/* Word breaks in UTF-8/UTF-16/UTF-32 strings. -*- coding: utf-8 -*- Copyright (C) 2009-2022 Free Software Foundation, Inc. Written by Bruno Haible , 2009. This file is free software. It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+". You can redistribute it and/or modify it under either - the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3, or (at your option) any later version, or - the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version, or - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+". This file is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License and the GNU General Public License for more details. You should have received a copy of the GNU Lesser General Public License and of the GNU General Public License along with this program. If not, see . */ /* This file implements section 4 "Word Boundaries" of Unicode Standard Annex #29 . */ void FUNC (const UNIT *s, size_t n, char *p) { if (n > 0) { const UNIT *s_end = s + n; /* Word break property of the last character. -1 at the very beginning of the string. */ int last_char_prop = -1; /* Format and Extend characters are ignored; this means, the mostly used unit is the complex character (= character with subsequent ignored characters). Word break property of the last complex character. -1 at the very beginning of the string. */ int last_compchar_prop = -1; char *last_compchar_ptr = NULL; /* For recognizing rules involving 3 complex characters: Word break property of the second-to-last complex character. -1 at the very beginning of the string. */ int secondlast_compchar_prop = -1; /* Number of consecutive regional indicator (RI) characters seen immediately before the current point. */ size_t ri_count = 0; /* Don't break inside multibyte characters. */ memset (p, 0, n); while (s < s_end) { ucs4_t uc; int count = U_MBTOUC_UNSAFE (&uc, s, s_end - s); int prop = uc_wordbreak_property (uc); /* No break at the start of the string. */ if (last_char_prop >= 0) { /* No break between CR and LF (WB3). */ if (last_char_prop == WBP_CR && prop == WBP_LF) /* *p = 0 */; /* Break before and after newlines (WB3a, WB3b). */ else if ((last_char_prop == WBP_CR || last_char_prop == WBP_LF || last_char_prop == WBP_NEWLINE) || (prop == WBP_CR || prop == WBP_LF || prop == WBP_NEWLINE)) *p = 1; /* No break within emoji zwj sequence (WB3c). */ else if (last_char_prop == WBP_ZWJ && uc_is_property_extended_pictographic (uc)) /* *p = 0 */; /* Keep horizontal whitespace together (WB3d). */ else if (last_char_prop == WBP_WSS && prop == WBP_WSS) /* *p = 0 */; /* Ignore Format and Extend characters (WB4). */ else if (prop == WBP_EXTEND || prop == WBP_FORMAT || prop == WBP_ZWJ) /* *p = 0 */; else { /* No break in these situations (see UAX #29): secondlast last current (ALetter | HL) (MidLetter | MidNumLet | SQ) × (ALetter | HL) (WB7) (ALetter | HL) × (MidLetter | MidNumLet | SQ) (ALetter | HL) (WB6) Numeric (MidNum | MidNumLet | SQ) × Numeric (WB11) Numeric × (MidNum | MidNumLet | SQ) Numeric (WB12) HL × DQ HL (WB7b) HL DQ × HL (WB7c) ^ (RI RI)* RI × RI (WB15) [^RI] (RI RI)* RI × RI (WB16) */ /* No break across certain punctuation. Also, disable word breaks that were recognized earlier (due to lookahead of only one complex character). */ if (((prop == WBP_ALETTER || prop == WBP_HL) && (last_compchar_prop == WBP_MIDLETTER || last_compchar_prop == WBP_MIDNUMLET || last_compchar_prop == WBP_SQ) && (secondlast_compchar_prop == WBP_ALETTER || secondlast_compchar_prop == WBP_HL)) || (prop == WBP_NUMERIC && (last_compchar_prop == WBP_MIDNUM || last_compchar_prop == WBP_MIDNUMLET || last_compchar_prop == WBP_SQ) && secondlast_compchar_prop == WBP_NUMERIC) || (prop == WBP_HL && last_compchar_prop == WBP_DQ && secondlast_compchar_prop == WBP_HL)) { *last_compchar_ptr = 0; /* *p = 0; */ } /* Break before RI, if odd number of RI's are preceding (WB15, WB16). */ else if (last_compchar_prop == WBP_RI && prop == WBP_RI) { if (ri_count % 2 == 0) *p = 1; /* else *p = 0 */ } /* Break after Format and Extend character. */ else if (last_compchar_prop == WBP_EXTEND || last_compchar_prop == WBP_FORMAT) *p = 1; else { int last_compchar_index = uniwbrk_prop_index[last_compchar_prop]; int index = uniwbrk_prop_index[prop]; /* Break between unknown pair (WB999). */ if (last_compchar_index < 0 || index < 0) *p = 1; /* Perform a single table lookup. */ else if (uniwbrk_table[last_compchar_index][index]) *p = 1; /* else *p = 0; */ } } } last_char_prop = prop; /* Ignore Format and Extend characters, except at the start of the line (WB4). */ if (last_compchar_prop < 0 || last_compchar_prop == WBP_CR || last_compchar_prop == WBP_LF || last_compchar_prop == WBP_NEWLINE || !(prop == WBP_EXTEND || prop == WBP_FORMAT || prop == WBP_ZWJ)) { secondlast_compchar_prop = last_compchar_prop; last_compchar_prop = prop; last_compchar_ptr = p; if (prop == WBP_RI) ri_count++; else ri_count = 0; } s += count; p += count; } } }