1/*
2******************************************************************************
3*   Copyright (C) 1996-2015, International Business Machines
4*   Corporation and others.  All Rights Reserved.
5******************************************************************************
6*/
7
8/**
9 * \file
10 * \brief C++ API: Collation Service.
11 */
12
13/**
14* File coll.h
15*
16* Created by: Helena Shih
17*
18* Modification History:
19*
20*  Date        Name        Description
21* 02/5/97      aliu        Modified createDefault to load collation data from
22*                          binary files when possible.  Added related methods
23*                          createCollationFromFile, chopLocale, createPathName.
24* 02/11/97     aliu        Added members addToCache, findInCache, and fgCache.
25* 02/12/97     aliu        Modified to create objects from RuleBasedCollator cache.
26*                          Moved cache out of Collation class.
27* 02/13/97     aliu        Moved several methods out of this class and into
28*                          RuleBasedCollator, with modifications.  Modified
29*                          createDefault() to call new RuleBasedCollator(Locale&)
30*                          constructor.  General clean up and documentation.
31* 02/20/97     helena      Added clone, operator==, operator!=, operator=, copy
32*                          constructor and getDynamicClassID.
33* 03/25/97     helena      Updated with platform independent data types.
34* 05/06/97     helena      Added memory allocation error detection.
35* 06/20/97     helena      Java class name change.
36* 09/03/97     helena      Added createCollationKeyValues().
37* 02/10/98     damiba      Added compare() with length as parameter.
38* 04/23/99     stephen     Removed EDecompositionMode, merged with
39*                          Normalizer::EMode.
40* 11/02/99     helena      Collator performance enhancements.  Eliminates the
41*                          UnicodeString construction and special case for NO_OP.
42* 11/23/99     srl         More performance enhancements. Inlining of
43*                          critical accessors.
44* 05/15/00     helena      Added version information API.
45* 01/29/01     synwee      Modified into a C++ wrapper which calls C apis
46*                          (ucol.h).
47* 2012-2014    markus      Rewritten in C++ again.
48*/
49
50#ifndef COLL_H
51#define COLL_H
52
53#include "unicode/utypes.h"
54
55#if !UCONFIG_NO_COLLATION
56
57#include "unicode/uobject.h"
58#include "unicode/ucol.h"
59#include "unicode/normlzr.h"
60#include "unicode/locid.h"
61#include "unicode/uniset.h"
62#include "unicode/umisc.h"
63#include "unicode/uiter.h"
64#include "unicode/stringpiece.h"
65
66U_NAMESPACE_BEGIN
67
68class StringEnumeration;
69
70#if !UCONFIG_NO_SERVICE
71/**
72 * @stable ICU 2.6
73 */
74class CollatorFactory;
75#endif
76
77/**
78* @stable ICU 2.0
79*/
80class CollationKey;
81
82/**
83* The <code>Collator</code> class performs locale-sensitive string
84* comparison.<br>
85* You use this class to build searching and sorting routines for natural
86* language text.
87* <p>
88* <code>Collator</code> is an abstract base class. Subclasses implement
89* specific collation strategies. One subclass,
90* <code>RuleBasedCollator</code>, is currently provided and is applicable
91* to a wide set of languages. Other subclasses may be created to handle more
92* specialized needs.
93* <p>
94* Like other locale-sensitive classes, you can use the static factory method,
95* <code>createInstance</code>, to obtain the appropriate
96* <code>Collator</code> object for a given locale. You will only need to
97* look at the subclasses of <code>Collator</code> if you need to
98* understand the details of a particular collation strategy or if you need to
99* modify that strategy.
100* <p>
101* The following example shows how to compare two strings using the
102* <code>Collator</code> for the default locale.
103* \htmlonly<blockquote>\endhtmlonly
104* <pre>
105* \code
106* // Compare two strings in the default locale
107* UErrorCode success = U_ZERO_ERROR;
108* Collator* myCollator = Collator::createInstance(success);
109* if (myCollator->compare("abc", "ABC") < 0)
110*   cout << "abc is less than ABC" << endl;
111* else
112*   cout << "abc is greater than or equal to ABC" << endl;
113* \endcode
114* </pre>
115* \htmlonly</blockquote>\endhtmlonly
116* <p>
117* You can set a <code>Collator</code>'s <em>strength</em> attribute to
118* determine the level of difference considered significant in comparisons.
119* Five strengths are provided: <code>PRIMARY</code>, <code>SECONDARY</code>,
120* <code>TERTIARY</code>, <code>QUATERNARY</code> and <code>IDENTICAL</code>.
121* The exact assignment of strengths to language features is locale dependent.
122* For example, in Czech, "e" and "f" are considered primary differences,
123* while "e" and "\u00EA" are secondary differences, "e" and "E" are tertiary
124* differences and "e" and "e" are identical. The following shows how both case
125* and accents could be ignored for US English.
126* \htmlonly<blockquote>\endhtmlonly
127* <pre>
128* \code
129* //Get the Collator for US English and set its strength to PRIMARY
130* UErrorCode success = U_ZERO_ERROR;
131* Collator* usCollator = Collator::createInstance(Locale::getUS(), success);
132* usCollator->setStrength(Collator::PRIMARY);
133* if (usCollator->compare("abc", "ABC") == 0)
134*     cout << "'abc' and 'ABC' strings are equivalent with strength PRIMARY" << endl;
135* \endcode
136* </pre>
137* \htmlonly</blockquote>\endhtmlonly
138*
139* The <code>getSortKey</code> methods
140* convert a string to a series of bytes that can be compared bitwise against
141* other sort keys using <code>strcmp()</code>. Sort keys are written as
142* zero-terminated byte strings.
143*
144* Another set of APIs returns a <code>CollationKey</code> object that wraps
145* the sort key bytes instead of returning the bytes themselves.
146* </p>
147* <p>
148* <strong>Note:</strong> <code>Collator</code>s with different Locale,
149* and CollationStrength settings will return different sort
150* orders for the same set of strings. Locales have specific collation rules,
151* and the way in which secondary and tertiary differences are taken into
152* account, for example, will result in a different sorting order for same
153* strings.
154* </p>
155* @see         RuleBasedCollator
156* @see         CollationKey
157* @see         CollationElementIterator
158* @see         Locale
159* @see         Normalizer
160* @version     2.0 11/15/01
161*/
162
163class U_I18N_API Collator : public UObject {
164public:
165
166    // Collator public enums -----------------------------------------------
167
168    /**
169     * Base letter represents a primary difference. Set comparison level to
170     * PRIMARY to ignore secondary and tertiary differences.<br>
171     * Use this to set the strength of a Collator object.<br>
172     * Example of primary difference, "abc" &lt; "abd"
173     *
174     * Diacritical differences on the same base letter represent a secondary
175     * difference. Set comparison level to SECONDARY to ignore tertiary
176     * differences. Use this to set the strength of a Collator object.<br>
177     * Example of secondary difference, "&auml;" >> "a".
178     *
179     * Uppercase and lowercase versions of the same character represents a
180     * tertiary difference.  Set comparison level to TERTIARY to include all
181     * comparison differences. Use this to set the strength of a Collator
182     * object.<br>
183     * Example of tertiary difference, "abc" &lt;&lt;&lt; "ABC".
184     *
185     * Two characters are considered "identical" when they have the same unicode
186     * spellings.<br>
187     * For example, "&auml;" == "&auml;".
188     *
189     * UCollationStrength is also used to determine the strength of sort keys
190     * generated from Collator objects.
191     * @stable ICU 2.0
192     */
193    enum ECollationStrength
194    {
195        PRIMARY    = UCOL_PRIMARY,  // 0
196        SECONDARY  = UCOL_SECONDARY,  // 1
197        TERTIARY   = UCOL_TERTIARY,  // 2
198        QUATERNARY = UCOL_QUATERNARY,  // 3
199        IDENTICAL  = UCOL_IDENTICAL  // 15
200    };
201
202    /**
203     * LESS is returned if source string is compared to be less than target
204     * string in the compare() method.
205     * EQUAL is returned if source string is compared to be equal to target
206     * string in the compare() method.
207     * GREATER is returned if source string is compared to be greater than
208     * target string in the compare() method.
209     * @see Collator#compare
210     * @deprecated ICU 2.6. Use C enum UCollationResult defined in ucol.h
211     */
212    enum EComparisonResult
213    {
214        LESS = UCOL_LESS,  // -1
215        EQUAL = UCOL_EQUAL,  // 0
216        GREATER = UCOL_GREATER  // 1
217    };
218
219    // Collator public destructor -----------------------------------------
220
221    /**
222     * Destructor
223     * @stable ICU 2.0
224     */
225    virtual ~Collator();
226
227    // Collator public methods --------------------------------------------
228
229    /**
230     * Returns TRUE if "other" is the same as "this".
231     *
232     * The base class implementation returns TRUE if "other" has the same type/class as "this":
233     * <code>typeid(*this) == typeid(other)</code>.
234     *
235     * Subclass implementations should do something like the following:
236     * <pre>
237     *   if (this == &other) { return TRUE; }
238     *   if (!Collator::operator==(other)) { return FALSE; }  // not the same class
239     *
240     *   const MyCollator &o = (const MyCollator&)other;
241     *   (compare this vs. o's subclass fields)
242     * </pre>
243     * @param other Collator object to be compared
244     * @return TRUE if other is the same as this.
245     * @stable ICU 2.0
246     */
247    virtual UBool operator==(const Collator& other) const;
248
249    /**
250     * Returns true if "other" is not the same as "this".
251     * Calls ! operator==(const Collator&) const which works for all subclasses.
252     * @param other Collator object to be compared
253     * @return TRUE if other is not the same as this.
254     * @stable ICU 2.0
255     */
256    virtual UBool operator!=(const Collator& other) const;
257
258    /**
259     * Makes a copy of this object.
260     * @return a copy of this object, owned by the caller
261     * @stable ICU 2.0
262     */
263    virtual Collator* clone(void) const = 0;
264
265    /**
266     * Creates the Collator object for the current default locale.
267     * The default locale is determined by Locale::getDefault.
268     * The UErrorCode& err parameter is used to return status information to the user.
269     * To check whether the construction succeeded or not, you should check the
270     * value of U_SUCCESS(err).  If you wish more detailed information, you can
271     * check for informational error results which still indicate success.
272     * U_USING_FALLBACK_ERROR indicates that a fall back locale was used. For
273     * example, 'de_CH' was requested, but nothing was found there, so 'de' was
274     * used. U_USING_DEFAULT_ERROR indicates that the default locale data was
275     * used; neither the requested locale nor any of its fall back locales
276     * could be found.
277     * The caller owns the returned object and is responsible for deleting it.
278     *
279     * @param err    the error code status.
280     * @return       the collation object of the default locale.(for example, en_US)
281     * @see Locale#getDefault
282     * @stable ICU 2.0
283     */
284    static Collator* U_EXPORT2 createInstance(UErrorCode&  err);
285
286    /**
287     * Gets the collation object for the desired locale. The
288     * resource of the desired locale will be loaded.
289     *
290     * Locale::getRoot() is the base collation table and all other languages are
291     * built on top of it with additional language-specific modifications.
292     *
293     * For some languages, multiple collation types are available;
294     * for example, "de@collation=phonebook".
295     * Starting with ICU 54, collation attributes can be specified via locale keywords as well,
296     * in the old locale extension syntax ("el@colCaseFirst=upper")
297     * or in language tag syntax ("el-u-kf-upper").
298     * See <a href="http://userguide.icu-project.org/collation/api">User Guide: Collation API</a>.
299     *
300     * The UErrorCode& err parameter is used to return status information to the user.
301     * To check whether the construction succeeded or not, you should check
302     * the value of U_SUCCESS(err).  If you wish more detailed information, you
303     * can check for informational error results which still indicate success.
304     * U_USING_FALLBACK_ERROR indicates that a fall back locale was used.  For
305     * example, 'de_CH' was requested, but nothing was found there, so 'de' was
306     * used.  U_USING_DEFAULT_ERROR indicates that the default locale data was
307     * used; neither the requested locale nor any of its fall back locales
308     * could be found.
309     *
310     * The caller owns the returned object and is responsible for deleting it.
311     * @param loc    The locale ID for which to open a collator.
312     * @param err    the error code status.
313     * @return       the created table-based collation object based on the desired
314     *               locale.
315     * @see Locale
316     * @see ResourceLoader
317     * @stable ICU 2.2
318     */
319    static Collator* U_EXPORT2 createInstance(const Locale& loc, UErrorCode& err);
320
321    /**
322     * The comparison function compares the character data stored in two
323     * different strings. Returns information about whether a string is less
324     * than, greater than or equal to another string.
325     * @param source the source string to be compared with.
326     * @param target the string that is to be compared with the source string.
327     * @return Returns a byte value. GREATER if source is greater
328     * than target; EQUAL if source is equal to target; LESS if source is less
329     * than target
330     * @deprecated ICU 2.6 use the overload with UErrorCode &
331     */
332    virtual EComparisonResult compare(const UnicodeString& source,
333                                      const UnicodeString& target) const;
334
335    /**
336     * The comparison function compares the character data stored in two
337     * different strings. Returns information about whether a string is less
338     * than, greater than or equal to another string.
339     * @param source the source string to be compared with.
340     * @param target the string that is to be compared with the source string.
341     * @param status possible error code
342     * @return Returns an enum value. UCOL_GREATER if source is greater
343     * than target; UCOL_EQUAL if source is equal to target; UCOL_LESS if source is less
344     * than target
345     * @stable ICU 2.6
346     */
347    virtual UCollationResult compare(const UnicodeString& source,
348                                      const UnicodeString& target,
349                                      UErrorCode &status) const = 0;
350
351    /**
352     * Does the same thing as compare but limits the comparison to a specified
353     * length
354     * @param source the source string to be compared with.
355     * @param target the string that is to be compared with the source string.
356     * @param length the length the comparison is limited to
357     * @return Returns a byte value. GREATER if source (up to the specified
358     *         length) is greater than target; EQUAL if source (up to specified
359     *         length) is equal to target; LESS if source (up to the specified
360     *         length) is less  than target.
361     * @deprecated ICU 2.6 use the overload with UErrorCode &
362     */
363    virtual EComparisonResult compare(const UnicodeString& source,
364                                      const UnicodeString& target,
365                                      int32_t length) const;
366
367    /**
368     * Does the same thing as compare but limits the comparison to a specified
369     * length
370     * @param source the source string to be compared with.
371     * @param target the string that is to be compared with the source string.
372     * @param length the length the comparison is limited to
373     * @param status possible error code
374     * @return Returns an enum value. UCOL_GREATER if source (up to the specified
375     *         length) is greater than target; UCOL_EQUAL if source (up to specified
376     *         length) is equal to target; UCOL_LESS if source (up to the specified
377     *         length) is less  than target.
378     * @stable ICU 2.6
379     */
380    virtual UCollationResult compare(const UnicodeString& source,
381                                      const UnicodeString& target,
382                                      int32_t length,
383                                      UErrorCode &status) const = 0;
384
385    /**
386     * The comparison function compares the character data stored in two
387     * different string arrays. Returns information about whether a string array
388     * is less than, greater than or equal to another string array.
389     * <p>Example of use:
390     * <pre>
391     * .       UChar ABC[] = {0x41, 0x42, 0x43, 0};  // = "ABC"
392     * .       UChar abc[] = {0x61, 0x62, 0x63, 0};  // = "abc"
393     * .       UErrorCode status = U_ZERO_ERROR;
394     * .       Collator *myCollation =
395     * .                         Collator::createInstance(Locale::getUS(), status);
396     * .       if (U_FAILURE(status)) return;
397     * .       myCollation->setStrength(Collator::PRIMARY);
398     * .       // result would be Collator::EQUAL ("abc" == "ABC")
399     * .       // (no primary difference between "abc" and "ABC")
400     * .       Collator::EComparisonResult result =
401     * .                             myCollation->compare(abc, 3, ABC, 3);
402     * .       myCollation->setStrength(Collator::TERTIARY);
403     * .       // result would be Collator::LESS ("abc" &lt;&lt;&lt; "ABC")
404     * .       // (with tertiary difference between "abc" and "ABC")
405     * .       result = myCollation->compare(abc, 3, ABC, 3);
406     * </pre>
407     * @param source the source string array to be compared with.
408     * @param sourceLength the length of the source string array.  If this value
409     *        is equal to -1, the string array is null-terminated.
410     * @param target the string that is to be compared with the source string.
411     * @param targetLength the length of the target string array.  If this value
412     *        is equal to -1, the string array is null-terminated.
413     * @return Returns a byte value. GREATER if source is greater than target;
414     *         EQUAL if source is equal to target; LESS if source is less than
415     *         target
416     * @deprecated ICU 2.6 use the overload with UErrorCode &
417     */
418    virtual EComparisonResult compare(const UChar* source, int32_t sourceLength,
419                                      const UChar* target, int32_t targetLength)
420                                      const;
421
422    /**
423     * The comparison function compares the character data stored in two
424     * different string arrays. Returns information about whether a string array
425     * is less than, greater than or equal to another string array.
426     * @param source the source string array to be compared with.
427     * @param sourceLength the length of the source string array.  If this value
428     *        is equal to -1, the string array is null-terminated.
429     * @param target the string that is to be compared with the source string.
430     * @param targetLength the length of the target string array.  If this value
431     *        is equal to -1, the string array is null-terminated.
432     * @param status possible error code
433     * @return Returns an enum value. UCOL_GREATER if source is greater
434     * than target; UCOL_EQUAL if source is equal to target; UCOL_LESS if source is less
435     * than target
436     * @stable ICU 2.6
437     */
438    virtual UCollationResult compare(const UChar* source, int32_t sourceLength,
439                                      const UChar* target, int32_t targetLength,
440                                      UErrorCode &status) const = 0;
441
442    /**
443     * Compares two strings using the Collator.
444     * Returns whether the first one compares less than/equal to/greater than
445     * the second one.
446     * This version takes UCharIterator input.
447     * @param sIter the first ("source") string iterator
448     * @param tIter the second ("target") string iterator
449     * @param status ICU status
450     * @return UCOL_LESS, UCOL_EQUAL or UCOL_GREATER
451     * @stable ICU 4.2
452     */
453    virtual UCollationResult compare(UCharIterator &sIter,
454                                     UCharIterator &tIter,
455                                     UErrorCode &status) const;
456
457    /**
458     * Compares two UTF-8 strings using the Collator.
459     * Returns whether the first one compares less than/equal to/greater than
460     * the second one.
461     * This version takes UTF-8 input.
462     * Note that a StringPiece can be implicitly constructed
463     * from a std::string or a NUL-terminated const char * string.
464     * @param source the first UTF-8 string
465     * @param target the second UTF-8 string
466     * @param status ICU status
467     * @return UCOL_LESS, UCOL_EQUAL or UCOL_GREATER
468     * @stable ICU 4.2
469     */
470    virtual UCollationResult compareUTF8(const StringPiece &source,
471                                         const StringPiece &target,
472                                         UErrorCode &status) const;
473
474    /**
475     * Transforms the string into a series of characters that can be compared
476     * with CollationKey::compareTo. It is not possible to restore the original
477     * string from the chars in the sort key.
478     * <p>Use CollationKey::equals or CollationKey::compare to compare the
479     * generated sort keys.
480     * If the source string is null, a null collation key will be returned.
481     *
482     * Note that sort keys are often less efficient than simply doing comparison.
483     * For more details, see the ICU User Guide.
484     *
485     * @param source the source string to be transformed into a sort key.
486     * @param key the collation key to be filled in
487     * @param status the error code status.
488     * @return the collation key of the string based on the collation rules.
489     * @see CollationKey#compare
490     * @stable ICU 2.0
491     */
492    virtual CollationKey& getCollationKey(const UnicodeString&  source,
493                                          CollationKey& key,
494                                          UErrorCode& status) const = 0;
495
496    /**
497     * Transforms the string into a series of characters that can be compared
498     * with CollationKey::compareTo. It is not possible to restore the original
499     * string from the chars in the sort key.
500     * <p>Use CollationKey::equals or CollationKey::compare to compare the
501     * generated sort keys.
502     * <p>If the source string is null, a null collation key will be returned.
503     *
504     * Note that sort keys are often less efficient than simply doing comparison.
505     * For more details, see the ICU User Guide.
506     *
507     * @param source the source string to be transformed into a sort key.
508     * @param sourceLength length of the collation key
509     * @param key the collation key to be filled in
510     * @param status the error code status.
511     * @return the collation key of the string based on the collation rules.
512     * @see CollationKey#compare
513     * @stable ICU 2.0
514     */
515    virtual CollationKey& getCollationKey(const UChar*source,
516                                          int32_t sourceLength,
517                                          CollationKey& key,
518                                          UErrorCode& status) const = 0;
519    /**
520     * Generates the hash code for the collation object
521     * @stable ICU 2.0
522     */
523    virtual int32_t hashCode(void) const = 0;
524
525    /**
526     * Gets the locale of the Collator
527     *
528     * @param type can be either requested, valid or actual locale. For more
529     *             information see the definition of ULocDataLocaleType in
530     *             uloc.h
531     * @param status the error code status.
532     * @return locale where the collation data lives. If the collator
533     *         was instantiated from rules, locale is empty.
534     * @deprecated ICU 2.8 This API is under consideration for revision
535     * in ICU 3.0.
536     */
537    virtual Locale getLocale(ULocDataLocaleType type, UErrorCode& status) const = 0;
538
539    /**
540     * Convenience method for comparing two strings based on the collation rules.
541     * @param source the source string to be compared with.
542     * @param target the target string to be compared with.
543     * @return true if the first string is greater than the second one,
544     *         according to the collation rules. false, otherwise.
545     * @see Collator#compare
546     * @stable ICU 2.0
547     */
548    UBool greater(const UnicodeString& source, const UnicodeString& target)
549                  const;
550
551    /**
552     * Convenience method for comparing two strings based on the collation rules.
553     * @param source the source string to be compared with.
554     * @param target the target string to be compared with.
555     * @return true if the first string is greater than or equal to the second
556     *         one, according to the collation rules. false, otherwise.
557     * @see Collator#compare
558     * @stable ICU 2.0
559     */
560    UBool greaterOrEqual(const UnicodeString& source,
561                         const UnicodeString& target) const;
562
563    /**
564     * Convenience method for comparing two strings based on the collation rules.
565     * @param source the source string to be compared with.
566     * @param target the target string to be compared with.
567     * @return true if the strings are equal according to the collation rules.
568     *         false, otherwise.
569     * @see Collator#compare
570     * @stable ICU 2.0
571     */
572    UBool equals(const UnicodeString& source, const UnicodeString& target) const;
573
574    /**
575     * Determines the minimum strength that will be used in comparison or
576     * transformation.
577     * <p>E.g. with strength == SECONDARY, the tertiary difference is ignored
578     * <p>E.g. with strength == PRIMARY, the secondary and tertiary difference
579     * are ignored.
580     * @return the current comparison level.
581     * @see Collator#setStrength
582     * @deprecated ICU 2.6 Use getAttribute(UCOL_STRENGTH...) instead
583     */
584    virtual ECollationStrength getStrength(void) const;
585
586    /**
587     * Sets the minimum strength to be used in comparison or transformation.
588     * <p>Example of use:
589     * <pre>
590     *  \code
591     *  UErrorCode status = U_ZERO_ERROR;
592     *  Collator*myCollation = Collator::createInstance(Locale::getUS(), status);
593     *  if (U_FAILURE(status)) return;
594     *  myCollation->setStrength(Collator::PRIMARY);
595     *  // result will be "abc" == "ABC"
596     *  // tertiary differences will be ignored
597     *  Collator::ComparisonResult result = myCollation->compare("abc", "ABC");
598     * \endcode
599     * </pre>
600     * @see Collator#getStrength
601     * @param newStrength the new comparison level.
602     * @deprecated ICU 2.6 Use setAttribute(UCOL_STRENGTH...) instead
603     */
604    virtual void setStrength(ECollationStrength newStrength);
605
606    /**
607     * Retrieves the reordering codes for this collator.
608     * @param dest The array to fill with the script ordering.
609     * @param destCapacity The length of dest. If it is 0, then dest may be NULL and the function
610     *  will only return the length of the result without writing any codes (pre-flighting).
611     * @param status A reference to an error code value, which must not indicate
612     * a failure before the function call.
613     * @return The length of the script ordering array.
614     * @see ucol_setReorderCodes
615     * @see Collator#getEquivalentReorderCodes
616     * @see Collator#setReorderCodes
617     * @see UScriptCode
618     * @see UColReorderCode
619     * @stable ICU 4.8
620     */
621     virtual int32_t getReorderCodes(int32_t *dest,
622                                     int32_t destCapacity,
623                                     UErrorCode& status) const;
624
625    /**
626     * Sets the ordering of scripts for this collator.
627     *
628     * <p>The reordering codes are a combination of script codes and reorder codes.
629     * @param reorderCodes An array of script codes in the new order. This can be NULL if the
630     * length is also set to 0. An empty array will clear any reordering codes on the collator.
631     * @param reorderCodesLength The length of reorderCodes.
632     * @param status error code
633     * @see ucol_setReorderCodes
634     * @see Collator#getReorderCodes
635     * @see Collator#getEquivalentReorderCodes
636     * @see UScriptCode
637     * @see UColReorderCode
638     * @stable ICU 4.8
639     */
640     virtual void setReorderCodes(const int32_t* reorderCodes,
641                                  int32_t reorderCodesLength,
642                                  UErrorCode& status) ;
643
644    /**
645     * Retrieves the reorder codes that are grouped with the given reorder code. Some reorder
646     * codes will be grouped and must reorder together.
647     * Beginning with ICU 55, scripts only reorder together if they are primary-equal,
648     * for example Hiragana and Katakana.
649     *
650     * @param reorderCode The reorder code to determine equivalence for.
651     * @param dest The array to fill with the script equivalence reordering codes.
652     * @param destCapacity The length of dest. If it is 0, then dest may be NULL and the
653     * function will only return the length of the result without writing any codes (pre-flighting).
654     * @param status A reference to an error code value, which must not indicate
655     * a failure before the function call.
656     * @return The length of the of the reordering code equivalence array.
657     * @see ucol_setReorderCodes
658     * @see Collator#getReorderCodes
659     * @see Collator#setReorderCodes
660     * @see UScriptCode
661     * @see UColReorderCode
662     * @stable ICU 4.8
663     */
664    static int32_t U_EXPORT2 getEquivalentReorderCodes(int32_t reorderCode,
665                                int32_t* dest,
666                                int32_t destCapacity,
667                                UErrorCode& status);
668
669    /**
670     * Get name of the object for the desired Locale, in the desired langauge
671     * @param objectLocale must be from getAvailableLocales
672     * @param displayLocale specifies the desired locale for output
673     * @param name the fill-in parameter of the return value
674     * @return display-able name of the object for the object locale in the
675     *         desired language
676     * @stable ICU 2.0
677     */
678    static UnicodeString& U_EXPORT2 getDisplayName(const Locale& objectLocale,
679                                         const Locale& displayLocale,
680                                         UnicodeString& name);
681
682    /**
683    * Get name of the object for the desired Locale, in the langauge of the
684    * default locale.
685    * @param objectLocale must be from getAvailableLocales
686    * @param name the fill-in parameter of the return value
687    * @return name of the object for the desired locale in the default language
688    * @stable ICU 2.0
689    */
690    static UnicodeString& U_EXPORT2 getDisplayName(const Locale& objectLocale,
691                                         UnicodeString& name);
692
693    /**
694     * Get the set of Locales for which Collations are installed.
695     *
696     * <p>Note this does not include locales supported by registered collators.
697     * If collators might have been registered, use the overload of getAvailableLocales
698     * that returns a StringEnumeration.</p>
699     *
700     * @param count the output parameter of number of elements in the locale list
701     * @return the list of available locales for which collations are installed
702     * @stable ICU 2.0
703     */
704    static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count);
705
706    /**
707     * Return a StringEnumeration over the locales available at the time of the call,
708     * including registered locales.  If a severe error occurs (such as out of memory
709     * condition) this will return null. If there is no locale data, an empty enumeration
710     * will be returned.
711     * @return a StringEnumeration over the locales available at the time of the call
712     * @stable ICU 2.6
713     */
714    static StringEnumeration* U_EXPORT2 getAvailableLocales(void);
715
716    /**
717     * Create a string enumerator of all possible keywords that are relevant to
718     * collation. At this point, the only recognized keyword for this
719     * service is "collation".
720     * @param status input-output error code
721     * @return a string enumeration over locale strings. The caller is
722     * responsible for closing the result.
723     * @stable ICU 3.0
724     */
725    static StringEnumeration* U_EXPORT2 getKeywords(UErrorCode& status);
726
727    /**
728     * Given a keyword, create a string enumeration of all values
729     * for that keyword that are currently in use.
730     * @param keyword a particular keyword as enumerated by
731     * ucol_getKeywords. If any other keyword is passed in, status is set
732     * to U_ILLEGAL_ARGUMENT_ERROR.
733     * @param status input-output error code
734     * @return a string enumeration over collation keyword values, or NULL
735     * upon error. The caller is responsible for deleting the result.
736     * @stable ICU 3.0
737     */
738    static StringEnumeration* U_EXPORT2 getKeywordValues(const char *keyword, UErrorCode& status);
739
740    /**
741     * Given a key and a locale, returns an array of string values in a preferred
742     * order that would make a difference. These are all and only those values where
743     * the open (creation) of the service with the locale formed from the input locale
744     * plus input keyword and that value has different behavior than creation with the
745     * input locale alone.
746     * @param keyword        one of the keys supported by this service.  For now, only
747     *                      "collation" is supported.
748     * @param locale        the locale
749     * @param commonlyUsed  if set to true it will return only commonly used values
750     *                      with the given locale in preferred order.  Otherwise,
751     *                      it will return all the available values for the locale.
752     * @param status ICU status
753     * @return a string enumeration over keyword values for the given key and the locale.
754     * @stable ICU 4.2
755     */
756    static StringEnumeration* U_EXPORT2 getKeywordValuesForLocale(const char* keyword, const Locale& locale,
757                                                                    UBool commonlyUsed, UErrorCode& status);
758
759    /**
760     * Return the functionally equivalent locale for the given
761     * requested locale, with respect to given keyword, for the
762     * collation service.  If two locales return the same result, then
763     * collators instantiated for these locales will behave
764     * equivalently.  The converse is not always true; two collators
765     * may in fact be equivalent, but return different results, due to
766     * internal details.  The return result has no other meaning than
767     * that stated above, and implies nothing as to the relationship
768     * between the two locales.  This is intended for use by
769     * applications who wish to cache collators, or otherwise reuse
770     * collators when possible.  The functional equivalent may change
771     * over time.  For more information, please see the <a
772     * href="http://userguide.icu-project.org/locale#TOC-Locales-and-Services">
773     * Locales and Services</a> section of the ICU User Guide.
774     * @param keyword a particular keyword as enumerated by
775     * ucol_getKeywords.
776     * @param locale the requested locale
777     * @param isAvailable reference to a fillin parameter that
778     * indicates whether the requested locale was 'available' to the
779     * collation service. A locale is defined as 'available' if it
780     * physically exists within the collation locale data.
781     * @param status reference to input-output error code
782     * @return the functionally equivalent collation locale, or the root
783     * locale upon error.
784     * @stable ICU 3.0
785     */
786    static Locale U_EXPORT2 getFunctionalEquivalent(const char* keyword, const Locale& locale,
787                                          UBool& isAvailable, UErrorCode& status);
788
789#if !UCONFIG_NO_SERVICE
790    /**
791     * Register a new Collator.  The collator will be adopted.
792     * Because ICU may choose to cache collators internally, this must be
793     * called at application startup, prior to any calls to
794     * Collator::createInstance to avoid undefined behavior.
795     * @param toAdopt the Collator instance to be adopted
796     * @param locale the locale with which the collator will be associated
797     * @param status the in/out status code, no special meanings are assigned
798     * @return a registry key that can be used to unregister this collator
799     * @stable ICU 2.6
800     */
801    static URegistryKey U_EXPORT2 registerInstance(Collator* toAdopt, const Locale& locale, UErrorCode& status);
802
803    /**
804     * Register a new CollatorFactory.  The factory will be adopted.
805     * Because ICU may choose to cache collators internally, this must be
806     * called at application startup, prior to any calls to
807     * Collator::createInstance to avoid undefined behavior.
808     * @param toAdopt the CollatorFactory instance to be adopted
809     * @param status the in/out status code, no special meanings are assigned
810     * @return a registry key that can be used to unregister this collator
811     * @stable ICU 2.6
812     */
813    static URegistryKey U_EXPORT2 registerFactory(CollatorFactory* toAdopt, UErrorCode& status);
814
815    /**
816     * Unregister a previously-registered Collator or CollatorFactory
817     * using the key returned from the register call.  Key becomes
818     * invalid after a successful call and should not be used again.
819     * The object corresponding to the key will be deleted.
820     * Because ICU may choose to cache collators internally, this should
821     * be called during application shutdown, after all calls to
822     * Collator::createInstance to avoid undefined behavior.
823     * @param key the registry key returned by a previous call to registerInstance
824     * @param status the in/out status code, no special meanings are assigned
825     * @return TRUE if the collator for the key was successfully unregistered
826     * @stable ICU 2.6
827     */
828    static UBool U_EXPORT2 unregister(URegistryKey key, UErrorCode& status);
829#endif /* UCONFIG_NO_SERVICE */
830
831    /**
832     * Gets the version information for a Collator.
833     * @param info the version # information, the result will be filled in
834     * @stable ICU 2.0
835     */
836    virtual void getVersion(UVersionInfo info) const = 0;
837
838    /**
839     * Returns a unique class ID POLYMORPHICALLY. Pure virtual method.
840     * This method is to implement a simple version of RTTI, since not all C++
841     * compilers support genuine RTTI. Polymorphic operator==() and clone()
842     * methods call this method.
843     * @return The class ID for this object. All objects of a given class have
844     *         the same class ID.  Objects of other classes have different class
845     *         IDs.
846     * @stable ICU 2.0
847     */
848    virtual UClassID getDynamicClassID(void) const = 0;
849
850    /**
851     * Universal attribute setter
852     * @param attr attribute type
853     * @param value attribute value
854     * @param status to indicate whether the operation went on smoothly or
855     *        there were errors
856     * @stable ICU 2.2
857     */
858    virtual void setAttribute(UColAttribute attr, UColAttributeValue value,
859                              UErrorCode &status) = 0;
860
861    /**
862     * Universal attribute getter
863     * @param attr attribute type
864     * @param status to indicate whether the operation went on smoothly or
865     *        there were errors
866     * @return attribute value
867     * @stable ICU 2.2
868     */
869    virtual UColAttributeValue getAttribute(UColAttribute attr,
870                                            UErrorCode &status) const = 0;
871
872    /**
873     * Sets the variable top to the top of the specified reordering group.
874     * The variable top determines the highest-sorting character
875     * which is affected by UCOL_ALTERNATE_HANDLING.
876     * If that attribute is set to UCOL_NON_IGNORABLE, then the variable top has no effect.
877     *
878     * The base class implementation sets U_UNSUPPORTED_ERROR.
879     * @param group one of UCOL_REORDER_CODE_SPACE, UCOL_REORDER_CODE_PUNCTUATION,
880     *              UCOL_REORDER_CODE_SYMBOL, UCOL_REORDER_CODE_CURRENCY;
881     *              or UCOL_REORDER_CODE_DEFAULT to restore the default max variable group
882     * @param errorCode Standard ICU error code. Its input value must
883     *                  pass the U_SUCCESS() test, or else the function returns
884     *                  immediately. Check for U_FAILURE() on output or use with
885     *                  function chaining. (See User Guide for details.)
886     * @return *this
887     * @see getMaxVariable
888     * @stable ICU 53
889     */
890    virtual Collator &setMaxVariable(UColReorderCode group, UErrorCode &errorCode);
891
892    /**
893     * Returns the maximum reordering group whose characters are affected by UCOL_ALTERNATE_HANDLING.
894     *
895     * The base class implementation returns UCOL_REORDER_CODE_PUNCTUATION.
896     * @return the maximum variable reordering group.
897     * @see setMaxVariable
898     * @stable ICU 53
899     */
900    virtual UColReorderCode getMaxVariable() const;
901
902    /**
903     * Sets the variable top to the primary weight of the specified string.
904     *
905     * Beginning with ICU 53, the variable top is pinned to
906     * the top of one of the supported reordering groups,
907     * and it must not be beyond the last of those groups.
908     * See setMaxVariable().
909     * @param varTop one or more (if contraction) UChars to which the variable top should be set
910     * @param len length of variable top string. If -1 it is considered to be zero terminated.
911     * @param status error code. If error code is set, the return value is undefined. Errors set by this function are: <br>
912     *    U_CE_NOT_FOUND_ERROR if more than one character was passed and there is no such contraction<br>
913     *    U_ILLEGAL_ARGUMENT_ERROR if the variable top is beyond
914     *    the last reordering group supported by setMaxVariable()
915     * @return variable top primary weight
916     * @deprecated ICU 53 Call setMaxVariable() instead.
917     */
918    virtual uint32_t setVariableTop(const UChar *varTop, int32_t len, UErrorCode &status) = 0;
919
920    /**
921     * Sets the variable top to the primary weight of the specified string.
922     *
923     * Beginning with ICU 53, the variable top is pinned to
924     * the top of one of the supported reordering groups,
925     * and it must not be beyond the last of those groups.
926     * See setMaxVariable().
927     * @param varTop a UnicodeString size 1 or more (if contraction) of UChars to which the variable top should be set
928     * @param status error code. If error code is set, the return value is undefined. Errors set by this function are: <br>
929     *    U_CE_NOT_FOUND_ERROR if more than one character was passed and there is no such contraction<br>
930     *    U_ILLEGAL_ARGUMENT_ERROR if the variable top is beyond
931     *    the last reordering group supported by setMaxVariable()
932     * @return variable top primary weight
933     * @deprecated ICU 53 Call setMaxVariable() instead.
934     */
935    virtual uint32_t setVariableTop(const UnicodeString &varTop, UErrorCode &status) = 0;
936
937    /**
938     * Sets the variable top to the specified primary weight.
939     *
940     * Beginning with ICU 53, the variable top is pinned to
941     * the top of one of the supported reordering groups,
942     * and it must not be beyond the last of those groups.
943     * See setMaxVariable().
944     * @param varTop primary weight, as returned by setVariableTop or ucol_getVariableTop
945     * @param status error code
946     * @deprecated ICU 53 Call setMaxVariable() instead.
947     */
948    virtual void setVariableTop(uint32_t varTop, UErrorCode &status) = 0;
949
950    /**
951     * Gets the variable top value of a Collator.
952     * @param status error code (not changed by function). If error code is set, the return value is undefined.
953     * @return the variable top primary weight
954     * @see getMaxVariable
955     * @stable ICU 2.0
956     */
957    virtual uint32_t getVariableTop(UErrorCode &status) const = 0;
958
959    /**
960     * Get a UnicodeSet that contains all the characters and sequences
961     * tailored in this collator.
962     * @param status      error code of the operation
963     * @return a pointer to a UnicodeSet object containing all the
964     *         code points and sequences that may sort differently than
965     *         in the root collator. The object must be disposed of by using delete
966     * @stable ICU 2.4
967     */
968    virtual UnicodeSet *getTailoredSet(UErrorCode &status) const;
969
970    /**
971     * Same as clone().
972     * The base class implementation simply calls clone().
973     * @return a copy of this object, owned by the caller
974     * @see clone()
975     * @deprecated ICU 50 no need to have two methods for cloning
976     */
977    virtual Collator* safeClone(void) const;
978
979    /**
980     * Get the sort key as an array of bytes from a UnicodeString.
981     * Sort key byte arrays are zero-terminated and can be compared using
982     * strcmp().
983     *
984     * Note that sort keys are often less efficient than simply doing comparison.
985     * For more details, see the ICU User Guide.
986     *
987     * @param source string to be processed.
988     * @param result buffer to store result in. If NULL, number of bytes needed
989     *        will be returned.
990     * @param resultLength length of the result buffer. If if not enough the
991     *        buffer will be filled to capacity.
992     * @return Number of bytes needed for storing the sort key
993     * @stable ICU 2.2
994     */
995    virtual int32_t getSortKey(const UnicodeString& source,
996                              uint8_t* result,
997                              int32_t resultLength) const = 0;
998
999    /**
1000     * Get the sort key as an array of bytes from a UChar buffer.
1001     * Sort key byte arrays are zero-terminated and can be compared using
1002     * strcmp().
1003     *
1004     * Note that sort keys are often less efficient than simply doing comparison.
1005     * For more details, see the ICU User Guide.
1006     *
1007     * @param source string to be processed.
1008     * @param sourceLength length of string to be processed.
1009     *        If -1, the string is 0 terminated and length will be decided by the
1010     *        function.
1011     * @param result buffer to store result in. If NULL, number of bytes needed
1012     *        will be returned.
1013     * @param resultLength length of the result buffer. If if not enough the
1014     *        buffer will be filled to capacity.
1015     * @return Number of bytes needed for storing the sort key
1016     * @stable ICU 2.2
1017     */
1018    virtual int32_t getSortKey(const UChar*source, int32_t sourceLength,
1019                               uint8_t*result, int32_t resultLength) const = 0;
1020
1021    /**
1022     * Produce a bound for a given sortkey and a number of levels.
1023     * Return value is always the number of bytes needed, regardless of
1024     * whether the result buffer was big enough or even valid.<br>
1025     * Resulting bounds can be used to produce a range of strings that are
1026     * between upper and lower bounds. For example, if bounds are produced
1027     * for a sortkey of string "smith", strings between upper and lower
1028     * bounds with one level would include "Smith", "SMITH", "sMiTh".<br>
1029     * There are two upper bounds that can be produced. If UCOL_BOUND_UPPER
1030     * is produced, strings matched would be as above. However, if bound
1031     * produced using UCOL_BOUND_UPPER_LONG is used, the above example will
1032     * also match "Smithsonian" and similar.<br>
1033     * For more on usage, see example in cintltst/capitst.c in procedure
1034     * TestBounds.
1035     * Sort keys may be compared using <TT>strcmp</TT>.
1036     * @param source The source sortkey.
1037     * @param sourceLength The length of source, or -1 if null-terminated.
1038     *                     (If an unmodified sortkey is passed, it is always null
1039     *                      terminated).
1040     * @param boundType Type of bound required. It can be UCOL_BOUND_LOWER, which
1041     *                  produces a lower inclusive bound, UCOL_BOUND_UPPER, that
1042     *                  produces upper bound that matches strings of the same length
1043     *                  or UCOL_BOUND_UPPER_LONG that matches strings that have the
1044     *                  same starting substring as the source string.
1045     * @param noOfLevels  Number of levels required in the resulting bound (for most
1046     *                    uses, the recommended value is 1). See users guide for
1047     *                    explanation on number of levels a sortkey can have.
1048     * @param result A pointer to a buffer to receive the resulting sortkey.
1049     * @param resultLength The maximum size of result.
1050     * @param status Used for returning error code if something went wrong. If the
1051     *               number of levels requested is higher than the number of levels
1052     *               in the source key, a warning (U_SORT_KEY_TOO_SHORT_WARNING) is
1053     *               issued.
1054     * @return The size needed to fully store the bound.
1055     * @see ucol_keyHashCode
1056     * @stable ICU 2.1
1057     */
1058    static int32_t U_EXPORT2 getBound(const uint8_t       *source,
1059            int32_t             sourceLength,
1060            UColBoundMode       boundType,
1061            uint32_t            noOfLevels,
1062            uint8_t             *result,
1063            int32_t             resultLength,
1064            UErrorCode          &status);
1065
1066
1067protected:
1068
1069    // Collator protected constructors -------------------------------------
1070
1071    /**
1072    * Default constructor.
1073    * Constructor is different from the old default Collator constructor.
1074    * The task for determing the default collation strength and normalization
1075    * mode is left to the child class.
1076    * @stable ICU 2.0
1077    */
1078    Collator();
1079
1080#ifndef U_HIDE_DEPRECATED_API
1081    /**
1082    * Constructor.
1083    * Empty constructor, does not handle the arguments.
1084    * This constructor is done for backward compatibility with 1.7 and 1.8.
1085    * The task for handling the argument collation strength and normalization
1086    * mode is left to the child class.
1087    * @param collationStrength collation strength
1088    * @param decompositionMode
1089    * @deprecated ICU 2.4. Subclasses should use the default constructor
1090    * instead and handle the strength and normalization mode themselves.
1091    */
1092    Collator(UCollationStrength collationStrength,
1093             UNormalizationMode decompositionMode);
1094#endif  /* U_HIDE_DEPRECATED_API */
1095
1096    /**
1097    * Copy constructor.
1098    * @param other Collator object to be copied from
1099    * @stable ICU 2.0
1100    */
1101    Collator(const Collator& other);
1102
1103public:
1104   /**
1105    * Used internally by registration to define the requested and valid locales.
1106    * @param requestedLocale the requested locale
1107    * @param validLocale the valid locale
1108    * @param actualLocale the actual locale
1109    * @internal
1110    */
1111    virtual void setLocales(const Locale& requestedLocale, const Locale& validLocale, const Locale& actualLocale);
1112
1113    /** Get the short definition string for a collator. This internal API harvests the collator's
1114     *  locale and the attribute set and produces a string that can be used for opening
1115     *  a collator with the same attributes using the ucol_openFromShortString API.
1116     *  This string will be normalized.
1117     *  The structure and the syntax of the string is defined in the "Naming collators"
1118     *  section of the users guide:
1119     *  http://userguide.icu-project.org/collation/concepts#TOC-Collator-naming-scheme
1120     *  This function supports preflighting.
1121     *
1122     *  This is internal, and intended to be used with delegate converters.
1123     *
1124     *  @param locale a locale that will appear as a collators locale in the resulting
1125     *                short string definition. If NULL, the locale will be harvested
1126     *                from the collator.
1127     *  @param buffer space to hold the resulting string
1128     *  @param capacity capacity of the buffer
1129     *  @param status for returning errors. All the preflighting errors are featured
1130     *  @return length of the resulting string
1131     *  @see ucol_openFromShortString
1132     *  @see ucol_normalizeShortDefinitionString
1133     *  @see ucol_getShortDefinitionString
1134     *  @internal
1135     */
1136    virtual int32_t internalGetShortDefinitionString(const char *locale,
1137                                                     char *buffer,
1138                                                     int32_t capacity,
1139                                                     UErrorCode &status) const;
1140
1141    /**
1142     * Implements ucol_strcollUTF8().
1143     * @internal
1144     */
1145    virtual UCollationResult internalCompareUTF8(
1146            const char *left, int32_t leftLength,
1147            const char *right, int32_t rightLength,
1148            UErrorCode &errorCode) const;
1149
1150    /**
1151     * Implements ucol_nextSortKeyPart().
1152     * @internal
1153     */
1154    virtual int32_t
1155    internalNextSortKeyPart(
1156            UCharIterator *iter, uint32_t state[2],
1157            uint8_t *dest, int32_t count, UErrorCode &errorCode) const;
1158
1159#ifndef U_HIDE_INTERNAL_API
1160    /** @internal */
1161    static inline Collator *fromUCollator(UCollator *uc) {
1162        return reinterpret_cast<Collator *>(uc);
1163    }
1164    /** @internal */
1165    static inline const Collator *fromUCollator(const UCollator *uc) {
1166        return reinterpret_cast<const Collator *>(uc);
1167    }
1168    /** @internal */
1169    inline UCollator *toUCollator() {
1170        return reinterpret_cast<UCollator *>(this);
1171    }
1172    /** @internal */
1173    inline const UCollator *toUCollator() const {
1174        return reinterpret_cast<const UCollator *>(this);
1175    }
1176#endif  // U_HIDE_INTERNAL_API
1177
1178private:
1179    /**
1180     * Assignment operator. Private for now.
1181     */
1182    Collator& operator=(const Collator& other);
1183
1184    friend class CFactory;
1185    friend class SimpleCFactory;
1186    friend class ICUCollatorFactory;
1187    friend class ICUCollatorService;
1188    static Collator* makeInstance(const Locale& desiredLocale,
1189                                  UErrorCode& status);
1190};
1191
1192#if !UCONFIG_NO_SERVICE
1193/**
1194 * A factory, used with registerFactory, the creates multiple collators and provides
1195 * display names for them.  A factory supports some number of locales-- these are the
1196 * locales for which it can create collators.  The factory can be visible, in which
1197 * case the supported locales will be enumerated by getAvailableLocales, or invisible,
1198 * in which they are not.  Invisible locales are still supported, they are just not
1199 * listed by getAvailableLocales.
1200 * <p>
1201 * If standard locale display names are sufficient, Collator instances can
1202 * be registered using registerInstance instead.</p>
1203 * <p>
1204 * Note: if the collators are to be used from C APIs, they must be instances
1205 * of RuleBasedCollator.</p>
1206 *
1207 * @stable ICU 2.6
1208 */
1209class U_I18N_API CollatorFactory : public UObject {
1210public:
1211
1212    /**
1213     * Destructor
1214     * @stable ICU 3.0
1215     */
1216    virtual ~CollatorFactory();
1217
1218    /**
1219     * Return true if this factory is visible.  Default is true.
1220     * If not visible, the locales supported by this factory will not
1221     * be listed by getAvailableLocales.
1222     * @return true if the factory is visible.
1223     * @stable ICU 2.6
1224     */
1225    virtual UBool visible(void) const;
1226
1227    /**
1228     * Return a collator for the provided locale.  If the locale
1229     * is not supported, return NULL.
1230     * @param loc the locale identifying the collator to be created.
1231     * @return a new collator if the locale is supported, otherwise NULL.
1232     * @stable ICU 2.6
1233     */
1234    virtual Collator* createCollator(const Locale& loc) = 0;
1235
1236    /**
1237     * Return the name of the collator for the objectLocale, localized for the displayLocale.
1238     * If objectLocale is not supported, or the factory is not visible, set the result string
1239     * to bogus.
1240     * @param objectLocale the locale identifying the collator
1241     * @param displayLocale the locale for which the display name of the collator should be localized
1242     * @param result an output parameter for the display name, set to bogus if not supported.
1243     * @return the display name
1244     * @stable ICU 2.6
1245     */
1246    virtual  UnicodeString& getDisplayName(const Locale& objectLocale,
1247                                           const Locale& displayLocale,
1248                                           UnicodeString& result);
1249
1250    /**
1251     * Return an array of all the locale names directly supported by this factory.
1252     * The number of names is returned in count.  This array is owned by the factory.
1253     * Its contents must never change.
1254     * @param count output parameter for the number of locales supported by the factory
1255     * @param status the in/out error code
1256     * @return a pointer to an array of count UnicodeStrings.
1257     * @stable ICU 2.6
1258     */
1259    virtual const UnicodeString * getSupportedIDs(int32_t &count, UErrorCode& status) = 0;
1260};
1261#endif /* UCONFIG_NO_SERVICE */
1262
1263// Collator inline methods -----------------------------------------------
1264
1265U_NAMESPACE_END
1266
1267#endif /* #if !UCONFIG_NO_COLLATION */
1268
1269#endif
1270