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intl/icu/source/common/unormimp.h

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1 /*
2 *******************************************************************************
3 *
4 * Copyright (C) 2001-2011, International Business Machines
5 * Corporation and others. All Rights Reserved.
6 *
7 *******************************************************************************
8 * file name: unormimp.h
9 * encoding: US-ASCII
10 * tab size: 8 (not used)
11 * indentation:4
12 *
13 * created on: 2001may25
14 * created by: Markus W. Scherer
15 */
16
17 #ifndef __UNORMIMP_H__
18 #define __UNORMIMP_H__
19
20 #include "unicode/utypes.h"
21
22 #if !UCONFIG_NO_NORMALIZATION
23
24 #include "udataswp.h"
25
26 /*
27 * The 2001-2010 implementation of the normalization code loads its data from
28 * unorm.icu, which is generated with the gennorm tool.
29 * The format of that file is described at the end of this file.
30 */
31
32 /* norm32 value constants */
33 enum {
34 /* quick check flags 0..3 set mean "no" for their forms */
35 _NORM_QC_NFC=0x11, /* no|maybe */
36 _NORM_QC_NFKC=0x22, /* no|maybe */
37 _NORM_QC_NFD=4, /* no */
38 _NORM_QC_NFKD=8, /* no */
39
40 _NORM_QC_ANY_NO=0xf,
41
42 /* quick check flags 4..5 mean "maybe" for their forms; test flags>=_NORM_QC_MAYBE */
43 _NORM_QC_MAYBE=0x10,
44 _NORM_QC_ANY_MAYBE=0x30,
45
46 _NORM_QC_MASK=0x3f,
47
48 _NORM_COMBINES_FWD=0x40,
49 _NORM_COMBINES_BACK=0x80,
50 _NORM_COMBINES_ANY=0xc0,
51
52 _NORM_CC_SHIFT=8, /* UnicodeData.txt combining class in bits 15..8 */
53 _NORM_CC_MASK=0xff00,
54
55 _NORM_EXTRA_SHIFT=16, /* 16 bits for the index to UChars and other extra data */
56 _NORM_EXTRA_INDEX_TOP=0xfc00, /* start of surrogate specials after shift */
57
58 _NORM_EXTRA_SURROGATE_MASK=0x3ff,
59 _NORM_EXTRA_SURROGATE_TOP=0x3f0, /* hangul etc. */
60
61 _NORM_EXTRA_HANGUL=_NORM_EXTRA_SURROGATE_TOP,
62 _NORM_EXTRA_JAMO_L,
63 _NORM_EXTRA_JAMO_V,
64 _NORM_EXTRA_JAMO_T
65 };
66
67 /* norm32 value constants using >16 bits */
68 #define _NORM_MIN_SPECIAL 0xfc000000
69 #define _NORM_SURROGATES_TOP 0xfff00000
70 #define _NORM_MIN_HANGUL 0xfff00000
71 #define _NORM_MIN_JAMO_V 0xfff20000
72 #define _NORM_JAMO_V_TOP 0xfff30000
73
74 /* value constants for auxTrie */
75 enum {
76 _NORM_AUX_COMP_EX_SHIFT=10,
77 _NORM_AUX_UNSAFE_SHIFT=11,
78 _NORM_AUX_NFC_SKIPPABLE_F_SHIFT=12
79 };
80
81 #define _NORM_AUX_MAX_FNC ((int32_t)1<<_NORM_AUX_COMP_EX_SHIFT)
82
83 #define _NORM_AUX_FNC_MASK (uint32_t)(_NORM_AUX_MAX_FNC-1)
84 #define _NORM_AUX_COMP_EX_MASK ((uint32_t)1<<_NORM_AUX_COMP_EX_SHIFT)
85 #define _NORM_AUX_UNSAFE_MASK ((uint32_t)1<<_NORM_AUX_UNSAFE_SHIFT)
86 #define _NORM_AUX_NFC_SKIP_F_MASK ((uint32_t)1<<_NORM_AUX_NFC_SKIPPABLE_F_SHIFT)
87
88 /* canonStartSets[0..31] contains indexes for what is in the array */
89 enum {
90 _NORM_SET_INDEX_CANON_SETS_LENGTH, /* number of uint16_t in canonical starter sets */
91 _NORM_SET_INDEX_CANON_BMP_TABLE_LENGTH, /* number of uint16_t in the BMP search table (contains pairs) */
92 _NORM_SET_INDEX_CANON_SUPP_TABLE_LENGTH,/* number of uint16_t in the supplementary search table (contains triplets) */
93
94 /* from formatVersion 2.3: */
95 _NORM_SET_INDEX_NX_CJK_COMPAT_OFFSET, /* uint16_t offset from canonStartSets[0] to the
96 exclusion set for CJK compatibility characters */
97 _NORM_SET_INDEX_NX_UNICODE32_OFFSET, /* uint16_t offset from canonStartSets[0] to the
98 exclusion set for Unicode 3.2 characters */
99 _NORM_SET_INDEX_NX_RESERVED_OFFSET, /* uint16_t offset from canonStartSets[0] to the
100 end of the previous exclusion set */
101
102 _NORM_SET_INDEX_TOP=32 /* changing this requires a new formatVersion */
103 };
104
105 /* more constants for canonical starter sets */
106
107 /* 14 bit indexes to canonical USerializedSets */
108 #define _NORM_MAX_CANON_SETS 0x4000
109
110 /* single-code point BMP sets are encoded directly in the search table except if result=0x4000..0x7fff */
111 #define _NORM_CANON_SET_BMP_MASK 0xc000
112 #define _NORM_CANON_SET_BMP_IS_INDEX 0x4000
113
114 /* indexes[] value names */
115 enum {
116 _NORM_INDEX_TRIE_SIZE, /* number of bytes in normalization trie */
117 _NORM_INDEX_UCHAR_COUNT, /* number of UChars in extra data */
118
119 _NORM_INDEX_COMBINE_DATA_COUNT, /* number of uint16_t words for combining data */
120 _NORM_INDEX_COMBINE_FWD_COUNT, /* number of code points that combine forward */
121 _NORM_INDEX_COMBINE_BOTH_COUNT, /* number of code points that combine forward and backward */
122 _NORM_INDEX_COMBINE_BACK_COUNT, /* number of code points that combine backward */
123
124 _NORM_INDEX_MIN_NFC_NO_MAYBE, /* first code point with quick check NFC NO/MAYBE */
125 _NORM_INDEX_MIN_NFKC_NO_MAYBE, /* first code point with quick check NFKC NO/MAYBE */
126 _NORM_INDEX_MIN_NFD_NO_MAYBE, /* first code point with quick check NFD NO/MAYBE */
127 _NORM_INDEX_MIN_NFKD_NO_MAYBE, /* first code point with quick check NFKD NO/MAYBE */
128
129 _NORM_INDEX_FCD_TRIE_SIZE, /* number of bytes in FCD trie */
130
131 _NORM_INDEX_AUX_TRIE_SIZE, /* number of bytes in the auxiliary trie */
132 _NORM_INDEX_CANON_SET_COUNT, /* number of uint16_t in the array of serialized USet */
133
134 _NORM_INDEX_TOP=32 /* changing this requires a new formatVersion */
135 };
136
137 enum {
138 /* FCD check: everything below this code point is known to have a 0 lead combining class */
139 _NORM_MIN_WITH_LEAD_CC=0x300
140 };
141
142 enum {
143 /**
144 * Bit 7 of the length byte for a decomposition string in extra data is
145 * a flag indicating whether the decomposition string is
146 * preceded by a 16-bit word with the leading and trailing cc
147 * of the decomposition (like for A-umlaut);
148 * if not, then both cc's are zero (like for compatibility ideographs).
149 */
150 _NORM_DECOMP_FLAG_LENGTH_HAS_CC=0x80,
151 /**
152 * Bits 6..0 of the length byte contain the actual length.
153 */
154 _NORM_DECOMP_LENGTH_MASK=0x7f
155 };
156
157 /** Constants for options flags for normalization. */
158 enum {
159 /** Options bit 0, do not decompose Hangul syllables. */
160 UNORM_NX_HANGUL=1,
161 /** Options bit 1, do not decompose CJK compatibility characters. */
162 UNORM_NX_CJK_COMPAT=2
163 };
164
165 /**
166 * Description of the format of unorm.icu version 2.3.
167 *
168 * Main change from version 1 to version 2:
169 * Use of new, common UTrie instead of normalization-specific tries.
170 * Change to version 2.1: add third/auxiliary trie with associated data.
171 * Change to version 2.2: add skippable (f) flag data (_NORM_AUX_NFC_SKIP_F_MASK).
172 * Change to version 2.3: add serialized sets for normalization exclusions
173 * stored inside canonStartSets[]
174 *
175 * For more details of how to use the data structures see the code
176 * in unorm.cpp (runtime normalization code) and
177 * in gennorm.c and gennorm/store.c (build-time data generation).
178 *
179 * For the serialized format of UTrie see utrie.c/UTrieHeader.
180 *
181 * - Overall partition
182 *
183 * unorm.dat customarily begins with a UDataInfo structure, see udata.h and .c.
184 * After that there are the following structures:
185 *
186 * int32_t indexes[_NORM_INDEX_TOP]; -- _NORM_INDEX_TOP=32, see enum in this file
187 *
188 * UTrie normTrie; -- size in bytes=indexes[_NORM_INDEX_TRIE_SIZE]
189 *
190 * uint16_t extraData[extraDataTop]; -- extraDataTop=indexes[_NORM_INDEX_UCHAR_COUNT]
191 * extraData[0] contains the number of units for
192 * FC_NFKC_Closure (formatVersion>=2.1)
193 *
194 * uint16_t combiningTable[combiningTableTop]; -- combiningTableTop=indexes[_NORM_INDEX_COMBINE_DATA_COUNT]
195 * combiningTableTop may include one 16-bit padding unit
196 * to make sure that fcdTrie is 32-bit-aligned
197 *
198 * UTrie fcdTrie; -- size in bytes=indexes[_NORM_INDEX_FCD_TRIE_SIZE]
199 *
200 * UTrie auxTrie; -- size in bytes=indexes[_NORM_INDEX_AUX_TRIE_SIZE]
201 *
202 * uint16_t canonStartSets[canonStartSetsTop] -- canonStartSetsTop=indexes[_NORM_INDEX_CANON_SET_COUNT]
203 * serialized USets and binary search tables, see below
204 *
205 *
206 * The indexes array contains lengths and sizes of the following arrays and structures
207 * as well as the following values:
208 * indexes[_NORM_INDEX_COMBINE_FWD_COUNT]=combineFwdTop
209 * -- one more than the highest combining index computed for forward-only-combining characters
210 * indexes[_NORM_INDEX_COMBINE_BOTH_COUNT]=combineBothTop-combineFwdTop
211 * -- number of combining indexes computed for both-ways-combining characters
212 * indexes[_NORM_INDEX_COMBINE_BACK_COUNT]=combineBackTop-combineBothTop
213 * -- number of combining indexes computed for backward-only-combining characters
214 *
215 * indexes[_NORM_INDEX_MIN_NF*_NO_MAYBE] (where *={ C, D, KC, KD })
216 * -- first code point with a quick check NF* value of NO/MAYBE
217 *
218 *
219 * - Tries
220 *
221 * The main structures are two UTrie tables ("compact arrays"),
222 * each with one index array and one data array.
223 * See utrie.h and utrie.c.
224 *
225 *
226 * - Tries in unorm.dat
227 *
228 * The first trie (normTrie above)
229 * provides data for the NF* quick checks and normalization.
230 * The second trie (fcdTrie above) provides data just for FCD checks.
231 *
232 *
233 * - norm32 data words from the first trie
234 *
235 * The norm32Table contains one 32-bit word "norm32" per code point.
236 * It contains the following bit fields:
237 * 31..16 extra data index, _NORM_EXTRA_SHIFT is used to shift this field down
238 * if this index is <_NORM_EXTRA_INDEX_TOP then it is an index into
239 * extraData[] where variable-length normalization data for this
240 * code point is found
241 * if this index is <_NORM_EXTRA_INDEX_TOP+_NORM_EXTRA_SURROGATE_TOP
242 * then this is a norm32 for a leading surrogate, and the index
243 * value is used together with the following trailing surrogate
244 * code unit in the second trie access
245 * if this index is >=_NORM_EXTRA_INDEX_TOP+_NORM_EXTRA_SURROGATE_TOP
246 * then this is a norm32 for a "special" character,
247 * i.e., the character is a Hangul syllable or a Jamo
248 * see _NORM_EXTRA_HANGUL etc.
249 * generally, instead of extracting this index from the norm32 and
250 * comparing it with the above constants,
251 * the normalization code compares the entire norm32 value
252 * with _NORM_MIN_SPECIAL, _NORM_SURROGATES_TOP, _NORM_MIN_HANGUL etc.
253 *
254 * 15..8 combining class (cc) according to UnicodeData.txt
255 *
256 * 7..6 _NORM_COMBINES_ANY flags, used in composition to see if a character
257 * combines with any following or preceding character(s)
258 * at all
259 * 7 _NORM_COMBINES_BACK
260 * 6 _NORM_COMBINES_FWD
261 *
262 * 5..0 quick check flags, set for "no" or "maybe", with separate flags for
263 * each normalization form
264 * the higher bits are "maybe" flags; for NF*D there are no such flags
265 * the lower bits are "no" flags for all forms, in the same order
266 * as the "maybe" flags,
267 * which is (MSB to LSB): NFKD NFD NFKC NFC
268 * 5..4 _NORM_QC_ANY_MAYBE
269 * 3..0 _NORM_QC_ANY_NO
270 * see further related constants
271 *
272 *
273 * - Extra data per code point
274 *
275 * "Extra data" is referenced by the index in norm32.
276 * It is variable-length data. It is only present, and only those parts
277 * of it are, as needed for a given character.
278 * The norm32 extra data index is added to the beginning of extraData[]
279 * to get to a vector of 16-bit words with data at the following offsets:
280 *
281 * [-1] Combining index for composition.
282 * Stored only if norm32&_NORM_COMBINES_ANY .
283 * [0] Lengths of the canonical and compatibility decomposition strings.
284 * Stored only if there are decompositions, i.e.,
285 * if norm32&(_NORM_QC_NFD|_NORM_QC_NFKD)
286 * High byte: length of NFKD, or 0 if none
287 * Low byte: length of NFD, or 0 if none
288 * Each length byte also has another flag:
289 * Bit 7 of a length byte is set if there are non-zero
290 * combining classes (cc's) associated with the respective
291 * decomposition. If this flag is set, then the decomposition
292 * is preceded by a 16-bit word that contains the
293 * leading and trailing cc's.
294 * Bits 6..0 of a length byte are the length of the
295 * decomposition string, not counting the cc word.
296 * [1..n] NFD
297 * [n+1..] NFKD
298 *
299 * Each of the two decompositions consists of up to two parts:
300 * - The 16-bit words with the leading and trailing cc's.
301 * This is only stored if bit 7 of the corresponding length byte
302 * is set. In this case, at least one of the cc's is not zero.
303 * High byte: leading cc==cc of the first code point in the decomposition string
304 * Low byte: trailing cc==cc of the last code point in the decomposition string
305 * - The decomposition string in UTF-16, with length code units.
306 *
307 *
308 * - Combining indexes and combiningTable[]
309 *
310 * Combining indexes are stored at the [-1] offset of the extra data
311 * if the character combines forward or backward with any other characters.
312 * They are used for (re)composition in NF*C.
313 * Values of combining indexes are arranged according to whether a character
314 * combines forward, backward, or both ways:
315 * forward-only < both ways < backward-only
316 *
317 * The index values for forward-only and both-ways combining characters
318 * are indexes into the combiningTable[].
319 * The index values for backward-only combining characters are simply
320 * incremented from the preceding index values to be unique.
321 *
322 * In the combiningTable[], a variable-length list
323 * of variable-length (back-index, code point) pair entries is stored
324 * for each forward-combining character.
325 *
326 * These back-indexes are the combining indexes of both-ways or backward-only
327 * combining characters that the forward-combining character combines with.
328 *
329 * Each list is sorted in ascending order of back-indexes.
330 * Each list is terminated with the last back-index having bit 15 set.
331 *
332 * Each pair (back-index, code point) takes up either 2 or 3
333 * 16-bit words.
334 * The first word of a list entry is the back-index, with its bit 15 set if
335 * this is the last pair in the list.
336 *
337 * The second word contains flags in bits 15..13 that determine
338 * if there is a third word and how the combined character is encoded:
339 * 15 set if there is a third word in this list entry
340 * 14 set if the result is a supplementary character
341 * 13 set if the result itself combines forward
342 *
343 * According to these bits 15..14 of the second word,
344 * the result character is encoded as follows:
345 * 00 or 01 The result is <=0x1fff and stored in bits 12..0 of
346 * the second word.
347 * 10 The result is 0x2000..0xffff and stored in the third word.
348 * Bits 12..0 of the second word are not used.
349 * 11 The result is a supplementary character.
350 * Bits 9..0 of the leading surrogate are in bits 9..0 of
351 * the second word.
352 * Add 0xd800 to these bits to get the complete surrogate.
353 * Bits 12..10 of the second word are not used.
354 * The trailing surrogate is stored in the third word.
355 *
356 *
357 * - FCD trie
358 *
359 * The FCD trie is very simple.
360 * It is a folded trie with 16-bit data words.
361 * In each word, the high byte contains the leading cc of the character,
362 * and the low byte contains the trailing cc of the character.
363 * These cc's are the cc's of the first and last code points in the
364 * canonical decomposition of the character.
365 *
366 * Since all 16 bits are used for cc's, lead surrogates must be tested
367 * by checking the code unit instead of the trie data.
368 * This is done only if the 16-bit data word is not zero.
369 * If the code unit is a leading surrogate and the data word is not zero,
370 * then instead of cc's it contains the offset for the second trie lookup.
371 *
372 *
373 * - Auxiliary trie and data
374 *
375 * The auxiliary 16-bit trie contains data for additional properties.
376 * Bits
377 * 15..13 reserved
378 * 12 not NFC_Skippable (f) (formatVersion>=2.2)
379 * 11 flag: not a safe starter for canonical closure
380 * 10 composition exclusion
381 * 9.. 0 index into extraData[] to FC_NFKC_Closure string
382 * (not for lead surrogate),
383 * or lead surrogate offset (for lead surrogate, if 9..0 not zero)
384 *
385 * - FC_NFKC_Closure strings in extraData[]
386 *
387 * Strings are either stored as a single code unit or as the length
388 * followed by that many units.
389 * const UChar *s=extraData+(index from auxTrie data bits 9..0);
390 * int32_t length;
391 * if(*s<0xff00) {
392 * // s points to the single-unit string
393 * length=1;
394 * } else {
395 * length=*s&0xff;
396 * ++s;
397 * }
398 *
399 * Conditions for "NF* Skippable" from Mark Davis' com.ibm.text.UCD.NFSkippable:
400 * (used in NormalizerTransliterator)
401 *
402 * A skippable character is
403 * a) unassigned, or ALL of the following:
404 * b) of combining class 0.
405 * c) not decomposed by this normalization form.
406 * AND if NFC or NFKC,
407 * d) can never compose with a previous character.
408 * e) can never compose with a following character.
409 * f) can never change if another character is added.
410 * Example: a-breve might satisfy all but f, but if you
411 * add an ogonek it changes to a-ogonek + breve
412 *
413 * a)..e) must be tested from norm32.
414 * Since f) is more complicated, the (not-)NFC_Skippable flag (f) is built
415 * into the auxiliary trie.
416 * The same bit is used for NFC and NFKC; (c) differs for them.
417 * As usual, we build the "not skippable" flags so that unassigned
418 * code points get a 0 bit.
419 * This bit is only valid after (a)..(e) test FALSE; test NFD_NO before (f) as well.
420 * Test Hangul LV syllables entirely in code.
421 *
422 *
423 * - structure inside canonStartSets[]
424 *
425 * This array maps from code points c to sets of code points (USerializedSet).
426 * The result sets are the code points whose canonical decompositions start
427 * with c.
428 *
429 * canonStartSets[] contains the following sub-arrays:
430 *
431 * indexes[_NORM_SET_INDEX_TOP]
432 * - contains lengths of sub-arrays etc.
433 *
434 * startSets[indexes[_NORM_SET_INDEX_CANON_SETS_LENGTH]-_NORM_SET_INDEX_TOP]
435 * - contains serialized sets (USerializedSet) of canonical starters for
436 * enumerating canonically equivalent strings
437 * indexes[_NORM_SET_INDEX_CANON_SETS_LENGTH] includes _NORM_SET_INDEX_TOP
438 * for details about the structure see uset.c
439 *
440 * bmpTable[indexes[_NORM_SET_INDEX_CANON_BMP_TABLE_LENGTH]]
441 * - a sorted search table for BMP code points whose results are
442 * either indexes to USerializedSets or single code points for
443 * single-code point sets;
444 * each entry is a pair of { code point, result } with result=(binary) yy xxxxxx xxxxxxxx
445 * if yy==01 then there is a USerializedSet at canonStartSets+x
446 * else build a USerializedSet with result as the single code point
447 *
448 * suppTable[indexes[_NORM_SET_INDEX_CANON_SUPP_TABLE_LENGTH]]
449 * - a sorted search table for supplementary code points whose results are
450 * either indexes to USerializedSets or single code points for
451 * single-code point sets;
452 * each entry is a triplet of { high16(cp), low16(cp), result }
453 * each code point's high-word may contain extra data in bits 15..5:
454 * if the high word has bit 15 set, then build a set with a single code point
455 * which is (((high16(cp)&0x1f00)<<8)|result;
456 * else there is a USerializedSet at canonStartSets+result
457 *
458 * FormatVersion 2.3 adds 2 serialized sets for normalization exclusions.
459 * They are stored in the data file so that the runtime normalization code need
460 * not depend on other properties and their data and implementation files.
461 * The _NORM_SET_INDEX_NX_..._OFFSET offsets in the canonStartSets index table
462 * give the location for each set.
463 * There is no set stored for UNORM_NX_HANGUL because it's trivial to create
464 * without using properties.
465 *
466 * Set contents:
467 *
468 * _NORM_SET_INDEX_NX_CJK_COMPAT_OFFSET (for UNORM_NX_CJK_COMPAT)
469 * [[:Ideographic:]&[:NFD_QC=No:]]
470 * =[CJK Ideographs]&[has canonical decomposition]
471 *
472 * _NORM_SET_INDEX_NX_UNICODE32_OFFSET (for UNORM_UNICODE_3_2)
473 * [:^Age=3.2:]
474 * =set with all code points that were not designated by the specified Unicode version
475 *
476 * _NORM_SET_INDEX_NX_RESERVED_OFFSET
477 * This is an offset that points to where the next, future set would start.
478 * Currently it indicates where the previous set ends, and thus its length.
479 * The name for this enum constant may in the future be applied to different
480 * index slots. In order to get the limit of a set, use its index slot and
481 * the immediately following one regardless of that one's enum name.
482 */
483
484 #endif /* #if !UCONFIG_NO_NORMALIZATION */
485
486 #endif

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