Hi,
I am trying to convert an FFI cstruct definition into a union.
More exactly, the previous definition was :
(define-cstruct _XEvent
((type EventType)))
with EventType being defined elsewhere.
But this was an incomplete definition, and I now want to translate the
following C union:
typedef union _XEvent {
int type; /* must not be changed; first element */
XAnyEvent xany;
XKeyEvent xkey;
// ... the rest for later
} XEvent;
I searched the collects directory, but I see only a single and too simple
_union use, so I'm not sure how to use it.
I guessed the following:
(define _XEvent
(_union EventType ; type
_XAnyEvent ; xany
_XKeyEvent ; xkey
; etc.
))
(define (XEvent-type ev) (union-ref ev 0))
(define (XEvent-xany ev) (union-ref ev 1))
(define (XEvent-xkey ev) (union-ref ev 2))
However, now I don't use define-cstruct anymore (it would not work with
_union, would it?), so I don't have all the -tag, -pointer, etc. bindings,
which I need.
What should I do ?
Thanks,
Laurent
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