* Developers don't need to know anything about the collation rules for various * languages. Any features requiring collation can use the collation object * associated with the current default locale, or with a specific locale * (like France or Japan) if appropriate. *
Because compare()'s algorithm is complex, it is faster to sort long lists * of words by retrieving sort keys or collation keys with getCollationKey(). * You can then cache the sort keys and compare them using CollationKey::compareTo(). * The following is a list of features of sort key: *
Collation subclasses implement different collation rules for different * languages and different applications. (phone book, dictionary, etc.) *
Use collation strength parameters, PRIMARY, SECONDARY, TERTIARY, and * IDENTICAL to specify the comparison level. * Each unicode character is assigned ordering priority: primary, secondary, * tertiary and no difference. *
Decomposition mode determines how composed characters are handled for * Unicode. *
NO_DECOMPOSITION is the fastest, but does not produce correct results, * except for languages that do not use accents. You should generally use at * least CANONICAL_DECOMPOSITION. FULL_DECOMPOSITION decomposes even more * characters. For example, it maps the Japanese half-width kana characters * to their normalized characters. For more information on the precise * mappings used, see http://unicode.org. * *
LESS, EQUAL, GREATER identifies the result * of unicode text strings comparison. *
Use the static method Collator::createInstance() to instantiate the class * by passing the desired locale as the argument. *
Example of use: *
* . ErrorCode status = ZERO_ERROR;
* . // Compare two strings in the default locale
* . Collator *myCollation = Collator::createInstance(status);
* . if (FAILURE(status)) return;
* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC");
* . delete myCollation;
*
* Another example: *
* . // compare two strings in French
* . Collator *myCollation = Collator.createInstance(Locale::FRANCE, status);
* . if (FAILURE(status)) return;
* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC");
*
* The following example demonstrates different ways of comparing two * strings: *
* . UnicodeString a("abcdefgh"), b("ijklmnop");
*
* . // This comparision is not as fast as collation keys.
* . // For multiple comparison, use CollationKey. Please see CollationKey
* . // class description for more description
* . if (myCollation->compare(a, b) == Collator::LESS) { // ... }
*
* . // Faster than compare when collation keys are cached
* . ErrorCode aKeyStatus, bKeyStatus;
* . CollationKey aKey, bKey;
* . aKey = myCollation->getCollationKey(a, aKey, aKeyStatus);
* . bKey = myCollation->getCollationKey(b, bKey, bKeyStatus);
* . if (SUCCESS(aKeyStatus)) && SUCCESS(bKeyStatus))
* . if (aKey.compareTo(bKey) == Collator::LESS)
* . { // ... }
*
*
* NOTE: Two collation keys from different collations cannot be * compared. Incorrect comparison result will be returned if you compare * two collation keys from different collators. * * @see RuleBasedCollator * @see CollationKey * @see Locale * @version 1.7 1/14/97 * @author Helena Shih */ #ifdef NLS_MAC #pragma export on #endif class T_COLLATE_API Collator { public : /** * NO_DECOMPOSITION : Accented characters will not be decomposed for sorting. * Please see class description for more details. * CANONICAL_DECOMPOSITION : Characters that are canonical variants according * to Unicode 2.0 will be decomposed for sorting. This is the default setting. * FULL_DECOMPOSITION : Both canonical variants and compatibility variants be * decomposed for sorting. */ enum EDecompositionMode { NO_DECOMPOSITION, CANONICAL_DECOMPOSITION, FULL_DECOMPOSITION }; /** * 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". * * ECollationStrength is also used to determine the strength of sort keys * generated from Collator objects. */ enum ECollationStrength { PRIMARY, SECONDARY, TERTIARY, IDENTICAL }; /** * 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 Collator#compare */ enum EComparisonResult { LESS = -1, EQUAL = 0, GREATER = 1 }; /** * Destructor */ virtual ~Collator(); /** * Returns true if "other" is the same as "this" */ virtual t_bool operator==(const Collator& other) const; /** * Returns true if "other" is not the same as "this". */ virtual t_bool operator!=(const Collator& other) const; /** * Makes a shallow copy of the current object. */ virtual Collator* clone() const = 0; /** * Creates the collator object for the current default locale. * The default locale is determined by Locale::getDefault. * @return the collation object of the default locale.(for example, en_US) * @see Locale#getDefault * The ErrorCode& 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 SUCCESS(err). If you wish more detailed information, you * can check for informational error results which still indicate success. * 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. 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. */ static Collator* createInstance( ErrorCode& err); /** * 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. * @param desiredLocale the desired locale to create the collation table * with. * @return the created table-based collation object based on the desired * locale. * @see Locale * @see ResourceLoader * The ErrorCode& 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 SUCCESS(err). If you wish more detailed information, you * can check for informational error results which still indicate success. * 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. 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. */ static Collator* createInstance( const Locale& loc, ErrorCode& err); /** * The following methods are obsolete in our current APIs. Some methods * were renamed in JDK 1.1. The older versions of the methods will be kept * around for compatibility but will be made obsolete in the future. */ // From createInstance static Collator* createDefault(ErrorCode& err); static Collator* createDefault(const Locale& loc, ErrorCode& err); // comparison /** * 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. *
Example of use: *
* . ErrorCode status = ZERO_ERROR;
* . Collator *myCollation = Collator::createInstance(Locale::US, status);
* . if (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", "ABC");
* . myCollation->setStrength(Collator::TERTIARY);
* . // result would be Collator::LESS (abc" <<< "ABC")
* . // (with tertiary difference between "abc" and "ABC")
* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC");
*
* @param source the source string to be compared with.
* @param target the string that is to be compared with the source string.
* @return 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
**/
virtual EComparisonResult compare( const UnicodeString& source,
const UnicodeString& target) const = 0;
/**
* Does the same thing as compare but limits the comparison to a specified length
* Example of use: *
* . ErrorCode status = ZERO_ERROR;
* . Collator *myCollation = Collator::createInstance(Locale::US, status);
* . if (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", "ABC",3);
* . myCollation->setStrength(Collator::TERTIARY);
* . // result would be Collator::LESS (abc" <<< "ABC")
* . // (with tertiary difference between "abc" and "ABC")
* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC",3);
*
* @param source the source string to be compared with.
* @param target the string that is to be compared with the source string.
* @param length the length the comparison is limitted to
* @return 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.
**/
virtual EComparisonResult compare( const UnicodeString& source,
const UnicodeString& target,
t_int32 length) const = 0;
/** 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. *
Example of use: *
* . ErrorCode status = ZERO_ERROR;
* . Collator *myCollation = Collator::createInstance(Locale::US, status);
* . if (FAILURE(status)) return;
* . myCollation->setStrength(Collator::PRIMARY);
* . ErrorCode key1Status, key2Status;
* . CollationKey CollationKey1
* . CollationKey1 = myCollation->getCollationKey("abc", CollationKey1, key1Status);
* . CollationKey CollationKey2
* . CollationKey2 = myCollation->getCollationKey("ABC", CollationKey2, key2Status);
* . if (FAILURE(key1Status) || FAILURE(key2Status)) { delete myCollation; return; }
* . // Use CollationKey::compare() to compare the sort keys
* . // result would be 0 (CollationKey1 == CollationKey2)
* . int result = CollationKey1.compare(CollationKey2);
* . myCollation->setStrength(Collator::TERTIARY);
* . CollationKey1 = myCollation->getCollationKey("abc", CollationKey1, key1Status);
* . CollationKey2 = myCollation->getCollationKey("ABC", CollationKey2, key2Status);
* . if (FAILURE(key1Status) || FAILURE(key2Status)) { delete myCollation; return; }
* . // Use CollationKey::compareTo to compare the collation keys
* . // result would be -1 (CollationKey1 < CollationKey2)
* . result = CollationKey1.compareTo(CollationKey2);
* . delete myCollation;
*
* If the source string is null, a null collation key will be returned. * @param source the source string to be transformed into a sort key. * @param key the collation key to be filled in * @return the collation key of the string based on the collation rules. * @see CollationKey#compare */ virtual CollationKey& getCollationKey( const UnicodeString& source, CollationKey& key, ErrorCode& status) const = 0; /** * Transforms the string into a unsigned short array that can be compared, * the caller owns the returned array. *
Example of use: *
* . ErrorCode status = ZERO_ERROR;
* . Collator *myCollation = Collator::createInstance(Locale::US, status);
* . if (FAILURE(status)) return;
* . myCollation->setStrength(Collator::PRIMARY);
* . ErrorCode key1Status, key2Status;
* . t_uint16 *array1 = 0;
* . t_uint16 *array2 = 0;
* . t_int32 array1Count, array2Count;
* . array1 = myCollation->getCollationKey("abc", array1Count, key1Status);
* . array2 = myCollation->getCollationKey("ABC", array2Count, key2Status);
* . if (FAILURE(key1Status) || FAILURE(key2Status)) { delete myCollation; return; }
* . // Use a loop to compare the two arrays
* . delete array1;
* . delete array2;
* . delete myCollation;
*
* If the source string is null, a null collation key will be returned. * @param source the source string to be transformed into a sort key. * @param count returns the number of elements in the returned array. * @return the collation key value array of the string based on the collation rules. * @see CollationKey#compare */ virtual UniChar* createCollationKeyValues( const UnicodeString& source, t_int32& count, ErrorCode& status) const = 0; /** * The following method is obsolete in our current APIs. Some methods * were renamed in JDK 1.1. The older versions of the methods will be kept * around for compatibility but will be made obsolete in the future. */ virtual SortKey& getSortKey( const UnicodeString& source, SortKey& key, ErrorCode& status) const; /** * Generates the hash code for the collation object */ virtual t_int32 hashCode() const = 0; /** * Convenience method for comparing two strings based on * the collation rules. * @param source the source string to be compared with. * @param target the target string to be compared with. * @return true if the first string is greater than the second one, * according to the collation rules. false, otherwise. * @see Collator#compare */ t_bool greater( const UnicodeString& source, const UnicodeString& target) const; /** * Convenience method for comparing two strings based on the collation * rules. * @param source the source string to be compared with. * @param target the target string to be compared with. * @return true if the first string is greater than or equal to the * second one, according to the collation rules. false, otherwise. * @see Collator#compare */ t_bool greaterOrEqual( const UnicodeString& source, const UnicodeString& target) const; /** * Convenience method for comparing two strings based on the collation * rules. * @param source the source string to be compared with. * @param target the target string to be compared with. * @return true if the strings are equal according to the collation * rules. false, otherwise. * @see Collator#compare */ t_bool equals( const UnicodeString& source, const UnicodeString& target) const; // getter/setter /** * Get the decomposition mode of the collator object. * @return the decomposition mode * @see Collator#setDecomposition */ EDecompositionMode getDecomposition() const; /** * Set the decomposition mode of the collator object. success is equal * to ILLEGAL_ARGUMENT_ERROR if error occurs. * @param the new decomposition mode * @see Collator#getDecomposition */ void setDecomposition( EDecompositionMode mode); /** * 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. * @return the current comparison level. * @see Collator#setStrength */ ECollationStrength getStrength() const; /** * Sets the minimum strength to be used in comparison or transformation. *
Example of use: *
* . ErrorCode status = ZERO_ERROR;
* . Collator *myCollation = Collator::createInstance(Locale::US, status);
* . if (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 Collator#getStrength
* @param newStrength the new comparison level.
*/
void setStrength( ECollationStrength newStrength);
/**
* Get name of the object for the desired Locale, in the desired langauge
* @param objectLocale must be from getAvailableLocales
* @param displayLocale specifies the desired locale for output
* @param name the fill-in parameter of the return value
* @return display-able name of the object for the object locale in the
* desired language
*/
static UnicodeString& getDisplayName( const Locale& objectLocale,
const Locale& displayLocale,
UnicodeString& name) ;
/**
* Get name of the object for the desired Locale, in the langauge of the
* default locale.
* @param objectLocale must be from getAvailableLocales
* @param name the fill-in parameter of the return value
* @return name of the object for the desired locale in the default
* language
*/
static UnicodeString& getDisplayName( const Locale& objectLocale,
UnicodeString& name) ;
/**
* Get the set of Locales for which Collations are installed
* @param count the output parameter of number of elements in the locale list
* @return the list of available locales which collations are installed
*/
static const Locale* getAvailableLocales(t_int32& count);
/**
* 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.
*
* Concrete subclasses of Format must implement getDynamicClassID()
* and also a static method and data member:
*
* static ClassID getStaticClassID() { return (ClassID)&fgClassID; }
* static char fgClassID;
*
* @return 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.
*/
virtual ClassID getDynamicClassID() const = 0;
/** Netscape
* Returns the version number for the collator
* format is major.minor ie: 01.00
*/
virtual const char* getVersionNumber();
protected:
/**
* Constructors
*/
Collator();
Collator(const Collator& other);
/**
* Assignment operator
*/
const Collator& operator=(const Collator& other);
//--------------------------------------------------------------------------
private:
ECollationStrength strength;
EDecompositionMode decmp;
};
#ifdef NLS_MAC
#pragma export off
#endif
inline t_bool
Collator::operator==(const Collator& other) const
{
t_bool result;
if (this == &other) result = TRUE;
else result = ((strength == other.strength) && (decmp == other.decmp));
return result;
}
inline t_bool
Collator::operator!=(const Collator& other) const
{
t_bool result;
result = !(*this == other);
return result;
}
inline Collator*
Collator::createDefault(ErrorCode& status)
{
return Collator::createInstance(status);
}
inline Collator*
Collator::createDefault(const Locale& loc,
ErrorCode& status)
{
return Collator::createInstance(loc, status);
}
inline SortKey&
Collator::getSortKey( const UnicodeString& source,
SortKey& key,
ErrorCode& status) const
{
return (SortKey&)getCollationKey(source, (CollationKey&)key, status);
}
#endif