public RPNToken Calculate(RPNToken x, RPNToken y, RPNToken fn)
{
RPNToken result;
if (!(x.TokenType == Outputs.Double && y.TokenType == Outputs.Double &&
fn.TokenType == Outputs.Operator))
{
return(new RPNToken("ERROR"));
}
switch (fn.Token)
{
case "-":
result = new RPNToken((x.Value - y.Value).ToString());
break;
case "+":
result = new RPNToken((x.Value + y.Value).ToString());
break;
case "*":
result = new RPNToken((x.Value * y.Value).ToString());
break;
case "/":
result = new RPNToken((x.Value / y.Value).ToString());
break;
default:
result = new RPNToken(Math.Pow(x.Value, y.Value).ToString());
break;
}
return(result);
}
// **********
// Entrypoint
// **********
static void Main(string[] args)
{
// ***********************************************************************************
// Fields :
// calculator - RPNArithmetic handles math / management of the stored RPN expressions
// previousCalculation - RPNToken storing previously the previously reduced expression
// userInput - ConsoleKey storing current userInput
// ***********************************************************************************
RPNArithmetic calculator = new RPNArithmetic();
RPNToken previousCalculation = new RPNToken("0");
ConsoleKey userInput;
// **********************
// Console User Interface
// **********************
do
{
DisplayMenu();
userInput = Console.ReadKey().Key;
switch (userInput)
{
case ConsoleKey.A:
Console.WriteLine();
GetRPNExpression(calculator);
break;
case ConsoleKey.L:
Console.WriteLine(
"\n\nThe previous calculation was {0}.", previousCalculation);
break;
case ConsoleKey.C:
CalculateAndDisplay(calculator, out previousCalculation);
break;
case ConsoleKey.S:
calculator.Display();
break;
case ConsoleKey.X:
calculator.Clear();
break;
}
Console.Write("\nPress any key to continue... ");
Console.ReadKey();
}while (userInput != ConsoleKey.Q);
}
protected static List <RPNToken> TryParseRPN(string line)
{
List <RPNToken> parsed = new List <RPNToken>();
foreach (string s in line.Split(' '))
{
RPNToken temp = new RPNToken(s);
parsed.Add(temp);
if (!(temp.TokenType == Outputs.Double || temp.TokenType == Outputs.Operator))
{
Console.WriteLine("\n\nLine could not be parsed: {0}\n\n", line);
parsed.Clear();
break;
}
}
return(parsed);
}
private static void CalculateAndDisplay(RPNArithmetic calculator, out RPNToken previousCalculation)
{
previousCalculation = calculator.ReduceStack();
Console.WriteLine("\n\nThe calculated value is {0}.", previousCalculation);
}
public void Push(RPNToken token)
{
stk.Push(token);
}
