/// <summary>
/// Processes primitive effects.
/// </summary>
/// <param name="relativeState">Relative state to be modified.</param>
private void ProcessPrimitiveEffects(IRelativeState relativeState)
{
foreach (var positivePredicate in Effects.GroundedPositivePredicateEffects)
{
if (relativeState.HasPredicate(positivePredicate))
{
relativeState.RemovePredicate(positivePredicate);
}
}
foreach (var negatedPredicate in Effects.GroundedNegativePredicateEffects)
{
if (relativeState.HasNegatedPredicate(negatedPredicate))
{
relativeState.RemoveNegatedPredicate(negatedPredicate);
}
}
foreach (var objectFunction in Effects.GroundedObjectFunctionAssignmentEffects)
{
var groundedValue = GroundingManager.GroundTermDeep(objectFunction.Value, OperatorSubstitution, relativeState);
ConstantTerm constantValue = groundedValue as ConstantTerm;
if (constantValue != null)
{
if (relativeState.GetObjectFunctionValue(objectFunction.Key) == constantValue.NameId)
{
relativeState.AssignObjectFunction(objectFunction.Key, ObjectFunctionTerm.UndefinedValue);
}
}
}
foreach (var numericFunction in Effects.GroundedNumericFunctionAssignmentEffects)
{
NumericAssignmentsBackwardsReplacer replacer = new NumericAssignmentsBackwardsReplacer(Effects.GroundedNumericFunctionAssignmentEffects, GroundingManager, OperatorSubstitution, new Substitution());
INumericExpression reducedAssignExpression = replacer.Replace(numericFunction.Value);
Number assignNumber = reducedAssignExpression as Number;
if (assignNumber != null)
{
if (relativeState.GetNumericFunctionValue(numericFunction.Key).Equals(assignNumber.Value))
{
relativeState.AssignNumericFunction(numericFunction.Key, NumericFunction.UndefinedValue);
}
}
}
}
/// <summary>
/// Generates all possible PDDL states meeting conditions specified by the relative state. Lazy generated via yield return.
/// </summary>
/// <param name="relativeState">Reference relative state.</param>
/// <param name="problem">Planning problem.</param>
/// <returns>All possible PDDL states meeting the conditions.</returns>
public static IEnumerable <IState> EnumerateStates(IRelativeState relativeState, Problem problem)
{
// note: numeric function assignments are not enumerated (as it is generally infinite), but only fixed by the values of the source state
Func <IAtom, bool?> predicateChecker = (predicate) =>
{
if (relativeState.HasPredicate(predicate))
{
return(true);
}
else if (relativeState.HasNegatedPredicate(predicate))
{
return(false);
}
return(null);
};
Func <IAtom, int> objectFunctionChecker = relativeState.GetObjectFunctionValue;
IState initState = new State(problem.IdManager);
foreach (var numericFunction in relativeState.GetNumericFunctions())
{
initState.AssignNumericFunction(numericFunction.Key, numericFunction.Value);
}
var predicates = problem.EvaluationManager.GroundingManager.GetAllGroundedPredicates();
var objectFunctions = problem.EvaluationManager.GroundingManager.GetAllGroundedObjectFunctions();
foreach (var state in EnumerateStatesByPredicates(0, predicates, initState, predicateChecker))
{
foreach (var resultState in EnumerateStatesByObjectFunctions(0, objectFunctions, state, objectFunctionChecker))
{
yield return(resultState);
}
}
}