/// <summary>
/// Convert the builder into an immutable state machinee.
/// </summary>
/// <returns>Immutable state machine.</returns>
/// <exception cref="InvalidOperationException">Thrown when there is no registered initial state.<br/>
/// Or when there are no registered states.<br/>
/// Or when a transition refers to a non-registered state.</exception>
public StateMachine <TState, TEvent, TParameter> Build()
{
if (!hasInitialState)
{
throw new InvalidOperationException("The state machine builder doesn't have registered an initial state.");
}
if (this.states.Count == 0)
{
throw new InvalidOperationException("The state machine builder doesn't have registered any state.");
}
Dictionary <TState, int> statesMap = new Dictionary <TState, int>();
int i = 0;
foreach (KeyValuePair <TState, StateBuilder <TState, TEvent, TParameter> > kv in this.states)
{
statesMap.Add(kv.Key, i++);
}
List <State <TState, TEvent> > states = new List <State <TState, TEvent> >();
ListSlot <Transition <TState, TEvent> > transitions = new ListSlot <Transition <TState, TEvent> >(new List <Transition <TState, TEvent> >());
// TODO: Use deconstruction pattern when upload to .Net Standard 2.1
foreach (KeyValuePair <TState, StateBuilder <TState, TEvent, TParameter> > kv in this.states)
{
states.Add(kv.Value.ToState(kv.Key, transitions, statesMap));
}
return(new StateMachine <TState, TEvent, TParameter>(initialState.TryGetStateIndex(statesMap), states, transitions.Extract()));
}
internal State <TState, TEvent> ToState(TState state, ListSlot <Transition <TState, TEvent> > transitions, Dictionary <TState, int> statesMap)
{
Dictionary <TEvent, int> trans = new Dictionary <TEvent, int>();
// TODO: Use deconstruction pattern when upload to .Net Standard 2.1
foreach (KeyValuePair <TEvent, TransitionBuilder <TState, TEvent, TParameter> > kv in this.transitions)
{
int slot = transitions.Reserve();
trans.Add(kv.Key, slot);
if (kv.Value is null)
{
transitions.Store(new Transition <TState, TEvent>(-1, null, (0, 0)), slot);
}
else
{
transitions.Store(kv.Value.ToTransition(transitions, statesMap, State), slot);
}
}
return(new State <TState, TEvent>(
state,
Helper.Combine(ref onEntry, ref onEntryWithParameter),
Helper.Combine(ref onExit, ref onExitWithParameter),
Helper.Combine(ref onUpdate, ref onUpdateWithParameter),
trans
));
}
internal override Transition <TState, TEvent> ToTransition(ListSlot <Transition <TState, TEvent> > transitions, Dictionary <TState, int> statesMap, TState currentState)
{
if (slaves == null)
{
return(new Transition <TState, TEvent>(GetGoto(statesMap, currentState), GetDo(), (0, 0), guard));
}
(int from, int to)range = transitions.Reserve(slaves.Count);
int i = range.from;
foreach (SlaveTransitionBuilder <TState, TEvent, TParameter, SlaveTransitionBuilder <TState, TEvent, TParameter, TParent> > slave in slaves)
{
transitions.Store(slave.ToTransition(transitions, statesMap, currentState), i);
i++;
}
Debug.Assert(i == range.to);
return(new Transition <TState, TEvent>(GetGoto(statesMap, currentState), GetDo(), range, guard));
}
internal abstract Transition <TState, TEvent> ToTransition(ListSlot <Transition <TState, TEvent> > transitions, Dictionary <TState, int> statesMap, TState currentState);