My latest post was on Injectionless DCI in Ruby was based on an approach using method_missing. I’ve since then diverted from that path. I started bench marking the code against simple ordinary method invocation and I wasn’t satisfied with the result. I could get the invocation of a role method down to a factor of 2.5 compared to a regular method call but could get any further improvement with my code using using method_missing so I needed a different approach which ended in a little piece of code I’ve called Moby it’s heavily inspired by how Marvin works and was surprisingly easy to write in Ruby.
All it really does is transformation of method invocation on roles. If there’s a suiting tole method it will call the role method if not it will send the message to self acting as a Ruby script would otherwise normally have done.
Since this happens at interpretation time there’s no performance hit when actually executing the method invocation. There will be an overload in the start up but once that’s paid there’s no penalty only the DCI goodies such as expressive code, separation between what the system is and what it does.
Being a first release and still having to convert more of the “canonical DCI examples” to use this piece of code I’m sure I’ll have to fix some bugs and make improvements to the code. The next example is the Dijkstra – Manhattan where I’m rewriting Jim Copliens #extend based version found on our fullOO site
When the Dijkstra example is done I will have to learn yet another new skill. How to construct a RubyGem until then the code can be found at http://github/runefs/Moby
Failing fast to learn a lot 