remove dead-code graph_to_tree

src/grew_graph.ml

@@ -249,45 +249,6 @@ module G_graph = struct
           ) graph.map Gid_map.empty
     }
 
-  exception Not_a_tree
-  type tree = T of (Gid.t * tree list)
-
-  let rec tree_to_string = function
-  | T (gid, daughters) ->
-    sprintf "%s [%s]"
-      (Gid.to_string gid)
-      ((String.concat) ";" (List.map tree_to_string daughters))
-
-  let graph_to_tree (g : t) : tree =
-    let rec build_sub_tree map forest gid =
-      if List.mem_assoc gid forest
-      then (map, forest)
-      else
-        let (new_map, daugthers, new_forest) = Massoc_gid.fold
-          (fun (acc_map, sub_trees, acc_forest) gid2 edge ->
-            if edge = G_edge.sub
-            then
-              (* ensure that gid2 is in forest *)
-              let (new_acc_map, new_acc_forest) = build_sub_tree acc_map acc_forest gid2 in
-              let sub = List.assoc gid2 new_acc_forest in
-              ( new_acc_map,
-                sub::sub_trees,
-                List.remove_assoc gid2 new_acc_forest
-              )
-            else (acc_map, sub_trees, acc_forest)
-        ) (map,[],forest) (G_node.get_next (Gid_map.find gid map)) in
-      (Gid_map.remove gid new_map, (gid, T (gid, List.rev daugthers))::new_forest) in
-
-    let rec loop (unused_map, forest) =
-      match (Gid_map.is_empty unused_map, forest) with
-      | (true, [(_,tree)]) -> tree
-      | (true, _) -> raise Not_a_tree
-      | _ ->
-        (* pick one unused node *)
-        let (gid,_) = Gid_map.choose unused_map in
-        loop (build_sub_tree unused_map forest gid) in
-    loop (g.map, [])
-
   let get_highest g = g.highest_index
 
   let find node_id graph = Gid_map.find node_id graph.map