/*
******************************************************************************
* Copyright (C) 1996-2001, International Business Machines *
* Corporation and others. All Rights Reserved. *
******************************************************************************
*/
/**
* File coll.h
*
* Created by: Helena Shih
*
* Modification History:
*
* Date Name Description
* 02/5/97 aliu Modified createDefault to load collation data from
* binary files when possible. Added related methods
* createCollationFromFile, chopLocale, createPathName.
* 02/11/97 aliu Added members addToCache, findInCache, and fgCache.
* 02/12/97 aliu Modified to create objects from RuleBasedCollator cache.
* Moved cache out of Collation class.
* 02/13/97 aliu Moved several methods out of this class and into
* RuleBasedCollator, with modifications. Modified
* createDefault() to call new RuleBasedCollator(Locale&)
* constructor. General clean up and documentation.
* 02/20/97 helena Added clone, operator==, operator!=, operator=, copy
* constructor and getDynamicClassID.
* 03/25/97 helena Updated with platform independent data types.
* 05/06/97 helena Added memory allocation error detection.
* 06/20/97 helena Java class name change.
* 09/03/97 helena Added createCollationKeyValues().
* 02/10/98 damiba Added compare() with length as parameter.
* 04/23/99 stephen Removed EDecompositionMode, merged with
* Normalizer::EMode.
* 11/02/99 helena Collator performance enhancements. Eliminates the
* UnicodeString construction and special case for NO_OP.
* 11/23/99 srl More performance enhancements. Inlining of
* critical accessors.
* 05/15/00 helena Added version information API.
* 01/29/01 synwee Modified into a C++ wrapper which calls C apis
* (ucoll.h).
*/
#ifndef COLL_H
#define COLL_H
#include "unicode/ucol.h"
#include "unicode/normlzr.h"
#include "unicode/locid.h"
U_NAMESPACE_BEGIN
class CollationKey;
/**
* 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.
*
*
* \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
*
*
*
* 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.
*
*
* \code
* //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;
* \endcode
*
*
*
* 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 RuleBasedCollator
* @see CollationKey
* @see CollationElementIterator
* @see Locale
* @see Normalizer
* @version 2.0 11/15/01
*/
class U_I18N_API Collator
{
public:
// Collator public enums -----------------------------------------------
/**
* 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.
* @stable
*/
enum ECollationStrength
{
PRIMARY = 0,
SECONDARY = 1,
TERTIARY = 2,
QUATERNARY = 3,
IDENTICAL = 15
};
/**
* 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
* @stable
*/
enum EComparisonResult
{
LESS = -1,
EQUAL = 0,
GREATER = 1
};
// Collator public destructor -----------------------------------------
/**
* Destructor
* @stable
*/
virtual ~Collator();
// Collator public methods --------------------------------------------
/**
* Returns true if "other" is the same as "this"
* @param other Collator object to be compared
* @return true if other is the same as this.
* @stable
*/
virtual UBool operator==(const Collator& other) const;
/**
* Returns true if "other" is not the same as "this".
* @param other Collator object to be compared
* @return true if other is not the same as this.
* @stable
*/
virtual UBool operator!=(const Collator& other) const;
/**
* Makes a shallow copy of the current object.
* @return a copy of this object
* @stable
*/
virtual Collator* clone(void) const = 0;
/**
* 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.
* @return the collation object of the default locale.(for example, en_US)
* @see Locale#getDefault
* @stable
*/
static Collator* createInstance(UErrorCode& 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.
* 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.
* @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
* @stable
*/
static Collator* createInstance(const Locale& loc, UErrorCode& err);
/**
* Create a Collator with a specific version.
* This is the same as createInstance(loc, err) except that getVersion() of
* the returned object is guaranteed to be the same as the version
* parameter.
* This is designed to be used to open the same collator for a given
* locale even when ICU is updated.
* The same locale and version guarantees the same sort keys and
* comparison results.
*
* @param loc The locale ID for which to open a collator.
* @param version The requested collator version.
* @param err A reference to a UErrorCode,
* must not indicate a failure before calling this function.
* @return A pointer to a Collator, or 0 if an error occurred
* or a collator with the requested version is not available.
*
* @see getVersion
* @draft ICU 1.8
*/
static Collator *createInstance(const Locale &loc, UVersionInfo version, UErrorCode &err);
/**
* 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.
* @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
* @stable
**/
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
* @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.
* @stable
*/
virtual EComparisonResult compare(const UnicodeString& source,
const UnicodeString& target,
int32_t length) const = 0;
/**
* 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.
* @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
* @stable
*/
virtual EComparisonResult compare(const UChar* source, int32_t sourceLength,
const UChar* target, int32_t targetLength)
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.
* 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
* @stable
*/
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. 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.
* @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
* @return the collation key of the string based on the collation rules.
* @see CollationKey#compare
* @stable
*/
virtual CollationKey& getCollationKey(const UChar*source,
int32_t sourceLength,
CollationKey& key,
UErrorCode& status) const = 0;
/**
* Generates the hash code for the collation object
* @stable
*/
virtual int32_t hashCode(void) const = 0;
/**
* Gets the locale of the Collator
* @draft ICU 2.1
*/
virtual const Locale getLocale(UErrorCode& status) 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
* @stable
*/
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
*/
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
*/
UBool equals(const UnicodeString& source, const UnicodeString& target) const;
/**
* 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
* @stable
*/
virtual ECollationStrength getStrength(void) const = 0;
/**
* 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::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");
* \endcode
*
* @see Collator#getStrength
* @param newStrength the new comparison level.
* @stable
*/
virtual void setStrength(ECollationStrength newStrength) = 0;
/**
* 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
* @stable
*/
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
* @stable
*/
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
* @stable
*/
static const Locale* getAvailableLocales(int32_t& count);
/**
* Gets the version information for a Collator.
* @param info the version # information, the result will be filled in
* @stable
*/
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.
* Concrete subclasses of Format must implement getDynamicClassID() and also
* a static method and data member:
* static UClassID getStaticClassID()
* {
* return (UClassID)&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.
* @stable
*/
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
* @draft ICU 1.8
*/
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
* @draft ICU 1.8
*/
virtual UColAttributeValue getAttribute(UColAttribute attr,
UErrorCode &status) = 0;
/**
* Sets the variable top to a collation element value of a string supplied.
* @param varTop one or more (if contraction) UChars 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:
* 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
* @return a 32 bit value containing the value of the variable top in upper 16 bits. Lower 16 bits are undefined
* @draft ICU 2.0
*/
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.
* @param varTop an UnicodeString size 1 or more (if contraction) of UChars to which the variable top should be set
* @param 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
* @return a 32 bit value containing the value of the variable top in upper 16 bits. Lower 16 bits are undefined
* @draft ICU 2.0
*/
virtual uint32_t setVariableTop(const UnicodeString varTop, UErrorCode &status) = 0;
/**
* Sets the variable top to a collation element value supplied. Variable top is set to the upper 16 bits.
* Lower 16 bits are ignored.
* @param varTop CE value, as returned by setVariableTop or ucol)getVariableTop
* @param status error code (not changed by function)
* @draft ICU 2.0
*/
virtual void setVariableTop(const uint32_t varTop, UErrorCode &status) = 0;
/**
* Gets the variable top value of a Collator.
* Lower 16 bits are undefined and should be ignored.
* @param status error code (not changed by function). If error code is set, the return value is undefined.
* @draft ICU 2.0
*/
virtual uint32_t getVariableTop(UErrorCode &status) const = 0;
/**
* Thread safe cloning operation
* @return pointer to the new clone, user should remove it.
* @draft ICU 1.8
*/
virtual Collator* safeClone(void) = 0;
/**
* 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().
* @param source string to be processed.
* @param result buffer to store result in. If NULL, number of bytes needed
* will be returned.
* @param resultLength length of the result buffer. If if not enough the
* buffer will be filled to capacity.
* @return Number of bytes needed for storing the sort key
* @draft ICU 1.8
*/
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 UChar buffer.
* Sort key byte arrays are zero-terminated and can be compared using
* strcmp().
* @param source string to be processed.
* @param sourceLength length of string to be processed.
* If -1, the string is 0 terminated and length will be decided by the
* function.
* @param result buffer to store result in. If NULL, number of bytes needed
* will be returned.
* @param resultLength length of the result buffer. If if not enough the
* buffer will be filled to capacity.
* @return Number of bytes needed for storing the sort key
* @draft ICU 1.8
*/
virtual int32_t getSortKey(const UChar*source, int32_t sourceLength,
uint8_t*result, int32_t resultLength) const = 0;
// start deprecated APIs
/**
* Get the decomposition mode of the Collator object.
* @return the decomposition mode
* @see Collator#setDecomposition
* @deprecated To be removed after 2002-sep-30; use getAttribute().
*/
virtual Normalizer::EMode getDecomposition(void) const = 0;
/**
* Set the decomposition mode of the Collator object. success is equal to
* U_ILLEGAL_ARGUMENT_ERROR if error occurs.
* @param the new decomposition mode
* @see Collator#getDecomposition
* @deprecated To be removed after 2002-sep-30; use setAttribute().
*/
virtual void setDecomposition(Normalizer::EMode mode) = 0;
protected:
// Collator protected constructors -------------------------------------
/**
* 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.
*/
Collator();
/**
* 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.
* @param collationStrength collation strength
* @param decompositionMode
*/
Collator(UCollationStrength collationStrength,
UNormalizationMode decompositionMode);
/**
* Copy constructor.
* @param other Collator object to be copied from
*/
Collator(const Collator& other);
// Collator protected methods -----------------------------------------
private:
// Collator private data members ---------------------------------------
/*
synwee : removed as attributes to be handled by child class
UCollationStrength strength;
Normalizer::EMode decmp;
*/
/* This is useless information */
/* static const UVersionInfo fVersion;*/
};
// Collator inline methods -----------------------------------------------
inline UBool Collator::operator==(const Collator& other) const
{
return (UBool)(this == &other);
}
inline UBool Collator::operator!=(const Collator& other) const
{
return (UBool)!(*this == other);
}
/*
synwee : removed since there's no attribute to be retrieved here
inline UCollationStrength Collator::getStrength() const
{
return strength;
}
inline Normalizer::EMode Collator::getDecomposition() const
{
return decmp;
}
*/
U_NAMESPACE_END
#endif