public void RunCommand(Command cmd, IEnumerable <decimal> args)
{
switch (cmd)
{
case Command.Quit:
case Command.Exit:
case Command.Help:
case Command.Unknown:
default:
throw new InvalidOperationException("CalculatorStack can't handle this command.");
case Command.Push:
if (args.Count() == 0)
{
throw new ArgumentException("number?");
}
else
{
foreach (decimal n in args)
{
Push(n);
}
}
break;
case Command.Pop:
{
decimal count = (args.Count() == 0) ? 1 : args.First();
if (count > m_stack.Count)
{
throw new ArgumentException("argument out of range");
}
for (int i = 0; i < count.AsInt(); i++)
{
Pop();
}
}
break;
case Command.Swap:
{
int ix = args.ElementAtOrDefault(0, 2).AsInt() - 1;
int iy = args.ElementAtOrDefault(1, 1).AsInt() - 1;
if (Math.Max(ix, iy) > m_stack.Count)
{
throw new ArgumentException("argument out of range");
}
decimal[] arr = m_stack.ToArray();
decimal temp = arr[ix];
arr[ix] = arr[iy];
arr[iy] = temp;
m_stack = new Stack <decimal>(arr.Reverse());
}
break;
case Command.Add:
{
decimal x, y;
GetTwo(out x, out y);
Push(y + x);
}
break;
case Command.Subtract:
{
decimal x, y;
GetTwo(out x, out y);
Push(y - x);
}
break;
case Command.Multiply:
{
decimal x, y;
GetTwo(out x, out y);
Push(y * x);
}
break;
case Command.Divide:
{
decimal x, y;
GetTwo(out x, out y);
Push(y / x);
}
break;
case Command.Modulo:
{
decimal x, y;
GetTwo(out x, out y);
Push(y % x);
}
break;
case Command.Power:
{
decimal x, y;
GetTwo(out x, out y);
try
{
Push((decimal)Math.Pow(decimal.ToDouble(y), decimal.ToDouble(x)));
}
catch (OverflowException)
{
Push(y);
Push(x);
throw new ArgumentException("overflow");
}
}
break;
case Command.Negate:
{
decimal x = GetOne();
Push(-x);
}
break;
}
}
[Pure] public static int MustBeInt(this decimal value) => value.AsInt() ?? throw new ArgumentOutOfRangeException(nameof(value), value, $"Must be a whole number in the range of valid {nameof(Int32)} values!");