#region license
// Copyright (c) 2005 - 2007 Ayende Rahien (ayende@ayende.com)
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
// 
//     * Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//     * Neither the name of Ayende Rahien nor the names of its
//     contributors may be used to endorse or promote products derived from this
//     software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
// THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion



using System;
using System.Collections;

namespace Ayende.NHibernateQueryAnalyzer.SchemaEditing
{

	#region Interface ISchemaErrorEnumerator

	/// <summary>
	/// Supports type-safe iteration over a collection that contains 
	/// <see cref="ISchemaError"/> elements.
	/// </summary>
	/// <remarks>
	/// <b>ISchemaErrorEnumerator</b> 
	/// provides an <see cref="IEnumerator"/> that is strongly typed for 
	/// <see cref="ISchemaError"/> elements.
	/// </remarks>

	public interface ISchemaErrorEnumerator 
	{
		#region Properties
		#region Current

		/// <summary>
		/// Gets the current <see cref="ISchemaError"/> 
		/// element in the collection.
		/// </summary>
		/// <value>
		/// The current <see cref="ISchemaError"/> 
		/// element in the collection.</value>
		/// <exception cref="InvalidOperationException"><para>
		/// The enumerator is positioned before the first element 
		/// of the collection or after the last element.
		/// </para><para>-or-</para><para>
		/// The collection was modified after the enumerator was created.
		/// </para></exception>
		/// <remarks>
		/// Please refer to <see cref="IEnumerator.Current"/> for details, 
		/// but note that <b>Current</b> fails if the collection was modified 
		/// since the last successful call to <see cref="MoveNext"/> or 
		/// <see cref="Reset"/>.
		/// </remarks>

		ISchemaError Current { get; }

		#endregion
		#endregion
		#region Methods
		#region MoveNext

		/// <summary>
		/// Advances the enumerator to the next element of the collection.
		/// </summary>
		/// <returns>
		/// <c>true</c> if the enumerator was successfully advanced 
		/// to the next element; <c>false</c> if the enumerator has 
		/// passed the end of the collection.</returns>
		/// <exception cref="InvalidOperationException">
		/// The collection was modified after the enumerator was created.
		/// </exception>
		/// <remarks>
		/// Please refer to <see cref="IEnumerator.MoveNext"/> for details.
		/// </remarks>

		bool MoveNext();

		#endregion
		#region Reset

		/// <summary>
		/// Sets the enumerator to its initial position,
		/// which is before the first element in the collection.
		/// </summary>
		/// <exception cref="InvalidOperationException">
		/// The collection was modified after the enumerator was created.
		/// </exception>
		/// <remarks>
		/// Please refer to <see cref="IEnumerator.Reset"/> for details.
		/// </remarks>

		void Reset();

		#endregion
		#endregion
	}

	#endregion
	#region Class SchemaErrorCollection

	/// <summary>
	/// Implements a strongly typed collection
	/// of <see cref="ISchemaError"/> elements.
	/// </summary>
	/// <remarks><para>
	/// <b>SchemaErrorCollection</b>
	/// provides an <see cref="ArrayList"/> that is strongly typed for
	/// <see cref="ISchemaError"/> elements.
	/// </para></remarks>

	[Serializable]
	public class SchemaErrorCollection:
		IList, ICloneable 
	{

		private readonly Data _data;

		#region Private Constructor

		/// <summary>
		/// Initializes a new instance of the
		/// <see cref="SchemaErrorCollection"/> class
		/// with the specified data container.
		/// </summary>
		/// <param name="data">
		/// The <see cref="Data"/> object to share with another instance.
		/// </param>
		/// <remarks>
		/// This constructor is used to create read-only wrappers.
		/// </remarks>

		private SchemaErrorCollection(Data data) 
		{
			_data = data;
		}

		#endregion
		#region Public Constructors
		#region SchemaErrorCollection()

		/// <overloads>
		/// Initializes a new instance of the
		/// <see cref="SchemaErrorCollection"/> class.
		/// </overloads>
		/// <summary>
		/// Initializes a new instance of the
		/// <see cref="SchemaErrorCollection"/> class
		/// that is empty and has the default initial capacity.
		/// </summary>
		/// <remarks>
		/// Please refer to <see cref="ArrayList()"/> for details.
		/// </remarks>

		public SchemaErrorCollection() 
		{
			_data = new Data();
			_data.Items = new ISchemaError[Data.DefaultCapacity];
		}

		#endregion
		#region SchemaErrorCollection(Int32)

		/// <summary>
		/// Initializes a new instance of the
		/// <see cref="SchemaErrorCollection"/> class
		/// that is empty and has the specified initial capacity.
		/// </summary>
		/// <param name="capacity">
		/// The initial number of elements that the new
		/// <see cref="SchemaErrorCollection"/> can contain.</param>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <paramref name="capacity"/> is less than zero.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList(Int32)"/> for details.
		/// </remarks>

		public SchemaErrorCollection(int capacity) 
		{
			if (capacity < 0)
				throw new ArgumentOutOfRangeException("capacity",
					capacity, "Argument cannot be negative.");

			_data = new Data();
			_data.Items = new ISchemaError[capacity];
		}

		#endregion
		#region SchemaErrorCollection(SchemaErrorCollection)

		/// <summary>
		/// Initializes a new instance of the
		/// <see cref="SchemaErrorCollection"/> class that
		/// contains elements copied from the specified collection and that
		/// has the same initial capacity as the number of elements copied.
		/// </summary>
		/// <param name="collection">
		/// The <see cref="SchemaErrorCollection"/>
		/// whose elements are copied to the new collection.</param>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="collection"/> is a null reference.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList(ICollection)"/> for details.
		/// </remarks>

		public SchemaErrorCollection(SchemaErrorCollection collection) 
		{
			if (collection == null)
				throw new ArgumentNullException("collection");

			_data = new Data();
			_data.Items = new ISchemaError[collection.Count];
			AddRange(collection._data.Items, collection.Count);
		}

		#endregion
		#region SchemaErrorCollection(ISchemaError[])

		/// <summary>
		/// Initializes a new instance of the
		/// <see cref="SchemaErrorCollection"/> class
		/// that contains elements copied from the specified
		/// <see cref="ISchemaError"/> array and that has the
		/// same initial capacity as the number of elements copied.
		/// </summary>
		/// <param name="array">
		/// An <see cref="Array"/> of <see cref="ISchemaError"/>
		/// elements that are copied to the new collection.</param>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="array"/> is a null reference.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList(ICollection)"/> for details.
		/// </remarks>

		public SchemaErrorCollection(ISchemaError[] array) 
		{
			if (array == null)
				throw new ArgumentNullException("array");

			_data = new Data();
			_data.Items = new ISchemaError[array.Length];
			AddRange(array, array.Length);
		}

		#endregion
		#endregion
		#region Public Properties
		#region Capacity

		/// <summary>
		/// Gets or sets the capacity of the <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <value>
		/// The number of elements that the
		/// <see cref="SchemaErrorCollection"/> can contain.
		/// </value>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <b>Capacity</b> is set to a value that is
		/// less than <see cref="Count"/>.</exception>
		/// <exception cref="NotSupportedException">
		/// The property is set, and the <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Capacity"/> for details.
		/// </remarks>

		public virtual int Capacity 
		{
			get { return _data.Items.Length; }
			set 
			{
				if (value < _data.Count)
					throw new ArgumentOutOfRangeException("Capacity",
						value, "Value cannot be less than Count.");

				_data.SetCapacity(value);
			}
		}

		#endregion
		#region Count

		/// <summary>
		/// Gets the number of elements contained in the
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <value>
		/// The number of elements contained in the
		/// <see cref="SchemaErrorCollection"/>.
		/// </value>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Count"/> for details.
		/// </remarks>

		public int Count 
		{
			get { return _data.Count; }
		}

		#endregion
		#region IsFixedSize

		/// <summary>
		/// Gets a value indicating whether the
		/// <see cref="SchemaErrorCollection"/> has a fixed size.
		/// </summary>
		/// <value>
		/// <c>true</c> if the <see cref="SchemaErrorCollection"/>
		/// has a fixed size; otherwise, <c>false</c>.
		/// The default is <c>false</c>.</value>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.IsFixedSize"/> for details.
		/// </remarks>

		public virtual bool IsFixedSize 
		{
			get { return false; }
		}

		#endregion
		#region IsReadOnly

		/// <summary>
		/// Gets a value indicating whether the
		/// <see cref="SchemaErrorCollection"/> is read-only.
		/// </summary>
		/// <value>
		/// <c>true</c> if the <see cref="SchemaErrorCollection"/>
		/// is read-only; otherwise, <c>false</c>.
		/// The default is <c>false</c>.</value>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.IsReadOnly"/> for details.
		/// </remarks>

		public virtual bool IsReadOnly 
		{
			get { return false; }
		}

		#endregion
		#region IsSynchronized

		/// <summary>
		/// Gets a value indicating whether access to the
		/// <see cref="SchemaErrorCollection"/> is synchronized (thread-safe).
		/// </summary>
		/// <value>
		/// <c>true</c> if access to the <see cref="SchemaErrorCollection"/>
		/// is synchronized (thread-safe); otherwise, <c>false</c>.
		/// The default is <c>false</c>.</value>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.IsSynchronized"/> for details.
		/// </remarks>

		public bool IsSynchronized 
		{
			get { return false; }
		}

		#endregion
		#region IsUnique

		/// <summary>
		/// Gets or sets a value indicating whether the
		/// <see cref="SchemaErrorCollection"/>
		/// ensures that all elements are unique.
		/// </summary>
		/// <value>
		/// <c>true</c> if the <see cref="SchemaErrorCollection"/>
		/// ensures that all elements are unique; otherwise,
		/// <c>false</c>. The default is <c>false</c>.</value>
		/// <exception cref="InvalidOperationException">
		/// The property is set to <c>true</c>, and the
		/// <see cref="SchemaErrorCollection"/>
		/// already contains duplicate elements.</exception>
		/// <exception cref="NotSupportedException">
		/// The property is set, and the
		/// <see cref="SchemaErrorCollection"/> is read-only.</exception>
		/// <remarks><para>
		/// <b>IsUnique</b> provides a set-like collection by ensuring that
		/// all elements in the <see cref="SchemaErrorCollection"/> 
		/// are unique.
		/// </para><para>
		/// When changed to <c>true</c>, this property throws an 
		/// <see cref="InvalidOperationException"/> if the 
		/// <b>SchemaErrorCollection</b> already contains duplicate
		/// elements. Any subsequent attempt to add an element that is
		/// already contained in the <b>SchemaErrorCollection</b> 
		/// will cause a <see cref="NotSupportedException"/>.
		/// </para></remarks>

		public virtual bool IsUnique 
		{
			get { return _data.IsUnique; }
			set 
			{
				if (value == _data.IsUnique) return;
				if (value) CheckUnique();
				_data.IsUnique = value;
			}
		}

		#endregion
		#region Item: SchemaError

		/// <summary>
		/// Gets or sets the <see cref="ISchemaError"/>
		/// element at the specified index.
		/// </summary>
		/// <param name="index">
		/// The zero-based index of the <see cref="ISchemaError"/>
		/// element to get or set.</param>
		/// <value>
		/// The <see cref="ISchemaError"/> element
		/// at the specified <paramref name="index"/>.
		/// </value>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <para><paramref name="index"/> is less than zero.</para>
		/// <para>-or-</para>
		/// <para><paramref name="index"/> is equal to or
		/// greater than <see cref="Count"/>.</para></exception>
		/// <exception cref="NotSupportedException"><para>
		/// The property is set, and the
		/// <see cref="SchemaErrorCollection"/> is read-only.
		/// </para><para>-or-</para><para>
		/// The property is set, the <b>SchemaErrorCollection</b>
		/// already contains the specified element at a different index,
		/// and the <b>SchemaErrorCollection</b> ensures
		/// that all elements are unique.</para></exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.this"/> for details.
		/// </remarks>

		public virtual ISchemaError this[int index] 
		{
			get 
			{
				if (index < 0)
					throw new ArgumentOutOfRangeException("index",
						index, "Argument cannot be negative.");

				if (index >= _data.Count)
					throw new ArgumentOutOfRangeException("index",
						index, "Argument must be less than Count.");

				return _data.Items[index];
			}
			set 
			{
				if (index < 0)
					throw new ArgumentOutOfRangeException("index",
						index, "Argument cannot be negative.");

				if (index >= _data.Count)
					throw new ArgumentOutOfRangeException("index",
						index, "Argument must be less than Count.");

				if (_data.IsUnique) CheckUnique(value, index);

				_data.Items[index] = value;
			}
		}

		#endregion
		#region IList.Item: Object

		/// <summary>
		/// Gets or sets the element at the specified index.
		/// </summary>
		/// <param name="index">
		/// The zero-based index of the element to get or set.</param>
		/// <value>
		/// The element at the specified <paramref name="index"/>.
		/// When the property is set, this value must be compatible
		/// with <see cref="ISchemaError"/>.
		/// </value>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <para><paramref name="index"/> is less than zero.</para>
		/// <para>-or-</para>
		/// <para><paramref name="index"/> is equal to
		/// or greater than <see cref="Count"/>.</para></exception>
		/// <exception cref="InvalidCastException">
		/// The property is set to a value that is not compatible
		/// with <see cref="ISchemaError"/>.</exception>
		/// <exception cref="NotSupportedException"><para>
		/// The property is set, and the
		/// <see cref="SchemaErrorCollection"/> is read-only.
		/// </para><para>-or-</para><para>
		/// The property is set, the <b>SchemaErrorCollection</b>
		/// already contains the specified element at a different index,
		/// and the <b>SchemaErrorCollection</b> ensures
		/// that all elements are unique.</para></exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.this"/> for details.
		/// </remarks>

		object IList.this[int index] 
		{
			get { return this[index]; }
			set { this[index] = (ISchemaError) value; }
		}

		#endregion
		#region SyncRoot

		/// <summary>
		/// Gets an object that can be used to synchronize access to the
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <value>
		/// An object that can be used to synchronize access to the
		/// <see cref="SchemaErrorCollection"/>.
		/// </value>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.SyncRoot"/> for details.
		/// </remarks>

		public object SyncRoot 
		{
			get { return _data; }
		}

		#endregion
		#endregion
		#region Public Methods
		#region Add(ISchemaError)

		/// <summary>
		/// Adds a <see cref="ISchemaError"/> to the end
		/// of the <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <param name="value">
		/// The <see cref="ISchemaError"/> object to be added
		/// to the end of the <see cref="SchemaErrorCollection"/>.
		/// This argument may be a null reference.
		/// </param>
		/// <returns>
		/// The <see cref="SchemaErrorCollection"/>
		/// index at which the <paramref name="value"/> has been added.
		/// </returns>
		/// <exception cref="NotSupportedException"><para>
		/// The <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.
		/// </para><para>-or-</para><para>
		/// The <b>SchemaErrorCollection</b>
		/// already contains <paramref name="value"/>,
		/// and the <b>SchemaErrorCollection</b>
		/// ensures that all elements are unique.</para></exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Add"/> for details.
		/// </remarks>

		public virtual int Add(ISchemaError value) 
		{
			if (_data.IsUnique) CheckUnique(value);

			int count = _data.Count;
			if (count == _data.Items.Length)
				_data.EnsureCapacity(count + 1);

			_data.Items[count] = value;
			return _data.Count++;
		}

		#endregion
		#region IList.Add(Object)

		/// <summary>
		/// Adds an <see cref="Object"/> to the end of the
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <param name="value">
		/// The object to be added to the end of the
		/// <see cref="SchemaErrorCollection"/>. This argument
		/// must be compatible with <see cref="ISchemaError"/>.
		/// This argument may be a null reference.
		/// </param>
		/// <returns>
		/// The <see cref="SchemaErrorCollection"/>
		/// index at which the <paramref name="value"/> has been added.
		/// </returns>
		/// <exception cref="InvalidCastException">
		/// <paramref name="value"/> is not compatible with
		/// <see cref="ISchemaError"/>.</exception>
		/// <exception cref="NotSupportedException"><para>
		/// The <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.
		/// </para><para>-or-</para><para>
		/// The <b>SchemaErrorCollection</b>
		/// already contains <paramref name="value"/>,
		/// and the <b>SchemaErrorCollection</b>
		/// ensures that all elements are unique.
		/// </para></exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Add"/> for details.
		/// </remarks>

		int IList.Add(object value) 
		{
			return Add((ISchemaError) value);
		}

		#endregion
		#region AddRange(SchemaErrorCollection)

		/// <overloads>
		/// Adds a range of elements to the end of the
		/// <see cref="SchemaErrorCollection"/>.
		/// </overloads>
		/// <summary>
		/// Adds the elements of another collection to the end of the
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <param name="collection">
		/// The <see cref="SchemaErrorCollection"/> whose elements
		/// should be added to the end of the current collection.</param>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="collection"/> is a null reference.</exception>
		/// <exception cref="NotSupportedException"><para>
		/// The <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.
		/// </para><para>-or-</para><para>
		/// The <b>SchemaErrorCollection</b> already contains one
		/// or more elements in <paramref name="collection"/>,
		/// and the <b>SchemaErrorCollection</b>
		/// ensures that all elements are unique.
		/// </para></exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.AddRange"/> for details.
		/// </remarks>

		public virtual void AddRange(SchemaErrorCollection collection) 
		{
			if (collection == null)
				throw new ArgumentNullException("collection");

			AddRange(collection._data.Items, collection.Count);    
		}

		#endregion
		#region AddRange(ISchemaError[])

		/// <summary>
		/// Adds the elements of a <see cref="ISchemaError"/> array
		/// to the end of the <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <param name="array">
		/// An <see cref="Array"/> of <see cref="ISchemaError"/>
		/// elements that should be added to the end of the
		/// <see cref="SchemaErrorCollection"/>.</param>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="array"/> is a null reference.</exception>
		/// <exception cref="NotSupportedException"><para>
		/// The <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.
		/// </para><para>-or-</para><para>
		/// The <b>SchemaErrorCollection</b> already contains
		/// one or more elements in <paramref name="array"/>,
		/// and the <b>SchemaErrorCollection</b>
		/// ensures that all elements are unique.
		/// </para></exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.AddRange"/> for details.
		/// </remarks>

		public virtual void AddRange(ISchemaError[] array) 
		{
			if (array == null)
				throw new ArgumentNullException("array");

			AddRange(array, array.Length);
		}

		#endregion
		#region BinarySearch(SchemaError, IComparer)

		/// <overloads>
		/// Uses a binary search algorithm to locate a specific element
		/// in the sorted <see cref="SchemaErrorCollection"/>
		/// or a portion of it.
		/// </overloads>
		/// <summary>
		/// Searches the entire sorted <see cref="SchemaErrorCollection"/>
		/// for an <see cref="ISchemaError"/> element using the
		/// specified comparer and returns the zero-based index of the element.
		/// </summary>
		/// <param name="value">
		/// The <see cref="ISchemaError"/> object to locate
		/// in the <see cref="SchemaErrorCollection"/>.
		/// This argument may be a null reference.
		/// </param>
		/// <param name="comparer">
		/// <para>The <see cref="IComparer"/> implementation
		/// to use when comparing elements.</para>
		/// <para>-or-</para>
		/// <para>A null reference to use the <see cref="IComparable"/>
		/// implementation of each element.</para></param>
		/// <returns>
		/// The zero-based index of <paramref name="value"/> in the sorted
		/// <see cref="SchemaErrorCollection"/>, if <paramref name="value"/>
		/// is found; otherwise, a negative number, which is the bitwise
		/// complement of the index of the next element that is larger than
		/// <paramref name="value"/> or, if there is no larger element, the
		/// bitwise complement of <see cref="Count"/>.</returns>
		/// <exception cref="ArgumentException">
		/// <paramref name="comparer"/> is a null reference,
		/// and SchemaError does not implement
		/// the <see cref="IComparable"/> interface.</exception>
		/// <remarks>
		/// Please refer to
		/// <see cref="ArrayList.BinarySearch(Object, IComparer)"/>
		/// for details.
		/// </remarks>

		public int BinarySearch(
			ISchemaError value, IComparer comparer) 
		{

			return Array.BinarySearch(_data.Items, 
				0, _data.Count, value, comparer);
		}

		#endregion
		#region BinarySearch(Int32, Int32, SchemaError, IComparer)

		/// <summary>
		/// Searches a section of the sorted
		/// <see cref="SchemaErrorCollection"/> for an
		/// <see cref="ISchemaError"/> element using the
		/// specified comparer and returns the zero-based index of the element.
		/// </summary>
		/// <param name="index">
		/// The zero-based starting index of the range of elements to search.
		/// </param>
		/// <param name="count">The number of elements to search.</param>
		/// <param name="value">
		/// The <see cref="ISchemaError"/> object to locate
		/// in the <see cref="SchemaErrorCollection"/>.
		/// This argument may be a null reference.
		/// </param>
		/// <param name="comparer">
		/// <para>The <see cref="IComparer"/> implementation
		/// to use when comparing elements.</para>
		/// <para>-or-</para>
		/// <para>A null reference to use the <see cref="IComparable"/>
		/// implementation of each element.</para></param>
		/// <returns>
		/// The zero-based index of <paramref name="value"/> in the sorted
		/// <see cref="SchemaErrorCollection"/>, if <paramref name="value"/>
		/// is found; otherwise, a negative number, which is the bitwise
		/// complement of the index of the next element that is larger than
		/// <paramref name="value"/> or, if there is no larger element, the
		/// bitwise complement of <see cref="Count"/>.</returns>
		/// <exception cref="ArgumentException"><para>
		/// <paramref name="index"/> and <paramref name="count"/>
		/// do not denote a valid range of elements in the
		/// <see cref="SchemaErrorCollection"/>.
		/// </para><para>-or-</para><para>
		/// <paramref name="comparer"/> is a null reference,
		/// and SchemaError does not implement
		/// the <see cref="IComparable"/> interface.
		/// </para></exception>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <para><paramref name="index"/> is less than zero.</para>
		/// <para>-or-</para>
		/// <para><paramref name="count"/> is less than zero.</para>
		/// </exception>
		/// <remarks>
		/// Please refer to
		/// <see cref="ArrayList.BinarySearch(Int32, Int32, Object, IComparer)"/>
		/// for details.
		/// </remarks>

		public int BinarySearch(int index, int count,
			ISchemaError value, IComparer comparer) 
		{

			if (index < 0)
				throw new ArgumentOutOfRangeException("index",
					index, "Argument cannot be negative.");

			if (count < 0)
				throw new ArgumentOutOfRangeException("count",
					count, "Argument cannot be negative.");

			if (index + count > _data.Count)
				throw new ArgumentException(
					"Arguments denote invalid range of elements.");

			return Array.BinarySearch(_data.Items,
				index, _data.Count, value, comparer);
		}

		#endregion
		#region Clear

		/// <summary>
		/// Removes all elements from the <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <exception cref="NotSupportedException">
		/// The <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Clear"/> for details.
		/// </remarks>

		public virtual void Clear() 
		{
			if (_data.Count == 0) return;
			Array.Clear(_data.Items, 0, _data.Count);
			_data.Count = 0;
		}

		#endregion
		#region Clone

		/// <summary>
		/// Creates a shallow copy of the <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <returns>
		/// A shallow copy of the <see cref="SchemaErrorCollection"/>.
		/// </returns>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Clone"/> for details.
		/// </remarks>

		public virtual object Clone() 
		{
			SchemaErrorCollection clone =
				new SchemaErrorCollection(_data.Count);

			Array.Copy(_data.Items, 0, clone._data.Items, 0, _data.Count);
			clone._data.Count = _data.Count;
			clone._data.IsUnique = _data.IsUnique;

			return clone;
		}

		#endregion
		#region Contains(ISchemaError)

		/// <summary>
		/// Determines whether the <see cref="SchemaErrorCollection"/>
		/// contains the specified <see cref="ISchemaError"/> element.
		/// </summary>
		/// <param name="value">
		/// The <see cref="ISchemaError"/> object to locate
		/// in the <see cref="SchemaErrorCollection"/>.
		/// This argument may be a null reference.
		/// </param>
		/// <returns>
		/// <c>true</c> if <paramref name="value"/> is found in the
		/// <see cref="SchemaErrorCollection"/>; otherwise, <c>false</c>.
		/// </returns>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Contains"/> for details.
		/// </remarks>

		public bool Contains(ISchemaError value) 
		{
			return (IndexOf(value) >= 0);
		}

		#endregion
		#region IList.Contains(Object)

		/// <summary>
		/// Determines whether the <see cref="SchemaErrorCollection"/>
		/// contains the specified element.
		/// </summary>
		/// <param name="value">
		/// The object to locate in the
		/// <see cref="SchemaErrorCollection"/>. This argument
		/// must be compatible with <see cref="ISchemaError"/>.
		/// This argument may be a null reference.
		/// </param>
		/// <returns>
		/// <c>true</c> if <paramref name="value"/> is found in the
		/// <see cref="SchemaErrorCollection"/>; otherwise, <c>false</c>.
		/// </returns>
		/// <exception cref="InvalidCastException">
		/// <paramref name="value"/> is not compatible with
		/// <see cref="ISchemaError"/>.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Contains"/> for details.
		/// </remarks>

		bool IList.Contains(object value) 
		{
			return Contains((ISchemaError) value);
		}

		#endregion
		#region CopyTo(ISchemaError[])

		/// <overloads>
		/// Copies the <see cref="SchemaErrorCollection"/>
		/// or a portion of it to a one-dimensional array.
		/// </overloads>
		/// <summary>
		/// Copies the entire <see cref="SchemaErrorCollection"/>
		/// to a one-dimensional <see cref="Array"/>
		/// of <see cref="ISchemaError"/> elements,
		/// starting at the beginning of the target array.
		/// </summary>
		/// <param name="array">
		/// The one-dimensional <see cref="Array"/> that is the destination
		/// of the <see cref="ISchemaError"/> elements copied from the
		/// <see cref="SchemaErrorCollection"/>.
		/// The <b>Array</b> must have zero-based indexing.</param>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="array"/> is a null reference.</exception>
		/// <exception cref="ArgumentException">
		/// The number of elements in the source
		/// <see cref="SchemaErrorCollection"/> is greater than
		/// the available space in the destination <paramref name="array"/>.
		/// </exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.CopyTo"/> for details.
		/// </remarks>

		public void CopyTo(ISchemaError[] array) 
		{
			((ICollection) this).CopyTo(array, 0);
		}

		#endregion
		#region CopyTo(ISchemaError[], Int32)

		/// <summary>
		/// Copies the entire <see cref="SchemaErrorCollection"/>
		/// to a one-dimensional <see cref="Array"/>
		/// of <see cref="ISchemaError"/> elements,
		/// starting at the specified index of the target array.
		/// </summary>
		/// <param name="array">
		/// The one-dimensional <see cref="Array"/> that is the destination
		/// of the <see cref="ISchemaError"/> elements copied from the
		/// <see cref="SchemaErrorCollection"/>.
		/// The <b>Array</b> must have zero-based indexing.</param>
		/// <param name="arrayIndex">
		/// The zero-based index in <paramref name="array"/>
		/// at which copying begins.</param>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="array"/> is a null reference.</exception>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <paramref name="arrayIndex"/> is less than zero.</exception>
		/// <exception cref="ArgumentException"><para>
		/// <paramref name="arrayIndex"/> is equal to or
		/// greater than the length of <paramref name="array"/>.
		/// </para><para>-or-</para><para>
		/// The number of elements in the source
		/// <see cref="SchemaErrorCollection"/> is greater
		/// than the available space from <paramref name="arrayIndex"/>
		/// to the end of the destination <paramref name="array"/>.
		/// </para></exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.CopyTo"/> for details.
		/// </remarks>

		public void CopyTo(ISchemaError[] array, int arrayIndex) 
		{
			((ICollection) this).CopyTo(array, arrayIndex);
		}

		#endregion
		#region ICollection.CopyTo(Array, Int32)

		/// <summary>
		/// Copies the entire <see cref="SchemaErrorCollection"/>
		/// to a one-dimensional <see cref="Array"/>,
		/// starting at the specified index of the target array.
		/// </summary>
		/// <param name="array">
		/// The one-dimensional <see cref="Array"/> that is the destination
		/// of the <see cref="ISchemaError"/> elements copied from the
		/// <see cref="SchemaErrorCollection"/>.
		/// The <b>Array</b> must have zero-based indexing.</param>
		/// <param name="arrayIndex">
		/// The zero-based index in <paramref name="array"/>
		/// at which copying begins.</param>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="array"/> is a null reference.</exception>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <paramref name="arrayIndex"/> is less than zero.</exception>
		/// <exception cref="ArgumentException"><para>
		/// <paramref name="array"/> is multidimensional.
		/// </para><para>-or-</para><para>
		/// <paramref name="arrayIndex"/> is equal to or
		/// greater than the length of <paramref name="array"/>.
		/// </para><para>-or-</para><para>
		/// The number of elements in the source
		/// <see cref="SchemaErrorCollection"/> is greater
		/// than the available space from <paramref name="arrayIndex"/>
		/// to the end of the destination <paramref name="array"/>.
		/// </para></exception>
		/// <exception cref="InvalidCastException">
		/// <see cref="ISchemaError"/>
		/// cannot be cast automatically to the type of the destination
		/// <paramref name="array"/>.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.CopyTo"/> for details.
		/// </remarks>

		void ICollection.CopyTo(Array array, int arrayIndex) 
		{
			_data.CheckTargetArray(array, arrayIndex);
			Array.Copy(_data.Items, 0, array, arrayIndex, _data.Count);
		}

		#endregion
		#region GetEnumerator: ISchemaErrorEnumerator

		/// <summary>
		/// Returns an <see cref="ISchemaErrorEnumerator"/> that can
		/// iterate through the <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <returns>
		/// An <see cref="ISchemaErrorEnumerator"/> for the entire
		/// <see cref="SchemaErrorCollection"/>.
		/// </returns>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.GetEnumerator"/> for details.
		/// </remarks>

		public ISchemaErrorEnumerator GetEnumerator() 
		{
			return new Enumerator(_data);
		}

		#endregion
		#region IEnumerable.GetEnumerator: IEnumerator

		/// <summary>
		/// Returns an <see cref="IEnumerator"/> that can iterate through the
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <returns>
		/// An <see cref="IEnumerator"/> for the entire
		/// <see cref="SchemaErrorCollection"/>.
		/// </returns>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.GetEnumerator"/> for details.
		/// </remarks>

		IEnumerator IEnumerable.GetEnumerator() 
		{
			return (IEnumerator) GetEnumerator();
		}

		#endregion
		#region IndexOf(ISchemaError)

		/// <summary>
		/// Returns the zero-based index of the first occurrence
		/// of the specified <see cref="ISchemaError"/> in the
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <param name="value">
		/// The <see cref="ISchemaError"/> object
		/// to locate in the <see cref="SchemaErrorCollection"/>.
		/// This argument may be a null reference.
		/// </param>
		/// <returns>
		/// The zero-based index of the first occurrence of
		/// <paramref name="value"/> in the <see cref="SchemaErrorCollection"/>,
		/// if found; otherwise, -1.</returns>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.IndexOf"/> for details.
		/// </remarks>

		public int IndexOf(ISchemaError value) 
		{
			int count = _data.Count;
			ISchemaError[] items = _data.Items;

			if ( value == null) 
			{
				for (int i = 0; i < count; i++)
					if (items[i] == null)
						return i;

				return -1;
			}

			for (int i = 0; i < count; i++)
				if (value.Equals(items[i]))
					return i;

			return -1;
		}

		#endregion
		#region IList.IndexOf(Object)

		/// <summary>
		/// Returns the zero-based index of the first occurrence
		/// of the specified <see cref="Object"/> in the
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <param name="value">
		/// The object to locate in the <see cref="SchemaErrorCollection"/>.
		/// This argument must be compatible with <see cref="ISchemaError"/>.
		/// This argument may be a null reference.
		/// </param>
		/// <returns>
		/// The zero-based index of the first occurrence of
		/// <paramref name="value"/> in the <see cref="SchemaErrorCollection"/>,
		/// if found; otherwise, -1.</returns>
		/// <exception cref="InvalidCastException">
		/// <paramref name="value"/> is not compatible with
		/// <see cref="ISchemaError"/>.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.IndexOf"/> for details.
		/// </remarks>

		int IList.IndexOf(object value) 
		{
			return IndexOf((ISchemaError) value);
		}

		#endregion
		#region Insert(Int32, SchemaError)

		/// <summary>
		/// Inserts a <see cref="ISchemaError"/> element into the
		/// <see cref="SchemaErrorCollection"/> at the specified index.
		/// </summary>
		/// <param name="index">
		/// The zero-based index at which <paramref name="value"/>
		/// should be inserted.</param>
		/// <param name="value">
		/// The <see cref="ISchemaError"/> object to insert
		/// into the <see cref="SchemaErrorCollection"/>.
		/// This argument may be a null reference.
		/// </param>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <para><paramref name="index"/> is less than zero.</para>
		/// <para>-or-</para><para>
		/// <paramref name="index"/> is greater than <see cref="Count"/>.
		/// </para></exception>
		/// <exception cref="NotSupportedException"><para>
		/// The <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.
		/// </para><para>-or-</para><para>
		/// The <b>SchemaErrorCollection</b>
		/// already contains <paramref name="value"/>,
		/// and the <b>SchemaErrorCollection</b>
		/// ensures that all elements are unique.
		/// </para></exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Insert"/> for details.
		/// </remarks>

		public virtual void Insert(int index, ISchemaError value) 
		{
			int count = _data.Count;

			if (index < 0)
				throw new ArgumentOutOfRangeException("index",
					index, "Argument cannot be negative.");

			if (index > count)
				throw new ArgumentOutOfRangeException("index",
					index, "Argument cannot exceed Count.");

			if (_data.IsUnique) CheckUnique(value);

			if (count == _data.Items.Length)
				_data.EnsureCapacity(count + 1);

			if (index < count)
				Array.Copy(_data.Items, index, 
					_data.Items, index + 1, count - index);

			_data.Items[index] = value;
			_data.Count++;
		}

		#endregion
		#region IList.Insert(Int32, Object)

		/// <summary>
		/// Inserts an element into the
		/// <see cref="SchemaErrorCollection"/> at the specified index.
		/// </summary>
		/// <param name="index">
		/// The zero-based index at which <paramref name="value"/>
		/// should be inserted.</param>
		/// <param name="value">
		/// The object to insert into the <see cref="SchemaErrorCollection"/>.
		/// This argument must be compatible with <see cref="ISchemaError"/>.
		/// This argument may be a null reference.
		/// </param>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <para><paramref name="index"/> is less than zero.</para>
		/// <para>-or-</para><para>
		/// <paramref name="index"/> is greater than <see cref="Count"/>.
		/// </para></exception>
		/// <exception cref="InvalidCastException"><paramref name="value"/>
		/// is not compatible with <see cref="ISchemaError"/>.</exception>
		/// <exception cref="NotSupportedException"><para>
		/// The <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.
		/// </para><para>-or-</para><para>
		/// The <b>SchemaErrorCollection</b>
		/// already contains <paramref name="value"/>,
		/// and the <b>SchemaErrorCollection</b>
		/// ensures that all elements are unique.
		/// </para></exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Insert"/> for details.
		/// </remarks>

		void IList.Insert(int index, object value) 
		{
			Insert(index, (ISchemaError) value);
		}

		#endregion
		#region ReadOnly

		/// <summary>
		/// Returns a read-only wrapper for the specified
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <param name="collection">
		/// The <see cref="SchemaErrorCollection"/> to wrap.</param>
		/// <returns>
		/// A read-only wrapper around <paramref name="collection"/>.
		/// </returns>
		/// <exception cref="ArgumentNullException">
		/// <paramref name="collection"/> is a null reference.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.ReadOnly"/> for details.
		/// </remarks>

		public static SchemaErrorCollection ReadOnly(
			SchemaErrorCollection collection) 
		{

			if (collection == null)
				throw new ArgumentNullException("collection");

			return new ReadOnlyWrapper(collection._data);
		}

		#endregion
		#region Remove(ISchemaError)

		/// <summary>
		/// Removes the first occurrence of the specified
		/// <see cref="ISchemaError"/> from the
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <param name="value">
		/// The <see cref="ISchemaError"/> object to remove
		/// from the <see cref="SchemaErrorCollection"/>.
		/// This argument may be a null reference.
		/// </param>
		/// <exception cref="NotSupportedException">
		/// The <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Remove"/> for details.
		/// </remarks>

		public void Remove(ISchemaError value) 
		{
			int index = IndexOf(value);
			if (index >= 0) RemoveAt(index);
		}

		#endregion
		#region IList.Remove(Object)

		/// <summary>
		/// Removes the first occurrence of the specified <see cref="Object"/>
		/// from the <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <param name="value">
		/// The object to remove from the
		/// <see cref="SchemaErrorCollection"/>. This argument
		/// must be compatible with <see cref="ISchemaError"/>.
		/// This argument may be a null reference.
		/// </param>
		/// <exception cref="InvalidCastException">
		/// <paramref name="value"/> is not compatible with
		/// <see cref="ISchemaError"/>.</exception>
		/// <exception cref="NotSupportedException">
		/// The <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Remove"/> for details.
		/// </remarks>

		void IList.Remove(object value) 
		{
			Remove((ISchemaError) value);
		}

		#endregion
		#region RemoveAt

		/// <summary>
		/// Removes the element at the specified index of the
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <param name="index">
		/// The zero-based index of the element to remove.</param>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <para><paramref name="index"/> is less than zero.</para>
		/// <para>-or-</para>
		/// <para><paramref name="index"/> is equal to or
		/// greater than <see cref="Count"/>.</para></exception>
		/// <exception cref="NotSupportedException">
		/// The <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.RemoveAt"/> for details.
		/// </remarks>

		public virtual void RemoveAt(int index) 
		{
			if (index < 0)
				throw new ArgumentOutOfRangeException("index",
					index, "Argument cannot be negative.");

			if (index >= _data.Count)
				throw new ArgumentOutOfRangeException("index",
					index, "Argument must be less than Count.");

			int count = --_data.Count;
			ISchemaError[] items = _data.Items;

			if (index < count)
				Array.Copy(items, index + 1, items, index, count - index);

			items[count] = null;
		}

		#endregion
		#region RemoveRange

		/// <summary>
		/// Removes the specified range of elements from the
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <param name="index">
		/// The zero-based starting index of the range of elements to remove.
		/// </param>
		/// <param name="count">The number of elements to remove.</param>
		/// <exception cref="ArgumentException">
		/// <paramref name="index"/> and <paramref name="count"/>
		/// do not denote a valid range of elements in the
		/// <see cref="SchemaErrorCollection"/>.</exception>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <para><paramref name="index"/> is less than zero.</para>
		/// <para>-or-</para>
		/// <para><paramref name="count"/> is less than zero.</para>
		/// </exception>
		/// <exception cref="NotSupportedException">
		/// The <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.RemoveRange"/> for details.
		/// </remarks>

		public virtual void RemoveRange(int index, int count) 
		{
			if (index < 0)
				throw new ArgumentOutOfRangeException("index",
					index, "Argument cannot be negative.");

			if (count < 0)
				throw new ArgumentOutOfRangeException("count",
					count, "Argument cannot be negative.");

			if (index + count > _data.Count)
				throw new ArgumentException(
					"Arguments denote invalid range of elements.");

			if (count == 0) return;
			_data.Count -= count;

			if (index < _data.Count)
				Array.Copy(_data.Items, index + count, 
					_data.Items, index, _data.Count - index);

			Array.Clear(_data.Items, _data.Count, count);
		}

		#endregion
		#region Reverse()

		/// <overloads>
		/// Reverses the order of the elements in the
		/// <see cref="SchemaErrorCollection"/> or a portion of it.
		/// </overloads>
		/// <summary>
		/// Reverses the order of the elements in the entire
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <exception cref="NotSupportedException">
		/// The <see cref="SchemaErrorCollection"/> is read-only.
		/// </exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Reverse"/> for details.
		/// </remarks>

		public virtual void Reverse() 
		{
			if (_data.Count > 1)
				Array.Reverse(_data.Items, 0, _data.Count);
		}

		#endregion
		#region Reverse(Int32, Int32)

		/// <summary>
		/// Reverses the order of the elements in the specified range.
		/// </summary>
		/// <param name="index">
		/// The zero-based starting index of the range of elements to reverse.
		/// </param>
		/// <param name="count">The number of elements to reverse.</param>
		/// <exception cref="ArgumentException">
		/// <paramref name="index"/> and <paramref name="count"/>
		/// do not denote a valid range of elements in the
		/// <see cref="SchemaErrorCollection"/>.</exception>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <para><paramref name="index"/> is less than zero.</para>
		/// <para>-or-</para>
		/// <para><paramref name="count"/> is less than zero.</para>
		/// </exception>
		/// <exception cref="NotSupportedException">
		/// The <see cref="SchemaErrorCollection"/> is read-only.
		/// </exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Reverse"/> for details.
		/// </remarks>

		public virtual void Reverse(int index, int count) 
		{
			if (index < 0)
				throw new ArgumentOutOfRangeException("index",
					index, "Argument cannot be negative.");

			if (count < 0)
				throw new ArgumentOutOfRangeException("count",
					count, "Argument cannot be negative.");

			if (index + count > _data.Count)
				throw new ArgumentException(
					"Arguments denote invalid range of elements.");

			if (count > 1 && _data.Count > 1)
				Array.Reverse(_data.Items, index, count);
		}

		#endregion
		#region Sort()

		/// <overloads>
		/// Sorts the elements in the <see cref="SchemaErrorCollection"/>
		/// or a portion of it.
		/// </overloads>
		/// <summary>
		/// Sorts the elements in the entire <see cref="SchemaErrorCollection"/>
		/// using the <see cref="IComparable"/> implementation of each element.
		/// </summary>
		/// <exception cref="NotSupportedException">
		/// The <see cref="SchemaErrorCollection"/> is read-only.
		/// </exception>
		/// <exception cref="InvalidOperationException">
		/// One or more elements in the <see cref="SchemaErrorCollection"/>
		/// do not implement the <see cref="IComparable"/> interface.
		/// </exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.Sort()"/> for details.
		/// </remarks>

		public virtual void Sort() 
		{
			if (_data.Count > 1)
				Array.Sort(_data.Items, 0, _data.Count);
		}

		#endregion
		#region Sort(IComparer)

		/// <summary>
		/// Sorts the elements in the entire
		/// <see cref="SchemaErrorCollection"/> using the specified comparer.
		/// </summary>
		/// <param name="comparer">
		/// <para>The <see cref="IComparer"/> implementation
		/// to use when comparing elements.</para>
		/// <para>-or-</para>
		/// <para>A null reference to use the <see cref="IComparable"/>
		/// implementation of each element.</para></param>
		/// <exception cref="NotSupportedException">
		/// The <see cref="SchemaErrorCollection"/> is read-only.
		/// </exception>
		/// <remarks>
		/// Please refer to
		/// <see cref="ArrayList.Sort(IComparer)"/> for details.
		/// </remarks>

		public virtual void Sort(IComparer comparer) 
		{
			if (_data.Count > 1)
				Array.Sort(_data.Items, 0, _data.Count, comparer);
		}

		#endregion
		#region Sort(Int32, Int32, IComparer)

		/// <summary>
		/// Sorts the elements in the specified range
		/// using the specified comparer.
		/// </summary>
		/// <param name="index">
		/// The zero-based starting index of the range of elements to sort.
		/// </param>
		/// <param name="count">The number of elements to sort.</param>
		/// <param name="comparer">
		/// <para>The <see cref="IComparer"/> implementation
		/// to use when comparing elements.</para>
		/// <para>-or-</para>
		/// <para>A null reference to use the <see cref="IComparable"/>
		/// implementation of each element.</para></param>
		/// <exception cref="ArgumentException">
		/// <paramref name="index"/> and <paramref name="count"/>
		/// do not denote a valid range of elements in the
		/// <see cref="SchemaErrorCollection"/>.</exception>
		/// <exception cref="ArgumentOutOfRangeException">
		/// <para><paramref name="index"/> is less than zero.</para>
		/// <para>-or-</para>
		/// <para><paramref name="count"/> is less than zero.</para>
		/// </exception>
		/// <exception cref="NotSupportedException">
		/// The <see cref="SchemaErrorCollection"/> is read-only.
		/// </exception>
		/// <remarks>
		/// Please refer to
		/// <see cref="ArrayList.Sort(Int32, Int32, IComparer)"/> for details.
		/// </remarks>

		public virtual void Sort(int index, int count, IComparer comparer) 
		{
			if (index < 0)
				throw new ArgumentOutOfRangeException("index",
					index, "Argument cannot be negative.");

			if (count < 0)
				throw new ArgumentOutOfRangeException("count",
					count, "Argument cannot be negative.");

			if (index + count > _data.Count)
				throw new ArgumentException(
					"Arguments denote invalid range of elements.");

			if (count > 1 && _data.Count > 1)
				Array.Sort(_data.Items, index, count, comparer);
		}

		#endregion
		#region ToArray

		/// <summary>
		/// Copies the elements of the <see cref="SchemaErrorCollection"/>
		/// to a new <see cref="Array"/> of
		/// <see cref="ISchemaError"/> elements.
		/// </summary>
		/// <returns>
		/// A one-dimensional <see cref="Array"/> of
		/// <see cref="ISchemaError"/> elements containing copies of the
		/// elements of the <see cref="SchemaErrorCollection"/>.
		/// </returns>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.ToArray"/> for details.
		/// </remarks>

		public ISchemaError[] ToArray() 
		{
			ISchemaError[] array = new ISchemaError[_data.Count];
			Array.Copy(_data.Items, array, _data.Count);
			return array;
		}

		#endregion
		#region TrimToSize

		/// <summary>
		/// Sets the capacity to the actual number of elements in the
		/// <see cref="SchemaErrorCollection"/>.
		/// </summary>
		/// <exception cref="NotSupportedException">
		/// The <see cref="SchemaErrorCollection"/> 
		/// is read-only or has a fixed size.</exception>
		/// <remarks>
		/// Please refer to <see cref="ArrayList.TrimToSize"/> for details.
		/// </remarks>

		public virtual void TrimToSize() 
		{
			_data.SetCapacity(_data.Count);
		}

		#endregion
		#endregion
		#region Private Methods
		#region AddRange

		private void AddRange(ISchemaError[] array, int range) 
		{
			if (range == 0) return;

			if (_data.IsUnique)
				foreach (ISchemaError value in array)
					CheckUnique(value);

			if (_data.Count + range > _data.Items.Length)
				_data.EnsureCapacity(_data.Count + range);

			Array.Copy(array, 0, _data.Items, _data.Count, range);
			_data.Count += range;
		}

		#endregion
		#region CheckUnique

		private void CheckUnique() 
		{
			ISchemaError[] items = _data.Items;
			for (int i = _data.Count - 1; i > 0; i--)
				if (IndexOf(items[i]) < i)
					throw new InvalidOperationException(
						"Collection cannot contain duplicate elements.");
		}

		private void CheckUnique(ISchemaError value) 
		{
			if (IndexOf(value) >= 0)
				throw new NotSupportedException(
					"Unique collections cannot contain duplicate elements.");
		}

		private void CheckUnique(ISchemaError value, int index) 
		{
			int existing = IndexOf(value);
			if (existing >= 0 && existing != index)
				throw new NotSupportedException(
					"Unique collections cannot contain duplicate elements.");
		}

		#endregion
		#endregion
		#region Class Data

		[Serializable]
			private sealed class Data 
		{
			public const int DefaultCapacity = 16;

			public ISchemaError[] Items;
			public int Count;
			public bool IsUnique;

			#region CheckTargetArray

			public void CheckTargetArray(Array array, int arrayIndex) 
			{
				if (array == null)
					throw new ArgumentNullException("array");

				if (array.Rank > 1)
					throw new ArgumentException(
						"Argument cannot be multidimensional.", "array");

				// skip length checks for empty collection and index zero
				if (arrayIndex == 0 && Count == 0)
					return;

				if (arrayIndex < 0)
					throw new ArgumentOutOfRangeException("arrayIndex",
						arrayIndex, "Argument cannot be negative.");

				if (arrayIndex >= array.Length)
					throw new ArgumentException(
						"Argument must be less than array length.", 
						"arrayIndex");

				if (Count > array.Length - arrayIndex)
					throw new ArgumentException(
						"Argument section must be large enough for collection.",
						"array");
			}

			#endregion
			#region EnsureCapacity

			public void EnsureCapacity(int minimum) 
			{
				int capacity = (Items.Length == 0 ?
				DefaultCapacity : Items.Length * 2);

				if (capacity < minimum) capacity = minimum;
				SetCapacity(capacity);
			}

			#endregion
			#region SetCapacity

			public void SetCapacity(int capacity) 
			{
				if (capacity == Items.Length) return;

				if (capacity == 0) 
				{
					Items = new ISchemaError[DefaultCapacity];
					return;
				}

				ISchemaError[] items = new ISchemaError[capacity];
				Array.Copy(Items, items, Count);
				Items = items;
			}

			#endregion
		}

		#endregion
		#region Class Enumerator

		[Serializable]
			private sealed class Enumerator:
			ISchemaErrorEnumerator, IEnumerator 
		{

			private readonly Data _data;
			private int _count, _index;

			internal Enumerator(Data data) 
			{
				_data = data;
				_count = data.Count;
				_index = -1;
			}

			public ISchemaError Current 
			{
				get 
				{
					if (_index < 0 || _index >= _data.Count)
						throw new InvalidOperationException(
							"Enumerator is not on a collection element.");

					return _data.Items[_index];
				}
			}

			object IEnumerator.Current 
			{
				get { return Current; }
			}

			public bool MoveNext() 
			{
				if (_count != _data.Count)
					throw new InvalidOperationException(
						"Enumerator invalidated by modification to collection.");

				return (++_index < _count);
			}

			public void Reset() 
			{
				_count = _data.Count;
				_index = -1;
			}
		}

		#endregion
		#region Class ReadOnlyWrapper

		private sealed class ReadOnlyWrapper: SchemaErrorCollection 
		{

			public ReadOnlyWrapper(Data data): base(data) { }

			public override int Capacity 
			{
				get { return base.Capacity; }
				set 
				{
					throw new NotSupportedException(
						  "Read-only collections cannot be modified."); }
			}

			public override bool IsFixedSize 
			{
				get { return true; }
			}

			public override bool IsReadOnly 
			{
				get { return true; }
			}

			public override bool IsUnique 
			{
				get { return base.IsUnique; }
				set 
				{
					throw new NotSupportedException(
						  "Read-only collections cannot be modified."); }
			}

			public override ISchemaError this[int index] 
			{
				get { return base[index]; }
				set 
				{
					throw new NotSupportedException(
						  "Read-only collections cannot be modified."); }
			}

			public override int Add(ISchemaError value) 
			{
				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}

			public override void AddRange(SchemaErrorCollection collection) 
			{
				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}

			public override void AddRange(ISchemaError[] array) 
			{
				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}

			public override void Clear() 
			{
				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}

			public override object Clone() 
			{
				SchemaErrorCollection wrapper = 
					(SchemaErrorCollection) base.Clone();

				return new ReadOnlyWrapper(wrapper._data);
			}

			public override void Insert(int index, ISchemaError value) 
			{
				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}

			public override void RemoveAt(int index) 
			{
				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}

			public override void RemoveRange(int index, int count) 
			{
				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}

			public override void Reverse() 
			{
				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}

			public override void Reverse(int index, int count) 
			{
				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}

			public override void Sort() 
			{
				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}

			public override void Sort(IComparer comparer) 
			{
				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}

			public override void Sort(
				int index, int count, IComparer comparer) 
			{

				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}

			public override void TrimToSize() 
			{
				throw new NotSupportedException(
					"Read-only collections cannot be modified.");
			}
		}

		#endregion
	}

	#endregion
}