From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: tomas@fabula.de Newsgroups: gmane.lisp.guile.devel Subject: Re: Items blocking release 1.6.1 (2002-04-21) Date: Thu, 25 Apr 2002 11:09:14 +0200 Sender: guile-devel-admin@gnu.org Message-ID: <20020425090914.GA19031@www> References: <87wuuyl1qj.fsf@zagadka.ping.de> NNTP-Posting-Host: localhost.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: main.gmane.org 1019725762 636 127.0.0.1 (25 Apr 2002 09:09:22 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Thu, 25 Apr 2002 09:09:22 +0000 (UTC) Cc: ttn@glug.org, rlb@defaultvalue.org, guile-devel@gnu.org, guile-user@gnu.org Return-path: Original-Received: from fencepost.gnu.org ([199.232.76.164]) by main.gmane.org with esmtp (Exim 3.33 #1 (Debian)) id 170fFh-0000A9-00 for ; Thu, 25 Apr 2002 11:09:21 +0200 Original-Received: from localhost ([127.0.0.1] helo=fencepost.gnu.org) by fencepost.gnu.org with esmtp (Exim 3.34 #1 (Debian)) id 170fFY-0002eL-00; Thu, 25 Apr 2002 05:09:12 -0400 Original-Received: from www.elogos.de ([212.18.192.92]) by fencepost.gnu.org with smtp (Exim 3.34 #1 (Debian)) id 170fCr-0002UN-00; Thu, 25 Apr 2002 05:06:25 -0400 Original-Received: by www.elogos.de (Postfix, from userid 5002) id C5CC11049A3; Thu, 25 Apr 2002 11:09:14 +0200 (CEST) Original-To: Marius Vollmer Content-Disposition: inline In-Reply-To: <87wuuyl1qj.fsf@zagadka.ping.de> User-Agent: Mutt/1.3.24i Errors-To: guile-devel-admin@gnu.org X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.0.9 Precedence: bulk List-Help: List-Post: List-Subscribe: , List-Id: Developers list for Guile, the GNU extensibility library List-Unsubscribe: , List-Archive: Xref: main.gmane.org gmane.lisp.guile.devel:522 X-Report-Spam: http://spam.gmane.org/gmane.lisp.guile.devel:522 Hi, it's not my intention to complicate further an already delicate discussion, but just to supply an user's point of view: On Tue, Apr 23, 2002 at 08:16:20PM +0200, Marius Vollmer wrote: [...] > Yes. The way the old 'bound?' was implemented was a bug. The mistake > (my mistake) back then was to fix this bug in a sub-optimal way, by > just removing the functionality. Now it is too late to change it > again; and changing it would be quite gratuitous, too. > > Using #f as the default default value is a sensible thing, I'd say, > and should even be recommended. As a provider of some functionality I'd sometimes like to be able to distinguish between `value was provided' and `value was not provided at all'. It'd be perfectly reasonable to agree on a value which means `not provided' (like Perl's undef or Pythons None): an user providing *such* a value hopefully knows what she's doing... > From a robustness standpoint, > distinguishing between explicitely specifying a keyword with its > default value in a function call, and not specifying it, should not be > done. That is, it is better to say "When you don't specify the :foo > keyword, it's value is defaulted to #f. A value of #f means bla." > instead of "When you don't specify the :foo keyword, it means bla." ...but #f seems to be just wrong, since it's an often-used `logical' value. Unspecified seems nice for something ``you don't specify'', doesn't it? (I know, you were against that on a previous posting). (BTW. I just resisted the temptation to propose '(), because that's quite another thread ;-> Thanks -- tomas _______________________________________________ Guile-devel mailing list Guile-devel@gnu.org http://mail.gnu.org/mailman/listinfo/guile-devel