Maintaining context in chatbots

One of the harder problems that chatbot developers face is, how to maintain the context of conversation. While all the popular frameworks provide an opinionated take on how to maintain this context, none of them seem to be either simple or complete. Here let me introduce a reactive approach to maintain the context. The elegance of this approach is that the pushed callback captures the state of variables as a part of its closure context. When the callback is called, this state is retained and we can time travel back to the state when the context was actually set.