From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: =?UTF-8?B?Sm/Do28gVMOhdm9yYQ==?= Newsgroups: gmane.emacs.devel Subject: =?UTF-8?Q?Re=3A_31395511=3A_=22Don=E2=80=99t_attempt_to_modify_constant_st?= =?UTF-8?Q?rings=22?= Date: Sat, 6 Jun 2020 12:47:45 +0100 Message-ID: References: <871rmvn7ge.fsf@gmail.com> <87lfl36abx.fsf@gmail.com> <1abe5965-b48e-6dee-1516-c5c233f09d01@cs.ucla.edu> <873679lel3.fsf@gmail.com> <87d06dje3d.fsf@gmail.com> <58642244-da07-c96d-21d5-d7d46714678d@cs.ucla.edu> Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="000000000000e634cb05a768f24d" Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="99169"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel , Pip Cet , Dmitry Gutov To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Jun 06 13:48:31 2020 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jhXJO-000Phy-L7 for ged-emacs-devel@m.gmane-mx.org; Sat, 06 Jun 2020 13:48:30 +0200 Original-Received: from localhost ([::1]:59862 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jhXJN-0005Mu-NL for ged-emacs-devel@m.gmane-mx.org; Sat, 06 Jun 2020 07:48:29 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:60468) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jhXIt-0004xi-2P for emacs-devel@gnu.org; Sat, 06 Jun 2020 07:47:59 -0400 Original-Received: from mail-il1-x132.google.com ([2607:f8b0:4864:20::132]:38086) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jhXIs-0001YP-79 for emacs-devel@gnu.org; Sat, 06 Jun 2020 07:47:58 -0400 Original-Received: by mail-il1-x132.google.com with SMTP id b5so12214474iln.5 for ; Sat, 06 Jun 2020 04:47:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=7RHqkjJt80Wj+IwILhsRoBxhaCV0egzr0MU0mPvP8y8=; b=ca5Qr8dmY+LkE11o+y/tmlKnHE3uwJNyuMqA1udf3Ea+5RHX4b7Dqhu0mctE1VMK3B Ij9dH7pNTY/jUT2g4z+JCuykS6Qhjoyp9d2nAYCvkQm93WBUoJsWSSlT82mQORVTlpHj qq8+lv/uA2qOVrOzjoHv2fcenLKf0+9qy4s5vkec2DpPWx9CiIGKm9MseIw25jMpp1W1 SvkJtLAru/hXysBDfDzIrDewo0tLbLPa4TIXC3lEpMe8FxFIUw3DfCiw+eUh0J9lMd+S 4FuHSdgH1D/NfCyjIxTlYN/r77ea9e5VQ6OdIlkt+GPnVKtnqsMXCcY+hL+FHymamf1B brfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=7RHqkjJt80Wj+IwILhsRoBxhaCV0egzr0MU0mPvP8y8=; b=Xg58siUNK50bFMng38g5MxbdsDF+H36PO2p/oGM5k4xfgxBLs81p0xSp2fUFfr+wUL KyUSCzWQH7P8YAnM2jF4ExYPDSCuNKoIK33ocYoR/0/Dd84BaNGjaLWQq+HdTYYK/y9M v/7Dd+b2P4C9u6ZR3UDOJVmXThIWN4I3WLAxeND0u/VBfCCT0BZ4GrjtqRUMmzO3mVoI d15osCmgYKyj6Vb1Bmu+1WseHrFcILU1DtAKV9mOBCrxkP+ibCoP/19PQk11XX4eLgKb aaVMLTDnZvMB5PvK/rxmUi0vKAV6nTQhjzKj1kJJUIRLGOK1pbfhqMhD90nDW0I4sbUH ocoQ== X-Gm-Message-State: AOAM532kzbc/zUqkk8vMBIoIGFIOD4LZ3HPl26dYWXTe6fNWJa4Qbhhp BJQQrFcKZjidHyRCnEr6WSrRogV9F5MFeIUylyU= X-Google-Smtp-Source: ABdhPJzGuS/NcjDmQPV0zRv+0noK4Sigb1LtWWYYV99VDN5P4eyD9Z+xvl0IFTNUl0CmRN9M4W7CyqG77jQ381GDA50= X-Received: by 2002:a05:6e02:c:: with SMTP id h12mr12400441ilr.125.1591444077162; Sat, 06 Jun 2020 04:47:57 -0700 (PDT) In-Reply-To: Received-SPF: pass client-ip=2607:f8b0:4864:20::132; envelope-from=joaotavora@gmail.com; helo=mail-il1-x132.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -10 X-Spam_score: -1.1 X-Spam_bar: - X-Spam_report: (-1.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, FROM_EXCESS_BASE64=0.979, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:251948 Archived-At: --000000000000e634cb05a768f24d Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sat, Jun 6, 2020 at 12:41 PM Jo=C3=A3o T=C3=A1vora wrote: > On Sat, Jun 6, 2020 at 2:43 AM Paul Eggert wrote: > >> On 6/5/20 4:19 PM, Jo=C3=A3o T=C3=A1vora wrote: >> > I totally agree it is >> > undefined behaviour to change structure of literals (quoted or >> > self-evaluating objects), also in Common Lisp, because compilers are >> > probably allowed to reuse parts of the internal structure of such >> > objects. But that's a far cry from having two different manifestation= s >> > of `equal` such objects _be_ the same object, but only for compiled >> > code. >> >> I don't understand this remark, as the idea that "compilers are allowed >> to reuse >> parts" necessarily implies that (eq "a" "a") can be t if the compiler >> decides to >> reuse the string. > > > Depending on the implementation of sequences, it could reuse only the > later parts of the sequences to maintain uniqueness and still have > I forgot to finish the sentence: "and still have some some reuse". Jo=C3=A3o --000000000000e634cb05a768f24d Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
On Sat, Jun 6, 2020 at 12:41 PM Jo=C3=A3o= T=C3=A1vora <joaotavora@gmail.c= om> wrote:
On Sat, Jun = 6, 2020 at 2:43 AM Paul Eggert <eggert@cs.ucla.edu> wrote:
On 6/5/20 4:19= PM, Jo=C3=A3o T=C3=A1vora wrote:
> I totally agree it is
> undefined behaviour to change structure of literals (quoted or
> self-evaluating objects), also in Common Lisp, because compilers are > probably allowed to reuse parts of the internal structure of such
> objects.=C2=A0 But that's a far cry from having two different mani= festations
> of `equal` such objects _be_ the same object, but only for compiled > code.

I don't understand this remark, as the idea that "compilers are al= lowed to reuse
parts" necessarily implies that (eq "a" "a") can b= e t if the compiler decides to
reuse the string.

Depending on the impleme= ntation of sequences, it could reuse only the
later parts of the = sequences to maintain uniqueness and still have

I forgot to finish the sentence: "and stil= l have some some reuse".

Jo=C3=A3o
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