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);
}
}
private void Search(bool isTopDown)
{
DateTime start = DateTime.Now;
resultsGridView.Rows.Clear();
List <List <Assignment> > res;
try
{
string query = FOLParser.RemoveUnquotedInstancesOf(queryBox.Text, " ");
res = FOLSearcher.Search(materialBox.Text, query, isTopDown);
TimeSpan duration = DateTime.Now.Subtract(start);
MessageBox.Show($"Time taken to evaluate: {duration.Hours} hours, {duration.Minutes} minutes, {duration.Seconds} seconds, {duration.Milliseconds} milliseconds.");
start = DateTime.Now;
DisplayResults(res);
duration = DateTime.Now.Subtract(start);
MessageBox.Show($"Time taken to display: {duration.Hours} hours, {duration.Minutes} minutes, {duration.Seconds} seconds, {duration.Milliseconds} milliseconds.");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
static List <List <Assignment> > FillInSolutions(List <List <Assignment> > left, List <List <Assignment> > right, string[] subwords)
{
string[] leftVars = FOLSearcher.GetFreeVars(left);
string[] rightVars = FOLSearcher.GetFreeVars(right);
string[] newLeftVars = rightVars.Where(r => !leftVars.Any(l => r == l)).ToArray();
return(FillInSolutions(left, newLeftVars, subwords));
}
public static List <List <Assignment> > EvaluateQuantifiedExpression(ParseTreeFOL_Q quantifiedExpression, string[] subwords, string body)
{
List <List <Assignment> > solutions;
if (quantifiedExpression.getExpression() == null)
{
solutions = EvaluateQuantifiedExpression(quantifiedExpression.getChild(), subwords, body);
FOLQuantifier quantifier = (FOLQuantifier)quantifiedExpression.getFOLQuantifier();
string variableName = quantifiedExpression.getQuantifiedVar();
if (quantifier == FOLQuantifier.E)
{
if (!solutions.Any(sol => sol.Any(assignment => assignment.GetVariableName() == variableName)))
{
solutions.RemoveAll(a => true);
}
else
{
solutions = FOLSearcher.removeVariable(solutions, variableName);
}
}
else
{
List <List <Assignment> > newSols = new List <List <Assignment> >();
List <List <Assignment> > solsWithoutVar = FOLSearcher.removeVariable(
solutions.ConvertAll(sol => new List <Assignment>(sol)),
variableName);
foreach (List <Assignment> solWithoutVar in solsWithoutVar)
{
bool include = true;
foreach (string word in subwords)
{
List <Assignment> sol = new List <Assignment>(solWithoutVar);
sol.Add(new Assignment(variableName, word));
if (!solutions.Any(solution => CompareSolutions(sol, solution)))
{
include = false;
}
}
if (include)
{
newSols.Add(solWithoutVar);
}
}
solutions = newSols;
}
}
else
{
solutions = EvaluateLogicalExpression(quantifiedExpression.getExpression(), subwords, body);
}
return(solutions);
}
public static List <List <Assignment> > evaluateParsedExpression(ParseTreeFOL_Q parsedExpression, string[] subwords, string[] freeVars, string body)
{
int[] freeVarValIndices = new int[freeVars.Length];
for (int i = 0; i < freeVarValIndices.Length; i++)
{
freeVarValIndices[i] = 0;
}
List <List <Assignment> > successfulValueCombinations = new List <List <Assignment> >();
do
{
List <Assignment> varVals = new List <Assignment> {
new Assignment("S", body)
};
for (int i = 0; i < freeVarValIndices.Length; i++)
{
Assignment varVal = new Assignment(freeVars[i], subwords[freeVarValIndices[i]]);
varVals.Add(varVal);
}
if (evaluateQuantifiedExpression(parsedExpression, subwords.ToArray(), varVals))
{
successfulValueCombinations.Add(varVals);
}
freeVarValIndices[freeVarValIndices.Length - 1]++;
for (int i = freeVarValIndices.Length - 1; i > 0; i--)
{
if (freeVarValIndices[i] >= subwords.Count())
{
freeVarValIndices[i] = 0;
freeVarValIndices[i - 1]++;
}
}
} while (freeVarValIndices[0] != subwords.Count());
successfulValueCombinations = FOLSearcher.removeVariable(successfulValueCombinations, "S");
return(successfulValueCombinations);
}
