rdbg: save/restore the sasa state between each step to allow backward moves.

lib/algo/algo.ml

-(* Time-stamp: <modified the 03/04/2019 (at 23:02) by Erwan Jahier> *)
+(* Time-stamp: <modified the 07/05/2019 (at 17:50) by Erwan Jahier> *)
 
 (** Process programmer API *)
 type varT = It | Ft | Bt | Et of int | St | Nt | At of varT * int
@@ -18,20 +18,20 @@ type neighbor = {
 type enable_fun = neighbor list -> local_env -> action list
 type step_fun   = neighbor list -> local_env -> action -> local_env
 
-type int_tables = {
-  vars: (string, vars)  Hashtbl.t;
-  init_vars: (string, neighbor list -> local_env)  Hashtbl.t;
-  enable: (string, enable_fun) Hashtbl.t;
-  step: (string, step_fun) Hashtbl.t;
-  actions: (string, action list) Hashtbl.t;
+type internal_tables = {
+  vars     : (string, vars)  Hashtbl.t;
+  init_vars: (string, neighbor list -> local_env) Hashtbl.t;
+  enable   : (string, enable_fun) Hashtbl.t;
+  step     : (string, step_fun)   Hashtbl.t;
+  actions  : (string, action list) Hashtbl.t;
 }
 
 let tbls = {
-  vars = Hashtbl.create 1;
+  vars      = Hashtbl.create 1;
   init_vars = Hashtbl.create 1;
-  enable = Hashtbl.create 1;
-  step = Hashtbl.create 1;
-  actions = Hashtbl.create 1;
+  enable    = Hashtbl.create 1;
+  step      = Hashtbl.create 1;
+  actions   = Hashtbl.create 1;
 }
 
 let verbose_level = ref 0
@@ -118,11 +118,14 @@ let rec (init_var: neighbor list -> varT -> value) =
     | At(t,i) -> A(Array.make i (init_var nl t))
 
 
-let (reg_init_vars : algo_id -> (neighbor list -> local_env) -> unit) = fun algo_id x ->
-  if !verbose_level > 0 then Printf.printf "Registering %s init_vars\n" algo_id;
-  flush stdout;
-  Hashtbl.replace tbls.init_vars algo_id x
-let (get_init_vars : algo_id -> (string * varT) list -> (neighbor list -> local_env)) =
+let (reg_init_vars : algo_id -> (neighbor list -> local_env) -> unit) =
+  fun algo_id x ->
+    if !verbose_level > 0 then Printf.printf "Registering %s init_vars\n" algo_id;
+    flush stdout;
+    Hashtbl.replace tbls.init_vars algo_id x
+      
+let (get_init_vars : algo_id -> (string * varT) list ->
+     (neighbor list -> local_env)) =
   fun algo_id vars ->
     let default_env =
       (fun nl v ->
@@ -137,7 +140,8 @@ let (get_init_vars : algo_id -> (string * varT) list -> (neighbor list -> local_
          try user_env nl v
          with e ->
            if !verbose_level > 1 then
-             Printf.eprintf "No init value for '%s' in user init function (%s).\n" v
+             Printf.eprintf
+               "No init value for '%s' in user init function (%s).\n" v
                (Printexc.to_string e);
            default_env nl v)
     with Not_found ->