id_tree

Project Status: No Longer Maintained

This project is no longer actively maintained.

There is a similar project called nary-tree which may interest some users of id-tree.

That project (nary-tree) is an actively maintained fork of my other tree library slab-tree (which, is also no longer maintained).

Thank you for your support and contributions to this project over the years!

A library for creating and modifying Tree structures.

Overview

In this implementation, the Tree owns all of the Nodes and all inter-Node relationships are managed with NodeIds.

Trees in this library are "just" trees. They do not allow cycles. They do not allow the creation of arbitrary Graph structures. There is no weight associated with edges between Nodes. In addition, each Node can have an arbitrary number of child Nodes.

It is important to note that this library does not support comparison-based Node insertion. In other words, this is not a Binary Search Tree (or any other kind of search tree) library. It is purely a library for storing data in a hierarchical manner. The caller must know the structure that they wish to build and then use this library to do so; this library will not make those structural decisions for you.

Example Usage

use id_tree::*;

fn main() {
    use id_tree::InsertBehavior::*;

    //      0
    //     / \
    //    1   2
    //   / \
    //  3   4
    let mut tree: Tree<i32> = TreeBuilder::new()
        .with_node_capacity(5)
        .build();

    let root_id: NodeId = tree.insert(Node::new(0), AsRoot).unwrap();
    let child_id: NodeId = tree.insert(Node::new(1), UnderNode(&root_id)).unwrap();
    tree.insert(Node::new(2), UnderNode(&root_id)).unwrap();
    tree.insert(Node::new(3), UnderNode(&child_id)).unwrap();
    tree.insert(Node::new(4), UnderNode(&child_id)).unwrap();

    println!("Pre-order:");
    for node in tree.traverse_pre_order(&root_id).unwrap() {
        print!("{}, ", node.data());
    }
    // results in the output "0, 1, 3, 4, 2, "
}

Project Goals

Allow caller control of as many allocations as possible (through pre-allocation)
Fast Node insertion and removal
Arbitrary Tree structure creation and manipulation

Non-Goals

Arbitrary Graph structure creation and manipulation
Comparison-based node insertion of any kind