/// <summary>
/// Enumerates ring backwards starting at key preceding x.
/// Skips duplicate values.
/// </summary>
public IEnumerable <KeyValuePair <TKey, TValue> > EnumerateFromNearestBackwardsDistinct(TKey key)
{
var items = new HashSet <TValue>();
var nearest = GetNearestBackwards(key, _root);
var enumerator = new EnumeratorDecreasing(_root, nearest, _comparer);
while (enumerator.MoveNext())
{
if (items.Add(enumerator.Current.Value))
{
yield return(enumerator.Current);
}
}
enumerator = new EnumeratorDecreasing(_root);
while (enumerator.MoveNext())
{
if (_comparer(enumerator.Current.Key, nearest.Key) == 0)
{
yield break;
}
if (items.Add(enumerator.Current.Value))
{
yield return(enumerator.Current);
}
}
}
/// <summary>
/// Enumerates ring backwards starting at key preceding x.
/// </summary>
public IEnumerable <KeyValuePair <TKey, TValue> > EnumerateFromNearestBackwards(TKey key)
{
var nearest = GetNearestBackwards(key, _root);
var enumerator = new EnumeratorDecreasing(_root, nearest, _comparer);
while (enumerator.MoveNext())
{
yield return(enumerator.Current);
}
enumerator = new EnumeratorDecreasing(_root);
while (enumerator.MoveNext())
{
if (_comparer(enumerator.Current.Key, nearest.Key) == 0)
{
yield break;
}
yield return(enumerator.Current);
}
}