X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcGenDeriv.lhs;h=2c04cf4bc34f0e53ff5299466a5966deb9cf6405;hb=b24792b081f7f74cf52c0c3178cb71fccfc1fcb3;hp=4e95ad31b2a0027027be76b86f8caf0da2296b1d;hpb=7fc01c4671980ea3c66d549c0ece4d82fd3f5ade;p=ghc-hetmet.git

diff --git a/compiler/typecheck/TcGenDeriv.lhs b/compiler/typecheck/TcGenDeriv.lhs
index 4e95ad3..2c04cf4 100644
--- a/compiler/typecheck/TcGenDeriv.lhs
+++ b/compiler/typecheck/TcGenDeriv.lhs
@@ -168,7 +168,7 @@ gen_Eq_binds loc tycon
   where
     (nullary_cons, nonnullary_cons)
        | isNewTyCon tycon = ([], tyConDataCons tycon)
-       | otherwise	      = partition isNullarySrcDataCon (tyConDataCons tycon)
+       | otherwise        = partition isNullarySrcDataCon (tyConDataCons tycon)
 
     no_nullary_cons = null nullary_cons
 
@@ -1457,11 +1457,13 @@ functorLikeTraverse var (FT { ft_triv = caseTrivial,     ft_var = caseVar
             where (_, xc) = go co x
                   (yr,yc) = go co y
         go co ty@(TyConApp con args)
-               | isTupleTyCon con = (caseTuple (tupleTyConBoxity con) xrs,True)
-               | null args        = (caseTrivial,False)	 -- T
-               | or (init xcs)    = (caseWrongArg,True)	 -- T (..var..)    ty
-               | last xcs         = 			 -- T (..no var..) ty
-	       	      		    (caseTyApp (fst (splitAppTy ty)) (last xrs),True)
+               | not (or xcs)     = (caseTrivial, False)   -- Variable does not occur
+               -- At this point we know that xrs, xcs is not empty,
+               -- and at least one xr is True
+               | isTupleTyCon con = (caseTuple (tupleTyConBoxity con) xrs, True)
+               | or (init xcs)    = (caseWrongArg, True)   -- T (..var..)    ty
+               | otherwise        =                        -- T (..no var..) ty
+                                    (caseTyApp (fst (splitAppTy ty)) (last xrs), True)
             where (xrs,xcs) = unzip (map (go co) args)
         go co (ForAllTy v x) | v /= var && xc = (caseForAll v xr,True)
             where (xr,xc) = go co x
@@ -1668,7 +1670,7 @@ genAuxBind loc (GenCon2Tag tycon)
     rdr_name = con2tag_RDR tycon
 
     sig_ty = HsCoreTy $ 
-             mkForAllTys (tyConTyVars tycon) $
+             mkSigmaTy (tyConTyVars tycon) (tyConStupidTheta tycon) $
              mkParentType tycon `mkFunTy` intPrimTy
 
     lots_of_constructors = tyConFamilySize tycon > 8