ACLs

[hcoop/domtool2.git] / src / env.sml

diff --git a/src/env.sml b/src/env.sml
index 48ec715..db92e6e 100644 (file)
--- a/src/env.sml
+++ b/src/env.sml
@@ -41,6 +41,48 @@ fun registerContainer (name, befor, after) =
     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;
@@ -70,6 +112,10 @@ fun mapFail f [] = SOME []
 fun list f (EList ls, _) = mapFail f ls
   | list _ _ = NONE
 
+fun none func f (_, []) = (f ();
+                          SM.empty)
+  | none func _ (_, es) = badArgs (func, es)
+
 fun one func (name, arg) f (_, [e]) =
     (case arg e of
         NONE => badArg (func, name, e)
@@ -85,17 +131,50 @@ fun two func (name1, arg1, name2, arg2) f (_, [e1, e2]) =
                                SM.empty))
   | two func _ _ (_, es) = badArgs (func, es)
 
+
+fun oneV func (name, arg) f (evs, [e]) =
+    (case arg e of
+        NONE => badArg (func, name, e)
+       | SOME v => (f (evs, v);
+                   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
+       NONE => raise Fail ("Unavailable environment variable " ^ name)
+      | SOME e =>
+       case arg e of
+           NONE => raise Fail ("Bad format for environment variable " ^ name)
+         | SOME v => v
+
 fun type_one func arg f =
     registerType (func, fn e =>
                           case arg e of
                               NONE => false
                             | SOME v => f v)
 
+fun action_none name f = registerAction (name, none name f)
 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)
 
+fun containerV_one name args (f, g) = registerContainer (name, oneV name args f, g)
+
 type env = SS.set * (typ * exp option) SM.map * SS.set
 val empty : env = (SS.empty, SM.empty, SS.empty)