You could check out all the references at the bottom of the README. The ranking implementation was heavily inspired by Brent Yorgey's Data.Enumeration.Invertibl

You could check out all the references at the bottom of the README. The ranking implementation was heavily inspired by Brent Yorgey's Data.Enumeration.Invertible [1] that he blogged about at [2]. [1] https://hackage.haskell.org/package/simple-enumeration-0.2/docs/Data-Enumeration-Invertible.html https://hackage.haskell.org/package/simple-enumeration-0.2/d... [2] https://byorgey.wordpress.com/2019/07/05/lightweight-invertible-enumerations-in-haskell https://byorgey.wordpress.com/2019/07/05/lightweight-inverti...