structure SM = StringMap
-fun lookup (evs, ev) =
+fun lookup ((root, evs), ev) =
case SM.find (evs, ev) of
- NONE => raise Fail ("Couldn't find an environment variable "
- ^ ev ^ " that type-checking has guaranteed")
+ NONE => (case SM.find (root, ev) of
+ NONE => raise Fail ("Couldn't find an environment variable "
+ ^ ev ^ " that type-checking has guaranteed")
+ | SOME v => v)
| SOME v => v
fun printEvs (name, evs) =
(name, rev args)
end
-fun exec' evs (eAll as (e, _)) =
+fun exec' (evsAll as (root, evs)) (eAll as (e, _)) =
case e of
ESkip => SM.empty
| ESet (ev, e) => SM.insert (SM.empty, ev, e)
| EGet (x, _, ev, e) =>
let
- val e' = Reduce.subst x (lookup (evs, ev)) e
+ val e' = Reduce.subst x (lookup (evsAll, ev)) e
in
- exec' evs (Reduce.reduceExp Env.empty e')
+ exec' evsAll (Reduce.reduceExp Env.empty e')
end
| ESeq es =>
let
val (new, _) =
foldl (fn (e, (new, keep)) =>
let
- val new' = exec' keep e
+ val new' = exec' (root, keep) e
in
(conjoin (new, new'),
conjoin (keep, new'))
end
| ELocal (e1, e2) =>
let
- val evs' = exec' evs e1
+ val evs' = exec' evsAll e1
in
- exec' (conjoin (evs, evs')) e2
+ exec' (root, (conjoin (evs, evs'))) e2
end
| EWith (e1, e2) =>
let
NONE => raise Fail "Unbound primitive container"
| SOME (action, cleanup) =>
let
- val evs' = action (evs, args)
- val evs'' = exec' evs e2
+ val evs' = action (conjoin (root, evs), args)
+ val evs'' = exec' evsAll e2
in
cleanup ();
evs'
in
case Env.action prim of
NONE => raise Fail "Unbound primitive action"
- | SOME action => action (evs, List.map (Reduce.reduceExp Env.empty) args)
+ | SOME action => action (conjoin (root, evs), List.map (Reduce.reduceExp Env.empty) args)
end
fun exec evs e =
Env.post ()
end
+val exec' = fn evs as (root, evs') => fn e => conjoin (evs', exec' evs e)
+
end