GHC.Rename.Utils

Documentation

checkDupRdrNames :: [Located RdrName] -> RnM ()

checkShadowedRdrNames :: [Located RdrName] -> RnM ()

checkDupNames :: [Name] -> RnM ()

checkDupAndShadowedNames :: (GlobalRdrEnv, LocalRdrEnv) -> [Name] -> RnM ()

dupNamesErr :: Outputable n => (n -> SrcSpan) -> NonEmpty n -> RnM ()

checkTupSize :: Int -> TcM ()

Ensure that a boxed or unboxed tuple has arity no larger than mAX_TUPLE_SIZE.

checkCTupSize :: Int -> TcM ()

Ensure that a constraint tuple has arity no larger than mAX_CTUPLE_SIZE.

addFvRn :: FreeVars -> RnM (thing, FreeVars) -> RnM (thing, FreeVars)

mapFvRn :: (a -> RnM (b, FreeVars)) -> [a] -> RnM ([b], FreeVars)

mapMaybeFvRn :: (a -> RnM (b, FreeVars)) -> Maybe a -> RnM (Maybe b, FreeVars)

warnUnusedMatches :: [Name] -> FreeVars -> RnM ()

warnUnusedTypePatterns :: [Name] -> FreeVars -> RnM ()

warnUnusedTopBinds :: [GlobalRdrElt] -> RnM ()

warnUnusedLocalBinds :: [Name] -> FreeVars -> RnM ()

checkUnusedRecordWildcard :: SrcSpan -> FreeVars -> Maybe [Name] -> RnM ()

Checks to see if we need to warn for -Wunused-record-wildcards or -Wredundant-record-wildcards

mkFieldEnv :: GlobalRdrEnv -> NameEnv (FieldLabelString, Parent)

Make a map from selector names to field labels and parent tycon names, to be used when reporting unused record fields.

unknownSubordinateErr :: SDoc -> RdrName -> SDoc

badQualBndrErr :: RdrName -> SDoc

typeAppErr :: String -> LHsType GhcPs -> SDoc

data HsDocContext

Constructors

TypeSigCtx SDoc

StandaloneKindSigCtx SDoc

PatCtx

SpecInstSigCtx

DefaultDeclCtx

ForeignDeclCtx (Located RdrName)

DerivDeclCtx

RuleCtx FastString

TyDataCtx (Located RdrName)

TySynCtx (Located RdrName)

TyFamilyCtx (Located RdrName)

FamPatCtx (Located RdrName)

ConDeclCtx [Located Name]

ClassDeclCtx (Located RdrName)

ExprWithTySigCtx

TypBrCtx

HsTypeCtx

HsTypePatCtx

GHCiCtx

SpliceTypeCtx (LHsType GhcPs)

ClassInstanceCtx

GenericCtx SDoc

pprHsDocContext :: HsDocContext -> SDoc

inHsDocContext :: HsDocContext -> SDoc

withHsDocContext :: HsDocContext -> SDoc -> SDoc

newLocalBndrRn :: Located RdrName -> RnM Name

newLocalBndrsRn :: [Located RdrName] -> RnM [Name]

bindLocalNames :: [Name] -> RnM a -> RnM a

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

addNameClashErrRn :: RdrName -> [GlobalRdrElt] -> RnM ()

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

checkInferredVars

Arguments

:: HsDocContext

-> Maybe SDoc

The error msg if the signature is not allowed to contain manually written inferred variables.

-> LHsSigType GhcPs

-> RnM ()

Throw an error message if a user attempts to quantify an inferred type variable in a place where specificity cannot be observed. For example, forall {a}. [a] -> [a] would be rejected to the inferred type variable {a}, but forall a. [a] -> [a] would be accepted. See Note [Unobservably inferred type variables].

noNestedForallsContextsErr :: SDoc -> LHsType GhcRn -> Maybe (SrcSpan, SDoc)

Examines a non-outermost type for foralls or contexts, which are assumed to be nested. For example, in the following declaration:

instance forall a. forall b. C (Either a b)

The outermost forall a is fine, but the nested forall b is not. We invoke noNestedForallsContextsErr on the type forall b. C (Either a b) to catch the nested forall and create a suitable error message. noNestedForallsContextsErr returns Just err_msg if such a forall or context is found, and returns Nothing otherwise.

This is currently used in the following places:

• In GADT constructor types (in rnConDecl). See Note [GADT abstract syntax] (Wrinkle: No nested foralls or contexts) in GHC.Hs.Type.
• In instance declaration types (in rnClsIntDecl and rnSrcDerivDecl in GHC.Rename.Module and renameSig in GHC.Rename.Bind). See Note [No nested foralls or contexts in instance types] in GHC.Hs.Type.

addNoNestedForallsContextsErr :: HsDocContext -> SDoc -> LHsType GhcRn -> RnM ()

A common way to invoke noNestedForallsContextsErr.