X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FdeSugar%2FCheck.lhs;h=6244b37bd6ec04c7e76985310697ce50fd72d3c7;hb=1fede4bc9501744bf2269ce2a4cb9fb735969caa;hp=75186feecbd736ee724111ebfb355a8b9780424a;hpb=0b957f9b7d093b563172d95dbf0b56878caeefd5;p=ghc-hetmet.git

diff --git a/compiler/deSugar/Check.lhs b/compiler/deSugar/Check.lhs
index 75186fe..6244b37 100644
--- a/compiler/deSugar/Check.lhs
+++ b/compiler/deSugar/Check.lhs
@@ -26,6 +26,8 @@ import Name
 import TysWiredIn
 import PrelNames
 import TyCon
+import Type
+import Unify( dataConCannotMatch )
 import SrcLoc
 import UniqSet
 import Util
@@ -433,11 +435,11 @@ get_lit :: Pat id -> Maybe HsLit
 -- Get a representative HsLit to stand for the OverLit
 -- It doesn't matter which one, because they will only be compared
 -- with other HsLits gotten in the same way
-get_lit (LitPat lit)			 = Just lit
-get_lit (NPat (HsIntegral i   _ _) mb _) = Just (HsIntPrim   (mb_neg mb i))
-get_lit (NPat (HsFractional f _ _) mb _) = Just (HsFloatPrim (mb_neg mb f))
-get_lit (NPat (HsIsString s   _ _)  _ _) = Just (HsStringPrim s)
-get_lit _                                = Nothing
+get_lit (LitPat lit)				          = Just lit
+get_lit (NPat (OverLit { ol_val = HsIntegral i})    mb _) = Just (HsIntPrim   (mb_neg mb i))
+get_lit (NPat (OverLit { ol_val = HsFractional f }) mb _) = Just (HsFloatPrim (mb_neg mb f))
+get_lit (NPat (OverLit { ol_val = HsIsString s })   _  _) = Just (HsStringPrim s)
+get_lit _                                	          = Nothing
 
 mb_neg :: Num a => Maybe b -> a -> a
 mb_neg Nothing  v = v
@@ -446,12 +448,13 @@ mb_neg (Just _) v = -v
 get_unused_cons :: [Pat Id] -> [DataCon]
 get_unused_cons used_cons = ASSERT( not (null used_cons) ) unused_cons
      where
-       (ConPatOut { pat_con = l_con }) = head used_cons
-       ty_con 	       = dataConTyCon (unLoc l_con)	-- Newtype observable
-       all_cons        = tyConDataCons ty_con
-       used_cons_as_id = map (\ (ConPatOut{ pat_con = L _ d}) -> d) used_cons
-       unused_cons     = uniqSetToList
-			 (mkUniqSet all_cons `minusUniqSet` mkUniqSet used_cons_as_id) 
+       used_set :: UniqSet DataCon
+       used_set = mkUniqSet [d | ConPatOut{ pat_con = L _ d} <- used_cons]
+       (ConPatOut { pat_ty = ty }) = head used_cons
+       Just (ty_con, inst_tys) = splitTyConApp_maybe ty
+       unused_cons = filterOut is_used (tyConDataCons ty_con)
+       is_used con = con `elementOfUniqSet` used_set
+		     || dataConCannotMatch inst_tys con
 
 all_vars :: [Pat Id] -> Bool
 all_vars []             = True