public override int Evaluate()
{
int value1 = _expr1.Evaluate();
int value2 = _expr2.Evaluate();
return(value1 - value2);
}
static void Main(string[] args)
{
Parser parser = new Parser();
string[] commands = new string[]
{
"+ 5 6",
"- 6 5",
"+ - 4 5 6",
"+ 4 - 5 6",
"+ - + - - 2 3 4 + - -5 6 + -7 8 9 10"
};
foreach (string command in commands)
{
ExpressionBase expression = parser.Parse(command);
Console.WriteLine("{0} = {1}", expression, expression.Evaluate());
}
}
// Also called Prefix notation
private static void PolishNotationExample()
{
var parser = new PolishNotationParser();
string[] commands =
{
"+ 5 6",
"- 6 5",
"+ - 4 5 6",
"+ 4 - 5 6",
"+ - + - - 2 3 4 + - -5 6 + -7 8 9 10"
};
foreach (string command in commands)
{
ExpressionBase expression = parser.Parse(command);
Console.WriteLine(command);
Console.WriteLine(expression);
Console.WriteLine(expression.Evaluate());
Console.WriteLine();
}
}