newtype-generics

A typeclass and set of functions for working with newtypes

http://github.com/sjakobi/newtype-generics

Version on this page:0.6
LTS Haskell 23.27:0.6.2@rev:4
Stackage Nightly 2025-07-10:0.6.2@rev:4
Latest on Hackage:0.6.2@rev:4

See all snapshots newtype-generics appears in

BSD-3-Clause licensed by Darius Jahandarie, Conor McBride, João Cristóvão, Simon Jakobi
Maintained by Simon Jakobi
This version can be pinned in stack with:newtype-generics-0.6@sha256:ac08e4b6caff80c8310649581ffba887e9d65b659c8b5697feaf32cf135b6c68,2010

Module documentation for 0.6

Depends on 2 packages(full list with versions):
base, transformers
Used by 2 packages in nightly-2021-04-06(full list with versions):
cabal-debian, 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 – 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