Re: [Help-smalltalk] dynamically creating a callback function

[Paolo Bonzini]

Krishna wrote:
> On 11/22/06, Brad Watson <address@hidden> wrote:
> > Does anyone have an idea on how a callback function mapped to a class 
> > and selector could be created dynamically ?  Lots of libraries that 
> > Ive examined have functions defined within them that require a 
> > callback function as one of the parameters.  It would be useful to be 
> > able define the callback function in smalltalk and then pass an 
> > address that maps it's way back to it.. Possible ?
>
> Checkout ffcall and libffi . Both offer the facility to build runtime
> trampolines. IIRC, CLISP uses ffcall.

If it is possiblle to pass an arbitrary pointer to the callback, you can 
use that to store the selector and receiver.  Then you use it to call 
back into Smalltalk.

Paolo