515 lines
22 KiB
C++
515 lines
22 KiB
C++
/*
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*******************************************************************************
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* *
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* COPYRIGHT: *
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* (C) Copyright Taligent, Inc., 1996 *
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* (C) Copyright International Business Machines Corporation, 1996-1999 *
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* Licensed Material - Program-Property of IBM - All Rights Reserved. *
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* US Government Users Restricted Rights - Use, duplication, or disclosure *
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* restricted by GSA ADP Schedule Contract with IBM Corp. *
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* *
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*******************************************************************************
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*/
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//=============================================================================
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//
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// File coll.h
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//
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//
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//
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// Created by: Helena Shih
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//
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// Modification History:
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//
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// Date Name Description
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// 02/5/97 aliu Modified createDefault to load collation data from
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// binary files when possible. Added related methods
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// createCollationFromFile, chopLocale, createPathName.
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// 02/11/97 aliu Added members addToCache, findInCache, and fgCache.
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// 02/12/97 aliu Modified to create objects from RuleBasedCollator cache.
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// Moved cache out of Collation class.
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// 02/13/97 aliu Moved several methods out of this class and into
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// RuleBasedCollator, with modifications. Modified
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// createDefault() to call new RuleBasedCollator(Locale&)
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// constructor. General clean up and documentation.
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// 02/20/97 helena Added clone, operator==, operator!=, operator=, copy
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// constructor and getDynamicClassID.
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// 03/25/97 helena Updated with platform independent data types.
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// 05/06/97 helena Added memory allocation error detection.
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// 6/20/97 helena Java class name change.
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// 09/03/97 helena Added createCollationKeyValues().
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// 02/10/98 damiba Added compare() with length as parameter.
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// 04/23/99 stephen Removed EDecompositionMode, merged with
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// Normalizer::EMode.
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//=============================================================================
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#ifndef COLL_H
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#define COLL_H
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#include "locid.h"
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#include "utypes.h"
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#include "unistr.h"
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#include "normlzr.h"
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class CollationKey;
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/**
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* The <code>Collator</code> class performs locale-sensitive
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* <code>String</code> comparison. You use this class to build
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* searching and sorting routines for natural language text.
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*
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* <p>
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* <code>Collator</code> is an abstract base class. Subclasses
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* implement specific collation strategies. One subclass,
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* <code>RuleBasedCollator</code>, is currently provided
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* and is applicable to a wide set of languages. Other
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* subclasses may be created to handle more specialized needs.
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*
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* <p>
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* Like other locale-sensitive classes, you can use the static
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* factory method, <code>getInstance</code>, to obtain the appropriate
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* <code>Collator</code> object for a given locale. You will only need
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* to look at the subclasses of <code>Collator</code> if you need
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* to understand the details of a particular collation strategy or
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* if you need to modify that strategy.
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*
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* <p>
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* The following example shows how to compare two strings using
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* the <code>Collator</code> for the default locale.
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* <blockquote>
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* <pre>
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* // Compare two strings in the default locale
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* UErrorCode success = U_ZERO_ERROR;
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* Collator* myCollator = Collator::createInstance(success);
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* if( myCollator->compare("abc", "ABC") < 0 ) {
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* cout << "abc is less than ABC" << endl;
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* }else{
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* cout << "abc is greater than or equal to ABC" << endl;
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* }
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* </pre>
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* </blockquote>
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*
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* <p>
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* You can set a <code>Collator</code>'s <em>strength</em> property
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* to determine the level of difference considered significant in
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* comparisons. Four strengths are provided: <code>PRIMARY</code>,
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* <code>SECONDARY</code>, <code>TERTIARY</code>, and <code>IDENTICAL</code>.
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* The exact assignment of strengths to language features is
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* locale dependant. For example, in Czech, "e" and "f" are considered
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* primary differences, while "e" and "\u00EA" are secondary differences,
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* "e" and "E" are tertiary differences and "e" and "e" are identical.
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* The following shows how both case and accents could be ignored for
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* US English.
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* <blockquote>
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* <pre>
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* //Get the Collator for US English and set its strength to PRIMARY
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* UErrorCode success = U_ZERO_ERROR;
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* Collator* usCollator = Collator::createInstance(Locale::US, success);
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* usCollator->setStrength(Collator::PRIMARY);
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* if( usCollator->compare("abc", "ABC") == 0 ) {
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* cout << "'abc' and 'ABC' strings are equivalent with strength PRIMARY" << endl;
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* }
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* </pre>
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* </blockquote>
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* <p>
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* For comparing <code>String</code>s exactly once, the <code>compare</code>
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* method provides the best performance. When sorting a list of
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* <code>String</code>s however, it is generally necessary to compare each
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* <code>String</code> multiple times. In this case, <code>CollationKey</code>s
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* provide better performance. The <code>CollationKey</code> class converts
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* a <code>String</code> to a series of bits that can be compared bitwise
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* against other <code>CollationKey</code>s. A <code>CollationKey</code> is
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* created by a <code>Collator</code> object for a given <code>String</code>.
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* <p>
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* <strong>Note:</strong> <code>Collator</code>s with different Locale,
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* CollationStrength and DecompositionMode settings will return different
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* sort orders for the same set of strings. Locales have specific
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* collation rules, and the way in which secondary and tertiary differences
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* are taken into account, for example, will result in a different sorting order
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* for same strings.
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* <p>
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*
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* @see RuleBasedCollator
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* @see CollationKey
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* @see CollationElementIterator
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* @see Locale
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* @see Normalizer
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* @version 1.7 1/14/97
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* @author Helena Shih
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*/
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class U_I18N_API Collator
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{
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public :
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/**
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* Base letter represents a primary difference. Set comparison
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* level to PRIMARY to ignore secondary and tertiary differences.
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* Use this to set the strength of a Collator object.
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* Example of primary difference, "abc" < "abd"
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*
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* Diacritical differences on the same base letter represent a secondary
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* difference. Set comparison level to SECONDARY to ignore tertiary
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* differences. Use this to set the strength of a Collator object.
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* Example of secondary difference, "<22>" >> "a".
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*
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* Uppercase and lowercase versions of the same character represents a
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* tertiary difference. Set comparison level to TERTIARY to include
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* all comparison differences. Use this to set the strength of a Collator
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* object.
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* Example of tertiary difference, "abc" <<< "ABC".
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*
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* Two characters are considered "identical" when they have the same
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* unicode spellings.
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* For example, "<22>" == "<22>".
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*
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* ECollationStrength is also used to determine the strength of sort keys
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* generated from Collator objects.
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*/
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enum ECollationStrength {
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PRIMARY = 0,
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SECONDARY = 1,
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TERTIARY = 2,
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IDENTICAL = 3
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};
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/**
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* LESS is returned if source string is compared to be less than target
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* string in the compare() method.
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* EQUAL is returned if source string is compared to be equal to target
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* string in the compare() method.
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* GREATER is returned if source string is compared to be greater than
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* target string in the compare() method.
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* @see Collator#compare
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*/
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enum EComparisonResult {
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LESS = -1,
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EQUAL = 0,
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GREATER = 1
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};
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/**
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* Destructor
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*/
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virtual ~Collator();
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/**
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* Returns true if "other" is the same as "this"
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*/
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virtual bool_t operator==(const Collator& other) const;
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/**
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* Returns true if "other" is not the same as "this".
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*/
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virtual bool_t operator!=(const Collator& other) const;
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/**
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* Makes a shallow copy of the current object.
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*/
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virtual Collator* clone(void) const = 0;
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/**
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* Creates the collator object for the current default locale.
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* The default locale is determined by Locale::getDefault.
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* @return the collation object of the default locale.(for example, en_US)
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* @see Locale#getDefault
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* The UErrorCode& err parameter is used to return status information to the user.
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* To check whether the construction succeeded or not, you should check
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* the value of SUCCESS(err). If you wish more detailed information, you
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* can check for informational error results which still indicate success.
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* U_USING_FALLBACK_ERROR indicates that a fall back locale was used. For
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* example, 'de_CH' was requested, but nothing was found there, so 'de' was
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* used. U_USING_DEFAULT_ERROR indicates that the default locale data was
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* used; neither the requested locale nor any of its fall back locales
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* could be found.
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* The caller owns the returned object and is responsible for deleting it.
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*/
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static Collator* createInstance( UErrorCode& err);
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/**
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* Gets the table-based collation object for the desired locale. The
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* resource of the desired locale will be loaded by ResourceLoader.
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* Locale::ENGLISH is the base collation table and all other languages are
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* built on top of it with additional language-specific modifications.
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* @param desiredLocale the desired locale to create the collation table
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* with.
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* @return the created table-based collation object based on the desired
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* locale.
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* @see Locale
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* @see ResourceLoader
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* The UErrorCode& err parameter is used to return status information to the user.
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* To check whether the construction succeeded or not, you should check
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* the value of SUCCESS(err). If you wish more detailed information, you
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* can check for informational error results which still indicate success.
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* U_USING_FALLBACK_ERROR indicates that a fall back locale was used. For
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* example, 'de_CH' was requested, but nothing was found there, so 'de' was
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* used. U_USING_DEFAULT_ERROR indicates that the default locale data was
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* used; neither the requested locale nor any of its fall back locales
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* could be found.
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* The caller owns the returned object and is responsible for deleting it.
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*/
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static Collator* createInstance( const Locale& loc,
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UErrorCode& err);
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// comparison
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/**
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* The comparison function compares the character data stored in two
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* different strings. Returns information about whether a string
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* is less than, greater than or equal to another string.
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* <p>Example of use:
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* <pre>
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* . UErrorCode status = U_ZERO_ERROR;
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* . Collator *myCollation = Collator::createInstance(Locale::US, status);
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* . if (FAILURE(status)) return;
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* . myCollation->setStrength(Collator::PRIMARY);
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* . // result would be Collator::EQUAL ("abc" == "ABC")
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* . // (no primary difference between "abc" and "ABC")
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* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC");
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* . myCollation->setStrength(Collator::TERTIARY);
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* . // result would be Collator::LESS (abc" <<< "ABC")
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* . // (with tertiary difference between "abc" and "ABC")
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* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC");
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* </pre>
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* @param source the source string to be compared with.
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* @param target the string that is to be compared with the source string.
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* @return Returns a byte value. GREATER if source is greater
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* than target; EQUAL if source is equal to target; LESS if source is less
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* than target
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**/
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virtual EComparisonResult compare( const UnicodeString& source,
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const UnicodeString& target) const = 0;
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/**
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* Does the same thing as compare but limits the comparison to a specified length
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* <p>Example of use:
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* <pre>
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* . UErrorCode status = U_ZERO_ERROR;
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* . Collator *myCollation = Collator::createInstance(Locale::US, status);
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* . if (FAILURE(status)) return;
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* . myCollation->setStrength(Collator::PRIMARY);
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* . // result would be Collator::EQUAL ("abc" == "ABC")
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* . // (no primary difference between "abc" and "ABC")
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* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC",3);
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* . myCollation->setStrength(Collator::TERTIARY);
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* . // result would be Collator::LESS (abc" <<< "ABC")
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* . // (with tertiary difference between "abc" and "ABC")
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* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC",3);
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* </pre>
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* @param source the source string to be compared with.
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* @param target the string that is to be compared with the source string.
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* @param length the length the comparison is limitted to
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* @return Returns a byte value. GREATER if source (up to the specified length) is greater
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* than target; EQUAL if source (up to specified length) is equal to target; LESS if source
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* (up to the specified length) is less than target.
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**/
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virtual EComparisonResult compare( const UnicodeString& source,
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const UnicodeString& target,
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int32_t length) const = 0;
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/** Transforms the string into a series of characters that can be compared
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* with CollationKey::compareTo. It is not possible to restore the original
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* string from the chars in the sort key. The generated sort key handles
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* only a limited number of ignorable characters.
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* <p>Use CollationKey::equals or CollationKey::compare to compare the
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* generated sort keys.
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* <p>Example of use:
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* <pre>
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* . UErrorCode status = U_ZERO_ERROR;
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* . Collator *myCollation = Collator::createInstance(Locale::US, status);
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* . if (FAILURE(status)) return;
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* . myCollation->setStrength(Collator::PRIMARY);
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* . UErrorCode key1Status, key2Status;
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* . CollationKey CollationKey1
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* . CollationKey1 = myCollation->getCollationKey("abc", CollationKey1, key1Status);
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* . CollationKey CollationKey2
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* . CollationKey2 = myCollation->getCollationKey("ABC", CollationKey2, key2Status);
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* . if (FAILURE(key1Status) || FAILURE(key2Status)) { delete myCollation; return; }
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* . // Use CollationKey::compare() to compare the sort keys
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* . // result would be 0 (CollationKey1 == CollationKey2)
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* . int result = CollationKey1.compare(CollationKey2);
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* . myCollation->setStrength(Collator::TERTIARY);
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* . CollationKey1 = myCollation->getCollationKey("abc", CollationKey1, key1Status);
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* . CollationKey2 = myCollation->getCollationKey("ABC", CollationKey2, key2Status);
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* . if (FAILURE(key1Status) || FAILURE(key2Status)) { delete myCollation; return; }
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* . // Use CollationKey::compareTo to compare the collation keys
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* . // result would be -1 (CollationKey1 < CollationKey2)
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* . result = CollationKey1.compareTo(CollationKey2);
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* . delete myCollation;
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* </pre>
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* <p>If the source string is null, a null collation key will be returned.
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* @param source the source string to be transformed into a sort key.
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* @param key the collation key to be filled in
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* @return the collation key of the string based on the collation rules.
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* @see CollationKey#compare
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*/
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virtual CollationKey& getCollationKey(const UnicodeString& source,
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CollationKey& key,
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UErrorCode& status) const = 0;
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/**
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* Generates the hash code for the collation object
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*/
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virtual int32_t hashCode(void) const = 0;
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/**
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* Convenience method for comparing two strings based on
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* the collation rules.
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* @param source the source string to be compared with.
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* @param target the target string to be compared with.
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* @return true if the first string is greater than the second one,
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* according to the collation rules. false, otherwise.
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* @see Collator#compare
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*/
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bool_t greater( const UnicodeString& source,
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const UnicodeString& target) const;
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/**
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* Convenience method for comparing two strings based on the collation
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* rules.
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* @param source the source string to be compared with.
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* @param target the target string to be compared with.
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* @return true if the first string is greater than or equal to the
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* second one, according to the collation rules. false, otherwise.
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* @see Collator#compare
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*/
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bool_t greaterOrEqual( const UnicodeString& source,
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const UnicodeString& target) const;
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/**
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* Convenience method for comparing two strings based on the collation
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* rules.
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* @param source the source string to be compared with.
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* @param target the target string to be compared with.
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* @return true if the strings are equal according to the collation
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* rules. false, otherwise.
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* @see Collator#compare
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*/
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bool_t equals( const UnicodeString& source,
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const UnicodeString& target) const;
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// getter/setter
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/**
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* Get the decomposition mode of the collator object.
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* @return the decomposition mode
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* @see Collator#setDecomposition
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*/
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Normalizer::EMode getDecomposition(void) const;
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/**
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* Set the decomposition mode of the collator object. success is equal
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* to U_ILLEGAL_ARGUMENT_ERROR if error occurs.
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* @param the new decomposition mode
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* @see Collator#getDecomposition
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*/
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void setDecomposition(Normalizer::EMode mode);
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/**
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* Determines the minimum strength that will be use in comparison or
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* transformation.
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* <p>E.g. with strength == SECONDARY, the tertiary difference is ignored
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* <p>E.g. with strength == PRIMARY, the secondary and tertiary difference
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* are ignored.
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* @return the current comparison level.
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* @see Collator#setStrength
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*/
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ECollationStrength getStrength(void) const;
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/**
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* Sets the minimum strength to be used in comparison or transformation.
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* <p>Example of use:
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* <pre>
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* . UErrorCode status = U_ZERO_ERROR;
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* . Collator *myCollation = Collator::createInstance(Locale::US, status);
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* . if (FAILURE(status)) return;
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* . myCollation->setStrength(Collator::PRIMARY);
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* . // result will be "abc" == "ABC"
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* . // tertiary differences will be ignored
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* . Collator::ComparisonResult result = myCollation->compare("abc", "ABC");
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* </pre>
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* @see Collator#getStrength
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* @param newStrength the new comparison level.
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*/
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void setStrength( ECollationStrength newStrength);
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/**
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* Get name of the object for the desired Locale, in the desired langauge
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* @param objectLocale must be from getAvailableLocales
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* @param displayLocale specifies the desired locale for output
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* @param name the fill-in parameter of the return value
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* @return display-able name of the object for the object locale in the
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* desired language
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*/
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static UnicodeString& getDisplayName( const Locale& objectLocale,
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const Locale& displayLocale,
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UnicodeString& name) ;
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/**
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* Get name of the object for the desired Locale, in the langauge of the
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* default locale.
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* @param objectLocale must be from getAvailableLocales
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* @param name the fill-in parameter of the return value
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* @return name of the object for the desired locale in the default
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* language
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*/
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static UnicodeString& getDisplayName( const Locale& objectLocale,
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UnicodeString& name) ;
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/**
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* Get the set of Locales for which Collations are installed
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* @param count the output parameter of number of elements in the locale list
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* @return the list of available locales which collations are installed
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*/
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static const Locale* getAvailableLocales(int32_t& count);
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/**
|
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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.
|
||
*
|
||
* 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(void) const = 0;
|
||
|
||
protected:
|
||
/**
|
||
* Constructors
|
||
*/
|
||
Collator();
|
||
Collator(ECollationStrength collationStrength,
|
||
Normalizer::EMode decompositionMode);
|
||
Collator(const Collator& other);
|
||
|
||
/**
|
||
* Assignment operator
|
||
*/
|
||
const Collator& operator=(const Collator& other);
|
||
|
||
//--------------------------------------------------------------------------
|
||
private:
|
||
|
||
ECollationStrength strength;
|
||
Normalizer::EMode decmp;
|
||
};
|
||
|
||
inline bool_t
|
||
Collator::operator==(const Collator& other) const
|
||
{
|
||
bool_t result;
|
||
if (this == &other) result = TRUE;
|
||
else result = ((strength == other.strength) && (decmp == other.decmp));
|
||
return result;
|
||
}
|
||
|
||
inline bool_t
|
||
Collator::operator!=(const Collator& other) const
|
||
{
|
||
bool_t result;
|
||
result = !(*this == other);
|
||
return result;
|
||
}
|
||
|
||
#endif
|