Language.Haskell.TH.Lens

Lenses, Prisms, and Traversals for working with Template Haskell.

Beware that the API offered in this module is subject to change, as it mirrors the API exposed by the template-haskell package, which frequently changes between different releases of GHC. An effort is made to identify the functions in this module which have different type signatures when compiled with different versions of template-haskell.

Traversals

class HasName t where

Has a Name

Methods

name :: Lens' t Name

Extract (or modify) the Name of something

Instances

HasName Name

Defined in Language.Haskell.TH.Lens

Methods

name :: Lens' Name Name

HasName InjectivityAnn

Defined in Language.Haskell.TH.Lens

Methods

name :: Lens' InjectivityAnn Name

HasName TypeFamilyHead

Defined in Language.Haskell.TH.Lens

Methods

name :: Lens' TypeFamilyHead Name

HasName Foreign

Defined in Language.Haskell.TH.Lens

Methods

name :: Lens' Foreign Name

HasName RuleBndr

Defined in Language.Haskell.TH.Lens

Methods

name :: Lens' RuleBndr Name

HasName Con

On template-haskell-2.11.0.0 or later, if a GadtC or RecGadtC has multiple Names, the leftmost Name will be chosen.

Defined in Language.Haskell.TH.Lens

Methods

name :: Lens' Con Name

HasName (TyVarBndr_ flag)

Defined in Language.Haskell.TH.Lens

Methods

name :: Lens' (TyVarBndr_ flag) Name

class HasTypes t where

Contains some amount of Types inside

Methods

types :: Traversal' t Type

Traverse all the types

Instances

HasTypes Type

Defined in Language.Haskell.TH.Lens

Methods

types :: Traversal' Type Type

HasTypes TySynEqn

Defined in Language.Haskell.TH.Lens

Methods

types :: Traversal' TySynEqn Type

HasTypes Foreign

Defined in Language.Haskell.TH.Lens

Methods

types :: Traversal' Foreign Type

HasTypes Con

Defined in Language.Haskell.TH.Lens

Methods

types :: Traversal' Con Type

HasTypes t => HasTypes [t]

Defined in Language.Haskell.TH.Lens

Methods

types :: Traversal' [t] Type

class HasTypeVars t where

Provides for the extraction of free type variables, and alpha renaming.

Methods

typeVarsEx :: Set Name -> Traversal' t Name

When performing substitution into this traversal you're not allowed to substitute in a name that is bound internally or you'll violate the Traversal laws, when in doubt generate your names with newName.

Instances

HasTypeVars Type

Defined in Language.Haskell.TH.Lens

Methods

typeVarsEx :: Set Name -> Traversal' Type Name

HasTypeVars Name

Defined in Language.Haskell.TH.Lens

Methods

typeVarsEx :: Set Name -> Traversal' Name Name

HasTypeVars Con

Defined in Language.Haskell.TH.Lens

Methods

typeVarsEx :: Set Name -> Traversal' Con Name

HasTypeVars t => HasTypeVars [t]

Defined in Language.Haskell.TH.Lens

Methods

typeVarsEx :: Set Name -> Traversal' [t] Name

HasTypeVars t => HasTypeVars (Maybe t)

Defined in Language.Haskell.TH.Lens

Methods

typeVarsEx :: Set Name -> Traversal' (Maybe t) Name

HasTypeVars (TyVarBndr_ flag)

Defined in Language.Haskell.TH.Lens

Methods

typeVarsEx :: Set Name -> Traversal' (TyVarBndr_ flag) Name

class SubstType t where

Provides substitution for types

Methods

substType :: Map Name Type -> t -> t

Perform substitution for types

Instances

SubstType Type

Defined in Language.Haskell.TH.Lens

Methods

substType :: Map Name Type -> Type -> Type

SubstType t => SubstType [t]

Defined in Language.Haskell.TH.Lens

Methods

substType :: Map Name Type -> [t] -> [t]

typeVars :: HasTypeVars t => Traversal' t Name

Traverse free type variables

substTypeVars :: HasTypeVars t => Map Name Name -> t -> t

Substitute using a map of names in for free type variables

conFields :: Traversal' Con BangType

Provides a Traversal of the types of each field of a constructor.

conNamedFields :: Traversal' Con VarBangType

Traversal of the types of the named fields of a constructor.

Lenses

Loc Lenses

locFileName :: Lens' Loc String

locPackage :: Lens' Loc String

locModule :: Lens' Loc String

locStart :: Lens' Loc CharPos

locEnd :: Lens' Loc CharPos

FunDep Lenses

funDepInputs :: Lens' FunDep [Name]

funDepOutputs :: Lens' FunDep [Name]

Match Lenses

matchPattern :: Lens' Match Pat

matchBody :: Lens' Match Body

matchDeclarations :: Lens' Match [Dec]

Fixity Lenses

fixityPrecedence :: Lens' Fixity Int

fixityDirection :: Lens' Fixity FixityDirection

Clause Lenses

clausePattern :: Lens' Clause [Pat]

clauseBody :: Lens' Clause Body

clauseDecs :: Lens' Clause [Dec]

FieldExp Lenses

fieldExpName :: Lens' FieldExp Name

fieldExpExpression :: Lens' FieldExp Exp

FieldPat Lenses

fieldPatName :: Lens' FieldPat Name

fieldPatPattern :: Lens' FieldPat Pat

TySynEqn Lenses

tySynEqnLHS :: Lens' TySynEqn Type

tySynEqnPatterns :: Lens' TySynEqn [Type]

tySynEqnResult :: Lens' TySynEqn Type

InjectivityAnn Lenses

injectivityAnnOutput :: Lens' InjectivityAnn Name

injectivityAnnInputs :: Lens' InjectivityAnn [Name]

TypeFamilyHead Lenses

typeFamilyHeadName :: Lens' TypeFamilyHead Name

typeFamilyHeadTyVarBndrs :: Lens' TypeFamilyHead [TyVarBndrUnit]

typeFamilyHeadResultSig :: Lens' TypeFamilyHead FamilyResultSig

typeFamilyHeadInjectivityAnn :: Lens' TypeFamilyHead (Maybe InjectivityAnn)

Bang Lenses

bangSourceUnpackedness :: Lens' Bang SourceUnpackedness

bangSourceStrictness :: Lens' Bang SourceStrictness

DerivClause Lenses

derivClauseStrategy :: Lens' DerivClause (Maybe DerivStrategy)

derivClauseCxt :: Lens' DerivClause Cxt

Prisms

Info Prisms

_ClassI :: Prism' Info (Dec, [InstanceDec])

_ClassOpI :: Prism' Info (Name, Type, ParentName)

_TyConI :: Prism' Info Dec

_FamilyI :: Prism' Info (Dec, [InstanceDec])

_PrimTyConI :: Prism' Info (Name, Arity, Unlifted)

_DataConI :: Prism' Info (Name, Type, ParentName)

_VarI :: Prism' Info (Name, Type, Maybe Dec)

_TyVarI :: Prism' Info (Name, Type)

_PatSynI :: Prism' Info (Name, PatSynType)

Dec Prisms

_FunD :: Prism' Dec (Name, [Clause])

_ValD :: Prism' Dec (Pat, Body, [Dec])

_DataD :: DataPrism' [TyVarBndrUnit] [Con]

_DataD :: Prism' Dec (Cxt, Name, [TyVarBndrUnit], Maybe Kind, [Con], [DerivClause]) -- template-haskell-2.12+
_DataD :: Prism' Dec (Cxt, Name, [Type],          Maybe Kind, [Con], Cxt)           -- Earlier versions

_NewtypeD :: DataPrism' [TyVarBndrUnit] Con

_NewtypeD :: Prism' Dec (Cxt, Name, [TyVarBndrUnit], Maybe Kind, Con, [DerivClause]) -- template-haskell-2.12+
_NewtypeD :: Prism' Dec (Cxt, Name, [Type],          Maybe Kind, Con, Cxt)           -- Earlier versions

_TySynD :: Prism' Dec (Name, [TyVarBndrUnit], Type)

_ClassD :: Prism' Dec (Cxt, Name, [TyVarBndrUnit], [FunDep], [Dec])

_InstanceD :: Prism' Dec (Maybe Overlap, Cxt, Type, [Dec])

_SigD :: Prism' Dec (Name, Type)

_ForeignD :: Prism' Dec Foreign

_InfixD :: Prism' Dec (Fixity, Name)

_PragmaD :: Prism' Dec Pragma

_DataInstD :: Prism' Dec (Cxt, Maybe [TyVarBndrUnit], Type, Maybe Kind, [Con], [DerivClause])

_DataInstD :: Prism' Dec (Cxt, Maybe [TyVarBndrUnit], Type, Maybe Kind, [Con], [DerivClause]) -- template-haskell-2.15+
_DataInstD :: Prism' Dec (Cxt, Name, [Type],                Maybe Kind, [Con], [DerivClause]) -- template-haskell-2.12 through 2.14
_DataInstD :: Prism' Dec (Cxt, Name, [Type],                Maybe Kind, [Con], Cxt)           -- Earlier versions

_NewtypeInstD :: Prism' Dec (Cxt, Maybe [TyVarBndrUnit], Type, Maybe Kind, Con, [DerivClause])

_NewtypeInstD :: Prism' Dec (Cxt, Maybe [TyVarBndrUnit], Type, Maybe Kind, Con, [DerivClause]) -- template-haskell-2.15+
_NewtypeInstD :: Prism' Dec (Cxt, Name, [Type],                Maybe Kind, Con, [DerivClause]) -- template-haskell-2.12 through 2.14
_NewtypeInstD :: Prism' Dec (Cxt, Name, [Type],                Maybe Kind, Con, Cxt)           -- Earlier versions

_TySynInstD :: Prism' Dec TySynEqn

_TySynInstD :: Prism' Dec TySynEqn             -- template-haskell-2.15+
_TySynInstD :: Prism' Dec (Name, TySynEqn)     -- template-haskell-2.9 through 2.14
_TySynInstD :: Prism' Dec (Name, [Type], Type) -- Earlier versions

_ClosedTypeFamilyD :: Prism' Dec (TypeFamilyHead, [TySynEqn])

_RoleAnnotD :: Prism' Dec (Name, [Role])

_StandaloneDerivD :: Prism' Dec (Maybe DerivStrategy, Cxt, Type)

_StandaloneDerivD :: Prism' Dec (Maybe DerivStrategy, Cxt, Type) -- template-haskell-2.12+
_StandaloneDerivD :: Prism' Dec                      (Cxt, Type) -- Earlier versions

_DefaultSigD :: Prism' Dec (Name, Type)

_DataFamilyD :: Prism' Dec (Name, [TyVarBndrUnit], Maybe Kind)

_OpenTypeFamilyD :: Prism' Dec TypeFamilyHead

_PatSynD :: Prism' Dec (Name, PatSynArgs, PatSynDir, Pat)

_PatSynSigD :: Prism' Dec (Name, PatSynType)

_ImplicitParamBindD :: Prism' Dec (String, Exp)

PatSynDir Prisms

_Unidir :: Prism' PatSynDir ()

_ImplBidir :: Prism' PatSynDir ()

_ExplBidir :: Prism' PatSynDir [Clause]

PatSynArgs Prisms

_PrefixPatSyn :: Prism' PatSynArgs [Name]

_InfixPatSyn :: Prism' PatSynArgs (Name, Name)

_RecordPatSyn :: Prism' PatSynArgs [Name]

Con Prisms

_NormalC :: Prism' Con (Name, [BangType])

_RecC :: Prism' Con (Name, [VarBangType])

_InfixC :: Prism' Con (BangType, Name, BangType)

_ForallC :: Prism' Con ([TyVarBndrSpec], Cxt, Con)

_GadtC :: Prism' Con ([Name], [BangType], Type)

_RecGadtC :: Prism' Con ([Name], [VarBangType], Type)

Overlap Prisms

_Overlappable :: Prism' Overlap ()

_Overlapping :: Prism' Overlap ()

_Overlaps :: Prism' Overlap ()

_Incoherent :: Prism' Overlap ()

SourceUnpackedness Prisms

_NoSourceUnpackedness :: Prism' SourceUnpackedness ()

_SourceNoUnpack :: Prism' SourceUnpackedness ()

_SourceUnpack :: Prism' SourceUnpackedness ()

SourceStrictness Prisms

_NoSourceStrictness :: Prism' SourceStrictness ()

_SourceLazy :: Prism' SourceStrictness ()

_SourceStrict :: Prism' SourceStrictness ()

DecidedStrictness Prisms

_DecidedLazy :: Prism' DecidedStrictness ()

_DecidedStrict :: Prism' DecidedStrictness ()

_DecidedUnpack :: Prism' DecidedStrictness ()

Foreign Prisms

_ImportF :: Prism' Foreign (Callconv, Safety, String, Name, Type)

_ExportF :: Prism' Foreign (Callconv, String, Name, Type)

Callconv Prisms

_CCall :: Prism' Callconv ()

_StdCall :: Prism' Callconv ()

_CApi :: Prism' Callconv ()

_Prim :: Prism' Callconv ()

_JavaScript :: Prism' Callconv ()

Safety Prisms

_Unsafe :: Prism' Safety ()

_Safe :: Prism' Safety ()

_Interruptible :: Prism' Safety ()

Pragma Prisms

_InlineP :: Prism' Pragma (Name, Inline, RuleMatch, Phases)

_SpecialiseP :: Prism' Pragma (Name, Type, Maybe Inline, Phases)

_SpecialiseInstP :: Prism' Pragma Type

_RuleP :: Prism' Pragma (String, Maybe [TyVarBndrUnit], [RuleBndr], Exp, Exp, Phases)

_RuleP :: Prism' Pragma (String, Maybe [TyVarBndrUnit], [RuleBndr], Exp, Exp, Phases) -- template-haskell-2.15+
_RuleP :: Prism' Pragma (String,                        [RuleBndr], Exp, Exp, Phases) -- Earlier versions

_AnnP :: Prism' Pragma (AnnTarget, Exp)

_LineP :: Prism' Pragma (Int, String)

_CompleteP :: Prism' Pragma ([Name], Maybe Name)

Inline Prisms

_NoInline :: Prism' Inline ()

_Inline :: Prism' Inline ()

_Inlinable :: Prism' Inline ()

RuleMatch Prisms

_ConLike :: Prism' RuleMatch ()

_FunLike :: Prism' RuleMatch ()

Phases Prisms

_AllPhases :: Prism' Phases ()

_FromPhase :: Prism' Phases Int

_BeforePhase :: Prism' Phases Int

RuleBndr Prisms

_RuleVar :: Prism' RuleBndr Name

_TypedRuleVar :: Prism' RuleBndr (Name, Type)

AnnTarget Prisms

_ModuleAnnotation :: Prism' AnnTarget ()

_TypeAnnotation :: Prism' AnnTarget Name

_ValueAnnotation :: Prism' AnnTarget Name

FunDep Prisms TODO make a lens

_FunDep :: Iso' FunDep ([Name], [Name])

FixityDirection Prisms

_InfixL :: Prism' FixityDirection ()

_InfixR :: Prism' FixityDirection ()

_InfixN :: Prism' FixityDirection ()

Exp Prisms

_VarE :: Prism' Exp Name

_ConE :: Prism' Exp Name

_LitE :: Prism' Exp Lit

_AppE :: Prism' Exp (Exp, Exp)

_AppTypeE :: Prism' Exp (Exp, Type)

_InfixE :: Prism' Exp (Maybe Exp, Exp, Maybe Exp)

_UInfixE :: Prism' Exp (Exp, Exp, Exp)

_ParensE :: Prism' Exp Exp

_LamE :: Prism' Exp ([Pat], Exp)

_LamCaseE :: Prism' Exp [Match]

_TupE :: Prism' Exp [Maybe Exp]

_TupE :: Prism' Exp [Maybe Exp] -- template-haskell-2.16+
_TupE :: Prism' Exp [Exp]       -- Earlier versions

_UnboxedTupE :: Prism' Exp [Maybe Exp]

_UnboxedTupE :: Prism' Exp [Maybe Exp] -- template-haskell-2.16+
_UnboxedTupE :: Prism' Exp [Exp]       -- Earlier versions

_UnboxedSumE :: Prism' Exp (Exp, SumAlt, SumArity)

_CondE :: Prism' Exp (Exp, Exp, Exp)

_MultiIfE :: Prism' Exp [(Guard, Exp)]

_LetE :: Prism' Exp ([Dec], Exp)

_CaseE :: Prism' Exp (Exp, [Match])

_DoE :: Prism' Exp [Stmt]

_DoE :: Prism' Exp (Maybe ModName, [Stmt]) -- template-haskell-2.17+
_DoE :: Prism' Exp [Stmt]                  -- Earlier versions

_CompE :: Prism' Exp [Stmt]

_ArithSeqE :: Prism' Exp Range

_ListE :: Prism' Exp [Exp]

_SigE :: Prism' Exp (Exp, Type)

_RecConE :: Prism' Exp (Name, [FieldExp])

_RecUpdE :: Prism' Exp (Exp, [FieldExp])

_StaticE :: Prism' Exp Exp

_UnboundVarE :: Prism' Exp Name

_LabelE :: Prism' Exp String

_MDoE :: Prism' Exp [Stmt]

_MDoE :: Prism' Exp (Maybe ModName, [Stmt]) -- template-haskell-2.17+
_MDoE :: Prism' Exp [Stmt]                  -- Earlier versions

_ImplicitParamVarE :: Prism' Exp String

Body Prisms

_GuardedB :: Prism' Body [(Guard, Exp)]

_NormalB :: Prism' Body Exp

Guard Prisms

_NormalG :: Prism' Guard Exp

_PatG :: Prism' Guard [Stmt]

Stmt Prisms

_BindS :: Prism' Stmt (Pat, Exp)

_LetS :: Prism' Stmt [Dec]

_NoBindS :: Prism' Stmt Exp

_ParS :: Prism' Stmt [[Stmt]]

_RecS :: Prism' Stmt [Stmt]

Range Prisms

_FromR :: Prism' Range Exp

_FromThenR :: Prism' Range (Exp, Exp)

_FromToR :: Prism' Range (Exp, Exp)

_FromThenToR :: Prism' Range (Exp, Exp, Exp)

Lit Prisms

_CharL :: Prism' Lit Char

_StringL :: Prism' Lit String

_IntegerL :: Prism' Lit Integer

_RationalL :: Prism' Lit Rational

_IntPrimL :: Prism' Lit Integer

_WordPrimL :: Prism' Lit Integer

_FloatPrimL :: Prism' Lit Rational

_DoublePrimL :: Prism' Lit Rational

_StringPrimL :: Prism' Lit [Word8]

_CharPrimL :: Prism' Lit Char

_BytesPrimL :: Prism' Lit Bytes

Pat Prisms

_LitP :: Prism' Pat Lit

_VarP :: Prism' Pat Name

_TupP :: Prism' Pat [Pat]

_UnboxedTupP :: Prism' Pat [Pat]

_UnboxedSumP :: Prism' Pat (Pat, SumAlt, SumArity)

_ConP :: Prism' Pat (Name, [Pat])

_ConP :: Prism' Pat (Name, [Type], [Pat]) -- template-haskell-2.18+
_ConP :: Prism' Pat (Name,         [Pat]) -- Earlier versions

_InfixP :: Prism' Pat (Pat, Name, Pat)

_UInfixP :: Prism' Pat (Pat, Name, Pat)

_ParensP :: Prism' Pat Pat

_TildeP :: Prism' Pat Pat

_BangP :: Prism' Pat Pat

_AsP :: Prism' Pat (Name, Pat)

_WildP :: Prism' Pat ()

_RecP :: Prism' Pat (Name, [FieldPat])

_ListP :: Prism' Pat [Pat]

_SigP :: Prism' Pat (Pat, Type)

_ViewP :: Prism' Pat (Exp, Pat)

Type Prisms

_ForallT :: Prism' Type ([TyVarBndrSpec], Cxt, Type)

_AppT :: Prism' Type (Type, Type)

_SigT :: Prism' Type (Type, Kind)

_VarT :: Prism' Type Name

_ConT :: Prism' Type Name

_PromotedT :: Prism' Type Name

_TupleT :: Prism' Type Int

_UnboxedTupleT :: Prism' Type Int

_UnboxedSumT :: Prism' Type SumArity

_ArrowT :: Prism' Type ()

_EqualityT :: Prism' Type ()

_ListT :: Prism' Type ()

_PromotedTupleT :: Prism' Type Int

_PromotedNilT :: Prism' Type ()

_PromotedConsT :: Prism' Type ()

_StarT :: Prism' Type ()

_ConstraintT :: Prism' Type ()

_LitT :: Prism' Type TyLit

_InfixT :: Prism' Type (Type, Name, Type)

_UInfixT :: Prism' Type (Type, Name, Type)

_ParensT :: Prism' Type Type

_WildCardT :: Prism' Type ()

_AppKindT :: Prism' Type (Type, Kind)

_ImplicitParamT :: Prism' Type (String, Type)

_ForallVisT :: Prism' Type ([TyVarBndrUnit], Type)

TyVarBndr Prisms

_PlainTV :: Prism' TyVarBndr Name

_PlainTV :: Prism' (TyVarBndr flag) (Name, flag) -- template-haskell-2.17+
_PlainTV :: Prism'  TyVarBndr        Name        -- Earlier versions

_KindedTV :: Prism' TyVarBndr (Name, Kind)

_KindedTV :: Prism' (TyVarBndr flag) (Name, flag, Kind) -- template-haskell-2.17+
_KindedTV :: Prism'  TyVarBndr       (Name,       Kind) -- Earlier versions

FamilyResultSig Prisms

_NoSig :: Prism' FamilyResultSig ()

_KindSig :: Prism' FamilyResultSig Kind

_TyVarSig :: Prism' FamilyResultSig TyVarBndrUnit

TyLit Prisms

_NumTyLit :: Prism' TyLit Integer

_StrTyLit :: Prism' TyLit String

Role Prisms

_NominalR :: Prism' Role ()

_RepresentationalR :: Prism' Role ()

_PhantomR :: Prism' Role ()

_InferR :: Prism' Role ()

DerivStrategy Prisms

_StockStrategy :: Prism' DerivStrategy ()

_AnyclassStrategy :: Prism' DerivStrategy ()

_NewtypeStrategy :: Prism' DerivStrategy ()