Lens: Lenses, Folds, and Traversals
This package provides families of lenses, isomorphisms, folds, traversals, getters and setters.
If you are looking for where to get started, a crash course video on how lens was constructed and how to use the basics is available on youtube. It is best watched in high definition to see the slides, but the slides are also available if you want to use them to follow along.
The FAQ, which provides links to a large number of different resources for learning about lenses and an overview of the derivation of these types can be found on the Lens Wiki along with a brief overview and some examples.
Documentation is available through github (for HEAD) or hackage for the current and preceding releases.
Field Guide
Examples
(See wiki/Examples )
First, import Control.Lens .
ghci> import Control.Lens
... continue reading