/*
* utls.c - Utility functions.
*
* Copyright (C) 2009-2011 by Hatuka*nezumi - IKEDA Soji.
*
* This file is part of the Sombok Package. This program is free
* software; you can redistribute it and/or modify it under the terms of
* either the GNU General Public License or the Artistic License, as
* specified in the README file.
*
*/
#include "sombok_constants.h"
#include "sombok.h"
/** @defgroup linebreak_utils utils
* @brief Callback functions used by linebreak
*@{*/
/** @name Preprocessing callback
* gcstring_t *callback(linebreak_t *lbobj, void *data, unistr_t *str, unistr_t *text)
*
* Preprocessing behaviors specified by item of ``prep_func'' member of
* linebreak_t. Corresponding item of ``prep_data'' member can be used to
* modify behavior.
* @param[in] obj linebreak object.
* @param[in] data an item of prep_data correspondig to callback.
* @param[in,out] substr pointer to Unicode string.
* @param[in] text whole text to be broken, or NULL.
* @return This callback is past twice by each substring of text:
*
* On the first pass, when text is not NULL, it should return the first
* occurrance in substr matching its criteria, update substr->str to be
* matching position and substr->len to be length. Otherwise, should set
* NULL to substr->str.
* Return value shall be discarded.
*
* On the second pass, when text is NULL, it should return new grapheme
* cluster string created from substr. Return value should not share
* Unicode buffer with substr (i.e. use gcstring_newcopy()).
*
* If error occurred, callback must set lbobj->errnum nonzero then return NULL.
*/
/*@{*/
static
int startswith(unistr_t * unistr, size_t idx, char *str, size_t len,
int cs)
{
size_t i;
unichar_t uc, c;
if (unistr->str == NULL)
return 0;
if (unistr->len - idx < len)
return 0;
for (i = 0; i < len; i++) {
uc = unistr->str[idx + i];
c = (unichar_t) str[i];
if (!cs) {
if ((unichar_t) 'A' <= uc && uc <= (unichar_t) 'Z')
uc += (unichar_t) ('a' - 'A');
if ((unichar_t) 'A' <= c && c <= (unichar_t) 'Z')
c += (unichar_t) ('a' - 'A');
}
if (uc != c)
return 0;
}
return 1;
}
#define is(str, i, c) \
((i) < (str)->len && (str)->str[i] == (c))
#define _is_alpha(s) \
(('a' <= (s) && (s) <= 'z') || ('A' <= (s) && (s) <= 'Z'))
#define is_alpha(str, i) \
((i) < (str)->len && _is_alpha((str)->str[i]))
#define _is_digit(s) \
('0' <= (s) && (s) <= '9')
#define is_digit(str, i) \
((i) < (str)->len && _is_digit((str)->str[i]))
#define _is_hexdig(s) \
(_is_digit(s) || ('a' <= (s) && (s) <= 'f') || ('A' <= (s) && (s) <= 'F'))
#define is_hexdig(str, i) \
((i) < (str)->len && _is_hexdig((str)->str[i]))
#define _is_sub_delim(s) \
((s) == '!' || (s) == '$' || (s) == '&' || (s) == '\'' || (s) == '(' || \
(s) == ')' || (s) == '*' || (s) == '+' || (s) == ',' || (s) == ';' || \
(s) == '=')
#define is_sub_delim(str, i) \
((i) < (str)->len && _is_sub_delim((str)->str[i]))
#define _is_unreserved(s) \
(_is_alpha(s) || _is_digit(s) || \
(s) == '-' || (s) == '.' || (s) == '_' || (s) == '~')
#define is_unreserved(str, i) \
((i) < (str)->len && _is_unreserved((str)->str[i]))
#define _is_pct_encoded(s) \
((s) == '%' || _is_hexdig(s))
#define is_pct_encoded(str, i) \
((i) < (str)->len && _is_pct_encoded((str)->str[i]))
#define _is_pchar(s) \
(_is_unreserved(s) || _is_pct_encoded(s) || _is_sub_delim(s) || \
(s) == ':' || (s) == '@')
#define is_pchar(str, i) \
((i) < (str)->len && _is_pchar((str)->str[i]))
/** Built-in preprocessing callback
*
* Built-in preprocessing callback to break or not to break URLs according to
* some rules by Chicago Manual of Style 15th ed.
* If data is NULL, prohibit break.
* Otherwise, allow break by rule above.
*/
gcstring_t *linebreak_prep_URIBREAK(linebreak_t * lbobj, void *data,
unistr_t * str, unistr_t * text)
{
gcstring_t *gcstr;
size_t i;
unichar_t *ptr;
/* Pass I */
if (text != NULL) {
/*
* Search URL in str.
* Following code loosely refers RFC3986 but some practical
* assumptions are put:
*
* o Broken pct-encoded sequences (e.g. single "%") are allowed.
* o scheme names must end with alphanumeric, must be longer than
* or equal to two octets, and must not contain more than one
* non-alphanumeric ("+", "-" or ".").
* o URLs containing neither non-empty path, query part nor fragment
* (e.g. "about:") are omitted: they are treated as ordinal words.
*/
for (ptr = NULL, i = 0; i < str->len; ptr = NULL, i++) {
int has_double_slash, has_authority, has_empty_path,
has_no_query, has_no_fragment;
size_t alphadigit, nonalphadigit;
/* skip non-alpha. */
if (!is_alpha(str, i))
continue;
ptr = str->str + i;
/* "url:" - case insensitive */
if (startswith(str, i, "url:", 4, 0))
i += 4;
/* scheme */
if (is_alpha(str, i))
i++;
else
continue;
nonalphadigit = 0;
alphadigit = 1;
while (1) {
if (is_alpha(str, i) || is_digit(str, i))
alphadigit++;
else if (is(str, i, '+') || is(str, i, '-') || is(str, i, '.'))
nonalphadigit++;
else
break;
i++;
}
if (alphadigit < 2 || 1 < nonalphadigit ||
! (is_digit(str, i - 1) || is_alpha(str, i - 1)))
continue;
/* ":" */
if (is(str, i, ':'))
i++;
else
continue;
/* hier-part */
has_double_slash = 0;
has_authority = 0;
has_empty_path = 0;
has_no_query = 0;
has_no_fragment = 0;
if (startswith(str, i, "//", 2, 0)) {
/* "//" */
has_double_slash = 1;
i += 2;
/* authority - FIXME:syntax relaxed */
if (is(str, i, '[') || is(str, i, ':') || is(str, i, '@') ||
is_unreserved(str, i) || is_pct_encoded(str, i) ||
is_sub_delim(str, i)) {
has_authority = 1;
i++;
while (is(str, i, '[') || is(str, i, ']') ||
is(str, i, ':') || is(str, i, '@') ||
is_unreserved(str, i) || is_pct_encoded(str, i) ||
is_sub_delim(str, i))
i++;
}
}
/* path */
if (has_double_slash) {
if (has_authority)
goto path_abempty;
else
goto path_absolute;
} /* else goto path_rootless; */
/* path_rootless: */
if (is_pchar(str, i)) { /* FIXME:path-noscheme not concerned */
i++;
while (is_pchar(str, i))
i++;
goto path_abempty;
} else {
has_empty_path = 1;
goto path_empty;
}
path_absolute:
if (startswith(str, i, "//", 2, 0))
continue;
else if (is(str, i, '/')) {
i++;
if (is_pchar(str, i)) {
i++;
while (is_pchar(str, i))
i++;
}
goto path_abempty;
} else
continue;
path_abempty:
if (is(str, i, '/')) {
i++;
while (is(str, i, '/') || is_pchar(str, i))
i++;
} /* else goto path_empty; */
path_empty:
;
/* query */
if (is(str, i, '?')) {
i++;
while (is(str, i, '/') || is(str, i, '?') || is_pchar(str, i))
i++;
} else
has_no_query = 1;
/* fragment */
if (is(str, i, '#')) {
i++;
while (is(str, i, '/') || is(str, i, '?') || is_pchar(str, i))
i++;
} else
has_no_fragment = 1;
if (has_empty_path && has_no_query && has_no_fragment)
continue;
break;
}
if (ptr != NULL)
str->len = i - (ptr - str->str);
str->str = ptr;
return NULL;
}
/* Pass II */
if ((gcstr = gcstring_newcopy(str, lbobj)) == NULL) {
lbobj->errnum = errno ? errno : ENOMEM;
return NULL;
}
/* non-break URI. */
if (data == NULL) {
for (i = 1; i < gcstr->gclen; i++)
gcstr->gcstr[i].flag = LINEBREAK_FLAG_PROHIBIT_BEFORE;
return gcstr;
}
/* break URI. */
if (startswith((unistr_t *) gcstr, 0, "url:", 4, 0)) {
gcstr->gcstr[4].flag = LINEBREAK_FLAG_ALLOW_BEFORE;
i = 5;
} else
i = 1;
for (; i < gcstr->gclen; i++) {
unichar_t u, v;
u = gcstr->str[gcstr->gcstr[i - 1].idx];
v = gcstr->str[gcstr->gcstr[i].idx];
/*
* Some rules based on CMoS 15th ed.
* 17.11 1.1: [/] ÷ [^/]
* 17.11 2: [-] ×
* 6.17 2: [.] ×
* 17.11 1.2: ÷ [-~.,_?#%]
* 17.11 1.3: ÷ [=&]
* 17.11 1.3: [=&] ÷
* Default: ALL × ALL
*/
if (u == '/' && v != '/')
gcstr->gcstr[i].flag = LINEBREAK_FLAG_ALLOW_BEFORE;
else if (u == '-' || u == '.')
gcstr->gcstr[i].flag = LINEBREAK_FLAG_PROHIBIT_BEFORE;
else if (v == '-' || v == '~' || v == '.' || v == ',' ||
v == '_' || v == '?' || v == '#' || v == '%' ||
u == '=' || v == '=' || u == '&' || v == '&')
gcstr->gcstr[i].flag = LINEBREAK_FLAG_ALLOW_BEFORE;
else
gcstr->gcstr[i].flag = LINEBREAK_FLAG_PROHIBIT_BEFORE;
}
/* Won't break punctuations at end of matches. */
for (i = gcstr->gclen - 1; 1 <= i; i--) {
unichar_t u = gcstr->str[gcstr->gcstr[i].idx];
if (gcstr->gcstr[i].flag == LINEBREAK_FLAG_ALLOW_BEFORE &&
(u == '"' || u == '.' || u == ':' || u == ';' || u == ',' ||
u == '>'))
gcstr->gcstr[i].flag = LINEBREAK_FLAG_PROHIBIT_BEFORE;
else
break;
}
return gcstr;
}
/*@}*/
/** @name Sizing callback
* double callback(linebreak_t *obj, double len, gcstring_t *pre, gcstring_t *spc, gcstring_t *str)
*
* Sizing behavior specified by ``sizing_func'' member of linebreak_t.
* ``sizing_data'' member can be used to modify behavior.
* @param[in] obj linebreak object.
* @param[in] len Number of columns of preceding grapheme cluster string.
* @param[in] pre Preceding grapheme cluster string.
* @param[in] spc Trailing spaces of preceding string.
* @param[in] str Appended grapheme cluster string.
* @return number of columns of pre+spc+str.
* If error occurred, callback must set lbobj->errnum nonzero then return NULL.
*/
/*@{*/
/** Built-in Sizing callback
*
* Built-in Sizing callback based on UAX #11.
*/
double linebreak_sizing_UAX11(linebreak_t * obj, double len,
gcstring_t * pre, gcstring_t * spc,
gcstring_t * str)
{
gcstring_t *spcstr;
if ((!spc || !spc->str || !spc->len) &&
(!str || !str->str || !str->len))
return len;
if (!spc || !spc->str)
spcstr = gcstring_copy(str);
else if ((spcstr = gcstring_concat(spc, str)) == NULL)
return -1.0;
len += (double) gcstring_columns(spcstr);
gcstring_destroy(spcstr);
return len;
}
/*@}*/
/** @name Formatting callback
* gcstring_t *callback(linebreak_t *lbobj, linebreak_state_t state, gcstring_t *gcstr)
*
* Formatting behaviors specified by ``format_func'' member of linebreak_t.
* ``formt_data'' member can be used to modify behavior.
* @param[in] obj linebreak object.
* @param[in] state state.
* @param[in] gcstr text fragment.
* @return new text fragment or, if no modification needed, NULL.
* If error occurred, callback must set lbobj->errnum nonzero then return NULL.
*
* Following table describes behavior of built-in format callbacks.
*
* @verbatim
* state| SIMPLE | NEWLINE | TRIM
* -----+-----------------+-------------------+-------------------
* SOT |
* SOP | not modify
* SOL |
* LINE |
* EOL | append newline | replace by newline| replace by newline
* EOP | not modify | replace by newline| remove SPACEs
* EOT | not modify | replace by newline| remove SPACEs
* ----------------------------------------------------------------
* @endverbatim
*/
/*@{*/
/** Built-in formatting callback
*
*/
gcstring_t *linebreak_format_SIMPLE(linebreak_t * lbobj,
linebreak_state_t state,
gcstring_t * gcstr)
{
gcstring_t *t, *result;
unistr_t unistr;
switch (state) {
case LINEBREAK_STATE_EOL:
if ((result = gcstring_copy(gcstr)) == NULL)
return NULL;
unistr.str = lbobj->newline.str;
unistr.len = lbobj->newline.len;
if ((t = gcstring_new(&unistr, lbobj)) == NULL)
return NULL;
if (gcstring_append(result, t) == NULL) {
t->str = NULL;
gcstring_destroy(t);
return NULL;
}
t->str = NULL;
gcstring_destroy(t);
return result;
default:
errno = 0;
return NULL;
}
}
/** Built-in formatting callback
*
*/
gcstring_t *linebreak_format_NEWLINE(linebreak_t * lbobj,
linebreak_state_t state,
gcstring_t * gcstr)
{
gcstring_t *result;
unistr_t unistr;
switch (state) {
case LINEBREAK_STATE_EOL:
case LINEBREAK_STATE_EOP:
case LINEBREAK_STATE_EOT:
unistr.str = lbobj->newline.str;
unistr.len = lbobj->newline.len;
if ((result = gcstring_newcopy(&unistr, lbobj)) == NULL)
return NULL;
return result;
default:
errno = 0;
return NULL;
}
}
/** Built-in formatting callback
*
*/
gcstring_t *linebreak_format_TRIM(linebreak_t * lbobj,
linebreak_state_t state,
gcstring_t * gcstr)
{
gcstring_t *result;
unistr_t unistr = { NULL, 0 };
size_t i;
switch (state) {
case LINEBREAK_STATE_EOL:
unistr.str = lbobj->newline.str;
unistr.len = lbobj->newline.len;
if ((result = gcstring_newcopy(&unistr, lbobj)) == NULL)
return NULL;
return result;
case LINEBREAK_STATE_EOP:
case LINEBREAK_STATE_EOT:
if (gcstr->str == NULL || gcstr->len == 0) {
if ((result = gcstring_newcopy(&unistr, lbobj)) == NULL)
return NULL;
return result;
}
for (i = 0; i < gcstr->gclen && gcstr->gcstr[i].lbc == LB_SP; i++);
if ((result = gcstring_substr(gcstr, i, gcstr->gclen)) == NULL)
return NULL;
return result;
default:
errno = 0;
return NULL;
}
}
/*@}*/
/** @name Urgent breaking callbacks
* gcstring_t *callback(linebreak_t *lbobj, gcstring_t *str)
*
* Urgent breaking behaviors specified by ``urgent_func'' member of
* linebreak_t. ``urgent_data'' member can be used to modify behavior.
* @param[in] obj linebreak object.
* @param[in] str text to be broken.
* @return new text or, if no modification needed, NULL.
* If error occurred, callback must set lbobj->errnum nonzero then return NULL.
*
* There are two built-in urgent breaking callbacks.
*/
/*@{*/
/** Built-in urgent brealing callback
*
* Abort processing. lbobj->errnum is set to LINEBREAK_ELONG.
*/
gcstring_t *linebreak_urgent_ABORT(linebreak_t * lbobj, gcstring_t * str)
{
lbobj->errnum = LINEBREAK_ELONG;
return NULL;
}
/** Built-in urgent brealing callback
*
* Force breaking lines.
*/
gcstring_t *linebreak_urgent_FORCE(linebreak_t * lbobj, gcstring_t * str)
{
gcstring_t *result, *s, empty = { NULL, 0, NULL, 0, 0, lbobj };
if (!str || !str->len)
return gcstring_new(NULL, lbobj);
result = gcstring_new(NULL, lbobj);
s = gcstring_copy(str);
while (1) {
size_t i;
gcstring_t *t;
double cols;
for (i = 0; i < s->gclen; i++) {
t = gcstring_substr(s, 0, i + 1);
if (lbobj->sizing_func != NULL)
cols =
(*(lbobj->sizing_func)) (lbobj, 0.0, &empty, &empty,
t);
else
cols = (double) t->gclen;
gcstring_destroy(t);
if (lbobj->colmax < cols)
break;
}
if (0 < i) {
t = gcstring_substr(s, 0, i);
if (t->gclen) {
t->gcstr[0].flag = LINEBREAK_FLAG_ALLOW_BEFORE;
gcstring_append(result, t);
}
gcstring_destroy(t);
t = gcstring_substr(s, i, s->gclen - i);
gcstring_destroy(s);
s = t;
if (!s->gclen)
break;
} else {
if (s->gclen) {
s->gcstr[0].flag = LINEBREAK_FLAG_ALLOW_BEFORE;
gcstring_append(result, s);
}
break;
}
}
gcstring_destroy(s);
return result;
}
/*@}*/
/** @name Preprocessing callbacks - obsoleted form
* gcstring_t *callback(linebreak_t *lbobj, unistr_t *str)
* Preprocessing behaviors specified by ``user_func'' member of linebreak_t.
* ``user_data'' member can be used to modify behavior.
* @param[in] obj linebreak object.
* @param[in] str Unicode string (not grapheme cluster string) to be processed.
* @return new grapheme cluster string. NULL means no data.
* If error occurred, callback must set lbobj->errnum nonzero then return NULL.
*
* Currently no built-in preprocessing callbacks are defined.
* NOTE: Feature of this callback described here is planned to be changed
* by next release.
*/