X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FdeSugar%2FDsExpr.lhs;h=45b02fb2e99d14f55a8cb0d4da9d7c2973846b18;hb=6aa2bf20adef309cbf6ff39f4989a96ef0338138;hp=5d7ff191dfa44dd71fc58af6af0bf7a46e76b395;hpb=10fcd78ccde892feccda3f5eacd221c1de75feea;p=ghc-hetmet.git

diff --git a/ghc/compiler/deSugar/DsExpr.lhs b/ghc/compiler/deSugar/DsExpr.lhs
index 5d7ff19..45b02fb 100644
--- a/ghc/compiler/deSugar/DsExpr.lhs
+++ b/ghc/compiler/deSugar/DsExpr.lhs
@@ -22,7 +22,7 @@ import TcHsSyn		( TypecheckedHsExpr, TypecheckedHsBinds, TypecheckedStmt, outPat
 --     So WATCH OUT; check each use of split*Ty functions.
 -- Sigh.  This is a pain.
 
-import TcType		( tcSplitAppTy, tcSplitFunTys, tcSplitTyConApp_maybe, tcTyConAppArgs,
+import TcType		( tcSplitAppTy, tcSplitFunTys, tcTyConAppArgs,
 			  isIntegerTy, tcSplitTyConApp, isUnLiftedType, Type )
 import Type		( splitFunTys )
 import CoreSyn
@@ -46,7 +46,7 @@ import DataCon		( DataCon, dataConWrapId, dataConFieldLabels, dataConInstOrigArg
 import DataCon		( isExistentialDataCon )
 import Literal		( Literal(..) )
 import TyCon		( tyConDataCons )
-import TysWiredIn	( tupleCon, listTyCon, charDataCon, intDataCon )
+import TysWiredIn	( tupleCon, charDataCon, intDataCon )
 import BasicTypes	( RecFlag(..), Boxity(..), ipNameName )
 import Maybes		( maybeToBool )
 import PrelNames	( hasKey, ratioTyConKey, toPName )
@@ -454,7 +454,7 @@ dictionaries.
 dsExpr (RecordUpdOut record_expr record_in_ty record_out_ty dicts [])
   = dsExpr record_expr
 
-dsExpr (RecordUpdOut record_expr record_in_ty record_out_ty dicts rbinds)
+dsExpr expr@(RecordUpdOut record_expr record_in_ty record_out_ty dicts rbinds)
   = getSrcLocDs			`thenDs` \ src_loc ->
     dsExpr record_expr	 	`thenDs` \ record_expr' ->
 
@@ -488,7 +488,9 @@ dsExpr (RecordUpdOut record_expr record_in_ty record_out_ty dicts rbinds)
 				    src_loc)
     in
 	-- Record stuff doesn't work for existentials
-    ASSERT( all (not . isExistentialDataCon) data_cons )
+	-- The type checker checks for this, but we need 
+	-- worry only about the constructors that are to be updated
+    ASSERT2( all (not . isExistentialDataCon) cons_to_upd, ppr expr )
 
 	-- It's important to generate the match with matchWrapper,
 	-- and the right hand sides with applications of the wrapper Id