void
u16_possible_linebreaks (const uint16_t *s, size_t n, const char *encoding, char *p)
{
int LBP_AI_REPLACEMENT = (is_cjk_encoding (encoding) ? LBP_ID : LBP_AL);
const uint16_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 = u16_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;
}
}
int
u16_width_linebreaks (const uint16_t *s, size_t n,
int width, int start_column, int at_end_columns,
const char *o, const char *encoding,
char *p)
{
const uint16_t *s_end;
char *last_p;
int last_column;
int piece_width;
u16_possible_linebreaks (s, n, encoding, p);
s_end = s + n;
last_p = NULL;
last_column = start_column;
piece_width = 0;
while (s < s_end)
{
ucs4_t uc;
int count = u16_mbtouc_unsafe (&uc, s, s_end - s);
/* Respect the override. */
if (o != NULL && *o != UC_BREAK_UNDEFINED)
*p = *o;
if (*p == UC_BREAK_POSSIBLE || *p == UC_BREAK_MANDATORY)
{
/* An atomic piece of text ends here. */
if (last_p != NULL && last_column + piece_width > width)
{
/* Insert a line break. */
*last_p = UC_BREAK_POSSIBLE;
last_column = 0;
}
}
if (*p == UC_BREAK_MANDATORY)
{
/* uc is a line break character. */
/* Start a new piece at column 0. */
last_p = NULL;
last_column = 0;
piece_width = 0;
}
else
{
/* uc is not a line break character. */
int w;
if (*p == UC_BREAK_POSSIBLE)
{
/* Start a new piece. */
last_p = p;
last_column += piece_width;
piece_width = 0;
/* No line break for the moment, may be turned into
UC_BREAK_POSSIBLE later, via last_p. */
}
*p = UC_BREAK_PROHIBITED;
w = uc_width (uc, encoding);
if (w >= 0) /* ignore control characters in the string */
piece_width += w;
}
s += count;
p += count;
if (o != NULL)
o += count;
}
/* The last atomic piece of text ends here. */
if (last_p != NULL && last_column + piece_width + at_end_columns > width)
{
/* Insert a line break. */
*last_p = UC_BREAK_POSSIBLE;
last_column = 0;
}
return last_column + piece_width;
}
