+lookupSigOccRn :: Maybe NameSet -- Just ns => source file; these are the binders
+ -- in the same group
+ -- Nothing => hs-boot file; signatures without
+ -- binders are expected
+ -> Sig RdrName
+ -> Located RdrName -> RnM (Located Name)
+lookupSigOccRn mb_bound_names sig
+ = wrapLocM $ \ rdr_name ->
+ do { mb_name <- lookupBindGroupOcc mb_bound_names (hsSigDoc sig) rdr_name
+ ; case mb_name of
+ Left err -> do { addErr err; return (mkUnboundName rdr_name) }
+ Right name -> return name }
+
+lookupBindGroupOcc :: Maybe NameSet -- Just ns => source file; these are the binders
+ -- in the same group
+ -- Nothing => hs-boot file; signatures without
+ -- binders are expected
+ -> SDoc
+ -> RdrName -> RnM (Either Message Name)
+-- Looks up the RdrName, expecting it to resolve to one of the
+-- bound names passed in. If not, return an appropriate error message
+lookupBindGroupOcc mb_bound_names what rdr_name
+ = do { local_env <- getLocalRdrEnv
+ ; case lookupLocalRdrEnv local_env rdr_name of
+ Just n -> check_local_name n
+ Nothing -> do -- Not defined in a nested scope
+
+ { env <- getGlobalRdrEnv
+ ; let gres = lookupGlobalRdrEnv env (rdrNameOcc rdr_name)
+ ; case (filter isLocalGRE gres) of
+ (gre:_) -> check_local_name (gre_name gre)
+ -- If there is more than one local GRE for the
+ -- same OccName, that will be reported separately
+ [] | null gres -> bale_out_with empty
+ | otherwise -> bale_out_with import_msg
+ }}
+ where
+ check_local_name name -- The name is in scope, and not imported
+ = case mb_bound_names of
+ Just bound_names | not (name `elemNameSet` bound_names)
+ -> bale_out_with local_msg
+ _other -> return (Right name)
+
+ bale_out_with msg
+ = return (Left (sep [ ptext (sLit "The") <+> what
+ <+> ptext (sLit "for") <+> quotes (ppr rdr_name)
+ , nest 2 $ ptext (sLit "lacks an accompanying binding")]
+ $$ nest 2 msg))
+
+ local_msg = parens $ ptext (sLit "The") <+> what <+> ptext (sLit "must be given where")
+ <+> quotes (ppr rdr_name) <+> ptext (sLit "is declared")
+
+ import_msg = parens $ ptext (sLit "You cannot give a") <+> what
+ <+> ptext (sLit "for an imported value")
+
+---------------
+lookupLocalDataTcNames :: NameSet -> SDoc -> RdrName -> RnM [Name]