Calling Objective C/Cocoa code from R

Guillaume,

I have a simulation model (command line tool) written in Objective C/ 
Cocoa. I would like to know if it is possible to call it from R and  
get the results into R as well. The documentation explains how to do  
it with C or Fortran, but I have not found anything with Objective C/ 
Cocoa. Has anyone tried do this or do you know an example explaining  
how?

ObjectiveC uses the same ABI as C (it's in fact just a very thin layer  
above C), so you can safely use R's C API. In addition, if you want to  
instantiate ObjC objects and pass messages (without going through  
function calls), you can use one of the ObjC packages around: Cocoa (http://www.rforge.net/Cocoa/ 
  ) or RObjectiveC (http://www.omegahat.org/RObjectiveC/ ).

All of the above assumes that you want to use that tool as a library  
(R supports ObjC in packages out of the box). If you want to just  
invoke it on the command line, you can use the regular system()  
interface.

Cheers,
Simon