containers := SM.insert (!containers, name, (befor, after))
fun container name = SM.find (!containers, name)
+local
+ val pr = ref (fn () => ())
+in
+
+fun registerPre f =
+ let
+ val old = !pr
+ in
+ pr := (fn () => (old (); f ()))
+ end
+fun pre () = !pr ()
+
+end
+
+local
+ val pst = ref (fn () => ())
+in
+
+fun registerPost f =
+ let
+ val old = !pst
+ in
+ pst := (fn () => (old (); f ()))
+ end
+fun post () = !pst ()
+
+end
+
+local
+ val pr = ref (fn () => ())
+in
+
+fun registerPreTycheck f =
+ let
+ val old = !pr
+ in
+ pr := (fn () => (old (); f ()))
+ end
+fun preTycheck () = !pr ()
+
+end
+
fun badArgs (name, args) =
(print ("Invalid arguments to " ^ name ^ "\n");
app (fn arg => Print.preface ("Argument: ", Print.p_exp arg)) args;
SM.empty))
| oneV func _ _ (_, es) = badArgs (func, es)
+fun twoV func (name1, arg1, name2, arg2) f (evs, [e1, e2]) =
+ (case (arg1 e1, arg2 e2) of
+ (NONE, _) => badArg (func, name1, e1)
+ | (_, NONE) => badArg (func, name2, e2)
+ | (SOME v1, SOME v2) => (f (evs, v1, v2);
+ SM.empty))
+ | twoV func _ _ (_, es) = badArgs (func, es)
+
fun env arg (evs, name) =
case SM.find (evs, name) of
fun action_one name args f = registerAction (name, one name args f)
fun action_two name args f = registerAction (name, two name args f)
+fun actionV_none name f = registerAction (name, fn (env, _) => (f env; env))
fun actionV_one name args f = registerAction (name, oneV name args f)
+fun actionV_two name args f = registerAction (name, twoV name args f)
fun container_none name (f, g) = registerContainer (name, none name f, g)
fun container_one name args (f, g) = registerContainer (name, one name args f, g)