At the Lisp conference (ilc09.org), in his invited talk, he mainly talked about macros, but he first did an introduction to the basic PLOT concepts, and this is one of the things he said. He has not released general info about PLOT since he feels it’s not ready yet, but I’m pretty sure he intends to. He insists that he’s just doing this as a hobby. It does support multimethods.

I don’t know enough about PLOT nor Clojure yet to compare them. So many technologies to learn, so little time.

You’re right, multiple dispatch (as in CLOS) makes things better. But keeping data and functionality separate is exactly my point — data should not be tied to a particular implementation.

Clojure supports CLOS-style multiple dispatch without classes. Each “multimethod” has an arbitrary “dispatch function” that determines which method gets called. It’s very flexible, and very powerful. http://clojure.org/multimethods

My personal opinion is the OOP was used to make programming accessible, for better or worse, to a larger group of people. When building applications a lot of times it makes sense to have your code conform more closely to exactly what you want it to do, instead of spending massive amounts of time defining objects and re-factoring your inheritance hierarchy.

I think your example of JSON is perfect representation of getting a lot of functionality out of a simple standard.

When you use languages which support multiple dispatch, you see that the argument for keeping data and functionality separate is strenghened, but at the same time there’s a clarity on your objects that lets them know which functions can be applied to them.

This may seem unclear but it’s difficult to explain other than you’re right, given the constraints of your language, but if you look past it, you will come around again.