--- /dev/null
+/* Line breaking of UTF-8 strings.
+ Copyright (C) 2001-2003, 2006-2008 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/tables.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 combining characters. */
+ q = p;
+ if (prop == LBP_CM)
+ {
+ /* Don't break just before a combining character. */
+ *p = UC_BREAK_PROHIBITED;
+ /* A combining character turns a preceding space into LBP_AL. */
+ if (seen_space != NULL)
+ {
+ q = seen_space;
+ seen_space = seen_space2;
+ prop = LBP_AL;
+ goto lookup_via_table;
+ }
+ }
+ else if (prop == LBP_SP)
+ {
+ /* Don't break just before a space. */
+ *p = UC_BREAK_PROHIBITED;
+ seen_space2 = seen_space;
+ seen_space = p;
+ }
+ else
+ {
+ lookup_via_table:
+ /* prop must be usable as an index for table 7.3 of UTR #14. */
+ if (!(prop >= 1 && 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
+ {
+ switch (unilbrk_table [last_prop-1] [prop-1])
+ {
+ 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 */
projects / gnulib.git / blobdiff