Re: Using a cl_object in Lisp

Hi Stewart,

cl_object's are declared as :object type in ECL's ffi, so

     (ffi:def-function "getObject" ((lo :pointer-void)) :returning :object)
     (ffi:def-function "setObject" ((lo :pointer-void) (clo :object)))

should work. CFFI does not support this as far as i know.

Hope that helps,
Marius Gerbershagen

Am 29.07.2018 um 00:40 schrieb Stewart M.:
> To clarify, the issue is not with C++, which I am successfully wrapping 
> with C.
> 
> The actual issue is using the c_object type in Lisp--if it comes back as 
> a CFFI pointer, how can I use it in Lisp as a Lisp object?  Is there 
> something like:
> 
>    (ffi:pointer-to-lisp-object ptr)
> 
> 
> --
> Stewart Milberger
> Kavalogic, Inc.
> 
> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> On July 28, 2018 2:46 PM, Stewart M. <sjm-mail-g/[email protected]> wrote:
> 
>> I am using CFFI with ECL to interface to a C++ library, which has a 
>> C++ class with a data member of type 'cl_object'.  Simplified, my C++ 
>> code is:
>>
>>   class LispObject
>>   {
>>   public:
>>     cl_object object;
>>   };
>>
>>   extern "C" cl_object getObject(LispObject* lo) { return lo->object; }
>>   extern "C" void setObject(LispObject* lo, cl_object clo) { 
>> lo->object = clo; }
>>
>> The full code is:
>>
>> https://common-lisp.net/viewvc/clive/trunk/src/extensions/corral/CliveCorral/LispObjectImpl.hpp?revision=149&view=markup#l59
>>
>> Can I somehow declare the 'cl_object' type for the 'getValue()' and 
>> 'setValue()' functions using CFFI 'defcfun' to get and set ECL 
>> objects?  Is there a technique using the lower-level FFI?  I am 
>> looking for a way to do this without compiling C code embedded in 
>> Lisp, which I am aware ECL can do.
>>
>> Thank you for any ideas!
>>
>> --
>> Stewart Milberger
>> Kavalogic, Inc.
>>
>