Re: [Chicken-users] Objective-C interface (sort of...)

[Thomas Chust]

Am 24.11.2005, 13:44 Uhr, schrieb felix winkelmann <address@hidden>:

> [...]
> libffi should work fine on OS X, so I don't see a problem here.

It should, but it never did for me... After all the failed attempts, I have
developed a certain dislike for the libffi library ;)

> objc_msgSendv() might not solve our problems, since we have to construct
> arguments by hand.

As far as I can see, the objc_msgSendv family of functions or the
NSInvocation class respectively offer functionality that is equivalent to
that of libffi. As NSInvocation is also available in GNUStep, I think it
would be most portable to solve the message passing using that class.

> [...]
> But we have to return a valid signature. If the selector represents
> something on the Scheme side, I see no way to construct the argument
> types of a method signature, since we have to type-information (or we
> can provide a list of type-specifications, which is probably the only
> way to handle this).
> [...]

You have to decide on a static parameter signature for each of your scheme
methods anyway, if you don't want to cause large scale confusion in  
external
code that might call methods of your class.

The changing or deletion of classes during runtime in general and of method
signatures in specific would be very problematic -- especially if you start
considering multithreaded or network messaging scenarios.

cu,
Thomas