Macro

Summary

Defines an FLI union type corresponding to the C union type.

Package

fli

Signature

define-c-union name &rest slot-descriptions => list

slot-descriptions ::= { slot-name | ( slot-name slot-type )}*

Arguments

name

The name of the new union type descriptor.

slot-descriptions

A sequence of symbols, possibly with type descriptions, naming the slots of the union.

slot-name

A symbol naming the slot.

slot-type

The FLI type of the slot.

Values

list

The list (:union name ) .

Description

The macro define-c-union is used to define an FLI union type specifier, which corresponds to the C union type. It is a convenience function, as a union type could also be defined using define-foreign-type.

A union is an aggregate type, or collection, of other FLI types. The types contained in a union are referred to as slots, and can be accessed using the foreign-slot-type and foreign-slot-value functions.

Example

In the following example a union is defined using define-c-union , and the corresponding C code is given.

(fli:define-c-union a-point (x :int)

                            (color :byte)

                            (ident :char))

union a-point {

  int x;

  byte color;

  char ident;

};

See also

define-c-enum
define-c-struct
define-c-typedef
define-foreign-type