/// <summary>
/// Adds the specified <see cref="BraidedTreeNode{TKey, TValue}"/> to the linked list,
/// sorted after the current instance.</summary>
/// <param name="node">
/// The <see cref="BraidedTreeNode{TKey, TValue}"/> to add.</param>
/// <remarks>
/// <b>AddList</b> updates the chains of <see cref="Previous"/> and <see cref="Next"/>
/// references so that the specified <paramref name="node"/> is sorted immediately after the
/// current instance.</remarks>
private void AddList(BraidedTreeNode <TKey, TValue> node)
{
node._next = _next;
node._previous = this;
_next = node;
node._next._previous = node;
}
/// <summary>
/// Removes the <see cref="BraidedTreeNode{TKey, TValue}"/>, which must be a leaf node, from
/// the tree structure.</summary>
/// <remarks><para>
/// <b>RemoveTree</b> sets the <see cref="Left"/> or <see cref="Right"/> reference of the
/// <see cref="Parent"/> node, whichever matches the current instance, to a null reference,
/// and updates the chains of <see cref="Previous"/> and <see cref="Next"/> references to
/// exclude the current instance.
/// </para><para>
/// All <see cref="BraidedTreeNode{TKey, TValue}"/> references of the current instance are
/// reset to default values, as with <see cref="Clear"/>. Moreover, <b>RemoveTree</b> sets
/// the <see cref="Tree"/> property to a null reference.</para></remarks>
internal void RemoveTree()
{
Debug.Assert(_left == null && _right == null);
if (_parent._left == this)
{
_parent._left = null;
}
else
{
Debug.Assert(_parent._right == this);
_parent._right = null;
}
_parent = null;
RemoveList();
_tree = null;
}
/// <summary>
/// Adds the specified <see cref="BraidedTreeNode{TKey, TValue}"/> to the tree structure, as
/// a leaf node of the current instance.</summary>
/// <param name="node">
/// The <see cref="BraidedTreeNode{TKey, TValue}"/> to add.</param>
/// <param name="isRight">
/// <c>true</c> to add <paramref name="node"/> as the <see cref="Right"/> descendant;
/// <c>false</c> to add <paramref name="node"/> as the <see cref="Left"/> descendant. The
/// corresponding property must be a null reference.</param>
/// <remarks>
/// <b>AddTree</b> also sets the <see cref="Parent"/> reference of the specified <paramref
/// name="node"/> to the current instance, and updates the chains of <see cref="Previous"/>
/// and <see cref="Next"/> references to include <paramref name="node"/>.</remarks>
internal void AddTree(BraidedTreeNode <TKey, TValue> node, bool isRight)
{
Debug.Assert(node._parent == null);
node._parent = this;
if (isRight)
{
Debug.Assert(_right == null);
_right = node;
AddList(node);
}
else
{
Debug.Assert(_left == null);
_left = node;
_previous.AddList(node);
}
}
/// <summary>
/// Rotates the <see cref="BraidedTreeNode{TKey, TValue}"/> to the right within the tree
/// structure.</summary>
/// <remarks>
/// <b>RotateRight</b> implements the <c>rotateRight</c> algorithm by Michael J. Laszlo,
/// <em>Computational Geometry and Computer Graphics in C++</em>, Prentice Hall 1996, p.58.
/// </remarks>
private void RotateRight()
{
BraidedTreeNode <TKey, TValue> y = this, x = y._left, p = y._parent;
y._left = x._right;
if (y._left != null)
{
y._left._parent = y;
}
if (p._right == y)
{
p._right = x;
}
else
{
p._left = x;
}
x._parent = p;
x._right = y;
y._parent = x;
}
/// <summary>
/// Rotates the <see cref="BraidedTreeNode{TKey, TValue}"/> to the left within the tree
/// structure.</summary>
/// <remarks>
/// <b>RotateLeft</b> implements the <c>rotateLeft</c> algorithm by Michael J. Laszlo,
/// <em>Computational Geometry and Computer Graphics in C++</em>, Prentice Hall 1996, p.58.
/// </remarks>
private void RotateLeft()
{
BraidedTreeNode <TKey, TValue> x = this, y = x._right, p = x._parent;
x._right = y._left;
if (x._right != null)
{
x._right._parent = x;
}
if (p._left == x)
{
p._left = y;
}
else
{
p._right = y;
}
y._parent = p;
y._left = x;
x._parent = y;
}
/// <summary>
/// Clears all references to other <see cref="BraidedTreeNode{TKey, TValue}"/> instances.
/// </summary>
/// <remarks>
/// <b>Clear</b> resets the <see cref="Previous"/> and <see cref="Next"/> properties to the
/// current instance, and the <see cref="Left"/>, <see cref="Right"/> and <see
/// cref="Parent"/>, properties to null references. Other properties remain unchanged,
/// including the <see cref="Tree"/> property.</remarks>
internal void Clear()
{
_next = _previous = this;
_left = _right = _parent = null;
}
/// <summary>
/// Removes the <see cref="BraidedTreeNode{TKey, TValue}"/> from the linked list.</summary>
/// <remarks>
/// <b>RemoveList</b> updates the chains of <see cref="Previous"/> and <see cref="Next"/>
/// references to exclude the current instance.</remarks>
private void RemoveList()
{
_previous._next = _next;
_next._previous = _previous;
_next = _previous = this;
}
