From: "Till Varoquaux" <till.varoquaux@gmail.com>
To: "David Teller" <David.Teller@univ-orleans.fr>
Cc: OCaml <caml-list@inria.fr>
Subject: Re: [Caml-list] "Warning U: this match case is unused." -- Yes, I know
Date: Wed, 27 Feb 2008 21:48:56 +0000 [thread overview]
Message-ID: <9d3ec8300802271348u62892bbdva98f880c9cb8ddc9@mail.gmail.com> (raw)
In-Reply-To: <1204147958.7005.17.camel@Blefuscu>
There is a function in camlp4 that checks for this:
Ast.is_irrefut_patt
Check that you have a recent ocaml. It used to be bugged (it was fixed
in mid september).
Cheers
On Wed, Feb 27, 2008 at 9:32 PM, David Teller
<David.Teller@univ-orleans.fr> wrote:
> Dear list,
>
> I'm currently working on a little Camlp4 extension which has to often
> generate pattern-matching clauses depending on user code -- and deal
> with match failures accordingly.
>
> Now, I guess
>
> 1. I can wrap the user's pattern-matching inside a try...with, catch any
> Match_failure and deal with it. However, ensuring that the Match_failure
> is the right one and that I'm not catching some other error in the code,
> all this while performing bindings satisfactorily will require numerous
> contorsions.
>
> 2. I can add a catch-all clause " _ -> deal_with_error ". While the
> semantics of this rewriting are exactly what I need, the compiler tends
> to print "Warning U: this match case is unused" whenever the user has
> already taken care of all cases. I would need to find a way to
> deactivate the warning for this specific clause. As I haven't found any
> way of doing that directly, I've been thinking about adding a "when
> True" to the second-to-last clause if that clause doesn't already have a
> "when", but I'd be glad to hear about better solutions.
>
> Thanks in advance,
> David
>
> --
> David Teller
> Security of Distributed Systems
> http://www.univ-orleans.fr/lifo/Members/David.Teller
> Angry researcher: French Universities need reforms, but the LRU act brings liquidations.
>
> _______________________________________________
> Caml-list mailing list. Subscription management:
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> Archives: http://caml.inria.fr
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>
--
http://till-varoquaux.blogspot.com/
next prev parent reply other threads:[~2008-02-27 21:48 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-27 21:32 David Teller
2008-02-27 21:48 ` Till Varoquaux [this message]
2008-02-27 21:56 ` [Caml-list] " David Teller
2008-02-27 22:09 ` Edgar Friendly
2008-02-27 22:21 ` David Teller
2008-02-27 22:30 ` Edgar Friendly
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