static void menu()
{
bool end = false;
while (end == false)
{
Console.WriteLine("Menu (Current Expression = \"" + exp + "\")");
Console.WriteLine("1 = Enter a new expression");
Console.WriteLine("2 = Set a variable value");
Console.WriteLine("3 = Evaluate tree");
Console.WriteLine("4 = Quit");
string userInput = Console.ReadLine();
if (int.TryParse(userInput, out var data))
{
switch (data)
{
case 1:
Console.Write("Enter new expression: ");
expTree.Clear();
exp = Console.ReadLine();
expTree = new ExpTree(exp);
break;
case 2:
Console.Write("Enter variable name: ");
string name = Console.ReadLine();
bool isInt = false;
while (!isInt)
{
Console.Write("Enter variable value: ");
string value = Console.ReadLine();
if (double.TryParse(value, out var v))
{
expTree.SetVar(name, v);
isInt = true;
}
else
{
Console.WriteLine("Invalid Input");
}
}
break;
case 3:
double result = expTree.Eval();
Console.WriteLine("{0}", result);
break;
case 4:
end = true;
break;
}
}
}
}
