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Character
[CORE API]

Character objects and API for them. More...

Variables: Keys of character properties
Key for script. These symbols are used as keys of character properties. The symbol Mscript has the name "script" and is used as the key of a character property. The value of such a property is a symbol representing the script to which the character belongs. Each symbol that represents a script has one of the names listed in the Unicode Technical Report #24.
MSymbol	Mscript
MSymbol	Mname
	Key for character name.
MSymbol	Mcategory
	Key for general category.
MSymbol	Mcombining_class
	Key for canonical combining class.
MSymbol	Mbidi_category
	Key for bidi category.
MSymbol	Msimple_case_folding
	Key for corresponding single lowercase character.
MSymbol	Mcomplicated_case_folding
	Key for corresponding multiple lowercase characters.
Defines
#define	MCHAR_MAX
	Maximum character code.
Functions
MSymbol	mchar_define_property (const char *name, MSymbol type)
	Define a character property.
void *	mchar_get_prop (int c, MSymbol key)
	Get the value of a character property.
int	mchar_put_prop (int c, MSymbol key, void *val)
	Set the value of a character property.
MCharTable *	mchar_get_prop_table (MSymbol key, MSymbol *type)
	Get the char-table for a character property.

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Detailed Description

The m17n library represents a character by a character code (an integer). The minimum character code is 0. The maximum character code is defined by the macro MCHAR_MAX. It is assured that MCHAR_MAX is not smaller than 0x3FFFFF (22 bits).

Characters 0 to 0x10FFFF are equivalent to the Unicode characters of the same code values.

A character can have zero or more properties called character properties. A character property consists of a key and a value, where key is a symbol and value is anything that can be cast to (void *). "The character property that belongs to character C and whose key is K" may be shortened to "the K property of C".

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Define Documentation

#define MCHAR_MAX

The macro MCHAR_MAX gives the maximum character code.

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Function Documentation

MSymbol mchar_define_property	(	const char *	name,
		MSymbol	type
	)

The mchar_define_property() function searches the m17n database for a data whose tags are <Mchar_table, type, sym >. Here, sym is a symbol whose name is name. type must be Mstring, Mtext, Msymbol, Minteger, or Mplist.

Return value:

If the operation was successful, mchar_define_property() returns sym. Otherwise it returns Mnil.

Errors:

MERROR_DB

See Also:

mchar_get_prop(), mchar_put_prop()

void* mchar_get_prop	(	int	c,
		MSymbol	key
	)

The mchar_get_prop() function searches character c for the character property whose key is key.

Return value:

If the operation was successful, mchar_get_prop() returns the value of the character property. Otherwise it returns NULL.

Errors:

MERROR_SYMBOL, MERROR_DB

See Also:

mchar_define_property(), mchar_put_prop()

int mchar_put_prop	(	int	c,
		MSymbol	key,
		void *	val
	)

The mchar_put_prop() function searches character c for the character property whose key is key and assigns val to the value of the found property.

Return value:

If the operation was successful, mchar_put_prop() returns 0. Otherwise, it returns -1.

Errors:

MERROR_SYMBOL, MERROR_DB

See Also:

mchar_define_property(), mchar_get_prop()

MCharTable* mchar_get_prop_table	(	MSymbol	key,
		MSymbol *	type
	)

The mchar_get_prop_table() function returns a char-table that contains the character property whose key is key. If type is not NULL, this function stores the type of the property in the place pointed by type. See mchar_define_property() for types of character property.

Return value:

If key is a valid character property key, this function returns a char-table. Otherwise NULL is retuned.

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Variable Documentation

MSymbol Mscript

MSymbol Mname

The symbol Mname has the name "name" and is used as the key of a character property. The value of such a property is a C-string representing the name of the character.

MSymbol Mcategory

The symbol Mcategory has the name "category" and is used as the key of a character property. The value of such a property is a symbol representing the general category of the character.

Each symbol that represents a general category has one of the names listed as abbreviations for General Category in Unicode.

MSymbol Mcombining_class

The symbol Mcombining_class has the name "combining-class" and is used as the key of a character property. The value of such a property is an integer that represents the canonical combining class of the character.

The meaning of each integer that represents a canonical combining class is identical to the one defined in Unicode.

MSymbol Mbidi_category

The symbol Mbidi_category has the name "bidi-category" and is used as the key of a character property. The value of such a property is a symbol that represents the bidirectional category of the character.

Each symbol that represents a bidirectional category has one of the names listed as types of Bidirectional Category in Unicode.

MSymbol Msimple_case_folding

The symbol Msimple_case_folding has the name "simple-case-folding" and is used as the key of a character property. The value of such a property is the corresponding single lowercase character that is used when comparing M-texts ignoring cases.

If a character requires a complicated comparison (i.e. cannot be compared by simply mapping to another single character), the value of such a property is 0xFFFF. In this case, the character has another property whose key is Mcomplicated_case_folding.

MSymbol Mcomplicated_case_folding

The symbol Mcomplicated_case_folding has the name "complicated-case-folding" and is used as the key of a character property. The value of such a property is the corresponding M-text that contains a sequence of lowercase characters to be used for comparing M-texts ignoring case.

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