// © 2016 and later: Unicode, Inc. and others. // License & terms of use: http://www.unicode.org/copyright.html /* ******************************************************************************* * * Copyright (C) 2001-2011, International Business Machines * Corporation and others. All Rights Reserved. * ******************************************************************************* * file name: unormimp.h * encoding: UTF-8 * 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 { … }; /* norm32 value constants using >16 bits */ #define _NORM_MIN_SPECIAL … #define _NORM_SURROGATES_TOP … #define _NORM_MIN_HANGUL … #define _NORM_MIN_JAMO_V … #define _NORM_JAMO_V_TOP … /* value constants for auxTrie */ enum { … }; #define _NORM_AUX_MAX_FNC … #define _NORM_AUX_FNC_MASK … #define _NORM_AUX_COMP_EX_MASK … #define _NORM_AUX_UNSAFE_MASK … #define _NORM_AUX_NFC_SKIP_F_MASK … /* canonStartSets[0..31] contains indexes for what is in the array */ enum { … }; /* more constants for canonical starter sets */ /* 14 bit indexes to canonical USerializedSets */ #define _NORM_MAX_CANON_SETS … /* single-code point BMP sets are encoded directly in the search table except if result=0x4000..0x7fff */ #define _NORM_CANON_SET_BMP_MASK … #define _NORM_CANON_SET_BMP_IS_INDEX … /* indexes[] value names */ enum { … }; enum { … }; enum { … }; /** Constants for options flags for normalization. */ enum { … }; /** * 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 char16_t *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
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