/* Line breaking of UTF-32 strings. Copyright (C) 2001-2003, 2006-2024 Free Software Foundation, Inc. Written by Bruno Haible , 2001. 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 . */ #include /* Specification. */ #include "unilbrk.h" #include "unilbrk/internal.h" #include #include "unilbrk/lbrktables.h" #include "uniwidth/cjk.h" /* This file implements Unicode Standard Annex #14 . */ void u32_possible_linebreaks_loop (const uint32_t *s, size_t n, const char *encoding, int cr, char *p) { if (n > 0) { int LBP_AI_REPLACEMENT = (is_cjk_encoding (encoding) ? LBP_ID1 : LBP_AL); const uint32_t *s_end = s + n; int prev_prop = LBP_BK; /* line break property of last character */ int last_prop = LBP_BK; /* line break property of last non-space character */ char *seen_space = NULL; /* Was a space seen after the last non-space character? */ /* Number of consecutive regional indicator (RI) characters seen immediately before the current point. */ size_t ri_count = 0; do { ucs4_t uc = *s; s++; int prop = unilbrkprop_lookup (uc); if (prop == LBP_BK || prop == LBP_LF || prop == LBP_CR) { /* (LB4,LB5,LB6) Mandatory break. */ *p = UC_BREAK_MANDATORY; /* cr is either LBP_CR or -1. In the first case, recognize a CR-LF sequence. */ if (prev_prop == cr && prop == LBP_LF) p[-1] = UC_BREAK_CR_BEFORE_LF; prev_prop = prop; last_prop = LBP_BK; seen_space = NULL; } else { /* Resolve property values whose behaviour is not fixed. */ switch (prop) { case LBP_AI: /* Resolve ambiguous. */ prop = LBP_AI_REPLACEMENT; break; case LBP_CB: /* This is arbitrary. */ prop = LBP_ID1; break; case LBP_SA: /* We don't handle complex scripts yet. Treat LBP_SA like LBP_XX. */ case LBP_XX: /* This is arbitrary. */ prop = LBP_AL; break; case LBP_QU2: /* For (LB15a): Replace LBP_QU2 with LBP_QU1 if the previous character's line break property was not one of BK, CR, LF, OP, QU, GL, SP, ZW. */ switch (prev_prop) { case LBP_BK: case LBP_CR: case LBP_LF: case LBP_OP1: case LBP_OP2: case LBP_QU1: case LBP_QU2: case LBP_QU3: case LBP_GL: case LBP_SP: case LBP_ZW: break; default: prop = LBP_QU1; break; } break; case LBP_QU3: /* For (LB15b): Replace LBP_QU3 with LBP_QU1 if the next character's line break property is not one of BK, CR, LF, SP, GL, WJ, CL, QU, CP, EX, IS, SY, ZW. */ { int next_prop; if (s < s_end) { ucs4_t next_uc = *s; next_prop = unilbrkprop_lookup (next_uc); } else next_prop = LBP_BK; switch (next_prop) { case LBP_BK: case LBP_CR: case LBP_LF: case LBP_SP: case LBP_GL: case LBP_WJ: case LBP_CL: case LBP_QU1: case LBP_QU2: case LBP_QU3: case LBP_CP1: case LBP_CP2: case LBP_EX: case LBP_IS: case LBP_SY: case LBP_ZW: break; default: prop = LBP_QU1; break; } } break; } /* Deal with spaces and combining characters. */ if (prop == LBP_SP) { /* (LB7) Don't break just before a space. */ *p = UC_BREAK_PROHIBITED; seen_space = p; } else if (prop == LBP_ZW) { /* (LB7) Don't break just before a zero-width space. */ *p = UC_BREAK_PROHIBITED; last_prop = LBP_ZW; seen_space = NULL; } else if (prop == LBP_CM || prop == LBP_ZWJ) { /* (LB9) Don't break just before a combining character or zero-width joiner, except immediately after a mandatory break character, space, or zero-width space. */ if (last_prop == LBP_BK) { /* (LB4,LB5,LB6) Don't break at the beginning of a line. */ *p = UC_BREAK_PROHIBITED; /* (LB10) Treat CM or ZWJ as AL. */ last_prop = LBP_AL; seen_space = NULL; } else if (last_prop == LBP_ZW || seen_space != NULL) { /* (LB8) Break after zero-width space. */ /* (LB18) Break after spaces. We do *not* implement the "legacy support for space character as base for combining marks" because now the NBSP CM sequence is recommended instead of SP CM. */ *p = UC_BREAK_POSSIBLE; /* (LB10) Treat CM or ZWJ as AL. */ last_prop = LBP_AL; seen_space = NULL; } else { /* Treat X CM as if it were X. */ *p = UC_BREAK_PROHIBITED; } } else { /* prop must be usable as an index for table 7.3 of UTR #14. */ if (!(prop >= 0 && prop < sizeof (unilbrk_table) / sizeof (unilbrk_table[0]))) abort (); if (last_prop == LBP_BK) { /* (LB4,LB5,LB6) Don't break at the beginning of a line. */ *p = UC_BREAK_PROHIBITED; } else if (last_prop == LBP_ZW) { /* (LB8) Break after zero-width space. */ *p = UC_BREAK_POSSIBLE; } else if (prev_prop == LBP_ZWJ) { /* (LB8a) Don't break right after a zero-width joiner. */ *p = UC_BREAK_PROHIBITED; } else if (last_prop == LBP_RI && prop == LBP_RI) { /* (LB30a) Break between two regional indicator symbols if and only if there are an even number of regional indicators preceding the position of the break. */ *p = (seen_space != NULL || (ri_count % 2) == 0 ? UC_BREAK_POSSIBLE : UC_BREAK_PROHIBITED); } else if (prev_prop == LBP_HL_BA) { /* (LB21a) Don't break after Hebrew + Hyphen/Break-After. */ *p = UC_BREAK_PROHIBITED; } else { switch (unilbrk_table [last_prop] [prop]) { case D: *p = UC_BREAK_POSSIBLE; break; case I: *p = (seen_space != NULL ? UC_BREAK_POSSIBLE : UC_BREAK_PROHIBITED); break; case P: *p = UC_BREAK_PROHIBITED; break; default: abort (); } } last_prop = prop; seen_space = NULL; } prev_prop = (prev_prop == LBP_HL && (prop == LBP_HY || prop == LBP_BA) ? LBP_HL_BA : prop); } if (prop == LBP_RI) ri_count++; else ri_count = 0; p++; } while (s < s_end); } } #if defined IN_LIBUNISTRING /* For backward compatibility with older versions of libunistring. */ # undef u32_possible_linebreaks void u32_possible_linebreaks (const uint32_t *s, size_t n, const char *encoding, char *p) { u32_possible_linebreaks_loop (s, n, encoding, -1, p); } #endif void u32_possible_linebreaks_v2 (const uint32_t *s, size_t n, const char *encoding, char *p) { u32_possible_linebreaks_loop (s, n, encoding, LBP_CR, p); }