Moduleghc-9.10.3GHC2021

GHC.Hs.Pat

16 types
29 values

Packageghc-9.10.3
Exports46
LanguageGHC2021
LicenceBSD-3-Clause
SourcePat.hs

datadata Pat p

Pattern

AnnKeywordId : AnnBang

Constructors

WildPat (XWildPat p)
Wildcard Pattern The sole reason for a type on a WildPat is to support hsPatType :: Pat Id -> Type
VarPat (XVarPat p) (LIdP p)
Variable Pattern
LazyPat (XLazyPat p) (LPat p)
Lazy Pattern ^ - AnnKeywordId : AnnTilde
AsPat (XAsPat p) (LIdP p) (LPat p)
As pattern ^ - AnnKeywordId : GHC.Parser.Annotation.AnnAt
ParPat (XParPat p) (LPat p)
Parenthesised pattern See Note [Parens in HsSyn] in GHC.Hs.Expr ^ - AnnKeywordId : AnnOpen '(', AnnClose ')'
BangPat (XBangPat p) (LPat p)
Bang pattern ^ - AnnKeywordId : AnnBang
ListPat (XListPat p) [LPat p]
Syntactic List
- AnnKeywordId : AnnOpen '[', AnnClose ']'
TuplePat (XTuplePat p) [LPat p] Boxity
Tuple sub-patterns
- AnnKeywordId : AnnOpen '(' or '(#', AnnClose ')' or '#)'
SumPat (XSumPat p) (LPat p) ConTag SumWidth
Anonymous sum pattern
- AnnKeywordId : AnnOpen '(#', AnnClose '#)'
ConPat
Constructor Pattern
- pat_con_ext :: XConPat p
- pat_con :: XRec p (ConLikeP p)
- pat_args :: HsConPatDetails p
ViewPat (XViewPat p) (LHsExpr p) (LPat p)
- AnnKeywordId : AnnRarrow
SplicePat (XSplicePat p) (HsUntypedSplice p)
- AnnKeywordId : AnnOpen '$(' AnnClose ')'
LitPat (XLitPat p) (HsLit p)
Literal Pattern Used for *non-overloaded* literal patterns: Int#, Char#, Int, Char, String, etc.
NPat (XNPat p) (XRec p (HsOverLit p)) (Maybe (SyntaxExpr p)) (SyntaxExpr p)
Natural Pattern
- AnnKeywordId : AnnVal +
NPlusKPat (XNPlusKPat p) (LIdP p) (XRec p (HsOverLit p)) (HsOverLit p) (SyntaxExpr p) (SyntaxExpr p)
n+k pattern
SigPat (XSigPat p) (LPat p) (HsPatSigType (NoGhcTc p))
- AnnKeywordId : AnnDcolon
EmbTyPat (XEmbTyPat p) (HsTyPat (NoGhcTc p))
InvisPat (XInvisPat p) (HsTyPat (NoGhcTc p))
XPat !(XXPat p)

Instances7Data, Outputable, HasType, ToHie, Anno, …

Data (Pat GhcPs)Defined in ghc-9.10.3 · GHC.Hs.Instances · orphan
Data (Pat GhcRn)Defined in ghc-9.10.3 · GHC.Hs.Instances · orphan
Data (Pat GhcTc)Defined in ghc-9.10.3 · GHC.Hs.Instances · orphan
OutputableBndrId p => Outputable (Pat (GhcPass p))Defined in ghc-9.10.3 · GHC.Hs.Pat · orphan
HiePass p => HasType (LocatedA (Pat (GhcPass p)))Defined in ghc-9.10.3 · GHC.Iface.Ext.Ast
HiePass p => ToHie (PScoped (LocatedA (Pat (GhcPass p))))Defined in ghc-9.10.3 · GHC.Iface.Ext.Ast
type Anno (Pat (GhcPass p)) = SrcSpanAnnADefined in ghc-9.10.3 · GHC.Hs.Pat · orphan

typetype LPat p = XRec p (Pat p)

valueisInvisArgPat :: Pat p -> Bool

valueisVisArgPat :: Pat p -> Bool

datadata EpAnnSumPat

Constructors

EpAnnSumPat
- sumPatParens :: [AddEpAnn]
- sumPatVbarsBefore :: [EpaLocation]
- sumPatVbarsAfter :: [EpaLocation]

Instances2Data, NoAnn

Data EpAnnSumPatDefined in ghc-9.10.3 · GHC.Hs.Pat
NoAnn EpAnnSumPatDefined in ghc-9.10.3 · GHC.Hs.Pat

datadata ConPatTc

This is the extension field for ConPat, added after typechecking It adds quite a few extra fields, to support elaboration of pattern matching.

Constructors

ConPatTc
- cpt_arg_tys :: [Type]
  The universal arg types 1-1 with the universal tyvars of the constructor/pattern synonym Use (conLikeResTy pat_con cpt_arg_tys) to get the type of the pattern
- cpt_tvs :: [TyVar]
  Existentially bound type variables in correctly-scoped order e.g. [k:* x:k]
- cpt_dicts :: [EvVar]
  Ditto *coercion variables* and *dictionaries* One reason for putting coercion variable here I think is to ensure their kinds are zonked
- cpt_binds :: TcEvBinds
  Bindings involving those dictionaries
- cpt_wrap :: HsWrapper
  Extra wrapper to pass to the matcher Only relevant for pattern-synonyms; ignored for data cons

Instances1Data

Data ConPatTcDefined in ghc-9.10.3 · GHC.Hs.Instances · orphan

familytype family ConLikeP x

Instances3ConLikeP

type ConLikeP GhcPs = RdrNameDefined in ghc-9.10.3 · GHC.Hs.Pat · orphan
type ConLikeP GhcRn = NameDefined in ghc-9.10.3 · GHC.Hs.Pat · orphan
type ConLikeP GhcTc = ConLikeDefined in ghc-9.10.3 · GHC.Hs.Pat · orphan

datadata HsPatExpansion a b

Constructors

HsPatExpanded a b

Instances2Data, Outputable

(Data a, Data b) => Data (HsPatExpansion a b)Defined in ghc-9.10.3 · GHC.Hs.Pat
(Outputable a, Outputable b) => Outputable (HsPatExpansion a b)Defined in ghc-9.10.3 · GHC.Hs.Pat

datadata XXPatGhcTc

Extension constructor for Pat, added after typechecking.

Constructors

CoPat
Coercion Pattern (translation only)
During desugaring a (CoPat co pat) turns into a cast with co on the scrutinee, followed by a match on pat.
- co_cpt_wrap :: HsWrapper
  Coercion Pattern If co :: t1 ~ t2, p :: t2, then (CoPat co p) :: t1
- co_pat_inner :: Pat GhcTc
  Why not LPat? Ans: existing locn will do
- co_pat_ty :: Type
  Type of whole pattern, t1
ExpansionPat (Pat GhcRn) (Pat GhcTc)
Pattern expansion: original pattern, and desugared pattern, for RebindableSyntax and other overloaded syntax such as OverloadedLists. See Note [Rebindable syntax and XXExprGhcRn].

Instances1Data

Data XXPatGhcTcDefined in ghc-9.10.3 · GHC.Hs.Instances · orphan

typetype HsConPatDetails p = HsConDetails (HsConPatTyArg (NoGhcTc p)) (LPat p) (HsRecFields p (LPat p))

Haskell Constructor Pattern Details

valuehsConPatArgs :: UnXRec p => HsConPatDetails p -> [LPat p]

valuehsConPatTyArgs :: HsConPatDetails p -> [HsConPatTyArg (NoGhcTc p)]

datadata HsConPatTyArg p

Type argument in a data constructor pattern, e.g. the @a in f (Just @a x) = ....

Constructors

HsConPatTyArg !(XConPatTyArg p) (HsTyPat p)

Instances4Data, Outputable

Data (HsConPatTyArg GhcPs)Defined in ghc-9.10.3 · GHC.Hs.Instances · orphan
Data (HsConPatTyArg GhcRn)Defined in ghc-9.10.3 · GHC.Hs.Instances · orphan
Data (HsConPatTyArg GhcTc)Defined in ghc-9.10.3 · GHC.Hs.Instances · orphan
Outputable (HsTyPat p) => Outputable (HsConPatTyArg p)Defined in ghc-9.10.3 · GHC.Hs.Pat · orphan

datadata HsRecFields p arg

Haskell Record Fields

HsRecFields is used only for patterns and expressions (not data type declarations)

Constructors

HsRecFields
- rec_flds :: [LHsRecField p arg]
- rec_dotdot :: Maybe (XRec p RecFieldsDotDot)

Instances5ToHie, Data, Outputable

(ToHie arg, HasLoc arg, Data arg, HiePass p) => ToHie (RContext (HsRecFields (GhcPass p) arg))Defined in ghc-9.10.3 · GHC.Iface.Ext.Ast
Data body => Data (HsRecFields GhcPs body)Defined in ghc-9.10.3 · GHC.Hs.Instances · orphan
Data body => Data (HsRecFields GhcRn body)Defined in ghc-9.10.3 · GHC.Hs.Instances · orphan
Data body => Data (HsRecFields GhcTc body)Defined in ghc-9.10.3 · GHC.Hs.Instances · orphan
(Outputable arg, Outputable (XRec p (HsRecField p arg)), XRec p RecFieldsDotDot ~ LocatedE RecFieldsDotDot) => Outputable (HsRecFields p arg)Defined in ghc-9.10.3 · GHC.Hs.Pat · orphan

datadata HsFieldBind lhs rhs

Haskell Field Binding

AnnKeywordId : AnnEqual,

For details on above see Note [exact print annotations] in GHC.Parser.Annotation

Constructors

HsFieldBind
- hfbAnn :: XHsFieldBind lhs
- hfbLHS :: lhs
- hfbRHS :: rhs
  Filled in by renamer when punning
- hfbPun :: Bool
  Note [Punning]

Instances7Functor, Foldable, Traversable, ToHie, Data, Outputable, …

Functor (HsFieldBind lhs)Defined in ghc-9.10.3 · Language.Haskell.Syntax.Pat
Foldable (HsFieldBind lhs)Defined in ghc-9.10.3 · Language.Haskell.Syntax.Pat
Traversable (HsFieldBind lhs)Defined in ghc-9.10.3 · Language.Haskell.Syntax.Pat
(ToHie (RFContext label), ToHie arg, HasLoc arg, Data arg, Data label) => ToHie (RContext (LocatedA (HsFieldBind label arg)))Defined in ghc-9.10.3 · GHC.Iface.Ext.Ast
(Data a, Data b) => Data (HsFieldBind a b)Defined in ghc-9.10.3 · GHC.Hs.Instances · orphan
(Outputable p, OutputableBndr p, Outputable arg) => Outputable (HsFieldBind p arg)Defined in ghc-9.10.3 · GHC.Hs.Pat · orphan
type Anno (HsFieldBind lhs rhs) = SrcSpanAnnADefined in ghc-9.10.3 · GHC.Hs.Pat · orphan

typetype LHsFieldBind p id arg = XRec p (HsFieldBind id arg)

Located Haskell Record Field

typetype HsRecField p arg = HsFieldBind (LFieldOcc p) arg

Haskell Record Field

typetype LHsRecField p arg = XRec p (HsRecField p arg)

Located Haskell Record Field

typetype HsRecUpdField p q = HsFieldBind (LAmbiguousFieldOcc p) (LHsExpr q)

Haskell Record Update Field

typetype LHsRecUpdField p q = XRec p (HsRecUpdField p q)

Located Haskell Record Update Field

newtypenewtype RecFieldsDotDot

Newtype to be able to have a specific XRec instance for the Int in rec_dotdot

Constructors

RecFieldsDotDot
- unRecFieldsDotDot :: Int

Instances4Eq, Data, Ord, Anno

Eq RecFieldsDotDotDefined in ghc-9.10.3 · Language.Haskell.Syntax.Pat
Data RecFieldsDotDotDefined in ghc-9.10.3 · Language.Haskell.Syntax.Pat
Ord RecFieldsDotDotDefined in ghc-9.10.3 · Language.Haskell.Syntax.Pat
type Anno RecFieldsDotDot = EpaLocationDefined in ghc-9.10.3 · GHC.Hs.Pat · orphan

valuehsRecFields :: UnXRec p => HsRecFields p arg -> [XCFieldOcc p]

valuehsRecFieldSel :: UnXRec p => HsRecField p arg -> XCFieldOcc p

valuehsRecFieldId :: HsRecField GhcTc arg -> Id

valuehsRecFieldsArgs :: UnXRec p => HsRecFields p arg -> [arg]

valuehsRecUpdFieldId :: HsFieldBind (LAmbiguousFieldOcc GhcTc) arg -> Located Id

valuehsRecUpdFieldOcc

:: HsFieldBind (LAmbiguousFieldOcc GhcTc) arg
-> LFieldOcc GhcTc

valuehsRecUpdFieldRdr :: HsRecUpdField (GhcPass p) q -> Located RdrName

valuemkPrefixConPat :: DataCon -> [LPat GhcTc] -> [Type] -> LPat GhcTc

valuemkCharLitPat :: SourceText -> Char -> LPat GhcTc

valuemkNilPat :: Type -> LPat GhcTc

valueisSimplePat :: LPat (GhcPass x) -> Maybe (IdP (GhcPass x))

Is the pattern any of combination of:

(pat)
pat :: Type
~pat
!pat
x (variable)

valueisPatSyn :: LPat GhcTc -> Bool

valuelooksLazyPatBind :: HsBind GhcTc -> Bool

valueisBangedLPat :: LPat (GhcPass p) -> Bool

valuegParPat :: IsPass p => LPat (GhcPass p) -> Pat (GhcPass p)

Parenthesize a pattern without token information

valuepatNeedsParens :: IsPass p => PprPrec -> Pat (GhcPass p) -> Bool

patNeedsParens p pat returns True if the pattern pat needs parentheses under precedence p.

valueparenthesizePat

:: IsPass p
=> PprPrec
-> LPat (GhcPass p)
-> LPat (GhcPass p)

parenthesizePat p pat checks if patNeedsParens p pat is true, and if so, surrounds pat with a ParPat. Otherwise, it simply returns pat.

valueisIrrefutableHsPatHelper

:: OutputableBndrId p
=> Bool
Are we in a -XStrict context? See Note [-XStrict and irrefutability]
-> LPat (GhcPass p)
-> Bool

(isIrrefutableHsPat p) is true if matching against p cannot fail in the sense of falling through to the next pattern. (NB: this is not quite the same as the (silly) defn in 3.17.2 of the Haskell 98 report.)

WARNING: isIrrefutableHsPat returns False if it's in doubt. Specifically on a ConPatIn, which is what it sees for a (LPat Name) in the renamer, it doesn't know the size of the constructor family, so it returns False. Result: only tuple patterns are considered irrefutable at the renamer stage.

But if it returns True, the pattern is definitely irrefutable Instantiates isIrrefutableHsPatHelperM with a trivial identity monad

valueisIrrefutableHsPatHelperM :: (Monad m, OutputableBndrId p) => LPatIrrefutableCheck m (GhcPass p)

valueisBoringHsPat :: OutputableBndrId p => LPat (GhcPass p) -> Bool

Is this pattern boring from the perspective of pattern-match checking, i.e. introduces no new pieces of long-distance information which could influence pattern-match checking?

See Note [Boring patterns].

valuecollectEvVarsPat :: Pat GhcTc -> Bag EvVar

valuecollectEvVarsPats :: [Pat GhcTc] -> Bag EvVar

valuepprParendLPat :: OutputableBndrId p => PprPrec -> LPat (GhcPass p) -> SDoc

valuepprConArgs

:: (OutputableBndrId p, Outputable (Anno (IdGhcP p)))
=> HsConPatDetails (GhcPass p)
-> SDoc

valuepprLPat :: OutputableBndrId p => LPat (GhcPass p) -> SDoc

Orphan instances

4 instances

OutputableBndrId p => Outputable (Pat (GhcPass p))
Outputable (HsTyPat p) => Outputable (HsConPatTyArg p)
(Outputable arg, Outputable (XRec p (HsRecField p arg)), XRec p RecFieldsDotDot ~ LocatedE RecFieldsDotDot) => Outputable (HsRecFields p arg)
(Outputable p, OutputableBndr p, Outputable arg) => Outputable (HsFieldBind p arg)