Visitorパターンの勉強用

Program.cs

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

namespace ConsoleApplication1
{
  interface IVisitor
  {
    void Visit(IAcceptor acceptor);
  }

  interface IAcceptor
  {
    void Accept(IVisitor visitor);
    int Value { get; set; }
    IAcceptor Child { get; set; }
  }

  class Visitor : IVisitor
  {
    public void Visit(IAcceptor acceptor)
    {
      var value = acceptor.Value;
      Console.WriteLine(
        value % 3 == 0 && value % 5 == 0
          ? "FizzBuzz"
          : value % 3 == 0
            ? "Fizz"
            : value % 5 == 0
              ? "Buzz"
              : value.ToString()
        );

      if (acceptor.Child != null)
      {
        acceptor.Child.Accept(this);
      }
    }
  }

  class Acceptor : IAcceptor
  {
    public void Accept(IVisitor visitor)
    {
      visitor.Visit(this);
    }

    public int Value { get; set; }

    public IAcceptor Child { get; set; } 
  }

  class Program
  {
    static void Main(string[] args)
    {
      var acceptors = Enumerable.Range(1, 20)
        .Select(x => new Acceptor { Value = x }).ToArray();

      var source = acceptors.Zip(acceptors.Skip(1), (x, y) => new {Current = x, Next = y});

      foreach (var item in source)
      {
        item.Current.Child = item.Next;
      }

      var root = source.First().Current;

      root.Accept(new Visitor());
    }
  }
}