]> > On Mon, Dec 02, 2002 at 04:55:06PM +0100, altavillasalvatore@libero.it wrote: > > Hi all, > > I would want to know if a function exists that allows me to make this: > > > > ["123";"45";"678"] -> [1;2;3;4;5;6;7;8;]. > > let f l = > let ret = ref [] in > String.iter > (fun c -> ret := ((int_of_char c) - (int_of_char '0')) :: !ret) > (List.fold_left (^) "" l); > List.rev !ret;; > > f ["123";"45";"678"];; > > Cheers, > Issac Trotts If you like puzzles, here is an additional exercise: 00) List which parens are useless in this code, according to which rules given in the simple guide-lines and syntactic conventions of http://pauillac.inria.fr/caml/FAQ/qrg-eng.html#parens and http://pauillac.inria.fr/caml/FAQ/pgl-eng.html#parens. 0) Rewrite this code to a more suitable form for a beginner, i.e. in a purely functional style with no side effect. 1) Try to avoid the useless List.rev at the end. 2) What is the complexity of your function f ? 3) Explain why the List.fold_left application is not only over complex but also runtime over consuming. Hope this helps. Cheers, Pierre Weis INRIA, Projet Cristal, Pierre.Weis@inria.fr, http://pauillac.inria.fr/~weis/ ------------------- 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