scuffed-code/icu4c/source/common/unicode/ubrk.h
2007-06-11 19:14:47 +00:00

479 lines
17 KiB
C

/*
******************************************************************************
* Copyright (C) 1996-2007, 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"
/**
* 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 void 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>
* 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>
* 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 allows users to interact with
* characters as they expect to, for example, when moving the cursor
* through a text string. Character boundary analysis provides correct
* navigation of through character strings, regardless of how the
* character is stored. For example, an accented character might be
* stored as a base character and a diacritical mark. What users
* consider to be a character can differ between languages.
* <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 snippits 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,
#endif /* U_HIDE_DEPRECATED_API */
UBRK_COUNT = 5
} 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.
* @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.
* @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.
* @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;
/**
* 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.
* @param text The text to be iterated over.
* @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);
/**
* Thread safe cloning operation
* @param bi iterator to be cloned
* @param stackBuffer 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. This will probably be enough to avoid memory allocations.
* @param pBufferSize 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);
/**
* A recommended size (in bytes) for the memory buffer to be passed to ubrk_saveClone().
* @stable ICU 2.0
*/
#define U_BRK_SAFECLONE_BUFFERSIZE 512
/**
* 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);
/**
* Sets an existing iterator to point to a new piece of text
* @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
* @param bi The iterator to use
* @param text The text to be set
* @param status The error code
* @draft ICU 3.4
*/
U_DRAFT 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);
/**
* Determine the text boundary following the current text 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);
/**
* Determine the text boundary preceding the current text 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);
/**
* Determine the index of the first character in the text being scanned.
* This is not always the same as index 0 of the text.
* @param bi The break iterator to use.
* @return The character index of the first character in the text being scanned.
* @see ubrk_last
* @stable ICU 2.0
*/
U_STABLE int32_t U_EXPORT2
ubrk_first(UBreakIterator *bi);
/**
* Determine 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);
/**
* Determine the text boundary preceding the specified offset.
* The value returned 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);
/**
* Determine the text 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 specfied 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 attemtping 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);
#endif /* #if !UCONFIG_NO_BREAK_ITERATION */
#endif