generic-lens-core

Generically derive traversals, lenses and prisms.

https://github.com/kcsongor/generic-lens

LTS Haskell 24.28:2.2.1.0@rev:2
Stackage Nightly 2026-01-18:2.3.0.0
Latest on Hackage:2.3.0.0

See all snapshots generic-lens-core appears in

BSD-3-Clause licensed by Csongor Kiss
Maintained by [email protected]
This version can be pinned in stack with:generic-lens-core-2.3.0.0@sha256:8837e26a0ed6b7c7872bcdabe610ba329d880c7a9c99b5e4bcb9348d46639738,3067

Module documentation for 2.3.0.0

  • Data
    • Data.GenericLens
      • Data.GenericLens.Internal
    • Data.Generics
      • Data.Generics.Internal
        • Data.Generics.Internal.Errors
        • Data.Generics.Internal.Families
          • Data.Generics.Internal.Families.Changing
          • Data.Generics.Internal.Families.Collect
          • Data.Generics.Internal.Families.Has
        • Data.Generics.Internal.GenericN
        • Data.Generics.Internal.Profunctor
          • Data.Generics.Internal.Profunctor.Iso
          • Data.Generics.Internal.Profunctor.Lens
          • Data.Generics.Internal.Profunctor.Prism
        • Data.Generics.Internal.VL
          • Data.Generics.Internal.VL.Traversal
        • Data.Generics.Internal.Void
        • Data.Generics.Internal.Wrapped
      • Data.Generics.Product
        • Data.Generics.Product.Internal
          • Data.Generics.Product.Internal.Fields
          • Data.Generics.Product.Internal.GLens
          • Data.Generics.Product.Internal.HList
          • Data.Generics.Product.Internal.Param
          • Data.Generics.Product.Internal.Positions
          • Data.Generics.Product.Internal.Subtype
          • Data.Generics.Product.Internal.Typed
          • Data.Generics.Product.Internal.Types
      • Data.Generics.Sum
        • Data.Generics.Sum.Internal
          • Data.Generics.Sum.Internal.Constructors
          • Data.Generics.Sum.Internal.Subtype
          • Data.Generics.Sum.Internal.Typed
Used by 2 packages in nightly-2026-01-18(full list with versions):
generic-lens, generic-optics

This library uses GHC.Generics to derive efficient optics (traversals, lenses and prisms) for algebraic data types in a type-directed way, with a focus on good type inference and error messages when possible.

This package is the shared internal logic of the generic-lens and generic-optics libraries.

Changes

generic-lens-core-2.3.0.0 (2025-08-27)

  • GHC 9.14 compatibility

generic-lens-core-2.2.1.0 (2022-01-22)

  • GHC 9.2 compatibility

generic-lens-core-2.2.0.0 (2021-07-13)

  • GHC 9.0 compatibility

generic-lens-core-2.1.0.0 (2021-01-25)

  • Expose Data.Generics.Product.Internal.Subtype (#127, Tom Harding)

generic-lens-core-2.0.0.0 (2020-02-11)

  • Initial release