I am writing a GUI binding but unfortunately could not find a OO-style dispatching scheme that I was happy with so I wrote my own ( https://gist.github.com/deech/6528a75e480378182052 ). The design goal is to: - provide a single function that will dispatch to a custom implementation based on the type of argument it is given - allow the user to extend and subclass the hierarchy and override functions in a way that doesn't involve recompiling the binding - use as few new extensions as possible - provide as familiar an API as possible, thereby allowing users to leverage existing documentation maintained by the C++ project. The look-and-feel of the API is on lines 128-140. It should just be a stand-alone file that can be loaded into GHCI. Thanks for your feedback! -deech