public string QueryRules(string ruleset, string query)
{
string s;
int term, answer;
int len;
try
{
s = "arxl_query(" + ruleset + ", false, `" + query + "`, ?answer)";
term = ls.ExecStr(s);
if (term == 0)
{
throw new Exception(FormatARulesError());
}
// The answer is a string in the 4th argument
// Could be any type, turn it into a string
answer = ls.GetArg(term, 4);
len = ls.StrTermLen(answer);
return(ls.TermToStr(answer, len + 1));
}
catch (LSException ex)
{
throw new Exception("Error getting arules error: " + ex.GetMsg());
}
}
// handle actions when button 'Get Result' is clicked
private void GetResult_Click(object sender, System.EventArgs e)
{
LogicServer ls;
int term;
try
{
// Initialize the logic server //
ls = new LogicServer();
ls.Init("");
const string x = @"C:\Program Files\amzi\ide\workspace\cpe425\bin\cpe425.xpl";
ls.Load(x);
// get boarding station and alighting station input and execute corresponding command in Prolog //
term = ls.ExecStr("shortest(" + (comboBox1.SelectedItem).ToString() + "," + (comboBox2.SelectedItem).ToString() + ", MinTime, MinRoute)");
// analyse the return value, if return value != 0, means the command was successfully executed //
if (term != 0)
{
// show out the shortest travel time,
TimeResult.Text = (ls.GetIntArg(term, 3)).ToString();
// show out the shortest travel route, as return value is list, we must recursively get all elements in this list //
int term1 = ls.GetArg(term, 4);
string s = ls.GetStrHead(term1);
while (ls.GetTail(term1) != 0)
{
s += " -> " + ls.GetStrHead(ls.GetTail(term1));
term1 = ls.GetTail(term1);
}
RouteResult.Text = s;
}
else
{
TimeResult.Text = "Invalid Request!";
RouteResult.Text = "Invalid Request!";
}
// close the logic server
ls.Close();
}
catch (LSException ex)
{
String message = ex.GetMessage();
}
}