Avoid using Queue.t for a one-shot data structure, especially an unordered one.

src/driver/call_provers.ml

@@ -400,15 +400,14 @@ let get_new_results ~blocking = (* TODO: handle ProverStarted events *)
 
 let forward_results ~blocking =
   get_new_results ~blocking;
-  let q = Queue.create () in
+  let q = ref [] in
   Hashtbl.iter (fun key element ->
     if element = ProverStarted && blocking then
       ()
     else
-      Queue.push (ServerCall key, element) q) result_buffer;
+      q := (ServerCall key, element) :: !q) result_buffer;
   Hashtbl.clear result_buffer;
-  q
-
+  !q
 
 let query_result_buffer id =
   try let r = Hashtbl.find result_buffer id in

src/driver/call_provers.mli

@@ -163,10 +163,8 @@ type prover_update =
   | ProverStarted
   | ProverFinished of prover_result
 
-
-val forward_results: blocking:bool -> (prover_call * prover_update) Queue.t
-(** returns new results that are given by why3server. *)
-
+val forward_results: blocking:bool -> (prover_call * prover_update) list
+(** returns new results from why3server, in an unordered fashion. *)
 
 val query_call : prover_call -> prover_update
 (** non-blocking function that reports any new updates