harg 🔩

harg is a library for configuring programs by scanning command line arguments, environment variables, default values and more. Under the hood, it uses a subset of optparse-applicative to expose regular arguments, switch arguments and subcommands. The library relies heavily on the use of higher kinded data (HKD) thanks to the barbies library. Using higgledy also helps reduce boilerplate code significantly.

Documentation

To find out more, check out the docs or the package page on hackage. There is also an example module that serves as an extensive demonstration of the library.

Roadmap

• Better errors using optparse-applicative's internals
• Allow user to pass optparse-applicative preferences
• Write tests

Credits

• jcpetruzza
• i-am-tom
• jmackie