/Utilities/Collections/UniqueChangeableList.cs

using System.Collections.Generic;

using Delta.Utilities.Helpers;

using NUnit.Framework;



namespace Delta.Utilities.Collections

{

	/// <summary>

	/// Same as ChangeableList, which allows to add and remove elements

	/// while enumerating, but this also checks if elements do already

	/// exists. It will not add duplicates, duplicates are ignored!

	/// </summary>

	public class UniqueChangeableList<T> : ChangeableList<T>

	{

		#region Add (Public)

		/// <summary>

		/// Add element, if it already exists, nothing will be added.

		/// </summary>

		/// <param name="item">Item</param>

		public override void Add(T item)

		{

			if (base.IndexOf(item) < 0)

			{

				base.Add(item);

			}

		}

		#endregion



		#region AddRange (Public)

		/// <summary>

		/// Add range, will just use Add to add all elements.

		/// </summary>

		/// <param name="c">Collection</param>

		public override void AddRange(ICollection<T> c)

		{

			foreach (T obj in c)

			{

				Add(obj);

			}

		}

		#endregion

	}



	/// <summary>

	/// UniqueChangeableList tests, needs to be an extra class because

	/// nesting in generic classes is not supported by NUnit or xUnit.

	/// </summary>

	public class UniqueChangeableListTests

	{

		#region TestUniqueChangeableList (Static)

		/// <summary>

		/// Test UniqueChangeableList. Note: Too slow for a dynamic unit test.

		/// </summary>

		[Test]

		public static void TestUniqueChangeableList()

		{

			UniqueChangeableList<int> list = new UniqueChangeableList<int>();

			list.Add(2);

			list.Add(3);

			list.Add(4);

			list.Add(2);

			Assert.Equal("2, 3, 4", list.Write());



			// Add element while enumerating (7) and remove a element (2)

			foreach (int num in list)

			{

				//Console.WriteLine("Num: " + num);

				if (num == 3)

				{

					list.Add(7);

				}

				else if (num == 2)

				{

					list.Remove(num);

				}

			}

			// The resulting list should now have changed from "2, 3, 4" to "3, 4, 7"

			Assert.Equal("3, 4, 7", list.Write());

		}

		#endregion

	}

}