Collections

Collection classes that are not standard built-in objects in JavaScript. This includes a vector, binary heap, binary search tree, and a red-black tree.

This module is being archived. BinaryHeap, BSTree, and RBTree have been added to Deno’s standard library in the collections directory. Use Deno’s standard library instead.

Installation

This is an ES Module written in TypeScript and can be used in Deno projects. ES Modules are the official standard format to package JavaScript code for reuse. A JavaScript bundle is provided with each release so that it can be used in Node.js packages or web browsers.

Deno

To include it in a Deno project, you can import directly from the TS files. This module is available in Deno’s third part module registry but can also be imported directly from GitHub using raw content URLs.

// Import from Deno's third party module registry
import { Vector } from "https://deno.land/x/collections@0.12.1/mod.ts";
// Import from GitHub
import { Vector } "https://raw.githubusercontent.com/udibo/collections/0.12.1/mod.ts";

If you do not need all of the sub-modules, you can choose to just import the sub-modules you need.

// Import from Deno's third party module registry
import { Vector } from "https://deno.land/x/collections@0.12.1/vector.ts";
// Import from GitHub
import { Vector } from "https://raw.githubusercontent.com/udibo/collections/0.12.1/vector.ts";

Node.js

Node.js fully supports ES Modules.

If a Node.js package has the type “module” specified in its package.json file, the JavaScript bundle can be imported as a .js file.

import { Vector } from "./collections_0.12.1.js";

The default type for Node.js packages is “commonjs”. To import the bundle into a commonjs package, the file extension of the JavaScript bundle must be changed from .js to .mjs.

import { Vector } from "./collections_0.12.1.mjs";

See Node.js Documentation for more information.

Browser

Most modern browsers support ES Modules.

The JavaScript bundle can be imported into ES modules. Script tags for ES modules must have the type attribute set to “module”.

<script type="module" src="main.js"></script>

// main.js
import { Vector } from "./collections_0.12.1.js";

You can also embed a module script directly into an HTML file by placing the JavaScript code within the body of the script tag.

<script type="module">
  import { Vector } from "./collections_0.12.1.js";
</script>

See MDN Documentation for more information.

Usage

Vector

A double-ended queue implemented with a growable ring buffer. Vector is faster than JavaScript’s built in Array class for unshifting and shifting because it only requires reallocation when increasing the capacity.

See deno docs for more information.

BinaryHeap

A priority queue implemented with a binary heap. The heap is in decending order by default, using JavaScript’s built in comparison operators to sort the values.

See deno docs for more information.

BinaryHeap Efficiency

Example

Creating and using max and min heaps:

import {
  ascend,
  BinaryHeap,
} from "https://deno.land/x/collections@0.12.1/mod.ts";

const maxHeap: BinaryHeap<number> = new BinaryHeap();
maxHeap.push(...[4, 1, 3, 6, 2]); // 5
maxHeap.peek(); // 6
maxHeap.pop(); // 6
maxHeap.peek(); // 4
maxHeap.pop(); // 4

const minHeap: BinaryHeap<number> = new BinaryHeap<number>(ascend);
minHeap.push(...[4, 5, 3, 6, 2]);
minHeap.peek(); // 2
minHeap.pop(); // 2
minHeap.peek(); // 3
minHeap.pop(); // 3

BSTree

An unbalanced binary search tree. The values are in ascending order by default, using JavaScript’s built in comparison operators to sort the values.

See deno docs for more information.

BSTree Efficiency

I recommend not using this due to its worst case. Instead you should use an AVL Tree or Red-Black Tree. AVL Trees are more strictly balanced than Red-Black Trees, so they can provide faster lookups. Red-Black Trees require fewer rotations than AVL Trees, so they can provide faster insertions and removal operations.

RBTree

A red-black tree. The values are in ascending order by default, using JavaScript’s built in comparison operators to sort the values.

See deno docs for more information.

RBTree Efficiency

Red-Black Trees require fewer rotations than AVL Trees, so they can provide faster insertions and removal operations. If you need faster lookups, you should use an AVL Tree instead.

License

MIT