[MacRuby-devel] integrating macruby into cocoa apps

I downloaded the early release of MacRuby hoping to integrate it into an existing cocoa application: I need to be able to run small amounts of user-supplied code to do custom string manipulations, and I thought MacRuby might be perfect for this. However, I don't see any obvious way to hand off an NSString with code and have it execute in some environment. Does such an API exist? The only entry point I saw was macruby_main(), which doesn't seem quite right, or ruby_exec_node() which looks pretty low-level. I realize that MacRuby is still in an early state, but I just wanted to be sure I wasn't overlooking something before I dug too much deeper. thanks, Niko