GHC.Rename.HsType · ghc-9.10.3

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.

valuernHsSigWcType

#

valuernHsPatSigType

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

#

valuernHsPatSigKind

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

#

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

#

valuernConDeclFields

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

#

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

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valuemkHsOpTyRn

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

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valuernScaledLHsType

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

#

datadata NegationHandling

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ReassociateNegation KeepNegationIntact

valuemkOpAppRn

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

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valuemkOpFormRn

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valuemkConOpPatRn

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

#

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

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valuecheckSectionPrec

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valuebindHsOuterTyVarBndrs

:: OutputableBndrFlag flag 'Renamed
=> HsDocContext
-> Maybe assoc
Just _ => an associated type decl
-> FreeKiTyVars
-> HsOuterTyVarBndrs flag GhcPs
-> (HsOuterTyVarBndrs flag GhcRn -> RnM (a, FreeVars))
-> RnM (a, FreeVars)

#

valuebindHsForAllTelescope

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

#

valuebindLHsTyVarBndr

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

#

valuebindLHsTyVarBndrs

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

#

datadata WarnUnusedForalls

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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].

WarnUnusedForalls NoWarnUnusedForalls

Instances1Outputable

Outputable WarnUnusedForallsDefined in ghc-9.10.3 · GHC.Rename.HsType

valuernImplicitTvOccs

:: 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.

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

#

valuebindHsQTyVars

:: HsDocContext
-> Maybe (a, [Name])
-> FreeKiTyVars
-> LHsQTyVars GhcPs
-> LHsQTyVars GhcRn -> FreeKiTyVars -> RnM (b, FreeVars)
-> RnM (b, FreeVars)

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typetype FreeKiTyVars = [LocatedN RdrName]

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valuefilterInScopeM :: FreeKiTyVars -> RnM FreeKiTyVars

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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.

valueextractHsTyRdrTyVars :: LHsType GhcPs -> FreeKiTyVars

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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]

valueextractHsTyRdrTyVarsKindVars :: LHsType GhcPs -> FreeKiTyVars

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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].

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

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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.

valueextractRdrKindSigVars :: LFamilyResultSig GhcPs -> FreeKiTyVars

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valueextractConDeclGADTDetailsTyVars

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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].