From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: ludo@gnu.org (Ludovic =?iso-8859-1?Q?Court=E8s?=) Newsgroups: gmane.lisp.guile.devel Subject: Re: scm_to_locale_stringbuf Date: Thu, 05 Feb 2009 23:26:26 +0100 Message-ID: <87tz78ikq5.fsf@gnu.org> References: <493834.3827.qm@web37902.mail.mud.yahoo.com> <874ozbjfwt.fsf@arudy.ossau.uklinux.net> <360535.25627.qm@web37903.mail.mud.yahoo.com> <87iqnrhwy5.fsf@arudy.ossau.uklinux.net> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1233872814 4176 80.91.229.12 (5 Feb 2009 22:26:54 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 5 Feb 2009 22:26:54 +0000 (UTC) To: guile-devel@gnu.org Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Thu Feb 05 23:28:08 2009 Return-path: Envelope-to: guile-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1LVChc-0001m2-8p for guile-devel@m.gmane.org; Thu, 05 Feb 2009 23:28:08 +0100 Original-Received: from localhost ([127.0.0.1]:44430 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LVCgI-0003ep-M6 for guile-devel@m.gmane.org; Thu, 05 Feb 2009 17:26:46 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LVCgG-0003eO-28 for guile-devel@gnu.org; Thu, 05 Feb 2009 17:26:44 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LVCgE-0003dh-8Q for guile-devel@gnu.org; Thu, 05 Feb 2009 17:26:43 -0500 Original-Received: from [199.232.76.173] (port=37890 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LVCgE-0003de-2l for guile-devel@gnu.org; Thu, 05 Feb 2009 17:26:42 -0500 Original-Received: from main.gmane.org ([80.91.229.2]:42061 helo=ciao.gmane.org) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1LVCgD-0004vN-No for guile-devel@gnu.org; Thu, 05 Feb 2009 17:26:41 -0500 Original-Received: from list by ciao.gmane.org with local (Exim 4.43) id 1LVCg6-0001v3-Ry for guile-devel@gnu.org; Thu, 05 Feb 2009 22:26:35 +0000 Original-Received: from reverse-83.fdn.fr ([80.67.176.83]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 05 Feb 2009 22:26:34 +0000 Original-Received: from ludo by reverse-83.fdn.fr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 05 Feb 2009 22:26:34 +0000 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 38 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: reverse-83.fdn.fr X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 17 =?iso-8859-1?Q?Pluvi=F4se?= an 217 de la =?iso-8859-1?Q?R=E9volution?= X-PGP-Key-ID: 0xEA52ECF4 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 821D 815D 902A 7EAB 5CEE D120 7FBA 3D4F EB1F 5364 X-OS: i686-pc-linux-gnu User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.3 (gnu/linux) Cancel-Lock: sha1:e7m0tgNynELvYTD3jBmvhRAs4AE= X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Developers list for Guile, the GNU extensibility library" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Errors-To: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.devel:8139 Archived-At: Hi, Neil Jerram writes: > I think the key thing is that scm_to_locale_stringbuf () will return > 2. This tells the caller that BUF wasn't big enough. Beyond that, we > shouldn't do something obviously misleading, but I don't think it > matters very much what we choose to do. Agreed. The caller is already able to determine that something's wrong if the return value is larger than MAX_LEN. > I guess there could be a scenario where the caller has a fixed size > buffer, and just wants to copy in as much of an arbitrary string as > will fit, and then use that possibly truncated string somehow. > Depending on the API that the string is being passed on to, any of the > following could be most useful: > > - padding the unused bytes of BUF with \0 (or some other value) > > - adding a single \0 (or other value) in the first unused byte > > - returning a pointer (or offset in bytes) to the first unused byte > > - returning the number of characters written. > > Returning both and > would allow the caller to do any of those efficiently, so perhaps we > should do that? I would say returning both "number of bytes needed for the full string" (as is the case) plus "number of bytes actually written" (which may be smaller than MAX_LEN in the case of multi-byte encoding). This would be an addition to the API, IMO, while `scm_to_locale_stringbuf ()' would keep behaving as described, with the limitations you outline above. Thanks, Ludo'.