{-# LANGUAGE BangPatterns #-}{-# LANGUAGE DeriveDataTypeable #-}{-# LANGUAGE FlexibleContexts #-}{-# LANGUAGE FlexibleInstances #-}{-# LANGUAGE GADTs #-}{-# LANGUAGE NoImplicitPrelude #-}{-# LANGUAGE DataKinds #-}{-# LANGUAGE PolyKinds #-}{-# LANGUAGE RankNTypes #-}{-# LANGUAGE ScopedTypeVariables #-}{-# LANGUAGE StandaloneDeriving #-}{-# LANGUAGE Trustworthy #-}{-# LANGUAGE TypeOperators #-}------------------------------------------------------------------------------- |-- Module : Data.Data-- Copyright : (c) The University of Glasgow, CWI 2001--2004-- License : BSD-style (see the file libraries/base/LICENSE)---- Maintainer : libraries@haskell.org-- Stability : experimental-- Portability : non-portable (local universal quantification)---- \"Scrap your boilerplate\" --- Generic programming in Haskell. See-- <http://www.haskell.org/haskellwiki/Research_papers/Generics#Scrap_your_boilerplate.21>.-- This module provides the 'Data' class with its primitives for-- generic programming, along with instances for many datatypes. It-- corresponds to a merge between the previous "Data.Generics.Basics"-- and almost all of "Data.Generics.Instances". The instances that are-- not present in this module were moved to the-- @Data.Generics.Instances@ module in the @syb@ package.---- For more information, please visit the new-- SYB wiki: <http://www.cs.uu.nl/wiki/bin/view/GenericProgramming/SYB>.-------------------------------------------------------------------------------moduleData.Data(-- * Module Data.Typeable re-exported for conveniencemoduleData.Typeable ,-- * The Data class for processing constructor applicationsData (gfoldl ,gunfold ,toConstr ,dataTypeOf ,dataCast1 ,-- mediate types and unary type constructorsdataCast2 ,-- mediate types and binary type constructors-- Generic maps defined in terms of gfoldlgmapT ,gmapQ ,gmapQl ,gmapQr ,gmapQi ,gmapM ,gmapMp ,gmapMo ),-- * Datatype representationsDataType ,-- abstract-- ** ConstructorsmkDataType ,mkIntType ,mkFloatType ,mkCharType ,mkNoRepType ,-- ** ObserversdataTypeName ,DataRep (..),dataTypeRep ,-- ** Convenience functionsrepConstr ,isAlgType ,dataTypeConstrs ,indexConstr ,maxConstrIndex ,isNorepType ,-- * Data constructor representationsConstr ,-- abstractConIndex ,-- alias for Int, start at 1Fixity (..),-- ** ConstructorsmkConstr ,mkIntegralConstr ,mkRealConstr ,mkCharConstr ,-- ** ObserversconstrType ,ConstrRep (..),constrRep ,constrFields ,constrFixity ,-- ** Convenience function: algebraic data typesconstrIndex ,-- ** From strings to constructors and vice versa: all data typesshowConstr ,readConstr ,-- * Convenience functions: take type constructors aparttyconUQname ,tyconModule ,-- * Generic operations defined in terms of 'gunfold'fromConstr ,fromConstrB ,fromConstrM )where------------------------------------------------------------------------------importData.Functor.Const importData.Either importData.Eq importData.Maybe importData.Monoid importData.Ord importData.Typeable importData.Version (Version (..))importGHC.Base hiding(Any,IntRep,FloatRep)importGHC.List importGHC.Num importGHC.Read importGHC.Show importText.Read (reads )-- Imports for the instancesimportData.Functor.Identity -- So we can give Data instance for IdentityimportData.Int -- So we can give Data instance for Int8, ...importData.Type.Coercion importData.Word -- So we can give Data instance for Word8, ...importGHC.Real -- So we can give Data instance for Ratio--import GHC.IOBase -- So we can give Data instance for IO, HandleimportGHC.Ptr -- So we can give Data instance for PtrimportGHC.ForeignPtr -- So we can give Data instance for ForeignPtrimportForeign.Ptr (IntPtr (..),WordPtr (..))-- So we can give Data instance for IntPtr and WordPtr--import GHC.Stable -- So we can give Data instance for StablePtr--import GHC.ST -- So we can give Data instance for ST--import GHC.Conc -- So we can give Data instance for MVar & Co.importGHC.Arr -- So we can give Data instance for ArrayimportqualifiedGHC.Generics asGenerics(Fixity (..))importGHC.Generics hiding(Fixity (..))-- So we can give Data instance for U1, V1, ...---------------------------------------------------------------------------------- The Data class--------------------------------------------------------------------------------{- |
The 'Data' class comprehends a fundamental primitive 'gfoldl' for
folding over constructor applications, say terms. This primitive can
be instantiated in several ways to map over the immediate subterms
of a term; see the @gmap@ combinators later in this class. Indeed, a
generic programmer does not necessarily need to use the ingenious gfoldl
primitive but rather the intuitive @gmap@ combinators. The 'gfoldl'
primitive is completed by means to query top-level constructors, to
turn constructor representations into proper terms, and to list all
possible datatype constructors. This completion allows us to serve
generic programming scenarios like read, show, equality, term generation.
The combinators 'gmapT', 'gmapQ', 'gmapM', etc are all provided with
default definitions in terms of 'gfoldl', leaving open the opportunity
to provide datatype-specific definitions.
(The inclusion of the @gmap@ combinators as members of class 'Data'
allows the programmer or the compiler to derive specialised, and maybe
more efficient code per datatype. /Note/: 'gfoldl' is more higher-order
than the @gmap@ combinators. This is subject to ongoing benchmarking
experiments. It might turn out that the @gmap@ combinators will be
moved out of the class 'Data'.)
Conceptually, the definition of the @gmap@ combinators in terms of the
primitive 'gfoldl' requires the identification of the 'gfoldl' function
arguments. Technically, we also need to identify the type constructor
@c@ for the construction of the result type from the folded term type.
In the definition of @gmapQ@/x/ combinators, we use phantom type
constructors for the @c@ in the type of 'gfoldl' because the result type
of a query does not involve the (polymorphic) type of the term argument.
In the definition of 'gmapQl' we simply use the plain constant type
constructor because 'gfoldl' is left-associative anyway and so it is
readily suited to fold a left-associative binary operation over the
immediate subterms. In the definition of gmapQr, extra effort is
needed. We use a higher-order accumulation trick to mediate between
left-associative constructor application vs. right-associative binary
operation (e.g., @(:)@). When the query is meant to compute a value
of type @r@, then the result type withing generic folding is @r -> r@.
So the result of folding is a function to which we finally pass the
right unit.
With the @-XDeriveDataTypeable@ option, GHC can generate instances of the
'Data' class automatically. For example, given the declaration
> data T a b = C1 a b | C2 deriving (Typeable, Data)
GHC will generate an instance that is equivalent to
> instance (Data a, Data b) => Data (T a b) where
> gfoldl k z (C1 a b) = z C1 `k` a `k` b
> gfoldl k z C2 = z C2
>
> gunfold k z c = case constrIndex c of
> 1 -> k (k (z C1))
> 2 -> z C2
>
> toConstr (C1 _ _) = con_C1
> toConstr C2 = con_C2
>
> dataTypeOf _ = ty_T
>
> con_C1 = mkConstr ty_T "C1" [] Prefix
> con_C2 = mkConstr ty_T "C2" [] Prefix
> ty_T = mkDataType "Module.T" [con_C1, con_C2]
This is suitable for datatypes that are exported transparently.
-}classTypeable a =>Data a where-- | Left-associative fold operation for constructor applications.---- The type of 'gfoldl' is a headache, but operationally it is a simple-- generalisation of a list fold.---- The default definition for 'gfoldl' is @'const' 'id'@, which is-- suitable for abstract datatypes with no substructures.gfoldl ::(foralld b .Data d =>c (d ->b )->d ->c b )-- ^ defines how nonempty constructor applications are-- folded. It takes the folded tail of the constructor-- application and its head, i.e., an immediate subterm,-- and combines them in some way.->(forallg .g ->c g )-- ^ defines how the empty constructor application is-- folded, like the neutral \/ start element for list-- folding.->a -- ^ structure to be folded.->c a -- ^ result, with a type defined in terms of @a@, but-- variability is achieved by means of type constructor-- @c@ for the construction of the actual result type.-- See the 'Data' instances in this file for an illustration of 'gfoldl'.gfoldl _z =z -- | Unfolding constructor applicationsgunfold ::(forallb r .Data b =>c (b ->r )->c r )->(forallr .r ->c r )->Constr ->c a -- | Obtaining the constructor from a given datum.-- For proper terms, this is meant to be the top-level constructor.-- Primitive datatypes are here viewed as potentially infinite sets of-- values (i.e., constructors).toConstr ::a ->Constr -- | The outer type constructor of the typedataTypeOf ::a ->DataType ---------------------------------------------------------------------------------- Mediate types and type constructors---------------------------------------------------------------------------------- | Mediate types and unary type constructors.---- In 'Data' instances of the form---- @-- instance (Data a, ...) => Data (T a)-- @---- 'dataCast1' should be defined as 'gcast1'.---- The default definition is @'const' 'Nothing'@, which is appropriate-- for instances of other forms.dataCast1 ::Typeable t =>(foralld .Data d =>c (t d ))->Maybe (c a )dataCast1 _=Nothing -- | Mediate types and binary type constructors.---- In 'Data' instances of the form---- @-- instance (Data a, Data b, ...) => Data (T a b)-- @---- 'dataCast2' should be defined as 'gcast2'.---- The default definition is @'const' 'Nothing'@, which is appropriate-- for instances of other forms.dataCast2 ::Typeable t =>(foralld e .(Data d ,Data e )=>c (t d e ))->Maybe (c a )dataCast2 _=Nothing ---------------------------------------------------------------------------------- Typical generic maps defined in terms of gfoldl---------------------------------------------------------------------------------- | A generic transformation that maps over the immediate subterms---- The default definition instantiates the type constructor @c@ in the-- type of 'gfoldl' to an identity datatype constructor, using the-- isomorphism pair as injection and projection.gmapT ::(forallb .Data b =>b ->b )->a ->a -- Use the Identity datatype constructor-- to instantiate the type constructor c in the type of gfoldl,-- and perform injections Identity and projections runIdentity accordingly.--gmapT f x0 =runIdentity(gfoldl k Identity x0 )wherek::Data d =>Identity (d ->b )->d ->Identity b k (Identity c )x =Identity (c (f x ))-- | A generic query with a left-associative binary operatorgmapQl ::forallr r' .(r ->r' ->r )->r ->(foralld .Data d =>d ->r' )->a ->r gmapQl o r f =getConst. gfoldl k z wherek::Data d =>Const r (d ->b )->d ->Const r b k c x =Const $ (getConstc )`o `f x z::g ->Const r g z _=Const r -- | A generic query with a right-associative binary operatorgmapQr ::forallr r' .(r' ->r ->r )->r ->(foralld .Data d =>d ->r' )->a ->r gmapQr o r0 f x0 =unQr(gfoldl k (const (Qr id ))x0 )r0 wherek::Data d =>Qr r (d ->b )->d ->Qr r b k (Qr c )x =Qr (\r ->c (f x `o `r ))-- | A generic query that processes the immediate subterms and returns a list-- of results. The list is given in the same order as originally specified-- in the declaration of the data constructors.gmapQ ::(foralld .Data d =>d ->u )->a ->[u ]gmapQ f =gmapQr (:)[]f -- | A generic query that processes one child by index (zero-based)gmapQi ::forallu .Int->(foralld .Data d =>d ->u )->a ->u gmapQi i f x =casegfoldl k z x of{Qi _q ->fromJust q }wherek::Data d =>Qi u (d ->b )->d ->Qi u b k (Qi i' q )a =Qi (i' + 1)(ifi ==i' thenJust (f a )elseq )z::g ->Qi q g z _=Qi 0Nothing -- | A generic monadic transformation that maps over the immediate subterms---- The default definition instantiates the type constructor @c@ in-- the type of 'gfoldl' to the monad datatype constructor, defining-- injection and projection using 'return' and '>>='.gmapM ::forallm .Monad m =>(foralld .Data d =>d ->m d )->a ->m a -- Use immediately the monad datatype constructor-- to instantiate the type constructor c in the type of gfoldl,-- so injection and projection is done by return and >>=.--gmapM f =gfoldl k return wherek::Data d =>m (d ->b )->d ->m b k c x =doc' <-c x' <-f x return (c' x' )-- | Transformation of at least one immediate subterm does not failgmapMp ::forallm .MonadPlus m =>(foralld .Data d =>d ->m d )->a ->m a {-
The type constructor that we use here simply keeps track of the fact
if we already succeeded for an immediate subterm; see Mp below. To
this end, we couple the monadic computation with a Boolean.
-}gmapMp f x =unMp(gfoldl k z x )>>= \(x' ,b )->ifb thenreturn x' elsemzero wherez::g ->Mp m g z g =Mp (return (g ,False))k::Data d =>Mp m (d ->b )->d ->Mp m b k (Mp c )y =Mp (c >>= \(h ,b )->(f y >>= \y' ->return (h y' ,True))`mplus `return (h y ,b ))-- | Transformation of one immediate subterm with successgmapMo ::forallm .MonadPlus m =>(foralld .Data d =>d ->m d )->a ->m a {-
We use the same pairing trick as for gmapMp,
i.e., we use an extra Bool component to keep track of the
fact whether an immediate subterm was processed successfully.
However, we cut of mapping over subterms once a first subterm
was transformed successfully.
-}gmapMo f x =unMp(gfoldl k z x )>>= \(x' ,b )->ifb thenreturn x' elsemzero wherez::g ->Mp m g z g =Mp (return (g ,False))k::Data d =>Mp m (d ->b )->d ->Mp m b k (Mp c )y =Mp (c >>= \(h ,b )->ifb thenreturn (h y ,b )else(f y >>= \y' ->return (h y' ,True))`mplus `return (h y ,b ))-- | Type constructor for adding counters to queriesdataQi q a =Qi Int(Maybe q )-- | The type constructor used in definition of gmapQrnewtypeQr r a =Qr {unQr ::r ->r }-- | The type constructor used in definition of gmapMpnewtypeMp m x =Mp {unMp ::m (x ,Bool)}---------------------------------------------------------------------------------- Generic unfolding---------------------------------------------------------------------------------- | Build a term skeletonfromConstr::Data a =>Constr ->a fromConstr =fromConstrB (errorWithoutStackTrace "Data.Data.fromConstr")-- | Build a term and use a generic function for subtermsfromConstrB::Data a =>(foralld .Data d =>d )->Constr ->a fromConstrB f =runIdentity. gunfold k z wherek::forallb r .Data b =>Identity (b ->r )->Identity r k c =Identity (runIdentityc f )z::forallr .r ->Identity r z =Identity -- | Monadic variation on 'fromConstrB'fromConstrM::forallm a .(Monad m ,Data a )=>(foralld .Data d =>m d )->Constr ->m a fromConstrM f =gunfold k z wherek::forallb r .Data b =>m (b ->r )->m r k c =do{c' <-c ;b <-f ;return (c' b )}z::forallr .r ->m r z =return ---------------------------------------------------------------------------------- Datatype and constructor representations------------------------------------------------------------------------------------ | Representation of datatypes.-- A package of constructor representations with names of type and module.--dataDataType =DataType {tycon ::String ,datarep ::DataRep }derivingShow -- ^ @since 4.0.0.0-- | Representation of constructors. Note that equality on constructors-- with different types may not work -- i.e. the constructors for 'False' and-- 'Nothing' may compare equal.dataConstr =Constr {conrep ::ConstrRep ,constring ::String ,confields ::[String ]-- for AlgRep only,confixity ::Fixity -- for AlgRep only,datatype ::DataType }-- | @since 4.0.0.0instanceShow Constr whereshow =constring-- | Equality of constructors---- @since 4.0.0.0instanceEqConstr wherec == c' =constrRep c ==constrRep c' -- | Public representation of datatypesdataDataRep =AlgRep [Constr ]|IntRep |FloatRep |CharRep |NoRep deriving(Eq-- ^ @since 4.0.0.0,Show -- ^ @since 4.0.0.0)-- The list of constructors could be an array, a balanced tree, or others.-- | Public representation of constructorsdataConstrRep =AlgConstr ConIndex |IntConstr Integer|FloatConstr Rational |CharConstr Charderiving(Eq-- ^ @since 4.0.0.0,Show -- ^ @since 4.0.0.0)-- | Unique index for datatype constructors,-- counting from 1 in the order they are given in the program text.typeConIndex =Int-- | Fixity of constructorsdataFixity =Prefix |Infix -- Later: add associativity and precedencederiving(Eq-- ^ @since 4.0.0.0,Show -- ^ @since 4.0.0.0)---------------------------------------------------------------------------------- Observers for datatype representations---------------------------------------------------------------------------------- | Gets the type constructor including the moduledataTypeName::DataType ->String dataTypeName =tycon-- | Gets the public presentation of a datatypedataTypeRep::DataType ->DataRep dataTypeRep =datarep-- | Gets the datatype of a constructorconstrType::Constr ->DataType constrType =datatype-- | Gets the public presentation of constructorsconstrRep::Constr ->ConstrRep constrRep =conrep-- | Look up a constructor by its representationrepConstr::DataType ->ConstrRep ->Constr repConstr dt cr =case(dataTypeRep dt ,cr )of(AlgRep cs ,AlgConstr i )->cs !! (i -1)(IntRep ,IntConstr i )->mkIntegralConstr dt i (FloatRep ,FloatConstr f )->mkRealConstr dt f (CharRep ,CharConstr c )->mkCharConstr dt c _->errorWithoutStackTrace "Data.Data.repConstr: The given ConstrRep does not fit to the given DataType."---------------------------------------------------------------------------------- Representations of algebraic data types---------------------------------------------------------------------------------- | Constructs an algebraic datatypemkDataType::String ->[Constr ]->DataType mkDataType str cs =DataType {tycon=str ,datarep=AlgRep cs }-- | Constructs a constructormkConstr::DataType ->String ->[String ]->Fixity ->Constr mkConstr dt str fields fix =Constr {conrep=AlgConstr idx ,constring=str ,confields=fields ,confixity=fix ,datatype=dt }whereidx =head [i |(c ,i )<-dataTypeConstrs dt `zip `[1..],showConstr c ==str ]-- | Gets the constructors of an algebraic datatypedataTypeConstrs::DataType ->[Constr ]dataTypeConstrs dt =casedatarepdt of(AlgRep cons )->cons _->errorWithoutStackTrace $ "Data.Data.dataTypeConstrs is not supported for "++ dataTypeName dt ++ ", as it is not an algebraic data type."-- | Gets the field labels of a constructor. The list of labels-- is returned in the same order as they were given in the original-- constructor declaration.constrFields::Constr ->[String ]constrFields =confields-- | Gets the fixity of a constructorconstrFixity::Constr ->Fixity constrFixity =confixity---------------------------------------------------------------------------------- From strings to constr's and vice versa: all data types---------------------------------------------------------------------------------- | Gets the string for a constructorshowConstr::Constr ->String showConstr =constring-- | Lookup a constructor via a stringreadConstr::DataType ->String ->Maybe Constr readConstr dt str =casedataTypeRep dt ofAlgRep cons ->idx cons IntRep ->mkReadCon (\i ->(mkPrimCon dt str (IntConstr i )))FloatRep ->mkReadCon ffloat CharRep ->mkReadCon (\c ->(mkPrimCon dt str (CharConstr c )))NoRep ->Nothing where-- Read a value and build a constructormkReadCon::Read t =>(t ->Constr )->Maybe Constr mkReadCon f =case(reads str )of[(t ,"")]->Just (f t )_->Nothing -- Traverse list of algebraic datatype constructorsidx::[Constr ]->Maybe Constr idx cons =letfit =filter ((==)str . showConstr )cons iniffit ==[]thenNothing elseJust (head fit )ffloat::Double->Constr ffloat =mkPrimCon dt str . FloatConstr . toRational ---------------------------------------------------------------------------------- Convenience functions: algebraic data types---------------------------------------------------------------------------------- | Test for an algebraic typeisAlgType::DataType ->BoolisAlgType dt =casedatarepdt of(AlgRep _)->True_->False-- | Gets the constructor for an index (algebraic datatypes only)indexConstr::DataType ->ConIndex ->Constr indexConstr dt idx =casedatarepdt of(AlgRep cs )->cs !! (idx -1)_->errorWithoutStackTrace $ "Data.Data.indexConstr is not supported for "++ dataTypeName dt ++ ", as it is not an algebraic data type."-- | Gets the index of a constructor (algebraic datatypes only)constrIndex::Constr ->ConIndex constrIndex con =caseconstrRep con of(AlgConstr idx )->idx _->errorWithoutStackTrace $ "Data.Data.constrIndex is not supported for "++ dataTypeName (constrType con )++ ", as it is not an algebraic data type."-- | Gets the maximum constructor index of an algebraic datatypemaxConstrIndex::DataType ->ConIndex maxConstrIndex dt =casedataTypeRep dt ofAlgRep cs ->length cs _->errorWithoutStackTrace $ "Data.Data.maxConstrIndex is not supported for "++ dataTypeName dt ++ ", as it is not an algebraic data type."---------------------------------------------------------------------------------- Representation of primitive types---------------------------------------------------------------------------------- | Constructs the 'Int' typemkIntType::String ->DataType mkIntType =mkPrimType IntRep -- | Constructs the 'Float' typemkFloatType::String ->DataType mkFloatType =mkPrimType FloatRep -- | Constructs the 'Char' typemkCharType::String ->DataType mkCharType =mkPrimType CharRep -- | Helper for 'mkIntType', 'mkFloatType'mkPrimType::DataRep ->String ->DataType mkPrimType dr str =DataType {tycon=str ,datarep=dr }-- Makes a constructor for primitive typesmkPrimCon::DataType ->String ->ConstrRep ->Constr mkPrimCon dt str cr =Constr {datatype=dt ,conrep=cr ,constring=str ,confields=errorWithoutStackTrace "Data.Data.confields",confixity=errorWithoutStackTrace "Data.Data.confixity"}mkIntegralConstr::(Integral a ,Show a )=>DataType ->a ->Constr mkIntegralConstr dt i =casedatarepdt ofIntRep ->mkPrimCon dt (show i )(IntConstr (toInteger i ))_->errorWithoutStackTrace $ "Data.Data.mkIntegralConstr is not supported for "++ dataTypeName dt ++ ", as it is not an Integral data type."mkRealConstr::(Real a ,Show a )=>DataType ->a ->Constr mkRealConstr dt f =casedatarepdt ofFloatRep ->mkPrimCon dt (show f )(FloatConstr (toRational f ))_->errorWithoutStackTrace $ "Data.Data.mkRealConstr is not supported for "++ dataTypeName dt ++ ", as it is not a Real data type."-- | Makes a constructor for 'Char'.mkCharConstr::DataType ->Char->Constr mkCharConstr dt c =casedatarepdt ofCharRep ->mkPrimCon dt (show c )(CharConstr c )_->errorWithoutStackTrace $ "Data.Data.mkCharConstr is not supported for "++ dataTypeName dt ++ ", as it is not an Char data type."---------------------------------------------------------------------------------- Non-representations for non-representable types---------------------------------------------------------------------------------- | Constructs a non-representation for a non-representable typemkNoRepType::String ->DataType mkNoRepType str =DataType {tycon=str ,datarep=NoRep }-- | Test for a non-representable typeisNorepType::DataType ->BoolisNorepType dt =casedatarepdt ofNoRep ->True_->False---------------------------------------------------------------------------------- Convenience for qualified type constructors---------------------------------------------------------------------------------- | Gets the unqualified type constructor:-- drop *.*.*... before name--tyconUQname::String ->String tyconUQname x =letx' =dropWhile (not. (==)'.')x inifx' ==[]thenx elsetyconUQname (tail x' )-- | Gets the module of a type constructor:-- take *.*.*... before nametyconModule::String ->String tyconModule x =let(a ,b )=break ((==)'.')x inifb ==""thenb elsea ++ tyconModule' (tail b )wheretyconModule' y =lety' =tyconModule y inify' ==""then""else('.':y' )---------------------------------------------------------------------------------------------------------------------------------------------------------------- Instances of the Data class for Prelude-like types.-- We define top-level definitions for representations.---------------------------------------------------------------------------------- | @since 4.0.0.0derivinginstanceData Bool------------------------------------------------------------------------------charType::DataType charType =mkCharType "Prelude.Char"-- | @since 4.0.0.0instanceData CharwheretoConstr x =mkCharConstr charType x gunfold _z c =caseconstrRep c of(CharConstr x )->z x _->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Char."dataTypeOf _=charType ------------------------------------------------------------------------------floatType::DataType floatType =mkFloatType "Prelude.Float"-- | @since 4.0.0.0instanceData FloatwheretoConstr =mkRealConstr floatType gunfold _z c =caseconstrRep c of(FloatConstr x )->z (realToFrac x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Float."dataTypeOf _=floatType ------------------------------------------------------------------------------doubleType::DataType doubleType =mkFloatType "Prelude.Double"-- | @since 4.0.0.0instanceData DoublewheretoConstr =mkRealConstr doubleType gunfold _z c =caseconstrRep c of(FloatConstr x )->z (realToFrac x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Double."dataTypeOf _=doubleType ------------------------------------------------------------------------------intType::DataType intType =mkIntType "Prelude.Int"-- | @since 4.0.0.0instanceData IntwheretoConstr x =mkIntegralConstr intType x gunfold _z c =caseconstrRep c of(IntConstr x )->z (fromIntegral x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Int."dataTypeOf _=intType ------------------------------------------------------------------------------integerType::DataType integerType =mkIntType "Prelude.Integer"-- | @since 4.0.0.0instanceData IntegerwheretoConstr =mkIntegralConstr integerType gunfold _z c =caseconstrRep c of(IntConstr x )->z x _->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Integer."dataTypeOf _=integerType -------------------------------------------------------------------------------- This follows the same style as the other integral 'Data' instances-- defined in "Data.Data"naturalType::DataType naturalType =mkIntType "Numeric.Natural.Natural"-- | @since 4.8.0.0instanceData Natural wheretoConstr x =mkIntegralConstr naturalType x gunfold _z c =caseconstrRep c of(IntConstr x )->z (fromIntegral x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Natural"dataTypeOf _=naturalType ------------------------------------------------------------------------------int8Type::DataType int8Type =mkIntType "Data.Int.Int8"-- | @since 4.0.0.0instanceData Int8 wheretoConstr x =mkIntegralConstr int8Type x gunfold _z c =caseconstrRep c of(IntConstr x )->z (fromIntegral x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Int8."dataTypeOf _=int8Type ------------------------------------------------------------------------------int16Type::DataType int16Type =mkIntType "Data.Int.Int16"-- | @since 4.0.0.0instanceData Int16 wheretoConstr x =mkIntegralConstr int16Type x gunfold _z c =caseconstrRep c of(IntConstr x )->z (fromIntegral x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Int16."dataTypeOf _=int16Type ------------------------------------------------------------------------------int32Type::DataType int32Type =mkIntType "Data.Int.Int32"-- | @since 4.0.0.0instanceData Int32 wheretoConstr x =mkIntegralConstr int32Type x gunfold _z c =caseconstrRep c of(IntConstr x )->z (fromIntegral x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Int32."dataTypeOf _=int32Type ------------------------------------------------------------------------------int64Type::DataType int64Type =mkIntType "Data.Int.Int64"-- | @since 4.0.0.0instanceData Int64 wheretoConstr x =mkIntegralConstr int64Type x gunfold _z c =caseconstrRep c of(IntConstr x )->z (fromIntegral x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Int64."dataTypeOf _=int64Type ------------------------------------------------------------------------------wordType::DataType wordType =mkIntType "Data.Word.Word"-- | @since 4.0.0.0instanceData WordwheretoConstr x =mkIntegralConstr wordType x gunfold _z c =caseconstrRep c of(IntConstr x )->z (fromIntegral x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Word"dataTypeOf _=wordType ------------------------------------------------------------------------------word8Type::DataType word8Type =mkIntType "Data.Word.Word8"-- | @since 4.0.0.0instanceData Word8 wheretoConstr x =mkIntegralConstr word8Type x gunfold _z c =caseconstrRep c of(IntConstr x )->z (fromIntegral x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Word8."dataTypeOf _=word8Type ------------------------------------------------------------------------------word16Type::DataType word16Type =mkIntType "Data.Word.Word16"-- | @since 4.0.0.0instanceData Word16 wheretoConstr x =mkIntegralConstr word16Type x gunfold _z c =caseconstrRep c of(IntConstr x )->z (fromIntegral x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Word16."dataTypeOf _=word16Type ------------------------------------------------------------------------------word32Type::DataType word32Type =mkIntType "Data.Word.Word32"-- | @since 4.0.0.0instanceData Word32 wheretoConstr x =mkIntegralConstr word32Type x gunfold _z c =caseconstrRep c of(IntConstr x )->z (fromIntegral x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Word32."dataTypeOf _=word32Type ------------------------------------------------------------------------------word64Type::DataType word64Type =mkIntType "Data.Word.Word64"-- | @since 4.0.0.0instanceData Word64 wheretoConstr x =mkIntegralConstr word64Type x gunfold _z c =caseconstrRep c of(IntConstr x )->z (fromIntegral x )_->errorWithoutStackTrace $ "Data.Data.gunfold: Constructor "++ show c ++ " is not of type Word64."dataTypeOf _=word64Type ------------------------------------------------------------------------------ratioConstr::Constr ratioConstr =mkConstr ratioDataType ":%"[]Infix ratioDataType::DataType ratioDataType =mkDataType "GHC.Real.Ratio"[ratioConstr ]-- NB: This Data instance intentionally uses the (%) smart constructor instead-- of the internal (:%) constructor to preserve the invariant that a Ratio-- value is reduced to normal form. See Trac #10011.-- | @since 4.0.0.0instance(Data a ,Integral a )=>Data (Ratio a )wheregfoldl k z (a :% b )=z (% )`k `a `k `b toConstr _=ratioConstr gunfold k z c |constrIndex c ==1=k (k (z (% )))gunfold___=errorWithoutStackTrace "Data.Data.gunfold(Ratio)"dataTypeOf _=ratioDataType ------------------------------------------------------------------------------nilConstr::Constr nilConstr =mkConstr listDataType "[]"[]Prefix consConstr::Constr consConstr =mkConstr listDataType "(:)"[]Infix listDataType::DataType listDataType =mkDataType "Prelude.[]"[nilConstr ,consConstr ]-- | @since 4.0.0.0instanceData a =>Data [a ]wheregfoldl _z []=z []gfoldlf z (x :xs )=z (:)`f `x `f `xs toConstr []=nilConstr toConstr(_:_)=consConstr gunfold k z c =caseconstrIndex c of1->z []2->k (k (z (:)))_->errorWithoutStackTrace "Data.Data.gunfold(List)"dataTypeOf _=listDataType dataCast1 f =gcast1 f ---- The gmaps are given as an illustration.-- This shows that the gmaps for lists are different from list maps.--gmapT _[]=[]gmapTf (x :xs )=(f x :f xs )gmapQ _[]=[]gmapQf (x :xs )=[f x ,f xs ]gmapM _[]=return []gmapMf (x :xs )=f x >>= \x' ->f xs >>= \xs' ->return (x' :xs' )-------------------------------------------------------------------------------- | @since 4.9.0.0derivinginstanceData a =>Data (NonEmpty a )-- | @since 4.0.0.0derivinginstanceData a =>Data (Maybe a )-- | @since 4.0.0.0derivinginstanceData Ordering-- | @since 4.0.0.0derivinginstance(Data a ,Data b )=>Data (Either a b )-- | @since 4.0.0.0derivinginstanceData ()-- | @since 4.0.0.0derivinginstance(Data a ,Data b )=>Data (a ,b )-- | @since 4.0.0.0derivinginstance(Data a ,Data b ,Data c )=>Data (a ,b ,c )-- | @since 4.0.0.0derivinginstance(Data a ,Data b ,Data c ,Data d )=>Data (a ,b ,c ,d )-- | @since 4.0.0.0derivinginstance(Data a ,Data b ,Data c ,Data d ,Data e )=>Data (a ,b ,c ,d ,e )-- | @since 4.0.0.0derivinginstance(Data a ,Data b ,Data c ,Data d ,Data e ,Data f )=>Data (a ,b ,c ,d ,e ,f )-- | @since 4.0.0.0derivinginstance(Data a ,Data b ,Data c ,Data d ,Data e ,Data f ,Data g )=>Data (a ,b ,c ,d ,e ,f ,g )-------------------------------------------------------------------------------- | @since 4.8.0.0instanceData a =>Data (Ptr a )wheretoConstr _=errorWithoutStackTrace "Data.Data.toConstr(Ptr)"gunfold __=errorWithoutStackTrace "Data.Data.gunfold(Ptr)"dataTypeOf _=mkNoRepType "GHC.Ptr.Ptr"dataCast1 x =gcast1 x -------------------------------------------------------------------------------- | @since 4.8.0.0instanceData a =>Data (ForeignPtr a )wheretoConstr _=errorWithoutStackTrace "Data.Data.toConstr(ForeignPtr)"gunfold __=errorWithoutStackTrace "Data.Data.gunfold(ForeignPtr)"dataTypeOf _=mkNoRepType "GHC.ForeignPtr.ForeignPtr"dataCast1 x =gcast1 x -- | @since 4.11.0.0derivinginstanceData IntPtr -- | @since 4.11.0.0derivinginstanceData WordPtr -------------------------------------------------------------------------------- The Data instance for Array preserves data abstraction at the cost of-- inefficiency. We omit reflection services for the sake of data abstraction.-- | @since 4.8.0.0instance(Data a ,Data b ,Ix a )=>Data (Array a b )wheregfoldl f z a =z (listArray (bounds a ))`f `(elems a )toConstr _=errorWithoutStackTrace "Data.Data.toConstr(Array)"gunfold __=errorWithoutStackTrace "Data.Data.gunfold(Array)"dataTypeOf _=mkNoRepType "Data.Array.Array"dataCast2 x =gcast2 x ------------------------------------------------------------------------------ Data instance for Proxy-- | @since 4.7.0.0derivinginstance(Data t )=>Data (Proxy t )-- | @since 4.7.0.0derivinginstance(a ~b ,Data a )=>Data (a :~: b )-- | @since 4.10.0.0derivinginstance(Typeable i ,Typeable j ,Typeable a ,Typeable b ,(a ::i )~~(b ::j ))=>Data (a :~~: b )-- | @since 4.7.0.0derivinginstance(Coerciblea b ,Data a ,Data b )=>Data (Coercion a b )-- | @since 4.9.0.0derivinginstanceData a =>Data (Identity a )-- | @since 4.10.0.0derivinginstance(Typeable k ,Data a ,Typeable (b ::k ))=>Data (Const a b )-- | @since 4.7.0.0derivinginstanceData Version ------------------------------------------------------------------------------ Data instances for Data.Monoid wrappers-- | @since 4.8.0.0derivinginstanceData a =>Data (Dual a )-- | @since 4.8.0.0derivinginstanceData All -- | @since 4.8.0.0derivinginstanceData Any -- | @since 4.8.0.0derivinginstanceData a =>Data (Sum a )-- | @since 4.8.0.0derivinginstanceData a =>Data (Product a )-- | @since 4.8.0.0derivinginstanceData a =>Data (First a )-- | @since 4.8.0.0derivinginstanceData a =>Data (Last a )-- | @since 4.8.0.0derivinginstance(Data (f a ),Data a ,Typeable f )=>Data (Alt f a )-- | @since 4.12.0.0derivinginstance(Data (f a ),Data a ,Typeable f )=>Data (Ap f a )------------------------------------------------------------------------------ Data instances for GHC.Generics representations-- | @since 4.9.0.0derivinginstanceData p =>Data (U1 p )-- | @since 4.9.0.0derivinginstanceData p =>Data (Par1 p )-- | @since 4.9.0.0derivinginstance(Data (f p ),Typeable f ,Data p )=>Data (Rec1 f p )-- | @since 4.9.0.0derivinginstance(Typeable i ,Data p ,Data c )=>Data (K1 i c p )-- | @since 4.9.0.0derivinginstance(Data p ,Data (f p ),Typeable c ,Typeable i ,Typeable f )=>Data (M1 i c f p )-- | @since 4.9.0.0derivinginstance(Typeable f ,Typeable g ,Data p ,Data (f p ),Data (g p ))=>Data ((f :+: g )p )-- | @since 4.9.0.0derivinginstance(Typeable (f ::Type->Type),Typeable (g ::Type->Type),Data p ,Data (f (g p )))=>Data ((f :.: g )p )-- | @since 4.9.0.0derivinginstanceData p =>Data (V1 p )-- | @since 4.9.0.0derivinginstance(Typeable f ,Typeable g ,Data p ,Data (f p ),Data (g p ))=>Data ((f :*: g )p )-- | @since 4.9.0.0derivinginstanceData Generics.Fixity -- | @since 4.9.0.0derivinginstanceData Associativity -- | @since 4.9.0.0derivinginstanceData SourceUnpackedness -- | @since 4.9.0.0derivinginstanceData SourceStrictness -- | @since 4.9.0.0derivinginstanceData DecidedStrictness ------------------------------------------------------------------------------ Data instances for Data.Ord-- | @since 4.12.0.0derivinginstanceData a =>Data (Down a )