IronRuby and C# 4 "dynamic"

dynamic_demo.cs

using System;
using IronRuby;
    
public class dynamic_demo {
  static void Main() {      
    var rb = Ruby.CreateEngine();
    rb.ExecuteFile("mock.rb");
    dynamic globals = rb.Runtime.Globals;

    // Call the Ruby "Mock" class constructor
    dynamic m = globals.Mock.@new();

    //The Ruby Mock instance dynamically responds to any member that is requested of it
    Console.WriteLine(
      m.the_csharp_compiler_cannot_possbily_know_this_method_exists_at_compile_time()
    );
  }
}

mock.rb

class Mock
  # instances of this class will dynamically respond to any method
  def method_missing(method_name)
    ["hello world", Math::PI][rand(2)]
  end
end