base-orphans

Scope

base-orphans defines orphan instances that mimic instances available in later versions of base to a wider (older) range of compilers. base-orphans does not export anything except the orphan instances themselves and complements base-compat.

Note that base-orphans doesn't cover every possible instance. See the What is not covered section for exceptions.

Usage

To use base-orphans, simply import Data.Orphans ().

What is covered

• Alternative, MonadPlus, and MonadZip instances for Proxy
• Alternative, Applicative, Bounded, Data, Enum, Foldable, Functor, Ix, Monad, MonadFix, MonadPlus, MonadZip, and Traversable instances for data types in GHC.Generics
• Alternative, Eq, Ord, Read, Show, Foldable, and Traversable instances for ZipList
• Applicative instance for K1 from GHC.Generics
• Applicative, Data, Eq1, Foldable, Functor, Ord1, Monad, MonadFix, MonadZip, Monoid, Num, Read, Read1, Semigroup, Show, Show1, and Traversable instances for Down
• Applicative and Alternative instances for ReadP and ReadPrec
• Applicative instance for strict and lazy ST
• Applicative, Foldable, Functor, Monad, and Traversable instances for Complex, Dual, First, Last, Product, and Sum
• Bits instance for Bool
• Bits, Bounded, and Integral instances for CDev
• Bits, Bounded, Enum, FiniteBits, Floating, Fractional, Integral, IsString, Ix, Num, Real, RealFloat, RealFrac, and Storable instances for Const and Identity
• Data instances for All, Any, and Const, IntPtr, and WordPtr
• Data, MonadFix and MonadZip instances for Alt, Dual, First, Last, Product, and Sum
• Data and IsList instances for Version
• Eq and Ord instances for Control.Exception.ErrorCall
• Eq, Ord, Read, and Show instances for data types in GHC.Generics
• Eq1, Ord1, Read1, and Show1 instances for NonEmpty
• Foldable instance for Either, (,) and Const
• Foldable and Traversable instances for Alt from Data.Monoid
• Functor instance for Handler, ArgOrder, OptDescr, and ArgDescr
• Functor, Applicative, Alternative, and MonadPlus instances for ArrowMonad
• Monad instance for (,)
• Monad instance for WrappedMonad
• MonadFail, Monoid, and Semigroup instances for strict ST
• MonadZip instance for Maybe
• Monoid, Eq, Ord, Read, and Show instances for Const
• Monoid instances for Identity and IO
• Num instance for Sum and Product
• Read instance for Fixed
• Semigroup instances for IO, Event and Lifetime
• Semigroup instances for V1, U1, Par1, Rec1, K1, M1, (:*:), and (:.:) from GHC.Generics. Monoid instances for the same types (except V1).
• Show instance for Fingerprint
• Storable instance for (), Complex, and Ratio
• Traversable instance for Either, (,) and Const
• Typeable instance for most data types, typeclasses, and promoted data constructors (when possible)

What is not covered

base-orphans does not define the following instances:

• Generic or Generic1 instances. These can be found in the Generics.Deriving.Instances module of the generic-deriving library.
• The Alternative IO and MonadPlus IO instances. These can be found in the Control.Monad.Trans.Error module of the transformers library.

Supported versions of GHC/base

• ghc-8.6.1 / base-4.12.0.0
• ghc-8.4.3 / base-4.11.1.0
• ghc-8.4.2 / base-4.11.1.0
• ghc-8.4.1 / base-4.11.0.0
• ghc-8.2.2 / base-4.10.1.0
• ghc-8.2.1 / base-4.10.0.0
• ghc-8.0.2 / base-4.9.1.0
• ghc-8.0.1 / base-4.9.0.0
• ghc-7.10.3 / base-4.8.2.0
• ghc-7.10.2 / base-4.8.1.0
• ghc-7.10.1 / base-4.8.0.0
• ghc-7.8.4 / base-4.7.0.2
• ghc-7.8.3 / base-4.7.0.1
• ghc-7.8.2 / base-4.7.0.0
• ghc-7.8.1 / base-4.7.0.0
• ghc-7.6.3 / base-4.6.0.1
• ghc-7.6.2 / base-4.6.0.1
• ghc-7.6.1 / base-4.6.0.0
• ghc-7.4.2 / base-4.5.1.0
• ghc-7.4.1 / base-4.5.0.0
• ghc-7.2.2 / base-4.4.1.0
• ghc-7.2.1 / base-4.4.0.0
• ghc-7.0.4 / base-4.3.1.0
• ghc-7.0.3 / base-4.3.1.0
• ghc-7.0.2 / base-4.3.1.0
• ghc-7.0.1 / base-4.3.0.0

We also make an attempt to keep base-orphans building with GHC HEAD, but due to its volatility, it may not work at any given point in time. If it doesn't, please report it!

Patches are welcome; add tests for new code!