Build your own language using Tree Notation.

JTree: Tree Notation SDK for TypeScript & Javascript


Who this package is for

Jtree is for people who want to design Tree Languages, make Tree editing tools, use TreeBase, or use the Tree Component Web Framework.

You can think of jtree as similar to the Java Development Kit, except for Tree Notation instead of Java.

Grammar Files

Jtree contains a Tree Language called "Grammar". You can write new Grammar files to define new languages. By creating a grammar file you get a parser, a type checker, syntax highlighting, autocomplete, a compiler, and virtual machine for executing your new language. Jtree also includes a simple web Tree Language Designer.

To make your language do really interesting things, you'll want to write some code to extend your language nodes in another language that you know. Jtree lets you create new languages using just Tree Notation, Tree Notation + TypeScript, or Tree Notation + Javascript. Tree Notation and Tree Languages can be built with any language, however, not just TypeScript and Javascript. We are looking for volunteers to build libraries/sdks in other host languages.

Using Jtree

Jtree currently includes around 10 compiled projects (aka "products") and more than a dozen Tree Languages.

jtree base library for npm projects:

const {jtree} = require("jtree") const tree = new jtree.TreeNode("hello world") console.log(tree.toString())

jtree base library for the browser:

<script src="https://jtree.treenotation.org/products/jtree.browser.js" />

jtree command line tool

npm install -g jtree jtree help


npm install -g jtree jtree base

jtree "sandbox" web app for exploring base Tree Notation

npm install -g jtree jtree kitchen open http://localhost:3333/

jtree "Designer" web app for building new Tree Languages

npm install -g jtree jtree kitchen open http://localhost:3333/designer

TreeComponentFramework for building web apps

(directions coming soon)

Sample Languages

More than 12 example Tree Languages for helping with various tasks

See the "langs/" folder.

Build Tools

If you look at the source, you will also see a set of build tools (such as Builder and TypeScriptRewriter). These are currently undocumented and not recommended for external use.

Building all tools and running tests

jtree build produceAll npm test


Jtree is a monorepo. With on average over 1 major version released each month for the past 2.5 years, it would take a lot of overhead to constantly be updating 10+ different repositories and modules every month. Once we're more confident in the theory and best practices, it might make sense to break this repo into independent modules.

That being said, we despise unnecessary dependencies as much as anyone. If anyone wants to create some automated submodules built from the projects in this monorepo, to allow for consuming of a smaller subset of the code and dependencies in this module, feel free to do so.

Development Status

All breaking changes are mentioned in releaseNotes.md. We follow semantic versioning, so breaking changes should not happen if you stay on the same major version.

Tree Notation Libraries in Other Languages

If you build a Tree Notation library/SDK in another language, let us know and we'll add a link.

If you are working on a Tree Notation library in a new host language, feel free to post an issue or ask for help in the reeNotation subreddit.

How to bump versions

jtree build updateVersion NEW_NUMBER

Alternatives Considered

This is the first Tree Notation library in existence, so there were no alternative implementations. Note and Space were predecessors to Tree Notation.

If a better alternative low level notation to Tree Notation is possible, it has yet to be discovered.

All that said, the important part of this repo is not the code but the design patterns. Tree Notation is very simple, and you can implement the patterns contained here in your own code without using this library. In fact, that is often the best way to use Tree Notation!

❤️ Public Domain ❤️

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