newtype-generics

A typeclass and set of functions for working with newtypes

http://github.com/haskell-github-trust/newtype-generics

LTS Haskell 24.43:0.6.2@rev:5
Stackage Nightly 2026-06-01:0.6.3
Latest on Hackage:0.6.3

See all snapshots newtype-generics appears in

BSD-3-Clause licensed by Darius Jahandarie, Conor McBride, João Cristóvão, Simon Jakobi
Maintained by Haskell Github Trust <https://github.com/haskell-github-trust>
This version can be pinned in stack with:newtype-generics-0.6.3@sha256:3c5e3a2e0a34ef416a889a593624d7349799222a270500cda928fda7194f28dd,2036

Module documentation for 0.6.3

Depends on 1 package(full list with versions):
base
Used by 2 packages in nightly-2026-06-01(full list with versions):
alternators, MemoTrie

Per Conor McBride, the Newtype typeclass represents the packing and unpacking of a newtype, and allows you to operate under that newtype with functions such as ala. Generics support was added in version 0.4, making this package a full replacement for the original newtype package, and a better alternative to newtype-th.

Changes

Changelog for newtype-generics

[0.6.3] – 2026-05-30

  • Maintainer switch to Haskell Github Trust
  • Support newer compilers.

[0.6.2] – 2022-05-19

  • Remove dependency on transformers.

0.6.1 – 2021-11-02

  • Support GHC-9.2

0.6 – 2021-02-04

  • Remove the deprecated Control.Newtype module.
  • Support GHC-9.0

0.5.4 – 2019-09-10

  • Add Newtype instance for Data.Monoid.Ap.
  • Support GHC-8.8.

0.5.3 – 2018-03-23

  • All code was moved to a new Control.Newtype.Generics module.
  • Control.Newtype re-exports Control.Newtype.Generics, but is deprecated and will be removed in the next major release.

0.5.2.2 – 2018-03-16

  • Adjust bounds for base and transformers

0.5.2.1 – 2018-02-16

  • Reupload due to README encoding issue

0.5.2 – 2018-02-16

Added

  • under2
  • over2

Other

  • Various documentation improvements

0.5.1

Added

  • Add more instances from base

0.5.0.1

Changes

  • Compatibility with GHC 8.2.1

0.5

Changes

  • Relax types of underF and overF to allow different input & output functors