Fix: the worst evil demon was wrong for no strictly decreasing potential function

lib/sasacore/evil.ml

-(* Time-stamp: <modified the 24/08/2020 (at 15:39) by Erwan Jahier> *)
+(* Time-stamp: <modified the 27/08/2020 (at 18:06) by Erwan Jahier> *)
 
 
 
@@ -20,8 +20,9 @@ let rec (comp : 'a cont -> 'a cont -> 'a cont) =
 let (enumerate : 'a list list -> 'a list cont) = fun all ->
   let rec f acc all =
     let res = match all with
-      | [] ->  Elt(acc, fun () -> NoMore)
-      | []::tl ->  f acc tl
+      | [] ->
+        if acc = [] then NoMore else Elt(acc, fun () -> NoMore)
+      | []::tl -> f acc tl
       | al::tl ->
          List.fold_left
            (fun cont_acc a ->
@@ -33,13 +34,14 @@ let (enumerate : 'a list list -> 'a list cont) = fun all ->
     in
     res
   in
+  assert(List.exists (fun l -> l<>[]) all);
   f [] all
 
 module StringMap = Map.Make(String)
 module StringSet = Set.Make(String)
 
 (*  split [all] into connected components *)
-let (connected_components : 'v pna list list -> 'v pna list list list) =
+let (_connected_components : 'v pna list list -> 'v pna list list list) =
   fun all ->
   let pid2pnal = 
     List.fold_left
@@ -107,25 +109,26 @@ let (worst: 'v Env.t -> ('v Process.t * 'v Register.neighbor list) list ->
   match Register.get_potential () with
   | None -> failwith "No potential function has been provided"
   | Some user_pf ->
-     let pf pnal = (* pnal contains a list of activated processes *)
-       let pidl = List.map (fun (p,_) -> p.Process.pid) p_nl_l in
-       let p_a_l =  List.map (fun (p,_,a) -> p.Process.pid, a) pnal in
-       let ne = Step.f pnal e in
-       let get_info pid =
-         {
-           Register.neighbors = snd (List.find (fun (p,_) -> p.Process.pid = pid) p_nl_l);
-           Register.curr = Env.get e pid ;
-           Register.next = Env.get ne pid ;
-           Register.action = List.assoc_opt pid p_a_l
-         }
-       in
-       user_pf pidl get_info
-     in
-     let alll = time "connected component" connected_components all in
-     let cpt = ref 0 in
-     let res_l =
-       List.map
-         (fun all ->
+    let pf pnal = (* pnal contains a list of activated processes *)
+      let pidl = List.map (fun (p,_) -> p.Process.pid) p_nl_l in
+      let p_a_l =  List.map (fun (p,_,a) -> p.Process.pid, a) pnal in
+      let ne = Step.f pnal e in
+      let get_info pid =
+        {
+          Register.neighbors = snd (List.find (fun (p,_) -> p.Process.pid = pid) p_nl_l);
+          Register.curr = Env.get e pid ;
+          Register.next = Env.get ne pid ;
+          Register.action = List.assoc_opt pid p_a_l
+        }
+      in
+      user_pf pidl get_info
+    in
+    (*let alll = time "connected component" connected_components all in*)
+    let alll = [all] in
+    let cpt = ref 0 in
+    let res_l =
+      List.map
+        (fun all ->
            let pnal1, p1, shedules =
              match  time "enumerate" enumerate all with
              | NoMore -> assert false
@@ -135,18 +138,18 @@ let (worst: 'v Env.t -> ('v Process.t * 'v Register.neighbor list) list ->
              match shedules with
              | NoMore -> (pnal_acc, v_acc)
              | Elt(pnal, c) ->
-                incr cpt;
-                let v = pf pnal in
-                if v < v_acc
-                then search_max (pnal_acc, v_acc) (c()) 
-                else search_max (pnal, v)  (c())
+               incr cpt;
+               let v = pf pnal in
+               if v < v_acc
+               then search_max (pnal_acc, v_acc) (c()) 
+               else search_max (pnal, v)  (c())
            in
            fst (time2 "search" search_max (pnal1, p1) (shedules()))
-         )
-         alll
-     in
-     Printf.printf "Number of connected components: %i (%i)\n%!" (List.length alll) !cpt;
-     List.flatten res_l
+        )
+        alll
+    in
+    Printf.printf "Number of connected components: %i (%i)\n%!" (List.length alll) !cpt;
+    List.flatten res_l
 
 (* exported *)
 let (bad: int -> 'v Env.t -> 'v pna list list -> 'v pna list) =