containers := SM.insert (!containers, name, (befor, after))
fun container name = SM.find (!containers, name)
-fun badArgs name = raise Fail ("Invalid arguments to " ^ name)
+fun badArgs (name, args) =
+ (print ("Invalid arguments to " ^ name ^ "\n");
+ app (fn arg => Print.preface ("Argument: ", Print.p_exp arg)) args;
+ raise Domain)
+fun badArg (func, arg, v) =
+ (print ("Invalid " ^ arg ^ " argument to " ^ func ^ "\n");
+ Print.preface ("Argument: ", Print.p_exp v);
+ raise Domain)
+
+type 'a arg = exp -> 'a option
+
+fun int (EInt n, _) = SOME n
+ | int _ = NONE
+
+fun string (EString s, _) = SOME s
+ | string _ = NONE
+
+fun mapFail f [] = SOME []
+ | mapFail f (h :: t) =
+ case f h of
+ NONE => NONE
+ | SOME h' =>
+ case mapFail f t of
+ NONE => NONE
+ | SOME t' => SOME (h' :: t')
+
+fun list f (EList ls, _) = mapFail f ls
+ | list _ _ = NONE
+
+fun one func (name, arg) f (_, [e]) =
+ (case arg e of
+ NONE => badArg (func, name, e)
+ | SOME v => (f v;
+ SM.empty))
+ | one func _ _ (_, es) = badArgs (func, es)
+
+fun two func (name1, arg1, name2, arg2) f (_, [e1, e2]) =
+ (case (arg1 e1, arg2 e2) of
+ (NONE, _) => badArg (func, name1, e1)
+ | (_, NONE) => badArg (func, name2, e2)
+ | (SOME v1, SOME v2) => (f (v1, v2);
+ SM.empty))
+ | two func _ _ (_, es) = badArgs (func, es)
+
+fun type_one func arg f =
+ registerType (func, fn e =>
+ case arg e of
+ NONE => false
+ | SOME v => f v)
+
+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 container_one name args (f, g) = registerContainer (name, one name args f, g)
type env = SS.set * (typ * exp option) SM.map
val empty : env = (SS.add (SS.singleton "int", "string"),