More unique Exceptions

[DatL4g]

trafficstars

Please separate your exceptions more uniquely as there is no way of operating special use-cases.

Functions throwing a IllegalStateException:

• spec (2x)
• dispatch
• checkSpecBlockSet

Maybe create something like this? Didn't create PR as I'm not sure how you want to adopt things, but here a simple example:

sealed interface FlowReduxException {
	data object AlreadyInitialized : IllegalStateException(
                "State machine spec has already been set. " +
                    "It's only allowed to call spec {...} once.",
            ), FlowReduxException

	data object AlreadyCollected : IllegalStateException(
                        "Can not collect state more than once at the same time. Make sure the" +
                            "previous collection is cancelled before starting a new one. " +
                            "Collecting state in parallel would lead to subtle bugs.",
                    ), FlowReduxException

	data object NotInitialized : IllegalStateException(
                """
                    No state machine specs are defined. Did you call spec { ... } in init {...}?
                    Example usage:

                    class MyStateMachine : FlowReduxStateMachine<State, Action>(InitialState) {

                        init{
                            spec {
                                inState<FooState> {
                                    on<BarAction> { ... }
                                }
                                ...
                            }
                        }
                    }
                """.trimIndent(),
            ), FlowReduxException

	data class NotCollected(val action: A) : IllegalStateException(
                "Cannot dispatch action $action because state Flow of this " +
                    "FlowReduxStateMachine is not collected yet. " +
                    "Start collecting the state Flow before dispatching any action.",
            ), FlowReduxException
}