diff options
Diffstat (limited to 'haddock-api')
| -rw-r--r-- | haddock-api/src/Haddock/Convert.hs | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/haddock-api/src/Haddock/Convert.hs b/haddock-api/src/Haddock/Convert.hs index 325d9cf6..96a08555 100644 --- a/haddock-api/src/Haddock/Convert.hs +++ b/haddock-api/src/Haddock/Convert.hs @@ -41,7 +41,8 @@ import TysWiredIn ( listTyConName, starKindTyConName, unitTy ) import PrelNames ( hasKey, eqTyConKey, funTyConKey, ipClassKey , tYPETyConKey, liftedRepDataConKey ) import Unique ( getUnique ) -import Util ( compareLength, filterByList, filterOut, splitAtList ) +import Util ( chkAppend, compareLength, dropList, filterByList, filterOut + , splitAtList ) import Var import VarSet @@ -543,7 +544,7 @@ synifyInstHead (_, preds, cls, types) = specializeInstHead $ InstHead -- Convert a family instance, this could be a type family or data family synifyFamInst :: FamInst -> Bool -> Either ErrMsg (InstHead GhcRn) synifyFamInst fi opaque = do - ityp' <- ityp $ fi_flavor fi + ityp' <- ityp fam_flavor return InstHead { ihdClsName = fi_fam fi , ihdTypes = map unLoc annot_ts @@ -552,11 +553,28 @@ synifyFamInst fi opaque = do where ityp SynFamilyInst | opaque = return $ TypeInst Nothing ityp SynFamilyInst = - return . TypeInst . Just . unLoc . synifyType WithinType $ fi_rhs fi + return . TypeInst . Just . unLoc $ synifyType WithinType fam_rhs ityp (DataFamilyInst c) = DataInst <$> synifyTyCon (Just $ famInstAxiom fi) c - fam_tc = famInstTyCon fi - ts = filterOutInvisibleTypes fam_tc $ fi_tys fi + fam_tc = famInstTyCon fi + fam_flavor = fi_flavor fi + fam_lhs = fi_tys fi + fam_rhs = fi_rhs fi + + eta_expanded_lhs + -- eta-expand lhs types, because sometimes data/newtype + -- instances are eta-reduced; See Trac #9692 + -- See Note [Eta reduction for data family axioms] in TcInstDcls in GHC + | DataFamilyInst rep_tc <- fam_flavor + = let (_, rep_tc_args) = splitTyConApp fam_rhs + etad_tyvars = dropList rep_tc_args $ tyConTyVars rep_tc + etad_tys = mkTyVarTys etad_tyvars + eta_exp_lhs = fam_lhs `chkAppend` etad_tys + in eta_exp_lhs + | otherwise + = fam_lhs + + ts = filterOutInvisibleTypes fam_tc eta_expanded_lhs synifyTypes = map (synifyType WithinType) ts' = synifyTypes ts annot_ts = zipWith3 annotHsType is_poly_tvs ts ts' |