Ord1 instance for Down is broken (#17472) · Issues · Glasgow Haskell Compiler / GHC · GitLab

Ord1 instance for Down is broken

Summary

https://twitter.com/Iceland_jack/status/1193558757122494466

Steps to reproduce

> import Data.Ord
> import Data.Functor.Classes
> compare1 (Down 1) (Down 2)
LT

Expected behavior

> compare1 (Down 1) (Down 2)
GT

Environment

GHC version used: 8.6.5

Optional:

Operating System: NixOS 19.09
System Architecture: x86-64