/* ******************************************************************************* * * Copyright (C) 2001, 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" #include "unicode/unorm.h" #ifdef XP_CPLUSPLUS # include "unicode/chariter.h" #endif #include "ustr_imp.h" /* * This new implementation of the normalization code loads its data from * unorm.dat, which is generated with the gennorm tool. * The format of that file is described at the end of this file. */ /* trie constants */ enum { /** * Normalization trie table shift value. * This value must be <=10: * above 10, a lead surrogate's block is smaller than a stage 2 block */ _NORM_TRIE_SHIFT=5, _NORM_STAGE_2_BLOCK_COUNT=1<<_NORM_TRIE_SHIFT, _NORM_STAGE_2_MASK=_NORM_STAGE_2_BLOCK_COUNT-1, _NORM_STAGE_1_BMP_COUNT=(1<<(16-_NORM_TRIE_SHIFT)), _NORM_SURROGATE_BLOCK_BITS=10-_NORM_TRIE_SHIFT, _NORM_SURROGATE_BLOCK_COUNT=(1<<_NORM_SURROGATE_BLOCK_BITS) }; /* this may be >0xffff and may not work as an enum */ #define _NORM_STAGE_1_MAX_COUNT (0x110000>>_NORM_TRIE_SHIFT) /* 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, /* ### not used */ _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 /* indexes[] value names */ enum { _NORM_INDEX_COUNT, _NORM_INDEX_TRIE_SHIFT, _NORM_INDEX_TRIE_INDEX_COUNT, _NORM_INDEX_TRIE_DATA_COUNT, _NORM_INDEX_UCHAR_COUNT, _NORM_INDEX_COMBINE_DATA_COUNT, _NORM_INDEX_COMBINE_FWD_COUNT, _NORM_INDEX_COMBINE_BOTH_COUNT, _NORM_INDEX_COMBINE_BACK_COUNT, _NORM_INDEX_MIN_NFC_NO_MAYBE, _NORM_INDEX_MIN_NFKC_NO_MAYBE, _NORM_INDEX_MIN_NFD_NO_MAYBE, _NORM_INDEX_MIN_NFKD_NO_MAYBE, _NORM_INDEX_FCD_TRIE_INDEX_COUNT, _NORM_INDEX_FCD_TRIE_DATA_COUNT, _NORM_INDEX_TOP=16 }; 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 }; /** * Is the normalizer data loaded? * This is used internally before other internal normalizer functions * are called. * It saves this check in each of many normalization calls that * are made for, e.g., collation. * * @param pErrorCode as usual * @return boolean value for whether the normalization data is loaded * * @internal */ U_CAPI UBool U_EXPORT2 unorm_haveData(UErrorCode *pErrorCode); /** * Internal API for normalizing. * Does not check for bad input. * @internal */ U_CAPI int32_t U_EXPORT2 unorm_internalNormalize(UChar *dest, int32_t destCapacity, const UChar *src, int32_t srcLength, UNormalizationMode mode, UBool ignoreHangul, UErrorCode *pErrorCode); /** * internal API, used by normlzr.cpp * @internal */ U_CAPI int32_t U_EXPORT2 unorm_decompose(UChar *dest, int32_t destCapacity, const UChar *src, int32_t srcLength, UBool compat, UBool ignoreHangul, UErrorCode *pErrorCode); /** * internal API, used by normlzr.cpp * @internal */ U_CAPI int32_t U_EXPORT2 unorm_compose(UChar *dest, int32_t destCapacity, const UChar *src, int32_t srcLength, UBool compat, UBool ignoreHangul, UErrorCode *pErrorCode); /** * Internal API, used by collation code. * Get access to the internal FCD trie table to be able to perform * incremental, per-code unit, FCD checks in collation. * One pointer is sufficient because the trie index values are offset * by the index size, so that the same pointer is used to access the trie data. * @internal */ U_CAPI const uint16_t * U_EXPORT2 unorm_getFCDTrie(UErrorCode *pErrorCode); #ifdef XP_CPLUSPLUS U_NAMESPACE_BEGIN /** * Internal API, used by collation code. * Get the FCD value for a code unit, with * bits 15..8 lead combining class * bits 7..0 trail combining class * * If c is a lead surrogate and the value is not 0, * then instead of combining classes the value * is used in unorm_getFCD16FromSurrogatePair() to get the real value * of the supplementary code point. * * @internal */ inline uint16_t unorm_getFCD16(const uint16_t *fcdTrieIndex, UChar c) { return fcdTrieIndex[ fcdTrieIndex[ c>>_NORM_TRIE_SHIFT ]+ (c&_NORM_STAGE_2_MASK) ]; } /** * Internal API, used by collation code. * Get the FCD value for a supplementary code point, with * bits 15..8 lead combining class * bits 7..0 trail combining class * * @param fcd16 The FCD value for the lead surrogate, not 0. * @param c2 The trail surrogate code unit. * * @internal */ inline uint16_t unorm_getFCD16FromSurrogatePair(const uint16_t *fcdTrieIndex, uint16_t fcd16, UChar c2) { /* the surrogate index in fcd16 is an absolute offset over the start of stage 1 */ uint32_t c= ((uint32_t)fcd16<<10)| (c2&0x3ff); return fcdTrieIndex[ fcdTrieIndex[ c>>_NORM_TRIE_SHIFT ]+ (c&_NORM_STAGE_2_MASK) ]; } U_NAMESPACE_END #endif U_CDECL_BEGIN struct UCharIterator; typedef struct UCharIterator UCharIterator; enum UCharIteratorOrigin { UITERATOR_START, UITERATOR_CURRENT, UITERATOR_END }; typedef enum UCharIteratorOrigin UCharIteratorOrigin; typedef int32_t U_CALLCONV UCharIteratorMove( UCharIterator *iter, int32_t delta, UCharIteratorOrigin origin); typedef UBool U_CALLCONV UCharIteratorHasNext(UCharIterator *iter); typedef UBool U_CALLCONV UCharIteratorHasPrevious(UCharIterator *iter); typedef UChar U_CALLCONV UCharIteratorCurrent(UCharIterator *iter); typedef UChar U_CALLCONV UCharIteratorNext(UCharIterator *iter); typedef UChar U_CALLCONV UCharIteratorPrevious(UCharIterator *iter); /** * C API for code unit iteration. * This can be used as a C wrapper around * CharacterIterator, Replaceable, or implemented using simple strings, etc. * * @internal for normalization */ struct UCharIterator { /** * (protected) Pointer to string or wrapped object or similar. * Not used by caller. */ void *context; /** * (protected) Length of string or similar. * Not used by caller. */ int32_t length; /** * (protected) Start index or similar. * Not used by caller. */ int32_t start; /** * (protected) Current index or similar. * Not used by caller. */ int32_t index; /** * (protected) Limit index or similar. * Not used by caller. */ int32_t limit; /** * (public) Moves the current position relative to the start or end of the * iteration range, or relative to the current position itself. * The movement is expressed in numbers of code units forward * or backward by specifying a positive or negative delta. * * @param delta can be positive, zero, or negative * @param origin move relative to the start, end, or current index * @return the new index */ UCharIteratorMove *move; /** * (public) Check if current() and next() can still * return another code unit. */ UCharIteratorHasNext *hasNext; /** * (public) Check if previous() can still return another code unit. */ UCharIteratorHasPrevious *hasPrevious; /** * (public) Return the code unit at the current position, * or 0xffff if there is none (index is at the end). */ UCharIteratorCurrent *current; /** * (public) Return the code unit at the current index and increment * the index (post-increment, like s[i++]), * or return 0xffff if there is none (index is at the end). */ UCharIteratorNext *next; /** * (public) Decrement the index and return the code unit from there * (pre-decrement, like s[--i]), * or return 0xffff if there is none (index is at the start). */ UCharIteratorPrevious *previous; }; /** * Internal API for iterative normalizing - see Normalizer. * @internal */ U_CAPI int32_t U_EXPORT2 unorm_nextNormalize(UChar *dest, int32_t destCapacity, UCharIterator *src, UNormalizationMode mode, UBool ignoreHangul, UErrorCode *pErrorCode); /** * Internal API for iterative normalizing - see Normalizer. * @internal */ U_CAPI int32_t U_EXPORT2 unorm_previousNormalize(UChar *dest, int32_t destCapacity, UCharIterator *src, UNormalizationMode mode, UBool ignoreHangul, UErrorCode *pErrorCode); U_CDECL_END /** * Description of the format of unorm.dat. * * 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). * * * - Overall partition * * unorm.dat customarily begins with a UDataInfo structure, see udata.h and .c. * After that there are the following arrays: * * uint16_t indexes[_NORM_INDEX_TOP]; -- _NORM_INDEX_TOP=indexes[0]=indexes[_NORM_INDEX_COUNT] * * uint16_t stage1[stage1Top]; -- stage1Top=indexes[_NORM_INDEX_TRIE_INDEX_COUNT] * uint32_t norm32Table[norm32TableTop]; -- norm32TableTop=indexes[_NORM_INDEX_TRIE_DATA_COUNT] * * uint16_t extraData[extraDataTop]; -- extraDataTop=indexes[_NORM_INDEX_UCHAR_COUNT] * uint16_t combiningTable[combiningTableTop]; -- combiningTableTop=indexes[_NORM_INDEX_COMBINE_DATA_COUNT] * * uint16_t fcdStage1[fcdStage1Top]; -- fcdStage1Top=indexes[_NORM_INDEX_FCD_TRIE_INDEX_COUNT] * uint16_t fcdTable[fcdTableTop]; -- fcdTableTop=indexes[_NORM_INDEX_FCD_TRIE_DATA_COUNT] * * * The indexes array contains lengths of the following arrays (and its own length) * as well as the following values: * indexes[_NORM_INDEX_COUNT]=_NORM_INDEX_TOP * -- length of indexes[] * indexes[_NORM_INDEX_TRIE_SHIFT]=_NORM_TRIE_SHIFT * -- for trie indexes: shift UChars by this much * 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 * * * - Tries * * The main structures are two trie tables ("compact arrays"), * each with one index array and one data array. * Generally, tries use the upper bits of an input value to access the index array, * which results in an index to the data array where a block of values is stored. * The lower bits of the same input value are then used to index inside that data * block to get to the specific data element for the input value. * * In order to use each trie with a single base pointer, the index values in * the index array are offset by the length of the index array. * With this, a base pointer to the trie index array is also directly used * with the index value to access the trie data array. * For example, if trieIndex[n] refers to offset m in trieData[] then * the actual value is q=trieIndex[n]=lengthof(trieIndex)+m * and you access trieIndex[q] instead of trieData[m]. * * * - Folded tries * * The tries here are extended to work for lookups on UTF-16 strings with * supplementary characters encoded with surrogate pairs. * They are called "folded tries". * * Each 16-bit code unit (UChar, not code point UChar32) is looked up this way. * If there is relevant data for any given code unit, then the data or the code unit * must be checked for whether it is a leading surrogate. * If so, then the data contains an offset that is used together with the following * trailing surrogate code unit value for a second trie access. * This uses a portion of the index array beyond what is accessible with 16-bit units, * i.e., it uses the part of the trie index array starting at its index * 0x10000>>_NORM_TRIE_SHIFT. * * Such folded tries are useful when processing UTF-16 strings, especially if * many code points do not have relevant data, so that the check for * surrogates and the second trie lookup are rarely performed. * It avoids the overhead of a double-index trie that is necessary if the input * is always with 21-bit code points. * * * - Tries in unorm.dat * * The first trie consists of the stage1 and the norm32Table arrays. * It provides data for the NF* quick checks and normalization. * The second trie consists of the fcdStage1 and the fcdTable arrays * and 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. */ #endif