// © 2016 and later: Unicode, Inc. and others. // License & terms of use: http://www.unicode.org/copyright.html /* ******************************************************************************* * Copyright (C) 2013-2015, International Business Machines * Corporation and others. All Rights Reserved. ******************************************************************************* * collationfastlatin.h * * created on: 2013aug09 * created by: Markus W. Scherer */ #ifndef __COLLATIONFASTLATIN_H__ #define __COLLATIONFASTLATIN_H__ #include "unicode/utypes.h" #if !UCONFIG_NO_COLLATION U_NAMESPACE_BEGIN struct CollationData; struct CollationSettings; class U_I18N_API CollationFastLatin /* all static */ { … }; /* * Format of the CollationFastLatin data table. * CollationFastLatin::VERSION = 2. * * This table contains data for a Latin-text collation fastpath. * The data is stored as an array of uint16_t which contains the following parts. * * uint16_t -- version & header length * Bits 15..8: version, must match the VERSION * 7..0: length of the header * * uint16_t varTops[header length - 1] * Version 2: * varTops[m] is the highest CollationFastLatin long-primary weight * of supported maxVariable group m * (special reorder group space, punct, symbol, currency). * * Version 1: * Each of these values maps the variable top lead byte of a supported maxVariable group * to the highest CollationFastLatin long-primary weight. * The values are stored in ascending order. * Bits 15..7: max fast-Latin long-primary weight (bits 11..3 shifted left by 4 bits) * 6..0: regular primary lead byte * * uint16_t miniCEs[0x1c0] * A mini collation element for each character U+0000..U+017F and U+2000..U+203F. * Each value encodes one or two mini CEs (two are possible if the first one * has a short mini primary and the second one is a secondary CE, i.e., primary == 0), * or points to an expansion or to a contraction table. * U+0000 always has a contraction entry, * so that NUL-termination need not be tested in the fastpath. * If the collation elements for a character or contraction cannot be encoded in this format, * then the BAIL_OUT value is stored. * For details see the comments for the class constants. * * uint16_t expansions[variable length]; * Expansion mini CEs contain an offset relative to just after the miniCEs table. * An expansions contains exactly 2 mini CEs. * * uint16_t contractions[variable length]; * Contraction mini CEs contain an offset relative to just after the miniCEs table. * It points to a list of tuples which map from a contraction suffix character to a result. * First uint16_t of each tuple: * Bits 10..9: Length of the result (1..3), see comments on CONTR_LENGTH_SHIFT. * Bits 8..0: Contraction character, see comments on CONTR_CHAR_MASK. * This is followed by 0, 1, or 2 uint16_t according to the length. * Each list is terminated by an entry with CONTR_CHAR_MASK. * Each list starts with such an entry which also contains the default result * for when there is no contraction match. * * ----------------- * Changes for version 2 (ICU 55) * * Special reorder groups do not necessarily start on whole primary lead bytes any more. * Therefore, the varTops data has a new format: * Version 1 stored the lead bytes of the highest root primaries for * the maxVariable-supported special reorder groups. * Now the top 16 bits would need to be stored, * and it is simpler to store only the fast-Latin weights. */ U_NAMESPACE_END #endif // !UCONFIG_NO_COLLATION #endif // __COLLATIONFASTLATIN_H__
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