diff options
Diffstat (limited to 'deps/icu-small/source/common/unormimp.h')
| -rw-r--r-- | deps/icu-small/source/common/unormimp.h | 486 |
1 files changed, 486 insertions, 0 deletions
diff --git a/deps/icu-small/source/common/unormimp.h b/deps/icu-small/source/common/unormimp.h new file mode 100644 index 0000000000..3dce76bc8f --- /dev/null +++ b/deps/icu-small/source/common/unormimp.h @@ -0,0 +1,486 @@ +/* +******************************************************************************* +* +* Copyright (C) 2001-2011, International Business Machines +* Corporation and others. All Rights Reserved. +* +******************************************************************************* +* file name: unormimp.h +* encoding: US-ASCII +* tab size: 8 (not used) +* indentation:4 +* +* created on: 2001may25 +* created by: Markus W. Scherer +*/ + +#ifndef __UNORMIMP_H__ +#define __UNORMIMP_H__ + +#include "unicode/utypes.h" + +#if !UCONFIG_NO_NORMALIZATION + +#include "udataswp.h" + +/* + * The 2001-2010 implementation of the normalization code loads its data from + * unorm.icu, which is generated with the gennorm tool. + * The format of that file is described at the end of this file. + */ + +/* norm32 value constants */ +enum { + /* quick check flags 0..3 set mean "no" for their forms */ + _NORM_QC_NFC=0x11, /* no|maybe */ + _NORM_QC_NFKC=0x22, /* no|maybe */ + _NORM_QC_NFD=4, /* no */ + _NORM_QC_NFKD=8, /* no */ + + _NORM_QC_ANY_NO=0xf, + + /* quick check flags 4..5 mean "maybe" for their forms; test flags>=_NORM_QC_MAYBE */ + _NORM_QC_MAYBE=0x10, + _NORM_QC_ANY_MAYBE=0x30, + + _NORM_QC_MASK=0x3f, + + _NORM_COMBINES_FWD=0x40, + _NORM_COMBINES_BACK=0x80, + _NORM_COMBINES_ANY=0xc0, + + _NORM_CC_SHIFT=8, /* UnicodeData.txt combining class in bits 15..8 */ + _NORM_CC_MASK=0xff00, + + _NORM_EXTRA_SHIFT=16, /* 16 bits for the index to UChars and other extra data */ + _NORM_EXTRA_INDEX_TOP=0xfc00, /* start of surrogate specials after shift */ + + _NORM_EXTRA_SURROGATE_MASK=0x3ff, + _NORM_EXTRA_SURROGATE_TOP=0x3f0, /* hangul etc. */ + + _NORM_EXTRA_HANGUL=_NORM_EXTRA_SURROGATE_TOP, + _NORM_EXTRA_JAMO_L, + _NORM_EXTRA_JAMO_V, + _NORM_EXTRA_JAMO_T +}; + +/* norm32 value constants using >16 bits */ +#define _NORM_MIN_SPECIAL 0xfc000000 +#define _NORM_SURROGATES_TOP 0xfff00000 +#define _NORM_MIN_HANGUL 0xfff00000 +#define _NORM_MIN_JAMO_V 0xfff20000 +#define _NORM_JAMO_V_TOP 0xfff30000 + +/* value constants for auxTrie */ +enum { + _NORM_AUX_COMP_EX_SHIFT=10, + _NORM_AUX_UNSAFE_SHIFT=11, + _NORM_AUX_NFC_SKIPPABLE_F_SHIFT=12 +}; + +#define _NORM_AUX_MAX_FNC ((int32_t)1<<_NORM_AUX_COMP_EX_SHIFT) + +#define _NORM_AUX_FNC_MASK (uint32_t)(_NORM_AUX_MAX_FNC-1) +#define _NORM_AUX_COMP_EX_MASK ((uint32_t)1<<_NORM_AUX_COMP_EX_SHIFT) +#define _NORM_AUX_UNSAFE_MASK ((uint32_t)1<<_NORM_AUX_UNSAFE_SHIFT) +#define _NORM_AUX_NFC_SKIP_F_MASK ((uint32_t)1<<_NORM_AUX_NFC_SKIPPABLE_F_SHIFT) + +/* canonStartSets[0..31] contains indexes for what is in the array */ +enum { + _NORM_SET_INDEX_CANON_SETS_LENGTH, /* number of uint16_t in canonical starter sets */ + _NORM_SET_INDEX_CANON_BMP_TABLE_LENGTH, /* number of uint16_t in the BMP search table (contains pairs) */ + _NORM_SET_INDEX_CANON_SUPP_TABLE_LENGTH,/* number of uint16_t in the supplementary search table (contains triplets) */ + + /* from formatVersion 2.3: */ + _NORM_SET_INDEX_NX_CJK_COMPAT_OFFSET, /* uint16_t offset from canonStartSets[0] to the + exclusion set for CJK compatibility characters */ + _NORM_SET_INDEX_NX_UNICODE32_OFFSET, /* uint16_t offset from canonStartSets[0] to the + exclusion set for Unicode 3.2 characters */ + _NORM_SET_INDEX_NX_RESERVED_OFFSET, /* uint16_t offset from canonStartSets[0] to the + end of the previous exclusion set */ + + _NORM_SET_INDEX_TOP=32 /* changing this requires a new formatVersion */ +}; + +/* more constants for canonical starter sets */ + +/* 14 bit indexes to canonical USerializedSets */ +#define _NORM_MAX_CANON_SETS 0x4000 + +/* single-code point BMP sets are encoded directly in the search table except if result=0x4000..0x7fff */ +#define _NORM_CANON_SET_BMP_MASK 0xc000 +#define _NORM_CANON_SET_BMP_IS_INDEX 0x4000 + +/* indexes[] value names */ +enum { + _NORM_INDEX_TRIE_SIZE, /* number of bytes in normalization trie */ + _NORM_INDEX_UCHAR_COUNT, /* number of UChars in extra data */ + + _NORM_INDEX_COMBINE_DATA_COUNT, /* number of uint16_t words for combining data */ + _NORM_INDEX_COMBINE_FWD_COUNT, /* number of code points that combine forward */ + _NORM_INDEX_COMBINE_BOTH_COUNT, /* number of code points that combine forward and backward */ + _NORM_INDEX_COMBINE_BACK_COUNT, /* number of code points that combine backward */ + + _NORM_INDEX_MIN_NFC_NO_MAYBE, /* first code point with quick check NFC NO/MAYBE */ + _NORM_INDEX_MIN_NFKC_NO_MAYBE, /* first code point with quick check NFKC NO/MAYBE */ + _NORM_INDEX_MIN_NFD_NO_MAYBE, /* first code point with quick check NFD NO/MAYBE */ + _NORM_INDEX_MIN_NFKD_NO_MAYBE, /* first code point with quick check NFKD NO/MAYBE */ + + _NORM_INDEX_FCD_TRIE_SIZE, /* number of bytes in FCD trie */ + + _NORM_INDEX_AUX_TRIE_SIZE, /* number of bytes in the auxiliary trie */ + _NORM_INDEX_CANON_SET_COUNT, /* number of uint16_t in the array of serialized USet */ + + _NORM_INDEX_TOP=32 /* changing this requires a new formatVersion */ +}; + +enum { + /* FCD check: everything below this code point is known to have a 0 lead combining class */ + _NORM_MIN_WITH_LEAD_CC=0x300 +}; + +enum { + /** + * Bit 7 of the length byte for a decomposition string in extra data is + * a flag indicating whether the decomposition string is + * preceded by a 16-bit word with the leading and trailing cc + * of the decomposition (like for A-umlaut); + * if not, then both cc's are zero (like for compatibility ideographs). + */ + _NORM_DECOMP_FLAG_LENGTH_HAS_CC=0x80, + /** + * Bits 6..0 of the length byte contain the actual length. + */ + _NORM_DECOMP_LENGTH_MASK=0x7f +}; + +/** Constants for options flags for normalization. */ +enum { + /** Options bit 0, do not decompose Hangul syllables. */ + UNORM_NX_HANGUL=1, + /** Options bit 1, do not decompose CJK compatibility characters. */ + UNORM_NX_CJK_COMPAT=2 +}; + +/** + * Description of the format of unorm.icu version 2.3. + * + * Main change from version 1 to version 2: + * Use of new, common UTrie instead of normalization-specific tries. + * Change to version 2.1: add third/auxiliary trie with associated data. + * Change to version 2.2: add skippable (f) flag data (_NORM_AUX_NFC_SKIP_F_MASK). + * Change to version 2.3: add serialized sets for normalization exclusions + * stored inside canonStartSets[] + * + * For more details of how to use the data structures see the code + * in unorm.cpp (runtime normalization code) and + * in gennorm.c and gennorm/store.c (build-time data generation). + * + * For the serialized format of UTrie see utrie.c/UTrieHeader. + * + * - Overall partition + * + * unorm.dat customarily begins with a UDataInfo structure, see udata.h and .c. + * After that there are the following structures: + * + * int32_t indexes[_NORM_INDEX_TOP]; -- _NORM_INDEX_TOP=32, see enum in this file + * + * UTrie normTrie; -- size in bytes=indexes[_NORM_INDEX_TRIE_SIZE] + * + * uint16_t extraData[extraDataTop]; -- extraDataTop=indexes[_NORM_INDEX_UCHAR_COUNT] + * extraData[0] contains the number of units for + * FC_NFKC_Closure (formatVersion>=2.1) + * + * uint16_t combiningTable[combiningTableTop]; -- combiningTableTop=indexes[_NORM_INDEX_COMBINE_DATA_COUNT] + * combiningTableTop may include one 16-bit padding unit + * to make sure that fcdTrie is 32-bit-aligned + * + * UTrie fcdTrie; -- size in bytes=indexes[_NORM_INDEX_FCD_TRIE_SIZE] + * + * UTrie auxTrie; -- size in bytes=indexes[_NORM_INDEX_AUX_TRIE_SIZE] + * + * uint16_t canonStartSets[canonStartSetsTop] -- canonStartSetsTop=indexes[_NORM_INDEX_CANON_SET_COUNT] + * serialized USets and binary search tables, see below + * + * + * The indexes array contains lengths and sizes of the following arrays and structures + * as well as the following values: + * indexes[_NORM_INDEX_COMBINE_FWD_COUNT]=combineFwdTop + * -- one more than the highest combining index computed for forward-only-combining characters + * indexes[_NORM_INDEX_COMBINE_BOTH_COUNT]=combineBothTop-combineFwdTop + * -- number of combining indexes computed for both-ways-combining characters + * indexes[_NORM_INDEX_COMBINE_BACK_COUNT]=combineBackTop-combineBothTop + * -- number of combining indexes computed for backward-only-combining characters + * + * indexes[_NORM_INDEX_MIN_NF*_NO_MAYBE] (where *={ C, D, KC, KD }) + * -- first code point with a quick check NF* value of NO/MAYBE + * + * + * - Tries + * + * The main structures are two UTrie tables ("compact arrays"), + * each with one index array and one data array. + * See utrie.h and utrie.c. + * + * + * - Tries in unorm.dat + * + * The first trie (normTrie above) + * provides data for the NF* quick checks and normalization. + * The second trie (fcdTrie above) provides data just for FCD checks. + * + * + * - norm32 data words from the first trie + * + * The norm32Table contains one 32-bit word "norm32" per code point. + * It contains the following bit fields: + * 31..16 extra data index, _NORM_EXTRA_SHIFT is used to shift this field down + * if this index is <_NORM_EXTRA_INDEX_TOP then it is an index into + * extraData[] where variable-length normalization data for this + * code point is found + * if this index is <_NORM_EXTRA_INDEX_TOP+_NORM_EXTRA_SURROGATE_TOP + * then this is a norm32 for a leading surrogate, and the index + * value is used together with the following trailing surrogate + * code unit in the second trie access + * if this index is >=_NORM_EXTRA_INDEX_TOP+_NORM_EXTRA_SURROGATE_TOP + * then this is a norm32 for a "special" character, + * i.e., the character is a Hangul syllable or a Jamo + * see _NORM_EXTRA_HANGUL etc. + * generally, instead of extracting this index from the norm32 and + * comparing it with the above constants, + * the normalization code compares the entire norm32 value + * with _NORM_MIN_SPECIAL, _NORM_SURROGATES_TOP, _NORM_MIN_HANGUL etc. + * + * 15..8 combining class (cc) according to UnicodeData.txt + * + * 7..6 _NORM_COMBINES_ANY flags, used in composition to see if a character + * combines with any following or preceding character(s) + * at all + * 7 _NORM_COMBINES_BACK + * 6 _NORM_COMBINES_FWD + * + * 5..0 quick check flags, set for "no" or "maybe", with separate flags for + * each normalization form + * the higher bits are "maybe" flags; for NF*D there are no such flags + * the lower bits are "no" flags for all forms, in the same order + * as the "maybe" flags, + * which is (MSB to LSB): NFKD NFD NFKC NFC + * 5..4 _NORM_QC_ANY_MAYBE + * 3..0 _NORM_QC_ANY_NO + * see further related constants + * + * + * - Extra data per code point + * + * "Extra data" is referenced by the index in norm32. + * It is variable-length data. It is only present, and only those parts + * of it are, as needed for a given character. + * The norm32 extra data index is added to the beginning of extraData[] + * to get to a vector of 16-bit words with data at the following offsets: + * + * [-1] Combining index for composition. + * Stored only if norm32&_NORM_COMBINES_ANY . + * [0] Lengths of the canonical and compatibility decomposition strings. + * Stored only if there are decompositions, i.e., + * if norm32&(_NORM_QC_NFD|_NORM_QC_NFKD) + * High byte: length of NFKD, or 0 if none + * Low byte: length of NFD, or 0 if none + * Each length byte also has another flag: + * Bit 7 of a length byte is set if there are non-zero + * combining classes (cc's) associated with the respective + * decomposition. If this flag is set, then the decomposition + * is preceded by a 16-bit word that contains the + * leading and trailing cc's. + * Bits 6..0 of a length byte are the length of the + * decomposition string, not counting the cc word. + * [1..n] NFD + * [n+1..] NFKD + * + * Each of the two decompositions consists of up to two parts: + * - The 16-bit words with the leading and trailing cc's. + * This is only stored if bit 7 of the corresponding length byte + * is set. In this case, at least one of the cc's is not zero. + * High byte: leading cc==cc of the first code point in the decomposition string + * Low byte: trailing cc==cc of the last code point in the decomposition string + * - The decomposition string in UTF-16, with length code units. + * + * + * - Combining indexes and combiningTable[] + * + * Combining indexes are stored at the [-1] offset of the extra data + * if the character combines forward or backward with any other characters. + * They are used for (re)composition in NF*C. + * Values of combining indexes are arranged according to whether a character + * combines forward, backward, or both ways: + * forward-only < both ways < backward-only + * + * The index values for forward-only and both-ways combining characters + * are indexes into the combiningTable[]. + * The index values for backward-only combining characters are simply + * incremented from the preceding index values to be unique. + * + * In the combiningTable[], a variable-length list + * of variable-length (back-index, code point) pair entries is stored + * for each forward-combining character. + * + * These back-indexes are the combining indexes of both-ways or backward-only + * combining characters that the forward-combining character combines with. + * + * Each list is sorted in ascending order of back-indexes. + * Each list is terminated with the last back-index having bit 15 set. + * + * Each pair (back-index, code point) takes up either 2 or 3 + * 16-bit words. + * The first word of a list entry is the back-index, with its bit 15 set if + * this is the last pair in the list. + * + * The second word contains flags in bits 15..13 that determine + * if there is a third word and how the combined character is encoded: + * 15 set if there is a third word in this list entry + * 14 set if the result is a supplementary character + * 13 set if the result itself combines forward + * + * According to these bits 15..14 of the second word, + * the result character is encoded as follows: + * 00 or 01 The result is <=0x1fff and stored in bits 12..0 of + * the second word. + * 10 The result is 0x2000..0xffff and stored in the third word. + * Bits 12..0 of the second word are not used. + * 11 The result is a supplementary character. + * Bits 9..0 of the leading surrogate are in bits 9..0 of + * the second word. + * Add 0xd800 to these bits to get the complete surrogate. + * Bits 12..10 of the second word are not used. + * The trailing surrogate is stored in the third word. + * + * + * - FCD trie + * + * The FCD trie is very simple. + * It is a folded trie with 16-bit data words. + * In each word, the high byte contains the leading cc of the character, + * and the low byte contains the trailing cc of the character. + * These cc's are the cc's of the first and last code points in the + * canonical decomposition of the character. + * + * Since all 16 bits are used for cc's, lead surrogates must be tested + * by checking the code unit instead of the trie data. + * This is done only if the 16-bit data word is not zero. + * If the code unit is a leading surrogate and the data word is not zero, + * then instead of cc's it contains the offset for the second trie lookup. + * + * + * - Auxiliary trie and data + * + * The auxiliary 16-bit trie contains data for additional properties. + * Bits + * 15..13 reserved + * 12 not NFC_Skippable (f) (formatVersion>=2.2) + * 11 flag: not a safe starter for canonical closure + * 10 composition exclusion + * 9.. 0 index into extraData[] to FC_NFKC_Closure string + * (not for lead surrogate), + * or lead surrogate offset (for lead surrogate, if 9..0 not zero) + * + * - FC_NFKC_Closure strings in extraData[] + * + * Strings are either stored as a single code unit or as the length + * followed by that many units. + * const UChar *s=extraData+(index from auxTrie data bits 9..0); + * int32_t length; + * if(*s<0xff00) { + * // s points to the single-unit string + * length=1; + * } else { + * length=*s&0xff; + * ++s; + * } + * + * Conditions for "NF* Skippable" from Mark Davis' com.ibm.text.UCD.NFSkippable: + * (used in NormalizerTransliterator) + * + * A skippable character is + * a) unassigned, or ALL of the following: + * b) of combining class 0. + * c) not decomposed by this normalization form. + * AND if NFC or NFKC, + * d) can never compose with a previous character. + * e) can never compose with a following character. + * f) can never change if another character is added. + * Example: a-breve might satisfy all but f, but if you + * add an ogonek it changes to a-ogonek + breve + * + * a)..e) must be tested from norm32. + * Since f) is more complicated, the (not-)NFC_Skippable flag (f) is built + * into the auxiliary trie. + * The same bit is used for NFC and NFKC; (c) differs for them. + * As usual, we build the "not skippable" flags so that unassigned + * code points get a 0 bit. + * This bit is only valid after (a)..(e) test FALSE; test NFD_NO before (f) as well. + * Test Hangul LV syllables entirely in code. + * + * + * - structure inside canonStartSets[] + * + * This array maps from code points c to sets of code points (USerializedSet). + * The result sets are the code points whose canonical decompositions start + * with c. + * + * canonStartSets[] contains the following sub-arrays: + * + * indexes[_NORM_SET_INDEX_TOP] + * - contains lengths of sub-arrays etc. + * + * startSets[indexes[_NORM_SET_INDEX_CANON_SETS_LENGTH]-_NORM_SET_INDEX_TOP] + * - contains serialized sets (USerializedSet) of canonical starters for + * enumerating canonically equivalent strings + * indexes[_NORM_SET_INDEX_CANON_SETS_LENGTH] includes _NORM_SET_INDEX_TOP + * for details about the structure see uset.c + * + * bmpTable[indexes[_NORM_SET_INDEX_CANON_BMP_TABLE_LENGTH]] + * - a sorted search table for BMP code points whose results are + * either indexes to USerializedSets or single code points for + * single-code point sets; + * each entry is a pair of { code point, result } with result=(binary) yy xxxxxx xxxxxxxx + * if yy==01 then there is a USerializedSet at canonStartSets+x + * else build a USerializedSet with result as the single code point + * + * suppTable[indexes[_NORM_SET_INDEX_CANON_SUPP_TABLE_LENGTH]] + * - a sorted search table for supplementary code points whose results are + * either indexes to USerializedSets or single code points for + * single-code point sets; + * each entry is a triplet of { high16(cp), low16(cp), result } + * each code point's high-word may contain extra data in bits 15..5: + * if the high word has bit 15 set, then build a set with a single code point + * which is (((high16(cp)&0x1f00)<<8)|result; + * else there is a USerializedSet at canonStartSets+result + * + * FormatVersion 2.3 adds 2 serialized sets for normalization exclusions. + * They are stored in the data file so that the runtime normalization code need + * not depend on other properties and their data and implementation files. + * The _NORM_SET_INDEX_NX_..._OFFSET offsets in the canonStartSets index table + * give the location for each set. + * There is no set stored for UNORM_NX_HANGUL because it's trivial to create + * without using properties. + * + * Set contents: + * + * _NORM_SET_INDEX_NX_CJK_COMPAT_OFFSET (for UNORM_NX_CJK_COMPAT) + * [[:Ideographic:]&[:NFD_QC=No:]] + * =[CJK Ideographs]&[has canonical decomposition] + * + * _NORM_SET_INDEX_NX_UNICODE32_OFFSET (for UNORM_UNICODE_3_2) + * [:^Age=3.2:] + * =set with all code points that were not designated by the specified Unicode version + * + * _NORM_SET_INDEX_NX_RESERVED_OFFSET + * This is an offset that points to where the next, future set would start. + * Currently it indicates where the previous set ends, and thus its length. + * The name for this enum constant may in the future be applied to different + * index slots. In order to get the limit of a set, use its index slot and + * the immediately following one regardless of that one's enum name. + */ + +#endif /* #if !UCONFIG_NO_NORMALIZATION */ + +#endif |