]> Here's a simple way of approximating what you want. It's ugly, but camlp4 could be used for providing the appropriate syntactic sugar, I imagine. exception Return let rval = ref None in try with Return -> match !rval with > On Tue, Oct 21, 2003 at 01:28:13PM -0400, William Lovas wrote: >> What you want is a return *statement*, but such a beast is incompatible >> with O'Caml, since O'Caml is an expression-oriented language. I don't >> see >> an easy way of making a `return' expression that behaves the way you >> want >> it to. > > Perhaps there's a misunderstanding here. I don't want to change the > expression-oriented nature of the language. The 'return' would and > must return the same type as the rest of the code. > >> Better, though, in my opinion, would be to adapt your >> mental syntax to fit the functional style than to adapt the functional >> language to cater to your imperative style. > > I'm really looking for help on this! My working theory at the moment > though is that writing UIs involves writing essentially imperative > code. One small example from some real code: > > let quit _ = > if !test_id = 0 then ( > GMain.Main.quit (); false > ) else ( > let icon = GMisc.image () in > icon#set_stock `DIALOG_QUESTION; > icon#set_icon_size `DIALOG; > let buttons = [ "Quit"; "Cancel" ] in > let ans = GToolbox.question_box ~title:"Quit" ~icon ~buttons > ("Are you sure you want to quit? This may lose any\n" ^ > "results from this assessment.") in > if ans = 1 then ( > GMain.Main.quit (); false (* User requested quit. *) > ) > else > true (* Don't close the window. *) > ) > in > > window#connect#destroy ~callback:GMain.quit; > window#event#connect#delete ~callback:quit; > quit_item#connect#activate ~callback:(fun () -> quit (); ()); > > I think there's definitely a case for being able to write: > > if !test_id = 0 then ( (* Not in a test - can quit immediately. *) > GMain.Main.quit (); > return false > ); > > (* .. rest of code ... *) > > But perhaps, as you say, I'm missing the functional solution to this. > > (I can dig around and find some more examples like this if it would help). > > Rich. > > -- > Richard Jones. http://www.annexia.org/ http://freshmeat.net/users/rwmj > Merjis Ltd. http://www.merjis.com/ - all your business data are belong to > you. > MAKE+ is a sane replacement for GNU autoconf/automake. One script > compiles, > RPMs, pkgs etc. Linux, BSD, Solaris. > http://www.annexia.org/freeware/makeplus/ > > ------------------- > 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 > ------------------- 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