From: Goswin von Brederlow <goswin-v-b@web.de>
To: caml-list@inria.fr
Subject: Re: [Caml-list] Segfault with open GADTs
Date: Tue, 18 Oct 2016 16:21:02 +0200 [thread overview]
Message-ID: <20161018142102.GA21704@frosties> (raw)
In-Reply-To: <ea2ae4ee-d242-0235-cce5-d90b7a59295b@digirati.com.br>
On Tue, Oct 18, 2016 at 11:52:40AM -0200, Andre Nathan wrote:
> On 10/18/2016 11:10 AM, Pierrick Couderc wrote:
> > Hi,
> >
> > It is supposed to work, but it seems thepattern-matching compiler does
> > not detect that M0.to_string is non exhaustive, thus it does not add a
> > Match_Failure in case the variant is unknown. With extensible variants,
> > a pattern matching is only exhaustive if you provide a wildcard or a
> > variable for variants added afterwards.
>
>
> Indeed, if I add a catch-all branch in M0.to_string then the code in
> that branch is run, with no segfault.
>
> But I guess my original idea of extending the type doesn't really work
> as I hoped, since with nested expressions like that, I'd need to find a
> way for M0.to_string to call back M1.to_string when a `T` is found.
>
> Back to the drawing board...
>
> Thanks,
> Andre
You can pass along the outermost to_string to all to_string
functions so they can restart from the outside when they recurse.
MfG
Goswin
next prev parent reply other threads:[~2016-10-18 14:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-18 12:47 Andre Nathan
2016-10-18 13:10 ` Pierrick Couderc
2016-10-18 13:52 ` Andre Nathan
2016-10-18 14:21 ` Goswin von Brederlow [this message]
2016-10-18 14:50 ` Andre Nathan
2016-10-18 13:16 ` Jeremy Yallop
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