--- /dev/null
+/* Grapheme cluster break function.
+ Copyright (C) 2010 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 : \
+ \
+ /* 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))
+
+static const unsigned short int gb_table[12] =
+ {
+ 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 */
+ };
+
+bool
+uc_is_grapheme_cluster_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;
+}
projects / gnulib.git / blobdiff