Improve handling of newtypes (fixes Trac 1495)

[ghc-hetmet.git] / compiler / types / TyCon.lhs

diff --git a/compiler/types/TyCon.lhs b/compiler/types/TyCon.lhs
index 7d11482..c495ebb 100644 (file)
--- a/compiler/types/TyCon.lhs
+++ b/compiler/types/TyCon.lhs
@@ -33,7 +33,7 @@ module TyCon(
        isEnumerationTyCon, isGadtSyntaxTyCon, isOpenTyCon,
        assocTyConArgPoss_maybe, isTyConAssoc, setTyConArgPoss,
        isTupleTyCon, isUnboxedTupleTyCon, isBoxedTupleTyCon, tupleTyConBoxity,
-       isRecursiveTyCon, newTyConRep, newTyConRhs, newTyConEtadRhs, newTyConCo_maybe,
+       isRecursiveTyCon, newTyConRhs, newTyConEtadRhs, newTyConCo_maybe,
        isHiBootTyCon, isSuperKindTyCon,
         isCoercionTyCon_maybe, isCoercionTyCon,
         isImplicitTyCon,
@@ -259,26 +259,11 @@ data AlgTyConRhs
                                -- Watch out!  If any newtypes become transparent
                                -- again check Trac #1072.
 
-       nt_etad_rhs :: ([TyVar], Type) ,
+       nt_etad_rhs :: ([TyVar], Type)
                        -- The same again, but this time eta-reduced
                        -- hence the [TyVar] which may be shorter than the declared 
                        -- arity of the TyCon.  See Note [Newtype eta]
-
-       nt_rep :: Type  -- Cached: the *ultimate* representation type
-                       -- By 'ultimate' I mean that the top-level constructor
-                       -- of the rep type is not itself a newtype or type synonym.
-                       -- The rep type isn't entirely simple:
-                       --  for a recursive newtype we pick () as the rep type
-                       --      newtype T = MkT T
-                       -- 
-                       -- This one does not need to be eta reduced; hence its
-                       -- free type variables are conveniently tyConTyVars
-                       -- Thus:
-                       --      newtype T a = MkT [(a,Int)]
-                       -- The rep type is [(a,Int)]
-                       -- NB: the rep type isn't necessarily the original RHS of the
-                       --     newtype decl, because the rep type looks through other
-    }                  --     newtypes.
+    }
 
 visibleDataCons :: AlgTyConRhs -> [DataCon]
 visibleDataCons AbstractTyCon                = []
@@ -871,9 +856,7 @@ tyConFamilySize (AlgTyCon   {algTcRhs = DataTyCon {data_cons = cons}}) =
 tyConFamilySize (AlgTyCon   {algTcRhs = NewTyCon {}})                  = 1
 tyConFamilySize (AlgTyCon   {algTcRhs = OpenTyCon {}})                 = 0
 tyConFamilySize (TupleTyCon {})                                               = 1
-#ifdef DEBUG
 tyConFamilySize other = pprPanic "tyConFamilySize:" (ppr other)
-#endif
 
 tyConSelIds :: TyCon -> [Id]
 tyConSelIds (AlgTyCon {algTcSelIds = fs}) = fs
@@ -894,10 +877,6 @@ newTyConEtadRhs :: TyCon -> ([TyVar], Type)
 newTyConEtadRhs (AlgTyCon {algTcRhs = NewTyCon { nt_etad_rhs = tvs_rhs }}) = tvs_rhs
 newTyConEtadRhs tycon = pprPanic "newTyConEtadRhs" (ppr tycon)
 
-newTyConRep :: TyCon -> ([TyVar], Type)
-newTyConRep (AlgTyCon {tyConTyVars = tvs, algTcRhs = NewTyCon { nt_rep = rep }}) = (tvs, rep)
-newTyConRep tycon = pprPanic "newTyConRep" (ppr tycon)
-
 newTyConCo_maybe :: TyCon -> Maybe TyCon
 newTyConCo_maybe (AlgTyCon {algTcRhs = NewTyCon { nt_co = co }}) = co
 newTyConCo_maybe _                                              = Nothing