ICU 76.1 76.1
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The Collator
class performs locale-sensitive string comparison.
More...
#include <coll.h>
Public Types | |
enum | ECollationStrength { PRIMARY = UCOL_PRIMARY , SECONDARY = UCOL_SECONDARY , TERTIARY = UCOL_TERTIARY , QUATERNARY = UCOL_QUATERNARY , IDENTICAL = UCOL_IDENTICAL } |
Base letter represents a primary difference. More... | |
enum | EComparisonResult { LESS = UCOL_LESS , EQUAL = UCOL_EQUAL , GREATER = UCOL_GREATER } |
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 bool | operator== (const Collator &other) const |
Returns true if "other" is the same as "this". | |
virtual bool | operator!= (const Collator &other) const |
Returns true if "other" is not the same as "this". | |
virtual Collator * | clone () const =0 |
Makes a copy of this 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 char16_t *source, int32_t sourceLength, const char16_t *target, int32_t targetLength) const |
The comparison function compares the character data stored in two different string arrays. | |
virtual UCollationResult | compare (const char16_t *source, int32_t sourceLength, const char16_t *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 CollationKey & | getCollationKey (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 CollationKey & | getCollationKey (const char16_t *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 () const =0 |
Generates the hash code for the collation object. | |
virtual 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. | |
auto | equal_to () const |
Creates a comparison function object that uses this collator. | |
auto | greater () const |
Creates a comparison function object that uses this collator. | |
auto | less () const |
Creates a comparison function object that uses this collator. | |
auto | not_equal_to () const |
Creates a comparison function object that uses this collator. | |
auto | greater_equal () const |
Creates a comparison function object that uses this collator. | |
auto | less_equal () const |
Creates a comparison function object that uses this collator. | |
virtual ECollationStrength | getStrength () const |
Determines the minimum strength that will be used in comparison or transformation. | |
virtual void | setStrength (ECollationStrength newStrength) |
Sets the minimum strength to be used in comparison or transformation. | |
virtual int32_t | getReorderCodes (int32_t *dest, int32_t destCapacity, UErrorCode &status) const |
Retrieves the reordering codes for this collator. | |
virtual void | setReorderCodes (const int32_t *reorderCodes, int32_t reorderCodesLength, UErrorCode &status) |
Sets the ordering of scripts for this collator. | |
virtual void | getVersion (UVersionInfo info) const =0 |
Gets the version information for a Collator. | |
virtual UClassID | getDynamicClassID () const override=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) const =0 |
Universal attribute getter. | |
virtual Collator & | setMaxVariable (UColReorderCode group, UErrorCode &errorCode) |
Sets the variable top to the top of the specified reordering group. | |
virtual UColReorderCode | getMaxVariable () const |
Returns the maximum reordering group whose characters are affected by UCOL_ALTERNATE_HANDLING. | |
virtual uint32_t | setVariableTop (const char16_t *varTop, int32_t len, UErrorCode &status)=0 |
Sets the variable top to the primary weight of the specified string. | |
virtual uint32_t | setVariableTop (const UnicodeString &varTop, UErrorCode &status)=0 |
Sets the variable top to the primary weight of the specified string. | |
virtual void | setVariableTop (uint32_t varTop, UErrorCode &status)=0 |
Sets the variable top to the specified primary weight. | |
virtual uint32_t | getVariableTop (UErrorCode &status) const =0 |
Gets the variable top value of a Collator. | |
virtual UnicodeSet * | getTailoredSet (UErrorCode &status) const |
Get a UnicodeSet that contains all the characters and sequences tailored in this collator. | |
virtual Collator * | safeClone () const |
Same as clone(). | |
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 a UnicodeString. | |
virtual int32_t | getSortKey (const char16_t *source, int32_t sourceLength, uint8_t *result, int32_t resultLength) const =0 |
Get the sort key as an array of bytes from a char16_t buffer. | |
virtual void | setLocales (const Locale &requestedLocale, const Locale &validLocale, const Locale &actualLocale) |
Used internally by registration to define the requested and valid locales. | |
virtual int32_t | internalGetShortDefinitionString (const char *locale, char *buffer, int32_t capacity, UErrorCode &status) const |
Get the short definition string for a collator. | |
virtual UCollationResult | internalCompareUTF8 (const char *left, int32_t leftLength, const char *right, int32_t rightLength, UErrorCode &errorCode) const |
Implements ucol_strcollUTF8(). | |
virtual int32_t | internalNextSortKeyPart (UCharIterator *iter, uint32_t state[2], uint8_t *dest, int32_t count, UErrorCode &errorCode) const |
Implements ucol_nextSortKeyPart(). | |
UCollator * | toUCollator () |
const UCollator * | toUCollator () const |
Public Member Functions inherited from icu::UObject | |
virtual | ~UObject () |
Destructor. | |
Static Public Member Functions | |
static Collator * | createInstance (UErrorCode &err) |
Creates the Collator object for the current default locale. | |
static Collator * | createInstance (const Locale &loc, UErrorCode &err) |
Gets the collation object for the desired locale. | |
static int32_t | getEquivalentReorderCodes (int32_t reorderCode, int32_t *dest, int32_t destCapacity, UErrorCode &status) |
Retrieves the reorder codes that are grouped with the given reorder code. | |
static UnicodeString & | getDisplayName (const Locale &objectLocale, const Locale &displayLocale, UnicodeString &name) |
Get name of the object for the desired Locale, in the desired language. | |
static UnicodeString & | getDisplayName (const Locale &objectLocale, UnicodeString &name) |
Get name of the object for the desired Locale, in the language of the default locale. | |
static const Locale * | getAvailableLocales (int32_t &count) |
Get the set of Locales for which Collations are installed. | |
static StringEnumeration * | getAvailableLocales () |
Return a StringEnumeration over the locales available at the time of the call, including registered locales. | |
static StringEnumeration * | getKeywords (UErrorCode &status) |
Create a string enumerator of all possible keywords that are relevant to collation. | |
static StringEnumeration * | getKeywordValues (const char *keyword, UErrorCode &status) |
Given a keyword, create a string enumeration of all values for that keyword that are currently in use. | |
static StringEnumeration * | getKeywordValuesForLocale (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 Collator * | fromUCollator (UCollator *uc) |
static const Collator * | fromUCollator (const UCollator *uc) |
Protected Member Functions | |
Collator () | |
Default constructor. | |
Collator (UCollationStrength collationStrength, UNormalizationMode decompositionMode) | |
Constructor. | |
Collator (const Collator &other) | |
Copy constructor. | |
Friends | |
class | CFactory |
class | SimpleCFactory |
class | ICUCollatorFactory |
class | ICUCollatorService |
The Collator
class performs locale-sensitive string comparison.
You use this class to build searching and sorting routines for natural language text.
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 localeelsestatic Collator * createInstance(UErrorCode &err)Creates the Collator object for the current default locale."Smart pointer" base class; do not use directly: use LocalPointer etc.Definition localpointer.h:68
You can set a Collator
's strength attribute 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 dependent. 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 PRIMARYusCollator->setStrength(Collator::PRIMARY);
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.
Another set of APIs returns a CollationKey
object that wraps the sort key bytes instead of returning the bytes themselves.
Note: Collator
s 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.
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, "ä" >> "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, "ä" == "ä".
UCollationStrength is also used to determine the strength of sort keys generated from Collator objects.
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.
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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.
collationStrength | collation strength |
decompositionMode |
Makes a copy of this object.
Implemented in icu::RuleBasedCollator.
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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.
Example of use:
. char16_t ABC[] = {0x41, 0x42, 0x43, 0}; // = "ABC" . char16_t abc[] = {0x61, 0x62, 0x63, 0}; // = "abc" . UErrorCode status = U_ZERO_ERROR; . Collator *myCollation = . Collator::createInstance(Locale::getUS(), status); . if (U_FAILURE(status)) return; . myCollation->setStrength(Collator::PRIMARY); . // result would be Collator::EQUAL ("abc" == "ABC") . // (no primary difference between "abc" and "ABC") . Collator::EComparisonResult result = . myCollation->compare(abc, 3, ABC, 3); . myCollation->setStrength(Collator::TERTIARY); . // result would be Collator::LESS ("abc" <<< "ABC") . // (with tertiary difference between "abc" and "ABC") . result = myCollation->compare(abc, 3, ABC, 3);
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. |
Reimplemented in icu::RuleBasedCollator.
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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.
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 |
Implemented in icu::RuleBasedCollator, and icu::RuleBasedCollator.
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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.
source | the source string to be compared with. |
target | the string that is to be compared with the source string. |
Reimplemented in icu::RuleBasedCollator.
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Does the same thing as compare but limits the comparison to a specified length.
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 |
Reimplemented in icu::RuleBasedCollator.
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Does the same thing as compare but limits the comparison to a specified length.
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 |
Implemented in icu::RuleBasedCollator, and icu::RuleBasedCollator.
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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.
source | the source string to be compared with. |
target | the string that is to be compared with the source string. |
status | possible error code |
Implemented in icu::RuleBasedCollator, and icu::RuleBasedCollator.
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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.
sIter | the first ("source") string iterator |
tIter | the second ("target") string iterator |
status | ICU status |
Reimplemented in icu::RuleBasedCollator, and icu::RuleBasedCollator.
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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.
source | the first UTF-8 string |
target | the second UTF-8 string |
status | ICU status |
Reimplemented in icu::RuleBasedCollator.
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Gets the collation object for the desired locale.
The resource of the desired locale will be loaded.
Locale::getRoot() is the base collation table and all other languages are built on top of it with additional language-specific modifications.
For some languages, multiple collation types are available; for example, "de@collation=phonebook". Starting with ICU 54, collation attributes can be specified via locale keywords as well, in the old locale extension syntax ("el@colCaseFirst=upper") or in language tag syntax ("el-u-kf-upper"). See User Guide: Collation API.
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.
loc | The locale ID for which to open a collator. |
err | the error code status. |
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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.
err | the error code status. |
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UBool icu::Collator::equals | ( | const UnicodeString & | source, |
const UnicodeString & | target | ||
) | const |
Convenience method for comparing two strings based on the collation rules.
source | the source string to be compared with. |
target | the target string to be compared with. |
Definition at line 1236 of file coll.h.
Referenced by icu::RuleBasedCollator::rbcFromUCollator(), and icu::RuleBasedCollator::rbcFromUCollator().
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Universal attribute getter.
attr | attribute type |
status | to indicate whether the operation went on smoothly or there were errors |
Implemented in icu::RuleBasedCollator.
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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.
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.
count | the output parameter of number of elements in the locale list |
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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
.
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. |
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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.
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.
Note that sort keys are often less efficient than simply doing comparison. For more details, see the ICU User Guide.
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. |
Implemented in icu::RuleBasedCollator.
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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.
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.
Note that sort keys are often less efficient than simply doing comparison. For more details, see the ICU User Guide.
source | the source string to be transformed into a sort key. |
key | the collation key to be filled in |
status | the error code status. |
Implemented in icu::RuleBasedCollator.
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Get name of the object for the desired Locale, in the desired language.
objectLocale | must be from getAvailableLocales |
displayLocale | specifies the desired locale for output |
name | the fill-in parameter of the return value |
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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.
Reimplemented from icu::UObject.
Implemented in icu::RuleBasedCollator.
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Retrieves the reorder codes that are grouped with the given reorder code.
Some reorder codes will be grouped and must reorder together. Beginning with ICU 55, scripts only reorder together if they are primary-equal, for example Hiragana and Katakana.
reorderCode | The reorder code to determine equivalence for. |
dest | The array to fill with the script equivalence reordering codes. |
destCapacity | The length of dest. If it is 0, then dest may be nullptr and the function will only return the length of the result without writing any codes (pre-flighting). |
status | A reference to an error code value, which must not indicate a failure before the function call. |
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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.
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 |
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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".
status | input-output error code |
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Given a keyword, create a string enumeration of all values for that keyword that are currently in use.
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 |
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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.
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 |
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Gets the locale of the Collator.
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. |
Implemented in icu::RuleBasedCollator.
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Returns the maximum reordering group whose characters are affected by UCOL_ALTERNATE_HANDLING.
The base class implementation returns UCOL_REORDER_CODE_PUNCTUATION.
Reimplemented in icu::RuleBasedCollator.
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Retrieves the reordering codes for this collator.
dest | The array to fill with the script ordering. |
destCapacity | The length of dest. If it is 0, then dest may be nullptr and the function will only return the length of the result without writing any codes (pre-flighting). |
status | A reference to an error code value, which must not indicate a failure before the function call. |
Reimplemented in icu::RuleBasedCollator.
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Get the sort key as an array of bytes from a char16_t buffer.
Sort key byte arrays are zero-terminated and can be compared using strcmp().
Note that sort keys are often less efficient than simply doing comparison. For more details, see the ICU User Guide.
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 nullptr, number of bytes needed will be returned. |
resultLength | length of the result buffer. If if not enough the buffer will be filled to capacity. |
Implemented in icu::RuleBasedCollator.
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Get the sort key as an array of bytes from a UnicodeString.
Sort key byte arrays are zero-terminated and can be compared using strcmp().
Note that sort keys are often less efficient than simply doing comparison. For more details, see the ICU User Guide.
source | string to be processed. |
result | buffer to store result in. If nullptr, number of bytes needed will be returned. |
resultLength | length of the result buffer. If if not enough the buffer will be filled to capacity. |
Implemented in icu::RuleBasedCollator.
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virtual |
Determines the minimum strength that will be used 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.
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virtual |
Get a UnicodeSet that contains all the characters and sequences tailored in this collator.
status | error code of the operation |
Reimplemented in icu::RuleBasedCollator.
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pure virtual |
Gets the variable top value of a Collator.
status | error code (not changed by function). If error code is set, the return value is undefined. |
Implemented in icu::RuleBasedCollator.
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pure virtual |
Gets the version information for a Collator.
info | the version # information, the result will be filled in |
Implemented in icu::RuleBasedCollator.
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inline |
UBool icu::Collator::greater | ( | const UnicodeString & | source, |
const UnicodeString & | target | ||
) | const |
Convenience method for comparing two strings based on the collation rules.
source | the source string to be compared with. |
target | the target string to be compared with. |
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inline |
UBool icu::Collator::greaterOrEqual | ( | const UnicodeString & | source, |
const UnicodeString & | target | ||
) | const |
Convenience method for comparing two strings based on the collation rules.
source | the source string to be compared with. |
target | the target string to be compared with. |
Generates the hash code for the collation object.
Implemented in icu::RuleBasedCollator.
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virtual |
Implements ucol_strcollUTF8().
Reimplemented in icu::RuleBasedCollator.
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virtual |
Get the short definition string for a collator.
This internal API harvests the collator's locale and the attribute set and produces a string that can be used for opening a collator with the same attributes using the ucol_openFromShortString API. This string will be normalized. The structure and the syntax of the string is defined in the "Naming collators" section of the users guide: https://unicode-org.github.io/icu/userguide/collation/concepts#collator-naming-scheme This function supports preflighting.
This is internal, and intended to be used with delegate converters.
locale | a locale that will appear as a collators locale in the resulting short string definition. If nullptr, the locale will be harvested from the collator. |
buffer | space to hold the resulting string |
capacity | capacity of the buffer |
status | for returning errors. All the preflighting errors are featured |
Reimplemented in icu::RuleBasedCollator.
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virtual |
Implements ucol_nextSortKeyPart().
Reimplemented in icu::RuleBasedCollator.
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inline |
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inline |
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inline |
Returns true if "other" is not the same as "this".
Calls ! operator==(const Collator&) const which works for all subclasses.
other | Collator object to be compared |
Returns true if "other" is the same as "this".
The base class implementation returns true if "other" has the same type/class as "this": typeid(*this) == typeid(other)
.
Subclass implementations should do something like the following:
if (this == &other) { return true; } if (!Collator::operator==(other)) { return false; } // not the same class const MyCollator &o = (const MyCollator&)other; (compare this vs. o's subclass fields)
other | Collator object to be compared |
Reimplemented in icu::RuleBasedCollator.
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static |
Register a new CollatorFactory.
The factory will be adopted. Because ICU may choose to cache collators internally, this must be called at application startup, prior to any calls to Collator::createInstance to avoid undefined behavior.
toAdopt | the CollatorFactory instance to be adopted |
status | the in/out status code, no special meanings are assigned |
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static |
Register a new Collator.
The collator will be adopted. Because ICU may choose to cache collators internally, this must be called at application startup, prior to any calls to Collator::createInstance to avoid undefined behavior.
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 |
Same as clone().
The base class implementation simply calls clone().
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pure virtual |
Universal attribute setter.
attr | attribute type |
value | attribute value |
status | to indicate whether the operation went on smoothly or there were errors |
Implemented in icu::RuleBasedCollator.
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virtual |
Used internally by registration to define the requested and valid locales.
requestedLocale | the requested locale |
validLocale | the valid locale |
actualLocale | the actual locale |
Reimplemented in icu::RuleBasedCollator.
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virtual |
Sets the variable top to the top of the specified reordering group.
The variable top determines the highest-sorting character which is affected by UCOL_ALTERNATE_HANDLING. If that attribute is set to UCOL_NON_IGNORABLE, then the variable top has no effect.
The base class implementation sets U_UNSUPPORTED_ERROR.
group | one of UCOL_REORDER_CODE_SPACE, UCOL_REORDER_CODE_PUNCTUATION, UCOL_REORDER_CODE_SYMBOL, UCOL_REORDER_CODE_CURRENCY; or UCOL_REORDER_CODE_DEFAULT to restore the default max variable group |
errorCode | Standard ICU error code. Its input value must pass the U_SUCCESS() test, or else the function returns immediately. Check for U_FAILURE() on output or use with function chaining. (See User Guide for details.) |
Reimplemented in icu::RuleBasedCollator.
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virtual |
Sets the ordering of scripts for this collator.
The reordering codes are a combination of script codes and reorder codes.
reorderCodes | An array of script codes in the new order. This can be nullptr if the length is also set to 0. An empty array will clear any reordering codes on the collator. |
reorderCodesLength | The length of reorderCodes. |
status | error code |
Reimplemented in icu::RuleBasedCollator.
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virtual |
Sets the minimum strength to be used in comparison or transformation.
Example of use:
myCollation->setStrength(Collator::PRIMARY);// result will be "abc" == "ABC"// tertiary differences will be ignored
newStrength | the new comparison level. |
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pure virtual |
Sets the variable top to the primary weight of the specified string.
Beginning with ICU 53, the variable top is pinned to the top of one of the supported reordering groups, and it must not be beyond the last of those groups. See setMaxVariable().
varTop | one or more (if contraction) char16_ts 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 contraction U_ILLEGAL_ARGUMENT_ERROR if the variable top is beyond the last reordering group supported by setMaxVariable() |
Implemented in icu::RuleBasedCollator.
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pure virtual |
Sets the variable top to the primary weight of the specified string.
Beginning with ICU 53, the variable top is pinned to the top of one of the supported reordering groups, and it must not be beyond the last of those groups. See setMaxVariable().
varTop | a UnicodeString size 1 or more (if contraction) of char16_ts 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 contraction U_ILLEGAL_ARGUMENT_ERROR if the variable top is beyond the last reordering group supported by setMaxVariable() |
Implemented in icu::RuleBasedCollator.
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pure virtual |
Sets the variable top to the specified primary weight.
Beginning with ICU 53, the variable top is pinned to the top of one of the supported reordering groups, and it must not be beyond the last of those groups. See setMaxVariable().
varTop | primary weight, as returned by setVariableTop or ucol_getVariableTop |
status | error code |
Implemented in icu::RuleBasedCollator.
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inline |
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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. Because ICU may choose to cache collators internally, this should be called during application shutdown, after all calls to Collator::createInstance to avoid undefined behavior.
key | the registry key returned by a previous call to registerInstance |
status | the in/out status code, no special meanings are assigned |