1 // © 2017 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 
4 // ucptrie.h (modified from utrie2.h)
5 // created: 2017dec29 Markus W. Scherer
6 
7 #ifndef __UCPTRIE_H__
8 #define __UCPTRIE_H__
9 
10 #include "unicode/utypes.h"
11 
12 #include "unicode/localpointer.h"
13 #include "unicode/ucpmap.h"
14 #include "unicode/utf8.h"
15 
16 U_CDECL_BEGIN
17 
18 /**
19  * \file
20  *
21  * This file defines an immutable Unicode code point trie.
22  *
23  * @see UCPTrie
24  * @see UMutableCPTrie
25  */
26 
27 #ifndef U_IN_DOXYGEN
28 /** @internal */
29 typedef union UCPTrieData {
30     /** @internal */
31     const void *ptr0;
32     /** @internal */
33     const uint16_t *ptr16;
34     /** @internal */
35     const uint32_t *ptr32;
36     /** @internal */
37     const uint8_t *ptr8;
38 } UCPTrieData;
39 #endif
40 
41 /**
42  * Immutable Unicode code point trie structure.
43  * Fast, reasonably compact, map from Unicode code points (U+0000..U+10FFFF) to integer values.
44  * For details see http://site.icu-project.org/design/struct/utrie
45  *
46  * Do not access UCPTrie fields directly; use public functions and macros.
47  * Functions are easy to use: They support all trie types and value widths.
48  *
49  * When performance is really important, macros provide faster access.
50  * Most macros are specific to either "fast" or "small" tries, see UCPTrieType.
51  * There are "fast" macros for special optimized use cases.
52  *
53  * The macros will return bogus values, or may crash, if used on the wrong type or value width.
54  *
55  * @see UMutableCPTrie
56  * @stable ICU 63
57  */
58 struct UCPTrie {
59 #ifndef U_IN_DOXYGEN
60     /** @internal */
61     const uint16_t *index;
62     /** @internal */
63     UCPTrieData data;
64 
65     /** @internal */
66     int32_t indexLength;
67     /** @internal */
68     int32_t dataLength;
69     /** Start of the last range which ends at U+10FFFF. @internal */
70     UChar32 highStart;
71     /** highStart>>12 @internal */
72     uint16_t shifted12HighStart;
73 
74     /** @internal */
75     int8_t type;  // UCPTrieType
76     /** @internal */
77     int8_t valueWidth;  // UCPTrieValueWidth
78 
79     /** padding/reserved @internal */
80     uint32_t reserved32;
81     /** padding/reserved @internal */
82     uint16_t reserved16;
83 
84     /**
85      * Internal index-3 null block offset.
86      * Set to an impossibly high value (e.g., 0xffff) if there is no dedicated index-3 null block.
87      * @internal
88      */
89     uint16_t index3NullOffset;
90     /**
91      * Internal data null block offset, not shifted.
92      * Set to an impossibly high value (e.g., 0xfffff) if there is no dedicated data null block.
93      * @internal
94      */
95     int32_t dataNullOffset;
96     /** @internal */
97     uint32_t nullValue;
98 
99 #ifdef UCPTRIE_DEBUG
100     /** @internal */
101     const char *name;
102 #endif
103 #endif
104 };
105 #ifndef U_IN_DOXYGEN
106 typedef struct UCPTrie UCPTrie;
107 #endif
108 
109 /**
110  * Selectors for the type of a UCPTrie.
111  * Different trade-offs for size vs. speed.
112  *
113  * @see umutablecptrie_buildImmutable
114  * @see ucptrie_openFromBinary
115  * @see ucptrie_getType
116  * @stable ICU 63
117  */
118 enum UCPTrieType {
119     /**
120      * For ucptrie_openFromBinary() to accept any type.
121      * ucptrie_getType() will return the actual type.
122      * @stable ICU 63
123      */
124     UCPTRIE_TYPE_ANY = -1,
125     /**
126      * Fast/simple/larger BMP data structure. Use functions and "fast" macros.
127      * @stable ICU 63
128      */
129     UCPTRIE_TYPE_FAST,
130     /**
131      * Small/slower BMP data structure. Use functions and "small" macros.
132      * @stable ICU 63
133      */
134     UCPTRIE_TYPE_SMALL
135 };
136 #ifndef U_IN_DOXYGEN
137 typedef enum UCPTrieType UCPTrieType;
138 #endif
139 
140 /**
141  * Selectors for the number of bits in a UCPTrie data value.
142  *
143  * @see umutablecptrie_buildImmutable
144  * @see ucptrie_openFromBinary
145  * @see ucptrie_getValueWidth
146  * @stable ICU 63
147  */
148 enum UCPTrieValueWidth {
149     /**
150      * For ucptrie_openFromBinary() to accept any data value width.
151      * ucptrie_getValueWidth() will return the actual data value width.
152      * @stable ICU 63
153      */
154     UCPTRIE_VALUE_BITS_ANY = -1,
155     /**
156      * The trie stores 16 bits per data value.
157      * It returns them as unsigned values 0..0xffff=65535.
158      * @stable ICU 63
159      */
160     UCPTRIE_VALUE_BITS_16,
161     /**
162      * The trie stores 32 bits per data value.
163      * @stable ICU 63
164      */
165     UCPTRIE_VALUE_BITS_32,
166     /**
167      * The trie stores 8 bits per data value.
168      * It returns them as unsigned values 0..0xff=255.
169      * @stable ICU 63
170      */
171     UCPTRIE_VALUE_BITS_8
172 };
173 #ifndef U_IN_DOXYGEN
174 typedef enum UCPTrieValueWidth UCPTrieValueWidth;
175 #endif
176 
177 /**
178  * Opens a trie from its binary form, stored in 32-bit-aligned memory.
179  * Inverse of ucptrie_toBinary().
180  *
181  * The memory must remain valid and unchanged as long as the trie is used.
182  * You must ucptrie_close() the trie once you are done using it.
183  *
184  * @param type selects the trie type; results in an
185  *             U_INVALID_FORMAT_ERROR if it does not match the binary data;
186  *             use UCPTRIE_TYPE_ANY to accept any type
187  * @param valueWidth selects the number of bits in a data value; results in an
188  *                  U_INVALID_FORMAT_ERROR if it does not match the binary data;
189  *                  use UCPTRIE_VALUE_BITS_ANY to accept any data value width
190  * @param data a pointer to 32-bit-aligned memory containing the binary data of a UCPTrie
191  * @param length the number of bytes available at data;
192  *               can be more than necessary
193  * @param pActualLength receives the actual number of bytes at data taken up by the trie data;
194  *                      can be NULL
195  * @param pErrorCode an in/out ICU UErrorCode
196  * @return the trie
197  *
198  * @see umutablecptrie_open
199  * @see umutablecptrie_buildImmutable
200  * @see ucptrie_toBinary
201  * @stable ICU 63
202  */
203 U_CAPI UCPTrie * U_EXPORT2
204 ucptrie_openFromBinary(UCPTrieType type, UCPTrieValueWidth valueWidth,
205                        const void *data, int32_t length, int32_t *pActualLength,
206                        UErrorCode *pErrorCode);
207 
208 /**
209  * Closes a trie and releases associated memory.
210  *
211  * @param trie the trie
212  * @stable ICU 63
213  */
214 U_CAPI void U_EXPORT2
215 ucptrie_close(UCPTrie *trie);
216 
217 /**
218  * Returns the trie type.
219  *
220  * @param trie the trie
221  * @return the trie type
222  * @see ucptrie_openFromBinary
223  * @see UCPTRIE_TYPE_ANY
224  * @stable ICU 63
225  */
226 U_CAPI UCPTrieType U_EXPORT2
227 ucptrie_getType(const UCPTrie *trie);
228 
229 /**
230  * Returns the number of bits in a trie data value.
231  *
232  * @param trie the trie
233  * @return the number of bits in a trie data value
234  * @see ucptrie_openFromBinary
235  * @see UCPTRIE_VALUE_BITS_ANY
236  * @stable ICU 63
237  */
238 U_CAPI UCPTrieValueWidth U_EXPORT2
239 ucptrie_getValueWidth(const UCPTrie *trie);
240 
241 /**
242  * Returns the value for a code point as stored in the trie, with range checking.
243  * Returns the trie error value if c is not in the range 0..U+10FFFF.
244  *
245  * Easier to use than UCPTRIE_FAST_GET() and similar macros but slower.
246  * Easier to use because, unlike the macros, this function works on all UCPTrie
247  * objects, for all types and value widths.
248  *
249  * @param trie the trie
250  * @param c the code point
251  * @return the trie value,
252  *         or the trie error value if the code point is not in the range 0..U+10FFFF
253  * @stable ICU 63
254  */
255 U_CAPI uint32_t U_EXPORT2
256 ucptrie_get(const UCPTrie *trie, UChar32 c);
257 
258 /**
259  * Returns the last code point such that all those from start to there have the same value.
260  * Can be used to efficiently iterate over all same-value ranges in a trie.
261  * (This is normally faster than iterating over code points and get()ting each value,
262  * but much slower than a data structure that stores ranges directly.)
263  *
264  * If the UCPMapValueFilter function pointer is not NULL, then
265  * the value to be delivered is passed through that function, and the return value is the end
266  * of the range where all values are modified to the same actual value.
267  * The value is unchanged if that function pointer is NULL.
268  *
269  * Example:
270  * \code
271  * UChar32 start = 0, end;
272  * uint32_t value;
273  * while ((end = ucptrie_getRange(trie, start, UCPMAP_RANGE_NORMAL, 0,
274  *                                NULL, NULL, &value)) >= 0) {
275  *     // Work with the range start..end and its value.
276  *     start = end + 1;
277  * }
278  * \endcode
279  *
280  * @param trie the trie
281  * @param start range start
282  * @param option defines whether surrogates are treated normally,
283  *               or as having the surrogateValue; usually UCPMAP_RANGE_NORMAL
284  * @param surrogateValue value for surrogates; ignored if option==UCPMAP_RANGE_NORMAL
285  * @param filter a pointer to a function that may modify the trie data value,
286  *     or NULL if the values from the trie are to be used unmodified
287  * @param context an opaque pointer that is passed on to the filter function
288  * @param pValue if not NULL, receives the value that every code point start..end has;
289  *     may have been modified by filter(context, trie value)
290  *     if that function pointer is not NULL
291  * @return the range end code point, or -1 if start is not a valid code point
292  * @stable ICU 63
293  */
294 U_CAPI UChar32 U_EXPORT2
295 ucptrie_getRange(const UCPTrie *trie, UChar32 start,
296                  UCPMapRangeOption option, uint32_t surrogateValue,
297                  UCPMapValueFilter *filter, const void *context, uint32_t *pValue);
298 
299 /**
300  * Writes a memory-mappable form of the trie into 32-bit aligned memory.
301  * Inverse of ucptrie_openFromBinary().
302  *
303  * @param trie the trie
304  * @param data a pointer to 32-bit-aligned memory to be filled with the trie data;
305  *             can be NULL if capacity==0
306  * @param capacity the number of bytes available at data, or 0 for pure preflighting
307  * @param pErrorCode an in/out ICU UErrorCode;
308  *                   U_BUFFER_OVERFLOW_ERROR if the capacity is too small
309  * @return the number of bytes written or (if buffer overflow) needed for the trie
310  *
311  * @see ucptrie_openFromBinary()
312  * @stable ICU 63
313  */
314 U_CAPI int32_t U_EXPORT2
315 ucptrie_toBinary(const UCPTrie *trie, void *data, int32_t capacity, UErrorCode *pErrorCode);
316 
317 /**
318  * Macro parameter value for a trie with 16-bit data values.
319  * Use the name of this macro as a "dataAccess" parameter in other macros.
320  * Do not use this macro in any other way.
321  *
322  * @see UCPTRIE_VALUE_BITS_16
323  * @stable ICU 63
324  */
325 #define UCPTRIE_16(trie, i) ((trie)->data.ptr16[i])
326 
327 /**
328  * Macro parameter value for a trie with 32-bit data values.
329  * Use the name of this macro as a "dataAccess" parameter in other macros.
330  * Do not use this macro in any other way.
331  *
332  * @see UCPTRIE_VALUE_BITS_32
333  * @stable ICU 63
334  */
335 #define UCPTRIE_32(trie, i) ((trie)->data.ptr32[i])
336 
337 /**
338  * Macro parameter value for a trie with 8-bit data values.
339  * Use the name of this macro as a "dataAccess" parameter in other macros.
340  * Do not use this macro in any other way.
341  *
342  * @see UCPTRIE_VALUE_BITS_8
343  * @stable ICU 63
344  */
345 #define UCPTRIE_8(trie, i) ((trie)->data.ptr8[i])
346 
347 /**
348  * Returns a trie value for a code point, with range checking.
349  * Returns the trie error value if c is not in the range 0..U+10FFFF.
350  *
351  * @param trie (const UCPTrie *, in) the trie; must have type UCPTRIE_TYPE_FAST
352  * @param dataAccess UCPTRIE_16, UCPTRIE_32, or UCPTRIE_8 according to the trie’s value width
353  * @param c (UChar32, in) the input code point
354  * @return The code point's trie value.
355  * @stable ICU 63
356  */
357 #define UCPTRIE_FAST_GET(trie, dataAccess, c) dataAccess(trie, _UCPTRIE_CP_INDEX(trie, 0xffff, c))
358 
359 /**
360  * Returns a 16-bit trie value for a code point, with range checking.
361  * Returns the trie error value if c is not in the range U+0000..U+10FFFF.
362  *
363  * @param trie (const UCPTrie *, in) the trie; must have type UCPTRIE_TYPE_SMALL
364  * @param dataAccess UCPTRIE_16, UCPTRIE_32, or UCPTRIE_8 according to the trie’s value width
365  * @param c (UChar32, in) the input code point
366  * @return The code point's trie value.
367  * @stable ICU 63
368  */
369 #define UCPTRIE_SMALL_GET(trie, dataAccess, c) \
370     dataAccess(trie, _UCPTRIE_CP_INDEX(trie, UCPTRIE_SMALL_MAX, c))
371 
372 /**
373  * UTF-16: Reads the next code point (UChar32 c, out), post-increments src,
374  * and gets a value from the trie.
375  * Sets the trie error value if c is an unpaired surrogate.
376  *
377  * @param trie (const UCPTrie *, in) the trie; must have type UCPTRIE_TYPE_FAST
378  * @param dataAccess UCPTRIE_16, UCPTRIE_32, or UCPTRIE_8 according to the trie’s value width
379  * @param src (const UChar *, in/out) the source text pointer
380  * @param limit (const UChar *, in) the limit pointer for the text, or NULL if NUL-terminated
381  * @param c (UChar32, out) variable for the code point
382  * @param result (out) variable for the trie lookup result
383  * @stable ICU 63
384  */
385 #define UCPTRIE_FAST_U16_NEXT(trie, dataAccess, src, limit, c, result) UPRV_BLOCK_MACRO_BEGIN { \
386     (c) = *(src)++; \
387     int32_t __index; \
388     if (!U16_IS_SURROGATE(c)) { \
389         __index = _UCPTRIE_FAST_INDEX(trie, c); \
390     } else { \
391         uint16_t __c2; \
392         if (U16_IS_SURROGATE_LEAD(c) && (src) != (limit) && U16_IS_TRAIL(__c2 = *(src))) { \
393             ++(src); \
394             (c) = U16_GET_SUPPLEMENTARY((c), __c2); \
395             __index = _UCPTRIE_SMALL_INDEX(trie, c); \
396         } else { \
397             __index = (trie)->dataLength - UCPTRIE_ERROR_VALUE_NEG_DATA_OFFSET; \
398         } \
399     } \
400     (result) = dataAccess(trie, __index); \
401 } UPRV_BLOCK_MACRO_END
402 
403 /**
404  * UTF-16: Reads the previous code point (UChar32 c, out), pre-decrements src,
405  * and gets a value from the trie.
406  * Sets the trie error value if c is an unpaired surrogate.
407  *
408  * @param trie (const UCPTrie *, in) the trie; must have type UCPTRIE_TYPE_FAST
409  * @param dataAccess UCPTRIE_16, UCPTRIE_32, or UCPTRIE_8 according to the trie’s value width
410  * @param start (const UChar *, in) the start pointer for the text
411  * @param src (const UChar *, in/out) the source text pointer
412  * @param c (UChar32, out) variable for the code point
413  * @param result (out) variable for the trie lookup result
414  * @stable ICU 63
415  */
416 #define UCPTRIE_FAST_U16_PREV(trie, dataAccess, start, src, c, result) UPRV_BLOCK_MACRO_BEGIN { \
417     (c) = *--(src); \
418     int32_t __index; \
419     if (!U16_IS_SURROGATE(c)) { \
420         __index = _UCPTRIE_FAST_INDEX(trie, c); \
421     } else { \
422         uint16_t __c2; \
423         if (U16_IS_SURROGATE_TRAIL(c) && (src) != (start) && U16_IS_LEAD(__c2 = *((src) - 1))) { \
424             --(src); \
425             (c) = U16_GET_SUPPLEMENTARY(__c2, (c)); \
426             __index = _UCPTRIE_SMALL_INDEX(trie, c); \
427         } else { \
428             __index = (trie)->dataLength - UCPTRIE_ERROR_VALUE_NEG_DATA_OFFSET; \
429         } \
430     } \
431     (result) = dataAccess(trie, __index); \
432 } UPRV_BLOCK_MACRO_END
433 
434 /**
435  * UTF-8: Post-increments src and gets a value from the trie.
436  * Sets the trie error value for an ill-formed byte sequence.
437  *
438  * Unlike UCPTRIE_FAST_U16_NEXT() this UTF-8 macro does not provide the code point
439  * because it would be more work to do so and is often not needed.
440  * If the trie value differs from the error value, then the byte sequence is well-formed,
441  * and the code point can be assembled without revalidation.
442  *
443  * @param trie (const UCPTrie *, in) the trie; must have type UCPTRIE_TYPE_FAST
444  * @param dataAccess UCPTRIE_16, UCPTRIE_32, or UCPTRIE_8 according to the trie’s value width
445  * @param src (const char *, in/out) the source text pointer
446  * @param limit (const char *, in) the limit pointer for the text (must not be NULL)
447  * @param result (out) variable for the trie lookup result
448  * @stable ICU 63
449  */
450 #define UCPTRIE_FAST_U8_NEXT(trie, dataAccess, src, limit, result) UPRV_BLOCK_MACRO_BEGIN { \
451     int32_t __lead = (uint8_t)*(src)++; \
452     if (!U8_IS_SINGLE(__lead)) { \
453         uint8_t __t1, __t2, __t3; \
454         if ((src) != (limit) && \
455             (__lead >= 0xe0 ? \
456                 __lead < 0xf0 ?  /* U+0800..U+FFFF except surrogates */ \
457                     U8_LEAD3_T1_BITS[__lead &= 0xf] & (1 << ((__t1 = *(src)) >> 5)) && \
458                     ++(src) != (limit) && (__t2 = *(src) - 0x80) <= 0x3f && \
459                     (__lead = ((int32_t)(trie)->index[(__lead << 6) + (__t1 & 0x3f)]) + __t2, 1) \
460                 :  /* U+10000..U+10FFFF */ \
461                     (__lead -= 0xf0) <= 4 && \
462                     U8_LEAD4_T1_BITS[(__t1 = *(src)) >> 4] & (1 << __lead) && \
463                     (__lead = (__lead << 6) | (__t1 & 0x3f), ++(src) != (limit)) && \
464                     (__t2 = *(src) - 0x80) <= 0x3f && \
465                     ++(src) != (limit) && (__t3 = *(src) - 0x80) <= 0x3f && \
466                     (__lead = __lead >= (trie)->shifted12HighStart ? \
467                         (trie)->dataLength - UCPTRIE_HIGH_VALUE_NEG_DATA_OFFSET : \
468                         ucptrie_internalSmallU8Index((trie), __lead, __t2, __t3), 1) \
469             :  /* U+0080..U+07FF */ \
470                 __lead >= 0xc2 && (__t1 = *(src) - 0x80) <= 0x3f && \
471                 (__lead = (int32_t)(trie)->index[__lead & 0x1f] + __t1, 1))) { \
472             ++(src); \
473         } else { \
474             __lead = (trie)->dataLength - UCPTRIE_ERROR_VALUE_NEG_DATA_OFFSET;  /* ill-formed*/ \
475         } \
476     } \
477     (result) = dataAccess(trie, __lead); \
478 } UPRV_BLOCK_MACRO_END
479 
480 /**
481  * UTF-8: Pre-decrements src and gets a value from the trie.
482  * Sets the trie error value for an ill-formed byte sequence.
483  *
484  * Unlike UCPTRIE_FAST_U16_PREV() this UTF-8 macro does not provide the code point
485  * because it would be more work to do so and is often not needed.
486  * If the trie value differs from the error value, then the byte sequence is well-formed,
487  * and the code point can be assembled without revalidation.
488  *
489  * @param trie (const UCPTrie *, in) the trie; must have type UCPTRIE_TYPE_FAST
490  * @param dataAccess UCPTRIE_16, UCPTRIE_32, or UCPTRIE_8 according to the trie’s value width
491  * @param start (const char *, in) the start pointer for the text
492  * @param src (const char *, in/out) the source text pointer
493  * @param result (out) variable for the trie lookup result
494  * @stable ICU 63
495  */
496 #define UCPTRIE_FAST_U8_PREV(trie, dataAccess, start, src, result) UPRV_BLOCK_MACRO_BEGIN { \
497     int32_t __index = (uint8_t)*--(src); \
498     if (!U8_IS_SINGLE(__index)) { \
499         __index = ucptrie_internalU8PrevIndex((trie), __index, (const uint8_t *)(start), \
500                                               (const uint8_t *)(src)); \
501         (src) -= __index & 7; \
502         __index >>= 3; \
503     } \
504     (result) = dataAccess(trie, __index); \
505 } UPRV_BLOCK_MACRO_END
506 
507 /**
508  * Returns a trie value for an ASCII code point, without range checking.
509  *
510  * @param trie (const UCPTrie *, in) the trie (of either fast or small type)
511  * @param dataAccess UCPTRIE_16, UCPTRIE_32, or UCPTRIE_8 according to the trie’s value width
512  * @param c (UChar32, in) the input code point; must be U+0000..U+007F
513  * @return The ASCII code point's trie value.
514  * @stable ICU 63
515  */
516 #define UCPTRIE_ASCII_GET(trie, dataAccess, c) dataAccess(trie, c)
517 
518 /**
519  * Returns a trie value for a BMP code point (U+0000..U+FFFF), without range checking.
520  * Can be used to look up a value for a UTF-16 code unit if other parts of
521  * the string processing check for surrogates.
522  *
523  * @param trie (const UCPTrie *, in) the trie; must have type UCPTRIE_TYPE_FAST
524  * @param dataAccess UCPTRIE_16, UCPTRIE_32, or UCPTRIE_8 according to the trie’s value width
525  * @param c (UChar32, in) the input code point, must be U+0000..U+FFFF
526  * @return The BMP code point's trie value.
527  * @stable ICU 63
528  */
529 #define UCPTRIE_FAST_BMP_GET(trie, dataAccess, c) dataAccess(trie, _UCPTRIE_FAST_INDEX(trie, c))
530 
531 /**
532  * Returns a trie value for a supplementary code point (U+10000..U+10FFFF),
533  * without range checking.
534  *
535  * @param trie (const UCPTrie *, in) the trie; must have type UCPTRIE_TYPE_FAST
536  * @param dataAccess UCPTRIE_16, UCPTRIE_32, or UCPTRIE_8 according to the trie’s value width
537  * @param c (UChar32, in) the input code point, must be U+10000..U+10FFFF
538  * @return The supplementary code point's trie value.
539  * @stable ICU 63
540  */
541 #define UCPTRIE_FAST_SUPP_GET(trie, dataAccess, c) dataAccess(trie, _UCPTRIE_SMALL_INDEX(trie, c))
542 
543 /* Internal definitions ----------------------------------------------------- */
544 
545 #ifndef U_IN_DOXYGEN
546 
547 /**
548  * Internal implementation constants.
549  * These are needed for the API macros, but users should not use these directly.
550  * @internal
551  */
552 enum {
553     /** @internal */
554     UCPTRIE_FAST_SHIFT = 6,
555 
556     /** Number of entries in a data block for code points below the fast limit. 64=0x40 @internal */
557     UCPTRIE_FAST_DATA_BLOCK_LENGTH = 1 << UCPTRIE_FAST_SHIFT,
558 
559     /** Mask for getting the lower bits for the in-fast-data-block offset. @internal */
560     UCPTRIE_FAST_DATA_MASK = UCPTRIE_FAST_DATA_BLOCK_LENGTH - 1,
561 
562     /** @internal */
563     UCPTRIE_SMALL_MAX = 0xfff,
564 
565     /**
566      * Offset from dataLength (to be subtracted) for fetching the
567      * value returned for out-of-range code points and ill-formed UTF-8/16.
568      * @internal
569      */
570     UCPTRIE_ERROR_VALUE_NEG_DATA_OFFSET = 1,
571     /**
572      * Offset from dataLength (to be subtracted) for fetching the
573      * value returned for code points highStart..U+10FFFF.
574      * @internal
575      */
576     UCPTRIE_HIGH_VALUE_NEG_DATA_OFFSET = 2
577 };
578 
579 /* Internal functions and macros -------------------------------------------- */
580 // Do not conditionalize with #ifndef U_HIDE_INTERNAL_API, needed for public API
581 
582 /** @internal */
583 U_INTERNAL int32_t U_EXPORT2
584 ucptrie_internalSmallIndex(const UCPTrie *trie, UChar32 c);
585 
586 /** @internal */
587 U_INTERNAL int32_t U_EXPORT2
588 ucptrie_internalSmallU8Index(const UCPTrie *trie, int32_t lt1, uint8_t t2, uint8_t t3);
589 
590 /**
591  * Internal function for part of the UCPTRIE_FAST_U8_PREVxx() macro implementations.
592  * Do not call directly.
593  * @internal
594  */
595 U_INTERNAL int32_t U_EXPORT2
596 ucptrie_internalU8PrevIndex(const UCPTrie *trie, UChar32 c,
597                             const uint8_t *start, const uint8_t *src);
598 
599 /** Internal trie getter for a code point below the fast limit. Returns the data index. @internal */
600 #define _UCPTRIE_FAST_INDEX(trie, c) \
601     ((int32_t)(trie)->index[(c) >> UCPTRIE_FAST_SHIFT] + ((c) & UCPTRIE_FAST_DATA_MASK))
602 
603 /** Internal trie getter for a code point at or above the fast limit. Returns the data index. @internal */
604 #define _UCPTRIE_SMALL_INDEX(trie, c) \
605     ((c) >= (trie)->highStart ? \
606         (trie)->dataLength - UCPTRIE_HIGH_VALUE_NEG_DATA_OFFSET : \
607         ucptrie_internalSmallIndex(trie, c))
608 
609 /**
610  * Internal trie getter for a code point, with checking that c is in U+0000..10FFFF.
611  * Returns the data index.
612  * @internal
613  */
614 #define _UCPTRIE_CP_INDEX(trie, fastMax, c) \
615     ((uint32_t)(c) <= (uint32_t)(fastMax) ? \
616         _UCPTRIE_FAST_INDEX(trie, c) : \
617         (uint32_t)(c) <= 0x10ffff ? \
618             _UCPTRIE_SMALL_INDEX(trie, c) : \
619             (trie)->dataLength - UCPTRIE_ERROR_VALUE_NEG_DATA_OFFSET)
620 
621 U_CDECL_END
622 
623 #endif  // U_IN_DOXYGEN
624 
625 #if U_SHOW_CPLUSPLUS_API
626 
627 U_NAMESPACE_BEGIN
628 
629 /**
630  * \class LocalUCPTriePointer
631  * "Smart pointer" class, closes a UCPTrie via ucptrie_close().
632  * For most methods see the LocalPointerBase base class.
633  *
634  * @see LocalPointerBase
635  * @see LocalPointer
636  * @stable ICU 63
637  */
638 U_DEFINE_LOCAL_OPEN_POINTER(LocalUCPTriePointer, UCPTrie, ucptrie_close);
639 
640 U_NAMESPACE_END
641 
642 #endif  // U_SHOW_CPLUSPLUS_API
643 
644 #endif
645