let file_of glob =
(* returns the file name to which belongs glob *)
let res = ref "" in
let all_files = Globals.FileIndex.get_files () in
begin
for j = 0 to (List.length all_files)-1 do
let f = (List.nth all_files j) in
let (_,globs) = Globals.FileIndex.find f in
for i = 0 to (List.length globs)-1 do
let elt = ((List.nth globs i) :> global) in
if (fun_equal elt glob) then
res:=f
done
done;
!res
end