aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/icu/include/unicode/coll.h
blob: f5564c73944bcb1bf30123fbe5818e7ca5398b27 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
******************************************************************************
*   Copyright (C) 1996-2016, International Business Machines
*   Corporation and others.  All Rights Reserved.
******************************************************************************
*/

/**
 * \file
 * \brief C++ API: Collation Service.
 */

/**
* File coll.h
*
* Created by: Helena Shih
*
* Modification History:
*
*  Date        Name        Description
* 02/5/97      aliu        Modified createDefault to load collation data from
*                          binary files when possible.  Added related methods
*                          createCollationFromFile, chopLocale, createPathName.
* 02/11/97     aliu        Added members addToCache, findInCache, and fgCache.
* 02/12/97     aliu        Modified to create objects from RuleBasedCollator cache.
*                          Moved cache out of Collation class.
* 02/13/97     aliu        Moved several methods out of this class and into
*                          RuleBasedCollator, with modifications.  Modified
*                          createDefault() to call new RuleBasedCollator(Locale&)
*                          constructor.  General clean up and documentation.
* 02/20/97     helena      Added clone, operator==, operator!=, operator=, copy
*                          constructor and getDynamicClassID.
* 03/25/97     helena      Updated with platform independent data types.
* 05/06/97     helena      Added memory allocation error detection.
* 06/20/97     helena      Java class name change.
* 09/03/97     helena      Added createCollationKeyValues().
* 02/10/98     damiba      Added compare() with length as parameter.
* 04/23/99     stephen     Removed EDecompositionMode, merged with
*                          Normalizer::EMode.
* 11/02/99     helena      Collator performance enhancements.  Eliminates the
*                          UnicodeString construction and special case for NO_OP.
* 11/23/99     srl         More performance enhancements. Inlining of
*                          critical accessors.
* 05/15/00     helena      Added version information API.
* 01/29/01     synwee      Modified into a C++ wrapper which calls C apis
*                          (ucol.h).
* 2012-2014    markus      Rewritten in C++ again.
*/

#ifndef COLL_H
#define COLL_H

#include "unicode/utypes.h"

#if U_SHOW_CPLUSPLUS_API

#if !UCONFIG_NO_COLLATION

#include "unicode/uobject.h"
#include "unicode/ucol.h"
#include "unicode/unorm.h"
#include "unicode/locid.h"
#include "unicode/uniset.h"
#include "unicode/umisc.h"
#include "unicode/uiter.h"
#include "unicode/stringpiece.h"

U_NAMESPACE_BEGIN

class StringEnumeration;

#if !UCONFIG_NO_SERVICE
/**
 * @stable ICU 2.6
 */
class CollatorFactory;
#endif

/**
* @stable ICU 2.0
*/
class CollationKey;

/**
* The <code>Collator</code> class performs locale-sensitive string
* comparison.<br>
* You use this class to build searching and sorting routines for natural
* language text.
* <p>
* <code>Collator</code> is an abstract base class. Subclasses implement
* specific collation strategies. One subclass,
* <code>RuleBasedCollator</code>, is currently provided and is applicable
* to a wide set of languages. Other subclasses may be created to handle more
* specialized needs.
* <p>
* Like other locale-sensitive classes, you can use the static factory method,
* <code>createInstance</code>, to obtain the appropriate
* <code>Collator</code> object for a given locale. You will only need to
* look at the subclasses of <code>Collator</code> if you need to
* understand the details of a particular collation strategy or if you need to
* modify that strategy.
* <p>
* The following example shows how to compare two strings using the
* <code>Collator</code> for the default locale.
* \htmlonly<blockquote>\endhtmlonly
* <pre>
* \code
* // Compare two strings in the default locale
* UErrorCode success = U_ZERO_ERROR;
* Collator* myCollator = Collator::createInstance(success);
* if (myCollator->compare("abc", "ABC") < 0)
*   cout << "abc is less than ABC" << endl;
* else
*   cout << "abc is greater than or equal to ABC" << endl;
* \endcode
* </pre>
* \htmlonly</blockquote>\endhtmlonly
* <p>
* You can set a <code>Collator</code>'s <em>strength</em> attribute to
* determine the level of difference considered significant in comparisons.
* Five strengths are provided: <code>PRIMARY</code>, <code>SECONDARY</code>,
* <code>TERTIARY</code>, <code>QUATERNARY</code> and <code>IDENTICAL</code>.
* The exact assignment of strengths to language features is locale dependent.
* For example, in Czech, "e" and "f" are considered primary differences,
* while "e" and "\u00EA" are secondary differences, "e" and "E" are tertiary
* differences and "e" and "e" are identical. The following shows how both case
* and accents could be ignored for US English.
* \htmlonly<blockquote>\endhtmlonly
* <pre>
* \code
* //Get the Collator for US English and set its strength to PRIMARY
* UErrorCode success = U_ZERO_ERROR;
* Collator* usCollator = Collator::createInstance(Locale::getUS(), success);
* usCollator->setStrength(Collator::PRIMARY);
* if (usCollator->compare("abc", "ABC") == 0)
*     cout << "'abc' and 'ABC' strings are equivalent with strength PRIMARY" << endl;
* \endcode
* </pre>
* \htmlonly</blockquote>\endhtmlonly
*
* The <code>getSortKey</code> methods
* convert a string to a series of bytes that can be compared bitwise against
* other sort keys using <code>strcmp()</code>. Sort keys are written as
* zero-terminated byte strings.
*
* Another set of APIs returns a <code>CollationKey</code> object that wraps
* the sort key bytes instead of returning the bytes themselves.
* </p>
* <p>
* <strong>Note:</strong> <code>Collator</code>s with different Locale,
* and CollationStrength settings will return different sort
* orders for the same set of strings. Locales have specific collation rules,
* and the way in which secondary and tertiary differences are taken into
* account, for example, will result in a different sorting order for same
* strings.
* </p>
* @see         RuleBasedCollator
* @see         CollationKey
* @see         CollationElementIterator
* @see         Locale
* @see         Normalizer2
* @version     2.0 11/15/01
*/

class U_I18N_API Collator : public UObject {
public:

    // Collator public enums -----------------------------------------------

    /**
     * Base letter represents a primary difference. Set comparison level to
     * PRIMARY to ignore secondary and tertiary differences.<br>
     * Use this to set the strength of a Collator object.<br>
     * 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.<br>
     * Example of secondary difference, "&auml;" >> "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.<br>
     * Example of tertiary difference, "abc" &lt;&lt;&lt; "ABC".
     *
     * Two characters are considered "identical" when they have the same unicode
     * spellings.<br>
     * For example, "&auml;" == "&auml;".
     *
     * UCollationStrength is also used to determine the strength of sort keys
     * generated from Collator objects.
     * @stable ICU 2.0
     */
    enum ECollationStrength
    {
        PRIMARY    = UCOL_PRIMARY,  // 0
        SECONDARY  = UCOL_SECONDARY,  // 1
        TERTIARY   = UCOL_TERTIARY,  // 2
        QUATERNARY = UCOL_QUATERNARY,  // 3
        IDENTICAL  = UCOL_IDENTICAL  // 15
    };


    // Cannot use #ifndef U_HIDE_DEPRECATED_API for the following, it is
    // used by virtual methods that cannot have that conditional.
#ifndef U_FORCE_HIDE_DEPRECATED_API
    /**
     * 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
     * @deprecated ICU 2.6. Use C enum UCollationResult defined in ucol.h
     */
    enum EComparisonResult
    {
        LESS = UCOL_LESS,  // -1
        EQUAL = UCOL_EQUAL,  // 0
        GREATER = UCOL_GREATER  // 1
    };
#endif  // U_FORCE_HIDE_DEPRECATED_API

    // Collator public destructor -----------------------------------------

    /**
     * Destructor
     * @stable ICU 2.0
     */
    virtual ~Collator();

    // Collator public methods --------------------------------------------

    /**
     * Returns TRUE if "other" is the same as "this".
     *
     * The base class implementation returns TRUE if "other" has the same type/class as "this":
     * `typeid(*this) == typeid(other)`.
     *
     * Subclass implementations should do something like the following:
     *
     *     if (this == &other) { return TRUE; }
     *     if (!Collator::operator==(other)) { return FALSE; }  // not the same class
     *
     *     const MyCollator &o = (const MyCollator&)other;
     *     (compare this vs. o's subclass fields)
     *
     * @param other Collator object to be compared
     * @return TRUE if other is the same as this.
     * @stable ICU 2.0
     */
    virtual UBool operator==(const Collator& other) const;

    /**
     * Returns true if "other" is not the same as "this".
     * Calls ! operator==(const Collator&) const which works for all subclasses.
     * @param other Collator object to be compared
     * @return TRUE if other is not the same as this.
     * @stable ICU 2.0
     */
    virtual UBool operator!=(const Collator& other) const;

    /**
     * Makes a copy of this object.
     * @return a copy of this object, owned by the caller
     * @stable ICU 2.0
     */
    virtual Collator* clone() const = 0;

    /**
     * Creates the Collator object for the current default locale.
     * The default locale is determined by Locale::getDefault.
     * The UErrorCode& err parameter is used to return status information to the user.
     * To check whether the construction succeeded or not, you should check the
     * value of U_SUCCESS(err).  If you wish more detailed information, you can
     * check for informational error results which still indicate success.
     * U_USING_FALLBACK_ERROR indicates that a fall back locale was used. For
     * example, 'de_CH' was requested, but nothing was found there, so 'de' was
     * used. U_USING_DEFAULT_ERROR indicates that the default locale data was
     * used; neither the requested locale nor any of its fall back locales
     * could be found.
     * The caller owns the returned object and is responsible for deleting it.
     *
     * @param err    the error code status.
     * @return       the collation object of the default locale.(for example, en_US)
     * @see Locale#getDefault
     * @stable ICU 2.0
     */
    static Collator* U_EXPORT2 createInstance(UErrorCode&  err);

    /**
     * Gets the collation object for the desired locale. The
     * resource of the desired locale will be loaded.
     *
     * Locale::getRoot() is the base collation table and all other languages are
     * built on top of it with additional language-specific modifications.
     *
     * For some languages, multiple collation types are available;
     * for example, "de@collation=phonebook".
     * Starting with ICU 54, collation attributes can be specified via locale keywords as well,
     * in the old locale extension syntax ("el@colCaseFirst=upper")
     * or in language tag syntax ("el-u-kf-upper").
     * See <a href="http://userguide.icu-project.org/collation/api">User Guide: Collation API</a>.
     *
     * The UErrorCode& err parameter is used to return status information to the user.
     * To check whether the construction succeeded or not, you should check
     * the value of U_SUCCESS(err).  If you wish more detailed information, you
     * can check for informational error results which still indicate success.
     * U_USING_FALLBACK_ERROR indicates that a fall back locale was used.  For
     * example, 'de_CH' was requested, but nothing was found there, so 'de' was
     * used.  U_USING_DEFAULT_ERROR indicates that the default locale data was
     * used; neither the requested locale nor any of its fall back locales
     * could be found.
     *
     * The caller owns the returned object and is responsible for deleting it.
     * @param loc    The locale ID for which to open a collator.
     * @param err    the error code status.
     * @return       the created table-based collation object based on the desired
     *               locale.
     * @see Locale
     * @see ResourceLoader
     * @stable ICU 2.2
     */
    static Collator* U_EXPORT2 createInstance(const Locale& loc, UErrorCode& err);

#ifndef U_FORCE_HIDE_DEPRECATED_API
    /**
     * The comparison function compares the character data stored in two
     * different strings. Returns information about whether a string is less
     * than, greater than or equal to another string.
     * @param source the source string to be compared with.
     * @param target the string that is to be compared with the source string.
     * @return Returns a byte value. GREATER if source is greater
     * than target; EQUAL if source is equal to target; LESS if source is less
     * than target
     * @deprecated ICU 2.6 use the overload with UErrorCode &
     */
    virtual EComparisonResult compare(const UnicodeString& source,
                                      const UnicodeString& target) const;
#endif  // U_FORCE_HIDE_DEPRECATED_API

    /**
     * The comparison function compares the character data stored in two
     * different strings. Returns information about whether a string is less
     * than, greater than or equal to another string.
     * @param source the source string to be compared with.
     * @param target the string that is to be compared with the source string.
     * @param status possible error code
     * @return Returns an enum value. UCOL_GREATER if source is greater
     * than target; UCOL_EQUAL if source is equal to target; UCOL_LESS if source is less
     * than target
     * @stable ICU 2.6
     */
    virtual UCollationResult compare(const UnicodeString& source,
                                      const UnicodeString& target,
                                      UErrorCode &status) const = 0;

#ifndef U_FORCE_HIDE_DEPRECATED_API
    /**
     * Does the same thing as compare but limits the comparison to a specified
     * length
     * @param source the source string to be compared with.
     * @param target the string that is to be compared with the source string.
     * @param length the length the comparison is limited 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.
     * @deprecated ICU 2.6 use the overload with UErrorCode &
     */
    virtual EComparisonResult compare(const UnicodeString& source,
                                      const UnicodeString& target,
                                      int32_t length) const;
#endif  // U_FORCE_HIDE_DEPRECATED_API

    /**
     * Does the same thing as compare but limits the comparison to a specified
     * length
     * @param source the source string to be compared with.
     * @param target the string that is to be compared with the source string.
     * @param length the length the comparison is limited to
     * @param status possible error code
     * @return Returns an enum value. UCOL_GREATER if source (up to the specified
     *         length) is greater than target; UCOL_EQUAL if source (up to specified
     *         length) is equal to target; UCOL_LESS if source (up to the specified
     *         length) is less  than target.
     * @stable ICU 2.6
     */
    virtual UCollationResult compare(const UnicodeString& source,
                                      const UnicodeString& target,
                                      int32_t length,
                                      UErrorCode &status) const = 0;

#ifndef U_FORCE_HIDE_DEPRECATED_API
    /**
     * The comparison function compares the character data stored in two
     * different string arrays. Returns information about whether a string array
     * is less than, greater than or equal to another string array.
     * <p>Example of use:
     * <pre>
     * .       char16_t ABC[] = {0x41, 0x42, 0x43, 0};  // = "ABC"
     * .       char16_t abc[] = {0x61, 0x62, 0x63, 0};  // = "abc"
     * .       UErrorCode status = U_ZERO_ERROR;
     * .       Collator *myCollation =
     * .                         Collator::createInstance(Locale::getUS(), status);
     * .       if (U_FAILURE(status)) return;
     * .       myCollation->setStrength(Collator::PRIMARY);
     * .       // result would be Collator::EQUAL ("abc" == "ABC")
     * .       // (no primary difference between "abc" and "ABC")
     * .       Collator::EComparisonResult result =
     * .                             myCollation->compare(abc, 3, ABC, 3);
     * .       myCollation->setStrength(Collator::TERTIARY);
     * .       // result would be Collator::LESS ("abc" &lt;&lt;&lt; "ABC")
     * .       // (with tertiary difference between "abc" and "ABC")
     * .       result = myCollation->compare(abc, 3, ABC, 3);
     * </pre>
     * @param source the source string array to be compared with.
     * @param sourceLength the length of the source string array.  If this value
     *        is equal to -1, the string array is null-terminated.
     * @param target the string that is to be compared with the source string.
     * @param targetLength the length of the target string array.  If this value
     *        is equal to -1, the string array is null-terminated.
     * @return Returns a byte value. GREATER if source is greater than target;
     *         EQUAL if source is equal to target; LESS if source is less than
     *         target
     * @deprecated ICU 2.6 use the overload with UErrorCode &
     */
    virtual EComparisonResult compare(const char16_t* source, int32_t sourceLength,
                                      const char16_t* target, int32_t targetLength)
                                      const;
#endif  // U_FORCE_HIDE_DEPRECATED_API

    /**
     * The comparison function compares the character data stored in two
     * different string arrays. Returns information about whether a string array
     * is less than, greater than or equal to another string array.
     * @param source the source string array to be compared with.
     * @param sourceLength the length of the source string array.  If this value
     *        is equal to -1, the string array is null-terminated.
     * @param target the string that is to be compared with the source string.
     * @param targetLength the length of the target string array.  If this value
     *        is equal to -1, the string array is null-terminated.
     * @param status possible error code
     * @return Returns an enum value. UCOL_GREATER if source is greater
     * than target; UCOL_EQUAL if source is equal to target; UCOL_LESS if source is less
     * than target
     * @stable ICU 2.6
     */
    virtual UCollationResult compare(const char16_t* source, int32_t sourceLength,
                                      const char16_t* target, int32_t targetLength,
                                      UErrorCode &status) const = 0;

    /**
     * Compares two strings using the Collator.
     * Returns whether the first one compares less than/equal to/greater than
     * the second one.
     * This version takes UCharIterator input.
     * @param sIter the first ("source") string iterator
     * @param tIter the second ("target") string iterator
     * @param status ICU status
     * @return UCOL_LESS, UCOL_EQUAL or UCOL_GREATER
     * @stable ICU 4.2
     */
    virtual UCollationResult compare(UCharIterator &sIter,
                                     UCharIterator &tIter,
                                     UErrorCode &status) const;

    /**
     * Compares two UTF-8 strings using the Collator.
     * Returns whether the first one compares less than/equal to/greater than
     * the second one.
     * This version takes UTF-8 input.
     * Note that a StringPiece can be implicitly constructed
     * from a std::string or a NUL-terminated const char * string.
     * @param source the first UTF-8 string
     * @param target the second UTF-8 string
     * @param status ICU status
     * @return UCOL_LESS, UCOL_EQUAL or UCOL_GREATER
     * @stable ICU 4.2
     */
    virtual UCollationResult compareUTF8(const StringPiece &source,
                                         const StringPiece &target,
                                         UErrorCode &status) const;

    /**
     * Transforms the string into a series of characters that can be compared
     * with CollationKey::compareTo. It is not possible to restore the original
     * string from the chars in the sort key.
     * <p>Use CollationKey::equals or CollationKey::compare to compare the
     * generated sort keys.
     * If the source string is null, a null collation key will be returned.
     *
     * Note that sort keys are often less efficient than simply doing comparison.
     * For more details, see the ICU User Guide.
     *
     * @param source the source string to be transformed into a sort key.
     * @param key the collation key to be filled in
     * @param status the error code status.
     * @return the collation key of the string based on the collation rules.
     * @see CollationKey#compare
     * @stable ICU 2.0
     */
    virtual CollationKey& getCollationKey(const UnicodeString&  source,
                                          CollationKey& key,
                                          UErrorCode& status) const = 0;

    /**
     * Transforms the string into a series of characters that can be compared
     * with CollationKey::compareTo. It is not possible to restore the original
     * string from the chars in the sort key.
     * <p>Use CollationKey::equals or CollationKey::compare to compare the
     * generated sort keys.
     * <p>If the source string is null, a null collation key will be returned.
     *
     * Note that sort keys are often less efficient than simply doing comparison.
     * For more details, see the ICU User Guide.
     *
     * @param source the source string to be transformed into a sort key.
     * @param sourceLength length of the collation key
     * @param key the collation key to be filled in
     * @param status the error code status.
     * @return the collation key of the string based on the collation rules.
     * @see CollationKey#compare
     * @stable ICU 2.0
     */
    virtual CollationKey& getCollationKey(const char16_t*source,
                                          int32_t sourceLength,
                                          CollationKey& key,
                                          UErrorCode& status) const = 0;
    /**
     * Generates the hash code for the collation object
     * @stable ICU 2.0
     */
    virtual int32_t hashCode(void) const = 0;

#ifndef U_FORCE_HIDE_DEPRECATED_API
    /**
     * Gets the locale of the Collator
     *
     * @param type can be either requested, valid or actual locale. For more
     *             information see the definition of ULocDataLocaleType in
     *             uloc.h
     * @param status the error code status.
     * @return locale where the collation data lives. If the collator
     *         was instantiated from rules, locale is empty.
     * @deprecated ICU 2.8 This API is under consideration for revision
     * in ICU 3.0.
     */
    virtual Locale getLocale(ULocDataLocaleType type, UErrorCode& status) const = 0;
#endif  // U_FORCE_HIDE_DEPRECATED_API

    /**
     * Convenience method for comparing two strings based on the collation rules.
     * @param source the source string to be compared with.
     * @param target the target string to be compared with.
     * @return true if the first string is greater than the second one,
     *         according to the collation rules. false, otherwise.
     * @see Collator#compare
     * @stable ICU 2.0
     */
    UBool greater(const UnicodeString& source, const UnicodeString& target)
                  const;

    /**
     * Convenience method for comparing two strings based on the collation rules.
     * @param source the source string to be compared with.
     * @param target the target string to be compared with.
     * @return true if the first string is greater than or equal to the second
     *         one, according to the collation rules. false, otherwise.
     * @see Collator#compare
     * @stable ICU 2.0
     */
    UBool greaterOrEqual(const UnicodeString& source,
                         const UnicodeString& target) const;

    /**
     * Convenience method for comparing two strings based on the collation rules.
     * @param source the source string to be compared with.
     * @param target the target string to be compared with.
     * @return true if the strings are equal according to the collation rules.
     *         false, otherwise.
     * @see Collator#compare
     * @stable ICU 2.0
     */
    UBool equals(const UnicodeString& source, const UnicodeString& target) const;

#ifndef U_FORCE_HIDE_DEPRECATED_API
    /**
     * Determines the minimum strength that will be used in comparison or
     * transformation.
     * <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
     * @deprecated ICU 2.6 Use getAttribute(UCOL_STRENGTH...) instead
     */
    virtual ECollationStrength getStrength(void) const;

    /**
     * Sets the minimum strength to be used in comparison or transformation.
     * <p>Example of use:
     * <pre>
     *  \code
     *  UErrorCode status = U_ZERO_ERROR;
     *  Collator*myCollation = Collator::createInstance(Locale::getUS(), status);
     *  if (U_FAILURE(status)) return;
     *  myCollation->setStrength(Collator::PRIMARY);
     *  // result will be "abc" == "ABC"
     *  // tertiary differences will be ignored
     *  Collator::ComparisonResult result = myCollation->compare("abc", "ABC");
     * \endcode
     * </pre>
     * @see Collator#getStrength
     * @param newStrength the new comparison level.
     * @deprecated ICU 2.6 Use setAttribute(UCOL_STRENGTH...) instead
     */
    virtual void setStrength(ECollationStrength newStrength);
#endif  // U_FORCE_HIDE_DEPRECATED_API

    /**
     * Retrieves the reordering codes for this collator.
     * @param dest The array to fill with the script ordering.
     * @param destCapacity The length of dest. If it is 0, then dest may be NULL and the function
     *  will only return the length of the result without writing any codes (pre-flighting).
     * @param status A reference to an error code value, which must not indicate
     * a failure before the function call.
     * @return The length of the script ordering array.
     * @see ucol_setReorderCodes
     * @see Collator#getEquivalentReorderCodes
     * @see Collator#setReorderCodes
     * @see UScriptCode
     * @see UColReorderCode
     * @stable ICU 4.8
     */
     virtual int32_t getReorderCodes(int32_t *dest,
                                     int32_t destCapacity,
                                     UErrorCode& status) const;

    /**
     * Sets the ordering of scripts for this collator.
     *
     * <p>The reordering codes are a combination of script codes and reorder codes.
     * @param reorderCodes An array of script codes in the new order. This can be NULL if the
     * length is also set to 0. An empty array will clear any reordering codes on the collator.
     * @param reorderCodesLength The length of reorderCodes.
     * @param status error code
     * @see ucol_setReorderCodes
     * @see Collator#getReorderCodes
     * @see Collator#getEquivalentReorderCodes
     * @see UScriptCode
     * @see UColReorderCode
     * @stable ICU 4.8
     */
     virtual void setReorderCodes(const int32_t* reorderCodes,
                                  int32_t reorderCodesLength,
                                  UErrorCode& status) ;

    /**
     * Retrieves the reorder codes that are grouped with the given reorder code. Some reorder
     * codes will be grouped and must reorder together.
     * Beginning with ICU 55, scripts only reorder together if they are primary-equal,
     * for example Hiragana and Katakana.
     *
     * @param reorderCode The reorder code to determine equivalence for.
     * @param dest The array to fill with the script equivalence reordering codes.
     * @param destCapacity The length of dest. If it is 0, then dest may be NULL and the
     * function will only return the length of the result without writing any codes (pre-flighting).
     * @param status A reference to an error code value, which must not indicate
     * a failure before the function call.
     * @return The length of the of the reordering code equivalence array.
     * @see ucol_setReorderCodes
     * @see Collator#getReorderCodes
     * @see Collator#setReorderCodes
     * @see UScriptCode
     * @see UColReorderCode
     * @stable ICU 4.8
     */
    static int32_t U_EXPORT2 getEquivalentReorderCodes(int32_t reorderCode,
                                int32_t* dest,
                                int32_t destCapacity,
                                UErrorCode& status);

    /**
     * Get name of the object for the desired Locale, in the desired language
     * @param objectLocale must be from getAvailableLocales
     * @param displayLocale specifies the desired locale for output
     * @param name the fill-in parameter of the return value
     * @return display-able name of the object for the object locale in the
     *         desired language
     * @stable ICU 2.0
     */
    static UnicodeString& U_EXPORT2 getDisplayName(const Locale& objectLocale,
                                         const Locale& displayLocale,
                                         UnicodeString& name);

    /**
    * Get name of the object for the desired Locale, in the language of the
    * default locale.
    * @param objectLocale must be from getAvailableLocales
    * @param name the fill-in parameter of the return value
    * @return name of the object for the desired locale in the default language
    * @stable ICU 2.0
    */
    static UnicodeString& U_EXPORT2 getDisplayName(const Locale& objectLocale,
                                         UnicodeString& name);

    /**
     * Get the set of Locales for which Collations are installed.
     *
     * <p>Note this does not include locales supported by registered collators.
     * If collators might have been registered, use the overload of getAvailableLocales
     * that returns a StringEnumeration.</p>
     *
     * @param count the output parameter of number of elements in the locale list
     * @return the list of available locales for which collations are installed
     * @stable ICU 2.0
     */
    static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count);

    /**
     * Return a StringEnumeration over the locales available at the time of the call,
     * including registered locales.  If a severe error occurs (such as out of memory
     * condition) this will return null. If there is no locale data, an empty enumeration
     * will be returned.
     * @return a StringEnumeration over the locales available at the time of the call
     * @stable ICU 2.6
     */
    static StringEnumeration* U_EXPORT2 getAvailableLocales(void);

    /**
     * Create a string enumerator of all possible keywords that are relevant to
     * collation. At this point, the only recognized keyword for this
     * service is "collation".
     * @param status input-output error code
     * @return a string enumeration over locale strings. The caller is
     * responsible for closing the result.
     * @stable ICU 3.0
     */
    static StringEnumeration* U_EXPORT2 getKeywords(UErrorCode& status);

    /**
     * Given a keyword, create a string enumeration of all values
     * for that keyword that are currently in use.
     * @param keyword a particular keyword as enumerated by
     * ucol_getKeywords. If any other keyword is passed in, status is set
     * to U_ILLEGAL_ARGUMENT_ERROR.
     * @param status input-output error code
     * @return a string enumeration over collation keyword values, or NULL
     * upon error. The caller is responsible for deleting the result.
     * @stable ICU 3.0
     */
    static StringEnumeration* U_EXPORT2 getKeywordValues(const char *keyword, UErrorCode& status);

    /**
     * Given a key and a locale, returns an array of string values in a preferred
     * order that would make a difference. These are all and only those values where
     * the open (creation) of the service with the locale formed from the input locale
     * plus input keyword and that value has different behavior than creation with the
     * input locale alone.
     * @param keyword        one of the keys supported by this service.  For now, only
     *                      "collation" is supported.
     * @param locale        the locale
     * @param commonlyUsed  if set to true it will return only commonly used values
     *                      with the given locale in preferred order.  Otherwise,
     *                      it will return all the available values for the locale.
     * @param status ICU status
     * @return a string enumeration over keyword values for the given key and the locale.
     * @stable ICU 4.2
     */
    static StringEnumeration* U_EXPORT2 getKeywordValuesForLocale(const char* keyword, const Locale& locale,
                                                                    UBool commonlyUsed, UErrorCode& status);

    /**
     * Return the functionally equivalent locale for the given
     * requested locale, with respect to given keyword, for the
     * collation service.  If two locales return the same result, then
     * collators instantiated for these locales will behave
     * equivalently.  The converse is not always true; two collators
     * may in fact be equivalent, but return different results, due to
     * internal details.  The return result has no other meaning than
     * that stated above, and implies nothing as to the relationship
     * between the two locales.  This is intended for use by
     * applications who wish to cache collators, or otherwise reuse
     * collators when possible.  The functional equivalent may change
     * over time.  For more information, please see the <a
     * href="http://userguide.icu-project.org/locale#TOC-Locales-and-Services">
     * Locales and Services</a> section of the ICU User Guide.
     * @param keyword a particular keyword as enumerated by
     * ucol_getKeywords.
     * @param locale the requested locale
     * @param isAvailable reference to a fillin parameter that
     * indicates whether the requested locale was 'available' to the
     * collation service. A locale is defined as 'available' if it
     * physically exists within the collation locale data.
     * @param status reference to input-output error code
     * @return the functionally equivalent collation locale, or the root
     * locale upon error.
     * @stable ICU 3.0
     */
    static Locale U_EXPORT2 getFunctionalEquivalent(const char* keyword, const Locale& locale,
                                          UBool& isAvailable, UErrorCode& status);

#if !UCONFIG_NO_SERVICE
    /**
     * Register a new Collator.  The collator will be adopted.
     * Because ICU may choose to cache collators internally, this must be
     * called at application startup, prior to any calls to
     * Collator::createInstance to avoid undefined behavior.
     * @param toAdopt the Collator instance to be adopted
     * @param locale the locale with which the collator will be associated
     * @param status the in/out status code, no special meanings are assigned
     * @return a registry key that can be used to unregister this collator
     * @stable ICU 2.6
     */
    static URegistryKey U_EXPORT2 registerInstance(Collator* toAdopt, const Locale& locale, UErrorCode& status);

    /**
     * Register a new CollatorFactory.  The factory will be adopted.
     * Because ICU may choose to cache collators internally, this must be
     * called at application startup, prior to any calls to
     * Collator::createInstance to avoid undefined behavior.
     * @param toAdopt the CollatorFactory instance to be adopted
     * @param status the in/out status code, no special meanings are assigned
     * @return a registry key that can be used to unregister this collator
     * @stable ICU 2.6
     */
    static URegistryKey U_EXPORT2 registerFactory(CollatorFactory* toAdopt, UErrorCode& status);

    /**
     * Unregister a previously-registered Collator or CollatorFactory
     * using the key returned from the register call.  Key becomes
     * invalid after a successful call and should not be used again.
     * The object corresponding to the key will be deleted.
     * Because ICU may choose to cache collators internally, this should
     * be called during application shutdown, after all calls to
     * Collator::createInstance to avoid undefined behavior.
     * @param key the registry key returned by a previous call to registerInstance
     * @param status the in/out status code, no special meanings are assigned
     * @return TRUE if the collator for the key was successfully unregistered
     * @stable ICU 2.6
     */
    static UBool U_EXPORT2 unregister(URegistryKey key, UErrorCode& status);
#endif /* UCONFIG_NO_SERVICE */

    /**
     * Gets the version information for a Collator.
     * @param info the version # information, the result will be filled in
     * @stable ICU 2.0
     */
    virtual void getVersion(UVersionInfo info) const = 0;

    /**
     * Returns a unique class ID POLYMORPHICALLY. Pure virtual method.
     * This method is to implement a simple version of RTTI, since not all C++
     * compilers support genuine RTTI. Polymorphic operator==() and clone()
     * methods call this method.
     * @return The class ID for this object. All objects of a given class have
     *         the same class ID.  Objects of other classes have different class
     *         IDs.
     * @stable ICU 2.0
     */
    virtual UClassID getDynamicClassID(void) const = 0;

    /**
     * Universal attribute setter
     * @param attr attribute type
     * @param value attribute value
     * @param status to indicate whether the operation went on smoothly or
     *        there were errors
     * @stable ICU 2.2
     */
    virtual void setAttribute(UColAttribute attr, UColAttributeValue value,
                              UErrorCode &status) = 0;

    /**
     * Universal attribute getter
     * @param attr attribute type
     * @param status to indicate whether the operation went on smoothly or
     *        there were errors
     * @return attribute value
     * @stable ICU 2.2
     */
    virtual UColAttributeValue getAttribute(UColAttribute attr,
                                            UErrorCode &status) const = 0;

    /**
     * Sets the variable top to the top of the specified reordering group.
     * The variable top determines the highest-sorting character
     * which is affected by UCOL_ALTERNATE_HANDLING.
     * If that attribute is set to UCOL_NON_IGNORABLE, then the variable top has no effect.
     *
     * The base class implementation sets U_UNSUPPORTED_ERROR.
     * @param group one of UCOL_REORDER_CODE_SPACE, UCOL_REORDER_CODE_PUNCTUATION,
     *              UCOL_REORDER_CODE_SYMBOL, UCOL_REORDER_CODE_CURRENCY;
     *              or UCOL_REORDER_CODE_DEFAULT to restore the default max variable group
     * @param errorCode Standard ICU error code. Its input value must
     *                  pass the U_SUCCESS() test, or else the function returns
     *                  immediately. Check for U_FAILURE() on output or use with
     *                  function chaining. (See User Guide for details.)
     * @return *this
     * @see getMaxVariable
     * @stable ICU 53
     */
    virtual Collator &setMaxVariable(UColReorderCode group, UErrorCode &errorCode);

    /**
     * Returns the maximum reordering group whose characters are affected by UCOL_ALTERNATE_HANDLING.
     *
     * The base class implementation returns UCOL_REORDER_CODE_PUNCTUATION.
     * @return the maximum variable reordering group.
     * @see setMaxVariable
     * @stable ICU 53
     */
    virtual UColReorderCode getMaxVariable() const;

#ifndef U_FORCE_HIDE_DEPRECATED_API
    /**
     * Sets the variable top to the primary weight of the specified string.
     *
     * Beginning with ICU 53, the variable top is pinned to
     * the top of one of the supported reordering groups,
     * and it must not be beyond the last of those groups.
     * See setMaxVariable().
     * @param varTop one or more (if contraction) char16_ts to which the variable top should be set
     * @param len length of variable top string. If -1 it is considered to be zero terminated.
     * @param status error code. If error code is set, the return value is undefined. Errors set by this function are: <br>
     *    U_CE_NOT_FOUND_ERROR if more than one character was passed and there is no such contraction<br>
     *    U_ILLEGAL_ARGUMENT_ERROR if the variable top is beyond
     *    the last reordering group supported by setMaxVariable()
     * @return variable top primary weight
     * @deprecated ICU 53 Call setMaxVariable() instead.
     */
    virtual uint32_t setVariableTop(const char16_t *varTop, int32_t len, UErrorCode &status) = 0;

    /**
     * Sets the variable top to the primary weight of the specified string.
     *
     * Beginning with ICU 53, the variable top is pinned to
     * the top of one of the supported reordering groups,
     * and it must not be beyond the last of those groups.
     * See setMaxVariable().
     * @param varTop a UnicodeString size 1 or more (if contraction) of char16_ts to which the variable top should be set
     * @param status error code. If error code is set, the return value is undefined. Errors set by this function are: <br>
     *    U_CE_NOT_FOUND_ERROR if more than one character was passed and there is no such contraction<br>
     *    U_ILLEGAL_ARGUMENT_ERROR if the variable top is beyond
     *    the last reordering group supported by setMaxVariable()
     * @return variable top primary weight
     * @deprecated ICU 53 Call setMaxVariable() instead.
     */
    virtual uint32_t setVariableTop(const UnicodeString &varTop, UErrorCode &status) = 0;

    /**
     * Sets the variable top to the specified primary weight.
     *
     * Beginning with ICU 53, the variable top is pinned to
     * the top of one of the supported reordering groups,
     * and it must not be beyond the last of those groups.
     * See setMaxVariable().
     * @param varTop primary weight, as returned by setVariableTop or ucol_getVariableTop
     * @param status error code
     * @deprecated ICU 53 Call setMaxVariable() instead.
     */
    virtual void setVariableTop(uint32_t varTop, UErrorCode &status) = 0;
#endif  // U_FORCE_HIDE_DEPRECATED_API

    /**
     * Gets the variable top value of a Collator.
     * @param status error code (not changed by function). If error code is set, the return value is undefined.
     * @return the variable top primary weight
     * @see getMaxVariable
     * @stable ICU 2.0
     */
    virtual uint32_t getVariableTop(UErrorCode &status) const = 0;

    /**
     * Get a UnicodeSet that contains all the characters and sequences
     * tailored in this collator.
     * @param status      error code of the operation
     * @return a pointer to a UnicodeSet object containing all the
     *         code points and sequences that may sort differently than
     *         in the root collator. The object must be disposed of by using delete
     * @stable ICU 2.4
     */
    virtual UnicodeSet *getTailoredSet(UErrorCode &status) const;

#ifndef U_FORCE_HIDE_DEPRECATED_API
    /**
     * Same as clone().
     * The base class implementation simply calls clone().
     * @return a copy of this object, owned by the caller
     * @see clone()
     * @deprecated ICU 50 no need to have two methods for cloning
     */
    virtual Collator* safeClone() const;
#endif  // U_FORCE_HIDE_DEPRECATED_API

    /**
     * Get the sort key as an array of bytes from a UnicodeString.
     * Sort key byte arrays are zero-terminated and can be compared using
     * strcmp().
     *
     * Note that sort keys are often less efficient than simply doing comparison.
     * For more details, see the ICU User Guide.
     *
     * @param source string to be processed.
     * @param result buffer to store result in. If NULL, number of bytes needed
     *        will be returned.
     * @param resultLength length of the result buffer. If if not enough the
     *        buffer will be filled to capacity.
     * @return Number of bytes needed for storing the sort key
     * @stable ICU 2.2
     */
    virtual int32_t getSortKey(const UnicodeString& source,
                              uint8_t* result,
                              int32_t resultLength) const = 0;

    /**
     * Get the sort key as an array of bytes from a char16_t buffer.
     * Sort key byte arrays are zero-terminated and can be compared using
     * strcmp().
     *
     * Note that sort keys are often less efficient than simply doing comparison.
     * For more details, see the ICU User Guide.
     *
     * @param source string to be processed.
     * @param sourceLength length of string to be processed.
     *        If -1, the string is 0 terminated and length will be decided by the
     *        function.
     * @param result buffer to store result in. If NULL, number of bytes needed
     *        will be returned.
     * @param resultLength length of the result buffer. If if not enough the
     *        buffer will be filled to capacity.
     * @return Number of bytes needed for storing the sort key
     * @stable ICU 2.2
     */
    virtual int32_t getSortKey(const char16_t*source, int32_t sourceLength,
                               uint8_t*result, int32_t resultLength) const = 0;

    /**
     * Produce a bound for a given sortkey and a number of levels.
     * Return value is always the number of bytes needed, regardless of
     * whether the result buffer was big enough or even valid.<br>
     * Resulting bounds can be used to produce a range of strings that are
     * between upper and lower bounds. For example, if bounds are produced
     * for a sortkey of string "smith", strings between upper and lower
     * bounds with one level would include "Smith", "SMITH", "sMiTh".<br>
     * There are two upper bounds that can be produced. If UCOL_BOUND_UPPER
     * is produced, strings matched would be as above. However, if bound
     * produced using UCOL_BOUND_UPPER_LONG is used, the above example will
     * also match "Smithsonian" and similar.<br>
     * For more on usage, see example in cintltst/capitst.c in procedure
     * TestBounds.
     * Sort keys may be compared using <TT>strcmp</TT>.
     * @param source The source sortkey.
     * @param sourceLength The length of source, or -1 if null-terminated.
     *                     (If an unmodified sortkey is passed, it is always null
     *                      terminated).
     * @param boundType Type of bound required. It can be UCOL_BOUND_LOWER, which
     *                  produces a lower inclusive bound, UCOL_BOUND_UPPER, that
     *                  produces upper bound that matches strings of the same length
     *                  or UCOL_BOUND_UPPER_LONG that matches strings that have the
     *                  same starting substring as the source string.
     * @param noOfLevels  Number of levels required in the resulting bound (for most
     *                    uses, the recommended value is 1). See users guide for
     *                    explanation on number of levels a sortkey can have.
     * @param result A pointer to a buffer to receive the resulting sortkey.
     * @param resultLength The maximum size of result.
     * @param status Used for returning error code if something went wrong. If the
     *               number of levels requested is higher than the number of levels
     *               in the source key, a warning (U_SORT_KEY_TOO_SHORT_WARNING) is
     *               issued.
     * @return The size needed to fully store the bound.
     * @see ucol_keyHashCode
     * @stable ICU 2.1
     */
    static int32_t U_EXPORT2 getBound(const uint8_t       *source,
            int32_t             sourceLength,
            UColBoundMode       boundType,
            uint32_t            noOfLevels,
            uint8_t             *result,
            int32_t             resultLength,
            UErrorCode          &status);


protected:

    // Collator protected constructors -------------------------------------

    /**
    * Default constructor.
    * Constructor is different from the old default Collator constructor.
    * The task for determing the default collation strength and normalization
    * mode is left to the child class.
    * @stable ICU 2.0
    */
    Collator();

#ifndef U_HIDE_DEPRECATED_API
    /**
    * Constructor.
    * Empty constructor, does not handle the arguments.
    * This constructor is done for backward compatibility with 1.7 and 1.8.
    * The task for handling the argument collation strength and normalization
    * mode is left to the child class.
    * @param collationStrength collation strength
    * @param decompositionMode
    * @deprecated ICU 2.4. Subclasses should use the default constructor
    * instead and handle the strength and normalization mode themselves.
    */
    Collator(UCollationStrength collationStrength,
             UNormalizationMode decompositionMode);
#endif  /* U_HIDE_DEPRECATED_API */

    /**
    * Copy constructor.
    * @param other Collator object to be copied from
    * @stable ICU 2.0
    */
    Collator(const Collator& other);

public:
   /**
    * Used internally by registration to define the requested and valid locales.
    * @param requestedLocale the requested locale
    * @param validLocale the valid locale
    * @param actualLocale the actual locale
    * @internal
    */
    virtual void setLocales(const Locale& requestedLocale, const Locale& validLocale, const Locale& actualLocale);

    /** Get the short definition string for a collator. This internal API harvests the collator's
     *  locale and the attribute set and produces a string that can be used for opening
     *  a collator with the same attributes using the ucol_openFromShortString API.
     *  This string will be normalized.
     *  The structure and the syntax of the string is defined in the "Naming collators"
     *  section of the users guide:
     *  http://userguide.icu-project.org/collation/concepts#TOC-Collator-naming-scheme
     *  This function supports preflighting.
     *
     *  This is internal, and intended to be used with delegate converters.
     *
     *  @param locale a locale that will appear as a collators locale in the resulting
     *                short string definition. If NULL, the locale will be harvested
     *                from the collator.
     *  @param buffer space to hold the resulting string
     *  @param capacity capacity of the buffer
     *  @param status for returning errors. All the preflighting errors are featured
     *  @return length of the resulting string
     *  @see ucol_openFromShortString
     *  @see ucol_normalizeShortDefinitionString
     *  @see ucol_getShortDefinitionString
     *  @internal
     */
    virtual int32_t internalGetShortDefinitionString(const char *locale,
                                                     char *buffer,
                                                     int32_t capacity,
                                                     UErrorCode &status) const;

    /**
     * Implements ucol_strcollUTF8().
     * @internal
     */
    virtual UCollationResult internalCompareUTF8(
            const char *left, int32_t leftLength,
            const char *right, int32_t rightLength,
            UErrorCode &errorCode) const;

    /**
     * Implements ucol_nextSortKeyPart().
     * @internal
     */
    virtual int32_t
    internalNextSortKeyPart(
            UCharIterator *iter, uint32_t state[2],
            uint8_t *dest, int32_t count, UErrorCode &errorCode) const;

#ifndef U_HIDE_INTERNAL_API
    /** @internal */
    static inline Collator *fromUCollator(UCollator *uc) {
        return reinterpret_cast<Collator *>(uc);
    }
    /** @internal */
    static inline const Collator *fromUCollator(const UCollator *uc) {
        return reinterpret_cast<const Collator *>(uc);
    }
    /** @internal */
    inline UCollator *toUCollator() {
        return reinterpret_cast<UCollator *>(this);
    }
    /** @internal */
    inline const UCollator *toUCollator() const {
        return reinterpret_cast<const UCollator *>(this);
    }
#endif  // U_HIDE_INTERNAL_API

private:
    /**
     * Assignment operator. Private for now.
     */
    Collator& operator=(const Collator& other);

    friend class CFactory;
    friend class SimpleCFactory;
    friend class ICUCollatorFactory;
    friend class ICUCollatorService;
    static Collator* makeInstance(const Locale& desiredLocale,
                                  UErrorCode& status);
};

#if !UCONFIG_NO_SERVICE
/**
 * A factory, used with registerFactory, the creates multiple collators and provides
 * display names for them.  A factory supports some number of locales-- these are the
 * locales for which it can create collators.  The factory can be visible, in which
 * case the supported locales will be enumerated by getAvailableLocales, or invisible,
 * in which they are not.  Invisible locales are still supported, they are just not
 * listed by getAvailableLocales.
 * <p>
 * If standard locale display names are sufficient, Collator instances can
 * be registered using registerInstance instead.</p>
 * <p>
 * Note: if the collators are to be used from C APIs, they must be instances
 * of RuleBasedCollator.</p>
 *
 * @stable ICU 2.6
 */
class U_I18N_API CollatorFactory : public UObject {
public:

    /**
     * Destructor
     * @stable ICU 3.0
     */
    virtual ~CollatorFactory();

    /**
     * Return true if this factory is visible.  Default is true.
     * If not visible, the locales supported by this factory will not
     * be listed by getAvailableLocales.
     * @return true if the factory is visible.
     * @stable ICU 2.6
     */
    virtual UBool visible(void) const;

    /**
     * Return a collator for the provided locale.  If the locale
     * is not supported, return NULL.
     * @param loc the locale identifying the collator to be created.
     * @return a new collator if the locale is supported, otherwise NULL.
     * @stable ICU 2.6
     */
    virtual Collator* createCollator(const Locale& loc) = 0;

    /**
     * Return the name of the collator for the objectLocale, localized for the displayLocale.
     * If objectLocale is not supported, or the factory is not visible, set the result string
     * to bogus.
     * @param objectLocale the locale identifying the collator
     * @param displayLocale the locale for which the display name of the collator should be localized
     * @param result an output parameter for the display name, set to bogus if not supported.
     * @return the display name
     * @stable ICU 2.6
     */
    virtual  UnicodeString& getDisplayName(const Locale& objectLocale,
                                           const Locale& displayLocale,
                                           UnicodeString& result);

    /**
     * Return an array of all the locale names directly supported by this factory.
     * The number of names is returned in count.  This array is owned by the factory.
     * Its contents must never change.
     * @param count output parameter for the number of locales supported by the factory
     * @param status the in/out error code
     * @return a pointer to an array of count UnicodeStrings.
     * @stable ICU 2.6
     */
    virtual const UnicodeString * getSupportedIDs(int32_t &count, UErrorCode& status) = 0;
};
#endif /* UCONFIG_NO_SERVICE */

// Collator inline methods -----------------------------------------------

U_NAMESPACE_END

#endif /* #if !UCONFIG_NO_COLLATION */

#endif /* U_SHOW_CPLUSPLUS_API */

#endif