/// <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 the expression.
/// </summary>
/// <param name="expression">Expression.</param>
public IElementCNF Visit(NumericCompareLiteralCNF expression)
{
// 1.) Evaluates both of the arguments by NumericAssignmentsBackwardsReplacer - every numeric function instance is replaced by
// the available numeric assignments from effects and the whole numeric expression is reduced (partially or fully evaluated).
// 2.) In case of the full reduction of both arguments, the numeric comparison is evaluated - if successfully, the whole condition
// is satisfied and we can remove it (i.e. return null).
// 3.) Otherwise, the modified numeric compare expression is returned, replacing the original condition.
var numericAssignEffects = Effects.GroundedNumericFunctionAssignmentEffects;
if (numericAssignEffects.Count == 0)
{
// no assignment effects available, just return a copy of the original expression
return(expression.Clone());
}
NumericAssignmentsBackwardsReplacer replacer = new NumericAssignmentsBackwardsReplacer(numericAssignEffects, GroundingManager, OperatorSubstitution, ExpressionSubstitution);
INumericExpression newLeftNumericExpression = replacer.Replace(expression.LeftArgument);
INumericExpression newRightNumericExpression = replacer.Replace(expression.RightArgument);
UsedGroundedFunctions.UnionWith(replacer.ReplacedFunctionAtomsInSubExpression);
Number leftNumber = newLeftNumericExpression as Number;
Number rightNumber = newRightNumericExpression as Number;
if (leftNumber != null && rightNumber != null)
{
bool relationHolds = NumericCompareExpression.ApplyCompare(expression.Operator, leftNumber.Value, rightNumber.Value);
if ((relationHolds && !expression.IsNegated) || (!relationHolds && expression.IsNegated))
{
// the numeric comparison was successful -> condition is satisfied, i.e. remove
return(null);
}
}
// modified numeric compare expression, replacing the original one
return(new NumericCompareLiteralCNF(expression.Operator, newLeftNumericExpression, newRightNumericExpression, expression.IsNegated));
}