83 lines
1.9 KiB
C#
Raw Normal View History

// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
using System;
using System.Collections.Generic;
using System.Linq;
namespace System.Reactive
{
class Lookup<K, E> : ILookup<K, E>
{
Dictionary<K, List<E>> d;
public Lookup(IEqualityComparer<K> comparer)
{
d = new Dictionary<K, List<E>>(comparer);
}
public void Add(K key, E element)
{
var list = default(List<E>);
if (!d.TryGetValue(key, out list))
d[key] = list = new List<E>();
list.Add(element);
}
public bool Contains(K key)
{
return d.ContainsKey(key);
}
public int Count
{
get { return d.Count; }
}
public IEnumerable<E> this[K key]
{
get { return Hide(d[key]); }
}
private IEnumerable<E> Hide(List<E> elements)
{
foreach (var x in elements)
yield return x;
}
public IEnumerator<IGrouping<K, E>> GetEnumerator()
{
foreach (var kv in d)
yield return new Grouping(kv);
}
class Grouping : IGrouping<K, E>
{
KeyValuePair<K, List<E>> kv;
public Grouping(KeyValuePair<K, List<E>> kv)
{
this.kv = kv;
}
public K Key
{
get { return kv.Key; }
}
public IEnumerator<E> GetEnumerator()
{
return kv.Value.GetEnumerator();
}
Collections.IEnumerator Collections.IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
}
Collections.IEnumerator Collections.IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
}
}