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deriving-compat: Backports of GHC deriving extensions

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

  • DeriveFoldable
  • DeriveFunctor
  • DeriveTraversable

The following changes have been backported:

  • In GHC 8.0, DeriveFoldable was changed to allow folding over data types with existential constraints.

  • In GHC 8.0, DeriveFoldable and DeriveTraversable were changed so as not to generate superfluous mempty or pure expressions in generated code. As a result, this allows deriving Traversable instances for datatypes with unlifted argument types.

  • In GHC 8.0, deriving Show was changed so that constructor fields with unlifted types are no longer shown with parentheses, and the output of showing an unlifted type is suffixed with the same number of hash signs as the corresponding primitive literals.

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

  • 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 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 to derive Lift using Template Haskell.

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Flags

Automatic Flags
NameDescriptionDefault
base-49

Use base-4.9 or later.

Enabled
new-functor-classes

Use a version of transformers or transformers-compat with a modern-style Data.Functor.Classes module. This flag cannot be used when building with transformers-0.4, since it comes with a different version of Data.Functor.Classes.

Enabled

Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info

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Versions [RSS] 0.1, 0.2, 0.2.1, 0.2.2, 0.3, 0.3.1, 0.3.2, 0.3.3, 0.3.4, 0.3.5, 0.3.6, 0.4, 0.4.1, 0.4.2, 0.4.3, 0.5, 0.5.1, 0.5.2, 0.5.3, 0.5.4, 0.5.5, 0.5.6, 0.5.7, 0.5.8, 0.5.9, 0.5.10, 0.6, 0.6.1, 0.6.2, 0.6.3, 0.6.4, 0.6.5, 0.6.6, 0.6.7 (info)
Change log CHANGELOG.md
Dependencies base (>=4.3 && <5), containers (>=0.1 && <0.6), ghc-boot-th, ghc-prim, template-haskell (>=2.5 && <2.12), transformers (>=0.2), transformers-compat (>=0.5) [details]
Tested with ghc ==7.0.4, ghc ==7.2.2, ghc ==7.4.2, ghc ==7.6.3, ghc ==7.8.4, ghc ==7.10.3, ghc ==8.0.1
License BSD-3-Clause
Copyright (C) 2015-2016 Ryan Scott
Author Ryan Scott
Maintainer Ryan Scott <ryan.gl.scott@gmail.com>
Category Compatibility
Home page https://github.com/haskell-compat/deriving-compat
Bug tracker https://github.com/haskell-compat/deriving-compat/issues
Source repo head: git clone https://github.com/haskell-compat/deriving-compat
Uploaded by ryanglscott at 2016-06-19T01:57:29Z
Distributions Arch:0.6.6, Debian:0.5.9, Fedora:0.6.6, LTSHaskell:0.6.7, NixOS:0.6.6, Stackage:0.6.7
Reverse Dependencies 24 direct, 51 indirect [details]
Downloads 48318 total (50 in the last 30 days)
Rating (no votes yet) [estimated by Bayesian average]
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Status Docs available [build log]
Last success reported on 2016-06-19 [all 1 reports]

Readme for deriving-compat-0.2.1

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deriving-compat

Hackage Hackage Dependencies Haskell Programming Language BSD3 License Build

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

  • DeriveFoldable
  • DeriveFunctor
  • DeriveTraversable

The following changes have been backported:

  • In GHC 8.0, DeriveFoldable was changed to allow folding over data types with existential constraints.
  • In GHC 8.0, DeriveFoldable and DeriveTraversable were changed so as not to generate superfluous mempty or pure expressions in generated code. As a result, this allows deriving Traversable instances for datatypes with unlifted argument types.
  • In GHC 8.0, deriving Show was changed so that constructor fields with unlifted types are no longer shown with parentheses, and the output of showing an unlifted type is suffixed with the same number of hash signs as the corresponding primitive literals.

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

  • 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 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 to derive Lift using Template Haskell.