Collator Class Reference

The Collator class performs locale-sensitive string comparison. More...

#include <coll.h>

Inheritance diagram for Collator:
UObject UMemory RuleBasedCollator

Public Types

enum  ECollationStrength {
  PRIMARY = 0, SECONDARY = 1, TERTIARY = 2, QUATERNARY = 3,
  IDENTICAL = 15
}
 

Base letter represents a primary difference.

More...
enum  EComparisonResult { LESS = -1, EQUAL = 0, GREATER = 1 }
 

LESS is returned if source string is compared to be less than target string in the compare() method.

More...

Public Member Functions

virtual ~Collator ()
 Destructor.
virtual UBool operator== (const Collator &other) const
 Returns true if "other" is the same as "this".
virtual UBool operator!= (const Collator &other) const
 Returns true if "other" is not the same as "this".
virtual Collatorclone (void) const =0
 Makes a shallow copy of the current object.
virtual EComparisonResult compare (const UnicodeString &source, const UnicodeString &target) const
 The comparison function compares the character data stored in two different strings.
virtual UCollationResult compare (const UnicodeString &source, const UnicodeString &target, UErrorCode &status) const =0
 The comparison function compares the character data stored in two different strings.
virtual EComparisonResult compare (const UnicodeString &source, const UnicodeString &target, int32_t length) const
 Does the same thing as compare but limits the comparison to a specified length.
virtual UCollationResult compare (const UnicodeString &source, const UnicodeString &target, int32_t length, UErrorCode &status) const =0
 Does the same thing as compare but limits the comparison to a specified length.
virtual EComparisonResult compare (const UChar *source, int32_t sourceLength, const UChar *target, int32_t targetLength) const
 The comparison function compares the character data stored in two different string arrays.
virtual UCollationResult compare (const UChar *source, int32_t sourceLength, const UChar *target, int32_t targetLength, UErrorCode &status) const =0
 The comparison function compares the character data stored in two different string arrays.
virtual UCollationResult compare (UCharIterator &sIter, UCharIterator &tIter, UErrorCode &status) const
 Compares two strings using the Collator.
virtual UCollationResult compareUTF8 (const StringPiece &source, const StringPiece &target, UErrorCode &status) const
 Compares two UTF-8 strings using the Collator.
virtual CollationKeygetCollationKey (const UnicodeString &source, CollationKey &key, UErrorCode &status) const =0
 Transforms the string into a series of characters that can be compared with CollationKey::compareTo.
virtual CollationKeygetCollationKey (const UChar *source, int32_t sourceLength, CollationKey &key, UErrorCode &status) const =0
 Transforms the string into a series of characters that can be compared with CollationKey::compareTo.
virtual int32_t hashCode (void) const =0
 Generates the hash code for the collation object.
virtual const Locale getLocale (ULocDataLocaleType type, UErrorCode &status) const =0
 Gets the locale of the Collator.
UBool greater (const UnicodeString &source, const UnicodeString &target) const
 Convenience method for comparing two strings based on the collation rules.
UBool greaterOrEqual (const UnicodeString &source, const UnicodeString &target) const
 Convenience method for comparing two strings based on the collation rules.
UBool equals (const UnicodeString &source, const UnicodeString &target) const
 Convenience method for comparing two strings based on the collation rules.
virtual ECollationStrength getStrength (void) const =0
 Determines the minimum strength that will be use in comparison or transformation.
virtual void setStrength (ECollationStrength newStrength)=0
 Sets the minimum strength to be used in comparison or transformation.
virtual void getVersion (UVersionInfo info) const =0
 Gets the version information for a Collator.
virtual UClassID getDynamicClassID (void) const =0
 Returns a unique class ID POLYMORPHICALLY.
virtual void setAttribute (UColAttribute attr, UColAttributeValue value, UErrorCode &status)=0
 Universal attribute setter.
virtual UColAttributeValue getAttribute (UColAttribute attr, UErrorCode &status)=0
 Universal attribute getter.
virtual uint32_t setVariableTop (const UChar *varTop, int32_t len, UErrorCode &status)=0
 Sets the variable top to a collation element value of a string supplied.
virtual uint32_t setVariableTop (const UnicodeString varTop, UErrorCode &status)=0
 Sets the variable top to a collation element value of a string supplied.
virtual void setVariableTop (const uint32_t varTop, UErrorCode &status)=0
 Sets the variable top to a collation element value supplied.
virtual uint32_t getVariableTop (UErrorCode &status) const =0
 Gets the variable top value of a Collator.
virtual UnicodeSetgetTailoredSet (UErrorCode &status) const
 Get an UnicodeSet that contains all the characters and sequences tailored in this collator.
virtual CollatorsafeClone (void)=0
 Thread safe cloning operation.
virtual int32_t getSortKey (const UnicodeString &source, uint8_t *result, int32_t resultLength) const =0
 Get the sort key as an array of bytes from an UnicodeString.
virtual int32_t getSortKey (const UChar *source, int32_t sourceLength, uint8_t *result, int32_t resultLength) const =0
 Get the sort key as an array of bytes from an UChar buffer.

Static Public Member Functions

static CollatorcreateInstance (UErrorCode &err)
 Creates the Collator object for the current default locale.
static CollatorcreateInstance (const Locale &loc, UErrorCode &err)
 Gets the table-based collation object for the desired locale.
static UnicodeStringgetDisplayName (const Locale &objectLocale, const Locale &displayLocale, UnicodeString &name)
 Get name of the object for the desired Locale, in the desired langauge.
static UnicodeStringgetDisplayName (const Locale &objectLocale, UnicodeString &name)
 Get name of the object for the desired Locale, in the langauge of the default locale.
static const LocalegetAvailableLocales (int32_t &count)
 Get the set of Locales for which Collations are installed.
static StringEnumerationgetAvailableLocales (void)
 Return a StringEnumeration over the locales available at the time of the call, including registered locales.
static StringEnumerationgetKeywords (UErrorCode &status)
 Create a string enumerator of all possible keywords that are relevant to collation.
static StringEnumerationgetKeywordValues (const char *keyword, UErrorCode &status)
 Given a keyword, create a string enumeration of all values for that keyword that are currently in use.
static StringEnumerationgetKeywordValuesForLocale (const char *keyword, const Locale &locale, UBool commonlyUsed, UErrorCode &status)
 Given a key and a locale, returns an array of string values in a preferred order that would make a difference.
static Locale getFunctionalEquivalent (const char *keyword, const Locale &locale, UBool &isAvailable, UErrorCode &status)
 Return the functionally equivalent locale for the given requested locale, with respect to given keyword, for the collation service.
static URegistryKey registerInstance (Collator *toAdopt, const Locale &locale, UErrorCode &status)
 Register a new Collator.
static URegistryKey registerFactory (CollatorFactory *toAdopt, UErrorCode &status)
 Register a new CollatorFactory.
static UBool unregister (URegistryKey key, UErrorCode &status)
 Unregister a previously-registered Collator or CollatorFactory using the key returned from the register call.
static int32_t getBound (const uint8_t *source, int32_t sourceLength, UColBoundMode boundType, uint32_t noOfLevels, uint8_t *result, int32_t resultLength, UErrorCode &status)
 Produce a bound for a given sortkey and a number of levels.
static UCollatorcreateUCollator (const char *loc, UErrorCode *status)
 used only by ucol_open, not for public use

Protected Member Functions

 Collator ()
 Default constructor.
 Collator (UCollationStrength collationStrength, UNormalizationMode decompositionMode)
 Constructor.
 Collator (const Collator &other)
 Copy constructor.
virtual void setLocales (const Locale &requestedLocale, const Locale &validLocale, const Locale &actualLocale)
 Used internally by registraton to define the requested and valid locales.

Friends

class CFactory
class SimpleCFactory
class ICUCollatorFactory
class ICUCollatorService

Detailed Description

The Collator class performs locale-sensitive string comparison.


You use this class to build searching and sorting routines for natural language text.
Important: The ICU collation service has been reimplemented in order to achieve better performance and UCA compliance. For details, see the collation design document.

Collator is an abstract base class. Subclasses implement specific collation strategies. One subclass, RuleBasedCollator, is currently provided and is applicable to a wide set of languages. Other subclasses may be created to handle more specialized needs.

Like other locale-sensitive classes, you can use the static factory method, createInstance, to obtain the appropriate Collator object for a given locale. You will only need to look at the subclasses of Collator if you need to understand the details of a particular collation strategy or if you need to modify that strategy.

The following example shows how to compare two strings using the Collator for the default locale.

 
 // Compare two strings in the default locale
 UErrorCode success = U_ZERO_ERROR;
 Collator* myCollator = Collator::createInstance(success);
 if (myCollator->compare("abc", "ABC") < 0)
   cout << "abc is less than ABC" << endl;
 else
   cout << "abc is greater than or equal to ABC" << endl;

You can set a Collator's strength property to determine the level of difference considered significant in comparisons. Five strengths are provided: PRIMARY, SECONDARY, TERTIARY, QUATERNARY and IDENTICAL. The exact assignment of strengths to language features is locale dependant. For example, in Czech, "e" and "f" are considered primary differences, while "e" and "\u00EA" are secondary differences, "e" and "E" are tertiary differences and "e" and "e" are identical. The following shows how both case and accents could be ignored for US English.

 
 //Get the Collator for US English and set its strength to PRIMARY
 UErrorCode success = U_ZERO_ERROR;
 Collator* usCollator = Collator::createInstance(Locale::US, success);
 usCollator->setStrength(Collator::PRIMARY);
 if (usCollator->compare("abc", "ABC") == 0)
     cout << "'abc' and 'ABC' strings are equivalent with strength PRIMARY" << endl;

For comparing strings exactly once, the compare method provides the best performance. When sorting a list of strings however, it is generally necessary to compare each string multiple times. In this case, sort keys provide better performance. The getSortKey methods convert a string to a series of bytes that can be compared bitwise against other sort keys using strcmp(). Sort keys are written as zero-terminated byte strings. They consist of several substrings, one for each collation strength level, that are delimited by 0x01 bytes. If the string code points are appended for UCOL_IDENTICAL, then they are processed for correct code point order comparison and may contain 0x01 bytes but not zero bytes.

An older set of APIs returns a CollationKey object that wraps the sort key bytes instead of returning the bytes themselves. Its use is deprecated, but it is still available for compatibility with Java.

Note: Collators with different Locale, and CollationStrength settings will return different sort orders for the same set of strings. Locales have specific collation rules, and the way in which secondary and tertiary differences are taken into account, for example, will result in a different sorting order for same strings.

See also:
RuleBasedCollator
CollationKey
CollationElementIterator
Locale
Normalizer
Version:
2.0 11/15/01

Definition at line 177 of file coll.h.


Member Enumeration Documentation

Base letter represents a primary difference.

Set comparison level to PRIMARY to ignore secondary and tertiary differences.
Use this to set the strength of a Collator object.
Example of primary difference, "abc" < "abd"

Diacritical differences on the same base letter represent a secondary difference. Set comparison level to SECONDARY to ignore tertiary differences. Use this to set the strength of a Collator object.
Example of secondary difference, "&auml;" >> "a".

Uppercase and lowercase versions of the same character represents a tertiary difference. Set comparison level to TERTIARY to include all comparison differences. Use this to set the strength of a Collator object.
Example of tertiary difference, "abc" <<< "ABC".

Two characters are considered "identical" when they have the same unicode spellings.
For example, "&auml;" == "&auml;".

UCollationStrength is also used to determine the strength of sort keys generated from Collator objects.

Stable:
ICU 2.0

Definition at line 207 of file coll.h.

LESS is returned if source string is compared to be less than target string in the compare() method.

EQUAL is returned if source string is compared to be equal to target string in the compare() method. GREATER is returned if source string is compared to be greater than target string in the compare() method.

See also:
Collator::compare
Deprecated:
ICU 2.6. Use C enum UCollationResult defined in ucol.h

Definition at line 226 of file coll.h.


Constructor & Destructor Documentation

virtual Collator::~Collator (  )  [virtual]

Destructor.

Stable:
ICU 2.0
Collator::Collator (  )  [protected]

Default constructor.

Constructor is different from the old default Collator constructor. The task for determing the default collation strength and normalization mode is left to the child class.

Stable:
ICU 2.0
Collator::Collator ( UCollationStrength  collationStrength,
UNormalizationMode  decompositionMode 
) [protected]

Constructor.

Empty constructor, does not handle the arguments. This constructor is done for backward compatibility with 1.7 and 1.8. The task for handling the argument collation strength and normalization mode is left to the child class.

Parameters:
collationStrength collation strength
decompositionMode 
Deprecated:
ICU 2.4. Subclasses should use the default constructor instead and handle the strength and normalization mode themselves.
Collator::Collator ( const Collator other  )  [protected]

Copy constructor.

Parameters:
other Collator object to be copied from
Stable:
ICU 2.0

Member Function Documentation

virtual Collator* Collator::clone ( void   )  const [pure virtual]

Makes a shallow copy of the current object.

Returns:
a copy of this object
Stable:
ICU 2.0

Implemented in RuleBasedCollator.

virtual UCollationResult Collator::compare ( UCharIterator sIter,
UCharIterator tIter,
UErrorCode status 
) const [virtual]

Compares two strings using the Collator.

Returns whether the first one compares less than/equal to/greater than the second one. This version takes UCharIterator input.

Parameters:
sIter the first ("source") string iterator
tIter the second ("target") string iterator
status ICU status
Returns:
UCOL_LESS, UCOL_EQUAL or UCOL_GREATER
Stable:
ICU 4.4

Reimplemented in RuleBasedCollator.

virtual UCollationResult Collator::compare ( const UChar source,
int32_t  sourceLength,
const UChar target,
int32_t  targetLength,
UErrorCode status 
) const [pure virtual]

The comparison function compares the character data stored in two different string arrays.

Returns information about whether a string array is less than, greater than or equal to another string array.

Parameters:
source the source string array to be compared with.
sourceLength the length of the source string array. If this value is equal to -1, the string array is null-terminated.
target the string that is to be compared with the source string.
targetLength the length of the target string array. If this value is equal to -1, the string array is null-terminated.
status possible error code
Returns:
Returns an enum value. UCOL_GREATER if source is greater than target; UCOL_EQUAL if source is equal to target; UCOL_LESS if source is less than target
Stable:
ICU 2.6

Implemented in RuleBasedCollator.

virtual EComparisonResult Collator::compare ( const UChar source,
int32_t  sourceLength,
const UChar target,
int32_t  targetLength 
) const [virtual]

The comparison function compares the character data stored in two different string arrays.

Returns information about whether a string array is less than, greater than or equal to another string array.

Parameters:
source the source string array to be compared with.
sourceLength the length of the source string array. If this value is equal to -1, the string array is null-terminated.
target the string that is to be compared with the source string.
targetLength the length of the target string array. If this value is equal to -1, the string array is null-terminated.
Returns:
Returns a byte value. GREATER if source is greater than target; EQUAL if source is equal to target; LESS if source is less than target
Deprecated:
ICU 2.6 use the overload with UErrorCode &

Reimplemented in RuleBasedCollator.

virtual UCollationResult Collator::compare ( const UnicodeString source,
const UnicodeString target,
int32_t  length,
UErrorCode status 
) const [pure virtual]

Does the same thing as compare but limits the comparison to a specified length.

Parameters:
source the source string to be compared with.
target the string that is to be compared with the source string.
length the length the comparison is limited to
status possible error code
Returns:
Returns an enum value. UCOL_GREATER if source (up to the specified length) is greater than target; UCOL_EQUAL if source (up to specified length) is equal to target; UCOL_LESS if source (up to the specified length) is less than target.
Stable:
ICU 2.6

Implemented in RuleBasedCollator.

virtual EComparisonResult Collator::compare ( const UnicodeString source,
const UnicodeString target,
int32_t  length 
) const [virtual]

Does the same thing as compare but limits the comparison to a specified length.

Parameters:
source the source string to be compared with.
target the string that is to be compared with the source string.
length the length the comparison is limited to
Returns:
Returns a byte value. GREATER if source (up to the specified length) is greater than target; EQUAL if source (up to specified length) is equal to target; LESS if source (up to the specified length) is less than target.
Deprecated:
ICU 2.6 use the overload with UErrorCode &

Reimplemented in RuleBasedCollator.

virtual UCollationResult Collator::compare ( const UnicodeString source,
const UnicodeString target,
UErrorCode status 
) const [pure virtual]

The comparison function compares the character data stored in two different strings.

Returns information about whether a string is less than, greater than or equal to another string.

Parameters:
source the source string to be compared with.
target the string that is to be compared with the source string.
status possible error code
Returns:
Returns an enum value. UCOL_GREATER if source is greater than target; UCOL_EQUAL if source is equal to target; UCOL_LESS if source is less than target
Stable:
ICU 2.6

Implemented in RuleBasedCollator.

virtual EComparisonResult Collator::compare ( const UnicodeString source,
const UnicodeString target 
) const [virtual]

The comparison function compares the character data stored in two different strings.

Returns information about whether a string is less than, greater than or equal to another string.

Parameters:
source the source string to be compared with.
target the string that is to be compared with the source string.
Returns:
Returns a byte value. GREATER if source is greater than target; EQUAL if source is equal to target; LESS if source is less than target
Deprecated:
ICU 2.6 use the overload with UErrorCode &

Reimplemented in RuleBasedCollator.

virtual UCollationResult Collator::compareUTF8 ( const StringPiece source,
const StringPiece target,
UErrorCode status 
) const [virtual]

Compares two UTF-8 strings using the Collator.

Returns whether the first one compares less than/equal to/greater than the second one. This version takes UTF-8 input. Note that a StringPiece can be implicitly constructed from a std::string or a NUL-terminated const char * string.

Parameters:
source the first UTF-8 string
target the second UTF-8 string
status ICU status
Returns:
UCOL_LESS, UCOL_EQUAL or UCOL_GREATER
Stable:
ICU 4.4
static Collator* Collator::createInstance ( const Locale loc,
UErrorCode err 
) [static]

Gets the table-based collation object for the desired locale.

The resource of the desired locale will be loaded by ResourceLoader. Locale::ENGLISH is the base collation table and all other languages are built on top of it with additional language-specific modifications. The UErrorCode& err 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_ERROR 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_ERROR 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.

Parameters:
loc The locale ID for which to open a collator.
err the error code status.
Returns:
the created table-based collation object based on the desired locale.
See also:
Locale
ResourceLoader
Stable:
ICU 2.2
static Collator* Collator::createInstance ( UErrorCode err  )  [static]

Creates the Collator object for the current default locale.

The default locale is determined by Locale::getDefault. The UErrorCode& err 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_ERROR 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_ERROR 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.

Parameters:
err the error code status.
Returns:
the collation object of the default locale.(for example, en_US)
See also:
Locale::getDefault
Stable:
ICU 2.0
static UCollator* Collator::createUCollator ( const char *  loc,
UErrorCode status 
) [static]

used only by ucol_open, not for public use

Internal:
Do not use. This API is for internal use only.
UBool Collator::equals ( const UnicodeString source,
const UnicodeString target 
) const

Convenience method for comparing two strings based on the collation rules.

Parameters:
source the source string to be compared with.
target the target string to be compared with.
Returns:
true if the strings are equal according to the collation rules. false, otherwise.
See also:
Collator::compare
Stable:
ICU 2.0
virtual UColAttributeValue Collator::getAttribute ( UColAttribute  attr,
UErrorCode status 
) [pure virtual]

Universal attribute getter.

Parameters:
attr attribute type
status to indicate whether the operation went on smoothly or there were errors
Returns:
attribute value
Stable:
ICU 2.2

Implemented in RuleBasedCollator.

static StringEnumeration* Collator::getAvailableLocales ( void   )  [static]

Return a StringEnumeration over the locales available at the time of the call, including registered locales.

If a severe error occurs (such as out of memory condition) this will return null. If there is no locale data, an empty enumeration will be returned.

Returns:
a StringEnumeration over the locales available at the time of the call
Stable:
ICU 2.6
static const Locale* Collator::getAvailableLocales ( int32_t &  count  )  [static]

Get the set of Locales for which Collations are installed.

Note this does not include locales supported by registered collators. If collators might have been registered, use the overload of getAvailableLocales that returns a StringEnumeration.

Parameters:
count the output parameter of number of elements in the locale list
Returns:
the list of available locales for which collations are installed
Stable:
ICU 2.0
static int32_t Collator::getBound ( const uint8_t *  source,
int32_t  sourceLength,
UColBoundMode  boundType,
uint32_t  noOfLevels,
uint8_t *  result,
int32_t  resultLength,
UErrorCode status 
) [static]

Produce a bound for a given sortkey and a number of levels.

Return value is always the number of bytes needed, regardless of whether the result buffer was big enough or even valid.
Resulting bounds can be used to produce a range of strings that are between upper and lower bounds. For example, if bounds are produced for a sortkey of string "smith", strings between upper and lower bounds with one level would include "Smith", "SMITH", "sMiTh".
There are two upper bounds that can be produced. If UCOL_BOUND_UPPER is produced, strings matched would be as above. However, if bound produced using UCOL_BOUND_UPPER_LONG is used, the above example will also match "Smithsonian" and similar.
For more on usage, see example in cintltst/capitst.c in procedure TestBounds. Sort keys may be compared using strcmp.

Parameters:
source The source sortkey.
sourceLength The length of source, or -1 if null-terminated. (If an unmodified sortkey is passed, it is always null terminated).
boundType Type of bound required. It can be UCOL_BOUND_LOWER, which produces a lower inclusive bound, UCOL_BOUND_UPPER, that produces upper bound that matches strings of the same length or UCOL_BOUND_UPPER_LONG that matches strings that have the same starting substring as the source string.
noOfLevels Number of levels required in the resulting bound (for most uses, the recommended value is 1). See users guide for explanation on number of levels a sortkey can have.
result A pointer to a buffer to receive the resulting sortkey.
resultLength The maximum size of result.
status Used for returning error code if something went wrong. If the number of levels requested is higher than the number of levels in the source key, a warning (U_SORT_KEY_TOO_SHORT_WARNING) is issued.
Returns:
The size needed to fully store the bound.
See also:
ucol_keyHashCode
Stable:
ICU 2.1
virtual CollationKey& Collator::getCollationKey ( const UChar source,
int32_t  sourceLength,
CollationKey key,
UErrorCode status 
) const [pure virtual]

Transforms the string into a series of characters that can be compared with CollationKey::compareTo.

It is not possible to restore the original string from the chars in the sort key. The generated sort key handles only a limited number of ignorable characters.

Use CollationKey::equals or CollationKey::compare to compare the generated sort keys.

If the source string is null, a null collation key will be returned.

Parameters:
source the source string to be transformed into a sort key.
sourceLength length of the collation key
key the collation key to be filled in
status the error code status.
Returns:
the collation key of the string based on the collation rules.
See also:
CollationKey::compare
Deprecated:
ICU 2.8 Use getSortKey(...) instead

Implemented in RuleBasedCollator.

virtual CollationKey& Collator::getCollationKey ( const UnicodeString source,
CollationKey key,
UErrorCode status 
) const [pure virtual]

Transforms the string into a series of characters that can be compared with CollationKey::compareTo.

It is not possible to restore the original string from the chars in the sort key. The generated sort key handles only a limited number of ignorable characters.

Use CollationKey::equals or CollationKey::compare to compare the generated sort keys. If the source string is null, a null collation key will be returned.

Parameters:
source the source string to be transformed into a sort key.
key the collation key to be filled in
status the error code status.
Returns:
the collation key of the string based on the collation rules.
See also:
CollationKey::compare
Deprecated:
ICU 2.8 Use getSortKey(...) instead

Implemented in RuleBasedCollator.

static UnicodeString& Collator::getDisplayName ( const Locale objectLocale,
UnicodeString name 
) [static]

Get name of the object for the desired Locale, in the langauge of the default locale.

Parameters:
objectLocale must be from getAvailableLocales
name the fill-in parameter of the return value
Returns:
name of the object for the desired locale in the default language
Stable:
ICU 2.0
static UnicodeString& Collator::getDisplayName ( const Locale objectLocale,
const Locale displayLocale,
UnicodeString name 
) [static]

Get name of the object for the desired Locale, in the desired langauge.

Parameters:
objectLocale must be from getAvailableLocales
displayLocale specifies the desired locale for output
name the fill-in parameter of the return value
Returns:
display-able name of the object for the object locale in the desired language
Stable:
ICU 2.0
virtual UClassID Collator::getDynamicClassID ( void   )  const [pure virtual]

Returns a unique class ID POLYMORPHICALLY.

Pure virtual method. 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.

Returns:
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

Implements UObject.

Implemented in RuleBasedCollator.

static Locale Collator::getFunctionalEquivalent ( const char *  keyword,
const Locale locale,
UBool isAvailable,
UErrorCode status 
) [static]

Return the functionally equivalent locale for the given requested locale, with respect to given keyword, for the collation service.

If two locales return the same result, then collators instantiated for these locales will behave equivalently. The converse is not always true; two collators may in fact be equivalent, but return different results, due to internal details. The return result has no other meaning than that stated above, and implies nothing as to the relationship between the two locales. This is intended for use by applications who wish to cache collators, or otherwise reuse collators when possible. The functional equivalent may change over time. For more information, please see the Locales and Services section of the ICU User Guide.

Parameters:
keyword a particular keyword as enumerated by ucol_getKeywords.
locale the requested locale
isAvailable reference to a fillin parameter that indicates whether the requested locale was 'available' to the collation service. A locale is defined as 'available' if it physically exists within the collation locale data.
status reference to input-output error code
Returns:
the functionally equivalent collation locale, or the root locale upon error.
Stable:
ICU 3.0
static StringEnumeration* Collator::getKeywords ( UErrorCode status  )  [static]

Create a string enumerator of all possible keywords that are relevant to collation.

At this point, the only recognized keyword for this service is "collation".

Parameters:
status input-output error code
Returns:
a string enumeration over locale strings. The caller is responsible for closing the result.
Stable:
ICU 3.0
static StringEnumeration* Collator::getKeywordValues ( const char *  keyword,
UErrorCode status 
) [static]

Given a keyword, create a string enumeration of all values for that keyword that are currently in use.

Parameters:
keyword a particular keyword as enumerated by ucol_getKeywords. If any other keyword is passed in, status is set to U_ILLEGAL_ARGUMENT_ERROR.
status input-output error code
Returns:
a string enumeration over collation keyword values, or NULL upon error. The caller is responsible for deleting the result.
Stable:
ICU 3.0
static StringEnumeration* Collator::getKeywordValuesForLocale ( const char *  keyword,
const Locale locale,
UBool  commonlyUsed,
UErrorCode status 
) [static]

Given a key and a locale, returns an array of string values in a preferred order that would make a difference.

These are all and only those values where the open (creation) of the service with the locale formed from the input locale plus input keyword and that value has different behavior than creation with the input locale alone.

Parameters:
keyword one of the keys supported by this service. For now, only "collation" is supported.
locale the locale
commonlyUsed if set to true it will return only commonly used values with the given locale in preferred order. Otherwise, it will return all the available values for the locale.
status ICU status
Returns:
a string enumeration over keyword values for the given key and the locale.
Stable:
ICU 4.4
virtual const Locale Collator::getLocale ( ULocDataLocaleType  type,
UErrorCode status 
) const [pure virtual]

Gets the locale of the Collator.

Parameters:
type can be either requested, valid or actual locale. For more information see the definition of ULocDataLocaleType in uloc.h
status the error code status.
Returns:
locale where the collation data lives. If the collator was instantiated from rules, locale is empty.
Deprecated:
ICU 2.8 This API is under consideration for revision in ICU 3.0.

Implemented in RuleBasedCollator.

virtual int32_t Collator::getSortKey ( const UChar source,
int32_t  sourceLength,
uint8_t *  result,
int32_t  resultLength 
) const [pure virtual]

Get the sort key as an array of bytes from an UChar buffer.

Sort key byte arrays are zero-terminated and can be compared using strcmp().

Parameters:
source string to be processed.
sourceLength length of string to be processed. If -1, the string is 0 terminated and length will be decided by the function.
result buffer to store result in. If NULL, number of bytes needed will be returned.
resultLength length of the result buffer. If if not enough the buffer will be filled to capacity.
Returns:
Number of bytes needed for storing the sort key
Stable:
ICU 2.2

Implemented in RuleBasedCollator.

virtual int32_t Collator::getSortKey ( const UnicodeString source,
uint8_t *  result,
int32_t  resultLength 
) const [pure virtual]

Get the sort key as an array of bytes from an UnicodeString.

Sort key byte arrays are zero-terminated and can be compared using strcmp().

Parameters:
source string to be processed.
result buffer to store result in. If NULL, number of bytes needed will be returned.
resultLength length of the result buffer. If if not enough the buffer will be filled to capacity.
Returns:
Number of bytes needed for storing the sort key
Stable:
ICU 2.2

Implemented in RuleBasedCollator.

virtual ECollationStrength Collator::getStrength ( void   )  const [pure virtual]

Determines the minimum strength that will be use in comparison or transformation.

E.g. with strength == SECONDARY, the tertiary difference is ignored

E.g. with strength == PRIMARY, the secondary and tertiary difference are ignored.

Returns:
the current comparison level.
See also:
Collator::setStrength
Deprecated:
ICU 2.6 Use getAttribute(UCOL_STRENGTH...) instead

Implemented in RuleBasedCollator.

virtual UnicodeSet* Collator::getTailoredSet ( UErrorCode status  )  const [virtual]

Get an UnicodeSet that contains all the characters and sequences tailored in this collator.

Parameters:
status error code of the operation
Returns:
a pointer to a UnicodeSet object containing all the code points and sequences that may sort differently than in the UCA. The object must be disposed of by using delete
Stable:
ICU 2.4

Reimplemented in RuleBasedCollator.

virtual uint32_t Collator::getVariableTop ( UErrorCode status  )  const [pure virtual]

Gets the variable top value of a Collator.

Lower 16 bits are undefined and should be ignored.

Parameters:
status error code (not changed by function). If error code is set, the return value is undefined.
Stable:
ICU 2.0

Implemented in RuleBasedCollator.

virtual void Collator::getVersion ( UVersionInfo  info  )  const [pure virtual]

Gets the version information for a Collator.

Parameters:
info the version # information, the result will be filled in
Stable:
ICU 2.0

Implemented in RuleBasedCollator.

UBool Collator::greater ( const UnicodeString source,
const UnicodeString target 
) const

Convenience method for comparing two strings based on the collation rules.

Parameters:
source the source string to be compared with.
target the target string to be compared with.
Returns:
true if the first string is greater than the second one, according to the collation rules. false, otherwise.
See also:
Collator::compare
Stable:
ICU 2.0
UBool Collator::greaterOrEqual ( const UnicodeString source,
const UnicodeString target 
) const

Convenience method for comparing two strings based on the collation rules.

Parameters:
source the source string to be compared with.
target the target string to be compared with.
Returns:
true if the first string is greater than or equal to the second one, according to the collation rules. false, otherwise.
See also:
Collator::compare
Stable:
ICU 2.0
virtual int32_t Collator::hashCode ( void   )  const [pure virtual]

Generates the hash code for the collation object.

Stable:
ICU 2.0

Implemented in RuleBasedCollator.

virtual UBool Collator::operator!= ( const Collator other  )  const [virtual]

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

Parameters:
other Collator object to be compared
Returns:
true if other is not the same as this.
Stable:
ICU 2.0
virtual UBool Collator::operator== ( const Collator other  )  const [virtual]

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

Parameters:
other Collator object to be compared
Returns:
true if other is the same as this.
Stable:
ICU 2.0
static URegistryKey Collator::registerFactory ( CollatorFactory toAdopt,
UErrorCode status 
) [static]

Register a new CollatorFactory.

The factory will be adopted.

Parameters:
toAdopt the CollatorFactory instance to be adopted
status the in/out status code, no special meanings are assigned
Returns:
a registry key that can be used to unregister this collator
Stable:
ICU 2.6
static URegistryKey Collator::registerInstance ( Collator toAdopt,
const Locale locale,
UErrorCode status 
) [static]

Register a new Collator.

The collator will be adopted.

Parameters:
toAdopt the Collator instance to be adopted
locale the locale with which the collator will be associated
status the in/out status code, no special meanings are assigned
Returns:
a registry key that can be used to unregister this collator
Stable:
ICU 2.6
virtual Collator* Collator::safeClone ( void   )  [pure virtual]

Thread safe cloning operation.

Returns:
pointer to the new clone, user should remove it.
Stable:
ICU 2.2

Implemented in RuleBasedCollator.

virtual void Collator::setAttribute ( UColAttribute  attr,
UColAttributeValue  value,
UErrorCode status 
) [pure virtual]

Universal attribute setter.

Parameters:
attr attribute type
value attribute value
status to indicate whether the operation went on smoothly or there were errors
Stable:
ICU 2.2

Implemented in RuleBasedCollator.

virtual void Collator::setLocales ( const Locale requestedLocale,
const Locale validLocale,
const Locale actualLocale 
) [protected, virtual]

Used internally by registraton to define the requested and valid locales.

Parameters:
requestedLocale the requested locale
validLocale the valid locale
actualLocale the actual locale
Internal:
Do not use. This API is for internal use only.

Reimplemented in RuleBasedCollator.

virtual void Collator::setStrength ( ECollationStrength  newStrength  )  [pure virtual]

Sets the minimum strength to be used in comparison or transformation.

Example of use:

  
  UErrorCode status = U_ZERO_ERROR;
  Collator*myCollation = Collator::createInstance(Locale::US, status);
  if (U_FAILURE(status)) return;
  myCollation->setStrength(Collator::PRIMARY);
  // result will be "abc" == "ABC"
  // tertiary differences will be ignored
  Collator::ComparisonResult result = myCollation->compare("abc", "ABC");
See also:
Collator::getStrength
Parameters:
newStrength the new comparison level.
Deprecated:
ICU 2.6 Use setAttribute(UCOL_STRENGTH...) instead

Implemented in RuleBasedCollator.

virtual void Collator::setVariableTop ( const uint32_t  varTop,
UErrorCode status 
) [pure virtual]

Sets the variable top to a collation element value supplied.

Variable top is set to the upper 16 bits. Lower 16 bits are ignored.

Parameters:
varTop CE value, as returned by setVariableTop or ucol)getVariableTop
status error code (not changed by function)
Stable:
ICU 2.0

Implemented in RuleBasedCollator.

virtual uint32_t Collator::setVariableTop ( const UnicodeString  varTop,
UErrorCode status 
) [pure virtual]

Sets the variable top to a collation element value of a string supplied.

Parameters:
varTop an UnicodeString size 1 or more (if contraction) of UChars to which the variable top should be set
status error code. If error code is set, the return value is undefined. Errors set by this function are:
U_CE_NOT_FOUND_ERROR if more than one character was passed and there is no such a contraction
U_PRIMARY_TOO_LONG_ERROR if the primary for the variable top has more than two bytes
Returns:
a 32 bit value containing the value of the variable top in upper 16 bits. Lower 16 bits are undefined
Stable:
ICU 2.0

Implemented in RuleBasedCollator.

virtual uint32_t Collator::setVariableTop ( const UChar varTop,
int32_t  len,
UErrorCode status 
) [pure virtual]

Sets the variable top to a collation element value of a string supplied.

Parameters:
varTop one or more (if contraction) UChars to which the variable top should be set
len length of variable top string. If -1 it is considered to be zero terminated.
status error code. If error code is set, the return value is undefined. Errors set by this function are:
U_CE_NOT_FOUND_ERROR if more than one character was passed and there is no such a contraction
U_PRIMARY_TOO_LONG_ERROR if the primary for the variable top has more than two bytes
Returns:
a 32 bit value containing the value of the variable top in upper 16 bits. Lower 16 bits are undefined
Stable:
ICU 2.0

Implemented in RuleBasedCollator.

static UBool Collator::unregister ( URegistryKey  key,
UErrorCode status 
) [static]

Unregister a previously-registered Collator or CollatorFactory using the key returned from the register call.

Key becomes invalid after a successful call and should not be used again. The object corresponding to the key will be deleted.

Parameters:
key the registry key returned by a previous call to registerInstance
status the in/out status code, no special meanings are assigned
Returns:
TRUE if the collator for the key was successfully unregistered
Stable:
ICU 2.6

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