ElixirScript

The goal is to convert a subset (or full set) of Elixir code to JavaScript. Allowing the ability to write JavaScript in Elixir. This is done by taking the Elixir AST, converting it into Spider Monkey AST. From there it uses escodegen to convert the Spider Monkey AST to JavaScript.

It also includes an escript cli named ex2js which takes files or Elixir code strings as input and outputs Spider Monkey AST or JavaScript code to output or files depending on the options

Requirements

Elixir
Node or io.js

Development

Clone the repo

git clone git@github.com:bryanjos/ex_to_js.git

Get dependencies

mix deps.get
npm install

Compile

mix compile

Test

mix test

To build distributable tarball

mix ex2js.dist

`ex2js-version-tar.gz` will be in the `dist` folder

Installation

uncompress ex2js.tar.gz.
use ex2js executable found in the ex2js/bin folder

Usage

$ ex2js -h
  usage: ex2js <input> [options]

  <input> path to elixir files or 
          the elixir code string if the -ex flag is used

  options:

  -o  --output [path]   places output at the given path
  -t  --ast             shows only produced spider monkey ast
  -ex --elixir          read input as elixir code string
  -st --stdio           reads from stdio
      --lib             writes the standard lib js to standard out
  -h  --help            this message

#Limitations

Must define each module you are going to use upfront

In Elixir, you can use Modules in your code like so

```elixir
defmodule MyModule do

    def my_function() do
        Another.Module.their_function()
    end
    
end
```

But in ElixirScript, you must explicitly say you are using the module

```elixir
defmodule MyModule do
    alias Another.Module
    
    def my_function() do
        Module.their_function()
    end
    
end

```

This is because each module is converted into an ES6 module and `import`, `alias`, and `require` are turned into ES6 import statements. This would also be how you would import third-party javascript modules. The only exception is that the standard library or any javascript that is global in scope. For instance, the standard library currently is expected to be in the global scope so that you can use it without importing it.

Not all of the Kernel.SpecialForms module is defined

The following aren't defined (yet):

try
__CALLER__
__DIR__
__ENV__
quote
unquote
unquote_slicing
receive
super

Most of the Standard Library isn't defined yet

A lot of functions in the Kernel module are implemented. The Enum, Atom, List, Tuple, Logger, and Range modules are either fully defined are not complete. The rest still need to be implemented. Some modules like System or File may not be useful or function in the browser and may end up being only useful when using ElixirScript outside of the browser.

No Macro support

Not sure how this would be implemented right now, but looking for ideas.

Pattern matching works but is still limited

Pattern matching does work quite well now, but the implementation still needs to be thoroughly tested in a number of situations.

Currently pattern matching on bitstrings isn't supported, but for every other case that one would use pattern matching, it should work.

There are probably more that I'm forgetting. Check the issues for what's implemented and what still is needed.

Example projects

todo-elixirscript The TodoMVC app using ElixirScript and Phoenix.
color_bar_spike A canvas drawing example using ElixirScript, React and Delorean

RichMorin / elixirscript