@hackage microlens-contra0.1.0.0

This package provides Fold and Getter that are fully compatible with lens; the downside is that this package depends on contravariant, which in its turn depends on a lot of other packages (but still less than lens).

The difference between Fold and SimpleFold is that you can use e.g. takingWhile/droppingWhile and backwards on the former but not on the latter. Most functions from lens that work with Fold would work with SimpleFold as well, tho.

This package is a part of the microlens family; see the readme on Github.