/// <summary>
/// Initialize a new sequence with the given initial contents, and optionally
/// an "owner" - this seq will then report that object to WhenSubmitting subscriptions.
/// </summary>
public ShieldedSeq(T[] items = null, object owner = null)
{
owner = owner ?? this;
_seq = new ShieldedSeqNc <T>(items, owner);
_count = new Shielded <int>(items == null ? 0 : items.Length, owner);
}
public ItemKeeper(T val, ItemKeeper next, object owner)
{
Value = val;
Next = new Shielded <ItemKeeper>(next, owner);
}
/// <summary>
/// Initializes a new tree, which will use a given comparer, or using the .NET default
/// comparer if none is specified.
/// </summary>
public ShieldedTreeNc(IComparer <TKey> comparer = null, object owner = null)
{
_owner = owner ?? this;
_head = new Shielded <Shielded <Node> >(this);
_comparer = comparer != null ? comparer : Comparer <TKey> .Default;
}
void DeleteOneChild(Shielded <Node> node)
{
// node has at most one child!
Shielded <Node> child = node.Value.Right == null ? node.Value.Left : node.Value.Right;
bool deleted = false;
if (child != null)
{
ReplaceNode(node, child);
deleted = true;
}
if (node.Value.Color == Color.Black)
{
if (child != null && child.Value.Color == Color.Red)
{
child.Modify((ref Node c) => c.Color = Color.Black);
}
else
{
// since we don't represent null leaves as nodes, we must start
// the process with the not yet removed parent in this case.
if (!deleted)
{
child = node;
}
while (true)
{
// delete case 1
if (child.Value.Parent != null)
{
// delete case 2
Shielded <Node> s = Sibling(child);
if (s.Value.Color == Color.Red)
{
child.Value.Parent.Modify((ref Node p) => p.Color = Color.Red);
s.Modify((ref Node sInn) => sInn.Color = Color.Black);
if (child == child.Value.Parent.Value.Left)
{
RotateLeft(child.Value.Parent);
}
else
{
RotateRight(child.Value.Parent);
}
s = Sibling(child);
}
// delete case 3
if ((child.Value.Parent.Value.Color == Color.Black) &&
(s.Value.Color == Color.Black) &&
(s.Value.Left == null || s.Value.Left.Value.Color == Color.Black) &&
(s.Value.Right == null || s.Value.Right.Value.Color == Color.Black))
{
s.Modify((ref Node sInn) => sInn.Color = Color.Red);
child = child.Value.Parent;
continue; // back to 1
}
else
{
// delete case 4
if ((child.Value.Parent.Value.Color == Color.Red) &&
(s.Value.Color == Color.Black) &&
(s.Value.Left == null || s.Value.Left.Value.Color == Color.Black) &&
(s.Value.Right == null || s.Value.Right.Value.Color == Color.Black))
{
s.Modify((ref Node sInn) => sInn.Color = Color.Red);
child.Value.Parent.Modify((ref Node p) => p.Color = Color.Black);
}
else
{
// delete case 5
if (s.Value.Color == Color.Black)
{
if ((child == child.Value.Parent.Value.Left) &&
(s.Value.Right == null || s.Value.Right.Value.Color == Color.Black) &&
(s.Value.Left != null && s.Value.Left.Value.Color == Color.Red))
{
s.Modify((ref Node sInn) =>
{
sInn.Color = Color.Red;
sInn.Left.Modify((ref Node l) => l.Color = Color.Black);
});
RotateRight(s);
s = Sibling(child);
}
else if ((child == child.Value.Parent.Value.Right) &&
(s.Value.Left == null || s.Value.Left.Value.Color == Color.Black) &&
(s.Value.Right != null && s.Value.Right.Value.Color == Color.Red))
{
s.Modify((ref Node sInn) =>
{
sInn.Color = Color.Red;
sInn.Right.Modify((ref Node r) => r.Color = Color.Black);
});
RotateLeft(s);
s = Sibling(child);
}
}
// delete case 6
child.Value.Parent.Modify((ref Node p) =>
{
var c = p.Color;
s.Modify((ref Node sInn) => sInn.Color = c);
p.Color = Color.Black;
});
if (child == child.Value.Parent.Value.Left)
{
s.Value.Right.Modify((ref Node r) => r.Color = Color.Black);
RotateLeft(child.Value.Parent);
}
else
{
s.Value.Left.Modify((ref Node l) => l.Color = Color.Black);
RotateRight(child.Value.Parent);
}
}
}
}
break;
}
}
}
if (!deleted)
{
// original node is still in the tree, and it still has no children.
if (node.Value.Parent != null)
{
node.Value.Parent.Modify((ref Node p) => {
if (p.Left == node)
{
p.Left = null;
}
else
{
p.Right = null;
}
});
}
else
{
_head.Value = null;
}
ClearLinks(node);
}
}
private void ClearLinks(Shielded <Node> node)
{
node.Modify((ref Node n) => n.Left = n.Right = n.Parent = null);
}
