w3rs/reducers — comment on commit 7e34ce664564c2696b261bdf4f0dfe9af3750434
File:  line 0
By w3rs:

Forgot to mention changing `foldMap (unit . f)` to `foldr (cons . f) mempty`, the main cause why I forked the package. No much sense having `Reducer` instance only to use `unit` and `mappend` instead of `cons`.