Lenses satisfy the properties of the Category type class, and are used to inspect and update individual elements of a data structue in a type-safe way. This library provides the simplest possible data types satisfying these properties.
"minilens" type aims to provide a very simple improvement on Haskell's record syntax: the idea of composable record accessors called 'Lens'es.
As of yet, there are no fancy Template Haskell APIs for generating lenses programmatically; you are expected to write your lenses by hand. Some handy helper functions are provided to help you do this.
This library was originally part of the Dao package, but has been branched into it's own package in the hopes that it will be useful in a wider variety of projects.