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glib/glib/gunidecomp.c
Matthias Clasen f13d561211 More header inclusion cleanup
2010-09-05 00:23:03 -04:00

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/* decomp.c - Character decomposition.
*
* Copyright (C) 1999, 2000 Tom Tromey
* Copyright 2000 Red Hat, Inc.
*
* The Gnome Library 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 2 of the
* License, or (at your option) any later version.
*
* The Gnome Library 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 the Gnome Library; see the file COPYING.LIB. If not,
* write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include <stdlib.h>
#include "gunicode.h"
#include "gunidecomp.h"
#include "gmem.h"
#include "gunicomp.h"
#include "gunicodeprivate.h"
#define CC_PART1(Page, Char) \
((combining_class_table_part1[Page] >= G_UNICODE_MAX_TABLE_INDEX) \
? (combining_class_table_part1[Page] - G_UNICODE_MAX_TABLE_INDEX) \
: (cclass_data[combining_class_table_part1[Page]][Char]))
#define CC_PART2(Page, Char) \
((combining_class_table_part2[Page] >= G_UNICODE_MAX_TABLE_INDEX) \
? (combining_class_table_part2[Page] - G_UNICODE_MAX_TABLE_INDEX) \
: (cclass_data[combining_class_table_part2[Page]][Char]))
#define COMBINING_CLASS(Char) \
(((Char) <= G_UNICODE_LAST_CHAR_PART1) \
? CC_PART1 ((Char) >> 8, (Char) & 0xff) \
: (((Char) >= 0xe0000 && (Char) <= G_UNICODE_LAST_CHAR) \
? CC_PART2 (((Char) - 0xe0000) >> 8, (Char) & 0xff) \
: 0))
/**
* g_unichar_combining_class:
* @uc: a Unicode character
*
* Determines the canonical combining class of a Unicode character.
*
* Return value: the combining class of the character
*
* Since: 2.14
**/
gint
g_unichar_combining_class (gunichar uc)
{
return COMBINING_CLASS (uc);
}
/* constants for hangul syllable [de]composition */
#define SBase 0xAC00
#define LBase 0x1100
#define VBase 0x1161
#define TBase 0x11A7
#define LCount 19
#define VCount 21
#define TCount 28
#define NCount (VCount * TCount)
#define SCount (LCount * NCount)
/**
* g_unicode_canonical_ordering:
* @string: a UCS-4 encoded string.
* @len: the maximum length of @string to use.
*
* Computes the canonical ordering of a string in-place.
* This rearranges decomposed characters in the string
* according to their combining classes. See the Unicode
* manual for more information.
**/
void
g_unicode_canonical_ordering (gunichar *string,
gsize len)
{
gsize i;
int swap = 1;
while (swap)
{
int last;
swap = 0;
last = COMBINING_CLASS (string[0]);
for (i = 0; i < len - 1; ++i)
{
int next = COMBINING_CLASS (string[i + 1]);
if (next != 0 && last > next)
{
gsize j;
/* Percolate item leftward through string. */
for (j = i + 1; j > 0; --j)
{
gunichar t;
if (COMBINING_CLASS (string[j - 1]) <= next)
break;
t = string[j];
string[j] = string[j - 1];
string[j - 1] = t;
swap = 1;
}
/* We're re-entering the loop looking at the old
character again. */
next = last;
}
last = next;
}
}
}
/* http://www.unicode.org/unicode/reports/tr15/#Hangul
* r should be null or have sufficient space. Calling with r == NULL will
* only calculate the result_len; however, a buffer with space for three
* characters will always be big enough. */
static void
decompose_hangul (gunichar s,
gunichar *r,
gsize *result_len)
{
gint SIndex = s - SBase;
/* not a hangul syllable */
if (SIndex < 0 || SIndex >= SCount)
{
if (r)
r[0] = s;
*result_len = 1;
}
else
{
gunichar L = LBase + SIndex / NCount;
gunichar V = VBase + (SIndex % NCount) / TCount;
gunichar T = TBase + SIndex % TCount;
if (r)
{
r[0] = L;
r[1] = V;
}
if (T != TBase)
{
if (r)
r[2] = T;
*result_len = 3;
}
else
*result_len = 2;
}
}
/* returns a pointer to a null-terminated UTF-8 string */
static const gchar *
find_decomposition (gunichar ch,
gboolean compat)
{
int start = 0;
int end = G_N_ELEMENTS (decomp_table);
if (ch >= decomp_table[start].ch &&
ch <= decomp_table[end - 1].ch)
{
while (TRUE)
{
int half = (start + end) / 2;
if (ch == decomp_table[half].ch)
{
int offset;
if (compat)
{
offset = decomp_table[half].compat_offset;
if (offset == G_UNICODE_NOT_PRESENT_OFFSET)
offset = decomp_table[half].canon_offset;
}
else
{
offset = decomp_table[half].canon_offset;
if (offset == G_UNICODE_NOT_PRESENT_OFFSET)
return NULL;
}
return &(decomp_expansion_string[offset]);
}
else if (half == start)
break;
else if (ch > decomp_table[half].ch)
start = half;
else
end = half;
}
}
return NULL;
}
/**
* g_unicode_canonical_decomposition:
* @ch: a Unicode character.
* @result_len: location to store the length of the return value.
*
* Computes the canonical decomposition of a Unicode character.
*
* Return value: a newly allocated string of Unicode characters.
* @result_len is set to the resulting length of the string.
**/
gunichar *
g_unicode_canonical_decomposition (gunichar ch,
gsize *result_len)
{
const gchar *decomp;
const gchar *p;
gunichar *r;
/* Hangul syllable */
if (ch >= 0xac00 && ch <= 0xd7a3)
{
decompose_hangul (ch, NULL, result_len);
r = g_malloc (*result_len * sizeof (gunichar));
decompose_hangul (ch, r, result_len);
}
else if ((decomp = find_decomposition (ch, FALSE)) != NULL)
{
/* Found it. */
int i;
*result_len = g_utf8_strlen (decomp, -1);
r = g_malloc (*result_len * sizeof (gunichar));
for (p = decomp, i = 0; *p != '\0'; p = g_utf8_next_char (p), i++)
r[i] = g_utf8_get_char (p);
}
else
{
/* Not in our table. */
r = g_malloc (sizeof (gunichar));
*r = ch;
*result_len = 1;
}
/* Supposedly following the Unicode 2.1.9 table means that the
decompositions come out in canonical order. I haven't tested
this, but we rely on it here. */
return r;
}
/* L,V => LV and LV,T => LVT */
static gboolean
combine_hangul (gunichar a,
gunichar b,
gunichar *result)
{
gint LIndex = a - LBase;
gint SIndex = a - SBase;
gint VIndex = b - VBase;
gint TIndex = b - TBase;
if (0 <= LIndex && LIndex < LCount
&& 0 <= VIndex && VIndex < VCount)
{
*result = SBase + (LIndex * VCount + VIndex) * TCount;
return TRUE;
}
else if (0 <= SIndex && SIndex < SCount && (SIndex % TCount) == 0
&& 0 < TIndex && TIndex < TCount)
{
*result = a + TIndex;
return TRUE;
}
return FALSE;
}
#define CI(Page, Char) \
((compose_table[Page] >= G_UNICODE_MAX_TABLE_INDEX) \
? (compose_table[Page] - G_UNICODE_MAX_TABLE_INDEX) \
: (compose_data[compose_table[Page]][Char]))
#define COMPOSE_INDEX(Char) \
(((Char >> 8) > (COMPOSE_TABLE_LAST)) ? 0 : CI((Char) >> 8, (Char) & 0xff))
static gboolean
combine (gunichar a,
gunichar b,
gunichar *result)
{
gushort index_a, index_b;
if (combine_hangul (a, b, result))
return TRUE;
index_a = COMPOSE_INDEX(a);
if (index_a >= COMPOSE_FIRST_SINGLE_START && index_a < COMPOSE_SECOND_START)
{
if (b == compose_first_single[index_a - COMPOSE_FIRST_SINGLE_START][0])
{
*result = compose_first_single[index_a - COMPOSE_FIRST_SINGLE_START][1];
return TRUE;
}
else
return FALSE;
}
index_b = COMPOSE_INDEX(b);
if (index_b >= COMPOSE_SECOND_SINGLE_START)
{
if (a == compose_second_single[index_b - COMPOSE_SECOND_SINGLE_START][0])
{
*result = compose_second_single[index_b - COMPOSE_SECOND_SINGLE_START][1];
return TRUE;
}
else
return FALSE;
}
if (index_a >= COMPOSE_FIRST_START && index_a < COMPOSE_FIRST_SINGLE_START &&
index_b >= COMPOSE_SECOND_START && index_b < COMPOSE_SECOND_SINGLE_START)
{
gunichar res = compose_array[index_a - COMPOSE_FIRST_START][index_b - COMPOSE_SECOND_START];
if (res)
{
*result = res;
return TRUE;
}
}
return FALSE;
}
gunichar *
_g_utf8_normalize_wc (const gchar *str,
gssize max_len,
GNormalizeMode mode)
{
gsize n_wc;
gunichar *wc_buffer;
const char *p;
gsize last_start;
gboolean do_compat = (mode == G_NORMALIZE_NFKC ||
mode == G_NORMALIZE_NFKD);
gboolean do_compose = (mode == G_NORMALIZE_NFC ||
mode == G_NORMALIZE_NFKC);
n_wc = 0;
p = str;
while ((max_len < 0 || p < str + max_len) && *p)
{
const gchar *decomp;
gunichar wc = g_utf8_get_char (p);
if (wc >= 0xac00 && wc <= 0xd7a3)
{
gsize result_len;
decompose_hangul (wc, NULL, &result_len);
n_wc += result_len;
}
else
{
decomp = find_decomposition (wc, do_compat);
if (decomp)
n_wc += g_utf8_strlen (decomp, -1);
else
n_wc++;
}
p = g_utf8_next_char (p);
}
wc_buffer = g_new (gunichar, n_wc + 1);
last_start = 0;
n_wc = 0;
p = str;
while ((max_len < 0 || p < str + max_len) && *p)
{
gunichar wc = g_utf8_get_char (p);
const gchar *decomp;
int cc;
gsize old_n_wc = n_wc;
if (wc >= 0xac00 && wc <= 0xd7a3)
{
gsize result_len;
decompose_hangul (wc, wc_buffer + n_wc, &result_len);
n_wc += result_len;
}
else
{
decomp = find_decomposition (wc, do_compat);
if (decomp)
{
const char *pd;
for (pd = decomp; *pd != '\0'; pd = g_utf8_next_char (pd))
wc_buffer[n_wc++] = g_utf8_get_char (pd);
}
else
wc_buffer[n_wc++] = wc;
}
if (n_wc > 0)
{
cc = COMBINING_CLASS (wc_buffer[old_n_wc]);
if (cc == 0)
{
g_unicode_canonical_ordering (wc_buffer + last_start, n_wc - last_start);
last_start = old_n_wc;
}
}
p = g_utf8_next_char (p);
}
if (n_wc > 0)
{
g_unicode_canonical_ordering (wc_buffer + last_start, n_wc - last_start);
last_start = n_wc;
}
wc_buffer[n_wc] = 0;
/* All decomposed and reordered */
if (do_compose && n_wc > 0)
{
gsize i, j;
int last_cc = 0;
last_start = 0;
for (i = 0; i < n_wc; i++)
{
int cc = COMBINING_CLASS (wc_buffer[i]);
if (i > 0 &&
(last_cc == 0 || last_cc < cc) &&
combine (wc_buffer[last_start], wc_buffer[i],
&wc_buffer[last_start]))
{
for (j = i + 1; j < n_wc; j++)
wc_buffer[j-1] = wc_buffer[j];
n_wc--;
i--;
if (i == last_start)
last_cc = 0;
else
last_cc = COMBINING_CLASS (wc_buffer[i-1]);
continue;
}
if (cc == 0)
last_start = i;
last_cc = cc;
}
}
wc_buffer[n_wc] = 0;
return wc_buffer;
}
/**
* g_utf8_normalize:
* @str: a UTF-8 encoded string.
* @len: length of @str, in bytes, or -1 if @str is nul-terminated.
* @mode: the type of normalization to perform.
*
* Converts a string into canonical form, standardizing
* such issues as whether a character with an accent
* is represented as a base character and combining
* accent or as a single precomposed character. The
* string has to be valid UTF-8, otherwise %NULL is
* returned. You should generally call g_utf8_normalize()
* before comparing two Unicode strings.
*
* The normalization mode %G_NORMALIZE_DEFAULT only
* standardizes differences that do not affect the
* text content, such as the above-mentioned accent
* representation. %G_NORMALIZE_ALL also standardizes
* the "compatibility" characters in Unicode, such
* as SUPERSCRIPT THREE to the standard forms
* (in this case DIGIT THREE). Formatting information
* may be lost but for most text operations such
* characters should be considered the same.
*
* %G_NORMALIZE_DEFAULT_COMPOSE and %G_NORMALIZE_ALL_COMPOSE
* are like %G_NORMALIZE_DEFAULT and %G_NORMALIZE_ALL,
* but returned a result with composed forms rather
* than a maximally decomposed form. This is often
* useful if you intend to convert the string to
* a legacy encoding or pass it to a system with
* less capable Unicode handling.
*
* Return value: a newly allocated string, that is the
* normalized form of @str, or %NULL if @str is not
* valid UTF-8.
**/
gchar *
g_utf8_normalize (const gchar *str,
gssize len,
GNormalizeMode mode)
{
gunichar *result_wc = _g_utf8_normalize_wc (str, len, mode);
gchar *result;
result = g_ucs4_to_utf8 (result_wc, -1, NULL, NULL, NULL);
g_free (result_wc);
return result;
}
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