TracLang

An implementation of TRAC Language, written in Ruby.

Add this line to your application's Gemfile:

gem 'trac_lang'

And then execute:

$ bundle

Or install it yourself as:

$ gem install trac_lang

Once it's installed, you can run:

$ trac_lang

from the command line to start the TRAC interpreter. You can also give it a file name of a file with TRAC commands in it to load those commands before you start the interpreter. Try the examples/util.trl file to get a number of useful utilities loaded.

TRAC is a macro language, meaning it consists solely of replacing strings of text with other strings. In spite of this simplicity, it is surprisingly powerful, to the point where you can create a version of the Y combinator, as follows:

#(DS,Y,( #(#(lambda,x,( #(f,(#(x,x))) )),#(lambda,x,( #(f,(#(x,x))) ))) )) #(SS,Y,f)

You can read about the different TRAC commands available in the examples/README.trl file, or read the original manual by the creator of TRAC, Calvin Mooers:

https://web.archive.org/web/20050205173449/http://tracfoundation.org:80/t64tech.htm

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/trac_lang. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.