
* @param regexp The compiled regular expression.
* @param 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.
* @param dest Buffer to receive the matching string data
* @param destCapacity Capacity of the dest buffer.
* @param status A reference to a UErrorCode to receive any errors.
* @return Length of matching data,
* or -1 if no applicable match.
* @stable ICU 3.0
*/
U_STABLE int32_t U_EXPORT2
uregex_group(URegularExpression *regexp,
int32_t groupNum,
UChar *dest,
int32_t destCapacity,
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.
*
* @param regexp The compiled regular expression.
* @param groupNum The capture group number
* @param status A reference to a UErrorCode to receive any errors.
* @return the starting position in the input of the text matched
* by the specified group.
* @stable ICU 3.0
*/
U_STABLE int32_t U_EXPORT2
uregex_start(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.
*
* @param regexp The compiled regular expression.
* @param groupNum The capture group number
* @param status A reference to a UErrorCode to receive any errors.
* @return the index of the position following the last matched character.
* @stable ICU 3.0
*/
U_STABLE int32_t U_EXPORT2
uregex_end(URegularExpression *regexp,
int32_t groupNum,
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. Clears any
* match region that may have been set.
*
* @param regexp The compiled regular expression.
* @param index The position in the text at which a
* uregex_findNext() should begin searching.
* @param status A reference to a UErrorCode to receive any errors.
* @stable ICU 3.0
*/
U_STABLE void U_EXPORT2
uregex_reset(URegularExpression *regexp,
int32_t index,
UErrorCode *status);
/** Sets the limits of the matching region for this URegularExpression.
* The region is the part of the input string that will be considered when matching.
* Invoking this method resets any saved state from the previous match,
* 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 regexp The compiled regular expression.
* @param regionStart The index to begin searches at.
* @param regionLimit The index to end searches at (exclusive).
* @param status A pointer to a UErrorCode to receive any errors.
* @stable ICU 4.0
*/
U_DRAFT void U_EXPORT2
uregex_setRegion(URegularExpression *regexp,
int32_t regionStart,
int32_t regionLimit,
UErrorCode *status);
/**
* Reports the start index of the matching region. Any matches found are limited to
* to the region bounded by regionStart (inclusive) and regionEnd (exclusive).
*
* @param regexp The compiled regular expression.
* @param status A pointer to a UErrorCode to receive any errors.
* @return The starting index of this matcher's region.
* @stable ICU 4.0
*/
U_DRAFT int32_t U_EXPORT2
uregex_regionStart(const URegularExpression *regexp,
UErrorCode *status);
/**
* Reports the end index (exclusive) of the matching region for this URegularExpression.
* Any matches found are limited to to the region bounded by regionStart (inclusive)
* and regionEnd (exclusive).
*
* @param regexp The compiled regular expression.
* @param status A pointer to a UErrorCode to receive any errors.
* @return The ending point of this matcher's region.
* @stable ICU 4.0
*/
U_DRAFT int32_t U_EXPORT2
uregex_regionEnd(const URegularExpression *regexp,
UErrorCode *status);
/**
* Queries the transparency of region bounds for this URegularExpression.
* See useTransparentBounds for a description of transparent and opaque bounds.
* By default, matching boundaries are opaque.
*
* @param regexp The compiled regular expression.
* @param status A pointer to a UErrorCode to receive any errors.
* @return TRUE if this matcher is using opaque bounds, false if it is not.
* @stable ICU 4.0
*/
U_DRAFT UBool U_EXPORT2
uregex_hasTransparentBounds(const URegularExpression *regexp,
UErrorCode *status);
/**
* Sets the transparency of region bounds for this URegularExpression.
* Invoking this function with an argument of TRUE will set matches to use transparent bounds.
* If the boolean argument is FALSE, then opaque bounds will be used.
*
* Using transparent bounds, the boundaries of the matching 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 matching region is visible to lookahead,
* lookbehind, and boundary matching constructs.
*
* By default, opaque bounds are used.
*
* @param regexp The compiled regular expression.
* @param b TRUE for transparent bounds; FALSE for opaque bounds
* @param status A pointer to a UErrorCode to receive any errors.
* @stable ICU 4.0
**/
U_DRAFT void U_EXPORT2
uregex_useTransparentBounds(URegularExpression *regexp,
UBool b,
UErrorCode *status);
/**
* Return true if this URegularExpression is using anchoring bounds.
* By default, anchoring region bounds are used.
*
* @param regexp The compiled regular expression.
* @param status A pointer to a UErrorCode to receive any errors.
* @return TRUE if this matcher is using anchoring bounds.
* @stable ICU 4.0
*/
U_DRAFT UBool U_EXPORT2
uregex_hasAnchoringBounds(const URegularExpression *regexp,
UErrorCode *status);
/**
* Set whether this URegularExpression 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 regexp The compiled regular expression.
* @param b TRUE if to enable anchoring bounds; FALSE to disable them.
* @param status A pointer to a UErrorCode to receive any errors.
* @stable ICU 4.0
*/
U_DRAFT void U_EXPORT2
uregex_useAnchoringBounds(URegularExpression *regexp,
UBool b,
UErrorCode *status);
/**
* 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.
*
* @param regexp The compiled regular expression.
* @param status A pointer to a UErrorCode to receive any errors.
* @return TRUE if the most recent match hit the end of input
* @stable ICU 4.0
*/
U_DRAFT UBool U_EXPORT2
uregex_hitEnd(const URegularExpression *regexp,
UErrorCode *status);
/**
* Return TRUE the most recent match succeeded and additional input could cause
* it to fail. If this function 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.
*
* @param regexp The compiled regular expression.
* @param status A pointer to a UErrorCode to receive any errors.
* @return TRUE if more input could cause the most recent match to no longer match.
* @stable ICU 4.0
*/
U_DRAFT UBool U_EXPORT2
uregex_requireEnd(const URegularExpression *regexp,
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.
*
* @param regexp The compiled regular expression.
* @param replacementText A string containing the replacement text.
* @param replacementLength The length of the replacement string, or
* -1 if it is NUL terminated.
* @param destBuf A (UChar *) buffer that will receive the result.
* @param destCapacity The capacity of the desitnation buffer.
* @param status A reference to a UErrorCode to receive any errors.
* @return 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
*/
U_STABLE int32_t U_EXPORT2
uregex_replaceAll(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.
*
* @param regexp The compiled regular expression.
* @param replacementText A string containing the replacement text.
* @param replacementLength The length of the replacement string, or
* -1 if it is NUL terminated.
* @param destBuf A (UChar *) buffer that will receive the result.
* @param destCapacity The capacity of the desitnation buffer.
* @param status a reference to a UErrorCode to receive any errors.
* @return 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
*/
U_STABLE int32_t U_EXPORT2
uregex_replaceFirst(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.
*
* <p>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.</p>
*
* <p>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.
*
* <p>For simple, prepackaged, non-incremental find-and-replace
* operations, see replaceFirst() or replaceAll().</p>
*
* @param regexp The regular expression object.
* @param 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.
* @param replacementLength The length of the replacement text string,
* or -1 if the string is NUL terminated.
* @param 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.
* @param destCapacity The size of the output buffer, On return, this
* parameter will be updated to reflect the space remaining
* unused in the output buffer.
* @param status A reference to a UErrorCode to receive any errors.
* @return 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
*
*/
U_STABLE int32_t U_EXPORT2
uregex_appendReplacement(URegularExpression *regexp,
const UChar *replacementText,
int32_t replacementLength,
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. <code>uregex_appendTail()</code> is intended
* to be invoked after one or more invocations of the
* <code>uregex_appendReplacement()</code> function.
*
* @param regexp The regular expression object. This is needed to
* obtain the input string and with the position
* of the last match within it.
* @param 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.
* @param destCapacity The size of the output buffer, On return, this
* value will be updated to reflect the space remaining
* unused in the output buffer.
* @param status A reference to a UErrorCode to receive any errors.
* @return 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
*/
U_STABLE int32_t U_EXPORT2
uregex_appendTail(URegularExpression *regexp,
UChar **destBuf,
int32_t *destCapacity,
UErrorCode *status);
/**
* Split a string into fields. Somewhat like split() from Perl.
* The pattern matches identify delimiters that separate the input
* into fields. The input data between the matches becomes the
* fields themselves.
* <p>
* 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.
*
* @param regexp The compiled regular expression.
* @param 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.
* @param destCapacity The capacity of the destBuf.
* @param 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.
* @param destFields An array to be filled with the position of each
* of the extracted fields within destBuf.
* @param 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.
* @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 3.0
*/
U_STABLE int32_t U_EXPORT2
uregex_split( URegularExpression *regexp,
UChar *destBuf,
int32_t destCapacity,
int32_t *requiredCapacity,
UChar *destFields[],
int32_t destFieldsCapacity,
UErrorCode *status);
/**
* Set a processing time limit for match operations with this URegularExpression.
*
* 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 regexp The compiled regular expression.
* @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
*/
U_DRAFT void U_EXPORT2
uregex_setTimeLimit(URegularExpression *regexp,
int32_t limit,
UErrorCode *status);
/**
* Get the time limit for for matches with this URegularExpression.
* A return value of zero indicates that there is no limit.
*
* @param regexp The compiled regular expression.
* @param status A reference to a UErrorCode to receive any errors.
* @return the maximum allowed time for a match, in units of processing steps.
* @stable ICU 4.0
*/
U_DRAFT int32_t U_EXPORT2
uregex_getTimeLimit(const URegularExpression *regexp,
UErrorCode *status);
/**
* Set the amount of heap storage avaliable for use by the match backtracking stack.
* <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 regexp The compiled regular expression.
* @param limit The maximum size, in bytes, of the matching backtrack stack.
* A value of -1 means no limit.
* The limit must be greater than zero, or -1.
* @param status A reference to a UErrorCode to receive any errors.
*
* @stable ICU 4.0
*/
U_DRAFT void U_EXPORT2
uregex_setStackLimit(URegularExpression *regexp,
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
*/
U_DRAFT int32_t U_EXPORT2
uregex_getStackLimit(const URegularExpression *regexp,
UErrorCode *status);
/**
* Function pointer for a regular expression matching callback function.
* When set, a callback function will be called periodically during matching
* operations. If the call back function returns FALSE, the matching
* operation will be terminated early.
*
* Note: the callback function must not call other functions on this
* URegularExpression.
*
* @param context context pointer. The callback function will be invoked
* with the context specified at the time that
* uregex_setMatchCallback() is called.
* @param steps the accumulated processing time, in match steps,
* for this matching operation.
* @return TRUE to continue the matching operation.
* FALSE to terminate the matching operation.
* @stable ICU 4.0
*/
U_CDECL_BEGIN
typedef UBool U_CALLCONV URegexMatchCallback (
const void *context,
int32_t steps);
U_CDECL_END
/**
* Set a callback function for this URegularExpression.
* During matching operations the function will be called periodically,
* giving the application the opportunity to terminate a long-running
* match.
*
* @param regexp The compiled regular expression.
* @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
*/
U_DRAFT void U_EXPORT2
uregex_setMatchCallback(URegularExpression *regexp,
URegexMatchCallback *callback,
const void *context,
UErrorCode *status);
/**
* Get the callback function for this URegularExpression.
*
* @param regexp The compiled regular expression.
* @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
*/
U_DRAFT void U_EXPORT2
uregex_getMatchCallback(const URegularExpression *regexp,
URegexMatchCallback **callback,
const void **context,
UErrorCode *status);
#endif /* !UCONFIG_NO_REGULAR_EXPRESSIONS */
#endif /* UREGEX_H */