changeset 7824:af4391ae3012

New modules 'unistr/u8-prev', 'unistr/u16-prev', 'unistr/u32-prev'.
author Bruno Haible <bruno@clisp.org>
date Tue, 09 Jan 2007 14:09:15 +0000
parents da256057d1fb
children d058f9b1cec5
files lib/unistr/u16-prev.c lib/unistr/u32-prev.c lib/unistr/u8-prev.c modules/unistr/u16-prev modules/unistr/u32-prev modules/unistr/u8-prev
diffstat 6 files changed, 260 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
new file mode 100644
--- /dev/null
+++ b/lib/unistr/u16-prev.c
@@ -0,0 +1,55 @@
+/* Iterate over previous character in UTF-16 string.
+   Copyright (C) 2002, 2006-2007 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"
+
+const uint16_t *
+u16_prev (ucs4_t *puc, const uint16_t *s, const uint16_t *start)
+{
+  /* Keep in sync with utf16-ucs4.h and utf16-ucs4.c.  */
+  if (s != start)
+    {
+      uint16_t c_1 = s[-1];
+
+      if (c_1 < 0xd800 || c_1 >= 0xe000)
+	{
+	  *puc = c_1;
+	  return s - 1;
+	}
+#if CONFIG_UNICODE_SAFETY
+      if (c_1 >= 0xdc00)
+#endif
+	if (s - 1 != start)
+	  {
+	    uint16_t c_2 = s[-2];
+
+#if CONFIG_UNICODE_SAFETY
+	    if (c_2 >= 0xd800 && c_2 < 0xdc00)
+#endif
+	      {
+		*puc = 0x10000 + ((c_2 - 0xd800) << 10) + (c_1 - 0xdc00);
+		return s - 2;
+	      }
+	  }
+    }
+  return NULL;
+}
new file mode 100644
--- /dev/null
+++ b/lib/unistr/u32-prev.c
@@ -0,0 +1,41 @@
+/* Iterate over previous character in UTF-32 string.
+   Copyright (C) 2002, 2006-2007 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"
+
+const uint32_t *
+u32_prev (ucs4_t *puc, const uint32_t *s, const uint32_t *start)
+{
+  if (s != start)
+    {
+      uint32_t c_1 = s[-1];
+
+#if CONFIG_UNICODE_SAFETY
+      if (c_1 < 0xd800 || (c_1 >= 0xe000 && c_1 < 0x110000))
+#endif
+	{
+	  *puc = c_1;
+	  return s - 1;
+	}
+    }
+  return NULL;
+}
new file mode 100644
--- /dev/null
+++ b/lib/unistr/u8-prev.c
@@ -0,0 +1,95 @@
+/* Iterate over previous character in UTF-8 string.
+   Copyright (C) 2002, 2006-2007 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"
+
+const uint8_t *
+u8_prev (ucs4_t *puc, const uint8_t *s, const uint8_t *start)
+{
+  /* Keep in sync with utf8-ucs4.h and utf8-ucs4.c.  */
+  if (s != start)
+    {
+      uint8_t c_1 = s[-1];
+
+      if (c_1 < 0x80)
+	{
+	  *puc = c_1;
+	  return s - 1;
+	}
+#if CONFIG_UNICODE_SAFETY
+      if ((c_1 ^ 0x80) < 0x40)
+#endif
+	if (s - 1 != start)
+	  {
+	    uint8_t c_2 = s[-2];
+
+	    if (c_2 >= 0xc2 && c_2 < 0xe0)
+	      {
+		*puc = ((unsigned int) (c_2 & 0x1f) << 6)
+		       | (unsigned int) (c_1 ^ 0x80);
+		return s - 2;
+	      }
+#if CONFIG_UNICODE_SAFETY
+	    if ((c_2 ^ 0x80) < 0x40)
+#endif
+	      if (s - 2 != start)
+		{
+		  uint8_t c_3 = s[-3];
+
+		  if (c_3 >= 0xe0 && c_3 < 0xf0
+#if CONFIG_UNICODE_SAFETY
+		      && (c_3 >= 0xe1 || c_2 >= 0xa0)
+		      && (c_3 != 0xed || c_2 < 0xa0)
+#endif
+		     )
+		    {
+		      *puc = ((unsigned int) (c_3 & 0x0f) << 12)
+		             | ((unsigned int) (c_2 ^ 0x80) << 6)
+		             | (unsigned int) (c_1 ^ 0x80);
+		      return s - 3;
+		    }
+#if CONFIG_UNICODE_SAFETY
+		  if ((c_3 ^ 0x80) < 0x40)
+#endif
+		    if (s - 3 != start)
+		      {
+			uint8_t c_4 = s[-4];
+
+			if (c_4 >= 0xf0 && c_4 < 0xf8
+#if CONFIG_UNICODE_SAFETY
+			    && (c_4 >= 0xf1 || c_3 >= 0x90)
+			    && (c_4 < 0xf4 || (c_4 == 0xf4 && c_3 < 0x90))
+#endif
+			   )
+			  {
+			    *puc = ((unsigned int) (c_4 & 0x07) << 18)
+			           | ((unsigned int) (c_3 ^ 0x80) << 12)
+			           | ((unsigned int) (c_2 ^ 0x80) << 6)
+			           | (unsigned int) (c_1 ^ 0x80);
+			    return s - 4;
+			  }
+		      }
+		}
+	  }
+    }
+  return NULL;
+}
new file mode 100644
--- /dev/null
+++ b/modules/unistr/u16-prev
@@ -0,0 +1,23 @@
+Description:
+Iterate over previous character in UTF-16 string.
+
+Files:
+lib/unistr/u16-prev.c
+
+Depends-on:
+unistr/base
+
+configure.ac:
+
+Makefile.am:
+lib_SOURCES += unistr/u16-prev.c
+
+Include:
+"unistr.h"
+
+License:
+LGPL
+
+Maintainer:
+Bruno Haible
+
new file mode 100644
--- /dev/null
+++ b/modules/unistr/u32-prev
@@ -0,0 +1,23 @@
+Description:
+Iterate over previous character in UTF-32 string.
+
+Files:
+lib/unistr/u32-prev.c
+
+Depends-on:
+unistr/base
+
+configure.ac:
+
+Makefile.am:
+lib_SOURCES += unistr/u32-prev.c
+
+Include:
+"unistr.h"
+
+License:
+LGPL
+
+Maintainer:
+Bruno Haible
+
new file mode 100644
--- /dev/null
+++ b/modules/unistr/u8-prev
@@ -0,0 +1,23 @@
+Description:
+Iterate over previous character in UTF-8 string.
+
+Files:
+lib/unistr/u8-prev.c
+
+Depends-on:
+unistr/base
+
+configure.ac:
+
+Makefile.am:
+lib_SOURCES += unistr/u8-prev.c
+
+Include:
+"unistr.h"
+
+License:
+LGPL
+
+Maintainer:
+Bruno Haible
+