Fix names of coercions in newtype instances

[ghc-hetmet.git] / compiler / basicTypes / MkId.lhs

diff --git a/compiler/basicTypes/MkId.lhs b/compiler/basicTypes/MkId.lhs
index bcfd33d..f72afb9 100644 (file)
--- a/compiler/basicTypes/MkId.lhs
+++ b/compiler/basicTypes/MkId.lhs
@@ -72,7 +72,7 @@ import Outputable
 import FastString
 import ListSetOps
 import Module
-\end{code}             
+\end{code}
 
 %************************************************************************
 %*                                                                     *
@@ -211,7 +211,6 @@ Now we want
 mkDataConIds :: Name -> Name -> DataCon -> DataConIds
 mkDataConIds wrap_name wkr_name data_con
   | isNewTyCon tycon                   -- Newtype, only has a worker
-  , not (isFamInstTyCon tycon)         -- unless it's a family instancex
   = DCIds Nothing nt_work_id                 
 
   | any isMarkedStrict all_strict_marks             -- Algebraic, needs wrapper
@@ -279,7 +278,7 @@ mkDataConIds wrap_name wkr_name data_con
                   wrapNewTypeBody tycon res_ty_args
                        (Var id_arg1)
 
-    id_arg1 = mkTemplateLocal 1 (head orig_arg_tys)
+    id_arg1 = ASSERT( not (null orig_arg_tys) ) mkTemplateLocal 1 (head orig_arg_tys)
 
        ----------- Wrapper --------------
        -- We used to include the stupid theta in the wrapper's args
@@ -492,7 +491,7 @@ mkRecordSelId tycon field_label
     data_cons_w_field = filter has_field data_cons     -- Can't be empty!
     has_field con     = field_label `elem` dataConFieldLabels con
 
-    con1       = head data_cons_w_field
+    con1       = ASSERT( not (null data_cons_w_field) ) head data_cons_w_field
     (univ_tvs, _, eq_spec, _, _, data_ty) = dataConFullSig con1
        -- For a data type family, the data_ty (and hence selector_ty) mentions
        -- only the family TyCon, not the instance TyCon