Hybrid textual and visual functional programming.

9 months after

Luna programming language

Visual and textual functional programming language with a focus on productivity, collaboration and development ergonomics.

Luna is a developer’s whiteboard on steroids. Design, prototype, develop and refactor any application simply by connecting visual elements together. Collaborate with co-workers, interactively fine tune parameters, inspect the results and visually profile the performance in real-time.

Visit The Luna Website to learn more!

This repository contains the Luna compiler core and its command line version. For the full (visual) Luna Studio, please take a look at the Luna Studio repository. For installation and management tools, there is Luna Manager.

Getting Started

This will get you up and running for Luna development, with only a minimal amount of setup required.

Luna's build system is nice and simple, allowing you to bootstrap the compiler as long as you have an installation of The Haskell Stack and the Haskell parser generator happy.

You can install the latter just by running stack install happy, which should build the tool for your system and put it in your stack binary folder.

System Requirements

Luna runs on all reasonably new Linuxes, MacOS, and Windows. Luna was mostly tested on Ubuntu >= 14.04, Fedora >= 23, MacOS >= 10.11 (El Capitan) and Windows 10, although it should run fine on all Linux distros like Mint, Debian or Arch. Please report any issues here on GitHub or shoot an email to [email protected].

Getting the Sources

Given you've probably been reading this document on GitHub, you might have an inkling where to look!. You can clone Luna using two methods:

  • Via HTTPS: We recommend you only use HTTPS if checking out the sources as read-only.
git clone
  • Via SSH: For those who plan on regularly making direct commits, cloning over SSH may provide a better user experience (but requires setting up your SSH Keys with GitHub).
git clone [email protected]:luna/luna.git

Building Luna

To build the command-line compiler interface along with all its sub-components, you will need to build the shell project. The instructions below assume that your luna repo is already cloned and we will refer to its location as $LUNA_REPO_PATH.

stack install

Note that the executable for the compiler will be located in $LUNA_REPO_PATH/dist/bin/public/luna folder. You may wish to add it to your $PATH.

Additionally, if you intend to simply use the Luna compiler (as opposed to tinkering with it, which requires frequent rebuilds), you may consider adding --ghc-options="-O2 -j4" to the stack install command. This should make the Luna compiler run considerably faster, at the cost of longer build times for building it.

Building Luna Components

It is also possible to build and test each component of Luna (e.g. core, parser) separately. To do this, pick the component you want from the following list, and then execute the following command:

stack build <component>
stack test <component>

Where <component> is one of the following:

  • luna-core (found in $LUNA_REPO_PATH/core)
  • lune-passes (found in $LUNA_REPO_PATH/passes)
  • luna-project (found in $LUNA_REPO_PATH/project)
  • luna-shell (found in $LUNA_REPO_PATH/shell)
  • luna-stdlib (found in $LUNA_REPO_PATH/stdlib)
  • luna-lexer (found in $LUNA_REPO_PATH/syntax/text/lexer)
  • luna-parser (found in $LUNA_REPO_PATH/syntax/text/parser)

Developing with Local Libraries

If you are hacking on the libraries that Luna uses, you'll want to be building Luna using your local copies of these libraries. These libraries should have their standard names and be located in the following path:


If your libraries are located in this path, you can use the local development stack .yaml file located in build/stack-local.yaml to build and test your version of Luna as follows:

stack build --stack-yaml build/stack-local.yaml

Running Luna

As a prerequisite, you need to set a LUNA_HOME variable to point to the location of the Luna standard library. Assuming your repo is at $LUNA_REPO_PATH, you will need to set LUNA_HOME to $LUNA_REPO_PATH/stdlib.

Next, you need to create the project: create a directory structure like this:

 ┖─ src/
    ┠─ Main.luna
    ┖─ any other *.luna files

A sample Main.luna file may look like this:

import Std.Base

def main:
    print "Hello world"
    print (2 + 2)

To compile and run the project, simply type luna in the main project directory.

Contributing to Luna

If you are interested in contributing to the development of Luna, please read the file.


This repository is licensed under the Apache 2.0, as specified in the LICENSE file.

Please be aware that, as the commercial backing for Luna, New Byte Order Sp. z o. o. reserves the right under the CLA to use contributions made to this repository as part of commercially available Luna products.

If these terms are unacceptable to you, please do not contribute to the repository.

The Contributor License Agreement

As part of your first contribution to this repository, you need to accept the Contributor License Agreement. You will automatically be asked to sign the CLA when you make your first pull request.

Any work intentionally submitted for inclusion in Luna shall be licensed under this CLA.

The CLA you sign applies to all repositories associated with the Luna project (Luna, Luna Studio, etc), so you will only have to sign it once at the start of your contributions.

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