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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
********************************************************************************
* Copyright (C) 1997-2016, International Business Machines
* Corporation and others. All Rights Reserved.
********************************************************************************
*
* File brkiter.h
*
* Modification History:
*
* Date Name Description
* 02/18/97 aliu Added typedef for TextCount. Made DONE const.
* 05/07/97 aliu Fixed DLL declaration.
* 07/09/97 jfitz Renamed BreakIterator and interface synced with JDK
* 08/11/98 helena Sync-up JDK1.2.
* 01/13/2000 helena Added UErrorCode parameter to createXXXInstance methods.
********************************************************************************
*/
#ifndef BRKITER_H
#define BRKITER_H
#include "unicode/utypes.h"
/**
* \file
* \brief C++ API: Break Iterator.
*/
#include "unicode/utypes.h"
#if U_SHOW_CPLUSPLUS_API
#if UCONFIG_NO_BREAK_ITERATION
U_NAMESPACE_BEGIN
/*
* Allow the declaration of APIs with pointers to BreakIterator
* even when break iteration is removed from the build.
*/
class BreakIterator;
U_NAMESPACE_END
#else
#include "unicode/uobject.h"
#include "unicode/unistr.h"
#include "unicode/chariter.h"
#include "unicode/locid.h"
#include "unicode/ubrk.h"
#include "unicode/strenum.h"
#include "unicode/utext.h"
#include "unicode/umisc.h"
U_NAMESPACE_BEGIN
/**
* The BreakIterator class implements methods for finding the location
* of boundaries in text. BreakIterator is an abstract base class.
* Instances of BreakIterator 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>
* 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 C++ API defined in this header file, a
* plain C API with equivalent functionality is defined in the
* file ubrk.h
* <p>
* Code snippets illustrating the use of the Break Iterator APIs
* are available in the ICU User Guide,
* https://unicode-org.github.io/icu/userguide/boundaryanalysis/
* and in the sample program icu/source/samples/break/break.cpp
*
*/
class U_COMMON_API BreakIterator : public UObject {
public:
/**
* destructor
* @stable ICU 2.0
*/
virtual ~BreakIterator();
/**
* Return true if another object is semantically equal to this
* one. The other object should be an instance of the same subclass of
* BreakIterator. Objects of different subclasses are considered
* unequal.
* <P>
* Return true if this BreakIterator is at the same position in the
* same text, and is the same class and type (word, line, etc.) of
* BreakIterator, as the argument. Text is considered the same if
* it contains the same characters, it need not be the same
* object, and styles are not considered.
* @stable ICU 2.0
*/
virtual bool operator==(const BreakIterator&) const = 0;
/**
* Returns the complement of the result of operator==
* @param rhs The BreakIterator to be compared for inequality
* @return the complement of the result of operator==
* @stable ICU 2.0
*/
bool operator!=(const BreakIterator& rhs) const { return !operator==(rhs); }
/**
* Return a polymorphic copy of this object. This is an abstract
* method which subclasses implement.
* @stable ICU 2.0
*/
virtual BreakIterator* clone() const = 0;
/**
* Return a polymorphic class ID for this object. Different subclasses
* will return distinct unequal values.
* @stable ICU 2.0
*/
virtual UClassID getDynamicClassID() const override = 0;
/**
* Return a CharacterIterator over the text being analyzed.
* @stable ICU 2.0
*/
virtual CharacterIterator& getText() const = 0;
/**
* Get a UText for the text being analyzed.
* The returned UText is a shallow clone of the UText used internally
* by the break iterator implementation. It can safely be used to
* access the text without impacting any break iterator operations,
* but the underlying text itself must not be altered.
*
* @param fillIn A UText to be filled in. If nullptr, a new UText will be
* allocated to hold the result.
* @param status receives any error codes.
* @return The current UText for this break iterator. If an input
* UText was provided, it will always be returned.
* @stable ICU 3.4
*/
virtual UText *getUText(UText *fillIn, UErrorCode &status) const = 0;
/**
* Change the text over which this operates. The text boundary is
* reset to the start.
*
* The BreakIterator will retain a reference to the supplied string.
* The caller must not modify or delete the text while the BreakIterator
* retains the reference.
*
* @param text The UnicodeString used to change the text.
* @stable ICU 2.0
*/
virtual void setText(const UnicodeString &text) = 0;
/**
* Reset the break iterator to operate over the text represented by
* the UText. The iterator position is reset to the start.
*
* 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.
*
* 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 next(), previous(), etc.
* will be UTF-8 string indices, not UTF-16 positions.
*
* @param text The UText used to change the text.
* @param status receives any error codes.
* @stable ICU 3.4
*/
virtual void setText(UText *text, UErrorCode &status) = 0;
/**
* Change the text over which this operates. The text boundary is
* reset to the start.
* Note that setText(UText *) provides similar functionality to this function,
* and is more efficient.
* @param it The CharacterIterator used to change the text.
* @stable ICU 2.0
*/
virtual void adoptText(CharacterIterator* it) = 0;
enum {
/**
* DONE is returned by previous() and next() after all valid
* boundaries have been returned.
* @stable ICU 2.0
*/
DONE = (int32_t)-1
};
/**
* Sets the current iteration position to the beginning of the text, position zero.
* @return The offset of the beginning of the text, zero.
* @stable ICU 2.0
*/
virtual int32_t first() = 0;
/**
* Set the iterator position to the index immediately BEYOND the last character in the text being scanned.
* @return The index immediately BEYOND the last character in the text being scanned.
* @stable ICU 2.0
*/
virtual int32_t last() = 0;
/**
* Set the iterator position to the boundary preceding the current boundary.
* @return The character index of the previous text boundary or DONE if all
* boundaries have been returned.
* @stable ICU 2.0
*/
virtual int32_t previous() = 0;
/**
* Advance the iterator to the boundary following the current boundary.
* @return The character index of the next text boundary or DONE if all
* boundaries have been returned.
* @stable ICU 2.0
*/
virtual int32_t next() = 0;
/**
* Return character index of the current iterator position within the text.
* @return The boundary most recently returned.
* @stable ICU 2.0
*/
virtual int32_t current() const = 0;
/**
* Advance the iterator to the first boundary following the specified offset.
* The value returned is always greater than the offset or
* the value BreakIterator.DONE
* @param offset the offset to begin scanning.
* @return The first boundary after the specified offset.
* @stable ICU 2.0
*/
virtual int32_t following(int32_t offset) = 0;
/**
* Set the iterator position to the first boundary preceding the specified offset.
* The value returned is always smaller than the offset or
* the value BreakIterator.DONE
* @param offset the offset to begin scanning.
* @return The first boundary before the specified offset.
* @stable ICU 2.0
*/
virtual int32_t preceding(int32_t offset) = 0;
/**
* Return true if the specified position is a boundary position.
* As a side effect, the current position of the iterator is set
* to the first boundary position at or following the specified offset.
* @param offset the offset to check.
* @return True if "offset" is a boundary position.
* @stable ICU 2.0
*/
virtual UBool isBoundary(int32_t offset) = 0;
/**
* Set the iterator position to the nth boundary from the current boundary
* @param n the number of boundaries to move by. A value of 0
* does nothing. Negative values move to previous boundaries
* and positive values move to later boundaries.
* @return The new iterator position, or
* DONE if there are fewer than |n| boundaries in the specified direction.
* @stable ICU 2.0
*/
virtual int32_t next(int32_t n) = 0;
/**
* For RuleBasedBreakIterators, return the status tag from the break rule
* that determined the boundary at the current iteration position.
* <p>
* For break iterator types that do not support a rule status,
* a default value of 0 is returned.
* <p>
* @return the status from the break rule that determined the boundary at
* the current iteration position.
* @see RuleBaseBreakIterator::getRuleStatus()
* @see UWordBreak
* @stable ICU 52
*/
virtual int32_t getRuleStatus() const;
/**
* For RuleBasedBreakIterators, get the status (tag) values from the break rule(s)
* that determined the boundary at the current iteration position.
* <p>
* For break iterator types that do not support rule status,
* no values are returned.
* <p>
* The returned status value(s) are stored into an array provided by the caller.
* The values are stored in sorted (ascending) order.
* If the capacity of the output array is insufficient to hold the data,
* the output will be truncated to the available length, and a
* U_BUFFER_OVERFLOW_ERROR will be signaled.
* <p>
* @see RuleBaseBreakIterator::getRuleStatusVec
*
* @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 boundary at the current iteration position.
* In the event of a U_BUFFER_OVERFLOW_ERROR, the return value
* is the total number of status values that were available,
* not the reduced number that were actually returned.
* @see getRuleStatus
* @stable ICU 52
*/
virtual int32_t getRuleStatusVec(int32_t *fillInVec, int32_t capacity, UErrorCode &status);
/**
* Create BreakIterator for word-breaks using the given locale.
* Returns an instance of a BreakIterator implementing word breaks.
* WordBreak is useful for word selection (ex. double click)
* @param where the locale.
* @param status the error code
* @return A BreakIterator for word-breaks. The UErrorCode& status
* parameter is used to return status information to the user.
* To check whether the construction succeeded or not, you should check
* the value of U_SUCCESS(err). If you wish more detailed information, you
* can check for informational error results which still indicate success.
* U_USING_FALLBACK_WARNING indicates that a fall back locale was used. For
* example, 'de_CH' was requested, but nothing was found there, so 'de' was
* used. U_USING_DEFAULT_WARNING indicates that the default locale data was
* used; neither the requested locale nor any of its fall back locales
* could be found.
* The caller owns the returned object and is responsible for deleting it.
* @stable ICU 2.0
*/
static BreakIterator* U_EXPORT2
createWordInstance(const Locale& where, UErrorCode& status);
/**
* Create BreakIterator for line-breaks using specified locale.
* Returns an instance of a BreakIterator implementing line breaks. Line
* breaks are logically possible line breaks, actual line breaks are
* usually determined based on display width.
* LineBreak is useful for word wrapping text.
* @param where the locale.
* @param status The error code.
* @return A BreakIterator for line-breaks. The UErrorCode& status
* parameter is used to return status information to the user.
* To check whether the construction succeeded or not, you should check
* the value of U_SUCCESS(err). If you wish more detailed information, you
* can check for informational error results which still indicate success.
* U_USING_FALLBACK_WARNING indicates that a fall back locale was used. For
* example, 'de_CH' was requested, but nothing was found there, so 'de' was
* used. U_USING_DEFAULT_WARNING indicates that the default locale data was
* used; neither the requested locale nor any of its fall back locales
* could be found.
* The caller owns the returned object and is responsible for deleting it.
* @stable ICU 2.0
*/
static BreakIterator* U_EXPORT2
createLineInstance(const Locale& where, UErrorCode& status);
/**
* Create BreakIterator for character-breaks using specified locale
* Returns an instance of a BreakIterator implementing character breaks.
* Character breaks are boundaries of combining character sequences.
* @param where the locale.
* @param status The error code.
* @return A BreakIterator for character-breaks. The UErrorCode& status
* parameter is used to return status information to the user.
* To check whether the construction succeeded or not, you should check
* the value of U_SUCCESS(err). If you wish more detailed information, you
* can check for informational error results which still indicate success.
* U_USING_FALLBACK_WARNING indicates that a fall back locale was used. For
* example, 'de_CH' was requested, but nothing was found there, so 'de' was
* used. U_USING_DEFAULT_WARNING indicates that the default locale data was
* used; neither the requested locale nor any of its fall back locales
* could be found.
* The caller owns the returned object and is responsible for deleting it.
* @stable ICU 2.0
*/
static BreakIterator* U_EXPORT2
createCharacterInstance(const Locale& where, UErrorCode& status);
/**
* Create BreakIterator for sentence-breaks using specified locale
* Returns an instance of a BreakIterator implementing sentence breaks.
* @param where the locale.
* @param status The error code.
* @return A BreakIterator for sentence-breaks. The UErrorCode& status
* parameter is used to return status information to the user.
* To check whether the construction succeeded or not, you should check
* the value of U_SUCCESS(err). If you wish more detailed information, you
* can check for informational error results which still indicate success.
* U_USING_FALLBACK_WARNING indicates that a fall back locale was used. For
* example, 'de_CH' was requested, but nothing was found there, so 'de' was
* used. U_USING_DEFAULT_WARNING indicates that the default locale data was
* used; neither the requested locale nor any of its fall back locales
* could be found.
* The caller owns the returned object and is responsible for deleting it.
* @stable ICU 2.0
*/
static BreakIterator* U_EXPORT2
createSentenceInstance(const Locale& where, UErrorCode& status);
#ifndef U_HIDE_DEPRECATED_API
/**
* Create BreakIterator for title-casing breaks using the specified locale
* Returns an instance of a BreakIterator implementing title breaks.
* The iterator returned locates title boundaries as described for
* Unicode 3.2 only. For Unicode 4.0 and above title boundary iteration,
* please use a word boundary iterator. See {@link #createWordInstance }.
*
* @param where the locale.
* @param status The error code.
* @return A BreakIterator for title-breaks. The UErrorCode& status
* parameter is used to return status information to the user.
* To check whether the construction succeeded or not, you should check
* the value of U_SUCCESS(err). If you wish more detailed information, you
* can check for informational error results which still indicate success.
* U_USING_FALLBACK_WARNING indicates that a fall back locale was used. For
* example, 'de_CH' was requested, but nothing was found there, so 'de' was
* used. U_USING_DEFAULT_WARNING indicates that the default locale data was
* used; neither the requested locale nor any of its fall back locales
* could be found.
* The caller owns the returned object and is responsible for deleting it.
* @deprecated ICU 64 Use createWordInstance instead.
*/
static BreakIterator* U_EXPORT2
createTitleInstance(const Locale& where, UErrorCode& status);
#endif /* U_HIDE_DEPRECATED_API */
/**
* Get the set of Locales for which TextBoundaries are installed.
* <p><b>Note:</b> this will not return locales added through the register
* call. To see the registered locales too, use the getAvailableLocales
* function that returns a StringEnumeration object </p>
* @param count the output parameter of number of elements in the locale list
* @return available locales
* @stable ICU 2.0
*/
static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count);
/**
* Get name of the object for the desired Locale, in the desired language.
* @param objectLocale must be from getAvailableLocales.
* @param displayLocale specifies the desired locale for output.
* @param name the fill-in parameter of the return value
* Uses best match.
* @return user-displayable name
* @stable ICU 2.0
*/
static UnicodeString& U_EXPORT2 getDisplayName(const Locale& objectLocale,
const Locale& displayLocale,
UnicodeString& name);
/**
* Get name of the object for the desired Locale, in the language of the
* default locale.
* @param objectLocale must be from getMatchingLocales
* @param name the fill-in parameter of the return value
* @return user-displayable name
* @stable ICU 2.0
*/
static UnicodeString& U_EXPORT2 getDisplayName(const Locale& objectLocale,
UnicodeString& name);
#ifndef U_FORCE_HIDE_DEPRECATED_API
/**
* Deprecated functionality. Use clone() instead.
*
* Thread safe client-buffer-based cloning operation
* Do NOT call delete on a safeclone, since 'new' is not used to create it.
* @param stackBuffer user allocated space for the new clone. If nullptr new memory will be allocated.
* If buffer is not large enough, new memory will be allocated.
* @param BufferSize reference to size of allocated space.
* If BufferSize == 0, a sufficient size for use in cloning will
* be returned ('pre-flighting')
* If BufferSize 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
*
* @deprecated ICU 52. Use clone() instead.
*/
virtual BreakIterator * createBufferClone(void *stackBuffer,
int32_t &BufferSize,
UErrorCode &status) = 0;
#endif // U_FORCE_HIDE_DEPRECATED_API
#ifndef U_HIDE_DEPRECATED_API
/**
* Determine whether the BreakIterator was created in user memory by
* createBufferClone(), and thus should not be deleted. Such objects
* must be closed by an explicit call to the destructor (not delete).
* @deprecated ICU 52. Always delete the BreakIterator.
*/
inline UBool isBufferClone();
#endif /* U_HIDE_DEPRECATED_API */
#if !UCONFIG_NO_SERVICE
/**
* Register a new break iterator of the indicated kind, to use in the given locale.
* The break iterator will be adopted. Clones of the iterator will be returned
* if a request for a break iterator of the given kind matches or falls back to
* this locale.
* Because ICU may choose to cache BreakIterators internally, this must
* be called at application startup, prior to any calls to
* BreakIterator::createXXXInstance to avoid undefined behavior.
* @param toAdopt the BreakIterator instance to be adopted
* @param locale the Locale for which this instance is to be registered
* @param kind the type of iterator for which this instance is to be registered
* @param status the in/out status code, no special meanings are assigned
* @return a registry key that can be used to unregister this instance
* @stable ICU 2.4
*/
static URegistryKey U_EXPORT2 registerInstance(BreakIterator* toAdopt,
const Locale& locale,
UBreakIteratorType kind,
UErrorCode& status);
/**
* Unregister a previously-registered BreakIterator using the key returned from the
* register call. Key becomes invalid after a successful call and should not be used again.
* The BreakIterator corresponding to the key will be deleted.
* Because ICU may choose to cache BreakIterators internally, this should
* be called during application shutdown, after all calls to
* BreakIterator::createXXXInstance to avoid undefined behavior.
* @param key the registry key returned by a previous call to registerInstance
* @param status the in/out status code, no special meanings are assigned
* @return true if the iterator for the key was successfully unregistered
* @stable ICU 2.4
*/
static UBool U_EXPORT2 unregister(URegistryKey key, UErrorCode& status);
/**
* Return a StringEnumeration over the locales available at the time of the call,
* including registered locales.
* @return a StringEnumeration over the locales available at the time of the call
* @stable ICU 2.4
*/
static StringEnumeration* U_EXPORT2 getAvailableLocales();
#endif
/**
* Returns the locale for this break iterator. Two flavors are available: valid and
* actual locale.
* @stable ICU 2.8
*/
Locale getLocale(ULocDataLocaleType type, UErrorCode& status) const;
#ifndef U_HIDE_INTERNAL_API
/** Get the locale for this break iterator object. You can choose between valid and actual locale.
* @param type type of the locale we're looking for (valid or actual)
* @param status error code for the operation
* @return the locale
* @internal
*/
const char *getLocaleID(ULocDataLocaleType type, UErrorCode& status) const;
#endif /* U_HIDE_INTERNAL_API */
/**
* Set the subject text string upon which the break iterator is operating
* without changing any other aspect of the matching 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 implementation 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 input The new (moved) text string.
* @param status Receives errors detected by this function.
* @return *this
*
* @stable ICU 49
*/
virtual BreakIterator &refreshInputText(UText *input, UErrorCode &status) = 0;
private:
static BreakIterator* buildInstance(const Locale& loc, const char *type, UErrorCode& status);
static BreakIterator* createInstance(const Locale& loc, int32_t kind, UErrorCode& status);
static BreakIterator* makeInstance(const Locale& loc, int32_t kind, UErrorCode& status);
friend class ICUBreakIteratorFactory;
friend class ICUBreakIteratorService;
protected:
// Do not enclose protected default/copy constructors with #ifndef U_HIDE_INTERNAL_API
// or else the compiler will create a public ones.
/** @internal */
BreakIterator();
/** @internal */
BreakIterator (const BreakIterator &other);
#ifndef U_HIDE_INTERNAL_API
/** @internal */
BreakIterator (const Locale& valid, const Locale &actual);
/** @internal. Assignment Operator, used by RuleBasedBreakIterator. */
BreakIterator &operator = (const BreakIterator &other);
#endif /* U_HIDE_INTERNAL_API */
private:
/** @internal (private) */
char actualLocale[ULOC_FULLNAME_CAPACITY];
char validLocale[ULOC_FULLNAME_CAPACITY];
char requestLocale[ULOC_FULLNAME_CAPACITY];
};
#ifndef U_HIDE_DEPRECATED_API
inline UBool BreakIterator::isBufferClone()
{
return false;
}
#endif /* U_HIDE_DEPRECATED_API */
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_BREAK_ITERATION */
#endif /* U_SHOW_CPLUSPLUS_API */
#endif // BRKITER_H
//eof
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