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 List <List <Assignment> > Search(string body, string query, bool topDownSearch)
{
List <string> subwords = getAllSubwords(body);
string folExpression = query.Substring(query.IndexOf(":=") + 2);
string freeVarsString = query.Substring(query.IndexOf('(') + 1).Substring(0, query.IndexOf(')') - 2);
string[] freeVars = freeVarsString.Split(',');
ParseTreeFOL_Q parsedExpression = FOLParser.Parse(folExpression, body);
List <List <Assignment> > res;
if (topDownSearch)
{
res = TopDownFOLEvaluator.evaluateParsedExpression(parsedExpression, subwords.ToArray(), freeVars, body);
}
else
{
res = BottomUpFOLEvaluator.EvaluateParsedExpression(parsedExpression, subwords.ToArray(), freeVars, body);
}
return(res);
}