| /* |
| *************************************************************************** |
| * Copyright (C) 1999-2008 International Business Machines Corporation * |
| * and others. All rights reserved. * |
| *************************************************************************** |
| |
| ********************************************************************** |
| * Date Name Description |
| * 10/22/99 alan Creation. |
| * 11/11/99 rgillam Complete port from Java. |
| ********************************************************************** |
| */ |
| |
| #ifndef RBBI_H |
| #define RBBI_H |
| |
| #include "unicode/utypes.h" |
| |
| /** |
| * \file |
| * \brief C++ API: Rule Based Break Iterator |
| */ |
| |
| #if !UCONFIG_NO_BREAK_ITERATION |
| |
| #include "unicode/brkiter.h" |
| #include "unicode/udata.h" |
| #include "unicode/parseerr.h" |
| #include "unicode/schriter.h" |
| #include "unicode/uchriter.h" |
| |
| |
| struct UTrie; |
| |
| U_NAMESPACE_BEGIN |
| |
| /** @internal */ |
| struct RBBIDataHeader; |
| class RuleBasedBreakIteratorTables; |
| class BreakIterator; |
| class RBBIDataWrapper; |
| class UStack; |
| class LanguageBreakEngine; |
| class UnhandledEngine; |
| struct RBBIStateTable; |
| |
| |
| |
| |
| /** |
| * |
| * A subclass of BreakIterator whose behavior is specified using a list of rules. |
| * <p>Instances of this class are most commonly created by the factory methods of |
| * BreakIterator::createWordInstance(), BreakIterator::createLineInstance(), etc., |
| * and then used via the abstract API in class BreakIterator</p> |
| * |
| * <p>See the ICU User Guide for information on Break Iterator Rules.</p> |
| * |
| * <p>This class is not intended to be subclassed. (Class DictionaryBasedBreakIterator |
| * is a subclass, but that relationship is effectively internal to the ICU |
| * implementation. The subclassing interface to RulesBasedBreakIterator is |
| * not part of the ICU API, and may not remain stable.</p> |
| * |
| */ |
| class U_COMMON_API RuleBasedBreakIterator : public BreakIterator { |
| |
| protected: |
| /** |
| * The UText through which this BreakIterator accesses the text |
| * @internal |
| */ |
| UText *fText; |
| |
| /** |
| * A character iterator that refers to the same text as the UText, above. |
| * Only included for compatibility with old API, which was based on CharacterIterators. |
| * Value may be adopted from outside, or one of fSCharIter or fDCharIter, below. |
| */ |
| CharacterIterator *fCharIter; |
| |
| /** |
| * When the input text is provided by a UnicodeString, this will point to |
| * a characterIterator that wraps that data. Needed only for the |
| * implementation of getText(), a backwards compatibility issue. |
| */ |
| StringCharacterIterator *fSCharIter; |
| |
| /** |
| * When the input text is provided by a UText, this |
| * dummy CharacterIterator over an empty string will |
| * be returned from getText() |
| */ |
| UCharCharacterIterator *fDCharIter; |
| |
| /** |
| * The rule data for this BreakIterator instance |
| * @internal |
| */ |
| RBBIDataWrapper *fData; |
| |
| /** Index of the Rule {tag} values for the most recent match. |
| * @internal |
| */ |
| int32_t fLastRuleStatusIndex; |
| |
| /** |
| * Rule tag value valid flag. |
| * Some iterator operations don't intrinsically set the correct tag value. |
| * This flag lets us lazily compute the value if we are ever asked for it. |
| * @internal |
| */ |
| UBool fLastStatusIndexValid; |
| |
| /** |
| * Counter for the number of characters encountered with the "dictionary" |
| * flag set. |
| * @internal |
| */ |
| uint32_t fDictionaryCharCount; |
| |
| /** |
| * When a range of characters is divided up using the dictionary, the break |
| * positions that are discovered are stored here, preventing us from having |
| * to use either the dictionary or the state table again until the iterator |
| * leaves this range of text. Has the most impact for line breaking. |
| * @internal |
| */ |
| int32_t* fCachedBreakPositions; |
| |
| /** |
| * The number of elements in fCachedBreakPositions |
| * @internal |
| */ |
| int32_t fNumCachedBreakPositions; |
| |
| /** |
| * if fCachedBreakPositions is not null, this indicates which item in the |
| * cache the current iteration position refers to |
| * @internal |
| */ |
| int32_t fPositionInCache; |
| |
| /** |
| * |
| * If present, UStack of LanguageBreakEngine objects that might handle |
| * dictionary characters. Searched from top to bottom to find an object to |
| * handle a given character. |
| * @internal |
| */ |
| UStack *fLanguageBreakEngines; |
| |
| /** |
| * |
| * If present, the special LanguageBreakEngine used for handling |
| * characters that are in the dictionary set, but not handled by any |
| * LangugageBreakEngine. |
| * @internal |
| */ |
| UnhandledEngine *fUnhandledBreakEngine; |
| |
| /** |
| * |
| * The type of the break iterator, or -1 if it has not been set. |
| * @internal |
| */ |
| int32_t fBreakType; |
| |
| protected: |
| //======================================================================= |
| // constructors |
| //======================================================================= |
| |
| /** |
| * Constant to be used in the constructor |
| * RuleBasedBreakIterator(RBBIDataHeader*, EDontAdopt, UErrorCode &); |
| * which does not adopt the memory indicated by the RBBIDataHeader* |
| * parameter. |
| * |
| * @internal |
| */ |
| enum EDontAdopt { |
| kDontAdopt |
| }; |
| |
| /** |
| * Constructor from a flattened set of RBBI data in malloced memory. |
| * RulesBasedBreakIterators built from a custom set of rules |
| * are created via this constructor; the rules are compiled |
| * into memory, then the break iterator is constructed here. |
| * |
| * The break iterator adopts the memory, and will |
| * free it when done. |
| * @internal |
| */ |
| RuleBasedBreakIterator(RBBIDataHeader* data, UErrorCode &status); |
| |
| /** |
| * Constructor from a flattened set of RBBI data in memory which need not |
| * be malloced (e.g. it may be a memory-mapped file, etc.). |
| * |
| * This version does not adopt the memory, and does not |
| * free it when done. |
| * @internal |
| */ |
| RuleBasedBreakIterator(const RBBIDataHeader* data, enum EDontAdopt dontAdopt, UErrorCode &status); |
| |
| |
| friend class RBBIRuleBuilder; |
| /** @internal */ |
| friend class BreakIterator; |
| |
| |
| |
| public: |
| |
| /** Default constructor. Creates an empty shell of an iterator, with no |
| * rules or text to iterate over. Object can subsequently be assigned to. |
| * @stable ICU 2.2 |
| */ |
| RuleBasedBreakIterator(); |
| |
| /** |
| * Copy constructor. Will produce a break iterator with the same behavior, |
| * and which iterates over the same text, as the one passed in. |
| * @param that The RuleBasedBreakIterator passed to be copied |
| * @stable ICU 2.0 |
| */ |
| RuleBasedBreakIterator(const RuleBasedBreakIterator& that); |
| |
| /** |
| * Construct a RuleBasedBreakIterator from a set of rules supplied as a string. |
| * @param rules The break rules to be used. |
| * @param parseError In the event of a syntax error in the rules, provides the location |
| * within the rules of the problem. |
| * @param status Information on any errors encountered. |
| * @stable ICU 2.2 |
| */ |
| RuleBasedBreakIterator( const UnicodeString &rules, |
| UParseError &parseError, |
| UErrorCode &status); |
| |
| |
| /** |
| * This constructor uses the udata interface to create a BreakIterator |
| * whose internal tables live in a memory-mapped file. "image" is an |
| * ICU UDataMemory handle for the pre-compiled break iterator tables. |
| * @param image handle to the memory image for the break iterator data. |
| * Ownership of the UDataMemory handle passes to the Break Iterator, |
| * which will be responsible for closing it when it is no longer needed. |
| * @param status Information on any errors encountered. |
| * @see udata_open |
| * @see #getBinaryRules |
| * @stable ICU 2.8 |
| */ |
| RuleBasedBreakIterator(UDataMemory* image, UErrorCode &status); |
| |
| /** |
| * Destructor |
| * @stable ICU 2.0 |
| */ |
| virtual ~RuleBasedBreakIterator(); |
| |
| /** |
| * Assignment operator. Sets this iterator to have the same behavior, |
| * and iterate over the same text, as the one passed in. |
| * @param that The RuleBasedBreakItertor passed in |
| * @return the newly created RuleBasedBreakIterator |
| * @stable ICU 2.0 |
| */ |
| RuleBasedBreakIterator& operator=(const RuleBasedBreakIterator& that); |
| |
| /** |
| * Equality operator. Returns TRUE if both BreakIterators are of the |
| * same class, have the same behavior, and iterate over the same text. |
| * @param that The BreakIterator to be compared for equality |
| * @return TRUE if both BreakIterators are of the |
| * same class, have the same behavior, and iterate over the same text. |
| * @stable ICU 2.0 |
| */ |
| virtual UBool operator==(const BreakIterator& that) const; |
| |
| /** |
| * Not-equal operator. If operator== returns TRUE, this returns FALSE, |
| * and vice versa. |
| * @param that The BreakIterator to be compared for inequality |
| * @return TRUE if both BreakIterators are not same. |
| * @stable ICU 2.0 |
| */ |
| UBool operator!=(const BreakIterator& that) const; |
| |
| /** |
| * Returns a newly-constructed RuleBasedBreakIterator with the same |
| * behavior, and iterating over the same text, as this one. |
| * Differs from the copy constructor in that it is polymorphic, and |
| * will correctly clone (copy) a derived class. |
| * clone() is thread safe. Multiple threads may simultaeneously |
| * clone the same source break iterator. |
| * @return a newly-constructed RuleBasedBreakIterator |
| * @stable ICU 2.0 |
| */ |
| virtual BreakIterator* clone() const; |
| |
| /** |
| * Compute a hash code for this BreakIterator |
| * @return A hash code |
| * @stable ICU 2.0 |
| */ |
| virtual int32_t hashCode(void) const; |
| |
| /** |
| * Returns the description used to create this iterator |
| * @return the description used to create this iterator |
| * @stable ICU 2.0 |
| */ |
| virtual const UnicodeString& getRules(void) const; |
| |
| //======================================================================= |
| // BreakIterator overrides |
| //======================================================================= |
| |
| /** |
| * <p> |
| * Return a CharacterIterator over the text being analyzed. |
| * The returned character iterator is owned by the break iterator, and must |
| * not be deleted by the caller. Repeated calls to this function may |
| * return the same CharacterIterator. |
| * </p> |
| * <p> |
| * The returned character iterator must not be used concurrently with |
| * the break iterator. If concurrent operation is needed, clone the |
| * returned character iterator first and operate on the clone. |
| * </p> |
| * <p> |
| * When the break iterator is operating on text supplied via a UText, |
| * this function will fail. Lacking any way to signal failures, it |
| * returns an CharacterIterator containing no text. |
| * The function getUText() provides similar functionality, |
| * is reliable, and is more efficient. |
| * </p> |
| * |
| * TODO: deprecate this function? |
| * |
| * @return An iterator over the text being analyzed. |
| * @stable ICU 2.0 |
| */ |
| virtual CharacterIterator& getText(void) const; |
| |
| |
| /** |
| * 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 NULL, 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; |
| |
| /** |
| * Set the iterator to analyze a new piece of text. This function resets |
| * the current iteration position to the beginning of the text. |
| * @param newText An iterator over the text to analyze. The BreakIterator |
| * takes ownership of the character iterator. The caller MUST NOT delete it! |
| * @stable ICU 2.0 |
| */ |
| virtual void adoptText(CharacterIterator* newText); |
| |
| /** |
| * Set the iterator to analyze a new piece of text. This function resets |
| * the current iteration position to the beginning of the text. |
| * @param newText The text to analyze. |
| * @stable ICU 2.0 |
| */ |
| virtual void setText(const UnicodeString& newText); |
| |
| /** |
| * 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. |
| * |
| * @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); |
| |
| /** |
| * Sets the current iteration position to the beginning of the text. |
| * @return The offset of the beginning of the text. |
| * @stable ICU 2.0 |
| */ |
| virtual int32_t first(void); |
| |
| /** |
| * Sets the current iteration position to the end of the text. |
| * @return The text's past-the-end offset. |
| * @stable ICU 2.0 |
| */ |
| virtual int32_t last(void); |
| |
| /** |
| * Advances the iterator either forward or backward the specified number of steps. |
| * Negative values move backward, and positive values move forward. This is |
| * equivalent to repeatedly calling next() or previous(). |
| * @param n The number of steps to move. The sign indicates the direction |
| * (negative is backwards, and positive is forwards). |
| * @return The character offset of the boundary position n boundaries away from |
| * the current one. |
| * @stable ICU 2.0 |
| */ |
| virtual int32_t next(int32_t n); |
| |
| /** |
| * Advances the iterator to the next boundary position. |
| * @return The position of the first boundary after this one. |
| * @stable ICU 2.0 |
| */ |
| virtual int32_t next(void); |
| |
| /** |
| * Moves the iterator backwards, to the last boundary preceding this one. |
| * @return The position of the last boundary position preceding this one. |
| * @stable ICU 2.0 |
| */ |
| virtual int32_t previous(void); |
| |
| /** |
| * Sets the iterator to refer to the first boundary position following |
| * the specified position. |
| * @param offset The position from which to begin searching for a break position. |
| * @return The position of the first break after the current position. |
| * @stable ICU 2.0 |
| */ |
| virtual int32_t following(int32_t offset); |
| |
| /** |
| * Sets the iterator to refer to the last boundary position before the |
| * specified position. |
| * @param offset The position to begin searching for a break from. |
| * @return The position of the last boundary before the starting position. |
| * @stable ICU 2.0 |
| */ |
| virtual int32_t preceding(int32_t offset); |
| |
| /** |
| * 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 offset the offset to check. |
| * @return True if "offset" is a boundary position. |
| * @stable ICU 2.0 |
| */ |
| virtual UBool isBoundary(int32_t offset); |
| |
| /** |
| * Returns the current iteration position. |
| * @return The current iteration position. |
| * @stable ICU 2.0 |
| */ |
| virtual int32_t current(void) const; |
| |
| |
| /** |
| * Return the status tag from the break rule that determined the most recently |
| * returned break position. For break rules that do not specify a |
| * status, a default value of 0 is returned. If more than one break rule |
| * would cause a boundary to be located at some position in the text, |
| * the numerically largest of the applicable status values is returned. |
| * <p> |
| * Of the standard types of ICU break iterators, only word break and |
| * line break provide status values. The values are defined in |
| * the header file ubrk.h. For Word breaks, the status allows distinguishing between words |
| * that contain alphabetic letters, "words" that appear to be numbers, |
| * punctuation and spaces, words containing ideographic characters, and |
| * more. For Line Break, the status distinguishes between hard (mandatory) breaks |
| * and soft (potential) break positions. |
| * <p> |
| * <code>getRuleStatus()</code> can be called after obtaining a boundary |
| * position from <code>next()</code>, <code>previous()</code>, or |
| * any other break iterator functions that returns a boundary position. |
| * <p> |
| * When creating custom break rules, one is free to define whatever |
| * status values may be convenient for the application. |
| * <p> |
| * Note: this function is not thread safe. It should not have been |
| * declared const, and the const remains only for compatibility |
| * reasons. (The function is logically const, but not bit-wise const). |
| * <p> |
| * @return the status from the break rule that determined the most recently |
| * returned break position. |
| * |
| * @see UWordBreak |
| * @stable ICU 2.2 |
| */ |
| virtual int32_t getRuleStatus() const; |
| |
| /** |
| * Get the status (tag) values from the break rule(s) that determined the most |
| * recently returned break position. |
| * <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. |
| * |
| * @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. |
| * 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 3.0 |
| */ |
| virtual int32_t getRuleStatusVec(int32_t *fillInVec, int32_t capacity, UErrorCode &status); |
| |
| /** |
| * Returns a unique class ID POLYMORPHICALLY. Pure virtual override. |
| * This method is to implement a simple version of RTTI, since not all |
| * C++ compilers support genuine RTTI. Polymorphic operator==() and |
| * clone() methods call this method. |
| * |
| * @return The class ID for this object. All objects of a |
| * given class have the same class ID. Objects of |
| * other classes have different class IDs. |
| * @stable ICU 2.0 |
| */ |
| virtual UClassID getDynamicClassID(void) const; |
| |
| /** |
| * Returns the class ID for this class. This is useful only for |
| * comparing to a return value from getDynamicClassID(). For example: |
| * |
| * Base* polymorphic_pointer = createPolymorphicObject(); |
| * if (polymorphic_pointer->getDynamicClassID() == |
| * Derived::getStaticClassID()) ... |
| * |
| * @return The class ID for all objects of this class. |
| * @stable ICU 2.0 |
| */ |
| static UClassID U_EXPORT2 getStaticClassID(void); |
| |
| /* |
| * Create a clone (copy) of this break iterator in memory provided |
| * by the caller. The idea is to increase performance by avoiding |
| * a storage allocation. Use of this functoin is NOT RECOMMENDED. |
| * Performance gains are minimal, and correct buffer management is |
| * tricky. Use clone() instead. |
| * |
| * @param stackBuffer The pointer to the memory into which the cloned object |
| * should be placed. If NULL, allocate heap memory |
| * for the cloned object. |
| * @param BufferSize The size of the buffer. If zero, return the required |
| * buffer size, but do not clone the object. If the |
| * size was too small (but not zero), allocate heap |
| * storage for the cloned object. |
| * |
| * @param status Error status. U_SAFECLONE_ALLOCATED_WARNING will be |
| * returned if the the provided buffer was too small, and |
| * the clone was therefore put on the heap. |
| * |
| * @return Pointer to the clone object. This may differ from the stackBuffer |
| * address if the byte alignment of the stack buffer was not suitable |
| * or if the stackBuffer was too small to hold the clone. |
| * @stable ICU 2.0 |
| */ |
| virtual BreakIterator * createBufferClone(void *stackBuffer, |
| int32_t &BufferSize, |
| UErrorCode &status); |
| |
| |
| /** |
| * Return the binary form of compiled break rules, |
| * which can then be used to create a new break iterator at some |
| * time in the future. Creating a break iterator from pre-compiled rules |
| * is much faster than building one from the source form of the |
| * break rules. |
| * |
| * The binary data can only be used with the same version of ICU |
| * and on the same platform type (processor endian-ness) |
| * |
| * @param length Returns the length of the binary data. (Out paramter.) |
| * |
| * @return A pointer to the binary (compiled) rule data. The storage |
| * belongs to the RulesBasedBreakIterator object, not the |
| * caller, and must not be modified or deleted. |
| * @internal |
| */ |
| virtual const uint8_t *getBinaryRules(uint32_t &length); |
| |
| |
| protected: |
| //======================================================================= |
| // implementation |
| //======================================================================= |
| /** |
| * Dumps caches and performs other actions associated with a complete change |
| * in text or iteration position. |
| * @internal |
| */ |
| virtual void reset(void); |
| |
| #if 0 |
| /** |
| * Return true if the category lookup for this char |
| * indicates that it is in the set of dictionary lookup chars. |
| * This function is intended for use by dictionary based break iterators. |
| * @return true if the category lookup for this char |
| * indicates that it is in the set of dictionary lookup chars. |
| * @internal |
| */ |
| virtual UBool isDictionaryChar(UChar32); |
| |
| /** |
| * Get the type of the break iterator. |
| * @internal |
| */ |
| virtual int32_t getBreakType() const; |
| #endif |
| |
| /** |
| * Set the type of the break iterator. |
| * @internal |
| */ |
| virtual void setBreakType(int32_t type); |
| |
| /** |
| * Common initialization function, used by constructors and bufferClone. |
| * (Also used by DictionaryBasedBreakIterator::createBufferClone().) |
| * @internal |
| */ |
| void init(); |
| |
| private: |
| |
| /** |
| * This method backs the iterator back up to a "safe position" in the text. |
| * This is a position that we know, without any context, must be a break position. |
| * The various calling methods then iterate forward from this safe position to |
| * the appropriate position to return. (For more information, see the description |
| * of buildBackwardsStateTable() in RuleBasedBreakIterator.Builder.) |
| * @param statetable state table used of moving backwards |
| * @internal |
| */ |
| int32_t handlePrevious(const RBBIStateTable *statetable); |
| |
| /** |
| * This method is the actual implementation of the next() method. All iteration |
| * vectors through here. This method initializes the state machine to state 1 |
| * and advances through the text character by character until we reach the end |
| * of the text or the state machine transitions to state 0. We update our return |
| * value every time the state machine passes through a possible end state. |
| * @param statetable state table used of moving forwards |
| * @internal |
| */ |
| int32_t handleNext(const RBBIStateTable *statetable); |
| |
| protected: |
| |
| /** |
| * This is the function that actually implements dictionary-based |
| * breaking. Covering at least the range from startPos to endPos, |
| * it checks for dictionary characters, and if it finds them determines |
| * the appropriate object to deal with them. It may cache found breaks in |
| * fCachedBreakPositions as it goes. It may well also look at text outside |
| * the range startPos to endPos. |
| * If going forward, endPos is the normal Unicode break result, and |
| * if goind in reverse, startPos is the normal Unicode break result |
| * @param startPos The start position of a range of text |
| * @param endPos The end position of a range of text |
| * @param reverse The call is for the reverse direction |
| * @internal |
| */ |
| int32_t checkDictionary(int32_t startPos, int32_t endPos, UBool reverse); |
| |
| private: |
| |
| /** |
| * This function returns the appropriate LanguageBreakEngine for a |
| * given character c. |
| * @param c A character in the dictionary set |
| * @internal |
| */ |
| const LanguageBreakEngine *getLanguageBreakEngine(UChar32 c); |
| |
| /** |
| * @internal |
| */ |
| void makeRuleStatusValid(); |
| |
| }; |
| |
| //------------------------------------------------------------------------------ |
| // |
| // Inline Functions Definitions ... |
| // |
| //------------------------------------------------------------------------------ |
| |
| inline UBool RuleBasedBreakIterator::operator!=(const BreakIterator& that) const { |
| return !operator==(that); |
| } |
| |
| U_NAMESPACE_END |
| |
| #endif /* #if !UCONFIG_NO_BREAK_ITERATION */ |
| |
| #endif |
