Fluent Type Switch

FluentTypeSwitch.cs

namespace Utilities
{
	using System;
	using System.Collections.Generic;
	using System.Linq;

	public class Switch
	{
		private readonly ICollection<Func<object, Action>> _cases;
		private bool _defaultUsed;

		public Switch(params Func<object, Action>[] cases)
		{
			if (cases == null)
			{
				_cases = Enumerable.Empty<Func<object, Action>>().ToList();
				return;
			}

			_cases = cases.ToList();
		}

		public Switch Case<T>(Action<T> action)
		{
			_cases.Add(o => o is T ? (Action)(() => action((T)o)) : (Action)null);
			return this;
		}

		public Switch Default(Action action)
		{
			if(_defaultUsed)
				throw new InvalidOperationException("Default can only be used once");

			_defaultUsed = true;

			Case<object>(x => action());
			return this;
		}

		public void Execute(object obj)
		{
			var @case = _cases
				.Select(f => f(obj))
				.FirstOrDefault(a => a != null);

			if (@case != null)
			{
				@case();
			}
		}
	}
}

===========================================================================
Usage: // where the various Execute methods are part of the class
1) var @switch = new Switch()
				.Case<Test1>(x => x.Execute("hello"))
				.Case<Test2>(x => x.Execute("there"))
				.Case<Test3>(x => x.Execute("want"))
				.Case<Test4>(x => x.Execute("to"))
				.Default(() => Console.WriteLine("party"));

			var t2 = new Test2();
			@switch.Execute(t2); // should execute the second case
			
2) var @switch = new Switch()
				.Case<Test1>(x => x.Execute("hello"))
				.Case<Test2>(x => x.Execute("there"))
				.Case<Test3>(x => x.Execute("want"))
				.Case<Test4>(x => x.Execute("to"))
				.Default(() => Console.WriteLine("party"));

			var t2 = string.Empty;
			@switch.Execute(t2); //Default should be executed

3) var @switch = new Switch()
				.Case<Test1>(x => x.Execute("hello"))
				.Case<Test2>(x => x.Execute("there"))
				.Case<Test3>(x => x.Execute("want"))
				.Case<Test4>(x => x.Execute("to"));

			var t2 = string.Empty;
			@switch.Execute(t2); //should fall through without executing anything