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/* Line breaking of UTF-32 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 "unilbrk/lbrktables.h"
#include "uniwidth/cjk.h"
void
u32_possible_linebreaks (const uint32_t *s, size_t n, const char *encoding, char *p)
{
int LBP_AI_REPLACEMENT = (is_cjk_encoding (encoding) ? LBP_ID : LBP_AL);
const uint32_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? */
while (s < s_end)
{
ucs4_t uc = *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++;
p++;
}
}
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