Elixir is a dynamic, functional language designed for building scalable and maintainable applications.

For more about Elixir, installation and documentation, check Elixir's website.

Compiling from source

To run Elixir from source, clone this repository to your machine, compile and test it:

git clone https://github.com/elixir-lang/elixir.git
cd elixir
make clean test

Note: if you are running on Windows, this article includes important notes for compiling Elixir from source on Windows.

If Elixir fails to build (specifically when pulling in a new version via git), be sure to remove any previous build artifacts by running make clean, then make test.

If tests pass, you are ready to move on to the Getting Started guide or to try Interactive Elixir by running bin/iex in your terminal.

However, if tests fail, it is likely you have an outdated Erlang version (Elixir requires Erlang 19.0 or later). You can check your Erlang version by calling erl in the command line. You will see some information as follows:

Erlang/OTP 19 [erts-8.0] [smp:2:2] [async-threads:10] [kernel-poll:false]

If you have properly set up your dependencies and tests still fail, you may want to open up a bug report, as explained next.

Bug reports

For reporting bugs, visit our issues tracker and follow the steps for reporting a new issue. Please disclose security vulnerabilities privately at [email protected].

Proposing new features

For proposing new features, please start a discussion in the Elixir Core mailing list. Keep in mind that it is your responsibility to argue and explain why a feature is useful and how it will impact the codebase and the community.

Once a proposal is accepted, it will be added to the issues tracker. The issues tracker focuses on actionable items and it holds a list of upcoming enhancements and pending bugs. All entries in the tracker are tagged for clarity and to ease collaboration.

Features and bug fixes that have already been merged and will be included in the next release are marked as "closed" in the issues tracker and are added to the CHANGELOG.

Finally, remember all interactions in our official spaces follow our Code of Conduct.

Contributing

We welcome everyone to contribute to Elixir. To do so, there are a few things you need to know about the code. First, Elixir code is divided in applications inside the lib folder:

• elixir - Contains Elixir's kernel and stdlib

• eex - Template engine that allows you to embed Elixir

• ex_unit - Simple test framework that ships with Elixir

• iex - IEx, Elixir's interactive shell

• logger - The built-in logger

• mix - Elixir's build tool

You can run all tests in the root directory with make test and you can also run tests for a specific framework make test_#{NAME}, for example, make test_ex_unit. If you just changed something in the Elixir's standard library, you can run only that portion through make test_stdlib.

In case you are changing a single file, you can compile and run tests only for that particular file for fast development cycles. For example, if you are changing the String module, you can compile it and run its tests as:

bin/elixirc lib/elixir/lib/string.ex -o lib/elixir/ebin
bin/elixir lib/elixir/test/elixir/string_test.exs

To recompile (including Erlang modules):

make compile

After your changes are done, please remember to run the full suite with make test and then mix format to guarantee all files are properly formatted.

If your contribution fails during the bootstrapping of the language, you can rebuild the language from scratch with:

make clean_elixir compile

Similarly, if you can't get Elixir to compile or the tests to pass after updating an existing checkout, run make clean compile. You can check the official build status on Travis-CI. More tasks can be found by reading the Makefile.

With tests running and passing, you are ready to contribute to Elixir and send a pull request. We have saved some excellent pull requests we have received in the past in case you are looking for some examples:

• Implement Enum.member? – Pull Request
• Add String.valid? – Pull Request
• Implement capture_io for ExUnit – Pull Request

Reviewing changes

Once a pull request is sent, the Elixir team will review your changes. We outline our process below to clarify the roles of everyone involved.

All pull requests must be approved by two committers before being merged into the repository. If any changes are necessary, the team will leave appropriate comments requesting changes to the code. Unfortunately we cannot guarantee a pull request will be merged, even when modifications are requested, as the Elixir team will re-evaluate the contribution as it changes.

Committers may also push style changes directly to your branch. If you would rather manage all changes yourself, you can disable "Allow edits from maintainers" feature when submitting your pull request.

The Elixir team may optionally assign someone to review a pull request. In case someone is assigned, they must explicitly approve the code before another team member can merge it.

When the review finishes, your pull request will be squashed and merged into the repository. If you have carefully organized your commits and believe they should be merged without squashing, leave a comment.

Building documentation

Building the documentation requires ExDoc to be installed and built alongside Elixir:

# After cloning and compiling Elixir, in its parent directory:
git clone git://github.com/elixir-lang/ex_doc.git
cd ex_doc && ../elixir/bin/mix do deps.get, compile
cd ../elixir && make docs

This will produce documentation sets for elixir, mix, etc. under the doc directory. If you are planning to contribute documentation, please check our best practices for writing documentation.

Development links

• Elixir Getting Started guide
• Elixir Documentation
• Elixir Core Mailing list (development)
• Issues tracker
• Code of Conduct
• #elixir-lang on Freenode IRC

License

"Elixir" and the Elixir logo are copyright (c) 2012 Plataformatec.

Elixir source code is released under Apache 2 License.

Check NOTICE and LICENSE files for more information.