// © 2016 and later: Unicode, Inc. and others. // License & terms of use: http://www.unicode.org/copyright.html /* ****************************************************************************** * Copyright (C) 1996-2015, International Business Machines Corporation and others. * All Rights Reserved. ****************************************************************************** */ #ifndef UBRK_H #define UBRK_H #include "unicode/utypes.h" #include "unicode/uloc.h" #include "unicode/utext.h" #include "unicode/localpointer.h" /** * A text-break iterator. * For usage in C programs. */ #ifndef UBRK_TYPEDEF_UBREAK_ITERATOR # define UBRK_TYPEDEF_UBREAK_ITERATOR /** * Opaque type representing an ICU Break iterator object. * @stable ICU 2.0 */ typedef struct UBreakIterator UBreakIterator; #endif #if !UCONFIG_NO_BREAK_ITERATION #include "unicode/parseerr.h" /** * \file * \brief C API: BreakIterator * * <h2> BreakIterator C API </h2> * * The BreakIterator C API defines methods for finding the location * of boundaries in text. Pointer to a UBreakIterator maintain a * current position and scan over text returning the index of characters * where boundaries occur. * <p> * Line boundary analysis determines where a text string can be broken * when line-wrapping. The mechanism correctly handles punctuation and * hyphenated words. * <p> * Note: The locale keyword "lb" can be used to modify line break * behavior according to the CSS level 3 line-break options, see * <http://dev.w3.org/csswg/css-text/#line-breaking>. For example: * "ja@lb=strict", "zh@lb=loose". * <p> * Sentence boundary analysis allows selection with correct * interpretation of periods within numbers and abbreviations, and * trailing punctuation marks such as quotation marks and parentheses. * <p> * Note: The locale keyword "ss" can be used to enable use of * segmentation suppression data (preventing breaks in English after * abbreviations such as "Mr." or "Est.", for example), as follows: * "en@ss=standard". * <p> * Word boundary analysis is used by search and replace functions, as * well as within text editing applications that allow the user to * select words with a double click. Word selection provides correct * interpretation of punctuation marks within and following * words. Characters that are not part of a word, such as symbols or * punctuation marks, have word-breaks on both sides. * <p> * Character boundary analysis identifies the boundaries of * "Extended Grapheme Clusters", which are groupings of codepoints * that should be treated as character-like units for many text operations. * Please see Unicode Standard Annex #29, Unicode Text Segmentation, * http://www.unicode.org/reports/tr29/ for additional information * on grapheme clusters and guidelines on their use. * <p> * Title boundary analysis locates all positions, * typically starts of words, that should be set to Title Case * when title casing the text. * <p> * The text boundary positions are found according to the rules * described in Unicode Standard Annex #29, Text Boundaries, and * Unicode Standard Annex #14, Line Breaking Properties. These * are available at http://www.unicode.org/reports/tr14/ and * http://www.unicode.org/reports/tr29/. * <p> * In addition to the plain C API defined in this header file, an * object oriented C++ API with equivalent functionality is defined in the * file brkiter.h. * <p> * Code snippets illustrating the use of the Break Iterator APIs * are available in the ICU User Guide, * http://icu-project.org/userguide/boundaryAnalysis.html * and in the sample program icu/source/samples/break/break.cpp */ /** The possible types of text boundaries. @stable ICU 2.0 */ typedef enum UBreakIteratorType { /** Character breaks @stable ICU 2.0 */ UBRK_CHARACTER = 0, /** Word breaks @stable ICU 2.0 */ UBRK_WORD = 1, /** Line breaks @stable ICU 2.0 */ UBRK_LINE = 2, /** Sentence breaks @stable ICU 2.0 */ UBRK_SENTENCE = 3, #ifndef U_HIDE_DEPRECATED_API /** * Title Case breaks * The iterator created using this type locates title boundaries as described for * Unicode 3.2 only. For Unicode 4.0 and above title boundary iteration, * please use Word Boundary iterator. * * @deprecated ICU 2.8 Use the word break iterator for titlecasing for Unicode 4 and later. */ UBRK_TITLE = 4, /** * One more than the highest normal UBreakIteratorType value. * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420. */ UBRK_COUNT = 5 #endif // U_HIDE_DEPRECATED_API } UBreakIteratorType; /** Value indicating all text boundaries have been returned. * @stable ICU 2.0 */ #define UBRK_DONE ((int32_t) -1) /** * Enum constants for the word break tags returned by * getRuleStatus(). A range of values is defined for each category of * word, to allow for further subdivisions of a category in future releases. * Applications should check for tag values falling within the range, rather * than for single individual values. * * The numeric values of all of these constants are stable (will not change). * * @stable ICU 2.2 */ typedef enum UWordBreak { /** Tag value for "words" that do not fit into any of other categories. * Includes spaces and most punctuation. */ UBRK_WORD_NONE = 0, /** Upper bound for tags for uncategorized words. */ UBRK_WORD_NONE_LIMIT = 100, /** Tag value for words that appear to be numbers, lower limit. */ UBRK_WORD_NUMBER = 100, /** Tag value for words that appear to be numbers, upper limit. */ UBRK_WORD_NUMBER_LIMIT = 200, /** Tag value for words that contain letters, excluding * hiragana, katakana or ideographic characters, lower limit. */ UBRK_WORD_LETTER = 200, /** Tag value for words containing letters, upper limit */ UBRK_WORD_LETTER_LIMIT = 300, /** Tag value for words containing kana characters, lower limit */ UBRK_WORD_KANA = 300, /** Tag value for words containing kana characters, upper limit */ UBRK_WORD_KANA_LIMIT = 400, /** Tag value for words containing ideographic characters, lower limit */ UBRK_WORD_IDEO = 400, /** Tag value for words containing ideographic characters, upper limit */ UBRK_WORD_IDEO_LIMIT = 500 } UWordBreak; /** * Enum constants for the line break tags returned by getRuleStatus(). * A range of values is defined for each category of * word, to allow for further subdivisions of a category in future releases. * Applications should check for tag values falling within the range, rather * than for single individual values. * * The numeric values of all of these constants are stable (will not change). * * @stable ICU 2.8 */ typedef enum ULineBreakTag { /** Tag value for soft line breaks, positions at which a line break * is acceptable but not required */ UBRK_LINE_SOFT = 0, /** Upper bound for soft line breaks. */ UBRK_LINE_SOFT_LIMIT = 100, /** Tag value for a hard, or mandatory line break */ UBRK_LINE_HARD = 100, /** Upper bound for hard line breaks. */ UBRK_LINE_HARD_LIMIT = 200 } ULineBreakTag; /** * Enum constants for the sentence break tags returned by getRuleStatus(). * A range of values is defined for each category of * sentence, to allow for further subdivisions of a category in future releases. * Applications should check for tag values falling within the range, rather * than for single individual values. * * The numeric values of all of these constants are stable (will not change). * * @stable ICU 2.8 */ typedef enum USentenceBreakTag { /** Tag value for for sentences ending with a sentence terminator * ('.', '?', '!', etc.) character, possibly followed by a * hard separator (CR, LF, PS, etc.) */ UBRK_SENTENCE_TERM = 0, /** Upper bound for tags for sentences ended by sentence terminators. */ UBRK_SENTENCE_TERM_LIMIT = 100, /** Tag value for for sentences that do not contain an ending * sentence terminator ('.', '?', '!', etc.) character, but * are ended only by a hard separator (CR, LF, PS, etc.) or end of input. */ UBRK_SENTENCE_SEP = 100, /** Upper bound for tags for sentences ended by a separator. */ UBRK_SENTENCE_SEP_LIMIT = 200 /** Tag value for a hard, or mandatory line break */ } USentenceBreakTag; /** * Masks to control line break word options (per the CSS word-break property). * NORMAL allows breaks between CJK characters in the middle of words. Other masks * prohibit breaks between characters of specific scripts (or all scripts) except as * determined by a dictionary, or by spaces or other mechanisms (Western-style breaking). * * @internal Apple only */ typedef enum ULineWordOptions { /** Allow breaks between characters of all CJK scripts */ UBRK_LINEWORD_NORMAL = 0, /** Prevent breaks between Hangul characters, except as determined by a dictionary. */ UBRK_LINEWORD_KEEP_HANGUL = 1, /** Prevent breaks between characters of any script, except as determined by a dictionary. */ UBRK_LINEWORD_KEEP_ALL = 0x7F } ULineWordOptions; /** * Open a new UBreakIterator for locating text boundaries for a specified locale. * A UBreakIterator may be used for detecting character, line, word, * and sentence breaks in text. * @param type The type of UBreakIterator to open: one of UBRK_CHARACTER, UBRK_WORD, * UBRK_LINE, UBRK_SENTENCE * @param locale The locale specifying the text-breaking conventions. Note that * locale keys such as "lb" and "ss" may be used to modify text break behavior, * see general discussion of BreakIterator C API. * @param text The text to be iterated over. May be null, in which case ubrk_setText() is * used to specify the text to be iterated. * @param textLength The number of characters in text, or -1 if null-terminated. * @param status A UErrorCode to receive any errors. * @return A UBreakIterator for the specified locale. * @see ubrk_openRules * @stable ICU 2.0 */ U_STABLE UBreakIterator* U_EXPORT2 ubrk_open(UBreakIteratorType type, const char *locale, const UChar *text, int32_t textLength, UErrorCode *status); /** * Open a new UBreakIterator for locating text boundaries using specified breaking rules. * The rule syntax is ... (TBD) * @param rules A set of rules specifying the text breaking conventions. * @param rulesLength The number of characters in rules, or -1 if null-terminated. * @param text The text to be iterated over. May be null, in which case ubrk_setText() is * used to specify the text to be iterated. * @param textLength The number of characters in text, or -1 if null-terminated. * @param parseErr Receives position and context information for any syntax errors * detected while parsing the rules. * @param status A UErrorCode to receive any errors. * @return A UBreakIterator for the specified rules. * @see ubrk_open * @stable ICU 2.2 */ U_STABLE UBreakIterator* U_EXPORT2 ubrk_openRules(const UChar *rules, int32_t rulesLength, const UChar *text, int32_t textLength, UParseError *parseErr, UErrorCode *status); /** * Open a new UBreakIterator for locating text boundaries using precompiled binary rules. * Opening a UBreakIterator this way is substantially faster than using ubrk_openRules. * Binary rules may be obtained using ubrk_getBinaryRules. The compiled rules are not * compatible across different major versions of ICU, nor across platforms of different * endianness or different base character set family (ASCII vs EBCDIC). * @param binaryRules A set of compiled binary rules specifying the text breaking * conventions. Ownership of the storage containing the compiled * rules remains with the caller of this function. The compiled * rules must not be modified or deleted during the life of the * break iterator. * @param rulesLength The length of binaryRules in bytes; must be >= 0. * @param text The text to be iterated over. May be null, in which case * ubrk_setText() is used to specify the text to be iterated. * @param textLength The number of characters in text, or -1 if null-terminated. * @param status Pointer to UErrorCode to receive any errors. * @return UBreakIterator for the specified rules. * @see ubrk_getBinaryRules * @stable ICU 59 */ U_STABLE UBreakIterator* U_EXPORT2 ubrk_openBinaryRules(const uint8_t *binaryRules, int32_t rulesLength, const UChar * text, int32_t textLength, UErrorCode * status); /** * Thread safe cloning operation * @param bi iterator to be cloned * @param stackBuffer <em>Deprecated functionality as of ICU 52, use NULL.</em><br> * user allocated space for the new clone. If NULL new memory will be allocated. * If buffer is not large enough, new memory will be allocated. * Clients can use the U_BRK_SAFECLONE_BUFFERSIZE. * @param pBufferSize <em>Deprecated functionality as of ICU 52, use NULL or 1.</em><br> * pointer to size of allocated space. * If *pBufferSize == 0, a sufficient size for use in cloning will * be returned ('pre-flighting') * If *pBufferSize is not enough for a stack-based safe clone, * new memory will be allocated. * @param status to indicate whether the operation went on smoothly or there were errors * An informational status value, U_SAFECLONE_ALLOCATED_ERROR, is used if any allocations were necessary. * @return pointer to the new clone * @stable ICU 2.0 */ U_STABLE UBreakIterator * U_EXPORT2 ubrk_safeClone( const UBreakIterator *bi, void *stackBuffer, int32_t *pBufferSize, UErrorCode *status); #ifndef U_HIDE_DEPRECATED_API /** * A recommended size (in bytes) for the memory buffer to be passed to ubrk_saveClone(). * @deprecated ICU 52. Do not rely on ubrk_safeClone() cloning into any provided buffer. */ #define U_BRK_SAFECLONE_BUFFERSIZE 1 #endif /* U_HIDE_DEPRECATED_API */ /** * Close a UBreakIterator. * Once closed, a UBreakIterator may no longer be used. * @param bi The break iterator to close. * @stable ICU 2.0 */ U_STABLE void U_EXPORT2 ubrk_close(UBreakIterator *bi); #if U_SHOW_CPLUSPLUS_API U_NAMESPACE_BEGIN /** * \class LocalUBreakIteratorPointer * "Smart pointer" class, closes a UBreakIterator via ubrk_close(). * For most methods see the LocalPointerBase base class. * * @see LocalPointerBase * @see LocalPointer * @stable ICU 4.4 */ U_DEFINE_LOCAL_OPEN_POINTER(LocalUBreakIteratorPointer, UBreakIterator, ubrk_close); U_NAMESPACE_END #endif #ifndef U_HIDE_INTERNAL_API /** * Set the ULineWordOptions for the specified break iterator. * * @param bi The iterator to use * @param lineWordOpts The ULineWordOptions to set. * @internal Apple only */ U_INTERNAL void U_EXPORT2 ubrk_setLineWordOpts(UBreakIterator* bi, ULineWordOptions lineWordOpts); #endif /* U_HIDE_INTERNAL_API */ /** * Sets an existing iterator to point to a new piece of text. * The break iterator retains a pointer to the supplied text. * The caller must not modify or delete the text while the BreakIterator * retains the reference. * * @param bi The iterator to use * @param text The text to be set * @param textLength The length of the text * @param status The error code * @stable ICU 2.0 */ U_STABLE void U_EXPORT2 ubrk_setText(UBreakIterator* bi, const UChar* text, int32_t textLength, UErrorCode* status); /** * Sets an existing iterator to point to a new piece of text. * * All index positions returned by break iterator functions are * native indices from the UText. For example, when breaking UTF-8 * encoded text, the break positions returned by \ref ubrk_next, \ref ubrk_previous, etc. * will be UTF-8 string indices, not UTF-16 positions. * * @param bi The iterator to use * @param text The text to be set. * This function makes a shallow clone of the supplied UText. This means * that the caller is free to immediately close or otherwise reuse the * UText that was passed as a parameter, but that the underlying text itself * must not be altered while being referenced by the break iterator. * @param status The error code * @stable ICU 3.4 */ U_STABLE void U_EXPORT2 ubrk_setUText(UBreakIterator* bi, UText* text, UErrorCode* status); /** * Determine the most recently-returned text boundary. * * @param bi The break iterator to use. * @return The character index most recently returned by \ref ubrk_next, \ref ubrk_previous, * \ref ubrk_first, or \ref ubrk_last. * @stable ICU 2.0 */ U_STABLE int32_t U_EXPORT2 ubrk_current(const UBreakIterator *bi); /** * Advance the iterator to the boundary following the current boundary. * * @param bi The break iterator to use. * @return The character index of the next text boundary, or UBRK_DONE * if all text boundaries have been returned. * @see ubrk_previous * @stable ICU 2.0 */ U_STABLE int32_t U_EXPORT2 ubrk_next(UBreakIterator *bi); /** * Set the iterator position to the boundary preceding the current boundary. * * @param bi The break iterator to use. * @return The character index of the preceding text boundary, or UBRK_DONE * if all text boundaries have been returned. * @see ubrk_next * @stable ICU 2.0 */ U_STABLE int32_t U_EXPORT2 ubrk_previous(UBreakIterator *bi); /** * Set the iterator position to zero, the start of the text being scanned. * @param bi The break iterator to use. * @return The new iterator position (zero). * @see ubrk_last * @stable ICU 2.0 */ U_STABLE int32_t U_EXPORT2 ubrk_first(UBreakIterator *bi); /** * Set the iterator position to the index immediately <EM>beyond</EM> the last character in the text being scanned. * This is not the same as the last character. * @param bi The break iterator to use. * @return The character offset immediately <EM>beyond</EM> the last character in the * text being scanned. * @see ubrk_first * @stable ICU 2.0 */ U_STABLE int32_t U_EXPORT2 ubrk_last(UBreakIterator *bi); /** * Set the iterator position to the first boundary preceding the specified offset. * The new position is always smaller than offset, or UBRK_DONE. * @param bi The break iterator to use. * @param offset The offset to begin scanning. * @return The text boundary preceding offset, or UBRK_DONE. * @see ubrk_following * @stable ICU 2.0 */ U_STABLE int32_t U_EXPORT2 ubrk_preceding(UBreakIterator *bi, int32_t offset); /** * Advance the iterator to the first boundary following the specified offset. * The value returned is always greater than offset, or UBRK_DONE. * @param bi The break iterator to use. * @param offset The offset to begin scanning. * @return The text boundary following offset, or UBRK_DONE. * @see ubrk_preceding * @stable ICU 2.0 */ U_STABLE int32_t U_EXPORT2 ubrk_following(UBreakIterator *bi, int32_t offset); /** * Get a locale for which text breaking information is available. * A UBreakIterator in a locale returned by this function will perform the correct * text breaking for the locale. * @param index The index of the desired locale. * @return A locale for which number text breaking information is available, or 0 if none. * @see ubrk_countAvailable * @stable ICU 2.0 */ U_STABLE const char* U_EXPORT2 ubrk_getAvailable(int32_t index); /** * Determine how many locales have text breaking information available. * This function is most useful as determining the loop ending condition for * calls to \ref ubrk_getAvailable. * @return The number of locales for which text breaking information is available. * @see ubrk_getAvailable * @stable ICU 2.0 */ U_STABLE int32_t U_EXPORT2 ubrk_countAvailable(void); /** * Returns true if the specified position is a boundary position. As a side * effect, leaves the iterator pointing to the first boundary position at * or after "offset". * @param bi The break iterator to use. * @param offset the offset to check. * @return True if "offset" is a boundary position. * @stable ICU 2.0 */ U_STABLE UBool U_EXPORT2 ubrk_isBoundary(UBreakIterator *bi, int32_t offset); /** * Return the status from the break rule that determined the most recently * returned break position. The values appear in the rule source * within brackets, {123}, for example. For rules that do not specify a * status, a default value of 0 is returned. * <p> * For word break iterators, the possible values are defined in enum UWordBreak. * @stable ICU 2.2 */ U_STABLE int32_t U_EXPORT2 ubrk_getRuleStatus(UBreakIterator *bi); /** * Get the statuses from the break rules that determined the most recently * returned break position. The values appear in the rule source * within brackets, {123}, for example. The default status value for rules * that do not explicitly provide one is zero. * <p> * For word break iterators, the possible values are defined in enum UWordBreak. * @param bi The break iterator to use * @param fillInVec an array to be filled in with the status values. * @param capacity the length of the supplied vector. A length of zero causes * the function to return the number of status values, in the * normal way, without attempting to store any values. * @param status receives error codes. * @return The number of rule status values from rules that determined * the most recent boundary returned by the break iterator. * @stable ICU 3.0 */ U_STABLE int32_t U_EXPORT2 ubrk_getRuleStatusVec(UBreakIterator *bi, int32_t *fillInVec, int32_t capacity, UErrorCode *status); /** * Return the locale of the break iterator. You can choose between the valid and * the actual locale. * @param bi break iterator * @param type locale type (valid or actual) * @param status error code * @return locale string * @stable ICU 2.8 */ U_STABLE const char* U_EXPORT2 ubrk_getLocaleByType(const UBreakIterator *bi, ULocDataLocaleType type, UErrorCode* status); /** * Set the subject text string upon which the break iterator is operating * without changing any other aspect of the state. * The new and previous text strings must have the same content. * * This function is intended for use in environments where ICU is operating on * strings that may move around in memory. It provides a mechanism for notifying * ICU that the string has been relocated, and providing a new UText to access the * string in its new position. * * Note that the break iterator never copies the underlying text * of a string being processed, but always operates directly on the original text * provided by the user. Refreshing simply drops the references to the old text * and replaces them with references to the new. * * Caution: this function is normally used only by very specialized * system-level code. One example use case is with garbage collection * that moves the text in memory. * * @param bi The break iterator. * @param text The new (moved) text string. * @param status Receives errors detected by this function. * * @stable ICU 49 */ U_STABLE void U_EXPORT2 ubrk_refreshUText(UBreakIterator *bi, UText *text, UErrorCode *status); /** * Get a compiled binary version of the rules specifying the behavior of a UBreakIterator. * The binary rules may be used with ubrk_openBinaryRules to open a new UBreakIterator * more quickly than using ubrk_openRules. The compiled rules are not compatible across * different major versions of ICU, nor across platforms of different endianness or * different base character set family (ASCII vs EBCDIC). Supports preflighting (with * binaryRules=NULL and rulesCapacity=0) to get the rules length without copying them to * the binaryRules buffer. However, whether preflighting or not, if the actual length * is greater than INT32_MAX, then the function returns 0 and sets *status to * U_INDEX_OUTOFBOUNDS_ERROR. * @param bi The break iterator to use. * @param binaryRules Buffer to receive the compiled binary rules; set to NULL for * preflighting. * @param rulesCapacity Capacity (in bytes) of the binaryRules buffer; set to 0 for * preflighting. Must be >= 0. * @param status Pointer to UErrorCode to receive any errors, such as * U_BUFFER_OVERFLOW_ERROR, U_INDEX_OUTOFBOUNDS_ERROR, or * U_ILLEGAL_ARGUMENT_ERROR. * @return The actual byte length of the binary rules, if <= INT32_MAX; * otherwise 0. If not preflighting and this is larger than * rulesCapacity, *status will be set to an error. * @see ubrk_openBinaryRules * @stable ICU 59 */ U_STABLE int32_t U_EXPORT2 ubrk_getBinaryRules(UBreakIterator *bi, uint8_t * binaryRules, int32_t rulesCapacity, UErrorCode * status); #endif /* #if !UCONFIG_NO_BREAK_ITERATION */ #endif