GHC.Rename.HsType

Documentation

rnHsType :: HsDocContext -> HsType GhcPs -> RnM (HsType GhcRn, FreeVars)

rnLHsType :: HsDocContext -> LHsType GhcPs -> RnM (LHsType GhcRn, FreeVars)

rnLHsTypes :: HsDocContext -> [LHsType GhcPs] -> RnM ([LHsType GhcRn], FreeVars)

rnContext :: HsDocContext -> LHsContext GhcPs -> RnM (LHsContext GhcRn, FreeVars)

rnMaybeContext :: HsDocContext -> Maybe (LHsContext GhcPs) -> RnM (Maybe (LHsContext GhcRn), FreeVars)

rnHsKind :: HsDocContext -> HsKind GhcPs -> RnM (HsKind GhcRn, FreeVars)

rnLHsKind :: HsDocContext -> LHsKind GhcPs -> RnM (LHsKind GhcRn, FreeVars)

rnLHsTypeArgs :: HsDocContext -> [LHsTypeArg GhcPs] -> RnM ([LHsTypeArg GhcRn], FreeVars)

rnHsSigType :: HsDocContext -> TypeOrKind -> LHsSigType GhcPs -> RnM (LHsSigType GhcRn, FreeVars)

rnHsWcType :: HsDocContext -> LHsWcType GhcPs -> RnM (LHsWcType GhcRn, FreeVars)

rnHsPatSigTypeBindingVars :: HsDocContext -> HsPatSigType GhcPs -> (HsPatSigType GhcRn -> RnM (r, FreeVars)) -> RnM (r, FreeVars)

data HsPatSigTypeScoping

Constructors

AlwaysBind

Always bind any free tyvars of the given type, regardless of whether we have a forall at the top.

For pattern type sigs, we do want to bring those type variables into scope, even if there's a forall at the top which usually stops that happening, e.g:

\ (x :: forall a. a -> b) -> e

Here we do bring b into scope.

RULES can also use AlwaysBind, such as in the following example:

{-# RULES \"f\" forall (x :: forall a. a -> b). f x = ... b ... #-}

This only applies to RULES that do not explicitly bind their type variables. If a RULE explicitly quantifies its type variables, then NeverBind is used instead. See also Note [Pattern signature binders and scoping] in GHC.Hs.Type.

NeverBind

Never bind any free tyvars. This is used for RULES that have both explicit type and term variable binders, e.g.:

{-# RULES \"const\" forall a. forall (x :: a) y. const x y = x #-}

The presence of the type variable binder forall a. implies that the free variables in the types of the term variable binders x and y are not bound. In the example above, there are no such free variables, but if the user had written (y :: b) instead of y in the term variable binders, then b would be rejected for being out of scope. See also Note [Pattern signature binders and scoping] in GHC.Hs.Type.

rnHsSigWcType :: HsDocContext -> LHsSigWcType GhcPs -> RnM (LHsSigWcType GhcRn, FreeVars)

rnHsPatSigType :: HsPatSigTypeScoping -> HsDocContext -> HsPatSigType GhcPs -> (HsPatSigType GhcRn -> RnM (a, FreeVars)) -> RnM (a, FreeVars)

newTyVarNameRn :: Maybe a -> LocatedN RdrName -> RnM Name

rnConDeclFields :: HsDocContext -> [FieldLabel] -> [LConDeclField GhcPs] -> RnM ([LConDeclField GhcRn], FreeVars)

lookupField :: FastStringEnv FieldLabel -> FieldOcc GhcPs -> FieldOcc GhcRn

rnLTyVar :: LocatedN RdrName -> RnM (LocatedN Name)

rnScaledLHsType :: HsDocContext -> HsScaled GhcPs (LHsType GhcPs) -> RnM (HsScaled GhcRn (LHsType GhcRn), FreeVars)

data NegationHandling

Constructors

ReassociateNegation

KeepNegationIntact

mkOpAppRn :: NegationHandling -> LHsExpr GhcRn -> LHsExpr GhcRn -> Fixity -> LHsExpr GhcRn -> RnM (HsExpr GhcRn)

mkNegAppRn :: LHsExpr GhcRn -> SyntaxExpr GhcRn -> RnM (HsExpr GhcRn)

mkOpFormRn :: LHsCmdTop GhcRn -> LHsExpr GhcRn -> Fixity -> LHsCmdTop GhcRn -> RnM (HsCmd GhcRn)

mkConOpPatRn :: LocatedN Name -> Fixity -> LPat GhcRn -> LPat GhcRn -> RnM (Pat GhcRn)

checkPrecMatch :: Name -> MatchGroup GhcRn body -> RnM ()

checkSectionPrec :: FixityDirection -> HsExpr GhcPs -> LHsExpr GhcRn -> LHsExpr GhcRn -> RnM ()

bindHsOuterTyVarBndrs

Arguments

:: OutputableBndrFlag flag 'Renamed

=> HsDocContext

-> Maybe assoc

Just _ => an associated type decl

-> FreeKiTyVars

-> HsOuterTyVarBndrs flag GhcPs

-> (HsOuterTyVarBndrs flag GhcRn -> RnM (a, FreeVars))

-> RnM (a, FreeVars)

bindHsForAllTelescope :: HsDocContext -> HsForAllTelescope GhcPs -> (HsForAllTelescope GhcRn -> RnM (a, FreeVars)) -> RnM (a, FreeVars)

bindLHsTyVarBndr :: HsDocContext -> Maybe a -> LHsTyVarBndr flag GhcPs -> (LHsTyVarBndr flag GhcRn -> RnM (b, FreeVars)) -> RnM (b, FreeVars)

bindLHsTyVarBndrs :: OutputableBndrFlag flag 'Renamed => HsDocContext -> WarnUnusedForalls -> Maybe a -> [LHsTyVarBndr flag GhcPs] -> ([LHsTyVarBndr flag GhcRn] -> RnM (b, FreeVars)) -> RnM (b, FreeVars)

data WarnUnusedForalls

Should GHC warn if a quantified type variable goes unused? Usually, the answer is "yes", but in the particular case of binding LHsQTyVars, we avoid emitting warnings. See Note [Suppress -Wunused-foralls when binding LHsQTyVars].

Constructors

WarnUnusedForalls

NoWarnUnusedForalls

Instances

Outputable WarnUnusedForalls

Defined in GHC.Rename.HsType

Methods

ppr :: WarnUnusedForalls -> SDoc

rnImplicitTvOccs

Arguments

:: Maybe assoc

Just _ => an associated type decl

-> FreeKiTyVars

Surface-syntax free vars that we will implicitly bind. May have duplicates, which are removed here.

-> ([Name] -> RnM (a, FreeVars))

-> RnM (a, FreeVars)

Create new renamed type variables corresponding to source-level ones. Duplicates are permitted, but will be removed. This is intended especially for the case of handling the implicitly bound free variables of a type signature.

bindSigTyVarsFV :: [Name] -> RnM (a, FreeVars) -> RnM (a, FreeVars)

bindHsQTyVars :: forall a b. HsDocContext -> Maybe a -> FreeKiTyVars -> LHsQTyVars GhcPs -> (LHsQTyVars GhcRn -> Bool -> RnM (b, FreeVars)) -> RnM (b, FreeVars)

type FreeKiTyVars = [LocatedN RdrName]

filterInScopeM :: FreeKiTyVars -> RnM FreeKiTyVars

Filter out any type and kind variables that are already in scope in the the environment's LocalRdrEnv. Note that this includes named wildcards, which look like perfectly ordinary type variables at this point.

extractHsTyRdrTyVars :: LHsType GhcPs -> FreeKiTyVars

extractHsTyRdrTyVars finds the type/kind variables of a HsType/HsKind. It's used when making the foralls explicit. See Note [Kind and type-variable binders]

extractHsTyRdrTyVarsKindVars :: LHsType GhcPs -> FreeKiTyVars

Extracts the free type/kind variables from the kind signature of a HsType. This is used to implicitly quantify over k in type T = Nothing :: Maybe k. The left-to-right order of variables is preserved. See Note [Kind and type-variable binders] and Note [Ordering of implicit variables] and Note [Implicit quantification in type synonyms].

extractHsTysRdrTyVars :: [LHsType GhcPs] -> FreeKiTyVars -> FreeKiTyVars

Extracts free type and kind variables from types in a list. When the same name occurs multiple times in the types, all occurrences are returned.

extractRdrKindSigVars :: LFamilyResultSig GhcPs -> FreeKiTyVars

extractConDeclGADTDetailsTyVars :: HsConDeclGADTDetails GhcPs -> FreeKiTyVars -> FreeKiTyVars

Extracts free type and kind variables from an argument in a GADT constructor, returning variable occurrences in left-to-right order. See Note [Ordering of implicit variables].

extractDataDefnKindVars :: HsDataDefn GhcPs -> FreeKiTyVars

Get type/kind variables mentioned in the kind signature, preserving left-to-right order:

• data T a (b :: k1) :: k2 -> k1 -> k2 -> Type -- result: [k2,k1]
• data T a (b :: k1) -- result: []

See Note [Ordering of implicit variables].

extractHsOuterTvBndrs :: HsOuterTyVarBndrs flag GhcPs -> FreeKiTyVars -> FreeKiTyVars

extractHsTyArgRdrKiTyVars :: [LHsTypeArg GhcPs] -> FreeKiTyVars

nubL :: Eq a => [GenLocated l a] -> [GenLocated l a]

nubN :: Eq a => [LocatedN a] -> [LocatedN a]