Re: [Chicken-users] Inheriting from C++ in Chicken

[John Lenz]

On 12/20/04 03:33:20, Joel Reymont wrote:
> Folks,
>
> I successfully wrapped the guichan (http://guichan.darkbits.org) library
> in Chicken using SWIG wrappers. I also wrapped the SDL while I was at it.
>
> Guichan has a base Widget class. I'd prefer to extend this class in
> Scheme rather than in C++. What's the easiest way to achieve this?
>
> It seems to me that the simplest way to accomplish this is by generating
> custom C++ code , i.e. making a pass on the TinyCLOS code to generate the
> wrapper C++ class.
>
> Am I right here? Are there any examples of Scheme code parsing Scheme
> code? Is the Chicken compiler code easy to adopt here or should I just do
> this in a totally different manner?

SWIG supports this in other language modules, python, ruby, java.  It is  
called directors, and is cross language polymorphism.

Check out the python section of the swig docs,
http://www.swig.org/Doc1.3/Python.html#directors
The java section has some stuff about it as well.

You can also check out some of the examples in SWIG.  That is, look at  
Examples/python/extend

Lastly, here is a little more info, but some of it in here might be  
obsolete.  This is the original proposal for the feature
http://stm.lbl.gov/~tm2/swig/ProxyDoc.html

It is on my TODO list to add something like this to chicken and guile.   
Most of the support in SWIG is there, just the few language specific parts  
need to be written.

In any case, they provide one possible way and you might want to research  
it.

John