skia / external / github.com / unicode-org / icu / refs/heads/userguide-migration / . / icu4c / source / common / unormimp.h

// © 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 { | |

/* 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 |