New modules 'unistr/u8-uctomb', 'unistr/u16-uctomb', 'unistr/u32-uctomb'.

[gnulib.git] / lib / unistr / u8-uctomb.c

diff --git a/lib/unistr/u8-uctomb.c b/lib/unistr/u8-uctomb.c
new file mode 100644 (file)
index 0000000..412ca14
--- /dev/null
+++ b/lib/unistr/u8-uctomb.c
@@ -0,0 +1,85 @@
+/* Store a character in UTF-8 string.
+   Copyright (C) 2002, 2005-2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2002.
+
+   This program is free software; you can redistribute it and/or modify it
+   under the terms of the GNU Library General Public License as published
+   by the Free Software Foundation; either version 2, 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+   USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "unistr.h"
+
+#if !HAVE_INLINE
+
+int
+u8_uctomb (uint8_t *s, ucs4_t uc, int n)
+{
+  if (uc < 0x80)
+    {
+      if (n > 0)
+       {
+         s[0] = uc;
+         return 1;
+       }
+      /* else return -2, below.  */
+    }
+  else
+    {
+      int count;
+
+      if (uc < 0x800)
+       count = 2;
+      else if (uc < 0x10000)
+       {
+         if (uc < 0xd800 || uc >= 0xe000)
+           count = 3;
+         else
+           return -1;
+       }
+#if 0
+      else if (uc < 0x200000)
+       count = 4;
+      else if (uc < 0x4000000)
+       count = 5;
+      else if (uc <= 0x7fffffff)
+       count = 6;
+#else
+      else if (uc < 0x110000)
+       count = 4;
+#endif
+      else
+       return -1;
+
+      if (n >= count)
+       {
+         switch (count) /* note: code falls through cases! */
+           {
+#if 0
+           case 6: s[5] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x4000000;
+           case 5: s[4] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x200000;
+#endif
+           case 4: s[3] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x10000;
+           case 3: s[2] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x800;
+           case 2: s[1] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0xc0;
+         /*case 1:*/ s[0] = uc;
+           }
+         return count;
+       }
+    }
+  return -2;
+}
+
+#endif