The ix and at lenses are really useful when working with map like structures. But the At and Ixed type classes rely on a type family that has the wrong kind to be able to work with DMap.
These two functions work as their lens counterparts and we don't have to depend on the entire lens package. So there is no penalty if someone is using this package and not using lens.
ryantrinkle
commented
6 years ago
The
ixandatlenses are really useful when working with map like structures. But theAtandIxedtype classes rely on a type family that has the wrong kind to be able to work withDMap.These two functions work as their lens counterparts and we don't have to depend on the entire lens package. So there is no penalty if someone is using this package and not using lens.