+
+-- Zonk the kind of a non-TC tyvar in case it is a coercion variable (their
+-- kind contains types).
+--
+zonkTyVar :: (TcTyVar -> TcM Type) -- What to do for an unbound mutable var
+ -> TyVar -> TcM TyVar
+zonkTyVar unbound_var_fn tv
+ | isCoVar tv
+ = do { kind <- zonkType unbound_var_fn (tyVarKind tv)
+ ; return $ setTyVarKind tv kind
+ }
+ | otherwise = return tv