Hi list, forgive me if this is a somewhat vague question... but is there some kind of framework/system/approach for Guile where you could have different parts of your code register callback functions to react to a certain signal or message raised by any other part of the code? I'm thinking like dbus where I guess you can sort of send off a message but not really care who receives it. In chickadee you can register callbacks for the various input events, and i think that basic idea could be extended so long as (1) you could have any kind of event/signal you wanted; (2) call backs added could be specified as either persistent or one-time call-backs. It seems like it wouldn't be too hard to code something like that with just lists of callback functions tied to names/data in a tree. But maybe somebody has already thought of that or would suggest a better approach. Just running into this challenge in development where a function like "new-game" has to do 8 different things to 6 different data structures, but why not instead just have the code dealing with the 6 different objects register callbacks to receive the 'new-game signal? I think message passing is the wrong term because in message passing you specify the message connections between the different objects, right? Signal bus maybe? -- http://upgradefromwindows.com