private static IEnumerable <TResult> JoinIterator <TOuter, TInner, TKey, TResult>(IEnumerable <TOuter> outer, IEnumerable <TInner> inner, Func <TOuter, TKey> outerKeySelector, Func <TInner, TKey> innerKeySelector, Func <TOuter, TInner, TResult> resultSelector, IEqualityComparer <TKey> comparer)
{
using (IEnumerator <TOuter> e = outer.GetEnumerator())
{
if (e.MoveNext())
{
Lookup <TKey, TInner> lookup = Lookup <TKey, TInner> .CreateForJoin(inner, innerKeySelector, comparer);
if (lookup.Count != 0)
{
do
{
TOuter item = e.Current;
Grouping <TKey, TInner> g = lookup.GetGrouping(outerKeySelector(item), false);
if (g != null)
{
int count = g.count;
TInner[] elements = g.elements;
for (int i = 0; i != count; ++i)
{
yield return(resultSelector(item, elements[i]));
}
}
} while (e.MoveNext());
}
}
}
}
private static IEnumerable <TResult> GroupJoinIterator <TOuter, TInner, TKey, TResult>(IEnumerable <TOuter> outer, IEnumerable <TInner> inner, Func <TOuter, TKey> outerKeySelector, Func <TInner, TKey> innerKeySelector, Func <TOuter, IEnumerable <TInner>, TResult> resultSelector, IEqualityComparer <TKey> comparer)
{
using (IEnumerator <TOuter> e = outer.GetEnumerator())
{
if (e.MoveNext())
{
Lookup <TKey, TInner> lookup = Lookup <TKey, TInner> .CreateForJoin(inner, innerKeySelector, comparer);
do
{
TOuter item = e.Current;
yield return(resultSelector(item, lookup[outerKeySelector(item)]));
}while (e.MoveNext());
}
}
}
