-Rewrote LINQ to JSON internals to use lists and dictionaries rather than a linked list

-Moved JPropertyDescriptor to Newtonsoft.Json.Linq namespace

Src/Newtonsoft.Json.Tests/Linq/ComponentModel/JPropertyDescriptorTests.cs

@@ -29,7 +29,6 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using NUnit.Framework;
-using Newtonsoft.Json.Linq.ComponentModel;
 using Newtonsoft.Json.Linq;
 
 namespace Newtonsoft.Json.Tests.Linq.ComponentModel

Src/Newtonsoft.Json.Tests/Linq/JArrayTests.cs

@@ -165,7 +165,7 @@ Parameter name: arrayIndex")]
     }
 
     [Test]
-    [ExpectedException(typeof(ArgumentOutOfRangeException), ExpectedMessage = @"index is equal to or greater than Count.
+    [ExpectedException(typeof(ArgumentOutOfRangeException), ExpectedMessage = @"Index is equal to or greater than Count.
 Parameter name: index")]
     public void RemoveAtOutOfRangeIndexShouldError()
     {
@@ -174,7 +174,7 @@ Parameter name: index")]
     }
 
     [Test]
-    [ExpectedException(typeof(ArgumentOutOfRangeException), ExpectedMessage = @"index is less than 0.
+    [ExpectedException(typeof(ArgumentOutOfRangeException), ExpectedMessage = @"Index is less than 0.
 Parameter name: index")]
     public void RemoveAtNegativeIndexShouldError()
     {
@@ -253,7 +253,7 @@ Parameter name: index")]
     }
 
     [Test]
-    [ExpectedException(typeof(ArgumentOutOfRangeException), ExpectedMessage = @"Specified argument was out of the range of valid values.
+    [ExpectedException(typeof(ArgumentOutOfRangeException), ExpectedMessage = @"Index was out of range. Must be non-negative and less than the size of the collection.
 Parameter name: index")]
     public void InsertNegativeIndexShouldThrow()
     {
@@ -262,7 +262,7 @@ Parameter name: index")]
     }
 
     [Test]
-    [ExpectedException(typeof(ArgumentOutOfRangeException), ExpectedMessage = @"Specified argument was out of the range of valid values.
+    [ExpectedException(typeof(ArgumentOutOfRangeException), ExpectedMessage = @"Index must be within the bounds of the List.
 Parameter name: index")]
     public void InsertOutOfRangeIndexShouldThrow()
     {

Src/Newtonsoft.Json.Tests/PerformanceTests.cs

@@ -121,6 +121,31 @@ namespace Newtonsoft.Json.Tests
       return result;
     }
 
+    [Test]
+    public void BuildJObject()
+    {
+      JObject o = new JObject();
+      for (int i = 0; i < 200; i++)
+      {
+        o[i.ToString()] = i;
+      }
+      string jsonText = o.ToString();
+
+      // this is extremely slow with 5000 interations
+      int interations = 100;
+
+      TimeOperation(() =>
+      {
+        JObject oo = null;
+        for (int i = 0; i < interations; i++)
+        {
+          oo = JObject.Parse(jsonText);
+        }
+
+        return oo;
+      }, "JObject");
+    }
+
     private void SerializeSize(object value)
     {
       // this is extremely slow with 5000 interations

Src/Newtonsoft.Json.Tests/Properties/AssemblyInfo.cs

@@ -41,5 +41,5 @@ using System.Runtime.InteropServices;
 // by using the '*' as shown below:
 [assembly: AssemblyVersion("4.0.2.0")]
 #if !PocketPC
-[assembly: AssemblyFileVersion("4.0.2.13722")]
+[assembly: AssemblyFileVersion("4.0.2.13728")]
 #endif

Src/Newtonsoft.Json/Linq/JArray.cs

@@ -39,6 +39,13 @@ namespace Newtonsoft.Json.Linq
   /// </summary>
   public class JArray : JContainer, IList<JToken>
   {
+    private IList<JToken> _values = new List<JToken>();
+
+    protected override IList<JToken> ChildrenTokens
+    {
+      get { return _values; }
+    }
+
     /// <summary>
     /// Gets the node type for this <see cref="JToken"/>.
     /// </summary>

Src/Newtonsoft.Json/Linq/JConstructor.cs

@@ -38,6 +38,12 @@ namespace Newtonsoft.Json.Linq
   public class JConstructor : JContainer
   {
     private string _name;
+    private IList<JToken> _values = new List<JToken>();
+
+    protected override IList<JToken> ChildrenTokens
+    {
+      get { return _values; }
+    }
 
     /// <summary>
     /// Gets or sets the name of this constructor.

Src/Newtonsoft.Json/Linq/JContainer.cs

@@ -33,9 +33,6 @@ using System.Diagnostics;
 using System.Globalization;
 using System.ComponentModel;
 using System.Collections.Specialized;
-#if !SILVERLIGHT
-using Newtonsoft.Json.Linq.ComponentModel;
-#endif
 
 namespace Newtonsoft.Json.Linq
 {
@@ -70,16 +67,11 @@ namespace Newtonsoft.Json.Linq
     public event NotifyCollectionChangedEventHandler CollectionChanged;
 #endif
 
-    private JToken _content;
+    protected abstract IList<JToken> ChildrenTokens { get; }
+
     private object _syncRoot;
     private bool _busy;
 
-    internal JToken Content
-    {
-      get { return _content; }
-      set { _content = value; }
-    }
-
     internal JContainer()
     {
     }
@@ -88,15 +80,9 @@ namespace Newtonsoft.Json.Linq
     {
       ValidationUtils.ArgumentNotNull(other, "c");
 
-      JToken content = other.Last;
-      if (content != null)
+      foreach (JToken child in other)
       {
-        do
-        {
-          content = content._next;
-          Add(content.CloneToken());
-        }
-        while (content != other.Last);
+        Add(child);
       }
     }
 
@@ -172,7 +158,7 @@ namespace Newtonsoft.Json.Linq
     /// </value>
     public override bool HasValues
     {
-      get { return (_content != null); }
+      get { return ChildrenTokens.Count > 0; }
     }
 
     internal bool ContentsEqual(JContainer container)
@@ -209,13 +195,7 @@ namespace Newtonsoft.Json.Linq
     /// </value>
     public override JToken First
     {
-      get
-      {
-        if (Last == null)
-          return null;
-
-        return Last._next;
-      }
+      get { return ChildrenTokens.FirstOrDefault(); }
     }
 
     /// <summary>
@@ -226,8 +206,7 @@ namespace Newtonsoft.Json.Linq
     /// </value>
     public override JToken Last
     {
-      [DebuggerStepThrough]
-      get { return _content; }
+      get { return ChildrenTokens.LastOrDefault(); }
     }
 
     /// <summary>
@@ -238,21 +217,7 @@ namespace Newtonsoft.Json.Linq
     /// </returns>
     public override JEnumerable<JToken> Children()
     {
-      return new JEnumerable<JToken>(ChildrenInternal());
-    }
-
-    internal IEnumerable<JToken> ChildrenInternal()
-    {
-      JToken first = First;
-      JToken current = first;
-      if (current == null)
-        yield break;
-
-      do
-      {
-        yield return current;
-      }
-      while ((current = current.Next) != null);
+      return new JEnumerable<JToken>(ChildrenTokens);
     }
 
     /// <summary>
@@ -264,7 +229,7 @@ namespace Newtonsoft.Json.Linq
     /// </returns>
     public override IEnumerable<T> Values<T>()
     {
-      return Children().Convert<JToken, T>();
+      return ChildrenTokens.Convert<JToken, T>();
     }
 
     /// <summary>
@@ -273,7 +238,7 @@ namespace Newtonsoft.Json.Linq
     /// <returns>An <see cref="IEnumerable{JToken}"/> containing the descendant tokens of the <see cref="JToken"/>.</returns>
     public IEnumerable<JToken> Descendants()
     {
-      foreach (JToken o in Children())
+      foreach (JToken o in ChildrenTokens)
       {
         yield return o;
         JContainer c = o as JContainer;
@@ -292,37 +257,11 @@ namespace Newtonsoft.Json.Linq
       return (content is IEnumerable && !(content is string) && !(content is JToken) && !(content is byte[]));
     }
 
-    internal virtual void AddItem(bool isLast, JToken previous, JToken item)
-    {
-      CheckReentrancy();
-
-      ValidateToken(item, null);
-
-      item = EnsureParentToken(item);
-
-      JToken next = (previous != null) ? previous._next : item;
-
-      item.Parent = this;
-      item.Next = next;
-
-      if (previous != null)
-        previous.Next = item;
-
-      if (isLast || previous == null)
-        _content = item;
-
-#if !SILVERLIGHT
-      if (ListChanged != null)
-        OnListChanged(new ListChangedEventArgs(ListChangedType.ItemAdded, IndexOfItem(item)));
-#endif
-#if SILVERLIGHT || !(NET20 || NET35)
-      if (CollectionChanged != null)
-        OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, item, IndexOfItem(item)));
-#endif
-    }
-
     internal JToken EnsureParentToken(JToken item)
     {
+      if (item == null)
+        return new JValue((object) null);
+
       if (item.Parent != null)
       {
         item = item.CloneToken();
@@ -343,142 +282,157 @@ namespace Newtonsoft.Json.Linq
       return item;
     }
 
-    internal void AddInternal(bool isLast, JToken previous, object content)
+    private class JTokenReferenceEqualityComparer : IEqualityComparer<JToken>
     {
-      if (IsMultiContent(content))
-      {
-        IEnumerable enumerable = (IEnumerable) content;
+      public static readonly JTokenReferenceEqualityComparer Instance = new JTokenReferenceEqualityComparer();
 
-        JToken multiPrevious = previous;
-        foreach (object c in enumerable)
-        {
-          AddInternal(isLast, multiPrevious, c);
-          multiPrevious = (multiPrevious != null) ? multiPrevious._next : Last;
-        }
+      public bool Equals(JToken x, JToken y)
+      {
+        return ReferenceEquals(x, y);
       }
-      else
-      {
-        JToken item = CreateFromContent(content);
 
-        AddItem(isLast, previous, item);
+      public int GetHashCode(JToken obj)
+      {
+        if (obj == null)
+          return 0;
+
+        return obj.GetHashCode();
       }
     }
 
     internal int IndexOfItem(JToken item)
     {
-      int index = 0;
-      foreach (JToken token in Children())
-      {
-        if (token == item)
-          return index;
-
-        index++;
-      }
-
-      return -1;
+      return ChildrenTokens.IndexOf(item, JTokenReferenceEqualityComparer.Instance);
     }
 
     internal virtual void InsertItem(int index, JToken item)
     {
-      if (index == 0)
-      {
-        AddFirst(item);
-      }
-      else
-      {
-        JToken token = GetItem(index);
-        AddInternal(false, token.Previous, item);
-      }
+      if (index > ChildrenTokens.Count)
+        throw new ArgumentOutOfRangeException("index", "Index must be within the bounds of the List.");
+
+      CheckReentrancy();
+
+      item = EnsureParentToken(item);
+
+      JToken previous = (index == 0) ? null : ChildrenTokens[index - 1];
+      // haven't inserted new token yet so next token is still at the inserting index
+      JToken next = (index == ChildrenTokens.Count) ? null : ChildrenTokens[index];
+
+      ValidateToken(item, null);
+
+      item.Parent = this;
+
+      item.Previous = previous;
+      if (previous != null)
+        previous.Next = item;
+
+      item.Next = next;
+      if (next != null)
+        next.Previous = item;
+      
+      ChildrenTokens.Insert(index, item);
+
+#if !SILVERLIGHT
+      if (ListChanged != null)
+        OnListChanged(new ListChangedEventArgs(ListChangedType.ItemAdded, index));
+#endif
+#if SILVERLIGHT || !(NET20 || NET35)
+      if (CollectionChanged != null)
+        OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, item, index));
+#endif
     }
 
     internal virtual void RemoveItemAt(int index)
     {
       if (index < 0)
-        throw new ArgumentOutOfRangeException("index", "index is less than 0.");
+        throw new ArgumentOutOfRangeException("index", "Index is less than 0.");
+      if (index >= ChildrenTokens.Count)
+        throw new ArgumentOutOfRangeException("index", "Index is equal to or greater than Count.");
 
       CheckReentrancy();
 
-      int currentIndex = 0;
-      foreach (JToken token in Children())
-      {
-        if (index == currentIndex)
-        {
-          token.Remove();
+      JToken item = ChildrenTokens[index];
+      JToken previous = (index == 0) ? null : ChildrenTokens[index - 1];
+      JToken next = (index == ChildrenTokens.Count - 1) ? null : ChildrenTokens[index + 1];
+
+      if (previous != null)
+        previous.Next = next;
+      if (next != null)
+        next.Previous = previous;
+
+      item.Parent = null;
+      item.Previous = null;
+      item.Next = null;
+
+      ChildrenTokens.RemoveAt(index);
 
 #if !SILVERLIGHT
-          OnListChanged(new ListChangedEventArgs(ListChangedType.ItemDeleted, index));
+      OnListChanged(new ListChangedEventArgs(ListChangedType.ItemDeleted, index));
 #endif
 #if SILVERLIGHT || !(NET20 || NET35)
-          OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, token, index));
+      OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, item, index));
 #endif
-
-          return;
-        }
-
-        currentIndex++;
-      }
-
-      throw new ArgumentOutOfRangeException("index", "index is equal to or greater than Count.");
     }
 
     internal virtual bool RemoveItem(JToken item)
     {
-      if (item == null || item.Parent != this)
-        return false;
-
-      CheckReentrancy();
-
-      JToken content = _content;
-
-      int itemIndex = 0;
-      while (content._next != item)
+      int index = IndexOfItem(item);
+      if (index >= 0)
       {
-        itemIndex++;
-        content = content._next;
+        RemoveItemAt(index);
+        return true;
       }
-      if (content == item)
-      {
-        // token is containers last child
-        _content = null;
-      }
-      else
-      {
-        if (_content == item)
-        {
-          _content = content;
-        }
-        content._next = item._next;
-      }
-      item.Parent = null;
-      item.Next = null;
 
-#if !SILVERLIGHT
-      OnListChanged(new ListChangedEventArgs(ListChangedType.ItemDeleted, itemIndex));
-#endif
-#if SILVERLIGHT || !(NET20 || NET35)
-      OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, item, itemIndex));
-#endif
-
-      return true;
+      return false;
     }
 
     internal virtual JToken GetItem(int index)
     {
-      return Children().ElementAt(index);
+      return ChildrenTokens[index];
     }
 
     internal virtual void SetItem(int index, JToken item)
     {
+      if (index < 0)
+        throw new ArgumentOutOfRangeException("index", "Index is less than 0.");
+      if (index >= ChildrenTokens.Count)
+        throw new ArgumentOutOfRangeException("index", "Index is equal to or greater than Count.");
+
+      JToken existing = ChildrenTokens[index];
+
+      if (IsTokenUnchanged(existing, item))
+        return;
+
       CheckReentrancy();
 
-      JToken token = GetItem(index);
-      token.Replace(item);
+      item = EnsureParentToken(item);
+
+      ValidateToken(item, existing);
+
+      JToken previous = (index == 0) ? null : ChildrenTokens[index - 1];
+      JToken next = (index == ChildrenTokens.Count - 1) ? null : ChildrenTokens[index + 1];
+
+      item.Parent = this;
+
+      item.Previous = previous;
+      if (previous != null)
+        previous.Next = item;
+
+      item.Next = next;
+      if (next != null)
+        next.Previous = item;
+
+      ChildrenTokens[index] = item;
+
+      existing.Parent = null;
+      existing.Previous = null;
+      existing.Next = null;
 
 #if !SILVERLIGHT
       OnListChanged(new ListChangedEventArgs(ListChangedType.ItemChanged, index));
 #endif
 #if SILVERLIGHT || !(NET20 || NET35)
-      OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Replace, item, token, index));
+      OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Replace, item, existing, index));
 #endif
     }
 
@@ -486,23 +440,15 @@ namespace Newtonsoft.Json.Linq
     {
       CheckReentrancy();
 
-      while (_content != null)
+      foreach (JToken item in ChildrenTokens)
       {
-        JToken o = _content;
-
-        JToken next = o._next;
-        if (o != _content || next != o._next)
-          throw new InvalidOperationException("This operation was corrupted by external code.");
-
-        if (next != o)
-          o._next = next._next;
-        else
-          _content = null;
-
-        next.Parent = null;
-        next._next = null;
+        item.Parent = null;
+        item.Previous = null;
+        item.Next = null;
       }
 
+      ChildrenTokens.Clear();
+
 #if !SILVERLIGHT
       OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, -1));
 #endif
@@ -516,51 +462,8 @@ namespace Newtonsoft.Json.Linq
       if (existing == null || existing.Parent != this)
         return;
 
-      if (IsTokenUnchanged(existing, replacement))
-        return;
-
-      CheckReentrancy();
-
-      replacement = EnsureParentToken(replacement);
-
-      ValidateToken(replacement, existing);
-
-      JToken content = _content;
-
-      int itemIndex = 0;
-      while (content._next != existing)
-      {
-        itemIndex++;
-        content = content._next;
-      }
-
-      if (content == existing)
-      {
-        // token is containers last child
-        _content = replacement;
-        replacement._next = replacement;
-      }
-      else
-      {
-        if (_content == existing)
-        {
-          _content = replacement;
-        }
-        content._next = replacement;
-        replacement._next = existing._next;
-      }
-
-      replacement.Parent = this;
-
-      existing.Parent = null;
-      existing.Next = null;
-
-#if !SILVERLIGHT
-      OnListChanged(new ListChangedEventArgs(ListChangedType.ItemChanged, itemIndex));
-#endif
-#if SILVERLIGHT || !(NET20 || NET35)
-      OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Replace, replacement, existing, itemIndex));
-#endif
+      int index = IndexOfItem(existing);
+      SetItem(index, replacement);
     }
 
     internal virtual bool ContainsItem(JToken item)
@@ -580,7 +483,7 @@ namespace Newtonsoft.Json.Linq
         throw new ArgumentException("The number of elements in the source JObject is greater than the available space from arrayIndex to the end of the destination array.");
 
       int index = 0;
-      foreach (JToken token in Children())
+      foreach (JToken token in ChildrenTokens)
       {
         array.SetValue(token, arrayIndex + index);
         index++;
@@ -589,7 +492,7 @@ namespace Newtonsoft.Json.Linq
 
     internal virtual int CountItems()
     {
-      return Children().Count();
+      return ChildrenTokens.Count;
     }
 
     internal static bool IsTokenUnchanged(JToken currentValue, JToken newValue)
@@ -619,9 +522,9 @@ namespace Newtonsoft.Json.Linq
     /// Adds the specified content as children of this <see cref="JToken"/>.
     /// </summary>
     /// <param name="content">The content to be added.</param>
-    public void Add(object content)
+    public virtual void Add(object content)
     {
-      AddInternal(true, Last, content);
+      AddInternal(ChildrenTokens.Count, content);
     }
 
     /// <summary>
@@ -630,7 +533,28 @@ namespace Newtonsoft.Json.Linq
     /// <param name="content">The content to be added.</param>
     public void AddFirst(object content)
     {
-      AddInternal(false, Last, content);
+      AddInternal(0, content);
+    }
+
+    internal void AddInternal(int index, object content)
+    {
+      if (IsMultiContent(content))
+      {
+        IEnumerable enumerable = (IEnumerable)content;
+
+        int multiIndex = index;
+        foreach (object c in enumerable)
+        {
+          AddInternal(multiIndex, c);
+          multiIndex++;
+        }
+      }
+      else
+      {
+        JToken item = CreateFromContent(content);
+
+        InsertItem(index, item);
+      }
     }
 
     internal JToken CreateFromContent(object content)
@@ -790,7 +714,7 @@ namespace Newtonsoft.Json.Linq
     internal int ContentsHashCode()
     {
       int hashCode = 0;
-      foreach (JToken item in Children())
+      foreach (JToken item in ChildrenTokens)
       {
         hashCode ^= item.GetDeepHashCode();
       }

Src/Newtonsoft.Json/Linq/JObject.cs

@@ -25,6 +25,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Collections.Specialized;
 using System.ComponentModel;
 #if !(NET35 || NET20 || WINDOWS_PHONE)
@@ -35,9 +36,6 @@ using System.Linq;
 using System.IO;
 using Newtonsoft.Json.Utilities;
 using System.Globalization;
-#if !PocketPC && !SILVERLIGHT
-using Newtonsoft.Json.Linq.ComponentModel;
-#endif
 
 namespace Newtonsoft.Json.Linq
 {
@@ -52,6 +50,46 @@ namespace Newtonsoft.Json.Linq
     , INotifyPropertyChanging
 #endif
   {
+    private class JPropertKeyedCollection : KeyedCollection<string, JToken>
+    {
+      public JPropertKeyedCollection(IEqualityComparer<string> comparer)
+        : base(comparer)
+      {
+      }
+
+      protected override string GetKeyForItem(JToken item)
+      {
+        return ((JProperty) item).Name;
+      }
+
+      protected override void InsertItem(int index, JToken item)
+      {
+        if (Dictionary == null)
+        {
+          base.InsertItem(index, item);
+        }
+        else
+        {
+          // need to override so that the dictionary key is always set rather than added
+          string keyForItem = GetKeyForItem(item);
+          Dictionary[keyForItem] = item;
+          Items.Insert(index, item);
+        }
+      }
+
+      public new IDictionary<string, JToken> Dictionary
+      {
+        get { return base.Dictionary; }
+      }
+    }
+
+    private JPropertKeyedCollection _properties = new JPropertKeyedCollection(StringComparer.Ordinal);
+
+    protected override IList<JToken> ChildrenTokens
+    {
+      get { return _properties; }
+    }
+
     /// <summary>
     /// Occurs when a property value changes.
     /// </summary>
@@ -111,14 +149,18 @@ namespace Newtonsoft.Json.Linq
       if (o.Type != JTokenType.Property)
         throw new ArgumentException("Can not add {0} to {1}.".FormatWith(CultureInfo.InvariantCulture, o.GetType(), GetType()));
 
-      // looping over all properties every time isn't good
-      // need to think about performance here
-      JProperty property = (JProperty)o;
-      foreach (JProperty childProperty in Children())
+      JProperty newProperty = (JProperty) o;
+
+      if (existing != null)
       {
-        if (childProperty != existing && string.Equals(childProperty.Name, property.Name, StringComparison.Ordinal))
-          throw new ArgumentException("Can not add property {0} to {1}. Property with the same name already exists on object.".FormatWith(CultureInfo.InvariantCulture, property.Name, GetType()));
+        JProperty existingProperty = (JProperty) existing;
+
+        if (newProperty.Name == existingProperty.Name)
+          return;
       }
+
+      if (_properties.Dictionary != null && _properties.Dictionary.TryGetValue(newProperty.Name, out existing))
+        throw new ArgumentException("Can not add property {0} to {1}. Property with the same name already exists on object.".FormatWith(CultureInfo.InvariantCulture, newProperty.Name, GetType()));
     }
 
     internal void InternalPropertyChanged(JProperty childProperty)
@@ -159,7 +201,7 @@ namespace Newtonsoft.Json.Linq
     /// <returns>An <see cref="IEnumerable{JProperty}"/> of this object's properties.</returns>
     public IEnumerable<JProperty> Properties()
     {
-      return Children().Cast<JProperty>();
+      return ChildrenTokens.Cast<JProperty>();
     }
 
     /// <summary>
@@ -169,9 +211,14 @@ namespace Newtonsoft.Json.Linq
     /// <returns>A <see cref="JProperty"/> with the specified name or null.</returns>
     public JProperty Property(string name)
     {
-      return Properties()
-        .Where(p => string.Equals(p.Name, name, StringComparison.Ordinal))
-        .SingleOrDefault();
+      if (_properties.Dictionary == null)
+        return null;
+      if (name == null)
+        return null;
+
+      JToken property;
+      _properties.Dictionary.TryGetValue(name, out property);
+      return (JProperty)property;
     }
 
     /// <summary>
@@ -318,7 +365,7 @@ namespace Newtonsoft.Json.Linq
     {
       writer.WriteStartObject();
 
-      foreach (JProperty property in ChildrenInternal())
+      foreach (JProperty property in ChildrenTokens)
       {
         property.WriteTo(writer, converters);
       }
@@ -339,12 +386,12 @@ namespace Newtonsoft.Json.Linq
 
     bool IDictionary<string, JToken>.ContainsKey(string key)
     {
-      return (Property(key) != null);
+      return _properties.Dictionary.ContainsKey(key);
     }
 
     ICollection<string> IDictionary<string, JToken>.Keys
     {
-      get { throw new NotImplementedException(); }
+      get { return _properties.Dictionary.Keys; }
     }
 
     /// <summary>
@@ -383,7 +430,7 @@ namespace Newtonsoft.Json.Linq
 
     ICollection<JToken> IDictionary<string, JToken>.Values
     {
-      get { throw new NotImplementedException(); }
+      get { return _properties.Dictionary.Values; }
     }
 
     #endregion
@@ -421,7 +468,7 @@ namespace Newtonsoft.Json.Linq
         throw new ArgumentException("The number of elements in the source JObject is greater than the available space from arrayIndex to the end of the destination array.");
 
       int index = 0;
-      foreach (JProperty property in Properties())
+      foreach (JProperty property in ChildrenTokens)
       {
         array[arrayIndex + index] = new KeyValuePair<string, JToken>(property.Name, property.Value);
         index++;
@@ -467,7 +514,7 @@ namespace Newtonsoft.Json.Linq
     /// </returns>
     public IEnumerator<KeyValuePair<string, JToken>> GetEnumerator()
     {
-      foreach (JProperty property in Properties())
+      foreach (JProperty property in ChildrenTokens)
       {
         yield return new KeyValuePair<string, JToken>(property.Name, property.Value);
       }

Src/Newtonsoft.Json/Linq/JProperty.cs

@@ -25,6 +25,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.ComponentModel;
 using System.Linq;
 using System.Text;
@@ -39,8 +40,14 @@ namespace Newtonsoft.Json.Linq
   /// </summary>
   public class JProperty : JContainer
   {
+    private readonly List<JToken> _content = new List<JToken>();
     private readonly string _name;
 
+    protected override IList<JToken> ChildrenTokens
+    {
+      get { return _content; }
+    }
+
     /// <summary>
     /// Gets the property name.
     /// </summary>
@@ -58,42 +65,24 @@ namespace Newtonsoft.Json.Linq
     public JToken Value
     {
       [DebuggerStepThrough]
-      get { return Content; }
+      get { return (ChildrenTokens.Count > 0) ? ChildrenTokens[0] : null; }
       set
       {
         CheckReentrancy();
 
         JToken newValue = value ?? new JValue((object) null);
 
-        if (Content == null)
+        if (ChildrenTokens.Count == 0)
         {
-          newValue = EnsureParentToken(newValue);
-
-          Content = newValue;
-          Content.Parent = this;
-          Content.Next = Content;
+          InsertItem(0, newValue);
         }
         else
         {
-          Content.Replace(newValue);
+          SetItem(0, newValue);
         }
       }
     }
 
-    internal override void ReplaceItem(JToken existing, JToken replacement)
-    {
-      if (IsTokenUnchanged(existing, replacement))
-        return;
-
-      if (Parent != null)
-        ((JObject)Parent).InternalPropertyChanging(this);
-
-      base.ReplaceItem(existing, replacement);
-
-      if (Parent != null)
-        ((JObject)Parent).InternalPropertyChanged(this);
-    }
-
     /// <summary>
     /// Initializes a new instance of the <see cref="JProperty"/> class from another <see cref="JProperty"/> object.
     /// </summary>
@@ -104,14 +93,6 @@ namespace Newtonsoft.Json.Linq
       _name = other.Name;
     }
 
-    internal override void AddItem(bool isLast, JToken previous, JToken item)
-    {
-      if (Value != null)
-        throw new Exception("{0} cannot have multiple values.".FormatWith(CultureInfo.InvariantCulture, typeof(JProperty)));
-
-      Value = item;
-    }
-
     internal override JToken GetItem(int index)
     {
       if (index != 0)
@@ -124,8 +105,17 @@ namespace Newtonsoft.Json.Linq
     {
       if (index != 0)
         throw new ArgumentOutOfRangeException();
-      
-      Value = item;
+
+      if (IsTokenUnchanged(Value, item))
+        return;
+
+      if (Parent != null)
+        ((JObject)Parent).InternalPropertyChanging(this);
+
+      base.SetItem(0, item);
+
+      if (Parent != null)
+        ((JObject)Parent).InternalPropertyChanged(this);
     }
 
     internal override bool RemoveItem(JToken item)
@@ -140,7 +130,10 @@ namespace Newtonsoft.Json.Linq
 
     internal override void InsertItem(int index, JToken item)
     {
-      throw new Exception("Cannot add or remove items from {0}.".FormatWith(CultureInfo.InvariantCulture, typeof(JProperty)));
+      if (Value != null)
+        throw new Exception("{0} cannot have multiple values.".FormatWith(CultureInfo.InvariantCulture, typeof(JProperty)));
+
+      base.InsertItem(0, item);
     }
 
     internal override bool ContainsItem(JToken item)
@@ -153,22 +146,6 @@ namespace Newtonsoft.Json.Linq
       throw new Exception("Cannot add or remove items from {0}.".FormatWith(CultureInfo.InvariantCulture, typeof(JProperty)));
     }
 
-    /// <summary>
-    /// Returns a collection of the child tokens of this token, in document order.
-    /// </summary>
-    /// <returns>
-    /// An <see cref="IEnumerable{T}"/> of <see cref="JToken"/> containing the child tokens of this <see cref="JToken"/>, in document order.
-    /// </returns>
-    public override JEnumerable<JToken> Children()
-    {
-      return new JEnumerable<JToken>(GetValueEnumerable());
-    }
-
-    private IEnumerable<JToken> GetValueEnumerable()
-    {
-      yield return Value;
-    }
-
     internal override bool DeepEquals(JToken node)
     {
       JProperty t = node as JProperty;

Src/Newtonsoft.Json/Linq/JPropertyDescriptor.cs

@@ -28,7 +28,7 @@ using System;
 using System.ComponentModel;
 using Newtonsoft.Json.Utilities;
 
-namespace Newtonsoft.Json.Linq.ComponentModel
+namespace Newtonsoft.Json.Linq
 {
   /// <summary>
   /// Represents a view of a <see cref="JProperty"/>.

Src/Newtonsoft.Json/Linq/JToken.cs

@@ -51,7 +51,8 @@ namespace Newtonsoft.Json.Linq
 #endif
   {
     private JContainer _parent;
-    internal JToken _next;
+    private JToken _previous;
+    private JToken _next;
     private static JTokenEqualityComparer _equalityComparer;
 
     private int? _lineNumber;
@@ -138,13 +139,7 @@ namespace Newtonsoft.Json.Linq
     /// <value>The <see cref="JToken"/> that contains the next sibling token.</value>
     public JToken Next
     {
-      get
-      {
-        if (_parent != null && _next != _parent.First)
-          return _next;
-
-        return null;
-      }
+      get { return _next; }
       internal set { _next = value; }
     }
 
@@ -154,20 +149,8 @@ namespace Newtonsoft.Json.Linq
     /// <value>The <see cref="JToken"/> that contains the previous sibling token.</value>
     public JToken Previous
     {
-      get
-      {
-        if (_parent == null)
-          return null;
-
-        JToken parentNext = _parent.Content._next;
-        JToken parentNextBefore = null;
-        while (parentNext != this)
-        {
-          parentNextBefore = parentNext;
-          parentNext = parentNext.Next;
-        }
-        return parentNextBefore;
-      }
+      get { return _previous; }
+      internal set { _previous = value; }
     }
 
     internal JToken()
@@ -183,7 +166,8 @@ namespace Newtonsoft.Json.Linq
       if (_parent == null)
         throw new InvalidOperationException("The parent is missing.");
 
-      _parent.AddInternal((Next == null), this, content);
+      int index = _parent.IndexOfItem(this);
+      _parent.AddInternal(index + 1, content);
     }
 
     /// <summary>
@@ -195,11 +179,8 @@ namespace Newtonsoft.Json.Linq
       if (_parent == null)
         throw new InvalidOperationException("The parent is missing.");
 
-      JToken previous = Previous;
-      if (previous == null)
-        previous = _parent.Last;
-
-      _parent.AddInternal(false, previous, content);
+      int index = _parent.IndexOfItem(this);
+      _parent.AddInternal(index, content);
     }
 
     /// <summary>

Src/Newtonsoft.Json/Newtonsoft.Json.Net20.csproj

@@ -96,8 +96,8 @@
     <Compile Include="Converters\RegexConverter.cs" />
     <Compile Include="Converters\StringEnumConverter.cs" />
     <Compile Include="JsonConstructorAttribute.cs" />
-    <Compile Include="Linq\ComponentModel\JPropertyDescriptor.cs" />
     <Compile Include="Linq\JPath.cs" />
+    <Compile Include="Linq\JPropertyDescriptor.cs" />
     <Compile Include="Linq\JRaw.cs" />
     <Compile Include="Required.cs" />
     <Compile Include="Serialization\DefaultReferenceResolver.cs" />

Src/Newtonsoft.Json/Newtonsoft.Json.Net35.csproj

@@ -104,6 +104,7 @@
     <Compile Include="Converters\StringEnumConverter.cs" />
     <Compile Include="ConstructorHandling.cs" />
     <Compile Include="JsonConstructorAttribute.cs" />
+    <Compile Include="Linq\JPropertyDescriptor.cs" />
     <Compile Include="Utilities\DynamicProxy.cs" />
     <Compile Include="Linq\JPath.cs" />
     <Compile Include="Linq\JRaw.cs" />
@@ -115,7 +116,6 @@
     <Compile Include="Serialization\JsonPrimitiveContract.cs" />
     <Compile Include="Serialization\DynamicValueProvider.cs" />
     <Compile Include="Serialization\ErrorEventArgs.cs" />
-    <Compile Include="Linq\ComponentModel\JPropertyDescriptor.cs" />
     <Compile Include="Serialization\DefaultReferenceResolver.cs" />
     <Compile Include="PreserveReferencesHandling.cs" />
     <Compile Include="IJsonLineInfo.cs" />

Src/Newtonsoft.Json/Newtonsoft.Json.Silverlight.csproj

@@ -127,7 +127,6 @@
     <Compile Include="JsonValidatingReader.cs" />
     <Compile Include="JsonWriter.cs" />
     <Compile Include="JsonWriterException.cs" />
-    <Compile Include="Linq\ComponentModel\JPropertyDescriptor.cs" />
     <Compile Include="Linq\Extensions.cs" />
     <Compile Include="Linq\IJEnumerable.cs" />
     <Compile Include="Linq\JArray.cs" />
@@ -137,6 +136,7 @@
     <Compile Include="Linq\JObject.cs" />
     <Compile Include="Linq\JPath.cs" />
     <Compile Include="Linq\JProperty.cs" />
+    <Compile Include="Linq\JPropertyDescriptor.cs" />
     <Compile Include="Linq\JRaw.cs" />
     <Compile Include="Linq\JToken.cs" />
     <Compile Include="Linq\JTokenEqualityComparer.cs" />

Src/Newtonsoft.Json/Newtonsoft.Json.WindowsPhone.csproj

@@ -100,7 +100,6 @@
     <Compile Include="JsonValidatingReader.cs" />
     <Compile Include="JsonWriter.cs" />
     <Compile Include="JsonWriterException.cs" />
-    <Compile Include="Linq\ComponentModel\JPropertyDescriptor.cs" />
     <Compile Include="Linq\Extensions.cs" />
     <Compile Include="Linq\IJEnumerable.cs" />
     <Compile Include="Linq\JArray.cs" />
@@ -110,6 +109,7 @@
     <Compile Include="Linq\JObject.cs" />
     <Compile Include="Linq\JPath.cs" />
     <Compile Include="Linq\JProperty.cs" />
+    <Compile Include="Linq\JPropertyDescriptor.cs" />
     <Compile Include="Linq\JRaw.cs" />
     <Compile Include="Linq\JToken.cs" />
     <Compile Include="Linq\JTokenEqualityComparer.cs" />

Src/Newtonsoft.Json/Newtonsoft.Json.csproj

@@ -114,7 +114,7 @@
     <Compile Include="Serialization\JsonPrimitiveContract.cs" />
     <Compile Include="Serialization\DynamicValueProvider.cs" />
     <Compile Include="Serialization\ErrorEventArgs.cs" />
-    <Compile Include="Linq\ComponentModel\JPropertyDescriptor.cs" />
+    <Compile Include="Linq\JPropertyDescriptor.cs" />
     <Compile Include="Serialization\DefaultReferenceResolver.cs" />
     <Compile Include="PreserveReferencesHandling.cs" />
     <Compile Include="IJsonLineInfo.cs" />
@@ -262,5 +262,6 @@
   <ItemGroup>
     <EmbeddedResource Include="Dynamic.snk" />
   </ItemGroup>
+  <ItemGroup />
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
 </Project>

Src/Newtonsoft.Json/Properties/AssemblyInfo.cs

@@ -110,7 +110,7 @@ using System.Security;
 // by using the '*' as shown below:
 [assembly: AssemblyVersion("4.0.2.0")]
 #if !PocketPC
-[assembly: AssemblyFileVersion("4.0.2.13722")]
+[assembly: AssemblyFileVersion("4.0.2.13728")]
 #endif
 
 [assembly: CLSCompliant(true)]

Src/Newtonsoft.Json/Serialization/JsonTypeReflector.cs

@@ -124,7 +124,6 @@ namespace Newtonsoft.Json.Serialization
         if (propertyInfo.IsVirtual())
         {
           Type currentType = propertyInfo.DeclaringType;
-          Type[] types = propertyInfo.GetIndexParameters().Select(p => p.ParameterType).ToArray();
 
           while (result == null && currentType != null)
           {

Src/Newtonsoft.Json/Utilities/CollectionUtils.cs

@@ -631,5 +631,39 @@ namespace Newtonsoft.Json.Utilities
 
       return -1;
     }
+
+    /// <summary>
+    /// Returns the index of the first occurrence in a sequence by using the default equality comparer.
+    /// </summary>
+    /// <typeparam name="TSource">The type of the elements of source.</typeparam>
+    /// <param name="list">A sequence in which to locate a value.</param>
+    /// <param name="value">The object to locate in the sequence</param>
+    /// <returns>The zero-based index of the first occurrence of value within the entire sequence, if found; otherwise, –1.</returns>
+    public static int IndexOf<TSource>(this IEnumerable<TSource> list, TSource value) where TSource : IEquatable<TSource>
+    {
+      return list.IndexOf<TSource>(value, EqualityComparer<TSource>.Default);
+    }
+
+    /// <summary>
+    /// Returns the index of the first occurrence in a sequence by using a specified IEqualityComparer.
+    /// </summary>
+    /// <typeparam name="TSource">The type of the elements of source.</typeparam>
+    /// <param name="list">A sequence in which to locate a value.</param>
+    /// <param name="value">The object to locate in the sequence</param>
+    /// <param name="comparer">An equality comparer to compare values.</param>
+    /// <returns>The zero-based index of the first occurrence of value within the entire sequence, if found; otherwise, –1.</returns>
+    public static int IndexOf<TSource>(this IEnumerable<TSource> list, TSource value, IEqualityComparer<TSource> comparer)
+    {
+      int index = 0;
+      foreach (TSource item in list)
+      {
+        if (comparer.Equals(item, value))
+        {
+          return index;
+        }
+        index++;
+      }
+      return -1;
+    }
   }
 }