Re: [clisp-list] Re: truly dynamic FFI in CVS

[Hoehle, Joerg-C. <Joe...@t-...>]

Hi,

Friday, August 08, 2003, 11:05:55 PM, somebody wrote:

>>> It's a pity that def-call-in hardly can be made dynamic while it
seems
>>> crucial for typical event-driven windows app.
>> well, this is caused by the non-dynamic nature of C/C++, right?
>But you have already done dynamic parameter/result translation! How
>about to made a fixed number of entry points/slots being defined by
>def-call-in ? (and clisp being compiled as a shared library)

I believe somebody is mislead. CLISP FFI has little problems with callbacks AFAIK. DEF-CALL-IN is not the way to go for dynamic callbacks. C/C++ is not the problem.

If you want to install a callback (e.g. for an event driven loop), you need to invoke a def-call-out :library function which takes a C-FUNCTION object as parameter somewhere (or a C-STRUCT which contains such).
A Lisp function passed as parameter thereof will be converted to a callback function pointer that the foreign (C/C++/xyz) world will receive and can use.

Please try it out.

Regards,
 Jorg Hohle.