/// <summary>
/// Evaluates the expression.
/// </summary>
/// <param name="expression">Expression.</param>
/// <returns>True if the expression is logically true, false otherwise.</returns>
public bool Visit(EqualsLiteralCNF expression)
{
bool evaluationResult = GroundingManager.GroundTermDeep(expression.LeftArgument, Substitution, ReferenceState).Equals(
GroundingManager.GroundTermDeep(expression.RightArgument, Substitution, ReferenceState));
return(!expression.IsNegated == evaluationResult);
}
/// <summary>
/// Visits and handles the effect.
/// </summary>
/// <param name="effect">Effect.</param>
public void Visit(ObjectAssignEffect effect)
{
IAtom groundedFunctionAtom = GroundingManager.GroundAtomDeep(effect.FunctionAtom, Substitution, State);
ITerm value = GroundingManager.GroundTermDeep(effect.Value, Substitution, State);
ConstantTerm constantTermValue = (ConstantTerm)value;
State.AssignObjectFunction(groundedFunctionAtom, constantTermValue.NameId);
}
/// <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>
/// Visits and evaluates equals expression.
/// </summary>
/// <param name="expression">Equals expression.</param>
/// <returns>True if the specified expression evaluates as true, false otherwise.</returns>
public bool Visit(EqualsExpression expression)
{
return(GroundingManager.GroundTermDeep(expression.LeftArgument, Substitution, ReferenceState).Equals(
GroundingManager.GroundTermDeep(expression.RightArgument, Substitution, ReferenceState)));
}
