Files
ICD.Common.Utils/ICD.Common/Utils/Collections/IcdHashSet.cs
2017-06-21 22:41:54 -04:00

270 lines
7.9 KiB
C#

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using ICD.Common.Properties;
namespace ICD.Common.Utils.Collections
{
/// <summary>
/// A collection containing only unique items.
/// </summary>
/// <typeparam name="T"></typeparam>
public sealed class IcdHashSet<T> : ICollection<T>
{
private readonly Dictionary<T, object> m_Dict;
#region Properties
/// <summary>
/// Returns a new, empty hashset.
/// </summary>
[PublicAPI]
public static IcdHashSet<T> NullSet { get { return new IcdHashSet<T>(); } }
/// <summary>
/// Gets the number of items contained in the <see cref="T:System.Collections.Generic.ICollection`1"/>.
/// </summary>
/// <returns>
/// The number of items contained in the <see cref="T:System.Collections.Generic.ICollection`1"/>.
/// </returns>
public int Count { get { return m_Dict.Count; } }
/// <summary>
/// Gets a value indicating whether the <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.
/// </summary>
/// <returns>
/// true if the <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only; otherwise, false.
/// </returns>
public bool IsReadOnly { get { return false; } }
#endregion
#region Constructors
/// <summary>
/// Constructor.
/// </summary>
public IcdHashSet()
{
m_Dict = new Dictionary<T, object>();
}
/// <summary>
/// Constructor.
/// </summary>
/// <param name="items"></param>
public IcdHashSet(IEnumerable<T> items)
: this()
{
if (items == null)
return;
AddRange(items);
}
#endregion
#region Methods
[PublicAPI]
public IcdHashSet<T> Union(IEnumerable<T> set)
{
IcdHashSet<T> unionSet = new IcdHashSet<T>(this);
if (set == null)
return unionSet;
unionSet.AddRange(set);
return unionSet;
}
[PublicAPI]
public IcdHashSet<T> Subtract(IEnumerable<T> set)
{
IcdHashSet<T> subtractSet = new IcdHashSet<T>(this);
if (set == null)
return subtractSet;
foreach (T item in set)
subtractSet.Remove(item);
return subtractSet;
}
[PublicAPI]
public bool IsSubsetOf(IcdHashSet<T> set)
{
IcdHashSet<T> setToCompare = set ?? NullSet;
return this.All(setToCompare.Contains);
}
[PublicAPI]
public IcdHashSet<T> Intersection(IcdHashSet<T> set)
{
IcdHashSet<T> intersectionSet = NullSet;
if (set == null)
return intersectionSet;
foreach (T item in this.Where(set.Contains))
intersectionSet.Add(item);
foreach (T item in set.Where(Contains))
intersectionSet.Add(item);
return intersectionSet;
}
/// <summary>
/// Returns items that are not common between both sets.
/// </summary>
/// <param name="set"></param>
/// <returns></returns>
[PublicAPI]
public IcdHashSet<T> NonIntersection(IcdHashSet<T> set)
{
return Subtract(set).Union(set.Subtract(this));
}
[PublicAPI]
public bool IsProperSubsetOf(IcdHashSet<T> set)
{
IcdHashSet<T> setToCompare = set ?? NullSet;
// Is a proper subset if A is a subset of B and A != B
return (IsSubsetOf(setToCompare) && !setToCompare.IsSubsetOf(this));
}
[PublicAPI]
public bool IsSupersetOf(IcdHashSet<T> set)
{
IcdHashSet<T> setToCompare = set ?? NullSet;
return setToCompare.IsSubsetOf(this);
}
[PublicAPI]
public bool IsProperSupersetOf(IcdHashSet<T> set)
{
IcdHashSet<T> setToCompare = set ?? NullSet;
// B is a proper superset of A if B is a superset of A and A != B
return (IsSupersetOf(setToCompare) && !setToCompare.IsSupersetOf(this));
}
#endregion
#region ICollection<T> Members
/// <summary>
/// Adds the item to the collection. Returns false if the item already exists.
/// </summary>
/// <param name="item"></param>
/// <returns></returns>
public bool Add(T item)
{
// ReSharper disable CompareNonConstrainedGenericWithNull
if (item == null)
// ReSharper restore CompareNonConstrainedGenericWithNull
throw new ArgumentNullException("item");
if (m_Dict.ContainsKey(item))
return false;
m_Dict[item] = null;
return true;
}
/// <summary>
/// Adds the item to the collection.
/// </summary>
/// <param name="item"></param>
void ICollection<T>.Add(T item)
{
Add(item);
}
/// <summary>
/// Adds each of the items in the sequence to the collection.
/// </summary>
/// <param name="items"></param>
public void AddRange(IEnumerable<T> items)
{
foreach (T item in items)
Add(item);
}
/// <summary>
/// Removes all items from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
/// </summary>
/// <exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only. </exception>
public void Clear()
{
m_Dict.Clear();
}
/// <summary>
/// Returns true if the IcdHashSet contains the given item.
/// </summary>
/// <param name="item"></param>
/// <returns></returns>
public bool Contains(T item)
{
return m_Dict.ContainsKey(item);
}
/// <summary>
/// Copies the items of the <see cref="T:System.Collections.Generic.ICollection`1"/> to an <see cref="T:System.Array"/>, starting at a particular <see cref="T:System.Array"/> index.
/// </summary>
/// <param name="array">The one-dimensional <see cref="T:System.Array"/> that is the destination of the items copied from <see cref="T:System.Collections.Generic.ICollection`1"/>. The <see cref="T:System.Array"/> must have zero-based indexing.</param><param name="arrayIndex">The zero-based index in <paramref name="array"/> at which copying begins.</param><exception cref="T:System.ArgumentNullException"><paramref name="array"/> is null.</exception><exception cref="T:System.ArgumentOutOfRangeException"><paramref name="arrayIndex"/> is less than 0.</exception><exception cref="T:System.ArgumentException"><paramref name="array"/> is multidimensional.-or-<paramref name="arrayIndex"/> is equal to or greater than the length of <paramref name="array"/>.-or-The number of items in the source <see cref="T:System.Collections.Generic.ICollection`1"/> is greater than the available space from <paramref name="arrayIndex"/> to the end of the destination <paramref name="array"/>.-or-Type T cannot be cast automatically to the type of the destination <paramref name="array"/>.</exception>
public void CopyTo(T[] array, int arrayIndex)
{
m_Dict.Keys.CopyTo(array, arrayIndex);
}
/// <summary>
/// Removes the first occurrence of a specific object from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
/// </summary>
/// <returns>
/// true if <paramref name="item"/> was successfully removed from the <see cref="T:System.Collections.Generic.ICollection`1"/>; otherwise, false. This method also returns false if <paramref name="item"/> is not found in the original <see cref="T:System.Collections.Generic.ICollection`1"/>.
/// </returns>
/// <param name="item">The object to remove from the <see cref="T:System.Collections.Generic.ICollection`1"/>.</param><exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.</exception>
public bool Remove(T item)
{
return m_Dict.Remove(item);
}
#endregion
#region Implementation of IEnumerable
/// <summary>
/// Returns an enumerator that iterates through the collection.
/// </summary>
/// <returns>
/// A <see cref="T:System.Collections.Generic.IEnumerator`1"/> that can be used to iterate through the collection.
/// </returns>
/// <filterpriority>1</filterpriority>
public IEnumerator<T> GetEnumerator()
{
return m_Dict.Keys.GetEnumerator();
}
/// <summary>
/// Returns an enumerator that iterates through a collection.
/// </summary>
/// <returns>
/// An <see cref="T:System.Collections.IEnumerator"/> object that can be used to iterate through the collection.
/// </returns>
/// <filterpriority>2</filterpriority>
IEnumerator IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
#endregion
}
}