From: Ingo Rohlfs
Subject: [CMUCL] Aliend Converting of C header to Lisp
Date: Sat, 30 Mar 2002 02:12:04 +0000
Message-ID: <m3663eiz2j.fsf@linux.local>

I had to convert this structur to an CMUCL Alien Function .. but had no
idea how to do this (cause of the little complicated types).
Can anybody give me a hint ?

typedef struct T_SYS {
  int (*type) (struct T_SYS *context, int tred );
  union {
    struct {
      int account;
      FILE *filep;
    } sysio;
    struct {
       int mem
    } system;
  }
} T_SYS;



Ingo

From: Tim Moore
Subject: Re: [CMUCL] Aliend Converting of C header to Lisp
Date: Sat, 30 Mar 2002 06:20:38 +0000
Message-ID: <a83lfm$79u$0@216.39.145.192>

On 30 Mar 2002 03:12:04 +0100, Ingo Rohlfs <·······@ex-astris.org> wrote:
>I had to convert this structur to an CMUCL Alien Function .. but had no
>idea how to do this (cause of the little complicated types).
>Can anybody give me a hint ?
>
>typedef struct T_SYS {
>  int (*type) (struct T_SYS *context, int tred );
>  union {
>    struct {
>      int account;
>      FILE *filep;
>    } sysio;
>    struct {
>       int mem
>    } system;
>  }
>} T_SYS;
>
>
>
>Ingo

Assuming that you don't actually want a union that defines no member:

(ALIEN:DEF-ALIEN-TYPE T-SYS
                       (ALIEN:STRUCT T-SYS
                        (TYPE
                         (*
                          (FUNCTION C-CALL:INT (* (ALIEN:STRUCT T-SYS))
                           C-CALL:INT)))
                        (FOO
                         (UNION NIL
                                (SYSIO
                                 (ALIEN:STRUCT NIL (ACCOUNT C-CALL:INT)
                                  (FILEP (* (* T)))))
                                (SYSTEM
                                 (ALIEN:STRUCT NIL (MEM C-CALL:INT)))))))

Tim