jeszcze jedno z dynamicami

gistfile1.txt

using System;

namespace SimplifyVisitor
{
    public class ConcreteVisitor : VisitorBase//<Node>
    {
        protected override void Visit(ConstantNode node)
        {
            Console.WriteLine("Visiting constant node");
        }

        protected override void Visit(PlusNode node)
        {
            Console.WriteLine("Visiting plus node");
        }

        protected override void Visit(MinusNode node)
        {
            Console.WriteLine("Visiting minus node");
        }
    }
}

gistfile2.txt

using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SimplifyVisitor
{
    public abstract class VisitorBase
    {
        public void Dispatch(Node node) 
        {
            this.Visit((dynamic)node);
        }

        protected abstract void Visit(ConstantNode node);
        protected abstract void Visit(PlusNode node);
        protected abstract void Visit(MinusNode node);
    }
}