*
* 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.
+ * see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * SECTION:unicode
+ * @Title: Unicode Manipulation
+ * @Short_description: functions operating on Unicode characters and
+ * UTF-8 strings
+ * @See_also: g_locale_to_utf8(), g_locale_from_utf8()
+ *
+ * This section describes a number of functions for dealing with
+ * Unicode characters and strings. There are analogues of the
+ * traditional `ctype.h` character classification and case conversion
+ * functions, UTF-8 analogues of some string utility functions,
+ * functions to perform normalization, case conversion and collation
+ * on UTF-8 strings and finally functions to convert between the UTF-8,
+ * UTF-16 and UCS-4 encodings of Unicode.
+ *
+ * The implementations of the Unicode functions in GLib are based
+ * on the Unicode Character Data tables, which are available from
+ * [www.unicode.org](http://www.unicode.org/).
+ * GLib 2.8 supports Unicode 4.0, GLib 2.10 supports Unicode 4.1,
+ * GLib 2.12 supports Unicode 5.0, GLib 2.16.3 supports Unicode 5.1,
+ * GLib 2.30 supports Unicode 6.0.
*/
#include "config.h"
*
* Determines the canonical combining class of a Unicode character.
*
- * Return value: the combining class of the character
+ * Returns: the combining class of the character
*
* Since: 2.14
**/
gsize *result_len)
{
gint SIndex = s - SBase;
+ gint TIndex = SIndex % TCount;
- /* not a hangul syllable */
- if (SIndex < 0 || SIndex >= SCount)
+ if (r)
{
- if (r)
- r[0] = s;
- *result_len = 1;
+ r[0] = LBase + SIndex / NCount;
+ r[1] = VBase + (SIndex % NCount) / TCount;
}
- else
- {
- gunichar L = LBase + SIndex / NCount;
- gunichar V = VBase + (SIndex % NCount) / TCount;
- gunichar T = TBase + SIndex % TCount;
+ if (TIndex)
+ {
if (r)
- {
- r[0] = L;
- r[1] = V;
- }
-
- if (T != TBase)
- {
- if (r)
- r[2] = T;
- *result_len = 3;
- }
- else
- *result_len = 2;
+ r[2] = TBase + TIndex;
+ *result_len = 3;
}
+ else
+ *result_len = 2;
}
/* returns a pointer to a null-terminated UTF-8 string */
*
* Computes the canonical decomposition of a Unicode character.
*
- * Return value: a newly allocated string of Unicode characters.
+ * Returns: a newly allocated string of Unicode characters.
* @result_len is set to the resulting length of the string.
*
* Deprecated: 2.30: Use the more flexible g_unichar_fully_decompose()
* a legacy encoding or pass it to a system with
* less capable Unicode handling.
*
- * Return value: a newly allocated string, that is the
+ * Returns: a newly allocated string, that is the
* normalized form of @str, or %NULL if @str is not
* valid UTF-8.
**/
gunichar *a,
gunichar *b)
{
- gint SIndex;
- gunichar L, V, T;
+ gint SIndex, TIndex;
- SIndex = ch - SBase;
-
- if (SIndex < 0 || SIndex >= SCount)
+ if (ch < SBase || ch >= SBase + SCount)
return FALSE; /* not a hangul syllable */
- L = LBase + SIndex / NCount;
- V = VBase + (SIndex % NCount) / TCount;
- T = TBase + SIndex % TCount;
+ SIndex = ch - SBase;
+ TIndex = SIndex % TCount;
- if (T != TBase)
+ if (TIndex)
{
- gint LIndex, VIndex;
- gunichar LV;
-
/* split LVT -> LV,T */
- LIndex = L - LBase;
- VIndex = V - VBase;
- LV = SBase + (LIndex * VCount + VIndex) * TCount;
-
- *a = LV;
- *b = T;
+ *a = ch - TIndex;
+ *b = TBase + TIndex;
}
else
{
/* split LV -> L,V */
- *a = L;
- *b = V;
+ *a = LBase + SIndex / NCount;
+ *b = VBase + (SIndex % NCount) / TCount;
}
return TRUE;
* recursively call this function on @a. Or use
* g_unichar_fully_decompose().
*
- * See <ulink url="http://unicode.org/reports/tr15/">UAX#15</ulink>
+ * See
+ * [UAX#15](http://unicode.org/reports/tr15/)
* for details.
*
* Returns: %TRUE if the character could be decomposed
* Performs a single composition step of the
* Unicode canonical composition algorithm.
*
- * This function does not perform algorithmic composition
- * for Hangul characters, and does not include compatibility
- * compositions. It does, however, include 'singleton'
- * compositions which replace a character by a single
- * other character. To obtain these, pass zero for @b.
- *
- * This function includes algorithmic Hangul Jamo composition.
+ * This function includes algorithmic Hangul Jamo composition,
+ * but it is not exactly the inverse of g_unichar_decompose().
+ * No composition can have either of @a or @b equal to zero.
+ * To be precise, this function composes if and only if
+ * there exists a Primary Composite P which is canonically
+ * equivalent to the sequence <@a,@b>. See the Unicode
+ * Standard for the definition of Primary Composite.
*
* If @a and @b do not compose a new character, @ch is set to zero.
*
- * See <ulink url="http://unicode.org/reports/tr15/">UAX#15</ulink>
+ * See
+ * [UAX#15](http://unicode.org/reports/tr15/)
* for details.
*
* Returns: %TRUE if the characters could be composed
* g_unichar_fully_decompose:
* @ch: a Unicode character.
* @compat: whether perform canonical or compatibility decomposition
- * @result: location to store decomposed result, or %NULL
+ * @result: (allow-none): location to store decomposed result, or %NULL
* @result_len: length of @result
*
* Computes the canonical or compatibility decomposition of a
* The decomposed sequence is placed in @result. Only up to
* @result_len characters are written into @result. The length
* of the full decomposition (irrespective of @result_len) is
- * returned by the function. For canonical decomposition, a
- * result buffer of length 4 is always enough, whereas for
- * compatibility decomposition, a buffer of 18 is enough.
+ * returned by the function. For canonical decomposition,
+ * currently all decompositions are of length at most 4, but
+ * this may change in the future (very unlikely though).
+ * At any rate, Unicode does guarantee that a buffer of length
+ * 18 is always enough for both compatibility and canonical
+ * decompositions, so that is the size recommended. This is provided
+ * as %G_UNICHAR_MAX_DECOMPOSITION_LENGTH.
*
- * See <ulink url="http://unicode.org/reports/tr15/">UAX#15</ulink>
+ * See
+ * [UAX#15](http://unicode.org/reports/tr15/)
* for details.
*
- * Return value: the length of the full decomposition.
+ * Returns: the length of the full decomposition.
*
* Since: 2.30
**/
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