From 2aa4a82499d4becd2284cdb482213d541b8804dd Mon Sep 17 00:00:00 2001
From: Daniel Baumann
+*
+* Like other locale-sensitive classes, you can use the static factory method,
+*
+* The following example shows how to compare two strings using the
+*
+* You can set a 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.
+* 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.
+* Collator
for the default locale.
+* \htmlonly\endhtmlonly
+*
\endhtmlonly
+*
+* \code
+* // 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;
+* \endcode
+*
+* \htmlonlyCollator
'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.
+* \htmlonly\endhtmlonly
+*
\endhtmlonly
+*
+* The
+* \code
+* //Get the Collator for US English and set its strength to PRIMARY
+* UErrorCode success = U_ZERO_ERROR;
+* Collator* usCollator = Collator::createInstance(Locale::getUS(), success);
+* usCollator->setStrength(Collator::PRIMARY);
+* if (usCollator->compare("abc", "ABC") == 0)
+* cout << "'abc' and 'ABC' strings are equivalent with strength PRIMARY" << endl;
+* \endcode
+*
+* \htmlonlygetSortKey
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.
+*
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); + *+ * @param source the source string array to be compared with. + * @param sourceLength the length of the source string array. If this value + * is equal to -1, the string array is null-terminated. + * @param target the string that is to be compared with the source string. + * @param targetLength the length of the target string array. If this value + * is equal to -1, the string array is null-terminated. + * @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 + * @deprecated ICU 2.6 use the overload with UErrorCode & + */ + virtual EComparisonResult compare(const char16_t* source, int32_t sourceLength, + const char16_t* target, int32_t targetLength) + const; +#endif // U_FORCE_HIDE_DEPRECATED_API + + /** + * 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. + * @param source the source string array to be compared with. + * @param sourceLength the length of the source string array. If this value + * is equal to -1, the string array is null-terminated. + * @param target the string that is to be compared with the source string. + * @param targetLength the length of the target string array. If this value + * is equal to -1, the string array is null-terminated. + * @param status possible error code + * @return 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 + */ + virtual UCollationResult compare(const char16_t* source, int32_t sourceLength, + const char16_t* target, int32_t targetLength, + UErrorCode &status) const = 0; + + /** + * 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. + * @param sIter the first ("source") string iterator + * @param tIter the second ("target") string iterator + * @param status ICU status + * @return UCOL_LESS, UCOL_EQUAL or UCOL_GREATER + * @stable ICU 4.2 + */ + virtual UCollationResult compare(UCharIterator &sIter, + UCharIterator &tIter, + UErrorCode &status) const; + + /** + * 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. + * @param source the first UTF-8 string + * @param target the second UTF-8 string + * @param status ICU status + * @return UCOL_LESS, UCOL_EQUAL or UCOL_GREATER + * @stable ICU 4.2 + */ + virtual UCollationResult compareUTF8(const StringPiece &source, + const StringPiece &target, + UErrorCode &status) const; + + /** + * 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. + * + * @param source the source string to be transformed into a sort key. + * @param key the collation key to be filled in + * @param status the error code status. + * @return the collation key of the string based on the collation rules. + * @see CollationKey#compare + * @stable ICU 2.0 + */ + 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. 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. + * + * @param source the source string to be transformed into a sort key. + * @param sourceLength length of the collation key + * @param key the collation key to be filled in + * @param status the error code status. + * @return the collation key of the string based on the collation rules. + * @see CollationKey#compare + * @stable ICU 2.0 + */ + virtual CollationKey& getCollationKey(const char16_t*source, + int32_t sourceLength, + CollationKey& key, + UErrorCode& status) const = 0; + /** + * Generates the hash code for the collation object + * @stable ICU 2.0 + */ + virtual int32_t hashCode(void) const = 0; + +#ifndef U_FORCE_HIDE_DEPRECATED_API + /** + * Gets the locale of the Collator + * + * @param type can be either requested, valid or actual locale. For more + * information see the definition of ULocDataLocaleType in + * uloc.h + * @param status the error code status. + * @return 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. + */ + virtual Locale getLocale(ULocDataLocaleType type, UErrorCode& status) const = 0; +#endif // U_FORCE_HIDE_DEPRECATED_API + + /** + * 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 + * @stable ICU 2.0 + */ + UBool 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 + * @stable ICU 2.0 + */ + UBool 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 + * @stable ICU 2.0 + */ + UBool equals(const UnicodeString& source, const UnicodeString& target) const; + +#ifndef U_FORCE_HIDE_DEPRECATED_API + /** + * 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. + * @return the current comparison level. + * @see Collator#setStrength + * @deprecated ICU 2.6 Use getAttribute(UCOL_STRENGTH...) instead + */ + virtual ECollationStrength getStrength(void) const; + + /** + * Sets the minimum strength to be used in comparison or transformation. + *
Example of use: + *
+ * \code + * UErrorCode status = U_ZERO_ERROR; + * Collator*myCollation = Collator::createInstance(Locale::getUS(), 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"); + * \endcode + *+ * @see Collator#getStrength + * @param newStrength the new comparison level. + * @deprecated ICU 2.6 Use setAttribute(UCOL_STRENGTH...) instead + */ + virtual void setStrength(ECollationStrength newStrength); +#endif // U_FORCE_HIDE_DEPRECATED_API + + /** + * Retrieves the reordering codes for this collator. + * @param dest The array to fill with the script ordering. + * @param destCapacity The length of dest. If it is 0, then dest may be NULL and the function + * will only return the length of the result without writing any codes (pre-flighting). + * @param status A reference to an error code value, which must not indicate + * a failure before the function call. + * @return The length of the script ordering array. + * @see ucol_setReorderCodes + * @see Collator#getEquivalentReorderCodes + * @see Collator#setReorderCodes + * @see UScriptCode + * @see UColReorderCode + * @stable ICU 4.8 + */ + virtual int32_t getReorderCodes(int32_t *dest, + int32_t destCapacity, + UErrorCode& status) const; + + /** + * Sets the ordering of scripts for this collator. + * + *
The reordering codes are a combination of script codes and reorder codes. + * @param reorderCodes An array of script codes in the new order. This can be NULL if the + * length is also set to 0. An empty array will clear any reordering codes on the collator. + * @param reorderCodesLength The length of reorderCodes. + * @param status error code + * @see ucol_setReorderCodes + * @see Collator#getReorderCodes + * @see Collator#getEquivalentReorderCodes + * @see UScriptCode + * @see UColReorderCode + * @stable ICU 4.8 + */ + virtual void setReorderCodes(const int32_t* reorderCodes, + int32_t reorderCodesLength, + UErrorCode& status) ; + + /** + * 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. + * + * @param reorderCode The reorder code to determine equivalence for. + * @param dest The array to fill with the script equivalence reordering codes. + * @param destCapacity The length of dest. If it is 0, then dest may be NULL and the + * function will only return the length of the result without writing any codes (pre-flighting). + * @param status A reference to an error code value, which must not indicate + * a failure before the function call. + * @return The length of the of the reordering code equivalence array. + * @see ucol_setReorderCodes + * @see Collator#getReorderCodes + * @see Collator#setReorderCodes + * @see UScriptCode + * @see UColReorderCode + * @stable ICU 4.8 + */ + static int32_t U_EXPORT2 getEquivalentReorderCodes(int32_t reorderCode, + int32_t* dest, + int32_t destCapacity, + UErrorCode& status); + + /** + * Get name of the object for the desired Locale, in the desired language + * @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 + * @stable ICU 2.0 + */ + static UnicodeString& U_EXPORT2 getDisplayName(const Locale& objectLocale, + const Locale& displayLocale, + UnicodeString& name); + + /** + * Get name of the object for the desired Locale, in the language 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 + * @stable ICU 2.0 + */ + static UnicodeString& U_EXPORT2 getDisplayName(const Locale& objectLocale, + UnicodeString& name); + + /** + * 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.
+ * + * @param count the output parameter of number of elements in the locale list + * @return the list of available locales for which collations are installed + * @stable ICU 2.0 + */ + static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count); + + /** + * 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. + * @return a StringEnumeration over the locales available at the time of the call + * @stable ICU 2.6 + */ + static StringEnumeration* U_EXPORT2 getAvailableLocales(void); + + /** + * 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". + * @param status input-output error code + * @return a string enumeration over locale strings. The caller is + * responsible for closing the result. + * @stable ICU 3.0 + */ + static StringEnumeration* U_EXPORT2 getKeywords(UErrorCode& status); + + /** + * Given a keyword, create a string enumeration of all values + * for that keyword that are currently in use. + * @param keyword a particular keyword as enumerated by + * ucol_getKeywords. If any other keyword is passed in, status is set + * to U_ILLEGAL_ARGUMENT_ERROR. + * @param status input-output error code + * @return 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* U_EXPORT2 getKeywordValues(const char *keyword, UErrorCode& status); + + /** + * 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. + * @param keyword one of the keys supported by this service. For now, only + * "collation" is supported. + * @param locale the locale + * @param 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. + * @param status ICU status + * @return a string enumeration over keyword values for the given key and the locale. + * @stable ICU 4.2 + */ + static StringEnumeration* U_EXPORT2 getKeywordValuesForLocale(const char* keyword, const Locale& locale, + UBool commonlyUsed, UErrorCode& status); + + /** + * 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. + * @param keyword a particular keyword as enumerated by + * ucol_getKeywords. + * @param locale the requested locale + * @param 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. + * @param status reference to input-output error code + * @return the functionally equivalent collation locale, or the root + * locale upon error. + * @stable ICU 3.0 + */ + static Locale U_EXPORT2 getFunctionalEquivalent(const char* keyword, const Locale& locale, + UBool& isAvailable, UErrorCode& status); + +#if !UCONFIG_NO_SERVICE + /** + * 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. + * @param toAdopt the Collator instance to be adopted + * @param locale the locale with which the collator will be associated + * @param status the in/out status code, no special meanings are assigned + * @return a registry key that can be used to unregister this collator + * @stable ICU 2.6 + */ + static URegistryKey U_EXPORT2 registerInstance(Collator* toAdopt, const Locale& locale, UErrorCode& status); + + /** + * 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. + * @param toAdopt the CollatorFactory instance to be adopted + * @param status the in/out status code, no special meanings are assigned + * @return a registry key that can be used to unregister this collator + * @stable ICU 2.6 + */ + static URegistryKey U_EXPORT2 registerFactory(CollatorFactory* toAdopt, UErrorCode& status); + + /** + * 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. + * @param key the registry key returned by a previous call to registerInstance + * @param status the in/out status code, no special meanings are assigned + * @return TRUE if the collator for the key was successfully unregistered + * @stable ICU 2.6 + */ + static UBool U_EXPORT2 unregister(URegistryKey key, UErrorCode& status); +#endif /* UCONFIG_NO_SERVICE */ + + /** + * Gets the version information for a Collator. + * @param info the version # information, the result will be filled in + * @stable ICU 2.0 + */ + virtual void getVersion(UVersionInfo info) const = 0; + + /** + * 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. + * @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. + * @stable ICU 2.0 + */ + virtual UClassID getDynamicClassID(void) const = 0; + + /** + * Universal attribute setter + * @param attr attribute type + * @param value attribute value + * @param status to indicate whether the operation went on smoothly or + * there were errors + * @stable ICU 2.2 + */ + virtual void setAttribute(UColAttribute attr, UColAttributeValue value, + UErrorCode &status) = 0; + + /** + * Universal attribute getter + * @param attr attribute type + * @param status to indicate whether the operation went on smoothly or + * there were errors + * @return attribute value + * @stable ICU 2.2 + */ + virtual UColAttributeValue getAttribute(UColAttribute attr, + UErrorCode &status) const = 0; + + /** + * 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. + * @param 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 + * @param 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.) + * @return *this + * @see getMaxVariable + * @stable ICU 53 + */ + virtual Collator &setMaxVariable(UColReorderCode group, UErrorCode &errorCode); + + /** + * Returns the maximum reordering group whose characters are affected by UCOL_ALTERNATE_HANDLING. + * + * The base class implementation returns UCOL_REORDER_CODE_PUNCTUATION. + * @return the maximum variable reordering group. + * @see setMaxVariable + * @stable ICU 53 + */ + virtual UColReorderCode getMaxVariable() const; + +#ifndef U_FORCE_HIDE_DEPRECATED_API + /** + * 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(). + * @param varTop one or more (if contraction) char16_ts to which the variable top should be set + * @param len length of variable top string. If -1 it is considered to be zero terminated. + * @param status error code. If error code is set, the return value is undefined. Errors set by this function are:+ * If standard locale display names are sufficient, Collator instances can + * be registered using registerInstance instead.
+ *+ * Note: if the collators are to be used from C APIs, they must be instances + * of RuleBasedCollator.
+ * + * @stable ICU 2.6 + */ +class U_I18N_API CollatorFactory : public UObject { +public: + + /** + * Destructor + * @stable ICU 3.0 + */ + virtual ~CollatorFactory(); + + /** + * Return true if this factory is visible. Default is true. + * If not visible, the locales supported by this factory will not + * be listed by getAvailableLocales. + * @return true if the factory is visible. + * @stable ICU 2.6 + */ + virtual UBool visible(void) const; + + /** + * Return a collator for the provided locale. If the locale + * is not supported, return NULL. + * @param loc the locale identifying the collator to be created. + * @return a new collator if the locale is supported, otherwise NULL. + * @stable ICU 2.6 + */ + virtual Collator* createCollator(const Locale& loc) = 0; + + /** + * Return the name of the collator for the objectLocale, localized for the displayLocale. + * If objectLocale is not supported, or the factory is not visible, set the result string + * to bogus. + * @param objectLocale the locale identifying the collator + * @param displayLocale the locale for which the display name of the collator should be localized + * @param result an output parameter for the display name, set to bogus if not supported. + * @return the display name + * @stable ICU 2.6 + */ + virtual UnicodeString& getDisplayName(const Locale& objectLocale, + const Locale& displayLocale, + UnicodeString& result); + + /** + * Return an array of all the locale names directly supported by this factory. + * The number of names is returned in count. This array is owned by the factory. + * Its contents must never change. + * @param count output parameter for the number of locales supported by the factory + * @param status the in/out error code + * @return a pointer to an array of count UnicodeStrings. + * @stable ICU 2.6 + */ + virtual const UnicodeString * getSupportedIDs(int32_t &count, UErrorCode& status) = 0; +}; +#endif /* UCONFIG_NO_SERVICE */ + +// Collator inline methods ----------------------------------------------- + +U_NAMESPACE_END + +#endif /* #if !UCONFIG_NO_COLLATION */ + +#endif /* U_SHOW_CPLUSPLUS_API */ + +#endif -- cgit v1.2.3