]> On Thu, 23 Oct 2003, Flavio Leonardo Cavalcanti de Moura wrote: > I am trying to build a procedure such that some reductions are > performed while a list (of redex) is not empty. The problem is that a > new list is needed at each step otherwise it will loop for ever. The > actual code is > > let normal exp = > let l = exp :: [] in > while (matchingApp exp [] []) <> [] do > exp := (appreduction exp (hd (matchingApp exp [] []))); > exp :: l done; l;; > > After the 'while' I would like to actualize the expression 'exp' with the > string (appreduction exp (hd (matchingApp exp [] []))). The problem is > that with := it does not work. How can I do that? I couldn't find anything > in the ocaml manual. I'm not 100% sure what you're trying to do here. Applying a function to every member of a list is easy- look at List.iter and List.fold_left. fold_left is especially useful for "accumulating" a result over the list. I think what you want to do is: let normal exp = let f l x = match l with | [] -> assert false | h :: t -> (appreduction h x) :: t in List.fold_left f [ exp ] (matchingApp exp [] []) ;; but I'm not sure. Give me a clue: what are the types of matchingApp and appreduction? Brian ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners