This file is indexed.

/usr/include/unicode/uregex.h is in libicu-dev 57.1-6+deb9u2.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   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
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
/*
**********************************************************************
*   Copyright (C) 2004-2016, International Business Machines
*   Corporation and others.  All Rights Reserved.
**********************************************************************
*   file name:  uregex.h
*   encoding:   US-ASCII
*   indentation:4
*
*   created on: 2004mar09
*   created by: Andy Heninger
*
*   ICU Regular Expressions, API for C
*/

/**
 * \file
 * \brief C API: Regular Expressions
 *
 * <p>This is a C wrapper around the C++ RegexPattern and RegexMatcher classes.</p>
 */

#ifndef UREGEX_H
#define UREGEX_H

#include "unicode/utext.h"
#include "unicode/utypes.h"

#if !UCONFIG_NO_REGULAR_EXPRESSIONS

#include "unicode/localpointer.h"
#include "unicode/parseerr.h"

struct URegularExpression;
/**
  * Structure representing a compiled regular expression, plus the results
  *    of a match operation.
  * @stable ICU 3.0
  */
typedef struct URegularExpression URegularExpression;


/**
 * Constants for Regular Expression Match Modes.
 * @stable ICU 2.4
 */
typedef enum URegexpFlag{

#ifndef U_HIDE_DRAFT_API 
    /** Forces normalization of pattern and strings. 
    Not implemented yet, just a placeholder, hence draft. 
    @draft ICU 2.4 */
    UREGEX_CANON_EQ         = 128,
#endif /* U_HIDE_DRAFT_API */
    /**  Enable case insensitive matching.  @stable ICU 2.4 */
    UREGEX_CASE_INSENSITIVE = 2,

    /**  Allow white space and comments within patterns  @stable ICU 2.4 */
    UREGEX_COMMENTS         = 4,

    /**  If set, '.' matches line terminators,  otherwise '.' matching stops at line end.
      *  @stable ICU 2.4 */
    UREGEX_DOTALL           = 32,
    
    /**  If set, treat the entire pattern as a literal string.  
      *  Metacharacters or escape sequences in the input sequence will be given 
      *  no special meaning. 
      *
      *  The flag UREGEX_CASE_INSENSITIVE retains its impact
      *  on matching when used in conjunction with this flag.
      *  The other flags become superfluous.
      *
      * @stable ICU 4.0
      */
    UREGEX_LITERAL = 16,

    /**   Control behavior of "$" and "^"
      *    If set, recognize line terminators within string,
      *    otherwise, match only at start and end of input string.
      *   @stable ICU 2.4 */
    UREGEX_MULTILINE        = 8,
    
    /**   Unix-only line endings.
      *   When this mode is enabled, only \\u000a is recognized as a line ending
      *    in the behavior of ., ^, and $.
      *   @stable ICU 4.0
      */
    UREGEX_UNIX_LINES = 1,

    /**  Unicode word boundaries.
      *     If set, \b uses the Unicode TR 29 definition of word boundaries.
      *     Warning: Unicode word boundaries are quite different from
      *     traditional regular expression word boundaries.  See
      *     http://unicode.org/reports/tr29/#Word_Boundaries
      *     @stable ICU 2.8
      */
    UREGEX_UWORD            = 256,

     /**  Error on Unrecognized backslash escapes.
       *     If set, fail with an error on patterns that contain
       *     backslash-escaped ASCII letters without a known special
       *     meaning.  If this flag is not set, these
       *     escaped letters represent themselves.
       *     @stable ICU 4.0
       */
     UREGEX_ERROR_ON_UNKNOWN_ESCAPES = 512

}  URegexpFlag;

/**
  *  Open (compile) an ICU regular expression.  Compiles the regular expression in
  *  string form into an internal representation using the specified match mode flags.
  *  The resulting regular expression handle can then be used to perform various
  *   matching operations.
  * 
  *
  * @param pattern        The Regular Expression pattern to be compiled. 
  * @param patternLength  The length of the pattern, or -1 if the pattern is
  *                       NUL terminated.
  * @param flags          Flags that alter the default matching behavior for
  *                       the regular expression, UREGEX_CASE_INSENSITIVE, for
  *                       example.  For default behavior, set this parameter to zero.
  *                       See <code>enum URegexpFlag</code>.  All desired flags
  *                       are bitwise-ORed together.
  * @param pe             Receives the position (line and column numbers) of any syntax
  *                       error within the source regular expression string.  If this
  *                       information is not wanted, pass NULL for this parameter.
  * @param status         Receives error detected by this function.
  * @stable ICU 3.0
  *
  */
U_STABLE URegularExpression * U_EXPORT2
uregex_open( const  UChar          *pattern,
                    int32_t         patternLength,
                    uint32_t        flags,
                    UParseError    *pe,
                    UErrorCode     *status);

/**
  *  Open (compile) an ICU regular expression.  Compiles the regular expression in
  *  string form into an internal representation using the specified match mode flags.
  *  The resulting regular expression handle can then be used to perform various
  *   matching operations.
  *  <p>
  *  The contents of the pattern UText will be extracted and saved. Ownership of the
  *   UText struct itself remains with the caller. This is to match the behavior of
  *   uregex_open().
  *
  * @param pattern        The Regular Expression pattern to be compiled. 
  * @param flags          Flags that alter the default matching behavior for
  *                       the regular expression, UREGEX_CASE_INSENSITIVE, for
  *                       example.  For default behavior, set this parameter to zero.
  *                       See <code>enum URegexpFlag</code>.  All desired flags
  *                       are bitwise-ORed together.
  * @param pe             Receives the position (line and column numbers) of any syntax
  *                       error within the source regular expression string.  If this
  *                       information is not wanted, pass NULL for this parameter.
  * @param status         Receives error detected by this function.
  *
  * @stable ICU 4.6
  */
U_STABLE URegularExpression *  U_EXPORT2
uregex_openUText(UText          *pattern,
                 uint32_t        flags,
                 UParseError    *pe,
                 UErrorCode     *status);

/**
  *  Open (compile) an ICU regular expression.  The resulting regular expression
  *   handle can then be used to perform various matching operations.
  *  <p>
  *   This function is the same as uregex_open, except that the pattern
  *   is supplied as an 8 bit char * string in the default code page.
  *
  * @param pattern        The Regular Expression pattern to be compiled, 
  *                       NUL terminated.  
  * @param flags          Flags that alter the default matching behavior for
  *                       the regular expression, UREGEX_CASE_INSENSITIVE, for
  *                       example.  For default behavior, set this parameter to zero.
  *                       See <code>enum URegexpFlag</code>.  All desired flags
  *                       are bitwise-ORed together.
  * @param pe             Receives the position (line and column numbers) of any syntax
  *                       error within the source regular expression string.  If this
  *                       information is not wanted, pass NULL for this parameter.
  * @param status         Receives errors detected by this function.
  * @return               The URegularExpression object representing the compiled
  *                       pattern.
  *
  * @stable ICU 3.0
  */
#if !UCONFIG_NO_CONVERSION
U_STABLE URegularExpression * U_EXPORT2
uregex_openC( const char           *pattern,
                    uint32_t        flags,
                    UParseError    *pe,
                    UErrorCode     *status);
#endif



/**
  *  Close the regular expression, recovering all resources (memory) it
  *   was holding.
  *
  * @param regexp   The regular expression to be closed.
  * @stable ICU 3.0
  */
U_STABLE void U_EXPORT2 
uregex_close(URegularExpression *regexp);

#if U_SHOW_CPLUSPLUS_API

U_NAMESPACE_BEGIN

/**
 * \class LocalURegularExpressionPointer
 * "Smart pointer" class, closes a URegularExpression via uregex_close().
 * For most methods see the LocalPointerBase base class.
 *
 * @see LocalPointerBase
 * @see LocalPointer
 * @stable ICU 4.4
 */
U_DEFINE_LOCAL_OPEN_POINTER(LocalURegularExpressionPointer, URegularExpression, uregex_close);

U_NAMESPACE_END

#endif

/**
 * Make a copy of a compiled regular expression.  Cloning a regular
 * expression is faster than opening a second instance from the source
 * form of the expression, and requires less memory.
 * <p>
 * Note that the current input string and the position of any matched text
 *  within it are not cloned; only the pattern itself and the
 *  match mode flags are copied.
 * <p>
 * Cloning can be particularly useful to threaded applications that perform
 * multiple match operations in parallel.  Each concurrent RE
 * operation requires its own instance of a URegularExpression.
 *
 * @param regexp   The compiled regular expression to be cloned.
 * @param status   Receives indication of any errors encountered
 * @return the cloned copy of the compiled regular expression.
 * @stable ICU 3.0
 */
U_STABLE URegularExpression * U_EXPORT2 
uregex_clone(const URegularExpression *regexp, UErrorCode *status);

/**
 *  Returns a pointer to the source form of the pattern for this regular expression.
 *  This function will work even if the pattern was originally specified as a UText.
 *
 * @param regexp     The compiled regular expression.
 * @param patLength  This output parameter will be set to the length of the
 *                   pattern string.  A NULL pointer may be used here if the
 *                   pattern length is not needed, as would be the case if
 *                   the pattern is known in advance to be a NUL terminated
 *                   string.
 * @param status     Receives errors detected by this function.
 * @return a pointer to the pattern string.  The storage for the string is
 *                   owned by the regular expression object, and must not be
 *                   altered or deleted by the application.  The returned string
 *                   will remain valid until the regular expression is closed.
 * @stable ICU 3.0
 */
U_STABLE const UChar * U_EXPORT2 
uregex_pattern(const URegularExpression *regexp,
                     int32_t            *patLength,
                     UErrorCode         *status);

/**
 *  Returns the source text of the pattern for this regular expression.
 *  This function will work even if the pattern was originally specified as a UChar string.
 *
 * @param regexp     The compiled regular expression.
 * @param status     Receives errors detected by this function.
 * @return the pattern text.  The storage for the text is owned by the regular expression
 *                   object, and must not be altered or deleted.
 *
 * @stable ICU 4.6
 */
U_STABLE UText * U_EXPORT2 
uregex_patternUText(const URegularExpression *regexp,
                          UErrorCode         *status);

/**
  * Get the match mode flags that were specified when compiling this regular expression.
  * @param status   Receives errors detected by this function.
  * @param regexp   The compiled regular expression.
  * @return         The match mode flags
  * @see URegexpFlag
  * @stable ICU 3.0
  */
U_STABLE int32_t U_EXPORT2 
uregex_flags(const  URegularExpression   *regexp,
                    UErrorCode           *status);


/**
  *  Set the subject text string upon which the regular expression will look for matches.
  *  This function may be called any number of times, allowing the regular
  *  expression pattern to be applied to different strings.
  *  <p>
  *  Regular expression matching operations work directly on the application's
  *  string data.  No copy is made.  The subject string data must not be
  *  altered after calling this function until after all regular expression
  *  operations involving this string data are completed.  
  *  <p>
  *  Zero length strings are permitted.  In this case, no subsequent match
  *  operation will dereference the text string pointer.
  *
  * @param regexp     The compiled regular expression.
  * @param text       The subject text string.
  * @param textLength The length of the subject text, or -1 if the string
  *                   is NUL terminated.
  * @param status     Receives errors detected by this function.
  * @stable ICU 3.0
  */
U_STABLE void U_EXPORT2 
uregex_setText(URegularExpression *regexp,
               const UChar        *text,
               int32_t             textLength,
               UErrorCode         *status);


/**
  *  Set the subject text string upon which the regular expression will look for matches.
  *  This function may be called any number of times, allowing the regular
  *  expression pattern to be applied to different strings.
  *  <p>
  *  Regular expression matching operations work directly on the application's
  *  string data; only a shallow clone is made.  The subject string data must not be
  *  altered after calling this function until after all regular expression
  *  operations involving this string data are completed.  
  *
  * @param regexp     The compiled regular expression.
  * @param text       The subject text string.
  * @param status     Receives errors detected by this function.
  *
  * @stable ICU 4.6
  */
U_STABLE void U_EXPORT2 
uregex_setUText(URegularExpression *regexp,
                UText              *text,
                UErrorCode         *status);

/**
  *  Get the subject text that is currently associated with this 
  *   regular expression object.  If the input was supplied using uregex_setText(),
  *   that pointer will be returned.  Otherwise, the characters in the input will
  *   be extracted to a buffer and returned.  In either case, ownership remains
  *   with the regular expression object.
  *
  *  This function will work even if the input was originally specified as a UText.
  *
  * @param regexp      The compiled regular expression.
  * @param textLength  The length of the string is returned in this output parameter. 
  *                    A NULL pointer may be used here if the
  *                    text length is not needed, as would be the case if
  *                    the text is known in advance to be a NUL terminated
  *                    string.
  * @param status      Receives errors detected by this function.
  * @return            Pointer to the subject text string currently associated with
  *                    this regular expression.
  * @stable ICU 3.0
  */
U_STABLE const UChar * U_EXPORT2 
uregex_getText(URegularExpression *regexp,
               int32_t            *textLength,
               UErrorCode         *status);

/**
  *  Get the subject text that is currently associated with this 
  *   regular expression object.
  *
  *  This function will work even if the input was originally specified as a UChar string.
  *
  * @param regexp      The compiled regular expression.
  * @param dest        A mutable UText in which to store the current input.
  *                    If NULL, a new UText will be created as an immutable shallow clone
  *                    of the actual input string.
  * @param status      Receives errors detected by this function.
  * @return            The subject text currently associated with this regular expression.
  *                    If a pre-allocated UText was provided, it will always be used and returned.
  *
  * @stable ICU 4.6
  */
U_STABLE UText * U_EXPORT2 
uregex_getUText(URegularExpression *regexp,
                UText              *dest,
                UErrorCode         *status);

/**
  *  Set the subject text string upon which the regular expression is looking for matches
  *  without changing any other aspect of the matching state.
  *  The new and previous text strings must have the same content.
  *
  *  This function is intended for use in environments where ICU is operating on 
  *  strings that may move around in memory.  It provides a mechanism for notifying
  *  ICU that the string has been relocated, and providing a new UText to access the
  *  string in its new position.
  *
  *  Note that the regular expression implementation never copies the underlying text
  *  of a string being matched, but always operates directly on the original text 
  *  provided by the user. Refreshing simply drops the references to the old text 
  *  and replaces them with references to the new.
  *
  *  Caution:  this function is normally used only by very specialized
  *            system-level code.   One example use case is with garbage collection 
  *            that moves the text in memory. 
  *
  * @param regexp     The compiled regular expression.
  * @param text       The new (moved) text string.
  * @param status     Receives errors detected by this function.
  *
  * @stable ICU 4.8
  */
U_STABLE void U_EXPORT2 
uregex_refreshUText(URegularExpression *regexp,
                    UText              *text,
                    UErrorCode         *status);

/**
  *   Attempts to match the input string against the pattern.
  *   To succeed, the match must extend to the end of the string,
  *   or cover the complete match region.
  *
  *   If startIndex >= zero the match operation starts at the specified
  *   index and must extend to the end of the input string.  Any region
  *   that has been specified is reset.
  *
  *   If startIndex == -1 the match must cover the input region, or the entire
  *   input string if no region has been set.  This directly corresponds to
  *   Matcher.matches() in Java
  *
  *    @param  regexp      The compiled regular expression.
  *    @param  startIndex  The input string (native) index at which to begin matching, or -1
  *                        to match the input Region.
  *    @param  status      Receives errors detected by this function.
  *    @return             TRUE if there is a match
  *    @stable ICU 3.0
  */
U_STABLE UBool U_EXPORT2 
uregex_matches(URegularExpression *regexp,
                int32_t            startIndex,
                UErrorCode        *status);

/**
  *   64bit version of uregex_matches.
  *   Attempts to match the input string against the pattern.
  *   To succeed, the match must extend to the end of the string,
  *   or cover the complete match region.
  *
  *   If startIndex >= zero the match operation starts at the specified
  *   index and must extend to the end of the input string.  Any region
  *   that has been specified is reset.
  *
  *   If startIndex == -1 the match must cover the input region, or the entire
  *   input string if no region has been set.  This directly corresponds to
  *   Matcher.matches() in Java
  *
  *    @param  regexp      The compiled regular expression.
  *    @param  startIndex  The input string (native) index at which to begin matching, or -1
  *                        to match the input Region.
  *    @param  status      Receives errors detected by this function.
  *    @return             TRUE if there is a match
  *   @stable ICU 4.6
  */
U_STABLE UBool U_EXPORT2 
uregex_matches64(URegularExpression *regexp,
                 int64_t            startIndex,
                 UErrorCode        *status);

/**
  *   Attempts to match the input string, starting from the specified index, against the pattern.
  *   The match may be of any length, and is not required to extend to the end
  *   of the input string.  Contrast with uregex_matches().
  *
  *   <p>If startIndex is >= 0 any input region that was set for this
  *   URegularExpression is reset before the operation begins.
  *
  *   <p>If the specified starting index == -1 the match begins at the start of the input 
  *   region, or at the start of the full string if no region has been specified.
  *   This corresponds directly with Matcher.lookingAt() in Java.
  *
  *   <p>If the match succeeds then more information can be obtained via the
  *    <code>uregexp_start()</code>, <code>uregexp_end()</code>,
  *    and <code>uregex_group()</code> functions.</p>
  *
  *    @param   regexp      The compiled regular expression.
  *    @param   startIndex  The input string (native) index at which to begin matching, or
  *                         -1 to match the Input Region
  *    @param   status      A reference to a UErrorCode to receive any errors.
  *    @return  TRUE if there is a match.
  *    @stable ICU 3.0
  */
U_STABLE UBool U_EXPORT2 
uregex_lookingAt(URegularExpression *regexp,
                 int32_t             startIndex,
                 UErrorCode         *status);

/**
  *   64bit version of uregex_lookingAt.
  *   Attempts to match the input string, starting from the specified index, against the pattern.
  *   The match may be of any length, and is not required to extend to the end
  *   of the input string.  Contrast with uregex_matches().
  *
  *   <p>If startIndex is >= 0 any input region that was set for this
  *   URegularExpression is reset before the operation begins.
  *
  *   <p>If the specified starting index == -1 the match begins at the start of the input 
  *   region, or at the start of the full string if no region has been specified.
  *   This corresponds directly with Matcher.lookingAt() in Java.
  *
  *   <p>If the match succeeds then more information can be obtained via the
  *    <code>uregexp_start()</code>, <code>uregexp_end()</code>,
  *    and <code>uregex_group()</code> functions.</p>
  *
  *    @param   regexp      The compiled regular expression.
  *    @param   startIndex  The input string (native) index at which to begin matching, or
  *                         -1 to match the Input Region
  *    @param   status      A reference to a UErrorCode to receive any errors.
  *    @return  TRUE if there is a match.
  *    @stable ICU 4.6
  */
U_STABLE UBool U_EXPORT2 
uregex_lookingAt64(URegularExpression *regexp,
                   int64_t             startIndex,
                   UErrorCode         *status);

/**
  *   Find the first matching substring of the input string that matches the pattern.
  *   If startIndex is >= zero the search for a match begins at the specified index,
  *          and any match region is reset.  This corresponds directly with
  *          Matcher.find(startIndex) in Java.
  *
  *   If startIndex == -1 the search begins at the start of the input region,
  *           or at the start of the full string if no region has been specified.
  *
  *   If a match is found, <code>uregex_start(), uregex_end()</code>, and
  *   <code>uregex_group()</code> will provide more information regarding the match.
  *
  *   @param   regexp      The compiled regular expression.
  *   @param   startIndex  The position (native) in the input string to begin the search, or
  *                        -1 to search within the Input Region.
  *   @param   status      A reference to a UErrorCode to receive any errors.
  *   @return              TRUE if a match is found.
  *   @stable ICU 3.0
  */
U_STABLE UBool U_EXPORT2 
uregex_find(URegularExpression *regexp,
            int32_t             startIndex, 
            UErrorCode         *status);

/**
  *   64bit version of uregex_find.
  *   Find the first matching substring of the input string that matches the pattern.
  *   If startIndex is >= zero the search for a match begins at the specified index,
  *          and any match region is reset.  This corresponds directly with
  *          Matcher.find(startIndex) in Java.
  *
  *   If startIndex == -1 the search begins at the start of the input region,
  *           or at the start of the full string if no region has been specified.
  *
  *   If a match is found, <code>uregex_start(), uregex_end()</code>, and
  *   <code>uregex_group()</code> will provide more information regarding the match.
  *
  *   @param   regexp      The compiled regular expression.
  *   @param   startIndex  The position (native) in the input string to begin the search, or
  *                        -1 to search within the Input Region.
  *   @param   status      A reference to a UErrorCode to receive any errors.
  *   @return              TRUE if a match is found.
  *   @stable ICU 4.6
  */
U_STABLE UBool U_EXPORT2 
uregex_find64(URegularExpression *regexp,
              int64_t             startIndex, 
              UErrorCode         *status);

/**
  *  Find the next pattern match in the input string.  Begin searching 
  *  the input at the location following the end of he previous match, 
  *  or at the start of the string (or region) if there is no 
  *  previous match.  If a match is found, <code>uregex_start(), uregex_end()</code>, and
  *  <code>uregex_group()</code> will provide more information regarding the match.
  *
  *  @param   regexp      The compiled regular expression.
  *  @param   status      A reference to a UErrorCode to receive any errors.
  *  @return              TRUE if a match is found.
  *  @see uregex_reset
  *  @stable ICU 3.0
  */
U_STABLE UBool U_EXPORT2 
uregex_findNext(URegularExpression *regexp,
                UErrorCode         *status);

/**
  *   Get the number of capturing groups in this regular expression's pattern.
  *   @param   regexp      The compiled regular expression.
  *   @param   status      A reference to a UErrorCode to receive any errors.
  *   @return the number of capture groups
  *   @stable ICU 3.0
  */
U_STABLE int32_t U_EXPORT2 
uregex_groupCount(URegularExpression *regexp,
                  UErrorCode         *status);

/**
  * Get the group number corresponding to a named capture group.
  * The returned number can be used with any function that access
  * capture groups by number.
  *
  * The function returns an error status if the specified name does not
  * appear in the pattern.
  *
  * @param  regexp      The compiled regular expression.
  * @param  groupName   The capture group name.
  * @param  nameLength  The length of the name, or -1 if the name is a
  *                     nul-terminated string.
  * @param  status      A pointer to a UErrorCode to receive any errors.
  *
  * @stable ICU 55
  */
U_STABLE int32_t U_EXPORT2
uregex_groupNumberFromName(URegularExpression *regexp,
                           const UChar        *groupName,
                           int32_t             nameLength,
                           UErrorCode          *status);


/**
  * Get the group number corresponding to a named capture group.
  * The returned number can be used with any function that access
  * capture groups by number.
  *
  * The function returns an error status if the specified name does not
  * appear in the pattern.
  *
  * @param  regexp      The compiled regular expression.
  * @param  groupName   The capture group name,
  *                     platform invariant characters only.
  * @param  nameLength  The length of the name, or -1 if the name is
  *                     nul-terminated.
  * @param  status      A pointer to a UErrorCode to receive any errors.
  *
  * @stable ICU 55
  */
U_STABLE int32_t U_EXPORT2
uregex_groupNumberFromCName(URegularExpression *regexp,
                            const char         *groupName,
                            int32_t             nameLength,
                            UErrorCode          *status);

/** Extract the string for the specified matching expression or subexpression.
  * Group #0 is the complete string of matched text.
  * Group #1 is the text matched by the first set of capturing parentheses.
  *
  *   @param   regexp       The compiled regular expression.
  *   @param   groupNum     The capture group to extract.  Group 0 is the complete
  *                         match.  The value of this parameter must be
  *                         less than or equal to the number of capture groups in
  *                         the pattern.
  *   @param   dest         Buffer to receive the matching string data
  *   @param   destCapacity Capacity of the dest buffer.
  *   @param   status       A reference to a UErrorCode to receive any errors.
  *   @return               Length of matching data,
  *                         or -1 if no applicable match.
  *   @stable ICU 3.0
  */
U_STABLE int32_t U_EXPORT2 
uregex_group(URegularExpression *regexp,
             int32_t             groupNum,
             UChar              *dest,
             int32_t             destCapacity,
             UErrorCode          *status);

/** Returns a shallow immutable clone of the entire input string with the current index set
  *   to the beginning of the requested capture group.  The capture group length is also
  *   returned via groupLength.
  * Group #0 is the complete string of matched text.
  * Group #1 is the text matched by the first set of capturing parentheses.
  *
  *   @param   regexp       The compiled regular expression.
  *   @param   groupNum     The capture group to extract.  Group 0 is the complete
  *                         match.  The value of this parameter must be
  *                         less than or equal to the number of capture groups in
  *                         the pattern.
  *   @param   dest         A mutable UText in which to store the current input.
  *                         If NULL, a new UText will be created as an immutable shallow clone
  *                         of the entire input string.
  *   @param   groupLength  The group length of the desired capture group. Output parameter.
  *   @param   status       A reference to a UErrorCode to receive any errors.
  *   @return               The subject text currently associated with this regular expression.
  *                         If a pre-allocated UText was provided, it will always be used and returned.

  *
  *   @stable ICU 4.6
  */
U_STABLE UText * U_EXPORT2 
uregex_groupUText(URegularExpression *regexp,
                  int32_t             groupNum,
                  UText              *dest,
                  int64_t            *groupLength,
                  UErrorCode         *status);

/**
  *   Returns the index in the input string of the start of the text matched by the
  *   specified capture group during the previous match operation.  Return -1 if
  *   the capture group was not part of the last match.
  *   Group #0 refers to the complete range of matched text.
  *   Group #1 refers to the text matched by the first set of capturing parentheses.
  *
  *    @param   regexp      The compiled regular expression.
  *    @param   groupNum    The capture group number
  *    @param   status      A reference to a UErrorCode to receive any errors.
  *    @return              the starting (native) position in the input of the text matched 
  *                         by the specified group.
  *    @stable ICU 3.0
  */
U_STABLE int32_t U_EXPORT2 
uregex_start(URegularExpression *regexp,
             int32_t             groupNum,
             UErrorCode          *status);

/**
  *   64bit version of uregex_start.
  *   Returns the index in the input string of the start of the text matched by the
  *   specified capture group during the previous match operation.  Return -1 if
  *   the capture group was not part of the last match.
  *   Group #0 refers to the complete range of matched text.
  *   Group #1 refers to the text matched by the first set of capturing parentheses.
  *
  *    @param   regexp      The compiled regular expression.
  *    @param   groupNum    The capture group number
  *    @param   status      A reference to a UErrorCode to receive any errors.
  *    @return              the starting (native) position in the input of the text matched 
  *                         by the specified group.
  *   @stable ICU 4.6
  */
U_STABLE int64_t U_EXPORT2 
uregex_start64(URegularExpression *regexp,
               int32_t             groupNum,
               UErrorCode          *status);

/**
  *   Returns the index in the input string of the position following the end
  *   of the text matched by the specified capture group.
  *   Return -1 if the capture group was not part of the last match.
  *   Group #0 refers to the complete range of matched text.
  *   Group #1 refers to the text matched by the first set of capturing parentheses.
  *
  *    @param   regexp      The compiled regular expression.
  *    @param   groupNum    The capture group number
  *    @param   status      A reference to a UErrorCode to receive any errors.
  *    @return              the (native) index of the position following the last matched character.
  *    @stable ICU 3.0
  */
U_STABLE int32_t U_EXPORT2 
uregex_end(URegularExpression   *regexp,
           int32_t               groupNum,
           UErrorCode           *status);

/**
  *   64bit version of uregex_end.
  *   Returns the index in the input string of the position following the end
  *   of the text matched by the specified capture group.
  *   Return -1 if the capture group was not part of the last match.
  *   Group #0 refers to the complete range of matched text.
  *   Group #1 refers to the text matched by the first set of capturing parentheses.
  *
  *    @param   regexp      The compiled regular expression.
  *    @param   groupNum    The capture group number
  *    @param   status      A reference to a UErrorCode to receive any errors.
  *    @return              the (native) index of the position following the last matched character.
  *   @stable ICU 4.6
  */
U_STABLE int64_t U_EXPORT2 
uregex_end64(URegularExpression *regexp,
             int32_t               groupNum,
             UErrorCode           *status);

/**
  *  Reset any saved state from the previous match.  Has the effect of
  *  causing uregex_findNext to begin at the specified index, and causing
  *  uregex_start(), uregex_end() and uregex_group() to return an error 
  *  indicating that there is no match information available.  Clears any
  *  match region that may have been set.
  *
  *    @param   regexp      The compiled regular expression.
  *    @param   index       The position (native) in the text at which a
  *                         uregex_findNext() should begin searching.
  *    @param   status      A reference to a UErrorCode to receive any errors.
  *    @stable ICU 3.0
  */
U_STABLE void U_EXPORT2 
uregex_reset(URegularExpression    *regexp,
             int32_t               index,
             UErrorCode            *status);

/**
  *  64bit version of uregex_reset.
  *  Reset any saved state from the previous match.  Has the effect of
  *  causing uregex_findNext to begin at the specified index, and causing
  *  uregex_start(), uregex_end() and uregex_group() to return an error 
  *  indicating that there is no match information available.  Clears any
  *  match region that may have been set.
  *
  *    @param   regexp      The compiled regular expression.
  *    @param   index       The position (native) in the text at which a
  *                         uregex_findNext() should begin searching.
  *    @param   status      A reference to a UErrorCode to receive any errors.
  *    @stable ICU 4.6
  */
U_STABLE void U_EXPORT2 
uregex_reset64(URegularExpression  *regexp,
               int64_t               index,
               UErrorCode            *status);

/**
  * Sets the limits of the matching region for this URegularExpression.
  * The region is the part of the input string that will be considered when matching.
  * Invoking this method resets any saved state from the previous match, 
  * then sets the region to start at the index specified by the start parameter
  * and end at the index specified by the end parameter.
  *
  * Depending on the transparency and anchoring being used (see useTransparentBounds
  * and useAnchoringBounds), certain constructs such as anchors may behave differently
  * at or around the boundaries of the region
  *
  * The function will fail if start is greater than limit, or if either index
  *  is less than zero or greater than the length of the string being matched.
  *
  * @param regexp The compiled regular expression.
  * @param regionStart  The (native) index to begin searches at.
  * @param regionLimit  The (native) index to end searches at (exclusive).
  * @param status A pointer to a UErrorCode to receive any errors.
  * @stable ICU 4.0
  */
U_STABLE void U_EXPORT2
uregex_setRegion(URegularExpression   *regexp,
                 int32_t               regionStart,
                 int32_t               regionLimit,
                 UErrorCode           *status);

/**
  * 64bit version of uregex_setRegion.
  * Sets the limits of the matching region for this URegularExpression.
  * The region is the part of the input string that will be considered when matching.
  * Invoking this method resets any saved state from the previous match, 
  * then sets the region to start at the index specified by the start parameter
  * and end at the index specified by the end parameter.
  *
  * Depending on the transparency and anchoring being used (see useTransparentBounds
  * and useAnchoringBounds), certain constructs such as anchors may behave differently
  * at or around the boundaries of the region
  *
  * The function will fail if start is greater than limit, or if either index
  *  is less than zero or greater than the length of the string being matched.
  *
  * @param regexp The compiled regular expression.
  * @param regionStart  The (native) index to begin searches at.
  * @param regionLimit  The (native) index to end searches at (exclusive).
  * @param status A pointer to a UErrorCode to receive any errors.
  * @stable ICU 4.6
  */
U_STABLE void U_EXPORT2 
uregex_setRegion64(URegularExpression *regexp,
                 int64_t               regionStart,
                 int64_t               regionLimit,
                 UErrorCode           *status);

/**
  *  Set the matching region and the starting index for subsequent matches
  *  in a single operation.
  *  This is useful because the usual function for setting the starting
  *  index, urgex_reset(), also resets any region limits.
  *
  * @param regexp The compiled regular expression.
  * @param regionStart  The (native) index to begin searches at.
  * @param regionLimit  The (native) index to end searches at (exclusive).
  * @param startIndex   The index in the input text at which the next 
  *                     match operation should begin.
  * @param status A pointer to a UErrorCode to receive any errors.
  * @stable ICU 4.6
  */
U_STABLE void U_EXPORT2 
uregex_setRegionAndStart(URegularExpression *regexp,
                 int64_t               regionStart,
                 int64_t               regionLimit,
                 int64_t               startIndex,
                 UErrorCode           *status);

/**
  * Reports the start index of the matching region. Any matches found are limited to
  * to the region bounded by regionStart (inclusive) and regionEnd (exclusive).
  *
  * @param regexp The compiled regular expression.
  * @param status A pointer to a UErrorCode to receive any errors.
  * @return The starting (native) index of this matcher's region.
  * @stable ICU 4.0
  */
U_STABLE int32_t U_EXPORT2
uregex_regionStart(const  URegularExpression   *regexp,
                          UErrorCode           *status);

/**
  * 64bit version of uregex_regionStart.
  * Reports the start index of the matching region. Any matches found are limited to
  * to the region bounded by regionStart (inclusive) and regionEnd (exclusive).
  *
  * @param regexp The compiled regular expression.
  * @param status A pointer to a UErrorCode to receive any errors.
  * @return The starting (native) index of this matcher's region.
  * @stable ICU 4.6
  */
U_STABLE int64_t U_EXPORT2 
uregex_regionStart64(const  URegularExpression   *regexp,
                            UErrorCode           *status);

/**
  * Reports the end index (exclusive) of the matching region for this URegularExpression.
  * Any matches found are limited to to the region bounded by regionStart (inclusive)
  * and regionEnd (exclusive).
  *
  * @param regexp The compiled regular expression.
  * @param status A pointer to a UErrorCode to receive any errors.
  * @return The ending point (native) of this matcher's region.
  * @stable ICU 4.0
  */
U_STABLE int32_t U_EXPORT2
uregex_regionEnd(const  URegularExpression   *regexp,
                        UErrorCode           *status);

/**
  * 64bit version of uregex_regionEnd.
  * Reports the end index (exclusive) of the matching region for this URegularExpression.
  * Any matches found are limited to to the region bounded by regionStart (inclusive)
  * and regionEnd (exclusive).
  *
  * @param regexp The compiled regular expression.
  * @param status A pointer to a UErrorCode to receive any errors.
  * @return The ending point (native) of this matcher's region.
  * @stable ICU 4.6
  */
U_STABLE int64_t U_EXPORT2 
uregex_regionEnd64(const  URegularExpression   *regexp,
                          UErrorCode           *status);

/**
  * Queries the transparency of region bounds for this URegularExpression.
  * See useTransparentBounds for a description of transparent and opaque bounds.
  * By default, matching boundaries are opaque.
  *
  * @param regexp The compiled regular expression.
  * @param status A pointer to a UErrorCode to receive any errors.
  * @return TRUE if this matcher is using opaque bounds, false if it is not.
  * @stable ICU 4.0
  */
U_STABLE UBool U_EXPORT2
uregex_hasTransparentBounds(const  URegularExpression   *regexp,
                                   UErrorCode           *status);


/**
  * Sets the transparency of region bounds for this URegularExpression.
  * Invoking this function with an argument of TRUE will set matches to use transparent bounds.
  * If the boolean argument is FALSE, then opaque bounds will be used.
  *
  * Using transparent bounds, the boundaries of the matching region are transparent
  * to lookahead, lookbehind, and boundary matching constructs. Those constructs can
  * see text beyond the boundaries of the region while checking for a match.
  *
  * With opaque bounds, no text outside of the matching region is visible to lookahead,
  * lookbehind, and boundary matching constructs.
  *
  * By default, opaque bounds are used.
  *
  * @param   regexp The compiled regular expression.
  * @param   b      TRUE for transparent bounds; FALSE for opaque bounds
  * @param   status A pointer to a UErrorCode to receive any errors.
  * @stable ICU 4.0
  **/
U_STABLE void U_EXPORT2  
uregex_useTransparentBounds(URegularExpression   *regexp, 
                            UBool                b,
                            UErrorCode           *status);


/**
  * Return true if this URegularExpression is using anchoring bounds.
  * By default, anchoring region bounds are used.
  *
  * @param  regexp The compiled regular expression.
  * @param  status A pointer to a UErrorCode to receive any errors.
  * @return TRUE if this matcher is using anchoring bounds.
  * @stable ICU 4.0
  */
U_STABLE UBool U_EXPORT2
uregex_hasAnchoringBounds(const  URegularExpression   *regexp,
                                 UErrorCode           *status);


/**
  * Set whether this URegularExpression is using Anchoring Bounds for its region.
  * With anchoring bounds, pattern anchors such as ^ and $ will match at the start
  * and end of the region.  Without Anchoring Bounds, anchors will only match at
  * the positions they would in the complete text.
  *
  * Anchoring Bounds are the default for regions.
  *
  * @param regexp The compiled regular expression.
  * @param b      TRUE if to enable anchoring bounds; FALSE to disable them.
  * @param status A pointer to a UErrorCode to receive any errors.
  * @stable ICU 4.0
  */
U_STABLE void U_EXPORT2
uregex_useAnchoringBounds(URegularExpression   *regexp,
                          UBool                 b,
                          UErrorCode           *status);

/**
  * Return TRUE if the most recent matching operation touched the
  *  end of the text being processed.  In this case, additional input text could
  *  change the results of that match.
  *
  *  @param regexp The compiled regular expression.
  *  @param status A pointer to a UErrorCode to receive any errors.
  *  @return  TRUE if the most recent match hit the end of input
  *  @stable ICU 4.0
  */
U_STABLE UBool U_EXPORT2
uregex_hitEnd(const  URegularExpression   *regexp,
                     UErrorCode           *status);

/**
  * Return TRUE the most recent match succeeded and additional input could cause
  * it to fail. If this function returns false and a match was found, then more input
  * might change the match but the match won't be lost. If a match was not found,
  * then requireEnd has no meaning.
  *
  * @param regexp The compiled regular expression.
  * @param status A pointer to a UErrorCode to receive any errors.
  * @return TRUE  if more input could cause the most recent match to no longer match.
  * @stable ICU 4.0
  */
U_STABLE UBool U_EXPORT2   
uregex_requireEnd(const  URegularExpression   *regexp,
                         UErrorCode           *status);





/**
  *    Replaces every substring of the input that matches the pattern
  *    with the given replacement string.  This is a convenience function that
  *    provides a complete find-and-replace-all operation.
  *
  *    This method scans the input string looking for matches of the pattern. 
  *    Input that is not part of any match is copied unchanged to the
  *    destination buffer.  Matched regions are replaced in the output
  *    buffer by the replacement string.   The replacement string may contain
  *    references to capture groups; these take the form of $1, $2, etc.
  *
  *    @param   regexp             The compiled regular expression.
  *    @param   replacementText    A string containing the replacement text.
  *    @param   replacementLength  The length of the replacement string, or
  *                                -1 if it is NUL terminated.
  *    @param   destBuf            A (UChar *) buffer that will receive the result.
  *    @param   destCapacity       The capacity of the destination buffer.
  *    @param   status             A reference to a UErrorCode to receive any errors.
  *    @return                     The length of the string resulting from the find
  *                                and replace operation.  In the event that the
  *                                destination capacity is inadequate, the return value
  *                                is still the full length of the untruncated string.
  *    @stable ICU 3.0
  */
U_STABLE int32_t U_EXPORT2 
uregex_replaceAll(URegularExpression    *regexp,
                  const UChar           *replacementText,
                  int32_t                replacementLength,
                  UChar                 *destBuf,
                  int32_t                destCapacity,
                  UErrorCode            *status);

/**
  *    Replaces every substring of the input that matches the pattern
  *    with the given replacement string.  This is a convenience function that
  *    provides a complete find-and-replace-all operation.
  *
  *    This method scans the input string looking for matches of the pattern. 
  *    Input that is not part of any match is copied unchanged to the
  *    destination buffer.  Matched regions are replaced in the output
  *    buffer by the replacement string.   The replacement string may contain
  *    references to capture groups; these take the form of $1, $2, etc.
  *
  *    @param   regexp         The compiled regular expression.
  *    @param   replacement    A string containing the replacement text.
  *    @param   dest           A mutable UText that will receive the result.
  *                             If NULL, a new UText will be created (which may not be mutable).
  *    @param   status         A reference to a UErrorCode to receive any errors.
  *    @return                 A UText containing the results of the find and replace.
  *                             If a pre-allocated UText was provided, it will always be used and returned.
  *
  *    @stable ICU 4.6
  */
U_STABLE UText * U_EXPORT2 
uregex_replaceAllUText(URegularExpression *regexp,
                       UText              *replacement,
                       UText              *dest,
                       UErrorCode         *status);

/**
  *    Replaces the first substring of the input that matches the pattern
  *    with the given replacement string.  This is a convenience function that
  *    provides a complete find-and-replace operation.
  *
  *    This method scans the input string looking for a match of the pattern. 
  *    All input that is not part of the match is copied unchanged to the
  *    destination buffer.  The matched region is replaced in the output
  *    buffer by the replacement string.   The replacement string may contain
  *    references to capture groups; these take the form of $1, $2, etc.
  *
  *    @param   regexp             The compiled regular expression.
  *    @param   replacementText    A string containing the replacement text.
  *    @param   replacementLength  The length of the replacement string, or
  *                                -1 if it is NUL terminated.
  *    @param   destBuf            A (UChar *) buffer that will receive the result.
  *    @param   destCapacity       The capacity of the destination buffer.
  *    @param   status             a reference to a UErrorCode to receive any errors.
  *    @return                     The length of the string resulting from the find
  *                                and replace operation.  In the event that the
  *                                destination capacity is inadequate, the return value
  *                                is still the full length of the untruncated string.
  *    @stable ICU 3.0
  */
U_STABLE int32_t U_EXPORT2 
uregex_replaceFirst(URegularExpression  *regexp,
                    const UChar         *replacementText,
                    int32_t              replacementLength,
                    UChar               *destBuf,
                    int32_t              destCapacity,
                    UErrorCode          *status);

/**
  *    Replaces the first substring of the input that matches the pattern
  *    with the given replacement string.  This is a convenience function that
  *    provides a complete find-and-replace operation.
  *
  *    This method scans the input string looking for a match of the pattern. 
  *    All input that is not part of the match is copied unchanged to the
  *    destination buffer.  The matched region is replaced in the output
  *    buffer by the replacement string.   The replacement string may contain
  *    references to capture groups; these take the form of $1, $2, etc.
  *
  *    @param   regexp         The compiled regular expression.
  *    @param   replacement    A string containing the replacement text.
  *    @param   dest           A mutable UText that will receive the result.
  *                             If NULL, a new UText will be created (which may not be mutable).
  *    @param   status         A reference to a UErrorCode to receive any errors.
  *    @return                 A UText containing the results of the find and replace.
  *                             If a pre-allocated UText was provided, it will always be used and returned.
  *
  *    @stable ICU 4.6
  */
U_STABLE UText * U_EXPORT2 
uregex_replaceFirstUText(URegularExpression *regexp,
                         UText              *replacement,
                         UText              *dest,
                         UErrorCode         *status);

/**
  *   Implements a replace operation intended to be used as part of an
  *   incremental find-and-replace.
  *
  *   <p>The input string, starting from the end of the previous match and ending at
  *   the start of the current match, is appended to the destination string.  Then the
  *   replacement string is appended to the output string,
  *   including handling any substitutions of captured text.</p>
  *
  *   <p>A note on preflight computation of buffersize and error handling:
  *   Calls to uregex_appendReplacement() and uregex_appendTail() are
  *   designed to be chained, one after another, with the destination
  *   buffer pointer and buffer capacity updated after each in preparation
  *   to for the next.  If the destination buffer is exhausted partway through such a
  *   sequence, a U_BUFFER_OVERFLOW_ERROR status will be returned.  Normal
  *   ICU conventions are for a function to perform no action if it is
  *   called with an error status, but for this one case, uregex_appendRepacement()
  *   will operate normally so that buffer size computations will complete
  *   correctly.
  *
  *   <p>For simple, prepackaged, non-incremental find-and-replace
  *      operations, see replaceFirst() or replaceAll().</p>
  *
  *   @param   regexp      The regular expression object.  
  *   @param   replacementText The string that will replace the matched portion of the
  *                        input string as it is copied to the destination buffer.
  *                        The replacement text may contain references ($1, for
  *                        example) to capture groups from the match.
  *   @param   replacementLength  The length of the replacement text string,
  *                        or -1 if the string is NUL terminated.
  *   @param   destBuf     The buffer into which the results of the
  *                        find-and-replace are placed.  On return, this pointer
  *                        will be updated to refer to the beginning of the
  *                        unused portion of buffer, leaving it in position for
  *                        a subsequent call to this function.
  *   @param   destCapacity The size of the output buffer,  On return, this
  *                        parameter will be updated to reflect the space remaining
  *                        unused in the output buffer.
  *   @param   status      A reference to a UErrorCode to receive any errors. 
  *   @return              The length of the result string.  In the event that
  *                        destCapacity is inadequate, the full length of the
  *                        untruncated output string is returned.
  *
  *   @stable ICU 3.0
  *
  */
U_STABLE int32_t U_EXPORT2 
uregex_appendReplacement(URegularExpression    *regexp,
                         const UChar           *replacementText,
                         int32_t                replacementLength,
                         UChar                **destBuf,
                         int32_t               *destCapacity,
                         UErrorCode            *status);

/**
  *   Implements a replace operation intended to be used as part of an
  *   incremental find-and-replace.
  *
  *   <p>The input string, starting from the end of the previous match and ending at
  *   the start of the current match, is appended to the destination string.  Then the
  *   replacement string is appended to the output string,
  *   including handling any substitutions of captured text.</p>
  *
  *   <p>For simple, prepackaged, non-incremental find-and-replace
  *      operations, see replaceFirst() or replaceAll().</p>
  *
  *   @param   regexp      The regular expression object.  
  *   @param   replacementText The string that will replace the matched portion of the
  *                        input string as it is copied to the destination buffer.
  *                        The replacement text may contain references ($1, for
  *                        example) to capture groups from the match.
  *   @param   dest        A mutable UText that will receive the result. Must not be NULL.
  *   @param   status      A reference to a UErrorCode to receive any errors. 
  *
  *   @stable ICU 4.6
  */
U_STABLE void U_EXPORT2 
uregex_appendReplacementUText(URegularExpression    *regexp,
                              UText                 *replacementText,
                              UText                 *dest,
                              UErrorCode            *status);

/**
  * As the final step in a find-and-replace operation, append the remainder
  * of the input string, starting at the position following the last match,
  * to the destination string. <code>uregex_appendTail()</code> is intended 
  *  to be invoked after one or more invocations of the
  *  <code>uregex_appendReplacement()</code> function.
  *
  *   @param   regexp      The regular expression object.  This is needed to 
  *                        obtain the input string and with the position
  *                        of the last match within it.
  *   @param   destBuf     The buffer in which the results of the
  *                        find-and-replace are placed.  On return, the pointer
  *                        will be updated to refer to the beginning of the
  *                        unused portion of buffer.
  *   @param   destCapacity The size of the output buffer,  On return, this
  *                        value will be updated to reflect the space remaining
  *                        unused in the output buffer.
  *   @param   status      A reference to a UErrorCode to receive any errors. 
  *   @return              The length of the result string.  In the event that
  *                        destCapacity is inadequate, the full length of the
  *                        untruncated output string is returned.
  *
  *   @stable ICU 3.0
  */
U_STABLE int32_t U_EXPORT2 
uregex_appendTail(URegularExpression    *regexp,
                  UChar                **destBuf,
                  int32_t               *destCapacity,
                  UErrorCode            *status);

/**
  * As the final step in a find-and-replace operation, append the remainder
  * of the input string, starting at the position following the last match,
  * to the destination string. <code>uregex_appendTailUText()</code> is intended 
  *  to be invoked after one or more invocations of the
  *  <code>uregex_appendReplacementUText()</code> function.
  *
  *   @param   regexp      The regular expression object.  This is needed to 
  *                        obtain the input string and with the position
  *                        of the last match within it.
  *   @param   dest        A mutable UText that will receive the result. Must not be NULL.
  *
  *   @param status        Error code
  *
  *   @return              The destination UText.
  *
  *   @stable ICU 4.6
  */
U_STABLE UText * U_EXPORT2 
uregex_appendTailUText(URegularExpression    *regexp,
                       UText                 *dest,
                       UErrorCode            *status);

 /**
   * Split a string into fields.  Somewhat like split() from Perl.
   *  The pattern matches identify delimiters that separate the input
   *  into fields.  The input data between the matches becomes the
   *  fields themselves.
   *
   *  Each of the fields is copied from the input string to the destination
   *  buffer, and NUL terminated.  The position of each field within
   *  the destination buffer is returned in the destFields array.
   *
   *  If the delimiter pattern includes capture groups, the captured text will
   *  also appear in the destination array of output strings, interspersed
   *  with the fields.  This is similar to Perl, but differs from Java, 
   *  which ignores the presence of capture groups in the pattern.
   * 
   *  Trailing empty fields will always be returned, assuming sufficient
   *  destination capacity.  This differs from the default behavior for Java
   *  and Perl where trailing empty fields are not returned.
   *
   *  The number of strings produced by the split operation is returned.
   *  This count includes the strings from capture groups in the delimiter pattern.
   *  This behavior differs from Java, which ignores capture groups.
   * 
   *    @param   regexp      The compiled regular expression.
   *    @param   destBuf     A (UChar *) buffer to receive the fields that
   *                         are extracted from the input string. These
   *                         field pointers will refer to positions within the
   *                         destination buffer supplied by the caller.  Any
   *                         extra positions within the destFields array will be
   *                         set to NULL.
   *    @param   destCapacity The capacity of the destBuf.
   *    @param   requiredCapacity  The actual capacity required of the destBuf.
   *                         If destCapacity is too small, requiredCapacity will return 
   *                         the total capacity required to hold all of the output, and
   *                         a U_BUFFER_OVERFLOW_ERROR will be returned.
   *    @param   destFields  An array to be filled with the position of each
   *                         of the extracted fields within destBuf.
   *    @param   destFieldsCapacity  The number of elements in the destFields array.
   *                If the number of fields found is less than destFieldsCapacity,
   *                the extra destFields elements are set to zero.
   *                If destFieldsCapacity is too small, the trailing part of the
   *                input, including any field delimiters, is treated as if it
   *                were the last field - it is copied to the destBuf, and
   *                its position is in the destBuf is stored in the last element
   *                of destFields.  This behavior mimics that of Perl.  It is not
   *                an error condition, and no error status is returned when all destField
   *                positions are used.
   * @param status  A reference to a UErrorCode to receive any errors.
   * @return        The number of fields into which the input string was split.
   * @stable ICU 3.0
   */
U_STABLE int32_t U_EXPORT2 
uregex_split(   URegularExpression      *regexp,
                  UChar                 *destBuf,
                  int32_t                destCapacity,
                  int32_t               *requiredCapacity,
                  UChar                 *destFields[],
                  int32_t                destFieldsCapacity,
                  UErrorCode            *status);

  /**
   * Split a string into fields.  Somewhat like split() from Perl.
   * The pattern matches identify delimiters that separate the input
   *  into fields.  The input data between the matches becomes the
   *  fields themselves.
   * <p>
   * The behavior of this function is not very closely aligned with uregex_split();
   * instead, it is based on (and implemented directly on top of) the C++ split method.
   *
   * @param regexp  The compiled regular expression.
   * @param destFields    An array of mutable UText structs to receive the results of the split.
   *                If a field is NULL, a new UText is allocated to contain the results for
   *                that field. This new UText is not guaranteed to be mutable.
   * @param destFieldsCapacity  The number of elements in the destination array.
   *                If the number of fields found is less than destCapacity, the
   *                extra strings in the destination array are not altered.
   *                If the number of destination strings is less than the number
   *                of fields, the trailing part of the input string, including any
   *                field delimiters, is placed in the last destination string.
   *                This behavior mimics that of Perl.  It is not  an error condition, and no
   *                error status is returned when all destField positions are used.
   * @param status  A reference to a UErrorCode to receive any errors.
   * @return        The number of fields into which the input string was split.
   *
   * @stable ICU 4.6
   */
U_STABLE int32_t U_EXPORT2 
uregex_splitUText(URegularExpression    *regexp,
                  UText                 *destFields[],
                  int32_t                destFieldsCapacity,
                  UErrorCode            *status);

/**
 * Set a processing time limit for match operations with this URegularExpression.
 *
 * Some patterns, when matching certain strings, can run in exponential time.
 * For practical purposes, the match operation may appear to be in an
 * infinite loop.
 * When a limit is set a match operation will fail with an error if the
 * limit is exceeded.
 * <p>
 * The units of the limit are steps of the match engine.
 * Correspondence with actual processor time will depend on the speed
 * of the processor and the details of the specific pattern, but will
 * typically be on the order of milliseconds.
 * <p>
 * By default, the matching time is not limited.
 * <p>
 *
 * @param   regexp      The compiled regular expression.
 * @param   limit       The limit value, or 0 for no limit.
 * @param   status      A reference to a UErrorCode to receive any errors.
 * @stable ICU 4.0
 */
U_STABLE void U_EXPORT2
uregex_setTimeLimit(URegularExpression      *regexp,
                    int32_t                  limit,
                    UErrorCode              *status);

/**
 * Get the time limit for for matches with this URegularExpression.
 * A return value of zero indicates that there is no limit.
 *
 * @param   regexp      The compiled regular expression.
 * @param   status      A reference to a UErrorCode to receive any errors.
 * @return the maximum allowed time for a match, in units of processing steps.
 * @stable ICU 4.0
 */
U_STABLE int32_t U_EXPORT2
uregex_getTimeLimit(const URegularExpression      *regexp,
                          UErrorCode              *status);

/**
 * Set the amount of heap storage available for use by the match backtracking stack.
 * <p>
 * ICU uses a backtracking regular expression engine, with the backtrack stack
 * maintained on the heap.  This function sets the limit to the amount of memory
 * that can be used  for this purpose.  A backtracking stack overflow will
 * result in an error from the match operation that caused it.
 * <p>
 * A limit is desirable because a malicious or poorly designed pattern can use
 * excessive memory, potentially crashing the process.  A limit is enabled
 * by default.
 * <p>
 * @param   regexp      The compiled regular expression.
 * @param   limit       The maximum size, in bytes, of the matching backtrack stack.
 *                      A value of zero means no limit.
 *                      The limit must be greater than or equal to zero.
 * @param   status      A reference to a UErrorCode to receive any errors.
 *
 * @stable ICU 4.0
 */
U_STABLE void U_EXPORT2
uregex_setStackLimit(URegularExpression      *regexp,
                     int32_t                  limit,
                     UErrorCode              *status);

/**
 * Get the size of the heap storage available for use by the back tracking stack.
 *
 * @return  the maximum backtracking stack size, in bytes, or zero if the
 *          stack size is unlimited.
 * @stable ICU 4.0
 */
U_STABLE int32_t U_EXPORT2
uregex_getStackLimit(const URegularExpression      *regexp,
                           UErrorCode              *status);


/**
 * Function pointer for a regular expression matching callback function.
 * When set, a callback function will be called periodically during matching
 * operations.  If the call back function returns FALSE, the matching
 * operation will be terminated early.
 *
 * Note:  the callback function must not call other functions on this
 *        URegularExpression.
 *
 * @param context  context pointer.  The callback function will be invoked
 *                 with the context specified at the time that
 *                 uregex_setMatchCallback() is called.
 * @param steps    the accumulated processing time, in match steps, 
 *                 for this matching operation.
 * @return         TRUE to continue the matching operation.
 *                 FALSE to terminate the matching operation.
 * @stable ICU 4.0
 */
U_CDECL_BEGIN
typedef UBool U_CALLCONV URegexMatchCallback (
                   const void *context,
                   int32_t     steps);
U_CDECL_END

/**
 * Set a callback function for this URegularExpression.
 * During matching operations the function will be called periodically,
 * giving the application the opportunity to terminate a long-running
 * match.
 *
 * @param   regexp      The compiled regular expression.
 * @param   callback    A pointer to the user-supplied callback function.
 * @param   context     User context pointer.  The value supplied at the
 *                      time the callback function is set will be saved
 *                      and passed to the callback each time that it is called.
 * @param   status      A reference to a UErrorCode to receive any errors.
 * @stable ICU 4.0
 */
U_STABLE void U_EXPORT2
uregex_setMatchCallback(URegularExpression      *regexp,
                        URegexMatchCallback     *callback,
                        const void              *context,
                        UErrorCode              *status);


/**
 *  Get the callback function for this URegularExpression.
 *
 * @param   regexp      The compiled regular expression.
 * @param   callback    Out parameter, receives a pointer to the user-supplied 
 *                      callback function.
 * @param   context     Out parameter, receives the user context pointer that
 *                      was set when uregex_setMatchCallback() was called.
 * @param   status      A reference to a UErrorCode to receive any errors.
 * @stable ICU 4.0
 */
U_STABLE void U_EXPORT2
uregex_getMatchCallback(const URegularExpression    *regexp,
                        URegexMatchCallback        **callback,
                        const void                 **context,
                        UErrorCode                  *status);

/**
 * Function pointer for a regular expression find callback function.
 * 
 * When set, a callback function will be called during a find operation
 * and for operations that depend on find, such as findNext, split and some replace
 * operations like replaceFirst.
 * The callback will usually be called after each attempt at a match, but this is not a
 * guarantee that the callback will be invoked at each character.  For finds where the
 * match engine is invoked at each character, this may be close to true, but less likely
 * for more optimized loops where the pattern is known to only start, and the match
 * engine invoked, at certain characters.
 * When invoked, this callback will specify the index at which a match operation is about
 * to be attempted, giving the application the opportunity to terminate a long-running
 * find operation.
 * 
 * If the call back function returns FALSE, the find operation will be terminated early.
 *
 * Note:  the callback function must not call other functions on this
 *        URegularExpression
 *
 * @param context  context pointer.  The callback function will be invoked
 *                 with the context specified at the time that
 *                 uregex_setFindProgressCallback() is called.
 * @param matchIndex  the next index at which a match attempt will be attempted for this
 *                 find operation.  If this callback interrupts the search, this is the
 *                 index at which a find/findNext operation may be re-initiated.
 * @return         TRUE to continue the matching operation.
 *                 FALSE to terminate the matching operation.
 * @stable ICU 4.6
 */
U_CDECL_BEGIN
typedef UBool U_CALLCONV URegexFindProgressCallback (
                   const void *context,
                   int64_t     matchIndex);
U_CDECL_END


/**
 *  Set the find progress callback function for this URegularExpression.
 *
 * @param   regexp      The compiled regular expression.
 * @param   callback    A pointer to the user-supplied callback function.
 * @param   context     User context pointer.  The value supplied at the
 *                      time the callback function is set will be saved
 *                      and passed to the callback each time that it is called.
 * @param   status      A reference to a UErrorCode to receive any errors.
 * @stable ICU 4.6
 */
U_STABLE void U_EXPORT2
uregex_setFindProgressCallback(URegularExpression              *regexp,
                                URegexFindProgressCallback      *callback,
                                const void                      *context,
                                UErrorCode                      *status);

/**
 *  Get the find progress callback function for this URegularExpression.
 *
 * @param   regexp      The compiled regular expression.
 * @param   callback    Out parameter, receives a pointer to the user-supplied 
 *                      callback function.
 * @param   context     Out parameter, receives the user context pointer that
 *                      was set when uregex_setFindProgressCallback() was called.
 * @param   status      A reference to a UErrorCode to receive any errors.
 * @stable ICU 4.6
 */
U_STABLE void U_EXPORT2
uregex_getFindProgressCallback(const URegularExpression          *regexp,
                                URegexFindProgressCallback        **callback,
                                const void                        **context,
                                UErrorCode                        *status);

#endif   /*  !UCONFIG_NO_REGULAR_EXPRESSIONS  */
#endif   /*  UREGEX_H  */