private static List <List <Assignment> > EvaluateLogicalExpression(ParseTreeFOL_O expression, string[] subwords, string body)
{
if (expression.getTerm() != null)
{
Term term = expression.getTerm();
string[] freeVars = FOLSearcher.GetFreeVars(term);
return(TopDownFOLEvaluator.evaluateParsedExpression(term, subwords, freeVars, body));
}
else
{
List <List <Assignment> > leftTable = EvaluateLogicalExpression(expression.getLeftChild(), subwords, body);
List <List <Assignment> > rightTable = EvaluateLogicalExpression(expression.getRightChild(), subwords, body);
rightTable = FillInSolutions(rightTable, leftTable, subwords);
leftTable = FillInSolutions(leftTable, rightTable, subwords);
if (expression.getFolOperator() == FOLOperator.Disjunction)
{
leftTable.AddRange(rightTable.Where(r => !leftTable.Any(l => CompareSolutions(l, r))));
}
else
{
leftTable.RemoveAll(l => !rightTable.Any(r => CompareSolutions(l, r)));
}
return(leftTable);
}
}
public static string[] GetFreeVars(ParseTreeFOL_O expression)
{
if (expression.getTerm() != null)
{
return(GetFreeVars(expression.getTerm()));
}
return(GetFreeVars(expression.getLeftChild()).ToList().Concat(GetFreeVars(expression.getRightChild()).ToList()).Distinct().ToArray());
}
private static bool evaluateLogicalExpression(ParseTreeFOL_O expressionTree, List <Assignment> varVals)
{
FOLOperator?op = expressionTree.getFolOperator();
if (expressionTree.getTerm() != null)
{
return(TermEvaluator.evaluateTerm(expressionTree.getTerm(), varVals));
}
else
{
if (op == FOLOperator.Conjunction)
{
return(evaluateLogicalExpression(expressionTree.getLeftChild(), varVals) &&
evaluateLogicalExpression(expressionTree.getRightChild(), varVals));
}
else if (op == FOLOperator.Disjunction)
{
return(evaluateLogicalExpression(expressionTree.getLeftChild(), varVals) ||
evaluateLogicalExpression(expressionTree.getRightChild(), varVals));
}
}
throw (new Exception("Bad expression parsing"));
}