From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: David Kastrup Newsgroups: gmane.lisp.guile.devel Subject: Re: Growable arrays? Date: Thu, 14 Jun 2012 16:47:05 +0200 Organization: Organization?!? Message-ID: <87vciuuf12.fsf@fencepost.gnu.org> References: <87hauku0mb.fsf@fencepost.gnu.org> <87sjdyyncv.fsf@netris.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: dough.gmane.org 1339685275 22977 80.91.229.3 (14 Jun 2012 14:47:55 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Thu, 14 Jun 2012 14:47:55 +0000 (UTC) To: guile-devel@gnu.org Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Thu Jun 14 16:47:54 2012 Return-path: Envelope-to: guile-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1SfBKu-0003tK-SM for guile-devel@m.gmane.org; Thu, 14 Jun 2012 16:47:48 +0200 Original-Received: from localhost ([::1]:37040 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SfBKu-0006PF-SJ for guile-devel@m.gmane.org; Thu, 14 Jun 2012 10:47:48 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:39930) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SfBKj-0006Cb-1l for guile-devel@gnu.org; Thu, 14 Jun 2012 10:47:46 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SfBKZ-0000YM-St for guile-devel@gnu.org; Thu, 14 Jun 2012 10:47:36 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:34486) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SfBKZ-0000Xp-M9 for guile-devel@gnu.org; Thu, 14 Jun 2012 10:47:27 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1SfBKT-0002Xu-Ea for guile-devel@gnu.org; Thu, 14 Jun 2012 16:47:21 +0200 Original-Received: from p508eb9b7.dip.t-dialin.net ([80.142.185.183]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 14 Jun 2012 16:47:21 +0200 Original-Received: from dak by p508eb9b7.dip.t-dialin.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 14 Jun 2012 16:47:21 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 28 Original-X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: p508eb9b7.dip.t-dialin.net X-Face: 2FEFf>]>q>2iw=B6, xrUubRI>pR&Ml9=ao@P@i)L:\urd*t9M~y1^:+Y]'C0~{mAl`oQuAl \!3KEIp?*w`|bL5qr,H)LFO6Q=qx~iH4DN; i"; /yuIsqbLLCh/!U#X[S~(5eZ41to5f%E@'ELIi$t^ Vc\LWP@J5p^rst0+('>Er0=^1{]M9!p?&:\z]|;&=NP3AhB!B_bi^]Pfkw User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1.50 (gnu/linux) Cancel-Lock: sha1:d9701koVQqMWoLVKlCi1mIa71vM= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Developers list for Guile, the GNU extensibility library" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Original-Sender: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.devel:14620 Archived-At: Mark H Weaver writes: > David Kastrup writes: >> Scheme/Guile vectors are fixed size. [...] It is a bit of a nuisance >> that one can grow a hashtable efficiently and on-demand, but not so an >> array. > > Although Scheme vectors should remain fixed-size for reasons I have > given elsewhere in this thread, Guile also includes a more complex > 'array' type that includes features such as arbitrary rank (i.e. number > of dimensions), arbitrary lower bounds (not just 0), and shared views on > the same underlying array with arbitrary affine mappings of indices. > > Guile 'arrays' cannot currently be resized, but I see no good reason for > this limitation. They are already quite complex, and already require a > second level of pointer indirection. > > What do other people think? Another complex type, this time with quite more serious memory and performance impact, that can't be implemented on top of a simple resizable common primitive and has an almost, but not quite, overlapping underlying feature set? It's almost as if you _like_ not being able to reuse code. -- David Kastrup