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
lens package, but explore a different
part of the design space. For a detailed introduction, see the Haddocks for the
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.
Offically 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
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.
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.
generic-optics: generic construction of optics using the
optics-sop: generic construction of optics using the
generics-soppackage, and optics for
template-haskell-optics: optics for working with types in the
TemplateHaskellto construct optics).
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