Imported Upstream version 0.9.1upstream/0.9.1

1 files changed, 261 insertions, 0 deletions

diff --git a/lib/unilbrk/u8-possible-linebreaks.c b/lib/unilbrk/u8-possible-linebreaks.c
new file mode 100644
index 00000000..94e14f40
--- /dev/null
+++ b/lib/unilbrk/u8-possible-linebreaks.c
@@ -0,0 +1,261 @@
+/* Line breaking of UTF-8 strings.
+   Copyright (C) 2001-2003, 2006-2009 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2001.
+
+   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 "unilbrk.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "unilbrk/lbrktables.h"
+#include "uniwidth/cjk.h"
+#include "unistr.h"
+
+void
+u8_possible_linebreaks (const uint8_t *s, size_t n, const char *encoding, char *p)
+{
+  int LBP_AI_REPLACEMENT = (is_cjk_encoding (encoding) ? LBP_ID : LBP_AL);
+  const uint8_t *s_end = s + n;
+  int last_prop = LBP_BK; /* line break property of last non-space character */
+  char *seen_space = NULL; /* Was a space seen after the last non-space character? */
+  char *seen_space2 = NULL; /* At least two spaces after the last non-space? */
+
+  /* Don't break inside multibyte characters.  */
+  memset (p, UC_BREAK_PROHIBITED, n);
+
+  while (s < s_end)
+    {
+      ucs4_t uc;
+      int count = u8_mbtouc_unsafe (&uc, s, s_end - s);
+      int prop = unilbrkprop_lookup (uc);
+
+      if (prop == LBP_BK)
+	{
+	  /* Mandatory break.  */
+	  *p = UC_BREAK_MANDATORY;
+	  last_prop = LBP_BK;
+	  seen_space = NULL;
+	  seen_space2 = NULL;
+	}
+      else
+	{
+	  char *q;
+
+	  /* Resolve property values whose behaviour is not fixed.  */
+	  switch (prop)
+	    {
+	    case LBP_AI:
+	      /* Resolve ambiguous.  */
+	      prop = LBP_AI_REPLACEMENT;
+	      break;
+	    case LBP_CB:
+	      /* This is arbitrary.  */
+	      prop = LBP_ID;
+	      break;
+	    case LBP_SA:
+	      /* We don't handle complex scripts yet.
+		 Treat LBP_SA like LBP_XX.  */
+	    case LBP_XX:
+	      /* This is arbitrary.  */
+	      prop = LBP_AL;
+	      break;
+	    }
+
+	  /* Deal with spaces and combining characters.  */
+	  q = p;
+	  if (prop == LBP_SP)
+	    {
+	      /* Don't break just before a space.  */
+	      *p = UC_BREAK_PROHIBITED;
+	      seen_space2 = seen_space;
+	      seen_space = p;
+	    }
+	  else if (prop == LBP_ZW)
+	    {
+	      /* Don't break just before a zero-width space.  */
+	      *p = UC_BREAK_PROHIBITED;
+	      last_prop = LBP_ZW;
+	      seen_space = NULL;
+	      seen_space2 = NULL;
+	    }
+	  else if (prop == LBP_CM)
+	    {
+	      /* Don't break just before a combining character, except immediately after a
+		 zero-width space.  */
+	      if (last_prop == LBP_ZW)
+		{
+		  /* Break after zero-width space.  */
+		  *p = UC_BREAK_POSSIBLE;
+		  /* A combining character turns a preceding space into LBP_ID.  */
+		  last_prop = LBP_ID;
+		}
+	      else
+		{
+		  *p = UC_BREAK_PROHIBITED;
+		  /* A combining character turns a preceding space into LBP_ID.  */
+		  if (seen_space != NULL)
+		    {
+		      q = seen_space;
+		      seen_space = seen_space2;
+		      prop = LBP_ID;
+		      goto lookup_via_table;
+		    }
+		}
+	    }
+	  else
+	    {
+	     lookup_via_table:
+	      /* prop must be usable as an index for table 7.3 of UTR #14.  */
+	      if (!(prop >= 0 && prop < sizeof (unilbrk_table) / sizeof (unilbrk_table[0])))
+		abort ();
+
+	      if (last_prop == LBP_BK)
+		{
+		  /* Don't break at the beginning of a line.  */
+		  *q = UC_BREAK_PROHIBITED;
+		}
+	      else if (last_prop == LBP_ZW)
+		{
+		  /* Break after zero-width space.  */
+		  *q = UC_BREAK_POSSIBLE;
+		}
+	      else
+		{
+		  switch (unilbrk_table [last_prop] [prop])
+		    {
+		    case D:
+		      *q = UC_BREAK_POSSIBLE;
+		      break;
+		    case I:
+		      *q = (seen_space != NULL ? UC_BREAK_POSSIBLE : UC_BREAK_PROHIBITED);
+		      break;
+		    case P:
+		      *q = UC_BREAK_PROHIBITED;
+		      break;
+		    default:
+		      abort ();
+		    }
+		}
+	      last_prop = prop;
+	      seen_space = NULL;
+	      seen_space2 = NULL;
+	    }
+	}
+
+      s += count;
+      p += count;
+    }
+}
+
+
+#ifdef TEST
+
+#include <stdio.h>
+#include <string.h>
+
+/* Read the contents of an input stream, and return it, terminated with a NUL
+   byte. */
+char *
+read_file (FILE *stream)
+{
+#define BUFSIZE 4096
+  char *buf = NULL;
+  int alloc = 0;
+  int size = 0;
+  int count;
+
+  while (! feof (stream))
+    {
+      if (size + BUFSIZE > alloc)
+	{
+	  alloc = alloc + alloc / 2;
+	  if (alloc < size + BUFSIZE)
+	    alloc = size + BUFSIZE;
+	  buf = realloc (buf, alloc);
+	  if (buf == NULL)
+	    {
+	      fprintf (stderr, "out of memory\n");
+	      exit (1);
+	    }
+	}
+      count = fread (buf + size, 1, BUFSIZE, stream);
+      if (count == 0)
+	{
+	  if (ferror (stream))
+	    {
+	      perror ("fread");
+	      exit (1);
+	    }
+	}
+      else
+	size += count;
+    }
+  buf = realloc (buf, size + 1);
+  if (buf == NULL)
+    {
+      fprintf (stderr, "out of memory\n");
+      exit (1);
+    }
+  buf[size] = '\0';
+  return buf;
+#undef BUFSIZE
+}
+
+int
+main (int argc, char * argv[])
+{
+  if (argc == 1)
+    {
+      /* Display all the break opportunities in the input string.  */
+      char *input = read_file (stdin);
+      int length = strlen (input);
+      char *breaks = malloc (length);
+      int i;
+
+      u8_possible_linebreaks ((uint8_t *) input, length, "UTF-8", breaks);
+
+      for (i = 0; i < length; i++)
+	{
+	  switch (breaks[i])
+	    {
+	    case UC_BREAK_POSSIBLE:
+	      /* U+2027 in UTF-8 encoding */
+	      putc (0xe2, stdout); putc (0x80, stdout); putc (0xa7, stdout);
+	      break;
+	    case UC_BREAK_MANDATORY:
+	      /* U+21B2 (or U+21B5) in UTF-8 encoding */
+	      putc (0xe2, stdout); putc (0x86, stdout); putc (0xb2, stdout);
+	      break;
+	    case UC_BREAK_PROHIBITED:
+	      break;
+	    default:
+	      abort ();
+	    }
+	  putc (input[i], stdout);
+	}
+
+      free (breaks);
+
+      return 0;
+    }
+  else
+    return 1;
+}
+
+#endif /* TEST */