gecko-dev/modules/libnls/headers/coll.h
1998-05-27 02:02:27 +00:00

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/*
*****************************************************************************************
* *
* COPYRIGHT: *
* (C) Copyright Taligent, Inc., 1996 *
* (C) Copyright International Business Machines Corporation, 1996 *
* Licensed Material - Program-Property of IBM - All Rights Reserved. *
* US Government Users Restricted Rights - Use, duplication, or disclosure *
* restricted by GSA ADP Schedule Contract with IBM Corp. *
* *
*****************************************************************************************
*/
//===============================================================================
//
// 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.
// 6/20/97 helena Java class name change.
// 09/03/97 helena Added createCollationKeyValues().
// 02/10/98 damiba Added compare() with length as parameter.
//===============================================================================
#ifndef _COLL
#define _COLL
#ifndef _LOCID
#include "locid.h"
#endif
#ifndef _PTYPES
#include "ptypes.h"
#endif
#ifndef _UNISTRING
#include "unistring.h"
#endif
/**
* The Collation class is an abstract class which provides Unicode text
* comparison services. Text collation supports language-sensitive
* comparison of strings, allowing for text searching and alphabetical
* sorting. The collation classes provide a choice of ordering
* strength (for example, to ignore or not ignore case differences) and
* handle ignored, expanding, and contracting characters.
* <p>
* Developers don't need to know anything about the collation rules for various
* languages. Any features requiring collation can use the collation object
* associated with the current default locale, or with a specific locale
* (like France or Japan) if appropriate.
* <UL TYPE=round>
* <LI><strong>Basic Collation</strong>: Correctly sorting strings is
* tricky, even in English. The results of a sort must be consistent
* ; any differences in strings must always be sorted the same
* way. The sort assigns relative priorities to different features of
* the text, based on the characters themselves and on the current
* ordering strength of the collation object. Correct comparison and
* sorting of natural languages requires the following:
* <UL TYPE=square>
* <LI>Ordering priorities: The first primary difference will
* determine the resultant order. No matter what the other
* characters are. For example, "cat" &lt; "dog". Some languages
* require primary, secondary, and tertiary ordering. For example,
* in Czech, case differences are a tertiary difference (A vs. a),
* accent differences are a secondary differece (e vs. <20>) and
* different base letters are a primary difference (d vs. e).
* <LI>Group characters: In collating some languages, a sequence of
* characters is treated as though it was a single letter of the
* alphabet. For example, "cx" &lt; "chx" &lt; "dx".
* <LI>Expanding characters: In some languages, a single character
* is treated as though it was a sequence of letters of the
* alphabet. For example, "aex" &lt; "<22>x" &lt; "aexx".
* <LI>Ignorable characters: Certain characters are ignored when
* collating. That is, they are not significant unless there are
* other differences in the remainder of the string. For example,
* "blackbird" &lt; "black-bird" &lt; "blackbirds"
* </UL>
* <LI><strong>Localizable Collation</strong>: Different collation objects
* associated with various locales handle the differences required
* when sorting text strings for different languages.
* <LI><strong>Customization</strong>: You can produce a new collation by
* adding to or changing an existing one.
* </UL>
* <p>Because compare()'s algorithm is complex, it is faster to sort long lists
* of words by retrieving sort keys or collation keys with getCollationKey().
* You can then cache the sort keys and compare them using CollationKey::compareTo().
* The following is a list of features of sort key:
* <UL Type=round>
* <LI>bit-ordered (so you can do bit-wise comparison on sort keys)
* <LI>use CollationKey.compareTo to compare sort keys
* <LI>faster than direct compare algorithm once the keys are generated
* </UL>
* <p>Collation subclasses implement different collation rules for different
* languages and different applications. (phone book, dictionary, etc.)
* <p>Use collation strength parameters, PRIMARY, SECONDARY, TERTIARY, and
* IDENTICAL to specify the comparison level.
* Each unicode character is assigned ordering priority: primary, secondary,
* tertiary and no difference.
* <p>Decomposition mode determines how composed characters are handled for
* Unicode.
* <UL Type=round>
* <LI>No Decomposition: With no decomposition, accented characters will
* not be sorted correctly; this should only be used if the source
* text is guaranteed to have no accented characters.
* <LI>Canonical Decomposition : Characters that are canonical variants
* according to Unicode 2.0 are decomposed in collation if canonical
* decomposition mode is set. This is the default, and is required
* for proper collation of accented characters.
* <LI>Full Decomposition : With full decomposition, both canonical
* variants and compatibility variants are decomposed. This causes
* not only accented characters to be sorted, but also characters that
* have special formats to be sorted with their norminal form. For
* example, the half-width and full-width ASCII and Katakana characters
* are then sorted properly.
* </UL>
* <P>NO_DECOMPOSITION is the fastest, but does not produce correct results,
* except for languages that do not use accents. You should generally use at
* least CANONICAL_DECOMPOSITION. FULL_DECOMPOSITION decomposes even more
* characters. For example, it maps the Japanese half-width kana characters
* to their normalized characters. For more information on the precise
* mappings used, see http://unicode.org.
*
* <p>LESS, EQUAL, GREATER identifies the result
* of unicode text strings comparison.
* <p>Use the static method Collator::createInstance() to instantiate the class
* by passing the desired locale as the argument.
* <p>Example of use:
* <pre>
* . ErrorCode status = ZERO_ERROR;
* . // Compare two strings in the default locale
* . Collator *myCollation = Collator::createInstance(status);
* . if (FAILURE(status)) return;
* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC");
* . delete myCollation;
* </pre>
* <p>Another example:
* <pre>
* . // compare two strings in French
* . Collator *myCollation = Collator.createInstance(Locale::FRANCE, status);
* . if (FAILURE(status)) return;
* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC");
* </pre>
* <p>The following example demonstrates different ways of comparing two
* strings:
* <pre>
* . UnicodeString a("abcdefgh"), b("ijklmnop");
*
* . // This comparision is not as fast as collation keys.
* . // For multiple comparison, use CollationKey. Please see CollationKey
* . // class description for more description
* . if (myCollation->compare(a, b) == Collator::LESS) { // ... }
*
* . // Faster than compare when collation keys are cached
* . ErrorCode aKeyStatus, bKeyStatus;
* . CollationKey aKey, bKey;
* . aKey = myCollation->getCollationKey(a, aKey, aKeyStatus);
* . bKey = myCollation->getCollationKey(b, bKey, bKeyStatus);
* . if (SUCCESS(aKeyStatus)) && SUCCESS(bKeyStatus))
* . if (aKey.compareTo(bKey) == Collator::LESS)
* . { // ... }
*
* </pre>
* <P><strong>NOTE</strong>: Two collation keys from different collations cannot be
* compared. Incorrect comparison result will be returned if you compare
* two collation keys from different collators.
*
* @see RuleBasedCollator
* @see CollationKey
* @see Locale
* @version 1.7 1/14/97
* @author Helena Shih
*/
#ifdef NLS_MAC
#pragma export on
#endif
class T_COLLATE_API Collator {
public :
/**
* NO_DECOMPOSITION : Accented characters will not be decomposed for sorting.
* Please see class description for more details.
* CANONICAL_DECOMPOSITION : Characters that are canonical variants according
* to Unicode 2.0 will be decomposed for sorting. This is the default setting.
* FULL_DECOMPOSITION : Both canonical variants and compatibility variants be
* decomposed for sorting.
*/
enum EDecompositionMode {
NO_DECOMPOSITION,
CANONICAL_DECOMPOSITION,
FULL_DECOMPOSITION
};
/**
* Base letter represents a primary difference. Set comparison
* level to PRIMARY to ignore secondary and tertiary differences.
* Use this to set the strength of a Collator object.
* Example of primary difference, "abc" &lt; "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, "<22>" >> "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" &lt;&lt;&lt; "ABC".
*
* Two characters are considered "identical" when they have the same
* unicode spellings.
* For example, "<22>" == "<22>".
*
* ECollationStrength is also used to determine the strength of sort keys
* generated from Collator objects.
*/
enum ECollationStrength {
PRIMARY,
SECONDARY,
TERTIARY,
IDENTICAL
};
/**
* LESS is returned if source string is compared to be less than target
* string in the compare() method.
* EQUAL is returned if source string is compared to be equal to target
* string in the compare() method.
* GREATER is returned if source string is compared to be greater than
* target string in the compare() method.
* @see Collator#compare
*/
enum EComparisonResult {
LESS = -1,
EQUAL = 0,
GREATER = 1
};
/**
* Destructor
*/
virtual ~Collator();
/**
* Returns true if "other" is the same as "this"
*/
virtual t_bool operator==(const Collator& other) const;
/**
* Returns true if "other" is not the same as "this".
*/
virtual t_bool operator!=(const Collator& other) const;
/**
* Makes a shallow copy of the current object.
*/
virtual Collator* clone() const = 0;
/**
* Creates the collator object for the current default locale.
* The default locale is determined by Locale::getDefault.
* @return the collation object of the default locale.(for example, en_US)
* @see Locale#getDefault
* The ErrorCode& err parameter is used to return status information to the user.
* To check whether the construction succeeded or not, you should check
* the value of SUCCESS(err). If you wish more detailed information, you
* can check for informational error results which still indicate success.
* USING_FALLBACK_ERROR indicates that a fall back locale was used. For
* example, 'de_CH' was requested, but nothing was found there, so 'de' was
* used. USING_DEFAULT_ERROR indicates that the default locale data was
* used; neither the requested locale nor any of its fall back locales
* could be found.
* The caller owns the returned object and is responsible for deleting it.
*/
static Collator* createInstance( ErrorCode& err);
/**
* Gets the table-based collation object for the desired locale. The
* resource of the desired locale will be loaded by ResourceLoader.
* Locale::ENGLISH is the base collation table and all other languages are
* built on top of it with additional language-specific modifications.
* @param desiredLocale the desired locale to create the collation table
* with.
* @return the created table-based collation object based on the desired
* locale.
* @see Locale
* @see ResourceLoader
* The ErrorCode& err parameter is used to return status information to the user.
* To check whether the construction succeeded or not, you should check
* the value of SUCCESS(err). If you wish more detailed information, you
* can check for informational error results which still indicate success.
* USING_FALLBACK_ERROR indicates that a fall back locale was used. For
* example, 'de_CH' was requested, but nothing was found there, so 'de' was
* used. USING_DEFAULT_ERROR indicates that the default locale data was
* used; neither the requested locale nor any of its fall back locales
* could be found.
* The caller owns the returned object and is responsible for deleting it.
*/
static Collator* createInstance( const Locale& loc,
ErrorCode& err);
/**
* The following methods are obsolete in our current APIs. Some methods
* were renamed in JDK 1.1. The older versions of the methods will be kept
* around for compatibility but will be made obsolete in the future.
*/
// From createInstance
static Collator* createDefault(ErrorCode& err);
static Collator* createDefault(const Locale& loc,
ErrorCode& err);
// comparison
/**
* The comparison function compares the character data stored in two
* different strings. Returns information about whether a string
* is less than, greater than or equal to another string.
* <p>Example of use:
* <pre>
* . ErrorCode status = ZERO_ERROR;
* . Collator *myCollation = Collator::createInstance(Locale::US, status);
* . if (FAILURE(status)) return;
* . myCollation->setStrength(Collator::PRIMARY);
* . // result would be Collator::EQUAL ("abc" == "ABC")
* . // (no primary difference between "abc" and "ABC")
* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC");
* . myCollation->setStrength(Collator::TERTIARY);
* . // result would be Collator::LESS (abc" &lt;&lt;&lt; "ABC")
* . // (with tertiary difference between "abc" and "ABC")
* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC");
* </pre>
* @param source the source string to be compared with.
* @param target the string that is to be compared with the source string.
* @return Returns a byte value. GREATER if source is greater
* than target; EQUAL if source is equal to target; LESS if source is less
* than target
**/
virtual EComparisonResult compare( const UnicodeString& source,
const UnicodeString& target) const = 0;
/**
* Does the same thing as compare but limits the comparison to a specified length
* <p>Example of use:
* <pre>
* . ErrorCode status = ZERO_ERROR;
* . Collator *myCollation = Collator::createInstance(Locale::US, status);
* . if (FAILURE(status)) return;
* . myCollation->setStrength(Collator::PRIMARY);
* . // result would be Collator::EQUAL ("abc" == "ABC")
* . // (no primary difference between "abc" and "ABC")
* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC",3);
* . myCollation->setStrength(Collator::TERTIARY);
* . // result would be Collator::LESS (abc" &lt;&lt;&lt; "ABC")
* . // (with tertiary difference between "abc" and "ABC")
* . Collator::EComparisonResult result = myCollation->compare("abc", "ABC",3);
* </pre>
* @param source the source string to be compared with.
* @param target the string that is to be compared with the source string.
* @param length the length the comparison is limitted to
* @return Returns a byte value. GREATER if source (up to the specified length) is greater
* than target; EQUAL if source (up to specified length) is equal to target; LESS if source
* (up to the specified length) is less than target.
**/
virtual EComparisonResult compare( const UnicodeString& source,
const UnicodeString& target,
t_int32 length) const = 0;
/** Transforms the string into a series of characters that can be compared
* with CollationKey::compareTo. It is not possible to restore the original
* string from the chars in the sort key. The generated sort key handles
* only a limited number of ignorable characters.
* <p>Use CollationKey::equals or CollationKey::compare to compare the
* generated sort keys.
* <p>Example of use:
* <pre>
* . ErrorCode status = ZERO_ERROR;
* . Collator *myCollation = Collator::createInstance(Locale::US, status);
* . if (FAILURE(status)) return;
* . myCollation->setStrength(Collator::PRIMARY);
* . ErrorCode key1Status, key2Status;
* . CollationKey CollationKey1
* . CollationKey1 = myCollation->getCollationKey("abc", CollationKey1, key1Status);
* . CollationKey CollationKey2
* . CollationKey2 = myCollation->getCollationKey("ABC", CollationKey2, key2Status);
* . if (FAILURE(key1Status) || FAILURE(key2Status)) { delete myCollation; return; }
* . // Use CollationKey::compare() to compare the sort keys
* . // result would be 0 (CollationKey1 == CollationKey2)
* . int result = CollationKey1.compare(CollationKey2);
* . myCollation->setStrength(Collator::TERTIARY);
* . CollationKey1 = myCollation->getCollationKey("abc", CollationKey1, key1Status);
* . CollationKey2 = myCollation->getCollationKey("ABC", CollationKey2, key2Status);
* . if (FAILURE(key1Status) || FAILURE(key2Status)) { delete myCollation; return; }
* . // Use CollationKey::compareTo to compare the collation keys
* . // result would be -1 (CollationKey1 &lt; CollationKey2)
* . result = CollationKey1.compareTo(CollationKey2);
* . delete myCollation;
* </pre>
* <p>If the source string is null, a null collation key will be returned.
* @param source the source string to be transformed into a sort key.
* @param key the collation key to be filled in
* @return the collation key of the string based on the collation rules.
* @see CollationKey#compare
*/
virtual CollationKey& getCollationKey( const UnicodeString& source,
CollationKey& key,
ErrorCode& status) const = 0;
/**
* Transforms the string into a unsigned short array that can be compared,
* the caller owns the returned array.
* <p>Example of use:
* <pre>
* . ErrorCode status = ZERO_ERROR;
* . Collator *myCollation = Collator::createInstance(Locale::US, status);
* . if (FAILURE(status)) return;
* . myCollation->setStrength(Collator::PRIMARY);
* . ErrorCode key1Status, key2Status;
* . t_uint16 *array1 = 0;
* . t_uint16 *array2 = 0;
* . t_int32 array1Count, array2Count;
* . array1 = myCollation->getCollationKey("abc", array1Count, key1Status);
* . array2 = myCollation->getCollationKey("ABC", array2Count, key2Status);
* . if (FAILURE(key1Status) || FAILURE(key2Status)) { delete myCollation; return; }
* . // Use a loop to compare the two arrays
* . delete array1;
* . delete array2;
* . delete myCollation;
* </pre>
* <p>If the source string is null, a null collation key will be returned.
* @param source the source string to be transformed into a sort key.
* @param count returns the number of elements in the returned array.
* @return the collation key value array of the string based on the collation rules.
* @see CollationKey#compare
*/
virtual UniChar* createCollationKeyValues( const UnicodeString& source,
t_int32& count,
ErrorCode& status) const = 0;
/**
* The following method is obsolete in our current APIs. Some methods
* were renamed in JDK 1.1. The older versions of the methods will be kept
* around for compatibility but will be made obsolete in the future.
*/
virtual SortKey& getSortKey( const UnicodeString& source,
SortKey& key,
ErrorCode& status) const;
/**
* Generates the hash code for the collation object
*/
virtual t_int32 hashCode() const = 0;
/**
* Convenience method for comparing two strings based on
* the collation rules.
* @param source the source string to be compared with.
* @param target the target string to be compared with.
* @return true if the first string is greater than the second one,
* according to the collation rules. false, otherwise.
* @see Collator#compare
*/
t_bool greater( const UnicodeString& source,
const UnicodeString& target) const;
/**
* Convenience method for comparing two strings based on the collation
* rules.
* @param source the source string to be compared with.
* @param target the target string to be compared with.
* @return true if the first string is greater than or equal to the
* second one, according to the collation rules. false, otherwise.
* @see Collator#compare
*/
t_bool greaterOrEqual( const UnicodeString& source,
const UnicodeString& target) const;
/**
* Convenience method for comparing two strings based on the collation
* rules.
* @param source the source string to be compared with.
* @param target the target string to be compared with.
* @return true if the strings are equal according to the collation
* rules. false, otherwise.
* @see Collator#compare
*/
t_bool equals( const UnicodeString& source,
const UnicodeString& target) const;
// getter/setter
/**
* Get the decomposition mode of the collator object.
* @return the decomposition mode
* @see Collator#setDecomposition
*/
EDecompositionMode getDecomposition() const;
/**
* Set the decomposition mode of the collator object. success is equal
* to ILLEGAL_ARGUMENT_ERROR if error occurs.
* @param the new decomposition mode
* @see Collator#getDecomposition
*/
void setDecomposition( EDecompositionMode mode);
/**
* Determines the minimum strength that will be use in comparison or
* transformation.
* <p>E.g. with strength == SECONDARY, the tertiary difference is ignored
* <p>E.g. with strength == PRIMARY, the secondary and tertiary difference
* are ignored.
* @return the current comparison level.
* @see Collator#setStrength
*/
ECollationStrength getStrength() const;
/**
* Sets the minimum strength to be used in comparison or transformation.
* <p>Example of use:
* <pre>
* . ErrorCode status = ZERO_ERROR;
* . Collator *myCollation = Collator::createInstance(Locale::US, status);
* . if (FAILURE(status)) return;
* . myCollation->setStrength(Collator::PRIMARY);
* . // result will be "abc" == "ABC"
* . // tertiary differences will be ignored
* . Collator::ComparisonResult result = myCollation->compare("abc", "ABC");
* </pre>
* @see Collator#getStrength
* @param newStrength the new comparison level.
*/
void setStrength( ECollationStrength newStrength);
/**
* Get name of the object for the desired Locale, in the desired langauge
* @param objectLocale must be from getAvailableLocales
* @param displayLocale specifies the desired locale for output
* @param name the fill-in parameter of the return value
* @return display-able name of the object for the object locale in the
* desired language
*/
static UnicodeString& getDisplayName( const Locale& objectLocale,
const Locale& displayLocale,
UnicodeString& name) ;
/**
* Get name of the object for the desired Locale, in the langauge of the
* default locale.
* @param objectLocale must be from getAvailableLocales
* @param name the fill-in parameter of the return value
* @return name of the object for the desired locale in the default
* language
*/
static UnicodeString& getDisplayName( const Locale& objectLocale,
UnicodeString& name) ;
/**
* Get the set of Locales for which Collations are installed
* @param count the output parameter of number of elements in the locale list
* @return the list of available locales which collations are installed
*/
static const Locale* getAvailableLocales(t_int32& count);
/**
* Returns a unique class ID POLYMORPHICALLY. Pure virtual method.
* This method is to implement a simple version of RTTI, since not all
* C++ compilers support genuine RTTI. Polymorphic operator==() and
* clone() methods call this method.
*
* Concrete subclasses of Format must implement getDynamicClassID()
* and also a static method and data member:
*
* static ClassID getStaticClassID() { return (ClassID)&fgClassID; }
* static char fgClassID;
*
* @return The class ID for this object. All objects of a
* given class have the same class ID. Objects of
* other classes have different class IDs.
*/
virtual ClassID getDynamicClassID() const = 0;
/** Netscape
* Returns the version number for the collator
* format is major.minor ie: 01.00
*/
virtual const char* getVersionNumber();
protected:
/**
* Constructors
*/
Collator();
Collator(const Collator& other);
/**
* Assignment operator
*/
const Collator& operator=(const Collator& other);
//--------------------------------------------------------------------------
private:
ECollationStrength strength;
EDecompositionMode decmp;
};
#ifdef NLS_MAC
#pragma export off
#endif
inline t_bool
Collator::operator==(const Collator& other) const
{
t_bool result;
if (this == &other) result = TRUE;
else result = ((strength == other.strength) && (decmp == other.decmp));
return result;
}
inline t_bool
Collator::operator!=(const Collator& other) const
{
t_bool result;
result = !(*this == other);
return result;
}
inline Collator*
Collator::createDefault(ErrorCode& status)
{
return Collator::createInstance(status);
}
inline Collator*
Collator::createDefault(const Locale& loc,
ErrorCode& status)
{
return Collator::createInstance(loc, status);
}
inline SortKey&
Collator::getSortKey( const UnicodeString& source,
SortKey& key,
ErrorCode& status) const
{
return (SortKey&)getCollationKey(source, (CollationKey&)key, status);
}
#endif