Code replication in module oracle.py

[tbazin]

The codes for classes FactorOracle, MO and VMO are all very close and share many identical lines, making it hard to uniformly update it.
This could probably be fixed by refactoring the code.

[wangsix]

My original intent was to have the basic FactorOracle as the parent class. FO and MO inherited FactOracle. For VMO, it`s a variant of MO that is still under experiment. I agree that right now it is pretty difficult to update everything consistently, so please let me know your suggestions.

[tbazin]

I'm currently looking at it to see to which extent we can take advantage of the inheritance mechanism to simplify everything. Might not be super easy, but it'll save us some hassle in the future!
I'll keep You update on that.

[tbazin]

For starters, I think the function add_state should be modified to be uniform across all implementations.
What really differs between the different versions is the way distances between data are computed and how new clusters are created, ie. the symbolization.

With this done, -- if I'm not mistaken -- the processing can be done on an abstract level, regardless of the underlying data's type.

[wangsix]

What do you mean by modifying them to be uniform? Thanks!

[tbazin]

Have it become an explicit function within the base class FactorOracle, with an implementation shared by all subclasses (this would find the lrs, the transitions, etc. based on purely comparing the symbols) which would make calls to some functions like symbolize (or whatever).
These auxiliary functions would themselves be sub-classed, with respect to the various implementations. They would for instance turn a concrete data-chunk for the VMO into a symbol for the Factor Oracle and add the corresponding symbol to the oracle's states.

Is it clear?