public MListIterator(MList <T> _list, MListNode <T> _previous)
{
list = _list;
previous = _previous;
current = null;
next = _previous.Next;
}
public void _Skip() // internal operation to do on Remove
{
if (next == null)
{
previous.Next = null; // end of list
next = current = previous = null;
return;
}
previous.Next = next;
current = null;
}
/// <summary>Step to next node. Return true if there was next.</summary>
public bool Next()
{
if (next == null)
{
return(false);
}
if (current != null)
{
previous = current; // current is null at the beginning and after Remove
}
current = next;
next = current.Next;
return(true);
}
public MListNode <T> InsertAfter(MListNode <T> position, T t)
{
// add a node after 'position', which can't be null
// special cases: first, only one, last
UT.assert(position != null);
MListNode <T> node = new MListNode <T> {
value = t, Next = position.Next
};
position.Next = node;
if (tail == position)
{
tail = node;
}
size++;
return(node);
}
public void AddLast(T t)
{
MListNode <T> node = new MListNode <T> {
value = t
};
if (size == 0)
{
root.Next = node;
}
else
{
tail.Next = node;
}
tail = node;
size++;
}
public void InsertBefore(T t)
{
UT.assert(current != null); // can't be beginning or end of list, or just deleted
previous = list.InsertAfter(previous, t); // add new node and update iterator's previous
}
tail; // last node, containing real data
// TODO: iterator for internal use to prevent 'new' calls
public MList()
{
root = new MListNode <T>(); tail = null;
}
