/*
 Copyright (c) 2003-2006 Niels Kokholm and Peter Sestoft
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
*/

using System;
using C5;
using NUnit.Framework;
using SCG = System.Collections.Generic;


namespace C5UnitTests.linkedlists.plain
{
  using CollectionOfInt = LinkedList<int>;

  [TestFixture]
  public class GenericTesters
  {

    [Test]
    public void TestEvents()
    {
      Fun<CollectionOfInt> factory = delegate() { return new CollectionOfInt(TenEqualityComparer.Default); };
      new C5UnitTests.Templates.Events.ListTester<CollectionOfInt>().Test(factory);
      new C5UnitTests.Templates.Events.QueueTester<CollectionOfInt>().Test(factory);
      new C5UnitTests.Templates.Events.StackTester<CollectionOfInt>().Test(factory);
    }

    [Test]
    public void Extensible()
    {
      C5UnitTests.Templates.Extensible.Clone.Tester<CollectionOfInt>();
      C5UnitTests.Templates.Extensible.Clone.ViewTester<CollectionOfInt>();
      C5UnitTests.Templates.Extensible.Serialization.Tester<CollectionOfInt>();
      C5UnitTests.Templates.Extensible.Serialization.ViewTester<CollectionOfInt>();
    }

    [Test]
    public void List()
    {
      C5UnitTests.Templates.List.Dispose.Tester<CollectionOfInt>();
      C5UnitTests.Templates.List.SCG_IList.Tester<CollectionOfInt>();
    }
  }

  static class Factory
  {
    public static ICollection<T> New<T>() { return new LinkedList<T>(); }
  }

  namespace Enumerable
  {
    [TestFixture]
    public class Multiops
    {
      private LinkedList<int> list;

      private Fun<int, bool> always, never, even;


      [SetUp]
      public void Init()
      {
        list = new LinkedList<int>();
        always = delegate { return true; };
        never = delegate { return false; };
        even = delegate(int i) { return i % 2 == 0; };
      }


      [Test]
      public void All()
      {
        Assert.IsTrue(list.All(always));
        Assert.IsTrue(list.All(never));
        Assert.IsTrue(list.All(even));
        list.Add(8);
        Assert.IsTrue(list.All(always));
        Assert.IsFalse(list.All(never));
        Assert.IsTrue(list.All(even));
        list.Add(5);
        Assert.IsTrue(list.All(always));
        Assert.IsFalse(list.All(never));
        Assert.IsFalse(list.All(even));
      }


      [Test]
      public void Exists()
      {
        Assert.IsFalse(list.Exists(always));
        Assert.IsFalse(list.Exists(never));
        Assert.IsFalse(list.Exists(even));
        list.Add(5);
        Assert.IsTrue(list.Exists(always));
        Assert.IsFalse(list.Exists(never));
        Assert.IsFalse(list.Exists(even));
        list.Add(8);
        Assert.IsTrue(list.Exists(always));
        Assert.IsFalse(list.Exists(never));
        Assert.IsTrue(list.Exists(even));
      }


      [Test]
      public void Apply()
      {
        int sum = 0;
        Act<int> a = delegate(int i) { sum = i + 10 * sum; };

        list.Apply(a);
        Assert.AreEqual(0, sum);
        sum = 0;
        list.Add(5); list.Add(8); list.Add(7); list.Add(5);
        list.Apply(a);
        Assert.AreEqual(5875, sum);
      }


      [TearDown]
      public void Dispose() { list = null; }
    }



    [TestFixture]
    public class GetEnumerator
    {
      private LinkedList<int> list;


      [SetUp]
      public void Init() { list = new LinkedList<int>(); }


      [Test]
      public void Empty()
      {
        SCG.IEnumerator<int> e = list.GetEnumerator();

        Assert.IsFalse(e.MoveNext());
      }


      [Test]
      public void Normal()
      {
        list.Add(5);
        list.Add(8);
        list.Add(5);
        list.Add(5);
        list.Add(10);
        list.Add(1);

        SCG.IEnumerator<int> e = list.GetEnumerator();

        Assert.IsTrue(e.MoveNext());
        Assert.AreEqual(5, e.Current);
        Assert.IsTrue(e.MoveNext());
        Assert.AreEqual(8, e.Current);
        Assert.IsTrue(e.MoveNext());
        Assert.AreEqual(5, e.Current);
        Assert.IsTrue(e.MoveNext());
        Assert.AreEqual(5, e.Current);
        Assert.IsTrue(e.MoveNext());
        Assert.AreEqual(10, e.Current);
        Assert.IsTrue(e.MoveNext());
        Assert.AreEqual(1, e.Current);
        Assert.IsFalse(e.MoveNext());
      }


      [Test]
      public void DoDispose()
      {
        list.Add(5);
        list.Add(8);
        list.Add(5);

        SCG.IEnumerator<int> e = list.GetEnumerator();

        e.MoveNext();
        e.MoveNext();
        e.Dispose();
      }


      [Test]
      [ExpectedException(typeof(CollectionModifiedException))]
      public void MoveNextAfterUpdate()
      {
        list.Add(5);
        list.Add(8);
        list.Add(5);

        SCG.IEnumerator<int> e = list.GetEnumerator();

        e.MoveNext();
        list.Add(99);
        e.MoveNext();
      }


      [TearDown]
      public void Dispose() { list = null; }
    }
  }

  namespace CollectionOrExtensible
  {
    [TestFixture]
    public class Formatting
    {
      ICollection<int> coll;
      IFormatProvider rad16;
      [SetUp]
      public void Init() { coll = Factory.New<int>(); rad16 = new RadixFormatProvider(16); }
      [TearDown]
      public void Dispose() { coll = null; rad16 = null; }
      [Test]
      public void Format()
      {
        Assert.AreEqual("[  ]", coll.ToString());
        coll.AddAll<int>(new int[] { -4, 28, 129, 65530 });
        Assert.AreEqual("[ -4, 28, 129, 65530 ]", coll.ToString());
        Assert.AreEqual("[ -4, 1C, 81, FFFA ]", coll.ToString(null, rad16));
        Assert.AreEqual("[ -4, 28, 129... ]", coll.ToString("L14", null));
        Assert.AreEqual("[ -4, 1C, 81... ]", coll.ToString("L14", rad16));
      }
    }

    [TestFixture]
    public class CollectionOrSink
    {
      private LinkedList<int> list;


      [SetUp]
      public void Init() { list = new LinkedList<int>(); }

      [Test]
      [ExpectedException(typeof(NullReferenceException))]
      public void NullEqualityComparerinConstructor1()
      {
        new LinkedList<int>(null);
      }

      [Test]
      public void Choose()
      {
        list.Add(7);
        Assert.AreEqual(7, list.Choose());
      }

      [Test]
      [ExpectedException(typeof(NoSuchItemException))]
      public void BadChoose()
      {
        list.Choose();
      }


      [Test]
      public void CountEtAl()
      {
        Assert.AreEqual(0, list.Count);
        Assert.IsTrue(list.IsEmpty);
        Assert.IsTrue(list.AllowsDuplicates);
        list.Add(5);
        Assert.AreEqual(1, list.Count);
        Assert.IsFalse(list.IsEmpty);
        list.Add(5);
        Assert.AreEqual(2, list.Count);
        Assert.IsFalse(list.IsEmpty);
        list.Add(8);
        Assert.AreEqual(3, list.Count);
      }


      [Test]
      public void AddAll()
      {
        list.Add(3); list.Add(4); list.Add(5);

        LinkedList<int> list2 = new LinkedList<int>();

        list2.AddAll(list);
        Assert.IsTrue(IC.eq(list2, 3, 4, 5));
        list.AddAll(list2);
        Assert.IsTrue(IC.eq(list2, 3, 4, 5));
        Assert.IsTrue(IC.eq(list, 3, 4, 5, 3, 4, 5));
      }


      [TearDown]
      public void Dispose() { list = null; }
    }

    [TestFixture]
    public class FindPredicate
    {
      private LinkedList<int> list;
      Fun<int, bool> pred;

      [SetUp]
      public void Init()
      {
        list = new LinkedList<int>(TenEqualityComparer.Default);
        pred = delegate(int i) { return i % 5 == 0; };
      }

      [TearDown]
      public void Dispose() { list = null; }

      [Test]
      public void Find()
      {
        int i;
        Assert.IsFalse(list.Find(pred, out i));
        list.AddAll<int>(new int[] { 4, 22, 67, 37 });
        Assert.IsFalse(list.Find(pred, out i));
        list.AddAll<int>(new int[] { 45, 122, 675, 137 });
        Assert.IsTrue(list.Find(pred, out i));
        Assert.AreEqual(45, i);
      }

      [Test]
      public void FindLast()
      {
        int i;
        Assert.IsFalse(list.FindLast(pred, out i));
        list.AddAll<int>(new int[] { 4, 22, 67, 37 });
        Assert.IsFalse(list.FindLast(pred, out i));
        list.AddAll<int>(new int[] { 45, 122, 675, 137 });
        Assert.IsTrue(list.FindLast(pred, out i));
        Assert.AreEqual(675, i);
      }

      [Test]
      public void FindIndex()
      {
        Assert.IsFalse(0 <= list.FindIndex(pred));
        list.AddAll<int>(new int[] { 4, 22, 67, 37 });
        Assert.IsFalse(0 <= list.FindIndex(pred));
        list.AddAll<int>(new int[] { 45, 122, 675, 137 });
        Assert.AreEqual(4, list.FindIndex(pred));
      }

      [Test]
      public void FindLastIndex()
      {
        Assert.IsFalse(0 <= list.FindLastIndex(pred));
        list.AddAll<int>(new int[] { 4, 22, 67, 37 });
        Assert.IsFalse(0 <= list.FindLastIndex(pred));
        list.AddAll<int>(new int[] { 45, 122, 675, 137 });
        Assert.AreEqual(6, list.FindLastIndex(pred));
      }
    }

    [TestFixture]
    public class UniqueItems
    {
      private LinkedList<int> list;

      [SetUp]
      public void Init() { list = new LinkedList<int>(); }

      [TearDown]
      public void Dispose() { list = null; }

      [Test]
      public void Test()
      {
        Assert.IsTrue(IC.seteq(list.UniqueItems()));
        Assert.IsTrue(IC.seteq(list.ItemMultiplicities()));
        list.AddAll<int>(new int[] { 7, 9, 7 });
        Assert.IsTrue(IC.seteq(list.UniqueItems(), 7, 9));
        Assert.IsTrue(IC.seteq(list.ItemMultiplicities(), 7, 2, 9, 1));
      }
    }

    [TestFixture]
    public class ArrayTest
    {
      private LinkedList<int> list;

      int[] a;


      [SetUp]
      public void Init()
      {
        list = new LinkedList<int>();
        a = new int[10];
        for (int i = 0; i < 10; i++)
          a[i] = 1000 + i;
      }


      [TearDown]
      public void Dispose() { list = null; }


      private string aeq(int[] a, params int[] b)
      {
        if (a.Length != b.Length)
          return "Lengths differ: " + a.Length + " != " + b.Length;

        for (int i = 0; i < a.Length; i++)
          if (a[i] != b[i])
            return String.Format("{0}'th elements differ: {1} != {2}", i, a[i], b[i]);

        return "Alles klar";
      }


      [Test]
      public void ToArray()
      {
        Assert.AreEqual("Alles klar", aeq(list.ToArray()));
        list.Add(7);
        list.Add(7);
        Assert.AreEqual("Alles klar", aeq(list.ToArray(), 7, 7));
      }


      [Test]
      public void CopyTo()
      {
        list.CopyTo(a, 1);
        Assert.AreEqual("Alles klar", aeq(a, 1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009));
        list.Add(6);
        list.CopyTo(a, 2);
        Assert.AreEqual("Alles klar", aeq(a, 1000, 1001, 6, 1003, 1004, 1005, 1006, 1007, 1008, 1009));
        list.Add(4);
        list.Add(4);
        list.Add(9);
        list.CopyTo(a, 4);
        Assert.AreEqual("Alles klar", aeq(a, 1000, 1001, 6, 1003, 6, 4, 4, 9, 1008, 1009));
        list.Clear();
        list.Add(7);
        list.CopyTo(a, 9);
        Assert.AreEqual("Alles klar", aeq(a, 1000, 1001, 6, 1003, 6, 4, 4, 9, 1008, 7));
      }


      [Test]
      [ExpectedException(typeof(ArgumentOutOfRangeException))]
      public void CopyToBad()
      {
        list.CopyTo(a, 11);
      }


      [Test]
      [ExpectedException(typeof(ArgumentOutOfRangeException))]
      public void CopyToBad2()
      {
        list.CopyTo(a, -1);
      }


      [Test]
      [ExpectedException(typeof(ArgumentOutOfRangeException))]
      public void CopyToTooFar()
      {
        list.Add(3);
        list.Add(3);
        list.CopyTo(a, 9);
      }
    }



    [TestFixture]
    public class Sync
    {
      private LinkedList<int> list;


      [SetUp]
      public void Init()
      {
        list = new LinkedList<int>();
      }


      [TearDown]
      public void Dispose() { list = null; }


      [Test]
      public void Get()
      {
        Assert.IsNotNull(((System.Collections.IList)list).SyncRoot);
      }
    }
  }




  namespace EditableCollection
  {
    [TestFixture]
    public class Searching
    {
      private LinkedList<int> list;


      [SetUp]
      public void Init() { list = new LinkedList<int>(); }


      [Test]
      public void Contains()
      {
        Assert.IsFalse(list.Contains(5));
        list.Add(5);
        Assert.IsTrue(list.Contains(5));
        Assert.IsFalse(list.Contains(7));
        list.Add(8);
        list.Add(10);
        Assert.IsTrue(list.Contains(5));
        Assert.IsFalse(list.Contains(7));
        Assert.IsTrue(list.Contains(8));
        Assert.IsTrue(list.Contains(10));
        list.Remove(8);
        Assert.IsTrue(list.Contains(5));
        Assert.IsFalse(list.Contains(7));
        Assert.IsFalse(list.Contains(8));
        Assert.IsTrue(list.Contains(10));
      }


      [Test]
      public void ContainsCount()
      {
        Assert.AreEqual(0, list.ContainsCount(5));
        list.Add(5);
        Assert.AreEqual(1, list.ContainsCount(5));
        Assert.AreEqual(0, list.ContainsCount(7));
        list.Add(8);
        Assert.AreEqual(1, list.ContainsCount(5));
        Assert.AreEqual(0, list.ContainsCount(7));
        Assert.AreEqual(1, list.ContainsCount(8));
        list.Add(5);
        Assert.AreEqual(2, list.ContainsCount(5));
        Assert.AreEqual(0, list.ContainsCount(7));
        Assert.AreEqual(1, list.ContainsCount(8));
      }


      [Test]
      public void RemoveAllCopies()
      {
        list.Add(5); list.Add(7); list.Add(5);
        Assert.AreEqual(2, list.ContainsCount(5));
        Assert.AreEqual(1, list.ContainsCount(7));
        list.RemoveAllCopies(5);
        Assert.AreEqual(0, list.ContainsCount(5));
        Assert.AreEqual(1, list.ContainsCount(7));
        list.Add(5); list.Add(8); list.Add(5);
        list.RemoveAllCopies(8);
        Assert.IsTrue(IC.eq(list, 7, 5, 5));
      }


      [Test]
      public void FindAll()
      {
        Fun<int, bool> f = delegate(int i) { return i % 2 == 0; };

        Assert.IsTrue(list.FindAll(f).IsEmpty);
        list.Add(5); list.Add(8); list.Add(5); list.Add(10); list.Add(8);
        Assert.IsTrue(((LinkedList<int>)list.FindAll(f)).Check());
        Assert.IsTrue(IC.eq(list.FindAll(f), 8, 10, 8));
      }


      [Test]
      public void ContainsAll()
      {
        LinkedList<int> list2 = new LinkedList<int>();

        Assert.IsTrue(list.ContainsAll(list2));
        list2.Add(4);
        Assert.IsFalse(list.ContainsAll(list2));
        list.Add(4);
        Assert.IsTrue(list.ContainsAll(list2));
        list.Add(5);
        Assert.IsTrue(list.ContainsAll(list2));
        list2.Add(4);
        Assert.IsFalse(list.ContainsAll(list2));
        list.Add(4);
        Assert.IsTrue(list.ContainsAll(list2));
      }


      [Test]
      public void RetainAll()
      {
        LinkedList<int> list2 = new LinkedList<int>();

        list.Add(4); list.Add(4); list.Add(5); list.Add(4); list.Add(6);
        list2.Add(5); list2.Add(4); list2.Add(7); list2.Add(7); list2.Add(4);
        list.RetainAll(list2);
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 4, 4, 5));
        list.Add(5); list.Add(4); list.Add(6);
        list2.Clear();
        list2.Add(5); list2.Add(5); list2.Add(6);
        list.RetainAll(list2);
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 5, 5, 6));
        list2.Clear();
        list2.Add(7); list2.Add(8); list2.Add(9);
        list.RetainAll(list2);
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list));
      }


      [Test]
      public void RemoveAll()
      {
        LinkedList<int> list2 = new LinkedList<int>();

        list.Add(4); list.Add(4); list.Add(5); list.Add(4); list.Add(6);
        list2.Add(5); list2.Add(4); list2.Add(7); list2.Add(7); list2.Add(4);
        list.RemoveAll(list2);
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 4, 6));
        list.Add(5); list.Add(4); list.Add(6);
        list2.Clear();
        list2.Add(6); list2.Add(5); list2.Add(5); list2.Add(6);
        list.RemoveAll(list2);
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 4, 4));
        list2.Clear();
        list2.Add(7); list2.Add(8); list2.Add(9);
        list.RemoveAll(list2);
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 4, 4));
      }


      [Test]
      public void Remove()
      {

        Assert.IsTrue(list.FIFO);
        list.Add(4); list.Add(4); list.Add(5); list.Add(4); list.Add(6);
        Assert.IsFalse(list.Remove(2));
        Assert.IsTrue(list.Check());
        Assert.IsTrue(list.Remove(4));
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 4, 5, 4, 6));
        Assert.AreEqual(6, list.RemoveLast());
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 4, 5, 4));
        list.Add(7);
        Assert.AreEqual(4, list.RemoveFirst());
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 5, 4, 7));

        list.FIFO = false;
        list.Clear();
        list.Add(4); list.Add(4); list.Add(5); list.Add(4); list.Add(6);
        Assert.IsFalse(list.Remove(2));
        Assert.IsTrue(list.Check());
        Assert.IsTrue(list.Remove(4));
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 4, 4, 5, 6));
        Assert.AreEqual(6, list.RemoveLast());
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 4, 4, 5));
        list.Add(7);
        Assert.AreEqual(4, list.RemoveFirst());
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 4, 5, 7));
      }


      [Test]
      public void Clear()
      {
        list.Add(7); list.Add(7);
        list.Clear();
        Assert.IsTrue(list.IsEmpty);
      }


      [TearDown]
      public void Dispose() { list = null; }
    }
  }




  namespace IIndexed
  {
    [TestFixture]
    public class Searching
    {
      private IIndexed<int> dit;


      [SetUp]
      public void Init()
      {
        dit = new LinkedList<int>();
      }


      [Test]
      public void IndexOf()
      {
        Assert.AreEqual(~0, dit.IndexOf(6));
        dit.Add(7);
        Assert.AreEqual(~1, dit.IndexOf(6));
        Assert.AreEqual(~1, dit.LastIndexOf(6));
        Assert.AreEqual(0, dit.IndexOf(7));
        dit.Add(5); dit.Add(7); dit.Add(8); dit.Add(7);
        Assert.AreEqual(~5, dit.IndexOf(6));
        Assert.AreEqual(0, dit.IndexOf(7));
        Assert.AreEqual(4, dit.LastIndexOf(7));
        Assert.AreEqual(3, dit.IndexOf(8));
        Assert.AreEqual(1, dit.LastIndexOf(5));
      }


      [TearDown]
      public void Dispose()
      {
        dit = null;
      }
    }



    [TestFixture]
    public class Removing
    {
      private IIndexed<int> dit;


      [SetUp]
      public void Init()
      {
        dit = new LinkedList<int>();
      }


      [Test]
      public void RemoveAt()
      {
        dit.Add(5); dit.Add(7); dit.Add(9); dit.Add(1); dit.Add(2);
        Assert.AreEqual(7, dit.RemoveAt(1));
        Assert.IsTrue(((LinkedList<int>)dit).Check());
        Assert.IsTrue(IC.eq(dit, 5, 9, 1, 2));
        Assert.AreEqual(5, dit.RemoveAt(0));
        Assert.IsTrue(((LinkedList<int>)dit).Check());
        Assert.IsTrue(IC.eq(dit, 9, 1, 2));
        Assert.AreEqual(2, dit.RemoveAt(2));
        Assert.IsTrue(((LinkedList<int>)dit).Check());
        Assert.IsTrue(IC.eq(dit, 9, 1));
      }


      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void RemoveAtBad0()
      {
        dit.RemoveAt(0);
      }


      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void RemoveAtBadM1()
      {
        dit.RemoveAt(-1);
      }


      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void RemoveAtBad1()
      {
        dit.Add(8);
        dit.RemoveAt(1);
      }


      [Test]
      public void RemoveInterval()
      {
        dit.RemoveInterval(0, 0);
        dit.Add(10); dit.Add(20); dit.Add(30); dit.Add(40); dit.Add(50); dit.Add(60);
        dit.RemoveInterval(3, 0);
        Assert.IsTrue(((LinkedList<int>)dit).Check());
        Assert.IsTrue(IC.eq(dit, 10, 20, 30, 40, 50, 60));
        dit.RemoveInterval(3, 1);
        Assert.IsTrue(((LinkedList<int>)dit).Check());
        Assert.IsTrue(IC.eq(dit, 10, 20, 30, 50, 60));
        dit.RemoveInterval(1, 3);
        Assert.IsTrue(((LinkedList<int>)dit).Check());
        Assert.IsTrue(IC.eq(dit, 10, 60));
        dit.RemoveInterval(0, 2);
        Assert.IsTrue(((LinkedList<int>)dit).Check());
        Assert.IsTrue(IC.eq(dit));
        dit.Add(10); dit.Add(20); dit.Add(30); dit.Add(40); dit.Add(50); dit.Add(60);
        dit.RemoveInterval(0, 2);
        Assert.IsTrue(((LinkedList<int>)dit).Check());
        Assert.IsTrue(IC.eq(dit, 30, 40, 50, 60));
        dit.RemoveInterval(2, 2);
        Assert.IsTrue(((LinkedList<int>)dit).Check());
        Assert.IsTrue(IC.eq(dit, 30, 40));
      }


      [TearDown]
      public void Dispose()
      {
        dit = null;
      }
    }
  }




  namespace IList_
  {
    [TestFixture]
    public class Searching
    {
      private IList<int> lst;


      [SetUp]
      public void Init() { lst = new LinkedList<int>(); }


      [TearDown]
      public void Dispose() { lst = null; }


      [Test]
      [ExpectedException(typeof(NoSuchItemException))]
      public void FirstBad()
      {
        int f = lst.First;
      }


      [Test]
      [ExpectedException(typeof(NoSuchItemException))]
      public void LastBad()
      {
        int f = lst.Last;
      }


      [Test]
      public void FirstLast()
      {
        lst.Add(19);
        Assert.AreEqual(19, lst.First);
        Assert.AreEqual(19, lst.Last);
        lst.Add(34); lst.InsertFirst(12);
        Assert.AreEqual(12, lst.First);
        Assert.AreEqual(34, lst.Last);
      }


      [Test]
      public void This()
      {
        lst.Add(34);
        Assert.AreEqual(34, lst[0]);
        lst[0] = 56;
        Assert.AreEqual(56, lst.First);
        lst.Add(7); lst.Add(7); lst.Add(7); lst.Add(7);
        lst[0] = 45; lst[2] = 78; lst[4] = 101;
        Assert.IsTrue(IC.eq(lst, 45, 7, 78, 7, 101));
      }


      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void ThisBadEmptyGet()
      {
        int f = lst[0];
      }


      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void ThisBadLowGet()
      {
        lst.Add(7);

        int f = lst[-1];
      }


      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void ThisBadHiGet()
      {
        lst.Add(6);

        int f = lst[1];
      }


      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void ThisBadEmptySet()
      {
        lst[0] = 4;
      }


      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void ThisBadLowSet()
      {
        lst.Add(7);
        lst[-1] = 9;
      }


      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void ThisBadHiSet()
      {
        lst.Add(6);
        lst[1] = 11;
      }
    }


    [TestFixture]
    public class Combined
    {
      private IList<KeyValuePair<int, int>> lst;


      [SetUp]
      public void Init()
      {
        lst = new LinkedList<KeyValuePair<int, int>>(new KeyValuePairEqualityComparer<int, int>());
        for (int i = 0; i < 10; i++)
          lst.Add(new KeyValuePair<int, int>(i, i + 30));
      }


      [TearDown]
      public void Dispose() { lst = null; }


      [Test]
      public void Find()
      {
        KeyValuePair<int, int> p = new KeyValuePair<int, int>(3, 78);

        Assert.IsTrue(lst.Find(ref p));
        Assert.AreEqual(3, p.Key);
        Assert.AreEqual(33, p.Value);
        p = new KeyValuePair<int, int>(13, 78);
        Assert.IsFalse(lst.Find(ref p));
      }


      [Test]
      public void FindOrAdd()
      {
        KeyValuePair<int, int> p = new KeyValuePair<int, int>(3, 78);

        Assert.IsTrue(lst.FindOrAdd(ref p));
        Assert.AreEqual(3, p.Key);
        Assert.AreEqual(33, p.Value);
        p = new KeyValuePair<int, int>(13, 79);
        Assert.IsFalse(lst.FindOrAdd(ref p));
        Assert.AreEqual(13, lst[10].Key);
        Assert.AreEqual(79, lst[10].Value);
      }


      [Test]
      public void Update()
      {
        KeyValuePair<int, int> p = new KeyValuePair<int, int>(3, 78);

        Assert.IsTrue(lst.Update(p));
        Assert.AreEqual(3, lst[3].Key);
        Assert.AreEqual(78, lst[3].Value);
        p = new KeyValuePair<int, int>(13, 78);
        Assert.IsFalse(lst.Update(p));
      }


      [Test]
      public void UpdateOrAdd1()
      {
        KeyValuePair<int, int> p = new KeyValuePair<int, int>(3, 78);

        Assert.IsTrue(lst.UpdateOrAdd(p));
        Assert.AreEqual(3, lst[3].Key);
        Assert.AreEqual(78, lst[3].Value);
        p = new KeyValuePair<int, int>(13, 79);
        Assert.IsFalse(lst.UpdateOrAdd(p));
        Assert.AreEqual(13, lst[10].Key);
        Assert.AreEqual(79, lst[10].Value);
      }

      [Test]
      public void UpdateOrAdd2()
      {
          ICollection<String> coll = new LinkedList<String>();
          // s1 and s2 are distinct objects but contain the same text:
          String old, s1 = "abc", s2 = ("def" + s1).Substring(3);
          Assert.IsFalse(coll.UpdateOrAdd(s1, out old));
          Assert.AreEqual(null, old);
          Assert.IsTrue(coll.UpdateOrAdd(s2, out old));
          Assert.IsTrue(Object.ReferenceEquals(s1, old));
          Assert.IsFalse(Object.ReferenceEquals(s2, old));
      }


      [Test]
      public void RemoveWithReturn()
      {
        KeyValuePair<int, int> p = new KeyValuePair<int, int>(3, 78);

        Assert.IsTrue(lst.Remove(p, out p));
        Assert.AreEqual(3, p.Key);
        Assert.AreEqual(33, p.Value);
        Assert.AreEqual(4, lst[3].Key);
        Assert.AreEqual(34, lst[3].Value);
        p = new KeyValuePair<int, int>(13, 78);
        Assert.IsFalse(lst.Remove(p, out p));
      }
    }


    [TestFixture]
    public class Inserting
    {
      private IList<int> lst;


      [SetUp]
      public void Init() { lst = new LinkedList<int>(); }


      [TearDown]
      public void Dispose() { lst = null; }


      [Test]
      public void Insert()
      {
        lst.Insert(0, 5);
        Assert.IsTrue(IC.eq(lst, 5));
        lst.Insert(0, 7);
        Assert.IsTrue(IC.eq(lst, 7, 5));
        lst.Insert(1, 4);
        Assert.IsTrue(IC.eq(lst, 7, 4, 5));
        lst.Insert(3, 2);
        Assert.IsTrue(IC.eq(lst, 7, 4, 5, 2));
      }

      [Test]
      public void InsertDuplicate()
      {
        lst.Insert(0, 5);
        Assert.IsTrue(IC.eq(lst, 5));
        lst.Insert(0, 7);
        Assert.IsTrue(IC.eq(lst, 7, 5));
        lst.Insert(1, 5);
        Assert.IsTrue(IC.eq(lst, 7, 5, 5));
      }

      [Test]
      public void InsertAllDuplicate1()
      {
        lst.Insert(0, 3);
        Assert.IsTrue(IC.eq(lst, 3));
        lst.Insert(0, 7);
        Assert.IsTrue(IC.eq(lst, 7, 3));
        lst.InsertAll<int>(1, new int[] { 1, 2, 3, 4 });
        Assert.IsTrue(IC.eq(lst, 7, 1, 2, 3, 4, 3));
        Assert.IsTrue(lst.Check());
      }
      [Test]
      public void InsertAllDuplicate2()
      {
        lst.Insert(0, 3);
        Assert.IsTrue(IC.eq(lst, 3));
        lst.Insert(0, 7);
        Assert.IsTrue(IC.eq(lst, 7, 3));
        lst.InsertAll<int>(1, new int[] { 5, 6, 5, 8 });
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 7, 5, 6, 5, 8, 3));
      }

      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void BadInsertLow()
      {
        lst.Add(7);
        lst.Insert(-1, 9);
      }


      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void BadInsertHi()
      {
        lst.Add(6);
        lst.Insert(2, 11);
      }


      [Test]
      public void FIFO()
      {
        for (int i = 0; i < 7; i++)
          lst.Add(2 * i);

        Assert.IsTrue(lst.FIFO);
        Assert.AreEqual(0, lst.Remove());
        Assert.AreEqual(2, lst.Remove());
        lst.FIFO = false;
        Assert.AreEqual(12, lst.Remove());
        Assert.AreEqual(10, lst.Remove());
        lst.FIFO = true;
        Assert.AreEqual(4, lst.Remove());
        Assert.AreEqual(6, lst.Remove());
      }


      [Test]
      public void InsertFirstLast()
      {
        lst.InsertFirst(4);
        lst.InsertLast(5);
        lst.InsertFirst(14);
        lst.InsertLast(15);
        lst.InsertFirst(24);
        lst.InsertLast(25);
        lst.InsertFirst(34);
        lst.InsertLast(55);
        Assert.IsTrue(IC.eq(lst, 34, 24, 14, 4, 5, 15, 25, 55));
      }


      [Test]
      public void InsertFirst()
      {
        lst.Add(2);
        lst.Add(3);
        lst.Add(2);
        lst.Add(5);
        lst.ViewOf(2).InsertFirst(7);
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 7, 2, 3, 2, 5));
        lst.ViewOf(3).InsertFirst(8);
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 7, 2, 8, 3, 2, 5));
        lst.ViewOf(5).InsertFirst(9);
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 7, 2, 8, 3, 2, 9, 5));
      }


      [Test]
      public void BadInsertFirst()
      {
        lst.Add(2);
        lst.Add(3);
        lst.Add(2);
        lst.Add(5);
        Assert.IsNull(lst.ViewOf(4));
      }


      [Test]
      public void InsertAfter()
      {
        lst.Add(1);
        lst.Add(2);
        lst.Add(3);
        lst.Add(2);
        lst.Add(5);
        lst.LastViewOf(2).InsertLast(7);
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 1, 2, 3, 2, 7, 5));
        lst.LastViewOf(1).InsertLast(8);
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 1, 8, 2, 3, 2, 7, 5));
        lst.LastViewOf(5).InsertLast(9);
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 1, 8, 2, 3, 2, 7, 5, 9));
      }


      [Test]
      public void BadInsertAfter()
      {
        lst.Add(2);
        lst.Add(3);
        lst.Add(2);
        lst.Add(5);
        Assert.IsNull(lst.ViewOf(4));
      }


      [Test]
      public void InsertAll()
      {
        lst.Add(1);
        lst.Add(2);
        lst.Add(3);
        lst.Add(4);

        IList<int> lst2 = new LinkedList<int>();

        lst2.Add(7); lst2.Add(8); lst2.Add(9);
        lst.InsertAll(0, lst2);
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 7, 8, 9, 1, 2, 3, 4));
        lst.InsertAll(7, lst2);
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 7, 8, 9, 1, 2, 3, 4, 7, 8, 9));
        lst.InsertAll(5, lst2);
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 7, 8, 9, 1, 2, 7, 8, 9, 3, 4, 7, 8, 9));
      }


      [Test]
      public void Map()
      {
        Fun<int, string> m = delegate(int i) { return "<<" + i + ">>"; };
        IList<string> r = lst.Map(m);

        Assert.IsTrue(r.Check());
        Assert.IsTrue(r.IsEmpty);
        lst.Add(1);
        lst.Add(2);
        lst.Add(3);
        lst.Add(4);
        r = lst.Map(m);
        Assert.IsTrue(r.Check());
        Assert.AreEqual(4, r.Count);
        for (int i = 0; i < 4; i++)
          Assert.AreEqual("<<" + (i + 1) + ">>", r[i]);
      }
      [Test]
      [ExpectedException(typeof(CollectionModifiedException))]
      public void BadMapper()
      {
        lst.Add(1);
        lst.Add(2);
        lst.Add(3);
        Fun<int, bool> m = delegate(int i) { if (i == 2) lst.Add(7); return true; };
        lst.Map(m);
      }

      [Test]
      [ExpectedException(typeof(CollectionModifiedException))]
      public void ModifyingFindAll()
      {
        lst.Add(1);
        lst.Add(2);
        lst.Add(3);
        Fun<int, bool> m = delegate(int i) { if (i == 2) lst.Add(7); return true; };
        lst.FindAll(m);
      }

      [Test]
      [ExpectedException(typeof(CollectionModifiedException))]
      public void BadMapperView()
      {
        lst = lst.View(0, 0);
        lst.Add(1);
        lst.Add(2);
        lst.Add(3);
        Fun<int, bool> m = delegate(int i) { if (i == 2) lst.Add(7); return true; };
        lst.Map(m);
      }

      [Test]
      [ExpectedException(typeof(CollectionModifiedException))]
      public void ModifyingFindAllView()
      {
        lst = lst.View(0, 0);
        lst.Add(1);
        lst.Add(2);
        lst.Add(3);
        Fun<int, bool> m = delegate(int i) { if (i == 2) lst.Add(7); return true; };
        lst.FindAll(m);
      }


      [Test]
      [ExpectedException(typeof(NoSuchItemException))]
      public void BadRemove() { lst.Remove(); }

      [Test]
      [ExpectedException(typeof(NoSuchItemException))]
      public void BadRemoveFirst() { lst.RemoveFirst(); }

      [Test]
      [ExpectedException(typeof(NoSuchItemException))]
      public void BadRemoveLast() { lst.RemoveLast(); }


      [Test]
      public void RemoveFirstLast()
      {
        lst.Add(1);
        lst.Add(2);
        lst.Add(3);
        lst.Add(4);
        Assert.AreEqual(1, lst.RemoveFirst());
        Assert.AreEqual(4, lst.RemoveLast());
        Assert.AreEqual(2, lst.RemoveFirst());
        Assert.AreEqual(3, lst.RemoveLast());
        Assert.IsTrue(lst.IsEmpty);
      }

      [Test]
      [ExpectedException(typeof(NoSuchItemException))]
      public void RemoveFirstEmpty()
      {
        lst.RemoveFirst();
      }

      [Test]
      [ExpectedException(typeof(NoSuchItemException))]
      public void RemoveLastEmpty()
      {
        lst.RemoveLast();
      }

      [Test]
      public void Reverse()
      {
        for (int i = 0; i < 10; i++)
          lst.Add(i);

        lst.Reverse();
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0));
        lst.View(0, 3).Reverse();
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 7, 8, 9, 6, 5, 4, 3, 2, 1, 0));
        lst.View(7, 0).Reverse();
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 7, 8, 9, 6, 5, 4, 3, 2, 1, 0));
        lst.View(7, 3).Reverse();
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 7, 8, 9, 6, 5, 4, 3, 0, 1, 2));
        lst.View(5, 1).Reverse();
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(IC.eq(lst, 7, 8, 9, 6, 5, 4, 3, 0, 1, 2));
      }


      [Test]
      [ExpectedException(typeof(ArgumentOutOfRangeException))]
      public void BadReverse()
      {
        for (int i = 0; i < 10; i++)
          lst.Add(i);

        lst.View(8, 3).Reverse();
      }
    }



    [TestFixture]
    public class SortingTests
    {
      private IList<int> lst;


      [SetUp]
      public void Init() { lst = new LinkedList<int>(); }


      [TearDown]
      public void Dispose() { lst = null; }


      [Test]
      public void Sort()
      {
        lst.Add(5); lst.Add(6); lst.Add(5); lst.Add(7); lst.Add(3);
        Assert.IsFalse(lst.IsSorted(new IC()));
        lst.Sort(new IC());
        Assert.IsTrue(lst.Check());
        Assert.IsTrue(lst.IsSorted());
        Assert.IsTrue(lst.IsSorted(new IC()));
        Assert.IsTrue(IC.eq(lst, 3, 5, 5, 6, 7));
      }


      [Test]
      public void Stability()
      {
        IList<KeyValuePair<int, string>> lst2 = new LinkedList<KeyValuePair<int, string>>();
        SCG.IComparer<KeyValuePair<int, string>> c = new KeyValuePairComparer<int, string>(new IC());

        lst2.Add(new KeyValuePair<int, string>(5, "a"));
        lst2.Add(new KeyValuePair<int, string>(5, "b"));
        lst2.Add(new KeyValuePair<int, string>(6, "c"));
        lst2.Add(new KeyValuePair<int, string>(4, "d"));
        lst2.Add(new KeyValuePair<int, string>(3, "e"));
        lst2.Add(new KeyValuePair<int, string>(4, "f"));
        lst2.Add(new KeyValuePair<int, string>(5, "handle"));
        Assert.IsFalse(lst2.IsSorted(c));
        lst2.Sort(c);
        Assert.IsTrue(lst2.IsSorted(c));

        KeyValuePair<int, string> p = lst2.RemoveFirst();

        Assert.AreEqual(3, p.Key);
        Assert.AreEqual("e", p.Value);
        p = lst2.RemoveFirst();
        Assert.AreEqual(4, p.Key);
        Assert.AreEqual("d", p.Value);
        p = lst2.RemoveFirst();
        Assert.AreEqual(4, p.Key);
        Assert.AreEqual("f", p.Value);
        p = lst2.RemoveFirst();
        Assert.AreEqual(5, p.Key);
        Assert.AreEqual("a", p.Value);
        p = lst2.RemoveFirst();
        Assert.AreEqual(5, p.Key);
        Assert.AreEqual("b", p.Value);
        p = lst2.RemoveFirst();
        Assert.AreEqual(5, p.Key);
        Assert.AreEqual("handle", p.Value);
        p = lst2.RemoveFirst();
        Assert.AreEqual(6, p.Key);
        Assert.AreEqual("c", p.Value);
        Assert.IsTrue(lst2.IsEmpty);
      }
    }
    [TestFixture]
    public class ShuffleTests
    {
      private IList<int> lst;


      [SetUp]
      public void Init() { lst = new LinkedList<int>(); }


      [TearDown]
      public void Dispose() { lst = null; }


      [Test]
      public void Shuffle()
      {
        lst.Add(5); lst.Add(6); lst.Add(5); lst.Add(7); lst.Add(3);
        for (int i = 0; i < 100; i++)
        {
          lst.Shuffle(new C5Random(i + 1));
          Assert.IsTrue(lst.Check(), "Check " + i);
          int[] lst2 = lst.ToArray();
          Sorting.IntroSort<int>(lst2);
          Assert.IsTrue(IC.eq(lst2, 3, 5, 5, 6, 7), "Contents " + i);
        }
      }
    }
  }


  namespace IStackQueue
  {
    [TestFixture]
    public class Stack
    {
      private IStack<int> list;


      [SetUp]
      public void Init() { list = new LinkedList<int>(); }


      [Test]
      public void Normal()
      {
        list.Push(7);
        list.Push(5);
        list.Push(7);
        list.Push(8);
        list.Push(9);
        Assert.AreEqual(9, list.Pop());
        Assert.AreEqual(8, list.Pop());
        Assert.AreEqual(7, list.Pop());
        Assert.AreEqual(5, list.Pop());
        Assert.AreEqual(7, list.Pop());
      }


      [Test]
      [ExpectedException(typeof(NoSuchItemException))]
      public void PopEmpty()
      {
        list.Push(5);
        Assert.AreEqual(5, list.Pop());
        list.Pop();
      }


      [TearDown]
      public void Dispose() { list = null; }
    }
    [TestFixture]
    public class Queue
    {
      private IQueue<int> list;


      [SetUp]
      public void Init() { list = new LinkedList<int>(); }


      [Test]
      public void Normal()
      {
        list.Enqueue(7);
        list.Enqueue(5);
        list.Enqueue(7);
        list.Enqueue(8);
        list.Enqueue(9);
        Assert.AreEqual(7, list.Dequeue());
        Assert.AreEqual(5, list.Dequeue());
        Assert.AreEqual(7, list.Dequeue());
        Assert.AreEqual(8, list.Dequeue());
        Assert.AreEqual(9, list.Dequeue());
      }


      [Test]
      [ExpectedException(typeof(NoSuchItemException))]
      public void DeQueueEmpty()
      {
        list.Enqueue(5);
        Assert.AreEqual(5, list.Dequeue());
        list.Dequeue();
      }


      [TearDown]
      public void Dispose() { list = null; }
    }
  }


  namespace Range
  {
    [TestFixture]
    public class Range
    {
      private IList<int> lst;


      [SetUp]
      public void Init() { lst = new LinkedList<int>(); }


      [TearDown]
      public void Dispose() { lst = null; }


      [Test]
      public void GetRange()
      {
        //Assert.IsTrue(IC.eq(lst[0, 0)));
        for (int i = 0; i < 10; i++) lst.Add(i);

        Assert.IsTrue(IC.eq(lst[0, 3], 0, 1, 2));
        Assert.IsTrue(IC.eq(lst[3, 4], 3, 4, 5, 6));
        Assert.IsTrue(IC.eq(lst[6, 4], 6, 7, 8, 9));
      }


      [Test]
      [ExpectedException(typeof(ArgumentOutOfRangeException))]
      public void BadGetRange()
      {
        object foo = lst[0, 11];
      }


      [Test]
      public void Backwards()
      {
        for (int i = 0; i < 10; i++) lst.Add(i);

        Assert.IsTrue(IC.eq(lst.Backwards(), 9, 8, 7, 6, 5, 4, 3, 2, 1, 0));
        Assert.IsTrue(IC.eq(lst[0, 4].Backwards(), 3, 2, 1, 0));
        Assert.IsTrue(IC.eq(lst[3, 4].Backwards(), 6, 5, 4, 3));
        Assert.IsTrue(IC.eq(lst[6, 4].Backwards(), 9, 8, 7, 6));
      }


      [Test]
      public void DirectionAndCount()
      {
        for (int i = 0; i < 10; i++) lst.Add(i);

        Assert.AreEqual(EnumerationDirection.Forwards, lst.Direction);
        Assert.AreEqual(EnumerationDirection.Forwards, lst[3, 7].Direction);
        Assert.AreEqual(EnumerationDirection.Backwards, lst[3, 7].Backwards().Direction);
        Assert.AreEqual(EnumerationDirection.Backwards, lst.Backwards().Direction);
        Assert.AreEqual(4, lst[3, 4].Count);
        Assert.AreEqual(4, lst[3, 4].Backwards().Count);
        Assert.AreEqual(10, lst.Backwards().Count);
      }


      [Test]
      [ExpectedException(typeof(CollectionModifiedException))]
      public void MoveNextAfterUpdate()
      {
        for (int i = 0; i < 10; i++) lst.Add(i);

        foreach (int i in lst)
        {
          lst.Add(45 + i);
        }
      }
    }
  }




  namespace View
  {
    [TestFixture]
    public class Simple
    {
      LinkedList<int> list, view;


      [SetUp]
      public void Init()
      {
        list = new LinkedList<int>();
        list.Add(0); list.Add(1); list.Add(2); list.Add(3);
        view = (LinkedList<int>)list.View(1, 2);
      }


      [TearDown]
      public void Dispose()
      {
        list = view = null;
      }


      void check()
      {
        Assert.IsTrue(list.Check());
        Assert.IsTrue(view.Check());
      }


      [Test]
      public void InsertPointer()
      {
        IList<int> view2 = list.View(2, 0);
        list.Insert(view2, 7);
        check();
        list.Insert(list, 8);
        check();
        view.Insert(view2, 9);
        check();
        view.Insert(list.View(3, 2), 10);
        check();
        view.Insert(list.ViewOf(0), 11);
        check();
        Assert.IsTrue(IC.eq(list, 0, 11, 1, 9, 7, 2, 10, 3, 8));
        Assert.IsTrue(IC.eq(view, 11, 1, 9, 7, 2, 10));
      }

      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void InsertPointerBad1()
      {
        view.Insert(list.View(0, 0), 7);
      }

      [Test]
      [ExpectedException(typeof(IndexOutOfRangeException))]
      public void InsertPointerBad2()
      {
        view.Insert(list, 7);
      }

      [Test]
      [ExpectedException(typeof(IncompatibleViewException))]
      public void InsertPointerBad3()
      {
        list.Insert(new ArrayList<int>(), 7);
      }

      [Test]
      [ExpectedException(typeof(IncompatibleViewException))]
      public void InsertPointerBad4()
      {
        list.Insert(new ArrayList<int>().View(0, 0), 7);
      }

      [Test]
      public void Span()
      {
        IList<int> span = list.View(1, 0).Span(list.View(2, 0));
        Assert.IsTrue(span.Check());
        Assert.AreEqual(1, span.Offset);
        Assert.AreEqual(1, span.Count);
        span = list.View(0, 2).Span(list.View(2, 2));
        Assert.IsTrue(span.Check());
        Assert.AreEqual(0, span.Offset);
        Assert.AreEqual(4, span.Count);
        span = list.View(3, 1).Span(list.View(1, 1));
        Assert.IsNull(span);
      }

      [Test]
      public void ViewOf()
      {
        for (int i = 0; i < 4; i++)
          list.Add(i);
        IList<int> v = view.ViewOf(2);
        Assert.IsTrue(v.Check());
        Assert.IsTrue(IC.eq(v, 2));
        Assert.AreEqual(2, v.Offset);
        v = list.ViewOf(2);
        Assert.IsTrue(v.Check());
        Assert.IsTrue(IC.eq(v, 2));
        Assert.AreEqual(2, v.Offset);
        v = list.LastViewOf(2);
        Assert.IsTrue(v.Check());
        Assert.IsTrue(IC.eq(v, 2));
        Assert.AreEqual(6, v.Offset);
      }

      [Test]
      public void BadViewOf()
      {
        Assert.IsNull(view.ViewOf(5));
        Assert.IsNull(view.LastViewOf(5));
        Assert.IsNull(view.ViewOf(3));
        Assert.IsNull(view.LastViewOf(3));
        Assert.IsNull(view.ViewOf(0));
        Assert.IsNull(view.LastViewOf(0));
      }

      [Test]
      public void ArrayStuff()
      {
        Assert.IsTrue(IC.eq(view.ToArray(), 1, 2));
        int[] extarray = new int[5];
        view.CopyTo(extarray, 2);
        Assert.IsTrue(IC.eq(extarray, 0, 0, 1, 2, 0));
      }


      [Test]
      public void Add()
      {
        check();
        Assert.IsTrue(IC.eq(list, 0, 1, 2, 3));
        Assert.IsTrue(IC.eq(view, 1, 2));
        view.InsertFirst(10);
        check();
        Assert.IsTrue(IC.eq(list, 0, 10, 1, 2, 3));
        Assert.IsTrue(IC.eq(view, 10, 1, 2));
        view.Clear();
        Assert.IsFalse(view.IsReadOnly);
        Assert.IsTrue(view.AllowsDuplicates);
        Assert.IsTrue(view.IsEmpty);
        check();
        Assert.IsTrue(IC.eq(list, 0, 3));
        Assert.IsTrue(IC.eq(view));
        view.Add(8);
        Assert.IsFalse(view.IsEmpty);
        Assert.IsTrue(view.AllowsDuplicates);
        Assert.IsFalse(view.IsReadOnly);
        check();
        Assert.IsTrue(IC.eq(list, 0, 8, 3));
        Assert.IsTrue(IC.eq(view, 8));
        view.Add(12);
        check();
        Assert.IsTrue(IC.eq(list, 0, 8, 12, 3));
        Assert.IsTrue(IC.eq(view, 8, 12));
        view./*ViewOf(12).*/InsertLast(15);
        check();
        Assert.IsTrue(IC.eq(list, 0, 8, 12, 15, 3));
        Assert.IsTrue(IC.eq(view, 8, 12, 15));
        view.ViewOf(12).InsertFirst(18);
        check();
        Assert.IsTrue(IC.eq(list, 0, 8, 18, 12, 15, 3));
        Assert.IsTrue(IC.eq(view, 8, 18, 12, 15));

        LinkedList<int> lst2 = new LinkedList<int>();

        lst2.Add(90); lst2.Add(92);
        view.AddAll(lst2);
        check();
        Assert.IsTrue(IC.eq(list, 0, 8, 18, 12, 15, 90, 92, 3));
        Assert.IsTrue(IC.eq(view, 8, 18, 12, 15, 90, 92));
        view.InsertLast(66);
        check();
        Assert.IsTrue(IC.eq(list, 0, 8, 18, 12, 15, 90, 92, 66, 3));
        Assert.IsTrue(IC.eq(view, 8, 18, 12, 15, 90, 92, 66));
      }


      [Test]
      public void Bxxx()
      {
        Assert.IsTrue(IC.eq(view.Backwards(), 2, 1));
        Assert.AreSame(list, view.Underlying);
        Assert.IsNull(list.Underlying);
        Assert.AreEqual(EnumerationDirection.Forwards, view.Direction);
        Assert.AreEqual(EnumerationDirection.Backwards, view.Backwards().Direction);
        Assert.AreEqual(0, list.Offset);
        Assert.AreEqual(1, view.Offset);
      }


      [Test]
      public void Contains()
      {
        Assert.IsTrue(view.Contains(1));
        Assert.IsFalse(view.Contains(0));

        LinkedList<int> lst2 = new LinkedList<int>();

        lst2.Add(2);
        Assert.IsTrue(view.ContainsAll(lst2));
        lst2.Add(3);
        Assert.IsFalse(view.ContainsAll(lst2));
        Assert.AreEqual(Speed.Linear, view.ContainsSpeed);
        Assert.AreEqual(2, view.Count);
        view.Add(1);
        Assert.AreEqual(1, view.ContainsCount(2));
        Assert.AreEqual(2, view.ContainsCount(1));
        Assert.AreEqual(3, view.Count);
      }


      [Test]
      public void CreateView()
      {
        LinkedList<int> view2 = (LinkedList<int>)view.View(1, 0);

        Assert.AreSame(list, view2.Underlying);
      }


      [Test]
      public void FIFO()
      {
        Assert.IsTrue(view.FIFO);
        view.Add(23); view.Add(24); view.Add(25);
        check();
        Assert.IsTrue(IC.eq(view, 1, 2, 23, 24, 25));
        Assert.AreEqual(1, view.Remove());
        check();
        Assert.IsTrue(IC.eq(view, 2, 23, 24, 25));
        view.FIFO = false;
        Assert.IsFalse(view.FIFO);
        Assert.AreEqual(25, view.Remove());
        check();
        Assert.IsTrue(IC.eq(view, 2, 23, 24));
      }


      [Test]
      public void MapEtc()
      {
        LinkedList<double> dbl = (LinkedList<double>)view.Map(new Fun<int, double>(delegate(int i) { return i / 10.0; }));

        Assert.IsTrue(dbl.Check());
        Assert.AreEqual(0.1, dbl[0]);
        Assert.AreEqual(0.2, dbl[1]);
        for (int i = 0; i < 10; i++) view.Add(i);

        list = (LinkedList<int>)view.FindAll(new Fun<int, bool>(delegate(int i) { return i % 4 == 1; }));
        Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 1, 1, 5, 9));
      }


      [Test]
      public void FL()
      {
        Assert.AreEqual(1, view.First);
        Assert.AreEqual(2, view.Last);
      }


      [Test]
      public void Indexing()
      {
        list.Clear();
        for (int i = 0; i < 20; i++) list.Add(i);

        view = (LinkedList<int>)list.View(5, 7);
        for (int i = 0; i < 7; i++) Assert.AreEqual(i + 5, view[i]);

        for (int i = 0; i < 7; i++) Assert.AreEqual(i, view.IndexOf(i + 5));

        for (int i = 0; i < 7; i++) Assert.AreEqual(i, view.LastIndexOf(i + 5));
      }


      [Test]
      public void INsert()
      {
        view.Insert(0, 34);
        view.Insert(1, 35);
        view.Insert(4, 36);
        Assert.IsTrue(view.Check());
        Assert.IsTrue(IC.eq(view, 34, 35, 1, 2, 36));

        IList<int> list2 = new LinkedList<int>();

        list2.AddAll(view);
        view.InsertAll(3, list2);
        Assert.IsTrue(view.Check());
        Assert.IsTrue(IC.eq(view, 34, 35, 1, 34, 35, 1, 2, 36, 2, 36));
      }


      [Test]
      public void Sort()
      {
        view.Add(45); view.Add(47); view.Add(46); view.Add(48);
        Assert.IsFalse(view.IsSorted(new IC()));
        view.Sort(new IC());
        check();
        Assert.IsTrue(IC.eq(list, 0, 1, 2, 45, 46, 47, 48, 3));
        Assert.IsTrue(IC.eq(view, 1, 2, 45, 46, 47, 48));
      }


      [Test]
      public void Remove()
      {
        view.FIFO = false;
        view.Add(1); view.Add(5); view.Add(3); view.Add(1); view.Add(3); view.Add(0);
        Assert.IsTrue(IC.eq(view, 1, 2, 1, 5, 3, 1, 3, 0));
        Assert.IsTrue(view.Remove(1));
        check();
        Assert.IsTrue(IC.eq(view, 1, 2, 1, 5, 3, 3, 0));
        Assert.IsTrue(view.Remove(1));
        check();
        Assert.IsTrue(IC.eq(view, 1, 2, 5, 3, 3, 0));
        Assert.IsTrue(view.Remove(0));
        check();
        Assert.IsTrue(IC.eq(view, 1, 2, 5, 3, 3));
        view.RemoveAllCopies(3);
        check();
        Assert.IsTrue(IC.eq(view, 1, 2, 5));
        Assert.IsTrue(IC.eq(list, 0, 1, 2, 5, 3));
        view.Add(1); view.Add(5); view.Add(3); view.Add(1); view.Add(3); view.Add(0);
        Assert.IsTrue(IC.eq(view, 1, 2, 5, 1, 5, 3, 1, 3, 0));

        view.FIFO = true;
        view.Clear(); view.Add(1); view.Add(2);

        view.Add(1); view.Add(5); view.Add(3); view.Add(1); view.Add(3); view.Add(0);
        Assert.IsTrue(IC.eq(view, 1, 2, 1, 5, 3, 1, 3, 0));
        Assert.IsTrue(view.Remove(1));
        check();
        Assert.IsTrue(IC.eq(view, 2, 1, 5, 3, 1, 3, 0));
        Assert.IsTrue(view.Remove(1));
        check();
        Assert.IsTrue(IC.eq(view, 2, 5, 3, 1, 3, 0));
        Assert.IsTrue(view.Remove(0));
        check();
        Assert.IsTrue(IC.eq(view, 2, 5, 3, 1, 3));
        view.RemoveAllCopies(3);
        check();
        Assert.IsTrue(IC.eq(view, 2, 5, 1));
        Assert.IsTrue(IC.eq(list, 0, 2, 5, 1, 3));
        view.Add(1); view.Add(5); view.Add(3); view.Add(1); view.Add(3); view.Add(0);
        Assert.IsTrue(IC.eq(view, 2, 5, 1, 1, 5, 3, 1, 3, 0));

        LinkedList<int> l2 = new LinkedList<int>();

        l2.Add(1); l2.Add(2); l2.Add(2); l2.Add(3); l2.Add(1);
        view.RemoveAll(l2);
        check();
        Assert.IsTrue(IC.eq(view, 5, 5, 1, 3, 0));
        view.RetainAll(l2);
        check();
        Assert.IsTrue(IC.eq(view, 1, 3));
        view.Add(2); view.Add(4); view.Add(5);
        Assert.AreEqual(1, view.RemoveAt(0));
        Assert.AreEqual(5, view.RemoveAt(3));
        Assert.AreEqual(2, view.RemoveAt(1));
        check();
        Assert.IsTrue(IC.eq(view, 3, 4));
        view.Add(8);
        Assert.AreEqual(3, view.RemoveFirst());
        Assert.AreEqual(8, view.RemoveLast());
        view.Add(2); view.Add(5); view.Add(3); view.Add(1);
        view.RemoveInterval(1, 2);
        check();
        Assert.IsTrue(IC.eq(view, 4, 3, 1));
      }


      [Test]
      public void Reverse()
      {
        view.Clear();
        for (int i = 0; i < 10; i++) view.Add(10 + i);

        view.View(3, 4).Reverse();
        check();
        Assert.IsTrue(IC.eq(view, 10, 11, 12, 16, 15, 14, 13, 17, 18, 19));
        view.Reverse();
        Assert.IsTrue(IC.eq(view, 19, 18, 17, 13, 14, 15, 16, 12, 11, 10));
        Assert.IsTrue(IC.eq(list, 0, 19, 18, 17, 13, 14, 15, 16, 12, 11, 10, 3));
      }


      [Test]
      public void Slide()
      {
        view.Slide(1);
        check();
        Assert.IsTrue(IC.eq(view, 2, 3));
        view.Slide(-2);
        check();
        Assert.IsTrue(IC.eq(view, 0, 1));
        view.Slide(0, 3);
        check();
        Assert.IsTrue(IC.eq(view, 0, 1, 2));
        view.Slide(2, 1);
        check();
        Assert.IsTrue(IC.eq(view, 2));
        Assert.AreEqual(view, view.Slide(-1, 0));
        check();
        Assert.IsTrue(IC.eq(view));
        view.Add(28);
        Assert.IsTrue(IC.eq(list, 0, 28, 1, 2, 3));
      }
      [Test]
      public void Iterate()
      {
        list.Clear();
        view = null;
        foreach (int i in new int[] { 2, 4, 8, 13, 6, 1, 2, 7 }) list.Add(i);

        view = (LinkedList<int>)list.View(list.Count - 2, 2);
        while (true)
        {
          //Console.WriteLine("View: {0}:  {1} --> {2}", view.Count, view.First, view.Last);
          if ((view.Last - view.First) % 2 == 1)
            view.Insert(1, 666);
          check();
          if (view.Offset == 0)
            break;
          else
            view.Slide(-1, 2);
        }
        //foreach (int cell in list) Console.Write(" " + cell);
        //Assert.IsTrue(list.Check());
        Assert.IsTrue(IC.eq(list, 2, 4, 8, 666, 13, 6, 1, 666, 2, 666, 7));
      }


      [Test]
      public void SyncRoot()
      {
        Assert.AreSame(((System.Collections.IList)view).SyncRoot, ((System.Collections.IList)list).SyncRoot);
      }
    }

    [TestFixture]
    public class MulipleViews
    {
      IList<int> list;
      IList<int>[][] views;
      [SetUp]
      public void Init()
      {
        list = new LinkedList<int>();
        for (int i = 0; i < 6; i++)
          list.Add(i);
        views = new IList<int>[7][];
        for (int i = 0; i < 7; i++)
        {
          views[i] = new IList<int>[7 - i];
          for (int j = 0; j < 7 - i; j++)
            views[i][j] = list.View(i, j);
        }
      }
      [TearDown]
      public void Dispose()
      {
        list = null;
        views = null;
      }
      [Test]
      public void Insert()
      {
        Assert.IsTrue(list.Check(), "list check before insert");
        list.Insert(3, 777);
        Assert.IsTrue(list.Check(), "list check after insert");
        for (int i = 0; i < 7; i++)
          for (int j = 0; j < 7 - i; j++)
          {
            Assert.AreEqual(i < 3 || (i == 3 && j == 0) ? i : i + 1, views[i][j].Offset, "view[" + i + "][" + j + "] offset");
            Assert.AreEqual(i < 3 && i + j > 3 ? j + 1 : j, views[i][j].Count, "view[" + i + "][" + j + "] count");
          }
      }
      [Test]
      public void RemoveAt()
      {
        Assert.IsTrue(list.Check(), "list check before remove");
        list.RemoveAt(3);
        Assert.IsTrue(list.Check(), "list check after remove");
        for (int i = 0; i < 7; i++)
          for (int j = 0; j < 7 - i; j++)
          {
            Assert.AreEqual(i <= 3 ? i : i - 1, views[i][j].Offset, "view[" + i + "][" + j + "] offset");
            Assert.AreEqual(i <= 3 && i + j > 3 ? j - 1 : j, views[i][j].Count, "view[" + i + "][" + j + "] count");
          }
      }

      [Test]
      public void RemoveInterval()
      {
        Assert.IsTrue(list.Check(), "list check before remove");
        list.RemoveInterval(3, 2);
        Assert.IsTrue(list.Check(), "list check after remove");
        for (int i = 0; i < 7; i++)
          for (int j = 0; j < 7 - i; j++)
          {
            Assert.AreEqual(i <= 3 ? i : i <= 5 ? 3 : i - 2, views[i][j].Offset, "view[" + i + "][" + j + "] offset");
            Assert.AreEqual(j == 0 ? 0 : i <= 3 && i + j > 4 ? j - 2 : i > 4 || i + j <= 3 ? j : j - 1, views[i][j].Count, "view[" + i + "][" + j + "] count");
          }
      }


      [Test]
      public void InsertAtEnd()
      {
        Assert.IsTrue(list.Check(), "list check before insert");
        list.InsertLast(777);
        Assert.IsTrue(list.Check(), "list check after insert");
        for (int i = 0; i < 7; i++)
          for (int j = 0; j < 7 - i; j++)
          {
            Assert.AreEqual(i, views[i][j].Offset, "view[" + i + "][" + j + "] offset");
            Assert.AreEqual(j, views[i][j].Count, "view[" + i + "][" + j + "] count");
          }
      }
      [Test]
      public void RemoveAtEnd()
      {
        Assert.IsTrue(list.Check(), "list check before remove");
        list.RemoveAt(5);
        Assert.IsTrue(list.Check(), "list check after remove");
        for (int i = 0; i < 7; i++)
          for (int j = 0; j < 7 - i; j++)
          {
            Assert.AreEqual(i <= 5 ? i : i - 1, views[i][j].Offset, "view[" + i + "][" + j + "] offset");
            Assert.AreEqual(i <= 5 && i + j > 5 ? j - 1 : j, views[i][j].Count, "view[" + i + "][" + j + "] count");
          }
      }
      [Test]
      public void InsertAtStart()
      {
        Assert.IsTrue(list.Check(), "list check before insert");
        list.Insert(0, 777);
        Assert.IsTrue(list.Check(), "list check after insert");
        for (int i = 0; i < 7; i++)
          for (int j = 0; j < 7 - i; j++)
          {
            Assert.AreEqual(i == 0 && j == 0 ? 0 : i + 1, views[i][j].Offset, "view[" + i + "][" + j + "] offset");
            Assert.AreEqual(j, views[i][j].Count, "view[" + i + "][" + j + "] count");
          }
      }
      [Test]
      public void RemoveAtStart()
      {
        Assert.IsTrue(list.Check(), "list check before remove");
        list.RemoveAt(0);
        Assert.IsTrue(list.Check(), "list check after remove");
        for (int i = 0; i < 7; i++)
          for (int j = 0; j < 7 - i; j++)
          {
            Assert.AreEqual(i == 0 ? i : i - 1, views[i][j].Offset, "view[" + i + "][" + j + "] offset");
            Assert.AreEqual(i == 0 && j > 0 ? j - 1 : j, views[i][j].Count, "view[" + i + "][" + j + "] count");
          }
      }
      [Test]
      public void Clear()
      {
        Assert.IsTrue(list.Check(), "list check before clear");
        views[2][3].Clear();
        Assert.IsTrue(list.Check(), "list check after clear");
        for (int i = 0; i < 7; i++)
          for (int j = 0; j < 7 - i; j++)
          {
            Assert.AreEqual(i < 2 ? i : i < 6 ? 2 : i - 3, views[i][j].Offset, "view[" + i + "][" + j + "] offset");
            Assert.AreEqual(s(i, j), views[i][j].Count, "view[" + i + "][" + j + "] count");
          }
      }

      private int s(int i, int j)
      {
        if (j == 0) return 0;
        int k = i + j - 1; //end
        if (i > 4 || k <= 1) return j;
        if (i >= 2) return k > 4 ? k - 4 : 0;
        if (i <= 2) return k >= 4 ? j - 3 : 2 - i;
        return -1;
      }
      [Test]
      public void InsertAll()
      {
        LinkedList<int> list2 = new LinkedList<int>();
        for (int i = 0; i < 5; i++) { list2.Add(100 + i); }
        Assert.IsTrue(list.Check(), "list check before insertAll");
        list.InsertAll(3, list2);
        Assert.IsTrue(list.Check(), "list check after insertAll");
        for (int i = 0; i < 7; i++)
          for (int j = 0; j < 7 - i; j++)
          {
            Assert.AreEqual(i < 3 || (i == 3 && j == 0) ? i : i + 5, views[i][j].Offset, "view[" + i + "][" + j + "] offset");
            Assert.AreEqual(i < 3 && i + j > 3 ? j + 5 : j, views[i][j].Count, "view[" + i + "][" + j + "] count");
          }
      }

      [Test]
      public void AddAll()
      {
        LinkedList<int> list2 = new LinkedList<int>();
        for (int i = 0; i < 5; i++) { list2.Add(100 + i); }
        Assert.IsTrue(list.Check(), "list check before AddAll");
        list.View(1, 2).AddAll(list2);
        Assert.IsTrue(list.Check(), "list check after AddAll");
        for (int i = 0; i < 7; i++)
          for (int j = 0; j < 7 - i; j++)
          {
            Assert.AreEqual(i < 3 || (i == 3 && j == 0) ? i : i + 5, views[i][j].Offset, "view[" + i + "][" + j + "] offset");
            Assert.AreEqual(i < 3 && i + j > 3 ? j + 5 : j, views[i][j].Count, "view[" + i + "][" + j + "] count");
          }
      }

      [Test]
      public void RemoveAll1()
      {
        LinkedList<int> list2 = new LinkedList<int>();
        list2.Add(1); list2.Add(3); list2.Add(4);

        for (int i = 0; i < 7; i++)
        {
          for (int j = 0; j < 7 - i; j++)
          {
            list = new LinkedList<int>();
            for (int k = 0; k < 6; k++) list.Add(k);
            LinkedList<int> v = (LinkedList<int>)list.View(i, j);
            list.RemoveAll(list2);
            Assert.IsTrue(list.Check(), "list check after RemoveAll, i=" + i + ", j=" + j);
          }
        }
      }
      [Test]
      public void RemoveAll2()
      {
        LinkedList<int> list2 = new LinkedList<int>();
        list2.Add(1); list2.Add(3); list2.Add(4);
        Assert.IsTrue(list.Check(), "list check before RemoveAll");
        list.RemoveAll(list2);

        Assert.AreEqual(0, views[0][0].Offset, "view [0][0] offset");
        Assert.AreEqual(0, views[0][1].Offset, "view [0][1] offset");
        Assert.AreEqual(0, views[0][2].Offset, "view [0][2] offset");
        Assert.AreEqual(0, views[0][3].Offset, "view [0][3] offset");
        Assert.AreEqual(0, views[0][4].Offset, "view [0][4] offset");
        Assert.AreEqual(0, views[0][5].Offset, "view [0][5] offset");
        Assert.AreEqual(0, views[0][6].Offset, "view [0][6] offset");
        Assert.AreEqual(1, views[1][0].Offset, "view [1][0] offset");
        Assert.AreEqual(1, views[1][1].Offset, "view [1][1] offset");
        Assert.AreEqual(1, views[1][2].Offset, "view [1][2] offset");
        Assert.AreEqual(1, views[1][3].Offset, "view [1][3] offset");
        Assert.AreEqual(1, views[1][4].Offset, "view [1][4] offset");
        Assert.AreEqual(1, views[1][5].Offset, "view [1][5] offset");
        Assert.AreEqual(1, views[2][0].Offset, "view [2][0] offset");
        Assert.AreEqual(1, views[2][1].Offset, "view [2][1] offset");
        Assert.AreEqual(1, views[2][2].Offset, "view [2][2] offset");
        Assert.AreEqual(1, views[2][3].Offset, "view [2][3] offset");
        Assert.AreEqual(1, views[2][4].Offset, "view [2][4] offset");
        Assert.AreEqual(2, views[3][0].Offset, "view [3][0] offset");
        Assert.AreEqual(2, views[3][1].Offset, "view [3][1] offset");
        Assert.AreEqual(2, views[3][2].Offset, "view [3][2] offset");
        Assert.AreEqual(2, views[3][3].Offset, "view [3][3] offset");
        Assert.AreEqual(2, views[4][0].Offset, "view [4][0] offset");
        Assert.AreEqual(2, views[4][1].Offset, "view [4][1] offset");
        Assert.AreEqual(2, views[4][2].Offset, "view [4][2] offset");
        Assert.AreEqual(2, views[5][0].Offset, "view [5][0] offset");
        Assert.AreEqual(2, views[5][1].Offset, "view [5][1] offset");
        Assert.AreEqual(3, views[6][0].Offset, "view [6][0] offset");

        Assert.AreEqual(0, views[0][0].Count, "view [0][0] count");
        Assert.AreEqual(1, views[0][1].Count, "view [0][1] count");
        Assert.AreEqual(1, views[0][2].Count, "view [0][2] count");
        Assert.AreEqual(2, views[0][3].Count, "view [0][3] count");
        Assert.AreEqual(2, views[0][4].Count, "view [0][4] count");
        Assert.AreEqual(2, views[0][5].Count, "view [0][5] count");
        Assert.AreEqual(3, views[0][6].Count, "view [0][6] count");
        Assert.AreEqual(0, views[1][0].Count, "view [1][0] count");
        Assert.AreEqual(0, views[1][1].Count, "view [1][1] count");
        Assert.AreEqual(1, views[1][2].Count, "view [1][2] count");
        Assert.AreEqual(1, views[1][3].Count, "view [1][3] count");
        Assert.AreEqual(1, views[1][4].Count, "view [1][4] count");
        Assert.AreEqual(2, views[1][5].Count, "view [1][5] count");
        Assert.AreEqual(0, views[2][0].Count, "view [2][0] count");
        Assert.AreEqual(1, views[2][1].Count, "view [2][1] count");
        Assert.AreEqual(1, views[2][2].Count, "view [2][2] count");
        Assert.AreEqual(1, views[2][3].Count, "view [2][3] count");
        Assert.AreEqual(2, views[2][4].Count, "view [2][4] count");
        Assert.AreEqual(0, views[3][0].Count, "view [3][0] count");
        Assert.AreEqual(0, views[3][1].Count, "view [3][1] count");
        Assert.AreEqual(0, views[3][2].Count, "view [3][2] count");
        Assert.AreEqual(1, views[3][3].Count, "view [3][3] count");
        Assert.AreEqual(0, views[4][0].Count, "view [4][0] count");
        Assert.AreEqual(0, views[4][1].Count, "view [4][1] count");
        Assert.AreEqual(1, views[4][2].Count, "view [4][2] count");
        Assert.AreEqual(0, views[5][0].Count, "view [5][0] count");
        Assert.AreEqual(1, views[5][1].Count, "view [5][1] count");
        Assert.AreEqual(0, views[6][0].Count, "view [6][0] count");

        Assert.IsTrue(list.Check(), "list check after RemoveAll");
      }

      [Test]
      public void RetainAll()
      {
        LinkedList<int> list2 = new LinkedList<int>();
        list2.Add(2); list2.Add(4); list2.Add(5);
        Assert.IsTrue(list.Check(), "list check before RetainAll");
        list.RetainAll(list2);
        Assert.AreEqual(0, views[0][0].Offset, "view [0][0] offset");
        Assert.AreEqual(0, views[0][1].Offset, "view [0][1] offset");
        Assert.AreEqual(0, views[0][2].Offset, "view [0][2] offset");
        Assert.AreEqual(0, views[0][3].Offset, "view [0][3] offset");
        Assert.AreEqual(0, views[0][4].Offset, "view [0][4] offset");
        Assert.AreEqual(0, views[0][5].Offset, "view [0][5] offset");
        Assert.AreEqual(0, views[0][6].Offset, "view [0][6] offset");
        Assert.AreEqual(0, views[1][0].Offset, "view [1][0] offset");
        Assert.AreEqual(0, views[1][1].Offset, "view [1][1] offset");
        Assert.AreEqual(0, views[1][2].Offset, "view [1][2] offset");
        Assert.AreEqual(0, views[1][3].Offset, "view [1][3] offset");
        Assert.AreEqual(0, views[1][4].Offset, "view [1][4] offset");
        Assert.AreEqual(0, views[1][5].Offset, "view [1][5] offset");
        Assert.AreEqual(0, views[2][0].Offset, "view [2][0] offset");
        Assert.AreEqual(0, views[2][1].Offset, "view [2][1] offset");
        Assert.AreEqual(0, views[2][2].Offset, "view [2][2] offset");
        Assert.AreEqual(0, views[2][3].Offset, "view [2][3] offset");
        Assert.AreEqual(0, views[2][4].Offset, "view [2][4] offset");
        Assert.AreEqual(1, views[3][0].Offset, "view [3][0] offset");
        Assert.AreEqual(1, views[3][1].Offset, "view [3][1] offset");
        Assert.AreEqual(1, views[3][2].Offset, "view [3][2] offset");
        Assert.AreEqual(1, views[3][3].Offset, "view [3][3] offset");
        Assert.AreEqual(1, views[4][0].Offset, "view [4][0] offset");
        Assert.AreEqual(1, views[4][1].Offset, "view [4][1] offset");
        Assert.AreEqual(1, views[4][2].Offset, "view [4][2] offset");
        Assert.AreEqual(2, views[5][0].Offset, "view [5][0] offset");
        Assert.AreEqual(2, views[5][1].Offset, "view [5][1] offset");
        Assert.AreEqual(3, views[6][0].Offset, "view [6][0] offset");

        Assert.AreEqual(0, views[0][0].Count, "view [0][0] count");
        Assert.AreEqual(0, views[0][1].Count, "view [0][1] count");
        Assert.AreEqual(0, views[0][2].Count, "view [0][2] count");
        Assert.AreEqual(1, views[0][3].Count, "view [0][3] count");
        Assert.AreEqual(1, views[0][4].Count, "view [0][4] count");
        Assert.AreEqual(2, views[0][5].Count, "view [0][5] count");
        Assert.AreEqual(3, views[0][6].Count, "view [0][6] count");
        Assert.AreEqual(0, views[1][0].Count, "view [1][0] count");
        Assert.AreEqual(0, views[1][1].Count, "view [1][1] count");
        Assert.AreEqual(1, views[1][2].Count, "view [1][2] count");
        Assert.AreEqual(1, views[1][3].Count, "view [1][3] count");
        Assert.AreEqual(2, views[1][4].Count, "view [1][4] count");
        Assert.AreEqual(3, views[1][5].Count, "view [1][5] count");
        Assert.AreEqual(0, views[2][0].Count, "view [2][0] count");
        Assert.AreEqual(1, views[2][1].Count, "view [2][1] count");
        Assert.AreEqual(1, views[2][2].Count, "view [2][2] count");
        Assert.AreEqual(2, views[2][3].Count, "view [2][3] count");
        Assert.AreEqual(3, views[2][4].Count, "view [2][4] count");
        Assert.AreEqual(0, views[3][0].Count, "view [3][0] count");
        Assert.AreEqual(0, views[3][1].Count, "view [3][1] count");
        Assert.AreEqual(1, views[3][2].Count, "view [3][2] count");
        Assert.AreEqual(2, views[3][3].Count, "view [3][3] count");
        Assert.AreEqual(0, views[4][0].Count, "view [4][0] count");
        Assert.AreEqual(1, views[4][1].Count, "view [4][1] count");
        Assert.AreEqual(2, views[4][2].Count, "view [4][2] count");
        Assert.AreEqual(0, views[5][0].Count, "view [5][0] count");
        Assert.AreEqual(1, views[5][1].Count, "view [5][1] count");
        Assert.AreEqual(0, views[6][0].Count, "view [6][0] count");


        Assert.IsTrue(list.Check(), "list check after RetainAll");
      }

      [Test]
      public void RemoveAllCopies()
      {
        LinkedList<int> list2 = new LinkedList<int>();
        list2.Add(0); list2.Add(2); list2.Add(2); list2.Add(2); list2.Add(5); list2.Add(2); list2.Add(1);
        for (int i = 0; i < 7; i++)
        {
          for (int j = 0; j < 7 - i; j++)
          {
            list = new LinkedList<int>();
            list.AddAll(list2);
            LinkedList<int> v = (LinkedList<int>)list.View(i, j);
            list.RemoveAllCopies(2);
            Assert.AreEqual(i == 0 ? 0 : i <= 4 ? 1 : i <= 6 ? 2 : 3, v.Offset, "v.Offset, i=" + i + ", j=" + j);
            Assert.AreEqual((i == 0 && j > 0 ? 1 : 0) + (i <= 4 && i + j > 4 ? 1 : 0) + (i <= 6 && i + j > 6 ? 1 : 0), v.Count, "v.Count, i=" + i + ", j=" + j);
            Assert.IsTrue(list.Check(), "list check after RemoveAllCopies, i=" + i + ", j=" + j);
          }
        }
      }

      private void checkDisposed(bool reverse, int start, int count)
      {
        int k = 0;
        for (int i = 0; i < 7; i++)
          for (int j = 0; j < 7 - i; j++)
          {
            if (i + j <= start || i >= start + count || (i <= start && i + j >= start + count) || (reverse && start <= i && start + count >= i + j))
            {
              try
              {
                k = views[i][j].Count;
              }
              catch (ViewDisposedException)
              {
                Assert.Fail("view[" + i + "][" + j + "] threw");
              }
              Assert.AreEqual(j, views[i][j].Count, "view[" + i + "][" + j + "] size");
              if (reverse && ((j > 0 && start <= i && start + count >= i + j) || (j == 0 && start < i && start + count > i)))
                Assert.AreEqual(start + (start + count - i - j), views[i][j].Offset, "view[" + i + "][" + j + "] offset (mirrored)");
              else
                Assert.AreEqual(i, views[i][j].Offset, "view[" + i + "][" + j + "] offset");
            }
            else
            {
              try
              {
                k = views[i][j].Count;
                Assert.Fail("view[" + i + "][" + j + "] no throw");
              }
              catch (ViewDisposedException) { }
            }
          }
      }

      [Test]
      public void Reverse()
      {
        int start = 2, count = 3;
        IList<int> list2 = list.View(start, count);
        Assert.IsTrue(list.Check(), "list check before Reverse");
        list2.Reverse();
        Assert.IsTrue(list.Check(), "list check after Reverse");
        checkDisposed(true, start, count);
      }
      [Test]
      public void Sort()
      {
        int start = 2, count = 3;
        IList<int> list2 = list.View(start, count);
        Assert.IsTrue(list.Check(), "list check before Sort");
        list2.Sort();
        Assert.IsTrue(list.Check(), "list check after Sort");
        checkDisposed(false, start, count);
      }
      [Test]
      public void Shuffle()
      {
        int start = 2, count = 3;
        IList<int> list2 = list.View(start, count);
        Assert.IsTrue(list.Check(), "list check before Shuffle");
        list2.Shuffle();
        Assert.IsTrue(list.Check(), "list check after Shuffle");
        checkDisposed(false, start, count);
      }


    }


    [TestFixture]
    public class Validity
    {
      IList<int> list;
      IList<int> view;
      [SetUp]
      public void Init()
      {
        list = new LinkedList<int>();
        for (int i = 0; i < 6; i++)
          list.Add(i);
        view = list.View(2, 3);
        view.Dispose();
      }
      [TearDown]
      public void Dispose()
      {
        list = null;
        view = null;
      }

      //Properties

      //
      /*ActiveEvents,
AllowsDuplicates,
ContainsSpeed,
Count,
CountSpeed,
Direction,
DuplicatesByCounting,
FIFO,
First,
EqualityComparer,
IsEmpty,
IsReadOnly,
this[int index],
this[int start, int count],
Last,
Offset,
SyncRoot,
Underlying
*/
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void Add()
      {
        view.Add(5);
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void AddAll_int_()
      {
        view.AddAll<int>(new int[] { });
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void AddAll()
      {
        view.AddAll<int>(new int[] { });
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void All()
      {
        view.All(delegate(int i) { return false; });
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void Apply()
      {
        view.Apply(delegate(int i) { });
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void Backwards()
      {
        view.Backwards();
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void Choose()
      {
        view.Choose();
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void Contains()
      {
        view.Contains(0);
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void Clear()
      {
        view.Clear();
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void ContainsAll()
      {
        view.ContainsAll<int>(new int[] { });
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void ContainsCount()
      {
        view.ContainsCount(0);
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void CopyTo()
      {
        view.CopyTo(new int[1], 0);
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void Dequeue()
      {
        ((LinkedList<int>)view).Dequeue();
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void Enqueue()
      {
        ((LinkedList<int>)view).Enqueue(0);
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void Exists()
      {
        view.Exists(delegate(int i) { return false; });
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void Filter()
      {
        view.Filter(delegate(int i) { return true; });
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void Find()
      {
        int i = 0;
        view.Find(ref i);
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void FindAll()
      {
        view.FindAll(delegate(int i) { return false; });
      }
      [Test]
      [ExpectedException(typeof(ViewDisposedException))]
      public void FindOrAdd()
      {
        int i = 0;
        view.FindOrAdd(ref i);
      }

      //TODO: wonder if it is allright to wait with the exception till the enumerator is actually used?
      /*    [Test]
      [ExpectedException(typeof(ListDisposedException))]
      public void GetEnumerator()
      {
        view.GetEnumerator();
      }
    */
      /*Method overview
      Check(),
      checkRange(int start, int count),
      Dispose(),
      Equals(object obj),
      Finalize(),
      fireBagItemsAdded(T item, int count),
      fireBagItemsRemoved(T item, int count),
      fireCollectionChanged(),
      fireCollectionCleared(int start, int count),
      fireItemAdded(T item),
      fireItemInserted(T item, int index),
      fireItemRemoved(T item),
      fireItemRemovedAt(T item, int index),
      GetEnumerator(),
      GetHashCode(),
      GetSequencedHashCode(),
      GetType(),
      GetUnsequencedHashCode(),
      IndexOf(T item),
      Insert(int i, T item),
      ViewOf().InsertLast(T item, T target),
      InsertAll(int i, IEnumerable<T> items),
      ViewOf().InsertFirst(T item, T target),
      InsertFirst(T item),
      InsertLast(T item),
      IsSorted(SCG.IComparer<T> c),
      LastIndexOf(T item),
      LastViewOf(T item),
      Map<V>(Fun<T,V> mapper),
      Map<V>(Fun<T,V> mapper, SCG.IEqualityComparer<V> equalityComparer),
      MemberwiseClone(),
      modifycheck(int stamp),
      Pop(),
      Push(T item),
      Remove(),
      Remove(T item),
      Remove(T item, out T removeditem),
      RemoveAll(IEnumerable<T> items),
      RemoveAllCopies(T item),
      RemoveAt(int i),
      RemoveFirst(),
      RemoveInterval(int start, int count),
      RemoveLast(),
      RetainAll(IEnumerable<T> items),
      Reverse(),
      Reverse(int start, int count),
      SequencedEquals(ISequenced<T> that),
      Shuffle(),
      Shuffle(System.Random rnd),
      Slide(int offset),
      Slide(int offset, int size),
      Sort(),
      Sort(SCG.IComparer<T> c),
      ToArray(),
      ToString(),
      UnsequencedEquals(ICollection<T> that),
      Update(T item),
      Update(T item, out T olditem),
      updatecheck(),
      UpdateOrAdd(T item),
      UpdateOrAdd(T item, out T olditem),
      View(int start, int count),
      ViewOf(T item)
            */
    }
  }




  namespace LinkedListOfTreesORLists
  {
    [TestFixture]
    public class MultiLevelUnorderedOfUnOrdered
    {
      private ICollection<int> dit, dat, dut;

      private ICollection<ICollection<int>> Dit, Dat, Dut;


      [SetUp]
      public void Init()
      {
        dit = new LinkedList<int>();
        dat = new TreeSet<int>(Comparer<int>.Default, EqualityComparer<int>.Default);
        dut = new LinkedList<int>();
        dit.Add(2); dit.Add(1);
        dat.Add(1); dat.Add(2);
        dut.Add(3);
        Dit = new LinkedList<ICollection<int>>();
        Dat = new LinkedList<ICollection<int>>();
        Dut = new LinkedList<ICollection<int>>();
      }


      [Test]
      public void Check()
      {
        Assert.IsTrue(dit.UnsequencedEquals(dat));
        Assert.IsFalse(dit.UnsequencedEquals(dut));
      }


      [Test]
      public void Multi()
      {
        Dit.Add(dit); Dit.Add(dut); Dit.Add(dit);
        Dat.Add(dut); Dat.Add(dit); Dat.Add(dat);
        Assert.IsTrue(Dit.UnsequencedEquals(Dat));
        Assert.IsFalse(Dit.UnsequencedEquals(Dut));
      }


      [TearDown]
      public void Dispose()
      {
        dit = dat = dut = null;
        Dit = Dat = Dut = null;
      }
    }



    [TestFixture]
    public class MultiLevelOrderedOfUnOrdered
    {
      private ICollection<int> dit, dat, dut;

      private ISequenced<ICollection<int>> Dit, Dat, Dut;


      [SetUp]
      public void Init()
      {
        dit = new LinkedList<int>();
        dat = new TreeSet<int>(Comparer<int>.Default, EqualityComparer<int>.Default);
        dut = new LinkedList<int>();
        dit.Add(2); dit.Add(1);
        dat.Add(1); dat.Add(2);
        dut.Add(3);
        Dit = new LinkedList<ICollection<int>>();
        Dat = new LinkedList<ICollection<int>>();
        Dut = new LinkedList<ICollection<int>>();
      }


      [Test]
      public void Check()
      {
        Assert.IsTrue(dit.UnsequencedEquals(dat));
        Assert.IsFalse(dit.UnsequencedEquals(dut));
      }


      [Test]
      public void Multi()
      {
        Dit.Add(dit); Dit.Add(dut); Dit.Add(dit);
        Dat.Add(dut); Dat.Add(dit); Dat.Add(dat);
        Dut.Add(dit); Dut.Add(dut); Dut.Add(dat);
        Assert.IsFalse(Dit.SequencedEquals(Dat));
        Assert.IsTrue(Dit.SequencedEquals(Dut));
      }


      [TearDown]
      public void Dispose()
      {
        dit = dat = dut = null;
        Dit = Dat = Dut = null;
      }
    }



    [TestFixture]
    public class MultiLevelUnOrderedOfOrdered
    {
      private ISequenced<int> dit, dat, dut, dot;

      private ICollection<ISequenced<int>> Dit, Dat, Dut, Dot;


      [SetUp]
      public void Init()
      {
        dit = new TreeSet<int>(Comparer<int>.Default, EqualityComparer<int>.Default);
        dat = new LinkedList<int>();
        dut = new LinkedList<int>();
        dot = new LinkedList<int>();
        dit.Add(2); dit.Add(1);
        dat.Add(2); dat.Add(1);
        dut.Add(3);
        dot.Add(1); dot.Add(2);
        Dit = new LinkedList<ISequenced<int>>();
        Dat = new LinkedList<ISequenced<int>>();
        Dut = new LinkedList<ISequenced<int>>();
        Dot = new LinkedList<ISequenced<int>>();
      }


      [Test]
      public void Check()
      {
        Assert.IsFalse(dit.SequencedEquals(dat));
        Assert.IsTrue(dit.SequencedEquals(dot));
        Assert.IsFalse(dit.SequencedEquals(dut));
      }


      [Test]
      public void Multi()
      {
        Dit.Add(dit); Dit.Add(dut); Dit.Add(dit);
        Dat.Add(dut); Dat.Add(dit); Dat.Add(dat);
        Dut.Add(dot); Dut.Add(dut); Dut.Add(dit);
        Dot.Add(dit); Dot.Add(dit); Dot.Add(dut);
        Assert.IsTrue(Dit.UnsequencedEquals(Dut));
        Assert.IsFalse(Dit.UnsequencedEquals(Dat));
        Assert.IsTrue(Dit.UnsequencedEquals(Dot));
      }


      [TearDown]
      public void Dispose()
      {
        dit = dat = dut = dot = null;
        Dit = Dat = Dut = Dot = null;
      }
    }



    [TestFixture]
    public class MultiLevelOrderedOfOrdered
    {
      private ISequenced<int> dit, dat, dut, dot;

      private ISequenced<ISequenced<int>> Dit, Dat, Dut, Dot;


      [SetUp]
      public void Init()
      {
        dit = new TreeSet<int>(Comparer<int>.Default, EqualityComparer<int>.Default);
        dat = new LinkedList<int>();
        dut = new LinkedList<int>();
        dot = new LinkedList<int>();
        dit.Add(2); dit.Add(1);
        dat.Add(2); dat.Add(1);
        dut.Add(3);
        dot.Add(1); dot.Add(2);
        Dit = new LinkedList<ISequenced<int>>();
        Dat = new LinkedList<ISequenced<int>>();
        Dut = new LinkedList<ISequenced<int>>();
        Dot = new LinkedList<ISequenced<int>>();
      }


      [Test]
      public void Check()
      {
        Assert.IsFalse(dit.SequencedEquals(dat));
        Assert.IsTrue(dit.SequencedEquals(dot));
        Assert.IsFalse(dit.SequencedEquals(dut));
      }


      [Test]
      public void Multi()
      {
        Dit.Add(dit); Dit.Add(dut); Dit.Add(dit);
        Dat.Add(dut); Dat.Add(dit); Dat.Add(dat);
        Dut.Add(dot); Dut.Add(dut); Dut.Add(dit);
        Dot.Add(dit); Dot.Add(dit); Dot.Add(dut);
        Assert.IsTrue(Dit.SequencedEquals(Dut));
        Assert.IsFalse(Dit.SequencedEquals(Dat));
        Assert.IsFalse(Dit.SequencedEquals(Dot));
      }


      [TearDown]
      public void Dispose()
      {
        dit = dat = dut = dot = null;
        Dit = Dat = Dut = Dot = null;
      }
    }
  }




  namespace HashingAndEquals
  {
    [TestFixture]
    public class ISequenced
    {
      private ISequenced<int> dit, dat, dut;


      [SetUp]
      public void Init()
      {
        dit = new LinkedList<int>();
        dat = new LinkedList<int>();
        dut = new LinkedList<int>();
      }


      [Test]
      public void EmptyEmpty()
      {
        Assert.IsTrue(dit.SequencedEquals(dat));
      }


      [Test]
      public void EmptyNonEmpty()
      {
        dit.Add(3);
        Assert.IsFalse(dit.SequencedEquals(dat));
        Assert.IsFalse(dat.SequencedEquals(dit));
      }

      [Test]
      public void HashVal()
      {
        Assert.AreEqual(CHC.sequencedhashcode(), dit.GetSequencedHashCode());
        dit.Add(3);
        Assert.AreEqual(CHC.sequencedhashcode(3), dit.GetSequencedHashCode());
        dit.Add(7);
        Assert.AreEqual(CHC.sequencedhashcode(3, 7), dit.GetSequencedHashCode());
        Assert.AreEqual(CHC.sequencedhashcode(), dut.GetSequencedHashCode());
        dut.Add(7);
        Assert.AreEqual(CHC.sequencedhashcode(7), dut.GetSequencedHashCode());
        dut.Add(3);
        Assert.AreEqual(CHC.sequencedhashcode(7, 3), dut.GetSequencedHashCode());
      }


      [Test]
      public void EqualHashButDifferent()
      {
        dit.Add(0); dit.Add(31);
        dat.Add(1); dat.Add(0);
        Assert.AreEqual(dit.GetSequencedHashCode(), dat.GetSequencedHashCode());
        Assert.IsFalse(dit.SequencedEquals(dat));
      }


      [Test]
      public void Normal()
      {
        dit.Add(3);
        dit.Add(7);
        dat.Add(3);
        Assert.IsFalse(dit.SequencedEquals(dat));
        Assert.IsFalse(dat.SequencedEquals(dit));
        dat.Add(7);
        Assert.IsTrue(dit.SequencedEquals(dat));
        Assert.IsTrue(dat.SequencedEquals(dit));
      }


      [Test]
      public void WrongOrder()
      {
        dit.Add(3);
        dut.Add(3);
        Assert.IsTrue(dit.SequencedEquals(dut));
        Assert.IsTrue(dut.SequencedEquals(dit));
        dit.Add(7);
        ((LinkedList<int>)dut).InsertFirst(7);
        Assert.IsFalse(dit.SequencedEquals(dut));
        Assert.IsFalse(dut.SequencedEquals(dit));
      }


      [Test]
      public void Reflexive()
      {
        Assert.IsTrue(dit.SequencedEquals(dit));
        dit.Add(3);
        Assert.IsTrue(dit.SequencedEquals(dit));
        dit.Add(7);
        Assert.IsTrue(dit.SequencedEquals(dit));
      }


      [TearDown]
      public void Dispose()
      {
        dit = null;
        dat = null;
        dut = null;
      }
    }



    [TestFixture]
    public class IEditableCollection
    {
      private ICollection<int> dit, dat, dut;


      [SetUp]
      public void Init()
      {
        dit = new LinkedList<int>();
        dat = new LinkedList<int>();
        dut = new LinkedList<int>();
      }


      [Test]
      public void EmptyEmpty()
      {
        Assert.IsTrue(dit.UnsequencedEquals(dat));
      }


      [Test]
      public void EmptyNonEmpty()
      {
        dit.Add(3);
        Assert.IsFalse(dit.UnsequencedEquals(dat));
        Assert.IsFalse(dat.UnsequencedEquals(dit));
      }


      [Test]
      public void HashVal()
      {
        Assert.AreEqual(CHC.unsequencedhashcode(), dit.GetUnsequencedHashCode());
        dit.Add(3);
        Assert.AreEqual(CHC.unsequencedhashcode(3), dit.GetUnsequencedHashCode());
        dit.Add(7);
        Assert.AreEqual(CHC.unsequencedhashcode(3, 7), dit.GetUnsequencedHashCode());
        Assert.AreEqual(CHC.unsequencedhashcode(), dut.GetUnsequencedHashCode());
        dut.Add(3);
        Assert.AreEqual(CHC.unsequencedhashcode(3), dut.GetUnsequencedHashCode());
        dut.Add(7);
        Assert.AreEqual(CHC.unsequencedhashcode(7, 3), dut.GetUnsequencedHashCode());
      }


      [Test]
      public void EqualHashButDifferent()
      {
        dit.Add(-1657792980); dit.Add(-1570288808);
        dat.Add(1862883298); dat.Add(-272461342);
        Assert.AreEqual(dit.GetUnsequencedHashCode(), dat.GetUnsequencedHashCode());
        Assert.IsFalse(dit.UnsequencedEquals(dat));
      }


      [Test]
      public void Normal()
      {
        dit.Add(3);
        dit.Add(7);
        dat.Add(3);
        Assert.IsFalse(dit.UnsequencedEquals(dat));
        Assert.IsFalse(dat.UnsequencedEquals(dit));
        dat.Add(7);
        Assert.IsTrue(dit.UnsequencedEquals(dat));
        Assert.IsTrue(dat.UnsequencedEquals(dit));
      }


      [Test]
      public void WrongOrder()
      {
        dit.Add(3);
        dut.Add(3);
        Assert.IsTrue(dit.UnsequencedEquals(dut));
        Assert.IsTrue(dut.UnsequencedEquals(dit));
        dit.Add(7);
        dut.Add(7);
        Assert.IsTrue(dit.UnsequencedEquals(dut));
        Assert.IsTrue(dut.UnsequencedEquals(dit));
      }


      [Test]
      public void Reflexive()
      {
        Assert.IsTrue(dit.UnsequencedEquals(dit));
        dit.Add(3);
        Assert.IsTrue(dit.UnsequencedEquals(dit));
        dit.Add(7);
        Assert.IsTrue(dit.UnsequencedEquals(dit));
      }


      [TearDown]
      public void Dispose()
      {
        dit = null;
        dat = null;
        dut = null;
      }
    }



    [TestFixture]
    public class MultiLevelUnorderedOfUnOrdered
    {
      private ICollection<int> dit, dat, dut;

      private ICollection<ICollection<int>> Dit, Dat, Dut;


      [SetUp]
      public void Init()
      {
        dit = new LinkedList<int>();
        dat = new LinkedList<int>();
        dut = new LinkedList<int>();
        dit.Add(2); dit.Add(1);
        dat.Add(1); dat.Add(2);
        dut.Add(3);
        Dit = new LinkedList<ICollection<int>>();
        Dat = new LinkedList<ICollection<int>>();
        Dut = new LinkedList<ICollection<int>>();
      }


      [Test]
      public void Check()
      {
        Assert.IsTrue(dit.UnsequencedEquals(dat));
        Assert.IsFalse(dit.UnsequencedEquals(dut));
      }


      [Test]
      public void Multi()
      {
        Dit.Add(dit); Dit.Add(dut); Dit.Add(dit);
        Dat.Add(dut); Dat.Add(dit); Dat.Add(dat);
        Assert.IsTrue(Dit.UnsequencedEquals(Dat));
        Assert.IsFalse(Dit.UnsequencedEquals(Dut));
      }


      [TearDown]
      public void Dispose()
      {
        dit = dat = dut = null;
        Dit = Dat = Dut = null;
      }
    }



    [TestFixture]
    public class MultiLevelOrderedOfUnOrdered
    {
      private ICollection<int> dit, dat, dut;

      private ISequenced<ICollection<int>> Dit, Dat, Dut;


      [SetUp]
      public void Init()
      {
        dit = new LinkedList<int>();
        dat = new LinkedList<int>();
        dut = new LinkedList<int>();
        dit.Add(2); dit.Add(1);
        dat.Add(1); dat.Add(2);
        dut.Add(3);
        Dit = new LinkedList<ICollection<int>>();
        Dat = new LinkedList<ICollection<int>>();
        Dut = new LinkedList<ICollection<int>>();
      }


      [Test]
      public void Check()
      {
        Assert.IsTrue(dit.UnsequencedEquals(dat));
        Assert.IsFalse(dit.UnsequencedEquals(dut));
      }


      [Test]
      public void Multi()
      {
        Dit.Add(dit); Dit.Add(dut); Dit.Add(dit);
        Dat.Add(dut); Dat.Add(dit); Dat.Add(dat);
        Dut.Add(dit); Dut.Add(dut); Dut.Add(dat);
        Assert.IsFalse(Dit.SequencedEquals(Dat));
        Assert.IsTrue(Dit.SequencedEquals(Dut));
      }


      [TearDown]
      public void Dispose()
      {
        dit = dat = dut = null;
        Dit = Dat = Dut = null;
      }
    }



    [TestFixture]
    public class MultiLevelUnOrderedOfOrdered
    {
      private ISequenced<int> dit, dat, dut, dot;

      private ICollection<ISequenced<int>> Dit, Dat, Dut, Dot;


      [SetUp]
      public void Init()
      {
        dit = new LinkedList<int>();
        dat = new LinkedList<int>();
        dut = new LinkedList<int>();
        dot = new LinkedList<int>();
        dit.Add(2); dit.Add(1);
        dat.Add(1); dat.Add(2);
        dut.Add(3);
        dot.Add(2); dot.Add(1);
        Dit = new LinkedList<ISequenced<int>>();
        Dat = new LinkedList<ISequenced<int>>();
        Dut = new LinkedList<ISequenced<int>>();
        Dot = new LinkedList<ISequenced<int>>();
      }


      [Test]
      public void Check()
      {
        Assert.IsFalse(dit.SequencedEquals(dat));
        Assert.IsTrue(dit.SequencedEquals(dot));
        Assert.IsFalse(dit.SequencedEquals(dut));
      }


      [Test]
      public void Multi()
      {
        Dit.Add(dit); Dit.Add(dut); Dit.Add(dit);
        Dat.Add(dut); Dat.Add(dit); Dat.Add(dat);
        Dut.Add(dot); Dut.Add(dut); Dut.Add(dit);
        Dot.Add(dit); Dot.Add(dit); Dot.Add(dut);
        Assert.IsTrue(Dit.UnsequencedEquals(Dut));
        Assert.IsFalse(Dit.UnsequencedEquals(Dat));
        Assert.IsTrue(Dit.UnsequencedEquals(Dot));
      }


      [TearDown]
      public void Dispose()
      {
        dit = dat = dut = dot = null;
        Dit = Dat = Dut = Dot = null;
      }
    }



    [TestFixture]
    public class MultiLevelOrderedOfOrdered
    {
      private ISequenced<int> dit, dat, dut, dot;

      private ISequenced<ISequenced<int>> Dit, Dat, Dut, Dot;


      [SetUp]
      public void Init()
      {
        dit = new LinkedList<int>();
        dat = new LinkedList<int>();
        dut = new LinkedList<int>();
        dot = new LinkedList<int>();
        dit.Add(2); dit.Add(1);
        dat.Add(1); dat.Add(2);
        dut.Add(3);
        dot.Add(2); dot.Add(1);
        Dit = new LinkedList<ISequenced<int>>();
        Dat = new LinkedList<ISequenced<int>>();
        Dut = new LinkedList<ISequenced<int>>();
        Dot = new LinkedList<ISequenced<int>>();
      }


      [Test]
      public void Check()
      {
        Assert.IsFalse(dit.SequencedEquals(dat));
        Assert.IsTrue(dit.SequencedEquals(dot));
        Assert.IsFalse(dit.SequencedEquals(dut));
      }


      [Test]
      public void Multi()
      {
        Dit.Add(dit); Dit.Add(dut); Dit.Add(dit);
        Dat.Add(dut); Dat.Add(dit); Dat.Add(dat);
        Dut.Add(dot); Dut.Add(dut); Dut.Add(dit);
        Dot.Add(dit); Dot.Add(dit); Dot.Add(dut);
        Assert.IsTrue(Dit.SequencedEquals(Dut));
        Assert.IsFalse(Dit.SequencedEquals(Dat));
        Assert.IsFalse(Dit.SequencedEquals(Dot));
      }


      [TearDown]
      public void Dispose()
      {
        dit = dat = dut = dot = null;
        Dit = Dat = Dut = Dot = null;
      }
    }
  }
}