+ ; writeTcRef dfun_n_var (extendOccSet set occ)
+ ; return occ }
+
+getConstraintVar :: TcM (TcRef WantedConstraints)
+getConstraintVar = do { env <- getLclEnv; return (tcl_lie env) }
+
+setConstraintVar :: TcRef WantedConstraints -> TcM a -> TcM a
+setConstraintVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
+
+emitConstraints :: WantedConstraints -> TcM ()
+emitConstraints ct
+ = do { lie_var <- getConstraintVar ;
+ updTcRef lie_var (`andWC` ct) }
+
+emitFlat :: WantedEvVar -> TcM ()
+emitFlat ct
+ = do { lie_var <- getConstraintVar ;
+ updTcRef lie_var (`addFlats` unitBag ct) }
+
+emitFlats :: Bag WantedEvVar -> TcM ()
+emitFlats ct
+ = do { lie_var <- getConstraintVar ;
+ updTcRef lie_var (`addFlats` ct) }
+
+emitImplication :: Implication -> TcM ()
+emitImplication ct
+ = do { lie_var <- getConstraintVar ;
+ updTcRef lie_var (`addImplics` unitBag ct) }
+
+emitImplications :: Bag Implication -> TcM ()
+emitImplications ct
+ = do { lie_var <- getConstraintVar ;
+ updTcRef lie_var (`addImplics` ct) }
+
+captureConstraints :: TcM a -> TcM (a, WantedConstraints)
+-- (captureConstraints m) runs m, and returns the type constraints it generates
+captureConstraints thing_inside
+ = do { lie_var <- newTcRef emptyWC ;
+ res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
+ thing_inside ;
+ lie <- readTcRef lie_var ;
+ return (res, lie) }