unigbrk: New modules for grapheme clusters.

[gnulib.git] / lib / unigbrk / u16-grapheme-breaks.c

diff --git a/lib/unigbrk/u16-grapheme-breaks.c b/lib/unigbrk/u16-grapheme-breaks.c
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+++ b/lib/unigbrk/u16-grapheme-breaks.c
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+/* Grapheme cluster breaks 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"
+
+#include "unistr.h"
+
+void
+u16_grapheme_breaks (const uint16_t *s, size_t n, char *p)
+{
+  ucs4_t prev;
+  int mblen;
+
+  prev = 0;
+  for (; n > 0; s += mblen, p += mblen, n -= mblen)
+    {
+      ucs4_t next;
+      int i;
+
+      mblen = u16_mbtouc (&next, s, n);
+
+      p[0] = uc_is_grapheme_cluster_break (prev, next);
+      if (mblen > 1)
+        p[1] = 0;
+
+      prev = next;
+    }
+}