6 Type Reference

:struct

FLI type descriptor

Summary

Converts between a Lisp object and a Cstruct.

Package

fli

Syntax

:struct &rest slots

slots ::= {symbol | (symbol type)}*

Arguments

slots: A sequence of one or more slots making up the structure.
symbol: A symbol naming the slot.
type: The slot type. If no type is given it defaults to an:int.

Description

The FLI:struct type is an aggregate type, and converts between a Lisp object and a Cstruct type. The FLI structure consists of a collection of one or more slots. Each slot has a name and a type.

The foreign-slot-names, foreign-slot-type, and foreign-slot-value functions can be used to access and change the slots of the structure. The convenience FLI function define-c-struct is provided to simplify the definition of structures.

Example

In the following example a structure for passing coordinates to Windows functions is defined.

(fli:define-c-struct tagPOINT (x :long) (y :long))

: An instance of the structure is allocated and bound to the Lisp variableplace.

(setq place 
      (fli:allocate-foreign-object :type 'tagPOINT))

: Finally, thex slot ofplace is set to be4 usingfli:foreign-slot-value.

(seft (fli:foreign-slot-value place 'x) 4)

See Also
: define-c-struct
: foreign-slot-names
: foreign-slot-offset
: foreign-slot-pointer
: foreign-slot-type
: foreign-slot-value