From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by pauillac.inria.fr (8.7.6/8.7.3) id HAA27160; Tue, 23 Dec 2003 07:21:18 +0100 (MET) X-Authentication-Warning: pauillac.inria.fr: majordomo set sender to owner-caml-list@pauillac.inria.fr using -f Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id HAA27132 for ; Tue, 23 Dec 2003 07:21:17 +0100 (MET) Received: from swordfish.cs.caltech.edu (swordfish.cs.caltech.edu [131.215.44.124]) by nez-perce.inria.fr (8.11.1/8.11.1) with ESMTP id hBN6LGv16684 for ; Tue, 23 Dec 2003 07:21:16 +0100 (MET) Received: from orchestra.cs.caltech.edu (orchestra.cs.caltech.edu [131.215.44.20]) by swordfish.cs.caltech.edu (Postfix) with ESMTP id 75662DF279; Mon, 22 Dec 2003 22:21:15 -0800 (PST) Received: by orchestra.cs.caltech.edu (Postfix, from userid 2554) id EEACF9BBAD; Mon, 22 Dec 2003 22:21:13 -0800 (PST) From: Michael Vanier To: tyler@ml1.net Cc: mgushee@havenrock.com, caml-list@inria.fr In-reply-to: (message from Tyler Eaves on Tue, 23 Dec 2003 01:11:08 -0500) Subject: Re: [Caml-list] Frustrated Beginner References: <1072152186.59938.30.camel@tylere> <29911.24.6.3.124.1072153159.squirrel@www.cs.fiu.edu> <1072152186.59938.30.camel@tylere> <20031223053451.GB1145@swordfish> Message-Id: <20031223062113.EEACF9BBAD@orchestra.cs.caltech.edu> Date: Mon, 22 Dec 2003 22:21:13 -0800 (PST) X-Loop: caml-list@inria.fr X-Spam: no; 0.00; vanier:01 mvanier:01 caml-list:01 caml-list:01 gushee:01 semicolons:01 semicolon:01 semicolon:01 model:01 foo:01 endline:01 endline:01 foo:01 bug:01 faq:01 Sender: owner-caml-list@pauillac.inria.fr Precedence: bulk To learn the functional style of programming I strongly recommend Abelson and Sussman's Structure and Interpretation of Computer Programs. Even though it uses scheme, not ocaml, the functional style easily transfers from one language to another. Mike > Cc: caml-list@inria.fr > From: Tyler Eaves > Date: Tue, 23 Dec 2003 01:11:08 -0500 > > > On Dec 23, 2003, at 12:34 AM, Matt Gushee wrote: > > > >> So why is O'Caml giving me so much trouble? > > > > Do you have any previous experience with functional programming (FP), > > or > > have you studied FP in school? If not, then you're learning both a new > > syntax and a very different programming paradigm at once, so you should > > expect a steep learning curve. But I think if you stick with it, after > > a > > while it will all start to make sense, and you'll be glad you made the > > effort. > > Not much, a (very) little Lisp. Not really enough to 'get it'. > > > >> I've been trying to pick it up for about a week now, read various > >> online tutorials. > > > > > http://www.merjis.com/richj/computers/ocaml/tutorial/ > This is the one I've gotten the most out of. > > >> My biggest source of problems seems to be the syntax. I'm totally > >> confused as far as ; vs ;; vs nothing, ... > > > > Yes, that is a bit tricky. You've undoubtedly read explanations of the > > semicolons, but sometimes it helps if you get the same information > > again > > in slightly different terms, so let me try: > > > > * A double semicolon ends a "sentence"--that is, it terminates a > > top-level construct such as a function definition--but not nested > > function definitions, because they're not "sentences," they're > > "phrases". > > > > You can omit ;; in most cases, but I would suggest at first using > > it everywhere it is allowed. When you omit the ;; and there is a > > syntax error in your code, the compiler often goes many lines past > > the real trouble spot before it detects an error, so using ;; > > everywhere can narrow down your search. > > > > * The single semicolon is perhaps a bit harder to understand, but I > > think it helps to keep in mind that OCaml is basically a functional > > language, yet it also supports imperative programming. Being > > functional means that there are no statements per se. It's all > > about > > evaluating expressions, and *every* expression returns a value. > > However, there are expressions that are functionally equivalent to > > statements. In order to conform to the functional model, they have > > to return a value, but there is no useful value to return. So they > > return the unit value, '()'. > > Okay, that helps. > > > Basically, whenever you are programming imperatively--when you have > > one of these pseudo-statements that return (), and when it this > > imperative phrase is not the final result of a function, you need > > to > > separate it from the following phrase with a single semicolon. A > > simple example: > > > > match foo with > > | None -> print_endline "Nothing"; "" > > | Some x -> print_endline x; x > > If I understand the match syntax correctly, in this case, x takes the > value of foo? > > This expression returns a string, but before returning, you want to > > print a message. Printing functions, of course, return (). > > > > Hope this helps a bit. Best of luck to you > > It does, quite a bit. Thanks to everyone else too, I've already gotten > something like 11 replies in an hour and a half :) > > ------------------- > 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