towards unboxing through newtypes

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

diff --git a/compiler/basicTypes/DataCon.lhs b/compiler/basicTypes/DataCon.lhs
index 3eaadf7..486745c 100644 (file)
--- a/compiler/basicTypes/DataCon.lhs
+++ b/compiler/basicTypes/DataCon.lhs
@@ -23,7 +23,8 @@ module DataCon (
        isNullarySrcDataCon, isNullaryRepDataCon, isTupleCon, isUnboxedTupleCon,
        isVanillaDataCon, classDataCon, 
 
-       splitProductType_maybe, splitProductType,
+       splitProductType_maybe, splitProductType, deepSplitProductType,
+        deepSplitProductType_maybe
     ) where
 
 #include "HsVersions.h"
@@ -31,13 +32,13 @@ module DataCon (
 import Type            ( Type, ThetaType, 
                          substTyWith, substTyVar, mkTopTvSubst, 
                          mkForAllTys, mkFunTys, mkTyConApp, mkTyVarTy, mkTyVarTys, 
-                         splitTyConApp_maybe, 
+                         splitTyConApp_maybe, newTyConInstRhs,
                          mkPredTys, isStrictPred, pprType
                        )
 import Coercion                ( isEqPred, mkEqPred )
 import TyCon           ( TyCon, FieldLabel, tyConDataCons, 
                          isProductTyCon, isTupleTyCon, isUnboxedTupleTyCon,
-                          isNewTyCon )
+                          isNewTyCon, isRecursiveTyCon )
 import Class           ( Class, classTyCon )
 import Name            ( Name, NamedThing(..), nameUnique )
 import Var             ( TyVar, Id )
@@ -409,7 +410,10 @@ mkDataCon name declared_infix
          eq_spec theta
          orig_arg_tys tycon
          stupid_theta ids
-  = con
+  = ASSERT( not (any isEqPred theta) )
+       -- We don't currently allow any equality predicates on
+       -- a data constructor (apart from the GADT ones in eq_spec)
+    con
   where
     is_vanilla = null ex_tvs && null eq_spec && null theta
     con = ASSERT( is_vanilla || not (isNewTyCon tycon) )
@@ -432,10 +436,9 @@ mkDataCon name declared_infix
        -- The 'arg_stricts' passed to mkDataCon are simply those for the
        -- source-language arguments.  We add extra ones for the
        -- dictionary arguments right here.
-    (more_eq_preds, dict_preds) = partition isEqPred theta
     dict_tys     = mkPredTys theta
     real_arg_tys = dict_tys                      ++ orig_arg_tys
-    real_stricts = map mk_dict_strict_mark dict_preds ++ arg_stricts
+    real_stricts = map mk_dict_strict_mark theta ++ arg_stricts
 
        -- Representation arguments and demands
        -- To do: eliminate duplication with MkId
@@ -601,10 +604,10 @@ dataConInstArgTys (MkData {dcRepArgTys = arg_tys,
 
 -- And the same deal for the original arg tys
 dataConInstOrigArgTys :: DataCon -> [Type] -> [Type]
-dataConInstOrigArgTys (MkData {dcOrigArgTys = arg_tys,
+dataConInstOrigArgTys dc@(MkData {dcOrigArgTys = arg_tys,
                               dcUnivTyVars = univ_tvs, 
                               dcExTyVars = ex_tvs}) inst_tys
- = ASSERT( length tyvars == length inst_tys )
+ = ASSERT2( length tyvars == length inst_tys, ptext SLIT("dataConInstOrigArgTys") <+> ppr dc <+> ppr inst_tys )
    map (substTyWith tyvars inst_tys) arg_tys
  where
    tyvars = univ_tvs ++ ex_tvs
@@ -685,6 +688,20 @@ splitProductType str ty
        Nothing    -> pprPanic (str ++ ": not a product") (pprType ty)
 
 
+deepSplitProductType_maybe ty
+  = do { (res@(tycon, tycon_args, _, _)) <- splitProductType_maybe ty
+       ; let {result 
+             | isNewTyCon tycon && not (isRecursiveTyCon tycon)
+             = deepSplitProductType_maybe (newTyConInstRhs tycon tycon_args)
+             | otherwise = Just res}
+       ; result
+       }
+          
+deepSplitProductType str ty 
+  = case deepSplitProductType_maybe ty of
+      Just stuff -> stuff
+      Nothing -> pprPanic (str ++ ": not a product") (pprType ty)
+
 computeRep :: [StrictnessMark]         -- Original arg strictness
           -> [Type]                    -- and types
           -> ([StrictnessMark],        -- Representation arg strictness
@@ -696,6 +713,7 @@ computeRep stricts tys
     unbox NotMarkedStrict ty = [(NotMarkedStrict, ty)]
     unbox MarkedStrict    ty = [(MarkedStrict,    ty)]
     unbox MarkedUnboxed   ty = zipEqual "computeRep" (dataConRepStrictness arg_dc) arg_tys
-                            where
-                              (_, _, arg_dc, arg_tys) = splitProductType "unbox_strict_arg_ty" ty
+                               where
+                                 (tycon, tycon_args, arg_dc, arg_tys) 
+                                     = deepSplitProductType "unbox_strict_arg_ty" ty
 \end{code}