1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 *******************************************************************************
5 *
6 * Copyright (C) 2002-2011, International Business Machines
7 * Corporation and others. All Rights Reserved.
8 *
9 *******************************************************************************
10 * file name: uset.cpp
11 * encoding: UTF-8
12 * tab size: 8 (not used)
13 * indentation:4
14 *
15 * created on: 2002mar07
16 * created by: Markus W. Scherer
17 *
18 * There are functions to efficiently serialize a USet into an array of uint16_t
19 * and functions to use such a serialized form efficiently without
20 * instantiating a new USet.
21 */
22
23 #include "unicode/utypes.h"
24 #include "unicode/uobject.h"
25 #include "unicode/uset.h"
26 #include "unicode/uniset.h"
27 #include "cmemory.h"
28 #include "unicode/ustring.h"
29 #include "unicode/parsepos.h"
30
31 U_NAMESPACE_USE
32
33 U_CAPI USet* U_EXPORT2
uset_openEmpty()34 uset_openEmpty() {
35 return (USet*) new UnicodeSet();
36 }
37
38 U_CAPI USet* U_EXPORT2
uset_open(UChar32 start,UChar32 end)39 uset_open(UChar32 start, UChar32 end) {
40 return (USet*) new UnicodeSet(start, end);
41 }
42
43 U_CAPI void U_EXPORT2
uset_close(USet * set)44 uset_close(USet* set) {
45 delete (UnicodeSet*) set;
46 }
47
48 U_CAPI USet * U_EXPORT2
uset_clone(const USet * set)49 uset_clone(const USet *set) {
50 return (USet*) (((UnicodeSet*) set)->UnicodeSet::clone());
51 }
52
53 U_CAPI UBool U_EXPORT2
uset_isFrozen(const USet * set)54 uset_isFrozen(const USet *set) {
55 return ((UnicodeSet*) set)->UnicodeSet::isFrozen();
56 }
57
58 U_CAPI void U_EXPORT2
uset_freeze(USet * set)59 uset_freeze(USet *set) {
60 ((UnicodeSet*) set)->UnicodeSet::freeze();
61 }
62
63 U_CAPI USet * U_EXPORT2
uset_cloneAsThawed(const USet * set)64 uset_cloneAsThawed(const USet *set) {
65 return (USet*) (((UnicodeSet*) set)->UnicodeSet::cloneAsThawed());
66 }
67
68 U_CAPI void U_EXPORT2
uset_set(USet * set,UChar32 start,UChar32 end)69 uset_set(USet* set,
70 UChar32 start, UChar32 end) {
71 ((UnicodeSet*) set)->UnicodeSet::set(start, end);
72 }
73
74 U_CAPI void U_EXPORT2
uset_addAll(USet * set,const USet * additionalSet)75 uset_addAll(USet* set, const USet *additionalSet) {
76 ((UnicodeSet*) set)->UnicodeSet::addAll(*((const UnicodeSet*)additionalSet));
77 }
78
79 U_CAPI void U_EXPORT2
uset_add(USet * set,UChar32 c)80 uset_add(USet* set, UChar32 c) {
81 ((UnicodeSet*) set)->UnicodeSet::add(c);
82 }
83
84 U_CAPI void U_EXPORT2
uset_addRange(USet * set,UChar32 start,UChar32 end)85 uset_addRange(USet* set, UChar32 start, UChar32 end) {
86 ((UnicodeSet*) set)->UnicodeSet::add(start, end);
87 }
88
89 U_CAPI void U_EXPORT2
uset_addString(USet * set,const char16_t * str,int32_t strLen)90 uset_addString(USet* set, const char16_t* str, int32_t strLen) {
91 // UnicodeString handles -1 for strLen
92 UnicodeString s(strLen<0, str, strLen);
93 ((UnicodeSet*) set)->UnicodeSet::add(s);
94 }
95
96 U_CAPI void U_EXPORT2
uset_addAllCodePoints(USet * set,const char16_t * str,int32_t strLen)97 uset_addAllCodePoints(USet* set, const char16_t *str, int32_t strLen) {
98 // UnicodeString handles -1 for strLen
99 UnicodeString s(str, strLen);
100 ((UnicodeSet*) set)->UnicodeSet::addAll(s);
101 }
102
103 U_CAPI void U_EXPORT2
uset_remove(USet * set,UChar32 c)104 uset_remove(USet* set, UChar32 c) {
105 ((UnicodeSet*) set)->UnicodeSet::remove(c);
106 }
107
108 U_CAPI void U_EXPORT2
uset_removeRange(USet * set,UChar32 start,UChar32 end)109 uset_removeRange(USet* set, UChar32 start, UChar32 end) {
110 ((UnicodeSet*) set)->UnicodeSet::remove(start, end);
111 }
112
113 U_CAPI void U_EXPORT2
uset_removeString(USet * set,const char16_t * str,int32_t strLen)114 uset_removeString(USet* set, const char16_t* str, int32_t strLen) {
115 UnicodeString s(strLen==-1, str, strLen);
116 ((UnicodeSet*) set)->UnicodeSet::remove(s);
117 }
118
119 U_CAPI void U_EXPORT2
uset_removeAllCodePoints(USet * set,const char16_t * str,int32_t length)120 uset_removeAllCodePoints(USet *set, const char16_t *str, int32_t length) {
121 UnicodeString s(length==-1, str, length);
122 ((UnicodeSet*) set)->UnicodeSet::removeAll(s);
123 }
124
125 U_CAPI void U_EXPORT2
uset_removeAll(USet * set,const USet * remove)126 uset_removeAll(USet* set, const USet* remove) {
127 ((UnicodeSet*) set)->UnicodeSet::removeAll(*(const UnicodeSet*)remove);
128 }
129
130 U_CAPI void U_EXPORT2
uset_retain(USet * set,UChar32 start,UChar32 end)131 uset_retain(USet* set, UChar32 start, UChar32 end) {
132 ((UnicodeSet*) set)->UnicodeSet::retain(start, end);
133 }
134
135 U_CAPI void U_EXPORT2
uset_retainString(USet * set,const char16_t * str,int32_t length)136 uset_retainString(USet *set, const char16_t *str, int32_t length) {
137 UnicodeString s(length==-1, str, length);
138 ((UnicodeSet*) set)->UnicodeSet::retain(s);
139 }
140
141 U_CAPI void U_EXPORT2
uset_retainAllCodePoints(USet * set,const char16_t * str,int32_t length)142 uset_retainAllCodePoints(USet *set, const char16_t *str, int32_t length) {
143 UnicodeString s(length==-1, str, length);
144 ((UnicodeSet*) set)->UnicodeSet::retainAll(s);
145 }
146
147 U_CAPI void U_EXPORT2
uset_retainAll(USet * set,const USet * retain)148 uset_retainAll(USet* set, const USet* retain) {
149 ((UnicodeSet*) set)->UnicodeSet::retainAll(*(const UnicodeSet*)retain);
150 }
151
152 U_CAPI void U_EXPORT2
uset_compact(USet * set)153 uset_compact(USet* set) {
154 ((UnicodeSet*) set)->UnicodeSet::compact();
155 }
156
157 U_CAPI void U_EXPORT2
uset_complement(USet * set)158 uset_complement(USet* set) {
159 ((UnicodeSet*) set)->UnicodeSet::complement();
160 }
161
162 U_CAPI void U_EXPORT2
uset_complementRange(USet * set,UChar32 start,UChar32 end)163 uset_complementRange(USet *set, UChar32 start, UChar32 end) {
164 ((UnicodeSet*) set)->UnicodeSet::complement(start, end);
165 }
166
167 U_CAPI void U_EXPORT2
uset_complementString(USet * set,const char16_t * str,int32_t length)168 uset_complementString(USet *set, const char16_t *str, int32_t length) {
169 UnicodeString s(length==-1, str, length);
170 ((UnicodeSet*) set)->UnicodeSet::complement(s);
171 }
172
173 U_CAPI void U_EXPORT2
uset_complementAllCodePoints(USet * set,const char16_t * str,int32_t length)174 uset_complementAllCodePoints(USet *set, const char16_t *str, int32_t length) {
175 UnicodeString s(length==-1, str, length);
176 ((UnicodeSet*) set)->UnicodeSet::complementAll(s);
177 }
178
179 U_CAPI void U_EXPORT2
uset_complementAll(USet * set,const USet * complement)180 uset_complementAll(USet* set, const USet* complement) {
181 ((UnicodeSet*) set)->UnicodeSet::complementAll(*(const UnicodeSet*)complement);
182 }
183
184 U_CAPI void U_EXPORT2
uset_clear(USet * set)185 uset_clear(USet* set) {
186 ((UnicodeSet*) set)->UnicodeSet::clear();
187 }
188
189 U_CAPI void U_EXPORT2
uset_removeAllStrings(USet * set)190 uset_removeAllStrings(USet* set) {
191 ((UnicodeSet*) set)->UnicodeSet::removeAllStrings();
192 }
193
194 U_CAPI UBool U_EXPORT2
uset_isEmpty(const USet * set)195 uset_isEmpty(const USet* set) {
196 return ((const UnicodeSet*) set)->UnicodeSet::isEmpty();
197 }
198
199 U_CAPI UBool U_EXPORT2
uset_hasStrings(const USet * set)200 uset_hasStrings(const USet* set) {
201 return ((const UnicodeSet*) set)->UnicodeSet::hasStrings();
202 }
203
204 U_CAPI UBool U_EXPORT2
uset_contains(const USet * set,UChar32 c)205 uset_contains(const USet* set, UChar32 c) {
206 return ((const UnicodeSet*) set)->UnicodeSet::contains(c);
207 }
208
209 U_CAPI UBool U_EXPORT2
uset_containsRange(const USet * set,UChar32 start,UChar32 end)210 uset_containsRange(const USet* set, UChar32 start, UChar32 end) {
211 return ((const UnicodeSet*) set)->UnicodeSet::contains(start, end);
212 }
213
214 U_CAPI UBool U_EXPORT2
uset_containsString(const USet * set,const char16_t * str,int32_t strLen)215 uset_containsString(const USet* set, const char16_t* str, int32_t strLen) {
216 UnicodeString s(strLen==-1, str, strLen);
217 return ((const UnicodeSet*) set)->UnicodeSet::contains(s);
218 }
219
220 U_CAPI UBool U_EXPORT2
uset_containsAll(const USet * set1,const USet * set2)221 uset_containsAll(const USet* set1, const USet* set2) {
222 return ((const UnicodeSet*) set1)->UnicodeSet::containsAll(* (const UnicodeSet*) set2);
223 }
224
225 U_CAPI UBool U_EXPORT2
uset_containsAllCodePoints(const USet * set,const char16_t * str,int32_t strLen)226 uset_containsAllCodePoints(const USet* set, const char16_t *str, int32_t strLen) {
227 // Create a string alias, since nothing is being added to the set.
228 UnicodeString s(strLen==-1, str, strLen);
229 return ((const UnicodeSet*) set)->UnicodeSet::containsAll(s);
230 }
231
232 U_CAPI UBool U_EXPORT2
uset_containsNone(const USet * set1,const USet * set2)233 uset_containsNone(const USet* set1, const USet* set2) {
234 return ((const UnicodeSet*) set1)->UnicodeSet::containsNone(* (const UnicodeSet*) set2);
235 }
236
237 U_CAPI UBool U_EXPORT2
uset_containsSome(const USet * set1,const USet * set2)238 uset_containsSome(const USet* set1, const USet* set2) {
239 return ((const UnicodeSet*) set1)->UnicodeSet::containsSome(* (const UnicodeSet*) set2);
240 }
241
242 U_CAPI int32_t U_EXPORT2
uset_span(const USet * set,const char16_t * s,int32_t length,USetSpanCondition spanCondition)243 uset_span(const USet *set, const char16_t *s, int32_t length, USetSpanCondition spanCondition) {
244 return ((UnicodeSet*) set)->UnicodeSet::span(s, length, spanCondition);
245 }
246
247 U_CAPI int32_t U_EXPORT2
uset_spanBack(const USet * set,const char16_t * s,int32_t length,USetSpanCondition spanCondition)248 uset_spanBack(const USet *set, const char16_t *s, int32_t length, USetSpanCondition spanCondition) {
249 return ((UnicodeSet*) set)->UnicodeSet::spanBack(s, length, spanCondition);
250 }
251
252 U_CAPI int32_t U_EXPORT2
uset_spanUTF8(const USet * set,const char * s,int32_t length,USetSpanCondition spanCondition)253 uset_spanUTF8(const USet *set, const char *s, int32_t length, USetSpanCondition spanCondition) {
254 return ((UnicodeSet*) set)->UnicodeSet::spanUTF8(s, length, spanCondition);
255 }
256
257 U_CAPI int32_t U_EXPORT2
uset_spanBackUTF8(const USet * set,const char * s,int32_t length,USetSpanCondition spanCondition)258 uset_spanBackUTF8(const USet *set, const char *s, int32_t length, USetSpanCondition spanCondition) {
259 return ((UnicodeSet*) set)->UnicodeSet::spanBackUTF8(s, length, spanCondition);
260 }
261
262 U_CAPI UBool U_EXPORT2
uset_equals(const USet * set1,const USet * set2)263 uset_equals(const USet* set1, const USet* set2) {
264 return *(const UnicodeSet*)set1 == *(const UnicodeSet*)set2;
265 }
266
267 U_CAPI int32_t U_EXPORT2
uset_indexOf(const USet * set,UChar32 c)268 uset_indexOf(const USet* set, UChar32 c) {
269 return ((UnicodeSet*) set)->UnicodeSet::indexOf(c);
270 }
271
272 U_CAPI UChar32 U_EXPORT2
uset_charAt(const USet * set,int32_t index)273 uset_charAt(const USet* set, int32_t index) {
274 return ((UnicodeSet*) set)->UnicodeSet::charAt(index);
275 }
276
277 U_CAPI int32_t U_EXPORT2
uset_size(const USet * set)278 uset_size(const USet* set) {
279 return ((const UnicodeSet*) set)->UnicodeSet::size();
280 }
281
282 U_NAMESPACE_BEGIN
283 /**
284 * This class only exists to provide access to the UnicodeSet private
285 * USet support API. Declaring a class a friend is more portable than
286 * trying to declare extern "C" functions as friends.
287 */
288 class USetAccess /* not : public UObject because all methods are static */ {
289 public:
290 /* Try to have the compiler inline these*/
getStringCount(const UnicodeSet & set)291 inline static int32_t getStringCount(const UnicodeSet& set) {
292 return set.stringsSize();
293 }
getString(const UnicodeSet & set,int32_t i)294 inline static const UnicodeString* getString(const UnicodeSet& set,
295 int32_t i) {
296 return set.getString(i);
297 }
298 private:
299 /* do not instantiate*/
300 USetAccess();
301 };
302 U_NAMESPACE_END
303
304 U_CAPI int32_t U_EXPORT2
uset_getRangeCount(const USet * set)305 uset_getRangeCount(const USet *set) {
306 return ((const UnicodeSet *)set)->UnicodeSet::getRangeCount();
307 }
308
309 U_CAPI int32_t U_EXPORT2
uset_getItemCount(const USet * uset)310 uset_getItemCount(const USet* uset) {
311 const UnicodeSet& set = *(const UnicodeSet*)uset;
312 return set.getRangeCount() + USetAccess::getStringCount(set);
313 }
314
315 U_CAPI int32_t U_EXPORT2
uset_getItem(const USet * uset,int32_t itemIndex,UChar32 * start,UChar32 * end,char16_t * str,int32_t strCapacity,UErrorCode * ec)316 uset_getItem(const USet* uset, int32_t itemIndex,
317 UChar32* start, UChar32* end,
318 char16_t* str, int32_t strCapacity,
319 UErrorCode* ec) {
320 if (U_FAILURE(*ec)) return 0;
321 const UnicodeSet& set = *(const UnicodeSet*)uset;
322 int32_t rangeCount;
323
324 if (itemIndex < 0) {
325 *ec = U_ILLEGAL_ARGUMENT_ERROR;
326 return -1;
327 } else if (itemIndex < (rangeCount = set.getRangeCount())) {
328 *start = set.getRangeStart(itemIndex);
329 *end = set.getRangeEnd(itemIndex);
330 return 0;
331 } else {
332 itemIndex -= rangeCount;
333 if (itemIndex < USetAccess::getStringCount(set)) {
334 const UnicodeString* s = USetAccess::getString(set, itemIndex);
335 return s->extract(str, strCapacity, *ec);
336 } else {
337 *ec = U_INDEX_OUTOFBOUNDS_ERROR;
338 return -1;
339 }
340 }
341 }
342
343 //U_CAPI UBool U_EXPORT2
344 //uset_getRange(const USet* set, int32_t rangeIndex,
345 // UChar32* pStart, UChar32* pEnd) {
346 // if ((uint32_t) rangeIndex >= (uint32_t) uset_getRangeCount(set)) {
347 // return false;
348 // }
349 // const UnicodeSet* us = (const UnicodeSet*) set;
350 // *pStart = us->getRangeStart(rangeIndex);
351 // *pEnd = us->getRangeEnd(rangeIndex);
352 // return true;
353 //}
354
355 /*
356 * Serialize a USet into 16-bit units.
357 * Store BMP code points as themselves with one 16-bit unit each.
358 *
359 * Important: the code points in the array are in ascending order,
360 * therefore all BMP code points precede all supplementary code points.
361 *
362 * Store each supplementary code point in 2 16-bit units,
363 * simply with higher-then-lower 16-bit halves.
364 *
365 * Precede the entire list with the length.
366 * If there are supplementary code points, then set bit 15 in the length
367 * and add the bmpLength between it and the array.
368 *
369 * In other words:
370 * - all BMP: (length=bmpLength) BMP, .., BMP
371 * - some supplementary: (length|0x8000) (bmpLength<length) BMP, .., BMP, supp-high, supp-low, ..
372 */
373 U_CAPI int32_t U_EXPORT2
uset_serialize(const USet * set,uint16_t * dest,int32_t destCapacity,UErrorCode * ec)374 uset_serialize(const USet* set, uint16_t* dest, int32_t destCapacity, UErrorCode* ec) {
375 if (ec==nullptr || U_FAILURE(*ec)) {
376 return 0;
377 }
378
379 return ((const UnicodeSet*) set)->UnicodeSet::serialize(dest, destCapacity,* ec);
380 }
381
382 U_CAPI UBool U_EXPORT2
uset_getSerializedSet(USerializedSet * fillSet,const uint16_t * src,int32_t srcLength)383 uset_getSerializedSet(USerializedSet* fillSet, const uint16_t* src, int32_t srcLength) {
384 int32_t length;
385
386 if(fillSet==nullptr) {
387 return false;
388 }
389 if(src==nullptr || srcLength<=0) {
390 fillSet->length=fillSet->bmpLength=0;
391 return false;
392 }
393
394 length=*src++;
395 if(length&0x8000) {
396 /* there are supplementary values */
397 length&=0x7fff;
398 if(srcLength<(2+length)) {
399 fillSet->length=fillSet->bmpLength=0;
400 return false;
401 }
402 fillSet->bmpLength=*src++;
403 } else {
404 /* only BMP values */
405 if(srcLength<(1+length)) {
406 fillSet->length=fillSet->bmpLength=0;
407 return false;
408 }
409 fillSet->bmpLength=length;
410 }
411 fillSet->array=src;
412 fillSet->length=length;
413 return true;
414 }
415
416 U_CAPI void U_EXPORT2
uset_setSerializedToOne(USerializedSet * fillSet,UChar32 c)417 uset_setSerializedToOne(USerializedSet* fillSet, UChar32 c) {
418 if(fillSet==nullptr || (uint32_t)c>0x10ffff) {
419 return;
420 }
421
422 fillSet->array=fillSet->staticArray;
423 if(c<0xffff) {
424 fillSet->bmpLength=fillSet->length=2;
425 fillSet->staticArray[0]=(uint16_t)c;
426 fillSet->staticArray[1]=(uint16_t)c+1;
427 } else if(c==0xffff) {
428 fillSet->bmpLength=1;
429 fillSet->length=3;
430 fillSet->staticArray[0]=0xffff;
431 fillSet->staticArray[1]=1;
432 fillSet->staticArray[2]=0;
433 } else if(c<0x10ffff) {
434 fillSet->bmpLength=0;
435 fillSet->length=4;
436 fillSet->staticArray[0]=(uint16_t)(c>>16);
437 fillSet->staticArray[1]=(uint16_t)c;
438 ++c;
439 fillSet->staticArray[2]=(uint16_t)(c>>16);
440 fillSet->staticArray[3]=(uint16_t)c;
441 } else /* c==0x10ffff */ {
442 fillSet->bmpLength=0;
443 fillSet->length=2;
444 fillSet->staticArray[0]=0x10;
445 fillSet->staticArray[1]=0xffff;
446 }
447 }
448
449 U_CAPI UBool U_EXPORT2
uset_serializedContains(const USerializedSet * set,UChar32 c)450 uset_serializedContains(const USerializedSet* set, UChar32 c) {
451 const uint16_t* array;
452
453 if(set==nullptr || (uint32_t)c>0x10ffff) {
454 return false;
455 }
456
457 array=set->array;
458 if(c<=0xffff) {
459 /* find c in the BMP part */
460 int32_t lo = 0;
461 int32_t hi = set->bmpLength-1;
462 if (c < array[0]) {
463 hi = 0;
464 } else if (c < array[hi]) {
465 for(;;) {
466 int32_t i = (lo + hi) >> 1;
467 if (i == lo) {
468 break; // Done!
469 } else if (c < array[i]) {
470 hi = i;
471 } else {
472 lo = i;
473 }
474 }
475 } else {
476 hi += 1;
477 }
478 return (UBool)(hi&1);
479 } else {
480 /* find c in the supplementary part */
481 uint16_t high=(uint16_t)(c>>16), low=(uint16_t)c;
482 int32_t base = set->bmpLength;
483 int32_t lo = 0;
484 int32_t hi = set->length - 2 - base;
485 if (high < array[base] || (high==array[base] && low<array[base+1])) {
486 hi = 0;
487 } else if (high < array[base+hi] || (high==array[base+hi] && low<array[base+hi+1])) {
488 for (;;) {
489 int32_t i = ((lo + hi) >> 1) & ~1; // Guarantee even result
490 int32_t iabs = i + base;
491 if (i == lo) {
492 break; // Done!
493 } else if (high < array[iabs] || (high==array[iabs] && low<array[iabs+1])) {
494 hi = i;
495 } else {
496 lo = i;
497 }
498 }
499 } else {
500 hi += 2;
501 }
502 /* count pairs of 16-bit units even per BMP and check if the number of pairs is odd */
503 return (UBool)(((hi+(base<<1))&2)!=0);
504 }
505 }
506
507 U_CAPI int32_t U_EXPORT2
uset_getSerializedRangeCount(const USerializedSet * set)508 uset_getSerializedRangeCount(const USerializedSet* set) {
509 if(set==nullptr) {
510 return 0;
511 }
512
513 return (set->bmpLength+(set->length-set->bmpLength)/2+1)/2;
514 }
515
516 U_CAPI UBool U_EXPORT2
uset_getSerializedRange(const USerializedSet * set,int32_t rangeIndex,UChar32 * pStart,UChar32 * pEnd)517 uset_getSerializedRange(const USerializedSet* set, int32_t rangeIndex,
518 UChar32* pStart, UChar32* pEnd) {
519 const uint16_t* array;
520 int32_t bmpLength, length;
521
522 if(set==nullptr || rangeIndex<0 || pStart==nullptr || pEnd==nullptr) {
523 return false;
524 }
525
526 array=set->array;
527 length=set->length;
528 bmpLength=set->bmpLength;
529
530 rangeIndex*=2; /* address start/limit pairs */
531 if(rangeIndex<bmpLength) {
532 *pStart=array[rangeIndex++];
533 if(rangeIndex<bmpLength) {
534 *pEnd=array[rangeIndex]-1;
535 } else if(rangeIndex<length) {
536 *pEnd=((((int32_t)array[rangeIndex])<<16)|array[rangeIndex+1])-1;
537 } else {
538 *pEnd=0x10ffff;
539 }
540 return true;
541 } else {
542 rangeIndex-=bmpLength;
543 rangeIndex*=2; /* address pairs of pairs of units */
544 length-=bmpLength;
545 if(rangeIndex<length) {
546 array+=bmpLength;
547 *pStart=(((int32_t)array[rangeIndex])<<16)|array[rangeIndex+1];
548 rangeIndex+=2;
549 if(rangeIndex<length) {
550 *pEnd=((((int32_t)array[rangeIndex])<<16)|array[rangeIndex+1])-1;
551 } else {
552 *pEnd=0x10ffff;
553 }
554 return true;
555 } else {
556 return false;
557 }
558 }
559 }
560
561 // TODO The old, internal uset.c had an efficient uset_containsOne function.
562 // Returned the one and only code point, or else -1 or something.
563 // Consider adding such a function to both C and C++ UnicodeSet/uset.
564 // See tools/gennorm/store.c for usage, now usetContainsOne there.
565
566 // TODO Investigate incorporating this code into UnicodeSet to improve
567 // efficiency.
568 // ---
569 // #define USET_GROW_DELTA 20
570 //
571 // static int32_t
572 // findChar(const UChar32* array, int32_t length, UChar32 c) {
573 // int32_t i;
574 //
575 // /* check the last range limit first for more efficient appending */
576 // if(length>0) {
577 // if(c>=array[length-1]) {
578 // return length;
579 // }
580 //
581 // /* do not check the last range limit again in the loop below */
582 // --length;
583 // }
584 //
585 // for(i=0; i<length && c>=array[i]; ++i) {}
586 // return i;
587 // }
588 //
589 // static UBool
590 // addRemove(USet* set, UChar32 c, int32_t doRemove) {
591 // int32_t i, length, more;
592 //
593 // if(set==nullptr || (uint32_t)c>0x10ffff) {
594 // return false;
595 // }
596 //
597 // length=set->length;
598 // i=findChar(set->array, length, c);
599 // if((i&1)^doRemove) {
600 // /* c is already in the set */
601 // return true;
602 // }
603 //
604 // /* how many more array items do we need? */
605 // if(i<length && (c+1)==set->array[i]) {
606 // /* c is just before the following range, extend that in-place by one */
607 // set->array[i]=c;
608 // if(i>0) {
609 // --i;
610 // if(c==set->array[i]) {
611 // /* the previous range collapsed, remove it */
612 // set->length=length-=2;
613 // if(i<length) {
614 // uprv_memmove(set->array+i, set->array+i+2, (length-i)*4);
615 // }
616 // }
617 // }
618 // return true;
619 // } else if(i>0 && c==set->array[i-1]) {
620 // /* c is just after the previous range, extend that in-place by one */
621 // if(++c<=0x10ffff) {
622 // set->array[i-1]=c;
623 // if(i<length && c==set->array[i]) {
624 // /* the following range collapsed, remove it */
625 // --i;
626 // set->length=length-=2;
627 // if(i<length) {
628 // uprv_memmove(set->array+i, set->array+i+2, (length-i)*4);
629 // }
630 // }
631 // } else {
632 // /* extend the previous range (had limit 0x10ffff) to the end of Unicode */
633 // set->length=i-1;
634 // }
635 // return true;
636 // } else if(i==length && c==0x10ffff) {
637 // /* insert one range limit c */
638 // more=1;
639 // } else {
640 // /* insert two range limits c, c+1 */
641 // more=2;
642 // }
643 //
644 // /* insert <more> range limits */
645 // if(length+more>set->capacity) {
646 // /* reallocate */
647 // int32_t newCapacity=set->capacity+set->capacity/2+USET_GROW_DELTA;
648 // UChar32* newArray=(UChar32* )uprv_malloc(newCapacity*4);
649 // if(newArray==nullptr) {
650 // return false;
651 // }
652 // set->capacity=newCapacity;
653 // uprv_memcpy(newArray, set->array, length*4);
654 //
655 // if(set->array!=set->staticBuffer) {
656 // uprv_free(set->array);
657 // }
658 // set->array=newArray;
659 // }
660 //
661 // if(i<length) {
662 // uprv_memmove(set->array+i+more, set->array+i, (length-i)*4);
663 // }
664 // set->array[i]=c;
665 // if(more==2) {
666 // set->array[i+1]=c+1;
667 // }
668 // set->length+=more;
669 //
670 // return true;
671 // }
672 //
673 // U_CAPI UBool U_EXPORT2
674 // uset_add(USet* set, UChar32 c) {
675 // return addRemove(set, c, 0);
676 // }
677 //
678 // U_CAPI void U_EXPORT2
679 // uset_remove(USet* set, UChar32 c) {
680 // addRemove(set, c, 1);
681 // }
682