diff options
Diffstat (limited to 'lib/unigbrk/uc-is-grapheme-break.c')
| -rw-r--r-- | lib/unigbrk/uc-is-grapheme-break.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/lib/unigbrk/uc-is-grapheme-break.c b/lib/unigbrk/uc-is-grapheme-break.c new file mode 100644 index 0000000..049cc4c --- /dev/null +++ b/lib/unigbrk/uc-is-grapheme-break.c @@ -0,0 +1,111 @@ +/* Grapheme cluster break function. + Copyright (C) 2010-2015 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 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. + + 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/>. */ + +#include <config.h> + +/* Specification. */ +#include "unigbrk.h" + +/* Evaluates to true if there is an extended grapheme cluster break between + code points with GBP_* values A and B, false if there is not. The comments + are the grapheme cluster boundary rules from in UAX #29. */ +#define UC_IS_GRAPHEME_BREAK(A, B) \ + (/* GB1 and GB2 are covered--just use a GBP_CONTROL character, such \ + as 0, for sot and eot. */ \ + \ + /* GB3 */ \ + (A) == GBP_CR && (B) == GBP_LF ? false : \ + \ + /* GB4 */ \ + (A) == GBP_CONTROL || (A) == GBP_CR || (A) == GBP_LF ? true : \ + \ + /* GB5 */ \ + (B) == GBP_CONTROL || (B) == GBP_CR || (B) == GBP_LF ? true : \ + \ + /* GB6 */ \ + (A) == GBP_L && ((B) == GBP_L || (B) == GBP_V \ + || (B) == GBP_LV || (B) == GBP_LVT) ? false : \ + \ + /* GB7 */ \ + ((A) == GBP_LV || (A) == GBP_V) \ + && ((B) == GBP_V || (B) == GBP_T) ? false : \ + \ + /* GB8 */ \ + ((A) == GBP_LVT || (A) == GBP_T) && (B) == GBP_T ? false : \ + \ + /* GB8a */ \ + (A) == GBP_RI && (B) == GBP_RI ? false : \ + \ + /* GB9 */ \ + (B) == GBP_EXTEND ? false : \ + \ + /* GB9a */ \ + (B) == GBP_SPACINGMARK ? false : \ + \ + /* GB9b */ \ + (A) == GBP_PREPEND ? false \ + \ + /* GB10 */ \ + : true) + +#define UC_GRAPHEME_BREAKS_FOR(A) \ + ( (UC_IS_GRAPHEME_BREAK(A, GBP_OTHER) << GBP_OTHER) \ + | (UC_IS_GRAPHEME_BREAK(A, GBP_CR) << GBP_CR) \ + | (UC_IS_GRAPHEME_BREAK(A, GBP_LF) << GBP_LF) \ + | (UC_IS_GRAPHEME_BREAK(A, GBP_CONTROL) << GBP_CONTROL) \ + | (UC_IS_GRAPHEME_BREAK(A, GBP_EXTEND) << GBP_EXTEND) \ + | (UC_IS_GRAPHEME_BREAK(A, GBP_PREPEND) << GBP_PREPEND) \ + | (UC_IS_GRAPHEME_BREAK(A, GBP_SPACINGMARK) << GBP_SPACINGMARK) \ + | (UC_IS_GRAPHEME_BREAK(A, GBP_L) << GBP_L) \ + | (UC_IS_GRAPHEME_BREAK(A, GBP_V) << GBP_V) \ + | (UC_IS_GRAPHEME_BREAK(A, GBP_T) << GBP_T) \ + | (UC_IS_GRAPHEME_BREAK(A, GBP_LV) << GBP_LV) \ + | (UC_IS_GRAPHEME_BREAK(A, GBP_LVT) << GBP_LVT) \ + | (UC_IS_GRAPHEME_BREAK(A, GBP_RI) << GBP_RI)) + +static const unsigned short int gb_table[13] = + { + UC_GRAPHEME_BREAKS_FOR(0), /* GBP_OTHER */ + UC_GRAPHEME_BREAKS_FOR(1), /* GBP_CR */ + UC_GRAPHEME_BREAKS_FOR(2), /* GBP_LF */ + UC_GRAPHEME_BREAKS_FOR(3), /* GBP_CONTROL */ + UC_GRAPHEME_BREAKS_FOR(4), /* GBP_EXTEND */ + UC_GRAPHEME_BREAKS_FOR(5), /* GBP_PREPEND */ + UC_GRAPHEME_BREAKS_FOR(6), /* GBP_SPACINGMARK */ + UC_GRAPHEME_BREAKS_FOR(7), /* GBP_L */ + UC_GRAPHEME_BREAKS_FOR(8), /* GBP_V */ + UC_GRAPHEME_BREAKS_FOR(9), /* GBP_T */ + UC_GRAPHEME_BREAKS_FOR(10), /* GBP_LV */ + UC_GRAPHEME_BREAKS_FOR(11), /* GBP_LVT */ + UC_GRAPHEME_BREAKS_FOR(12), /* GBP_RI */ + }; + +bool +uc_is_grapheme_break (ucs4_t a, ucs4_t b) +{ + int a_gcp, b_gcp; + + if ((a | b) < 0x300) + { + /* GB3 is the only relevant rule for this case. */ + return a != '\r' || b != '\n'; + } + + a_gcp = uc_graphemeclusterbreak_property (a); + b_gcp = uc_graphemeclusterbreak_property (b); + return (gb_table[a_gcp] >> b_gcp) & 1; +} |