Does anyone know if there is a nice way to build the Finite State Machine
(FSM) of a Ruby regexp ?

Assuming the native ruby regexp parser used a (more or less explicit) FSM
I first thought that there was some builtin way to access or re-build it
but, after reading some reference docs (Regexp class) and posts I can't
see any useful methods to do this. But I would be happy to be wrong about
this...

As an alternative solution, I wonder if someone knows about a module that
could parse Ruby regexps (accepting exactly the same regexp grammar as
Ruby) and let me read the associated FSM (or whatever graph-like structure
representing the regexp).

Any help will be greatly appreciated. Thanks sincerely.