TAVLTree¶

AVL tree component.

Declaration¶

Source position: avl_tree.pp line 89

type

  TAVLTree = class
  public
    constructor Create(const OnCompareMethod: TListSortCompare);
    constructor Create;
    constructor CreateObjectCompare;
    destructor Destroy;
    property OnCompare: TListSortCompare; {rw}
    property OnObjectCompare: TObjectSortCompare; {rw}
    property NodeClass: TAVLTreeNodeClass; {rw}
    procedure SetNodeManager;
    function NewNode : TAVLTreeNode;
    procedure DisposeNode;
    procedure Add(ANode: TAVLTreeNode);
    function Add(Data: Pointer) : TAVLTreeNode;
    function AddAscendingSequence : TAVLTreeNode;
    procedure Delete;
    function Remove : Boolean;
    function RemovePointer : Boolean;
    procedure MoveDataLeftMost;
    procedure MoveDataRightMost;
    procedure Clear;
    procedure FreeAndClear;
    procedure FreeAndDelete;
    function Equals : Boolean;
    function IsEqual : Boolean;
    procedure Assign;
    property Root: TAVLTreeNode; {r}
    property Count: SizeInt; {r}
    function Compare : Integer;
    function Find : TAVLTreeNode;
    function FindKey : TAVLTreeNode;
    function FindNearestKey : TAVLTreeNode;
    function FindSuccessor : TAVLTreeNode;
    function FindPrecessor : TAVLTreeNode;
    function FindLowest : TAVLTreeNode;
    function FindHighest : TAVLTreeNode;
    function FindNearest : TAVLTreeNode;
    function FindPointer : TAVLTreeNode;
    function FindLeftMost : TAVLTreeNode;
    function FindRightMost : TAVLTreeNode;
    function FindLeftMostKey : TAVLTreeNode;
    function FindRightMostKey : TAVLTreeNode;
    function FindLeftMostSameKey : TAVLTreeNode;
    function FindRightMostSameKey : TAVLTreeNode;
    function GetEnumerator : TAVLTreeNodeEnumerator;
    function GetEnumeratorHighToLow : TAVLTreeNodeEnumerator;
    procedure ConsistencyCheck;
    procedure WriteReportToStream;
    function NodeToReportStr : string;
    function ReportAsString : string;
  end;

Inheritance¶

Description¶

TAVLTree maintains a balanced AVL tree. The tree consists of TAVLTreeNode nodes, each of which has a Data pointer associated with it. The TAVLTree component offers methods to balance and search the tree.

By default, the list is searched with a simple pointer comparison algorithm, but a custom search mechanism can be specified in the OnCompare property.

Properties¶

Member	Visibility	Description
Count read only	public	Number of nodes in the tree.
NodeClass	public	Node class to create.
Root read only	public	Root node of the tree.

Methods¶

Member	Visibility	Description
Add	public	Add a new node to the tree.
AddAscendingSequence	public
Assign	public	Assign another tree.
Clear	public	Clears the tree.
Compare	public	Compare 2 nodes.
ConsistencyCheck	public	Check the consistency of the tree.
Create	public	Create a new instance of TAVLTree.
CreateObjectCompare	public	Create an instance of the tree with extended compare method.
Delete	public	Delete a node from the tree.
Destroy	public	Destroy the TAVLTree instance.
DisposeNode	public	Dispose of a node outside of the tree.
Equals	public	Check if two trees are equal.
Find	public	Find a data item in the tree.
FindHighest	public	Find the highest (rightmost) node in the tree.
FindKey	public	Find a data item in the tree using alternate compare mechanism.
FindLeftMost	public	Find the node most left to a specified data node.
FindLeftMostKey	public	Find the node most left to a specified key node.
FindLeftMostSameKey	public	Find the node most left to a specified node with the same data.
FindLowest	public	Find the lowest (leftmost) node in the tree.
FindNearest	public	Find the node closest to the data in the tree.
FindNearestKey	public	Find nearest key for a data pointer.
FindPointer	public	Search for a data pointer.
FindPrecessor	public
FindRightMost	public	Find the node most right to a specified node.
FindRightMostKey	public	Find the node most right to a specified key node.
FindRightMostSameKey	public	Find the node most right of a specified node with the same data.
FindSuccessor	public	Find successor to node.
FreeAndClear	public	Clears the tree and frees nodes.
FreeAndDelete	public	Delete a node from the tree and destroy it.
GetEnumerator	public	Get an enumerator for the tree.
GetEnumeratorHighToLow	public	Return an enumerator that enumerates the tree in reversed order.
IsEqual	public	Check whether 2 tree instances are equal.
MoveDataLeftMost	public	Move data to the nearest left element.
MoveDataRightMost	public	Move data to the nearest right element.
NewNode	public	Create a new tree node.
NodeToReportStr	public	Create a textual dump of the tree.
Remove	public	Remove a data item from the list.
RemovePointer	public	Remove a pointer item from the list.
ReportAsString	public	Return the tree report as a string.
SetNodeManager	public	Set the node instance manager to use.
WriteReportToStream	public	Write the contents of the tree consistency check to the stream.

Events¶

Member	Visibility	Description
OnCompare	public	Compare function used when comparing nodes.
OnObjectCompare	public	Compare handler.