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      1 /*
      2 ******************************************************************************
      3 *
      4 *   Copyright (C) 1999-2009, International Business Machines
      5 *   Corporation and others.  All Rights Reserved.
      6 *
      7 ******************************************************************************
      8 *   file name:  ubidi.c
      9 *   encoding:   US-ASCII
     10 *   tab size:   8 (not used)
     11 *   indentation:4
     12 *
     13 *   created on: 1999jul27
     14 *   created by: Markus W. Scherer, updated by Matitiahu Allouche
     15 */
     16 
     17 #include "cmemory.h"
     18 #include "unicode/utypes.h"
     19 #include "unicode/ustring.h"
     20 #include "unicode/uchar.h"
     21 #include "unicode/ubidi.h"
     22 #include "ubidi_props.h"
     23 #include "ubidiimp.h"
     24 #include "uassert.h"
     25 
     26 /*
     27  * General implementation notes:
     28  *
     29  * Throughout the implementation, there are comments like (W2) that refer to
     30  * rules of the BiDi algorithm in its version 5, in this example to the second
     31  * rule of the resolution of weak types.
     32  *
     33  * For handling surrogate pairs, where two UChar's form one "abstract" (or UTF-32)
     34  * character according to UTF-16, the second UChar gets the directional property of
     35  * the entire character assigned, while the first one gets a BN, a boundary
     36  * neutral, type, which is ignored by most of the algorithm according to
     37  * rule (X9) and the implementation suggestions of the BiDi algorithm.
     38  *
     39  * Later, adjustWSLevels() will set the level for each BN to that of the
     40  * following character (UChar), which results in surrogate pairs getting the
     41  * same level on each of their surrogates.
     42  *
     43  * In a UTF-8 implementation, the same thing could be done: the last byte of
     44  * a multi-byte sequence would get the "real" property, while all previous
     45  * bytes of that sequence would get BN.
     46  *
     47  * It is not possible to assign all those parts of a character the same real
     48  * property because this would fail in the resolution of weak types with rules
     49  * that look at immediately surrounding types.
     50  *
     51  * As a related topic, this implementation does not remove Boundary Neutral
     52  * types from the input, but ignores them wherever this is relevant.
     53  * For example, the loop for the resolution of the weak types reads
     54  * types until it finds a non-BN.
     55  * Also, explicit embedding codes are neither changed into BN nor removed.
     56  * They are only treated the same way real BNs are.
     57  * As stated before, adjustWSLevels() takes care of them at the end.
     58  * For the purpose of conformance, the levels of all these codes
     59  * do not matter.
     60  *
     61  * Note that this implementation never modifies the dirProps
     62  * after the initial setup.
     63  *
     64  *
     65  * In this implementation, the resolution of weak types (Wn),
     66  * neutrals (Nn), and the assignment of the resolved level (In)
     67  * are all done in one single loop, in resolveImplicitLevels().
     68  * Changes of dirProp values are done on the fly, without writing
     69  * them back to the dirProps array.
     70  *
     71  *
     72  * This implementation contains code that allows to bypass steps of the
     73  * algorithm that are not needed on the specific paragraph
     74  * in order to speed up the most common cases considerably,
     75  * like text that is entirely LTR, or RTL text without numbers.
     76  *
     77  * Most of this is done by setting a bit for each directional property
     78  * in a flags variable and later checking for whether there are
     79  * any LTR characters or any RTL characters, or both, whether
     80  * there are any explicit embedding codes, etc.
     81  *
     82  * If the (Xn) steps are performed, then the flags are re-evaluated,
     83  * because they will then not contain the embedding codes any more
     84  * and will be adjusted for override codes, so that subsequently
     85  * more bypassing may be possible than what the initial flags suggested.
     86  *
     87  * If the text is not mixed-directional, then the
     88  * algorithm steps for the weak type resolution are not performed,
     89  * and all levels are set to the paragraph level.
     90  *
     91  * If there are no explicit embedding codes, then the (Xn) steps
     92  * are not performed.
     93  *
     94  * If embedding levels are supplied as a parameter, then all
     95  * explicit embedding codes are ignored, and the (Xn) steps
     96  * are not performed.
     97  *
     98  * White Space types could get the level of the run they belong to,
     99  * and are checked with a test of (flags&MASK_EMBEDDING) to
    100  * consider if the paragraph direction should be considered in
    101  * the flags variable.
    102  *
    103  * If there are no White Space types in the paragraph, then
    104  * (L1) is not necessary in adjustWSLevels().
    105  */
    106 
    107 /* to avoid some conditional statements, use tiny constant arrays */
    108 static const Flags flagLR[2]={ DIRPROP_FLAG(L), DIRPROP_FLAG(R) };
    109 static const Flags flagE[2]={ DIRPROP_FLAG(LRE), DIRPROP_FLAG(RLE) };
    110 static const Flags flagO[2]={ DIRPROP_FLAG(LRO), DIRPROP_FLAG(RLO) };
    111 
    112 #define DIRPROP_FLAG_LR(level) flagLR[(level)&1]
    113 #define DIRPROP_FLAG_E(level) flagE[(level)&1]
    114 #define DIRPROP_FLAG_O(level) flagO[(level)&1]
    115 
    116 /* UBiDi object management -------------------------------------------------- */
    117 
    118 U_CAPI UBiDi * U_EXPORT2
    119 ubidi_open(void)
    120 {
    121     UErrorCode errorCode=U_ZERO_ERROR;
    122     return ubidi_openSized(0, 0, &errorCode);
    123 }
    124 
    125 U_CAPI UBiDi * U_EXPORT2
    126 ubidi_openSized(int32_t maxLength, int32_t maxRunCount, UErrorCode *pErrorCode) {
    127     UBiDi *pBiDi;
    128 
    129     /* check the argument values */
    130     if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
    131         return NULL;
    132     } else if(maxLength<0 || maxRunCount<0) {
    133         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
    134         return NULL;    /* invalid arguments */
    135     }
    136 
    137     /* allocate memory for the object */
    138     pBiDi=(UBiDi *)uprv_malloc(sizeof(UBiDi));
    139     if(pBiDi==NULL) {
    140         *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
    141         return NULL;
    142     }
    143 
    144     /* reset the object, all pointers NULL, all flags FALSE, all sizes 0 */
    145     uprv_memset(pBiDi, 0, sizeof(UBiDi));
    146 
    147     /* get BiDi properties */
    148     pBiDi->bdp=ubidi_getSingleton(pErrorCode);
    149     if(U_FAILURE(*pErrorCode)) {
    150         uprv_free(pBiDi);
    151         return NULL;
    152     }
    153 
    154     /* allocate memory for arrays as requested */
    155     if(maxLength>0) {
    156         if( !getInitialDirPropsMemory(pBiDi, maxLength) ||
    157             !getInitialLevelsMemory(pBiDi, maxLength)
    158         ) {
    159             *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
    160         }
    161     } else {
    162         pBiDi->mayAllocateText=TRUE;
    163     }
    164 
    165     if(maxRunCount>0) {
    166         if(maxRunCount==1) {
    167             /* use simpleRuns[] */
    168             pBiDi->runsSize=sizeof(Run);
    169         } else if(!getInitialRunsMemory(pBiDi, maxRunCount)) {
    170             *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
    171         }
    172     } else {
    173         pBiDi->mayAllocateRuns=TRUE;
    174     }
    175 
    176     if(U_SUCCESS(*pErrorCode)) {
    177         return pBiDi;
    178     } else {
    179         ubidi_close(pBiDi);
    180         return NULL;
    181     }
    182 }
    183 
    184 /*
    185  * We are allowed to allocate memory if memory==NULL or
    186  * mayAllocate==TRUE for each array that we need.
    187  * We also try to grow memory as needed if we
    188  * allocate it.
    189  *
    190  * Assume sizeNeeded>0.
    191  * If *pMemory!=NULL, then assume *pSize>0.
    192  *
    193  * ### this realloc() may unnecessarily copy the old data,
    194  * which we know we don't need any more;
    195  * is this the best way to do this??
    196  */
    197 U_CFUNC UBool
    198 ubidi_getMemory(BidiMemoryForAllocation *bidiMem, int32_t *pSize, UBool mayAllocate, int32_t sizeNeeded) {
    199     void **pMemory = (void **)bidiMem;
    200     /* check for existing memory */
    201     if(*pMemory==NULL) {
    202         /* we need to allocate memory */
    203         if(mayAllocate && (*pMemory=uprv_malloc(sizeNeeded))!=NULL) {
    204             *pSize=sizeNeeded;
    205             return TRUE;
    206         } else {
    207             return FALSE;
    208         }
    209     } else {
    210         if(sizeNeeded<=*pSize) {
    211             /* there is already enough memory */
    212             return TRUE;
    213         }
    214         else if(!mayAllocate) {
    215             /* not enough memory, and we must not allocate */
    216             return FALSE;
    217         } else {
    218             /* we try to grow */
    219             void *memory;
    220             /* in most cases, we do not need the copy-old-data part of
    221              * realloc, but it is needed when adding runs using getRunsMemory()
    222              * in setParaRunsOnly()
    223              */
    224             if((memory=uprv_realloc(*pMemory, sizeNeeded))!=NULL) {
    225                 *pMemory=memory;
    226                 *pSize=sizeNeeded;
    227                 return TRUE;
    228             } else {
    229                 /* we failed to grow */
    230                 return FALSE;
    231             }
    232         }
    233     }
    234 }
    235 
    236 U_CAPI void U_EXPORT2
    237 ubidi_close(UBiDi *pBiDi) {
    238     if(pBiDi!=NULL) {
    239         pBiDi->pParaBiDi=NULL;          /* in case one tries to reuse this block */
    240         if(pBiDi->dirPropsMemory!=NULL) {
    241             uprv_free(pBiDi->dirPropsMemory);
    242         }
    243         if(pBiDi->levelsMemory!=NULL) {
    244             uprv_free(pBiDi->levelsMemory);
    245         }
    246         if(pBiDi->runsMemory!=NULL) {
    247             uprv_free(pBiDi->runsMemory);
    248         }
    249         if(pBiDi->parasMemory!=NULL) {
    250             uprv_free(pBiDi->parasMemory);
    251         }
    252         if(pBiDi->insertPoints.points!=NULL) {
    253             uprv_free(pBiDi->insertPoints.points);
    254         }
    255 
    256         uprv_free(pBiDi);
    257     }
    258 }
    259 
    260 /* set to approximate "inverse BiDi" ---------------------------------------- */
    261 
    262 U_CAPI void U_EXPORT2
    263 ubidi_setInverse(UBiDi *pBiDi, UBool isInverse) {
    264     if(pBiDi!=NULL) {
    265         pBiDi->isInverse=isInverse;
    266         pBiDi->reorderingMode = isInverse ? UBIDI_REORDER_INVERSE_NUMBERS_AS_L
    267                                           : UBIDI_REORDER_DEFAULT;
    268     }
    269 }
    270 
    271 U_CAPI UBool U_EXPORT2
    272 ubidi_isInverse(UBiDi *pBiDi) {
    273     if(pBiDi!=NULL) {
    274         return pBiDi->isInverse;
    275     } else {
    276         return FALSE;
    277     }
    278 }
    279 
    280 /* FOOD FOR THOUGHT: currently the reordering modes are a mixture of
    281  * algorithm for direct BiDi, algorithm for inverse BiDi and the bizarre
    282  * concept of RUNS_ONLY which is a double operation.
    283  * It could be advantageous to divide this into 3 concepts:
    284  * a) Operation: direct / inverse / RUNS_ONLY
    285  * b) Direct algorithm: default / NUMBERS_SPECIAL / GROUP_NUMBERS_WITH_R
    286  * c) Inverse algorithm: default / INVERSE_LIKE_DIRECT / NUMBERS_SPECIAL
    287  * This would allow combinations not possible today like RUNS_ONLY with
    288  * NUMBERS_SPECIAL.
    289  * Also allow to set INSERT_MARKS for the direct step of RUNS_ONLY and
    290  * REMOVE_CONTROLS for the inverse step.
    291  * Not all combinations would be supported, and probably not all do make sense.
    292  * This would need to document which ones are supported and what are the
    293  * fallbacks for unsupported combinations.
    294  */
    295 U_CAPI void U_EXPORT2
    296 ubidi_setReorderingMode(UBiDi *pBiDi, UBiDiReorderingMode reorderingMode) {
    297     if ((pBiDi!=NULL) && (reorderingMode >= UBIDI_REORDER_DEFAULT)
    298                         && (reorderingMode < UBIDI_REORDER_COUNT)) {
    299         pBiDi->reorderingMode = reorderingMode;
    300         pBiDi->isInverse = (UBool)(reorderingMode == UBIDI_REORDER_INVERSE_NUMBERS_AS_L);
    301     }
    302 }
    303 
    304 U_CAPI UBiDiReorderingMode U_EXPORT2
    305 ubidi_getReorderingMode(UBiDi *pBiDi) {
    306     if (pBiDi!=NULL) {
    307         return pBiDi->reorderingMode;
    308     } else {
    309         return UBIDI_REORDER_DEFAULT;
    310     }
    311 }
    312 
    313 U_CAPI void U_EXPORT2
    314 ubidi_setReorderingOptions(UBiDi *pBiDi, uint32_t reorderingOptions) {
    315     if (reorderingOptions & UBIDI_OPTION_REMOVE_CONTROLS) {
    316         reorderingOptions&=~UBIDI_OPTION_INSERT_MARKS;
    317     }
    318     if (pBiDi!=NULL) {
    319         pBiDi->reorderingOptions=reorderingOptions;
    320     }
    321 }
    322 
    323 U_CAPI uint32_t U_EXPORT2
    324 ubidi_getReorderingOptions(UBiDi *pBiDi) {
    325     if (pBiDi!=NULL) {
    326         return pBiDi->reorderingOptions;
    327     } else {
    328         return 0;
    329     }
    330 }
    331 
    332 /* perform (P2)..(P3) ------------------------------------------------------- */
    333 
    334 /*
    335  * Get the directional properties for the text,
    336  * calculate the flags bit-set, and
    337  * determine the paragraph level if necessary.
    338  */
    339 static void
    340 getDirProps(UBiDi *pBiDi) {
    341     const UChar *text=pBiDi->text;
    342     DirProp *dirProps=pBiDi->dirPropsMemory;    /* pBiDi->dirProps is const */
    343 
    344     int32_t i=0, i0, i1, length=pBiDi->originalLength;
    345     Flags flags=0;      /* collect all directionalities in the text */
    346     UChar32 uchar;
    347     DirProp dirProp=0, paraDirDefault=0;/* initialize to avoid compiler warnings */
    348     UBool isDefaultLevel=IS_DEFAULT_LEVEL(pBiDi->paraLevel);
    349     /* for inverse BiDi, the default para level is set to RTL if there is a
    350        strong R or AL character at either end of the text                           */
    351     UBool isDefaultLevelInverse=isDefaultLevel && (UBool)
    352             (pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_LIKE_DIRECT ||
    353              pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL);
    354     int32_t lastArabicPos=-1;
    355     int32_t controlCount=0;
    356     UBool removeBiDiControls = (UBool)(pBiDi->reorderingOptions &
    357                                        UBIDI_OPTION_REMOVE_CONTROLS);
    358 
    359     typedef enum {
    360          NOT_CONTEXTUAL,                /* 0: not contextual paraLevel */
    361          LOOKING_FOR_STRONG,            /* 1: looking for first strong char */
    362          FOUND_STRONG_CHAR              /* 2: found first strong char       */
    363     } State;
    364     State state;
    365     int32_t paraStart=0;                /* index of first char in paragraph */
    366     DirProp paraDir;                    /* == CONTEXT_RTL within paragraphs
    367                                            starting with strong R char      */
    368     DirProp lastStrongDir=0;            /* for default level & inverse BiDi */
    369     int32_t lastStrongLTR=0;            /* for STREAMING option             */
    370 
    371     if(pBiDi->reorderingOptions & UBIDI_OPTION_STREAMING) {
    372         pBiDi->length=0;
    373         lastStrongLTR=0;
    374     }
    375     if(isDefaultLevel) {
    376         paraDirDefault=pBiDi->paraLevel&1 ? CONTEXT_RTL : 0;
    377         paraDir=paraDirDefault;
    378         lastStrongDir=paraDirDefault;
    379         state=LOOKING_FOR_STRONG;
    380     } else {
    381         state=NOT_CONTEXTUAL;
    382         paraDir=0;
    383     }
    384     /* count paragraphs and determine the paragraph level (P2..P3) */
    385     /*
    386      * see comment in ubidi.h:
    387      * the DEFAULT_XXX values are designed so that
    388      * their bit 0 alone yields the intended default
    389      */
    390     for( /* i=0 above */ ; i<length; ) {
    391         /* i is incremented by UTF_NEXT_CHAR */
    392         i0=i;           /* index of first code unit */
    393         UTF_NEXT_CHAR(text, i, length, uchar);
    394         i1=i-1;         /* index of last code unit, gets the directional property */
    395         flags|=DIRPROP_FLAG(dirProp=(DirProp)ubidi_getCustomizedClass(pBiDi, uchar));
    396         dirProps[i1]=dirProp|paraDir;
    397         if(i1>i0) {     /* set previous code units' properties to BN */
    398             flags|=DIRPROP_FLAG(BN);
    399             do {
    400                 dirProps[--i1]=(DirProp)(BN|paraDir);
    401             } while(i1>i0);
    402         }
    403         if(state==LOOKING_FOR_STRONG) {
    404             if(dirProp==L) {
    405                 state=FOUND_STRONG_CHAR;
    406                 if(paraDir) {
    407                     paraDir=0;
    408                     for(i1=paraStart; i1<i; i1++) {
    409                         dirProps[i1]&=~CONTEXT_RTL;
    410                     }
    411                 }
    412                 continue;
    413             }
    414             if(dirProp==R || dirProp==AL) {
    415                 state=FOUND_STRONG_CHAR;
    416                 if(paraDir==0) {
    417                     paraDir=CONTEXT_RTL;
    418                     for(i1=paraStart; i1<i; i1++) {
    419                         dirProps[i1]|=CONTEXT_RTL;
    420                     }
    421                 }
    422                 continue;
    423             }
    424         }
    425         if(dirProp==L) {
    426             lastStrongDir=0;
    427             lastStrongLTR=i;            /* i is index to next character */
    428         }
    429         else if(dirProp==R) {
    430             lastStrongDir=CONTEXT_RTL;
    431         }
    432         else if(dirProp==AL) {
    433             lastStrongDir=CONTEXT_RTL;
    434             lastArabicPos=i-1;
    435         }
    436         else if(dirProp==B) {
    437             if(pBiDi->reorderingOptions & UBIDI_OPTION_STREAMING) {
    438                 pBiDi->length=i;        /* i is index to next character */
    439             }
    440             if(isDefaultLevelInverse && (lastStrongDir==CONTEXT_RTL) &&(paraDir!=lastStrongDir)) {
    441                 for( ; paraStart<i; paraStart++) {
    442                     dirProps[paraStart]|=CONTEXT_RTL;
    443                 }
    444             }
    445             if(i<length) {              /* B not last char in text */
    446                 if(!((uchar==CR) && (text[i]==LF))) {
    447                     pBiDi->paraCount++;
    448                 }
    449                 if(isDefaultLevel) {
    450                     state=LOOKING_FOR_STRONG;
    451                     paraStart=i;        /* i is index to next character */
    452                     paraDir=paraDirDefault;
    453                     lastStrongDir=paraDirDefault;
    454                 }
    455             }
    456         }
    457         if(removeBiDiControls && IS_BIDI_CONTROL_CHAR(uchar)) {
    458             controlCount++;
    459         }
    460     }
    461     if(isDefaultLevelInverse && (lastStrongDir==CONTEXT_RTL) &&(paraDir!=lastStrongDir)) {
    462         for(i1=paraStart; i1<length; i1++) {
    463             dirProps[i1]|=CONTEXT_RTL;
    464         }
    465     }
    466     if(isDefaultLevel) {
    467         pBiDi->paraLevel=GET_PARALEVEL(pBiDi, 0);
    468     }
    469     if(pBiDi->reorderingOptions & UBIDI_OPTION_STREAMING) {
    470         if((lastStrongLTR>pBiDi->length) &&
    471            (GET_PARALEVEL(pBiDi, lastStrongLTR)==0)) {
    472             pBiDi->length = lastStrongLTR;
    473         }
    474         if(pBiDi->length<pBiDi->originalLength) {
    475             pBiDi->paraCount--;
    476         }
    477     }
    478     /* The following line does nothing new for contextual paraLevel, but is
    479        needed for absolute paraLevel.                               */
    480     flags|=DIRPROP_FLAG_LR(pBiDi->paraLevel);
    481 
    482     if(pBiDi->orderParagraphsLTR && (flags&DIRPROP_FLAG(B))) {
    483         flags|=DIRPROP_FLAG(L);
    484     }
    485 
    486     pBiDi->controlCount = controlCount;
    487     pBiDi->flags=flags;
    488     pBiDi->lastArabicPos=lastArabicPos;
    489 }
    490 
    491 /* perform (X1)..(X9) ------------------------------------------------------- */
    492 
    493 /* determine if the text is mixed-directional or single-directional */
    494 static UBiDiDirection
    495 directionFromFlags(UBiDi *pBiDi) {
    496     Flags flags=pBiDi->flags;
    497     /* if the text contains AN and neutrals, then some neutrals may become RTL */
    498     if(!(flags&MASK_RTL || ((flags&DIRPROP_FLAG(AN)) && (flags&MASK_POSSIBLE_N)))) {
    499         return UBIDI_LTR;
    500     } else if(!(flags&MASK_LTR)) {
    501         return UBIDI_RTL;
    502     } else {
    503         return UBIDI_MIXED;
    504     }
    505 }
    506 
    507 /*
    508  * Resolve the explicit levels as specified by explicit embedding codes.
    509  * Recalculate the flags to have them reflect the real properties
    510  * after taking the explicit embeddings into account.
    511  *
    512  * The BiDi algorithm is designed to result in the same behavior whether embedding
    513  * levels are externally specified (from "styled text", supposedly the preferred
    514  * method) or set by explicit embedding codes (LRx, RLx, PDF) in the plain text.
    515  * That is why (X9) instructs to remove all explicit codes (and BN).
    516  * However, in a real implementation, this removal of these codes and their index
    517  * positions in the plain text is undesirable since it would result in
    518  * reallocated, reindexed text.
    519  * Instead, this implementation leaves the codes in there and just ignores them
    520  * in the subsequent processing.
    521  * In order to get the same reordering behavior, positions with a BN or an
    522  * explicit embedding code just get the same level assigned as the last "real"
    523  * character.
    524  *
    525  * Some implementations, not this one, then overwrite some of these
    526  * directionality properties at "real" same-level-run boundaries by
    527  * L or R codes so that the resolution of weak types can be performed on the
    528  * entire paragraph at once instead of having to parse it once more and
    529  * perform that resolution on same-level-runs.
    530  * This limits the scope of the implicit rules in effectively
    531  * the same way as the run limits.
    532  *
    533  * Instead, this implementation does not modify these codes.
    534  * On one hand, the paragraph has to be scanned for same-level-runs, but
    535  * on the other hand, this saves another loop to reset these codes,
    536  * or saves making and modifying a copy of dirProps[].
    537  *
    538  *
    539  * Note that (Pn) and (Xn) changed significantly from version 4 of the BiDi algorithm.
    540  *
    541  *
    542  * Handling the stack of explicit levels (Xn):
    543  *
    544  * With the BiDi stack of explicit levels,
    545  * as pushed with each LRE, RLE, LRO, and RLO and popped with each PDF,
    546  * the explicit level must never exceed UBIDI_MAX_EXPLICIT_LEVEL==61.
    547  *
    548  * In order to have a correct push-pop semantics even in the case of overflows,
    549  * there are two overflow counters:
    550  * - countOver60 is incremented with each LRx at level 60
    551  * - from level 60, one RLx increases the level to 61
    552  * - countOver61 is incremented with each LRx and RLx at level 61
    553  *
    554  * Popping levels with PDF must work in the opposite order so that level 61
    555  * is correct at the correct point. Underflows (too many PDFs) must be checked.
    556  *
    557  * This implementation assumes that UBIDI_MAX_EXPLICIT_LEVEL is odd.
    558  */
    559 static UBiDiDirection
    560 resolveExplicitLevels(UBiDi *pBiDi) {
    561     const DirProp *dirProps=pBiDi->dirProps;
    562     UBiDiLevel *levels=pBiDi->levels;
    563     const UChar *text=pBiDi->text;
    564 
    565     int32_t i=0, length=pBiDi->length;
    566     Flags flags=pBiDi->flags;       /* collect all directionalities in the text */
    567     DirProp dirProp;
    568     UBiDiLevel level=GET_PARALEVEL(pBiDi, 0);
    569 
    570     UBiDiDirection direction;
    571     int32_t paraIndex=0;
    572 
    573     /* determine if the text is mixed-directional or single-directional */
    574     direction=directionFromFlags(pBiDi);
    575 
    576     /* we may not need to resolve any explicit levels, but for multiple
    577        paragraphs we want to loop on all chars to set the para boundaries */
    578     if((direction!=UBIDI_MIXED) && (pBiDi->paraCount==1)) {
    579         /* not mixed directionality: levels don't matter - trailingWSStart will be 0 */
    580     } else if((pBiDi->paraCount==1) &&
    581               (!(flags&MASK_EXPLICIT) ||
    582                (pBiDi->reorderingMode > UBIDI_REORDER_LAST_LOGICAL_TO_VISUAL))) {
    583         /* mixed, but all characters are at the same embedding level */
    584         /* or we are in "inverse BiDi" */
    585         /* and we don't have contextual multiple paragraphs with some B char */
    586         /* set all levels to the paragraph level */
    587         for(i=0; i<length; ++i) {
    588             levels[i]=level;
    589         }
    590     } else {
    591         /* continue to perform (Xn) */
    592 
    593         /* (X1) level is set for all codes, embeddingLevel keeps track of the push/pop operations */
    594         /* both variables may carry the UBIDI_LEVEL_OVERRIDE flag to indicate the override status */
    595         UBiDiLevel embeddingLevel=level, newLevel, stackTop=0;
    596 
    597         UBiDiLevel stack[UBIDI_MAX_EXPLICIT_LEVEL];        /* we never push anything >=UBIDI_MAX_EXPLICIT_LEVEL */
    598         uint32_t countOver60=0, countOver61=0;  /* count overflows of explicit levels */
    599 
    600         /* recalculate the flags */
    601         flags=0;
    602 
    603         for(i=0; i<length; ++i) {
    604             dirProp=NO_CONTEXT_RTL(dirProps[i]);
    605             switch(dirProp) {
    606             case LRE:
    607             case LRO:
    608                 /* (X3, X5) */
    609                 newLevel=(UBiDiLevel)((embeddingLevel+2)&~(UBIDI_LEVEL_OVERRIDE|1)); /* least greater even level */
    610                 if(newLevel<=UBIDI_MAX_EXPLICIT_LEVEL) {
    611                     stack[stackTop]=embeddingLevel;
    612                     ++stackTop;
    613                     embeddingLevel=newLevel;
    614                     if(dirProp==LRO) {
    615                         embeddingLevel|=UBIDI_LEVEL_OVERRIDE;
    616                     }
    617                     /* we don't need to set UBIDI_LEVEL_OVERRIDE off for LRE
    618                        since this has already been done for newLevel which is
    619                        the source for embeddingLevel.
    620                      */
    621                 } else if((embeddingLevel&~UBIDI_LEVEL_OVERRIDE)==UBIDI_MAX_EXPLICIT_LEVEL) {
    622                     ++countOver61;
    623                 } else /* (embeddingLevel&~UBIDI_LEVEL_OVERRIDE)==UBIDI_MAX_EXPLICIT_LEVEL-1 */ {
    624                     ++countOver60;
    625                 }
    626                 flags|=DIRPROP_FLAG(BN);
    627                 break;
    628             case RLE:
    629             case RLO:
    630                 /* (X2, X4) */
    631                 newLevel=(UBiDiLevel)(((embeddingLevel&~UBIDI_LEVEL_OVERRIDE)+1)|1); /* least greater odd level */
    632                 if(newLevel<=UBIDI_MAX_EXPLICIT_LEVEL) {
    633                     stack[stackTop]=embeddingLevel;
    634                     ++stackTop;
    635                     embeddingLevel=newLevel;
    636                     if(dirProp==RLO) {
    637                         embeddingLevel|=UBIDI_LEVEL_OVERRIDE;
    638                     }
    639                     /* we don't need to set UBIDI_LEVEL_OVERRIDE off for RLE
    640                        since this has already been done for newLevel which is
    641                        the source for embeddingLevel.
    642                      */
    643                 } else {
    644                     ++countOver61;
    645                 }
    646                 flags|=DIRPROP_FLAG(BN);
    647                 break;
    648             case PDF:
    649                 /* (X7) */
    650                 /* handle all the overflow cases first */
    651                 if(countOver61>0) {
    652                     --countOver61;
    653                 } else if(countOver60>0 && (embeddingLevel&~UBIDI_LEVEL_OVERRIDE)!=UBIDI_MAX_EXPLICIT_LEVEL) {
    654                     /* handle LRx overflows from level 60 */
    655                     --countOver60;
    656                 } else if(stackTop>0) {
    657                     /* this is the pop operation; it also pops level 61 while countOver60>0 */
    658                     --stackTop;
    659                     embeddingLevel=stack[stackTop];
    660                 /* } else { (underflow) */
    661                 }
    662                 flags|=DIRPROP_FLAG(BN);
    663                 break;
    664             case B:
    665                 stackTop=0;
    666                 countOver60=countOver61=0;
    667                 level=GET_PARALEVEL(pBiDi, i);
    668                 if((i+1)<length) {
    669                     embeddingLevel=GET_PARALEVEL(pBiDi, i+1);
    670                     if(!((text[i]==CR) && (text[i+1]==LF))) {
    671                         pBiDi->paras[paraIndex++]=i+1;
    672                     }
    673                 }
    674                 flags|=DIRPROP_FLAG(B);
    675                 break;
    676             case BN:
    677                 /* BN, LRE, RLE, and PDF are supposed to be removed (X9) */
    678                 /* they will get their levels set correctly in adjustWSLevels() */
    679                 flags|=DIRPROP_FLAG(BN);
    680                 break;
    681             default:
    682                 /* all other types get the "real" level */
    683                 if(level!=embeddingLevel) {
    684                     level=embeddingLevel;
    685                     if(level&UBIDI_LEVEL_OVERRIDE) {
    686                         flags|=DIRPROP_FLAG_O(level)|DIRPROP_FLAG_MULTI_RUNS;
    687                     } else {
    688                         flags|=DIRPROP_FLAG_E(level)|DIRPROP_FLAG_MULTI_RUNS;
    689                     }
    690                 }
    691                 if(!(level&UBIDI_LEVEL_OVERRIDE)) {
    692                     flags|=DIRPROP_FLAG(dirProp);
    693                 }
    694                 break;
    695             }
    696 
    697             /*
    698              * We need to set reasonable levels even on BN codes and
    699              * explicit codes because we will later look at same-level runs (X10).
    700              */
    701             levels[i]=level;
    702         }
    703         if(flags&MASK_EMBEDDING) {
    704             flags|=DIRPROP_FLAG_LR(pBiDi->paraLevel);
    705         }
    706         if(pBiDi->orderParagraphsLTR && (flags&DIRPROP_FLAG(B))) {
    707             flags|=DIRPROP_FLAG(L);
    708         }
    709 
    710         /* subsequently, ignore the explicit codes and BN (X9) */
    711 
    712         /* again, determine if the text is mixed-directional or single-directional */
    713         pBiDi->flags=flags;
    714         direction=directionFromFlags(pBiDi);
    715     }
    716 
    717     return direction;
    718 }
    719 
    720 /*
    721  * Use a pre-specified embedding levels array:
    722  *
    723  * Adjust the directional properties for overrides (->LEVEL_OVERRIDE),
    724  * ignore all explicit codes (X9),
    725  * and check all the preset levels.
    726  *
    727  * Recalculate the flags to have them reflect the real properties
    728  * after taking the explicit embeddings into account.
    729  */
    730 static UBiDiDirection
    731 checkExplicitLevels(UBiDi *pBiDi, UErrorCode *pErrorCode) {
    732     const DirProp *dirProps=pBiDi->dirProps;
    733     DirProp dirProp;
    734     UBiDiLevel *levels=pBiDi->levels;
    735     const UChar *text=pBiDi->text;
    736 
    737     int32_t i, length=pBiDi->length;
    738     Flags flags=0;  /* collect all directionalities in the text */
    739     UBiDiLevel level;
    740     uint32_t paraIndex=0;
    741 
    742     for(i=0; i<length; ++i) {
    743         level=levels[i];
    744         dirProp=NO_CONTEXT_RTL(dirProps[i]);
    745         if(level&UBIDI_LEVEL_OVERRIDE) {
    746             /* keep the override flag in levels[i] but adjust the flags */
    747             level&=~UBIDI_LEVEL_OVERRIDE;     /* make the range check below simpler */
    748             flags|=DIRPROP_FLAG_O(level);
    749         } else {
    750             /* set the flags */
    751             flags|=DIRPROP_FLAG_E(level)|DIRPROP_FLAG(dirProp);
    752         }
    753         if((level<GET_PARALEVEL(pBiDi, i) &&
    754             !((0==level)&&(dirProp==B))) ||
    755            (UBIDI_MAX_EXPLICIT_LEVEL<level)) {
    756             /* level out of bounds */
    757             *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
    758             return UBIDI_LTR;
    759         }
    760         if((dirProp==B) && ((i+1)<length)) {
    761             if(!((text[i]==CR) && (text[i+1]==LF))) {
    762                 pBiDi->paras[paraIndex++]=i+1;
    763             }
    764         }
    765     }
    766     if(flags&MASK_EMBEDDING) {
    767         flags|=DIRPROP_FLAG_LR(pBiDi->paraLevel);
    768     }
    769 
    770     /* determine if the text is mixed-directional or single-directional */
    771     pBiDi->flags=flags;
    772     return directionFromFlags(pBiDi);
    773 }
    774 
    775 /******************************************************************
    776  The Properties state machine table
    777 *******************************************************************
    778 
    779  All table cells are 8 bits:
    780       bits 0..4:  next state
    781       bits 5..7:  action to perform (if > 0)
    782 
    783  Cells may be of format "n" where n represents the next state
    784  (except for the rightmost column).
    785  Cells may also be of format "s(x,y)" where x represents an action
    786  to perform and y represents the next state.
    787 
    788 *******************************************************************
    789  Definitions and type for properties state table
    790 *******************************************************************
    791 */
    792 #define IMPTABPROPS_COLUMNS 14
    793 #define IMPTABPROPS_RES (IMPTABPROPS_COLUMNS - 1)
    794 #define GET_STATEPROPS(cell) ((cell)&0x1f)
    795 #define GET_ACTIONPROPS(cell) ((cell)>>5)
    796 #define s(action, newState) ((uint8_t)(newState+(action<<5)))
    797 
    798 static const uint8_t groupProp[] =          /* dirProp regrouped */
    799 {
    800 /*  L   R   EN  ES  ET  AN  CS  B   S   WS  ON  LRE LRO AL  RLE RLO PDF NSM BN  */
    801     0,  1,  2,  7,  8,  3,  9,  6,  5,  4,  4,  10, 10, 12, 10, 10, 10, 11, 10
    802 };
    803 enum { DirProp_L=0, DirProp_R=1, DirProp_EN=2, DirProp_AN=3, DirProp_ON=4, DirProp_S=5, DirProp_B=6 }; /* reduced dirProp */
    804 
    805 /******************************************************************
    806 
    807       PROPERTIES  STATE  TABLE
    808 
    809  In table impTabProps,
    810       - the ON column regroups ON and WS
    811       - the BN column regroups BN, LRE, RLE, LRO, RLO, PDF
    812       - the Res column is the reduced property assigned to a run
    813 
    814  Action 1: process current run1, init new run1
    815         2: init new run2
    816         3: process run1, process run2, init new run1
    817         4: process run1, set run1=run2, init new run2
    818 
    819  Notes:
    820   1) This table is used in resolveImplicitLevels().
    821   2) This table triggers actions when there is a change in the Bidi
    822      property of incoming characters (action 1).
    823   3) Most such property sequences are processed immediately (in
    824      fact, passed to processPropertySeq().
    825   4) However, numbers are assembled as one sequence. This means
    826      that undefined situations (like CS following digits, until
    827      it is known if the next char will be a digit) are held until
    828      following chars define them.
    829      Example: digits followed by CS, then comes another CS or ON;
    830               the digits will be processed, then the CS assigned
    831               as the start of an ON sequence (action 3).
    832   5) There are cases where more than one sequence must be
    833      processed, for instance digits followed by CS followed by L:
    834      the digits must be processed as one sequence, and the CS
    835      must be processed as an ON sequence, all this before starting
    836      assembling chars for the opening L sequence.
    837 
    838 
    839 */
    840 static const uint8_t impTabProps[][IMPTABPROPS_COLUMNS] =
    841 {
    842 /*                        L ,     R ,    EN ,    AN ,    ON ,     S ,     B ,    ES ,    ET ,    CS ,    BN ,   NSM ,    AL ,  Res */
    843 /* 0 Init        */ {     1 ,     2 ,     4 ,     5 ,     7 ,    15 ,    17 ,     7 ,     9 ,     7 ,     0 ,     7 ,     3 ,  DirProp_ON },
    844 /* 1 L           */ {     1 , s(1,2), s(1,4), s(1,5), s(1,7),s(1,15),s(1,17), s(1,7), s(1,9), s(1,7),     1 ,     1 , s(1,3),   DirProp_L },
    845 /* 2 R           */ { s(1,1),     2 , s(1,4), s(1,5), s(1,7),s(1,15),s(1,17), s(1,7), s(1,9), s(1,7),     2 ,     2 , s(1,3),   DirProp_R },
    846 /* 3 AL          */ { s(1,1), s(1,2), s(1,6), s(1,6), s(1,8),s(1,16),s(1,17), s(1,8), s(1,8), s(1,8),     3 ,     3 ,     3 ,   DirProp_R },
    847 /* 4 EN          */ { s(1,1), s(1,2),     4 , s(1,5), s(1,7),s(1,15),s(1,17),s(2,10),    11 ,s(2,10),     4 ,     4 , s(1,3),  DirProp_EN },
    848 /* 5 AN          */ { s(1,1), s(1,2), s(1,4),     5 , s(1,7),s(1,15),s(1,17), s(1,7), s(1,9),s(2,12),     5 ,     5 , s(1,3),  DirProp_AN },
    849 /* 6 AL:EN/AN    */ { s(1,1), s(1,2),     6 ,     6 , s(1,8),s(1,16),s(1,17), s(1,8), s(1,8),s(2,13),     6 ,     6 , s(1,3),  DirProp_AN },
    850 /* 7 ON          */ { s(1,1), s(1,2), s(1,4), s(1,5),     7 ,s(1,15),s(1,17),     7 ,s(2,14),     7 ,     7 ,     7 , s(1,3),  DirProp_ON },
    851 /* 8 AL:ON       */ { s(1,1), s(1,2), s(1,6), s(1,6),     8 ,s(1,16),s(1,17),     8 ,     8 ,     8 ,     8 ,     8 , s(1,3),  DirProp_ON },
    852 /* 9 ET          */ { s(1,1), s(1,2),     4 , s(1,5),     7 ,s(1,15),s(1,17),     7 ,     9 ,     7 ,     9 ,     9 , s(1,3),  DirProp_ON },
    853 /*10 EN+ES/CS    */ { s(3,1), s(3,2),     4 , s(3,5), s(4,7),s(3,15),s(3,17), s(4,7),s(4,14), s(4,7),    10 , s(4,7), s(3,3),  DirProp_EN },
    854 /*11 EN+ET       */ { s(1,1), s(1,2),     4 , s(1,5), s(1,7),s(1,15),s(1,17), s(1,7),    11 , s(1,7),    11 ,    11 , s(1,3),  DirProp_EN },
    855 /*12 AN+CS       */ { s(3,1), s(3,2), s(3,4),     5 , s(4,7),s(3,15),s(3,17), s(4,7),s(4,14), s(4,7),    12 , s(4,7), s(3,3),  DirProp_AN },
    856 /*13 AL:EN/AN+CS */ { s(3,1), s(3,2),     6 ,     6 , s(4,8),s(3,16),s(3,17), s(4,8), s(4,8), s(4,8),    13 , s(4,8), s(3,3),  DirProp_AN },
    857 /*14 ON+ET       */ { s(1,1), s(1,2), s(4,4), s(1,5),     7 ,s(1,15),s(1,17),     7 ,    14 ,     7 ,    14 ,    14 , s(1,3),  DirProp_ON },
    858 /*15 S           */ { s(1,1), s(1,2), s(1,4), s(1,5), s(1,7),    15 ,s(1,17), s(1,7), s(1,9), s(1,7),    15 , s(1,7), s(1,3),   DirProp_S },
    859 /*16 AL:S        */ { s(1,1), s(1,2), s(1,6), s(1,6), s(1,8),    16 ,s(1,17), s(1,8), s(1,8), s(1,8),    16 , s(1,8), s(1,3),   DirProp_S },
    860 /*17 B           */ { s(1,1), s(1,2), s(1,4), s(1,5), s(1,7),s(1,15),    17 , s(1,7), s(1,9), s(1,7),    17 , s(1,7), s(1,3),   DirProp_B }
    861 };
    862 
    863 /*  we must undef macro s because the levels table have a different
    864  *  structure (4 bits for action and 4 bits for next state.
    865  */
    866 #undef s
    867 
    868 /******************************************************************
    869  The levels state machine tables
    870 *******************************************************************
    871 
    872  All table cells are 8 bits:
    873       bits 0..3:  next state
    874       bits 4..7:  action to perform (if > 0)
    875 
    876  Cells may be of format "n" where n represents the next state
    877  (except for the rightmost column).
    878  Cells may also be of format "s(x,y)" where x represents an action
    879  to perform and y represents the next state.
    880 
    881  This format limits each table to 16 states each and to 15 actions.
    882 
    883 *******************************************************************
    884  Definitions and type for levels state tables
    885 *******************************************************************
    886 */
    887 #define IMPTABLEVELS_COLUMNS (DirProp_B + 2)
    888 #define IMPTABLEVELS_RES (IMPTABLEVELS_COLUMNS - 1)
    889 #define GET_STATE(cell) ((cell)&0x0f)
    890 #define GET_ACTION(cell) ((cell)>>4)
    891 #define s(action, newState) ((uint8_t)(newState+(action<<4)))
    892 
    893 typedef uint8_t ImpTab[][IMPTABLEVELS_COLUMNS];
    894 typedef uint8_t ImpAct[];
    895 
    896 /* FOOD FOR THOUGHT: each ImpTab should have its associated ImpAct,
    897  * instead of having a pair of ImpTab and a pair of ImpAct.
    898  */
    899 typedef struct ImpTabPair {
    900     const void * pImpTab[2];
    901     const void * pImpAct[2];
    902 } ImpTabPair;
    903 
    904 /******************************************************************
    905 
    906       LEVELS  STATE  TABLES
    907 
    908  In all levels state tables,
    909       - state 0 is the initial state
    910       - the Res column is the increment to add to the text level
    911         for this property sequence.
    912 
    913  The impAct arrays for each table of a pair map the local action
    914  numbers of the table to the total list of actions. For instance,
    915  action 2 in a given table corresponds to the action number which
    916  appears in entry [2] of the impAct array for that table.
    917  The first entry of all impAct arrays must be 0.
    918 
    919  Action 1: init conditional sequence
    920         2: prepend conditional sequence to current sequence
    921         3: set ON sequence to new level - 1
    922         4: init EN/AN/ON sequence
    923         5: fix EN/AN/ON sequence followed by R
    924         6: set previous level sequence to level 2
    925 
    926  Notes:
    927   1) These tables are used in processPropertySeq(). The input
    928      is property sequences as determined by resolveImplicitLevels.
    929   2) Most such property sequences are processed immediately
    930      (levels are assigned).
    931   3) However, some sequences cannot be assigned a final level till
    932      one or more following sequences are received. For instance,
    933      ON following an R sequence within an even-level paragraph.
    934      If the following sequence is R, the ON sequence will be
    935      assigned basic run level+1, and so will the R sequence.
    936   4) S is generally handled like ON, since its level will be fixed
    937      to paragraph level in adjustWSLevels().
    938 
    939 */
    940 
    941 static const ImpTab impTabL_DEFAULT =   /* Even paragraph level */
    942 /*  In this table, conditional sequences receive the higher possible level
    943     until proven otherwise.
    944 */
    945 {
    946 /*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
    947 /* 0 : init       */ {     0 ,     1 ,     0 ,     2 ,     0 ,     0 ,     0 ,  0 },
    948 /* 1 : R          */ {     0 ,     1 ,     3 ,     3 , s(1,4), s(1,4),     0 ,  1 },
    949 /* 2 : AN         */ {     0 ,     1 ,     0 ,     2 , s(1,5), s(1,5),     0 ,  2 },
    950 /* 3 : R+EN/AN    */ {     0 ,     1 ,     3 ,     3 , s(1,4), s(1,4),     0 ,  2 },
    951 /* 4 : R+ON       */ { s(2,0),     1 ,     3 ,     3 ,     4 ,     4 , s(2,0),  1 },
    952 /* 5 : AN+ON      */ { s(2,0),     1 , s(2,0),     2 ,     5 ,     5 , s(2,0),  1 }
    953 };
    954 static const ImpTab impTabR_DEFAULT =   /* Odd  paragraph level */
    955 /*  In this table, conditional sequences receive the lower possible level
    956     until proven otherwise.
    957 */
    958 {
    959 /*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
    960 /* 0 : init       */ {     1 ,     0 ,     2 ,     2 ,     0 ,     0 ,     0 ,  0 },
    961 /* 1 : L          */ {     1 ,     0 ,     1 ,     3 , s(1,4), s(1,4),     0 ,  1 },
    962 /* 2 : EN/AN      */ {     1 ,     0 ,     2 ,     2 ,     0 ,     0 ,     0 ,  1 },
    963 /* 3 : L+AN       */ {     1 ,     0 ,     1 ,     3 ,     5 ,     5 ,     0 ,  1 },
    964 /* 4 : L+ON       */ { s(2,1),     0 , s(2,1),     3 ,     4 ,     4 ,     0 ,  0 },
    965 /* 5 : L+AN+ON    */ {     1 ,     0 ,     1 ,     3 ,     5 ,     5 ,     0 ,  0 }
    966 };
    967 static const ImpAct impAct0 = {0,1,2,3,4,5,6};
    968 static const ImpTabPair impTab_DEFAULT = {{&impTabL_DEFAULT,
    969                                            &impTabR_DEFAULT},
    970                                           {&impAct0, &impAct0}};
    971 
    972 static const ImpTab impTabL_NUMBERS_SPECIAL =   /* Even paragraph level */
    973 /*  In this table, conditional sequences receive the higher possible level
    974     until proven otherwise.
    975 */
    976 {
    977 /*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
    978 /* 0 : init       */ {     0 ,     2 ,    1 ,      1 ,     0 ,     0 ,     0 ,  0 },
    979 /* 1 : L+EN/AN    */ {     0 ,     2 ,    1 ,      1 ,     0 ,     0 ,     0 ,  2 },
    980 /* 2 : R          */ {     0 ,     2 ,    4 ,      4 , s(1,3),     0 ,     0 ,  1 },
    981 /* 3 : R+ON       */ { s(2,0),     2 ,    4 ,      4 ,     3 ,     3 , s(2,0),  1 },
    982 /* 4 : R+EN/AN    */ {     0 ,     2 ,    4 ,      4 , s(1,3), s(1,3),     0 ,  2 }
    983   };
    984 static const ImpTabPair impTab_NUMBERS_SPECIAL = {{&impTabL_NUMBERS_SPECIAL,
    985                                                    &impTabR_DEFAULT},
    986                                                   {&impAct0, &impAct0}};
    987 
    988 static const ImpTab impTabL_GROUP_NUMBERS_WITH_R =
    989 /*  In this table, EN/AN+ON sequences receive levels as if associated with R
    990     until proven that there is L or sor/eor on both sides. AN is handled like EN.
    991 */
    992 {
    993 /*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
    994 /* 0 init         */ {     0 ,     3 , s(1,1), s(1,1),     0 ,     0 ,     0 ,  0 },
    995 /* 1 EN/AN        */ { s(2,0),     3 ,     1 ,     1 ,     2 , s(2,0), s(2,0),  2 },
    996 /* 2 EN/AN+ON     */ { s(2,0),     3 ,     1 ,     1 ,     2 , s(2,0), s(2,0),  1 },
    997 /* 3 R            */ {     0 ,     3 ,     5 ,     5 , s(1,4),     0 ,     0 ,  1 },
    998 /* 4 R+ON         */ { s(2,0),     3 ,     5 ,     5 ,     4 , s(2,0), s(2,0),  1 },
    999 /* 5 R+EN/AN      */ {     0 ,     3 ,     5 ,     5 , s(1,4),     0 ,     0 ,  2 }
   1000 };
   1001 static const ImpTab impTabR_GROUP_NUMBERS_WITH_R =
   1002 /*  In this table, EN/AN+ON sequences receive levels as if associated with R
   1003     until proven that there is L on both sides. AN is handled like EN.
   1004 */
   1005 {
   1006 /*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
   1007 /* 0 init         */ {     2 ,     0 ,     1 ,     1 ,     0 ,     0 ,     0 ,  0 },
   1008 /* 1 EN/AN        */ {     2 ,     0 ,     1 ,     1 ,     0 ,     0 ,     0 ,  1 },
   1009 /* 2 L            */ {     2 ,     0 , s(1,4), s(1,4), s(1,3),     0 ,     0 ,  1 },
   1010 /* 3 L+ON         */ { s(2,2),     0 ,     4 ,     4 ,     3 ,     0 ,     0 ,  0 },
   1011 /* 4 L+EN/AN      */ { s(2,2),     0 ,     4 ,     4 ,     3 ,     0 ,     0 ,  1 }
   1012 };
   1013 static const ImpTabPair impTab_GROUP_NUMBERS_WITH_R = {
   1014                         {&impTabL_GROUP_NUMBERS_WITH_R,
   1015                          &impTabR_GROUP_NUMBERS_WITH_R},
   1016                         {&impAct0, &impAct0}};
   1017 
   1018 
   1019 static const ImpTab impTabL_INVERSE_NUMBERS_AS_L =
   1020 /*  This table is identical to the Default LTR table except that EN and AN are
   1021     handled like L.
   1022 */
   1023 {
   1024 /*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
   1025 /* 0 : init       */ {     0 ,     1 ,     0 ,     0 ,     0 ,     0 ,     0 ,  0 },
   1026 /* 1 : R          */ {     0 ,     1 ,     0 ,     0 , s(1,4), s(1,4),     0 ,  1 },
   1027 /* 2 : AN         */ {     0 ,     1 ,     0 ,     0 , s(1,5), s(1,5),     0 ,  2 },
   1028 /* 3 : R+EN/AN    */ {     0 ,     1 ,     0 ,     0 , s(1,4), s(1,4),     0 ,  2 },
   1029 /* 4 : R+ON       */ { s(2,0),     1 , s(2,0), s(2,0),     4 ,     4 , s(2,0),  1 },
   1030 /* 5 : AN+ON      */ { s(2,0),     1 , s(2,0), s(2,0),     5 ,     5 , s(2,0),  1 }
   1031 };
   1032 static const ImpTab impTabR_INVERSE_NUMBERS_AS_L =
   1033 /*  This table is identical to the Default RTL table except that EN and AN are
   1034     handled like L.
   1035 */
   1036 {
   1037 /*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
   1038 /* 0 : init       */ {     1 ,     0 ,     1 ,     1 ,     0 ,     0 ,     0 ,  0 },
   1039 /* 1 : L          */ {     1 ,     0 ,     1 ,     1 , s(1,4), s(1,4),     0 ,  1 },
   1040 /* 2 : EN/AN      */ {     1 ,     0 ,     1 ,     1 ,     0 ,     0 ,     0 ,  1 },
   1041 /* 3 : L+AN       */ {     1 ,     0 ,     1 ,     1 ,     5 ,     5 ,     0 ,  1 },
   1042 /* 4 : L+ON       */ { s(2,1),     0 , s(2,1), s(2,1),     4 ,     4 ,     0 ,  0 },
   1043 /* 5 : L+AN+ON    */ {     1 ,     0 ,     1 ,     1 ,     5 ,     5 ,     0 ,  0 }
   1044 };
   1045 static const ImpTabPair impTab_INVERSE_NUMBERS_AS_L = {
   1046                         {&impTabL_INVERSE_NUMBERS_AS_L,
   1047                          &impTabR_INVERSE_NUMBERS_AS_L},
   1048                         {&impAct0, &impAct0}};
   1049 
   1050 static const ImpTab impTabR_INVERSE_LIKE_DIRECT =   /* Odd  paragraph level */
   1051 /*  In this table, conditional sequences receive the lower possible level
   1052     until proven otherwise.
   1053 */
   1054 {
   1055 /*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
   1056 /* 0 : init       */ {     1 ,     0 ,     2 ,     2 ,     0 ,     0 ,     0 ,  0 },
   1057 /* 1 : L          */ {     1 ,     0 ,     1 ,     2 , s(1,3), s(1,3),     0 ,  1 },
   1058 /* 2 : EN/AN      */ {     1 ,     0 ,     2 ,     2 ,     0 ,     0 ,     0 ,  1 },
   1059 /* 3 : L+ON       */ { s(2,1), s(3,0),     6 ,     4 ,     3 ,     3 , s(3,0),  0 },
   1060 /* 4 : L+ON+AN    */ { s(2,1), s(3,0),     6 ,     4 ,     5 ,     5 , s(3,0),  3 },
   1061 /* 5 : L+AN+ON    */ { s(2,1), s(3,0),     6 ,     4 ,     5 ,     5 , s(3,0),  2 },
   1062 /* 6 : L+ON+EN    */ { s(2,1), s(3,0),     6 ,     4 ,     3 ,     3 , s(3,0),  1 }
   1063 };
   1064 static const ImpAct impAct1 = {0,1,11,12};
   1065 /* FOOD FOR THOUGHT: in LTR table below, check case "JKL 123abc"
   1066  */
   1067 static const ImpTabPair impTab_INVERSE_LIKE_DIRECT = {
   1068                         {&impTabL_DEFAULT,
   1069                          &impTabR_INVERSE_LIKE_DIRECT},
   1070                         {&impAct0, &impAct1}};
   1071 
   1072 static const ImpTab impTabL_INVERSE_LIKE_DIRECT_WITH_MARKS =
   1073 /*  The case handled in this table is (visually):  R EN L
   1074 */
   1075 {
   1076 /*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
   1077 /* 0 : init       */ {     0 , s(6,3),     0 ,     1 ,     0 ,     0 ,     0 ,  0 },
   1078 /* 1 : L+AN       */ {     0 , s(6,3),     0 ,     1 , s(1,2), s(3,0),     0 ,  4 },
   1079 /* 2 : L+AN+ON    */ { s(2,0), s(6,3), s(2,0),     1 ,     2 , s(3,0), s(2,0),  3 },
   1080 /* 3 : R          */ {     0 , s(6,3), s(5,5), s(5,6), s(1,4), s(3,0),     0 ,  3 },
   1081 /* 4 : R+ON       */ { s(3,0), s(4,3), s(5,5), s(5,6),     4 , s(3,0), s(3,0),  3 },
   1082 /* 5 : R+EN       */ { s(3,0), s(4,3),     5 , s(5,6), s(1,4), s(3,0), s(3,0),  4 },
   1083 /* 6 : R+AN       */ { s(3,0), s(4,3), s(5,5),     6 , s(1,4), s(3,0), s(3,0),  4 }
   1084 };
   1085 static const ImpTab impTabR_INVERSE_LIKE_DIRECT_WITH_MARKS =
   1086 /*  The cases handled in this table are (visually):  R EN L
   1087                                                      R L AN L
   1088 */
   1089 {
   1090 /*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
   1091 /* 0 : init       */ { s(1,3),     0 ,     1 ,     1 ,     0 ,     0 ,     0 ,  0 },
   1092 /* 1 : R+EN/AN    */ { s(2,3),     0 ,     1 ,     1 ,     2 , s(4,0),     0 ,  1 },
   1093 /* 2 : R+EN/AN+ON */ { s(2,3),     0 ,     1 ,     1 ,     2 , s(4,0),     0 ,  0 },
   1094 /* 3 : L          */ {     3 ,     0 ,     3 , s(3,6), s(1,4), s(4,0),     0 ,  1 },
   1095 /* 4 : L+ON       */ { s(5,3), s(4,0),     5 , s(3,6),     4 , s(4,0), s(4,0),  0 },
   1096 /* 5 : L+ON+EN    */ { s(5,3), s(4,0),     5 , s(3,6),     4 , s(4,0), s(4,0),  1 },
   1097 /* 6 : L+AN       */ { s(5,3), s(4,0),     6 ,     6 ,     4 , s(4,0), s(4,0),  3 }
   1098 };
   1099 static const ImpAct impAct2 = {0,1,7,8,9,10};
   1100 static const ImpTabPair impTab_INVERSE_LIKE_DIRECT_WITH_MARKS = {
   1101                         {&impTabL_INVERSE_LIKE_DIRECT_WITH_MARKS,
   1102                          &impTabR_INVERSE_LIKE_DIRECT_WITH_MARKS},
   1103                         {&impAct0, &impAct2}};
   1104 
   1105 static const ImpTabPair impTab_INVERSE_FOR_NUMBERS_SPECIAL = {
   1106                         {&impTabL_NUMBERS_SPECIAL,
   1107                          &impTabR_INVERSE_LIKE_DIRECT},
   1108                         {&impAct0, &impAct1}};
   1109 
   1110 static const ImpTab impTabL_INVERSE_FOR_NUMBERS_SPECIAL_WITH_MARKS =
   1111 /*  The case handled in this table is (visually):  R EN L
   1112 */
   1113 {
   1114 /*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
   1115 /* 0 : init       */ {     0 , s(6,2),     1 ,     1 ,     0 ,     0 ,     0 ,  0 },
   1116 /* 1 : L+EN/AN    */ {     0 , s(6,2),     1 ,     1 ,     0 , s(3,0),     0 ,  4 },
   1117 /* 2 : R          */ {     0 , s(6,2), s(5,4), s(5,4), s(1,3), s(3,0),     0 ,  3 },
   1118 /* 3 : R+ON       */ { s(3,0), s(4,2), s(5,4), s(5,4),     3 , s(3,0), s(3,0),  3 },
   1119 /* 4 : R+EN/AN    */ { s(3,0), s(4,2),     4 ,     4 , s(1,3), s(3,0), s(3,0),  4 }
   1120 };
   1121 static const ImpTabPair impTab_INVERSE_FOR_NUMBERS_SPECIAL_WITH_MARKS = {
   1122                         {&impTabL_INVERSE_FOR_NUMBERS_SPECIAL_WITH_MARKS,
   1123                          &impTabR_INVERSE_LIKE_DIRECT_WITH_MARKS},
   1124                         {&impAct0, &impAct2}};
   1125 
   1126 #undef s
   1127 
   1128 typedef struct {
   1129     const ImpTab * pImpTab;             /* level table pointer          */
   1130     const ImpAct * pImpAct;             /* action map array             */
   1131     int32_t startON;                    /* start of ON sequence         */
   1132     int32_t startL2EN;                  /* start of level 2 sequence    */
   1133     int32_t lastStrongRTL;              /* index of last found R or AL  */
   1134     int32_t state;                      /* current state                */
   1135     UBiDiLevel runLevel;                /* run level before implicit solving */
   1136 } LevState;
   1137 
   1138 /*------------------------------------------------------------------------*/
   1139 
   1140 static void
   1141 addPoint(UBiDi *pBiDi, int32_t pos, int32_t flag)
   1142   /* param pos:     position where to insert
   1143      param flag:    one of LRM_BEFORE, LRM_AFTER, RLM_BEFORE, RLM_AFTER
   1144   */
   1145 {
   1146 #define FIRSTALLOC  10
   1147     Point point;
   1148     InsertPoints * pInsertPoints=&(pBiDi->insertPoints);
   1149 
   1150     if (pInsertPoints->capacity == 0)
   1151     {
   1152         pInsertPoints->points=uprv_malloc(sizeof(Point)*FIRSTALLOC);
   1153         if (pInsertPoints->points == NULL)
   1154         {
   1155             pInsertPoints->errorCode=U_MEMORY_ALLOCATION_ERROR;
   1156             return;
   1157         }
   1158         pInsertPoints->capacity=FIRSTALLOC;
   1159     }
   1160     if (pInsertPoints->size >= pInsertPoints->capacity) /* no room for new point */
   1161     {
   1162         void * savePoints=pInsertPoints->points;
   1163         pInsertPoints->points=uprv_realloc(pInsertPoints->points,
   1164                                            pInsertPoints->capacity*2*sizeof(Point));
   1165         if (pInsertPoints->points == NULL)
   1166         {
   1167             pInsertPoints->points=savePoints;
   1168             pInsertPoints->errorCode=U_MEMORY_ALLOCATION_ERROR;
   1169             return;
   1170         }
   1171         else  pInsertPoints->capacity*=2;
   1172     }
   1173     point.pos=pos;
   1174     point.flag=flag;
   1175     pInsertPoints->points[pInsertPoints->size]=point;
   1176     pInsertPoints->size++;
   1177 #undef FIRSTALLOC
   1178 }
   1179 
   1180 /* perform rules (Wn), (Nn), and (In) on a run of the text ------------------ */
   1181 
   1182 /*
   1183  * This implementation of the (Wn) rules applies all rules in one pass.
   1184  * In order to do so, it needs a look-ahead of typically 1 character
   1185  * (except for W5: sequences of ET) and keeps track of changes
   1186  * in a rule Wp that affect a later Wq (p<q).
   1187  *
   1188  * The (Nn) and (In) rules are also performed in that same single loop,
   1189  * but effectively one iteration behind for white space.
   1190  *
   1191  * Since all implicit rules are performed in one step, it is not necessary
   1192  * to actually store the intermediate directional properties in dirProps[].
   1193  */
   1194 
   1195 static void
   1196 processPropertySeq(UBiDi *pBiDi, LevState *pLevState, uint8_t _prop,
   1197                    int32_t start, int32_t limit) {
   1198     uint8_t cell, oldStateSeq, actionSeq;
   1199     const ImpTab * pImpTab=pLevState->pImpTab;
   1200     const ImpAct * pImpAct=pLevState->pImpAct;
   1201     UBiDiLevel * levels=pBiDi->levels;
   1202     UBiDiLevel level, addLevel;
   1203     InsertPoints * pInsertPoints;
   1204     int32_t start0, k;
   1205 
   1206     start0=start;                           /* save original start position */
   1207     oldStateSeq=(uint8_t)pLevState->state;
   1208     cell=(*pImpTab)[oldStateSeq][_prop];
   1209     pLevState->state=GET_STATE(cell);       /* isolate the new state */
   1210     actionSeq=(*pImpAct)[GET_ACTION(cell)]; /* isolate the action */
   1211     addLevel=(*pImpTab)[pLevState->state][IMPTABLEVELS_RES];
   1212 
   1213     if(actionSeq) {
   1214         switch(actionSeq) {
   1215         case 1:                         /* init ON seq */
   1216             pLevState->startON=start0;
   1217             break;
   1218 
   1219         case 2:                         /* prepend ON seq to current seq */
   1220             start=pLevState->startON;
   1221             break;
   1222 
   1223         case 3:                         /* L or S after possible relevant EN/AN */
   1224             /* check if we had EN after R/AL */
   1225             if (pLevState->startL2EN >= 0) {
   1226                 addPoint(pBiDi, pLevState->startL2EN, LRM_BEFORE);
   1227             }
   1228             pLevState->startL2EN=-1;  /* not within previous if since could also be -2 */
   1229             /* check if we had any relevant EN/AN after R/AL */
   1230             pInsertPoints=&(pBiDi->insertPoints);
   1231             if ((pInsertPoints->capacity == 0) ||
   1232                 (pInsertPoints->size <= pInsertPoints->confirmed))
   1233             {
   1234                 /* nothing, just clean up */
   1235                 pLevState->lastStrongRTL=-1;
   1236                 /* check if we have a pending conditional segment */
   1237                 level=(*pImpTab)[oldStateSeq][IMPTABLEVELS_RES];
   1238                 if ((level & 1) && (pLevState->startON > 0)) {  /* after ON */
   1239                     start=pLevState->startON;   /* reset to basic run level */
   1240                 }
   1241                 if (_prop == DirProp_S)                /* add LRM before S */
   1242                 {
   1243                     addPoint(pBiDi, start0, LRM_BEFORE);
   1244                     pInsertPoints->confirmed=pInsertPoints->size;
   1245                 }
   1246                 break;
   1247             }
   1248             /* reset previous RTL cont to level for LTR text */
   1249             for (k=pLevState->lastStrongRTL+1; k<start0; k++)
   1250             {
   1251                 /* reset odd level, leave runLevel+2 as is */
   1252                 levels[k]=(levels[k] - 2) & ~1;
   1253             }
   1254             /* mark insert points as confirmed */
   1255             pInsertPoints->confirmed=pInsertPoints->size;
   1256             pLevState->lastStrongRTL=-1;
   1257             if (_prop == DirProp_S)            /* add LRM before S */
   1258             {
   1259                 addPoint(pBiDi, start0, LRM_BEFORE);
   1260                 pInsertPoints->confirmed=pInsertPoints->size;
   1261             }
   1262             break;
   1263 
   1264         case 4:                         /* R/AL after possible relevant EN/AN */
   1265             /* just clean up */
   1266             pInsertPoints=&(pBiDi->insertPoints);
   1267             if (pInsertPoints->capacity > 0)
   1268                 /* remove all non confirmed insert points */
   1269                 pInsertPoints->size=pInsertPoints->confirmed;
   1270             pLevState->startON=-1;
   1271             pLevState->startL2EN=-1;
   1272             pLevState->lastStrongRTL=limit - 1;
   1273             break;
   1274 
   1275         case 5:                         /* EN/AN after R/AL + possible cont */
   1276             /* check for real AN */
   1277             if ((_prop == DirProp_AN) && (NO_CONTEXT_RTL(pBiDi->dirProps[start0]) == AN) &&
   1278                 (pBiDi->reorderingMode!=UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL))
   1279             {
   1280                 /* real AN */
   1281                 if (pLevState->startL2EN == -1) /* if no relevant EN already found */
   1282                 {
   1283                     /* just note the righmost digit as a strong RTL */
   1284                     pLevState->lastStrongRTL=limit - 1;
   1285                     break;
   1286                 }
   1287                 if (pLevState->startL2EN >= 0)  /* after EN, no AN */
   1288                 {
   1289                     addPoint(pBiDi, pLevState->startL2EN, LRM_BEFORE);
   1290                     pLevState->startL2EN=-2;
   1291                 }
   1292                 /* note AN */
   1293                 addPoint(pBiDi, start0, LRM_BEFORE);
   1294                 break;
   1295             }
   1296             /* if first EN/AN after R/AL */
   1297             if (pLevState->startL2EN == -1) {
   1298                 pLevState->startL2EN=start0;
   1299             }
   1300             break;
   1301 
   1302         case 6:                         /* note location of latest R/AL */
   1303             pLevState->lastStrongRTL=limit - 1;
   1304             pLevState->startON=-1;
   1305             break;
   1306 
   1307         case 7:                         /* L after R+ON/EN/AN */
   1308             /* include possible adjacent number on the left */
   1309             for (k=start0-1; k>=0 && !(levels[k]&1); k--);
   1310             if(k>=0) {
   1311                 addPoint(pBiDi, k, RLM_BEFORE);             /* add RLM before */
   1312                 pInsertPoints=&(pBiDi->insertPoints);
   1313                 pInsertPoints->confirmed=pInsertPoints->size;   /* confirm it */
   1314             }
   1315             pLevState->startON=start0;
   1316             break;
   1317 
   1318         case 8:                         /* AN after L */
   1319             /* AN numbers between L text on both sides may be trouble. */
   1320             /* tentatively bracket with LRMs; will be confirmed if followed by L */
   1321             addPoint(pBiDi, start0, LRM_BEFORE);    /* add LRM before */
   1322             addPoint(pBiDi, start0, LRM_AFTER);     /* add LRM after  */
   1323             break;
   1324 
   1325         case 9:                         /* R after L+ON/EN/AN */
   1326             /* false alert, infirm LRMs around previous AN */
   1327             pInsertPoints=&(pBiDi->insertPoints);
   1328             pInsertPoints->size=pInsertPoints->confirmed;
   1329             if (_prop == DirProp_S)            /* add RLM before S */
   1330             {
   1331                 addPoint(pBiDi, start0, RLM_BEFORE);
   1332                 pInsertPoints->confirmed=pInsertPoints->size;
   1333             }
   1334             break;
   1335 
   1336         case 10:                        /* L after L+ON/AN */
   1337             level=pLevState->runLevel + addLevel;
   1338             for(k=pLevState->startON; k<start0; k++) {
   1339                 if (levels[k]<level)
   1340                     levels[k]=level;
   1341             }
   1342             pInsertPoints=&(pBiDi->insertPoints);
   1343             pInsertPoints->confirmed=pInsertPoints->size;   /* confirm inserts */
   1344             pLevState->startON=start0;
   1345             break;
   1346 
   1347         case 11:                        /* L after L+ON+EN/AN/ON */
   1348             level=pLevState->runLevel;
   1349             for(k=start0-1; k>=pLevState->startON; k--) {
   1350                 if(levels[k]==level+3) {
   1351                     while(levels[k]==level+3) {
   1352                         levels[k--]-=2;
   1353                     }
   1354                     while(levels[k]==level) {
   1355                         k--;
   1356                     }
   1357                 }
   1358                 if(levels[k]==level+2) {
   1359                     levels[k]=level;
   1360                     continue;
   1361                 }
   1362                 levels[k]=level+1;
   1363             }
   1364             break;
   1365 
   1366         case 12:                        /* R after L+ON+EN/AN/ON */
   1367             level=pLevState->runLevel+1;
   1368             for(k=start0-1; k>=pLevState->startON; k--) {
   1369                 if(levels[k]>level) {
   1370                     levels[k]-=2;
   1371                 }
   1372             }
   1373             break;
   1374 
   1375         default:                        /* we should never get here */
   1376             U_ASSERT(FALSE);
   1377             break;
   1378         }
   1379     }
   1380     if((addLevel) || (start < start0)) {
   1381         level=pLevState->runLevel + addLevel;
   1382         for(k=start; k<limit; k++) {
   1383             levels[k]=level;
   1384         }
   1385     }
   1386 }
   1387 
   1388 static void
   1389 resolveImplicitLevels(UBiDi *pBiDi,
   1390                       int32_t start, int32_t limit,
   1391                       DirProp sor, DirProp eor) {
   1392     const DirProp *dirProps=pBiDi->dirProps;
   1393 
   1394     LevState levState;
   1395     int32_t i, start1, start2;
   1396     uint8_t oldStateImp, stateImp, actionImp;
   1397     uint8_t gprop, resProp, cell;
   1398     UBool inverseRTL;
   1399     DirProp nextStrongProp=R;
   1400     int32_t nextStrongPos=-1;
   1401 
   1402     levState.startON = -1;  /* silence gcc flow analysis */
   1403 
   1404     /* check for RTL inverse BiDi mode */
   1405     /* FOOD FOR THOUGHT: in case of RTL inverse BiDi, it would make sense to
   1406      * loop on the text characters from end to start.
   1407      * This would need a different properties state table (at least different
   1408      * actions) and different levels state tables (maybe very similar to the
   1409      * LTR corresponding ones.
   1410      */
   1411     inverseRTL=(UBool)
   1412         ((start<pBiDi->lastArabicPos) && (GET_PARALEVEL(pBiDi, start) & 1) &&
   1413          (pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_LIKE_DIRECT  ||
   1414           pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL));
   1415     /* initialize for levels state table */
   1416     levState.startL2EN=-1;              /* used for INVERSE_LIKE_DIRECT_WITH_MARKS */
   1417     levState.lastStrongRTL=-1;          /* used for INVERSE_LIKE_DIRECT_WITH_MARKS */
   1418     levState.state=0;
   1419     levState.runLevel=pBiDi->levels[start];
   1420     levState.pImpTab=(const ImpTab*)((pBiDi->pImpTabPair)->pImpTab)[levState.runLevel&1];
   1421     levState.pImpAct=(const ImpAct*)((pBiDi->pImpTabPair)->pImpAct)[levState.runLevel&1];
   1422     processPropertySeq(pBiDi, &levState, sor, start, start);
   1423     /* initialize for property state table */
   1424     if(dirProps[start]==NSM) {
   1425         stateImp = 1 + sor;
   1426     } else {
   1427         stateImp=0;
   1428     }
   1429     start1=start;
   1430     start2=start;
   1431 
   1432     for(i=start; i<=limit; i++) {
   1433         if(i>=limit) {
   1434             gprop=eor;
   1435         } else {
   1436             DirProp prop, prop1;
   1437             prop=NO_CONTEXT_RTL(dirProps[i]);
   1438             if(inverseRTL) {
   1439                 if(prop==AL) {
   1440                     /* AL before EN does not make it AN */
   1441                     prop=R;
   1442                 } else if(prop==EN) {
   1443                     if(nextStrongPos<=i) {
   1444                         /* look for next strong char (L/R/AL) */
   1445                         int32_t j;
   1446                         nextStrongProp=R;   /* set default */
   1447                         nextStrongPos=limit;
   1448                         for(j=i+1; j<limit; j++) {
   1449                             prop1=NO_CONTEXT_RTL(dirProps[j]);
   1450                             if(prop1==L || prop1==R || prop1==AL) {
   1451                                 nextStrongProp=prop1;
   1452                                 nextStrongPos=j;
   1453                                 break;
   1454                             }
   1455                         }
   1456                     }
   1457                     if(nextStrongProp==AL) {
   1458                         prop=AN;
   1459                     }
   1460                 }
   1461             }
   1462             gprop=groupProp[prop];
   1463         }
   1464         oldStateImp=stateImp;
   1465         cell=impTabProps[oldStateImp][gprop];
   1466         stateImp=GET_STATEPROPS(cell);      /* isolate the new state */
   1467         actionImp=GET_ACTIONPROPS(cell);    /* isolate the action */
   1468         if((i==limit) && (actionImp==0)) {
   1469             /* there is an unprocessed sequence if its property == eor   */
   1470             actionImp=1;                    /* process the last sequence */
   1471         }
   1472         if(actionImp) {
   1473             resProp=impTabProps[oldStateImp][IMPTABPROPS_RES];
   1474             switch(actionImp) {
   1475             case 1:             /* process current seq1, init new seq1 */
   1476                 processPropertySeq(pBiDi, &levState, resProp, start1, i);
   1477                 start1=i;
   1478                 break;
   1479             case 2:             /* init new seq2 */
   1480                 start2=i;
   1481                 break;
   1482             case 3:             /* process seq1, process seq2, init new seq1 */
   1483                 processPropertySeq(pBiDi, &levState, resProp, start1, start2);
   1484                 processPropertySeq(pBiDi, &levState, DirProp_ON, start2, i);
   1485                 start1=i;
   1486                 break;
   1487             case 4:             /* process seq1, set seq1=seq2, init new seq2 */
   1488                 processPropertySeq(pBiDi, &levState, resProp, start1, start2);
   1489                 start1=start2;
   1490                 start2=i;
   1491                 break;
   1492             default:            /* we should never get here */
   1493                 U_ASSERT(FALSE);
   1494                 break;
   1495             }
   1496         }
   1497     }
   1498     /* flush possible pending sequence, e.g. ON */
   1499     processPropertySeq(pBiDi, &levState, eor, limit, limit);
   1500 }
   1501 
   1502 /* perform (L1) and (X9) ---------------------------------------------------- */
   1503 
   1504 /*
   1505  * Reset the embedding levels for some non-graphic characters (L1).
   1506  * This function also sets appropriate levels for BN, and
   1507  * explicit embedding types that are supposed to have been removed
   1508  * from the paragraph in (X9).
   1509  */
   1510 static void
   1511 adjustWSLevels(UBiDi *pBiDi) {
   1512     const DirProp *dirProps=pBiDi->dirProps;
   1513     UBiDiLevel *levels=pBiDi->levels;
   1514     int32_t i;
   1515 
   1516     if(pBiDi->flags&MASK_WS) {
   1517         UBool orderParagraphsLTR=pBiDi->orderParagraphsLTR;
   1518         Flags flag;
   1519 
   1520         i=pBiDi->trailingWSStart;
   1521         while(i>0) {
   1522             /* reset a sequence of WS/BN before eop and B/S to the paragraph paraLevel */
   1523             while(i>0 && (flag=DIRPROP_FLAG_NC(dirProps[--i]))&MASK_WS) {
   1524                 if(orderParagraphsLTR&&(flag&DIRPROP_FLAG(B))) {
   1525                     levels[i]=0;
   1526                 } else {
   1527                     levels[i]=GET_PARALEVEL(pBiDi, i);
   1528                 }
   1529             }
   1530 
   1531             /* reset BN to the next character's paraLevel until B/S, which restarts above loop */
   1532             /* here, i+1 is guaranteed to be <length */
   1533             while(i>0) {
   1534                 flag=DIRPROP_FLAG_NC(dirProps[--i]);
   1535                 if(flag&MASK_BN_EXPLICIT) {
   1536                     levels[i]=levels[i+1];
   1537                 } else if(orderParagraphsLTR&&(flag&DIRPROP_FLAG(B))) {
   1538                     levels[i]=0;
   1539                     break;
   1540                 } else if(flag&MASK_B_S) {
   1541                     levels[i]=GET_PARALEVEL(pBiDi, i);
   1542                     break;
   1543                 }
   1544             }
   1545         }
   1546     }
   1547 }
   1548 
   1549 #define BIDI_MIN(x, y)   ((x)<(y) ? (x) : (y))
   1550 #define BIDI_ABS(x)      ((x)>=0  ? (x) : (-(x)))
   1551 static void
   1552 setParaRunsOnly(UBiDi *pBiDi, const UChar *text, int32_t length,
   1553                 UBiDiLevel paraLevel, UErrorCode *pErrorCode) {
   1554     void *runsOnlyMemory;
   1555     int32_t *visualMap;
   1556     UChar *visualText;
   1557     int32_t saveLength, saveTrailingWSStart;
   1558     const UBiDiLevel *levels;
   1559     UBiDiLevel *saveLevels;
   1560     UBiDiDirection saveDirection;
   1561     UBool saveMayAllocateText;
   1562     Run *runs;
   1563     int32_t visualLength, i, j, visualStart, logicalStart,
   1564             runCount, runLength, addedRuns, insertRemove,
   1565             start, limit, step, indexOddBit, logicalPos,
   1566             index0, index1;
   1567     uint32_t saveOptions;
   1568 
   1569     pBiDi->reorderingMode=UBIDI_REORDER_DEFAULT;
   1570     if(length==0) {
   1571         ubidi_setPara(pBiDi, text, length, paraLevel, NULL, pErrorCode);
   1572         goto cleanup3;
   1573     }
   1574     /* obtain memory for mapping table and visual text */
   1575     runsOnlyMemory=uprv_malloc(length*(sizeof(int32_t)+sizeof(UChar)+sizeof(UBiDiLevel)));
   1576     if(runsOnlyMemory==NULL) {
   1577         *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
   1578         goto cleanup3;
   1579     }
   1580     visualMap=runsOnlyMemory;
   1581     visualText=(UChar *)&visualMap[length];
   1582     saveLevels=(UBiDiLevel *)&visualText[length];
   1583     saveOptions=pBiDi->reorderingOptions;
   1584     if(saveOptions & UBIDI_OPTION_INSERT_MARKS) {
   1585         pBiDi->reorderingOptions&=~UBIDI_OPTION_INSERT_MARKS;
   1586         pBiDi->reorderingOptions|=UBIDI_OPTION_REMOVE_CONTROLS;
   1587     }
   1588     paraLevel&=1;                       /* accept only 0 or 1 */
   1589     ubidi_setPara(pBiDi, text, length, paraLevel, NULL, pErrorCode);
   1590     if(U_FAILURE(*pErrorCode)) {
   1591         goto cleanup3;
   1592     }
   1593     /* we cannot access directly pBiDi->levels since it is not yet set if
   1594      * direction is not MIXED
   1595      */
   1596     levels=ubidi_getLevels(pBiDi, pErrorCode);
   1597     uprv_memcpy(saveLevels, levels, pBiDi->length*sizeof(UBiDiLevel));
   1598     saveTrailingWSStart=pBiDi->trailingWSStart;
   1599     saveLength=pBiDi->length;
   1600     saveDirection=pBiDi->direction;
   1601 
   1602     /* FOOD FOR THOUGHT: instead of writing the visual text, we could use
   1603      * the visual map and the dirProps array to drive the second call
   1604      * to ubidi_setPara (but must make provision for possible removal of
   1605      * BiDi controls.  Alternatively, only use the dirProps array via
   1606      * customized classifier callback.
   1607      */
   1608     visualLength=ubidi_writeReordered(pBiDi, visualText, length,
   1609                                       UBIDI_DO_MIRRORING, pErrorCode);
   1610     ubidi_getVisualMap(pBiDi, visualMap, pErrorCode);
   1611     if(U_FAILURE(*pErrorCode)) {
   1612         goto cleanup2;
   1613     }
   1614     pBiDi->reorderingOptions=saveOptions;
   1615 
   1616     pBiDi->reorderingMode=UBIDI_REORDER_INVERSE_LIKE_DIRECT;
   1617     paraLevel^=1;
   1618     /* Because what we did with reorderingOptions, visualText may be shorter
   1619      * than the original text. But we don't want the levels memory to be
   1620      * reallocated shorter than the original length, since we need to restore
   1621      * the levels as after the first call to ubidi_setpara() before returning.
   1622      * We will force mayAllocateText to FALSE before the second call to
   1623      * ubidi_setpara(), and will restore it afterwards.
   1624      */
   1625     saveMayAllocateText=pBiDi->mayAllocateText;
   1626     pBiDi->mayAllocateText=FALSE;
   1627     ubidi_setPara(pBiDi, visualText, visualLength, paraLevel, NULL, pErrorCode);
   1628     pBiDi->mayAllocateText=saveMayAllocateText;
   1629     ubidi_getRuns(pBiDi, pErrorCode);
   1630     if(U_FAILURE(*pErrorCode)) {
   1631         goto cleanup1;
   1632     }
   1633     /* check if some runs must be split, count how many splits */
   1634     addedRuns=0;
   1635     runCount=pBiDi->runCount;
   1636     runs=pBiDi->runs;
   1637     visualStart=0;
   1638     for(i=0; i<runCount; i++, visualStart+=runLength) {
   1639         runLength=runs[i].visualLimit-visualStart;
   1640         if(runLength<2) {
   1641             continue;
   1642         }
   1643         logicalStart=GET_INDEX(runs[i].logicalStart);
   1644         for(j=logicalStart+1; j<logicalStart+runLength; j++) {
   1645             index0=visualMap[j];
   1646             index1=visualMap[j-1];
   1647             if((BIDI_ABS(index0-index1)!=1) || (saveLevels[index0]!=saveLevels[index1])) {
   1648                 addedRuns++;
   1649             }
   1650         }
   1651     }
   1652     if(addedRuns) {
   1653         if(getRunsMemory(pBiDi, runCount+addedRuns)) {
   1654             if(runCount==1) {
   1655                 /* because we switch from UBiDi.simpleRuns to UBiDi.runs */
   1656                 pBiDi->runsMemory[0]=runs[0];
   1657             }
   1658             runs=pBiDi->runs=pBiDi->runsMemory;
   1659             pBiDi->runCount+=addedRuns;
   1660         } else {
   1661             goto cleanup1;
   1662         }
   1663     }
   1664     /* split runs which are not consecutive in source text */
   1665     for(i=runCount-1; i>=0; i--) {
   1666         runLength= i==0 ? runs[0].visualLimit :
   1667                           runs[i].visualLimit-runs[i-1].visualLimit;
   1668         logicalStart=runs[i].logicalStart;
   1669         indexOddBit=GET_ODD_BIT(logicalStart);
   1670         logicalStart=GET_INDEX(logicalStart);
   1671         if(runLength<2) {
   1672             if(addedRuns) {
   1673                 runs[i+addedRuns]=runs[i];
   1674             }
   1675             logicalPos=visualMap[logicalStart];
   1676             runs[i+addedRuns].logicalStart=MAKE_INDEX_ODD_PAIR(logicalPos,
   1677                                             saveLevels[logicalPos]^indexOddBit);
   1678             continue;
   1679         }
   1680         if(indexOddBit) {
   1681             start=logicalStart;
   1682             limit=logicalStart+runLength-1;
   1683             step=1;
   1684         } else {
   1685             start=logicalStart+runLength-1;
   1686             limit=logicalStart;
   1687             step=-1;
   1688         }
   1689         for(j=start; j!=limit; j+=step) {
   1690             index0=visualMap[j];
   1691             index1=visualMap[j+step];
   1692             if((BIDI_ABS(index0-index1)!=1) || (saveLevels[index0]!=saveLevels[index1])) {
   1693                 logicalPos=BIDI_MIN(visualMap[start], index0);
   1694                 runs[i+addedRuns].logicalStart=MAKE_INDEX_ODD_PAIR(logicalPos,
   1695                                             saveLevels[logicalPos]^indexOddBit);
   1696                 runs[i+addedRuns].visualLimit=runs[i].visualLimit;
   1697                 runs[i].visualLimit-=BIDI_ABS(j-start)+1;
   1698                 insertRemove=runs[i].insertRemove&(LRM_AFTER|RLM_AFTER);
   1699                 runs[i+addedRuns].insertRemove=insertRemove;
   1700                 runs[i].insertRemove&=~insertRemove;
   1701                 start=j+step;
   1702                 addedRuns--;
   1703             }
   1704         }
   1705         if(addedRuns) {
   1706             runs[i+addedRuns]=runs[i];
   1707         }
   1708         logicalPos=BIDI_MIN(visualMap[start], visualMap[limit]);
   1709         runs[i+addedRuns].logicalStart=MAKE_INDEX_ODD_PAIR(logicalPos,
   1710                                             saveLevels[logicalPos]^indexOddBit);
   1711     }
   1712 
   1713   cleanup1:
   1714     /* restore initial paraLevel */
   1715     pBiDi->paraLevel^=1;
   1716   cleanup2:
   1717     /* restore real text */
   1718     pBiDi->text=text;
   1719     pBiDi->length=saveLength;
   1720     pBiDi->originalLength=length;
   1721     pBiDi->direction=saveDirection;
   1722     /* the saved levels should never excess levelsSize, but we check anyway */
   1723     if(saveLength>pBiDi->levelsSize) {
   1724         saveLength=pBiDi->levelsSize;
   1725     }
   1726     uprv_memcpy(pBiDi->levels, saveLevels, saveLength*sizeof(UBiDiLevel));
   1727     pBiDi->trailingWSStart=saveTrailingWSStart;
   1728     /* free memory for mapping table and visual text */
   1729     uprv_free(runsOnlyMemory);
   1730     if(pBiDi->runCount>1) {
   1731         pBiDi->direction=UBIDI_MIXED;
   1732     }
   1733   cleanup3:
   1734     pBiDi->reorderingMode=UBIDI_REORDER_RUNS_ONLY;
   1735 }
   1736 
   1737 /* ubidi_setPara ------------------------------------------------------------ */
   1738 
   1739 U_CAPI void U_EXPORT2
   1740 ubidi_setPara(UBiDi *pBiDi, const UChar *text, int32_t length,
   1741               UBiDiLevel paraLevel, UBiDiLevel *embeddingLevels,
   1742               UErrorCode *pErrorCode) {
   1743     UBiDiDirection direction;
   1744 
   1745     /* check the argument values */
   1746     RETURN_VOID_IF_NULL_OR_FAILING_ERRCODE(pErrorCode);
   1747     if(pBiDi==NULL || text==NULL || length<-1 ||
   1748        (paraLevel>UBIDI_MAX_EXPLICIT_LEVEL && paraLevel<UBIDI_DEFAULT_LTR)) {
   1749         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
   1750         return;
   1751     }
   1752 
   1753     if(length==-1) {
   1754         length=u_strlen(text);
   1755     }
   1756 
   1757     /* special treatment for RUNS_ONLY mode */
   1758     if(pBiDi->reorderingMode==UBIDI_REORDER_RUNS_ONLY) {
   1759         setParaRunsOnly(pBiDi, text, length, paraLevel, pErrorCode);
   1760         return;
   1761     }
   1762 
   1763     /* initialize the UBiDi structure */
   1764     pBiDi->pParaBiDi=NULL;          /* mark unfinished setPara */
   1765     pBiDi->text=text;
   1766     pBiDi->length=pBiDi->originalLength=pBiDi->resultLength=length;
   1767     pBiDi->paraLevel=paraLevel;
   1768     pBiDi->direction=UBIDI_LTR;
   1769     pBiDi->paraCount=1;
   1770 
   1771     pBiDi->dirProps=NULL;
   1772     pBiDi->levels=NULL;
   1773     pBiDi->runs=NULL;
   1774     pBiDi->insertPoints.size=0;         /* clean up from last call */
   1775     pBiDi->insertPoints.confirmed=0;    /* clean up from last call */
   1776 
   1777     /*
   1778      * Save the original paraLevel if contextual; otherwise, set to 0.
   1779      */
   1780     if(IS_DEFAULT_LEVEL(paraLevel)) {
   1781         pBiDi->defaultParaLevel=paraLevel;
   1782     } else {
   1783         pBiDi->defaultParaLevel=0;
   1784     }
   1785 
   1786     if(length==0) {
   1787         /*
   1788          * For an empty paragraph, create a UBiDi object with the paraLevel and
   1789          * the flags and the direction set but without allocating zero-length arrays.
   1790          * There is nothing more to do.
   1791          */
   1792         if(IS_DEFAULT_LEVEL(paraLevel)) {
   1793             pBiDi->paraLevel&=1;
   1794             pBiDi->defaultParaLevel=0;
   1795         }
   1796         if(paraLevel&1) {
   1797             pBiDi->flags=DIRPROP_FLAG(R);
   1798             pBiDi->direction=UBIDI_RTL;
   1799         } else {
   1800             pBiDi->flags=DIRPROP_FLAG(L);
   1801             pBiDi->direction=UBIDI_LTR;
   1802         }
   1803 
   1804         pBiDi->runCount=0;
   1805         pBiDi->paraCount=0;
   1806         pBiDi->pParaBiDi=pBiDi;         /* mark successful setPara */
   1807         return;
   1808     }
   1809 
   1810     pBiDi->runCount=-1;
   1811 
   1812     /*
   1813      * Get the directional properties,
   1814      * the flags bit-set, and
   1815      * determine the paragraph level if necessary.
   1816      */
   1817     if(getDirPropsMemory(pBiDi, length)) {
   1818         pBiDi->dirProps=pBiDi->dirPropsMemory;
   1819         getDirProps(pBiDi);
   1820     } else {
   1821         *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
   1822         return;
   1823     }
   1824     /* the processed length may have changed if UBIDI_OPTION_STREAMING */
   1825     length= pBiDi->length;
   1826     pBiDi->trailingWSStart=length;  /* the levels[] will reflect the WS run */
   1827     /* allocate paras memory */
   1828     if(pBiDi->paraCount>1) {
   1829         if(getInitialParasMemory(pBiDi, pBiDi->paraCount)) {
   1830             pBiDi->paras=pBiDi->parasMemory;
   1831             pBiDi->paras[pBiDi->paraCount-1]=length;
   1832         } else {
   1833             *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
   1834             return;
   1835         }
   1836     } else {
   1837         /* initialize paras for single paragraph */
   1838         pBiDi->paras=pBiDi->simpleParas;
   1839         pBiDi->simpleParas[0]=length;
   1840     }
   1841 
   1842     /* are explicit levels specified? */
   1843     if(embeddingLevels==NULL) {
   1844         /* no: determine explicit levels according to the (Xn) rules */\
   1845         if(getLevelsMemory(pBiDi, length)) {
   1846             pBiDi->levels=pBiDi->levelsMemory;
   1847             direction=resolveExplicitLevels(pBiDi);
   1848         } else {
   1849             *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
   1850             return;
   1851         }
   1852     } else {
   1853         /* set BN for all explicit codes, check that all levels are 0 or paraLevel..UBIDI_MAX_EXPLICIT_LEVEL */
   1854         pBiDi->levels=embeddingLevels;
   1855         direction=checkExplicitLevels(pBiDi, pErrorCode);
   1856         if(U_FAILURE(*pErrorCode)) {
   1857             return;
   1858         }
   1859     }
   1860 
   1861     /*
   1862      * The steps after (X9) in the UBiDi algorithm are performed only if
   1863      * the paragraph text has mixed directionality!
   1864      */
   1865     pBiDi->direction=direction;
   1866     switch(direction) {
   1867     case UBIDI_LTR:
   1868         /* make sure paraLevel is even */
   1869         pBiDi->paraLevel=(UBiDiLevel)((pBiDi->paraLevel+1)&~1);
   1870 
   1871         /* all levels are implicitly at paraLevel (important for ubidi_getLevels()) */
   1872         pBiDi->trailingWSStart=0;
   1873         break;
   1874     case UBIDI_RTL:
   1875         /* make sure paraLevel is odd */
   1876         pBiDi->paraLevel|=1;
   1877 
   1878         /* all levels are implicitly at paraLevel (important for ubidi_getLevels()) */
   1879         pBiDi->trailingWSStart=0;
   1880         break;
   1881     default:
   1882         /*
   1883          *  Choose the right implicit state table
   1884          */
   1885         switch(pBiDi->reorderingMode) {
   1886         case UBIDI_REORDER_DEFAULT:
   1887             pBiDi->pImpTabPair=&impTab_DEFAULT;
   1888             break;
   1889         case UBIDI_REORDER_NUMBERS_SPECIAL:
   1890             pBiDi->pImpTabPair=&impTab_NUMBERS_SPECIAL;
   1891             break;
   1892         case UBIDI_REORDER_GROUP_NUMBERS_WITH_R:
   1893             pBiDi->pImpTabPair=&impTab_GROUP_NUMBERS_WITH_R;
   1894             break;
   1895         case UBIDI_REORDER_INVERSE_NUMBERS_AS_L:
   1896             pBiDi->pImpTabPair=&impTab_INVERSE_NUMBERS_AS_L;
   1897             break;
   1898         case UBIDI_REORDER_INVERSE_LIKE_DIRECT:
   1899             if (pBiDi->reorderingOptions & UBIDI_OPTION_INSERT_MARKS) {
   1900                 pBiDi->pImpTabPair=&impTab_INVERSE_LIKE_DIRECT_WITH_MARKS;
   1901             } else {
   1902                 pBiDi->pImpTabPair=&impTab_INVERSE_LIKE_DIRECT;
   1903             }
   1904             break;
   1905         case UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL:
   1906             if (pBiDi->reorderingOptions & UBIDI_OPTION_INSERT_MARKS) {
   1907                 pBiDi->pImpTabPair=&impTab_INVERSE_FOR_NUMBERS_SPECIAL_WITH_MARKS;
   1908             } else {
   1909                 pBiDi->pImpTabPair=&impTab_INVERSE_FOR_NUMBERS_SPECIAL;
   1910             }
   1911             break;
   1912         default:
   1913             /* we should never get here */
   1914             U_ASSERT(FALSE);
   1915             break;
   1916         }
   1917         /*
   1918          * If there are no external levels specified and there
   1919          * are no significant explicit level codes in the text,
   1920          * then we can treat the entire paragraph as one run.
   1921          * Otherwise, we need to perform the following rules on runs of
   1922          * the text with the same embedding levels. (X10)
   1923          * "Significant" explicit level codes are ones that actually
   1924          * affect non-BN characters.
   1925          * Examples for "insignificant" ones are empty embeddings
   1926          * LRE-PDF, LRE-RLE-PDF-PDF, etc.
   1927          */
   1928         if(embeddingLevels==NULL && pBiDi->paraCount<=1 &&
   1929                                    !(pBiDi->flags&DIRPROP_FLAG_MULTI_RUNS)) {
   1930             resolveImplicitLevels(pBiDi, 0, length,
   1931                                     GET_LR_FROM_LEVEL(GET_PARALEVEL(pBiDi, 0)),
   1932                                     GET_LR_FROM_LEVEL(GET_PARALEVEL(pBiDi, length-1)));
   1933         } else {
   1934             /* sor, eor: start and end types of same-level-run */
   1935             UBiDiLevel *levels=pBiDi->levels;
   1936             int32_t start, limit=0;
   1937             UBiDiLevel level, nextLevel;
   1938             DirProp sor, eor;
   1939 
   1940             /* determine the first sor and set eor to it because of the loop body (sor=eor there) */
   1941             level=GET_PARALEVEL(pBiDi, 0);
   1942             nextLevel=levels[0];
   1943             if(level<nextLevel) {
   1944                 eor=GET_LR_FROM_LEVEL(nextLevel);
   1945             } else {
   1946                 eor=GET_LR_FROM_LEVEL(level);
   1947             }
   1948 
   1949             do {
   1950                 /* determine start and limit of the run (end points just behind the run) */
   1951 
   1952                 /* the values for this run's start are the same as for the previous run's end */
   1953                 start=limit;
   1954                 level=nextLevel;
   1955                 if((start>0) && (NO_CONTEXT_RTL(pBiDi->dirProps[start-1])==B)) {
   1956                     /* except if this is a new paragraph, then set sor = para level */
   1957                     sor=GET_LR_FROM_LEVEL(GET_PARALEVEL(pBiDi, start));
   1958                 } else {
   1959                     sor=eor;
   1960                 }
   1961 
   1962                 /* search for the limit of this run */
   1963                 while(++limit<length && levels[limit]==level) {}
   1964 
   1965                 /* get the correct level of the next run */
   1966                 if(limit<length) {
   1967                     nextLevel=levels[limit];
   1968                 } else {
   1969                     nextLevel=GET_PARALEVEL(pBiDi, length-1);
   1970                 }
   1971 
   1972                 /* determine eor from max(level, nextLevel); sor is last run's eor */
   1973                 if((level&~UBIDI_LEVEL_OVERRIDE)<(nextLevel&~UBIDI_LEVEL_OVERRIDE)) {
   1974                     eor=GET_LR_FROM_LEVEL(nextLevel);
   1975                 } else {
   1976                     eor=GET_LR_FROM_LEVEL(level);
   1977                 }
   1978 
   1979                 /* if the run consists of overridden directional types, then there
   1980                    are no implicit types to be resolved */
   1981                 if(!(level&UBIDI_LEVEL_OVERRIDE)) {
   1982                     resolveImplicitLevels(pBiDi, start, limit, sor, eor);
   1983                 } else {
   1984                     /* remove the UBIDI_LEVEL_OVERRIDE flags */
   1985                     do {
   1986                         levels[start++]&=~UBIDI_LEVEL_OVERRIDE;
   1987                     } while(start<limit);
   1988                 }
   1989             } while(limit<length);
   1990         }
   1991         /* check if we got any memory shortage while adding insert points */
   1992         if (U_FAILURE(pBiDi->insertPoints.errorCode))
   1993         {
   1994             *pErrorCode=pBiDi->insertPoints.errorCode;
   1995             return;
   1996         }
   1997         /* reset the embedding levels for some non-graphic characters (L1), (X9) */
   1998         adjustWSLevels(pBiDi);
   1999         break;
   2000     }
   2001     /* add RLM for inverse Bidi with contextual orientation resolving
   2002      * to RTL which would not round-trip otherwise
   2003      */
   2004     if((pBiDi->defaultParaLevel>0) &&
   2005        (pBiDi->reorderingOptions & UBIDI_OPTION_INSERT_MARKS) &&
   2006        ((pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_LIKE_DIRECT) ||
   2007         (pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL))) {
   2008         int32_t i, j, start, last;
   2009         DirProp dirProp;
   2010         for(i=0; i<pBiDi->paraCount; i++) {
   2011             last=pBiDi->paras[i]-1;
   2012             if((pBiDi->dirProps[last] & CONTEXT_RTL)==0) {
   2013                 continue;           /* LTR paragraph */
   2014             }
   2015             start= i==0 ? 0 : pBiDi->paras[i - 1];
   2016             for(j=last; j>=start; j--) {
   2017                 dirProp=NO_CONTEXT_RTL(pBiDi->dirProps[j]);
   2018                 if(dirProp==L) {
   2019                     if(j<last) {
   2020                         while(NO_CONTEXT_RTL(pBiDi->dirProps[last])==B) {
   2021                             last--;
   2022                         }
   2023                     }
   2024                     addPoint(pBiDi, last, RLM_BEFORE);
   2025                     break;
   2026                 }
   2027                 if(DIRPROP_FLAG(dirProp) & MASK_R_AL) {
   2028                     break;
   2029                 }
   2030             }
   2031         }
   2032     }
   2033 
   2034     if(pBiDi->reorderingOptions & UBIDI_OPTION_REMOVE_CONTROLS) {
   2035         pBiDi->resultLength -= pBiDi->controlCount;
   2036     } else {
   2037         pBiDi->resultLength += pBiDi->insertPoints.size;
   2038     }
   2039     pBiDi->pParaBiDi=pBiDi;             /* mark successful setPara */
   2040 }
   2041 
   2042 U_CAPI void U_EXPORT2
   2043 ubidi_orderParagraphsLTR(UBiDi *pBiDi, UBool orderParagraphsLTR) {
   2044     if(pBiDi!=NULL) {
   2045         pBiDi->orderParagraphsLTR=orderParagraphsLTR;
   2046     }
   2047 }
   2048 
   2049 U_CAPI UBool U_EXPORT2
   2050 ubidi_isOrderParagraphsLTR(UBiDi *pBiDi) {
   2051     if(pBiDi!=NULL) {
   2052         return pBiDi->orderParagraphsLTR;
   2053     } else {
   2054         return FALSE;
   2055     }
   2056 }
   2057 
   2058 U_CAPI UBiDiDirection U_EXPORT2
   2059 ubidi_getDirection(const UBiDi *pBiDi) {
   2060     if(IS_VALID_PARA_OR_LINE(pBiDi)) {
   2061         return pBiDi->direction;
   2062     } else {
   2063         return UBIDI_LTR;
   2064     }
   2065 }
   2066 
   2067 U_CAPI const UChar * U_EXPORT2
   2068 ubidi_getText(const UBiDi *pBiDi) {
   2069     if(IS_VALID_PARA_OR_LINE(pBiDi)) {
   2070         return pBiDi->text;
   2071     } else {
   2072         return NULL;
   2073     }
   2074 }
   2075 
   2076 U_CAPI int32_t U_EXPORT2
   2077 ubidi_getLength(const UBiDi *pBiDi) {
   2078     if(IS_VALID_PARA_OR_LINE(pBiDi)) {
   2079         return pBiDi->originalLength;
   2080     } else {
   2081         return 0;
   2082     }
   2083 }
   2084 
   2085 U_CAPI int32_t U_EXPORT2
   2086 ubidi_getProcessedLength(const UBiDi *pBiDi) {
   2087     if(IS_VALID_PARA_OR_LINE(pBiDi)) {
   2088         return pBiDi->length;
   2089     } else {
   2090         return 0;
   2091     }
   2092 }
   2093 
   2094 U_CAPI int32_t U_EXPORT2
   2095 ubidi_getResultLength(const UBiDi *pBiDi) {
   2096     if(IS_VALID_PARA_OR_LINE(pBiDi)) {
   2097         return pBiDi->resultLength;
   2098     } else {
   2099         return 0;
   2100     }
   2101 }
   2102 
   2103 /* paragraphs API functions ------------------------------------------------- */
   2104 
   2105 U_CAPI UBiDiLevel U_EXPORT2
   2106 ubidi_getParaLevel(const UBiDi *pBiDi) {
   2107     if(IS_VALID_PARA_OR_LINE(pBiDi)) {
   2108         return pBiDi->paraLevel;
   2109     } else {
   2110         return 0;
   2111     }
   2112 }
   2113 
   2114 U_CAPI int32_t U_EXPORT2
   2115 ubidi_countParagraphs(UBiDi *pBiDi) {
   2116     if(!IS_VALID_PARA_OR_LINE(pBiDi)) {
   2117         return 0;
   2118     } else {
   2119         return pBiDi->paraCount;
   2120     }
   2121 }
   2122 
   2123 U_CAPI void U_EXPORT2
   2124 ubidi_getParagraphByIndex(const UBiDi *pBiDi, int32_t paraIndex,
   2125                           int32_t *pParaStart, int32_t *pParaLimit,
   2126                           UBiDiLevel *pParaLevel, UErrorCode *pErrorCode) {
   2127     int32_t paraStart;
   2128 
   2129     /* check the argument values */
   2130     RETURN_VOID_IF_NULL_OR_FAILING_ERRCODE(pErrorCode);
   2131     RETURN_VOID_IF_NOT_VALID_PARA_OR_LINE(pBiDi, *pErrorCode);
   2132     RETURN_VOID_IF_BAD_RANGE(paraIndex, 0, pBiDi->paraCount, *pErrorCode);
   2133 
   2134     pBiDi=pBiDi->pParaBiDi;             /* get Para object if Line object */
   2135     if(paraIndex) {
   2136         paraStart=pBiDi->paras[paraIndex-1];
   2137     } else {
   2138         paraStart=0;
   2139     }
   2140     if(pParaStart!=NULL) {
   2141         *pParaStart=paraStart;
   2142     }
   2143     if(pParaLimit!=NULL) {
   2144         *pParaLimit=pBiDi->paras[paraIndex];
   2145     }
   2146     if(pParaLevel!=NULL) {
   2147         *pParaLevel=GET_PARALEVEL(pBiDi, paraStart);
   2148     }
   2149 }
   2150 
   2151 U_CAPI int32_t U_EXPORT2
   2152 ubidi_getParagraph(const UBiDi *pBiDi, int32_t charIndex,
   2153                           int32_t *pParaStart, int32_t *pParaLimit,
   2154                           UBiDiLevel *pParaLevel, UErrorCode *pErrorCode) {
   2155     uint32_t paraIndex;
   2156 
   2157     /* check the argument values */
   2158     /* pErrorCode will be checked by the call to ubidi_getParagraphByIndex */
   2159     RETURN_IF_NULL_OR_FAILING_ERRCODE(pErrorCode, -1);
   2160     RETURN_IF_NOT_VALID_PARA_OR_LINE(pBiDi, *pErrorCode, -1);
   2161     pBiDi=pBiDi->pParaBiDi;             /* get Para object if Line object */
   2162     RETURN_IF_BAD_RANGE(charIndex, 0, pBiDi->length, *pErrorCode, -1);
   2163 
   2164     for(paraIndex=0; charIndex>=pBiDi->paras[paraIndex]; paraIndex++);
   2165     ubidi_getParagraphByIndex(pBiDi, paraIndex, pParaStart, pParaLimit, pParaLevel, pErrorCode);
   2166     return paraIndex;
   2167 }
   2168 
   2169 U_CAPI void U_EXPORT2
   2170 ubidi_setClassCallback(UBiDi *pBiDi, UBiDiClassCallback *newFn,
   2171                        const void *newContext, UBiDiClassCallback **oldFn,
   2172                        const void **oldContext, UErrorCode *pErrorCode)
   2173 {
   2174     RETURN_VOID_IF_NULL_OR_FAILING_ERRCODE(pErrorCode);
   2175     if(pBiDi==NULL) {
   2176         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
   2177         return;
   2178     }
   2179     if( oldFn )
   2180     {
   2181         *oldFn = pBiDi->fnClassCallback;
   2182     }
   2183     if( oldContext )
   2184     {
   2185         *oldContext = pBiDi->coClassCallback;
   2186     }
   2187     pBiDi->fnClassCallback = newFn;
   2188     pBiDi->coClassCallback = newContext;
   2189 }
   2190 
   2191 U_CAPI void U_EXPORT2
   2192 ubidi_getClassCallback(UBiDi *pBiDi, UBiDiClassCallback **fn, const void **context)
   2193 {
   2194     if(pBiDi==NULL) {
   2195         return;
   2196     }
   2197     if( fn )
   2198     {
   2199         *fn = pBiDi->fnClassCallback;
   2200     }
   2201     if( context )
   2202     {
   2203         *context = pBiDi->coClassCallback;
   2204     }
   2205 }
   2206 
   2207 U_CAPI UCharDirection U_EXPORT2
   2208 ubidi_getCustomizedClass(UBiDi *pBiDi, UChar32 c)
   2209 {
   2210     UCharDirection dir;
   2211 
   2212     if( pBiDi->fnClassCallback == NULL ||
   2213         (dir = (*pBiDi->fnClassCallback)(pBiDi->coClassCallback, c)) == U_BIDI_CLASS_DEFAULT )
   2214     {
   2215         return ubidi_getClass(pBiDi->bdp, c);
   2216     } else {
   2217         return dir;
   2218     }
   2219 }
   2220 
   2221