/// <summary>
/// Advances the enumerator to the next element of the collection.
/// </summary>
/// <returns>
/// true if the enumerator was successfully advanced to the next element; false if the enumerator has passed the end of the collection.
/// </returns>
/// <exception cref="InvalidOperationException">The collection was modified after the enumerator was created. </exception>
public bool MoveNext()
{
this.ThrowIfDisposed();
if (_bucket.IsEmpty)
{
_currentPosition = Position.End;
return(false);
}
switch (_currentPosition)
{
case Position.BeforeFirst:
_currentPosition = Position.First;
return(true);
case Position.First:
if (_bucket._additionalElements.IsEmpty)
{
_currentPosition = Position.End;
return(false);
}
_currentPosition = Position.Additional;
_additionalEnumerator = new ImmutableList <T> .Enumerator(_bucket._additionalElements);
return(_additionalEnumerator.MoveNext());
case Position.Additional:
return(_additionalEnumerator.MoveNext());
case Position.End:
return(false);
default:
throw new InvalidOperationException();
}
}
