optics family of Haskell
packages make it possible to define and use Lenses, Traversals, Prisms and other
optics, using an abstract interface. They are roughly comparable in
functionality with the
package, but explore a different part of the design space. For a detailed
introduction, see the Haddocks for the main
Authors and contributors
The authors of the
optics family of packages are:
- Adam Gundry
- Andres Löh
- Andrzej Rybczak
- Oleg Grenrus
Our thanks go to those who have (involuntarily) contributed code and ideas to
optics. In particular, we have liberally reused parts of the
lens package by
Edward Kmett and contributors.
Officially supported packages
opticsis a "batteries-included" package with many dependencies. It incorporates:
optics-core: core definitions with a minimal dependency footprint.
optics-extra: extra definitions and instances that extend
optics-core, incurring dependencies on various boot library packages.
optics-th: machinery to construct optics using
indexed-profunctors: internal definitions of indexed profunctor representation.
optics-vl: utilities for compatibility with van Laarhoven isomorphisms and prisms, as defined in the
lenslibrary. This package is not included in
opticsas it imposes a dependency on
profunctors. Note that
optics-corealready supports conversion for van Laarhoven lenses and various other optics.
template-haskell-optics: optics for working with types in the
TemplateHaskellto construct optics).
Work in progress packages
These packages have not (yet) been officially released. If you find them useful, we would welcome offers to maintain these packages.
optics-sop: generic construction of optics using the
generics-soppackage, and optics for
These packages are for internal use only, and are not intended to be released:
metametapost: generates diagrams used in the documentation, and an example of using
optics-codegen: code generator for the
Jointype family used internally by