xref: /aosp_15_r20/external/cronet/third_party/icu/source/common/uniset_closure.cpp (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
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) 2011, International Business Machines
7 *   Corporation and others.  All Rights Reserved.
8 *
9 *******************************************************************************
10 *   file name:  uniset_closure.cpp
11 *   encoding:   UTF-8
12 *   tab size:   8 (not used)
13 *   indentation:4
14 *
15 *   created on: 2011may30
16 *   created by: Markus W. Scherer
17 *
18 *   UnicodeSet::closeOver() and related methods moved here from uniset_props.cpp
19 *   to simplify dependencies.
20 *   In particular, this depends on the BreakIterator, but the BreakIterator
21 *   code also builds UnicodeSets from patterns and needs uniset_props.
22 */
23 
24 #include "unicode/brkiter.h"
25 #include "unicode/locid.h"
26 #include "unicode/parsepos.h"
27 #include "unicode/uniset.h"
28 #include "unicode/utf16.h"
29 #include "cmemory.h"
30 #include "ruleiter.h"
31 #include "ucase.h"
32 #include "uprops.h"
33 #include "util.h"
34 #include "uvector.h"
35 
36 U_NAMESPACE_BEGIN
37 
38 // TODO memory debugging provided inside uniset.cpp
39 // could be made available here but probably obsolete with use of modern
40 // memory leak checker tools
41 #define _dbgct(me)
42 
43 //----------------------------------------------------------------
44 // Constructors &c
45 //----------------------------------------------------------------
46 
UnicodeSet(const UnicodeString & pattern,uint32_t options,const SymbolTable * symbols,UErrorCode & status)47 UnicodeSet::UnicodeSet(const UnicodeString& pattern,
48                        uint32_t options,
49                        const SymbolTable* symbols,
50                        UErrorCode& status) {
51     applyPattern(pattern, options, symbols, status);
52     _dbgct(this);
53 }
54 
UnicodeSet(const UnicodeString & pattern,ParsePosition & pos,uint32_t options,const SymbolTable * symbols,UErrorCode & status)55 UnicodeSet::UnicodeSet(const UnicodeString& pattern, ParsePosition& pos,
56                        uint32_t options,
57                        const SymbolTable* symbols,
58                        UErrorCode& status) {
59     applyPattern(pattern, pos, options, symbols, status);
60     _dbgct(this);
61 }
62 
63 //----------------------------------------------------------------
64 // Public API
65 //----------------------------------------------------------------
66 
applyPattern(const UnicodeString & pattern,uint32_t options,const SymbolTable * symbols,UErrorCode & status)67 UnicodeSet& UnicodeSet::applyPattern(const UnicodeString& pattern,
68                                      uint32_t options,
69                                      const SymbolTable* symbols,
70                                      UErrorCode& status) {
71     ParsePosition pos(0);
72     applyPattern(pattern, pos, options, symbols, status);
73     if (U_FAILURE(status)) return *this;
74 
75     int32_t i = pos.getIndex();
76 
77     if (options & USET_IGNORE_SPACE) {
78         // Skip over trailing whitespace
79         ICU_Utility::skipWhitespace(pattern, i, true);
80     }
81 
82     if (i != pattern.length()) {
83         status = U_ILLEGAL_ARGUMENT_ERROR;
84     }
85     return *this;
86 }
87 
applyPattern(const UnicodeString & pattern,ParsePosition & pos,uint32_t options,const SymbolTable * symbols,UErrorCode & status)88 UnicodeSet& UnicodeSet::applyPattern(const UnicodeString& pattern,
89                               ParsePosition& pos,
90                               uint32_t options,
91                               const SymbolTable* symbols,
92                               UErrorCode& status) {
93     if (U_FAILURE(status)) {
94         return *this;
95     }
96     if (isFrozen()) {
97         status = U_NO_WRITE_PERMISSION;
98         return *this;
99     }
100     // Need to build the pattern in a temporary string because
101     // _applyPattern calls add() etc., which set pat to empty.
102     UnicodeString rebuiltPat;
103     RuleCharacterIterator chars(pattern, symbols, pos);
104     applyPattern(chars, symbols, rebuiltPat, options, &UnicodeSet::closeOver, 0, status);
105     if (U_FAILURE(status)) return *this;
106     if (chars.inVariable()) {
107         // syntaxError(chars, "Extra chars in variable value");
108         status = U_MALFORMED_SET;
109         return *this;
110     }
111     setPattern(rebuiltPat);
112     return *this;
113 }
114 
115 // USetAdder implementation
116 // Does not use uset.h to reduce code dependencies
117 static void U_CALLCONV
_set_add(USet * set,UChar32 c)118 _set_add(USet *set, UChar32 c) {
119     ((UnicodeSet *)set)->add(c);
120 }
121 
122 static void U_CALLCONV
_set_addRange(USet * set,UChar32 start,UChar32 end)123 _set_addRange(USet *set, UChar32 start, UChar32 end) {
124     ((UnicodeSet *)set)->add(start, end);
125 }
126 
127 static void U_CALLCONV
_set_addString(USet * set,const char16_t * str,int32_t length)128 _set_addString(USet *set, const char16_t *str, int32_t length) {
129     ((UnicodeSet *)set)->add(UnicodeString((UBool)(length<0), str, length));
130 }
131 
132 //----------------------------------------------------------------
133 // Case folding API
134 //----------------------------------------------------------------
135 
136 // add the result of a full case mapping to the set
137 // use str as a temporary string to avoid constructing one
138 static inline void
addCaseMapping(UnicodeSet & set,int32_t result,const char16_t * full,UnicodeString & str)139 addCaseMapping(UnicodeSet &set, int32_t result, const char16_t *full, UnicodeString &str) {
140     if(result >= 0) {
141         if(result > UCASE_MAX_STRING_LENGTH) {
142             // add a single-code point case mapping
143             set.add(result);
144         } else {
145             // add a string case mapping from full with length result
146             str.setTo((UBool)false, full, result);
147             set.add(str);
148         }
149     }
150     // result < 0: the code point mapped to itself, no need to add it
151     // see ucase.h
152 }
153 
154 namespace {
155 
156 /** For case closure on a large set, look only at code points with relevant properties. */
maybeOnlyCaseSensitive(const UnicodeSet & src,UnicodeSet & subset)157 const UnicodeSet &maybeOnlyCaseSensitive(const UnicodeSet &src, UnicodeSet &subset) {
158     // The subset must have been constructed with all code points,
159     // so that the retainAll() intersection effectively copies all single code points from src.
160     U_ASSERT(subset.contains(0, 0x10ffff));
161     if (src.size() < 30) {
162         return src;
163     }
164     // Return the intersection of the src code points with Case_Sensitive ones.
165     UErrorCode errorCode = U_ZERO_ERROR;
166     const UnicodeSet *sensitive =
167         CharacterProperties::getBinaryPropertySet(UCHAR_CASE_SENSITIVE, errorCode);
168     if (U_FAILURE(errorCode)) {
169         return src;
170     }
171     // Start by copying the "smaller" set.
172     // (We "copy" by intersecting all Unicode *code points* with the first set,
173     // which omits any strings.)
174     if (src.getRangeCount() > sensitive->getRangeCount()) {
175         subset.retainAll(*sensitive);
176         subset.retainAll(src);
177     } else {
178         subset.retainAll(src);
179         subset.retainAll(*sensitive);
180     }
181     return subset;
182 }
183 
184 // Per-character scf = Simple_Case_Folding of a string.
185 // (Normally when we case-fold a string we use full case foldings.)
scfString(const UnicodeString & s,UnicodeString & scf)186 bool scfString(const UnicodeString &s, UnicodeString &scf) {
187     // Iterate over the raw buffer for best performance.
188     const char16_t *p = s.getBuffer();
189     int32_t length = s.length();
190     // Loop while not needing modification.
191     for (int32_t i = 0; i < length;) {
192         UChar32 c;
193         U16_NEXT(p, i, length, c);  // post-increments i
194         UChar32 scfChar = u_foldCase(c, U_FOLD_CASE_DEFAULT);
195         if (scfChar != c) {
196             // Copy the characters before c.
197             scf.setTo(p, i - U16_LENGTH(c));
198             // Loop over the rest of the string and keep case-folding.
199             for (;;) {
200                 scf.append(scfChar);
201                 if (i == length) {
202                     return true;
203                 }
204                 U16_NEXT(p, i, length, c);  // post-increments i
205                 scfChar = u_foldCase(c, U_FOLD_CASE_DEFAULT);
206             }
207         }
208     }
209     return false;
210 }
211 
212 }  // namespace
213 
closeOver(int32_t attribute)214 UnicodeSet& UnicodeSet::closeOver(int32_t attribute) {
215     if (isFrozen() || isBogus()) {
216         return *this;
217     }
218     switch (attribute & USET_CASE_MASK) {
219     case 0:
220         break;
221     case USET_CASE_INSENSITIVE:
222         closeOverCaseInsensitive(/* simple= */ false);
223         break;
224     case USET_ADD_CASE_MAPPINGS:
225         closeOverAddCaseMappings();
226         break;
227     case USET_SIMPLE_CASE_INSENSITIVE:
228         closeOverCaseInsensitive(/* simple= */ true);
229         break;
230     default:
231         // bad option (unreachable)
232         break;
233     }
234     return *this;
235 }
236 
closeOverCaseInsensitive(bool simple)237 void UnicodeSet::closeOverCaseInsensitive(bool simple) {
238     // Start with input set to guarantee inclusion.
239     UnicodeSet foldSet(*this);
240     // Full case mappings closure:
241     // Remove strings because the strings will actually be reduced (folded);
242     // therefore, start with no strings and add only those needed.
243     // Do this before processing code points, because they may add strings.
244     if (!simple && foldSet.hasStrings()) {
245         foldSet.strings->removeAllElements();
246     }
247 
248     USetAdder sa = {
249         foldSet.toUSet(),
250         _set_add,
251         _set_addRange,
252         _set_addString,
253         nullptr, // don't need remove()
254         nullptr // don't need removeRange()
255     };
256 
257     UnicodeSet subset(0, 0x10ffff);
258     const UnicodeSet &codePoints = maybeOnlyCaseSensitive(*this, subset);
259 
260     // Iterate over the ranges of single code points. Nested loop for each code point.
261     int32_t n = codePoints.getRangeCount();
262 
263     for (int32_t i=0; i<n; ++i) {
264         UChar32 start = codePoints.getRangeStart(i);
265         UChar32 end   = codePoints.getRangeEnd(i);
266 
267         if (simple) {
268             for (UChar32 cp=start; cp<=end; ++cp) {
269                 ucase_addSimpleCaseClosure(cp, &sa);
270             }
271         } else {
272             for (UChar32 cp=start; cp<=end; ++cp) {
273                 ucase_addCaseClosure(cp, &sa);
274             }
275         }
276     }
277     if (hasStrings()) {
278         UnicodeString str;
279         for (int32_t j=0; j<strings->size(); ++j) {
280             const UnicodeString *pStr = (const UnicodeString *) strings->elementAt(j);
281             if (simple) {
282                 if (scfString(*pStr, str)) {
283                     foldSet.remove(*pStr).add(str);
284                 }
285             } else {
286                 str = *pStr;
287                 str.foldCase();
288                 if(!ucase_addStringCaseClosure(str.getBuffer(), str.length(), &sa)) {
289                     foldSet.add(str); // does not map to code points: add the folded string itself
290                 }
291             }
292         }
293     }
294     *this = foldSet;
295 }
296 
closeOverAddCaseMappings()297 void UnicodeSet::closeOverAddCaseMappings() {
298     // Start with input set to guarantee inclusion.
299     UnicodeSet foldSet(*this);
300 
301     UnicodeSet subset(0, 0x10ffff);
302     const UnicodeSet &codePoints = maybeOnlyCaseSensitive(*this, subset);
303 
304     // Iterate over the ranges of single code points. Nested loop for each code point.
305     int32_t n = codePoints.getRangeCount();
306     UChar32 result;
307     const char16_t *full;
308     UnicodeString str;
309 
310     for (int32_t i=0; i<n; ++i) {
311         UChar32 start = codePoints.getRangeStart(i);
312         UChar32 end   = codePoints.getRangeEnd(i);
313 
314         // add case mappings
315         // (does not add long s for regular s, or Kelvin for k, for example)
316         for (UChar32 cp=start; cp<=end; ++cp) {
317             result = ucase_toFullLower(cp, nullptr, nullptr, &full, UCASE_LOC_ROOT);
318             addCaseMapping(foldSet, result, full, str);
319 
320             result = ucase_toFullTitle(cp, nullptr, nullptr, &full, UCASE_LOC_ROOT);
321             addCaseMapping(foldSet, result, full, str);
322 
323             result = ucase_toFullUpper(cp, nullptr, nullptr, &full, UCASE_LOC_ROOT);
324             addCaseMapping(foldSet, result, full, str);
325 
326             result = ucase_toFullFolding(cp, &full, 0);
327             addCaseMapping(foldSet, result, full, str);
328         }
329     }
330     if (hasStrings()) {
331         Locale root("");
332 #if !UCONFIG_NO_BREAK_ITERATION
333         UErrorCode status = U_ZERO_ERROR;
334         BreakIterator *bi = BreakIterator::createWordInstance(root, status);
335         if (U_SUCCESS(status)) {
336 #endif
337             for (int32_t j=0; j<strings->size(); ++j) {
338                 const UnicodeString *pStr = (const UnicodeString *) strings->elementAt(j);
339                 (str = *pStr).toLower(root);
340                 foldSet.add(str);
341 #if !UCONFIG_NO_BREAK_ITERATION
342                 (str = *pStr).toTitle(bi, root);
343                 foldSet.add(str);
344 #endif
345                 (str = *pStr).toUpper(root);
346                 foldSet.add(str);
347                 (str = *pStr).foldCase();
348                 foldSet.add(str);
349             }
350 #if !UCONFIG_NO_BREAK_ITERATION
351         }
352         delete bi;
353 #endif
354     }
355     *this = foldSet;
356 }
357 
358 U_NAMESPACE_END
359