Note: TypedRuby is not currently under active development.

TypedRuby is a gradual static type checker for Ruby. TypedRuby statically analyses your code and, with the help of type annotations, helps you find bugs sooner rather than later.

TypedRuby is designed to be gradually introduced into an existing code base, one method at a time. TypedRuby will ensure the type safety of methods that carry type annotations and will ignore any methods that don't.

Here's a quick example:

def add(Integer a, Integer b) => Integer
  a + b
end

def greet(String name) => nil
  puts "Hello #{name}!"
end

Check out the documentation for an introductory guide and more details!

Add typedruby to your Gemfile and you're ready to go!

TypedRuby is written in Rust, and uses Ragel and Bison in its parser.

You'll need to install Bison through Homebrew - TypedRuby requires a newer version than what OS X ships with:

brew install bison

You'll also need to install Ragel and Rust if you don't have them already:

brew install ragel rust

Then:

PATH="$(brew --prefix bison)/bin:$PATH" cargo build