lens-family

Lens Families

Version on this page:	1.2.2
LTS Haskell 23.19:	2.1.3
Stackage Nightly 2025-04-22:	2.1.3
Latest on Hackage:	2.1.3

See all snapshots lens-family appears in

BSD-3-Clause licensed by Russell O'Connor

Maintained by Russell O'Connor

This version can be pinned in stack with:lens-family-1.2.2@sha256:7bcad928c1e027e843574983975f2a2c8a3be369eba9a381ea7a290f9fc86660,1755

Module documentation for 1.2.2

Lens
- Lens.Family2

Depends on 5 packages(full list with versions):

base, containers, lens-family-core, mtl, transformers

Used by 4 packages in lts-11.22(full list with versions):

lens-simple, proto-lens, proto-lens-arbitrary, proto-lens-descriptors

This package provides first class functional references. In addition to the usual operations of getting, setting and composition, plus integration with monad state, lens families provide some unique features:

Polymorphic updating
Traversals
Cast projection functions to read-only lenses
Cast "toList" functions to read-only traversals
Cast semantic editor combinators to modify-only traversals.