]> > Is there a way to transform string to ( 'a, out_channel, unit, unit) > format. I need this function to use it with something like : > > Printf.printf (my_fun "X, Y") "coucou";; No, not in a type-safe manner. The type of a format string depends on the "%" specifiers found in the string itself, and OCaml can't infer or check types at run-time. However, for the purpose of internationalization, the following operation suffices: given a (compile-time constant) format and a (dynamically computed) string, check that the string can be viewed as a format with the same format type as the constant format, and return the string as a format. In OCaml 3.06, this can be done as follows: let re_fmt = Str.regexp "%[#0-9.*+ -]*[lnL]?[sScCdioxXunfeEgGFbBatn[]" let string_of_format (s : ('a, 'b, 'c) format) = (Obj.magic s : string) let extract_formats s = List.fold_right (fun part accu -> match part with Str.Text _ -> accu | Str.Delim d -> d :: accu) (Str.full_split re_fmt s) [] let conv_format (src: ('a, 'b, 'c) format) (dst: string) = if extract_formats (string_of_format src) = extract_formats dst then (Obj.magic dst : ('a, 'b, 'c) format) else failwith "conv_format" Remark 1: yes, there's a lot of "Obj.magic" in this code, and yes, this is a deadly sin, but in this particular instance it is all type-safe nonetheless. Remark 2: the matching of the two formats can be relaxed, e.g. the code above will not allow the conversion of "%6d" into "%8x", although both formats have the same type. This is left as an exercise for the reader. But for internationalization purposes, I doubt you need that additional flexibility. Then, assuming you have a function "gettext : string -> string" to translate strings according to the user-selected language, you can extend it to formats as follows: let getformat f = conv_format f (gettext (string_of_format f)) and use it with printf functions like this: printf (getformat "My name is %s and I'm %d years old") "Bob" 12 > you read my mind. Indeed, the question concern an internationalization > module ( let's call libgettext-ocaml ). It is basically a binding of > gettext. I hope the above is enough to get you off the ground. - Xavier Leroy ------------------- 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