public override bool MoveNext()
{
switch (_state)
{
case 1:
_node = _prepended;
_state = 2;
goto case 2;
case 2:
if (_node != null)
{
_current = _node.Item;
_node = _node.Linked;
return(true);
}
GetSourceEnumerator();
_state = 3;
goto case 3;
case 3:
if (LoadFromEnumerator())
{
return(true);
}
if (_appended == null)
{
return(false);
}
_enumerator = ((IEnumerable <TSource>)_appended.ToArray(_appendCount)).GetEnumerator();
_state = 4;
goto case 4;
case 4:
return(LoadFromEnumerator());
}
Dispose();
return(false);
}
private TSource[] LazyToArray()
{
Debug.Assert(GetCount(onlyIfCheap: true) == -1);
var builder = new LargeArrayBuilder <TSource>(initialize: true);
for (SingleLinkedNode <TSource> node = _prepended; node != null; node = node.Linked)
{
builder.Add(node.Item);
}
builder.AddRange(_source);
if (_appended != null)
{
foreach (TSource item in _appended.ToArray())
{
builder.Add(item);
}
}
return(builder.ToArray());
}