I'd like a variant of the #use directive for reading in an OCaml
source file, but with the property that it halts immediately on the
first error anywhere in a nesting of #use'd files. For example,
suppose you have a file "root.ml" containing

  let x = 1;;

  #use "branch.ml";;

  let y = 2;;

and a file "branch.ml" containing

  let u = 3;;

  let v = failwith "X";;

  let w = 4;;

Then I want the following to stop immediately on the failure inside
"branch.ml" and hence not evaluate the "y = 2" line in "root.ml" as it
currently does:

          Objective Caml version 3.10.0

  # #use "root.ml";;
  val x : int = 1
  val u : int = 3
  Exception: Failure "X".
  val y : int = 2

On the other hand, I'd want it to keep the results of the x = 1 and
u = 3 lines, not roll back everything. Is this easy to accomplish?
(By the way, I'm ultimately interested in using this together with
camlp5, and possibly with the new camlp4, if that makes a difference.)

John.