node package manager

reason

Reason Meta Language Toolchain

Reason: Build Systems Rapidly

  • Approachable syntax.
  • Powerful, automatic source code formatting.
  • Adopt incrementally with JavaScript/C interop.
  • Ahead-of-time compilation to assembly - without a language level VM.
  • Rapidly develop and share projects.

Installing Reason via npm is the easiest way to get started. (npm version > 3.0 is required - install here).

Installing the ExampleProject using npm is the easiest way to get started with Reason. It will install the master Reason branch and all of the dependencies for you into a local directory based sandbox. It even includes the compiler, IDE support, and REPL. Simply delete the directory when you're done and it's gone from your computer.

git clone https://github.com/reasonml/ExampleProject.git
cd ExampleProject
npm install
npm start

While it's installing, read about how to use ExampleProject to compile your simple project and use its built-in editor support and top level.

The ExampleProject uses a very simple build system called rebuild that comes with Reason, and is enough to start a small project. For large-scale development, we are currently developing a build and namespacing workflow called rebel, which is built on jenga. It is an early work in progress, but you can also try it out via RebelExampleProject. rebel currently takes a long time to compile the first time it's used, so for getting started quickly, use ExampleProject instead.

rebel features:

  • Easy to use bucklescript integration (currently broken)
  • Easy to use js_of_ocaml integration.
  • Automatic namespacing based on your package.json package name.
  • Automatic generation of .merlin files (soon).
  • Powered by jenga, a fast, parallel, recoverable build system.
  • Uses modern compiler features such as "module aliases" for faster compilation of projects.

The OPAM installation doesn't use the isolated directory based sandbox model that ExampleProject does, but if you are very familiar with opam, you should be able to work out conflicts in the global switch, or create a new switch for the purpose of using Reason.

# On OSX, install opam via Homebrew: 
brew update
brew install opam
# On Linux, see here (you will need opam >= 1.2.2): http://opam.ocaml.org/doc/Install.html 
 
opam init
# Add this to your ~/.bashrc (or ~/.zshrc): 
#   eval $(opam config env) 
 
opam update
opam switch 4.02.3
eval $(opam config env)
+opam pin add -y reason 'https://github.com/facebook/reason.git#1.3.0'

Test the installation by compiling the following program:

echo 'print_string "Hello world"' > Hello.re
 
rebuild Hello.native # Automatically generates Hello.native from Hello.re 
 
./Hello.native
 

Check out the docs which guide you through the basic syntax and toolchain features.

Contribute back to that documentation in the docs folder.

Get in touch! We're on IRC freenode #reasonml, and Discord.

# On OSX, install opam via Homebrew:
brew update
brew install opam
# On Linux, see here (you will need opam >= 1.2.2): http://opam.ocaml.org/doc/Install.html
 
opam init
# Add this to your ~/.bashrc (or ~/.zshrc):
#   eval $(opam config env)
 
opam update
opam switch 4.02.3
eval $(opam config env)
git clone git@github.com:facebook/reason.git
cd reason
opam pin add -y reason .

New content is licensed under the MIT license, works that are forked from other projects are under their original licenses. MIT license

Editor plugins (which have also been forked) in the editorSupport/ directory include their own licenses.