1/*
2******************************************************************************
3*
4*   Copyright (C) 1999-2012, 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 "unicode/utf16.h"
23#include "ubidi_props.h"
24#include "ubidiimp.h"
25#include "uassert.h"
26
27/*
28 * General implementation notes:
29 *
30 * Throughout the implementation, there are comments like (W2) that refer to
31 * rules of the BiDi algorithm in its version 5, in this example to the second
32 * rule of the resolution of weak types.
33 *
34 * For handling surrogate pairs, where two UChar's form one "abstract" (or UTF-32)
35 * character according to UTF-16, the second UChar gets the directional property of
36 * the entire character assigned, while the first one gets a BN, a boundary
37 * neutral, type, which is ignored by most of the algorithm according to
38 * rule (X9) and the implementation suggestions of the BiDi algorithm.
39 *
40 * Later, adjustWSLevels() will set the level for each BN to that of the
41 * following character (UChar), which results in surrogate pairs getting the
42 * same level on each of their surrogates.
43 *
44 * In a UTF-8 implementation, the same thing could be done: the last byte of
45 * a multi-byte sequence would get the "real" property, while all previous
46 * bytes of that sequence would get BN.
47 *
48 * It is not possible to assign all those parts of a character the same real
49 * property because this would fail in the resolution of weak types with rules
50 * that look at immediately surrounding types.
51 *
52 * As a related topic, this implementation does not remove Boundary Neutral
53 * types from the input, but ignores them wherever this is relevant.
54 * For example, the loop for the resolution of the weak types reads
55 * types until it finds a non-BN.
56 * Also, explicit embedding codes are neither changed into BN nor removed.
57 * They are only treated the same way real BNs are.
58 * As stated before, adjustWSLevels() takes care of them at the end.
59 * For the purpose of conformance, the levels of all these codes
60 * do not matter.
61 *
62 * Note that this implementation never modifies the dirProps
63 * after the initial setup.
64 *
65 *
66 * In this implementation, the resolution of weak types (Wn),
67 * neutrals (Nn), and the assignment of the resolved level (In)
68 * are all done in one single loop, in resolveImplicitLevels().
69 * Changes of dirProp values are done on the fly, without writing
70 * them back to the dirProps array.
71 *
72 *
73 * This implementation contains code that allows to bypass steps of the
74 * algorithm that are not needed on the specific paragraph
75 * in order to speed up the most common cases considerably,
76 * like text that is entirely LTR, or RTL text without numbers.
77 *
78 * Most of this is done by setting a bit for each directional property
79 * in a flags variable and later checking for whether there are
80 * any LTR characters or any RTL characters, or both, whether
81 * there are any explicit embedding codes, etc.
82 *
83 * If the (Xn) steps are performed, then the flags are re-evaluated,
84 * because they will then not contain the embedding codes any more
85 * and will be adjusted for override codes, so that subsequently
86 * more bypassing may be possible than what the initial flags suggested.
87 *
88 * If the text is not mixed-directional, then the
89 * algorithm steps for the weak type resolution are not performed,
90 * and all levels are set to the paragraph level.
91 *
92 * If there are no explicit embedding codes, then the (Xn) steps
93 * are not performed.
94 *
95 * If embedding levels are supplied as a parameter, then all
96 * explicit embedding codes are ignored, and the (Xn) steps
97 * are not performed.
98 *
99 * White Space types could get the level of the run they belong to,
100 * and are checked with a test of (flags&MASK_EMBEDDING) to
101 * consider if the paragraph direction should be considered in
102 * the flags variable.
103 *
104 * If there are no White Space types in the paragraph, then
105 * (L1) is not necessary in adjustWSLevels().
106 */
107
108/* to avoid some conditional statements, use tiny constant arrays */
109static const Flags flagLR[2]={ DIRPROP_FLAG(L), DIRPROP_FLAG(R) };
110static const Flags flagE[2]={ DIRPROP_FLAG(LRE), DIRPROP_FLAG(RLE) };
111static const Flags flagO[2]={ DIRPROP_FLAG(LRO), DIRPROP_FLAG(RLO) };
112
113#define DIRPROP_FLAG_LR(level) flagLR[(level)&1]
114#define DIRPROP_FLAG_E(level) flagE[(level)&1]
115#define DIRPROP_FLAG_O(level) flagO[(level)&1]
116
117/* UBiDi object management -------------------------------------------------- */
118
119U_CAPI UBiDi * U_EXPORT2
120ubidi_open(void)
121{
122    UErrorCode errorCode=U_ZERO_ERROR;
123    return ubidi_openSized(0, 0, &errorCode);
124}
125
126U_CAPI UBiDi * U_EXPORT2
127ubidi_openSized(int32_t maxLength, int32_t maxRunCount, UErrorCode *pErrorCode) {
128    UBiDi *pBiDi;
129
130    /* check the argument values */
131    if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
132        return NULL;
133    } else if(maxLength<0 || maxRunCount<0) {
134        *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
135        return NULL;    /* invalid arguments */
136    }
137
138    /* allocate memory for the object */
139    pBiDi=(UBiDi *)uprv_malloc(sizeof(UBiDi));
140    if(pBiDi==NULL) {
141        *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
142        return NULL;
143    }
144
145    /* reset the object, all pointers NULL, all flags FALSE, all sizes 0 */
146    uprv_memset(pBiDi, 0, sizeof(UBiDi));
147
148    /* get BiDi properties */
149    pBiDi->bdp=ubidi_getSingleton();
150
151    /* allocate memory for arrays as requested */
152    if(maxLength>0) {
153        if( !getInitialDirPropsMemory(pBiDi, maxLength) ||
154            !getInitialLevelsMemory(pBiDi, maxLength)
155        ) {
156            *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
157        }
158    } else {
159        pBiDi->mayAllocateText=TRUE;
160    }
161
162    if(maxRunCount>0) {
163        if(maxRunCount==1) {
164            /* use simpleRuns[] */
165            pBiDi->runsSize=sizeof(Run);
166        } else if(!getInitialRunsMemory(pBiDi, maxRunCount)) {
167            *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
168        }
169    } else {
170        pBiDi->mayAllocateRuns=TRUE;
171    }
172
173    if(U_SUCCESS(*pErrorCode)) {
174        return pBiDi;
175    } else {
176        ubidi_close(pBiDi);
177        return NULL;
178    }
179}
180
181/*
182 * We are allowed to allocate memory if memory==NULL or
183 * mayAllocate==TRUE for each array that we need.
184 * We also try to grow memory as needed if we
185 * allocate it.
186 *
187 * Assume sizeNeeded>0.
188 * If *pMemory!=NULL, then assume *pSize>0.
189 *
190 * ### this realloc() may unnecessarily copy the old data,
191 * which we know we don't need any more;
192 * is this the best way to do this??
193 */
194U_CFUNC UBool
195ubidi_getMemory(BidiMemoryForAllocation *bidiMem, int32_t *pSize, UBool mayAllocate, int32_t sizeNeeded) {
196    void **pMemory = (void **)bidiMem;
197    /* check for existing memory */
198    if(*pMemory==NULL) {
199        /* we need to allocate memory */
200        if(mayAllocate && (*pMemory=uprv_malloc(sizeNeeded))!=NULL) {
201            *pSize=sizeNeeded;
202            return TRUE;
203        } else {
204            return FALSE;
205        }
206    } else {
207        if(sizeNeeded<=*pSize) {
208            /* there is already enough memory */
209            return TRUE;
210        }
211        else if(!mayAllocate) {
212            /* not enough memory, and we must not allocate */
213            return FALSE;
214        } else {
215            /* we try to grow */
216            void *memory;
217            /* in most cases, we do not need the copy-old-data part of
218             * realloc, but it is needed when adding runs using getRunsMemory()
219             * in setParaRunsOnly()
220             */
221            if((memory=uprv_realloc(*pMemory, sizeNeeded))!=NULL) {
222                *pMemory=memory;
223                *pSize=sizeNeeded;
224                return TRUE;
225            } else {
226                /* we failed to grow */
227                return FALSE;
228            }
229        }
230    }
231}
232
233U_CAPI void U_EXPORT2
234ubidi_close(UBiDi *pBiDi) {
235    if(pBiDi!=NULL) {
236        pBiDi->pParaBiDi=NULL;          /* in case one tries to reuse this block */
237        if(pBiDi->dirPropsMemory!=NULL) {
238            uprv_free(pBiDi->dirPropsMemory);
239        }
240        if(pBiDi->levelsMemory!=NULL) {
241            uprv_free(pBiDi->levelsMemory);
242        }
243        if(pBiDi->runsMemory!=NULL) {
244            uprv_free(pBiDi->runsMemory);
245        }
246        if(pBiDi->parasMemory!=NULL) {
247            uprv_free(pBiDi->parasMemory);
248        }
249        if(pBiDi->insertPoints.points!=NULL) {
250            uprv_free(pBiDi->insertPoints.points);
251        }
252
253        uprv_free(pBiDi);
254    }
255}
256
257/* set to approximate "inverse BiDi" ---------------------------------------- */
258
259U_CAPI void U_EXPORT2
260ubidi_setInverse(UBiDi *pBiDi, UBool isInverse) {
261    if(pBiDi!=NULL) {
262        pBiDi->isInverse=isInverse;
263        pBiDi->reorderingMode = isInverse ? UBIDI_REORDER_INVERSE_NUMBERS_AS_L
264                                          : UBIDI_REORDER_DEFAULT;
265    }
266}
267
268U_CAPI UBool U_EXPORT2
269ubidi_isInverse(UBiDi *pBiDi) {
270    if(pBiDi!=NULL) {
271        return pBiDi->isInverse;
272    } else {
273        return FALSE;
274    }
275}
276
277/* FOOD FOR THOUGHT: currently the reordering modes are a mixture of
278 * algorithm for direct BiDi, algorithm for inverse BiDi and the bizarre
279 * concept of RUNS_ONLY which is a double operation.
280 * It could be advantageous to divide this into 3 concepts:
281 * a) Operation: direct / inverse / RUNS_ONLY
282 * b) Direct algorithm: default / NUMBERS_SPECIAL / GROUP_NUMBERS_WITH_R
283 * c) Inverse algorithm: default / INVERSE_LIKE_DIRECT / NUMBERS_SPECIAL
284 * This would allow combinations not possible today like RUNS_ONLY with
285 * NUMBERS_SPECIAL.
286 * Also allow to set INSERT_MARKS for the direct step of RUNS_ONLY and
287 * REMOVE_CONTROLS for the inverse step.
288 * Not all combinations would be supported, and probably not all do make sense.
289 * This would need to document which ones are supported and what are the
290 * fallbacks for unsupported combinations.
291 */
292U_CAPI void U_EXPORT2
293ubidi_setReorderingMode(UBiDi *pBiDi, UBiDiReorderingMode reorderingMode) {
294    if ((pBiDi!=NULL) && (reorderingMode >= UBIDI_REORDER_DEFAULT)
295                        && (reorderingMode < UBIDI_REORDER_COUNT)) {
296        pBiDi->reorderingMode = reorderingMode;
297        pBiDi->isInverse = (UBool)(reorderingMode == UBIDI_REORDER_INVERSE_NUMBERS_AS_L);
298    }
299}
300
301U_CAPI UBiDiReorderingMode U_EXPORT2
302ubidi_getReorderingMode(UBiDi *pBiDi) {
303    if (pBiDi!=NULL) {
304        return pBiDi->reorderingMode;
305    } else {
306        return UBIDI_REORDER_DEFAULT;
307    }
308}
309
310U_CAPI void U_EXPORT2
311ubidi_setReorderingOptions(UBiDi *pBiDi, uint32_t reorderingOptions) {
312    if (reorderingOptions & UBIDI_OPTION_REMOVE_CONTROLS) {
313        reorderingOptions&=~UBIDI_OPTION_INSERT_MARKS;
314    }
315    if (pBiDi!=NULL) {
316        pBiDi->reorderingOptions=reorderingOptions;
317    }
318}
319
320U_CAPI uint32_t U_EXPORT2
321ubidi_getReorderingOptions(UBiDi *pBiDi) {
322    if (pBiDi!=NULL) {
323        return pBiDi->reorderingOptions;
324    } else {
325        return 0;
326    }
327}
328
329U_CAPI UBiDiDirection U_EXPORT2
330ubidi_getBaseDirection(const UChar *text,
331int32_t length){
332
333    int32_t i;
334    UChar32 uchar;
335    UCharDirection dir;
336
337    if( text==NULL || length<-1 ){
338        return UBIDI_NEUTRAL;
339    }
340
341    if(length==-1) {
342        length=u_strlen(text);
343    }
344
345    for( i = 0 ; i < length; ) {
346        /* i is incremented by U16_NEXT */
347        U16_NEXT(text, i, length, uchar);
348        dir = u_charDirection(uchar);
349        if( dir == U_LEFT_TO_RIGHT )
350                return UBIDI_LTR;
351        if( dir == U_RIGHT_TO_LEFT || dir ==U_RIGHT_TO_LEFT_ARABIC )
352                return UBIDI_RTL;
353    }
354    return UBIDI_NEUTRAL;
355}
356
357/* perform (P2)..(P3) ------------------------------------------------------- */
358
359static DirProp
360firstL_R_AL(UBiDi *pBiDi) {
361    /* return first strong char after the last B in prologue if any */
362    const UChar *text=pBiDi->prologue;
363    int32_t length=pBiDi->proLength;
364    int32_t i;
365    UChar32 uchar;
366    DirProp dirProp, result=ON;
367    for(i=0; i<length; ) {
368        /* i is incremented by U16_NEXT */
369        U16_NEXT(text, i, length, uchar);
370        dirProp=(DirProp)ubidi_getCustomizedClass(pBiDi, uchar);
371        if(result==ON) {
372            if(dirProp==L || dirProp==R || dirProp==AL) {
373                result=dirProp;
374            }
375        } else {
376            if(dirProp==B) {
377                result=ON;
378            }
379        }
380    }
381    return result;
382}
383
384/*
385 * Get the directional properties for the text,
386 * calculate the flags bit-set, and
387 * determine the paragraph level if necessary.
388 */
389static void
390getDirProps(UBiDi *pBiDi) {
391    const UChar *text=pBiDi->text;
392    DirProp *dirProps=pBiDi->dirPropsMemory;    /* pBiDi->dirProps is const */
393
394    int32_t i=0, i1, length=pBiDi->originalLength;
395    Flags flags=0;      /* collect all directionalities in the text */
396    UChar32 uchar;
397    DirProp dirProp=0, paraDirDefault=0;/* initialize to avoid compiler warnings */
398    UBool isDefaultLevel=IS_DEFAULT_LEVEL(pBiDi->paraLevel);
399    /* for inverse BiDi, the default para level is set to RTL if there is a
400       strong R or AL character at either end of the text                           */
401    UBool isDefaultLevelInverse=isDefaultLevel && (UBool)
402            (pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_LIKE_DIRECT ||
403             pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL);
404    int32_t lastArabicPos=-1;
405    int32_t controlCount=0;
406    UBool removeBiDiControls = (UBool)(pBiDi->reorderingOptions &
407                                       UBIDI_OPTION_REMOVE_CONTROLS);
408
409    typedef enum {
410         NOT_CONTEXTUAL,                /* 0: not contextual paraLevel */
411         LOOKING_FOR_STRONG,            /* 1: looking for first strong char */
412         FOUND_STRONG_CHAR              /* 2: found first strong char       */
413    } State;
414    State state;
415    int32_t paraStart=0;                /* index of first char in paragraph */
416    DirProp paraDir;                    /* == CONTEXT_RTL within paragraphs
417                                           starting with strong R char      */
418    DirProp lastStrongDir=0;            /* for default level & inverse BiDi */
419    int32_t lastStrongLTR=0;            /* for STREAMING option             */
420
421    if(pBiDi->reorderingOptions & UBIDI_OPTION_STREAMING) {
422        pBiDi->length=0;
423        lastStrongLTR=0;
424    }
425    if(isDefaultLevel) {
426        DirProp lastStrong;
427        paraDirDefault=pBiDi->paraLevel&1 ? CONTEXT_RTL : 0;
428        if(pBiDi->proLength>0 &&
429           (lastStrong=firstL_R_AL(pBiDi))!=ON) {
430            paraDir=(lastStrong==L) ? 0 : CONTEXT_RTL;
431            state=FOUND_STRONG_CHAR;
432        } else {
433            paraDir=paraDirDefault;
434            state=LOOKING_FOR_STRONG;
435        }
436        lastStrongDir=paraDir;
437    } else {
438        state=NOT_CONTEXTUAL;
439        paraDir=0;
440    }
441    /* count paragraphs and determine the paragraph level (P2..P3) */
442    /*
443     * see comment in ubidi.h:
444     * the DEFAULT_XXX values are designed so that
445     * their bit 0 alone yields the intended default
446     */
447    for( /* i=0 above */ ; i<length; ) {
448        /* i is incremented by U16_NEXT */
449        U16_NEXT(text, i, length, uchar);
450        flags|=DIRPROP_FLAG(dirProp=(DirProp)ubidi_getCustomizedClass(pBiDi, uchar));
451        dirProps[i-1]=dirProp|paraDir;
452        if(uchar>0xffff) {  /* set the lead surrogate's property to BN */
453            flags|=DIRPROP_FLAG(BN);
454            dirProps[i-2]=(DirProp)(BN|paraDir);
455        }
456        if(state==LOOKING_FOR_STRONG) {
457            if(dirProp==L) {
458                state=FOUND_STRONG_CHAR;
459                if(paraDir) {
460                    paraDir=0;
461                    for(i1=paraStart; i1<i; i1++) {
462                        dirProps[i1]&=~CONTEXT_RTL;
463                    }
464                }
465                continue;
466            }
467            if(dirProp==R || dirProp==AL) {
468                state=FOUND_STRONG_CHAR;
469                if(paraDir==0) {
470                    paraDir=CONTEXT_RTL;
471                    for(i1=paraStart; i1<i; i1++) {
472                        dirProps[i1]|=CONTEXT_RTL;
473                    }
474                }
475                continue;
476            }
477        }
478        if(dirProp==L) {
479            lastStrongDir=0;
480            lastStrongLTR=i;            /* i is index to next character */
481        }
482        else if(dirProp==R) {
483            lastStrongDir=CONTEXT_RTL;
484        }
485        else if(dirProp==AL) {
486            lastStrongDir=CONTEXT_RTL;
487            lastArabicPos=i-1;
488        }
489        else if(dirProp==B) {
490            if(pBiDi->reorderingOptions & UBIDI_OPTION_STREAMING) {
491                pBiDi->length=i;        /* i is index to next character */
492            }
493            if(isDefaultLevelInverse && (lastStrongDir==CONTEXT_RTL) &&(paraDir!=lastStrongDir)) {
494                for( ; paraStart<i; paraStart++) {
495                    dirProps[paraStart]|=CONTEXT_RTL;
496                }
497            }
498            if(i<length) {              /* B not last char in text */
499                if(!((uchar==CR) && (text[i]==LF))) {
500                    pBiDi->paraCount++;
501                }
502                if(isDefaultLevel) {
503                    state=LOOKING_FOR_STRONG;
504                    paraStart=i;        /* i is index to next character */
505                    paraDir=paraDirDefault;
506                    lastStrongDir=paraDirDefault;
507                }
508            }
509        }
510        if(removeBiDiControls && IS_BIDI_CONTROL_CHAR(uchar)) {
511            controlCount++;
512        }
513    }
514    if(isDefaultLevelInverse && (lastStrongDir==CONTEXT_RTL) &&(paraDir!=lastStrongDir)) {
515        for(i1=paraStart; i1<length; i1++) {
516            dirProps[i1]|=CONTEXT_RTL;
517        }
518    }
519    if(isDefaultLevel) {
520        pBiDi->paraLevel=GET_PARALEVEL(pBiDi, 0);
521    }
522    if(pBiDi->reorderingOptions & UBIDI_OPTION_STREAMING) {
523        if((lastStrongLTR>pBiDi->length) &&
524           (GET_PARALEVEL(pBiDi, lastStrongLTR)==0)) {
525            pBiDi->length = lastStrongLTR;
526        }
527        if(pBiDi->length<pBiDi->originalLength) {
528            pBiDi->paraCount--;
529        }
530    }
531    /* The following line does nothing new for contextual paraLevel, but is
532       needed for absolute paraLevel.                               */
533    flags|=DIRPROP_FLAG_LR(pBiDi->paraLevel);
534
535    if(pBiDi->orderParagraphsLTR && (flags&DIRPROP_FLAG(B))) {
536        flags|=DIRPROP_FLAG(L);
537    }
538
539    pBiDi->controlCount = controlCount;
540    pBiDi->flags=flags;
541    pBiDi->lastArabicPos=lastArabicPos;
542}
543
544/* perform (X1)..(X9) ------------------------------------------------------- */
545
546/* determine if the text is mixed-directional or single-directional */
547static UBiDiDirection
548directionFromFlags(UBiDi *pBiDi) {
549    Flags flags=pBiDi->flags;
550    /* if the text contains AN and neutrals, then some neutrals may become RTL */
551    if(!(flags&MASK_RTL || ((flags&DIRPROP_FLAG(AN)) && (flags&MASK_POSSIBLE_N)))) {
552        return UBIDI_LTR;
553    } else if(!(flags&MASK_LTR)) {
554        return UBIDI_RTL;
555    } else {
556        return UBIDI_MIXED;
557    }
558}
559
560/*
561 * Resolve the explicit levels as specified by explicit embedding codes.
562 * Recalculate the flags to have them reflect the real properties
563 * after taking the explicit embeddings into account.
564 *
565 * The BiDi algorithm is designed to result in the same behavior whether embedding
566 * levels are externally specified (from "styled text", supposedly the preferred
567 * method) or set by explicit embedding codes (LRx, RLx, PDF) in the plain text.
568 * That is why (X9) instructs to remove all explicit codes (and BN).
569 * However, in a real implementation, this removal of these codes and their index
570 * positions in the plain text is undesirable since it would result in
571 * reallocated, reindexed text.
572 * Instead, this implementation leaves the codes in there and just ignores them
573 * in the subsequent processing.
574 * In order to get the same reordering behavior, positions with a BN or an
575 * explicit embedding code just get the same level assigned as the last "real"
576 * character.
577 *
578 * Some implementations, not this one, then overwrite some of these
579 * directionality properties at "real" same-level-run boundaries by
580 * L or R codes so that the resolution of weak types can be performed on the
581 * entire paragraph at once instead of having to parse it once more and
582 * perform that resolution on same-level-runs.
583 * This limits the scope of the implicit rules in effectively
584 * the same way as the run limits.
585 *
586 * Instead, this implementation does not modify these codes.
587 * On one hand, the paragraph has to be scanned for same-level-runs, but
588 * on the other hand, this saves another loop to reset these codes,
589 * or saves making and modifying a copy of dirProps[].
590 *
591 *
592 * Note that (Pn) and (Xn) changed significantly from version 4 of the BiDi algorithm.
593 *
594 *
595 * Handling the stack of explicit levels (Xn):
596 *
597 * With the BiDi stack of explicit levels,
598 * as pushed with each LRE, RLE, LRO, and RLO and popped with each PDF,
599 * the explicit level must never exceed UBIDI_MAX_EXPLICIT_LEVEL==61.
600 *
601 * In order to have a correct push-pop semantics even in the case of overflows,
602 * there are two overflow counters:
603 * - countOver60 is incremented with each LRx at level 60
604 * - from level 60, one RLx increases the level to 61
605 * - countOver61 is incremented with each LRx and RLx at level 61
606 *
607 * Popping levels with PDF must work in the opposite order so that level 61
608 * is correct at the correct point. Underflows (too many PDFs) must be checked.
609 *
610 * This implementation assumes that UBIDI_MAX_EXPLICIT_LEVEL is odd.
611 */
612static UBiDiDirection
613resolveExplicitLevels(UBiDi *pBiDi) {
614    const DirProp *dirProps=pBiDi->dirProps;
615    UBiDiLevel *levels=pBiDi->levels;
616    const UChar *text=pBiDi->text;
617
618    int32_t i=0, length=pBiDi->length;
619    Flags flags=pBiDi->flags;       /* collect all directionalities in the text */
620    DirProp dirProp;
621    UBiDiLevel level=GET_PARALEVEL(pBiDi, 0);
622
623    UBiDiDirection direction;
624    int32_t paraIndex=0;
625
626    /* determine if the text is mixed-directional or single-directional */
627    direction=directionFromFlags(pBiDi);
628
629    /* we may not need to resolve any explicit levels, but for multiple
630       paragraphs we want to loop on all chars to set the para boundaries */
631    if((direction!=UBIDI_MIXED) && (pBiDi->paraCount==1)) {
632        /* not mixed directionality: levels don't matter - trailingWSStart will be 0 */
633    } else if((pBiDi->paraCount==1) &&
634              (!(flags&MASK_EXPLICIT) ||
635               (pBiDi->reorderingMode > UBIDI_REORDER_LAST_LOGICAL_TO_VISUAL))) {
636        /* mixed, but all characters are at the same embedding level */
637        /* or we are in "inverse BiDi" */
638        /* and we don't have contextual multiple paragraphs with some B char */
639        /* set all levels to the paragraph level */
640        for(i=0; i<length; ++i) {
641            levels[i]=level;
642        }
643    } else {
644        /* continue to perform (Xn) */
645
646        /* (X1) level is set for all codes, embeddingLevel keeps track of the push/pop operations */
647        /* both variables may carry the UBIDI_LEVEL_OVERRIDE flag to indicate the override status */
648        UBiDiLevel embeddingLevel=level, newLevel, stackTop=0;
649
650        UBiDiLevel stack[UBIDI_MAX_EXPLICIT_LEVEL];        /* we never push anything >=UBIDI_MAX_EXPLICIT_LEVEL */
651        uint32_t countOver60=0, countOver61=0;  /* count overflows of explicit levels */
652
653        /* recalculate the flags */
654        flags=0;
655
656        for(i=0; i<length; ++i) {
657            dirProp=NO_CONTEXT_RTL(dirProps[i]);
658            switch(dirProp) {
659            case LRE:
660            case LRO:
661                /* (X3, X5) */
662                newLevel=(UBiDiLevel)((embeddingLevel+2)&~(UBIDI_LEVEL_OVERRIDE|1)); /* least greater even level */
663                if(newLevel<=UBIDI_MAX_EXPLICIT_LEVEL) {
664                    stack[stackTop]=embeddingLevel;
665                    ++stackTop;
666                    embeddingLevel=newLevel;
667                    if(dirProp==LRO) {
668                        embeddingLevel|=UBIDI_LEVEL_OVERRIDE;
669                    }
670                    /* we don't need to set UBIDI_LEVEL_OVERRIDE off for LRE
671                       since this has already been done for newLevel which is
672                       the source for embeddingLevel.
673                     */
674                } else if((embeddingLevel&~UBIDI_LEVEL_OVERRIDE)==UBIDI_MAX_EXPLICIT_LEVEL) {
675                    ++countOver61;
676                } else /* (embeddingLevel&~UBIDI_LEVEL_OVERRIDE)==UBIDI_MAX_EXPLICIT_LEVEL-1 */ {
677                    ++countOver60;
678                }
679                flags|=DIRPROP_FLAG(BN);
680                break;
681            case RLE:
682            case RLO:
683                /* (X2, X4) */
684                newLevel=(UBiDiLevel)(((embeddingLevel&~UBIDI_LEVEL_OVERRIDE)+1)|1); /* least greater odd level */
685                if(newLevel<=UBIDI_MAX_EXPLICIT_LEVEL) {
686                    stack[stackTop]=embeddingLevel;
687                    ++stackTop;
688                    embeddingLevel=newLevel;
689                    if(dirProp==RLO) {
690                        embeddingLevel|=UBIDI_LEVEL_OVERRIDE;
691                    }
692                    /* we don't need to set UBIDI_LEVEL_OVERRIDE off for RLE
693                       since this has already been done for newLevel which is
694                       the source for embeddingLevel.
695                     */
696                } else {
697                    ++countOver61;
698                }
699                flags|=DIRPROP_FLAG(BN);
700                break;
701            case PDF:
702                /* (X7) */
703                /* handle all the overflow cases first */
704                if(countOver61>0) {
705                    --countOver61;
706                } else if(countOver60>0 && (embeddingLevel&~UBIDI_LEVEL_OVERRIDE)!=UBIDI_MAX_EXPLICIT_LEVEL) {
707                    /* handle LRx overflows from level 60 */
708                    --countOver60;
709                } else if(stackTop>0) {
710                    /* this is the pop operation; it also pops level 61 while countOver60>0 */
711                    --stackTop;
712                    embeddingLevel=stack[stackTop];
713                /* } else { (underflow) */
714                }
715                flags|=DIRPROP_FLAG(BN);
716                break;
717            case B:
718                stackTop=0;
719                countOver60=countOver61=0;
720                level=GET_PARALEVEL(pBiDi, i);
721                if((i+1)<length) {
722                    embeddingLevel=GET_PARALEVEL(pBiDi, i+1);
723                    if(!((text[i]==CR) && (text[i+1]==LF))) {
724                        pBiDi->paras[paraIndex++]=i+1;
725                    }
726                }
727                flags|=DIRPROP_FLAG(B);
728                break;
729            case BN:
730                /* BN, LRE, RLE, and PDF are supposed to be removed (X9) */
731                /* they will get their levels set correctly in adjustWSLevels() */
732                flags|=DIRPROP_FLAG(BN);
733                break;
734            default:
735                /* all other types get the "real" level */
736                if(level!=embeddingLevel) {
737                    level=embeddingLevel;
738                    if(level&UBIDI_LEVEL_OVERRIDE) {
739                        flags|=DIRPROP_FLAG_O(level)|DIRPROP_FLAG_MULTI_RUNS;
740                    } else {
741                        flags|=DIRPROP_FLAG_E(level)|DIRPROP_FLAG_MULTI_RUNS;
742                    }
743                }
744                if(!(level&UBIDI_LEVEL_OVERRIDE)) {
745                    flags|=DIRPROP_FLAG(dirProp);
746                }
747                break;
748            }
749
750            /*
751             * We need to set reasonable levels even on BN codes and
752             * explicit codes because we will later look at same-level runs (X10).
753             */
754            levels[i]=level;
755        }
756        if(flags&MASK_EMBEDDING) {
757            flags|=DIRPROP_FLAG_LR(pBiDi->paraLevel);
758        }
759        if(pBiDi->orderParagraphsLTR && (flags&DIRPROP_FLAG(B))) {
760            flags|=DIRPROP_FLAG(L);
761        }
762
763        /* subsequently, ignore the explicit codes and BN (X9) */
764
765        /* again, determine if the text is mixed-directional or single-directional */
766        pBiDi->flags=flags;
767        direction=directionFromFlags(pBiDi);
768    }
769
770    return direction;
771}
772
773/*
774 * Use a pre-specified embedding levels array:
775 *
776 * Adjust the directional properties for overrides (->LEVEL_OVERRIDE),
777 * ignore all explicit codes (X9),
778 * and check all the preset levels.
779 *
780 * Recalculate the flags to have them reflect the real properties
781 * after taking the explicit embeddings into account.
782 */
783static UBiDiDirection
784checkExplicitLevels(UBiDi *pBiDi, UErrorCode *pErrorCode) {
785    const DirProp *dirProps=pBiDi->dirProps;
786    DirProp dirProp;
787    UBiDiLevel *levels=pBiDi->levels;
788    const UChar *text=pBiDi->text;
789
790    int32_t i, length=pBiDi->length;
791    Flags flags=0;  /* collect all directionalities in the text */
792    UBiDiLevel level;
793    uint32_t paraIndex=0;
794
795    for(i=0; i<length; ++i) {
796        level=levels[i];
797        dirProp=NO_CONTEXT_RTL(dirProps[i]);
798        if(level&UBIDI_LEVEL_OVERRIDE) {
799            /* keep the override flag in levels[i] but adjust the flags */
800            level&=~UBIDI_LEVEL_OVERRIDE;     /* make the range check below simpler */
801            flags|=DIRPROP_FLAG_O(level);
802        } else {
803            /* set the flags */
804            flags|=DIRPROP_FLAG_E(level)|DIRPROP_FLAG(dirProp);
805        }
806        if((level<GET_PARALEVEL(pBiDi, i) &&
807            !((0==level)&&(dirProp==B))) ||
808           (UBIDI_MAX_EXPLICIT_LEVEL<level)) {
809            /* level out of bounds */
810            *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
811            return UBIDI_LTR;
812        }
813        if((dirProp==B) && ((i+1)<length)) {
814            if(!((text[i]==CR) && (text[i+1]==LF))) {
815                pBiDi->paras[paraIndex++]=i+1;
816            }
817        }
818    }
819    if(flags&MASK_EMBEDDING) {
820        flags|=DIRPROP_FLAG_LR(pBiDi->paraLevel);
821    }
822
823    /* determine if the text is mixed-directional or single-directional */
824    pBiDi->flags=flags;
825    return directionFromFlags(pBiDi);
826}
827
828/******************************************************************
829 The Properties state machine table
830*******************************************************************
831
832 All table cells are 8 bits:
833      bits 0..4:  next state
834      bits 5..7:  action to perform (if > 0)
835
836 Cells may be of format "n" where n represents the next state
837 (except for the rightmost column).
838 Cells may also be of format "s(x,y)" where x represents an action
839 to perform and y represents the next state.
840
841*******************************************************************
842 Definitions and type for properties state table
843*******************************************************************
844*/
845#define IMPTABPROPS_COLUMNS 14
846#define IMPTABPROPS_RES (IMPTABPROPS_COLUMNS - 1)
847#define GET_STATEPROPS(cell) ((cell)&0x1f)
848#define GET_ACTIONPROPS(cell) ((cell)>>5)
849#define s(action, newState) ((uint8_t)(newState+(action<<5)))
850
851static const uint8_t groupProp[] =          /* dirProp regrouped */
852{
853/*  L   R   EN  ES  ET  AN  CS  B   S   WS  ON  LRE LRO AL  RLE RLO PDF NSM BN  */
854    0,  1,  2,  7,  8,  3,  9,  6,  5,  4,  4,  10, 10, 12, 10, 10, 10, 11, 10
855};
856enum { DirProp_L=0, DirProp_R=1, DirProp_EN=2, DirProp_AN=3, DirProp_ON=4, DirProp_S=5, DirProp_B=6 }; /* reduced dirProp */
857
858/******************************************************************
859
860      PROPERTIES  STATE  TABLE
861
862 In table impTabProps,
863      - the ON column regroups ON and WS
864      - the BN column regroups BN, LRE, RLE, LRO, RLO, PDF
865      - the Res column is the reduced property assigned to a run
866
867 Action 1: process current run1, init new run1
868        2: init new run2
869        3: process run1, process run2, init new run1
870        4: process run1, set run1=run2, init new run2
871
872 Notes:
873  1) This table is used in resolveImplicitLevels().
874  2) This table triggers actions when there is a change in the Bidi
875     property of incoming characters (action 1).
876  3) Most such property sequences are processed immediately (in
877     fact, passed to processPropertySeq().
878  4) However, numbers are assembled as one sequence. This means
879     that undefined situations (like CS following digits, until
880     it is known if the next char will be a digit) are held until
881     following chars define them.
882     Example: digits followed by CS, then comes another CS or ON;
883              the digits will be processed, then the CS assigned
884              as the start of an ON sequence (action 3).
885  5) There are cases where more than one sequence must be
886     processed, for instance digits followed by CS followed by L:
887     the digits must be processed as one sequence, and the CS
888     must be processed as an ON sequence, all this before starting
889     assembling chars for the opening L sequence.
890
891
892*/
893static const uint8_t impTabProps[][IMPTABPROPS_COLUMNS] =
894{
895/*                        L ,     R ,    EN ,    AN ,    ON ,     S ,     B ,    ES ,    ET ,    CS ,    BN ,   NSM ,    AL ,  Res */
896/* 0 Init        */ {     1 ,     2 ,     4 ,     5 ,     7 ,    15 ,    17 ,     7 ,     9 ,     7 ,     0 ,     7 ,     3 ,  DirProp_ON },
897/* 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 },
898/* 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 },
899/* 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 },
900/* 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 },
901/* 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 },
902/* 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 },
903/* 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 },
904/* 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 },
905/* 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 },
906/*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 },
907/*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 },
908/*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 },
909/*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 },
910/*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 },
911/*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 },
912/*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 },
913/*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 }
914};
915
916/*  we must undef macro s because the levels table have a different
917 *  structure (4 bits for action and 4 bits for next state.
918 */
919#undef s
920
921/******************************************************************
922 The levels state machine tables
923*******************************************************************
924
925 All table cells are 8 bits:
926      bits 0..3:  next state
927      bits 4..7:  action to perform (if > 0)
928
929 Cells may be of format "n" where n represents the next state
930 (except for the rightmost column).
931 Cells may also be of format "s(x,y)" where x represents an action
932 to perform and y represents the next state.
933
934 This format limits each table to 16 states each and to 15 actions.
935
936*******************************************************************
937 Definitions and type for levels state tables
938*******************************************************************
939*/
940#define IMPTABLEVELS_COLUMNS (DirProp_B + 2)
941#define IMPTABLEVELS_RES (IMPTABLEVELS_COLUMNS - 1)
942#define GET_STATE(cell) ((cell)&0x0f)
943#define GET_ACTION(cell) ((cell)>>4)
944#define s(action, newState) ((uint8_t)(newState+(action<<4)))
945
946typedef uint8_t ImpTab[][IMPTABLEVELS_COLUMNS];
947typedef uint8_t ImpAct[];
948
949/* FOOD FOR THOUGHT: each ImpTab should have its associated ImpAct,
950 * instead of having a pair of ImpTab and a pair of ImpAct.
951 */
952typedef struct ImpTabPair {
953    const void * pImpTab[2];
954    const void * pImpAct[2];
955} ImpTabPair;
956
957/******************************************************************
958
959      LEVELS  STATE  TABLES
960
961 In all levels state tables,
962      - state 0 is the initial state
963      - the Res column is the increment to add to the text level
964        for this property sequence.
965
966 The impAct arrays for each table of a pair map the local action
967 numbers of the table to the total list of actions. For instance,
968 action 2 in a given table corresponds to the action number which
969 appears in entry [2] of the impAct array for that table.
970 The first entry of all impAct arrays must be 0.
971
972 Action 1: init conditional sequence
973        2: prepend conditional sequence to current sequence
974        3: set ON sequence to new level - 1
975        4: init EN/AN/ON sequence
976        5: fix EN/AN/ON sequence followed by R
977        6: set previous level sequence to level 2
978
979 Notes:
980  1) These tables are used in processPropertySeq(). The input
981     is property sequences as determined by resolveImplicitLevels.
982  2) Most such property sequences are processed immediately
983     (levels are assigned).
984  3) However, some sequences cannot be assigned a final level till
985     one or more following sequences are received. For instance,
986     ON following an R sequence within an even-level paragraph.
987     If the following sequence is R, the ON sequence will be
988     assigned basic run level+1, and so will the R sequence.
989  4) S is generally handled like ON, since its level will be fixed
990     to paragraph level in adjustWSLevels().
991
992*/
993
994static const ImpTab impTabL_DEFAULT =   /* Even paragraph level */
995/*  In this table, conditional sequences receive the higher possible level
996    until proven otherwise.
997*/
998{
999/*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
1000/* 0 : init       */ {     0 ,     1 ,     0 ,     2 ,     0 ,     0 ,     0 ,  0 },
1001/* 1 : R          */ {     0 ,     1 ,     3 ,     3 , s(1,4), s(1,4),     0 ,  1 },
1002/* 2 : AN         */ {     0 ,     1 ,     0 ,     2 , s(1,5), s(1,5),     0 ,  2 },
1003/* 3 : R+EN/AN    */ {     0 ,     1 ,     3 ,     3 , s(1,4), s(1,4),     0 ,  2 },
1004/* 4 : R+ON       */ { s(2,0),     1 ,     3 ,     3 ,     4 ,     4 , s(2,0),  1 },
1005/* 5 : AN+ON      */ { s(2,0),     1 , s(2,0),     2 ,     5 ,     5 , s(2,0),  1 }
1006};
1007static const ImpTab impTabR_DEFAULT =   /* Odd  paragraph level */
1008/*  In this table, conditional sequences receive the lower possible level
1009    until proven otherwise.
1010*/
1011{
1012/*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
1013/* 0 : init       */ {     1 ,     0 ,     2 ,     2 ,     0 ,     0 ,     0 ,  0 },
1014/* 1 : L          */ {     1 ,     0 ,     1 ,     3 , s(1,4), s(1,4),     0 ,  1 },
1015/* 2 : EN/AN      */ {     1 ,     0 ,     2 ,     2 ,     0 ,     0 ,     0 ,  1 },
1016/* 3 : L+AN       */ {     1 ,     0 ,     1 ,     3 ,     5 ,     5 ,     0 ,  1 },
1017/* 4 : L+ON       */ { s(2,1),     0 , s(2,1),     3 ,     4 ,     4 ,     0 ,  0 },
1018/* 5 : L+AN+ON    */ {     1 ,     0 ,     1 ,     3 ,     5 ,     5 ,     0 ,  0 }
1019};
1020static const ImpAct impAct0 = {0,1,2,3,4,5,6};
1021static const ImpTabPair impTab_DEFAULT = {{&impTabL_DEFAULT,
1022                                           &impTabR_DEFAULT},
1023                                          {&impAct0, &impAct0}};
1024
1025static const ImpTab impTabL_NUMBERS_SPECIAL =   /* Even paragraph level */
1026/*  In this table, conditional sequences receive the higher possible level
1027    until proven otherwise.
1028*/
1029{
1030/*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
1031/* 0 : init       */ {     0 ,     2 ,    1 ,      1 ,     0 ,     0 ,     0 ,  0 },
1032/* 1 : L+EN/AN    */ {     0 ,     2 ,    1 ,      1 ,     0 ,     0 ,     0 ,  2 },
1033/* 2 : R          */ {     0 ,     2 ,    4 ,      4 , s(1,3),     0 ,     0 ,  1 },
1034/* 3 : R+ON       */ { s(2,0),     2 ,    4 ,      4 ,     3 ,     3 , s(2,0),  1 },
1035/* 4 : R+EN/AN    */ {     0 ,     2 ,    4 ,      4 , s(1,3), s(1,3),     0 ,  2 }
1036  };
1037static const ImpTabPair impTab_NUMBERS_SPECIAL = {{&impTabL_NUMBERS_SPECIAL,
1038                                                   &impTabR_DEFAULT},
1039                                                  {&impAct0, &impAct0}};
1040
1041static const ImpTab impTabL_GROUP_NUMBERS_WITH_R =
1042/*  In this table, EN/AN+ON sequences receive levels as if associated with R
1043    until proven that there is L or sor/eor on both sides. AN is handled like EN.
1044*/
1045{
1046/*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
1047/* 0 init         */ {     0 ,     3 , s(1,1), s(1,1),     0 ,     0 ,     0 ,  0 },
1048/* 1 EN/AN        */ { s(2,0),     3 ,     1 ,     1 ,     2 , s(2,0), s(2,0),  2 },
1049/* 2 EN/AN+ON     */ { s(2,0),     3 ,     1 ,     1 ,     2 , s(2,0), s(2,0),  1 },
1050/* 3 R            */ {     0 ,     3 ,     5 ,     5 , s(1,4),     0 ,     0 ,  1 },
1051/* 4 R+ON         */ { s(2,0),     3 ,     5 ,     5 ,     4 , s(2,0), s(2,0),  1 },
1052/* 5 R+EN/AN      */ {     0 ,     3 ,     5 ,     5 , s(1,4),     0 ,     0 ,  2 }
1053};
1054static const ImpTab impTabR_GROUP_NUMBERS_WITH_R =
1055/*  In this table, EN/AN+ON sequences receive levels as if associated with R
1056    until proven that there is L on both sides. AN is handled like EN.
1057*/
1058{
1059/*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
1060/* 0 init         */ {     2 ,     0 ,     1 ,     1 ,     0 ,     0 ,     0 ,  0 },
1061/* 1 EN/AN        */ {     2 ,     0 ,     1 ,     1 ,     0 ,     0 ,     0 ,  1 },
1062/* 2 L            */ {     2 ,     0 , s(1,4), s(1,4), s(1,3),     0 ,     0 ,  1 },
1063/* 3 L+ON         */ { s(2,2),     0 ,     4 ,     4 ,     3 ,     0 ,     0 ,  0 },
1064/* 4 L+EN/AN      */ { s(2,2),     0 ,     4 ,     4 ,     3 ,     0 ,     0 ,  1 }
1065};
1066static const ImpTabPair impTab_GROUP_NUMBERS_WITH_R = {
1067                        {&impTabL_GROUP_NUMBERS_WITH_R,
1068                         &impTabR_GROUP_NUMBERS_WITH_R},
1069                        {&impAct0, &impAct0}};
1070
1071
1072static const ImpTab impTabL_INVERSE_NUMBERS_AS_L =
1073/*  This table is identical to the Default LTR table except that EN and AN are
1074    handled like L.
1075*/
1076{
1077/*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
1078/* 0 : init       */ {     0 ,     1 ,     0 ,     0 ,     0 ,     0 ,     0 ,  0 },
1079/* 1 : R          */ {     0 ,     1 ,     0 ,     0 , s(1,4), s(1,4),     0 ,  1 },
1080/* 2 : AN         */ {     0 ,     1 ,     0 ,     0 , s(1,5), s(1,5),     0 ,  2 },
1081/* 3 : R+EN/AN    */ {     0 ,     1 ,     0 ,     0 , s(1,4), s(1,4),     0 ,  2 },
1082/* 4 : R+ON       */ { s(2,0),     1 , s(2,0), s(2,0),     4 ,     4 , s(2,0),  1 },
1083/* 5 : AN+ON      */ { s(2,0),     1 , s(2,0), s(2,0),     5 ,     5 , s(2,0),  1 }
1084};
1085static const ImpTab impTabR_INVERSE_NUMBERS_AS_L =
1086/*  This table is identical to the Default RTL table except that EN and AN are
1087    handled like L.
1088*/
1089{
1090/*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
1091/* 0 : init       */ {     1 ,     0 ,     1 ,     1 ,     0 ,     0 ,     0 ,  0 },
1092/* 1 : L          */ {     1 ,     0 ,     1 ,     1 , s(1,4), s(1,4),     0 ,  1 },
1093/* 2 : EN/AN      */ {     1 ,     0 ,     1 ,     1 ,     0 ,     0 ,     0 ,  1 },
1094/* 3 : L+AN       */ {     1 ,     0 ,     1 ,     1 ,     5 ,     5 ,     0 ,  1 },
1095/* 4 : L+ON       */ { s(2,1),     0 , s(2,1), s(2,1),     4 ,     4 ,     0 ,  0 },
1096/* 5 : L+AN+ON    */ {     1 ,     0 ,     1 ,     1 ,     5 ,     5 ,     0 ,  0 }
1097};
1098static const ImpTabPair impTab_INVERSE_NUMBERS_AS_L = {
1099                        {&impTabL_INVERSE_NUMBERS_AS_L,
1100                         &impTabR_INVERSE_NUMBERS_AS_L},
1101                        {&impAct0, &impAct0}};
1102
1103static const ImpTab impTabR_INVERSE_LIKE_DIRECT =   /* Odd  paragraph level */
1104/*  In this table, conditional sequences receive the lower possible level
1105    until proven otherwise.
1106*/
1107{
1108/*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
1109/* 0 : init       */ {     1 ,     0 ,     2 ,     2 ,     0 ,     0 ,     0 ,  0 },
1110/* 1 : L          */ {     1 ,     0 ,     1 ,     2 , s(1,3), s(1,3),     0 ,  1 },
1111/* 2 : EN/AN      */ {     1 ,     0 ,     2 ,     2 ,     0 ,     0 ,     0 ,  1 },
1112/* 3 : L+ON       */ { s(2,1), s(3,0),     6 ,     4 ,     3 ,     3 , s(3,0),  0 },
1113/* 4 : L+ON+AN    */ { s(2,1), s(3,0),     6 ,     4 ,     5 ,     5 , s(3,0),  3 },
1114/* 5 : L+AN+ON    */ { s(2,1), s(3,0),     6 ,     4 ,     5 ,     5 , s(3,0),  2 },
1115/* 6 : L+ON+EN    */ { s(2,1), s(3,0),     6 ,     4 ,     3 ,     3 , s(3,0),  1 }
1116};
1117static const ImpAct impAct1 = {0,1,11,12};
1118/* FOOD FOR THOUGHT: in LTR table below, check case "JKL 123abc"
1119 */
1120static const ImpTabPair impTab_INVERSE_LIKE_DIRECT = {
1121                        {&impTabL_DEFAULT,
1122                         &impTabR_INVERSE_LIKE_DIRECT},
1123                        {&impAct0, &impAct1}};
1124
1125static const ImpTab impTabL_INVERSE_LIKE_DIRECT_WITH_MARKS =
1126/*  The case handled in this table is (visually):  R EN L
1127*/
1128{
1129/*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
1130/* 0 : init       */ {     0 , s(6,3),     0 ,     1 ,     0 ,     0 ,     0 ,  0 },
1131/* 1 : L+AN       */ {     0 , s(6,3),     0 ,     1 , s(1,2), s(3,0),     0 ,  4 },
1132/* 2 : L+AN+ON    */ { s(2,0), s(6,3), s(2,0),     1 ,     2 , s(3,0), s(2,0),  3 },
1133/* 3 : R          */ {     0 , s(6,3), s(5,5), s(5,6), s(1,4), s(3,0),     0 ,  3 },
1134/* 4 : R+ON       */ { s(3,0), s(4,3), s(5,5), s(5,6),     4 , s(3,0), s(3,0),  3 },
1135/* 5 : R+EN       */ { s(3,0), s(4,3),     5 , s(5,6), s(1,4), s(3,0), s(3,0),  4 },
1136/* 6 : R+AN       */ { s(3,0), s(4,3), s(5,5),     6 , s(1,4), s(3,0), s(3,0),  4 }
1137};
1138static const ImpTab impTabR_INVERSE_LIKE_DIRECT_WITH_MARKS =
1139/*  The cases handled in this table are (visually):  R EN L
1140                                                     R L AN L
1141*/
1142{
1143/*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
1144/* 0 : init       */ { s(1,3),     0 ,     1 ,     1 ,     0 ,     0 ,     0 ,  0 },
1145/* 1 : R+EN/AN    */ { s(2,3),     0 ,     1 ,     1 ,     2 , s(4,0),     0 ,  1 },
1146/* 2 : R+EN/AN+ON */ { s(2,3),     0 ,     1 ,     1 ,     2 , s(4,0),     0 ,  0 },
1147/* 3 : L          */ {     3 ,     0 ,     3 , s(3,6), s(1,4), s(4,0),     0 ,  1 },
1148/* 4 : L+ON       */ { s(5,3), s(4,0),     5 , s(3,6),     4 , s(4,0), s(4,0),  0 },
1149/* 5 : L+ON+EN    */ { s(5,3), s(4,0),     5 , s(3,6),     4 , s(4,0), s(4,0),  1 },
1150/* 6 : L+AN       */ { s(5,3), s(4,0),     6 ,     6 ,     4 , s(4,0), s(4,0),  3 }
1151};
1152static const ImpAct impAct2 = {0,1,7,8,9,10};
1153static const ImpTabPair impTab_INVERSE_LIKE_DIRECT_WITH_MARKS = {
1154                        {&impTabL_INVERSE_LIKE_DIRECT_WITH_MARKS,
1155                         &impTabR_INVERSE_LIKE_DIRECT_WITH_MARKS},
1156                        {&impAct0, &impAct2}};
1157
1158static const ImpTabPair impTab_INVERSE_FOR_NUMBERS_SPECIAL = {
1159                        {&impTabL_NUMBERS_SPECIAL,
1160                         &impTabR_INVERSE_LIKE_DIRECT},
1161                        {&impAct0, &impAct1}};
1162
1163static const ImpTab impTabL_INVERSE_FOR_NUMBERS_SPECIAL_WITH_MARKS =
1164/*  The case handled in this table is (visually):  R EN L
1165*/
1166{
1167/*                         L ,     R ,    EN ,    AN ,    ON ,     S ,     B , Res */
1168/* 0 : init       */ {     0 , s(6,2),     1 ,     1 ,     0 ,     0 ,     0 ,  0 },
1169/* 1 : L+EN/AN    */ {     0 , s(6,2),     1 ,     1 ,     0 , s(3,0),     0 ,  4 },
1170/* 2 : R          */ {     0 , s(6,2), s(5,4), s(5,4), s(1,3), s(3,0),     0 ,  3 },
1171/* 3 : R+ON       */ { s(3,0), s(4,2), s(5,4), s(5,4),     3 , s(3,0), s(3,0),  3 },
1172/* 4 : R+EN/AN    */ { s(3,0), s(4,2),     4 ,     4 , s(1,3), s(3,0), s(3,0),  4 }
1173};
1174static const ImpTabPair impTab_INVERSE_FOR_NUMBERS_SPECIAL_WITH_MARKS = {
1175                        {&impTabL_INVERSE_FOR_NUMBERS_SPECIAL_WITH_MARKS,
1176                         &impTabR_INVERSE_LIKE_DIRECT_WITH_MARKS},
1177                        {&impAct0, &impAct2}};
1178
1179#undef s
1180
1181typedef struct {
1182    const ImpTab * pImpTab;             /* level table pointer          */
1183    const ImpAct * pImpAct;             /* action map array             */
1184    int32_t startON;                    /* start of ON sequence         */
1185    int32_t startL2EN;                  /* start of level 2 sequence    */
1186    int32_t lastStrongRTL;              /* index of last found R or AL  */
1187    int32_t state;                      /* current state                */
1188    UBiDiLevel runLevel;                /* run level before implicit solving */
1189} LevState;
1190
1191/*------------------------------------------------------------------------*/
1192
1193static void
1194addPoint(UBiDi *pBiDi, int32_t pos, int32_t flag)
1195  /* param pos:     position where to insert
1196     param flag:    one of LRM_BEFORE, LRM_AFTER, RLM_BEFORE, RLM_AFTER
1197  */
1198{
1199#define FIRSTALLOC  10
1200    Point point;
1201    InsertPoints * pInsertPoints=&(pBiDi->insertPoints);
1202
1203    if (pInsertPoints->capacity == 0)
1204    {
1205        pInsertPoints->points=uprv_malloc(sizeof(Point)*FIRSTALLOC);
1206        if (pInsertPoints->points == NULL)
1207        {
1208            pInsertPoints->errorCode=U_MEMORY_ALLOCATION_ERROR;
1209            return;
1210        }
1211        pInsertPoints->capacity=FIRSTALLOC;
1212    }
1213    if (pInsertPoints->size >= pInsertPoints->capacity) /* no room for new point */
1214    {
1215        void * savePoints=pInsertPoints->points;
1216        pInsertPoints->points=uprv_realloc(pInsertPoints->points,
1217                                           pInsertPoints->capacity*2*sizeof(Point));
1218        if (pInsertPoints->points == NULL)
1219        {
1220            pInsertPoints->points=savePoints;
1221            pInsertPoints->errorCode=U_MEMORY_ALLOCATION_ERROR;
1222            return;
1223        }
1224        else  pInsertPoints->capacity*=2;
1225    }
1226    point.pos=pos;
1227    point.flag=flag;
1228    pInsertPoints->points[pInsertPoints->size]=point;
1229    pInsertPoints->size++;
1230#undef FIRSTALLOC
1231}
1232
1233/* perform rules (Wn), (Nn), and (In) on a run of the text ------------------ */
1234
1235/*
1236 * This implementation of the (Wn) rules applies all rules in one pass.
1237 * In order to do so, it needs a look-ahead of typically 1 character
1238 * (except for W5: sequences of ET) and keeps track of changes
1239 * in a rule Wp that affect a later Wq (p<q).
1240 *
1241 * The (Nn) and (In) rules are also performed in that same single loop,
1242 * but effectively one iteration behind for white space.
1243 *
1244 * Since all implicit rules are performed in one step, it is not necessary
1245 * to actually store the intermediate directional properties in dirProps[].
1246 */
1247
1248static void
1249processPropertySeq(UBiDi *pBiDi, LevState *pLevState, uint8_t _prop,
1250                   int32_t start, int32_t limit) {
1251    uint8_t cell, oldStateSeq, actionSeq;
1252    const ImpTab * pImpTab=pLevState->pImpTab;
1253    const ImpAct * pImpAct=pLevState->pImpAct;
1254    UBiDiLevel * levels=pBiDi->levels;
1255    UBiDiLevel level, addLevel;
1256    InsertPoints * pInsertPoints;
1257    int32_t start0, k;
1258
1259    start0=start;                           /* save original start position */
1260    oldStateSeq=(uint8_t)pLevState->state;
1261    cell=(*pImpTab)[oldStateSeq][_prop];
1262    pLevState->state=GET_STATE(cell);       /* isolate the new state */
1263    actionSeq=(*pImpAct)[GET_ACTION(cell)]; /* isolate the action */
1264    addLevel=(*pImpTab)[pLevState->state][IMPTABLEVELS_RES];
1265
1266    if(actionSeq) {
1267        switch(actionSeq) {
1268        case 1:                         /* init ON seq */
1269            pLevState->startON=start0;
1270            break;
1271
1272        case 2:                         /* prepend ON seq to current seq */
1273            start=pLevState->startON;
1274            break;
1275
1276        case 3:                         /* L or S after possible relevant EN/AN */
1277            /* check if we had EN after R/AL */
1278            if (pLevState->startL2EN >= 0) {
1279                addPoint(pBiDi, pLevState->startL2EN, LRM_BEFORE);
1280            }
1281            pLevState->startL2EN=-1;  /* not within previous if since could also be -2 */
1282            /* check if we had any relevant EN/AN after R/AL */
1283            pInsertPoints=&(pBiDi->insertPoints);
1284            if ((pInsertPoints->capacity == 0) ||
1285                (pInsertPoints->size <= pInsertPoints->confirmed))
1286            {
1287                /* nothing, just clean up */
1288                pLevState->lastStrongRTL=-1;
1289                /* check if we have a pending conditional segment */
1290                level=(*pImpTab)[oldStateSeq][IMPTABLEVELS_RES];
1291                if ((level & 1) && (pLevState->startON > 0)) {  /* after ON */
1292                    start=pLevState->startON;   /* reset to basic run level */
1293                }
1294                if (_prop == DirProp_S)                /* add LRM before S */
1295                {
1296                    addPoint(pBiDi, start0, LRM_BEFORE);
1297                    pInsertPoints->confirmed=pInsertPoints->size;
1298                }
1299                break;
1300            }
1301            /* reset previous RTL cont to level for LTR text */
1302            for (k=pLevState->lastStrongRTL+1; k<start0; k++)
1303            {
1304                /* reset odd level, leave runLevel+2 as is */
1305                levels[k]=(levels[k] - 2) & ~1;
1306            }
1307            /* mark insert points as confirmed */
1308            pInsertPoints->confirmed=pInsertPoints->size;
1309            pLevState->lastStrongRTL=-1;
1310            if (_prop == DirProp_S)            /* add LRM before S */
1311            {
1312                addPoint(pBiDi, start0, LRM_BEFORE);
1313                pInsertPoints->confirmed=pInsertPoints->size;
1314            }
1315            break;
1316
1317        case 4:                         /* R/AL after possible relevant EN/AN */
1318            /* just clean up */
1319            pInsertPoints=&(pBiDi->insertPoints);
1320            if (pInsertPoints->capacity > 0)
1321                /* remove all non confirmed insert points */
1322                pInsertPoints->size=pInsertPoints->confirmed;
1323            pLevState->startON=-1;
1324            pLevState->startL2EN=-1;
1325            pLevState->lastStrongRTL=limit - 1;
1326            break;
1327
1328        case 5:                         /* EN/AN after R/AL + possible cont */
1329            /* check for real AN */
1330            if ((_prop == DirProp_AN) && (NO_CONTEXT_RTL(pBiDi->dirProps[start0]) == AN) &&
1331                (pBiDi->reorderingMode!=UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL))
1332            {
1333                /* real AN */
1334                if (pLevState->startL2EN == -1) /* if no relevant EN already found */
1335                {
1336                    /* just note the righmost digit as a strong RTL */
1337                    pLevState->lastStrongRTL=limit - 1;
1338                    break;
1339                }
1340                if (pLevState->startL2EN >= 0)  /* after EN, no AN */
1341                {
1342                    addPoint(pBiDi, pLevState->startL2EN, LRM_BEFORE);
1343                    pLevState->startL2EN=-2;
1344                }
1345                /* note AN */
1346                addPoint(pBiDi, start0, LRM_BEFORE);
1347                break;
1348            }
1349            /* if first EN/AN after R/AL */
1350            if (pLevState->startL2EN == -1) {
1351                pLevState->startL2EN=start0;
1352            }
1353            break;
1354
1355        case 6:                         /* note location of latest R/AL */
1356            pLevState->lastStrongRTL=limit - 1;
1357            pLevState->startON=-1;
1358            break;
1359
1360        case 7:                         /* L after R+ON/EN/AN */
1361            /* include possible adjacent number on the left */
1362            for (k=start0-1; k>=0 && !(levels[k]&1); k--);
1363            if(k>=0) {
1364                addPoint(pBiDi, k, RLM_BEFORE);             /* add RLM before */
1365                pInsertPoints=&(pBiDi->insertPoints);
1366                pInsertPoints->confirmed=pInsertPoints->size;   /* confirm it */
1367            }
1368            pLevState->startON=start0;
1369            break;
1370
1371        case 8:                         /* AN after L */
1372            /* AN numbers between L text on both sides may be trouble. */
1373            /* tentatively bracket with LRMs; will be confirmed if followed by L */
1374            addPoint(pBiDi, start0, LRM_BEFORE);    /* add LRM before */
1375            addPoint(pBiDi, start0, LRM_AFTER);     /* add LRM after  */
1376            break;
1377
1378        case 9:                         /* R after L+ON/EN/AN */
1379            /* false alert, infirm LRMs around previous AN */
1380            pInsertPoints=&(pBiDi->insertPoints);
1381            pInsertPoints->size=pInsertPoints->confirmed;
1382            if (_prop == DirProp_S)            /* add RLM before S */
1383            {
1384                addPoint(pBiDi, start0, RLM_BEFORE);
1385                pInsertPoints->confirmed=pInsertPoints->size;
1386            }
1387            break;
1388
1389        case 10:                        /* L after L+ON/AN */
1390            level=pLevState->runLevel + addLevel;
1391            for(k=pLevState->startON; k<start0; k++) {
1392                if (levels[k]<level)
1393                    levels[k]=level;
1394            }
1395            pInsertPoints=&(pBiDi->insertPoints);
1396            pInsertPoints->confirmed=pInsertPoints->size;   /* confirm inserts */
1397            pLevState->startON=start0;
1398            break;
1399
1400        case 11:                        /* L after L+ON+EN/AN/ON */
1401            level=pLevState->runLevel;
1402            for(k=start0-1; k>=pLevState->startON; k--) {
1403                if(levels[k]==level+3) {
1404                    while(levels[k]==level+3) {
1405                        levels[k--]-=2;
1406                    }
1407                    while(levels[k]==level) {
1408                        k--;
1409                    }
1410                }
1411                if(levels[k]==level+2) {
1412                    levels[k]=level;
1413                    continue;
1414                }
1415                levels[k]=level+1;
1416            }
1417            break;
1418
1419        case 12:                        /* R after L+ON+EN/AN/ON */
1420            level=pLevState->runLevel+1;
1421            for(k=start0-1; k>=pLevState->startON; k--) {
1422                if(levels[k]>level) {
1423                    levels[k]-=2;
1424                }
1425            }
1426            break;
1427
1428        default:                        /* we should never get here */
1429            U_ASSERT(FALSE);
1430            break;
1431        }
1432    }
1433    if((addLevel) || (start < start0)) {
1434        level=pLevState->runLevel + addLevel;
1435        for(k=start; k<limit; k++) {
1436            levels[k]=level;
1437        }
1438    }
1439}
1440
1441static DirProp
1442lastL_R_AL(UBiDi *pBiDi) {
1443    /* return last strong char at the end of the prologue */
1444    const UChar *text=pBiDi->prologue;
1445    int32_t length=pBiDi->proLength;
1446    int32_t i;
1447    UChar32 uchar;
1448    DirProp dirProp;
1449    for(i=length; i>0; ) {
1450        /* i is decremented by U16_PREV */
1451        U16_PREV(text, 0, i, uchar);
1452        dirProp=(DirProp)ubidi_getCustomizedClass(pBiDi, uchar);
1453        if(dirProp==L) {
1454            return DirProp_L;
1455        }
1456        if(dirProp==R || dirProp==AL) {
1457            return DirProp_R;
1458        }
1459        if(dirProp==B) {
1460            return DirProp_ON;
1461        }
1462    }
1463    return DirProp_ON;
1464}
1465
1466static DirProp
1467firstL_R_AL_EN_AN(UBiDi *pBiDi) {
1468    /* return first strong char or digit in epilogue */
1469    const UChar *text=pBiDi->epilogue;
1470    int32_t length=pBiDi->epiLength;
1471    int32_t i;
1472    UChar32 uchar;
1473    DirProp dirProp;
1474    for(i=0; i<length; ) {
1475        /* i is incremented by U16_NEXT */
1476        U16_NEXT(text, i, length, uchar);
1477        dirProp=(DirProp)ubidi_getCustomizedClass(pBiDi, uchar);
1478        if(dirProp==L) {
1479            return DirProp_L;
1480        }
1481        if(dirProp==R || dirProp==AL) {
1482            return DirProp_R;
1483        }
1484        if(dirProp==EN) {
1485            return DirProp_EN;
1486        }
1487        if(dirProp==AN) {
1488            return DirProp_AN;
1489        }
1490    }
1491    return DirProp_ON;
1492}
1493
1494static void
1495resolveImplicitLevels(UBiDi *pBiDi,
1496                      int32_t start, int32_t limit,
1497                      DirProp sor, DirProp eor) {
1498    const DirProp *dirProps=pBiDi->dirProps;
1499
1500    LevState levState;
1501    int32_t i, start1, start2;
1502    uint8_t oldStateImp, stateImp, actionImp;
1503    uint8_t gprop, resProp, cell;
1504    UBool inverseRTL;
1505    DirProp nextStrongProp=R;
1506    int32_t nextStrongPos=-1;
1507
1508    levState.startON = -1;  /* silence gcc flow analysis */
1509
1510    /* check for RTL inverse BiDi mode */
1511    /* FOOD FOR THOUGHT: in case of RTL inverse BiDi, it would make sense to
1512     * loop on the text characters from end to start.
1513     * This would need a different properties state table (at least different
1514     * actions) and different levels state tables (maybe very similar to the
1515     * LTR corresponding ones.
1516     */
1517    inverseRTL=(UBool)
1518        ((start<pBiDi->lastArabicPos) && (GET_PARALEVEL(pBiDi, start) & 1) &&
1519         (pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_LIKE_DIRECT  ||
1520          pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL));
1521    /* initialize for levels state table */
1522    levState.startL2EN=-1;              /* used for INVERSE_LIKE_DIRECT_WITH_MARKS */
1523    levState.lastStrongRTL=-1;          /* used for INVERSE_LIKE_DIRECT_WITH_MARKS */
1524    levState.state=0;
1525    levState.runLevel=pBiDi->levels[start];
1526    levState.pImpTab=(const ImpTab*)((pBiDi->pImpTabPair)->pImpTab)[levState.runLevel&1];
1527    levState.pImpAct=(const ImpAct*)((pBiDi->pImpTabPair)->pImpAct)[levState.runLevel&1];
1528    if(start==0 && pBiDi->proLength>0) {
1529        DirProp lastStrong=lastL_R_AL(pBiDi);
1530        if(lastStrong!=DirProp_ON) {
1531            sor=lastStrong;
1532        }
1533    }
1534    processPropertySeq(pBiDi, &levState, sor, start, start);
1535    /* initialize for property state table */
1536    if(NO_CONTEXT_RTL(dirProps[start])==NSM) {
1537        stateImp = 1 + sor;
1538    } else {
1539        stateImp=0;
1540    }
1541    start1=start;
1542    start2=start;
1543
1544    for(i=start; i<=limit; i++) {
1545        if(i>=limit) {
1546            gprop=eor;
1547        } else {
1548            DirProp prop, prop1;
1549            prop=NO_CONTEXT_RTL(dirProps[i]);
1550            if(inverseRTL) {
1551                if(prop==AL) {
1552                    /* AL before EN does not make it AN */
1553                    prop=R;
1554                } else if(prop==EN) {
1555                    if(nextStrongPos<=i) {
1556                        /* look for next strong char (L/R/AL) */
1557                        int32_t j;
1558                        nextStrongProp=R;   /* set default */
1559                        nextStrongPos=limit;
1560                        for(j=i+1; j<limit; j++) {
1561                            prop1=NO_CONTEXT_RTL(dirProps[j]);
1562                            if(prop1==L || prop1==R || prop1==AL) {
1563                                nextStrongProp=prop1;
1564                                nextStrongPos=j;
1565                                break;
1566                            }
1567                        }
1568                    }
1569                    if(nextStrongProp==AL) {
1570                        prop=AN;
1571                    }
1572                }
1573            }
1574            gprop=groupProp[prop];
1575        }
1576        oldStateImp=stateImp;
1577        cell=impTabProps[oldStateImp][gprop];
1578        stateImp=GET_STATEPROPS(cell);      /* isolate the new state */
1579        actionImp=GET_ACTIONPROPS(cell);    /* isolate the action */
1580        if((i==limit) && (actionImp==0)) {
1581            /* there is an unprocessed sequence if its property == eor   */
1582            actionImp=1;                    /* process the last sequence */
1583        }
1584        if(actionImp) {
1585            resProp=impTabProps[oldStateImp][IMPTABPROPS_RES];
1586            switch(actionImp) {
1587            case 1:             /* process current seq1, init new seq1 */
1588                processPropertySeq(pBiDi, &levState, resProp, start1, i);
1589                start1=i;
1590                break;
1591            case 2:             /* init new seq2 */
1592                start2=i;
1593                break;
1594            case 3:             /* process seq1, process seq2, init new seq1 */
1595                processPropertySeq(pBiDi, &levState, resProp, start1, start2);
1596                processPropertySeq(pBiDi, &levState, DirProp_ON, start2, i);
1597                start1=i;
1598                break;
1599            case 4:             /* process seq1, set seq1=seq2, init new seq2 */
1600                processPropertySeq(pBiDi, &levState, resProp, start1, start2);
1601                start1=start2;
1602                start2=i;
1603                break;
1604            default:            /* we should never get here */
1605                U_ASSERT(FALSE);
1606                break;
1607            }
1608        }
1609    }
1610    /* flush possible pending sequence, e.g. ON */
1611    if(limit==pBiDi->length && pBiDi->epiLength>0) {
1612        DirProp firstStrong=firstL_R_AL_EN_AN(pBiDi);
1613        if(firstStrong!=DirProp_ON) {
1614            eor=firstStrong;
1615        }
1616    }
1617    processPropertySeq(pBiDi, &levState, eor, limit, limit);
1618}
1619
1620/* perform (L1) and (X9) ---------------------------------------------------- */
1621
1622/*
1623 * Reset the embedding levels for some non-graphic characters (L1).
1624 * This function also sets appropriate levels for BN, and
1625 * explicit embedding types that are supposed to have been removed
1626 * from the paragraph in (X9).
1627 */
1628static void
1629adjustWSLevels(UBiDi *pBiDi) {
1630    const DirProp *dirProps=pBiDi->dirProps;
1631    UBiDiLevel *levels=pBiDi->levels;
1632    int32_t i;
1633
1634    if(pBiDi->flags&MASK_WS) {
1635        UBool orderParagraphsLTR=pBiDi->orderParagraphsLTR;
1636        Flags flag;
1637
1638        i=pBiDi->trailingWSStart;
1639        while(i>0) {
1640            /* reset a sequence of WS/BN before eop and B/S to the paragraph paraLevel */
1641            while(i>0 && (flag=DIRPROP_FLAG_NC(dirProps[--i]))&MASK_WS) {
1642                if(orderParagraphsLTR&&(flag&DIRPROP_FLAG(B))) {
1643                    levels[i]=0;
1644                } else {
1645                    levels[i]=GET_PARALEVEL(pBiDi, i);
1646                }
1647            }
1648
1649            /* reset BN to the next character's paraLevel until B/S, which restarts above loop */
1650            /* here, i+1 is guaranteed to be <length */
1651            while(i>0) {
1652                flag=DIRPROP_FLAG_NC(dirProps[--i]);
1653                if(flag&MASK_BN_EXPLICIT) {
1654                    levels[i]=levels[i+1];
1655                } else if(orderParagraphsLTR&&(flag&DIRPROP_FLAG(B))) {
1656                    levels[i]=0;
1657                    break;
1658                } else if(flag&MASK_B_S) {
1659                    levels[i]=GET_PARALEVEL(pBiDi, i);
1660                    break;
1661                }
1662            }
1663        }
1664    }
1665}
1666
1667U_CAPI void U_EXPORT2
1668ubidi_setContext(UBiDi *pBiDi,
1669                 const UChar *prologue, int32_t proLength,
1670                 const UChar *epilogue, int32_t epiLength,
1671                 UErrorCode *pErrorCode) {
1672    /* check the argument values */
1673    RETURN_VOID_IF_NULL_OR_FAILING_ERRCODE(pErrorCode);
1674    if(pBiDi==NULL || proLength<-1 || epiLength<-1 ||
1675       (prologue==NULL && proLength!=0) || (epilogue==NULL && epiLength!=0)) {
1676        *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
1677        return;
1678    }
1679
1680    if(proLength==-1) {
1681        pBiDi->proLength=u_strlen(prologue);
1682    } else {
1683        pBiDi->proLength=proLength;
1684    }
1685    if(epiLength==-1) {
1686        pBiDi->epiLength=u_strlen(epilogue);
1687    } else {
1688        pBiDi->epiLength=epiLength;
1689    }
1690    pBiDi->prologue=prologue;
1691    pBiDi->epilogue=epilogue;
1692}
1693
1694static void
1695setParaSuccess(UBiDi *pBiDi) {
1696    pBiDi->proLength=0;                 /* forget the last context */
1697    pBiDi->epiLength=0;
1698    pBiDi->pParaBiDi=pBiDi;             /* mark successful setPara */
1699}
1700
1701#define BIDI_MIN(x, y)   ((x)<(y) ? (x) : (y))
1702#define BIDI_ABS(x)      ((x)>=0  ? (x) : (-(x)))
1703static void
1704setParaRunsOnly(UBiDi *pBiDi, const UChar *text, int32_t length,
1705                UBiDiLevel paraLevel, UErrorCode *pErrorCode) {
1706    void *runsOnlyMemory;
1707    int32_t *visualMap;
1708    UChar *visualText;
1709    int32_t saveLength, saveTrailingWSStart;
1710    const UBiDiLevel *levels;
1711    UBiDiLevel *saveLevels;
1712    UBiDiDirection saveDirection;
1713    UBool saveMayAllocateText;
1714    Run *runs;
1715    int32_t visualLength, i, j, visualStart, logicalStart,
1716            runCount, runLength, addedRuns, insertRemove,
1717            start, limit, step, indexOddBit, logicalPos,
1718            index0, index1;
1719    uint32_t saveOptions;
1720
1721    pBiDi->reorderingMode=UBIDI_REORDER_DEFAULT;
1722    if(length==0) {
1723        ubidi_setPara(pBiDi, text, length, paraLevel, NULL, pErrorCode);
1724        goto cleanup3;
1725    }
1726    /* obtain memory for mapping table and visual text */
1727    runsOnlyMemory=uprv_malloc(length*(sizeof(int32_t)+sizeof(UChar)+sizeof(UBiDiLevel)));
1728    if(runsOnlyMemory==NULL) {
1729        *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
1730        goto cleanup3;
1731    }
1732    visualMap=runsOnlyMemory;
1733    visualText=(UChar *)&visualMap[length];
1734    saveLevels=(UBiDiLevel *)&visualText[length];
1735    saveOptions=pBiDi->reorderingOptions;
1736    if(saveOptions & UBIDI_OPTION_INSERT_MARKS) {
1737        pBiDi->reorderingOptions&=~UBIDI_OPTION_INSERT_MARKS;
1738        pBiDi->reorderingOptions|=UBIDI_OPTION_REMOVE_CONTROLS;
1739    }
1740    paraLevel&=1;                       /* accept only 0 or 1 */
1741    ubidi_setPara(pBiDi, text, length, paraLevel, NULL, pErrorCode);
1742    if(U_FAILURE(*pErrorCode)) {
1743        goto cleanup3;
1744    }
1745    /* we cannot access directly pBiDi->levels since it is not yet set if
1746     * direction is not MIXED
1747     */
1748    levels=ubidi_getLevels(pBiDi, pErrorCode);
1749    uprv_memcpy(saveLevels, levels, pBiDi->length*sizeof(UBiDiLevel));
1750    saveTrailingWSStart=pBiDi->trailingWSStart;
1751    saveLength=pBiDi->length;
1752    saveDirection=pBiDi->direction;
1753
1754    /* FOOD FOR THOUGHT: instead of writing the visual text, we could use
1755     * the visual map and the dirProps array to drive the second call
1756     * to ubidi_setPara (but must make provision for possible removal of
1757     * BiDi controls.  Alternatively, only use the dirProps array via
1758     * customized classifier callback.
1759     */
1760    visualLength=ubidi_writeReordered(pBiDi, visualText, length,
1761                                      UBIDI_DO_MIRRORING, pErrorCode);
1762    ubidi_getVisualMap(pBiDi, visualMap, pErrorCode);
1763    if(U_FAILURE(*pErrorCode)) {
1764        goto cleanup2;
1765    }
1766    pBiDi->reorderingOptions=saveOptions;
1767
1768    pBiDi->reorderingMode=UBIDI_REORDER_INVERSE_LIKE_DIRECT;
1769    paraLevel^=1;
1770    /* Because what we did with reorderingOptions, visualText may be shorter
1771     * than the original text. But we don't want the levels memory to be
1772     * reallocated shorter than the original length, since we need to restore
1773     * the levels as after the first call to ubidi_setpara() before returning.
1774     * We will force mayAllocateText to FALSE before the second call to
1775     * ubidi_setpara(), and will restore it afterwards.
1776     */
1777    saveMayAllocateText=pBiDi->mayAllocateText;
1778    pBiDi->mayAllocateText=FALSE;
1779    ubidi_setPara(pBiDi, visualText, visualLength, paraLevel, NULL, pErrorCode);
1780    pBiDi->mayAllocateText=saveMayAllocateText;
1781    ubidi_getRuns(pBiDi, pErrorCode);
1782    if(U_FAILURE(*pErrorCode)) {
1783        goto cleanup1;
1784    }
1785    /* check if some runs must be split, count how many splits */
1786    addedRuns=0;
1787    runCount=pBiDi->runCount;
1788    runs=pBiDi->runs;
1789    visualStart=0;
1790    for(i=0; i<runCount; i++, visualStart+=runLength) {
1791        runLength=runs[i].visualLimit-visualStart;
1792        if(runLength<2) {
1793            continue;
1794        }
1795        logicalStart=GET_INDEX(runs[i].logicalStart);
1796        for(j=logicalStart+1; j<logicalStart+runLength; j++) {
1797            index0=visualMap[j];
1798            index1=visualMap[j-1];
1799            if((BIDI_ABS(index0-index1)!=1) || (saveLevels[index0]!=saveLevels[index1])) {
1800                addedRuns++;
1801            }
1802        }
1803    }
1804    if(addedRuns) {
1805        if(getRunsMemory(pBiDi, runCount+addedRuns)) {
1806            if(runCount==1) {
1807                /* because we switch from UBiDi.simpleRuns to UBiDi.runs */
1808                pBiDi->runsMemory[0]=runs[0];
1809            }
1810            runs=pBiDi->runs=pBiDi->runsMemory;
1811            pBiDi->runCount+=addedRuns;
1812        } else {
1813            goto cleanup1;
1814        }
1815    }
1816    /* split runs which are not consecutive in source text */
1817    for(i=runCount-1; i>=0; i--) {
1818        runLength= i==0 ? runs[0].visualLimit :
1819                          runs[i].visualLimit-runs[i-1].visualLimit;
1820        logicalStart=runs[i].logicalStart;
1821        indexOddBit=GET_ODD_BIT(logicalStart);
1822        logicalStart=GET_INDEX(logicalStart);
1823        if(runLength<2) {
1824            if(addedRuns) {
1825                runs[i+addedRuns]=runs[i];
1826            }
1827            logicalPos=visualMap[logicalStart];
1828            runs[i+addedRuns].logicalStart=MAKE_INDEX_ODD_PAIR(logicalPos,
1829                                            saveLevels[logicalPos]^indexOddBit);
1830            continue;
1831        }
1832        if(indexOddBit) {
1833            start=logicalStart;
1834            limit=logicalStart+runLength-1;
1835            step=1;
1836        } else {
1837            start=logicalStart+runLength-1;
1838            limit=logicalStart;
1839            step=-1;
1840        }
1841        for(j=start; j!=limit; j+=step) {
1842            index0=visualMap[j];
1843            index1=visualMap[j+step];
1844            if((BIDI_ABS(index0-index1)!=1) || (saveLevels[index0]!=saveLevels[index1])) {
1845                logicalPos=BIDI_MIN(visualMap[start], index0);
1846                runs[i+addedRuns].logicalStart=MAKE_INDEX_ODD_PAIR(logicalPos,
1847                                            saveLevels[logicalPos]^indexOddBit);
1848                runs[i+addedRuns].visualLimit=runs[i].visualLimit;
1849                runs[i].visualLimit-=BIDI_ABS(j-start)+1;
1850                insertRemove=runs[i].insertRemove&(LRM_AFTER|RLM_AFTER);
1851                runs[i+addedRuns].insertRemove=insertRemove;
1852                runs[i].insertRemove&=~insertRemove;
1853                start=j+step;
1854                addedRuns--;
1855            }
1856        }
1857        if(addedRuns) {
1858            runs[i+addedRuns]=runs[i];
1859        }
1860        logicalPos=BIDI_MIN(visualMap[start], visualMap[limit]);
1861        runs[i+addedRuns].logicalStart=MAKE_INDEX_ODD_PAIR(logicalPos,
1862                                            saveLevels[logicalPos]^indexOddBit);
1863    }
1864
1865  cleanup1:
1866    /* restore initial paraLevel */
1867    pBiDi->paraLevel^=1;
1868  cleanup2:
1869    /* restore real text */
1870    pBiDi->text=text;
1871    pBiDi->length=saveLength;
1872    pBiDi->originalLength=length;
1873    pBiDi->direction=saveDirection;
1874    /* the saved levels should never excess levelsSize, but we check anyway */
1875    if(saveLength>pBiDi->levelsSize) {
1876        saveLength=pBiDi->levelsSize;
1877    }
1878    uprv_memcpy(pBiDi->levels, saveLevels, saveLength*sizeof(UBiDiLevel));
1879    pBiDi->trailingWSStart=saveTrailingWSStart;
1880    /* free memory for mapping table and visual text */
1881    uprv_free(runsOnlyMemory);
1882    if(pBiDi->runCount>1) {
1883        pBiDi->direction=UBIDI_MIXED;
1884    }
1885  cleanup3:
1886    pBiDi->reorderingMode=UBIDI_REORDER_RUNS_ONLY;
1887}
1888
1889/* ubidi_setPara ------------------------------------------------------------ */
1890
1891U_CAPI void U_EXPORT2
1892ubidi_setPara(UBiDi *pBiDi, const UChar *text, int32_t length,
1893              UBiDiLevel paraLevel, UBiDiLevel *embeddingLevels,
1894              UErrorCode *pErrorCode) {
1895    UBiDiDirection direction;
1896
1897    /* check the argument values */
1898    RETURN_VOID_IF_NULL_OR_FAILING_ERRCODE(pErrorCode);
1899    if(pBiDi==NULL || text==NULL || length<-1 ||
1900       (paraLevel>UBIDI_MAX_EXPLICIT_LEVEL && paraLevel<UBIDI_DEFAULT_LTR)) {
1901        *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
1902        return;
1903    }
1904
1905    if(length==-1) {
1906        length=u_strlen(text);
1907    }
1908
1909    /* special treatment for RUNS_ONLY mode */
1910    if(pBiDi->reorderingMode==UBIDI_REORDER_RUNS_ONLY) {
1911        setParaRunsOnly(pBiDi, text, length, paraLevel, pErrorCode);
1912        return;
1913    }
1914
1915    /* initialize the UBiDi structure */
1916    pBiDi->pParaBiDi=NULL;          /* mark unfinished setPara */
1917    pBiDi->text=text;
1918    pBiDi->length=pBiDi->originalLength=pBiDi->resultLength=length;
1919    pBiDi->paraLevel=paraLevel;
1920    pBiDi->direction=UBIDI_LTR;
1921    pBiDi->paraCount=1;
1922
1923    pBiDi->dirProps=NULL;
1924    pBiDi->levels=NULL;
1925    pBiDi->runs=NULL;
1926    pBiDi->insertPoints.size=0;         /* clean up from last call */
1927    pBiDi->insertPoints.confirmed=0;    /* clean up from last call */
1928
1929    /*
1930     * Save the original paraLevel if contextual; otherwise, set to 0.
1931     */
1932    if(IS_DEFAULT_LEVEL(paraLevel)) {
1933        pBiDi->defaultParaLevel=paraLevel;
1934    } else {
1935        pBiDi->defaultParaLevel=0;
1936    }
1937
1938    if(length==0) {
1939        /*
1940         * For an empty paragraph, create a UBiDi object with the paraLevel and
1941         * the flags and the direction set but without allocating zero-length arrays.
1942         * There is nothing more to do.
1943         */
1944        if(IS_DEFAULT_LEVEL(paraLevel)) {
1945            pBiDi->paraLevel&=1;
1946            pBiDi->defaultParaLevel=0;
1947        }
1948        if(paraLevel&1) {
1949            pBiDi->flags=DIRPROP_FLAG(R);
1950            pBiDi->direction=UBIDI_RTL;
1951        } else {
1952            pBiDi->flags=DIRPROP_FLAG(L);
1953            pBiDi->direction=UBIDI_LTR;
1954        }
1955
1956        pBiDi->runCount=0;
1957        pBiDi->paraCount=0;
1958        setParaSuccess(pBiDi);          /* mark successful setPara */
1959        return;
1960    }
1961
1962    pBiDi->runCount=-1;
1963
1964    /*
1965     * Get the directional properties,
1966     * the flags bit-set, and
1967     * determine the paragraph level if necessary.
1968     */
1969    if(getDirPropsMemory(pBiDi, length)) {
1970        pBiDi->dirProps=pBiDi->dirPropsMemory;
1971        getDirProps(pBiDi);
1972    } else {
1973        *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
1974        return;
1975    }
1976    /* the processed length may have changed if UBIDI_OPTION_STREAMING */
1977    length= pBiDi->length;
1978    pBiDi->trailingWSStart=length;  /* the levels[] will reflect the WS run */
1979    /* allocate paras memory */
1980    if(pBiDi->paraCount>1) {
1981        if(getInitialParasMemory(pBiDi, pBiDi->paraCount)) {
1982            pBiDi->paras=pBiDi->parasMemory;
1983            pBiDi->paras[pBiDi->paraCount-1]=length;
1984        } else {
1985            *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
1986            return;
1987        }
1988    } else {
1989        /* initialize paras for single paragraph */
1990        pBiDi->paras=pBiDi->simpleParas;
1991        pBiDi->simpleParas[0]=length;
1992    }
1993
1994    /* are explicit levels specified? */
1995    if(embeddingLevels==NULL) {
1996        /* no: determine explicit levels according to the (Xn) rules */\
1997        if(getLevelsMemory(pBiDi, length)) {
1998            pBiDi->levels=pBiDi->levelsMemory;
1999            direction=resolveExplicitLevels(pBiDi);
2000        } else {
2001            *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
2002            return;
2003        }
2004    } else {
2005        /* set BN for all explicit codes, check that all levels are 0 or paraLevel..UBIDI_MAX_EXPLICIT_LEVEL */
2006        pBiDi->levels=embeddingLevels;
2007        direction=checkExplicitLevels(pBiDi, pErrorCode);
2008        if(U_FAILURE(*pErrorCode)) {
2009            return;
2010        }
2011    }
2012
2013    /*
2014     * The steps after (X9) in the UBiDi algorithm are performed only if
2015     * the paragraph text has mixed directionality!
2016     */
2017    pBiDi->direction=direction;
2018    switch(direction) {
2019    case UBIDI_LTR:
2020        /* make sure paraLevel is even */
2021        pBiDi->paraLevel=(UBiDiLevel)((pBiDi->paraLevel+1)&~1);
2022
2023        /* all levels are implicitly at paraLevel (important for ubidi_getLevels()) */
2024        pBiDi->trailingWSStart=0;
2025        break;
2026    case UBIDI_RTL:
2027        /* make sure paraLevel is odd */
2028        pBiDi->paraLevel|=1;
2029
2030        /* all levels are implicitly at paraLevel (important for ubidi_getLevels()) */
2031        pBiDi->trailingWSStart=0;
2032        break;
2033    default:
2034        /*
2035         *  Choose the right implicit state table
2036         */
2037        switch(pBiDi->reorderingMode) {
2038        case UBIDI_REORDER_DEFAULT:
2039            pBiDi->pImpTabPair=&impTab_DEFAULT;
2040            break;
2041        case UBIDI_REORDER_NUMBERS_SPECIAL:
2042            pBiDi->pImpTabPair=&impTab_NUMBERS_SPECIAL;
2043            break;
2044        case UBIDI_REORDER_GROUP_NUMBERS_WITH_R:
2045            pBiDi->pImpTabPair=&impTab_GROUP_NUMBERS_WITH_R;
2046            break;
2047        case UBIDI_REORDER_INVERSE_NUMBERS_AS_L:
2048            pBiDi->pImpTabPair=&impTab_INVERSE_NUMBERS_AS_L;
2049            break;
2050        case UBIDI_REORDER_INVERSE_LIKE_DIRECT:
2051            if (pBiDi->reorderingOptions & UBIDI_OPTION_INSERT_MARKS) {
2052                pBiDi->pImpTabPair=&impTab_INVERSE_LIKE_DIRECT_WITH_MARKS;
2053            } else {
2054                pBiDi->pImpTabPair=&impTab_INVERSE_LIKE_DIRECT;
2055            }
2056            break;
2057        case UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL:
2058            if (pBiDi->reorderingOptions & UBIDI_OPTION_INSERT_MARKS) {
2059                pBiDi->pImpTabPair=&impTab_INVERSE_FOR_NUMBERS_SPECIAL_WITH_MARKS;
2060            } else {
2061                pBiDi->pImpTabPair=&impTab_INVERSE_FOR_NUMBERS_SPECIAL;
2062            }
2063            break;
2064        default:
2065            /* we should never get here */
2066            U_ASSERT(FALSE);
2067            break;
2068        }
2069        /*
2070         * If there are no external levels specified and there
2071         * are no significant explicit level codes in the text,
2072         * then we can treat the entire paragraph as one run.
2073         * Otherwise, we need to perform the following rules on runs of
2074         * the text with the same embedding levels. (X10)
2075         * "Significant" explicit level codes are ones that actually
2076         * affect non-BN characters.
2077         * Examples for "insignificant" ones are empty embeddings
2078         * LRE-PDF, LRE-RLE-PDF-PDF, etc.
2079         */
2080        if(embeddingLevels==NULL && pBiDi->paraCount<=1 &&
2081                                   !(pBiDi->flags&DIRPROP_FLAG_MULTI_RUNS)) {
2082            resolveImplicitLevels(pBiDi, 0, length,
2083                                    GET_LR_FROM_LEVEL(GET_PARALEVEL(pBiDi, 0)),
2084                                    GET_LR_FROM_LEVEL(GET_PARALEVEL(pBiDi, length-1)));
2085        } else {
2086            /* sor, eor: start and end types of same-level-run */
2087            UBiDiLevel *levels=pBiDi->levels;
2088            int32_t start, limit=0;
2089            UBiDiLevel level, nextLevel;
2090            DirProp sor, eor;
2091
2092            /* determine the first sor and set eor to it because of the loop body (sor=eor there) */
2093            level=GET_PARALEVEL(pBiDi, 0);
2094            nextLevel=levels[0];
2095            if(level<nextLevel) {
2096                eor=GET_LR_FROM_LEVEL(nextLevel);
2097            } else {
2098                eor=GET_LR_FROM_LEVEL(level);
2099            }
2100
2101            do {
2102                /* determine start and limit of the run (end points just behind the run) */
2103
2104                /* the values for this run's start are the same as for the previous run's end */
2105                start=limit;
2106                level=nextLevel;
2107                if((start>0) && (NO_CONTEXT_RTL(pBiDi->dirProps[start-1])==B)) {
2108                    /* except if this is a new paragraph, then set sor = para level */
2109                    sor=GET_LR_FROM_LEVEL(GET_PARALEVEL(pBiDi, start));
2110                } else {
2111                    sor=eor;
2112                }
2113
2114                /* search for the limit of this run */
2115                while(++limit<length && levels[limit]==level) {}
2116
2117                /* get the correct level of the next run */
2118                if(limit<length) {
2119                    nextLevel=levels[limit];
2120                } else {
2121                    nextLevel=GET_PARALEVEL(pBiDi, length-1);
2122                }
2123
2124                /* determine eor from max(level, nextLevel); sor is last run's eor */
2125                if((level&~UBIDI_LEVEL_OVERRIDE)<(nextLevel&~UBIDI_LEVEL_OVERRIDE)) {
2126                    eor=GET_LR_FROM_LEVEL(nextLevel);
2127                } else {
2128                    eor=GET_LR_FROM_LEVEL(level);
2129                }
2130
2131                /* if the run consists of overridden directional types, then there
2132                   are no implicit types to be resolved */
2133                if(!(level&UBIDI_LEVEL_OVERRIDE)) {
2134                    resolveImplicitLevels(pBiDi, start, limit, sor, eor);
2135                } else {
2136                    /* remove the UBIDI_LEVEL_OVERRIDE flags */
2137                    do {
2138                        levels[start++]&=~UBIDI_LEVEL_OVERRIDE;
2139                    } while(start<limit);
2140                }
2141            } while(limit<length);
2142        }
2143        /* check if we got any memory shortage while adding insert points */
2144        if (U_FAILURE(pBiDi->insertPoints.errorCode))
2145        {
2146            *pErrorCode=pBiDi->insertPoints.errorCode;
2147            return;
2148        }
2149        /* reset the embedding levels for some non-graphic characters (L1), (X9) */
2150        adjustWSLevels(pBiDi);
2151        break;
2152    }
2153    /* add RLM for inverse Bidi with contextual orientation resolving
2154     * to RTL which would not round-trip otherwise
2155     */
2156    if((pBiDi->defaultParaLevel>0) &&
2157       (pBiDi->reorderingOptions & UBIDI_OPTION_INSERT_MARKS) &&
2158       ((pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_LIKE_DIRECT) ||
2159        (pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL))) {
2160        int32_t i, j, start, last;
2161        DirProp dirProp;
2162        for(i=0; i<pBiDi->paraCount; i++) {
2163            last=pBiDi->paras[i]-1;
2164            if((pBiDi->dirProps[last] & CONTEXT_RTL)==0) {
2165                continue;           /* LTR paragraph */
2166            }
2167            start= i==0 ? 0 : pBiDi->paras[i - 1];
2168            for(j=last; j>=start; j--) {
2169                dirProp=NO_CONTEXT_RTL(pBiDi->dirProps[j]);
2170                if(dirProp==L) {
2171                    if(j<last) {
2172                        while(NO_CONTEXT_RTL(pBiDi->dirProps[last])==B) {
2173                            last--;
2174                        }
2175                    }
2176                    addPoint(pBiDi, last, RLM_BEFORE);
2177                    break;
2178                }
2179                if(DIRPROP_FLAG(dirProp) & MASK_R_AL) {
2180                    break;
2181                }
2182            }
2183        }
2184    }
2185
2186    if(pBiDi->reorderingOptions & UBIDI_OPTION_REMOVE_CONTROLS) {
2187        pBiDi->resultLength -= pBiDi->controlCount;
2188    } else {
2189        pBiDi->resultLength += pBiDi->insertPoints.size;
2190    }
2191    setParaSuccess(pBiDi);              /* mark successful setPara */
2192}
2193
2194U_CAPI void U_EXPORT2
2195ubidi_orderParagraphsLTR(UBiDi *pBiDi, UBool orderParagraphsLTR) {
2196    if(pBiDi!=NULL) {
2197        pBiDi->orderParagraphsLTR=orderParagraphsLTR;
2198    }
2199}
2200
2201U_CAPI UBool U_EXPORT2
2202ubidi_isOrderParagraphsLTR(UBiDi *pBiDi) {
2203    if(pBiDi!=NULL) {
2204        return pBiDi->orderParagraphsLTR;
2205    } else {
2206        return FALSE;
2207    }
2208}
2209
2210U_CAPI UBiDiDirection U_EXPORT2
2211ubidi_getDirection(const UBiDi *pBiDi) {
2212    if(IS_VALID_PARA_OR_LINE(pBiDi)) {
2213        return pBiDi->direction;
2214    } else {
2215        return UBIDI_LTR;
2216    }
2217}
2218
2219U_CAPI const UChar * U_EXPORT2
2220ubidi_getText(const UBiDi *pBiDi) {
2221    if(IS_VALID_PARA_OR_LINE(pBiDi)) {
2222        return pBiDi->text;
2223    } else {
2224        return NULL;
2225    }
2226}
2227
2228U_CAPI int32_t U_EXPORT2
2229ubidi_getLength(const UBiDi *pBiDi) {
2230    if(IS_VALID_PARA_OR_LINE(pBiDi)) {
2231        return pBiDi->originalLength;
2232    } else {
2233        return 0;
2234    }
2235}
2236
2237U_CAPI int32_t U_EXPORT2
2238ubidi_getProcessedLength(const UBiDi *pBiDi) {
2239    if(IS_VALID_PARA_OR_LINE(pBiDi)) {
2240        return pBiDi->length;
2241    } else {
2242        return 0;
2243    }
2244}
2245
2246U_CAPI int32_t U_EXPORT2
2247ubidi_getResultLength(const UBiDi *pBiDi) {
2248    if(IS_VALID_PARA_OR_LINE(pBiDi)) {
2249        return pBiDi->resultLength;
2250    } else {
2251        return 0;
2252    }
2253}
2254
2255/* paragraphs API functions ------------------------------------------------- */
2256
2257U_CAPI UBiDiLevel U_EXPORT2
2258ubidi_getParaLevel(const UBiDi *pBiDi) {
2259    if(IS_VALID_PARA_OR_LINE(pBiDi)) {
2260        return pBiDi->paraLevel;
2261    } else {
2262        return 0;
2263    }
2264}
2265
2266U_CAPI int32_t U_EXPORT2
2267ubidi_countParagraphs(UBiDi *pBiDi) {
2268    if(!IS_VALID_PARA_OR_LINE(pBiDi)) {
2269        return 0;
2270    } else {
2271        return pBiDi->paraCount;
2272    }
2273}
2274
2275U_CAPI void U_EXPORT2
2276ubidi_getParagraphByIndex(const UBiDi *pBiDi, int32_t paraIndex,
2277                          int32_t *pParaStart, int32_t *pParaLimit,
2278                          UBiDiLevel *pParaLevel, UErrorCode *pErrorCode) {
2279    int32_t paraStart;
2280
2281    /* check the argument values */
2282    RETURN_VOID_IF_NULL_OR_FAILING_ERRCODE(pErrorCode);
2283    RETURN_VOID_IF_NOT_VALID_PARA_OR_LINE(pBiDi, *pErrorCode);
2284    RETURN_VOID_IF_BAD_RANGE(paraIndex, 0, pBiDi->paraCount, *pErrorCode);
2285
2286    pBiDi=pBiDi->pParaBiDi;             /* get Para object if Line object */
2287    if(paraIndex) {
2288        paraStart=pBiDi->paras[paraIndex-1];
2289    } else {
2290        paraStart=0;
2291    }
2292    if(pParaStart!=NULL) {
2293        *pParaStart=paraStart;
2294    }
2295    if(pParaLimit!=NULL) {
2296        *pParaLimit=pBiDi->paras[paraIndex];
2297    }
2298    if(pParaLevel!=NULL) {
2299        *pParaLevel=GET_PARALEVEL(pBiDi, paraStart);
2300    }
2301}
2302
2303U_CAPI int32_t U_EXPORT2
2304ubidi_getParagraph(const UBiDi *pBiDi, int32_t charIndex,
2305                          int32_t *pParaStart, int32_t *pParaLimit,
2306                          UBiDiLevel *pParaLevel, UErrorCode *pErrorCode) {
2307    uint32_t paraIndex;
2308
2309    /* check the argument values */
2310    /* pErrorCode will be checked by the call to ubidi_getParagraphByIndex */
2311    RETURN_IF_NULL_OR_FAILING_ERRCODE(pErrorCode, -1);
2312    RETURN_IF_NOT_VALID_PARA_OR_LINE(pBiDi, *pErrorCode, -1);
2313    pBiDi=pBiDi->pParaBiDi;             /* get Para object if Line object */
2314    RETURN_IF_BAD_RANGE(charIndex, 0, pBiDi->length, *pErrorCode, -1);
2315
2316    for(paraIndex=0; charIndex>=pBiDi->paras[paraIndex]; paraIndex++);
2317    ubidi_getParagraphByIndex(pBiDi, paraIndex, pParaStart, pParaLimit, pParaLevel, pErrorCode);
2318    return paraIndex;
2319}
2320
2321U_CAPI void U_EXPORT2
2322ubidi_setClassCallback(UBiDi *pBiDi, UBiDiClassCallback *newFn,
2323                       const void *newContext, UBiDiClassCallback **oldFn,
2324                       const void **oldContext, UErrorCode *pErrorCode)
2325{
2326    RETURN_VOID_IF_NULL_OR_FAILING_ERRCODE(pErrorCode);
2327    if(pBiDi==NULL) {
2328        *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
2329        return;
2330    }
2331    if( oldFn )
2332    {
2333        *oldFn = pBiDi->fnClassCallback;
2334    }
2335    if( oldContext )
2336    {
2337        *oldContext = pBiDi->coClassCallback;
2338    }
2339    pBiDi->fnClassCallback = newFn;
2340    pBiDi->coClassCallback = newContext;
2341}
2342
2343U_CAPI void U_EXPORT2
2344ubidi_getClassCallback(UBiDi *pBiDi, UBiDiClassCallback **fn, const void **context)
2345{
2346    if(pBiDi==NULL) {
2347        return;
2348    }
2349    if( fn )
2350    {
2351        *fn = pBiDi->fnClassCallback;
2352    }
2353    if( context )
2354    {
2355        *context = pBiDi->coClassCallback;
2356    }
2357}
2358
2359U_CAPI UCharDirection U_EXPORT2
2360ubidi_getCustomizedClass(UBiDi *pBiDi, UChar32 c)
2361{
2362    UCharDirection dir;
2363
2364    if( pBiDi->fnClassCallback == NULL ||
2365        (dir = (*pBiDi->fnClassCallback)(pBiDi->coClassCallback, c)) == U_BIDI_CLASS_DEFAULT )
2366    {
2367        return ubidi_getClass(pBiDi->bdp, c);
2368    } else {
2369        return dir;
2370    }
2371}
2372
2373