ObjectExtensions.cs

/* -- Clone Extension License --
The MIT License (MIT)
Copyright (c) 2014 Burtsev Alexey

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.Collections.Generic;
using System.Reflection;
using System.ArrayExtensions;

namespace System
{
	public static class ObjectExtensions
	{
		private static readonly MethodInfo CloneMethod = typeof(Object).GetMethod("MemberwiseClone", BindingFlags.NonPublic | BindingFlags.Instance);

		public static bool IsPrimitive(this Type type)
		{
			if (type == typeof(String)) return true;
			return (type.IsValueType & type.IsPrimitive);
		}

		public static Object Copy(this Object originalObject)
		{
			return InternalCopy(originalObject, new Dictionary<Object, Object>(new ReferenceEqualityComparer()));
		}
		private static Object InternalCopy(Object originalObject, IDictionary<Object, Object> visited)
		{
			if (originalObject == null) return null;
			var typeToReflect = originalObject.GetType();
			if (IsPrimitive(typeToReflect)) return originalObject;
			if (visited.ContainsKey(originalObject)) return visited[originalObject];
			if (typeof(Delegate).IsAssignableFrom(typeToReflect)) return null;
			var cloneObject = CloneMethod.Invoke(originalObject, null);
			if (typeToReflect.IsArray)
			{
				var arrayType = typeToReflect.GetElementType();
				if (IsPrimitive(arrayType) == false)
				{
					Array clonedArray = (Array)cloneObject;
					clonedArray.ForEach((array, indices) => array.SetValue(InternalCopy(clonedArray.GetValue(indices), visited), indices));
				}

			}
			visited.Add(originalObject, cloneObject);
			CopyFields(originalObject, visited, cloneObject, typeToReflect);
			RecursiveCopyBaseTypePrivateFields(originalObject, visited, cloneObject, typeToReflect);
			return cloneObject;
		}

		private static void RecursiveCopyBaseTypePrivateFields(object originalObject, IDictionary<object, object> visited, object cloneObject, Type typeToReflect)
		{
			if (typeToReflect.BaseType != null)
			{
				RecursiveCopyBaseTypePrivateFields(originalObject, visited, cloneObject, typeToReflect.BaseType);
				CopyFields(originalObject, visited, cloneObject, typeToReflect.BaseType, BindingFlags.Instance | BindingFlags.NonPublic, info => info.IsPrivate);
			}
		}

		private static void CopyFields(object originalObject, IDictionary<object, object> visited, object cloneObject, Type typeToReflect, BindingFlags bindingFlags = BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy, Func<FieldInfo, bool> filter = null)
		{
			foreach (FieldInfo fieldInfo in typeToReflect.GetFields(bindingFlags))
			{
				if (filter != null && filter(fieldInfo) == false) continue;
				if (IsPrimitive(fieldInfo.FieldType)) continue;
				var originalFieldValue = fieldInfo.GetValue(originalObject);
				var clonedFieldValue = InternalCopy(originalFieldValue, visited);
				fieldInfo.SetValue(cloneObject, clonedFieldValue);
			}
		}
		public static T Copy<T>(this T original)
		{
			return (T)Copy((Object)original);
		}
	}

	public class ReferenceEqualityComparer : EqualityComparer<Object>
	{
		public override bool Equals(object x, object y)
		{
			return ReferenceEquals(x, y);
		}
		public override int GetHashCode(object obj)
		{
			if (obj == null) return 0;
			return obj.GetHashCode();
		}
	}

	namespace ArrayExtensions
	{
		public static class ArrayExtensions
		{
			public static void ForEach(this Array array, Action<Array, int[]> action)
			{
				if (array.LongLength == 0) return;
				ArrayTraverse walker = new ArrayTraverse(array);
				do action(array, walker.Position);
				while (walker.Step());
			}
		}

		internal class ArrayTraverse
		{
			public int[] Position;
			private int[] maxLengths;

			public ArrayTraverse(Array array)
			{
				maxLengths = new int[array.Rank];
				for (int i = 0; i < array.Rank; ++i)
				{
					maxLengths[i] = array.GetLength(i) - 1;
				}
				Position = new int[array.Rank];
			}

			public bool Step()
			{
				for (int i = 0; i < Position.Length; ++i)
				{
					if (Position[i] < maxLengths[i])
					{
						Position[i]++;
						for (int j = 0; j < i; j++)
						{
							Position[j] = 0;
						}
						return true;
					}
				}
				return false;
			}
		}
	}

}