On Thu, Apr 17, 2003 at 06:20:34PM +0900, daniel wrote: > I known this all (I'm using a thread now). I'm only searching for an > implementation of a callback fn... > > I'm checking tk now (it's ``bind?? functions). You could mean several things by a 'callback function': - you can simply past a Proc object. It keeps all the bindings to the environment it was created in, and can be called at any time by <var>.call(args) - you might be thinking of a Binding object, which is as far as I understand just the variable binding part without the actual proc to run :-) http://www.rubycentral.com/book/ref_c_binding.html - you might be thinking of continuations But the nearest thing to what I understand by a 'callback function' is simply a Proc that you pass to the person you want to call you back. Regards, Brian.