summaryrefslogtreecommitdiffstats
path: root/intl/icu/source/common/normalizer2impl.h
blob: a6bf967979f48a26938a4eeb1aba38c5ed914f7e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
// Copyright (C) 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
*
*   Copyright (C) 2009-2014, International Business Machines
*   Corporation and others.  All Rights Reserved.
*
*******************************************************************************
*   file name:  normalizer2impl.h
*   encoding:   US-ASCII
*   tab size:   8 (not used)
*   indentation:4
*
*   created on: 2009nov22
*   created by: Markus W. Scherer
*/

#ifndef __NORMALIZER2IMPL_H__
#define __NORMALIZER2IMPL_H__

#include "unicode/utypes.h"

#if !UCONFIG_NO_NORMALIZATION

#include "unicode/normalizer2.h"
#include "unicode/unistr.h"
#include "unicode/unorm.h"
#include "unicode/utf16.h"
#include "mutex.h"
#include "uset_imp.h"
#include "utrie2.h"

U_NAMESPACE_BEGIN

struct CanonIterData;

class U_COMMON_API Hangul {
public:
    /* Korean Hangul and Jamo constants */
    enum {
        JAMO_L_BASE=0x1100,     /* "lead" jamo */
        JAMO_L_END=0x1112,
        JAMO_V_BASE=0x1161,     /* "vowel" jamo */
        JAMO_V_END=0x1175,
        JAMO_T_BASE=0x11a7,     /* "trail" jamo */
        JAMO_T_END=0x11c2,

        HANGUL_BASE=0xac00,
        HANGUL_END=0xd7a3,

        JAMO_L_COUNT=19,
        JAMO_V_COUNT=21,
        JAMO_T_COUNT=28,

        JAMO_VT_COUNT=JAMO_V_COUNT*JAMO_T_COUNT,

        HANGUL_COUNT=JAMO_L_COUNT*JAMO_V_COUNT*JAMO_T_COUNT,
        HANGUL_LIMIT=HANGUL_BASE+HANGUL_COUNT
    };

    static inline UBool isHangul(UChar32 c) {
        return HANGUL_BASE<=c && c<HANGUL_LIMIT;
    }
    static inline UBool
    isHangulWithoutJamoT(UChar c) {
        c-=HANGUL_BASE;
        return c<HANGUL_COUNT && c%JAMO_T_COUNT==0;
    }
    static inline UBool isJamoL(UChar32 c) {
        return (uint32_t)(c-JAMO_L_BASE)<JAMO_L_COUNT;
    }
    static inline UBool isJamoV(UChar32 c) {
        return (uint32_t)(c-JAMO_V_BASE)<JAMO_V_COUNT;
    }

    /**
     * Decomposes c, which must be a Hangul syllable, into buffer
     * and returns the length of the decomposition (2 or 3).
     */
    static inline int32_t decompose(UChar32 c, UChar buffer[3]) {
        c-=HANGUL_BASE;
        UChar32 c2=c%JAMO_T_COUNT;
        c/=JAMO_T_COUNT;
        buffer[0]=(UChar)(JAMO_L_BASE+c/JAMO_V_COUNT);
        buffer[1]=(UChar)(JAMO_V_BASE+c%JAMO_V_COUNT);
        if(c2==0) {
            return 2;
        } else {
            buffer[2]=(UChar)(JAMO_T_BASE+c2);
            return 3;
        }
    }

    /**
     * Decomposes c, which must be a Hangul syllable, into buffer.
     * This is the raw, not recursive, decomposition. Its length is always 2.
     */
    static inline void getRawDecomposition(UChar32 c, UChar buffer[2]) {
        UChar32 orig=c;
        c-=HANGUL_BASE;
        UChar32 c2=c%JAMO_T_COUNT;
        if(c2==0) {
            c/=JAMO_T_COUNT;
            buffer[0]=(UChar)(JAMO_L_BASE+c/JAMO_V_COUNT);
            buffer[1]=(UChar)(JAMO_V_BASE+c%JAMO_V_COUNT);
        } else {
            buffer[0]=orig-c2;  // LV syllable
            buffer[1]=(UChar)(JAMO_T_BASE+c2);
        }
    }
private:
    Hangul();  // no instantiation
};

class Normalizer2Impl;

class U_COMMON_API ReorderingBuffer : public UMemory {
public:
    ReorderingBuffer(const Normalizer2Impl &ni, UnicodeString &dest) :
        impl(ni), str(dest),
        start(NULL), reorderStart(NULL), limit(NULL),
        remainingCapacity(0), lastCC(0) {}
    ~ReorderingBuffer() {
        if(start!=NULL) {
            str.releaseBuffer((int32_t)(limit-start));
        }
    }
    UBool init(int32_t destCapacity, UErrorCode &errorCode);

    UBool isEmpty() const { return start==limit; }
    int32_t length() const { return (int32_t)(limit-start); }
    UChar *getStart() { return start; }
    UChar *getLimit() { return limit; }
    uint8_t getLastCC() const { return lastCC; }

    UBool equals(const UChar *start, const UChar *limit) const;

    // For Hangul composition, replacing the Leading consonant Jamo with the syllable.
    void setLastChar(UChar c) {
        *(limit-1)=c;
    }

    UBool append(UChar32 c, uint8_t cc, UErrorCode &errorCode) {
        return (c<=0xffff) ?
            appendBMP((UChar)c, cc, errorCode) :
            appendSupplementary(c, cc, errorCode);
    }
    // s must be in NFD, otherwise change the implementation.
    UBool append(const UChar *s, int32_t length,
                 uint8_t leadCC, uint8_t trailCC,
                 UErrorCode &errorCode);
    UBool appendBMP(UChar c, uint8_t cc, UErrorCode &errorCode) {
        if(remainingCapacity==0 && !resize(1, errorCode)) {
            return FALSE;
        }
        if(lastCC<=cc || cc==0) {
            *limit++=c;
            lastCC=cc;
            if(cc<=1) {
                reorderStart=limit;
            }
        } else {
            insert(c, cc);
        }
        --remainingCapacity;
        return TRUE;
    }
    UBool appendZeroCC(UChar32 c, UErrorCode &errorCode);
    UBool appendZeroCC(const UChar *s, const UChar *sLimit, UErrorCode &errorCode);
    void remove();
    void removeSuffix(int32_t suffixLength);
    void setReorderingLimit(UChar *newLimit) {
        remainingCapacity+=(int32_t)(limit-newLimit);
        reorderStart=limit=newLimit;
        lastCC=0;
    }
    void copyReorderableSuffixTo(UnicodeString &s) const {
        s.setTo(reorderStart, (int32_t)(limit-reorderStart));
    }
private:
    /*
     * TODO: Revisit whether it makes sense to track reorderStart.
     * It is set to after the last known character with cc<=1,
     * which stops previousCC() before it reads that character and looks up its cc.
     * previousCC() is normally only called from insert().
     * In other words, reorderStart speeds up the insertion of a combining mark
     * into a multi-combining mark sequence where it does not belong at the end.
     * This might not be worth the trouble.
     * On the other hand, it's not a huge amount of trouble.
     *
     * We probably need it for UNORM_SIMPLE_APPEND.
     */

    UBool appendSupplementary(UChar32 c, uint8_t cc, UErrorCode &errorCode);
    void insert(UChar32 c, uint8_t cc);
    static void writeCodePoint(UChar *p, UChar32 c) {
        if(c<=0xffff) {
            *p=(UChar)c;
        } else {
            p[0]=U16_LEAD(c);
            p[1]=U16_TRAIL(c);
        }
    }
    UBool resize(int32_t appendLength, UErrorCode &errorCode);

    const Normalizer2Impl &impl;
    UnicodeString &str;
    UChar *start, *reorderStart, *limit;
    int32_t remainingCapacity;
    uint8_t lastCC;

    // private backward iterator
    void setIterator() { codePointStart=limit; }
    void skipPrevious();  // Requires start<codePointStart.
    uint8_t previousCC();  // Returns 0 if there is no previous character.

    UChar *codePointStart, *codePointLimit;
};

class U_COMMON_API Normalizer2Impl : public UObject {
public:
    Normalizer2Impl() : normTrie(NULL), fCanonIterData(NULL) {
        fCanonIterDataInitOnce.reset();
    }
    virtual ~Normalizer2Impl();

    void init(const int32_t *inIndexes, const UTrie2 *inTrie,
              const uint16_t *inExtraData, const uint8_t *inSmallFCD);

    void addLcccChars(UnicodeSet &set) const;
    void addPropertyStarts(const USetAdder *sa, UErrorCode &errorCode) const;
    void addCanonIterPropertyStarts(const USetAdder *sa, UErrorCode &errorCode) const;

    // low-level properties ------------------------------------------------ ***

    const UTrie2 *getNormTrie() const { return normTrie; }

    UBool ensureCanonIterData(UErrorCode &errorCode) const;

    uint16_t getNorm16(UChar32 c) const { return UTRIE2_GET16(normTrie, c); }

    UNormalizationCheckResult getCompQuickCheck(uint16_t norm16) const {
        if(norm16<minNoNo || MIN_YES_YES_WITH_CC<=norm16) {
            return UNORM_YES;
        } else if(minMaybeYes<=norm16) {
            return UNORM_MAYBE;
        } else {
            return UNORM_NO;
        }
    }
    UBool isAlgorithmicNoNo(uint16_t norm16) const { return limitNoNo<=norm16 && norm16<minMaybeYes; }
    UBool isCompNo(uint16_t norm16) const { return minNoNo<=norm16 && norm16<minMaybeYes; }
    UBool isDecompYes(uint16_t norm16) const { return norm16<minYesNo || minMaybeYes<=norm16; }

    uint8_t getCC(uint16_t norm16) const {
        if(norm16>=MIN_NORMAL_MAYBE_YES) {
            return (uint8_t)norm16;
        }
        if(norm16<minNoNo || limitNoNo<=norm16) {
            return 0;
        }
        return getCCFromNoNo(norm16);
    }
    static uint8_t getCCFromYesOrMaybe(uint16_t norm16) {
        return norm16>=MIN_NORMAL_MAYBE_YES ? (uint8_t)norm16 : 0;
    }

    /**
     * Returns the FCD data for code point c.
     * @param c A Unicode code point.
     * @return The lccc(c) in bits 15..8 and tccc(c) in bits 7..0.
     */
    uint16_t getFCD16(UChar32 c) const {
        if(c<0) {
            return 0;
        } else if(c<0x180) {
            return tccc180[c];
        } else if(c<=0xffff) {
            if(!singleLeadMightHaveNonZeroFCD16(c)) { return 0; }
        }
        return getFCD16FromNormData(c);
    }
    /**
     * Returns the FCD data for the next code point (post-increment).
     * Might skip only a lead surrogate rather than the whole surrogate pair if none of
     * the supplementary code points associated with the lead surrogate have non-zero FCD data.
     * @param s A valid pointer into a string. Requires s!=limit.
     * @param limit The end of the string, or NULL.
     * @return The lccc(c) in bits 15..8 and tccc(c) in bits 7..0.
     */
    uint16_t nextFCD16(const UChar *&s, const UChar *limit) const {
        UChar32 c=*s++;
        if(c<0x180) {
            return tccc180[c];
        } else if(!singleLeadMightHaveNonZeroFCD16(c)) {
            return 0;
        }
        UChar c2;
        if(U16_IS_LEAD(c) && s!=limit && U16_IS_TRAIL(c2=*s)) {
            c=U16_GET_SUPPLEMENTARY(c, c2);
            ++s;
        }
        return getFCD16FromNormData(c);
    }
    /**
     * Returns the FCD data for the previous code point (pre-decrement).
     * @param start The start of the string.
     * @param s A valid pointer into a string. Requires start<s.
     * @return The lccc(c) in bits 15..8 and tccc(c) in bits 7..0.
     */
    uint16_t previousFCD16(const UChar *start, const UChar *&s) const {
        UChar32 c=*--s;
        if(c<0x180) {
            return tccc180[c];
        }
        if(!U16_IS_TRAIL(c)) {
            if(!singleLeadMightHaveNonZeroFCD16(c)) {
                return 0;
            }
        } else {
            UChar c2;
            if(start<s && U16_IS_LEAD(c2=*(s-1))) {
                c=U16_GET_SUPPLEMENTARY(c2, c);
                --s;
            }
        }
        return getFCD16FromNormData(c);
    }

    /** Returns the FCD data for U+0000<=c<U+0180. */
    uint16_t getFCD16FromBelow180(UChar32 c) const { return tccc180[c]; }
    /** Returns TRUE if the single-or-lead code unit c might have non-zero FCD data. */
    UBool singleLeadMightHaveNonZeroFCD16(UChar32 lead) const {
        // 0<=lead<=0xffff
        uint8_t bits=smallFCD[lead>>8];
        if(bits==0) { return false; }
        return (UBool)((bits>>((lead>>5)&7))&1);
    }
    /** Returns the FCD value from the regular normalization data. */
    uint16_t getFCD16FromNormData(UChar32 c) const;

    void makeCanonIterDataFromNorm16(UChar32 start, UChar32 end, uint16_t norm16,
                                     CanonIterData &newData, UErrorCode &errorCode) const;

    /**
     * Gets the decomposition for one code point.
     * @param c code point
     * @param buffer out-only buffer for algorithmic decompositions
     * @param length out-only, takes the length of the decomposition, if any
     * @return pointer to the decomposition, or NULL if none
     */
    const UChar *getDecomposition(UChar32 c, UChar buffer[4], int32_t &length) const;

    /**
     * Gets the raw decomposition for one code point.
     * @param c code point
     * @param buffer out-only buffer for algorithmic decompositions
     * @param length out-only, takes the length of the decomposition, if any
     * @return pointer to the decomposition, or NULL if none
     */
    const UChar *getRawDecomposition(UChar32 c, UChar buffer[30], int32_t &length) const;

    UChar32 composePair(UChar32 a, UChar32 b) const;

    UBool isCanonSegmentStarter(UChar32 c) const;
    UBool getCanonStartSet(UChar32 c, UnicodeSet &set) const;

    enum {
        MIN_CCC_LCCC_CP=0x300
    };

    enum {
        MIN_YES_YES_WITH_CC=0xff01,
        JAMO_VT=0xff00,
        MIN_NORMAL_MAYBE_YES=0xfe00,
        JAMO_L=1,
        MAX_DELTA=0x40
    };

    enum {
        // Byte offsets from the start of the data, after the generic header.
        IX_NORM_TRIE_OFFSET,
        IX_EXTRA_DATA_OFFSET,
        IX_SMALL_FCD_OFFSET,
        IX_RESERVED3_OFFSET,
        IX_RESERVED4_OFFSET,
        IX_RESERVED5_OFFSET,
        IX_RESERVED6_OFFSET,
        IX_TOTAL_SIZE,

        // Code point thresholds for quick check codes.
        IX_MIN_DECOMP_NO_CP,
        IX_MIN_COMP_NO_MAYBE_CP,

        // Norm16 value thresholds for quick check combinations and types of extra data.
        IX_MIN_YES_NO,  // Mappings & compositions in [minYesNo..minYesNoMappingsOnly[.
        IX_MIN_NO_NO,
        IX_LIMIT_NO_NO,
        IX_MIN_MAYBE_YES,

        IX_MIN_YES_NO_MAPPINGS_ONLY,  // Mappings only in [minYesNoMappingsOnly..minNoNo[.

        IX_RESERVED15,
        IX_COUNT
    };

    enum {
        MAPPING_HAS_CCC_LCCC_WORD=0x80,
        MAPPING_HAS_RAW_MAPPING=0x40,
        MAPPING_NO_COMP_BOUNDARY_AFTER=0x20,
        MAPPING_LENGTH_MASK=0x1f
    };

    enum {
        COMP_1_LAST_TUPLE=0x8000,
        COMP_1_TRIPLE=1,
        COMP_1_TRAIL_LIMIT=0x3400,
        COMP_1_TRAIL_MASK=0x7ffe,
        COMP_1_TRAIL_SHIFT=9,  // 10-1 for the "triple" bit
        COMP_2_TRAIL_SHIFT=6,
        COMP_2_TRAIL_MASK=0xffc0
    };

    // higher-level functionality ------------------------------------------ ***

    // NFD without an NFD Normalizer2 instance.
    UnicodeString &decompose(const UnicodeString &src, UnicodeString &dest,
                             UErrorCode &errorCode) const;
    /**
     * Decomposes [src, limit[ and writes the result to dest.
     * limit can be NULL if src is NUL-terminated.
     * destLengthEstimate is the initial dest buffer capacity and can be -1.
     */
    void decompose(const UChar *src, const UChar *limit,
                   UnicodeString &dest, int32_t destLengthEstimate,
                   UErrorCode &errorCode) const;

    const UChar *decompose(const UChar *src, const UChar *limit,
                           ReorderingBuffer *buffer, UErrorCode &errorCode) const;
    void decomposeAndAppend(const UChar *src, const UChar *limit,
                            UBool doDecompose,
                            UnicodeString &safeMiddle,
                            ReorderingBuffer &buffer,
                            UErrorCode &errorCode) const;
    UBool compose(const UChar *src, const UChar *limit,
                  UBool onlyContiguous,
                  UBool doCompose,
                  ReorderingBuffer &buffer,
                  UErrorCode &errorCode) const;
    const UChar *composeQuickCheck(const UChar *src, const UChar *limit,
                                   UBool onlyContiguous,
                                   UNormalizationCheckResult *pQCResult) const;
    void composeAndAppend(const UChar *src, const UChar *limit,
                          UBool doCompose,
                          UBool onlyContiguous,
                          UnicodeString &safeMiddle,
                          ReorderingBuffer &buffer,
                          UErrorCode &errorCode) const;
    const UChar *makeFCD(const UChar *src, const UChar *limit,
                         ReorderingBuffer *buffer, UErrorCode &errorCode) const;
    void makeFCDAndAppend(const UChar *src, const UChar *limit,
                          UBool doMakeFCD,
                          UnicodeString &safeMiddle,
                          ReorderingBuffer &buffer,
                          UErrorCode &errorCode) const;

    UBool hasDecompBoundary(UChar32 c, UBool before) const;
    UBool isDecompInert(UChar32 c) const { return isDecompYesAndZeroCC(getNorm16(c)); }

    UBool hasCompBoundaryBefore(UChar32 c) const {
        return c<minCompNoMaybeCP || hasCompBoundaryBefore(c, getNorm16(c));
    }
    UBool hasCompBoundaryAfter(UChar32 c, UBool onlyContiguous, UBool testInert) const;

    UBool hasFCDBoundaryBefore(UChar32 c) const { return c<MIN_CCC_LCCC_CP || getFCD16(c)<=0xff; }
    UBool hasFCDBoundaryAfter(UChar32 c) const {
        uint16_t fcd16=getFCD16(c);
        return fcd16<=1 || (fcd16&0xff)==0;
    }
    UBool isFCDInert(UChar32 c) const { return getFCD16(c)<=1; }
private:
    UBool isMaybe(uint16_t norm16) const { return minMaybeYes<=norm16 && norm16<=JAMO_VT; }
    UBool isMaybeOrNonZeroCC(uint16_t norm16) const { return norm16>=minMaybeYes; }
    static UBool isInert(uint16_t norm16) { return norm16==0; }
    static UBool isJamoL(uint16_t norm16) { return norm16==1; }
    static UBool isJamoVT(uint16_t norm16) { return norm16==JAMO_VT; }
    UBool isHangul(uint16_t norm16) const { return norm16==minYesNo; }
    UBool isCompYesAndZeroCC(uint16_t norm16) const { return norm16<minNoNo; }
    // UBool isCompYes(uint16_t norm16) const {
    //     return norm16>=MIN_YES_YES_WITH_CC || norm16<minNoNo;
    // }
    // UBool isCompYesOrMaybe(uint16_t norm16) const {
    //     return norm16<minNoNo || minMaybeYes<=norm16;
    // }
    // UBool hasZeroCCFromDecompYes(uint16_t norm16) const {
    //     return norm16<=MIN_NORMAL_MAYBE_YES || norm16==JAMO_VT;
    // }
    UBool isDecompYesAndZeroCC(uint16_t norm16) const {
        return norm16<minYesNo ||
               norm16==JAMO_VT ||
               (minMaybeYes<=norm16 && norm16<=MIN_NORMAL_MAYBE_YES);
    }
    /**
     * A little faster and simpler than isDecompYesAndZeroCC() but does not include
     * the MaybeYes which combine-forward and have ccc=0.
     * (Standard Unicode 5.2 normalization does not have such characters.)
     */
    UBool isMostDecompYesAndZeroCC(uint16_t norm16) const {
        return norm16<minYesNo || norm16==MIN_NORMAL_MAYBE_YES || norm16==JAMO_VT;
    }
    UBool isDecompNoAlgorithmic(uint16_t norm16) const { return norm16>=limitNoNo; }

    // For use with isCompYes().
    // Perhaps the compiler can combine the two tests for MIN_YES_YES_WITH_CC.
    // static uint8_t getCCFromYes(uint16_t norm16) {
    //     return norm16>=MIN_YES_YES_WITH_CC ? (uint8_t)norm16 : 0;
    // }
    uint8_t getCCFromNoNo(uint16_t norm16) const {
        const uint16_t *mapping=getMapping(norm16);
        if(*mapping&MAPPING_HAS_CCC_LCCC_WORD) {
            return (uint8_t)*(mapping-1);
        } else {
            return 0;
        }
    }
    // requires that the [cpStart..cpLimit[ character passes isCompYesAndZeroCC()
    uint8_t getTrailCCFromCompYesAndZeroCC(const UChar *cpStart, const UChar *cpLimit) const;

    // Requires algorithmic-NoNo.
    UChar32 mapAlgorithmic(UChar32 c, uint16_t norm16) const {
        return c+norm16-(minMaybeYes-MAX_DELTA-1);
    }

    // Requires minYesNo<norm16<limitNoNo.
    const uint16_t *getMapping(uint16_t norm16) const { return extraData+norm16; }
    const uint16_t *getCompositionsListForDecompYes(uint16_t norm16) const {
        if(norm16==0 || MIN_NORMAL_MAYBE_YES<=norm16) {
            return NULL;
        } else if(norm16<minMaybeYes) {
            return extraData+norm16;  // for yesYes; if Jamo L: harmless empty list
        } else {
            return maybeYesCompositions+norm16-minMaybeYes;
        }
    }
    const uint16_t *getCompositionsListForComposite(uint16_t norm16) const {
        const uint16_t *list=extraData+norm16;  // composite has both mapping & compositions list
        return list+  // mapping pointer
            1+  // +1 to skip the first unit with the mapping lenth
            (*list&MAPPING_LENGTH_MASK);  // + mapping length
    }
    /**
     * @param c code point must have compositions
     * @return compositions list pointer
     */
    const uint16_t *getCompositionsList(uint16_t norm16) const {
        return isDecompYes(norm16) ?
                getCompositionsListForDecompYes(norm16) :
                getCompositionsListForComposite(norm16);
    }

    const UChar *copyLowPrefixFromNulTerminated(const UChar *src,
                                                UChar32 minNeedDataCP,
                                                ReorderingBuffer *buffer,
                                                UErrorCode &errorCode) const;
    UBool decomposeShort(const UChar *src, const UChar *limit,
                         ReorderingBuffer &buffer, UErrorCode &errorCode) const;
    UBool decompose(UChar32 c, uint16_t norm16,
                    ReorderingBuffer &buffer, UErrorCode &errorCode) const;

    static int32_t combine(const uint16_t *list, UChar32 trail);
    void addComposites(const uint16_t *list, UnicodeSet &set) const;
    void recompose(ReorderingBuffer &buffer, int32_t recomposeStartIndex,
                   UBool onlyContiguous) const;

    UBool hasCompBoundaryBefore(UChar32 c, uint16_t norm16) const;
    const UChar *findPreviousCompBoundary(const UChar *start, const UChar *p) const;
    const UChar *findNextCompBoundary(const UChar *p, const UChar *limit) const;

    const UChar *findPreviousFCDBoundary(const UChar *start, const UChar *p) const;
    const UChar *findNextFCDBoundary(const UChar *p, const UChar *limit) const;

    int32_t getCanonValue(UChar32 c) const;
    const UnicodeSet &getCanonStartSet(int32_t n) const;

    // UVersionInfo dataVersion;

    // Code point thresholds for quick check codes.
    UChar32 minDecompNoCP;
    UChar32 minCompNoMaybeCP;

    // Norm16 value thresholds for quick check combinations and types of extra data.
    uint16_t minYesNo;
    uint16_t minYesNoMappingsOnly;
    uint16_t minNoNo;
    uint16_t limitNoNo;
    uint16_t minMaybeYes;

    const UTrie2 *normTrie;
    const uint16_t *maybeYesCompositions;
    const uint16_t *extraData;  // mappings and/or compositions for yesYes, yesNo & noNo characters
    const uint8_t *smallFCD;  // [0x100] one bit per 32 BMP code points, set if any FCD!=0
    uint8_t tccc180[0x180];  // tccc values for U+0000..U+017F

public:  // CanonIterData is public to allow access from C callback functions.
    UInitOnce       fCanonIterDataInitOnce;
    CanonIterData  *fCanonIterData;
};

// bits in canonIterData
#define CANON_NOT_SEGMENT_STARTER 0x80000000
#define CANON_HAS_COMPOSITIONS 0x40000000
#define CANON_HAS_SET 0x200000
#define CANON_VALUE_MASK 0x1fffff

/**
 * ICU-internal shortcut for quick access to standard Unicode normalization.
 */
class U_COMMON_API Normalizer2Factory {
public:
    static const Normalizer2 *getFCDInstance(UErrorCode &errorCode);
    static const Normalizer2 *getFCCInstance(UErrorCode &errorCode);
    static const Normalizer2 *getNoopInstance(UErrorCode &errorCode);

    static const Normalizer2 *getInstance(UNormalizationMode mode, UErrorCode &errorCode);

    static const Normalizer2Impl *getNFCImpl(UErrorCode &errorCode);
    static const Normalizer2Impl *getNFKCImpl(UErrorCode &errorCode);
    static const Normalizer2Impl *getNFKC_CFImpl(UErrorCode &errorCode);

    // Get the Impl instance of the Normalizer2.
    // Must be used only when it is known that norm2 is a Normalizer2WithImpl instance.
    static const Normalizer2Impl *getImpl(const Normalizer2 *norm2);
private:
    Normalizer2Factory();  // No instantiation.
};

U_NAMESPACE_END

U_CAPI int32_t U_EXPORT2
unorm2_swap(const UDataSwapper *ds,
            const void *inData, int32_t length, void *outData,
            UErrorCode *pErrorCode);

/**
 * Get the NF*_QC property for a code point, for u_getIntPropertyValue().
 * @internal
 */
U_CFUNC UNormalizationCheckResult
unorm_getQuickCheck(UChar32 c, UNormalizationMode mode);

/**
 * Gets the 16-bit FCD value (lead & trail CCs) for a code point, for u_getIntPropertyValue().
 * @internal
 */
U_CFUNC uint16_t
unorm_getFCD16(UChar32 c);

/**
 * Format of Normalizer2 .nrm data files.
 * Format version 2.0.
 *
 * Normalizer2 .nrm data files provide data for the Unicode Normalization algorithms.
 * ICU ships with data files for standard Unicode Normalization Forms
 * NFC and NFD (nfc.nrm), NFKC and NFKD (nfkc.nrm) and NFKC_Casefold (nfkc_cf.nrm).
 * Custom (application-specific) data can be built into additional .nrm files
 * with the gennorm2 build tool.
 *
 * Normalizer2.getInstance() causes a .nrm file to be loaded, unless it has been
 * cached already. Internally, Normalizer2Impl.load() reads the .nrm file.
 *
 * A .nrm file begins with a standard ICU data file header
 * (DataHeader, see ucmndata.h and unicode/udata.h).
 * The UDataInfo.dataVersion field usually contains the Unicode version
 * for which the data was generated.
 *
 * After the header, the file contains the following parts.
 * Constants are defined as enum values of the Normalizer2Impl class.
 *
 * Many details of the data structures are described in the design doc
 * which is at http://site.icu-project.org/design/normalization/custom
 *
 * int32_t indexes[indexesLength]; -- indexesLength=indexes[IX_NORM_TRIE_OFFSET]/4;
 *
 *      The first eight indexes are byte offsets in ascending order.
 *      Each byte offset marks the start of the next part in the data file,
 *      and the end of the previous one.
 *      When two consecutive byte offsets are the same, then the corresponding part is empty.
 *      Byte offsets are offsets from after the header,
 *      that is, from the beginning of the indexes[].
 *      Each part starts at an offset with proper alignment for its data.
 *      If necessary, the previous part may include padding bytes to achieve this alignment.
 *
 *      minDecompNoCP=indexes[IX_MIN_DECOMP_NO_CP] is the lowest code point
 *      with a decomposition mapping, that is, with NF*D_QC=No.
 *      minCompNoMaybeCP=indexes[IX_MIN_COMP_NO_MAYBE_CP] is the lowest code point
 *      with NF*C_QC=No (has a one-way mapping) or Maybe (combines backward).
 *
 *      The next five indexes are thresholds of 16-bit trie values for ranges of
 *      values indicating multiple normalization properties.
 *          minYesNo=indexes[IX_MIN_YES_NO];
 *          minNoNo=indexes[IX_MIN_NO_NO];
 *          limitNoNo=indexes[IX_LIMIT_NO_NO];
 *          minMaybeYes=indexes[IX_MIN_MAYBE_YES];
 *          minYesNoMappingsOnly=indexes[IX_MIN_YES_NO_MAPPINGS_ONLY];
 *      See the normTrie description below and the design doc for details.
 *
 * UTrie2 normTrie; -- see utrie2_impl.h and utrie2.h
 *
 *      The trie holds the main normalization data. Each code point is mapped to a 16-bit value.
 *      Rather than using independent bits in the value (which would require more than 16 bits),
 *      information is extracted primarily via range checks.
 *      For example, a 16-bit value norm16 in the range minYesNo<=norm16<minNoNo
 *      means that the character has NF*C_QC=Yes and NF*D_QC=No properties,
 *      which means it has a two-way (round-trip) decomposition mapping.
 *      Values in the range 2<=norm16<limitNoNo are also directly indexes into the extraData
 *      pointing to mappings, compositions lists, or both.
 *      Value norm16==0 means that the character is normalization-inert, that is,
 *      it does not have a mapping, does not participate in composition, has a zero
 *      canonical combining class, and forms a boundary where text before it and after it
 *      can be normalized independently.
 *      For details about how multiple properties are encoded in 16-bit values
 *      see the design doc.
 *      Note that the encoding cannot express all combinations of the properties involved;
 *      it only supports those combinations that are allowed by
 *      the Unicode Normalization algorithms. Details are in the design doc as well.
 *      The gennorm2 tool only builds .nrm files for data that conforms to the limitations.
 *
 *      The trie has a value for each lead surrogate code unit representing the "worst case"
 *      properties of the 1024 supplementary characters whose UTF-16 form starts with
 *      the lead surrogate. If all of the 1024 supplementary characters are normalization-inert,
 *      then their lead surrogate code unit has the trie value 0.
 *      When the lead surrogate unit's value exceeds the quick check minimum during processing,
 *      the properties for the full supplementary code point need to be looked up.
 *
 * uint16_t maybeYesCompositions[MIN_NORMAL_MAYBE_YES-minMaybeYes];
 * uint16_t extraData[];
 *
 *      There is only one byte offset for the end of these two arrays.
 *      The split between them is given by the constant and variable mentioned above.
 *
 *      The maybeYesCompositions array contains compositions lists for characters that
 *      combine both forward (as starters in composition pairs)
 *      and backward (as trailing characters in composition pairs).
 *      Such characters do not occur in Unicode 5.2 but are allowed by
 *      the Unicode Normalization algorithms.
 *      If there are no such characters, then minMaybeYes==MIN_NORMAL_MAYBE_YES
 *      and the maybeYesCompositions array is empty.
 *      If there are such characters, then minMaybeYes is subtracted from their norm16 values
 *      to get the index into this array.
 *
 *      The extraData array contains compositions lists for "YesYes" characters,
 *      followed by mappings and optional compositions lists for "YesNo" characters,
 *      followed by only mappings for "NoNo" characters.
 *      (Referring to pairs of NFC/NFD quick check values.)
 *      The norm16 values of those characters are directly indexes into the extraData array.
 *
 *      The data structures for compositions lists and mappings are described in the design doc.
 *
 * uint8_t smallFCD[0x100]; -- new in format version 2
 *
 *      This is a bit set to help speed up FCD value lookups in the absence of a full
 *      UTrie2 or other large data structure with the full FCD value mapping.
 *
 *      Each smallFCD bit is set if any of the corresponding 32 BMP code points
 *      has a non-zero FCD value (lccc!=0 or tccc!=0).
 *      Bit 0 of smallFCD[0] is for U+0000..U+001F. Bit 7 of smallFCD[0xff] is for U+FFE0..U+FFFF.
 *      A bit for 32 lead surrogates is set if any of the 32k corresponding
 *      _supplementary_ code points has a non-zero FCD value.
 *
 *      This bit set is most useful for the large blocks of CJK characters with FCD=0.
 *
 * Changes from format version 1 to format version 2 ---------------------------
 *
 * - Addition of data for raw (not recursively decomposed) mappings.
 *   + The MAPPING_NO_COMP_BOUNDARY_AFTER bit in the extraData is now also set when
 *     the mapping is to an empty string or when the character combines-forward.
 *     This subsumes the one actual use of the MAPPING_PLUS_COMPOSITION_LIST bit which
 *     is then repurposed for the MAPPING_HAS_RAW_MAPPING bit.
 *   + For details see the design doc.
 * - Addition of indexes[IX_MIN_YES_NO_MAPPINGS_ONLY] and separation of the yesNo extraData into
 *   distinct ranges (combines-forward vs. not)
 *   so that a range check can be used to find out if there is a compositions list.
 *   This is fully equivalent with formatVersion 1's MAPPING_PLUS_COMPOSITION_LIST flag.
 *   It is needed for the new (in ICU 49) composePair(), not for other normalization.
 * - Addition of the smallFCD[] bit set.
 */

#endif  /* !UCONFIG_NO_NORMALIZATION */
#endif  /* __NORMALIZER2IMPL_H__ */