]> On Thursday 05 December 2002 12:46 pm, Oleg wrote: > To help the original poster earn extra credit, I'll write the function in > the three languages I [sort of] know: > > typedef std::list<char*> LS; > typedef std::list<int> LI; > > void f(LS& input, LI& output) { > for(LS::iterator i = input.begin(); i != input.end(); ++i) > for(char* p = *i; *p != '\0'; ++p) > output.push_back(int(*p) - int('0')); > } Isn't there a foreach() algorithm in STL? > let rec f_aux lst i acc = > match lst with > > | [] -> acc > | x :: y when i = String.length x -> f_aux y 0 acc > | x :: y -> f_aux lst (i + 1) (digit x.[i] :: acc) > > let f lst = List.rev (f_aux lst 0 []) Ah, the use of List.rev... :-) Of course, without it, it is hard. Here's my two attempts: let f4 strs = let to_ord c = int_of_char c - int_of_char '0' in let rec strings_to_list = function | [] -> [] | str :: strs -> let rec to_list s k n = if k = n then strings_to_list strs else to_ord s.[k] :: to_list s (k + 1) n in to_list str 0 (String.length str) in strings_to_list strs This one is unfortunately not tail recursive, but it is neat in the sense that it doesn't use any library function except int_of_char. let f5 strs = let to_ord c = int_of_char c - int_of_char '0' in let rec strings_to_list acc = function | [] -> acc | str :: strs -> let rec to_list acc s k n = if k = n then strings_to_list acc strs else to_list (to_ord s.[k] :: acc) s (k + 1) n in to_list acc str 0 (String.length str) in List.rev(strings_to_list [] strs) Equivalent to Oleg's I believe? PKE. -- _ \`. Pål-Kristian Engstad, Senior Software Engineer, \ `| Naughty Dog, Inc., 1315 3rd Street Promenade, __\ |`. Santa Monica, CA 90046, USA. (310) 752-1000 x799. / /o mailto:engstad@naughtydog.com http://www.naughtydog.com / '~ mailto:mrengstad@yahoo.com http://www.engstad.com / ,' Hang-gliding Rulez! ~' ------------------- 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