[project @ 2000-04-20 10:56:05 by simonpj]

- Fix bug in TcExpr.tcMonoExpr (RecordUpd ...), where I hadn't
  propagated the recent change (to be H98ish) that record selectors
  for types with a context are overloaded:
	data Eq a => T a { f1 :: a }

  Here	f1 :: Eq a => T a -> a

  I don't like this, but Mark persuaded me that this was the
  Right Thing if we are to have contexts in data decls at all
  (which we should not)

ghc/compiler/deSugar/DsExpr.lhs

@@ -32,7 +32,7 @@ import Match		( matchWrapper, matchSimply )
 import CostCentre	( mkUserCC )
 import FieldLabel	( FieldLabel )
 import Id		( Id, idType, recordSelectorFieldLabel )
-import DataCon		( DataCon, dataConId, dataConTyCon, dataConArgTys, dataConFieldLabels )
+import DataCon		( DataCon, dataConWrapId, dataConTyCon, dataConArgTys, dataConFieldLabels )
 import PrelInfo		( rEC_CON_ERROR_ID, rEC_UPD_ERROR_ID, iRREFUT_PAT_ERROR_ID, addr2IntegerId )
 import TyCon		( isNewTyCon )
 import DataCon		( isExistentialDataCon )
@@ -507,7 +507,7 @@ dsExpr (RecordUpdOut record_expr record_out_ty dicts rbinds)
 	    let 
 		val_args = zipWithEqual "dsExpr:RecordUpd" mk_val_arg
 					(dataConFieldLabels con) arg_ids
-		rhs = foldl HsApp (DictApp (TyApp (HsVar (dataConId con)) 
+		rhs = foldl HsApp (DictApp (TyApp (HsVar (dataConWrapId con)) 
 						  out_inst_tys)
 					   dicts)
 				  val_args

ghc/compiler/typecheck/TcExpr.lhs

@@ -57,8 +57,8 @@ import Name		( Name, getName )
 import Type		( mkFunTy, mkAppTy, mkTyVarTy, mkTyVarTys,
 			  ipName_maybe,
 			  splitFunTy_maybe, splitFunTys, isNotUsgTy,
-			  mkTyConApp,
-			  splitForAllTys, splitRhoTy,
+			  mkTyConApp, splitSigmaTy, 
+			  splitRhoTy,
 			  isTauTy, tyVarsOfType, tyVarsOfTypes, 
 			  isForAllTy, splitAlgTyConApp, splitAlgTyConApp_maybe,
 			  boxedTypeKind, mkArrowKind,
@@ -562,8 +562,9 @@ tcMonoExpr expr@(RecordUpd record_expr rbinds) res_ty
 	-- Figure out the tycon and data cons from the first field name
     let
 	(Just sel_id : _)	  = maybe_sel_ids
-	(_, tau)	      	  = ASSERT( isNotUsgTy (idType sel_id) )
-                                    splitForAllTys (idType sel_id)
+	(_, _, tau)	      	  = ASSERT( isNotUsgTy (idType sel_id) )
+                                    splitSigmaTy (idType sel_id)	-- Selectors can be overloaded
+									-- when the data type has a context
 	Just (data_ty, _)     	  = splitFunTy_maybe tau	-- Must succeed since sel_id is a selector
 	(tycon, _, data_cons) 	  = splitAlgTyConApp data_ty
 	(con_tyvars, theta, _, _, _, _) = dataConSig (head data_cons)