Thorsten Ohl (TP2) wrote: > Hi, > > for ages, I've been using the following (somewhat hackish) approach to > pretty printing source code that requires special lexical markers to > allow statements that continue over more than one line. (e.g. in > Fortran > > foo = 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 & > + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 & > + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 & > + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 & > + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 & > + 1 + 1 + 1 + 1 + 1 + 1 + 1 > > and in /bin/sh we have the same with "\\" instead of "&"): > > open Format;; > > let continuing = ref true;; > > let wrap_newline () = > let out, flush, newline, space = get_all_formatter_output_functions > () in > let newline' () = > if !continuing then > out " &" 0 2; > newline () in > set_all_formatter_output_functions out flush newline' space;; > > let nl () = > continuing := false; > print_newline (); > continuing := true;; > > let _ = > wrap_newline ();; > > (* Nonsensical example: *) > for statement = 1 to 3 do > printf " @[<2>foo = 1"; > for i = 1 to 100 do > printf "@, + 1" > done; > nl () > done;; > > The requirement to end each statement with "nl ()" is tedious in real > world applications and the use of the global variable "continuing" > violates my sense of aesthetics... > > Is there a more idiomatic approach that I'm missing?
Given the imperative nature of the Format module interface, your solution seems right to me. Maybe you'll output up to 2 bytes beyond the margin but I guess that's ok. You may also consider using easy-format, which offers a functional interface on top of Format. The programmer's job is to create a tree containing strings and parameters while the actual printing is done by a single function call. That said, easy-format does not support custom newline strings although I could add the feature. Link: http://martin.jambon.free.fr/easy-format.html Martin -- http://mjambon.com/ _______________________________________________ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
