From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <dra-news@metastack.com>
X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr
X-Spam-Level: 
X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled 
	version=3.1.3
Received: from concorde.inria.fr (concorde.inria.fr [192.93.2.39])
	by yquem.inria.fr (Postfix) with ESMTP id 81677BC69
	for <caml-list@yquem.inria.fr>; Wed, 21 Feb 2007 23:56:28 +0100 (CET)
Received: from orion.metastack.com (no-dns-yet.demon.co.uk [80.177.38.218] (may be forged))
	by concorde.inria.fr (8.13.6/8.13.6) with ESMTP id l1LMuRPj026065
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL)
	for <caml-list@yquem.inria.fr>; Wed, 21 Feb 2007 23:56:28 +0100
Received: from treble (cpc2-cmbg6-0-0-cust535.cmbg.cable.ntl.com [81.107.34.24])
	(authenticated bits=0)
	by orion.metastack.com (8.13.4/8.13.3) with ESMTP id l1LM9luX002084
	(version=TLSv1/SSLv3 cipher=RC4-MD5 bits=128 verify=NO)
	for <caml-list@yquem.inria.fr>; Wed, 21 Feb 2007 22:09:48 GMT
From: "David Allsopp" <dra-news@metastack.com>
To: <caml-list@yquem.inria.fr>
References: <20070221223151.97901BC76@yquem.inria.fr>
Subject: Re: [Caml-list] warning on value shadowing
Date: Wed, 21 Feb 2007 22:56:26 -0000
Organization: MetaStack Solutions Ltd.
Message-ID: <00f301c7560b$84b8c8c0$6a7ba8c0@treble>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="US-ASCII"
Content-Transfer-Encoding: 7bit
X-Mailer: Microsoft Office Outlook 11
In-Reply-To: <20070221223151.97901BC76@yquem.inria.fr>
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028
Thread-Index: AcdWAa/vF/rgU1zSTGa7fcBeDVkOGQAB1dBg
X-Miltered: at concorde with ID 45DCCE1B.000 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)!
X-Spam: no; 0.00; foo:01 quux:01 foo:01 quux:01 redefining:01 pervasives:01 wrote:01 imho:01 clearer:01 caml-list:01 define:01 compiling:02 renaming:02 programming:03 module:03 

> On Wednesday 21 February 2007 20:41, Sam Steingold wrote:
> > Proposal:
> > When both foo.ml and bar.ml define zot and quux.ml opens both Foo and
> > Bar, there should be a warning (when compiling quux) about Foo.zot being
> > shadowed by Bar.zot (or vice versa, depending on the order of the open
> > statements).
>
> I think this is such a common style (I use shadowing deliberately all the 
> time) that it would be very annoying to be warned about it.

I agree --- local shadowing is too useful a programming style to have
warnings issued. Though redefining a value at global level is possibly worth
having a warning about.

IMHO Pervasives is the only module that should be opened --- renaming a
module with "module Foo = SomeVeryLongModuleNameYouDontWantToTypeLots" is
better (makes clearer code) than "open ... ". But that's just another
opinion...