Language.Haskell.TH.Lens

lens-4.13.2.1: Lenses, Folds and Traversals

Copyright | (C) 2012-2016 Edward Kmett
License | BSD-style (see the file LICENSE)
Maintainer | Edward Kmett <ekmett@gmail.com>
Stability | experimental
Portability | TemplateHaskell
Safe Haskell | Trustworthy
Language | Haskell98

Language.Haskell.TH.Lens

Contents

- Traversals
- Lenses
  - Loc Lenses
  - FunDep Lenses
  - Match Lenses
  - Fixity Lenses
  - Clause Lenses
  - FieldExp Lenses
  - FieldPat Lenses
  - TySynEqn Lenses
- Prisms
  - Info Prisms
  - Dec Prisms
  - Con Prisms
  - Strict Prisms
  - Foreign Prisms
  - Callconv Prisms
  - Safety Prisms
  - Pragma Prisms
  - Inline Prisms
  - RuleMatch Prisms
  - Phases Prisms
  - RuleBndr Prisms
  - AnnTarget Prisms
  - FunDep Prisms TODO make a lens
  - FamFlavour Prisms
  - FixityDirection Prisms
  - Exp Prisms
  - Body Prisms
  - Guard Prisms
  - Stmt Prisms
  - Range Prisms
  - Lit Prisms
  - Pat Prisms
  - Type Prisms
  - TyVarBndr Prisms
  - TyLit Prisms
  - Role Prisms

Description

Lenses, Prisms, and Traversals for working with Template Haskell

Synopsis

- class HasName t where
  - name :: Lens' t Name
- class HasTypes t where
  - types :: Traversal' t Type
- class HasTypeVars t where
  - typeVarsEx :: Set Name -> Traversal' t Name
- class SubstType t where
  - substType :: Map Name Type -> t -> t
- typeVars :: HasTypeVars t => Traversal' t Name
- substTypeVars :: HasTypeVars t => Map Name Name -> t -> t
- conFields :: Traversal' Con StrictType
- conNamedFields :: Traversal' Con VarStrictType
- locFileName :: Lens' Loc String
- locPackage :: Lens' Loc String
- locModule :: Lens' Loc String
- locStart :: Lens' Loc CharPos
- locEnd :: Lens' Loc CharPos
- funDepInputs :: Lens' FunDep [Name]
- funDepOutputs :: Lens' FunDep [Name]
- matchPattern :: Lens' Match Pat
- matchBody :: Lens' Match Body
- matchDeclarations :: Lens' Match [Dec]
- fixityPrecedence :: Lens' Fixity Int
- fixityDirection :: Lens' Fixity FixityDirection
- clausePattern :: Lens' Clause [Pat]
- clauseBody :: Lens' Clause Body
- clauseDecs :: Lens' Clause [Dec]
- fieldExpName :: Lens' FieldExp Name
- fieldExpExpression :: Lens' FieldExp Exp
- fieldPatName :: Lens' FieldPat Name
- fieldPatPattern :: Lens' FieldPat Pat
- tySynEqnPatterns :: Lens' TySynEqn [Type]
- tySynEqnResult :: Lens' TySynEqn Type
- _ClassI :: Prism' Info (Dec, [InstanceDec])
- _ClassOpI :: Prism' Info (Name, Type, ParentName, Fixity)
- _TyConI :: Prism' Info Dec
- _FamilyI :: Prism' Info (Dec, [Dec])
- _PrimTyConI :: Prism' Info (Name, Arity, Unlifted)
- _DataConI :: Prism' Info (Name, Type, ParentName, Fixity)
- _VarI :: Prism' Info (Name, Type, Maybe Dec, Fixity)
- _TyVarI :: Prism' Info (Name, Type)
- _FunD :: Prism' Dec (Name, [Clause])
- _ValD :: Prism' Dec (Pat, Body, [Dec])
- _DataD :: Prism' Dec (Cxt, Name, [TyVarBndr], [Con], [Name])
- _NewtypeD :: Prism' Dec (Cxt, Name, [TyVarBndr], Con, [Name])
- _TySynD :: Prism' Dec (Name, [TyVarBndr], Type)
- _ClassD :: Prism' Dec (Cxt, Name, [TyVarBndr], [FunDep], [Dec])
- _InstanceD :: Prism' Dec (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, Name, [Type], [Con], [Name])
- _NewtypeInstD :: Prism' Dec (Cxt, Name, [Type], Con, [Name])
- _TySynInstD :: Prism' Dec (Name, TySynEqn)
- _ClosedTypeFamilyD :: Prism' Dec (Name, [TyVarBndr], Maybe Kind, [TySynEqn])
- _RoleAnnotD :: Prism' Dec (Name, [Role])
- _StandaloneDerivD :: Prism' Dec (Cxt, Type)
- _DefaultSigD :: Prism' Dec (Name, Type)
- _FamilyD :: Prism' Dec (FamFlavour, Name, [TyVarBndr], Maybe Kind)
- _NormalC :: Prism' Con (Name, [StrictType])
- _RecC :: Prism' Con (Name, [VarStrictType])
- _InfixC :: Prism' Con (StrictType, Name, StrictType)
- _ForallC :: Prism' Con ([TyVarBndr], Cxt, Con)
- _IsStrict :: Prism' Strict ()
- _NotStrict :: Prism' Strict ()
- _Unpacked :: Prism' Strict ()
- _ImportF :: Prism' Foreign (Callconv, Safety, String, Name, Type)
- _ExportF :: Prism' Foreign (Callconv, String, Name, Type)
- _CCall :: Prism' Callconv ()
- _StdCall :: Prism' Callconv ()
- _CApi :: Prism' Callconv ()
- _Prim :: Prism' Callconv ()
- _JavaScript :: Prism' Callconv ()
- _Unsafe :: Prism' Safety ()
- _Safe :: Prism' Safety ()
- _Interruptible :: Prism' Safety ()
- _InlineP :: Prism' Pragma (Name, Inline, RuleMatch, Phases)
- _SpecialiseP :: Prism' Pragma (Name, Type, Maybe Inline, Phases)
- _SpecialiseInstP :: Prism' Pragma Type
- _RuleP :: Prism' Pragma (String, [RuleBndr], Exp, Exp, Phases)
- _AnnP :: Prism' Pragma (AnnTarget, Exp)
- _LineP :: Prism' Pragma (Int, String)
- _NoInline :: Prism' Inline ()
- _Inline :: Prism' Inline ()
- _Inlinable :: Prism' Inline ()
- _ConLike :: Prism' RuleMatch ()
- _FunLike :: Prism' RuleMatch ()
- _AllPhases :: Prism' Phases ()
- _FromPhase :: Prism' Phases Int
- _BeforePhase :: Prism' Phases Int
- _RuleVar :: Prism' RuleBndr Name
- _TypedRuleVar :: Prism' RuleBndr (Name, Type)
- _ModuleAnnotation :: Prism' AnnTarget ()
- _TypeAnnotation :: Prism' AnnTarget Name
- _ValueAnnotation :: Prism' AnnTarget Name
- _FunDep :: Iso' FunDep ([Name], [Name])
- _TypeFam :: Prism' FamFlavour ()
- _DataFam :: Prism' FamFlavour ()
- _InfixL :: Prism' FixityDirection ()
- _InfixR :: Prism' FixityDirection ()
- _InfixN :: Prism' FixityDirection ()
- _VarE :: Prism' Exp Name
- _ConE :: Prism' Exp Name
- _LitE :: Prism' Exp Lit
- _AppE :: Prism' Exp (Exp, Exp)
- _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 [Exp]
- _UnboxedTupE :: Prism' Exp [Exp]
- _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]
- _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
- _GuardedB :: Prism' Body [(Guard, Exp)]
- _NormalB :: Prism' Body Exp
- _NormalG :: Prism' Guard Exp
- _PatG :: Prism' Guard [Stmt]
- _BindS :: Prism' Stmt (Pat, Exp)
- _LetS :: Prism' Stmt [Dec]
- _NoBindS :: Prism' Stmt Exp
- _ParS :: Prism' Stmt [[Stmt]]
- _FromR :: Prism' Range Exp
- _FromThenR :: Prism' Range (Exp, Exp)
- _FromToR :: Prism' Range (Exp, Exp)
- _FromThenToR :: Prism' Range (Exp, Exp, Exp)
- _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]
- _LitP :: Prism' Pat Lit
- _VarP :: Prism' Pat Name
- _TupP :: Prism' Pat [Pat]
- _UnboxedTupP :: Prism' Pat [Pat]
- _ConP :: Prism' Pat (Name, [Pat])
- _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)
- _ForallT :: Prism' Type ([TyVarBndr], 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
- _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
- _PlainTV :: Prism' TyVarBndr Name
- _KindedTV :: Prism' TyVarBndr (Name, Kind)
- _NumTyLit :: Prism' TyLit Integer
- _StrTyLit :: Prism' TyLit String
- _NominalR :: Prism' Role ()
- _RepresentationalR :: Prism' Role ()
- _PhantomR :: Prism' Role ()
- _InferR :: Prism' Role ()

# Traversals

class HasName t where

Has a `Name`

Methods

name :: Lens' t Name

Extract (or modify) the `Name` of something

Instances

HasName Name |
HasName TyVarBndr |
HasName Foreign |
HasName RuleBndr |
HasName Con | On `template-haskell-2.11.0.0` or later, if a `GadtC` or `RecGadtC` has multiple `Name`s, the leftmost `Name` will be chosen.

class HasTypes t where

Contains some amount of `Type`s inside

Methods

types :: Traversal' t Type

Traverse all the types

Instances

HasTypes Type |
HasTypes TySynEqn |
HasTypes Foreign |
HasTypes Con |
HasTypes t => HasTypes [t] |

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 |
HasTypeVars Name |
HasTypeVars TyVarBndr |
HasTypeVars Con |
HasTypeVars t => HasTypeVars [t] |
HasTypeVars t => HasTypeVars (Maybe t) |

class SubstType t where

Provides substitution for types

Methods

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

Perform substitution for types

Instances

SubstType Type |
SubstType t => SubstType [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 StrictType

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

conNamedFields :: Traversal' Con VarStrictType

`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

tySynEqnPatterns :: Lens' TySynEqn [Type]

tySynEqnResult :: Lens' TySynEqn Type

# Prisms

## Info Prisms

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

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

_TyConI :: Prism' Info Dec

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

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

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

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

_TyVarI :: Prism' Info (Name, Type)

## Dec Prisms

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

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

_DataD :: Prism' Dec (Cxt, Name, [TyVarBndr], [Con], [Name])

_NewtypeD :: Prism' Dec (Cxt, Name, [TyVarBndr], Con, [Name])

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

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

_InstanceD :: Prism' Dec (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, Name, [Type], [Con], [Name])

_NewtypeInstD :: Prism' Dec (Cxt, Name, [Type], Con, [Name])

_TySynInstD :: Prism' Dec (Name, TySynEqn)

_ClosedTypeFamilyD :: Prism' Dec (Name, [TyVarBndr], Maybe Kind, [TySynEqn])

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

_StandaloneDerivD :: Prism' Dec (Cxt, Type)

_DefaultSigD :: Prism' Dec (Name, Type)

_FamilyD :: Prism' Dec (FamFlavour, Name, [TyVarBndr], Maybe Kind)

## Con Prisms

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

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

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

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

## Strict Prisms

_IsStrict :: Prism' Strict ()

_NotStrict :: Prism' Strict ()

_Unpacked :: Prism' Strict ()

## 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, [RuleBndr], Exp, Exp, Phases)

_AnnP :: Prism' Pragma (AnnTarget, Exp)

_LineP :: Prism' Pragma (Int, String)

## 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])

## FamFlavour Prisms

_TypeFam :: Prism' FamFlavour ()

_DataFam :: Prism' FamFlavour ()

## 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)

_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 [Exp]

_UnboxedTupE :: Prism' Exp [Exp]

_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]

_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

## 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]]

## 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]

## Pat Prisms

_LitP :: Prism' Pat Lit

_VarP :: Prism' Pat Name

_TupP :: Prism' Pat [Pat]

_UnboxedTupP :: Prism' Pat [Pat]

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

_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 ([TyVarBndr], 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

_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

## TyVarBndr Prisms

_PlainTV :: Prism' TyVarBndr Name

_KindedTV :: Prism' TyVarBndr (Name, Kind)

## TyLit Prisms

_NumTyLit :: Prism' TyLit Integer

_StrTyLit :: Prism' TyLit String

## Role Prisms

_NominalR :: Prism' Role ()

_RepresentationalR :: Prism' Role ()

_PhantomR :: Prism' Role ()

_InferR :: Prism' Role ()