M-Ary Tree

An implementation of an m-ary tree in TypeScript.

!npm

---

Install

``bash
yarn add m-ary-tree
`

`bash
npm install m-ary-tree
`

Usage

For detailed use see the API Documentation

$3

`typescript
import { Tree } from 'm-ary-tree';

const tree = new Tree(0);

tree.insert(0, 1);
tree.insert(0, 2);
`

$3

Each node inserted should have a unique key. Values are optional.

`typescript
import { Tree } from 'm-ary-tree';

const tree = new Tree(0);

tree.insert(0, 1) // node with key 1 and no data
tree.insert(0, 2, 'foo') // node with key 2 and data foo
`

$3

Use maxChildren option to limit child nodes, thus producing binary or ternary trees etc.

`typescript
const tree = new Tree(1, null, {
maxChildren: 2,
});
`

$3

All traversals are implemented as generators.

`typescript
for (const node of tree.postOrderTraversal()) {
// ...
}
`

$3

TypeScript generics are supported:

`typescript
type MyNodeType = string

const tree = new Tree(0, 'foo');

console.log(tree.data) // 'foo'
`

Motivation

This library was created while experimenting with tree drawing algorithms.

There are currently two positioning algorithms implemented:

- Node-Positioning Algorithm for General Trees by John Q. Walker
- Drawing Non-layered Tidy Trees in Linear Time by Atze van der Ploeg

$3

In this implementation all nodes must be the same width and height.

`typescript
import { calculateCoordinates } from 'm-ary-tree/dist/positioning-algorithms/Walker/calculateCoordinates';
import { Tree, preOrderTraversal } from 'm-ary-tree';

const tree = new Tree(0);

tree.insert(0, 1);
tree.insert(0, 2);
tree.insert(0, 3);

calculateCoordinates(tree, {
nodeWidth: 50,
nodeHeight: 50,
nodeSpacingX: 100,
nodeSpacingY: 30,
});

const positionedTree = calculateCoordinates(tree);

for (const node of preOrderTraversal(positionedTree)) {
expect(typeof node.data.x).toBe('number')
expect(typeof node.data.y).toBe('number')
expect(typeof node.data.width).toBe('number')
expect(typeof node.data.height).toBe('number')
}
`

$3

In this implementation all nodes can be different sizes.

`typescript
import { calculateCoordinates } from 'm-ary-tree/dist/positioning-algorithms/Walker/calculateCoordinates';
import { Tree, preOrderTraversal } from 'm-ary-tree';

const tree = new Tree(0, {
width: 60,
height: 25,
});

tree.insert(0, 1, {
width: 50,
height: 20,
});

tree.insert(0, 2, {
width: 50,
height: 60,
});

const positionedTree = calculateCoordinates(tree, {
nodeSpacingX: 100,
nodeSpacingY: 30,
});

for (const node of preOrderTraversal(positionedTree)) {
expect(typeof node.data.x).toBe('number')
expect(typeof node.data.y).toBe('number')
expect(typeof node.data.width).toBe('number')
expect(typeof node.data.height).toBe('number')
}
``