Ruby on WebAssembly
This is the repo for the
wasm gem and also a place to start a conversation about Ruby and WebAssembly, and how our community might leverage this new capability. For some background, check out my blog post on the subject. This is largely an experiment at the moment — there are plenty of things this gem doesn't do, but it's a starting point and will hopefully get you up and running quickly so we can learn and explore together.
Feel free to open an issue about anything at all, even just to chat. Enjoy!
Building the gem and dependencies
rake to build this gem and install locally.
rake mruby_latest to set the MRuby submodule to the latest release and
rake mruby_master to switch to the master branch.
rake build_mruby to build an MRuby static library for WebAssembly, which will be placed in the
assets/ directory (a prebuilt one is already there).
When a new version of MRuby is released, update the version number in the
rake mruby_latest, and
Using the gem
Get it with
gem install wasm
Once installed, you'll have access to the
ruby-wasm command-line utility. Use this utility to build and serve Ruby apps for WebAssembly. Running it without any options will print its usage. Troubleshoot your WebAssembly toolchain with
What this gem currently does:
- Compile a single Ruby script to a binary
What it doesn't do yet (maybe something you'd like to work on
- Build several scripts at a time, or pull in others via
- Use any arbitrary Ruby gem; we're using MRuby here, so you can use mrbgems (see list)
- Fetch and interpret a Ruby script on page load
A quick example
First, make sure you have the WebAssembly toolchain installed and activated — see the "Getting Started" guide for details.
Start by cloning this repo (the
--recursive option also grabs the MRuby submodule and initializes it):
git clone --recursive https://github.com/blacktm/ruby-wasm.git
cd into the directory. Notice there's a file called
hello.rb — we're going to build it for WebAssembly!
Make sure you have this
wasm gem installed. Remember, you can check for issues using
Now, we'll build (or compile) the "Hello Ruby!" app using:
ruby-wasm build hello.rb
This will create a
build/ directory and generate the following files:
app.wasm— Our compiled Ruby app in binary WebAssembly format
.wasmbinary and initialize the WebAssembly environment (learn more)
app.html— A simple HTML template with a
.wasm binary). Run
ruby-wasm serve to do this.
Finally, open your favorite web browser and go to
http://localhost:8000/app.html. Open your web inspector / developer tools and you'll see "Hello Ruby!" printed in the console. Exciting!