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GHC 9.14.1 · lts/ghc-9.14.x · 6d5fdfd · 2026-10-12

Moduleghc-lib-parser-9.14.1.20251220GHC2021

GHC.Core.PatSyn

Contents

Main data types
Type deconstruction

Synopsis

data PatSyn
type PatSynMatcher
type PatSynBuilder
value mkPatSyn
value patSynName
value patSynArity
value patSynVisArity
value patSynIsInfix
value patSynResultType
value isVanillaPatSyn
value patSynArgs
value patSynMatcher
value patSynBuilder
value patSynUnivTyVarBinders
value patSynExTyVars
value patSynExTyVarBinders
value patSynSig
value patSynSigBndr
value patSynInstArgTys
value patSynInstResTy
value patSynFieldLabels
value patSynFieldType
value pprPatSynType

Packageghc-lib-parser-9.14.1.20251220
Exports23
LanguageGHC2021
LicenceBSD-3-Clause
SourcePatSyn.hs

Main data types

datadata PatSyn

Pattern Synonym

See Note [Pattern synonym representation] See Note [Pattern synonym signature contexts]

Instances6Eq, Data, Uniquable, Outputable, NamedThing, OutputableBndr

Eq PatSynDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Core.PatSyn
Data PatSynDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Core.PatSyn
Uniquable PatSynDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Core.PatSyn
Outputable PatSynDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Core.PatSyn
NamedThing PatSynDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Core.PatSyn
OutputableBndr PatSynDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Core.PatSyn

typetype PatSynMatcher = (Name, Type, Bool)

typetype PatSynBuilder = Maybe (Name, Type, Bool)

valuemkPatSyn

:: Name
-> Bool
Is the pattern synonym declared infix?
-> ([InvisTVBinder], ThetaType)
Universally-quantified type variables and required dicts
-> ([InvisTVBinder], ThetaType)
Existentially-quantified type variables and provided dicts
-> [FRRType]
Original arguments
-> Type
Original result type
-> PatSynMatcher
Matcher
-> PatSynBuilder
Builder
-> [FieldLabel]
Names of fields for a record pattern synonym
-> PatSyn

Build a new pattern synonym

Type deconstruction

valuepatSynName :: PatSyn -> Name

The Name of the PatSyn, giving it a unique, rooted identification

valuepatSynArity :: PatSyn -> Arity

Arity of the pattern synonym

valuepatSynVisArity :: PatSyn -> VisArity

Number of visible arguments of the pattern synonym

valuepatSynIsInfix :: PatSyn -> Bool

Should the PatSyn be presented infix?

valuepatSynResultType :: PatSyn -> Type

valueisVanillaPatSyn :: PatSyn -> Bool

Is this a 'vanilla' pattern synonym (no existentials, no provided constraints)?

valuepatSynArgs :: PatSyn -> [Type]

valuepatSynMatcher :: PatSyn -> PatSynMatcher

valuepatSynBuilder :: PatSyn -> PatSynBuilder

valuepatSynUnivTyVarBinders :: PatSyn -> [InvisTVBinder]

valuepatSynExTyVars :: PatSyn -> [TyVar]

valuepatSynExTyVarBinders :: PatSyn -> [InvisTVBinder]

valuepatSynSig

:: PatSyn
-> ([TyVar], ThetaType, [TyVar], ThetaType, [Scaled Type], Type)

valuepatSynSigBndr

:: PatSyn
-> ([InvisTVBinder], ThetaType, [InvisTVBinder], ThetaType, [Scaled Type], Type)

valuepatSynInstArgTys :: PatSyn -> [Type] -> [Type]

valuepatSynInstResTy :: PatSyn -> [Type] -> Type

valuepatSynFieldLabels :: PatSyn -> [FieldLabel]

valuepatSynFieldType :: PatSyn -> FieldLabelString -> Type

Extract the type for any given labelled field of the DataCon

valuepprPatSynType :: PatSyn -> SDoc

Print the type of a pattern synonym. The foralls are printed explicitly