Thank you,
I've now a better understanding of DSL with Groovy.
Recently I've had to implement the State pattern in Java and C#, and it's clear that using a such DSL is more clear and concise !

In my C# application I've used an event (with the delegate notion) to notify some other part of my code when the current state moved from one state to another.
It would be interesting to do so with Groovy in order to execute some custom code when the FSM changes its current state.

Bertrand Goetzmann.
http://www.odelia-technologies.com/