From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <goswin-v-b@web.de>
Received: from mail3-relais-sop.national.inria.fr (mail3-relais-sop.national.inria.fr [192.134.164.104])
	by yquem.inria.fr (Postfix) with ESMTP id D9214BBAF
	for <caml-list@yquem.inria.fr>; Thu, 20 May 2010 07:11:55 +0200 (CEST)
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: AsUCAENh9EvZSMDji2dsb2JhbACRc4wPFQEBAQoLCgcPBR+8ToURBA
X-IronPort-AV: E=Sophos;i="4.53,268,1272837600"; 
   d="scan'208";a="50916902"
Received: from fmmailgate02.web.de ([217.72.192.227])
  by mail3-smtp-sop.national.inria.fr with ESMTP; 20 May 2010 07:11:55 +0200
Received:  from smtp08.web.de  ( [172.20.5.216])
	by fmmailgate02.web.de (Postfix) with ESMTP id C08E11616A716
	for <caml-list@yquem.inria.fr>; Thu, 20 May 2010 07:11:54 +0200 (CEST)
Received: from [78.43.204.177] (helo=frosties.localdomain)
	by smtp08.web.de with asmtp (TLSv1:AES256-SHA:256)
	(WEB.DE 4.110 #4)
	id 1OEy30-0002ct-00
	for caml-list@yquem.inria.fr; Thu, 20 May 2010 07:11:54 +0200
Received: from mrvn by frosties.localdomain with local (Exim 4.71)
	(envelope-from <goswin-v-b@web.de>)
	id 1OEy36-00081j-Aj
	for caml-list@yquem.inria.fr; Thu, 20 May 2010 07:12:00 +0200
From: Goswin von Brederlow <goswin-v-b@web.de>
To: <caml-list@yquem.inria.fr>
Subject: Problem with recursive class and non-class types
Date: Thu, 20 May 2010 07:12:00 +0200
Message-ID: <87mxvvma1r.fsf@frosties.localdomain>
User-Agent: Gnus/5.110009 (No Gnus v0.9) XEmacs/21.4.22 (linux, no MULE)
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Sender: goswin-v-b@web.de
X-Sender: goswin-v-b@web.de
X-Provags-ID: V01U2FsdGVkX18NAQgbJunSWsShLMy3qcrUSoT0n+HBsfLsaVlN
	dF4M9j6BdvpydF65IN7gfa+xVJUZMp3mvJmDIpFXRoh+xYwSka
	QxCSjm3MQ=
X-Spam: no; 0.00; recursive:01 foo:01 val:01 mutable:01 foo:01 val:01 mutable:01 baz:01 mfg:98 define:02 types:05 types:05 problem:05 object:09 object:09 

Hi,

I want to define the two types below:

type foo = { bar : bar; }
class bar = object val mutable foo : foo list = [] end

Is there another way of doing this other than:

# type 'a foo = { bar : 'a; } 
  class bar = object val mutable foo : #bar foo list = [] end;;
type 'a foo = { bar : 'a; }
class bar : object val mutable foo : #bar foo list end

I don't want any 'a foo other than 'a = #bar. It is too easy to create a
baz foo and then much later get a type error when trying to use it as
bar foo. I want the error where the foo gets created.

MfG
        Goswin