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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
******************************************************************************
* 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 U_SHOW_CPLUSPLUS_API
#if !UCONFIG_NO_COLLATION
#include "unicode/unistr.h"
#include "unicode/uobject.h"
struct UCollationElements;
struct UHashtable;
U_NAMESPACE_BEGIN
struct CollationData;
class CharacterIterator;
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:
* <pre>
* "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').</pre>
* And in German phonebook collation,
* <pre> \htmlonly "æb"-> the first key is key('a'), the second key is key('e'), and
* the third key is key('b'). \endhtmlonly </pre>
* 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.
* <p>Example of the iterator usage: (without error checking)
* <pre>
* \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
* </pre>
* <p>
* 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 specified position will be returned. If a change of
* direction is done without one of these calls, the result is undefined.
* <p>
* 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 <strong>int32_t</strong>.
*
* Note, CollationElementIterator should not be subclassed.
* @see Collator
* @see RuleBasedCollator
* @version 1.8 Jan 16 2001
*/
class U_I18N_API CollationElementIterator final : public UObject {
public:
// CollationElementIterator public data member ------------------------------
enum {
/**
* NULLORDER indicates that an error has occurred 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
*/
bool 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
*/
bool operator!=(const CollationElementIterator& other) const;
/**
* Resets the cursor to the beginning of the string.
* @stable ICU 2.0
*/
void reset();
/**
* 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 occurred 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 occurred 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() 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 override;
/**
* 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<CollationElementIterator *>(uc);
}
/** @internal */
static inline const CollationElementIterator *fromUCollationElements(const UCollationElements *uc) {
return reinterpret_cast<const CollationElementIterator *>(uc);
}
/** @internal */
inline UCollationElements *toUCollationElements() {
return reinterpret_cast<UCollationElements *>(this);
}
/** @internal */
inline const UCollationElements *toUCollationElements() const {
return reinterpret_cast<const UCollationElements *>(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() = delete; // 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 /* U_SHOW_CPLUSPLUS_API */
#endif
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