import qualified GHC
-import GHC ( TyThing(..), SrcLoc )
-import DataCon ( dataConResTys )
+import TyCon ( tyConFamInst_maybe )
+import Type ( pprTypeApp )
+import GHC ( TyThing(..), SrcLoc )
import Outputable
-- -----------------------------------------------------------------------------
pprTyThingHdr exts (ATyCon tyCon) = pprTyConHdr exts tyCon
pprTyThingHdr exts (AClass cls) = pprClassHdr exts cls
-pprTyConHdr exts tyCon =
- addFamily (ptext keyword) <+> ppr_bndr tyCon <+> hsep (map ppr vars)
+pprTyConHdr exts tyCon
+ | Just (fam_tc, tys) <- tyConFamInst_maybe tyCon
+ = ptext keyword <+> ptext SLIT("instance") <+> pprTypeApp (ppr_bndr tyCon) tys
+ | otherwise
+ = ptext keyword <+> opt_family <+> ppr_bndr tyCon <+> hsep (map ppr vars)
where
vars | GHC.isPrimTyCon tyCon ||
GHC.isFunTyCon tyCon = take (GHC.tyConArity tyCon) GHC.alphaTyVars
| GHC.isNewTyCon tyCon = SLIT("newtype")
| otherwise = SLIT("data")
- addFamily keytext
- | GHC.isOpenTyCon tyCon = keytext <> ptext SLIT(" family")
- | otherwise = keytext
+ opt_family
+ | GHC.isOpenTyCon tyCon = ptext SLIT("family")
+ | otherwise = empty
pprDataConSig exts dataCon =
ppr_bndr dataCon <+> dcolon <+> pprType exts (GHC.dataConType dataCon)
| otherwise = ppr_bndr dataCon <+> dcolon <+>
sep [ ppr_tvs, GHC.pprThetaArrow theta, pp_tau ]
where
- (tyvars, theta, argTypes) = GHC.dataConSig dataCon
+ (tyvars, theta, argTypes, res_ty) = GHC.dataConSig dataCon
tyCon = GHC.dataConTyCon dataCon
labels = GHC.dataConFieldLabels dataCon
- res_tys = dataConResTys dataCon
qualVars = filter (flip notElem (GHC.tyConTyVars tyCon)) tyvars
stricts = GHC.dataConStrictMarks dataCon
tys_w_strs = zip stricts argTypes
hsep (map ppr qualVars) <> dot
-- printing out the dataCon as a type signature, in GADT style
- pp_tau = foldr add pp_res_ty tys_w_strs
- pp_res_ty = ppr_bndr tyCon <+> hsep (map GHC.pprParendType res_tys)
+ pp_tau = foldr add (ppr res_ty) tys_w_strs
add (str,ty) pp_ty = pprBangTy str ty <+> arrow <+> pp_ty
pprParendBangTy (strict,ty)