icuSources/common/uprops.c

   1 /*
   2 *******************************************************************************
   3 *
   4 *   Copyright (C) 2002-2006, International Business Machines
   5 *   Corporation and others.  All Rights Reserved.
   6 *
   7 *******************************************************************************
   8 *   file name:  uprops.h
   9 *   encoding:   US-ASCII
  10 *   tab size:   8 (not used)
  11 *   indentation:4
  12 *
  13 *   created on: 2002feb24
  14 *   created by: Markus W. Scherer
  15 *
  16 *   Implementations for mostly non-core Unicode character properties
  17 *   stored in uprops.icu.
  18 *
  19 *   With the APIs implemented here, almost all properties files and
  20 *   their associated implementation files are used from this file,
  21 *   including those for normalization and case mappings.
  22 */
  23
  24 #include "unicode/utypes.h"
  25 #include "unicode/uchar.h"
  26 #include "unicode/uscript.h"
  27 #include "cstring.h"
  28 #include "ucln_cmn.h"
  29 #include "umutex.h"
  30 #include "unormimp.h"
  31 #include "ubidi_props.h"
  32 #include "uprops.h"
  33 #include "ucase.h"
  34
  35 #define LENGTHOF(array) (int32_t)(sizeof(array)/sizeof((array)[0]))
  36
  37 /* cleanup ------------------------------------------------------------------ */
  38
  39 static const UBiDiProps *gBdp=NULL;
  40
  41 static UBool U_CALLCONV uprops_cleanup(void) {
  42     gBdp=NULL;
  43     return TRUE;
  44 }
  45
  46 /* bidi/shaping properties API ---------------------------------------------- */
  47
  48 /* get the UBiDiProps singleton, or else its dummy, once and for all */
  49 static const UBiDiProps *
  50 getBiDiProps() {
  51     /*
  52      * This lazy intialization with double-checked locking (without mutex protection for
  53      * the initial check) is transiently unsafe under certain circumstances.
  54      * Check the readme and use u_init() if necessary.
  55      */
  56
  57     /* the initial check is performed by the GET_BIDI_PROPS() macro */
  58     const UBiDiProps *bdp;
  59     UErrorCode errorCode=U_ZERO_ERROR;
  60
  61     bdp=ubidi_getSingleton(&errorCode);
  62     if(U_FAILURE(errorCode)) {
  63         errorCode=U_ZERO_ERROR;
  64         bdp=ubidi_getDummy(&errorCode);
  65         if(U_FAILURE(errorCode)) {
  66             return NULL;
  67         }
  68     }
  69
  70     umtx_lock(NULL);
  71     if(gBdp==NULL) {
  72         gBdp=bdp;
  73         bdp=NULL;
  74         ucln_common_registerCleanup(UCLN_COMMON_UPROPS, uprops_cleanup);
  75     }
  76     umtx_unlock(NULL);
  77
  78     return gBdp;
  79 }
  80
  81 /* see comment for GET_CASE_PROPS() */
  82 #define GET_BIDI_PROPS() (gBdp!=NULL ? gBdp : getBiDiProps())
  83
  84 /* general properties API functions ----------------------------------------- */
  85
  86 static const struct {
  87     int32_t column;
  88     uint32_t mask;
  89 } binProps[UCHAR_BINARY_LIMIT]={
  90     /*
  91      * column and mask values for binary properties from u_getUnicodeProperties().
  92      * Must be in order of corresponding UProperty,
  93      * and there must be exacly one entry per binary UProperty.
  94      *
  95      * Properties with mask 0 are handled in code.
  96      * For them, column is the UPropertySource value.
  97      */
  98     {  1,               U_MASK(UPROPS_ALPHABETIC) },
  99     {  1,               U_MASK(UPROPS_ASCII_HEX_DIGIT) },
 100     { UPROPS_SRC_BIDI,  0 },                                    /* UCHAR_BIDI_CONTROL */
 101     { UPROPS_SRC_BIDI,  0 },                                    /* UCHAR_BIDI_MIRRORED */
 102     {  1,               U_MASK(UPROPS_DASH) },
 103     {  1,               U_MASK(UPROPS_DEFAULT_IGNORABLE_CODE_POINT) },
 104     {  1,               U_MASK(UPROPS_DEPRECATED) },
 105     {  1,               U_MASK(UPROPS_DIACRITIC) },
 106     {  1,               U_MASK(UPROPS_EXTENDER) },
 107     { UPROPS_SRC_NORM,  0 },                                    /* UCHAR_FULL_COMPOSITION_EXCLUSION */
 108     {  1,               U_MASK(UPROPS_GRAPHEME_BASE) },
 109     {  1,               U_MASK(UPROPS_GRAPHEME_EXTEND) },
 110     {  1,               U_MASK(UPROPS_GRAPHEME_LINK) },
 111     {  1,               U_MASK(UPROPS_HEX_DIGIT) },
 112     {  1,               U_MASK(UPROPS_HYPHEN) },
 113     {  1,               U_MASK(UPROPS_ID_CONTINUE) },
 114     {  1,               U_MASK(UPROPS_ID_START) },
 115     {  1,               U_MASK(UPROPS_IDEOGRAPHIC) },
 116     {  1,               U_MASK(UPROPS_IDS_BINARY_OPERATOR) },
 117     {  1,               U_MASK(UPROPS_IDS_TRINARY_OPERATOR) },
 118     { UPROPS_SRC_BIDI,  0 },                                    /* UCHAR_JOIN_CONTROL */
 119     {  1,               U_MASK(UPROPS_LOGICAL_ORDER_EXCEPTION) },
 120     { UPROPS_SRC_CASE,  0 },                                    /* UCHAR_LOWERCASE */
 121     {  1,               U_MASK(UPROPS_MATH) },
 122     {  1,               U_MASK(UPROPS_NONCHARACTER_CODE_POINT) },
 123     {  1,               U_MASK(UPROPS_QUOTATION_MARK) },
 124     {  1,               U_MASK(UPROPS_RADICAL) },
 125     { UPROPS_SRC_CASE,  0 },                                    /* UCHAR_SOFT_DOTTED */
 126     {  1,               U_MASK(UPROPS_TERMINAL_PUNCTUATION) },
 127     {  1,               U_MASK(UPROPS_UNIFIED_IDEOGRAPH) },
 128     { UPROPS_SRC_CASE,  0 },                                    /* UCHAR_UPPERCASE */
 129     {  1,               U_MASK(UPROPS_WHITE_SPACE) },
 130     {  1,               U_MASK(UPROPS_XID_CONTINUE) },
 131     {  1,               U_MASK(UPROPS_XID_START) },
 132     { UPROPS_SRC_CASE,  0 },                                    /* UCHAR_CASE_SENSITIVE */
 133     {  2,               U_MASK(UPROPS_V2_S_TERM) },
 134     {  2,               U_MASK(UPROPS_V2_VARIATION_SELECTOR) },
 135     { UPROPS_SRC_NORM,  0 },                                    /* UCHAR_NFD_INERT */
 136     { UPROPS_SRC_NORM,  0 },                                    /* UCHAR_NFKD_INERT */
 137     { UPROPS_SRC_NORM,  0 },                                    /* UCHAR_NFC_INERT */
 138     { UPROPS_SRC_NORM,  0 },                                    /* UCHAR_NFKC_INERT */
 139     { UPROPS_SRC_NORM,  0 },                                    /* UCHAR_SEGMENT_STARTER */
 140     {  2,               U_MASK(UPROPS_V2_PATTERN_SYNTAX) },
 141     {  2,               U_MASK(UPROPS_V2_PATTERN_WHITE_SPACE) },
 142     { UPROPS_SRC_CHAR_AND_PROPSVEC,  0 },                       /* UCHAR_POSIX_ALNUM */
 143     { UPROPS_SRC_CHAR,  0 },                                    /* UCHAR_POSIX_BLANK */
 144     { UPROPS_SRC_CHAR,  0 },                                    /* UCHAR_POSIX_GRAPH */
 145     { UPROPS_SRC_CHAR,  0 },                                    /* UCHAR_POSIX_PRINT */
 146     { UPROPS_SRC_CHAR,  0 }                                     /* UCHAR_POSIX_XDIGIT */
 147 };
 148
 149 U_CAPI UBool U_EXPORT2
 150 u_hasBinaryProperty(UChar32 c, UProperty which) {
 151     /* c is range-checked in the functions that are called from here */
 152     if(which<UCHAR_BINARY_START || UCHAR_BINARY_LIMIT<=which) {
 153         /* not a known binary property */
 154     } else {
 155         uint32_t mask=binProps[which].mask;
 156         int32_t column=binProps[which].column;
 157         if(mask!=0) {
 158             /* systematic, directly stored properties */
 159             return (u_getUnicodeProperties(c, column)&mask)!=0;
 160         } else {
 161             if(column==UPROPS_SRC_CASE) {
 162                 return ucase_hasBinaryProperty(c, which);
 163             } else if(column==UPROPS_SRC_NORM) {
 164 #if !UCONFIG_NO_NORMALIZATION
 165                 /* normalization properties from unorm.icu */
 166                 switch(which) {
 167                 case UCHAR_FULL_COMPOSITION_EXCLUSION:
 168                     return unorm_internalIsFullCompositionExclusion(c);
 169                 case UCHAR_NFD_INERT:
 170                 case UCHAR_NFKD_INERT:
 171                 case UCHAR_NFC_INERT:
 172                 case UCHAR_NFKC_INERT:
 173                     return unorm_isNFSkippable(c, (UNormalizationMode)(which-UCHAR_NFD_INERT+UNORM_NFD));
 174                 case UCHAR_SEGMENT_STARTER:
 175                     return unorm_isCanonSafeStart(c);
 176                 default:
 177                     break;
 178                 }
 179 #endif
 180             } else if(column==UPROPS_SRC_BIDI) {
 181                 /* bidi/shaping properties */
 182                 const UBiDiProps *bdp=GET_BIDI_PROPS();
 183                 if(bdp!=NULL) {
 184                     switch(which) {
 185                     case UCHAR_BIDI_MIRRORED:
 186                         return ubidi_isMirrored(bdp, c);
 187                     case UCHAR_BIDI_CONTROL:
 188                         return ubidi_isBidiControl(bdp, c);
 189                     case UCHAR_JOIN_CONTROL:
 190                         return ubidi_isJoinControl(bdp, c);
 191                     default:
 192                         break;
 193                     }
 194                 }
 195                 /* else return FALSE below */
 196             } else if(column==UPROPS_SRC_CHAR) {
 197                 switch(which) {
 198                 case UCHAR_POSIX_BLANK:
 199                     return u_isblank(c);
 200                 case UCHAR_POSIX_GRAPH:
 201                     return u_isgraphPOSIX(c);
 202                 case UCHAR_POSIX_PRINT:
 203                     return u_isprintPOSIX(c);
 204                 case UCHAR_POSIX_XDIGIT:
 205                     return u_isxdigit(c);
 206                 default:
 207                     break;
 208                 }
 209             } else if(column==UPROPS_SRC_CHAR_AND_PROPSVEC) {
 210                 switch(which) {
 211                 case UCHAR_POSIX_ALNUM:
 212                     return u_isalnumPOSIX(c);
 213                 default:
 214                     break;
 215                 }
 216             }
 217         }
 218     }
 219     return FALSE;
 220 }
 221
 222 U_CAPI int32_t U_EXPORT2
 223 u_getIntPropertyValue(UChar32 c, UProperty which) {
 224     UErrorCode errorCode;
 225     int32_t type;
 226
 227     if(which<UCHAR_BINARY_START) {
 228         return 0; /* undefined */
 229     } else if(which<UCHAR_BINARY_LIMIT) {
 230         return (int32_t)u_hasBinaryProperty(c, which);
 231     } else if(which<UCHAR_INT_START) {
 232         return 0; /* undefined */
 233     } else if(which<UCHAR_INT_LIMIT) {
 234         switch(which) {
 235         case UCHAR_BIDI_CLASS:
 236             return (int32_t)u_charDirection(c);
 237         case UCHAR_BLOCK:
 238             return (int32_t)ublock_getCode(c);
 239         case UCHAR_CANONICAL_COMBINING_CLASS:
 240 #if !UCONFIG_NO_NORMALIZATION
 241             return u_getCombiningClass(c);
 242 #else
 243             return 0;
 244 #endif
 245         case UCHAR_DECOMPOSITION_TYPE:
 246             return (int32_t)(u_getUnicodeProperties(c, 2)&UPROPS_DT_MASK);
 247         case UCHAR_EAST_ASIAN_WIDTH:
 248             return (int32_t)(u_getUnicodeProperties(c, 0)&UPROPS_EA_MASK)>>UPROPS_EA_SHIFT;
 249         case UCHAR_GENERAL_CATEGORY:
 250             return (int32_t)u_charType(c);
 251         case UCHAR_JOINING_GROUP:
 252             return ubidi_getJoiningGroup(GET_BIDI_PROPS(), c);
 253         case UCHAR_JOINING_TYPE:
 254             return ubidi_getJoiningType(GET_BIDI_PROPS(), c);
 255         case UCHAR_LINE_BREAK:
 256             return (int32_t)(u_getUnicodeProperties(c, 0)&UPROPS_LB_MASK)>>UPROPS_LB_SHIFT;
 257         case UCHAR_NUMERIC_TYPE:
 258             type=(int32_t)GET_NUMERIC_TYPE(u_getUnicodeProperties(c, -1));
 259             if(type>U_NT_NUMERIC) {
 260                 /* keep internal variants of U_NT_NUMERIC from becoming visible */
 261                 type=U_NT_NUMERIC;
 262             }
 263             return type;
 264         case UCHAR_SCRIPT:
 265             errorCode=U_ZERO_ERROR;
 266             return (int32_t)uscript_getScript(c, &errorCode);
 267         case UCHAR_HANGUL_SYLLABLE_TYPE:
 268             return uchar_getHST(c);
 269 #if !UCONFIG_NO_NORMALIZATION
 270         case UCHAR_NFD_QUICK_CHECK:
 271         case UCHAR_NFKD_QUICK_CHECK:
 272         case UCHAR_NFC_QUICK_CHECK:
 273         case UCHAR_NFKC_QUICK_CHECK:
 274             return (int32_t)unorm_getQuickCheck(c, (UNormalizationMode)(which-UCHAR_NFD_QUICK_CHECK+UNORM_NFD));
 275         case UCHAR_LEAD_CANONICAL_COMBINING_CLASS:
 276             return unorm_getFCD16FromCodePoint(c)>>8;
 277         case UCHAR_TRAIL_CANONICAL_COMBINING_CLASS:
 278             return unorm_getFCD16FromCodePoint(c)&0xff;
 279 #endif
 280         case UCHAR_GRAPHEME_CLUSTER_BREAK:
 281             return (int32_t)(u_getUnicodeProperties(c, 2)&UPROPS_GCB_MASK)>>UPROPS_GCB_SHIFT;
 282         case UCHAR_SENTENCE_BREAK:
 283             return (int32_t)(u_getUnicodeProperties(c, 2)&UPROPS_SB_MASK)>>UPROPS_SB_SHIFT;
 284         case UCHAR_WORD_BREAK:
 285             return (int32_t)(u_getUnicodeProperties(c, 2)&UPROPS_WB_MASK)>>UPROPS_WB_SHIFT;
 286         default:
 287             return 0; /* undefined */
 288         }
 289     } else if(which==UCHAR_GENERAL_CATEGORY_MASK) {
 290         return U_MASK(u_charType(c));
 291     } else {
 292         return 0; /* undefined */
 293     }
 294 }
 295
 296 U_CAPI int32_t U_EXPORT2
 297 u_getIntPropertyMinValue(UProperty which) {
 298     return 0; /* all binary/enum/int properties have a minimum value of 0 */
 299 }
 300
 301 U_CAPI int32_t U_EXPORT2
 302 u_getIntPropertyMaxValue(UProperty which) {
 303     if(which<UCHAR_BINARY_START) {
 304         return -1; /* undefined */
 305     } else if(which<UCHAR_BINARY_LIMIT) {
 306         return 1; /* maximum TRUE for all binary properties */
 307     } else if(which<UCHAR_INT_START) {
 308         return -1; /* undefined */
 309     } else if(which<UCHAR_INT_LIMIT) {
 310         switch(which) {
 311         case UCHAR_BIDI_CLASS:
 312         case UCHAR_JOINING_GROUP:
 313         case UCHAR_JOINING_TYPE:
 314             return ubidi_getMaxValue(GET_BIDI_PROPS(), which);
 315         case UCHAR_BLOCK:
 316             return (uprv_getMaxValues(0)&UPROPS_BLOCK_MASK)>>UPROPS_BLOCK_SHIFT;
 317         case UCHAR_CANONICAL_COMBINING_CLASS:
 318         case UCHAR_LEAD_CANONICAL_COMBINING_CLASS:
 319         case UCHAR_TRAIL_CANONICAL_COMBINING_CLASS:
 320             return 0xff; /* TODO do we need to be more precise, getting the actual maximum? */
 321         case UCHAR_DECOMPOSITION_TYPE:
 322             return uprv_getMaxValues(2)&UPROPS_DT_MASK;
 323         case UCHAR_EAST_ASIAN_WIDTH:
 324             return (uprv_getMaxValues(0)&UPROPS_EA_MASK)>>UPROPS_EA_SHIFT;
 325         case UCHAR_GENERAL_CATEGORY:
 326             return (int32_t)U_CHAR_CATEGORY_COUNT-1;
 327         case UCHAR_LINE_BREAK:
 328             return (uprv_getMaxValues(0)&UPROPS_LB_MASK)>>UPROPS_LB_SHIFT;
 329         case UCHAR_NUMERIC_TYPE:
 330             return (int32_t)U_NT_COUNT-1;
 331         case UCHAR_SCRIPT:
 332             return uprv_getMaxValues(0)&UPROPS_SCRIPT_MASK;
 333         case UCHAR_HANGUL_SYLLABLE_TYPE:
 334             return (int32_t)U_HST_COUNT-1;
 335 #if !UCONFIG_NO_NORMALIZATION
 336         case UCHAR_NFD_QUICK_CHECK:
 337         case UCHAR_NFKD_QUICK_CHECK:
 338             return (int32_t)UNORM_YES; /* these are never "maybe", only "no" or "yes" */
 339         case UCHAR_NFC_QUICK_CHECK:
 340         case UCHAR_NFKC_QUICK_CHECK:
 341             return (int32_t)UNORM_MAYBE;
 342 #endif
 343         case UCHAR_GRAPHEME_CLUSTER_BREAK:
 344             return (uprv_getMaxValues(2)&UPROPS_GCB_MASK)>>UPROPS_GCB_SHIFT;
 345         case UCHAR_SENTENCE_BREAK:
 346             return (uprv_getMaxValues(2)&UPROPS_SB_MASK)>>UPROPS_SB_SHIFT;
 347         case UCHAR_WORD_BREAK:
 348             return (uprv_getMaxValues(2)&UPROPS_WB_MASK)>>UPROPS_WB_SHIFT;
 349         default:
 350             return -1; /* undefined */
 351         }
 352     } else {
 353         return -1; /* undefined */
 354     }
 355 }
 356
 357 U_CAPI UPropertySource U_EXPORT2
 358 uprops_getSource(UProperty which) {
 359     if(which<UCHAR_BINARY_START) {
 360         return UPROPS_SRC_NONE; /* undefined */
 361     } else if(which<UCHAR_BINARY_LIMIT) {
 362         if(binProps[which].mask!=0) {
 363             return UPROPS_SRC_PROPSVEC;
 364         } else {
 365             return (UPropertySource)binProps[which].column;
 366         }
 367     } else if(which<UCHAR_INT_START) {
 368         return UPROPS_SRC_NONE; /* undefined */
 369     } else if(which<UCHAR_INT_LIMIT) {
 370         switch(which) {
 371         case UCHAR_GENERAL_CATEGORY:
 372         case UCHAR_NUMERIC_TYPE:
 373             return UPROPS_SRC_CHAR;
 374
 375         case UCHAR_HANGUL_SYLLABLE_TYPE:
 376             return UPROPS_SRC_HST;
 377
 378         case UCHAR_CANONICAL_COMBINING_CLASS:
 379         case UCHAR_NFD_QUICK_CHECK:
 380         case UCHAR_NFKD_QUICK_CHECK:
 381         case UCHAR_NFC_QUICK_CHECK:
 382         case UCHAR_NFKC_QUICK_CHECK:
 383         case UCHAR_LEAD_CANONICAL_COMBINING_CLASS:
 384         case UCHAR_TRAIL_CANONICAL_COMBINING_CLASS:
 385             return UPROPS_SRC_NORM;
 386
 387         case UCHAR_BIDI_CLASS:
 388         case UCHAR_JOINING_GROUP:
 389         case UCHAR_JOINING_TYPE:
 390             return UPROPS_SRC_BIDI;
 391
 392         default:
 393             return UPROPS_SRC_PROPSVEC;
 394         }
 395     } else if(which<UCHAR_STRING_START) {
 396         switch(which) {
 397         case UCHAR_GENERAL_CATEGORY_MASK:
 398         case UCHAR_NUMERIC_VALUE:
 399             return UPROPS_SRC_CHAR;
 400
 401         default:
 402             return UPROPS_SRC_NONE;
 403         }
 404     } else if(which<UCHAR_STRING_LIMIT) {
 405         switch(which) {
 406         case UCHAR_AGE:
 407             return UPROPS_SRC_PROPSVEC;
 408
 409         case UCHAR_BIDI_MIRRORING_GLYPH:
 410             return UPROPS_SRC_BIDI;
 411
 412         case UCHAR_CASE_FOLDING:
 413         case UCHAR_LOWERCASE_MAPPING:
 414         case UCHAR_SIMPLE_CASE_FOLDING:
 415         case UCHAR_SIMPLE_LOWERCASE_MAPPING:
 416         case UCHAR_SIMPLE_TITLECASE_MAPPING:
 417         case UCHAR_SIMPLE_UPPERCASE_MAPPING:
 418         case UCHAR_TITLECASE_MAPPING:
 419         case UCHAR_UPPERCASE_MAPPING:
 420             return UPROPS_SRC_CASE;
 421
 422         case UCHAR_ISO_COMMENT:
 423         case UCHAR_NAME:
 424         case UCHAR_UNICODE_1_NAME:
 425             return UPROPS_SRC_NAMES;
 426
 427         default:
 428             return UPROPS_SRC_NONE;
 429         }
 430     } else {
 431         return UPROPS_SRC_NONE; /* undefined */
 432     }
 433 }
 434
 435 /*----------------------------------------------------------------
 436  * Inclusions list
 437  *----------------------------------------------------------------*/
 438
 439 /*
 440  * Return a set of characters for property enumeration.
 441  * The set implicitly contains 0x110000 as well, which is one more than the highest
 442  * Unicode code point.
 443  *
 444  * This set is used as an ordered list - its code points are ordered, and
 445  * consecutive code points (in Unicode code point order) in the set define a range.
 446  * For each two consecutive characters (start, limit) in the set,
 447  * all of the UCD/normalization and related properties for
 448  * all code points start..limit-1 are all the same,
 449  * except for character names and ISO comments.
 450  *
 451  * All Unicode code points U+0000..U+10ffff are covered by these ranges.
 452  * The ranges define a partition of the Unicode code space.
 453  * ICU uses the inclusions set to enumerate properties for generating
 454  * UnicodeSets containing all code points that have a certain property value.
 455  *
 456  * The Inclusion List is generated from the UCD. It is generated
 457  * by enumerating the data tries, and code points for hardcoded properties
 458  * are added as well.
 459  *
 460  * --------------------------------------------------------------------------
 461  *
 462  * The following are ideas for getting properties-unique code point ranges,
 463  * with possible optimizations beyond the current implementation.
 464  * These optimizations would require more code and be more fragile.
 465  * The current implementation generates one single list (set) for all properties.
 466  *
 467  * To enumerate properties efficiently, one needs to know ranges of
 468  * repetitive values, so that the value of only each start code point
 469  * can be applied to the whole range.
 470  * This information is in principle available in the uprops.icu/unorm.icu data.
 471  *
 472  * There are two obstacles:
 473  *
 474  * 1. Some properties are computed from multiple data structures,
 475  *    making it necessary to get repetitive ranges by intersecting
 476  *    ranges from multiple tries.
 477  *
 478  * 2. It is not economical to write code for getting repetitive ranges
 479  *    that are precise for each of some 50 properties.
 480  *
 481  * Compromise ideas:
 482  *
 483  * - Get ranges per trie, not per individual property.
 484  *   Each range contains the same values for a whole group of properties.
 485  *   This would generate currently five range sets, two for uprops.icu tries
 486  *   and three for unorm.icu tries.
 487  *
 488  * - Combine sets of ranges for multiple tries to get sufficient sets
 489  *   for properties, e.g., the uprops.icu main and auxiliary tries
 490  *   for all non-normalization properties.
 491  *
 492  * Ideas for representing ranges and combining them:
 493  *
 494  * - A UnicodeSet could hold just the start code points of ranges.
 495  *   Multiple sets are easily combined by or-ing them together.
 496  *
 497  * - Alternatively, a UnicodeSet could hold each even-numbered range.
 498  *   All ranges could be enumerated by using each start code point
 499  *   (for the even-numbered ranges) as well as each limit (end+1) code point
 500  *   (for the odd-numbered ranges).
 501  *   It should be possible to combine two such sets by xor-ing them,
 502  *   but no more than two.
 503  *
 504  * The second way to represent ranges may(?!) yield smaller UnicodeSet arrays,
 505  * but the first one is certainly simpler and applicable for combining more than
 506  * two range sets.
 507  *
 508  * It is possible to combine all range sets for all uprops/unorm tries into one
 509  * set that can be used for all properties.
 510  * As an optimization, there could be less-combined range sets for certain
 511  * groups of properties.
 512  * The relationship of which less-combined range set to use for which property
 513  * depends on the implementation of the properties and must be hardcoded
 514  * - somewhat error-prone and higher maintenance but can be tested easily
 515  * by building property sets "the simple way" in test code.
 516  *
 517  * ---
 518  *
 519  * Do not use a UnicodeSet pattern because that causes infinite recursion;
 520  * UnicodeSet depends on the inclusions set.
 521  *
 522  * ---
 523  *
 524  * uprv_getInclusions() is commented out starting 2004-sep-13 because
 525  * uniset_props.cpp now calls the uxyz_addPropertyStarts() directly,
 526  * and only for the relevant property source.
 527  */
 528 #if 0
 529
 530 U_CAPI void U_EXPORT2
 531 uprv_getInclusions(const USetAdder *sa, UErrorCode *pErrorCode) {
 532     if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
 533         return;
 534     }
 535
 536 #if !UCONFIG_NO_NORMALIZATION
 537     unorm_addPropertyStarts(sa, pErrorCode);
 538 #endif
 539     uchar_addPropertyStarts(sa, pErrorCode);
 540     uhst_addPropertyStarts(sa, pErrorCode);
 541     ucase_addPropertyStarts(ucase_getSingleton(pErrorCode), sa, pErrorCode);
 542     ubidi_addPropertyStarts(ubidi_getSingleton(pErrorCode), sa, pErrorCode);
 543 }
 544
 545 #endif