public static void Main(string[] args)
{
var e = new AdditionExpression(
new DoubleExpression(1),
new AdditionExpression(
new DoubleExpression(2),
new DoubleExpression(3)));
var ep = new ExpressionPrinter();
ep.Visit(e);
Console.WriteLine(ep);
var calc = new ExpressionCalculator();
calc.Visit(e);
Console.WriteLine($"{ep} = {calc.Result}");
Console.WriteLine("Taxi Visitor!");
CustomerStructure o = new CustomerStructure();
o.Attach(new TaxiCustomer("Andrzej"));
o.Attach(new TaxiCustomer("Seba"));
o.Attach(new TaxiCustomer("Pudzian"));
o.Attach(new RichCustomer("Musk"));
o.Attach(new PoorCustomer("Żul"));
Taxi t1 = new Taxi1();
Taxi t2 = new Taxi2();
o.Accept(t1);
Console.WriteLine();
o.Accept(t2);
Console.WriteLine("Acyclic visitor");
var expression = new AcyclicVisitor.AdditionExpression(
new AcyclicVisitor.DoubleExpression(1),
new AcyclicVisitor.AdditionExpression(
new AcyclicVisitor.DoubleExpression(2),
new AcyclicVisitor.DoubleExpression(3)));
var acyclic_ep = new AcyclicVisitor.ExpressionPrinter();
acyclic_ep.Visit(expression);
Console.WriteLine(acyclic_ep.ToString());
Console.WriteLine();
Console.WriteLine("Code exercise");
var simple = new Coding.Exercise.AdditionExpression(new Coding.Exercise.Value(2), new Coding.Exercise.Value(3));
var exercise_ep = new Coding.Exercise.ExpressionPrinter();
exercise_ep.Visit(simple);
Console.WriteLine(exercise_ep.ToString());
Console.ReadLine();
}