NAME

Symbol - Symbol objects and API for them.

Typedefs

typedef struct MSymbolStruct * MSymbol
Type of symbols.

MSymbol msymbol (const char *name)
Get a symbol. MSymbol msymbol_as_managing_key (const char *name)
Create a managing key. int msymbol_is_managing_key (MSymbol symbol)
Check if a symbol is a managing key. MSymbol msymbol_exist (const char *name)
Search for a symbol that has a specified name. char * msymbol_name (MSymbol symbol)
Get symbol name. int msymbol_put (MSymbol symbol, MSymbol key, void *val)
Set the value of a symbol property. void * msymbol_get (MSymbol symbol, MSymbol key)
Get the value of a symbol property. int msymbol_put_func (MSymbol symbol, MSymbol key, M17NFunc func)
Set the value (function pointer) of a symbol property. M17NFunc msymbol_get_func (MSymbol symbol, MSymbol key)
Get the value (function pointer) of a symbol property.

Variables

MSymbol Mnil
Symbol whose name is 'nil'. MSymbol Mt
Symbol whose name is 't'. MSymbol Mstring
Symbol whose name is 'string'. MSymbol Msymbol
Symbol whose name is 'symbol'.

Detailed Description

Symbol objects and API for them.

The m17n library uses objects called symbols as unambiguous identifiers. Symbols are similar to atoms in the X library, but a symbol can have zero or more symbol properties. A symbol property consists of a key and a value, where key is also a symbol and value is anything that can be cast to (void *). 'The symbol property that belongs to the symbol S and whose key is K' may be shortened to 'K property of S'.

Symbols are used mainly in the following three ways.

•: As keys of symbol properties and other properties.

•: To represent various objects, e.g. charsets, coding systems, fontsets.

•: As arguments of the m17n library functions to control their behavior.

There is a special kind of symbol, a managing key. The value of a property whose key is a managing key must be a managed object. See Managed Object for the detail.

Typedef Documentation

typedef struct MSymbolStruct* MSymbol

Type of symbols.

The type MSymbol is for a symbol object. Its internal structure is concealed from application programs.

Variable Documentation

MSymbol Mnil

Symbol whose name is 'nil'.

The symbol Mnil has the name 'nil' and, in general, represents false or no. When coerced to 'int', its value is zero. Mnil can't have any symbol property.

MSymbol Mt

Symbol whose name is 't'.

The symbol Mt has the name 't' and, in general, represents true or yes.

MSymbol Mstring

Symbol whose name is 'string'.

The symbol Mstring has the name 'string' and is used as an argument of the functions mchar_define_property(), etc.

MSymbol Msymbol

Symbol whose name is 'symbol'.

The symbol Msymbol has the name 'symbol' and is used as an argument of the functions mchar_define_property(), etc.

COPYRIGHT

Copyright (C) 2001 Information-technology Promotion Agency (IPA)
Copyright (C) 2001-2009 National Institute of Advanced Industrial Science and Technology (AIST)
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License <http://www.gnu.org/licenses/fdl.html>.