Lunar

The Lua 5.1 superset programming language.

Check out the language documentation and examples which contains information about Lunar's syntax and semantics.

THIS PROJECT IS NOW ABANDONED IN FAVOR OF ROBLOX'S TYPED LUA. Maybe it will be picked up in the future again, but the main motivation drive is gone now.

Goals: what we want

• embeds most idioms into the language (default args, named varargs, classes, etc)
• implements type checking and type inference
• implements a language server for LSP features (intellisense, goto def, etc)
• interoperate with Lua, both ways. Code written in Lunar should be as easy to use in Lua.

Roadmap

These are the general idea of what we want to implement for Lunar. It does not cover everything in detail, and it's not strictly in any particular order.

• Syntax
  • Classes
  • Self-assignment operators
  • Lambda expressions
  • Import/export
  • Interfaces
  • Extension methods
• Language Features (via Lunar's Compiler API)
  • Semantic highlighting
  • Static type checking
  • Intellisense
  • Static code analyzers
  • Code refactorings/rewriters
  • Linting with autofixes where possible.

Getting Started

Lunar is written for Lua 5.1, therefore you need the Lua 5.1 runtime. On some installs of Lua, you might not have ./?.lua and ./?/init.lua in your LUA_PATH. Configure your system environment variables and append ;./?.lua;./?/init.lua into LUA_PATH.

Installing from Source

Currently this is required as we do not have precompiled binaries to install Lunar for you.

What you need

• Git
• Lua for Windows or Lua 5.1
• LuaRocks (included with Lua for Windows)
• LuaFileSystem (included with Lua for Windows)

If you are working on Lunar itself, you need busted, which can be installed through luarocks install busted

Downloading the Source

From the command line, which is Command Prompt or Powershell for Windows, and Terminal for Linux.

• git clone https://github.com/lunarlang/lunar
• cd ./lunar

Alternatively, you can download the source as a zipped file. In the top right of this page, you can find a green button, click that and below that should be a Download ZIP button.

• Extract the files from the downloaded .zip file.
• For Linux, you should open a Terminal where the extracted files are located.

Installing

• Linux
  • Run chmod +x ./install.sh
  • Run sudo ./install.sh
  • Test by running lunarc
• Windows
  • Find the install.bat file and open it
  • Test by running lunarc
    • You may need to open a new Command Prompt or Powershell.

Reinstalling and Uninstalling

We've included a way to reinstall and uninstall Lunar. Follow the Installing steps, and then you should be prompted to press R to reinstall, or U to uninstall.

To update Lunar, you can use git pull from the downloaded git repository from when you originally installed Lunar, and then follow the Installing steps, using R to reinstall.

Setting up your project

• Open your project in your editor of choice, though we recommend VSCode.
• Ensure your source code is in a separate folder, typically named src
• In the project folder, create a .lunarconfig file.
  • In Windows, the File Explorer will not allow you to create a file without a name. You must do this through an editor such as VSCode.
• In your .lunarconfig, add this:
  • Do not use local in the configuration file.

include = { "src" }
out_dir = "out"

• Once completed, save the file, and attempt running lunarc from the command line.
• If you receive an issue that isn't listed in Common issues, please create an issue and let us know what message you got. Alternatively, you can join our Discord server and ask in the #help channel.

Common issues

• required dependency 'LuaFileSystem' was not found, install with 'luarocks install luafilesystem'
  • Lunar is unable to find LuaFileSystem, or you do not have it installed. Check your LUA_PATH environment variable to ensure it points to a directory that contains LuaFileSystem.
• Could not find '.lunarconfig'
  • Ensure you are running lunarc from your projects directory, and ensure it contains a .lunarconfig file.
• 'include' or 'out_dir' was not defined in '.lunarconfig'
  • Please check the structure of your .lunarconfig to ensure it is valid.
• Syntax errors
  • These are typically caused by own code, however it is possible that it may be an issue with Lunar. If your code worked normally before, or it should work, please create an issue so we can track this.

If you did all of the above correctly, you should be able to compile your projects with lunarc.