The CollationElementIterator class is used as an iterator to walk through
each character of an international string. More...

#include <coleitr.h>

Inheritance diagram for icu::CollationElementIterator:

Public Types
enum	{ NULLORDER = (int32_t)0xffffffff }

Public Member Functions
	CollationElementIterator (const CollationElementIterator &other)
	Copy constructor. More...

virtual	~CollationElementIterator ()
	Destructor. More...

bool	operator== (const CollationElementIterator &other) const
	Returns true if "other" is the same as "this". More...

bool	operator!= (const CollationElementIterator &other) const
	Returns true if "other" is not the same as "this". More...

void	reset (void)
	Resets the cursor to the beginning of the string. More...

int32_t	next (UErrorCode &status)
	Gets the ordering priority of the next character in the string. More...

int32_t	previous (UErrorCode &status)
	Get the ordering priority of the previous collation element in the string. More...

int32_t	getMaxExpansion (int32_t order) const
	Return the maximum length of any expansion sequences that end with the specified comparison order. More...

int32_t	strengthOrder (int32_t order) const
	Gets the comparison order in the desired strength. More...

void	setText (const UnicodeString &str, UErrorCode &status)
	Sets the source string. More...

void	setText (CharacterIterator &str, UErrorCode &status)
	Sets the source string. More...

int32_t	getOffset (void) const
	Gets the offset of the currently processed character in the source string. More...

void	setOffset (int32_t newOffset, UErrorCode &status)
	Sets the offset of the currently processed character in the source string. More...

virtual UClassID	getDynamicClassID () const override
	ICU "poor man's RTTI", returns a UClassID for the actual class. More...

UCollationElements *	toUCollationElements ()

const UCollationElements *	toUCollationElements () const

Public Member Functions inherited from icu::UObject
virtual	~UObject ()
	Destructor. More...

virtual UClassID	getDynamicClassID () const
	ICU4C "poor man's RTTI", returns a UClassID for the actual ICU class. More...

Static Public Member Functions
static int32_t	primaryOrder (int32_t order)
	Gets the primary order of a collation order. More...

static int32_t	secondaryOrder (int32_t order)
	Gets the secondary order of a collation order. More...

static int32_t	tertiaryOrder (int32_t order)
	Gets the tertiary order of a collation order. More...

static UBool	isIgnorable (int32_t order)
	Checks if a comparison order is ignorable. More...

static UClassID	getStaticClassID ()
	ICU "poor man's RTTI", returns a UClassID for this class. More...

static CollationElementIterator *	fromUCollationElements (UCollationElements *uc)

static const CollationElementIterator *	fromUCollationElements (const UCollationElements *uc)

Friends
class	RuleBasedCollator

class	UCollationPCE

Detailed Description

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,

  "æb"-> the first key is key('a'), the second key is key('e'), and
       the third key is key('b').

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)

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;
}
icu::CollationElementIterator
The CollationElementIterator class is used as an iterator to walk through   each character of an inte...
Definition: coleitr.h:121
icu::CollationElementIterator::reset
void reset(void)
Resets the cursor to the beginning of the string.
icu::CollationElementIterator::previous
int32_t previous(UErrorCode &status)
Get the ordering priority of the previous collation element in the string.
icu::CollationElementIterator::next
int32_t next(UErrorCode &status)
Gets the ordering priority of the next character in the string.
icu::Collator::createInstance
static Collator * createInstance(UErrorCode &err)
Creates the Collator object for the current default locale.
icu::RuleBasedCollator
The RuleBasedCollator class provides the implementation of Collator, using data-driven tables.
Definition: tblcoll.h:115
icu::RuleBasedCollator::createCollationElementIterator
virtual CollationElementIterator * createCollationElementIterator(const UnicodeString &source) const
Creates a collation element iterator for the source string.
icu::UnicodeString
UnicodeString is a string class that stores Unicode characters directly and provides similar function...
Definition: unistr.h:296
UErrorCode
UErrorCode
Standard ICU4C error code type, a substitute for exceptions.
Definition: utypes.h:415
U_ZERO_ERROR
@ U_ZERO_ERROR
No error, no warning.
Definition: utypes.h:449

<p<blockquote>‍

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.

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 also: Collator; RuleBasedCollator

Version: 1.8 Jan 16 2001

Definition at line 121 of file coleitr.h.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

Enumerator

NULLORDER

NULLORDER indicates that an error has occurred while processing.

Stable:: ICU 2.0

Definition at line 126 of file coleitr.h.

Constructor & Destructor Documentation

◆ CollationElementIterator()

icu::CollationElementIterator::CollationElementIterator ( const CollationElementIterator & other )

Copy constructor.

Parameters

other the object to be copied from

Stable:: ICU 2.0

◆ ~CollationElementIterator()

virtual icu::CollationElementIterator::~CollationElementIterator ( )

virtual

Destructor.

Stable:: ICU 2.0

Member Function Documentation

◆ fromUCollationElements() [1/2]

static const CollationElementIterator * icu::CollationElementIterator::fromUCollationElements ( const UCollationElements * uc )

inlinestatic

Internal:: Do not use. This API is for internal use only.

Definition at line 297 of file coleitr.h.

◆ fromUCollationElements() [2/2]

static CollationElementIterator * icu::CollationElementIterator::fromUCollationElements ( UCollationElements * uc )

inlinestatic

Internal:: Do not use. This API is for internal use only.

Definition at line 293 of file coleitr.h.

◆ getDynamicClassID()

virtual UClassID icu::CollationElementIterator::getDynamicClassID ( ) const

overridevirtual

ICU "poor man's RTTI", returns a UClassID for the actual class.

Stable:: ICU 2.2

Reimplemented from icu::UObject.

◆ getMaxExpansion()

int32_t icu::CollationElementIterator::getMaxExpansion ( int32_t order ) const

Return the maximum length of any expansion sequences that end with the specified comparison order.

Parameters

order a collation order returned by previous or next.

Returns: 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

◆ getOffset()

int32_t icu::CollationElementIterator::getOffset ( void ) const

Gets the offset of the currently processed character in the source string.

Returns: the offset of the character.

Stable:: ICU 2.0

◆ getStaticClassID()

static UClassID icu::CollationElementIterator::getStaticClassID ( )

static

ICU "poor man's RTTI", returns a UClassID for this class.

Stable:: ICU 2.2

◆ isIgnorable()

UBool icu::CollationElementIterator::isIgnorable ( int32_t order )

inlinestatic

Checks if a comparison order is ignorable.

Parameters

order the collation order.

Returns: true if a character is ignorable, false otherwise.

Stable:: ICU 2.0

Definition at line 400 of file coleitr.h.

◆ next()

int32_t icu::CollationElementIterator::next ( UErrorCode & status )

Gets the ordering priority of the next character in the string.

Parameters

status the error code status.

Returns: 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

◆ operator!=()

bool icu::CollationElementIterator::operator!= ( const CollationElementIterator & other ) const

Returns true if "other" is not the same as "this".

Parameters

other the object to be compared

Returns: true if "other" is not the same as "this"

Stable:: ICU 2.0

◆ operator==()

bool icu::CollationElementIterator::operator== ( const CollationElementIterator & other ) const

Returns true if "other" is the same as "this".

Parameters

other the object to be compared

Returns: true if "other" is the same as "this"

Stable:: ICU 2.0

◆ previous()

int32_t icu::CollationElementIterator::previous ( UErrorCode & status )

Get the ordering priority of the previous collation element in the string.

Parameters

status the error code status.

Returns: 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

◆ primaryOrder()

int32_t icu::CollationElementIterator::primaryOrder ( int32_t order )

inlinestatic

Gets the primary order of a collation order.

Parameters

order the collation order

Returns: the primary order of a collation order.

Stable:: ICU 2.0

Definition at line 385 of file coleitr.h.

◆ reset()

void icu::CollationElementIterator::reset ( void )

Resets the cursor to the beginning of the string.

Stable:: ICU 2.0

◆ secondaryOrder()

int32_t icu::CollationElementIterator::secondaryOrder ( int32_t order )

inlinestatic

Gets the secondary order of a collation order.

Parameters

order the collation order

Returns: the secondary order of a collation order.

Stable:: ICU 2.0

Definition at line 390 of file coleitr.h.

◆ setOffset()

void icu::CollationElementIterator::setOffset	(	int32_t	newOffset,
		UErrorCode &	status
	)

Sets the offset of the currently processed character in the source string.

Parameters

newOffset	the new offset.
status	the error code status.

Returns: the offset of the character.

Stable:: ICU 2.0

◆ setText() [1/2]

void icu::CollationElementIterator::setText	(	CharacterIterator &	str,
		UErrorCode &	status
	)

Sets the source string.

Parameters

str	the source character iterator.
status	the error code status.

Stable:: ICU 2.0

◆ setText() [2/2]

void icu::CollationElementIterator::setText	(	const UnicodeString &	str,
		UErrorCode &	status
	)

Sets the source string.

Parameters

str	the source string.
status	the error code status.

Stable:: ICU 2.0

◆ strengthOrder()

int32_t icu::CollationElementIterator::strengthOrder ( int32_t order ) const

Gets the comparison order in the desired strength.

Ignore the other differences.

Parameters

order The order value

Stable:: ICU 2.0

◆ tertiaryOrder()

int32_t icu::CollationElementIterator::tertiaryOrder ( int32_t order )

inlinestatic

Gets the tertiary order of a collation order.

Parameters

order the collation order

Returns: the tertiary order of a collation order.

Stable:: ICU 2.0

Definition at line 395 of file coleitr.h.

◆ toUCollationElements() [1/2]

UCollationElements * icu::CollationElementIterator::toUCollationElements ( )

inline

Internal:: Do not use. This API is for internal use only.

Definition at line 301 of file coleitr.h.

◆ toUCollationElements() [2/2]

const UCollationElements * icu::CollationElementIterator::toUCollationElements ( ) const

inline

Internal:: Do not use. This API is for internal use only.

Definition at line 305 of file coleitr.h.

Friends And Related Function Documentation

◆ RuleBasedCollator

friend class RuleBasedCollator

friend

Definition at line 311 of file coleitr.h.

◆ UCollationPCE

friend class UCollationPCE

friend

Definition at line 312 of file coleitr.h.

The documentation for this class was generated from the following file:

coleitr.h

Public Types

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ CollationElementIterator()

◆ ~CollationElementIterator()

Member Function Documentation

◆ fromUCollationElements() [1/2]

◆ fromUCollationElements() [2/2]

◆ getDynamicClassID()

◆ getMaxExpansion()

◆ getOffset()

◆ getStaticClassID()

◆ isIgnorable()

◆ next()

◆ operator!=()

◆ operator==()

◆ previous()

◆ primaryOrder()

◆ reset()

◆ secondaryOrder()

◆ setOffset()

◆ setText() [1/2]

◆ setText() [2/2]

◆ strengthOrder()

◆ tertiaryOrder()

◆ toUCollationElements() [1/2]

◆ toUCollationElements() [2/2]

Friends And Related Function Documentation

◆ RuleBasedCollator

◆ UCollationPCE