private IList <State> FindBranches(State s)
{
var branches = new List <State>();
var exp = _actionsToPerform.Observations[s.CurrentTime + 1].ToList();
var effect =
_currentAction?.Effects.FirstOrDefault(e => e.Time == s.CurrentTime + 1 - _currentAction.StartTime); //check
if (effect != null)
{
exp.Add(effect.Expression);
}
if (exp.Any())
{
//get conjunction
var fullExp = exp[0];
for (var i = 1; i < exp.Count; i++)
{
fullExp = new Expression.And(fullExp, exp[i]);
}
//convert expression to branches
//get all true evaluation -> foreach generate new state
var list = ExpressionMethods.GetAllFluentEvaluationsSatisfyingExpression(fullExp);
branches.AddRange(list.Select(fluentValues => new State
{
CurrentTime = s.CurrentTime + 1,
Fluents = fluentValues,
CurrentAction = _currentAction?.Action
}));
}
else
{
//fluents are derieved from parent
branches.Add(new State {
CurrentTime = s.CurrentTime + 1, Fluents = s.Fluents, CurrentAction = _currentAction?.Action
});
}
return(branches);
}
private bool FillState(State s)
{
if (s.CurrentTime < 0)
{
return(true); //accept the root artificial state at -1 time.
}
if (_currentAction != null)
{
if (_currentAction.StartTime + (_currentAction.Effects.Any() ? _currentAction.Effects.Max(e => e.Time) : 0) == s.CurrentTime)
{
_currentAction = null; //finish action
}
else
{
//set dependent fluents to occlusion
var expressions = _currentAction.Effects
.Where(e => e.Time + _currentAction.StartTime > s.CurrentTime).Select(e => e.Expression);
//foreach exp get all fluents to single list
//set each fluent from the list to occlusion
var fluents = new List <int>();
foreach (var expression in expressions)
{
fluents.AddRange(ExpressionMethods.FindAllFluentsInExpression(expression));
}
foreach (var i in fluents.Distinct())
{
s.Fluents[i] = FluentValue.UnderOcclusion;
}
}
}
//add triggers for state check all triggers sentence condition
foreach (var triggers in _sentences.Where(sen => sen is SenI.Triggers).Cast <SenI.Triggers>())
{
if (triggers.Condition == null ||
ExpressionMethods.CheckExpressionSatisfaction(triggers.Condition, s.Fluents) == FluentValue.True)
{
_actionsToPerform.Actions[s.CurrentTime].Add(triggers.Action);
}
}
//add releases observation
foreach (var releases in _sentences.Where(sen => sen is SenI.Releases).Cast <SenI.Releases>())
{
if (releases.Condition != null &&
ExpressionMethods.CheckExpressionSatisfaction(releases.Condition, s.Fluents) !=
FluentValue.True)
{
continue;
}
if (releases.Duration + s.CurrentTime <= _scenario.Time)
{
_actionsToPerform.Observations[releases.Duration + s.CurrentTime].Add(releases.Result);
}
}
if (GetActionsForTime(s.CurrentTime, out var action) && action > 0)
{
//start action
_currentAction = new ActionExecution
{
Action = action,
StartTime = s.CurrentTime
};
foreach (var causes in _sentences.OfType <SenI.Causes>().Where(se => se.Action == action))
{
if (ExpressionMethods.CheckExpressionSatisfaction(causes.Condition, s.Fluents) != FluentValue.True)
{
continue;
}
_currentAction.Effects.Add(new ActionEffect
{
Expression = causes.Result,
Time = causes.Duration
});
}
//invokes
foreach (var invokes in _sentences.OfType <SenI.Invokes>().Where(i => i.Invoker == action &&
(i.Condition == null || ExpressionMethods.CheckExpressionSatisfaction(i.Condition, s.Fluents) == FluentValue.True)))
{
var time = _currentAction.StartTime + _currentAction.Effects.Max(e => e.Time) + invokes.Delay;
if (time <= _scenario.Time)
{
_actionsToPerform.Actions[time].Add(invokes.Invokee);
}
}
}
//check state!
//check observations
var obs = _actionsToPerform.Observations[s.CurrentTime];
if (obs?.Any(o => ExpressionMethods.CheckExpressionSatisfaction(o, s.Fluents) != FluentValue.True) ?? false)
{
return(false); //model contradictory!
}
//check actions
var acs = _actionsToPerform.Actions[s.CurrentTime] ?? new List <int>();
return(acs.Count <= 1 || acs[0] == _currentAction.Action);
}
