/* ****************************************************************************** * Copyright (C) 1997-2014, International Business Machines * Corporation and others. All Rights Reserved. ****************************************************************************** */ /** * \file * \brief C++ API: Collation Element Iterator. */ /** * File coleitr.h * * Created by: Helena Shih * * Modification History: * * Date Name Description * * 8/18/97 helena Added internal API documentation. * 08/03/98 erm Synched with 1.2 version CollationElementIterator.java * 12/10/99 aliu Ported Thai collation support from Java. * 01/25/01 swquek Modified into a C++ wrapper calling C APIs (ucoliter.h) * 02/19/01 swquek Removed CollationElementsIterator() since it is * private constructor and no calls are made to it * 2012-2014 markus Rewritten in C++ again. */ #ifndef COLEITR_H #define COLEITR_H #include "unicode/utypes.h" #if !UCONFIG_NO_COLLATION #include "unicode/unistr.h" #include "unicode/uobject.h" struct UCollationElements; struct UHashtable; U_NAMESPACE_BEGIN struct CollationData; class CollationIterator; class RuleBasedCollator; class UCollationPCE; class UVector32; /** * The CollationElementIterator class is used as an iterator to walk through * each character of an international string. Use the iterator to return the * ordering priority of the positioned character. The ordering priority of a * character, which we refer to as a key, defines how a character is collated in * the given collation object. * For example, consider the following in Slovak and in traditional Spanish collation: *
*        "ca" -> the first key is key('c') and second key is key('a').
*        "cha" -> the first key is key('ch') and second key is key('a').
* And in German phonebook collation, *
 \htmlonly       "æb"-> the first key is key('a'), the second key is key('e'), and
*        the third key is key('b'). \endhtmlonly 
* The key of a character, is an integer composed of primary order(short), * secondary order(char), and tertiary order(char). Java strictly defines the * size and signedness of its primitive data types. Therefore, the static * functions primaryOrder(), secondaryOrder(), and tertiaryOrder() return * int32_t to ensure the correctness of the key value. *

Example of the iterator usage: (without error checking) *

* \code
*   void CollationElementIterator_Example()
*   {
*       UnicodeString str = "This is a test";
*       UErrorCode success = U_ZERO_ERROR;
*       RuleBasedCollator* rbc =
*           (RuleBasedCollator*) RuleBasedCollator::createInstance(success);
*       CollationElementIterator* c =
*           rbc->createCollationElementIterator( str );
*       int32_t order = c->next(success);
*       c->reset();
*       order = c->previous(success);
*       delete c;
*       delete rbc;
*   }
* \endcode
* 
*

* The method next() returns the collation order of the next character based on * the comparison level of the collator. The method previous() returns the * collation order of the previous character based on the comparison level of * the collator. The Collation Element Iterator moves only in one direction * between calls to reset(), setOffset(), or setText(). That is, next() * and previous() can not be inter-used. Whenever previous() is to be called after * next() or vice versa, reset(), setOffset() or setText() has to be called first * to reset the status, shifting pointers to either the end or the start of * the string (reset() or setText()), or the specified position (setOffset()). * Hence at the next call of next() or previous(), the first or last collation order, * or collation order at the spefcifieid position will be returned. If a change of * direction is done without one of these calls, the result is undefined. *

* The result of a forward iterate (next()) and reversed result of the backward * iterate (previous()) on the same string are equivalent, if collation orders * with the value 0 are ignored. * Character based on the comparison level of the collator. A collation order * consists of primary order, secondary order and tertiary order. The data * type of the collation order is int32_t. * * Note, CollationElementIterator should not be subclassed. * @see Collator * @see RuleBasedCollator * @version 1.8 Jan 16 2001 */ class U_I18N_API CollationElementIterator U_FINAL : public UObject { public: // CollationElementIterator public data member ------------------------------ enum { /** * NULLORDER indicates that an error has occured while processing * @stable ICU 2.0 */ NULLORDER = (int32_t)0xffffffff }; // CollationElementIterator public constructor/destructor ------------------- /** * Copy constructor. * * @param other the object to be copied from * @stable ICU 2.0 */ CollationElementIterator(const CollationElementIterator& other); /** * Destructor * @stable ICU 2.0 */ virtual ~CollationElementIterator(); // CollationElementIterator public methods ---------------------------------- /** * Returns true if "other" is the same as "this" * * @param other the object to be compared * @return true if "other" is the same as "this" * @stable ICU 2.0 */ UBool operator==(const CollationElementIterator& other) const; /** * Returns true if "other" is not the same as "this". * * @param other the object to be compared * @return true if "other" is not the same as "this" * @stable ICU 2.0 */ UBool operator!=(const CollationElementIterator& other) const; /** * Resets the cursor to the beginning of the string. * @stable ICU 2.0 */ void reset(void); /** * Gets the ordering priority of the next character in the string. * @param status the error code status. * @return the next character's ordering. otherwise returns NULLORDER if an * error has occured or if the end of string has been reached * @stable ICU 2.0 */ int32_t next(UErrorCode& status); /** * Get the ordering priority of the previous collation element in the string. * @param status the error code status. * @return the previous element's ordering. otherwise returns NULLORDER if an * error has occured or if the start of string has been reached * @stable ICU 2.0 */ int32_t previous(UErrorCode& status); /** * Gets the primary order of a collation order. * @param order the collation order * @return the primary order of a collation order. * @stable ICU 2.0 */ static inline int32_t primaryOrder(int32_t order); /** * Gets the secondary order of a collation order. * @param order the collation order * @return the secondary order of a collation order. * @stable ICU 2.0 */ static inline int32_t secondaryOrder(int32_t order); /** * Gets the tertiary order of a collation order. * @param order the collation order * @return the tertiary order of a collation order. * @stable ICU 2.0 */ static inline int32_t tertiaryOrder(int32_t order); /** * Return the maximum length of any expansion sequences that end with the * specified comparison order. * @param order a collation order returned by previous or next. * @return maximum size of the expansion sequences ending with the collation * element or 1 if collation element does not occur at the end of any * expansion sequence * @stable ICU 2.0 */ int32_t getMaxExpansion(int32_t order) const; /** * Gets the comparison order in the desired strength. Ignore the other * differences. * @param order The order value * @stable ICU 2.0 */ int32_t strengthOrder(int32_t order) const; /** * Sets the source string. * @param str the source string. * @param status the error code status. * @stable ICU 2.0 */ void setText(const UnicodeString& str, UErrorCode& status); /** * Sets the source string. * @param str the source character iterator. * @param status the error code status. * @stable ICU 2.0 */ void setText(CharacterIterator& str, UErrorCode& status); /** * Checks if a comparison order is ignorable. * @param order the collation order. * @return TRUE if a character is ignorable, FALSE otherwise. * @stable ICU 2.0 */ static inline UBool isIgnorable(int32_t order); /** * Gets the offset of the currently processed character in the source string. * @return the offset of the character. * @stable ICU 2.0 */ int32_t getOffset(void) const; /** * Sets the offset of the currently processed character in the source string. * @param newOffset the new offset. * @param status the error code status. * @return the offset of the character. * @stable ICU 2.0 */ void setOffset(int32_t newOffset, UErrorCode& status); /** * ICU "poor man's RTTI", returns a UClassID for the actual class. * * @stable ICU 2.2 */ virtual UClassID getDynamicClassID() const; /** * ICU "poor man's RTTI", returns a UClassID for this class. * * @stable ICU 2.2 */ static UClassID U_EXPORT2 getStaticClassID(); #ifndef U_HIDE_INTERNAL_API /** @internal */ static inline CollationElementIterator *fromUCollationElements(UCollationElements *uc) { return reinterpret_cast(uc); } /** @internal */ static inline const CollationElementIterator *fromUCollationElements(const UCollationElements *uc) { return reinterpret_cast(uc); } /** @internal */ inline UCollationElements *toUCollationElements() { return reinterpret_cast(this); } /** @internal */ inline const UCollationElements *toUCollationElements() const { return reinterpret_cast(this); } #endif // U_HIDE_INTERNAL_API private: friend class RuleBasedCollator; friend class UCollationPCE; /** * CollationElementIterator constructor. This takes the source string and the * collation object. The cursor will walk thru the source string based on the * predefined collation rules. If the source string is empty, NULLORDER will * be returned on the calls to next(). * @param sourceText the source string. * @param order the collation object. * @param status the error code status. */ CollationElementIterator(const UnicodeString& sourceText, const RuleBasedCollator* order, UErrorCode& status); // Note: The constructors should take settings & tailoring, not a collator, // to avoid circular dependencies. // However, for operator==() we would need to be able to compare tailoring data for equality // without making CollationData or CollationTailoring depend on TailoredSet. // (See the implementation of RuleBasedCollator::operator==().) // That might require creating an intermediate class that would be used // by both CollationElementIterator and RuleBasedCollator // but only contain the part of RBC== related to data and rules. /** * CollationElementIterator constructor. This takes the source string and the * collation object. The cursor will walk thru the source string based on the * predefined collation rules. If the source string is empty, NULLORDER will * be returned on the calls to next(). * @param sourceText the source string. * @param order the collation object. * @param status the error code status. */ CollationElementIterator(const CharacterIterator& sourceText, const RuleBasedCollator* order, UErrorCode& status); /** * Assignment operator * * @param other the object to be copied */ const CollationElementIterator& operator=(const CollationElementIterator& other); CollationElementIterator(); // default constructor not implemented /** Normalizes dir_=1 (just after setOffset()) to dir_=0 (just after reset()). */ inline int8_t normalizeDir() const { return dir_ == 1 ? 0 : dir_; } static UHashtable *computeMaxExpansions(const CollationData *data, UErrorCode &errorCode); static int32_t getMaxExpansion(const UHashtable *maxExpansions, int32_t order); // CollationElementIterator private data members ---------------------------- CollationIterator *iter_; // owned const RuleBasedCollator *rbc_; // aliased uint32_t otherHalf_; /** * <0: backwards; 0: just after reset() (previous() begins from end); * 1: just after setOffset(); >1: forward */ int8_t dir_; /** * Stores offsets from expansions and from unsafe-backwards iteration, * so that getOffset() returns intermediate offsets for the CEs * that are consistent with forward iteration. */ UVector32 *offsets_; UnicodeString string_; }; // CollationElementIterator inline method definitions -------------------------- inline int32_t CollationElementIterator::primaryOrder(int32_t order) { return (order >> 16) & 0xffff; } inline int32_t CollationElementIterator::secondaryOrder(int32_t order) { return (order >> 8) & 0xff; } inline int32_t CollationElementIterator::tertiaryOrder(int32_t order) { return order & 0xff; } inline UBool CollationElementIterator::isIgnorable(int32_t order) { return (order & 0xffff0000) == 0; } U_NAMESPACE_END #endif /* #if !UCONFIG_NO_COLLATION */ #endif