Check in the pristine copy of ICU 4.6...

icu46/source/common/unicode/ubrk.h

+/*
+******************************************************************************
+* Copyright (C) 1996-2010, 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>
+ * 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 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,
+#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);
+
+#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
+
+/**
+ * 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.
+ *             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);
+
+/**
+ * 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