/* Copyright 2002-2004 by Aidant Systems, Inc., and by Jason Smith. */
#region License
/*
* Copyright 2002-2005 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#endregion
#region Imports
using System;
using System.Collections;
#endregion
namespace Spring.Collections{
/// <summary>
/// Implements an immutable (read-only)
/// <see cref="Spring.Collections.ISet"/> wrapper.
/// </summary>
/// <remarks>
/// <p>
/// Although this class is advertised as immutable, it really isn't.
/// Anyone with access to the wrapped <see cref="Spring.Collections.ISet"/>
/// can still change the data. So <see cref="System.Object.GetHashCode"/>
/// is not implemented for this <see cref="Spring.Collections.ISet"/>, as
/// is the case for all <see cref="Spring.Collections.ISet"/>
/// implementations in this library. This design decision was based on the
/// efficiency of not having to <b>clone</b> the wrapped
/// <see cref="Spring.Collections.ISet"/> every time you wrap a mutable
/// <see cref="Spring.Collections.ISet"/>.
/// </p>
/// </remarks>
[Serializable]
public sealed class ImmutableSet : Set
{
private const string ErrorMessage = "Object is immutable.";
private ISet _mBasisSet;
internal ISet BasisSet
{
get { return _mBasisSet; }
}
/// <summary>
/// Constructs an immutable (read-only)
/// <see cref="Spring.Collections.ISet"/> wrapper.
/// </summary>
/// <param name="basisSet">
/// The <see cref="Spring.Collections.ISet"/> that is to be wrapped.
/// </param>
public ImmutableSet(ISet basisSet)
{
_mBasisSet = basisSet;
}
/// <summary>
/// Adds the specified element to this set if it is not already present.
/// </summary>
/// <param name="element">The object to add to the set.</param>
/// <returns>
/// <see langword="true"/> is the object was added,
/// <see langword="true"/> if the object was already present.
/// </returns>
/// <exception cref="System.NotSupportedException"/>
public override sealed bool Add(object element)
{
throw CreateNotSupportedException();
}
/// <summary>
/// Adds all the elements in the specified collection to the set if
/// they are not already present.
/// </summary>
/// <param name="collection">A collection of objects to add to the set.</param>
/// <returns>
/// <see langword="true"/> is the set changed as a result of this
/// operation.
/// </returns>
/// <exception cref="System.NotSupportedException"/>
public override sealed bool AddAll(ICollection collection)
{
throw CreateNotSupportedException();
}
/// <summary>
/// Removes all objects from this set.
/// </summary>
/// <exception cref="System.NotSupportedException"/>
public override sealed void Clear()
{
throw CreateNotSupportedException();
}
/// <summary>
/// Returns <see langword="true"/> if this set contains the specified
/// element.
/// </summary>
/// <param name="element">The element to look for.</param>
/// <returns>
/// <see langword="true"/> if this set contains the specified element.
/// </returns>
public override sealed bool Contains(object element)
{
return _mBasisSet.Contains(element);
}
/// <summary>
/// Returns <see langword="true"/> if the set contains all the
/// elements in the specified collection.
/// </summary>
/// <param name="collection">A collection of objects.</param>
/// <returns>
/// <see langword="true"/> if the set contains all the elements in the
/// specified collection.
/// </returns>
public override sealed bool ContainsAll(ICollection collection)
{
return _mBasisSet.ContainsAll(collection);
}
/// <summary>
/// Returns <see langword="true"/> if this set contains no elements.
/// </summary>
public override sealed bool IsEmpty
{
get { return _mBasisSet.IsEmpty; }
}
/// <summary>
/// Removes the specified element from the set.
/// </summary>
/// <param name="element">The element to be removed.</param>
/// <returns>
/// <see langword="true"/> if the set contained the specified element.
/// </returns>
/// <exception cref="System.NotSupportedException"/>
public override sealed bool Remove(object element)
{
throw CreateNotSupportedException();
}
/// <summary>
/// Remove all the specified elements from this set, if they exist in
/// this set.
/// </summary>
/// <param name="collection">A collection of elements to remove.</param>
/// <returns>
/// <see langword="true"/> if the set was modified as a result of this
/// operation.
/// </returns>
/// <exception cref="System.NotSupportedException"/>
public override sealed bool RemoveAll(ICollection collection)
{
throw CreateNotSupportedException();
}
/// <summary>
/// Retains only the elements in this set that are contained in the
/// specified collection.
/// </summary>
/// <param name="collection">
/// The collection that defines the set of elements to be retained.
/// </param>
/// <returns>
/// <see langword="true"/> if this set changed as a result of this
/// operation.
/// </returns>
/// <exception cref="System.NotSupportedException"/>
public override sealed bool RetainAll(ICollection collection)
{
throw CreateNotSupportedException();
}
private static NotSupportedException CreateNotSupportedException()
{
return new NotSupportedException(ImmutableSet.ErrorMessage);
}
/// <summary>
/// Copies the elements in the <see cref="Spring.Collections.ISet"/> to
/// an array.
/// </summary>
/// <remarks>
/// <p>
/// The type of array needs to be compatible with the objects in the
/// <see cref="Spring.Collections.ISet"/>, obviously.
/// </p>
/// </remarks>
/// <param name="array">
/// An array that will be the target of the copy operation.
/// </param>
/// <param name="index">
/// The zero-based index where copying will start.
/// </param>
public override sealed void CopyTo(Array array, int index)
{
_mBasisSet.CopyTo(array, index);
}
/// <summary>
/// The number of elements currently contained in this collection.
/// </summary>
public override sealed int Count
{
get { return _mBasisSet.Count; }
}
/// <summary>
/// Returns <see langword="true"/> if the
/// <see cref="Spring.Collections.ISet"/> is synchronized across
/// threads.
/// </summary>
/// <remarks>
/// <p>
/// Note that enumeration is inherently not thread-safe. Use the
/// <see cref="SyncRoot"/> to lock the object during enumeration.
/// </p>
/// </remarks>
public override sealed bool IsSynchronized
{
get { return _mBasisSet.IsSynchronized; }
}
/// <summary>
/// An object that can be used to synchronize this collection to make
/// it thread-safe.
/// </summary>
/// <value>
/// An object that can be used to synchronize this collection to make
/// it thread-safe.
/// </value>
public override sealed object SyncRoot
{
get { return _mBasisSet.SyncRoot; }
}
/// <summary>
/// Gets an enumerator for the elements in the
/// <see cref="Spring.Collections.ISet"/>.
/// </summary>
/// <returns>
/// An <see cref="System.Collections.IEnumerator"/> over the elements
/// in the <see cref="Spring.Collections.ISet"/>.
/// </returns>
public override sealed IEnumerator GetEnumerator()
{
return _mBasisSet.GetEnumerator();
}
/// <summary>
/// Returns a clone of the <see cref="Spring.Collections.ISet"/>
/// instance.
/// </summary>
/// <returns>A clone of this object.</returns>
public override sealed object Clone()
{
return new ImmutableSet(_mBasisSet);
}
/// <summary>
/// Performs a "union" of the two sets, where all the elements
/// in both sets are present.
/// </summary>
/// <param name="setOne">A collection of elements.</param>
/// <returns>
/// A new <see cref="Spring.Collections.ISet"/> containing the union of
/// this <see cref="Spring.Collections.ISet"/> with the specified
/// collection. Neither of the input objects is modified by the union.
/// </returns>
/// <see cref="Spring.Collections.ISet.Union(ISet)"/>
public override sealed ISet Union(ISet setOne)
{
ISet m = this;
while (m is ImmutableSet)
{
m = ((ImmutableSet) m).BasisSet;
}
return new ImmutableSet(m.Union(setOne));
}
/// <summary>
/// Performs an "intersection" of the two sets, where only the elements
/// that are present in both sets remain.
/// </summary>
/// <param name="setOne">A set of elements.</param>
/// <returns>
/// The intersection of this set with <paramref name="setOne"/>.
/// </returns>
/// <see cref="Spring.Collections.ISet.Intersect(ISet)"/>
public override sealed ISet Intersect(ISet setOne)
{
ISet m = this;
while (m is ImmutableSet)
{
m = ((ImmutableSet) m).BasisSet;
}
return new ImmutableSet(m.Intersect(setOne));
}
/// <summary>
/// Performs a "minus" of this set from the <paramref name="setOne"/>
/// set.
/// </summary>
/// <param name="setOne">A set of elements.</param>
/// <returns>
/// A set containing the elements from this set with the elements in
/// <paramref name="setOne"/> removed.
/// </returns>
/// <seealso cref="Spring.Collections.ISet.Minus(ISet)"/>
public override sealed ISet Minus(ISet setOne)
{
ISet m = this;
while (m is ImmutableSet)
{
m = ((ImmutableSet) m).BasisSet;
}
return new ImmutableSet(m.Minus(setOne));
}
/// <summary>
/// Performs an "exclusive-or" of the two sets, keeping only those
/// elements that are in one of the sets, but not in both.
/// </summary>
/// <param name="setOne">A set of elements.</param>
/// <returns>
/// A set containing the result of
/// <c><paramref name="setOne"/> ^ this</c>.
/// </returns>
/// <seealso cref="Spring.Collections.ISet.ExclusiveOr(ISet)"/>
public override sealed ISet ExclusiveOr(ISet setOne)
{
ISet m = this;
while (m is ImmutableSet)
{
m = ((ImmutableSet) m).BasisSet;
}
return new ImmutableSet(m.ExclusiveOr(setOne));
}
}
}
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