private static double ResolvePostfix(Queue <object> postFix)
{
Stack <double> state = new Stack <double>();
while (postFix.Count > 0)
{
while (postFix.Count > 0 && postFix.Peek() is double)
{
state.Push((double)postFix.Dequeue());
}
if (postFix.Count > 0)
{
Functions.Function func = postFix.Dequeue() as Functions.Function;
List <double> parameters = new List <double>();
for (int i = 0; i < func.ParameterCount; i++)
{
parameters.Add(state.Pop());
}
parameters.Reverse();
state.Push(func.Call(parameters));
}
}
if (state.Count != 1)
{
throw new Exception("Failed to evaluate expression. No result available");
}
return(state.Pop());
}
public void Push(Functions.Function in_func)
{
if (Count >= in_func.ParameterCount)
{
List <double> parameters = new List <double>();
for (int i = in_func.ParameterCount; i > 0; i--)
{
parameters.Add(this[Count - i].Value);
RemoveAt(Count - i);
}
string expression = in_func.Name + "(";
for (int i = 0; i < parameters.Count; i++)
{
expression += parameters[i].ToString();
if (i != parameters.Count - 1)
{
expression += ",";
}
}
expression += ")";
Push(in_func.Call(parameters), expression);
}
else
{
throw new Exception("Not enough operand on the stack. Add at least two numbers in the stack.");
}
}