diff options
Diffstat (limited to 'lib/unigbrk/u-grapheme-breaks.h')
| -rw-r--r-- | lib/unigbrk/u-grapheme-breaks.h | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/lib/unigbrk/u-grapheme-breaks.h b/lib/unigbrk/u-grapheme-breaks.h new file mode 100644 index 00000000..18d8bcb1 --- /dev/null +++ b/lib/unigbrk/u-grapheme-breaks.h @@ -0,0 +1,131 @@ +/* Grapheme cluster break function. + Copyright (C) 2010-2017 Free Software Foundation, Inc. + Written by Ben Pfaff <blp@cs.stanford.edu>, 2010. + + This program is free software: you can redistribute it and/or + modify it under the terms of either: + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + + or + + * the GNU General Public License as published by the Free + Software Foundation; either version 2 of the License, or (at your + option) any later version. + + or both in parallel, as here. + This program 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 for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +void +FUNC (const UNIT *s, size_t n, char *p) +{ + if (n > 0) + { + const UNIT *s_end = s + n; + + /* Grapheme Cluster break property of the last character. + -1 at the very beginning of the string. */ + int last_char_prop = -1; + + /* Grapheme Cluster break property of the last complex character. + -1 at the very beginning of the string. */ + int last_compchar_prop = -1; + + 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 (&uc, s, s_end - s); + int prop = uc_graphemeclusterbreak_property (uc); + + /* Break at the start of the string (GB1). */ + if (last_char_prop < 0) + *p = 1; + else + { + /* No break between CR and LF (GB3). */ + if (last_char_prop == GBP_CR && prop == GBP_LF) + /* *p = 0 */; + /* Break before and after newlines (GB4, GB5). */ + else if ((last_char_prop == GBP_CR + || last_char_prop == GBP_LF + || last_char_prop == GBP_CONTROL) + || (prop == GBP_CR + || prop == GBP_LF + || prop == GBP_CONTROL)) + *p = 1; + /* No break between Hangul syllable sequences (GB6, GB7, GB8). */ + else if ((last_char_prop == GBP_L + && (prop == GBP_L + || prop == GBP_V + || prop == GBP_LV + || prop == GBP_LVT)) + || ((last_char_prop == GBP_LV + || last_char_prop == GBP_V) + && (prop == GBP_V + || prop == GBP_T)) + || ((last_char_prop == GBP_LVT + || last_char_prop == GBP_T) + && prop == GBP_T)) + /* *p = 0 */; + /* No break before extending characters or ZWJ (GB9). */ + else if (prop == GBP_EXTEND || prop == GBP_ZWJ) + /* *p = 0 */; + /* No break before SpacingMarks (GB9a). */ + else if (prop == GBP_SPACINGMARK) + /* *p = 0 */; + /* No break after Prepend characters (GB9b). */ + else if (last_char_prop == GBP_PREPEND) + /* *p = 0 */; + /* No break within emoji modifier sequences (GB10). */ + else if ((last_compchar_prop == GBP_EB + || last_compchar_prop == GBP_EBG) + && prop == GBP_EM) + /* *p = 0 */; + /* No break within emoji zwj sequences (GB11). */ + else if (last_char_prop == GBP_ZWJ + && (prop == GBP_GAZ + || prop == GBP_EBG)) + /* *p = 0 */; + /* No break between RI if there is an odd number of RI + characters before (GB12, GB13). */ + else if (prop == GBP_RI) + { + if (ri_count % 2 == 0) + *p = 1; + /* else *p = 0; */ + } + /* Break everywhere (GBP999). */ + else + *p = 1; + } + + last_char_prop = prop; + + if (!(prop == GBP_EXTEND + && (last_compchar_prop == GBP_EB + || last_compchar_prop == GBP_EBG))) + last_compchar_prop = prop; + + if (prop == GBP_RI) + ri_count++; + else + ri_count = 0; + + s += count; + p += count; + } + } +} |