From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Andy Wingo Newsgroups: gmane.lisp.guile.devel Subject: Re: Guile: What's wrong with this? Date: Wed, 04 Jan 2012 12:32:26 -0500 Message-ID: <87r4zfqsph.fsf@pobox.com> References: <4F027F35.5020001@gmail.com> <1325603029.22166.YahooMailNeo@web37906.mail.mud.yahoo.com> <4F032C41.3070300@gmail.com> <877h17hjj2.fsf@netris.org> <1325687351.71432.YahooMailNeo@web37906.mail.mud.yahoo.com> <874nwbs9c4.fsf@pobox.com> <87hb0bgzkt.fsf@fencepost.gnu.org> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: dough.gmane.org 1325698371 14333 80.91.229.12 (4 Jan 2012 17:32:51 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 4 Jan 2012 17:32:51 +0000 (UTC) Cc: guile-devel@gnu.org To: David Kastrup Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Wed Jan 04 18:32:47 2012 Return-path: Envelope-to: guile-devel@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1RiUhi-0004Xd-RM for guile-devel@m.gmane.org; Wed, 04 Jan 2012 18:32:46 +0100 Original-Received: from localhost ([::1]:48851 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RiUhf-0005V4-CL for guile-devel@m.gmane.org; Wed, 04 Jan 2012 12:32:43 -0500 Original-Received: from eggs.gnu.org ([140.186.70.92]:37606) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RiUhc-0005Ul-GU for guile-devel@gnu.org; Wed, 04 Jan 2012 12:32:41 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RiUhb-0000uP-5w for guile-devel@gnu.org; Wed, 04 Jan 2012 12:32:40 -0500 Original-Received: from a-pb-sasl-sd.pobox.com ([74.115.168.62]:42792 helo=sasl.smtp.pobox.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RiUhU-0000tc-Fa; Wed, 04 Jan 2012 12:32:32 -0500 Original-Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by a-pb-sasl-sd.pobox.com (Postfix) with ESMTP id 86F628280; Wed, 4 Jan 2012 12:32:31 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=3TKc5S20QPG3GViUwV8ovvWbaMo=; b=NfaK3y G4FjAS+7Iof8dbUPRAzu6Xa+K2jVka5R6fiQplYtrcz8JTv8DP6AZo3cUbTj1e/c DZj0Fmy5N5hNTIuFnacO4Hip13m2AEG+Sst5udFNKvXv+q5SZKnMqPOdZIXWNX5X DR69jHZInAOAwYgfPSL0CuM3eKJZ/FVp00apE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; q=dns; s=sasl; b=kuPmJHGqnQtF9pH8L5qfgsqYY32yUdlR TGvzvBCf1wlvhZs4foh3xj7pBvbozpOILwhG9J1CWvRxHNHaFGzjIShDHJSIP+Mc rQ+AFrKgMGtBHc3EpcXdzFR20z9Kbt7gZ5DPjmMdEmbY/74xP7eN0dJhdO8B0fcH l480D0Gc0ME= Original-Received: from a-pb-sasl-sd.pobox.com (unknown [127.0.0.1]) by a-pb-sasl-sd.pobox.com (Postfix) with ESMTP id 7FB6F827F; Wed, 4 Jan 2012 12:32:31 -0500 (EST) Original-Received: from badger (unknown [70.63.131.29]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by a-pb-sasl-sd.pobox.com (Postfix) with ESMTPSA id AA311827A; Wed, 4 Jan 2012 12:32:30 -0500 (EST) In-Reply-To: <87hb0bgzkt.fsf@fencepost.gnu.org> (David Kastrup's message of "Wed, 04 Jan 2012 18:14:10 +0100") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) X-Pobox-Relay-ID: 145C9D7E-36FA-11E1-9CBE-65B1DE995924-02397024!a-pb-sasl-sd.pobox.com X-detected-operating-system: by eggs.gnu.org: Solaris 10 (beta) X-Received-From: 74.115.168.62 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:13273 Archived-At: On Wed 04 Jan 2012 12:14, David Kastrup writes: > Andy Wingo writes: > >> We could add a compiler option to turn string literals into >> (string-copy FOO). Perhaps that's the thing to do. > > What for? It would mean that a literal would not be eq? to itself, a > nightmare for memoization purposes. (eq? "hello" "hello") This expression may be true or false. It will be true in some circumstances and false in others, in all versions of Guile. > And for what? For making code with explicitly undefined behavior > exhibit a particular behavior that is undesirable in general. The Scheme reports and the Guile manual are both positive and negative specification: they require the implementation to do certain things, and they allow it to do certain others. Eq? on literals is one of the liberties afforded to the implementation, and with good reason. Correct programs don't assume anything about the identities (in the sense of eq?) of literals. Andy -- http://wingolog.org/