Question

I have the following interface:

public IStateMachineConfigurator
{
  ??? Configure(StateMachine machine);
}

In the implementation I am calling some of the StateMachine methods to configure it like this:

machine.Configure(States.State1)
       .Allow(Triggers.Trigger1);

The question is, can I rely on the fact that the StateMachine object is a reference or should I use a return value or a return parameter like ref/out?

EDIT:
The state machine itself comes from a library and thus I cannot decide it’s implementation.

Answer 1

Yes, you can rely on the fact that StateMachine is an object reference. Some people might choose to return a bool or perhaps an enum to give the programmer some kind of hint as to what happened in the Configure method (ie. success/fail/no change/etc.). Others might choose to throw an exception in the event something goes wrong.

All are perfectly valid, just be careful how deep you chain the method together, as something like:

machine.Configure().Allow().someMethod().someOtherMethod()

Gets difficult to debug and trace.