protected ProgressiveLookup(Progressor <IGrouping <TKey, T> > progressor, NullAwareDictionary <TKey, IGrouping <TKey, T> > cache, IEqualityComparer <TKey>?keyComparer, IEqualityComparer <T>?itemComparer)
{
_cache = cache ?? throw new ArgumentNullException(nameof(cache));
Progressor = progressor ?? throw new ArgumentNullException(nameof(progressor));
_subscription = Progressor.SubscribeAction(obj => _cache.Add(obj.Key, obj));
Comparer = keyComparer ?? EqualityComparer <TKey> .Default;
ItemComparer = itemComparer ?? EqualityComparer <T> .Default;
Keys = EnumerationList <TKey> .Create(this.ConvertProgressive(input => input.Key));
}
public HashSet(IEnumerable <T> collection)
{
if (collection == null)
{
throw new ArgumentNullException("collection");
}
_wrapped = new NullAwareDictionary <T, object>();
foreach (var item in collection)
{
_wrapped[item] = null;
}
}
public IEnumerator <IGrouping <TKey, TElement> > GetEnumerator()
{
var groupings = new NullAwareDictionary <TKey, Tuple <Grouping <TKey, TElement>, List <TElement> > >(_comparer);
foreach (var item in _source)
{
var key = _keySelector(item);
if (!groupings.TryGetValue(key, out var tuple))
{
var collection = new List <TElement>();
tuple = new Tuple <Grouping <TKey, TElement>, List <TElement> >(new Grouping <TKey, TElement>(key, collection), collection);
groupings.Add(key, tuple);
}
tuple.Item2.Add(_elementSelector(item));
}
return(Enumerator(groupings));
}
public IEnumerator <TResult> GetEnumerator()
{
var groupings = new NullAwareDictionary <TKey, Lookup <TKey, TElement> .Grouping>(_comparer);
foreach (var item in _source)
{
var key = _keySelector(item);
Lookup <TKey, TElement> .Grouping grouping;
if (!groupings.TryGetValue(key, out grouping))
{
grouping = new Lookup <TKey, TElement> .Grouping(key);
groupings.Add(key, grouping);
}
grouping.Items.Add(_elementSelector(item));
}
return(Enumerator(groupings));
}