From: David Rajchenbach-Teller <David.Teller@ens-lyon.org>
To: Su Zhang <westlifezs@gmail.com>
Cc: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] how can I express empty element?
Date: Mon, 09 Mar 2009 14:03:37 +0100 [thread overview]
Message-ID: <1236603817.18569.4.camel@Blefuscu> (raw)
In-Reply-To: <e2842950903082059r2497acd6re851fcc229a893c8@mail.gmail.com>
No, that's not possible. :: is an algebraic constructor, which means,
among other things, that it accepts no neutral element (well, except
when the list is infinite, but that's probably not what you're looking
for).
Cheers,
David
On Sun, 2009-03-08 at 22:59 -0500, Su Zhang wrote:
> Hi all,
>
> I have a question on ocaml, is there a way to write a empty element
> say a which can make a::ax=ax ? I tried to find out in library, yet I
> didn't get the right way out, and it doesn't work if I make a=[], so
> do you know whether there is a technique can realize this function?
> I've got stuck on this point for a very long time.
>
> thanks
>
> --
> Su Zhang
> PHD Student
> Computer Information and Science
> Kansas State University
>
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--
David Teller-Rajchenbach
Security of Distributed Systems
http://www.univ-orleans.fr/lifo/Members/David.Teller
« Ce matin Un crétin A tué un chercheur. » (air connu)
Latest News of French Research: System being liquidated. Researchers angry.
next prev parent reply other threads:[~2009-03-09 13:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-09 3:59 Su Zhang
2009-03-09 13:03 ` David Rajchenbach-Teller [this message]
2009-03-09 13:14 ` [Caml-list] " AUGER Cedric
2009-03-09 16:07 ` Laurent Le Brun
2009-03-10 8:47 ` Grünewald Michaël
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