= do { let (binds, sigs, ats, docs) = cvBindsAndSigs (unLoc where_cls)
= do { let (binds, sigs, ats, docs) = cvBindsAndSigs (unLoc where_cls)
; (cls, tparams) <- checkTyClHdr tycl_hdr
; tyvars <- checkTyVars tparams -- Only type vars allowed
; checkKindSigs ats
; (cls, tparams) <- checkTyClHdr tycl_hdr
; tyvars <- checkTyVars tparams -- Only type vars allowed
; checkKindSigs ats
; (tyvars, typats) <- checkTParams is_family tparams
; return (L loc (TyData { tcdND = new_or_data, tcdCtxt = cxt, tcdLName = tc,
tcdTyVars = tyvars, tcdTyPats = typats,
; (tyvars, typats) <- checkTParams is_family tparams
; return (L loc (TyData { tcdND = new_or_data, tcdCtxt = cxt, tcdLName = tc,
tcdTyVars = tyvars, tcdTyPats = typats,
+checkDatatypeContext :: Maybe (LHsContext RdrName) -> P ()
+checkDatatypeContext Nothing = return ()
+checkDatatypeContext (Just (L loc _))
+ = do allowed <- extension datatypeContextsEnabled
+ unless allowed $
+ parseError loc "Illegal datatype context (use -XDatatypeContexts)"
+
checkTyClHdr :: LHsType RdrName
-> P (Located RdrName, -- the head symbol (type or class name)
[LHsType RdrName]) -- parameters of head symbol
checkTyClHdr :: LHsType RdrName
-> P (Located RdrName, -- the head symbol (type or class name)
[LHsType RdrName]) -- parameters of head symbol