# `deriving-compat`
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[Hackage: deriving-compat]:
  http://hackage.haskell.org/package/deriving-compat
  "deriving-compat package on Hackage"
[Haskell.org]:
  http://www.haskell.org
  "The Haskell Programming Language"
[tl;dr Legal: BSD3]:
  https://tldrlegal.com/license/bsd-3-clause-license-%28revised%29
  "BSD 3-Clause License (Revised)"

Provides Template Haskell functions that mimic deriving extensions that were introduced or modified in recent versions of GHC. Currently, the following typeclasses/extensions are covered:

* Deriving `Bounded`
* Deriving `Enum`
* Deriving `Ix`
* Deriving `Eq`, `Eq1`, and `Eq2`
* Deriving `Ord`, `Ord1`, and `Ord2`
* Deriving `Read`, `Read1`, and `Read2`
* Deriving `Show`, `Show1`, and `Show2`
* `DeriveFoldable`
* `DeriveFunctor`
* `DeriveTraversable`
* `GeneralizedNewtypeDeriving` (with GHC 8.2 or later)
* `DerivingVia` (with GHC 8.2 or later)

See the `Data.Deriving` module for a full list of backported changes.

Note that some recent GHC typeclasses/extensions are not covered by this package:

* `DeriveDataTypeable`
* `DeriveGeneric`, which was introducted in GHC 7.2 for deriving `Generic` instances, and modified in GHC 7.6 to allow derivation of `Generic1` instances. Use `Generics.Deriving.TH` from [`generic-deriving`](http://hackage.haskell.org/package/generic-deriving) to derive `Generic(1)` using Template Haskell.
* `DeriveLift`, which was introduced in GHC 8.0 for deriving `Lift` instances. Use `Language.Haskell.TH.Lift` from [`th-lift`](http://hackage.haskell.org/package/th-lift) to derive `Lift` using Template Haskell.
* The `Bifunctor` typeclass, which was introduced in GHC 7.10, as well as the `Bifoldable` and `Bitraversable` typeclasses, which were introduced in GHC 8.2. Use `Data.Bifunctor.TH` from [`bifunctors`](http://hackage.haskell.org/package/bifunctors) to derive these typeclasses using Template Haskell.